KBA Process No. 2 english

Transcription

Issue 2005
No.
PRODUCTS · PRACTICES · PERSPECTIVES
www.kba-print.com
Contents
The future of offset has long since begun!
Waterless and keyless
K
BA and Metronic, a subsidiary, have
been spearheading advances in keyless,
waterless offset over the past few years and
are the sole providers of this groundbreaking
technology. A clear vision, highly-focused research and development activities and strategic alliances have culminated in the creation
of cost-effective, high-quality systems suitable for both new and existing business segments.
Innovative presses like our 74 Karat and
Metronic’s CD Print and oc200 have already
proven the competitiveness of this new process through their superior performance in dayto-day production. Keyless, waterless offset
furnishes a basis for standardising high-volume print production by stripping out many of
the technical parameters which in conventional wet offset can seriously impair the
printed image, and by limiting or totally eliminating subjective intervention by the press
crew.
2
We shall continue to drive advances in a
technology which offers incalculable benefits
in the form of cost-efficiency, ecology, userfriendliness, print quality and applications.
The most recent examples of keyless, waterless offset presses are our Genius 52, Rapida
74 Gravuflow and Cortina, and Metronic’s
Premius. We believe the Cortina’s trailblazing
technology will bring about a step change in
the newspaper printing market.
This issue of KBA Process presents objective information by competent internal and
external print professionals on the history,
current state of the art and future prospects of
keyless, waterless offset. In addition to contributions on the core technology and potential
applications of the individual press types,
there are market surveys of printing plates and
inks, the results of independent comparative
cost analyses, a discussion of environmental
issues and print samples demonstrating the
quality gains that can be achieved.
Editorial
2
Milestones
Waterless planography
3
Current approaches
Interaction of
materials
Keyless inking
units
Temperature control
in inking units
Temperature control
in newspaper offset
7
12
16
18
Consumables
Plates
Waterless inks
Waterless UV offset
24
31
36
Quality
Quality benefits of
waterless offset
Standardised,
high-volume printing
39
42
Cost-efficiency
Benefits of keyless,
waterless technology
Comparative cost analysis
Environment
Eco-friendly technology
BREF file on
the printing industry
45
48
50
53
Handling
Convenience, productivity
Applications
Waterless offset
today
Commercial, packaging
and plastic printing
Waterless newspaper
offset
55
65
67
73
Outlook
Future prospects, advances 77
Contacts
Resources/partners
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Editorial
Albrecht Bolza-Schünemann,
president and CEO of Koenig & Bauer AG,
pictured after accepting the EWPA’s
environmental award for the waterless
Rapida 74 G at Drupa 2004
Waterless works!
Waterless offset has been around for more than 30 years. When the
process was first mooted, the prospect of eliminating at a single
stroke all the problems associated with fount solution, simply by
adding a silicone coating to the printing plate, was greeted with
loud acclaim. However, this rapidly subsided and waterless was
eclipsed by conventional offset, which experienced headlong
growth throughout the seventies, eighties and nineties of the last
century.
Widely dismissed as occupational therapy for tree-huggers or,
at best, pie-in-the-sky visionaries, waterless offset first gained a
foothold in Europe when Scandinavia tightened up its environmental legislation. In the USA the process has attracted a relatively
modest circle of supporters. Japan is the only country where it has
cornered a sizeable share of the market.
There were a number of reasons for its relegation to a niche
application. One was the high cost of plates, largely due to the
patent protection enjoyed by Japanese plate manufacturer Toray.
Another was printers’ reluctance to pay a premium for a better image quality. On top of this, the plates scratched easily and ink transfer was relatively unstable because at that time temperature control
was less advanced. It was not until the Toray patent expired and
other plate manufacturers such as KodakPolychrome, Agfa and
Presstek launched their own waterless plates (or at least developed
them to market maturity) that waterless offset experienced something of a renaissance. At Drupa 1995 a number of orders were
booked for waterless commercial web offset presses.
The tide turned for dampener-free technology with the launch
in the 1990s of DI offset presses, almost all of which are waterless.
These include Heidelberg’s GTO-DI and Quickmaster DI, and our
own 74 Karat. Drupa 2000 saw waterless offset become a major
topic in the industry once again with the launch of our Cortina mini
tower press, whose novel concept demonstrated that waterless offset is fully capable of printing newspapers in a strikingly superior
quality at high speeds and with a minimum of waste.
Unlike other press manufacturers we have not been content
merely to eliminate fount solution and “tack on” air- or water-based
systems for controlling temperature: in our innovative waterless
presses we have gone one step further by eliminating ink keys as
well, and incorporating a dedicated high-precision, quick-reacting
temperature control system for the anilox rollers and plate cylinders.
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So almost 200 years after Friedrich Koenig invented the rollertype inking unit, which in essence remains the state of technology
in conventional offset, another benchmark innovation by KBA –
the elimination of water and keys – has opened up a new approach
to the standardised and precisely repeatable production of highquality prints.
Our engagement dates back to the mid-1990s, when collaboration with Metronic (now a subsidiary) culminated in waterless,
keyless presses for printing smart cards and digital data storage
media. At Print ’97 in Chicago we gave the first public demonstrations of the 74 Karat, a joint venture with Scitex. At Drupa 2000
we unveiled our Cortina newspaper offset press, which was hailed
as revolutionary by many in the trade. It was followed at Ipex 2002
by a small-format sheetfed press, the aptly named Genius 52, and
at Drupa 2004 by a half-format unit-type press, the Rapida 74 G
(G = Gravuflow).
Today our sheetfed, web offset and special presses featuring
waterless, keyless technology deliver compelling practical evidence that economy and ecology, standardisation and quality are by
no means mutually exclusive. The sale of 29 Cortina four-high towers in less than 15 months to six users in the Netherlands, Germany,
Belgium and Switzerland, the market success of the Genius 52
(particularly the UV version), the superb quality delivered by the
74 Karat on paper, cartonboard or plastic and the performance of
our new Rapida 74 Gravuflow give us reason to believe that, with
print runs steadily diminishing, quality demands rising and environmental issues subject to ever tighter regulations, our visionary
concept will gain widespread acceptance.
Hence this issue of KBA Process. We hope the insight it furnishes on the history of waterless, keyless offset, the technology
and materials involved, its applications, cost-efficiency and environmental credentials will give you a balanced picture on which to
base your own informed opinion. Thank you for your interest.
Yours,
Milestones | History of planographic printing
Milestones in the evolution of
waterless planographic printing
Ever since planographic printing presses were invented there
have been attempts to eliminate dampening from the process.
The world’s first offset press was
built in New York in 1903 by
Ira W Rubel for a San Francisco
firm, Union Lithographic, which
was destroyed by an earthquake
prior to taking delivery. The
press was not commissioned until
1907 following the company’s
reconstruction
(photo: Smithsonian Institute,
Washington, DC)
That this is possible, and can function, was demonstrated 150
years ago with the invention of the collotype press. But in the timescale of high-volume print production, the waterless offset era
began in the late 1970s, following a number of false starts. KBA
recently set major milestones along this long and winding road
with its 74 Karat, Genius 52, Rapida 74 G and Cortina.
First planographic processes
with dampening: lithography
using stone and zinc
B
oth wet and waterless
offset printing trace
their origins back to
lithography, a process invented
in 1798 by an aspiring poet and
playwright, Alois Senefelder, in
a do-it-yourself effort to reduce
printing costs. When he could
no longer afford copper plates
he started experimenting with
slabs of the cheap limestone he
bought from a quarry in nearby
Solnhofen for milling ink. At
first he etched the stone, but
later he drew the image using a
concoction of wax, soap and
lampblack (a formula he had
devised to correct mistakes on
copper plates), moistened the
stone with water and then applied greasy ink with a roller.
The ink adhered to the sticky
concoction but was repelled by
the water. He called this process “chemical printing”. The
image could then be transferred
either directly to paper or to one
or more other slabs which then
functioned as originals for
multiple reproduction. This
transformed printing from a laborious, time-consuming craft
into a faster, relatively highvolume production process.
Of the companies that later
formed the KBA group, Albert
& Cie in Frankenthal was the
first to build a lithographic
press in 1886. That same year
Ruddiman Johnston in Edinburgh replaced the stone slabs
in a planographic press with
mechanically roughened (granulated) zinc plates which were
a much lighter mass to accelerate and brake. They were
the forerunners of wraparound
plates.
Indirect image transfer –
initially via a cardboard sheet,
later via a rubber blanket –
evolved in England in the early
1880s in conjunction with
metal decorating. In 1903 three
Americans – Robert F Rogers,
LS Morris and Ira Washington
Rubel – registered separate and
independent patents on the
principles of, and presses for,
an indirect printing process on
rubber blankets which also
could be used to print on paper.
Rubel, whose patent was the
first to mention the word “offset”, was alerted to the superior
quality of indirect printing
when a number of sheets were
printed on the back, off the
blanket, after being misfed. He
built and marketed the world’s
first sheetfed offset press.
Caspar Hermann, a German
whose patent applications had
been submitted just too late in
1903, converted a letterpress
web press to offset in 1905 for
an American press manufac-
turer, Harris, using a zinc plate
and rubber blanket. Hermann is
credited with bringing offset to
Germany a few years later and
refining the technology.
First planographic process
without dampening: collotype
Alphonse Louis Poitevin, a
Frenchman, tried to reproduce
photographs by creating prints
from glass photographic plates.
First he copied the original
negative to produce a duplicate
positive on a plate coated with
hardened dichromate gelatine
containing silver halide crystals. He then moistened the
plate with water to make the
crystals swell. This gave rise to
a relief image which reproduced the tonal values as continuous tones. So dampening in
collotype printing does not occur during impression but as
part of a pre-impression se
Collotype, invented in the midnineteenth century, was the first
waterless planographic printing
process
(photos: Günther)
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Toray’s Waterless Plate launched in 1977 signalled the breakthrough for
waterless offset
quence that transforms the
positive photographic plate into
a printing plate. However, since
the maximum of 1,000 prints or
so that can be obtained from
such a plate is far too low for
high-volume production, this
process is still confined to short
runs for the reproduction of
fine art – and is still based on
glass plates.
First waterless invention:
no market interest
Stabilising the dampening
process has been an issue ever
since planographic printing
presses were invented, and although major advances have
been made with the adoption of
isopropyl alcohol on the one
hand and ingenious refinements in the design of dampeners on the other, the process is
by no means perfect. So there
has been no lack of efforts to
eliminate fount solution from
offset completely, with the emphasis nowadays on environmental issues.
Once again Caspar Hermann, the hapless inventor,
played a role. In 1919 he was
denied a patent for his “offset
printing process without dampening”. In 1930, at the end of a
five-year period of employment at Neuburger, a Viennese
press manufacturer, he experimented with plates coated with
silicone by Eggen, a company
in Viersen, and ink components
supplied by Kast + Ehinger in
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Stuttgart. The following year he
used these plates and inks to
produce four-colour prints on a
sheetfed offset press in Vienna
and monochrome supplements
on a blanket-to-blanket newspaper press of his own design in
Leipzig. He exhibited the results at the Leipzig spring fair
and later in the USA, but failed
to find any takers for his novel,
high-quality process. And, yet
again, he was unable to obtain a
patent.
All subsequent advances in
waterless offset printing formes
can be traced back to Hermann’s basic invention: the use
of silicone as an ink-repellent
coating. Which is why waterless offset is sometimes called
siligraphy.
three years later – and discarded in 1976 after spending
millions of dollars on its development. It discovered that the
silicone surface of non-printing
areas was insufficiently stable
and too easily scratched, particularly on B1 and B2 (40” and
20”) presses and during long
print runs. And since the plates
could only be used for short
runs on small-format presses,
but were far too expensive for
this market, printers stopped
buying them. Also, the ink industry underestimated the potential this technology offered
and failed to provide suitable
inks. Be that as it may, the name
3M gave this process, “driography”, is still occasionally
used as a synonym for waterless offset.
A number of ink manufacturers took a different route
from that associated with silicone plates: their aim was to
dispense with the need for
fount solution in the press by
formulating
pre-emulsified
inks for printing on conventional plates. Although their
initial efforts failed, the idea
was later adopted and modified
by Flint Ink (see chapter on
current approaches).
First product to attain
market maturity:
Toray’s Waterless Plate
Toray Industries, an eminent Japanese company that
specialises in the development
and manufacture of polymers,
acquired 3M’s driography patent in 1972 along with a
number of patents registered by
Scott Paper, which was working on a similar project. In 1975
Toray registered a patent in
which the term “waterless offset printing” appeared for the
first time, and by Drupa 1977
was already able to exhibit a
waterless plate. A year later it
started marketing a positive
waterless plate, TAP, since
Temperature control is indispensable for maintaining stable printing
conditions in a waterless offset press like this version of a Rapida 105 sheetfed
press
First saleable waterless
technologies: reverse
lithography and driography
The first waterless printing
process to be introduced after
the Second World War was reverse lithography, which was
developed in 1966 by two US
engineers, Greubel and Russell,
for odourless printing on packaging. They replaced water
with a dampening solution of
volatile hydrocarbons that
spread on the silicone and displaced the ink – a process that
was highly susceptible to tinting.
At Drupa 1967 a US company, 3M, unveiled a waterless
offset plate that it patented
Filter and
pump
Glycol cooler
Cooling aggregate
most printing plants in Japan
tend to use positive working
plates. For the US market,
where negative platemaking is
the norm, Toray unveiled a waterless negative plate, TAN, at
Print 1980 and launched it on
the market in 1982.
Paper and ink manufacturers in Japan supported this
technology, so it was able to
gain a foothold. But in
America, anything resembling
driography was viewed with a
certain amount of scepticism.
Admittedly, until the early
1990s there were a lot of teething troubles to tackle: the silicone layer was not sufficiently
scratch-resistant, the non-image areas were prone to tinting
as the temperature rose in the
course of the print run and, due
to the lack of an emulsifier, the
inks were too viscose and
caused picking. KBA and other
leading press manufacturers
were quick to combat tinting
with temperature control systems in the printing units – a
feature that also enhances process stability in wet offset. Inks
with a lower level of viscosity
were developed and Toray improved the silicone layer. The
number of Toray users worldwide, and even in the US, has
since risen dramatically.
First special-interest group:
WPA
Unveiled at Imprinta 97, KBA’s 74 Karat was the first waterless offset press to combine on-press imaging with keyless
inking, in this case using Gravuflow units. This photo was taken at the official market launch at Drupa 2000
number of waterless printing
plants worldwide.
In 1996 Toray’s German
importer, marks-3zet in Mülheim (Ruhr), helped to establish the European Waterless
Printing Association (EWPA)
whose activities include the
promotion of waterless offset
with UV inks (WL-UV).
First laser-imageable
waterless plate:
Presstek PEARLdry
Waterless offset received
fresh impulses from digital
printing and CTP. Presstek, a
company founded in 1987, set
its sights on inventing a printing plate that could be laserimaged and required no further
chemical development, enabling plates or film to be
imaged in the press. Presstek
registered the technology under
the name DI (Direct Imaging).
The principle was applied for
the first time in a modified
Heidelberg GTO exhibited at
Print 1991 in Chicago, and
later attained market maturity
in a Heidelberg Quickmaster
DI 46-4 shown at Drupa 1995.
Since the on-press imaging
unit replaced the dampener,
Presstek focused its efforts on
developing waterless film. The
result was PEARLdry, which
can be used both as a DI film
and for CTP. PEARLdry is
imaged by ablation, ie the IR
laser burns off the silicone layer
to expose the ink-bearing polymer layer underneath.
Kodak Polychrome Graphics (KPG) was awarded a
patent in 1994 for an IR lasersensitive negative plate that required chemical development
similar to that for Toray’s TAN.
The impressive quality enhancement achieved in waterless offset persuaded Arthur W
Lefebvre, an American print
entrepreneur, to establish the
Waterless Printing Association
(WPA) in 1992. The WPA’s
mission is to promote an exchange of information on technical advances and to convince
both printers and print buyers
of waterless offset’s manifold
benefits.
In 1993 Toray Industries
was instrumental in founding
the Japan Waterless Printing
Association (JWPA). At that
time Japan boasted the largest
At Drupa 2000 KBA also unveiled
the world’s first waterless coldset
web press – the Cortina
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KPG coined the term “comp u t e r- t o - w a t e r l e s s - p l a t e ”
(CTWP) to describe thermal
laser plate imaging. Unlike
Toray, KPG dispensed with a
scratch-proof protective film
on top of the silicone. These
thermal waterless printing
plates are now marketed in
North America as Scorpion
X54 and Scorpion X54 Plus.
Toray itself launched a
CTWP negative plate, the TAC,
in 1999. The current (fourth)
version, the RG5, differs from
other waterless plates in that
it can be measured using a
dotmeter.
At Drupa 2004 Creo unveiled a CTWP film, Clarus
WL.
company which is now a KBA
subsidiary, culminated in the
development of a revolutionary
new inking process that dispensed with both water and ink
keys. Metronic subsequently
built this system into its oc 200
press series, running it with
Toray plates and UV-cured waterless offset inks. Waterless
anilox offset, as it is also called,
has since become the technology of choice for printing plastic cards.
Further advances have been
made and new models now feature in KBA’s Genius 52
(Metronic inking units), 74
Karat and Rapida 74 G
(Gravuflow inking units) and
Cortina (Newsflow inking
units). KBA has thus given
waterless offset a significant
boost by developing the appropriate presses. And the elimination of ink keys as well as water
has not just simplified the process – it signals a major step towards standardising the entire
print production sequence.
First waterless newspaper
press: KBA Cortina
Presstek’s ProFire DI imaging head works by laser ablation (photo: Presstek)
The Cortina mentioned
above is the world’s first waterless coldset web press. A prototype unveiled at Drupa 2000
was followed in 2002 by the
first press-hall installations.
The Cortina has taken waterless
offset into yet another sector
that was previously the preserve of wet offset: high-volume newspaper production.
First waterless, keyless inking
units: KBA and Metronic
In 1994 a long-standing
collaborative alliance between
KBA and Metronic, a local
Dieter Kleeberg
Waterless offset – definition and demarcation
W
aterless offset, as the name indicates, is an indirect printing process
based on the application of ink to a planographic printing forme
where certain areas accept it and others repel it to create an image which is
then transferred onto paper indirectly (ie from a forme with right reading
image) via a rubber blanket.
The term planographic means printing from a flat surface. Although
there is, in fact, a minimal difference in height between the image and nonimage areas, this is of minor significance. For example, the image areas in
the photogelatine layer on a collotype plate and between the silicone-coated
areas on a waterless offset plate are typically 2µm (0.08 thou) lower than the
non-image areas . But it would be a mistake to define waterless offset as a
form of gravure (in the US, the term silicone intaglio is often heard along
with driography), because waterless offset inks are much more viscose and
in planographic printing presses are applied neither by immersion nor flooding and doctoring, nor are they dried through the evaporation of a solvent.
Moreover, the ink is transferred by splitting it, not by emptying the cells, as
is the case in gravure. And a waterless offset screen is not the same as the
height- and area-variable cell structure typical of gravure.
Many printers describe waterless offset as dry offset, which is incorrect
because that term is reserved for letterset, an indirect form of letterpress.
Properties of waterless offset compared to other proven printing processes entailing a flat printing forme or indirect image
transfer * layer of silver halide emulsion, diazo colloid or polymerisable resin; ** photo and thermal polymers, also for laser ablation and phase change
Principle
Printing process
Forme profile
Forme material
Image-area material
Non-image-area material
Ink consistency
Planographic with dampening
lithography (stone)
direct
flat
original and
duplicate stone
original ink or
transfer print
porous limestone
moistened with water
high-viscosity paste
lithography (zinc)
direct
flat
wraparound
zinc plate
transfer ink,
later photo emulsion*
granulated zinc
conventional offset
indirect via
rubber blanket
almost flat
wraparound metal plate
or PET film
copper (on chrome), later photo metal (oxide) moistened
emulsion* (on aluminium oxide) with water (0 - 12% IPA)
dilitho newspaper offset
direct
almost flat
wraparound trimetal
plate
copper or
brass and chrome
iron or aluminium oxide
low viscosity (coldset)
Planographic without dampening
collotype
direct
almost flat
glass plate
partially swollen dichromate
gelatine relief
water-glycerinated
gelatine
medium viscosity
waterless offset
indirect via
rubber blanket
almost flat
wraparound metal plate
or PET film
polymers**
silicone
indirect via r.b.
raised
wraparound relief plate
etched metal, polymers**
recessed
low viscosity
indirect via
ink pad
recessed
metal relief plate
cells in metal
or polymer surface
doctored cell walls
high viscosity, thinned
Letterpress
“dry” offset, letterset
Gravure
pad transfer
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Current approaches | Consumables
Optimising the interaction
of ink, plates and other consumables
At present two approaches are being pursued to improve the consumables used in waterless
offset. One focuses on dedicated waterless plates and films, the other on conventional plates.
Each requires a different type of ink and, to a lesser extent, modified blankets and substrates.
Advances in the use of conventional plates have not yet made them a viable alternative to
dedicated waterless plates.
Wet offset ink emulsifies
with fount solution
In their initial state wet
offset inks are highly viscose,
ie they can have a dynamic
viscosity of up to 100 Pa·s (67
pdl s/ft2). When the ink film is
distributed and split in the
inking unit it is subjected to
deforming mechanical forces
which generate heat. The viscosity falls by around 8% with
Viscosity
200
Pa·s
150
10
Tackmeter
scale
7.5
100
5
2.5
50
1
0
0
10
20
30
40
Temperature
50
60 °C 70
Typical behaviour of ink at different temperatures. Viscosity and tack decrease
as the temperature increases
every degree Celsius that the
temperature rises. As a result
the ink loses its paste-like
consistency (thixotropy) and
emulsifies with the fount solution. If the fount solution
film is re-split from the printing forme back into the inking
unit, and bridge rollers are
used between the dampening
and inking units, it is possible
to achieve an optimum emul-
Rheological properties of inks
I
Tack
W
aterless
offset,
by definition, dispenses with the
need for the fount solution essential in conventional wet
offset. Since waterless offset
ink is neither displaced by,
nor emulsified with, fount solution, it must have different
properties from its wet offset
counterparts. Common to
both types of ink is that they
alter their rheological characteristics during the printing
process (see box: “Rheological properties of ink”).
nk flow depends on the adhesive and cohesive forces operating
among its ingredients. Temperature, processing speed, pressure and
shearing forces also influence the rate of flow and thus the resultant
image.
Viscosity (flow resistance): the higher the viscosity (ie the lower the
propensity to flow), the more uniform the ink film on the printing forme.
The two key features of a paste-like ink are its dynamic viscosity
(quotient of the shear stress and speed), measured with a rotational viscosimeter, and its static viscosity, measured with a falling rod viscosimeter in accordance with ISO 12644. Other methods are used to specify
and regulate the viscosity of liquid inks.
Thixotropy: the propensity of highly viscose ink to become less
viscose when subjected to mechanical stress (lateral distribution, splitting, agitation). Its reconversion to the original paste-like condition is
called relaxation.
sification of up to 70%. This
reduces viscosity still further,
very much like a thinner. So
wet offset inks have a medium
viscosity when they are being
worked.
Waterless offset inks
no longer cause picking…
It follows that waterless
offset inks must have a lower
initial viscosity to compensate for the lack of emulsification.
The first waterless inks
formulated were much too
viscose and tacky, so when
they were used in sheetfed
offset they caused picking on
the paper surface. This was
one of the teething troubles
associated with Toray plates
for several years.
In fact, modern waterless
inks are still highly viscose,
but because they have the
same tack as wet offset inks
they can be used to deliver a
good quality print on practically all the same materials,
even on weakly sized paper or
newsprint. If the ink were less
viscous, heat would make it
too liquid: an uncontrolled increase in temperature would
cause ink build-up on the nonimage areas, and thus tinting.
This is why precise temperature control is absolutely essential (see final section on
page 10).
Flow: the distance that a specific volume (1ml or 0.03fl.oz) of vertically flowing ink covers in a specific time (10 minutes). Even inks with
a higher viscosity should cover at least 4cm (11/2”).
Yield value: the viscosity level at which ink no longer displays an
innate propensity to spread; important for the afterflow of ink in the ink
trough, a sharp dot definition and a clean-cut delineation of non-image
areas.
Tack: the propensity of ink to split or resist splitting, measured as
per ISO 12634 with a rotary tackmeter. The higher the tack, the stronger
the adhesion to the plate and blanket (and thus the propensity to pick)
and the sharper the image reproduction.
Length: ink flow characteristic, demonstrated by the length of the
“string” created when the ink is poured or scooped out. Ink that creates a
long string before breaking flows better and is more suitable for pumping
systems. Short(-stringing) ink breaks off quickly, is less inclined to mist
and produces a sharper image.
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…and are partially
water-washable
Sun Chemical has ensured
that washing waterless inks is
as environmentally friendly
as printing with them. Its Instant Dry ink, launched at
Drupa 2000, can be washed
off the rollers and blankets
with water instead of solvent.
Its most recent waterless inks,
Irodry W2 and DriLith W2
(W2 = water washable), are
used in KBA sheetfed presses.
W2 inks are based on nonvolatile organic fatty acid
esters instead of mineral oil
and have the advantage of being de-inkable, quick-drying,
powder-free and rub-resistant,
with a standard dot gain and a
stable structure (uniform viscosity).
Formulating waterless inks
for specific plate materials
Waterless offset inks must
be formulated for a compound
plate comprising silicone rubber on top of a light- or heatsensitive polymer. The 2µm
(78µin) silicone layer is oleophobic, ie it repels oil and thus
ink, whereas the polymer is
oleophilic.
While most waterless inks
are suitable for most waterless
plates, there are certain differences (just as there are in wet
offset) between inks for
sheetfed and those for web
presses (heatset and coldset)
and between inks that dry by
oxidation and those that are
cured by radiation. Nowadays
waterless sheetfed offset inks
are usually formulated ductfresh as a fair compromise
between maximising their
drying properties and minimising cleaning requirements.
Direct imaging consumables, which until Drupa 2004
were confined to Presstek’s
PEARLdry and PEARLdry
Plus films and plates, also require specially formulated
inks. For this reason the only
inks that KBA recommends
for its 74 Karat are ones that
have been tested and ap8
KBA Process
2 | 2005
proved. The same applies to
inks for the KBA Cortina waterless newspaper press. Here,
the less viscose inks offered
by various manufacturers
must be capable of working
with the specified plate types.
Waterless offset plate:
coated with silicone…
Silicones are silicon-oxide-bearing chain or ring molecules in which silicon atoms
bond to residual hydrocarbon
atoms such as methyl. When
the basic material is processed
these residual molecules reticulate to produce oil, fat,
resin, latex or rubber. A simple rubber-like mass of dimethyl silicone (CH3)2SiO has
proved to be the most suitable
material for waterless offset
plates.
Caspar Hermann used silicone in his ingenious experiments in 1930, and research to
date has been unable to better
it. It works on the principle
that oily solvents released
from the ink when it is split in
the ink train are absorbed by
the silicone. When the ink
forme roller revolves against
the plate cylinder the silicone
surface becomes saturated
and then coated with these
solvent particles, which thus
assume the function of fount
water as a separator. The interfacial tension subsequently
created between the solvent
layer and the ink by the rollers
is so weak that no ink can adhere to these areas (ink manufacturers refer to this solvent
layer as a WFBL – weak fluid
boundary layer). This complex model has been retained
because although other materials, such as Teflon, have just
as weak a surface tension as
silicone, they have proved to
be useless as an ink repellent.
1
2
3
4
Because the weak fluid boundary
layer (WFBL) is created within a few
revolutions there is less waste in
waterless offset.
1) the waterless plate is fully inked
with the first pass by the forme
rollers
2) solvent particles (beige) from the
ink immediately penetrate the
silicone layer (yellow)
3) after saturating the silicone the
solvent collects on the surface
4) the forme rollers pick up the ink
again from the solvent-covered
silicone areas, so it is only split on
the polymer image areas (green)
tion. Photopolymers are sensitive to light and UV radiation, ie embedded photoinitiators trigger the creation
of radicals which in onedimensionally
reticulated
substances (eg resins) result
in a stronger reticulation, and
thus hardening, or enhance
the reaction to developing fluids. Thermal polymers react
to heat radiation, eg from an
infrared (IR) laser, which totally transforms or even destroys the polymer structure
so it can easily be removed by
developing, washing, brushing etc. Light- or IR-sensitive
polymers, which reject the
overlying silicone layer when
burned or developed, are used
on waterless plates.
Unlike the silicone or the
solvent layer on top of it, the
exposed polymer beneath has
a high surface tension, so the
interfacial tension between
the polymer and the ink is also
high, causing the ink to adhere. This interfacial tension
is roughly as strong as that between the ink and the rubber
rollers (for inking the forme)
and the ink and the blanket
(image transfer), so the ink is
split upon contact. In effect,
especially if the ink is not
emulsified, the polymer must
possess the same ink-splitting
properties as the oleophilic
thermal or photopolymer
copying layer in wet offset.
Waterless offset plates
Polymers on a waterless
plate differ substantially from
the photo- and thermal polymers on a wet offset plate.
Firstly, the waterless polymer layer is not on top but beneath the silicone, which
means it is imaged through it.
On Toray plates there is an additional transparent protective
film over the silicone during
imaging.
Secondly, polymers on a
wet offset plate react to
imaging by hardening or softening. The softened or nonhardened areas are removed
during chemical and/or mechanical development. Waterless polymers, by contrast,
cause the overlying silicone
layer to peel off. This can occur in different ways: through
chemical development, washing with water or some other
process that entails neither.
Chemical development
Waterless plates that are
developed chemically are currently available from Toray
and KPG. Imaging can be
…and polymer
Polymers are organic substances made of reticulated
molecules. Nowadays thousands of polymers are known
whose properties can be
changed by chemical reac-
Toray’s Waterless Plate Processor
incorporates a three-step sequence:
pre-treatment with solution,
development with tap water and
after-treatment with another solution.
Some plate types are then washed up
with water
negative, positive, analogue
or digital. Negative plates are
first pre-treated with solvent
to desensitise the polymer
(ie make it light- or heatresistant) and to enhance the
silicone’s adherence to the
non-image areas. A developing fluid is then applied to the
imaged areas, which loosens
the silicone and causes it to
swell. It is then rinsed or
brushed off. Positive plates
require no preliminary treatment to increase adherence.
The polymer layer itself is
bonded with the aluminium
packing via an adhesive layer
of primer.
In 1999 and 2003 the
University of Saskatchewan
(Canada) published details of
a process for “siliconising”
used wet offset aluminium
plates. Both the stripped – but
for waterless offset unnecessarily roughened – face and
the smooth reverse side of the
plate can be used. But
siliconising and developing
processes are only for craftsmen and not to be recommended for standardised
production.
Water-based development
At Drupa 2004 Toray
launched the TAC-W2, a prototype negative writing CTP
plate made of IR-sensitive
water-soluble polymer that is
laser-imaged at 150 to 200
mJ/cm2 (0.55 - 0.736 ft pdl/
in2). This new polymer-coated
plate requires no chemical
development, just water: after
laser-imaging it is merely
rinsed off.
Phase-switch thermal polymer layers are also developed using water. When
imaged with an IR laser beam
they change instantly from a
solid to a near-liquid. At the
same time they become more
soluble in water, so the areas
covered with this liquefied
polymer can be simply rinsed
with water to expose the aluminium oxide layer beneath.
Positive writing wet offset
plates are manufactured by
Agfa (:Thermolite, :Litespeed-
Cleaning (brushes
rotating in
water bath)
IR laser beam
Thermal reaction
Warming
Ink-repellent
silicone layer
Residue removal
(peeling)
Ink-receptive
heat-sensitive
polymer layer
Cooling
Primer
Aluminium layer
TAC-W2 is the prototype of a negative writing CTP plate developed by Toray.
In the image areas the heat-sensitive polymer layer reacts with the overlying
silicone, which can then simply be brushed off in a water bath
Spray). Lastra also had some
in the pipeline prior to its
acquisition by Agfa. Positive
writing waterless offset plates
are not yet available. Phaseswitch polymers could also be
adopted for waterless plates:
during the developing process
the silicone could simply be
washed off with the softened
water-soluble polymer particles. But so far no plate maker
has indicated that it is pursuing this avenue.
Between the silicone layer
and the aluminium or polyester underlay there are not one
but two polymer layers. The
upper one reflects the infrared
rays and burns off together
with the overlying silicone.
The residue is removed in the
off-press or on-press imaging
unit to expose the ink-bearing
areas on the underlying polymer layer.
Dry ablative development
Waterless inks for
wet offset plates:
not pre-emulsified…
One alternative to chemical or water-based processing
is laser ablation. Ablative
metal plates are currently only available from Presstek,
though in summer 2004 Creo
launched a rival product, the
Clarus WL polyester film for
direct-imaging offset presses.
This plate has already been
tested successfully on both
sheetfed and web offset
presses. Ablative plates are
negative writing, ie the IR laser acts on the image areas.
It is a well-known fact that
wet offset entails more than
the application of ink onto
paper. The ink must have an
optimum degree of emulsification in order to achieve a
stable ink/water balance. The
volume of ink increases by
10 to 20 per cent through the
absorption of fount solution
when the fount solution film
is re-split from the plate back
into the ink train or via a
bridge roller between the
dampening and inking units.
IR laser beam
Ablation
during irradiation
Ablation
Ink-repellent
silicone layer
Heat-sensitive
polymer layer
Ink-receptive
polymer layer
Aluminium or
polyester layer
Earlier tests by various ink
manufacturers and US press
manufacturer Goss therefore
focused on printing with preemulsified ink. The aim was
to dispense with the need to
apply fount solution inside the
press by mixing the fount solution into the ink during
manufacture or in an ink mixing unit in the press hall. That
would not, of course, be waterless offset in the true sense,
but the result would be similar, since there would be no
dampener. Be that as it may,
tests along these lines were
unsuccessful as it was found
that pre-emulsified ink – even
with special additives – did
not eliminate the need for
fount solution on the printing
forme. The emulsions tested
not only proved to be unstable, heat-sensitive and unsuitable for long print runs, but
also had to be reformulated
for each of the press types
tested. So there could be no
talk of relieving the press operator’s workload.
…but totally reformulated
But the idea of developing
a waterless offset ink for conventional plates was not abandoned. Flint Ink, in particular,
has since produced some acceptable results, though the
inks it has developed do not
yet represent a competitive alternative. While Flint Ink describes them as single fluid
inks and has registered the abbreviation SFI as a trademark,
other ink manufacturers like
Sun Chemical use the term
single fluid ink as a generic
description for waterless offset inks because the second
fluid, the fount solution, has
been eliminated.
At Drupa 2000, after seven years of research, Flint Ink
unveiled a unique SFI ink.
Residue removal
(extraction,
wiping)
Imaging and developing sequence in
a Presstek negative writing CTP
plate: the upper polymer layer burns
off, destroying the overlying silicone.
The residue is then removed to
expose the underlying polymer layer
that will later bear the ink
KBA Process
2 | 2005
9
How the properties of various consumables influence ink transfer in waterless offset
Parameter
Ink
Plate(silicone layer)
Plate(polymer layer)
Rollers
Blanket
Substrate
Interfacial tension
to all other
materials
to solvent in the ink,
ink repulsion
ink adhesion
ink adhesion on
rubber surface
ink adhesion on
blanket surface
printability
Roughness, capillarity
—
ability to absorb solvent
from ink
ink adhesion
ink adhesion on
rubber surface
ink adhesion on
blanket surface
printability,
absorbency
Ink viscosity
runability
—
wetting
distributing quality
wetting
wetting, penetration
Ink tack
runability
—
ink splitting
ink splitting
ink splitting
ink splitting, picking on
paper and cartons
Ink formulation
runability
ink repulsion
ink attraction
ink splitting
ink splitting
ink splitting, drying
Temperature
runability
temperature control
prevents tinting
—
temp. control promotes —
consistent rheology
Viscoelasticity
shearing
propensity
shearing
—
shearing of
blanket surface
shearing of
blanket surface
print quality
on synthetics
Compressibility
—
—
—
shearing of
blanket surface
microcells control
dot gain
print quality
Hardness
—
developing process,
print-run stability
print-run stability
print-run stability
of the forme
optimum dot
reproduction,
print-run stability of
printing forme
(runability)
Dimensional stability
—
(carrier substrate
influences register)
(carrier substrate
influences register)
—
—
(runability
Surface properties
Structural properties
The initial sheetfed offset formula was followed by a
heatset formula in 2002. Flint
Ink’s SFI is neither pre-emulsified nor a conventional waterless offset ink, but contains
patented chemicals that prevent the ink from adhering to
the non-image areas – ie the
exposed aluminium oxide
layer – on a conventional wet
offset plate. The biggest outstanding issue seems to be
that the non-image areas are
prone to tinting as they wear –
apparently after 40,000 to
100,000 revolutions, depending on the plate type. SFI
process and spot inks will not
be released on the market until beta tests have been concluded to the users’ total satisfaction.
Flint Ink claims that SFI
can be used for the same applications as wet offset inks,
and that it is also suitable for
analogue and CTP plates
because there are no temperature controls or speed limitations, no ink misting and no
reaction with blankets and
rollers. Also, the ink film is
scratch-proof and can be
aqueous or UV-coated or else
laminated with a synthetic
film.
Impact of temperature control…
10
KBA Process
2 | 2005
The interaction of the ink
and the plates in waterless offset must be viewed in conjunction with other processes
and press components. Precise temperature control, a
feature of all waterless presses, is a major influence. A lot
of wet offset presses today are
shipped either with a preconfigured interface for a
temperature control system or
with such a system already
fitted. This not only ensures a
stable ink/water balance within the press but is also a basic
essential for waterless offset.
The system includes a
coolant circuit that keeps the
temperature of the relevant
roller and cylinder assemblies
within a range of 18°C to
32°C. Press manufacturers
have invested a lot of knowhow in enhancing the efficacy
of such temperature controls,
which must serve two basic
purposes: they must ensure
that the rollers and cylinders
have the specified optimum
temperature profile, and they
must compensate for any sudden build-up of heat during
temporary standstills.
…on blankets and rollers
For blankets and rollers
the same applies as in wet offset: they must be resistant to
the solvent(s) stated on the ink
packaging or the type of radiation used for drying or –
since UV waterless inks are
now available – curing.
Waterless offset inks may
differ from wet offset inks in
their ink-splitting properties.
This can mean that a blanket
that is suitable for wet offset is
not necessarily suitable for
waterless offset. Rubber rollers are less sensitive in this respect and can even be used in
hybrid offset presses that run
both wet and waterless.
Waterless offset is a process with high quality standards, capable of reproducing
particularly fine screens with
extreme highlights and shadows. In sheetfed it is essential
to choose a blanket capable of
printing absolutely uniform
solids, ie one that has a finely
ground and polished face
compound with a maximum
hardness of 80° Shore A and a
compressibility of 0.16 to
0.21mm (0.006” - 0.008”) at
a maximum standard compressive force of 1350kPa
(28,195lbf/ft2) for a controlled
dot gain. For newspaper
production, on the other hand,
the rougher the blanket, the
better. Special waterless offset blankets are available
from a number of manufacturers. KBA, for example, is cur-
drying
rently collaborating with all
major
manufacturers
to
optimise its waterless newspaper technology.
…and substrates
Since waterless inks contain no fount solution that
must evaporate or be absorbed, they generally dry
faster than wet offset inks,
so the absorbency of the
substrate plays a smaller role
than in wet offset. Printthrough can occur, however,
if waterless inks are applied to
highly absorbent stock.
With both waterless and
wet offset inks, it is the
chemical or physical properties of the paper surface that
are usually responsible for
chalking or repulsion problems. Although papermakers
have yet to offer an explicitly
waterless paper, non-absorbent substrates like film, synthetics or sealed paper, which
can often only be printed in
wet offset using UV inks,
are ideal. Print production
on plastic cards (eg with
Metronic’s oc200) or plastic
and lenticular film (eg with
the waterless offset KBA 74
Karat) are evidence of this.
Dieter Kleeberg
Resources/alliance partners
W
e wish to thank all our
alliance partners for their
invaluable support in advancing
and optimising waterless, keyless
offset for shopfloor applications.
Westland Gummiwerke GmbH,
D-Melle,
www.westland-worldwide.de
(rollers)
Plates, pre-press
Inks
Press kit and peripherals
Axima GmbH,
D-Freiburg/Breisgau,
www.axima.de
(temperature control systems)
Baldwin Germany GmbH,
D-Augsburg,
www.baldwintech.com
(temperature control and blanket
washing systems)
Ludwig E. Betz GmbH,
D-Marktheidenfeld,
www.betz.de
(ink pumping systems)
Felix Böttcher GmbH,
D-Cologne,
www.boettcher.de (rollers)
ContiTech ElastomerBeschichtungen GmbH,
D-Northeim,
www.contiair.com (blankets)
Day International GmbH,
D-Reutlingen,
www.dayintl.com (blankets)
Elettra srl,
I-Olgiate Molgora/LC,
www.elettra-online.com
(blanket washing systems)
Idab Wamac GmbH,
D-Hamburg,
www.idabwamac.com
(post-press/mailroom)
MacDermid Graphic Arts S.A.,
F-Cernay,
www.macdermid.com
(blankets)
Müller Martini VersandSysteme AG,
CH-Zofingen,
www.mullermartini.com
(post-press/mailroom)
Reeves S.p.A.,
I-Lodi Vecchio,
www.reeves.it
(blankets)
Sauer Walzenfabrik GmbH,
Eurolab, D-Berlin,
www.sauer-roller.com
(rollers)
Technotrans AG,
D-Sassenberg,
www.technotrans.de
(temperature control systems)
Zeller+Gmelin GmbH,
D-Eislingen,
www.zeller-gmelin.de
ANI Printing Inks:
Akzo Nobel Inks,
DK-Brøndby/S-Trelleborg, and
Lindgens Druckfarben GmbH,
D-Cologne,
www.aninks.com
BASF Drucksysteme GmbH,
D-Stuttgart,
and BASF Druk Inkt BV,
NL-Doetinchem,
www.basf-printing-systems.com
Classic Colours,
GB-Reading,
www.classiccolours.co.uk
Epple Druckfarben AG,
D-Neusäss,
and Sicolor GmbH,
D-Neusäss,
www.epple-druckfarben.de,
www.sicolor.de
Flint Ink,
USA-Ann Arbor/Mi,
and Flint-Schmidt GmbH,
D-Frankfurt/M.,
www.flintink.com,
www.flint-schmidt.com
Huber-Gruppe, Michael Huber
München GmbH,
D-Kirchheim,
www.huber-gruppe.com,
www.mhm.de
Prüfbau
Dr.-Ing. H. Dürner GmbH,
D-Peissenberg,
www.pruefbau.de
(ink rheology tests)
Creo EMEA S.A.,
B-Waterloo,
www.creo.com
Ernst Marks GmbH,
waterless printing centre,
D-Mülheim/Ruhr,
www.marks-3zet.de
HumanEyes Technologies Ltd.,
IL-Jerusalem/USA-New York,
www.humaneyes.com
Kodak Polychrome Graphics
(KPG), D-Osterode,
www.kpgraphics.com
Perlen Papier AG,
CH-Perlen,
www.perlen.ch
Nela Brüder Neumeister GmbH,
D-Lahr,
www.nela.de
SCA Graphic Sundsvall AB,
Ortviken Paper Mill,
S-Sundsvall,
www.sca.se
Presstek, Inc.,
USA-Hudson/NH,
www.presstek.com
Toray Industries Inc.,
J-Urayasu,
www.toray.co.jp/waterless,
www.waterless.org,
www.waterless-print.com
Paper, substrates
Aylesford Newsprint Ltd.,
GB-Aylesford/Kent,
www.aylesford-newsprint.co.uk
HIT Paper Trading GmbH,
JSC Volga, A-Wien,
www.hit-papertrading.com,
www.volga-paper.ru
Holmen Paper GmbH,
D-Hamburg,
www.holmenpaper.com
IGEPA Group,
D-Reinbek,
www.igepa.de
Siegwerk Druckfarben AG,
D-Siegburg,
www.siegwerk.de
Kübler & Niethammer Papierfabrik Kriebstein AG,
D-Kriebstein,
www.k-n-paper.de
Toyo Color America, LLC,
A Toyo Ink Company,
USA-Englewood Cliffs/NJ,
www.toyocolor.com
Norske Skog,
A-Bruck/Muhr,
www.norske-skog.at
Papierfabrik Palm,
D-Aalen,
www.papierfabrik-palm.de,
www.wellenwunder.de/internet/
papier/
Sicpa Group,
CH-Prilly,
www.sicpa.com
SunChemical Ltd.,
European Coldset Centre (ECC),
GB-London,
and SunChemical Hartmann
Druckfarben GmbH,
D-Frankfurt/M,
www.sunchemical.com
Myllykoski Sales AG,
Utzenstorf Papier,
CH-Utzenstorf,
and Myllykoski Sales GmbH,
D-Dachau,
www.myllykoski.com,
www.utzenstorf-papier.ch
Klöckner Pentaplast GmbH,
D-Montabaur,
www.kpfilms.com
Lang Papier,
D-Dachau,
www.langpapier.de
Mochenwangen Papier GmbH,
D-Mochenwangen,
www.mochenwangen-papier.de
Schönfelder Papierfabrik GmbH,
D-Annaberg-Buchholz,
www.schoenfelderpapierfabrik.de
Steinbeis Temming
Papier GmbH,
D-Glückstadt,
www.steinbeis-temming.de
StoraEnso Deutschland GmbH,
D-Hamburg,
www.storaenso.com
UPM-Kymmene Sales GmbH,
D-Hamburg,
www.upm-kymmene.com
Associations, consultation,
certification
Berufsgenossenschaft Druck u.
Papierverarbeitung,
D-Wiesbaden,
www.bgdp.de
European Waterless Printing
Association (EWPA),
c/o Druck & Beratung
Detlef Braun,
D-Mühlheim/Ruhr,
www.ewpa.org, www.wluv.de
Japan Waterless Printing
Association (JWPA),
J-Tokyo,
[email protected]
Ökopol Institut für Ökologie
und Politik GmbH,
D-Hamburg,
www.oekopol.de
(WPA),
USA-Chicago/IL,
www.waterless.org
KBA Process
2 | 2005
11
Current approaches | Inking-unit design
Waterless and keyless –
new inking unit designs
Eliminating fount solution in offset is just the first step towards simplifying this widely popular printing process. The second step is to dispense
with ink keys. Both moves support the transition to an offset process that is no longer subject to manual intervention, and thus human error, via
the press settings – a basic precondition for standardising the entire print production chain. When developing keyless inking units for waterless
offset KBA was able to draw on a wealth of experience with waterless UV printing on plastic cards and CDs, keyless newspaper production
and inline coating.
C
onventional film inking units in offset
presses have a fiveassembly ink train:
• an ink trough with metering
elements (ink keys or slides
that press against a one-piece
or segmented ink knife);
• a rotating duct roller (temperature-controllable);
• a vibrator roller between the
duct roller and distributor
rollers on sheetfed presses, or
a film roller on web presses;
• several oscillating ink rollers that are either coated with
rilsan or copper (ink drum,
temperature controlled), or
made of rubber;
• one or more pairs of rubber
rollers for applying ink to the
printing forme.
Ink feed is defined as single- or double-train, depending on how the ink is split by
the oscillating ink rollers onto
the pairs of ink forme rollers.
In single-train inking, the ink
80
%
Change in relative viscosity
Conventional: long inking units
with ink keys, duct roller,
vibrator roller etc
60
40
20
0
0
0.5
1.0
..5
2.0
Change in temperature
KBA Process
2 | 2005
3.0
Ink viscosity in the controlled area is almost linearly dependent on
temperature. A temperature fluctuation of just 1 Kelvin causes a relative
change in viscosity of more than 20%
is transported to the rear pair
of ink forme rollers indirectly
from the front pair via an
oversize bridge roller. KBA
generally favours single-train
inking in sheetfed offset and
double-train in web offset.
However, the inking unit developed by Ryobi for the
KBA 46 Karat waterless DI
sheetfed offset press has a
double train.
Rider rollers at the distributor rollers and/or the
front pair of ink forme rollers
can be engaged as bridge rollers to create a “short circuit”
to the dampening unit. Alternatively, a larger-diameter
forme roller can transfer both
ink and fount solution to the
printing plate. These engineering refinements have
Left: The 46 Karat waterless DI
offset press has double-train inking
units
12
2.5 K
long since proven their worth
in KBA’s Varidamp dampeners.
…and temperature control
Long inking units in conventional offset presses with
dampening units are designed
to split the ink repeatedly and
thus reduce the thickness of
the ink film from a few tenths
of a millimetre on the duct
roller to around 4µm (0.15
thou) on the plate, and to
achieve a stable ink emulsification. The ink forme rollers,
which number between two
and four, also have the function of preventing ghosting on
the plate. These functions are
the same in waterless offset,
provided a precise temperature control system is installed in place of the disengaged or absent dampening
units.
Provision for connection
to a temperature control circuit is now a standard feature
of all Rapida presses. A growing number of printing plants
are opting for an all-in temperature control system, not
just because it is essential
with waterless offset but because it also promotes a more
stable print in wet offset and
dramatically reduces IPA
emissions. Temperature control is already essential in
commercial web offset and is
therefore a standard feature of
all Compacta presses. KBA
customises Baldwin, Technotrans and other temperature
control systems to suit individual press configurations.
Baldwin CombiLiner
ink temperature
control unit linked to
other feed systems
for a Rapida
Schematic of the five keyless inking
units in a Genius 52:
1 doctor-blade chamber
2 screen roller
3 ink forme roller
4 plate cylinder
5 blanket cylinder
6 quadruple-size impression cylinder
1
2
3
4
5
is not needed for the printed
image it is simply wiped off
again and returned to the ink
circulation system. In sheetfed offset presses where the
ink forme rollers have the
same diameter as the plate
cylinder, no oscillation is
needed because this type of
short inking unit is totally
ghosting-free. The Cortina
inking unit features two additional self-oscillating distributor rollers alongside the
two forme rollers. The duct,
vibrator and film rollers are
replaced by an anilox roller
doctoring system and are
therefore eliminated along
with the ink keys.
6
The process parameters
the press crew must master
are thus reduced to a minimum, and with them potential
problems. But the groundwork for reliably reproduces
images – and thus standardisation – is laid in pre-press.
ICC profiles and print characteristics should nowadays be
an integral part of the routine
in any quality-conscious
graphic enterprise, so waterless, keyless offset should
demand no additional capabilities. Pre-press precision is,
after all, just as essential for
quality production with long
inking units incorporating ink
keys. And ink keys are no substitute for precise, immaculate
plate exposure because they
cannot correct oversized, undersized or missing dots: they
merely enable the colour tone
in an image or solid to be adjusted via over- or under-inking – provided there are no
The temperature of the screen rollers and plate cylinders at the keyless inking
units in the Genius 52 UV press is also controlled
The new alternative:
keyless inking units
Although long inking
units would also transfer the
ink in the desired thickness to
the printing forme on a waterless offset press, they are surplus to requirements because
keyless inking units work
with much greater precision
and are not subject to manual
intervention by the operator.
So far KBA and its subsidiary
Metronic are the only manufacturers to embrace this alternative means of further
simplifying and standardising
waterless offset. Thus the
screen roller on the 74 Karat,
Genius 52 and Rapida 74 G is
accompanied by just one ink
forme roller. Both rollers have
the same diameter as the plate
and blanket cylinders. On the
13mps (2,560fpm) Cortina
newspaper press there are
four rollers because its higher
printing speed means that
emptying the screen of ink
plays a more critical role.
When KBA decided to
adopt short inking units it also
decided to dispense with
zone-wide ink metering. A
uniform, precisely specified
volume of ink is offered up to
the printing plate or plates
(depending on the image)
across the entire format width
via a screen (or anilox) roller,
doctoring system and forme
roller(s). If a particular colour
Schematic of the four Gravuflow
short inking units in a 74 Karat
KBA Process
2 | 2005
13
Current approaches | Inking-unit design
Comparison of conventional and keyless waterless offset inking units
Functions
Conventional (long)
in Rapidas and Compactas
Keyless (short)
Gravuflow in 74 Karat
and Rapida 74 G
Newsflow in Cortina
Metronic in Genius 52
and Metronic presses
Ink feed
manual, optional cartridge
or pump
cartridge
pump
manual
Ink key metering
ink trough with ink keys
and knives
none
none
none
Ink volume metering
rotating duct roller, timed
dancing vibrator roller or film roller
doctor-blade
chamber + rotating screen roller
doctor-blade bar +
rotating screen roller
doctor-blade
chamber + rotating screen roller
Ink distribution
several distributor rollers
and ink drum
none
2 rilsan and 2 rubber rollers
none
Plate inking
up to 4 pairs of
rubber forme rollers
1 x 1:1 forme roller
with blanket
2 rubber forme rollers
1 x 1:1 forme roller
with blanket
Image transfer
conventional blanket
with bar
conventional blanket
with bar
minigap blanket
with metal back
minigap blanket
with metal back
Relative dimensions
duct roller ≥ distributor/
ink forme rollers ink form roller <<
plate/blanket cylinders
plate/blanket cyl. < impression cyl.
screen roller < ink forme roller
ink forme roller < plate/blanket
cylinders
plate/blanket cyl. < impression cyl.
screen roller > ink forme rollers
ink forme roller << plate/
blanket cylinders
(blanket-to-blanket)
screen roller = ink forme roller
ink forme roller = plate/
blanket cylinders
plate/blanket cyl. = impression cylinder
Temperature control
duct roller + ink drum
screen roller + plate cylinder
Schematic showing a Gravuflow
short inking unit in a Rapida 74 G
and a conventional inking unit in a
Rapida
waterless plate, a blanket cylinder and an impression cylinder. The rollers and cylinders
all have the same diameter.
This technology also comes
into play in Metronic’s CD
Print and Premius presses for
printing CDs, DVDs, minidiscs and unusual optical
business cards.
keyless inking units. Its oc200
UV press, which can print and
coat pairs of plastic cards up
to an ISO format of 86 x
54mm (31/4” x 2”), has been
one of its best-selling lines
since 1994. The mini printing
unit incorporates an anilox
roller, an ink forme roller, a
plate cylinder fitted with a
Printing unit with Gravuflow short inking unit in a Rapida 74 G:
1 ink cartridge, 2 chambered doctor blade, 3 screen roller, 4 ink forme roller,
5 plate cylinder, 6 blanket cylinder, 7 impression cylinder
other images or solids positioned around the circumference.
However painful it may be
for many experienced printers, the fact remains that any
subsequent adjustment made
via the ink keys and duct
roller speed is a subjective intervention in the printing
process and runs counter to
the concept of standardised
production with objectively
defined parameters and reliably repeatable results. And
as a rule it also generates
needless waste.
Metronic’s
proprietary
short inking unit formed the
basis for the one in the compact Genius 52 waterless offset press, a prototype of which
was unveiled to great acclaim
at Ipex 2002. The marketing
concept for the Genius is twopronged, with KBA selling
the oxidative ink version for
paper and board and Metronic
selling the UV version for
film and plastic printing in its
specialist niche markets.
1
2
3
Groundbreakers:
Gravuflow and Newsflow
4
Metronic’s
established
short inking units and KBA’s
current short inking units for
waterless offset originated
5
6
7
6
5
7
Metronic: card and CD printing
as the basis for development
Metronic, which is located
in Veitshöchheim near Würzburg, collaborated with KBA
for many years before it became a subsidiary in 2004,
and was the first press manufacturer worldwide to develop
a waterless offset press with
14
KBA Process
2 | 2005
3
8
4
7
5
2
1
6
The Newsflow short inking unit in
the Cortina is a Gravuflow unit
modified for newspaper presses:
1 ink pump
2 blade on/off
3 doctor-blade bar
4 temperature-controlled ceramic
anilox or Gravuflow roller
5 rubber rollers
6 rilsan inking rollers
7 rubber ink forme rollers
8 temperature-controlled plate
cylinder
from a common development
platform, but while Metronic
specialised in UV systems for
printing cards, discs and film,
KBA focused on sheetfed offset and newspaper web
presses. The systems that
evolved – Gravuflow inking
units in the 74 Karat and later
in the Rapida 74 G, Newsflow
inking units in the Cortina –
boast some unique features.
Even though wet offset,
with its huge installed base
and wide-ranging applications, will remain the dominant printing process for some
time to come, KBA predicts
that keyless inking units like
its Gravuflow and Newsflow
are the route the industry will
take. Sooner or later economic and ecological considerations will drive the adoption of waterless offset in general, and keyless waterless
offset in particular, by players
in both the sheetfed and the
web press markets – and there
are some hard facts to back
this up. Since print runs in
commercial web offset are
still very long, in the web
press market KBA is using the
Cortina initially to target the
newspaper sector, where run
lengths are diminishing on the
back of greater localisation
and split editions.
waterless anilox inking units
10
8
The development of the Newsflow
unit benefited from KBA’s in-depth
experience in anilox wet offset, eg in
the Anilox-Commander:
1 ink pump, 2 ink trough (split for
different colour impositions in the
printing couple), 3 doctor blade,
4 ink feed, 5 anilox rollers,
6 and 8 ink forme roller,
7 rider roller, 9 plate cylinder,
10 blanket cylinder (blanket-toblanket), 11 web, 12 dampening
forme roller, 13 dampening rollers,
14 dampening distributor roller,
15 spray bar
9
7
12
13
6
13
14
5
4
15
3
2
1
11
comprise four assemblies
with the following functions:
• an ink-feed system (cartridges, pumps);
• a chambered doctoring system (doctor blade chamber or
holder);
• a constantly rotating, temperature-controlled metering
roller (Gravuflow or anilox
roller with ceramic-coated,
hatched surface);
• a
1:1
blanket-covered
forme roller on sheetfed
presses or several smaller
rubber rollers (connected by
oscillating ink rollers) in
newspaper presses.
The doctoring system has
two blades – a working blade
and a sealing blade – which
when thrown against the
anilox roller create a temporary “bath” that floods the
hatched surface with ink. As
the roller rotates under the
bath the working blade wipes
off the excess ink. KBA’s
doctoring systems for keyless inking are not the same
as the ones for flexo presses
or coaters. The open chamber
system for slower-running
sheetfed presses and the
closed bar system with pump
for high-speed newspaper
presses were specifically
engineered to handle highviscose inks like those used
in waterless processes.
Keyless inking units such
as these must, of course, also
feature temperature control.
The temperature on the surface of the screen roller and
plate cylinder in KBA’s
sheetfed presses and Cortina
is speed-dependent and controlled within tight tolerances.
The winning features of the Gravuflow (left) and Newsflow inking units are easy access and handling, a fast run-up to
saleable colour and long-run colour stability
In-depth experience in short
inking and coating technologies
for conventional presses
Alongside its alliance with
Metronic, KBA can also draw
on many years of in-house experience in the design and development of keyless waterless offset systems, among
them anilox short inking units
for newspaper presses in the
1990s and anilox coaters for
sheetfed offset presses.
Over the past ten years
some 20 Colora, Commander
and Express presses totalling
around 600 wet offset printing
couples with anilox short inking units have rolled off the
KBA production line. Other
keyless presses shipped by
KBA include Flexo-Courier
and Colormax CIC newspaper flexo presses and various
letterpress models which have
since been discontinued. KBA
has also launched a flexo
sheetfed press, the KBA
Corrugraph, for printing corrugated and solid board.
The know-how KBA has
amassed in developing inline
coating
technology
for
sheetfed offset has also been
applied to the development of
short inking systems. Tworoller units, which applied a
variable thickness of coating,
have long since been displaced by modified flexo
printing units that can apply a
coating film precisely defined
by the pick-up volume of the
specified screen roller.
Dieter Kleeberg, Georg Schneider
KBA Process
2 | 2005
15
Current approaches | Technotrans temperature control
How technotrans in Sassenberg, Germany, controls the temperature at the screen rollers
and plate cylinders on keyless sheetfed presses
Temperature control in inking units
T
he basic laws of thermal
dynamics obviously apply in offset as well. Most of
the kinetic energy generated
by the drives is converted into
heat through external friction
(surfaces) and internal friction (ink splitting, cylinder
deflection). It is a well-known
fact that this heat has a major
impact on the printing process
and the quality of the prints
delivered. This is because any
change in temperature in the
inking and printing units
affects the rheological properties of the ink. So maintaining
a constant temperature is fundamental to obtaining consistently reproducible high-quality prints, all the more so in
waterless in offset.
Kinetic energy is converted into heat at three main
sources:
• the rollers, more specifically the duct and oscillating
ink rollers in conventional
inking units and the screen
rollers in short inking units,
due to roller friction and the
energy consumed in overcoming the load and shear force
exerted by the ink;
• the gears and bearings on
all the rollers and cylinders,
due to sliding friction;
• the rubber blankets and
elastomer roller covering, due
to fulling.
inking unit should have a
dedicated system to accommodate differences in the
amount of heat generated
within the individual printing
units, both in absolute terms
and relative to each other.
Within a printing unit, differences in temperature arise
between the duct roller and
the distributor rollers in conventional inking units, and
between the screen roller and
the plate cylinder in short inking units. Where the tempera-
faces it follows that the temperature of the cooling water,
particularly at the plate cylinder, must be increased in line
with press speed, otherwise
problems with tinting etc may
occur. Ink application and
density in a keyless inking
unit are controlled solely via
the screen roller and temperature. At high speeds the screen
on the roller surface is not
emptied so completely, so the
temperature at the screen
roller must be increased to
Left: Heat sources (red) in a printing
unit with conventional inking system
Below: Technotrans’ beta.z zonal
temperature control system with
external beta.cooling system
Stabilising temperature
The most effective means
of stabilising the temperature
of the ink is to control the
temperature of the inking
unit. Conventional inking
units are usually connected to
a single-circuit system. This
has become a standard feature
on all heatset web presses and
is widely used in sheetfed offset. In waterless offset presses
with keyless inking units,
temperature control is essential – so essential that each
16
KBA Process
2 | 2005
ture of one printing unit varies
relative to another, this is
caused by differences in roller
adjustment, in the volume of
ink being transferred and in
the properties of the different
colour inks.
As press speed increases,
so does the heat in the inking
unit, while the optical density
of the ink decreases because it
comes into contact with the
nip for a shorter length of
time. So to maintain a constant temperature on all sur-
compensate. Long ink trains,
by contrast, must be cooled
more at higher speeds in order
to maintain a constant temperature in the inking unit.
Distinctive features
of temperature control systems
for short inking units
Unlike conventional inking units, in which the ink is
controlled via the ink keys
and duct roller, keyless units
have no mechanical means of
influencing ink transfer. Instead they must alter the
rheological properties of the
ink, and this is only possible if
the press has a quick-reacting
temperature control system
which functions via the screen
rollers.
When the ink hits the
plate, interfacial tension
causes it to split between the
image and non-image areas.
So the tack of waterless inks
must not exceed a specific
range. If it is too high it can
cause linting or picking on the
blanket cylinder, if it is too
low it can cause tinting. Since
temperature has a major impact – a change of just one degree can result in a 20%
change in tack – temperature
control is crucial. Maintaining
consistently stable production
parameters prevents not only
tinting and smearing but also
premature clogging. In practice, this problem is solved by
controlling the temperature of
the plate cylinder via an internal flow of water, just like the
screen rollers.
Because so many parameters come into play in
keyless inking units, temperature control technology plays
a central role in controlling
the printing process, and the
quality and performance it
delivers are even more important than in conventional inking units.
To ensure that the image is
inked uniformly, the temperature at the screen rollers and
plate cylinders must remain
constant relative to production speed and press temperature throughout the entire
print run. The basic settings
for each inking unit depend on
the substrate, ink type and
specified ink volume. If the
ink density is to be changed,
this must be done by changing
the temperature in the relevant screen roller circuit via
To support waterless offset, the
technotrans temperature control
system in the 74 Karat has dedicated
circulation systems for each of the
two plate cylinders and four screen
rollers in the Gravuflow inking unit.
The cooling water is pumped from
a standalone chilling system also
supplied by technotrans
the dedicated circulation system connected to the temperature control device.
Even in waterless short
inking units, water is used to
influence the surface temperature and keep it constant.
Since less heat is generated
at the plate cylinder than at
the screen roller, different
temperature limits apply so
separate temperature control
circuits are required. This is
how the temperature in the
Genius 52, 74 Karat, Rapida
74 G and Cortina is controlled.
Since the optimum temperature is not the same
throughout the press, it is customary to install control devices for the individual zones.
The number of circuits varies
depending on the type of
system, and each circuit is
controlled individually via a
dedicated circulating pump,
heating element and control
valve. Some systems monitor
the temperature of the roller
surface indirectly, by measuring the temperature of the
water returning from the
cylinders; others have IR heat
sensors that measure the
surface temperature of the
cylinders directly.
Zonal temperature control
systems pump the cooling water from an external source, eg
a cold-water aggregate or an
existing system. An external
source is best for medium- to
high-performance
systems
like those installed with the 74
Karat and Rapida 74 G. Temperature control systems with
a lower cooling output, like
technotrans’ sigma.tz for the
Genius, have an internal chilling device.
The efficacy and performance of a temperature control
system is largely determined
by the following factors:
• the design of the hydraulic
water-circulating system, the
type of flow (turbulent or
nonturbulent) in the screen
rollers and plate cylinders,
and the difference in temperature between the circulating
water and the surface of the
components being cooled;
• energy transfer within the
screen rollers and plate cylinders, and the speed at which
energy flows between the circulating water and the roller
surface;
• the measuring accuracy of
the
built-in
temperature
gauge;
• the accuracy with which the
temperature in each individual circuit is controlled;
• the speed at which the temperature responds to changes
in parameters such as press
speed and specified colour
density;
• the reliability of the pumping system between the temperature control device and
the press.
Technotrans has collaborated closely with KBA to enhance the speed and accuracy
of its temperature control
technology to meet the specific requirements of waterless, keyless inking units.
Double-walled roller
Water circulation through a conventional roller (top) and through the
double-walled roller with spiral piping now customary in waterless offset
(bottom)
Drawbacks of conventional rollers:
- large volume of water results in a high level of inertia;
- laminar (slow) flow of water within the roller prevents optimum energy
exchange;
- ventilation a problem;
- flow unreliable, especially during rotation;
- big drop in temperature across the roller.
Benefits of double-walled rollers:
- small volume of water, so less inertia;
- turbulent (rapid) flow within the roller promotes rapid energy exchange;
- ventilation less of a problem;
- forced flow, and therefore smoother;
- much smaller drop in temperature thanks to rapid flow of water
The precision with which
the temperature in a keyless
inking unit must be controlled
cannot be achieved solely by
the temperature control system. The construction of the
inking and screen rollers also
influences reaction speeds
and therefore plays a major
role in maintaining a constant
temperature across the roller
width.
The oscillating ink rollers
in conventional inking units
often have a very simple design: the cooling water is
pumped along a small-bore
pipe inserted through the
spindle, exits at the other end
and returns to the point of en-
The temperature at the plate
cylinders on the Genius 52 is
controlled via a single circulation
system, the five screen rollers in the
keyless inking unit via dedicated
systems. The photo shows the
technotrans sigma.tz temperature
control unit with integrated watercooling device
try at a relatively low velocity
via the cavity between the
pipe and the roller shell. Although this is better than no
temperature control at all,
heat exchange and thus response times are as sluggish
as the flow of water and may
result in temperature differences between the drive and
operating side.
A double-walled design is
much more effective and has
now been widely adopted for
screen rollers. The cavity
within the roller sleeve is narrower, causing the water to
flow – and thus heat to dissipate – much faster. Spiral piping around the axle results in a
uniform temperature across
the roller.
To sum up, it may be said
that alongside the basic temperature control system mentioned above, which is the
norm on virtually all presses,
an additional temperature
control system, eg zonal for
the screen rollers and collective for the plate cylinders, is
a standard and essential feature on keyless inking units to
ensure the necessary degree
of control in waterless offset.
The choice of configuration depends on the type of
press, its format, speed and
output.
Andreas Harig,
temperature control systems
manager, technotrans AG
Hubert Peick,
temperature control systems
development, technotrans AG
KBA Process
2 | 2005
17
Current approaches | KBA temperature control
How KBA developed a precise, quick-response temperature control system for the Cortina keyless mini tower press
Temperature control in waterless newspaper offset
T
he incursion of wet offset
into newspaper production was accompanied by an
inflow of arcane terminology
from physics, chemistry and
surface analysis that reflected
the complexity of the parameters involved. Simplifying
the process offers tremendous
potential for enhancing its
efficiency and predictability.
Back in the 1970s waterless
offset was brought into play as
a means of improving the
printing process as it then
stood, and of making it easier
to control. It soon became apparent that effective temperature control in the inking and
printing units was crucial to
the reliable functioning and
overall stability of waterless
offset during extended production runs.
Waterless offset with
keyless inking units
KBA has been engaged in
developing waterless offset
presses with keyless inking
units (Gravuflow, Newsflow)
since the mid-nineties. R&D
activities have been founded
on the knowledge gained since
1989 in anilox wet offset. In
1995
development
work
started on a waterless digital
offset press, the 74 Karat,
which featured Gravuflow
inking units. Collaboration
with leading ink manufacturers, plus a string of in-house
technical experiments, soon
revealed a need to enhance
temperature control.
The late 1990s saw initial
moves towards adopting waterless offset for coldset newspaper production, in the form
of the Cortina and its keyless
Newsflow inking system.
Joint development work with
the ink industry brought forth
a succession of advances
which culminated in the current high performance level
and market maturity of the
Cortina.
18
KBA Process
2 | 2005
mum temperature is 26°C
(79°F). But upon closer analysis this turned out to be a misconception – for just about any
inking unit in general and for
the short-train Newsflow inking unit in particular. What we
found was that the temperature
of the anilox roller surface influences the viscosity of the
ink and can therefore be used
to control the volume of ink
transferred. The temperature
of the plate cylinder surface
also influences the image
transfer properties of the plate.
Figure 1: Graphical user interface for the STC at the Cortina console. The
stored temperature control curves and tolerances for each anilox roller and
each pair of plate cylinders can be individually modified using a light pen or
mouse. The co-ordinates are reference temperatures at predetermined speeds
New process advances...
While a waterless capability is regarded as an optional
extra for presses with conventional roller frames, it is the
fundamental technology for
which the 74 Karat, Rapida 74
G and Cortina were specifically engineered. One of our
major objectives was to promote widespread acceptance
of this process, and to this end
we have worked hand in hand
with leading ink and plate
manufacturers. The benefits of
the Gravuflow inking system
in sheetfed presses and of the
Newsflow inking system in
the Cortina newspaper press
soon became apparent. The
most immediate of these is that
it is much easier to maintain a
constant temperature in a compact inking unit. And other innovative features, such as automatically adjustable roller
locks, operate that much more
efficiently if they are in a stable environment. At the same
time new features such as this
also help to reduce needless
energy input.
For a long time, the experience gained from working
with long-train inking units in
waterless offset nurtured the
conviction that maintaining a
stable surface temperature on
the rollers and cylinders was
the key issue. At first, received
wisdom dictated that the opti-
Figure 2: Ramp-controlled temperature changes at an anilox roller surface
in steps of +3°C, +4°C, -5°C, +5°C, -7°C and +7°C.
The ramp reveals the delays arising from the lengths of the relevant pipe runs.
The sequences took place while the anilox roller was idle and at an ambient
temperature of 22°C. Colour key: red = reference surface temperature curve,
dark blue = actual surface temperature curve, light blue = cooling water
temperature
…and fresh challenges in
high-performance newspaper
production
On the Cortina, which runs
at a much higher speed than a
sheetfed offset press, the surface temperature of the ink
rollers and plate cylinder is
governed by press speed and is
adjusted automatically. To obtain saleable copies during the
run-up to production speed the
surface temperature must be
increased dynamically, in
other words “synchronised”
with press speed. The same applies, but in the opposite direction, during press run-down.
Experienced press operators
will no doubt appreciate the
difficulties involved in achieving a 10°C (18°F) change
in temperature – in just 90
seconds – at an anilox roller
weighing
around
100kg
(220lbs) or more, depending
on its size. The corresponding
rise or fall in temperature at
the plate cylinder is not quite
as big, but the mass involved is
many times greater. To assist
the printer in day-to-day operation and to make handling
much easier, the relevant temperatures are stored at the console, just like the dampening
curve in wet offset (see figure
1).
Temperature-governed
values were calculated for the
various inks used. While this
Figure 3: Thermal images of an
anilox roller: at crawl speed (above)
and at 20,000cyl rph (below). The
angle of observation meant that two
images had to be taken to show the
complete roller. The doctor
chambers can be clearly seen. Red
shows the rise in temperature at the
blade in line with the increase in
speed. The temperature is uniform
across the entire width in all
operating states
enables ink density to be controlled across the entire cylinder width, it does limit the
ability to achieve a uniform
density across the print width.
This prompted us to calculate
specific tolerance ranges for
controlling temperature and
thus density. The technology
applied to ensure that the temperature control systems remain within this tolerance
range is called, logically
enough, surface temperature
control (STC).
Figure 3 depicts thermal
images of an anilox roller in
the Cortina, revealing the high
precision of the temperature
control technology. The upper
images were taken while the
press was running at crawl
speed, the lower ones at a
speed of 20,000 cylinder rph.
It can be seen that the temperature across the width is extremely constant, and that the
temperature of the ink is not
governed by the temperature
of the doctor blade, which
rises sharply as the press speed
increases. With the type of
camera used, two shots had to
be positioned side by side to
capture the full width of the
anilox roller.
Figure 4: Heat generation and dissipation in a waterless, keyless inking unit
Ink flow start
Heat source
Ink pump ~ 400 W
(viscous ink friction)
Doctor blade 1mW/mm2
(friction)
(Oscillating) ink roller
(viscous rubber friction)
Forme roller
Blanket
~ 500 - 1000W/m2
Paper
(if Tpaper > Tink)
Heat sink
Ink duct wall,
ink surface (heat
conduction/convection)
Temperature-controlled
anilox roller -0.7mW/mm2,
air convection
-0.3mW/mm2
Air convection
Mastering temperature control
One of the fundamental
tasks in developing the Cortina was to determine which
parameters
(temperature,
flow) needed to be varied, and
in which range, to enable the
press to meet current and future expectations in respect of
format and speed. This required a detailed understanding not only of the power input
(inking unit, blanket fulling)
but also of the mechanisms for
dissipating heat: convection,
radiation, conduction via the
paper, with the press functioning as a heat sink (see figure
4). It followed that the surface
temperature had to be kept stable within certain limits, and
to achieve this a number of
peripheral parameters specific
to the waterless process had to
be factored in: the thermal
properties of the ink, the
impact of heat on ink transfer,
and the fact that the roller and
cylinder temperature must not
be allowed to fall below dew
point.
The technology favoured
by KBA is based on the transmission of heat through a fluid
inside the anilox roller and
plate cylinder. Initially there
were some other systems, for
example air convection, which
appeared equally if not more
appealing since they act directly on the surface. However, air has a much smaller
heat capacity than water. Approximately 3.4m3 of dry air
are needed to dissipate the
same amount of heat as one litre of water (see deduction).
So we would have had to work
with correspondingly lower
temperatures and a bigger volume of convected air. Lower
temperatures would have resulted in water condensation
and thus massive problems
within the press (rust and web
breaks through dripping water
– in a “waterless” press!). And
large volumes of air would
soon have led to almost insurmountable problems from the
physical and technical point of
view.
Hydrodynamically
and thermodynamically
optimised design
But deciding on a basic
principle was not the end of
the tale. Highly dynamic temperature control cannot be
achieved solely by controlling
and regulating the surface
temperature (STC). Each of
the components involved must
also be optimised relative to
the others, as must the interaction among them. Here, a major objective was to ensure that
the STC did not develop into
an energy guzzler. The relevant rollers and cylinders had
to have a much more limited
Deduction
Heat capacities c:
cwater = 1.0 kcal/kg·K and cair = 0.241 kcal/kg·K
Temperature-controlled
plate cylinder
Paper
(if Tpaper > Tink)
Ink flow end
Densities :
pwater = 1.0 kg/l and pair = 1.2·10-3 kg/l
From the products
cwater · pwater = 1.0 kcal/l·K and cair · pair = 2.9·10-4 kcal/l·K
follow the ratios
1.0 : 2.9·10-4 or 3.448 m3 dry air : 1 l water
KBA Process
2 | 2005
19
Current approaches | KBA temperature control
heat capacity and heat transmission properties than those
connected to the temperature
control systems normally used
in the printing industry. This
reduces the charge-changing
losses and times. A further improvement was achieved by
largely decoupling active and
passive heat capacities. Design modifications enabled the
heat transmission properties of
the anilox roller to be enhanced by a factor of three and
its heat capacity reduced by a
factor of six. At the same time
the flow rate was doubled,
which also increased the dynamics.
STC draws on a supply of
cooling and heating water in
order to ensure that the surface
temperature is adjusted to the
target value within a precisely
defined tolerance range and
within a precisely defined
time-frame. Here, too, there
was further potential for process enhancement, eg by
optimising the flow route and
the cross-section of the rollers
and cylinders, and by reducing
flow resistance while preserving accessibility. The installation of more suitable pumps
and valves led to a further advance over the previous state
of the art. Figure 5 shows the
temperature control unit used
in the first Cortina production
press.
Optimised control and
regulating system
The advances achieved in
the design of the anilox roller,
plate cylinder and STC laid the
foundations for a highly dynamic control system. An
analysis of the sheer numbers
Figure 5: 3-D view of a temperature
control unit from the operating side.
The heating and cooling water
modules are on the left and the right,
in the centre are three sub-units with
four circuits apiece for temperature
control at the anilox rollers and
plate cylinders. They contain three
switch cabinets and four pressure
equalisers
20
KBA Process
2 | 2005
Figure 6: Schematic of a
temperature control circuit for a
plate cylinder or anilox roller. The
temperature control unit (TCU)
contains an inner circuit that feeds
to the roller or cylinder and two
outer circuits that supply heating
and cooling water (HW and CW):
[1] Switch for HW/CW
[2] Meter for volume of water
pumped
The return water is piped separately
for greater energy efficiency
Figure 7, upper graph: Ramp-controlled temperature change
by ∆T = -5°C at the surface of an anilox roller. The delay
caused by the 10m pipe run is clearly visible. This delay poses
a major challenge: despite the time lag a transient response
must be achieved without overshooting or slowing the system
down. Notwithstanding, the actual temperature (blue) closely
follows the reference temperature (red). (yellow: anilox roller
index)
Lower graph: This shows the same sequence measured with
an infra-red line camera incorporating 128 measuring pixels
across the width of the anilox roller. The time scale in both
graphs is the same. From the thermal point of view, an idle
roller is more or less neutral: the change in the temperature
profile across the roller width is caused by the cooling water
beneath the surface, which takes a few seconds to flow from
one side to the other
of Pt100 and IR sensors required and the dynamic ratios
involved clearly revealed that
the control system would require a high level of sophistication. The STC system incorporates twelve temperature
control circuits per tower
whose properties can vary
enormously according to production conditions. A single
circuit is shown in figure 6. Simultaneous, highly dynamic
control demands real-time systems capable of carrying out
their allotted tasks reliably and
faultlessly. Here we were able
to draw on the services
of an external specialist with
considerable experience in
configuring big commercial
installations and control technology for highly complex
systems.
The purpose of the control
technology in the Cortina is to
achieve the correct temperature at the surface of the anilox
roller and plate cylinder for the
relevant operational status.
There is still a certain potential
for enhancing efficiency at the
control level. The ambient
temperature, for instance, can
be factored in when calculating the pre-run temperature.
This enables the control system to function more accurately so there is no risk of
overcooling, which would increase operating costs. Furthermore, the duration of a
(long) print run can also be
included in the calculations
and the reference temperature
for the cooling water raised
accordingly. Both measures
can substantially reduce energy consumption. Thus the
amount of energy required to
dissipate the heat input in
many operational states can be
reduced to just 5% of what
would otherwise be needed.
The flawless functioning
of the control unit is illustrated
in figure 7. The upper chart
shows the temperature ramp
for changing the temperature
on an anilox roller surface by
-5°C (ie cooling it by 5°C). In
the lower chart the same
sequence is analysed using an
infra-red line camera across
the width of the anilox roller.
Large-scale industrial
applications
Translating this concept
into a workable system for industrial applications entailed
modularising the STC to support a standardised design
which can be tested after final
assembly and prior to shipping.
The STC now comprises
three modules: cooling water
and heating water (the two basic elements) and temperature
controls, which are identical
for the anilox rollers and the
plate cylinders (figure 5). The
three sub-units each have four
circuits, giving a total of
twelve, and control the temperature at eight inking units
(ie anilox rollers) plus the four
plate cylinder assemblies in a
Cortina four-high tower. The
plate cylinders for the same
colour are connected to the
same circuit. A central, realtime control unit governs the
entire STC system; alongside
the control unit the three
switch cabinets house input/
output units for the pumps,
valves and sensors.
All the relevant components can be accessed easily
from the front for greater convenience when carrying out
routine inspections and minor
maintenance tasks. Various
options are available for accommodating presshall architecture when planning the
pipework for the cooling and
heating circuits.
Reliability writ large
The components in the
STC system had to be optimised for a press hall environment where reliability is
key. To safeguard this reliability, components were chosen
which can furnish data on their
status or whose status can be
Figure 8: Changing the surface temperature of an anilox roller in a Cortina at a production speed of up to 25,000cyl
rph. The speed-dependent reference value is calculated online using the temperature control curves specified at the
console. The high-speed control system must achieve a temperature rise of almost 10°C by the time the press hits
25,000cyl rph. During the run-up and run-down phases the Cortina prints waste-free. Colour key: red = reference
surface temperature, blue = actual temperature, black = press speed, yellow = anilox roller index
Figure 9: Cortina run-up to 35,000cyl rph and temperature change at the anilox roller surface as per temperature
control curve. The ink used here requires a smaller increase in temperature for each change in speed. Although press
speed is 40% faster than in figure 7, the total temperature increase that the control system must achieve is just 5%
smaller. The plotted line also reveals how, roughly 4 minutes after the higher production speed was reached, the press
operator at the console intervened manually with a light pen to reduce the target surface temperature by 0.4°C.
This isolated correction was implemented by the controls in a minimum of time. Colour key: see figure 8
monitored. The circulating
systems were designed in such
a way as to ensure that if any
unit fails, its functions can be
assumed by an adjacent unit.
Separate parameters devised
specifically for just such an
eventuality then come into
force. Similarly, provision has
been made to enable the entire
STC to switch to emergency
mode and take up the slack in
the event of an individual STC
failure. Where no adjacent unit
exists, a redundant unit is installed (eg a double pump).
This multipronged approach
guarantees a high degree of
reliability while maintaining
cost efficiency. The Pt100 sensors used, which are found in
millions of systems worldwide, measure absolute temperature and can be exchanged
with no need for recalibration.
The temperature control circuit does not even have to be
opened.
The creation of such a sophisticated temperature control system, in conjunction
with a raft of other features,
has substantially enhanced the
process technology. As a result
the Cortina is exceptionally
economical to operate. The advances that have been made
are reflected in the large
number of patent applications
submitted in the course of its
development. When planning
a new press hall additional
efficiency and cost savings
potential can be tapped by
including provision for an
energy conservation system
that enables process heat to be
ducted elsewhere for other
purposes.
Dr Matthias Müller, KBA
Dr Karl Schaschek,
head of KBA research
KBA Process
2 | 2005
21
Current approaches | Gravuflow and Newsflow
Gravuflow in the Rapida 74 G and 74 Karat
Gravuflow and Newsflow inking units
T
he Gravuflow inking unit was originally developed for the
74 Karat. The revolutionary engineering principles on
which its design was based have long since entered the mainstream, and the Gravuflow unit has subsequently been modified
for use in Rapida sheetfed offset presses. One of its peculiarities
is that the blanket on the ink forme roller has pre-attached
Right and below: In
the working position
the doctor-blade bar
is connected to the
ink supply from the
cartridge and rests
on the anilox roller
with the working and
sealing blades
exerting a
predefined pressure
(left-hand
schematic)
clamping bars. This type of blanket is used mainly because it
delivers a better image on solids and is much easier to replace
when damaged or worn. The blanket cylinders on the 74 Karat
and Rapida 74 G are fitted with conventional blankets clamped
on with bars; the Genius 52 has metal-backed blankets.
The temperature of each screen roller
and plate cylinder can be controlled
individually with absolute precision via
an external heat exchanger. Although
the ability to alter set parameters runs
counter to the concept of standardised
production, in exceptional cases the
press operator can influence ink
viscosity and thus colour density via
the temperature controls. This may be
advisable to adjust ink density when the
absorbency of the paper surface varies
across the cylinder width
Above: The blade chamber
can be rapidly swung into the
cleaning position prior to the
automatic cleaning cycle.
Ink feed is automatically
suspended
The chambered doctor blade and screen roller apply a uniform ink film
directly to the single-size ink forme roller with each rotation
Newsflow in the Cortina
E
ach Newsflow unit
has its own dedicated drive. As in a
Gravuflow unit the temperature of the screen
roller and plate cylinder
is controlled, but not that
of the ink trough. Temperature control response is virtually in real time. The blanket cylinder – like the
one in the compact Genius 52 – is fitted with metal-backed blankets and a minigap clamping system.
22
KBA Process
2 | 2005
Thanks to their exceptionally compact, space-saving design, Newsflow
inking units fit neatly into the “four-low” Cortina (left), but are nonetheless
easily accessible (above)
New-generation anilox rollers
K
BA’s Gravuflow and Newsflow waterless keyless inking
units feature specially developed anilox rollers with a
chromium-oxide ceramic surface that is resistant to abrasion by
the doctor blade. The anilox rollers in the Cortina have a service
life of around 200 to 300 million revolutions, so they do not
need changing for several years.
Following extensive laboratory and pressroom tests KBA
replaced the multicell pattern typically found on screen rollers
with a hatch-like pattern which is, in fact, a single, spiral groove
laser-engraved in the ceramic surface.
With this new pattern, the volume of ink transferred by the
anilox roller remains uniform across the entire width of the
roller. The only way the printer can transfer more or less ink is to
adjust the temperature, since a change in temperature alters the
viscosity of the ink. A higher temperature, which reduces viscosity, will increase the volume of ink transferred. Substantial
changes in speed have the same effect. When the Cortina runs
up to production speed its quick-response temperature control
system, which is governed by press speed, automatically compensates for loss of colour. Colour density can be adjusted in a
similar fashion to accommodate different paper qualities.
So the roller surface is not the only major parameter involved. And the bigger the roller, the more critical the temperature. As a result, new engineering principles had to be applied
for controlling the temperature of the Newsflow anilox rollers in
the Cortina to guarantee the fastest possible response. This is
why the temperature of each and every anilox roller is controlled individually.
As a comparison:
microscopic image
of cells on a
laser-engraved
anilox roller
(photo: Praxair)
Microscopic image of the hatching on screen rollers. The cell walls showing
traces of laser radiation are clearly visible, the base of the grooves is darker
and less distinct
(photos: Zecher)
The different profiles created
on a roller surface by YAG and
CO2 lasers. The YAG laser,
being ten times finer than the
CO2, achieves a profile much
closer to the U-shaped ideal that enables the cell or groove to be emptied
completely. The volume of ink transferred is therefore consistently uniform,
which is not the case with the more angular profile created by a CO2 laser
(graphic: Praxair)
The aniloy rollers (green and grey) and forme rollers in the Genius 52 printing
units have the same circumference as the plate and blanket cylinders. Linear
guides for the zero-play bearings on all four components support rapid roller
changes. The inking-unit rollers in the Genius 52 no longer have to be
adjusted
KBA Process
2 | 2005
23
Consumables | Plates and film
Analogue and digital plate media –
market review and processing
Looking at the number of plate suppliers and the range of materials
The differences lie in the composition of the other layers, the imaging
available, it is easy to understand why users would like a broader
technology for which they are constructed and the method and
choice. One feature common to all specialist plates and films for
complexity of subsequent processing. There is a conspicuous move
waterless offset is that the image-free areas are coated with silicone.
towards CTP exposure.
Compare final costs,
not initial prices
F
irst of all, let’s set the
record straight. Yes, the
additional silicone layer
does push up the price of waterless offset plates compared
to wet offset plates, and this
price difference is an argument
all too frequently advanced by
sceptics. Yet in many cases –
particularly for short runs – it
is often cheaper, overall, to
print with waterless offset
plates than with wet offset
plates. What sceptics tend to
lose sight of is the fact that the
higher price is more than offset
by the savings gained from
lower water consumption,
fewer chemicals (dampening
additives), the elimination of
setting, control and maintenance work at the dampeners
and a dramatic reduction in
production waste. Above all, if
combined with keyless inking
units, waterless offset supports
a more advanced degree of
standardisation both in prepress and in the press room,
which delivers a consistently
higher print-to-print and runto-run quality over the long
horizon.
Boosting sales the only way
to push down prices
Nevertheless, it is still
worth talking about the price.
For printers and press vendors
– not to mention sceptics –
lower plate prices would naturally be very welcome, and in
recent years KBA has worked
closely with plate manufactur24
KBA Process
2 | 2005
Overview of waterless offset plates and films currently available that are not restricted to
specific makes of press
(KPG Scorpion only available in North America)
Analogue UV exposure
positive working
Creo
–
KPG
–
Presstek –
Toray
TAP-HG2 (1)
negative working
–
–
–
TAN-E (1)
Wet processing + cleaning
chemical + water wash
Creo
–
KPG
X54 Scorpion/Scorpion+
Presstek –
–
Toray
TAC-RG5/RL7 (1)
–
TAPH-G2 (1)
TAPD-G1 (1)
TAPD-G3 (1)
TAPD-G5 (1)
TAN-E (1)
Digital thermal laser imaging
Max. format
negative writable only
Clarus WL (2)
X54 Scorpion/Scorpion+
PEARLdry/+ (1, 2), ProFire Digital Media (2)
TAC-RG5/RL7 (1), TAC-W2 (1)
00 (A3+, 460 x 340 mm)
4 (A0–, to 1152 mm wide)
4 (A0–, 813 x 1118 mm)
7B (1240 x 1610 mm)
Ablation + cleaning
Max. run length
water-washable
–
dry
30,000 (S)
Clarus WL (2)
100,000 (S, H, C)
–
20,000(2)–100,000(1) (S)
–
PEARLdry/PEARLdry Plus (1, 2)
20,000 (S)
–
ProFire Digital Media (2)
100,000 (S, H, C)
–
–
200,000 (S, H, C)?
TAC-W2 (1)
–
100,000 - 200,000 (S)
–
–
150,000 - 300,000 (S, H)
–
–
200,000 - 500,000 (H)
–
–
400,000 - 1,000,000 (H)
–
–
300,000 - 500,000 (S, H)
–
–
Material: (1) aluminium plates, (2) polyester film off the roll. Suitable for: (S) sheetfed offset, (H) heatset, (C) coldset with CTP
ers Toray, Presstek and Kodak
Polychrome Graphics (KPG)
to achieve substantial advances in this field. Market
forces dictate that prices fall
when there is more competition, in this case a broader base
of plate manufacturers or a
wider choice of plates, and
when increased demand enables manufacturers to exploit
economies of scale. Despite
appearances to the contrary,
the few suppliers that do offer
such plates are not exploiting
their market dominance: the
higher prices obtaining are
due, on the one hand, to higher
manufacturing costs (the application of a silicone layer as
an additional production sequence in a separate produc-
tion line) and, on the other, to
the fact that the present level of
demand does not enable existing platemaking lines for waterless plates to be run at full
capacity.
Simplifying the complex
process by which plates are
coated with polymer and
scratch-resistant silicone is no
easy task, and there are no
breakthrough products in the
offing. So a price reduction in
the foreseeable future can only
be achieved by a more widespread adoption of waterless
offset and a dramatic leap in
plate sales. For plate suppliers,
waterless offset is still very
much a niche market.
The Clarus WL, a chemistry-free
waterless polyester plate launched
by Creo at the last Drupa, came on
the market early this year.
At present it is only available in rolls
and is therefore suitable for use in
the 46 Karat
Having said that, the strategy pursued by certain companies which have developed
their own waterless plates and
run successful tests on them –
some at KBA – would seem to
indicate a lack of sensitivity
both to current consumer demand and to future potential,
since they do little to promote
the large-scale acceptance of
waterless offset, yet have expressed reluctance to enter the
waterless plate market until
Chemical developing process for the waterless CTP plates manufactured by
Kodak Polychrome Graphics and Toray Industries: [1] pre-treatment,
[2] development, [3] after-treatment (inking of image areas),
[4] optional washing (removal of chemical residue)
(graphic: Toray)
annual consumption has risen
to a minimum of 10 million
square metres (100-millionplus square feet). This fixation
on volume sits ill with the image projected by major suppliers as drivers of innovation
with their fingers on the industry pulse. The contrast with all
the leading ink manufacturers,
who have been quick to recognise that waterless offset will
soon become a high-growth
market and are busily investing to expand their product
palettes, could not be more
striking.
Structure and working principle of
Toray’s waterless plates: negative
working (TAN = analogue, TAC =
CTP) on the left, positive working
(TAP) on the right.
A) Unprocessed plate:
Structure: transparent protective
film [1]; silicone rubber [2];
photosensitive polymer (analogue:
UV-sensitive; digital: heat-sensitive)
[3]; primer (adhesive) [4];
aluminium base [5].
B) Exposure:
A laser beam passes through the
negative (TAN) or positive (TAP)
film copy [6] and protective film [1],
or through the protective film alone
where there is no film copy (TAC). In
an analogue or digital negative
plate, exposure to light weakens the
bond between the silicone rubber
layer [2] and the photosensitive
polymer layer [3], in a positive plate
it strengthens it.
C) Development:
The protective film is peeled off.
A pre-treatment solution is applied
to the negative plate to desensitise
the polymer layer and to strengthen
the bond (symbolised by crosses)
between the silicone [2] and the
polymer [3] in unexposed areas [7].
The silicone rubber is then
chemically loosened from the
photosensitive layer in the exposed
areas [8] and removed with rotating
brushes and water.
The bond between [2] and [3] in
exposed areas [8] in the positive
plate is already strong (step B). A
chemical developer is applied, the
silicone rubber is loosened in the
unexposed areas [7] and removed,
also with rotating brushes and water.
The subsequent procedure for all
three types of plate – with the
exception of the new waterdeveloped TAC-W2 unveiled at
Drupa 2004 – is the same: rotating
brushes improve ink acceptance in
the image areas and pairs of
pressure rollers then remove all
chemical residue. The plate is dried
by air. It does not have to be
gummed like a wet offset plate.
D) Processed plate:
Non-image (ink-repellent) areas [9]
have retained their silicone coating,
while image (ink-receptive) areas
[10] have been stripped down to the
polymer layer.
E) Printing:
Only the image areas are covered
with a layer of ink [11].
Shrinking number
of plate manufacturers
The total number of plate
manufacturers, both of conventional and CTP wet offset
plates, is also steadily diminishing from year to year. In
2004 Agfa acquired Lastra, an
Italian group which in 2002
had taken over Mitsubishi
Chemical’s plate-making division, Western Lithotech. FujiKBA Process
2 | 2005
25
film has pledged its film material to a single press manufacturer. The remaining globally
active players in this market –
Creo, KPG, Presstek and Toray
– already offer waterless
plates, though not necessarily
worldwide. So Agfa and
Fujifilm could well enter the
arena as two new players with
global operations, while the
current suppliers may be expected to offer a bigger selection of plates in the medium
term with broader capabilities
for waterless sheetfed offset,
heatset, coldset and specialised
UV applications.
Chemically processed
analogue plates:
Toray’s TAP and TAN-E
Toray’s waterless plates are
the classics in waterless offset.
They are based on 3M’s Dry
Plate patents and were refined
by Toray to their present level
of sophistication. Toray Industries is a Japanese corporation
specialising in the production
of polymers, and plate manufacture represents a minor item
in its product portfolio. So the
company deserves all the more
credit for maintaining a dedicated research laboratory and,
more recently, for investing in
an additional platemaking line.
With this move Toray has increased its annual waterless
plate production capacity from
around 6 million square metres
offset, heatset publication and
coldset newspaper print production as well as for printing
UV-curable inks on synthetics
and labels.
Toray is the only manufacturer that still offers analogue
waterless plates: the positiveworking TAP and negativeworking TAN-E. Both must be
handled in a yellow light environment. The TAN-E and
TAPH-G2 are the most popular
analogue waterless plates for
sheetfed offset. In web offset,
where print runs are usually
much longer, the more stable
TAPD versions are commonly
used.
Move towards CTP
Structure and working principle of Presstek’s PEARLdry processless plate:
the infra-red laser beam [1] creates an image element, eg a halftone dot [2]
by burning off the ink-repellent silicone layer [3] and the heat-sensitive,
image-forming polymer layer [4] beneath it to expose the ink-receptive
polymer layer [5] which is attached directly to the aluminium or polyester
base [6]
(source: Presstek)
Presstek has pioneered laser
ablation. Its PEARLdry system is
available as individual, aluminiumbacked plates (left) or as a roll of
polyester-based film (below). Plates
can be imaged either on-press in the
74 Karat or off-press in thermal
platesetters, the rolls can only be
imaged on-press and are used in
presses such as the 46 Karat
(photos: Presstek)
26
KBA Process
2 | 2005
to 18 million square metres
(64m - 194m ft2).
Toray and prominent Toray
dealers like marks-3zet and
Schneidler have promoted, and
continue to promote, the
worldwide adoption of waterless offset. Following the failure of 3M’s driography in the
USA and a successful renaissance in Japan, the “Land of
the rising sun” has led the field
in waterless offset print production for more than 20 years
and boasts a higher percentage
of totally or partially waterless
printing plants than anywhere
else on earth. With a membership of nigh on 100, the Japan
(JWPA) is the envy of its foreign counterparts. The worldwide success of Toray’s waterless plates – whether analogue
or digital – is founded, among
other things, on the fact that
they can be used in sheetfed
In waterless offset, as in
conventional wet offset, there
is an inexorable move towards
computer-to-plate (CTP). This
has been driven not only by a
swelling number of graphic
enterprises kitting up with
thermal platesetters, but also
by the installation of offset
presses with on-press imaging
(eg 74 Karat, 46 Karat and
Heidelberg Quickmaster DI) at
a whole slew of pre-press and
print operations. Although
analogue plates still constitute
a large proportion of the plates
consumed in waterless offset,
their numbers are steadily
shrinking. Toray’s rivals all
focus exclusively on digitally
imageable media, and even
Toray itself offers digital alternatives. Products still under
development will also be CTPcapable.
Because of their composition, thermal CTP is the only
imaging process suitable for
waterless plates. This is certainly no drawback, while the
benefits are many: fluctuationfree imaging (with no danger
of over- or under-exposure), a
uniformly sharp image definition and daylight-safe processing in the platesetter. At
present four plate manufacturers – Creo, KPG, Presstek and
Toray – offer consumables and
systems for off-press and/or
on-press CTP which are freely
available on the market. A fifth
Speculation and Visions
Future alternatives to plates
As has already been mentioned, moving into the waterless market or expanding their existing presence is not a priority for some plate makers.
KPG has expressed no intention of moving beyond the North American
market, although this is largely a matter of sales policy and could be
revised at any time. And Creo is unwilling to reveal whether it is aiming to
extend its Clarus WL technology to single, aluminium-backed plates and,
if so, which brand name it would use. Tests have already proved that this
would be possible, so we shall just have to wait and see. At present Creo is
focusing on optimising its Clarus PL processless aluminium plate, which
was also launched at Drupa 2004 but is only suitable for wet offset.
Whether Fujifilm will be able to market its Saphira Caleidoplate
processless film for presses other than the Heidelberg Quickmaster DI is
doubtful. This would depend on the contractual commitments made and
the patent situation. Alongside
co-developer Heidelberg, Presstek
would also have a word to say,
since the technology impinges on
its patents and PEARLdry OEM
business.
Agfa is conducting research
into laser-imageable CTP thermal
waterless plates and has already
carried out print tests in collaboration with KBA. However, it has no
concrete plans for a market launch
since it estimates that the current
sales potential does not justify the
cost of production. According to
Agfa management, the company
will take the wraps off a finished
product “when the time is ripe”.
Other technologies that have been
developed for laser-exposable
polymer plates – for example
phase change (:Thermolite Plus
plates) or the fusion of thermoplastic particles (:Azura plates) –
appear to be unsuitable, since waterless offset cannot dispense with
the silicone layer. On both types of
wet offset plate, the thermal laser
imaging process causes the image areas to become ink-receptive, so there
is no need for developer.
Wet offset plates should not be dismissed out of hand. As we have
already pointed out in a previous chapter, Flint Ink’s SFI inks could also
be used in waterless offset, though their performance has not yet been
proven in practice. But they could certainly be used with no further
thought in the Gravuflow inking system for the 74 Karat and Rapida 74 G
and, if formulated for coldset, in the Newsflow inking system for the
Cortina. However, although less expensive than waterless plates, going for
product, Fuji’s Photo Film developed in association with
Heidelberg, is only available in
conjunction with the Saphira
Caleidoplate 46 which, together with the variable-format
Smart Spooling Mechanism, is
confined to use with Heidelberg’s Quickmaster DI 46-4.
One feature common to all
these waterless CTP materials
is that they can be used in daylight conditions and are negative-writing. This means that
during exposure the laser beam
impacts on the image-bearing
areas. The infra-red radiation
either completely destroys the
overlying silicone layer (ablation) or facilitates its subsequent removal by chemical
processing. Processless plates
can be obtained from Creo,
Fujifilm/Heidelberg or Presstek, chemically processed
plates from KPG and Toray.
CtWP plate:
KPG’s X54 Scorpion
In 1994 Kodak Polychrome Graphics coined the
term “computer to waterless
wet offset plates and SFI has two drawbacks. The first is that dependency
on a limited number of plate manufacturers is exchanged for dependency
on a single ink manufacturer. The second is that the print quality delivered
with conventional plates cannot compare with the exceptionally dot-sharp
image and enhanced dot gain properties of silicone-coated plates.
Alternative plate technologies
Erasable, rewritable offset plates are still a long way away. At present
there are no suitable materials whose properties can be changed at will
from ink-receptive to ink-repellent, and the general consensus among industry insiders is that it is not possible to create such a plate because polymerisation processes are irreversible and other materials are even less
promising. But if a technological breakthrough were to be made, a waterless version would certainly be
possible: as far as the materials are
concerned there would be no need
to accommodate the application of
water as well as ink to the plate.
Besides, it is questionable whether
offset with dampening will still be
in use so far in the future.
Agfa and MAN have taken a
new approach to non-reusable image-bearing systems. With Agfa’s
LiteSpeed (a spray-on version of
the processless :Thermo-lite Plus)
and MAN Roland’s DICO (digital
changeover) the material on which
the image is created and transferred to the substrate is erased to
make way for a new imaging cycle
in which a liquid “printing forme”
is applied directly to an electrochemically grained and anodised
aluminium base (LiteSpeed) or
plate sleeve (DICO). Both processes, though based on different
technologies – phase change in the
case of LiteSpeed, laser ablation
in the case of DICO – require
dampening.
Dynamic image-generating processes are based on a different principle from these two static processes. Here, temporarily active printing
formes, not physically stable ones, must be created. Perhaps the nearest to
waterless offset is HP Indigo’s digital printing press. The “printing ink” is
in fact a liquid toner, ElectroInk, particles of which are distributed on the
photoconductive drum in accordance with an electrostatic charge profile,
and subsequently transferred to the substrate via the blanket. ElectroInk is
highly viscous and becomes printable only after the addition of oil.
(photo: Presstek)
plate” (CtWP) to describe the
imaging process used for the
first chemically developed
CTP waterless plates. Its first
product, the Thermal Waterless Plate, needed no protective anti-scratch silicone layer.
At Graph Expo 2002 its successor, the Scorpion, was unveiled. At present, availability
of KPG’s X54 Scorpion and
X54 Scorpion Plus thermal
waterless plates is limited to
North America. The beta version of the Cortina at reiff in
Offenburg, which has since
been dismantled, was fitted
with KPG plates as part of an
agreement which covered beta
testing but did not extend to
sales.
Because it must be chemically processed the Scorpion
can only be configured as an
off-press CTP plate. It can be
treated with the same processors and chemicals as Toray’s
TAC or analogue negativeworking plate, the TAN. Since
dot gain is virtually the same,
due to their similar compositions, gold-coloured Scorpion
plates can be used alongside
green Toray plates in the press.
KBA Process
2 | 2005
27
Platesetters and modules suitable for waterless CTP
(errors and omissions excepted. Also includes discontinued systems still in operation.)
System
Imaging
architecture
Agfa
external drum
Acento E/S
internal drum
Galileo TS/T
internal drum
Galileo Talant
external drum
Xcalibur 45/VLF50/60/70/80
Creo
external drum
Lotem 400/800/800II
Lotem 400/800/800II Quantum external drum
external drum
Magnus VLF
on-press module
Creo-Laserkopf
external drum
Trendsetter 800/800II/VLF
Trends. 400/800/800II Quantum external drum
external drum
Trendsetter News
Duoyuan
external drum
DYCTP 600II
external drum
DYCTP 800I
Fuji Photo Film
external drum
Luxel T-6000 CTP
external drum
Luxel T-9000 CTP
external drum
Luxel T-9800 CTP
external drum
Ultima
Heidelberg
external drum
Suprasetter 74/105
external drum
Topsetter 74/P102
Kodak Polychrome Graphics
flatbed
Newsetter TH 100/180
Krause Biagosch
internal drum
LaserStar LS 110/140/170/200
Lithotech
external drum
Andromeda A540/750/1300
external drum
Andromeda Z750
Lüscher
patent internal dr.
XPose! 75/130/160/180/190
patent internal dr.
simultanXPose! 130
Presstek
external drum
Dimension 200/400/800
external drum
Dimension 200/400 Excel
on-press module
Pearl/ProFire
on-press module
ProFire Excel
off-press module
SureFire
Sack
external drum
CTP-0900
external drum
CTP-1300
Screen Media Technology (Dainippon Screen)
external drum
PlateRite PT-R4100/4300
PlateRite PT-R8000/8100/8600 external drum
external drum
PlateRite PT-R8800
external drum
Ultima 16000/32000Z/32000
Specifically for newspaper printing
To weaken the adhesion of
the silicone to the heat-sensitive polymer layer beneath it
the Scorpion requires a 170mJ/
cm2 laser beam with a spectral
sensitivity of 800 to 850nm
(ideal oscillating wavelength:
830nm). It can image a 20µm
(20 micron) spot and offers a 1
to 99% resolution at 200 lines
per inch (80l/cm) or a 2 to 98%
resolution at 300lpi (120lpc).
CTP plates: Toray’s
TAC-RG5/RL7 and TAC-W2
Toray’s TAC-RG5 is the
fourth generation in the Japanese firm’s family of chemically processed TAC plates for
thermal CTP. The TAC-JG5
was launched on the market in
1999, followed by the TAC28
KBA Process
2 | 2005
Thermal laser
Max. resolution Max. plate format (mm)
(dpi)
diodes
Nd:YAG
Nd:YAG (ablative)
diodes + GLV or solid state
3600
3600
2400
2400
1130 x 820
1130 x 820
1130 x 820
1160 x 820 to 2030 x 1475
diodes
SQUAREspot diodes
diodes
diodes/SQUAREspot (ablative)
diodes
SQUAREspot diodes
SQUAREspot diodes
3556
2540
2400
2540 or 3556
2400
2400
1200, 2400 opt.
622 x 750 to 905 x 1130
622 x 750 to 905 x 1130
2108 x 1600
any
838 x 1118 to 1473 x 2032
838 x 762 to 838 x 1118
660 x 960
solid state
solid state
n/a
n/a
4 pages
8 pages
diodes
diodes
diodes + GLV
diodes + GLV
4000
4000
2540
2540
830 x 645
1160 x 940
1160 x 940
2124 x 1270
IDS diodes
diodes
2540
4000
750 x 680 to 1140 x 930
660 x 830 to 1160 x 940
diodes
1270
650 x 960
Nd:YAG
2540 to 3810
820 x 1050 to 1380 x 2000
Nd:YAG or diodes
Nd:YAG
3810
1270
675 x 540 to 840 x 1050
657 x 750
diodes
diodes
2400
5080
760 x 650 to 2050 x 1500
1130 x 950
ProFire II diodes (ablative)
ProFire Image plus d. (ablative)
diodes (ablative)
Image plus diodes (ablative)
diodes (1064 nm, also ablative)
2540
2540
2540
2540
2540
500 x 530 to 813 x 1118
500 x 530 to 680 x 780
max. width 2 pages
max. width 2 pages
max. width 2 pages
diodes
Nd:YAG (ablative)
4000
3810
900 x 745
1300 x 650
diodes
diodes
diodes + GLV
diodes + GLV
4000
4000
2540
2540
830 x 645
1160 x 940
1160 x 940
1470 x 1165 to 2382 x 1276
CG5, which was more scratchresistant and easier to measure
optically. Its successor, the
TAC-UG5, had improved processing tolerances. The newgeneration TAC-RG5 has even
better scratch-resistance, enhanced stability in long print
runs and is scanner-compatible. Printers can order the
same plate without a scratchresistant film. This version is
called the TAC-RL7.
The TAC-RG5, like KPG’s
Scorpion, can be exposed in
any type of thermal platesetter.
The plate can image a 10µm
spot and can reproduce the full
tonal scale at a screen resolution of 80lpc (200lpi). Runlength
stability
currently
ranges from 100,000 to
150,000 impressions, depending on the paper and the type of
production (sheetfed or web).
KBA believes that this figure
could be greatly improved.
The TAC-W2 slated for
launching early next year will
simplify plate processing still
further. Compared to previous
TAC plates the TAC-W2 reduces wet processing to brushing, rinsing and drying. The
plates must be exposed in a
830nm thermal platesetter at
between 150 and 200mJ/cm2
and support a maximum resolution of 4500dpi. The average
run length is claimed to be
50% higher.
Processless CTP plates:
Presstek’s PEARLdry and ProFire
Digital Media
US systems manufacturer
Presstek pioneered on-press
CTP imaging and has registered the trade name DI (Direct
Imaging). Initially the process
worked by electrode erosion,
later Presstek fitted ProFire
and Pearl imaging heads with
thermal ablative lasers. ProFire is the standard imaging
head for the 46 Karat. Maximum resolution is 2540dpi,
minimum spot size 21µm, with
an option of 1270dpi and a
28µm spot.
Presstek developed two
processless plates, PEARLdry/
PEARLdry Plus, specifically
for the ProFire system. The
74 Karat consumes aluminium-backed plates (PEARLdry), the 46 Karat operates
with a polyester substrate
spooled from a roll (PEARLdry Plus). During exposure the
infra-red laser beam creates an
image element, eg a halftone
dot, by burning off the ink-repellent silicone layer and the
heat-sensitive, image-forming
polymer layer beneath it to expose the ink-receptive polymer
layer. Process debris is removed mechanically. As on
Toray’s and KPG’s chemically
processed plates, the image elements on Presstek plates are
slightly recessed relative to the
non-image areas, since these
are still covered by the other
layers.
At the end of 2004 Presstek
brought out a new, more advanced version of its ProFire
imaging head. Called ProFire
Excel, this offers the same
resolution of 2540dpi but
works with a 16µm spot which
can reproduce extremely fine
screens (120lpc or 300lpi) and
supports stochastic screening.
It is to be found both in
Presstek’s Dimension and in
OEM systems for DI waterless
offset presses, among them a
new version of the 46 Karat
known as the 46 KaratPLUS.
This consumes Presstek’s new
ProFire Excel-enabled ProFire
Digital Media, a processless
film which, like previous types
of polyester film, is rated for
up to 20,000 impressions.
Optical measurement on waterless plates
A
dopting computer-toplate (CTP) eliminates a
practical measuring object:
the film copy. Previously, a
simple transmission densitometer was adequate for determining the reproduction of
halftone values at a co-exposed screen gradation scale.
This was necessary to linearise the configuration of the
RIP film imaging unit on the
field of the co-exposed screen
gradation scale. Another possibility is a reflection colour
densitometer, which measures
the entire plate surface and
from the degree of light absorption calculates a grey
value which it then converts
into a halftone value. Dot meters employ a planimetric
method of analysis which is
even more precise: the con-
among them KPG’s Scorpion.
This is due to the intense reflection in non-image areas
from the combined layers of
aluminium, primer, polymer
and silicone (which together,
incidentally, create the characteristic gold plate colour).
Not even a colour densitometer with a polarisation filter
can deliver usable values. The
usual practice was to expose
Preview and analysis images of 50% screen fields on KPG Scorpion, Toray RL7 and Presstek PEARLdry waterless
aluminium plates (l-r), captured with a TECHKON DMS 910 dot meter and calculated with DMS Pro software
one hand and to monitor compliance with transmission
characteristics or dot gain on
the other. Whether the plate
remained within the specified
imaging
tolerances
was
checked visually at a special
co-exposed control patch on
the plate.
Now, in the absence of
film, the configuration of the
RIP platesetter must be measured on the plate. This can be
done with a dot meter whose
camera sensor captures each
tours of the halftone elements
are captured in the microscopic enlargement and above
a specified threshold value
evaluated as image-bearing.
This enables the actual degree
of solids coverage to be calculated.
Dot meters cannot be used
on analogue waterless plates,
but this does not matter because the film is measured instead. Setting these aside,
there are some CTP plates
which can cause problems,
and measure wet offset thermal plates and use the values
obtained for waterless plate
exposure.
Toray improved on this
technology, first with the
TAC-CG5 and more recently
with the TAC-RG5/RL7,
which supports the use of dot
meters. The solution to the
problem was to change the
composition of the primer
layer which causes the polymer layer to adhere to the aluminium base. Anti-reflection
Processless CTP plates:
Creo’s Clarus WL
1524 to 2400dpi (Trendsetter)
or 3556dpi (Lotem) and can
hold a 14µm spot. SQUAREspot technology, which can
hold a 10µm spot and works
to a resolution of 2400 or
2540dpi, delivers a razor-sharp
edge definition and is certified
for second-generation FM
screening with Creo’s Staccato
system. SQUAREspot is also
available with a 1200dpi capability specifically for newspaper production.
Creo, like Presstek, also
makes modules for on-press
imaging. Creo laser heads in
the 74 Karat can write 2540dpi
with a 15µm spot. Creo’s engagement in the plate market is
Creo is the leading manufacturer of thermal platesetters. The two types of imaging technology used in them
differ in their edge definition.
The standard technology can
reproduce any resolution from
properties were incorporated
which substantially weakened
reflection from the aluminium
surface. Once the metallic
sheen of the aluminium had
been suppressed, the level of
light reflected by the silicone
surface was too low to influence the scan readings.
Processless plates like
Presstek’s PEARLdry have
always been easy to measure.
Neither the silicone layer nor
the exposed polymer cause
problems with light reflection. This is because the heatsensitive layer beneath the
silicone eliminates all reflection, while the oleophilic
polymer on the aluminium
diffuses any light reflected; if
polyester is used as a base instead of aluminium there is no
disruptive reflection at all.
Apart from the fact that
CTP plates are negative working, the decisive factor as far
as scanning is concerned is
the contrast between the nonimage silicone and the imagebearing polymer in the preview image of the scanning
device:
• Toray TAC – image areas
dark green, silicone light
green, therefore a positive image – measurement and analysis in positive mode;
• Presstek PEARLdry – image
areas light silver, silicone
dark, therefore a negative image – measurement and analysis in negative mode.
Disregarding these basic
rules can result in false readings.
relatively recent. At Drupa
2004 it unveiled the Clarus
WL, which has been available
commercially since early this
year. The plate is composed of
on-press CTP material on a
polyester base, formulated for
ablation with thermal imaging
heads. Creo’s black Clarus
WL, however, has a slightly
KBA Process
2 | 2005
29
Left: The 46 KaratPLUS – shown here on the Presstek stand at Drupa 2004 –
operates with Presstek’s new ProFire Excel imaging modules and new ProFire
Digital Media, a processless film
(photo: Stein)
Below: A Toray TAC in the semi-automatic plate-changing system at a
KBA Rapida 74 G on the marks-3zet stand at Drupa
(photo: Kleeberg)
Agfa’s Xcalibur is the first thermal platesetter to
feature the grating light valve (GLV) technology
unveiled at Drupa 2004 by US company Silicon
Light Machines
(photo: Agfa)
different composition from
Presstek’s PEARLdry, and the
company claims that ablation
on the Clarus WL generates
very little debris. Run-length
stability is around 30,000
prints, making the Clarus an
alternative to Presstek’s previously unchallenged PEARLdry film.
The Clarus WL is supplied
in rolls of 28 to 35 sections, depending on press type. So they
can only be used on presses
with an automatic unwinding
and rewinding (spooling) system in the plate cylinder. These
include the 46 Karat and other
presses based on Ryobi’s 3404
DI, along with Heidelberg’s
Quickmaster DI 46-4 and
30
KBA Process
2 | 2005
Creo’s high-automation Trendsetter VLF thermal
platesetter has a resolution of 2400dpi
(photo: Kleeberg)
Adast’s Dominant DI/CDI plus
their OEM versions in the
USA.
So initially the Clarus WL
can only be exposed using
Presstek laser heads because
Creo laser heads feature solely
in larger offset presses like the
74 Karat and Rapida 74 G,
which consume aluminium
plates. Creo is already working
on this and will no doubt soon
produce an appropriate aluminium plate with a much
longer service life.
Suitable CTP platesetters
Thermal platesetters are
the only type of platesetter
suitable for digitally imaging
At Drupa 2004 Presstek unveiled its Dimension
400 thermal platesetter featuring ProFire Excel
technology
(photo: Kleeberg)
waterless plates. However, users have very little freedom of
choice because manufacturers
generally specify precisely
which plates can and cannot be
imaged with the system concerned. The reason for this is
that plates differ a lot in the energy input required for exposure. With waterless plates, the
intensity of the laser beam can
vary substantially because
plates exposed by ablation
consume more energy than
chemically processed plates.
This means that lasers
configured for “normal”, nonablative plates are too weak to
image processless ablative
plates. On top of this, plates
exposed by ablation must be
cleaned after imaging to remove debris from the surface.
Conversely, the laser power required for ablation is much
more intense than for chemically processed plates. This
need not be a disadvantage
since it enables the plates to be
processed with a weaker solution. This is the case, for example, with Toray’s TAC-RG5/
RL7 plates which are exposed
in Presstek’s Dimension platesetters. Waterless plates are
more easily scratched, so great
care must be taken to avoid
such damage during automatic
plate handling and transport
within the platesetter.
Dieter Kleeberg
Consumables | Waterless inks
Waterless offset inks can be
used for the same range of
applications as wet offset ones,
and more besides, enabling
printers to move into new lines
Waterless inks – specific
properties and applications
of business. KBA has made a
signal
contribution
advancing
waterless
towards
innovation
inking
in
technology
by collaborating closely with
ink manufacturers to optimise
keyless inking systems.
The use of quick-change ink cartridges at the 74 Karat
is all part of KBA’s easy-handling concept
(photos: KBA, Kleeberg)
Diversified ink market
I
nk is one of three components – the others being
plates and temperaturecontrolled inking units – that
form the crux of waterless offset. Happily, there are a lot
more manufacturers of waterless inks than there are manufacturers of plates, and the
characteristic properties of
the individual ink series are
correspondingly diverse. This
offers print entrepreneurs a
rich and varied choice of interesting applications. Also,
the proverbially high standard
of service provided by ink
manufacturers, who are always ready to formulate or
modify inks to customer
specifications, applies equally
in waterless offset.
KBA has been delighted
by ink manufacturers’ eagerness to collaborate on development projects, particularly
the Cortina newspaper press
whose waterless coldset technology represented uncharted
territory for all concerned.
Trends:
silicone oil substitutes…
Formulating modern waterless inks is no trivial affair.
In addressing ever more so-
phisticated demands with regard to runability and print
quality, ink manufacturers
have progressed well beyond
the stage of taking inks from
their existing wet offset range
and simply adding silicone
oil. Nowadays most of the
waterless offset inks the
chemists concoct in their
laboratories are dedicated formulae.
Using silicone oil or silicone derivatives – whether
purely as an additive to a wet
offset ink or as a basic component of a dedicated waterless
ink – is the simplest way to
obtain a separating agent
which does not permit the ink
to adhere to the siliconecoated areas of the plate. As
we have explained in a previous chapter, “Optimising the
interaction of ink, plates and
other consumables” (pages 710), waterless inks require a
separator which assumes the
function of the fount solution
to create a weak fluid bound
Four compelling reasons for using silicone-oil substitutes:
Epple’s aniva inks support a larger
colour gamut than Euroscale inks.
In waterless offset, only users of
the 46 Karat can enjoy the many
benefits that aniva pigmentation
brings
(source: Epple)
1. Silicone oil does not adhere to anything. Too much silicone oil in the ink can even cause ink repellence
on the image-bearing polymer layers of the plate. Too much silicone oil can impair overall process stability in the inking unit and result in the opposite effect from that desired.
2. Silicone oil does not adhere to surfaces, but it can penetrate them. While this effect may be desirable on
the non-printing areas of the plate (silicone oil “saturates” the silicone and creates an ink-repellent layer),
it can give rise to problems at the rubber rollers and blankets. Even if there is no excess silicone oil in the
ink, over a period of time “silicone contamination” of the rubber can still occur because traces of silicone
oil remain on the rubber after each pass no matter how thoroughly the blankets and rollers are cleaned.
This impairs ink splitting, because a layer of ink-repellent silicone oil is formed on the surface of the
rubber. Silicone contamination can cause even worse problems during ink changes.
3. Silicone oil disguises ink tack. Tack is the sum of an ink’s viscosity, its propensity to pick and its
behaviour in printed piles. Because the silicone oil on the surface of the split or transferred ink layer
covers the ink molecules, the true degree of ink tack cannot be measured, even with special tests. This can
have unpleasant consequences in the form of picking, smudging or blocking.
4. Silicone oil can impair finishing quality by preventing the coating, laminate, mounting film or hotstamping foil from adhering to the ink film. This primarily applies to oxidative inks, but also to UV
waterless inks.
KBA Process
2 | 2005
31
ary layer (WFBL). Silicone
oil is non-flammable, does
not gum and does not alter its
viscosity with changes in temperature, so it fulfils this function very well.
Nevertheless, ink manufacturers have been busily
searching for substitutes.
There are technical rather
than environmental reasons
for this (see box on previous
page). The choice of separator
has become a key aspect of
ink formulation and its composition is normally a closely
guarded secret. So the press
operator does not have to
worry about the silicone-oil
content of the ink. All he has
to do – but this is important –
is carefully follow the instructions on the label. When
choosing waterless inks he
must take good note of the
substrates and types of coating for which they are suitable
and those for which they are
not. Arguments advanced by
critics of waterless offset,
based on the drawbacks of
silicone oil, are thus no longer
relevant.
For the plastic printing version of the 74 Karat and the
Rapida 74 G KBA recommends Zeller+Gmelin’s Toracard
TF inks which have already proven their superior
performance in the Genius 52
(photo: Kleeberg)
74 Karat printer Stephan Vanlent and his colleagues at
Vignold in Essen have built a nitrogen cabinet in which the
ink in full ink troughs stays fresh overnight (photo: Stein)
…and more environmentally
friendly alternatives
The elimination of fount
solution makes waterless offset a relatively ecological
printing process. But that’s
not all. Inks based on vegetable oils, which have long been
available for wet offset, have
now been formulated for
waterless offset, albeit limited
to sheetfed applications. So
even more printers can take
advantage of this welcome
alternative to switch to renewable raw materials. Waterless
newspaper technology has not
advanced quite as far.
A further option for buffing up the environmental credentials of waterless offset is
to use water-washable ink.
Substituting a water-based
agent for a solvent-based
agent in the roller- and blanket-washing systems reduces
emissions of VOCs (volatile
organic compounds) at the
press to zero. Sun Chemical,
32
KBA Process
2 | 2005
The Gravuflow inking units for the Rapida 74 G are also fed from cartridges
(photo: KBA)
the world’s biggest manufacturer of inks, has pioneered
this technology in the market
for waterless inks. At Drupa
2000 the company demonstrated a water-washable ink,
Instant Dry, on a Heidelberg
Quickmaster DI. Since then
Sun Chemical has brought
further water-washable waterless inks onto the market under the names Irodry W2 and
DriLith W2. These inks have
the added advantage that the
prints no longer need to be
powder-sprayed and yet are
ready for finishing just as fast.
Also, paper printed with such
inks is easy to de-ink, which
cannot be said of paper
printed with most other waterwashable inks.
At Ifra Expo 2003 in Leipzig, KBA and Sun Chemical
signed an agreement to work
jointly on developing waterwashable coldset inks. The
agreement includes, among
other things, an exclusive
three-year period of collaboration on the Cortina, during
which Sun Chemical will develop and refine its Shark W
ink series, the water-washable
alternative to its solventwashable waterless coldset
ink, Shark C.
Waterless inks for
sheetfed offset
The choice of inks on offer in this market sector is the
largest and most diversified.
Waterless inks for sheetfed
offset from a sheet size of 500
x 700mm up are generally
formulated duct-fresh, with
special formulae suitable for
perfecting or quick-drying.
Oxidation, penetration and
UV curing can be used as drying processes. Gloss- or mattcoated paper surfaces, and
non-absorbent materials like
plastic and metallised film,
can all be printed with such
inks.
This market sector embraces all temperature-controllable KBA Rapida presses,
including the Rapida 74 G and
the 74 Karat DI offset press.
KBA’s Genius 52 and
Metronic’s Genius 52 UV,
though engineered for a
smaller sheet size, must also
be included in this category
since they differ from their
format counterparts in incorporating precise, high-powered temperature controls.
Sheetfed offset is the
“showground” of waterless
offset. This is where an unparalleled level of print
sophistication is matched by
an unparalleled standard of
quality. It is where waterless
offset can really pull out all
the stops and, in conjunction
with
frequency-modulated
screening and HiFi colour or
other non-standard ink scales,
produce some stunning results. It comes up trumps not
only on the level of gloss that
can be achieved but also on
the sharp detail, homogeneous solids and fluctuationfree quality delivered. On top
of this a few ink series, for example K+E Novaless Power
Dry, enable prints to be finished almost immediately:
their penetration time has
been reduced to less than two
minutes and guillotine-safe
setting to 20 minutes – just
25% of the usual time.
What is most important
when running UV inks and
printing non-absorbent materials is to follow the instructions for use. In addition,
runability tests are recommended if certain types of ink
and critical materials are to be
run together for the first time.
UV-cured waterless inks can
print just about any type of
plastic film.
Waterless inks for
small formats
Some ink manufacturers
formulate inks specifically for
the small-format sheetfed off-
At Ifra Expo 2003 KBA and Sun Chemical signed a three-year collaborative
agreement to develop Shark W water-washable inks exclusively for the
Cortina. From the left: Klaus Schmidt, marketing director at KBA; Michael
Griem, corporate vice president of Sun Chemical; Claus Bolza-Schünemann,
deputy president of KBA; Wes William Lucas, chairman, president and CEO
of Sun Chemical Corporation; Felipe Mellado, corporate vice president
marketing and technology at Sun Chemical Europe; and Peter Benz,
Cortina project manager at KBA
(photo: KBA)
set sector, which includes
small-format direct-imaging
presses. The reason is that,
with the exception of the KBA
Genius 52, Metronic Genius
52 UV and 46 Karat (plus
Ryobi 3404 DI and other
OEM versions), most of these
presses have no form of temperature control. This is be-
cause they run at lower speeds
than bigger presses (and so do
not generate as much heat),
and are usually used for less
sophisticated products. Dispensing with temperature
control is thus a good way of
keeping the price down. As a
result the inks formulated for
this format can operate in a
broader temperature tolerance
range than those for bigger
presses, with the maximum
tolerable temperature relatively high. Running such
inks on bigger presses would
impair output and the quality
of ink transfer.
Waterless inks for narrowweb production also fall into
this category. Here, UV inks
are the most common type
used, often in tandem with
other printing processes, depending on job specifications.
Products typically printed
with waterless UV inks on
narrow webs are folding cartons and adhesive labels made
of paper or plastic, eg transparent film for a “no-label”
look.
The smallest products that
can be printed are CDs,
DVDs, optical business cards
and plastic cards in one-up
and multi-up production.
Metronic, which has acquired
a high level of competence in
this market, recommends
Sipca’s highly specialised UV
inks for such applications.
Waterless inks for
IR radiation
Sheetfed offset on non-absorbent materials demands a
special type of waterless ink:
one that dries purely through
IR-accelerated oxidation. For
this particular application
KBA has approved Zeller+
Gmelin’s Toracard TF ink series which can be used in the
74 Karat, the Rapida 74 G and
the Genius 52 to print specific types of film: polyvinyl
chloride (PVC), acrylonitrile
buta-diene styrene (ABS),
poly-carbonate (PC), polystyrene (PS) and polyester (polyethylene terephthalate, PET).
Toracard, unlike UV inks, is
not suitable for printing
pretreated polyolefine film
Siegwerk, developer of Aridas
coldset waterless inks, produces
more than 20,000 tonnes of ink a
year for printing newspapers and
inserts
(photo: Siegwerk)
KBA Process
2 | 2005
33
such as polyethylene (PE) or
polypropylene (PP). The benefits of IR drying over UV
curing are that the technology
is less complex and the exhaust air ozone-free. Moreover, the ink adheres firmly to
the substrate, so applying special aqueous coatings inline or
laminating the prints offline is
no problem.
Waterless inks that dry by
solvent evaporation are to be
found in narrow-web printing.
To reduce the drying time, not
just of waterless offset inks
but also of inks used in hybrid
inline printing processes, the
presses typically feature compact IR and hot-air dryers.
Printing with waterless
inks is also possible in heatset
web offset. But despite the
standard of quality achieved,
waterless technology has
failed to gain ground and the
number of users is extremely
small, and shrinking. One of
the reasons is that plate durability does not support multimillion print runs. On top of
this, earlier users willing to
pioneer waterless inking in
heatset web offset complained
of a conspicuous lack of
support by suppliers of consumables, and of a lack of response to issues such as high
plate prices, poor temperature
control at the press and waterless inks that had not been satisfactorily reformulated for
web presses. Added to which
customers proved unwilling
to pay even a minor premium
for the superior print quality
that this more ecological production process delivers.
KBA, too, has no immediate
plans to expand its focus beyond waterless coldset, which
by virtue of the high print
quality possible with the
Cortina now enables newspaper printers to add semi-commercials to their product mix.
Waterless inks for
newspaper web offset
The Cortina is the only
newspaper offset press on the
market with a waterless capa-
bility. It represents an outstanding contribution by KBA
towards enhancing the environmental performance of
newspaper presses: no dampening solution, little or no
VOC emissions (depending
on the type of ink and washing agent used) and extraordinarily low waste levels – KBA
has defined the benchmarks
by which potential rivals will
be gauged.
In this scenario, ink plays
a major role. Since waterless
inks for coldset production
were non-existent when the
Cortina was first mooted, all
the major manufacturers of
conventional coldset inks
were brought to the table
The design of the ink ducts for the Cortina has undergone a number of
modifications to enable them to handle low-viscosity waterless inks with
maximum efficiency
(photo: KBA)
The Huber Group has developed a
number of inks under its “Highly
Improved Technology” banner.
These include a coldset series,
Rollo-Temp Dry, which delivered an
outstanding print quality on the
Cortina
along with leading paper and
plate manufacturers. A workshop was held on 8 June 2004
at which the six participating
ink manufacturers, Finnish
paper manufacturer UPM
Kymmene and a maker of
measuring instruments and
materials testing devices,
Prüfbau, analysed the advances achieved to date. Virtually all waterless inks have
now reached a high level of
performance, and each has its
individual merits. Some inks
have attained a standard of sophistication that enables them
to be run with an easy mind
in day-to-day newspaper production with the Cortina. The
press line that came on stream
in February in the Netherlands is evidence of this.
As with wet offset inks for
newspaper production, one of
the key objectives in developing waterless coldset inks is to
On temperature windows and tack
T
he drying method, mechanical and chemical fastness, optical properties (eg tonal reproduction, detail definition, gloss capability) and
settings (duct-fresh, quick-drying) are standard items of information provided on ink cans. Manufacturers of waterless inks furnish information on
other runability characteristics: the optimum temperature range is always
given and, possibly, the tack. Physically and rheologically, temperature
“windows” and tack are related: the higher the tack, the higher the necessary printing temperature. However, a general formula – if tack is x, then
temperature must be y – does not apply because each ink series has its own
optimum tack/temperature ratio.
The recommended working temperature range is the key criterion,
which is why this is stated on the ink label. This is the only process
variable that the press operator can control directly, by setting a target
temperature within a specific tolerance range at the temperature control
unit.
In this specific context, tack refers to the ink tact ex works – ie, the
initial tack at production start-up. This value naturally changes, together
with viscosity, in the course of the print run because when the ink is split it
is exposed to forces which do not apply in its quiescent state. Tack determines how strongly the ink adheres to the plate and blankets, and indicates
the splitting resistance of an ink film.
34
KBA Process
2 | 2005
ISO 12634 prescribes the conditions for determining tack. A rotary
tackmeter must be used comprising a temperature-controlled system drive
roller and a distributor roller with a measuring roller on top. Tripping the
measuring roller at a prespecified speed or distance per time unit furnishes
the tack value. Although values vary depending on the type of tackmeter
used (Prüfbau Inkomat, IGT Tacktester), they correlate with each other.
The most popular measuring devices are Tacko und Inko.
Despite the fact that a higher tack makes ink more prone to pick, ink
manufacturers recommend a medium tack (eg around 12 Inko, measured
with an Inkomat) as the minimum value because this reduces the risk of
toning and delivers greater detail definition. Due to the tack-related connection between temperature and toning (which can occur when the maximum temperature is exceeded) the specified temperature range is known
as the “critical tone temperature” (CTT) or “critical toning index” (CTI).
It can vary from 2° to 15°C, start at around 18°C (depending on the manufacturer and application) and end, if the tolerance window is especially
broad, at 35°C. Tolerances for temperature control systems can be correspondingly narrow or broad. Broad tolerances apply primarily for smallformat presses with no dedicated temperature control system. For the
more standardised, cost-effective print production supported by presses
like the KBA Cortina, a narrow temperature range is desirable.
achieve the right degree of
penetration to support problem-free processing in the
folder at maximum production speed. Another is to make
the most of the quality benefits that waterless offset delivers on typical improved
newsprint: a more brilliant
print through higher gloss,
homogeneous solids coverage, a larger colour gamut,
and enhanced detail reproduction through finer screens.
This enables waterless coldset
to print high-quality colour
supplements. A welcome
side-effect of using these
slightly more viscous inks, in
tandem with Newsflow inking units, is that the ink misting typically associated with
high-performance presses no
longer occurs.
Dieter Kleeberg
*KBA approves inks in conjunction with plates,
particularly for presses with direct imaging
and/or keyless inking systems and individually
for the 46 Karat, jointly forthe 74 Karat,
Rapida 74 G and Genius 52. Sicpa UV inks are
recommended for Metronic’s Genius 52 UV.
Most of the coldset inks listed here were
formulated and tested exclusively for runability
in the Cortina, but are at different stages of
development. KBA reserves the right to make
additions and deletions to the list of approved
consumables at any time.
Status: December 2004
Summary of waterless offset ink brands and applications
(Errors and omissions excepted. Availability may be geographically restricted.)
Ink series
Setting process
Applications
KBA-approved*
ANI Group (ANI, Lindgens, Trenal) and BASF (K+E)
ANI Lito Flora Dry
oxidation/penetration
ANI-Dry Futura
penetration
Trenal Morgana
penetration
K+E Novaless S 74
K+E Novaless S 220 Universal
K+E Novaless S 240 Power Dry
K+E Newsking Sahara
penetration
K+E Webking WL (upon request) IR/hot-air evaporation
sheetfed offset
coldset
coldset; discontinued
DI sheetfed offset with 74 Karat
sheetfed offset
small-format DI sheetfed offset
coldset
heatset
Braden Sutphin
DI Waterless
Brancher
Hadron
UV curing
packaging, labels, plastic cards/film
Classic Colours
Sahara Eco-Dry
Nevada HG
Nevada Oxi Mk2
n/a
oxidation
IR/hot-air evaporation
DI sheetfed offset
sheetfed offset, DI sheetfed offset
plastic cards/film + toner-based printing/coating
narrow-web heatset, special effect inks
Dainichiseika (Daicolor)
Japanese data only
—
—
Encres Dubuit
CD Plus
OW Metro
OW Label, more upon request
UV curing
UV curing
UV curing
CDs, DVDs etc
CDs, DVDs etc
narrow-web label printing
Epple Ink and Sicolor
Euro 7415x/Sicolor Euro 5832x
DI-Waterless/Sicolor DI-W5839x
Euro Karat/Sicolor 58140x
aniva Euro/Standard 780xx
Euro 54129
NN (upon request)
UV curing
IR/hot-air evaporation
sheetfed offset
DI sheetfed offset
DI sheetfed offset, specifically for KBA
packaging, labels, plastic cards/film
heatset
Flint Ink (Flint Ink, Flint-Schmidt)
ArrowStar KG
Board Perfect EU 8416
EuroStar NN waterless
penetration
coldset
SFI
oxid./pen., evaporation conventional plate development project
Huber Group (Michael Huber, Hostmann-Steinberg)
Reflecta Dry 5070 HIT
sheetfed offset
WL-UV-Temp Euro/special inks
UV curing
sheetfed offset, plastic cards/film, CDs, DVDs
Rollo-Temp Dry
penetration
coldset
Inctec
Japanese data only
—
—
Jänecke+Schneemann
Ancor WLP 81 B 75-78
Supra UV 565
UV curing
cards, CDs
RUCO
050 UV
UV curing
CDs, DVDs, PE and PP labels
055 UV
UV curing
PE and PP cards/film with coating
Sericol
Seridisc OF
UV curing
CDs, DVDs etc
Sicpa Group
Euro 970
Sicura 41 WL
UV curing
narrow-web label printing
Sicura Disc 41 WL
UV curing
CDs, DVDs
Sicura Card 110N WA
UV curing
plastic cards with coating, film
more upon request
oxidation/penetration, UV numerous specialised applications
Siegwerk
Aridas
coldset
SunChemical (SunChemical, Coates Lorilleux, Hartmann, Kohl & Madden, US Inks, Usher-Walker)
Irodry 7001
small-format sheetfed offset, direct imaging
Irodry 7005 + Pantone 27xxx
medium- and large-format sheetfed offset
Irodry 7074
Irodry W2 7300, DriLith W2
sheetfed offset with water-washable inks
Shark C
coldset
Shark W
coldset with water-washable inks
K&M Sharp & Dry
K&MCure UV Waterless
UV curing
UV applications 4 and 6 colours
Superior Printing Ink
Super Tech Aqua-Not B
sheetfed offset high-performance series
Super Tech Aqua-Not GL
sheetfed offset universal
Super Tech Aqua-Not LT, HT
sheetfed offset with no temperature control
Super Tech Aqua-Not 2000
Toyo Ink (TI Japan, TI America)
Aqualess Ultra L/M
sheetfed offset
Aqualess Karat
Aqualess Ecoo
DI sheetfed offset
Aqualess UV
UV curing
plastic cards/film, CDs, DVDs
Van Son Royal Dutch Printing Ink Factory
SonaDry VS8000 + Pantone
Quickson SonaDry + Pantone
SonaDry UV + Pantone
UV curing
plastic cards/film, CDs, DVDs
Zeller+Gmelin
Toralux T1
DI sheetfed offset
Toracard TF
IR-accelerated oxidation
plastic cards (coated), certain films
Toracur W2
UV curing
narrow-web label printing, plastic film
Cortina project
previous Cortina project
74 Karat, Rapida 74 G, Genius
46 Karat
Cortina project
46 Karat “Power Mix”
74K, Rapida 74 G, Genius (US)
Cortina project
Cortina project
46 Karat
Metronic WL UV version
Metronic WL UV version
Cortina project
46 Karat
74/46 Karat, Ra74 G, Genius
Cortina project
Cortina project
46 Karat
46 Karat
KBA Process
2 | 2005
35
Consumables | Waterless UV inks
Adopting UV inks in wet offset
enables print providers to offer a
broader range of products and
to finish prints immediately, with
no post-impression delay for
Waterless UV offset –
a winning combination
drying. Both these benefits can
be combined with those of
waterless offset.
UV printing in general
U
V inks and coatings
consist of fluid components which reticulate to form a solid, dry film
when exposed to a highenergy source of ultraviolet
radiation. Curing is virtually
instantaneous, though the duration of this process depends
on press speed and the
number of UV lamps used,
their intensity and the kind of
material being printed. Almost all UV inks are based on
materials to which polyfunctional epoxy, polyester or
polyurethane vinyl have been
added along with dyes, additives and photo-initiators that
trigger polymerisation and
thus the creation of a reticulated film. Although UV inks
may be described unequivocally as solvent-free, they do
require the use of solventbased washing and cleaning
agents in the press.
UV curing is of particular
interest to all sectors of the
printing and packaging industry where rapid drying and a
durable high gloss are needed
to allow immediate finishing.
Applications range from furniture manufacture and automotive parts to coatings and
the bank cards in your wallet.
Nowadays, even music and
The Genius 52 UV waterless offset press prints high-quality plastic cards in
multi-up production
(photo: KBA)
software CDs and DVDs are
printed with UV inks – a large
proportion of them on waterless offset presses. KBA subsidiary Metronic holds the
pole position in the market for
plastic cards and CDs/DVDs.
But a lot of conventional
presses can also be converted
to run UV inks and coatings.
The same applies to standalone coaters. UV presses can
be used to print solid board
and carton (including drug
and food packaging), plastics
and metal, and for product
identification.
Why UV?
The future success of a
graphic enterprise, and the
market opportunities it can
exploit, will largely depend
on whether its performance
and products address emerging demand and applications.
UV presses enable printers to
enter new, less volatile markets. Since most of the presses
made – including those from
KBA – can be engineered or
converted for UV, investment
costs are easy to calculate and
control.
The H-1/04 colour-density and ink-trapping control strip developed by Druck & Beratung D. Braun for waterless UV offset
36
KBA Process
2 | 2005
An increasing number of CDs and
DVDs are being printed in waterless
UV offset on Metronic’s CD Print
(photo: Metronic)
Time gain: because UV
inks harden instantly when
exposed to UV radiation there
are no lengthy drying times,
so prints can be finished or
turned without delay.
Quality gain: high-speed
curing also eliminates the
need to powder-spray, so the
innate gloss of the ink is not
impaired. Because the ink
dries immediately, the final
result can be assessed immediately: there is no further ink
penetration or drying.
Ecology gain: UV curing
also eliminates the need for
KBA and Metronic waterless offset presses with UV capability
solvents in the ink, so there
are no VOC emissions. And
contrary to widespread belief,
there are no health hazards.
What is more, the dramatic
drop in emissions brings a
corresponding drop in the cost
of waste disposal.
Finishing gain: the solid
or spot, gloss or clear coatings
used in UV printing facilitate
in-house finishing.
Incursion into waterless UV
Anyone wishing to take
waterless UV offset on board
should not attempt to do so
without professional advice
and training. This is because
the process demands not only
a certain level of skill at the
press but also a clear idea at
the planning stage of the technical specifications required
for the range of products that
are to be printed. On top of
this the press crew must become acquainted with the
peculiarities of the printing
process and the UV-specific
functions involved. For example, standard settings for conveying the substrate inside the
press cannot be transferred
1:1 from paper and carton to
film and other synthetic materials. To avoid unnecessary
costs from lost production it is
advisable to provide instruction for the press crew.
The optimum UV radiation level of the lamps must
be adjusted according to the
specific consumables – the
inks, coating(s) and substrate
– being handled, since their
thermal sensitivity can vary
substantially. Correct maintenance, eg cleaning the reflectors and changing defective
lamps, also plays a part.
In waterless as in wet UV
offset, inks and coatings must
Model
Type of inking system
Waterless UV applications
Remarks
KBA Rapida
KBA Rapida 74 G
Metronic Genius 52 UV
Metronic CD Print
Metronic Premius
Metronic oc200
conventional
keyless (Gravuflow)
keyless (Metronic)
keyless (Metronic)
keyless (Metronic)
keyless (Metronic)
folding cartons, compounds, plastic film
folding cartons, compounds, plastic film
plastic film/cards, compounds, carton
CDs, DVDs, optical business cards
CDs, DVDs, optical business cards
Plastic cards
all formats UV-compatible in principle
suitable UV inks currently being tested
UV version of Genius 52
waterless UV inks only
Narrow-web waterless offset presses for labels and packaging
(errors and omissions excepted)
Model
Basic printing process
Hybrid processes
Dryer*
Codimag Viva 340 Waterless
Codimag Viva 340 Letterpress
Drent Goebel VSOP
ETI Metronome
Etipol Combi 2000
Edelmann Color-Print V52/V72
Megamarc-Malbate MecaOffset
Nilpeter M 3300
RDP Marathon Web Litho
Sanjo Carton Box
Sanjo PO3 270/350
waterless offset
letterpress
waterless and wet offset (sleeves)
flexo, screen
waterless and wet offset, screen
waterless offset, wet offset
waterless offset
waterless offset, wet offset, flexo
waterless offset, wet offset
letterpress
letterpress, wet offset
letterpress, flexo, screen
waterless offset, flexo, screen
letterpress, flexo, screen, gravure, digital
waterless and wet offset, letterpress, digital
letterpress, flexo, screen
letterpress, flexo, screen, digital
flexo
screen, gravure, conventional flexo
letterpress, flexo, screen, gravure, digital
UV, IR support
UV, IR support
UV, hot-air option
UV, IR/hot-air, EB option
UV
UV
IR, hot-air, UV, EB option
UV
UV
* With one exception, UV lamps are standard fittings, so waterless offset with UV inks is the norm.
Source: Etiketten-Labels (www.flexo.de)
Waterless UV offset is an attractive
alternative to conventional processes
for narrow-web production. The
photo shows a Viva 340 Waterless
press
(photo: Codimag)
Left: Metronic’s oc200 has cornered
the market in waterless UV card
printing with subsequent UV coating
(photo: Metronic)
be suitable for the substrate to
be printed. In case of doubt,
eg if a substrate has not been
printed before, printability
and convertibility tests must
be carried out. Even the sequence in which the inks are
applied has a decisive impact
on quality. Normally an ink’s
suitability for a specific substrate can be read off the label,
and ink manufacturers offer
KBA Process
2 | 2005
37
Consumables | Waterless UV inks
Waterless UV specialist
D
etlef Braun, the author,
boasts more than 20
years’ experience in waterless
UV offset and is a respected
consultant on implementing
and optimising this process.
A qualified letterpress and
offset printer, from 1983 to
1995 Braun held the post of
technical manager at marks3zet, a major promoter of waterless offset in the German
print industry, and in this
capacity was responsible for
the wide-scale launching of
Toray’s waterless offset
plates. In May 1995 he became joint proprietor of a
Düsseldorf printing company,
the first worldwide to adopt
digitally imaged waterless
UV offset. The five-colour
coater press installed at that
time had a customised
Eltosch delivery extension
and printed paper and board,
plastic cards, stickers, mousepads, overhead transparencies and dummies using the
first Toray waterless CTP
plates to hit the market. In
July 2001 Braun also became
the sole owner of Druck &
Beratung in Mülheim (Ruhr),
which provides training in
waterless UV offset anywhere in the world on behalf
of all the leading press manufacturers (www.wluv.de).
“Yes, there’s a learning
curve as far as the technology
is concerned,” Braun concedes, “but UV printing is not
as hard as some people would
have you believe. However, it
is advisable to get some competent instruction and not try
and re-invent the wheel. The
consumables involved are too
costly to waste on learning by
your mistakes.” Braun promotes waterless UV offset to
his clients as an alternative
or addition to their existing
product portfolio. A filmprinting capability opens up
new and lucrative markets
where price negotiations are
not a major aspect of the daily
routine. His company helps
printers become acquainted
(photo: Print & Produktion 5/04)
Specialist for WL-UV-Print
explicit instructions. At any
rate, it is important to create
print characteristic curves for
the various substrates.
Dedicated control strip
Since waterless inks –
whether for conventional or
UV offset – have a high tack,
Druck & Beratung has devised a dedicated control
strip, the H-1/04. The individual patches, which can of
course also be checked with a
densitometer or spectral photometer, are triangular in
shape. This enables them to
overcome the forces of adhesion more easily, resulting in a
clean rupture, or “quick release”, when the ink is split
between the blanket and the
38
KBA Process
2 | 2005
with the technology on site,
until they have become totally proficient and can win
accounts through their performance, reliability and
trouble-shooting skills.
Detlef Braun is also chairman of the European Waterless Printing Association
(www.ewpa.org) which was
established to promote the
widespread adoption of waterless offset, and in this capacity is actively engaged in
advancing this technology.
Membership of the EWPA is
drawn from users and manufacturers of printing presses,
inks, blankets and plates.
With environmental issues
moving to the fore in press
engineering, waterless offset’s low-emission credentials are attracting a steady influx of new members to the
EWPA. Detlef Braun is a firm
adherent: “Whether with or
without UV – in waterless
offset you control only what
the customer wants to see:
colour and brilliance!”
substrate. They therefore furnish a realistic representation
of the substrate’s ink trapping
characteristics. Using standard rectangular patches, particularly on thin film, would
produce undesirable and misleading results because ink
adhesion tends to make the
film bulge at the edges. The
triangular geometry reduces
by almost 99% the adhesive
forces exerted on the substrate
at the angle of rupture.
The H-1/04 control strip
proved its efficacy in the Waterless Competence Centre on
the marks-3zet stand at Drupa
2004, in tandem with a
Metronic Genius 52 UV waterless press and KBA’s new
Rapida 74 G featuring
Gravuflow inking units. Al-
though the Rapida 74 G at
Drupa was run with oxidative
inks, tests are already being
conducted with waterless UV
offset inks. The European Waterless Printing Association
(EWPA), of which the author
is the chairman, and the
Berufsgenossenschaft Druck
& Papier (Germany’s equivalent of the UK’s H&SE or
America’s
OSHA)
have
jointly affirmed the Rapida 74
G’s environmental credentials
with the award of Emission
Reduced Waterless Offset
(ERWLO) certification.
Detlef Braun
Druck & Beratung D. Braun
Quality | Enhancement
Waterless offset has the edge
over wet offset in the print
quality that can be achieved.
Presses with long inking units
have proved this beyond doubt
Quality benefits
of waterless offset
– as have presses with keyless
inking units, which deliver a
consistently uniform print quality
into the bargain. The quality
gain is particularly striking in
newspaper production with the
Cortina.
But
this
superior
The surface of an imaged Presstek
PEARLdry waterless plate viewed
under a scanning electron
microscope. The silicone layer
sharply delineates the screen dots
and thereby limits dot gain
(source: Zeller+Gmelin/Presstek)
technology also enables the
small-format
Genius
52
to
address the high end of the
market.
There is less dot gain on a waterless plate than on a wet offset plate.
The graph was created using a TECHKON DMS 910 dot meter on a
Toray TAC-RGL7 plate and calculated using DMS Pro software
Quality delivers
bottom-line benefits
W
hen a commercial
or packaging printer makes the transition to waterless offset, his
decision is informed not
purely by cost and environmental considerations but
also by the potential quality
gains. He sees the move as a
chance to expand, because enhancing his product quality
alongside his environmental
credentials delivers a number
of bottom-line benefits.
First and foremost, a better print quality enables him
to differentiate his products
from those of his competitors.
In addition, establishing a
name as a quality waterless
printer makes it easier for him
to acquire – and retain – more
lucrative business entailing
optically challenging and
technically more sophisticated printwork while at the
same time promoting loyalty
in his existing quality-oriented customer base. If he can
do all this and also quote a
lower price, so much the bet-
ter. Added to which, working
with waterless offset (especially if this incorporates
keyless inking) and producing
prints of an exceptionally
high quality will steadily enhance his prowess, so that he
is capable of handling any
challenges that may come his
way in the future.
Even where no more than
an average standard of quality
is perfectly adequate, waterless offset may still be worth
taking on board. This is because it is widely acknowledged that waterless offset
can handle certain types of
uncoated stock that would
cause serious problems in wet
offset. And the Cortina newspaper press is proof that an
amazingly high print quality
can be achieved on newsprint.
Quality opens up
niche markets
The 74 Karat’s reproductive accuracy and precisely
calibrated print parameters allow it to simulate other printing processes with a startling
degree of fidelity. As a result
it is predestined for use as a
high-volume proofing sys-
tem. A lot of printers who
originally installed the press
to exploit its cost-efficiency
in short- to medium-run colour have been quick to pick
up on this, expanding from
run-of-the-mill jobs to the
much more lucrative business
of producing proof prints or
advance copies of high-quality jobs which, for technical
reasons (run length or specified printing process, eg UV
sheetfed offset, heatset), must
be printed on another press.
The technological superiority of the compact and innovative Genius 52 has enabled
The smaller volume of ink applied
with frequency-modulate screening
allows semi-commercials to be
printed on coldset presses. Waterless
coldset enhances the quality of such
products even further and enables
several different types of stock to be
printed
(source: REWE)
KBA Process
2 | 2005
39
Quality | Enhancement
users to redefine the image of
small-format offset, while its
ability to print four- or fivecolour products to a standard
well above the average offers
traditional small-format printers an effective tool for competing on quality, where the
job permits, against printers
running bigger presses. Conversely, medium- and largeformat printers can install a
Genius to expand their highquality portfolios into smaller
formats that were previously
uneconomic.
Microscopic images of four-colour
screens for newspaper production:
the blurred 40lpc (100lpi) screen
(top) is for a conventional coldset
press, the more sharply defined
60lpc (150lpi) screen (below)
is for a KBA Cortina
confident that the Cortina
could realistically be modified for heatset semi-commercial production at a later date.
Quality enhancement
fosters newspaper trends
Outstanding detail
reproduction
The quality arguments in
favour of waterless newspaper production are as compelling as the economic ones.
The Cortina supports two
major trends which have
emerged over the past ten
years: towards a higher colour
content and almost unlimited
flexibility in colour imposition. It does this by elevating
the quality of colour reproduction to a standard previously considered to be beyond
the capabilities of coldset
newspaper offset.
Coldset inks dry by penetrating the substrate, and up
until now it has only been
possible to increase ink laydown in solids and images at
the expense of overall quality,
especially if the images are
positioned back-to-back. Advertising agencies and adver-
All waterless offset printing plates can reproduce
exceptionally fine detail.
Thanks to the low dot gain
even negative dots remain
open in shadows. As a result it
is generally possible to print a
much higher screen resolution
(well above 200lpc or 500lpi,
with no significant dot loss in
extreme highlights or shadows) as well as FM screens
with small dot sizes. In fact
with the Cortina newspaper
press a 60lpc (150lpi) screen
is the norm, and it can handle
FM screens with equal ease.
On most types of digital
waterless plate (depending on
resolution and laser spot overlap) the full tonal range is retained on a screen of up to
80lpc (200lpi) or so. On a
120lpc (300lpi) screen the 1%
and 99% dot values are lost.
tisers have been less and less
willing to accept this lower
standard for their colour
newspaper ads. The usual response has been to offer substantial discounts, but with
margins already wafer-thin
this is not a policy that newspaper publishers can afford to
maintain in the long run.
Switching to waterless
offset would be a much more
effective – and profitable – response. But the elimination of
fount solution and the negative consequences it can bring
(eg fan-out, density fluctuations from one copy to the
next) is not the only reason.
There has also been a big improvement in the penetration
properties of waterless coldset inks and in the screens that
can be reproduced (60lpc and
FM). All this enables newspapers to enhance their appeal as
advertising media through the
excellence of their print quality.
As for flexibility, a waterless coldset press like the
Cortina delivers such a high
quality that it can print semicommercial products (flyers,
advertising and special supplements etc) more cost-effectively than heatset. So
newspaper publishers can finally print a string of other
products alongside high-quality newspapers on one and the
same press. Expanding the
product range allows them to
increase the level of plant utilisation. Judging by the advances already made, KBA is
Left: The Cortina beta
press at reiff in Offenburg
delivered a print quality
previously unattainable in
newspaper offset
Right: The Cortina News
was printed “live” using a
60lpc screen at a number of
events organised by KBA
40
KBA Process
2 | 2005
And the figures for analogue
Toray plates are just as good.
This level of performance is
attributable to the fact that the
image areas are slightly recessed. Screen dots, edges
and fine lines are defined with
razor-sharp precision by the
edges of the silicone layer,
and the ink has little opportunity to spread sideways during transfer to the blanket.
Brilliant colour
The absence of fount solution delivers another benefit:
waterless offset inks cannot
be watered down by emulsification, so they retain their full
strength. This means that
higher full-solid densities can
be achieved in waterless offset, and the gamut is larger.
Dispensing with fount solution has an equally beneficial
impact on ink gloss, which in
wet offset is impaired by the
addition of water during
emulsification. In the absence
of water the film-forming
components can spread more
evenly, so the surface is
smoother. More brilliant
prints are the result.
With KBA keyless inking
units there is the added bonus
that ink application by the
anilox roller is precisely defined and thus represents a reproducible value. This further
advance towards standardisation by both the Gravuflow
and the Newsflow inking sys-
The 74 Karat at Aug. Heinrigs in Aachen is primarily used for advance runs,
samples and short runs of folding cartons. The press is modified to simulate
long-run print jobs in UV wet offset with the aid of colour charts
tems furnishes a key criterion
for calibrating the production
process – the basis for generating reliable and precise ICC
profiles within an end-to-end
colour-management scenario.
Photographic-quality prints
The
above-mentioned
benefits with regard to detail
and colour reproduction move
waterless offset well up the
quality league. As a result this
process is being used to print
an ever-increasing volume of
high-end promotional literature. Waterless offset is frequently used in tandem with
other technologies to produce
photographic-quality prints. It
is the perfect vehicle for reproducing stochastic screens
and colour scales based on an
expanded gamut. This is because higher ink densities can
be transferred in waterless
offset than in wet offset.
Waterless offset also delivers an unparalleled image
quality on CDs, DVDs, plastic film and cards, which is
one reason why screen printing has lost ground in these
sectors. Metronic, which has
cornered the card printing
market, has contributed in no
small way to this trend by expanding the range of applications possible with the Genius
52 UV.
Maintaining a consistently
high standard
Waterless offset is already
a highly stable process, and
any fluctuations that may still
occur can be minimised by installing KBA or Metronic
systems. The ability to define
the volume of ink transferred
by the anilox roller is not the
only reason for this stability:
the keyless inking units used
in sheetfed offset are also insensitive to ghosting. With
Gravuflow inking units and
the inking units in the KBA
Genius 52 and Metronic
presses, every dot on the inkforme roller is always applied
to the same point on the plate.
Because of the high production speed at which the
Cortina runs, certain concessions had to be made in the
design of the Newsflow inking units with regard to the
number and diameters of the
inking rollers. In newspaper
production, however, this has
no significant impact on the
print quality that can be
achieved.
KBA and Metronic have
thus added a further benefit to
the existing quality gains that
waterless offset delivers: the
ability to print perfect,
ghosting-free solids and halftones. And if that is not
enough, the press runs up to
saleable colour in an amazingly small number of copies
and this colour remains
constant throughout the print
run.
Klaus Schmidt, Dieter Kleeberg
Perfect division of labour at Grütter
in Ronnenberg: the magazine body is
printed in heatset web offset, the
high-quality cover on a 74 Karat
KBA Process
2 | 2005
41
Quality | Standardisation
Making the transition to standardised,
high-volume print production
Print’s chances of surviving as a craft are virtually non-existent. But the
elimination of water in the offset press room does not, in itself, toll the
death knell for the “black art”. It is only when presses with keyless as
well as waterless inking units take the floor that the foundations are
laid for the transition to industrialised print production in the sense of
a standardised, high-volume workflow. In the press room, as in other
links of the production chain, the ultimate objective must be to deliver
an image that is 100% reproducible from one print to the next and
from one run to the next, based on objective, unequivocally defined
process parameters.
Digital pre-press the model
C
omputer-integrated
manufacture (CIM) as
a model for industrial
production is steadily winning
hearts and minds in the print industry. CIM typically entails an
advanced level of automation
and the creation of an extensive
networking system. Standardisation is a key criterion for au-
tomating the production chain
while safeguarding against customer dissatisfaction caused by
loss of quality.
The early incursion of alldigital workflows in pre-press
compelled media and print providers to adopt an objective and
recordable form of communication for their digital pre-print
output. More specifically, it entailed taking on board cali-
Colour management to ICC specifications has become an elementary step in
standardising digital pre-press and press production. The photo shows an
analysis of a European Color Initiative (ECI) test chart using an X-Rite
DTP70 spectral photometer
(photo: Kleeberg)
brated processes for colour
space transformation and
imaging, which in turn furnished the means of replacing
traditional, craft-based reproduction techniques with auto-
mated processes and high-tech
publishing scenarios. This evolution has found expression in
an influx of what is now familiar terminology – workflow automation, preflight, ICC colour
management and computer-toplate – along with data formats
such as TIFF, PDF, JDF and
XML, whose applications are
firmly anchored in diverse industrial and ISO standards.
Calibrated presses
The press room is now experiencing similar pressures as
part of a move to standardise
and extensively automate the
entire value-added chain – in
short, to complete the transition
to high-volume print production. So calibrated processes
must also be adopted at the
press. “Calibrated” in this context means that it must be possi-
For Holger Müller, production
manager at Aug. Heinrigs
Druck+Verpackung in Aachen,
standardisation is the very essence
of the 74 Karat. The test plates
shown here…
42
KBA Process
2 | 2005
…and the colour charts printed to
requirements by Karat operator
Daniel Strahl are used to correct
proofs and advance runs for UV
sheetfed offset
(photos: Kleeberg)
ble to set a defined initial status
at the press for the relevant permutations of plates, blankets,
ink, substrate and printing pressure. It follows that plate exposure, too, must be a calibrated
process.
The tonal and colour reproduction properties of each specific permutation are captured
in characteristic print curves
and ICC press profiles to enable pre-press to generate output-compliant imaging data. If
one of the components in this
permutation is changed, the
characteristic curves and profiles become invalid and must
be recalculated. For profile
generation in a 74 Karat production environment KBA
recommends optional Profile
Wizard software from Creo,
while the “Power Mix” package it offers with the 46 Karat
includes aniva-Euroscale inks,
for enhanced colour fidelity,
and a Minolta proofing system.
Hands-off ink application
In a scenario such as this
there is no longer room for the
press operator to indulge his individual preferences and make
subjective assessments. In an
industrial production environment, objective criteria must be
the sole criteria on which quality assurance is based. By making the transition to waterless
and keyless inking, hands-on
ink application (to say nothing
of dampening) is banished from
the printing process, with the
result that the quality defined in
pre-press can be reproduced
immaculately in the print.
But there is no need for the
press operator to feel that his
competence has been curtailed.
He is merely being relieved of
certain routine tasks which –
and this has been proved beyond all doubt – do not neces-
sarily produce a better image.
Instead, he can focus his whole
attention on monitoring quality
and preparing for the next job:
tasks for which he will have
computer-aided tools at his disposal. As a result his workload
is much less strenuous and entails fewer repetitive, time-consuming chores. This enhances
both productivity and quality.
His responsibilities may have
been redefined for an industrialised context, but they have
certainly not been curtailed.
Total workflow standardisation
Eliminating operator intervention in the inking process by
switching to Gravuflow, Newsflow or Metronic inking units
closes the final gap in an allstandardised production flow
from pre-press to press. All
other processes, even those at
the press, have long since been
automated and calibrated.
However, up until now the operator’s ability to influence ink
KBA Process
2 | 2005
43
Quality | Standardisation
A perfect match! At Druckforum
2003 the focus was on the “Power
Mix” standardisation package
offered by KBA, Epple and Minolta
comprising a 46 Karat, Epple’s
aniva-Euro inks and a Minolta
CF9001 printing, copying and
scanning device for checking the
colour fidelity of prints off the press
(photo: KBA)
With the 74 Karat, the standardised production of special colours is remarkably simple. At Grid Studio in Belgrade all
the Pantone colours that can be reproduced with process inks are printed on a test sheet and submitted to the customer
for approval
(photo: Kleeberg)
application has jeopardised the
binding nature, the accuracy
and the validity of all the other
process parameters.
Even though ISO 9000 accreditation no longer makes
headlines, it remains an integral
component of quality management at many production
plants. And it shows that the
quality bar is not set in stone,
but steadily rises in line with
industry capabilities. The lack
of a game plan for total standardisation may well make it
much harder in future to furnish
evidence on a regular basis of
compliance with prevailing
quality norms.
Reliably reproducible images
It is universally acknowledged that the ability to reproduce identical prints in a
uniform quality throughout the
print run, and from one run to
the next, is a logical consequence of a standardised production environment. But
KBA has developed a mature and
highly competitive technology for the
Cortina. In the course of this
development ink viscosity, which was
initially excessively high (above) has
been reduced to the optimum level,
which was found to be very much
lower (below)
(photos: KBA)
44
KBA Process
2 | 2005
standardisation, and more specifically the standardised application of ink on the substrate
via waterless inking systems,
offers many more advantages,
one of them being distributethen-print scenarios in which
two or more production plants
must co-ordinate their activities. Although they may be geographically remote from each
other, working from the same
single print file enables them to
produce prints that look as if
they have come off a single
press. The 74 Karat has long
been able to play to its specific
strengths in such scenarios.
And the Cortina would be the
perfect “output device” for distribute-then-print newspaper
production, since it would enable the various sites to print,
say, different local sections but
identical national and international sections.
Competitive technology
from KBA
KBA’s focus on waterless
and keyless inking technology
represents a new departure in
print production. But a new departure in this instance does not
mean that users must abandon
familiar shores and set sail
without a compass in uncharted
waters. On the contrary, the basic technology is not only familiar but well-proven in
shopfloor operation in the form
of Gravuflow and Metronic
inking units. The experience
and know-how that KBA has
gained over the years have been
incorporated in the Newsflow
inking unit and in the Cortina,
which has since attained market
maturity. As a result, KBA
presses with waterless, keyless
inking technology represent the
only practical concept currently
available for standardising
high-volume print production.
Dieter Kleeberg
Cost-efficiency | Comparison
Banishing water and ink keys
boosts press economics
Waterless offset is not only more environmentally friendly than conventional offset, thanks to the absence of fount solution, but in many cases
it is also more cost-effective, even though the prices for ink and plates are higher. KBA’s innovative keyless inking technology delivers further
cost savings by cutting the volume of start-up and production waste, shortening makeready times, reducing the number of operator tasks and
limiting VOC emissions. The futuristic design of the Cortina newspaper press, its compact footprint, ease of maintenance and product flexibility
bring additional cost-efficiency benefits.
Cost savings from eliminating
fount solution
E
ven waterless presses
with conventional inking units offer substantial cost savings over wet offset
presses purely by dispensing
with fount solution. One reason
is that there has been a sharp
rise in the price of isopropyl
alcohol (IPA), especially in
recent years. Another is that
water consumption is reduced
to zero, which is good for the
environment. At the same time
there is no outlay for dampening additives and dampener
maintenance, and makeready
no longer entails adjusting the
settings to achieve the correct
ink/water balance. This not
only shortens makeready times,
but also cuts waste. What is
more, during the production
run there is no need to monitor
dampening feed. And where
there’s no water, there’s no rust.
One of the additional advantages of waterless plates is
that they do not have to be
gummed. The ink-receptive
and ink-repellent areas of the
plate retain their respective
properties without a coating of
gum arabic.
Additional cost savings
from eliminating ink keys
Compared to conventional
waterless offset presses the
keyless inking units made by
KBA and Metronic deliver dramatic cost savings which gen-
Fast finish: the 74 Karat with inline aqueous coater and IR dryer allows
fresh prints to be turned or finished without delay
erally far outweigh the higher
cost of plates (currently +50%),
ink (+20%) and temperature
control, particularly for short to
medium runs. At a time when
average run lengths are steadily
shrinking, the overall balance,
after factoring in all cost parameters, tilts in favour of waterless, keyless offset compared
to conventional wet offset
presses (see the cost-efficiency
calculations and analyses in
the next chapter).
The higher level of costefficiency is driven by the technological benefits that keyless
inking brings:
• There are fewer rollers in a
keyless inking unit, so the ini-
Couldn’t be neater: including the
plinth and UV lamps the Metronic
Genius 52 UV has a footprint
measuring just 4.17m (13’8”)
x 3.28m (10’9”) and stands just
1.91m (6’3”) high
tial outlay and the running costs
over the total service life of the
press are both lower. Properly
manufactured anilox rollers
have a service life of several
years.
• An anilox roller replaces
key-wide inking and applies a
uniform film of ink, eliminating both ink keys and the associated setting elements. So
there is no need for costly presetting and remote-control
electronics for the ink-key profiles.
• The automation of imagebased ink application simplifies
the entire production process
and press handling. The opera
Synergy gains: the Rapida 74 G
unites the 74 Karat’s Gravuflow
keyless inking technology with the
flexibility, automation and speed
advantages of unit-built Rapida
presses
KBA Process
2 | 2005
45
Cost-efficiency | Comparison
Four-high comparison:
the 3.7m (12’) Cortina is dwarfed
by towers of arch-type (left) or
H-type units (right)
Green field preservation: if a single-floor version meets press specs,
a four-high Cortina can be installed in a standard factory hall
tor has more time for other
tasks, and above all for quality
assurance. He must control far
fewer parameters and is therefore likely to make far fewer
errors. This improves process
stability.
• The reduction in presetting
and operating tasks cuts
makeready times and reduces
start-up waste. This enables
shorter runs to be printed costeffectively.
• The reduction in operator
tasks enables the press to be
operated by a smaller crew.
Presses like the 74 Karat,
Rapida 74 G and Genius 52 are
suitable for one-man operation.
The Cortina newspaper press
can be handled by a smaller
crew than comparable conventional presses.
• The standardisation of the
inking process based on calibrated print parameters promotes a more standardised,
high-volume production sequence. The individual pro-
cesses can be scheduled and
predicted more accurately,
deadlines met more reliably
and costs reduced on an ongoing basis. This offers print providers an effective tool for
cushioning margins against
pricing pressures.
It is evident from the above
that waterless, keyless inking
technology is an innovative
contribution towards boosting
cost-efficiency in print production, and that investing in
presses with waterless and
keyless inking units may almost be regarded as visionary.
In this context the adoption of
Gravuflow inking technology
for unit-type presses is a logical
step: since on-press plate exposure limits the range of applications possible with the compact
74 Karat DI offset press to
printing plants with no CTP
pre-press, the Rapida 74 G is an
interesting option for the large
and growing number of printers
with CTP platesetters.
Additional cost savings
with the Cortina
The Cortina waterless coldset press offers specific cost-efficiency benefits for newspaper
production. Here, a simple
equation applies: the bigger the
press line, the greater the savings potential. The Cortina can
be configured for the same
maximum possible number of
full-colour broadsheet or tabloid pages as a conventional
press, but is much more compact. So the savings it brings in
terms of labour, space requirement and building costs increase in direct proportion to
the size of the press line it
replaces. The reduction in personnel requirements for press
operation and maintenance deliver the biggest cost benefits.
The time savings gained
during makeready – eg with the
automatic plate-changing system developed exclusively for
the Cortina – can be exploited
either by extending editorial
close for greater immediacy, or
by cutting overall production
times (and thus nightshifts and
the bonuses they attract). The
additional production time
gained through the high level of
automation can be used either
to print a wider range of editions, eg with a more local
content or targeting more specialised interests, or to win
new, additional contracts for
higher-quality products such as
semi-commercials.
Space-saving
Newsflow
inking units and the elimination
of dampening systems have
enabled KBA design engineers
to create a four-high tower that
stands just 3.7m (12’) high, yet
is more accessible and easier to
handle than any press that has
gone before. The reduction in
press height means that it is
now possible to install an eighthigh tower in an existing press
hall instead of having to construct a new building at great
expense. It is even possible to
install a four-high press in an
existing standard industrial
building such as a supermarket
hall, which generally has much
less headroom. The space
gains, along with the cost savings achieved by eliminating
the need for new premises, can,
in some cases, dramatically re-
Height comparison: this photo taken
in the Würzburg assembly hall shows
that a Cortina four-high tower
(right) is in fact slightly shorter than
a Commander 9-cylinder satellite
printing unit (left)
46
KBA Process
2 | 2005
High automation: the operator merely has to load the new plates in the
Cortina printing unit; the used plates are removed and the new ones mounted
automatically in less than 100 seconds
Low maintenance: the automatically adjustable roller locks on the
Cortina support quick and easy roller changes and ensure an optimum
roller tension
duce the total cost of the investment. For old-established
newspaper plants one of the
most valuable benefits is that
the printing and colour capabilities of an existing conventional press line can be expanded without suffering the
negative consequences associated with having to move to a
new production site – the cost
of dismantling and re-erecting
existing press lines and equipment, kitting out the new building, installing new infrastructure and configuring a new network etc.
As a result only the amount of
heat necessary is generated and
not one degree more, so that energy consumption for air-conditioning the press hall can be
substantially reduced or even
eliminated.
Keyless inking units are not
the only new features in the
Cortina that deliver additional
cost savings and flexibility
gains. The Stepin system developed for the printing units enables them to glide apart at the
touch of a button to afford rapid
access to the blanket cylinders
and washing bars for mainte-
The higher energy costs
arising from the need for a temperature-control system are not
entirely outweighed by savings
elsewhere, though the Cortina’s
design engineers did manage to
claw back most of them. They
did this by choosing a temperature control system (see chapters on inking units, pp 16-23)
with a high-performance profile: STC (surface temperature
control) precisely specifies the
optimum temperature at any
point in the press, while its flow
geometry ensures that this is
reached in a minimum of time.
Advantages of the various Cortina newspaper press configurations.
1 Floor-mounted press for 48 pages 4/4:
• just one operating level
• fast access to printing couples
• reduced height
• potential drawbacks: paper logistics, press length
2 Floor-mounted press for 32 pages 4/4:
• flying plate changes possible in 4/4
• extremely compact
• short web paths
nance tasks or to remove paper
following web jams. Maintenance work has also been reduced by installing automatically adjustable roller locks and
by using non-misting waterless
coldset inks, which dramatically reduce the amount of
cleaning agent and rags required.
Peter Benz, product engineering
manager for newspaper presses and
project manager for the Cortina
3 Single-storey substructure press for 80 pages 4/4:
• one operating level at printing couples
• reduced height at printing couples
• one operating level at reelstand
4 Two-storey substructure press for 64 pages 4/4:
• compact tower with two operating levels in print zone
• customer: Centre d’Impression Edipresse Lausanne s.a.
in Bussigny, Switzerland.
KBA Process
2 | 2005
47
Cost-efficiency | Calculations
Detailed comparative cost analyses
Proven cost-efficiency
Comprehensive comparative cost analyses for the 74 Karat, Genius 52 and Cortina, based on detailed production data, prove that waterless,
keyless offset is not only an innovative technology but also cost-effective. This chapter focuses on the compelling economic benefits of these
specific presses, drawing on independent studies by the Saxon Institute for the Printing Industry (SID) in Leipzig.
74 Karat
€140
n 2002 the SID conducted a comparison of
overheads and production
costs for the 74 Karat, the
Heidelberg Speedmaster SM
74-4 DI and the Heidelberg
Speedmaster SM 74-4 + CTP.
The comparison, which was
based on a similar level of
equipment, reveals that, for
shorter runs (3,700 to 5,000
sheets, depending on the type
of job), direct imaging with
the 74 Karat is more cost-effective than conventional offset with an upstream digital
workflow plus CTP (SM 74-4
+ CTP).
The biggest single cost
factor in the calculation is
platemaking, which at around
55 for the 74 Karat is very
much lower than for CTF
(around 125) and CTP ( 80)
plates (see fig. 1). The
Heidelberg SM 74-4 DI, being a unit-type press with one
imaging unit per printing unit,
does not offer the advantages
of direct imaging technology,
and is beaten on cost by both
the 74 Karat and the SM 74-4
+ CTP. The comparatively
poor showing by the SM 74-4
DI is largely due to its higher
price. On top of this,
makeready time and the volume of start-up waste with the
SM 74-4 DI – especially in
short runs – push production
costs well above those for the
74 Karat.
Our own calculations
show that for a specific run
length (from 200 to 1,500 or
more copies, depending on
the digital printing process
and system) the cost of printing A3 sheets in full colour on
€120
48
KBA Process
2 | 2005
€100
€80
€60
€40
€20
€0
Platemaking
with CTF
Platemaking
with CTP
6
Sheet count [in millions]
I
Film production
Film
Plate production
Plates
1 Comparison of plate costs for the
74 Karat and plate-processing costs
for CTF and CTP (source: SID
2002, “Comparison of overheads
and cost efficiency – 74 Karat,
Heidelberg Speedmaster SM 74-4 DI
and Heidelberg Speedmaster
SM 74-4 + CTP”)
74 Karat
5
4
SM 74 DI
Platemaking
for 74 Karat
2 Comparison of
annual 4/4 sheet
capacity relative
to run length
(source: KBA)
3
SM 74 + CtP
2
primarily thanks to its short
makeready times compared to
the Heidelberg Speedmaster
SM 74-4 DI and SM 74-4 +
CTP or Indigo and Xerox
presses (fig. 2).
Indigo
1
KBA Genius 52
Xerox
0
0 0 0 0 0 0 0 0 0 0
100 200 500 1,00 2,00 3,00 4,00 5,00 6,00 7,00 8,00 9,00 0,00
1
Run [no. of copies]
both sides is lower with the 74
Karat than with toner- or
inkjet-based digital printing
presses, and that the cost difference increases in direct
proportion to run length, up to
a ceiling of 10,000 sheets. If
no variable data are involved,
longer runs can be printed
more cost-effectively in offset
with the 74 Karat, so there is
no need to invest in a complete CTF or CTP pre-press.
Annual sheet capacity in
A3 depends on run length, but
is highest with the 74 Karat,
In 2003 the SID ran a series of calculations comparing
overheads and production
costs for the KBA Genius 52
with those for Heidelberg’s
Printmaster GTO 52, Printmaster PM 52 and NexPress
2100. A similar level of equipment, ie four printing units for
a sheet size of 360mm x
520mm (14” x 201/2”), was
1.50
€
1.25
Genius 52
GTO 52
PM 52
1.00
0.75
0.50
1.25
0.00
0
500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000
Run [no. of copies]
3 Per-copy costs of a 4-page A4
brochure printed 4/4 on a KBA
Genius 52 and on a Heidelberg
Printmaster GTO 52 and
Printmaster PM 52. (source: SID
2003, “Overheads and cost
efficiency – KBA Genius 52,
Heidelberg Printmaster GTO 52,
Printmaster PM 52 and NexPress
2100”)
taken as the starting point.
The SID found that the Genius 52 is more cost-effective
than the Printmaster GTO 52
and PM 52 for runs of between 200 and 2,000 copies
(fig. 3).
Fewer makeready sequences and faster run-up to
saleable copies are its two key
advantages, and these have
the biggest impact in production scenarios featuring numerous short-run colour jobs.
Ink changes, which according
to the SID study took longer
on the Genius 52 than on the
Printmaster GTO 52 and PM
52, have since been dramatically shortened by the adoption of new features, though
because the Genius 52 fourcolour offers the option of
simulating a complete range
of special colours with standard process inks, there is seldom any need to change the
ink. Moreover, the standard
model of the Genius 52 already provides for the addition of a fifth printing unit, so
colour capacity can be expanded at no great expense as
the need arises.
The comparative cost
analysis for the Genius 52 and
the NexPress 2100 shows that
the Genius is more cost-effective for typical digital print
jobs in runs of up to 5,000
copies or thereabouts. This
excludes jobs entailing variable data, eg personalised
print.
100
100
–25 %
75
75
50
50
25
25
48 pages 4/4
Wet offset press
KBA Cortina
48 pages 4/4
made in both labour (-25%)
and paper costs (-5%), as fig.
4 shows.
Further savings can be
achieved in the consumption
of consumables (wiping water, cleaning agents etc),
maintenance and repairs and
imputed overheads (including
buildings, heating and airconditioning), though these
are offset by higher costs for
energy and (at present) plates
and ink. Even after stripping
out potential gains from lower
can cut production costs by
5% to 10% compared to a wet
offset press. The calculations
were based on the costs generated by a 48-page 4/4 Cortina
with automatic plate changing
and by a new-generation wet
offset press. The initial capital
outlay for both presses was
the same, and both printed numerous split editions with a
total circulation of 120,000
copies. The calculations revealed that, with the Cortina,
substantial savings can be
%
Wet offset
KBA Cortina
Labour
23.0
17.2
Paper
41.7
39.6
KBA Cortina
building costs and additional
income from increased production
capabilities,
the
Cortina can still deliver a cut
in costs of between 5% and
7% (fig. 5). Where the installation of a new four-high
tower press with the same colour and pagination capability,
but conventional wet offset
technology, would entail
structural changes that could
be avoided with the compact
KBA Cortina, a cost reduction
of 10% or more can be
achieved.
KBA has devised a comparative cost analysis which
allows a detailed cost comparison to be made for any
newspaper production plant
where a Cortina would replace an existing wet offset
press. Based on authentic data
relating to consumables, labour, run structure etc, this
analysis is available as a special service to newspaper
publishers seriously contemplating going waterless with
the Cortina.
Dr Bernd Heusinger
Plates
4.1
5.8
Ink
Other materials
Maintenance
2.6
1.2
1.9
3.1
1.0
1.2
Imputed depreciation
allowance
5 Cost comparison between wet
offset press and KBA Cortina for
48-page 4/4 product
(source: KBA)
Wet offset press
4 The biggest savings potential with the Cortina versus a wet offset press lies in the cost of labour (left)
and paper (right)
(source: KBA)
KBA Cortina
KBA has carried out extensive calculations for a
number of newspaper production plants, using authentic
pressroom data. These have
demonstrated that the Cortina
–5 %
12.9
12.9
Imputed interest
6.5
6.5
Space and heating
6.1
5.3
100.0
92.6
Total
KBA Process
2 | 2005
49
Environment | Emissions
Waterless, keyless technology
enhances press ecology
Eliminating water is one way to burnish the environmental credentials of offset printing, and taking on
board the keyless inking technology developed by KBA and Metronic is another. The proof is to be found
in the huge waste savings delivered by presses that combine these two virtues and in the environmental
certificates awarded to the Genius 52, 46 Karat, 74 Karat and Rapida 74 G by the Expert Committee for
Printing and Paper Converting attached to the Berufsgenossenschaft (BG), the German equivalent of the
H&SE in the UK and OSHA in the US. Nor is the Newsflow inking system the only green technology
incorporated in our Cortina newspaper press.
The waterless, keyless Gravuflow
inking units in the 74 Karat and
Rapida 74 G support standardised,
more ecological print production
(photo: Kleeberg)
Starting from an
eco-friendly basis
M
ore often than not,
temperature control systems for
conventional waterless inking
units are wet offset systems
that have merely been modified to function without water.
Research engineers at KBA
and its subsidiary Metronic,
however, took a totally new
approach: for the first time in
the history of offset technology they created inking units
specifically for waterless offset, ie with a minimum
number of ink-splitting points
and thus largely ghostingfree. This has revolutionised
press design. The most striking feature of the Genius 52,
the 74 Karat and, above all,
the Cortina is their ultra-compact footprint.
With legislators, employees and public opinion both in
Europe and in other parts of
the world (Australia, Singapore) steadily becoming more
attuned to environmental issues, KBA and Metronic deliberately set out to enhance
the environmental sustainability of the relevant process
parameters. The conservation
of natural resources has long
been an integral aspect of our
corporate philosophy, and as
a highly innovative press
manufacturer with global operations we are committed to
protecting the environment
50
KBA Process
2 | 2005
Short inking units – a feature common to the Genius 52 and all other keyless
presses – have fewer rollers and are therefore require less cleaning solution
(photo: Metronic)
and promoting the use of renewable materials in all the
new products we develop.
Environmental focus
sharpens competitive edge
Increasingly rigorous regulations and laws are imposing a clear environmental
strategy on users and suppliers alike. In Switzerland, for
example, the call to limit the
emission of VOCs (volatile
organic compounds) is particularly strong, and as an incentive the reduction of VOC
emissions is rewarded by the
government with tax concessions. In this respect, printers
in Switzerland and other
countries where environmental legislation is rigorously
upheld (eg Scandinavia) have
a competitive advantage in
that they can reduce their tax
burden – and thus the minimum prices they must charge
– by adopting environmentally friendly technologies
and processes.
And because such laws
and guidelines are continually
being tightened up (see next
chapter on IPPC and BREF),
adopting
environmentally
friendly technology is often
an effective safeguard against
unpleasant legislative surprises in the future. Printers
In future Toray’s CTP plates can
be processed without chemicals,
just with water
(photo: KBA)
who already comply with or
anticipate such regulations by
investing in reduced-emission
technology when they replace
or expand their existing
equipment do not have to
worry about being forced to
comply at a later date when it
may be both more costly and
less convenient to do so.
What is more, cutting
emissions has become an image issue for commercial,
newspaper and packaging
plants – and a good image can
be a key advantage in the market. A wave of ISO 9000 certification for quality management in the mid-1990s was
followed by a wave of ISO
The Rapida 74 G can be fitted with
an optional automatic washing
system for the anilox and ink-forme
rollers. The premoistened fleece roll
is sufficient for 40 low-emission
washing sequences
(photo: Kleeberg)
14000 certification for the environmental protection management that this entails.
KBA and Metronic support
printers’ efforts to achieve
such accreditation by designing more ecological presses –
not just in waterless offset
but in wet offset, too. The
advances that KBA has
spearheaded in this technology culminated in the award
of an “Emission Tested” certificate by the BG for the
medium-format Rapida 105 at
Drupa 2000. All our other
Rapida press types, from B2
to VLF, have since achieved
the same level of compliance.
There are now a large number
of KBA sheetfed and web offset presses operating with
reduced alcohol levels or no
alcohol at all.
VOCs, temperature control
and plates
The elimination of fount
solution in waterless offset
also eliminates the need for
volatile dampening additives.
So IPA does not even feature
on the VOC gauge. Water is
required solely for temperature control and runs in sealed
circulating systems. Although
temperature control increases
energy consumption, this is
not as big a drawback as it
may at first appear because in
many cases it is offset by a
lower consumption of energy
for controlling the pressroom
climate, since the heat generated can be recovered via a
heat exchanger and used to
heat water and space. Apart
from which temperature controls are being used increasingly in wet offset anyway,
either to stabilise the printing
process during long runs or
for low-alcohol print production.
The Rapida 74 G’s reduced emission
levels were confirmed at its world
debut at Drupa 2004 by Germany’s
BG and by the European Waterless
Printing Association
(photo: Kleeberg)
Plates also play a major
role in waterless offset ecology. Toray is busy modifying
its CTP plates so they can be
processed in a water-based
solution, with no chemical additives. Processless plates require no wet development at
all. One advantage common
to all waterless plates is that
they do not need gumming.
Less chemistry, less waste
What differentiates KBA
from the rest of the players in
the field is the fact that it has
reduced emissions still further
by adopting keyless inking
technology. It stands to reason
that shorter ink trains with
fewer rollers will also consume less washing solution
and therefore fewer chemicals. In the new Rapida 74 G
the efficiency of the cleaning
agent has been enhanced by
automating the washing cycle
for the blankets, impression
cylinder and (optionally with
premoistened cleaning cloths)
for the anilox and ink-forme
rollers.
So it will come as no surprise that even the basic version of the new Rapida 74 G
generates emission levels that
are already well below the
permitted maximum. At its
premiere at Drupa 2004 it was
awarded both an “Emission
Tested” certificate by the BG
and an “Emission Reduced
Waterless Offset” seal of approval by the European Waterless Printing Association
(EWPA).
A fundamental feature of
units is their low level of startup waste. This not only delivers substantial savings in
day-to-day production but
also enables jobs to be printed
which would be uneconomic
if waste levels were any
higher. Some examples that
spring to mind are products
printed on more costly substrates such as aluminiumcoated or designer paper,
high-grade carton or plastic
film, all of which are becoming increasingly popular. On
top of this, keyless inking
units consume fewer natural
resources such as wood and
mineral oil. Gravuflow inking
units run up to saleable colour
in a maximum of just ten copies, as has been proven time
and time again during print
demonstrations and on the
shopfloor. So standardised
production based on calibrated parameters can also enhance pressroom ecology.
Cortina delivers further
environmental benefits
The emission and waste
levels generated by the
Cortina and its Newsflow ink
KBA Process
2 | 2005
51
Environment | Emissions
Left: This is what clean
newspaper production is
all about: no ink misting,
so less cleaning at the
Cortina
(photo: KBA)
Right: An economical
built-in blanket washing
system is all part of the
Cortina’s environmental
concept
(photo: KBA)
Below: Dedicated drives
for the inking units, plate
and impression cylinders
virtually eliminate oil in
the Cortina (photo: KBA)
ing units – even when printing
a full four colours on both
sides of the web – are no
higher than with the Gravuflow inking units fitted in the
74 Karat, Rapida 74 G and
Genius 52 sheetfed offset
presses. Since the output of a
newspaper press is four times
higher than that of a sheetfed
press, the environmental benefits are substantial.
But the Cortina has a lot
more to offer when it comes to
green technology. Up until
now, dedicated drives for the
printing couples were considered the state of the art: the
Cortina is the world’s first offset press to feature dedicated
drives for each cylinder and
inking unit. Oil-lubricated
gears have thus been consigned to history – in the
Cortina there is virtually no
oil at all!
Energy consumption by
the Cortina is also impressively low. Because the temperature control system responds incredibly fast and
only consumes the precise
level of energy required in
any specific operating status,
heat generation is relatively
low. This in turn reduces the
amount of energy required for
climate control in the press
room and may, depending on
local conditions, completely
eliminate the need for air-conditioning. In waterless offset,
where it is normally important
to maintain a constant ambient temperature of slightly
under 30°C, this is no small
consideration.
52
KBA Process
2 | 2005
The Cortina’s advanced
level of automation has an impact beyond a substantial saving in waste: the integrated
blanket-washing unit and automatic ink pumping system
also consume less energy, less
cleaning solution and less ink.
Klaus Schmidt,
Dieter Kleeberg,
Peter Benz
The doctoring system in
the Cortina – basically a blade
with a sealed chamber – has
been optimised for a new generation of waterless coldset
inks whose slightly higher
viscosity poses something of
a challenge. The inks now on
the market can be printed easily and have no propensity to
mist. So there is no ink contamination – even in the immediate vicinity of the inking
units – and thus no need for
cleaning agents and cloths.
This also reduces emissions.
Sun Chemical has developed
a series of water-washable
coldset inks, Shark W, exclusively for the Cortina project
and it will be interesting to see
how they perform.
In November 2004 the BG awarded
the 46 Karat, 74 Karat and Genius 52
its coveted “emission tested” certificate
Environment | Directives
New BREF poses challenge
for the print industry
The standards to which the print industry must work will soon be defined in a BREF – a “Best Available Techniques reference document”.
Currently still in draft form, the BREF is the product of a 1996 EU directive aimed at harmonising production licensing procedures. The
techniques specified in a BREF must be valid and feasible. They serve as a driver towards improved environmental performance across the
European Union, but at an acceptable cost. For the print industry they represent both a challenge and an opportunity.
C
ouncil Directive 96/
61/EC concerning Integrated
Pollution
Prevention and Control, or
IPPC for short, was the product of a concerted move to
create a common set of EU
regulations for granting industrial permits. One of the
main motives for issuing such
a directive was to put an end
to environmental dumping,
the practice of shifting production from one EU state to
another where regulations are
less restrictive.
The IPPC directive primarily specifies the parameters
for all future licensing procedures, or “permitting processes” as they are known in
EU-speak. These parameters
are the standards defined in
the relevant BREF. They
apply to all industrial plants
contributing to environmental
pollution in any member state
through toxic waste, say, or
the emission of acidifying
substances, greenhouse gases
or VOCs.
in the works or already approved can be downloaded
free of charge from the
website run by the European
Integrated Pollution Prevention and Control Bureau
(EIPPCB). The European
IPPC Bureau, as it is also
known, was established in Seville, Spain, by the European
Commission for the purpose
of co-ordinating current data
on the best available techniques.
Sevilla Process
Determining Best Available
Techniques
Index page relating to print products and offset printing
Best Available Techniques
(BAT) are being introduced
with the ultimate goal of reversing the current impact of
production patterns, which
are unsustainable. Manufacturing permits must be holistic, or “integrated”: they must
take into account the complete environmental performance of the plant concerned, ie
emissions to air, water and
land, generation of waste, use
of raw materials, energy efficiency, noise, accident prevention, risk management etc.
The best available techniques
are determined after weighing
the potential environmental
benefits against the economic
cost of implementation. This
is to ensure that a positive
impact on one environmental
aspect, for example the benefits of adopting a specific
clean-air technology, would
not be cancelled out by its
detrimental effect on another
(excessively high energy consumption and thus expense).
The aim is to devise effective
yet affordable guidelines for
curtailing environmental pollution by the industries targeted.
Information on the best
available techniques currently
Instead of imposing panEuropean threshold values the
IPPC seeks a consensus to determine the best available
techniques. This has been
dubbed the Sevilla or Seville
Process after the Bureau’s
geographical location. Networks of experts representing
stakeholder groups – industry,
the authorities, environmental
NGOs – from 31 countries are
engaged in establishing a
common framework of BATs
as defined in the IPPC directive.
Technical work groups
(TWGs) manned by these experts collate current data on
the environmental impact of
the relevant techniques and
determine appropriate, practice-proven measures for reducing pollution in each of the
sectors concerned. Following
intensive debate among the
work groups the results are
formulated by the EIPPCB in
a BREF and submitted to the
relevant EU organs for approval.
KBA Process
2 | 2005
53
Environment | Directives
The entire process, from
the initial posting of the working draft on the EIPPCB
server to the publication of the
final, approved BREF, can
take three years. The draft is
regularly revised so that the
authorising authorities and
the general public can keep
abreast of progress to date in
all significant branches of industry. BREFs have already
been approved for the papermaking, cement and steelworking industries.
BREF for the print industry
The BREF relating to the
print industry is currently a
work in progress. It applies
to all plants requiring a licence under EU or national
regulations, in other words
“installations for the surface
treatment of substances, objects or products using organic solvents, in particular
for dressing, printing, coating,
degreasing,
waterproofing,
sizing, painting, cleaning or
impregnating, with a consumption capacity of more
than 150 kg per hour or more
than 200 tonnes per year”
(IPPC Appendix I, section
6.7).
The BREF code for the
reference document is STS
because it governs any kind of
surface treatment using solvents (eg serial paint spraying
in the automotive industry
and the production of adhesive tape). The draft embraces
both
sector-specific
and
cross-process
technologies
(the treatment of exhaust
gases, waste and energy management, solvent recovery
etc). This focus means that
printing plants are just one of
many categories of installation to which this new BREF
applies.
Print production is classified by the main process used.
Until now the only printing
processes handled in greater
depth have been those where
solvent consumption has
generally exceeded 150kg
(330lbs) per hour or 200t (220
US tons) per annum: heatset
54
KBA Process
2 | 2005
offset, packaging flexo, packaging gravure and publication
rotogravure. It has not yet
been conclusively determined
whether further printing processes should be examined in
more detail. Some may already be regulated by other
directives, for example if they
are part of a bigger installation featuring a variety of
processes.
The environmentally relevant aspects of offset print
production are VOC emissions (more specifically, technologies for reducing alcohol
levels in fount solution and
emissions during cleaning
cycles), mineral-oil components in ink waste, contaminated waste water and the
consumption of resources
(paper, energy).
Waterless offset is not being treated as a separate printing process but as a potential
BAT, ie as a means of reducing the environmental impact
of traditional offset. In view
of the differences in performance parameters, emissions
and waste levels – particularly
in conjunction with KBA
keyless inking units – it is debatable whether this is the
best solution.
Following and supporting
the print BREF debate
The Sevilla Process on the
BREF relating to the print industry was initiated in March
T
2003. The first draft (see excerpt) was posted on the
EIPPCB website in May last
year. The final version is unlikely to be ready until early
2006.
At present the print media
industry is represented in the
TWG by three trade associations: Intergraf, the European Rotogravure Association
(ERA) and the European
Waterless Printing Association (EWPA). Representatives
would welcome more active
support from trade association members and print entrepreneurs, particularly when
it comes to input on
reference data and practical
experience.
For many players in the
print industry the Sevilla
Process is “a long way away,
and there are more important
things to do.” But an attitude
such as this can be risky.
There is the very real possibility that information (eg as to
whether specific anti-pollution technologies are practicable) may be set in stone in a
BREF without sufficient feedback from the shopfloor. Such
technologies could later return to haunt the industry if
the licensing authority inserts
additional clauses in the licensing procedures which it is
difficult, if not downright impossible, to have deleted because they are detailed in the
BREF.
Input based on a critical
he author, Christian Tebert, is employed by Ökopol
(www.oekopol.de; e-mail: [email protected]), a Hamburgbased business consultancy that devises international concepts
and strategies for promoting effective environmental protection
in internal workflows. A qualified engineer, Mr Tebert specialises in the practical, conceptual and strategic aspects of corporate
environmental management, not only for trade associations and
corporations but also on behalf of the EU commission and Germany’s Ministry for the Environment. His expertise in issues
relating to print is backed by a wealth of experience gained in
monitoring licensing procedures and optimising environmental
performance at numerous printing plants in Europe and Latin
America. He is co-author of a paper on the current state of technology in the German print industry which Ökopol produced at
the request of the German government for the Seville Process on
the BREF embracing printing plants
(http://www.umweltbundesamt.de/uba-info-medien/dateien/
2457.htm).
review of the draft BREF can
help to avoid this. For example, in alliance with its member corporations the ERA
alone has made 93 submissions to the EIPPCB challenging the adequacy or accuracy
of declarations contained in
the BREF.
Opportunities
Quite apart from this,
actively supporting the exchange of information in
Seville offers a number of opportunities. For German entrepreneurs, one of these is the
possibility of having Germany’s more rigorous environmental standards incorporated
in the pan-European regulating system, which would help
to level the playing field. Another is that reviewing the
draft BREF and the reference
parameters it contains can
broaden your outlook while at
the same time sharpening
your focus on your own
operations. Experience has
shown that this can help you
to spot untapped potential for
optimising your production
flow.
We therefore strongly recommend you to keep abreast
of the debate on the BREF
concerning print. For further
information log onto the
IPPC
website
(http://
europa.eu.int/comm/environment/ippc/index.htm)
or
download the draft BREF
from the EIPPCB website
(http://eippcb.jrc.es/pages/
FActivities.htm. Click on
Utilities and Members, then
on Direct Access to Public Areas, where you will find a list
of documents).
Support your local trade
association in defending your
interests in the European forum by submitting relevant
reference data to the panel experts.
Your contact for waterless
offset is Manfred Hamann
([email protected]),
who is a member of the
EWPA.
Christian Tebert
Ökopol
Handling | KBA and Metronic Presses
Highly productive yet easy to operate
This chapter provides a run-down of the winning features incorpo-
handling, which makes for a pleasant working environment while
rated in the waterless and keyless presses that bear the KBA and
promoting an optimum print quality, peak productivity and maximum
Metronic labels. The most fundamental of these is their ease of
flexibility.
Smaller footprint…
E
liminating water delivers two substantial
benefits: the printing
units take up less space, because the entire dampening
train has been stripped out,
and they are much more
accessible. Easy access to the
inking unit and other subassemblies is a feature common
to all KBA and Metronic
waterless presses.
If, in addition to this, the
number of rollers in the inking
unit can be reduced by replacing the ink keys and vibrator
roller with an anilox roller
that applies a predefined volume of ink, this makes press
operation even simpler. Also,
ink feed can be automated to a
greater or lesser degree with
cartridges and pumping systems to suit the size of the
press line and the consistency
of the ink.
…frees up space for new
constellations
The compactness of the
inking units is reflected in the
overall dimensions of these
new-generation presses, and
this is perhaps the most striking visual feature of the Genius 52, the 74 Karat and the
Cortina. Since both the footprint and the headroom occupied by a press must be paid
for, these presses offer a
genuine competitive advantage purely by taking up a
smaller volume of space.
Not only this, a compact
design also enables innovations in the printing process
and press ergonomics to be incorporated which would not
be economically feasible with
a conventional design. These
include the Cortina’s ingen-
ious Stepin system, which facilitates maintenance work at
the press by making the blanket cylinders and washing
bars freely accessible: the two
halves of the four-high tower
simply glide apart at the touch
of a button.
The major benefits that
can be gained with KBA and
Metronic waterless, keyless
presses are detailed below to
illustrate how the various innovations have been implemented in waterless offset.
Dieter Kleeberg, Georg Schneider,
Mike Engelhardt, Peter Benz
Metronic CD Print, Premius and oc200/oc100
M
etronic can claim a
pioneering role in developing the first practical applications for waterless offset
in conjunction with keyless
inking. Some years ago the
company collaborated with
KBA to develop an inking
unit capable of applying special UV inks to non-absorbent
materials. The system that
emerged, which Metronic has
dubbed a four-roller system,
more accurately comprises an
anilox roller, an ink-forme
roller, the plate cylinder and
the blanket cylinder, plus the
ink duct. The fact that all the
rollers and cylinders have
the same circumference effectively eliminates ghosting.
Operating presses fitted
with these four-roller inking
units is as simple as the inking
Metronic’s CD Print: on the right the feeder with rails and CD/DVD
magazine, in the centre the printing unit flanked by the four inking units
unit design itself. Their compact dimensions shrink the
footprint and thus the area of
costly production space required. They are equally at
home in long, ultra-narrow
press lines with multiple
printing units or other
processing stations.
This technological innovation enabled Metronic to
corner two high-growth markets: printing CDs and DVDs
with its CD Print and Premius
presses, and plastic cards with
its oc200 and the entry-level
version, the oc100. Waterless
offset delivers a much better
image on such substrates and
at much higher speeds than
the previous processes used,
which were usually silkscreen and pad printing. The
CD Print and Premius use
silk-screen printing only to
apply a solid primer on CDs
and DVDs. The choice of
peripherals – white primer
coater for CDs and DVDs,
cleaning systems, static eliminator, primer applicator for
plastic cards, intermediate
dryers – is virtually the same
for waterless UV offset as for
traditional UV processes.
One of the many benefits
of UV printing – whether with
or without a UV coating – is
that even non-absorbent materials can be finished without delay. For card printing
Metronic offers its univerSYS
KBA Process
2 | 2005
55
Above: Automatic register-true plate insertion at the
Metronic Premius
A slimline Metronic oc200, shown here with
(from the right) a diagonal feeder magazine for two
parallel card streams, a card-cleaning module, a primer module,
six printing modules, a coater, a UV dryer and a delivery or tumbler module
inkjet personalisation system
which can print names or
codes etc, apply labels and
even heat-stamp scratch-off
foil (eg PIN codes or codes to
activate prepaid cards for mobiles phones) onto multi-colour preprinted cards. The
UDA150-S heat-stamping device is available as an alternative.
Since they are designed
for small print formats the
modules are relatively small
and handy. Plate changing –
which is automatic even on
the Premius – could hardly
be simpler. Makeready and
maintenance tasks are reduced to an absolute minimum and the plate cylinder
is aligned automatically in
register. Parallel substrate
streams in the oc200 (with
automatic tumbling prior to
re-insertion in the feeder
magazine for perfecting) and
the ability of the Premius to
accommodate CDs with nonstandard contours are features
that could only be implemented in small dimensions
such as these.
56
KBA Process
2 | 2005
The Metronic Premius has serial
printing modules for printing data
storage media
The transport system in Metronic’s
Premius works partially by air
suction and can adapt to different
shapes, so the press can print data
storage media with non-standard
contours
Metronic CD Print
Printing process
Printing units
Inking units
Temperature control
Plates
Inline finishing
Substrates
Substrate transport
Controls
Automation
waterless UV offset for printing optical data storage media
choice of 4 to 6 push-in modules in one unit
Metronic’s keyless, ghosting-free four-roller system
anilox rollers and plate cylinder
all makes of waterless plate, digital and analogue
screen or flexo for white primer or coating; UV dryer after printing unit, primer/coater unit
plastic data storage media in standard thicknesses
on conveyor belts
console with swivelling touch-screen
• plate cylinder alignment at press standstill
• roller, blanket and cylinder washing
• central touch-screen setting/adjustment of process parameters, initiation of print run and washing cycle
Maximum rated output 6,000 discs/h
Formats
• standard CDs and DVDs, non-standard sizes optional
• offset plate format 253 x 150 mm; 0.15 mm thick
Dimensions L x W x H 6,486 x 2,920 x 1,820 mm (4 printing units)
Metronic Premius
Printing process
waterless UV offset for printing optical data storage media
Printing units
4 unit-type
Inking units
Temperature control
Plates
Inline finishing
double flatbed screen printing unit for white primer and coating or spot colour; UV dryer after each printing unit
Substrates
plastic data storage media in standard thicknesses
Substrate transport
shape-adaptable suction system for one-up or two-up
Controls
console with swivelling touch-screen
Automation
• complete register-true plate change in 5 mins
• central touch-screen setting/adjustment of process parameters, initiation of print run and washing cycle
• optional Code Check (reads data storage media code in feeder) and Print Check
(pre-delivery image quality control)
Maximum rated output 7,200 discs/h
Formats
• standard CDs, DVDs, mini-discs and non-standard shapes (CD business cards), non-standard sizes optional
• offset plate format 404 x 150 mm; 0.3 mm thick
Dimensions L x W x H 5,400 x 1,300 (with feeder 2,180) x 2,570 mm
Metronic oc200/oc100
Printing process
waterless UV offset for printing plastic cards
Printing units
4 to 6 unit-type modules, in the oc100 two split inking modules (for 2 parallel print passes Y+C and M+K
or 1 pass with two colours)
Inking units
Temperature control
anilox rollers (also in coater) and plate cylinder
Plates
Inline finishing
oc200: waterless offset module for applying primer before first printing module, coater after last printing module,
intermediate UV dryer after each primer/printing/coating module, end-of-press UV dryer; oc100: separate passes
for primer and coating
Substrates
plastic cards (ABS, PVC, PET, PC, PS) 0.5 mm (optional 0.35 mm) to 1.2 mm thick, with and without cavity
(pre-embossing for chips etc)
Card transport
oc100/oc200: magazine for 500 cards, 2 parallel substrate streams on belts; oc200: automatic return after
tumbling for perfecting pass
Controls
console with swivelling touch-screen at delivery
Automation
• plate cylinder alignment at press standstill
• optical double-sheet and cavity control
• central touch-screen setting/adjustment of process parameters, initiation of plate changes, print run
and washing cycle
Maximum rated output oc200: 15,000 cards/h 4 colours plus coating; oc100: 12,000 cards/h 2 colours or 6,000 cards/h 4 colours plus
primer and coating passes
Formats (portrait)
• ISO format cards 85.5 x 54 mm
• plate format 150 x 150 mm; 0.15 mm thick
Dimensions L x W x H oc200 standard version 10,540 x 755 x 2,400 mm, oc100 4,640 x 700 x 980 mm
KBA Genius 52 and Metronic Genius 52 UV
T
he Genius 52 furnishes
a level of versatility that
many players in the popular
B3 (20”) format had long
been seeking in vain. Its winning features include convenient one-man operation, short
walking distances, a futuristic
design, the automation of all
essential functions (including
register-true plating-up and
blanket washing), fast job
changes with just a few sheets
start-up waste, high-quality
reproduction (even of challenging images, thanks to a
winning combination of temperature-controlled waterless
offset and ghosting-free keyless inking units) and the ability to handle an exceptionally
wide range of substrates from
paper and cartonboard with
the standard KBA version to
various types of plastic film
with the UV version available
from Metronic. The Genius
52 raises the bar in small format by offering printers an
effective tool for implementing standardised, high-quality
print production.
A footprint of just nine
square metres (97ft2) for a
four- or five-colour press
complete with auxiliaries –
what better way to cut overheads! KBA is planning to
offer an aqueous coater at a
later date as an alternative to
the optional fifth printing
unit. The printing units and
keyless inking units are
positioned around a central,
quadruple-size
impression
cylinder. This not only saves
space and allows easy access
to all the components but also
guarantees that the sheets are
printed in one gripper bite and
thus in precise register. For
quality reasons the ink-forme
rollers are fitted with a blanket. They need no adjustment.
The press can be accessed
for operational, cleaning and
maintenance tasks by simply
raising the guards over the
inking units and delivery and
pushing the side guards apart.
The Genius 52 fits five colours into a
much smaller space than is possible
with a unit-type press
The ghosting-free inking units are grouped as V-shaped assemblies around a quadruplesize impression cylinder for a low-curvature sheet run and one-bite impression
Even the control console with
touch-screen display can be
slid from one end of the press
to the other, so the console is
within easy reach at every
stage of production. The display can be angled up or down
for greater convenience. The
press operator needs to learn
just a few easy-read data
screens containing basic production data and press settings.
Automation is viewed not
as an end in itself but as a tool
for enhancing cost-efficiency,
and has been incorporated
only where it is most logical
for makeready, handling and
quality control purposes. One
example is the automatic
plate-changing facility featuring a new type of pneumatic
lock-up and register system
which guarantees registertrue plate mounting. The new
plates are fed into the changing shafts while the guards
are still in place and then
mounted automatically. No
further register correction is
normally required. Even so,
the press also features automatic adjustment of the
sidelay and circumferential
register. The latter may, for
example, be necessary when
switching from paper to board
or vice versa.
At the end of the print run
the used plates are ejected by
pushbutton into the changing
shaft and removed manually.
One feature that distinguishes
the Genius 52 from rival
presses is that the plates for
the original job can be re-used
for repeat jobs. On a four-col
When open, the KBA Genius 52 and Metronic Genius 52 UV afford easy access
to the inking and printing units for operational and maintenance tasks
KBA Process
2 | 2005
57
The automatic plate-changing system for the Genius 52 features a new type
of pneumatic lock
The touch-screen console can be slid from one end of the press to the other
for maximum convenience
our press a complete plate
change takes less than five
minutes, on the five-colour
version around six minutes.
Individual plate changes, eg
for imprinting different languages with the fifth printing
unit in an existing four-colour
set, can be initiated at the control console.
The sheets are guided
from the infeed pile over the
suction-belt feed board to the
infeed by a high-performance
stream feeder with rear-edge
separation and cantilevered
suction head. The infeed incorporates electropneumatic
skewed and missing sheet detectors. The sheets are then
transferred to the impressioncylinder grippers via a double-size infeed drum. The
oversize diameters of the
infeed drum and impression
cylinder allow rigid substrates
such as cartonboard and
synthetics to be transported
smoothly, with minimum curvature. The sheets are trans-
A
46 Karat
lthough the 46 Karat
digital offset press was
not developed by KBA (it is
based on Ryobi’s 3404 DI),
there are certain similarities in
the basic concept. Like the 74
Karat it has a triple-size central impression cylinder and
double-size plate and blanket
cylinders. Since each plate
cylinder holds two plates only
two imaging heads are needed
instead of four, which cuts
costs. Although the 46 Karat
does not have keyless inking
units, it is nonetheless extremely compact, with the
same footprint as a conventional two-colour press. Print58
KBA Process
2 | 2005
ferred to the delivery pile by a
chain-gripper system with an
integrated powder sprayer. A
vacuum sheet brake and sheet
jogger for the side and rear
edges ensure precise stacking.
Test sheets can be removed at
the touch of a button.
KBA Genius 52 and Metronic Genius 52 UV
Printing process
waterless sheetfed offset for printing commercials and labels or waterless UV sheetfed offset for printing
plastic film and cards
Printing unit
1 four-colour satellite (V-shape) with central quadruple-size impression cylinder (register-true impression in
one gripper bite), 5th colour optional
Inking units
keyless, ghosting-free KBA/Metronic (full-solid densities and tonal values to ISO 12647)
Temperature control
Plates
all makes of waterless plates, digital and analogue
Perfecting
n/a
Inline finishing
coater instead of 5th inking unit (in preparation); coater and UV dryer on the Genius 52 UV
Substrates
paper and lightweight board; non-absorbent substrates (plastic film, composites, metal-coated materials)
on the Genius 52 UV
Substrate thickness
0.06 to 0.35 mm; 0.1 to 0.5 mm (0.8 mm optional) on the Genius 52 UV
Controls
sliding console with swivelling touch-screen
Automation
• complete register-true plate change in less than 5 mins
• blanket washing, optional doctor-chamber washing, cleaning plate for inking unit
• central touch-screen setting/adjustment of format, substrate thickness and plate cylinder registration, initiation of
plate changes, print run and washing cycle
Maximum rated output 8,000 sph, depending on substrate and image
Formats (landscape)
• max. sheet size 360 x 520 mm
• min. sheet size 210 x 297 mm (A4)
• max. print format 350 x 510 mm (10 mm gripper margin), 340 x 500 mm with the Genius 52 UV
• Plate format 404 x 540 mm; 0.3 mm thick
Pile heights
at feeder 500 mm, at delivery 400 mm; optional nonstop pile change
Dimensions L x W x H 2,300 (UV 4,170) x 3,278 x 1,906 mm (incl. touch-screen/steps, excl. air cabinet, cold water unit and
optional Creo Lotem 200K CTP thermal platesetter)
ers who opt to replace their
original kit with a 46 Karat
benefit from KBA’s acknowledged high standard of global
service and support while enjoying some exclusive features such as compatibility
with Epple’s new aniva inks,
which have an expanded
gamut and are available in
conjunction with the relevant
software and digital proofing
device as part of a “Power
Mix” package.
The user-friendly design of the
46 Karat includes easy-change rolls
of polyester plates
The 46 Karat features
Presstek’s ProFire on-press
imaging units and consumes
PEARLdry Plus laser-ablative polyester plates fed from
a spool inside each plate cylinder. Used plates are wound
onto a second spool inside the
same cylinder. This system
ensures correct mounting and
register-true impression. The
plates are imaged at a speed of
18,000rph with the plate cylinders disengaged from the
inking units and sheet transport system. All four colours
can be imaged at a resolution
of 1,270dpi in just 140 seconds.
The 46 KaratPLUS launched
at Drupa 2004 features an
even finer imaging head, La-
ser ProFire Excel, which is
compatible with frequencymodulated screens and consumes dedicated Presstek
polyester plates. New software for the inking program
cuts start-up waste still further
by ensuring that the ink profiles are set correctly immediately the program is actuated.
A new prestacking system
46 Karat and 46 KaratPLUS
Printing process
waterless DI offset for printing commercials
Printing unit
1 four-colour satellite (V-shaped) with central triple-size impression cylinder (register-true impression
in one gripper bite) and 2 double-size plate and blanket cylinders (two-up mounting of Y+C and M+K)
Inking units
Ryobi with zone-wide metering (14 rollers incl. 1 vibrator and 4 ink-forme rollers)
Temperature control
plate cylinder
Plates (spool)
Presstek PEARLdry Plus, for the 46 KaratPLUS Presstek ProFire Excel Media (both polyester)
On-press imaging
• Presstek ProFire multibeam thermal laser ablation, for the 46 KaratPLUS Presstek ProFire Excel
• max. resolution 2,540 dpi at min. laser spot of 2 µm (80 lpc screen), min. Excel laser spot 16 µm
(120 lpc and FM screen)
• digital front-end (Presstek DI rip) for embedding in PDF or PostScript workflow with digital proofing
scenario
(incl. KBA “Power Mix” option for Konica Minolta CF 9001 to simulate aniva-Euro inks)
Perfecting
n/a
Inline finishing
none, but IR dryer
Substrates
gloss- or matt-coated paper, lightweight cartonboard
Substrate thickness
0.06 to 0.3 mm
Controls
console beside the delivery
Automation
• plate mounting from four rolls integrated in the plate cylinder (28 jobs) and spooling of printed plates
(30 s for all 4 colours)
• roller, blanket and plate cylinder washing
• central setting/adjustment at the console of ink-key profile (scan densitometer optional) and initiation
of plate changes, register-true imaging, print run and washing cycle
Maximum rated output 7,000 sph, depending on substrate and image
Formats (portrait)
• min. sheet size 100 x 90 mm
• max. print format 450 x 330 mm (imaging area); 0.18 mm thick
• film 340 mm wide, 0.18 mm thick
Pile heights
400 mm at feeder and delivery
Dimensions L x W x H 3,280 x 1,970 x 1,680 mm (incl. steps, excl. console, air cabinet, cold water unit)
T
he 74 Karat targets media, pre-press, offset and
digital print providers looking
to establish a second line of
business at the short-run end
of the quality offset market or
those who in the market for
proof and pre-production
printing.
Over the past five years
the 74 Karat’s outstanding
performance has gained it a
reputation for superior quality
and cost-efficiency in a broad
span of run lengths. It was the
first sheetfed offset press to
feature keyless, ghosting-free
inking units. Its winning features include double-size
plate and blanket cylinders
with two-up mounting and a
triple-size impression cylinder, which make this B2 (29”)
press much more compact
than a four-colour unit-type
press for the same sheet size.
Like the Genius 52 and 46
Karat, the 74 Karat prints the
sheets register-true in a single
gripper bite.
74 Karat
The Presstek PEARLdry
aluminium plates are retrieved automatically from
the storage cassette, mounted
and imaged in precise register. All four plates are imaged
simultaneously by two imaging units fitted with Creo’s
thermal ablation lasers which
are noted for their superior
imaging quality. Imaging
from RIP is an integral part of
the one-man press operation,
which means it is actuated and
monitored by the press operator. A complete job change –
Compact, neat and easily accessible:
that’s the 46 Karat
enables a fresh pile of sheets
to be prepared while the press
is still running, either for the
same job in the case of an extended print run, or for the
next job. The 46 KaratPLUS
also boasts a new, high-performance power-sprayer, the
WEKO AP110, which is more
efficient and consumes less
powder than its predecessors.
Automation modules include a washing system for
the inking rollers, blankets
and plate cylinders, with
plates cleaned using a roll of
cloth, not a spray.
washing the blankets, changing, imaging, cleaning and
inking the plates – takes
around 17 minutes, depending
on the complexity of the print
job. Fast average makeready
times, together with a low
maximum start-up waste of
ten sheets, means that jobs
can be scheduled and costed
with much greater precision.
Below: The inking units, ink
cartridges and plate magazine on
the 74 Karat can be easily accessed
by opening the door-like cladding at
the back of the press. The photo
shows the press operator inserting
an ink duct
The 74 Karat is a four-colour sheetfed offset press designed
for one-man operation
KBA Process
2 | 2005
59
Left: The quickchange ink
cartridges for the
74 Karat support
continuous ink
pumping with very
little ink waste
Right: In order to
clean the coater
or change the
coating blanket
the 74 Karat press
operator must
open the cladding
on top of the press
Print production can be
embedded in a PDF or PostScript workflow complete
with direct digital production
proof and remote or internetassisted softproof scenarios.
This, in tandem with the calibrated printing parameters of
the Gravuflow inking units,
makes it possible to predict
and reproduce the final print
with 100% accuracy and supports standardised quality offset print production at no
extra cost, both in-house and
at remote locations for distribute then print. Many 74 Karat
users have developed new
business lines that would previously have been rejected as
uneconomic or impossible to
implement.
An integrated aqueous
coater, in conjunction with an
IR or hot-air dryer above the
delivery, was brought on the
market at Ipex 2002, and
since then all new buyers of
the 74 Karat have opted for
this version because the coating not only gives the prints a
higher gloss but also allows
them to be passed through the
press a second time almost
straight away or bound and
otherwise finished in roughly
an hour. Since the sheets are
guided to the impression cylinder in such a way that they
are printed on the underside
60
KBA Process
2 | 2005
but delivered print side up,
there is no need to tumble the
pile for a second pass, regardless of whether the same set of
plates is to be used or new
ones with on-press imaging.
And with the feeder and delivery both at the same end of the
press all the operator has to do
is rotate the pile horizontally
180° and insert it beneath the
stream feeder. This makes
handling much easier and
saves a lot of unnecessary legwork. The operator only has
to go to the other end of the
press for cleaning and maintenance work, to check the level
of the ink (which can be read
through a window in the door74 Karat
Printing process
Printing unit
like cladding on the rear of the
press) and to change the ink
cartridges.
The 74 Karat can be
configured with an optional
package for printing plastic.
This includes sheet guides
to accommodate thicker substrates (also suitable for
cartonboard), modified washing units, a static eliminator, a
dedicated set of ink ducts (so
there is no need to waste time
cleaning out the original ducts
when changing the ink),
blankets with modified ink
transfer properties and, of
course, special inks and aqueous coatings. The package
enables the press to print a
wide variety of plastic cards
even without a UV capability.
The 74 Karat made a big
impact on visitors to Drupa
when it printed lenticular
images (3-D, flip-flop and
animation effects) with the
aid of Litho3D Karat software
supplied by HumanEyes
Technologies.
waterless DI offset for printing commercials, labels, packaging and pre-production runs
1 four-colour satellite (V-shaped) with central triple-size impression cylinder (register-true impression
in one gripper bite) and 2 double-size plate and blanket cylinders (two-up mounting of Y+C and M+K)
Inking units
keyless, ghosting-free Gravuflow (full-solid densities and tonal values to ISO 12647)
Temperature control
Plates
currently only Presstek PEARLdry (aluminium), Creo plates in preparation
On-press imaging
• Creo thermal laser ablation with 40 IR laser diodes per imaging head
• max. resolution 2,540 dpi with min. laser spot of 15 µm (80 lpc screen minimum)
• digital front-end (Creo Brisque) for embedding in PDF or PostScript workflow with digital proofing scenario
Perfecting
n/a
Inline finishing
integrated aqueous coater with IR/hot-air dryer
Substrates
gloss- or matt-coated paper, lightweight cartonboard; with plastic package medium board,
composites and plastic film
Substrate thickness
0.06 to 0.3 mm, with plastic package 0.5 mm
Substrate weights
60 to 350 gsm, with coating from 90 to 350 gsm
User interface
at console and delivery
Automation
• plate infeed from two 20-plate cassettes (for 10 jobs), ejection of used plates
• washing units for ink-forme rollers, blankets and impression cylinder
• central setting/adjustment at console of format, substrate thickness and registration, initiation of
plate changes, register-true imaging, print run and washing cycle
• ink pumping from 2 kg cartridges
Maximum rated output 10,000 sph depending on substrate and image, with coater 8,000 sph
Formats (landscape)
• min. sheet size 297 x 210 mm
• max. print format 735 x 508 mm (image area)
Pile heights
600 mm at feeder and delivery
Dimensions L x W x H 3,880 x 2,310 x 2,400 mm (incl. coater, excl. console, air cabinet, cold-water system)
I
n contrast to the 74 Karat
the Rapida 74 G targets
printing plants with a thermal
CTP workflow in place. By
uniting the best of the Karat
and the Rapidas it may safely
be said that KBA has redefined the standard in B2. Users enjoy the full benefits of
the 74 Karat’s Gravuflow inking technology, which eliminates ink-related presetting
and thus not only reduces job
changeover times at the
Rapida 74 G but also takes a
lot of the stress out of press
operation by running up to
saleable colour in just ten
sheets and maintaining absolute colour and register consistency both throughout the
entire print run and from one
run to the next. It is also virtually ghosting-free and therefore reproduces immaculate
solids. These highly desirable
Karat properties have been
combined with those of the
Rapidas’ more versatile unittype construction, which offers a choice of two to eight
printing units (with or without
a delivery extension), perfecting at any point in the printing
sequence and the ability to
handle a wide range of substrates and apply a variety of
individual or serial coatings
(aqueous, primer, UV, special
effects; solid and spot).
The Rapida 74 G unveiled
at Drupa 2004 is, of course,
based on the new-generation
Rapida 74, which has much
more to offer than a visual
makeover. A high-performance stream feeder reliably
separates any type of stock,
from lightweight paper to
rigid plastic. The multi-chamber vacuum system in the
suction-belt feed table automatically adapts to substrate
thickness and guides the
sheets with absolute precision
to the rotary infeed. This comprises a suction drum, a
single-size feed drum and a
double-size transfer drum
which can be skewed to compensate for badly cut sheets.
The gripper systems on the
Rapida 74 G bearer press are
set in such a way that the com-
KBA Rapida 74 G
The fact that this Rapida 74 G is used for printing all kinds of plastic can be
seen at a glance: it is configured with a Corona tower, four printing units with
Gravuflow inking units, a coater and a delivery extension. A new air-cleaning
system (ACS), which substantially reduces dust and emissions, is positioned
above the closed delivery hood
plete range of substrates can
be processed with no manual
adjustment. The 7 o’clock arrangement of the double-size
impression cylinder and blanket cylinder ensures that the
sheets are always fully printed
prior to transfer or perfecting,
which minimises sheet-run
problems and enhances print
quality. Optimised fan settings for a contact-free sheet
travel can be stored at the
Ergotronic console for each
type of substrate and job. The
press can be converted from
straight to perfecting mode,
and vice versa, in less than
two minutes.
The optional equipment
available for printing board
and plastic includes a capacitive and ultrasonic doublesheet detector, special guide
rollers, dedicated sheet guides
that control the sheets by running along the outer edges (so
there is no contact with the
image area), static eliminators, Teflon coatings on the
cover lays and – exclusive to
KBA – a Corona tower.
The Corona tower, available
exclusively from KBA for Rapida
presses, increases the surface tension
of plastic substrates a few
milliseconds prior to impression,
to enhance their ink acceptance
properties. This enables less expensive,
untreated plastics to be used
KBA Rapida 74 G
Printing process
Printing units
Inking units
Temperature control
Plates
Perfecting
Inline finishing
Substrates
waterless sheetfed offset for printing commercials, labels and packaging
choice of 2 to 8 in unit-type design, 7 o’clock cylinder configuration
keyless, ghosting-free Gravuflow (full-solid densities and tonal values to ISO 12647)
currently only Toray Waterless
freely selectable
optional coater/double coater with various types of coating, modular dryer system (IR, hot-air/cold-air, UV)
lightweight paper to cartonboard and non-absorbent substrates (plastic film, composites, metal-coated
materials); optional package with Corona tower for plastic and cartonboard
Substrate thickness
0.06 to 0.5 mm or 1 mm as option
Controls
at Ergotronic console and delivery
Automation
• SPC register-true plate-changing system
• washing system for Gravuflow/ink-forme roller, blanket and impression cylinders
• total integration in KBA Opera and JDF scenario possible
• central setting/adjustment at the console of format, substrate thickness and circumferential/sidelay/
diagonal register (optional Automatic Camera Register Control), initiation of print run and washing cycle
• ink pumping from 2 kg cartridges
Maximum rated output 15,000 sph depending on image and job (even with 8 printing units and perfecting)
Formats (landscape)
• max. sheet size 520 x 740 mm in straight and perfecting
• minimum sheet size 210 x 297 mm straight, 300 x 297 mm perfecting
• max. print format 510 x 730 mm (10 mm gripper margin), 500 x 730 mm in perfecting
• plate format 557 x 743 mm (copy line 24 mm)
• blanket format 630 x 745 mm
• coating format for blanket 565 x 750 mm, coating plate 565 x 740 mm
Pile heights
standard: 1,100 mm at feeder and delivery; options: 1,350 mm and nonstop facilities
Dimensions
and other features as for Rapida 74
KBA Process
2 | 2005
61
KBA Cortina
The Cortina would not exist
without Peter Benz (left) and
Georg Schneider, two of the R&D
team at KBA responsible for
developing and optimising waterless
and keyless offset for newspaper
production
T
he Cortina is arguably the
most revolutionary press
that KBA has developed since
the company founders mechanised print production almost
200 years ago. The first newspaper press worldwide to
unite waterless, keyless and
gearless offset technology in a
uniquely compact form, it
represents a step-change in
printing technology. Its avantgarde concept incorporates a
raft of innovations that deliver
unprecedented benefits with
regard to ease of operation,
environmental performance,
cost-efficiency and reproductive quality.
Above all, taking the waterless route has, at a stroke,
eliminated or sidelined many
of the issues that have plagued
wet offset newspaper production ever since its inception
and given rise to ever greater
complexity. These include an
excessive volume of startup waste, operator-dependent
print quality, preparation of
the fount solution, the setting
and maintenance of dampening units, ink/water balance,
the degree of emulsification,
ink contamination, poor ink
take-up, inconsistent colour
reproduction, press contamination from ink mist, and water-induced fan-out (lateral
web stretch between one
printing unit and the next) re-
Before the plates can be mounted in
the Cortina – either semiautomatically or with KBA’s
optional automatic system,
PlateTronic A – they must be bent
at both edges
sulting in fluctuations in web
tension and thus registration.
With the Cortina, these process weaknesses – the stuff of
nightmares for operators of
coldset wet offset presses – no
longer cause fear and trembling in the presshall. Other
press parameters that could
previously give rise to untold
problems have been reduced
to a manageable level, even
when the press is running at
high speeds.
All this has been achieved
by focusing on essentials and
by dispensing with the need
for ever more complex (and
thus ever more vulnerable)
technical
and
electronic
compensation systems. The
systematic development work
involved in bringing waterless newspaper offset to commercial maturity included
more than 350 ink tests and
consumed more than 1,500
reels of paper.
With the automatic plate feeder developed for the Cortina the plates merely have to be inserted in the changing shafts,
the rest is done via an opto-electronically controlled pneumatic system
(photos: KBA)
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The uniquely compact design of the Cortina newspaper
press supports a high colour
content and high pagination
in a minimum of space. Its
modular construction enables
the press to be configured to
suit presshall architecture: as
a single-floor inline version,
eg for erection in a standard
industrial building, or as a
substructure version with one
main operating level and the
reelstands located beneath.
Left and above: the use of blanket
plates instead of standard blankets
enables the cylinder gap to be
reduced to a minimum, hence the
term minigap. The blankets are
clamped on pneumatically
The pneumatically operated clamp
for automatic plating-up on a
minigap cylinder
1 Leading Edge us plate
2 Hose (airless)
3 Clamp with claw spring
The superstructure and folder
also contribute to the overall
compactness. Where there is
sufficient headroom, two
3.7m (12’) four-high towers
can be stacked with supplementary foundation to create
an 8.4m (27’6’’) eight-high
tower.
Above: Semi-automatic plate
changing is a standard feature
of the Cortina
Below: Once the blanket plate has
been inserted the self-adjusting
clamping system goes into action
The ability to configure
presses as compact eight-high
towers also enables fullcolour flying imprint changes
to be carried out much more
cost-effectively than was
previously possible. This versatility – and the possibility
of integrating computer-topress imaging systems at a
later date – is supported by the
design of the printing units,
which are gearless, oil-free
and incorporate dedicated
AC drives for each cylinder
and inking unit. The same
versatility also supports distribute-then-print scenarios
in tandem with digital data
transmission and on-site computer-to-plate.
Automated plate changing
is another winning feature.
All the plates are pre-bent at
both edges. The plates for the
next edition can be placed
ready for mounting at the
printing couples while the
current edition is still running.
With an automatic plate
feeder the press operator
merely has to insert the plates
in the relevant feed magazine:
they are then mounted pneumatically, in register, within
a matter of seconds. If a semiautomatic plate-changing system is in place the operator
must position the plates by
hand precisely at the infeed.
Both systems automatically
eject the used plates.
The blanket and plate cylinders have been specifically
engineered to minimise vibration. The cylinder gap for
pneumatically mounting the
plates and blankets (which are
in fact blanket plates) has
been reduced to just a few
millimetres. This minigap, already well-proven in KBA’s
Compacta commercial press
lines and new Commander
6/2 newspaper presses, reduces the risk of streaking on
wide webs and at high press
speeds.
Despite their compact design the printing units are remarkably easy to access for
maintenance work, eg blanket
changes. Pressing the relevant
button causes the two halves
of the four-high tower to glide
apart. KBA has called this
system Stepin because the operator can enter the printing
unit as easily as if he were
stepping through a door. If the
inking rollers need changing,
the inking units can be partially swung down.
The Cortina features automatic roller locks and an
integrated blanket washing
systems to ensure a consistently uniform print quality
and a minimum of manual
tasks during cleaning and
maintenance work. The roller
locks in the Newsflow keyless
Left: Stepin – at the touch of a
button the printing unit splits down
the middle between the blanket
cylinders and the two halves
glide apart
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63
Plate cylinder
Anilox roller
Above: Automatic roller locks in the Cortina (shown here without the inking
units) ensure that the ink rollers are set correctly at all times.
Left: Configuration of the roller lock system:
1 Rubber-coated ink-form roller,
2 Rilsan roller,
3 Rubber roller;
A Journal for ink-forme roller,
B Pneumatic cylinder on/off,
C Clamp for roller lock,
D Clamp for rubber roller,
E Roller lock,
F Roller bearing
(photo: Kleeberg)
inking units guarantee that the
rollers are always set correctly, both relative to each
other and to the plate. And the
blanket washing units, which
are available with rolls of dry
or pre-moistened cloths, ensure that the blankets are always cleaned thoroughly.
A labour-saving chain
web-up system feeds the web
in to a superstructure and
folder that are just as compact
and operator-friendly as the
rest of the press. The turner
bars are equally neat and ergonomic. There is a choice of
two proven folders: the KF 3
or KF 5. These are the only
subassemblies in which oil
still features.
The Cortina’s advanced
console
technology
and
module-based
automation
system enable it to be linked
to a management information
system (MIS). The relevant
interfaces for newspaper
production workflows are
included in the KBA Opera
networking software.
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Right: The four stacked printing
units can be easily accessed via a lift
KBA Cortina
Printing process
Printing units
waterless coldset web offset for printing newspapers and semi-commercials
freely configurable for 16, 32, 48, 64, 80 pages in compact four- or eight-high towers, glide-apart Stepin
system, flying imprint options, each unit 4/4 blanket-to-blanket, dedicated drives for cylinders and
inking units (world first in offset: no oil in the press), low-vibration minigaps in plate and blanket cylinders
Inking units
keyless Newsflow with 2 ink-forme rollers (full-solid densities and tonal values to ISO 12647)
Temperature control
STC (Surface Temperature Control) for anilox rollers and plate cylinders; full-solid density controlled via
temperature control curves
Plates
Toray Waterless, Presstek PEARLdry and KPG Scorpion, successful tests with prototypes from other
manufacturers
Reelstand/infeed
depending on configuration 32 to 96 pages with 1 to 6 KBA Pastomat reelstands (incl. Pastomat RC
for reel diameter of 1,500 mm); labour-saving chain web-up system
Web leads
vertical in all printing units
Superstructure
compact turner bars and former
Inline finishing
length and cross perforation, KBA KF3 (2:3:3) or KF5 (2:5:5) jaw folders, ribbon and section stitchers,
quarterfold etc
Substrates
all customary standard and improved newsprint
Controls
1 to 2 high-tech consoles, remote panels at printing units
Automation
• automatic or semi-automatic register-true plate changing system for pre-bent plates (PlateTronic A optional)
• washing system for anilox/ink-forme rollers and blanket cylinders (Baldwin, Elettra)
• total integration in KBA Opera possible
• central setting/adjustment at console of temperature controls, format, substrate,
roller locks and circumferential/sidelay register, initiation of print run and cleaning cycle
• choice of instrumentation and control systems (eg colour and cut-off register)
• ink pumping via pipe system
• setting of roller locks
• optional imprinter, flying plate changes for 4/4 possible
Maximum rated output 80,000 cph in straight-run production
Formats
freely selectable within single and double width, eg
• beta press at reiff in Offenburg, Germany: 1x16 pp section in Berliner format, 4/4 throughout,
max. web width 1,260 mm, cylinder circumference 940 mm, cut-off 470 mm
• first installation at Rodi Rotatiedruk in Broek op Langedijk, Netherlands: 3 four-high towers for
48 pp broadsheet or 96 pp tabloid, 4/4 throughout (1 tower with automatic plate changing),
max. web width 1,680 mm, cylinder circumference 1,156 mm, cut-off 578 mm
Height
3.7 m for 4-high tower with 1 operating level (fits in many existing industrial buildings), 8.4 m for 8-high
tower with 2 operating levels, with or without substructure for reelstand
Applications | Statement
Waterless offset is still a topic of
much debate. Does it really
exist, is it dying out – or do
we no longer notice it because
it has long since become part
Where does waterless offset
stand today?
of the mainstream? This chapter
argues that the waterless movement is stronger than ever
before.
T
he only difference is
that the process has
taken a route that noone could have foreseen ten
years ago. The catch-phrases
of that time, such as “colour
brilliance”, “reduced dot
gain”, “superfine screens”,
“generous ink film thicknesses” and “simply the best
image quality”, still apply today. But advances like direct
imaging, thermal CTP, anilox
or short-train inking technology, water-based inks, waterless newspaper production,
UV curing etc have since been
added – in other words technologies that would be difficult to take on board without
waterless offset and in which
it has established a firm foothold. Whereas ten years ago
there were fewer than 100
“hardcore” waterless offset
operations in Germany, now
there are well over 800.
Commercial printing
Where are these users,
what do they print and what
substrates do they handle?
First of all there is the abovementioned hard core. These
include commercial print operations of all sizes, with
presses ranging from one to
12 colours in various formats
and analogue or digital prepress. They primarily exploit
the quality and cost benefits
of waterless offset, though
naturally environmental and
health considerations also
play a key role: waterless off-
At Drupa 2004 KBA demonstrated
its new Rapida 74 G on the marks3zet stand
(photos: Kleeberg)
set is the only technology that
makes it possible to print any
substrate while at the same
time totally eliminating alcohol and alcohol substitutes.
Digital printing
Then there is digital offset. It started out as a rare and
tender little shoot, now it is
being cultivated by a whole
battalion of prominent manufacturers. And it has culminated in KBA’s successful
launching of the 74 Karat and
46 Karat. Both of them waterless presses with on-press
plate imaging – a technology
which, though not undis-
puted, prevents copy shops,
xerography and similar systems from monopolising the
field of digital print and significantly expands the capabilities of digital workflow
integration compared to conventional offset with CTP
pre-press. And at present no
all-digital printing system is
capable of processing such
enormous volumes of data in
such a short time as a digitally
integrated waterless offset
press.
Carton printing
Another of waterless offset’s domains is a niche appli
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65
Applications | Statement
costs than in conventional wet
offset – not to mention greater
customer loyalty through a
better print quality. The
EWPA is working on this
project with the German
equivalent of the UK’s H&SE
and USA’s OSHA as well as
with various other EU environmental agencies, and is
keen to preserve objectivity.
Two eight-colour presses, one
waterless and one conventional offset, with similar job
structures are to operate at a
prominent industrial printing
plant for a period of one year.
Both presses are well
equipped for the relevant
process; the wet offset press
will print with reduced alcohol levels. The study should
produce some interesting
results, and could well give
waterless offset a major boost
if the direct comparison
proves that the system benefits are reflected in economic
benefits as well.
cation, more specifically print
production on all types of
non-absorbent substrates. For
example, around 95% of all
telephone, credit and customer cards produced today
are printed in waterless offset:
laminated cards on conventional sheetfed offset presses,
and single-ply or injectionmoulded cards on special waterless presses – a field of
business in which KBA’s subsidiary Metronic has been
successful for many years.
Label, packaging and data
storage media printing
The situation is similar in
the self-adhesive label sector.
Since new packaging regulations came into force in Germany it has been compulsory
to apply labels that match the
product, eg polyester labels
on polyester shampoo bottles,
so as to make it easier to sort
and dispose of waste products. Here waterless UV offset has established a place
alongside the more costly gravure and silk-screen printing
processes. It primarily plays
to its system strengths of low
waste levels, which with expensive substrates can deliver
substantial savings. Manufacturers of narrow-web label
printing presses have been
quick to pick up on this and
now offer very few presses
with dampening.
Another field of application is deep-draw packaging:
there is scarcely a margarine
tub that is not printed in waterless offset. And if you are
wondering how high-quality
full-colour images are printed
on CDs and DVDs, you can
have one guess.
Outdated criticisms
Despite all these demonstrations of success the
Gordian knot in commercial
print production has still not
been cut, although industrial
applications of waterless offset are now no longer in question. What is the reason?
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As the German importer of Toray plates and the associated handling
systems, marks-3zet was an early pioneer of waterless offset in
Germany and Europe
(photo: Kleeberg)
For a long time one argument was the dependence on
just one plate manufacturer.
But now the incumbent provider, Toray, which offers a
complete range of analogue
and CTP plates, has been
joined by US manufacturers
Presstek, with its digital
PEARLdry plate, and Kodak
Polychrome Graphics (KPG),
also with a digital thermal
plate. As waterless offset becomes more popular, other
plate makers are sure to move
in, especially since the original patent held by Toray for
waterless plates has now expired.
A
further
argument
against waterless offset is the
cost of plates, which is much
higher. You would think that
with more manufacturers in
the market the price would
fall. However, this has not
been the case, since the plates
are more expensive to make
and sometimes entail a vac-
uum environment and as
many as six coating passes
and may still have a high volume of rejects. This is because coating with silicone is
one of the most challenging
coating techniques around
and no manufacturer has yet
succeeded in dispensing with
silicone as the ink-repellent
layer for waterless plates.
A German pioneer and importer of Toray plates, marks3zet in Mülheim a.d. Ruhr,
never tires of emphasising the
need to compare not just plate
costs but the entire production
costs.
The European Waterless
Printing Association (EWPA)
is currently conducting an
ambitious project to determine whether the notably
large savings in developing
chemicals, dampening additives, alcohol, start-up and
production waste and press
makeready can result in similar or even lower production
Outlook
In the middle of last year
Toray started up a new, much
more efficient platemaking
line. As soon as water-based
inks attain commercial maturity, making powder-free print
and high-speed offline/inline
finishing in sheetfed presses
more convenient than ever before, no-one will be able to
deny the compelling arguments in favour of waterless
offset. Soon or later other
keyless presses will range
alongside KBA’s Genius 52,
74 Karat, Rapida 74 G and
Cortina, eliminating colour
fluctuations, ghosting and ink
fade. If press operation and
running costs are cut dramatically, waterless offset will
gain further momentum.
Hans-Joachim Koch,
Technical director, marks-3zet
Applications | Examples
Waterless applications in
commercial, packaging and plastic
printing
Waterless offset in general, and with keyless inking in particular, can
special inks on non-absorbent substrates both feature strongly. KBA
open up whole new fields of application. In this scenario, presses
and Metronic have developed systems suitable for widely diverse
with integrated plate imaging and presses with the ability to apply
markets, and a few examples of these are described below.
Leading the field in
waterless technology
But although provision
for waterless operation is
made in all big Rapidas, those
that actually run without
dampening are the exception
rather than the rule. There is a
much broader acceptance of
waterless offset in half- to medium formats. Scandinavia, in
particular, which has a more
fragmented print industry and
rigorous legislation concerning VOC emissions, has seen
several installations of waterless Rapida 74s and 105s over
the past few years. Some
of them print plastic with
Toracard TF inks from
Zeller+Gmelin. Combining as
they do the superior sheet
travel and application flexibility of the Rapidas with all
the benefits of waterless offset, they are a natural progression from the wet offset
Rapidas that have already
demonstrated their prowess in
plastic printing with UV inks.
K
BA and its subsidiary
Metronic are the sole
purveyors of waterless, keyless offset technology in the global market,
having pioneered its development with farsighted determination. Through strategic
alliances with major manufacturers of ink, plates, blankets, paper, screen rollers and
other components they have
created innovative printing
systems that not only enhance
the quality of traditional offset production but also materially expand the range of
applications for which it can
viably be used. Once the 74
Karat and Metronic presses
had proven their competitive
edge, further systems were
developed to commercial
maturity. The most recent of
these are the Genius 52 and
Rapida 74 G sheetfed offset
presses and the Cortina newspaper press.
Conventional waterless with
KBA Rapida…
When considering the
new, broader applications
possible, the KBA presses
that were modified rather than
developed specifically for
waterless offset should also
be taken into account. In principle, the entire Rapida sheet-
Top: A new Rapida 74 G at Swedish media enterprise Cela Grafiska prints all
kinds of commercials. Bottom: The four proud proprietors at the press
(photos: Clever)
fed offset range – from the B2
(29”) Rapida 74 to the size 7
(63”) Rapida 162a – can operate dampener-free provided
the presses are connected to a
temperature control system,
and this is why they are preequipped with interfaces for
adding the relevant subassemblies at a later date. The
biggest waterless plate format
currently available, 1610 x
1240mm (631/2” x 483/4”)
from Toray, is suitable for use
on large-format KBA presses,
most of which already feature
temperature control in order
to stabilise the wet offset
process in dimensions such as
these.
…and keyless with the
Rapida 74 G
Not surprisingly, Scandinavia is where the world’s
first users of the new Rapida
74 G are to be found. Fitting
the Rapida 74 with Gravuflow
inking units delivers both
quality and efficiency benefits
in commercial, cartonboard
and plastic print production.
One major argument that is
often put forward in favour of
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67
The Rapida 74 G at Swedish
packaging specialist Eson Pac prints
drug packaging (photo: Eson Pac)
waterless printing is the low
volume of start-up waste,
which is just ten sheets maximum. On top of this the Rapida 74 G’s unit-type design
affords greater flexibility than
the 74 Karat in configuring
the press (which can thus include multiple printing units
plus perfecting and coating
options). Rated press speed is
also faster. The printing plants
targeted are those:
• specialising in commercial,
packaging and niche applications (eg plastic printing in
offset or silk-screen);
• seeking to enhance their
cost-efficiency, productivity
and quality in short-run scenarios;
• wishing to retain the flexibility a unit-type press can
deliver;
• or with CTP systems in
place and a need to change
plates faster than is possible
with the 74 Karat and its onpress imaging.
The pilot press, which was
put through its paces at Drupa
2004 on the marks-3zet stand,
was shipped directly from the
show to Swedish print media
enterprise Cela Grafiska in
Värnersborg. The four-colour
coater version at this 20-employee advertising agency
turned commercial printing
plant replaced a conventional
sheetfed offset press. Cela
prints just about anything that
can be put to paper or board
for the commercials and packaging its customers specify.
“As soon as the Rapida 74
G was unveiled, we knew it
was the press for us,” says
Joachim Friberg, one of Cela
Grafiska’s four owners. “Its
format, broad substrate range,
four-colour capability with
inline coating option, its superior print quality and – thanks
to its waterless offset technology – low tolerances within
the print run were just the
ticket for the jobs we handle.
With the Rapida 74 G we can
compete on price both in
smaller formats and in bigger
formats up to B1. This is because our customers are now
confident that the proof and
print will be identical. The
quality delivered, especially
in image and solids reproduction, beats other offset presses
hands-down.”
Another Swedish printer,
folding carton specialist Eson
Pac, went straight for a brace
of Rapidas 74 Gs and now
prints waterless on two fivecolour versions with inline
coating at its drug packaging
plant in Varberg. The third
Scandinavian print enterprise
to put a Rapida 74 G into operation, in this case a six-colour with dual coating, is
Hojrup Eskefabrik in Glamsbjerg, Denmark.
At present a number of
UV inks are being tested for
compatibility with the Rapida
74 G. So the range of substrates it can print will expand
even further by the end of the
year.
Digital offset with the
74 Karat…
The 74 Karat digital offset
press was developed specifically for waterless sheetfed
offset with on-press imaging.
Many users opted for the 74
Karat because they wanted to
embed the press in an all-digital workflow. Its technology
Below and left: Configuring the 74 Karat with a coater and IR/hot-air dryer
enables users like Aug. Heinrigs Druck und Verpackung in Aachen, Germany,
to exploit new business opportunities. Alongside runs of polyglot drug
packaging the company mainly prints advance runs of cosmetic packaging
where the colours must match colours printed in UV wet offset
(photos: Kleeberg)
Above and left: Another German printer, Huwig in Riegelsberg, prints
magazine bodies and covers, promotional literature and even sticky labels on
its 74 Karat
(photos: Stein)
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…now for plastic film too
These high-quality drinks labels with
imitation woodgrain print were
produced on the 74 Karat at Grid
Studio in Belgrade, Serbia
(photo: Kleeberg)
is designed to ensure that no
“analogue back-doors” are
left open, as they are with
presses that merely connect
wet offset with direct imaging
technology. This philosophy,
together with the total automation of plate-mounting and
imaging sequences and the
calibration of essential parameters with Gravuflow technology, enables users to
standardise their B2 production processes.
The 74 Karat targets:
• offset print entrepreneurs
wishing to print short to
medium runs of four-colour
promos and packaging;
• digital print providers looking for a cost-effective means
of addressing the high end of
the market for short- to medium-run colour;
Hans Huhn, managing director of
Merkur in Leipzig, Germany,
displays a six-up film sheet for
mousepads, printed on a 74 Karat
with plastic option
Cartridges of Zeller+Gmelin’s
Toracard TF ink and a set of ink
ducts stand ready for high-speed ink
changes on the plastic printing
version of the 74 Karat at Merkur
(photos: Kleeberg)
A new 74 Karat with plastic printing
package at DigiGraf, an advertising
agency with pre-press department in
Bologna, Italy, enables the company
to print jobs that previously had to
be outsourced. The photo shows
DigiGraf proprietor Andrea Caroli
(2nd r) flanked by (from the left)
Daniele Sangalli of KBA-Italia, KBA
sales director Thomas Kagemann
and Falk Sparbert, also of KBA
(photo: KBA)
• pre-press and media service
providers wishing to develop
new lines of business;
• silk-screen, flexo and UV
printers wishing to combine
waterless offset with evaporative inks for printing plastic,
metallised and lenticular film
and composites more costeffectively.
No matter what your company’s original line of business and investment targets
may be, the creation of proofs
and advance runs are another
option which the cost-efficiency and the standardised
workflow of the 74 Karat
have revived and made profit-
able – an example of how new
technologies can create new
markets. Most users have now
included such services in their
portfolios.
Since an integrated aqueous coater with IR/hot-air
dryer became available for the
74 Karat all new buyers have
specified this option. Inline
coating allows the sheets to be
passed through the press a
second time without delay
and/or finished much sooner.
It also improves abrasion resistance by protecting the surface, while the higher gloss
level enhances the visual impact of the prints.
The plastic printing version, which operates with inks
that dry by evaporation,
would not be possible without
the coater. One of the ink series approved for the Karat is
Zeller+Gmelin’s Toracard TF,
which is already used in
Metronic’s Genius 52 UV for
film printing. The siliconefree Toracard TF inks are
suitable for printing PVC
(polyvinyl chloride), ABS
(acrylonitrile-butadienestyrene), PC (polycarbonate),
PS (polystyrene) and PET
(polyethylene terephthalate),
enable very fine screens to be
printed, can be easily laminated and expand at the same
rate as the substrate when subjected to IR radiation. It has
been found that ink transfer is
best with UV-resistant blankets.
The aqueous coating must
also be specially formulated
for plastic film. KBA recommends a water-soluble protective PVC coating, Tipadur
Printcoat P-1203 B3, which
was formulated specifically
for the 74 Karat by Tippl in
Vienna.
The first 74 Karat press to
feature a plastic printing
package was installed in August 2003 by one of the biggest specialist printers of synthetic materials in the USA,
Serigraph of West Bend, Illinois. Merkur Druck- und
Kopierzentrum in Leipzig,
Germany, followed suit four
months later. This option expands the range of printable
substrates to include bank,
telephone and customer cards,
mousepads and decorations,
banners and price tags, document sleeves and covers,
packaging and display components, labels and tags, calendars and teaching materials,
projector and lightbox films.
The cards are printed in multiup production and can subsequently be finished by embossing or applying memory
chips, for example.
“Plastic is not just plastic,” explains Merkur md
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69
In conjunction with HumanEyes software
the plastic printing version of the 74
Karat can print lenticular film to create
3-D effects (ice cream), animated
sequences (swan) and flip-flop images
(Stitch)
(photos: KBA)
Hans Huhn, speaking from
his experience with various
types of film. “Films can differ a lot in the static charge
they generate, their printability and expansion under
heat. The smoothest, in the
truest sense of the word, is
Pentaprint.” A PVC film from
the
Klöckner
Pentaplast
group in Montabaur, Pentaprint is available in matt,
gloss, reinforced white and
clear.
Hahn continues: “Even
with a static eliminator, a
residual charge will always
remain in the film. If the production schedule permits, the
piles are allowed to rest for
at least a day.” He is well
pleased with his 74 Karat and
stands by his decision to add a
plastic-printing option. “Adding this capability enabled us
to raise our competitive profile and expand our client
base, as the large number of
new orders and prospects
shows. Quality and cost-efficiency are a huge improvement on silk-screen, though
you have to keep a close tab
on the cost of ink and blankets, which is higher than
in silk-screen, and on job
changeover times. But this
option will boost our bottom
line, there’s no doubt about
that.”
At Drupa 2004 KBA demonstrated lenticular printing
powered by HumanEyes Litho3D Karat software. In a
matter of minutes, using a
Dutch printer Jansen Drukkerijen
in Gilze organised an open day to
promote the 46 Karat it has
installed alongside its 74 Karat
(photo: KBA)
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standard commercial digital
camera, images were created
and printed featuring 3-D,
animated or flip-flop effects.
…and the 46 Karat
Many of the 46 Karat’s
properties are the same as
those of its “big sister”, the 74
Karat: on-press imaging, register-true four-colour printing
in one gripper bite, a superior
print quality, the ability to
handle substrates ranging
from lightweight paper to
light carton-board, and a competitive price-performance ratio for short to medium runs,
not just of four-colour products but of mono and two-col-
our products as well. The 46
KaratPLUS version unveiled at
Drupa 2004 boasts Presstek’s
new ProFire Excel laser system which enables it to print
even finer screens, stochastic
included.
The 46 Karat is unique
among waterless offset presses in that it can operate with
Epple’s exclusive aniva Euro
(or in America aniva Standard) ink series. The pigment
particles for the relevant
standard scale are exceptionally finely ground and cluster
together more densely in a
non-mineral binding agent,
so less light is scattered. This
means that higher colour
densities (C 1.9, M 1.8, Y 1.7,
K 2.4) can be achieved with
an ink layer which is very little thicker than normal, expanding the offset colour
gamut into that of a photographic print. So there is no
need for special inks. KBA offers support in the form of a
complete aniva package comprising an instruction manual,
comprehensive on-site training, dedicated software and a
standardisation test form. It
also offers existing and prospective users of the 46 Karat
and 74 Karat practical seminars on digital offset (workflow and applications) and
digital pre-press (eg sheet assembly with Preps, colour
management).
An
expanded
colour
gamut and moiré-free screening are essential for a photographic-quality print. They
enable 46 Karat users to compete successfully not only
against direct rivals operating
Gloor Cross Media in Munich is the
proud owner of a 74 Karat and a 46
Karat with “Power Mix” package.
Here press operator Bernd
Lommatzsch checks the match
between the digital proof off a
Konica Minolta CF 3102 and a
sheet off the 46 Karat (photo: KBA)
A 46 Karat at Die Drucker Agens &
Ketterl in Vienna, Austria, prints the
cast lists for the city’s world-famous
state opera
(photo: Kleeberg)
A combination of colour management and Epple’s aniva Euro inks enables the 46 Karat at Laser Litho4
in Düsseldorf, Germany, to print photographic-quality images
(photos: KBA)
other DI offset presses in the
same format but also against
printers addressing high-end
markets with large-format
presses.
A special option offered in
association with quick-drying, rub-resistant aniva inks is
known as “Power Mix” and
embraces a digital proofing
scenario with an embedded
printing and copying system
from Konica Minolta. Colour
management profiles can be
used with the toner-based system to output digital proofs
which faithfully simulate the
images delivered with aniva
inks. It enables the client to
be offered the alternative of
having ultra-short runs and
personalised prints produced
even more cheaply on the
proofing device instead of on
the 46 Karat. However, the
contrast in toner-based prints
is less pronounced and the
colours less brilliant than in
waterless offset.
One example of a printing
house that has successfully
implemented the Power Mix
package in the press room is
Laser Litho4 in Düsseldorf,
Germany, where a Konica
Minolta CF 3102 copying
system with an output of 31
colour pages a minute is in
operation. Before buying the
kit the company checked out
other toner and inkjet proofing systems with regard to
colour fidelity, print quality,
substrate flexibility and costefficiency, but soon came to
the conclusion that the Power
Mix package delivered the
best results.
Commercial printing with the
KBA Genius 52…
The compact and flexible
Genius 52 for the popular B3
(201/2”) format furnishes
sheetfed offset printers with
an economical and innovative
production tool for four- or
five-colour print production
in short to medium runs. The
“The Genius has enormous potential. It can print four jobs an hour,
each with a run length of up to 1,000 sheets, and is cost-effective for
a workload of just over five jobs per day.” Patrice Flahaut,
managing director of Access Printing in Paris and a pioneer user of
the KBA Genius 52
(photo: KBA)
Genius 52 is especially attractive for printing plants and
pre-press businesses that already work with thermal CTP
or are planning to invest in it
but for operational or other
reasons wish to maintain their
analogue plate lines rather
than invest in a DI press in
this format. But it could also
be the answer for printers
seeking a more space-saving
alternative
to
unit-type
presses or a versatile but more
economical and less complex
press for quality short-run
print production in B3.
The Genius 52 enables
small-format printers to upgrade their commercial portfolio and offers large-format
printers a passport to smaller
formats, eg for printing magazine covers or short runs of
paper products and lightweight cartons.
At Drupa 2004 KBA and
Creo signed an agreement
bundling the Genius 52 with
Creo’s Lotem 200K thermal
platesetter in Europe, the
Middle East and Africa, with
Creo providing support with
marketing, sales, installation,
training and after-sales service. For Toray plates KBA
recommends a plate processor
from marks-3zet, the Cessor
KTW 650-G.
…and plastic printing with the
Metronic Genius 52 UV
The waterless UV version
of the Genius 52, manufactured by Metronic, can be
used to print plastic film.
Metronic’s sales team has primarily focused on winning
accounts in the card printing
market, which is booming.
Here the magic formula is
smart cards – plastic cards
with transponders, microprocessors and/or magnetic strips
as safety features for cashfree payment. Customer and
discount cards are another, increasingly popular, application. The explosive expansion
Right: Metronic’s Genius 52 UV
delivers a superb print quality on
plastic cards such as the smart cards
on this sheet
(photo: Metronic)
Below: The Genius 52 at Dutch printer
PrintGroep Cuijk near Nijmegen runs up to
saleable – and precisely predictable – colour
in a maximum of just ten sheets (photo: KBA)
KBA Process
2 | 2005
71
Two parallel copy streams allow the
Metronic oc200 to work and turn
piles of cards using the same colour
imposition in the second pass as in
the first
(photo: Metronic)
of mobile telephony worldwide is compensating for
stagnant sales of telephone
cards by cranking up demand
for SIM cards for charging or
operating mobile handsets.
Metronic’s many satisfied users in this sector include such
prominent specialists as Inplastor in Sweden (the printing arm of the biggest card
provider in northern Europe,
XPonCard Group), IPT Printing in Lebanon (one of the
leading printers of telephone
and bank cards in the Middle
East) and NamITech in South
Africa (the biggest producer
of plastic cards in Africa, in
alliance with Giesecke &
Devrient).
Metronic is expanding its
sales activities to target further applications because the
Genius 52 UV is just as suitable for printing promotional
products such as mousepads,
lenticular film, show cards or
pocket diaries. Other potential
products are organisational
tools (schedules, year planners etc), document covers
and files, plastic labels and
teaching aids (eg rulers and
maps). Another niche market
with strong growth potential
is plastic tags, for example the
plant tags inserted in the pots
delivered to nurseries and
DIY stores. Plant tags, like
ISO format cards and pocket
diaries, are all printed in
multi-up production.
Specialist UV waterless print
applications from Metronic
Metronic’s specialist focus on plastic printing presses
is evident in its card-printing
A flexible, high-performance disc
transport system makes the Metronic
Premius a universal printing system
for optical data storage media
(photo: Metronic)
72
KBA Process
2 | 2005
Easy access, short makereadies and photographic-quality prints are the
benefits enjoyed by users of Metronic’s CD Print
(photo: Metronic)
presses, the oc200 and entrylevel oc100, and by its CD
presses, the CD Print and the
Premius. Like the Genius 52
UV, all four presses incorporate waterless UV offset technology. Metronic has also
developed inkjet-based digital
printing systems, some of
which, for example the
univerSYS and imprinters for
personalisation, are also used
to print cards.
The oc200 can be configured with up to six printing
modules and inline-coating
modules. Makeready takes
around 20 minutes. In recent
years the press has enabled
Metronic to expand its lead in
the card printing sector, with
reference installations at the
world’s leading card and
security print specialists –
Axalto, Gemplus and Giesecke & Devrient.
Prominent names also feature in the user list for presses
to print optical data storage
media. The four- to six-colour
CD Print, for example, is in
action at electronics giants
Pioneer and Canon Video,
while the four-colour Premius
was the press of choice for
Sony. For the long print runs
which are routine at such big
companies there is no cost-effective alternative to offset,
which is used here in conjunction with other processes, eg
for applying a pre-impression
white primer or post-impression coating. The CD Print
and Premius have an average
output of 6,000 to 7,200 discs
per hour. High-speed plate
changes on both presses make
them the more cost-effective
choice for shorter print runs.
Another compelling argument
for users is the photographic
print quality delivered by the
waterless offset technology.
The Premius, launched on
the market in 2004, sports a
high-performance disc transport system which is exceptionally flexible: not only can
it be loaded with single or
double lines, it also accepts
data storage devices with nonstandard contours. This enables it to print minidiscs and
optical business cards alongside DVDs and CDs. The
most popular extras available
with the Premius are a code
identification system and a
camera-based quality control
system.
Dieter Kleeberg
Applications | Cortina
Why should newspapers go waterless?
Changes in the media market
demand new mindset
The recent economic recession has impacted severely on advertising
spend and thus on newspaper revenues. At the same time advertisers
are demanding a near-commercial print quality, the internet is steadily eroding newspapers’ share of classified ads, and traditional print
media are struggling to attract young people focused on cyberspace
and mobiles. If newspapers are to maintain their prominent position
in the media arena they must cut their production costs and enhance
their appeal.
A Mecca for innovation-minded newspaper printers: the KBA Cortina that was in operation for two years at reiff zeitungsdruck in Offenburg
T
he ultra-compact Cortina tower press cannot
influence the editorial
or layout quality of a newspaper but its keyless waterless
offset technology can make a
substantial contribution towards enhancing print quality
and cost-efficiency.
Wet offset technology
ever more complex
Newspapers have been
printed in offset for almost 40
years now, on presses featuring
ink keys, roller-type inking
units and every possible type of
dampeners, and boasting an increasingly advanced level of
automation and ever higher
production speeds. A sizeable
proportion of the greater technical complexity involved is
concentrated in the systems for
presetting the inking units,
achieving the correct ink/water
balance and maintaining colour
registration during the produc-
tion run. When mono printing
was the norm this was no great
problem, but with the spread of
colour printing during the past
15 years, efforts to enhance immediacy by cutting production
times have resulted in an even
higher level of automation and
mounting pressure on the operator to deliver a high print
quality while at the same time
minimising waste.
Weaknesses are “normal”
In the good years, paper
costs arising from waste had
only a peripheral effect on
newspapers’ profit margins,
which were generally comfortingly wide. Start-up waste
numbering several thousand
copies – a level still encountered in a lot of printing plants
during full-colour production –
was shrugged off as the normal
state of technology.
Start-up waste levels of 50
or 75 copies trumpeted in promotions or even specified in
new contracts can only be
achieved in wet offset under
ideal production conditions and
with presses that have been laboriously prepared with a high
input of time and labour. They
cannot be achieved in daily
production with plates produced just minutes prior to the
production run. This is because
the image is influenced by too
many parameters and the individual capabilities of different
operators. Experienced printers
are well aware of this.
Even today, many members
of the industry consider it perfectly natural for the press operator to spend practically the
entire production run adjusting
Both newspapers and semicommercials can be printed in
waterless coldset on the Cortina
KBA Process
2 | 2005
73
only masked to a greater or
lesser extent. Some press operators are more skilled at doing this than others, but none
can produce a predictably good
print if the pre-press work is not
up to scratch. Corrections on
one page of full-colour ads are
inevitably followed by a quality
compromise on the subsequent
page. Such manual intervention
is scarcely in keeping with a
standardised, automated production flow.
Semi-automatic plate changers
guarantee fast, convenient edition
changes. With automatic plate
changers, the plates for the next job
can be placed in the feed shafts
during the current production run.
A complete plate change takes less
than 100 seconds, regardless of the
number of plates. Computer-to-press
cannot compete on either cost
efficiency or time
the ink keys and dampener
settings at the console in order
to compensate for real or
perceived deviations from the
optimum ink/water balance.
Temperature control is considered by some to be totally
superfluous, even though it can
substantially reduce temperature-related fluctuations in
colour density and the number
of setting sequences required.
Received wisdom has it that
printing newspapers is not what
it used to be, so you have to put
up with a few comprises on
quality in coldset production,
don’t you?!
It’s no good carrying on
as before
Basically there are three responses: you can take the easy
way out and just carry on as before, accepting all the negative
phenomena of wet offset as inevitable; you can treat the unwanted side-effects by taking
on board even more complex
technology; or you can tackle
the root cause. Here, the first
step is to ask the question: “Is
this really the right way to maximise production and cost efficiency, user-friendliness and
quality?” As costs escalate and
revenues diminish, decision74
KBA Process
2 | 2005
Remote controls for setting the ink keys are sought in vain at the Cortina
console, because there are none
User-friendly and cost-effective: waterless newspaper offset with the
innovative Cortina. The photo shows the compact design of the four-high
tower relative to the Pastostar reelstand in the foreground
makers with their eye on the
long term are virtually being
compelled to address this basic
issue. KBA has certainly done
so, which is why the Cortina
was created.
Reducing process errors
Anyone with an inkling of
technology will appreciate that
the ease with which any given
process can be mastered is inversely proportionate to the
number of parameters influencing it. And no doubt most of us
have learned from experience
that the easiest and quickest
way to obtain a clear, predictable result is to have as few
people as possible bringing
their different perceptions and
capabilities to bear. So it follows that the core objectives in
developing the Cortina were
(and are) to reduce the number
of parameters and variables influencing the printing process,
to create consistently uniform
production conditions – even
during extended print runs – by
employing advanced technology and high-performance temperature control, and to free
hard-pressed personnel from
the constant need to intervene
in order to maintain the correct
ink/water balance.
Quality defined in pre-press...
In an age of computer-toplate and digital workflows,
print quality should be unambiguously defined in the very
first link of the production
chain, ie in pre-press. This is
because, however advanced the
printing press may be, imperfections or inaccuracies in the
originals and plates cannot be
corrected via the ink keys, but
...and reproduced faithfully
by the press
The answer is to eliminate
the parameters that cause these
problems – the dampening solution and ink keys – and to
control the temperature of the
inking unit throughout the production run. This, in conjunction with a huge reduction in
the ink train to just a doctor
blade, anilox roller and forme
rollers, guarantees a uniformly
high and freely reproducible
print quality. Not only is technology much more consistent
than people, whose form fluctuates from day to day, but waterless offset, by its very nature,
remains much more stable than
wet offset during the production run because there is no permanent conflict between ink
and water.
The Cortina functions as a
giant, high-powered “copier”,
and as such reliably reproduces, times without number,
exactly what is on the printing
plate. No more and no less.
Since the beta press was installed in Offenburg countless
newspaper printers have been
able to witness this for themselves. The 16-page press was
dismantled in autumn 2004 after successfully completing its
two-year test phase and will be
installed as a production press
at a small newspaper plant in
Lower Saxony in spring 2005.
New departure after 200 years
of roller inking units
200 years ago Friedrich
Koenig and Andreas Bauer,
founding fathers of Koenig &
Bauer AG, invented the rollertype inking unit with its greater
or lesser number of splitting
positions and adjusting keys for
zone-wide inking. There is no
doubt that, despite the associated difficulties, this inking
technology has proven its superior performance in sheetfed
and web printing alike for generation upon generation. Even
after 188 years, KBA still gen-
erates most of its income from
presses incorporating the fundamental inking system devised by its founders. Nonetheless, or perhaps precisely for
this reason, a new departure in
process technology such as
waterless and keyless offset
should not be dismissed out of
hand but should be accepted as
a profound and compelling solution by the world’s first and
most experienced press manufacturer to the changing issues
confronting the newspaper industry in the 21st century.
Although the press operator
at the Cortina has been “deprived” of two familiar tools,
ink keys and dampeners, he has
been given a good deal in exchange:
• more time for monitoring
quality,
• much easier press handling
and maintenance,
• less physical exertion during
makeready for the next edition
thanks to short distances and
high-speed automatic plate
changes,
• an excellent and freely reproducible print quality up to a
screen resolution of 60l/cm
(150lpi) on both standard and
improved newsprint,
KBA Cortina: configurations
The first Cortina to roll off the
production line – a 48pp single-floor
version – was shipped to Rodi
Rotatiedruk near Amsterdam
in late 2004
Above: Belgian newspaper printing
house De Persgroep in Asse, near
Brussels, is also making the
transition to waterless offset with
a big Cortina press line
Right: The Cortina for Rodi
Rotatiedruk will be followed in mid2005 by two 48pp Cortinas destined
for Freiburger Druck
(Badische Zeitung)
Baden-Württemberg’s leading publisher of gazettes and newsletters,
Nussbaum Medien in Weil der Stadt, is making the transition to waterless
offset with the purchase of a Cortina with automatic plate changing. The
German company, which took MAN’s first Dicoweb press, placed the order
for the keyless mini tower press following exhaustive tests and trial runs to
check its suitability for printing large numbers of low-circulation copies –
Nussbaum’s typical production scenario – cost-effectively and in a superior
quality
Dutch contract printer and
KBA user Dijkman Offset in Diemen
near Amsterdam has also opted for a 32-page Cortina
with automatic plate changers
KBA Process
2 | 2005
75
• a clean press environment,
no ink mist or water vapour,
• and an automatically minimised, stress-free waste level
during start-up.
In other words: far from
posing a threat to press operators, the Cortina relieves them
of routine tasks that are often
both arduous and dull. Their
skills are just as much in demand, but can now be employed to better effect.
A lot of questions,
but just one answer
Those who still find it hard
to accept the Cortina philoso-
phy, should work through the
following list of questions in
order to compare this waterless
offset press objectively with a
conventional wet offset press:
• How are waste levels, are
they lower?
• How is registration, is it more
precise?
• How is the print quality, is it
superior?
• How is web tension, is it less
of a problem?
• How is handling, is it less
complex?
• How is maintenance, is less
required?
• How is cost efficiency, is it
higher?
• How are emissions, are they
lower?
As far as the Cortina is concerned, all these questions can
be answered with a resounding
“yes”.
Conclusion
If waterless offset with the
Cortina in its current form had
been available 40 years ago,
then wet offset, with all its acknowledged technical shortcomings, would never have
been adopted for newspaper
production. That is something
decision-makers in the traditionally conservative newspa-
KBA Cortina: winning features
Compact design
• Just 3.7m (12ft) high, excluding superstructure
• Little or no investment needed in new buildings
• Easier handling, shorter distances
• No fan-out in full-colour production
• Space-saving option of eight-high tower
• Supports distribute-then-print scenarios
Waterless offset
• Less waste, consistently high print quality
• No problems with web tension
• No problems with ink/water balance
• Stress-free operation in continuous production
• Reduced emissions
• 60l/cm (150lpi) screen on standard and improved stock
Keyless inking unit
• More consistent colour reproduction, less waste
• Greater automation and standardisation, fewer variables
• No operator-dependent inking
• Identical print at multiple locations
• Optimum reproduction of pre-press quality
• Reduced labour input for press presetting
• No ink misting at high speeds
Dedicated cylinder drives
• Easy handling during makeready and maintenance
• Supports direct imaging at later date
• Fewer emissions (no oil, less noise)
Additional features/automation
• Fast, automatic temperature control (stored acceleration curves)
• Semi-automatic plate changers a standard feature to ease operation
• Optional automatic plate changers (change any number of plates in less than 100
seconds)
• Automatically adjustable roller locks reduce maintenance, promote uniform
printing conditions
• Glide-apart towers (Stepin™) afford easy access
• Minigaps on blanket cylinders for fast blanket changes
• Minigaps and pneumatic clamps on plate cylinders
• Cutting-edge console technology supports integration in digital workflow
76
KBA Process
2 | 2005
per industry would do well to
ponder. Some, in Germany,
Belgium and the Netherlands,
have already reached their own
conclusions and in the 12
months since Ifra Expo 2003 in
Leipzig have placed orders for
a total of 25 Cortina tower
presses. KBA’s success with
waterless in a challenging market climate should not be underestimated and, hopefully,
augurs a fundamental rethink in
the industry.
Klaus Schmidt
Outlook
The technology of the future
Even back in the early years of its shopfloor applications, waterless,
friendly process in keeping with the industry’s enhanced awareness.
keyless offset compellingly confirmed that it has the potential to sim-
Although there are still some challenges to overcome, the many draw-
plify the fundamentals of offset printing, make it more cost-effective
backs associated with wet offset since its inception all those years
and thus more competitive, and to re-invent it as an environmentally
ago have now been scaled back or even eliminated.
What has been accomplished
perior print quality are a recommendation in themselves. Support from a larger number of
plate manufacturers would promote a more rapid adoption of
waterless offset from which
everyone would profit. But
even with plate prices at their
current level, waterless offset
is, in many cases, still more
economical than wet offset.
Unfortunately, not all potential
users have reached the same
conclusion. This is because
they often consider plate costs
in isolation, instead of calculating total production costs. KBA
Process is an attempt to dispel
any lingering doubts by furnishing hard facts and background information.
N
otwithstanding the
sophistication of the
technology involved
and the quality it can deliver,
offset print production with
dampening is basically a relict
from the origins of indirect
flatbed printing. The ability of
the press operator to influence
inking via the keys – an ability
that dates back 200 years to
Friedrich Koenig’s invention of
the cylinder printing press – is
another relict. In view of the
widespread shortage of skilled
press personnel and a concomitant move towards standardisation and automation in the press
room, it can hardly be argued
that long ink trains with numerous ink-splitting points and
lateral oscillation are the
optimum, enduring technology.
There are too many process parameters to control, and this is
not made any easier by the
subjective perceptions of the
press crew. So there were
ample reasons for developing
an entirely new concept.
KBA and Metronic have
made a pivotal contribution by
advancing and simplifying offset with the introduction of waterless, keyless inking units. By
eliminating human intervention
and complex parameters that
are difficult to control they
have taken a vital first step towards transforming print production from a craft-based
process into a standardised,
highly automated industrial sequence. At last a move has been
made to bridge the gap between
the pre-press workflow, which
has long been based on standardised processes, and the postpress and mailroom workflows,
which are becoming ever more
highly automated.
Whether on a larger or a
smaller scale – with the KBA
Cortina or Metronic presses –
the subsequent benefits are
clear for all to see: a compact
footprint, rapid makeready and
minimum start-up waste, a uniformly high print quality
throughout the production run,
less manual intervention and
lower manning levels, time
gains for quality control and the
parallel preparation of the next
job, a more pleasant working
environment, substantial cost
savings and a dramatic reduction in emissions.
The advances that have
been made in inking technology are most conspicuous in
the Cortina. They are part of a
holistic concept aimed at redefining newspaper production in
the 21st century to make it more
cost-effective, ecological and
capable of delivering a quality
that is unsurpassed.
What must still be done
In print sectors where circulations are steadily diminish-
ing, waterless offset with
keyless inking furnishes an effective tool for protecting profit
margins. Nonetheless, it would
be presumptuous to claim that
its potential has already been
exploited to the full. Which is
why KBA and Metronic will
continue their pursuit of excellence in both the process and its
broader applications across a
raft of dedicated press platforms – witness the Rapida 74
G and Cortina.
An increase in the supply of
waterless offset plates on the
market would be more than
welcome, and certainly in the
interests of users. Although
prices have already come down
a lot, there is still room for further reductions, despite the
higher manufacturing cost.
KBA has declared its commitment to waterless technology
and has walked the talk with
heavy expenditure on R&D.
The insights it has gained from
the frontiers of waterless innovation have been distilled into
products like the Karat and
Cortina, whose success and su-
Prospects are bright
Waterless offset with keyless inking is more than just an
alternative to wet offset. As existing press lines are upgraded
or extended, the technology
may well displace wet offset for
many applications. Already,
KBA customers are increasingly exploiting the benefits
this innovative process offers in
order to differentiate their products in the marketplace by
boosting quality and cost-efficiency. They are deploying new
business models to corner or
carve out profitable niche markets by offering unique features
and an expanded substrate
capability. You can enjoy similar success if you are willing to
engage in this debate without
prejudice in order to determine
the technology that would be
most effective for your specific
enterprise.
Dieter Kleeberg
KBA Process
2 | 2005
77
Impressum
Koenig & Bauer AG
Würzburg Facility
Friedrich-Koenig-Str. 4
97080 Würzburg
Germany
Tel: +49 931 909-0
Fax: +49 931 909-4101
Web: www.kba-print.com
E-mail: [email protected]
Koenig & Bauer AG
Frankenthal Facility
Johann-Klein-Str. 1
67227 Frankenthal
Germany
Tel: +49 6233 873-0
Fax: +49 6233 873-3222
Web: www.kba-print.com
Koenig & Bauer AG
Radebeul Facility
Friedrich-List-Str. 47-49
01445 Radebeul
Germany
Tel. +49 351 833-0
Fax: +49 351 833-1001
Web: www.kba-planeta.com
Metronic AG
A member of the KBA Group
Benzstrasse 11
97209 Veitshöchheim
Germany
Tel: +49 931 9085-0
Fax: +49 931 9085-100
Web: www.metronic-ag.com
KBA Process
is a sporadic publication created to facilitate strategic investment
planning by providing detailed, practical information on the current
status and future prospects of new technologies and advances.
Publications to date: KBA Process No. 1
“Focus on Direct Offset on Corrugated” (1/2002).
Publisher:
KBA Group
(www.kba-print.com)
Editors:
Klaus Schmidt (KBA marketing director),
[email protected]
Dieter Kleeberg (Kleeberg & Stein), trade journalist, PR service
provider to the print industry, [email protected]
Authors:
Peter Benz (KBA)
Detlef Braun (Druck & Beratung WLUV)
Mike Engelhardt (KBA)
Andreas Harig (technotrans)
Dr Bernd Heusinger (KBA)
Dieter Kleeberg (Kleeberg & Stein)
Hans-Joachim Koch (marks-3zet)
Dr Matthias Müller (KBA)
Hubert Peick (technotrans)
Dr Karl Schaschek (KBA)
Klaus Schmidt (KBA)
Georg Schneider (KBA)
Christian Tebert (Ökopol)
Layout:
Jürgen Bender (KBA)
Translation:
Christina Degens-Kupp (KBA)
Product specifications and features may be changed without prior
notice. No part of this publication may be reproduced in any way
without the publisher’s permission and source data. Although registered trademarks, copyrighted and patented products are not specified as such, this does not mean that they are, or may be treated as,
public domain. Gravuflow™, Karat™, Newsflow™, Rapida 74
G™ and STEPIN™ are registered trademarks of Koenig & Bauer
AG. Metronic® is a registered trademark of Metronic AG.
If you wish to receive our free customer magazine, KBA Report,
and are not yet a subscriber, please contact Anja Enders in the
marketing department:
Tel: +49 931 909-4518
Fax:+49 931 909-6015
Printed in Germany
78
KBA Process
2 | 2005
KBA on ecological print production
Water is life
But not in print!
Sustainable development, the careful husbandry of valuable raw materials
and the conscious avoidance of waste and emissions: these are natural
commitments for any responsible entrepreneur. Which is why environmental
awareness is written into our guiding principles. And why we pioneer new,
more ecological technologies for sheetfed and web offset.
Economy and ecology need not be mutually exclusive – and we’re out to
prove it.
Koenig & Bauer AG, Würzburg and Radebeul Facilities, www.kba-print.com
Metronic AG, www.metronic-ag.com
KBA Process
2 | 2005
KBA_I_327_KBAProzess_d,e,f,i,sp
22.03.2005
9:05 Uhr
9:06
Seite 1
People & Print
From the inventor
of the printing press
Leading technology
KBA.I.327 e
Expanding the frontiers of print technology has been our driving force for
the past 188 years. Inspired by our founder, Friedrich Koenig, creator of the
world's first mechanical printing press in 1811. And culminating today in
our Rapida 74 Gravuflow sheetfed offset press, our 74 Karat DI offset press
and our compact Cortina waterless newspaper press.
KBA. Creator of presses with groundbreaking yet cost-effective technology
to keep you ahead of the field. Backed by the ingenuity and dedication of
7,800 employees and a wealth of know-how that is unique in its depth and
breadth.
Koenig & Bauer AG (KBA)
Würzburg, phone: +49 931 909-0, fax: +49 931 909-4101, e-mail: [email protected]
Frankenthal, phone: +49 6233 873-0, fax: +49 6233 873-3222, e-mail: [email protected]
Radebeul near Dresden, phone: +49 351 833-0, fax: +49 351 833-1001, e-mail: [email protected]
www.kba-print.com

KBA Process No. 2 english

Transcription

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