Sandvik steel belt systems for pressing, lamination and casting English

Sandvik steel belt systems
for pressing, lamination
and casting
Sandvik steel belt technology forms the basis
of all our single and double belt systems
Sandvik steel belts
around the world
Steel belt advantages at a glance:
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Durable
Hard, smooth surface
Temperature stability
Corrosion resistance
Ease of cleaning
Endless weld possible
Good wear resistance
High thermal conductivity
High tensile strength
Excellent repairability
Recyclable – steel belt can
be remelted
As a world leader in our field, we can deliver steel belts
in materials, grades and sizes to suit any steel belt-based
processing application, with a choice of finishes and
accessories to meet any special requirements.
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Various grades of stainless or carbon steel
Polished or plated surfaces
Side retainer and retaining strips
Perforations
Longitudinal welding (for belt widths > 2.0 m)
Steel belt-based solutions designed
to meet your process requirements
Double belt presses for plastics, fiber composites, thin films for high gloss lamination
and for flexible circuit boards
Sheet casting systems with temperature profiles for engineered stone/artificial marble
Film casting systems for filter membranes, ceramic and technical films
Our extensive experience in steel belt-based processing
technology – gained from manufacturing and installing
literally thousands of systems across the chemical and
food industries – has resulted in the development of a
range of advanced solutions based on either single or
double belt systems.
Process
Product types
Process applications
Pressing/
lamination
Fiber composites
Metal composites
Flooring
Thin films
Insulating panels
• Heating and calibrating
• Isochoric or isobaric
pressing
• Bonding
• Cooling
Sheet casting
Engineered stone/artificial
marble (based on acrylic,
polyester or epoxy resin)
Thermoplastic sheets
(PE, PP, PA, PVC, PET, etc.)
• Controlled heating and
calibrating
• Curing
• Cooling
Film casting
Filter membrane
Ceramic films
Membrane for solar and fuel
cells
Optical films
• Calibrating
• Drying
• Tempering
• Stretching
Double belt press for
fiber composites
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Sandvik double belt press –
multiple processes, a single solution
Isochoric
Isobaric
Characteristic
Constant, uniform volume
(gap is constant)
Constant, uniform pressure
(gap is defined by material
infeed tolerances and process)
Press type
Fixed roller, sliding shoe,
circulating roller
Isobaric
Thickness /
pressure
• Product thickness is
determined by belt gap
• Pressure depends on infeed
material tolerances
• Uniform material feed delivers
uniform product thickness
• Applied pressure remains
constant at all times
Pros
• Relatively simple design
• Relatively low investment costs
• Active gap control
• High pressure possible
• Thin product possible
• Active pressure control
Cons
• Limited suitability for thin products • Higher investment costs
• Pressure inside product is
• Greater requirement for
determined by the infeed
production know-how
material tolerance
Various press types
Type
Fixed roller
Circulating
roller
Structure
Isobaric
Sliding shoe
oil
Applied
pressure
0 Level
Max. pressure
Max. temperature
70 kN/m
(line pressure)
10 bar
70 bar
0.5 bar
280 °C, Air
350 °C, IR
350 °C, Oil
300 °C, Oil
350 °C, Oil
A complete, continuous production process can be
designed by combining different press modules in a single
double belt press. This ability to create a multi-stage
system incorporating controlled heating, cooling and
tempering – all within one press – enables the
development of highly efficient processing solutions.
These various press modules are available in the form of
pilot units at our test centers, enabling you to assess the
benefits of a double belt press solution using your own
products.
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Fixed roller
Isochoric double belt press
with fixed rollers
Double belt press for fiber composites
Fixed roller module
with air plenums
The fixed roller press is based on the simple calibration
principle and is ideally suited to low and medium pressure
applications.
However, as this type of press can also deliver extremely
high linear forces, it is also a viable alternative to more
complex high pressure presses.
Another important benefit of this press type is the low
friction of the rollers, which means that fixed roller
presses can be built to almost any length.
Typical applications
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Plastic fiber composites
Natural fiber composites
Thermoplastic sheets (PE, PP, PA, PVC, PET etc)
Engineered stone (acrylic / polyester resin etc)
Insulation boards for construction industry
(thermal & acoustic)
Other low pressure applications
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Circulating
roller
Isochoric double belt press with
circulating rollers
Isochoric double belt press with
circulating rollers
The circulating roller press provides the ideal solution
for the continuous production of glass fiber-reinforced
plastics such as GMT. In this process, the glass fiber mats
and plastics (PP/PE) are fed into the press and, through
the application of heat and pressure, the glass fiber is
impregnated with the molten plastic. The product is then
pressed, calibrated and cooled down under
pressure.
One of the key characteristics of the circulating roller
press is the close positioning of the rollers, creating
surface pressure on the product; this is an important
factor on products that create a back pressure.
The isochoric circulating roller principle is suitable for
low, medium and high pressure applications.
Typical applications
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Glass fiber-reinforced plastics
Ski laminates
Fiber composites for automotive and aviation
industries
Other applications requiring surface pressure
Isobaric
Isobaric double belt press
with hydraulic pressure cushion
The isobaric double belt system works according to the
hydrostatic principle; hydraulic oil is pressed directly
against the back side of the steel belts. This same oil is
used for the transfer of thermal energy required for
heating or cooling the product.
The isobaric system enables very high pressure to be
delivered uniformly. The Sandvik isobaric press works
with standard cold rolled steel belts as well as with
mirror polished steel belts for shiny film surfaces.
Typical applications
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Metal composites
Fiber composites
Flooring, decorative sheets
Thin films
High gloss films
Sintered products
Printed circuit boards (PCBs)
Sliding shoe
Double belt press
with sliding shoe technology
The Sandvik double belt
press can also incorporate a
module that uses heated or
cooled sliding shoes to
deliver highly efficient heat
transfer. The applied
pressure is minimal
(minimising wear of the
steel belt and platens) so
sliding shoe technology is
used in combination with
other press modules.
Typical applications
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Isochoric and isobaric applications
Flooring
Wood plastic composites
Thermoplastic laminates
Low pressure applications (up to 0.5 bar)
Flexible circuit boards
Sliding shoe technique
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Steel belt system for sheet casting
In this application, a compound consisting of differently
sized particles, colour pigments and resin is fed, in a
uniform layer, across the whole width of the lower of the
two steel belts.
The thickness of the product is then calibrated between
the upper and lower steel belts, while side retainers are
used to define the width of the sheet.
From here, the product proceeds through controlled
polymerization, curing and cooling stages before reaching
downstream longitudinal and transverse cutters which
are used to cut the material
to the desired size.
Product processing
Heating/tempering
Polymerizing
Single belt technology solutions are also available
Film unwinder
Polymerization
Curing
Cooling
Hot air
Cold air
or water
Film winder Cutting
Calibration roller
Raw material
Hot water
Hot air or water
Temperature
Exotherm
peak
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Product
engineered stone / artificial marble
The Sandvik double belt press system offers a number of
major process benefits compared with single belt systems
for this growing application:
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Symmetric conditions (processing from both sides)
Precise thickness calibration
Simple variation of product width
Transverse cutting
Double belt unit for engineered stone
Longitudinal cutting
Cooling
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Casting box
Extruder or feed pipe
Process:
Polymerization reaction
Feeding:
Casting knife
Heating:
Hot air or water on upper or
lower belt
Cooling:
Cold air or water on upper or
lower belt
Double roll feeder
Typical applications
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Engineered stone based on acrylic or polyester resin
Mineral sheets based on epoxy resin or PET
Thermoplastic sheets
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Single belt casting unit for thin films
and membranes
This steel belt-based casting system offers the chemical
processor a range of benefits including the ability to
produce microporous membranes of a quality
unattainable by any other method. It also offers
significant process and quality advantages to
manufacturers of different types of thin film products.
In the Sandvik film casting process, a polished steel belt is
coated with the liquid product. The cast layer is then
transported on the belt through a series of carefully
controlled process phases (usually involving heat and
mass transfer).
Once these processes have been completed, the solid
formed product is removed from the belt. At this stage
the product will be in either final or ‘green’ form, the
latter requiring further processing such as leaching or
directional orientation.
Advantages of steel belt technology
• Ultra-efficient continuous production
• Film thickness / flatness to fine tolerances
• High clarity
• Films can be made from materials which cannot be
thermoformed (e.g. polyimide)
• Multiple process zones on the same machine
• Very thin films
• Low stress in the formed film
• Complete polymerization
Heat exchanger
Product
Leach/extraction tank(s)
Air drying
Automatic
slitter and winder
Optical quality control
Post dryer
Typical applications
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Filter media – nitrocellulose-based material
Ceramic tapes for electronic industry
Membranes for fuel and solar cells
Pharmaceutical and edible films
Optical films
Sandvik test center
Fully equipped to handle a broad range of products and applications
Whether you’re simply looking to carry out initial tests or
wanting to go a stage further with pilot production trials,
you can do so – using your products – on the systems
available at any our regional test centers. Alternatively,
we can arrange the installation of one of our mobile
pilot units at your own production facility.
fixed roller
Pilot double belt press unit with various process modules
at our German test center in Fellbach.
calibration roller
circulating rollers
isobaric module
The modular design of a Sandvik steel belt-based press –
with a range of heating and cooling elements – means we
can deliver an efficient solution for practically any process
or application.
Isobaric press at our Japanese test center.
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Sandvik Process Systems –
Product Center Industrial Processing
PC Industrial Processing –
a worldwide operation with its
headquarters in Fellbach, Germany.
A complete service from one
trusted supplier:
Sandvik Process Systems is a single source supplier of
processing plants, steel belts and service. We offer all the
flexibility, responsiveness and customer focus of a
mid-size company, backed-up by the strength and stability
of the global Sandvik organization.
We provide a complete service – one based on real
expertise and professionalism – from initial discussions
and advice, through pilot tests and planning, to
construction, commissioning, start-up and ongoing
service.
PS-458 ENG 02.2011 – Printed in Germany
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