Materials Engineering: A Breath of Fresh Air
Weidmann Plastics Technology AG in Switzerland overmolds thermoplastic elastomer (TPE) sealing lips onto cowl vent substrates made from glass-reinforced polypropylene (PP).
Cowl vents sit
between the windshield and the
engine compartment of Peugeot
207 and 307 Series cars, span the
vehicle width, and pass fresh air
from the outside to the cabin. The
overmolded sealing lips are up to
1.5 m (nearly 5 ft) long and are
part of a single molding cycle for
the three-component part that includes
the structural PP substrate,
the TPE sealing lip, and a molded in
viewport for reading the vehicle
chassis number.
The Tekron TPE, supplied in
Europe by Chem Polymer, a unit
of Teknor Apex, Pawtucket, R.I.,
provides flow properties necessary
to maintain precise tolerances and
a smooth, attractive surface along
the entire length of the cowl vent
part, reports Weidmann. The TPE
features good weather resistance,
as well as the heat stability and low
compression set for maintaining
seal integrity at the elevated temperatures
seen in the cowl vent just
above the engine bay.
Teknor TPEs are based on
styrenic-block copolymers. They
withstand temperatures to 120°C
and stay flexible below 60°C.
“One key benefit that Tekron TPEs
provide for Weidmann’s cowl vent
seal is their essentially nonreactive
response to oxygen and ozone,”
says Nick Sandland, Teknor Apex’s
European market manager for
TPEs.
Make contact
Thermoplastic Elastomer Div.
Teknor Apex
(401) 725-8000
teknorapex.com
Weidmann Plastics Technology AG
41-55-221-4106
www.weidmann-plastics.com