Metal Slitting Pro Application Guide

Metal Slitting Pro
Application Guide
Rockwell Automation solution for the
power and control of metal slitting lines
Uncoiler
Shear
Slitter
Entry Loop
Tension
Stand
Recoiler
Exit Loop
Turnstile
Coil Car
Typical Slitting Line
Rockwell Automation – Metal Slitting Controls
If a drive is used on the uncoiler, the material goes directly
Metal slitting lines can be found in nearly every major city
into the slitter heads as described above and the uncoiler
worldwide. The machine’s function is to take large rolls of
drive acts as both the threadup motor and the hold-back
material (steel, aluminum, copper, etc.) and slit it into
brake. In this case, the operator sets tension and the con-
widths and lengths end users require for their machines
trol system/drive controls the tension in the strip.
(tube, strapping – almost an endless number of applications). The purpose of this paper is to describe Rockwell
Shear
Automation’s standard approach to drives and controls for
Many metal slitting lines have a shear entry section. This
these machines.
section does not typically have a motor, but the control
system is required to perform a number of logic functions
Metal Slitting Machine - Overview
(i.e. peeler control, side control, shear control, footage
counter, etc.).
Uncoiler
The uncoiler’s function is to take a new roll of metal and in
a coordinated fashion feed the material into the slitting
heads. This is accomplished by either a brake with a fixed
speed threadup motor or by a variable speed motor driving
the uncoiler. When a brake is used, the material typically
feeds via a thread-up motor through the shear directly into
the slitting heads. Once the slitting head has the material,
the brake holds tension in the material and the fixed speed
motor turns off. The operator either manually sets brake
tension or the control system sets and controls brake ten-
PHOTO FPO
sion, via E/P transducer.
Typical Uncoiler
2
Entry Loop
the exit loop. This tension can be created via friction pads
Some lines have an entry loop – this is typical of light gauge,
(top and bottom) that hydraulically press together to hold
tension free slitting. Here the uncoiler must be driven by a
the strip back from the recoiler. Another method is to use
variable speed drive. The operator sets loop position and a
two rolls instead of pads. These rolls could have a mechan-
feedback device in the loop pit is used to control the loop.
ical brake holding back or a regenerative variable speed
drive, which could reduce scratching on the metal because
Slitting Head
of its ability to speed match.
The slitting head is a pair of rolls nipped together. These
rolls have the knives in them that actually cut the metal. On
Recoiler
simpler machines, the slitter is not driven except for a
The recoiler section of the metal slitting line produces the
thread-up fixed speed motor. More complex machines that
coils of slitted material that are typically banded and shipped
have looping pits and multi-modes of operation will have a
to customers for a variety of applications. The recoiler is the
variable speed drive on the slitter.
master section for the slitting line and always includes a
variable speed drive. There is usually a “drag tach” that
mounts after the tension stand and gives strip speed feedback. This feedback is used by the recoiler drive to maintain
constant strip speed as the recoiled roll gets bigger.
Auxiliary Equipment
The sections listed above are the primary sections of a
metal slitting line. Some machines could also have the
Slitting Head
Exit Loop
following auxiliary equipment:
●
Scrap Handling – Typically the outside slitter slits trim
Most slitting machines that produce more than two mults
the edge of the metal. These edge trims are not
(or slits of coil), will have an exit loop. The operator manually
recoiled, but are removed as scrap. Scrap choppers
adjusts this loop position via trim potentiometer. The main
and scrap ballers are the most common examples of
purpose of the exit loop is to compensate for the varying
scrap handling. Scrap choppers are more common on
gauge throughout the strip, typically the gauge of the mate-
heavy gauge slitters and are used to chop the scrap
rial is thicker in the center than the outside of the strip.
into small pieces as it's removed by a conveyor. More
Thus the outside coils will be smaller in diameter than the
commonly used on lighter gauged slitters, scrap
inside coils, causing less material to be recoiled for every
ballers wind the scrap into a ball. Both are typically
revolution of the recoiler as we move further from the
fixed speed motors and require a motor starter.
center of the strip. For this reason, it is common to see the
●
Coil Handling – The coils of metal coming into the
center mults almost taught (no loop) and the outside mults
metal slitting line and the coils of slitted metal leaving
near the bottom of the looping pit.
the line can either be handled mechanically with turnstiles and fork lifts or can be automatic with coil cars
Tension Stand
and conveyors. On lines with automatic coil handling,
This section has many different names (synchro, drag
there are typically digital I/O and fixed speed AC
carpet, etc.), but functionally it is very common. It creates
motors involved.
the necessary tension for the recoiler to pull against after
3
●
●
●
Tension Leveling – Some metal slitting lines will have
must be driven with a variable speed drive. (If your
tension levelers inline with the slitting process. Tension
machine has dual loops, contact your Rockwell
levelers will have a variable speed drive associated
Automation representative for configuration
with them.
assistance.)
Automatic Tool Change – Sophisticated slitting lines
will have the ability to automatically change the posi-
Rockwell Automation Control Solution
tion of the knives in the slitter. This option requires a
Recent advances in technology by Rockwell Automation
special setup screen for the HMI and a significant
have allowed the prepackaging of application modules to
amount of digital I/O.
quickly and cost-effectively solve complex machine control.
Digital I/O and Motor Starters – Most slitting lines have
This is our approach to applying this technology to metal
threading features and other machine controls that
slitting lines:
require digital logic in addition to what’s required for
controlling the major sections described above. There
Controller
are also a number of fixed speed motors for hydraulics,
At the heart of our slitting solution is a ControlLogix™ con-
pinchrolls, etc., which require AC motor starters.
troller. This state-of-the-art controller employs a multi-tasking environment, which allows the entire machine control
Modes of Operation
to be segmented into pre-engineered software modules.
The metal slitting machine can have a number of modes of
Now, you select the modules that match your machine.
operation:
Since it’s pre-engineered, much of the cost of custom pro-
●
Pull-Through Mode: This is the simplest slitting line. At
gramming, engineering and start-up have been reduced.
a minimum, it has a brake on the uncoiler, a slitting
head that is not a variable speed drive and a driven
recoiler. The uncoiler brake sets the tension in the
material and the recoiler sets its speed. No loops are
possible in this configuration. This is used when only
edge trimmer or two mult slitting is required.
●
Slitter Assist Mode: This mode is like the pull-through
mode except the slitter has a variable speed drive. By
powering the slitter, better slitting is possible in the
PHOTO FPO
strip. The operator in this mode has an additional
adjustment to set the tension pulled by the slitter drive.
●
ControlLogix™ Controller
Exit Loop Mode: When three or more mults are
desired, an exit loop can be used. The same drive con-
●
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figuration is used as with the “slitter assist mode,”
Networks
except the slitter speed will now be controlled by the
The standard network incorporated in a Rockwell
operator adjusting the loop adjust potentiometer.
Automation preconfigured metal slitting line is
Dual Loop Mode: A few machines are designed for
ControlNet™. This network is high-speed, open and com-
“tension free” slitting. In this case, both entry and exit
patible with the complete family of Rockwell Automation
loops are employed and all major sections of the line
control products.
Operator Interface (HMI)
Standard Application Modules
Since the major components of
Rockwell Automation has years of experience in designing
the Rockwell Automation metal
systems for metal slitting lines – both new machines and
slitting line solutions are on
ControlNet™, all process and
PHOTO FPO
retrofits. We’ve taken this experience and developed standard application modules; these modules are field-proven,
diagnostic information is available for display and
so you get the advantages of reduced engineering and
interaction with the operator. By pre-programming these
start-up time. Yet we’ve included the ability to customize
displays into proven user-friendly designs, we’ve made
these modules for your machine control logic and options.
complex HMIs affordable. Every machine is supplied with
Each option includes the software, hardware and drawings
the following screens:
to implement this function.
Machine Overview –
Increases efficiency by
Available Modules:
providing the operator a
●
Slitting Line Master/HMI – This module is required for
visual display of drive and
each line and is the master for the slitting line. It
machine parameters in
includes software and hardware for control of the
both a bar graph and
recoiler and operator interface.
digital format.
Fault Summary – This
Functions include:
screen identifies alarms
▲
Line start/stop
and faults. When a fault
▲
Line speed set
occurs that causes the line
▲
Line fast stop
to shut down, all faults are
▲
Line E-stop/reset
identified and the first fault
▲
Recoiler jog fwd/rev
flashes.
▲
Recoiler mandrel expand/hold/collapse
▲
Full set of operator screens (described above).
Line Run Permissive – The
line run permissive screen
lists all drives, auxiliary
●
Uncoiler Control – There are a variety of options avail-
and other associated
able to control either a mechanical brake or a variable
equipment required to start
speed drive on the uncoiler.
the slitting line.
Functions include:
Automated Stop On Length
▲
Uncoiler tension set
or Diameter Set-up – The
▲
Uncoiler jog fwd/rev
operator sets up the auto-
▲
Uncoiler over/under
mated stop on length or
▲
Uncoiler mandrel expand/hold/collapse
diameter counters via this
▲
Hold-down roll raise/lower
screen.
▲
Uncoiler thread table raise/lower
5
●
Slitter Control – There are a variety of options avail-
Slitting Line Options
able to control either a mechanical or a variable speed
In addition to the modules for each of the major sections of
drive on the slitter.
the slitting line, there are numerous options available by
which you can fine-tune the Rockwell Automation slitting
Functions include:
line control system to your machine.
▲
Slitter load/loop adjust
▲
Slitter jog fwd/rev
Motor Starters – For auxiliary fixed speed AC motor NEMA
▲
Looping pit raise/lower
size 1, 2 or 3 motor starters can be specified either revers-
▲
Tight/loop select
ing or non-reversing. This option includes the starter,
required I/O, operator devices and documentation.
●
Tension Roll – This option controls a variable speed
drive on the tension roll.
Digital I/O – I/O modules can be specified in groups of
16 points, this requires the customer to specify the function
Functions include:
▲
Tension stand load adjust
▲
Tension stand jog fwd/rev
▲
Tension roll open/close
and operation. The module includes the hardware, programming and documentation.
0perator Interface – Additional operator devices (push
buttons, pilot lights selector switches, etc. can be specified
Drives and Motors
along with additional operator enclosures (push button
Metal slitting lines can be powered by either AC or DC
stations, wall-mounted stations and main benchboard
Rockwell Automation drives and motors. We have available
extension).
a wide choice of features and configurations available to fit
each application and environment.
Standard Operator’s Benchboard
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For More Information
If you would like more information about Rockwell
Automation metal slitting machine configured applications,
contact your local Rockwell Automation representative or
authorized distributor. We have a complete application
guide and worksheets that will help you specify and price a
control system for your machine.
IMAGE FPO
Putting It All Together — Example of slitting line specification sheet
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Publication DSMETA-AP001A-EN-P
© 2000 Rockwell International Corporation. All rights reserved. Printed in USA.