Feature Articles - Bemis Contract Group
Bemis Contract Group Works with CAE Services on Mercury Marine
Project
 Sheboygan
Falls, WI-based Bemis Contract Group, a division of Bemis Manufacturing,
prides itself in bringing the latest injection and extrusion technologies
to a select group of industry segments. The Bemis Contract Group
(BCG) brings value through expertise in product and tool design,
as well as product development and project management. All of its
machines are computer controlled and robotically attended. Some
are state of the art multi-material molding capable. Sizes range
from 165 to 6,600 ton. The facility operates 24/7 and is part of
a two million square foot corporate headquarters. BCG’s other
facility in Lenoir, NC is similarly equipped.
Bemis Contract Group project engineer Jeff Lallensack recently
worked with CAE Services Corporation, a plastic engineering service
provider serving various markets including medical, electronic,
packaging, and automotive. Mercury Marine contacted Lallensack
to design and manufacture a complex engine cover and associated
mold for its Verado family of new four-stroke marine outboard engines.
The customer approached Bemis engineers with industrial design
sketches – no CAD models were yet generated.
"The cost of the analyses was
definitely less expensive than trial and error methods. We were
able to save two to three weeks in manufacturing time.”
"We asked CAE Services to become involved in this project
because of the complexity of the part, the material involved, and
concerns
about part warpage,” says Lallensack. The material proposed
for this application, Zytel 70G 33, a 33 percent glass-filled nylon,
had never been used before. The marine top is Class-A painted and
is a show-surface part. “Aesthetics were critical in this
application,” Lallensack notes. “Due to the complexity
of the part, assembly requirements, and other issues, we decided
to employ CAE Services’ Moldflow analysis expertise.”
 The 13-pound part required a single cavity mold. Other specifications
included part strength and durability. “A boater had to be
able to stand on the engine cover at a temperature of approximately
200 degrees. In addition, when the part is assembled, it mates
with other parts so the shape of the lid was critical,” Lallensack
says. The part also contains the latching mechanism for it to attach
to the rest of the cowling.
Lallensack and his team relied on the
CAE Services analyses to provide information about what areas of
the part were critical
in terms of its mold. They wanted results that predicted any hot
spots in order to achieve even cooling throughout the tool. “We
also relied on the analyses to determine if there were any warpage
problems so that we could address them prior to building the tool,” Lallensack
notes.
"I have recommended [CAE Services]
to internal and external colleagues. I have worked with the firm
for nearly
four years, and to this date, I’ve agreed with every analysis
they have provided us.”
Tim Lankisch, part of the CAE Services engineering team, adds, “Using
Moldflow Plastics Insight (MPI) software, we introduced flow leaders to
promote more flow to a certain area of the mold. We found that the last
area of fill was causing a knit line on this cosmetic part. By introducing
flow leaders we could see what the effects of thickening certain wall sections.
This process worked very well by adding just a half millimeter of wall section.”
In terms of warpage, Lankisch and his team analyzed the warpage and found
that there were a couple of issues causing inward warpage of the part. “In
addition, there were some cooling and shrinkage issues,” Lankisch
adds. “In total, we and our customer were able to understand what
the warpage was going to look like prior to molding the part.”
Lallensack says the analysis results correlated very closely with reality. “You
can’t predict exactly how the part will mold, however, the Moldflow
results do provide a trend or direction of the warp we would experience.”
 Within two to three weeks of initially contacting CAE Services, Lallensack
had the results they originally anticipated. Due to the complexity of the
mold and the part, Bemis deemed the analysis as an insurance policy. “By
working with CAE Services, we wanted to avoid expensive tool changes in
the future, adhere to project deadlines, and maintain customer satisfaction,” adds
Lallensack. In doing so, Bemis incurred little to no rework. “The
analyses assured that our part and mold were accurate.
"The cost
of the analyses was definitely less expensive than trial and error
methods. We were able to save two to three weeks in manufacturing
time,” Lallensack adds. For this project, he said the Moldflow analyses
were very good tools for predicting filling patterns and venting
issues.
As for CAE Services, Lallensack says that he will continue to work with
the firm. “I have recommended them to internal and external colleagues.
I have worked with the firm for nearly four years, and to this
date, I’ve
agreed with every analysis they have provided us.”
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