D RMG Mechanical Descalers

Material costs usually constitute over 50% of the total manufacturing costs.
These costs can be cut 20% by mechanically descaling in-house.
RMG
Mechanical
Descalers
3.1
Economic Considerations
Almost all wire products are produced
from coiled wire drawn from either
chemically or mechanically descaled
rod. Due to economic and environmental considerations chemical descaling
(pickling and liming) has become a
thing of the past, with two possible
exceptions:
Almost any company that purchases
cold-drawn wire can lower costs and
improve productivity by procuring inexpensive green (non-descaled) rod and
producing their own cleaned and drawn
wire in-line with their existing production process. Two immediate cost benefits will be realized:
1. Cold-heading-quality wire which requires an extremely clean surface for enhancing the extrusion process.
1. Material costs can be cut 20%.
2. Plating-quality wire which requires an extremely clean surface for elec tro-chemical bonding, and appear-
ance purposes.
Virtually all other wire products can,
and should, be produced from mechanically-descaled material especially parts
that are subsequently plastic coated or
painted.
Mechanical descaling can be accomplished either at the wire mill or, better yet, immediately before the wire is
converted into its final or semi-finished
form. The problem of providing suitable
coatings or corrosion resistance when
descaled and drawn wire is produced at
a remote wire mill precludes procuring
mechanically-descaled wire from these
commercial mills. Therefore, the most
practical method of producing this material is just before the wire is converted
into a straightened, formed, or welded
part on site. This especially applies
when wire diameter is .218” (5.5 mm)
and larger which permits combination
single-hole drawing and descaling.
2. Since rod coils are usually available in weights that are double the weight of wire coils, the production pro- cess can become much more efficient because of the longer sustained pro-
duction runs with minimum time lost for coil changeover.
Reverse-Bending Mechanical
Descalers
There are two principle methods of
mechanical descaling: Shot-blasting and
reverse-bending.
Shot-blasting is usually confined to rod
diameters larger than .625” (16 mm).
Reverse-bending the rod is predominantly done on rod diameters less than
.625” (16 mm). This simple process
employs, in most cases, two sheaves
oriented at right angles to each other.
The rod is pulled over and through the
sheaves which causes reverse flexing
and both compresive and tensile bending on all four sectors of the rod.
The combination of the reverse bending
and stretching forces causes the rod to
severely elongate and, in fact, it is this
elongating process that causes the scale
to break away from the surface of its
steel parent. Steel is relatively elastic;
the laminar ferrous oxide scale is almost
completely inelastic and easily fractures
and falls away from the rod.
The amount of scale, and the strength
of the bond which holds it to the rod’s
surface, varies with the rod mill’s manufacturing practices and is controllable.
It is important to tell your rod supplier
that you plan to mechanically-descale
the rod. The mill can then contribute
to somewhat easier scale removal by
controlling rod production time and
temperatures. Keeping the rod’s surface
dry and storing indoors also facilitates
scale removal.
The amount of elongation imposed
on the rod as it traverses through the
descaler is a direct function of the
pitch diameter of the reverse-bending
sheaves. Scale starts to break loose at an
elongation of about 5%. At 8% to 9%
most of the scale has broken off.
Cleaning Techniques
The breaker rolls can only reverse-bend
the wire. Residual dust and scale must
be cleaned off the rod before descaling
is considered complete. The “air wipe”
method using a carbide-inserted guide
assembly has proven to be the most economic and effective method of surface
dust removal. Using an exiting air-wipe
assembly and a liquid lube box on the
wire drawing machine provides the best
combination for effectively cleaning
the material especially when the lube
system includes a recirculating pump,
a particle settling tank, and a filtering
system.
Rockford Manufacturing Group Inc.
14343 Industrial Parkway • South Beloit, Illinois 61080
Phone 815.624.2500 • Fax 815.624.7254 • Email: [email protected] • Website: www.rmgfelm.com
7/06
Descalers
Introduction
RMG
MD-10 Descaler
Attachment
For in-line wire drawing machines...
diameter range 7/32” (5.5 mm) through 13/32” (10.0 mm)
3.2
General Specifications
The RMG MD-10 Mechanical Descaler
provides the industry’s simplest and
most practical system for scale breaking
and removal. The MD-10 consists of
four principle parts:
1. An entrance guide assembly with hardened guide rollers.
Descalers
2. A two-roll reverse bending assembly with replaceable carbide inserts.
3. A carbide-inserted air wipe assembly for blowing off residual dust. Air consumption is very low. When used with a wire drawer, an electrically- interlocked solenoid valve is pro- vided which automatically shuts off air supply when the wire drawer stops.
4. A hinged, covered enclosure with facilities for connecting to a dust collecting unit for accumulation and removal of scale.
The MD-10 accommodates two rod
diameter ranges: 7/32” (5.6 mm) to
9/32” (7.1 mm) using 2.5” (63.5 mm)
pitch-diameter breaker rolls and 9/32”
(7.1 mm) to 13/32” (10.4 mm) using
3.25” (82.5 mm) diameter breaker rolls.
The MD-10 descaler is designed to be
used with RMG in-line wire drawers
that have provision for attaching the
descaler. Existing wire drawers can be
modified in order to accept a descaler.
RMG’s Model 67 28” (700 mm)
capstan wire drawer is used, in most
cases, to provide the tractive drawing
force for pulling the rod through the
descaler’s breaker rolls and for drawing
the wire. However, on relatively slowspeed applications of about 100 fpm
(31 m/min) and slower, it is possible to
adapt a smaller Model 56 (24”/600 mm
capstan), providing the wire diameter
after drawing will be under .200”
(5.0 mm).
Features and Benefits
Simplicity and Ease of Set-up: designed
to permit the operator to set-up the
machine quickly and easily.
Easy Scale Removal: for either dumping into tote pans or for use with central
station scale-handling and dust collecting equipment.
RMG Model 67 In-Line Wire Drawing Machine with standard frame MD-10
Descaler attachment.
RMG Model 67 In-Line Wire Drawing Machine with reverse frame MD-10 Descaler attachment. This configuration is typically used in wire products applications.
MD-10 Descaler Set-up
Descalers
3.3
1. Point head- end of rod.
2. Use file to remove fins or flash.
3. Remove air wipe.
4. Insert pointed end through des- caler entrance and
pull out approxi- mately elev-
en feet beyond draw box.
5. Bend back toward rear of machine forming “hairpin” and push loop over horizontal roll...
6. ...and then underneath and around vertical roll...
7. ...and up around and over the top...
8. ...and through the exiting end of the des-
caler. Note that the air wipe assem-
bly has already been removed.
9. Slide the air wipe assem-
bly over the head-end of the rod.
10. Before replacing
air wipe, push wire end through draw box and attach gripper chain.
11. Insert air wipe into housing and secure using latch-
ing lever.
12. Connect the air sup-
ply to the air wipe connector.
13. Wire drawing can now begin.
CAUTION AT START-UP: Observe
loop in descaler to insure it does not get caught as it initially forms around vertical roll. CLOSE COVER prior to operation.
CAUTION: OBSERVE ALL BASIC SAFETY PRECAUTIONS DURING DESCALER SET-UP.
Rockford Manufacturing Group Inc.
14343 Industrial Parkway • South Beloit, Illinois 61080
Phone 815.624.2500 • Fax 815.624.7254 • Email: [email protected] • Website: www.rmgfelm.com
11/06
For in-line wire drawing machines...
diameter range 7/32” (5.5 mm) through 9/16” (14.0 mm)
RMG
MD-14 Descaler
Attachment
3.4
Features and Benefits
RMG’s larger MD-14 Mechanical Descalers provide the same features available on the smaller
MD-10 descalers, including these advantages:
1. An entrance guide assembly with
hardened guide rollers.
2. A two-roll reverse bending assembly with
replaceable carbide inserts.
Descalers
3. A carbide-inserted air wipe assembly for blow ing off residual dust. Air consumption is very low. When used with a wire drawer, an elec-
trically-interlocked solenoid valve is provided which automatically shuts off air supply when the wire drawer stops.
4. A spring counter-balanced, hinged
covered enclosure with facilities for
connecting to a dust collecting unit for accu-
mulation and removal of scale.
5. The industry’s easiest set-up
mechanism for 9/16” (14.0 mm) rod.
(See reverse for set-up procedure.)
6. Free-standing construction ready for instal- lation in front of an RMG in-line wire drawing machine. Risers to match any wire line height are quoted separately.
7. Machines available for either left-to-right (reverse frame) or right-to-left
(standard frame) rod flow.
8. The industry’s huskiest sealed bearing assem- bly using standard bearings.
Roller assembly showing construction of
carbide-inserted roller, shaft, and bearing
housing. The entire assembly is held in place
by four bolts and can very easily be removed
from the descaler for routine servicing.
RMG MD-14 Mechanical Descaler shown
with High Speed Model 910 Wire Drawer.
MD-14 Descaler Set-up
1. Point head-
2. Use file to
remove fins or
flash.
3. Remove
guide roller,
as shown.
4. Remove air
wipe.
5. Push wire
through descaler and hang
airwipe on
wire. DO NOT
reinsert airwipe
at this time.
6. Insert wire
through drawbox and attach
gripper chain.
7. Insert air
wipe into housing and secure
using latching
lever.
8. Connect the
air supply to
the air wipe
connector.
9. Align wire
with rollers;
use bar, if
necessary, to
position wire.
10. Insert bar
into pivoting
assembly and
rotate.
11. Continue
rotating pivoting assembly.
12. Move bar
to second hole
in pivoting
assembly and
continue
rotating until
it locks into
place.
13. Raise roller
assembly to
vertical position.
14. Lower
hold-down
roller assembly
and lock by
sliding handle
forward.
15. Use pry
bar to position wire in
between guide
rollers.
16. Replace
guide roller.
17. Replace
pry bar.
Finished setup position is
pictured here.
CLOSE DOOR
prior to operation.
Descalers
3.5 end of rod.
CAUTION: OBSERVE ALL BASIC SAFETY PRECAUTIONS DURING DESCALER SET-UP.
Rockford Manufacturing Group Inc.
14343 Industrial Parkway • South Beloit, Illinois 61080
Phone 815.624.2500 • Fax 815.624.7254 • Email: [email protected] • Website: www.rmgfelm.com
7/06