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The automation edge
Robots are a
key tool for remaining competitive in times like
these. |
Feb/March 2009
Plastics in Canada Magazine |
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SAS Automation's RFID system for end-of-arm
tooling. |
What
can automation offer a molder today? The average
shop is looking at tight acquisition budgets and as
many gloomy predictions about 2009 as last year
there were upbeat ones. And all that means any
purchase needs careful justification.
Sepro America LLC (Pittsburgh, Pa.), formerly a
joint-venture of French-based Sepro with Conair
(Pittsburgh, Pa.), is following a common tendency in
offering two robot ranges: the moderately priced
Axess robots, for the simpler pick and place
applications' and its more capable Generation IV
robots, which offer additional control capabilities,
higher speeds and the ability to tie in with
peripheral equipment.
"You don't see this same pricing differential in
automation systems that integrate robots, conveyors
and peripheral equipment into a manufacturing cell,"
says Jim Healy vice-president of sales and
marketing. "The specifications (and cost) of these
systems tend to be very applications-driven.
However, as we have gained more and more experience
with them, the engineering requirements and the cost
to the customer have been trending level or
downward, even as the capabilities, of the systems
increase."
Quick-change tooling has been improving since the
1990s, and Sepro today offers quick-change tooling,
plates on its robots as standard features. It also
offers quick-disconnects on electrical and pneumatic
lines.
"We can also offer an ID system that
automatically verifies that die EOAT on the robot
matches the mold that it is to be used with, and
that the robot program is installed," he says, "In
fact, tooling changes and robot set-up can usually
be accomplished in less time than it takes to change
a mold and adjust machine settings. When it comes to
changing jobs these days, die delays are more on the
molding machine side, not on the robot side."
John Westbeld, engineering manager at SAS
Automation (Xenia, Ohio) observes that complexity in
molding cells and systems is increasing.
"Costs are decreasing, but not complexity," he
says. "It seems to be the trend from our vantage
point that molders are trying to automate systems
that they would not have considered before. The
reasons for automating are the same—labor costs,
quality, and ergonomics—but the drive to decrease
costs to be competitive has increased."
SAS specializes in quick-change systems for EOAT.
In the second half of 2008, the company began
offering EOAT with RFID tags to automatically ensure
the correct tooling is operating with the
corresponding operation and equipment.
SAS has applied an RFID tag in an EOAT mounting
plate, Westbeld says, that can identify itself when
mounted and installed on a standard quick change
mounting chuck, which mounts to the robot. Important
features of this system are that it identifies the
correct robotic EOAT gripper is mounted to the robot
running the applicable program and confirms the rest
of the critical equipment is installed. This
includes the correct die or mold in stamping,
plastics or packaging operations.
RFID, he notes, is low-cost insurance against
robot, tooling and part damage because it quickly
ensures the correct tooling is running. RFID tags
prevent costly damage due to system crashes, reduce
labor costs, and are critical during line
changeovers.
Engel Canada (Guelph, Ont.) has also broadened
its EOAT quick-change offering with a manual system
with a dovetail, that uses two wing-nuts for
mounting and dismounting.
"Not much has changed in the EOAT itself," says
automation manager Harold Luttmann, "but this system
costs just hundreds of dollars, whereas a full
quick-change system from most suppliers can run into
the thousands."
"Rather than designing a cell to run one specific
application or part, we are designing systems that
are more modular, to be able to run multiple
applications with simple adjustments."
Another recent innovation from Engel is a color
touch screen on its new RC-200 control. This control
pendant allows the setting of all robot, as well as
machine parameters, when integrated through the
injection molding machine.
"This opens up the ergonomics of the control,"
Luttmann says, "allowing the operator to set up
processing parameters from anywhere within reach of
the hand pendant. Normally, this can only be done
from in front of the machine controller."
Wittmann is another supplier that has improved
its quick-change system. Christian Weiss, technical
sales, robots and automation with Wittmann Canada
(Richmond Hill, Ont.) says the new system is both
less expensive than its predecessor, and works
better.
"We previously used a dovetail style slide, but
that design had a tendency to jam," he says. "We've
changed to a two-piece cam lock with built-in
fittings for up to 10 parts. The two component
halves mate together, and then there's a lock that
holds the EOAT."
Vacuum cups for EOAT have been improved to the
point they don't have their old tendency to mark
parts, he adds.
"The new cups are quicker in their action," he
says, "and the repeatability of the robot with
suction cups is distinctly increased."
There are spring-loaded compensators on the cups.
The robot moves with the ejector strike, and takes
away the parts in one motion, preventing EOAT damage
from unsynchronized ejector strokes. Over a year's
production, this offers considerable cycle savings.
Tying
robots directly into the injection molding machine
control offers obvious advantages, and Wittmann now
offers this with its new R8 robot controls, shown at
the recent Expoplast show in Montreal, and with the
Battenfeld line of injection presses its parent
company now owns. This capability, which links the
controls of the robots with Battenfeld's Unilog B6
control, was first shown at last year's Fakuma show
in Germany.
And on the IML side, Wittmann offers its W717
top-entry robot for IML is designed for customers
wanting to probe this technology before investing in
expensive dedicated systems.
"It purely places the label into the mold," Weiss
says, "but it doesn't remove the finished part. It
allows you to get into IML, and test the market."
Engel has also seen growth in IML. It shipped two
systems in the last part of 2008, one to the US and
one to a Canadian customer.
While there's an obvious reluctance to spend by
most processors right now, automation continues to
be one area where the logic of faster and more
precise manufacturing is inescapable. Fast, high-end
robots offer one approach to the problems of
cost-efficiency, but there are also low-cost
solutions available.
Designed arid used properly, these can yield the
dramatic improvements in productivity that make the
difference between a plant that is no longer viable,
and one that is still around when the economy is
growing again.
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