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LeVic Plastics overcomes challenges
with its approach to tooling, including a creative way to vent using
porous mold steel.
Ron Knight became an owner at molder/moldmaker LeVic Plastics
in Grandview, MO in 1977, five years after it was founded. From the
start, it has been a comprehensive operation offering not only
molding and moldmaking, but also secondary tooling and operations,
assembly, and engineering. Markets served include medical,
aerospace, electronic, consumer, and industrial.
LeVic is a growing company today, despite the competition from
offshore moldmaking and molding companies. Knight believes its
growth is due to a strategic change in how the company approaches
manufacturing: LeVic has adopted a solution-oriented approach. As a
solution provider, it is open to, and regularly tests, different
manufacturing processes. This view has paid off, both in retaining
customers and acquiring new ones, especially those in important
growth markets. It is able to supply its customers with a
good-quality part out of a wide range of commodity and engineering
resins.
In aggressively going after production challenges, LeVic has found a
niche as a solution provider, a place where companies can bring
their challenges for review. Ron is not afraid to try new ways to
grow his business, which means educating existing and future
customers in a changing, growing market to ensure better part
quality at an affordable cost.
A new way to vent trapped gas
An example of turning its attention to solutions involves a change
in the way LeVic vents some of its molds. According to Knight,
certain mold geometries have one problem that plagues moldbuilders.
“They trap gas in the most difficult places, and this gas must be
released,” he says.
The most common and least expensive practice is to place inserts
and/or vent pins in the mold. While this method works for a certain
percentage of parts, it may be unacceptable to the finished surface
on others because of insert or pin lines that are created.
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This medical part (above) used
in bacterial analysis could tolerate no weldlines.
Traditional inserts left a weldline, as seen directly below
the medical part, but Porcerax eliminated it (top).
LeVic molds buttons for
the interiors of planes. They require mold inserts that
often result in burns, trapped gas, or weldlines, which are
considered unacceptable. LeVic uses Porcerax to solve the
problem.
According to Knight, this
medical part is molded with zero surface imperfections
because the mold is vented with porous steel.
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LeVic solves this problem by placing Porcerax II (International Mold
Steel, Florence, KY) inserts within some of its molds. This is a
sintered, porous mold steel that is 25% air by volume. The pores
allow trapped gases to escape directly through the steel. While this
solution saves labor in moldbuilding, it is also the only way to
produce certain medical and aerospace parts.
Knight comments on several benefits of using the porous inserts.
“We are able to use several fill speeds or ram speeds for
injection on our electric Toshiba machines, and the scrap rate
dropped to almost zero. There are no weldlines or gas trapped in
critical areas, and we also see a large increase in usable parts per
hour due to zero surface imperfections.”
In one case, a seemingly impossible part was tooled successfully.
“Medical parts often present the toughest molding challenges, as
many times they require sealed surfaces,” says Knight. “This
particular part is involved in bacterial analysis and can’t
tolerate a weldline, no matter how small. In tests using K-Resin, we
placed an insert inside the mold, and the result was a weldline.
Then we placed Porcerax II in the mold with no resulting weldline.”
Successful production of the part has brought additional medical
business to LeVic.
IMM - June 2006
Reprinted with
permission from Canon Comunicaitons, LLC
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 International Mold Steel, Inc.
6796 Powerline Drive
Florence, KY 41042 USA
Tel: (859) 342-6000 or 1-800-625-6653
Fax: (859) 342-6006
Sales: salesdesk@imsteel.com
Literature: info@imsteel.com
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