Solutions Start in the Mold
overcomes challenges with its approach to
tooling, including a creative way to vent using
porous mold steel.
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).
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.
to Knight, this medical part is molded
with zero surface imperfections because
the mold is vented with porous 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
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.
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
Mold Steel, Inc. is a licensed distributor of Porcerax II, a
Mold Steel, Inc.
6796 Powerline Drive
Florence, KY 41042 USA
Tel: (859) 342-6000 or 1-800-625-6653
Fax: (859) 342-6006