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Amodel PPA Thermostat Housing Delivers
Performance for the Long Haul

After seven years and 85,000 miles of actual vehicle use, a Dodge Neon 2.0-liter thermostat housing molded from Amodel polyphthalamide (PPA) showed no measurable change -- no dimensional changes, no surface degradation and no change in the performance of the polymer. BP Amoco representatives obtained the thermostat housing after learning the Dodge Neon was in a scrap metal yard following an automobile accident. Engineers decided to do a follow-up study on the material, a product of BP Amoco Polymers, Livonia, MI, that has successfully replaced metal in many automotive applications for almost 10 years.

Before and after studies reflect no visible change
Before	After

In 1994, Amodel A-1133 HS (a 33% glass-filled, heat-stabilized grade) was selected to replace die-cast aluminum in this thermostat housing application because of the resin's excellent corrosion resistance, approximate 20% weight reduction and overall cost savings. The material was chosen over conventional nylons because of its superior chemical resistance to long-term exposure to engine coolants at 275°F (135°C), as well as its lower moisture absorption, improved hydrolytic stability and higher thermal resistance. It passed testing for both pressurized thermal shock and thermal cycling, showing that parts molded from Amodel PPA could provide the high strength, dimensional stability and extreme thermal performance required for a leak-proof thermostat housing. Currently, Amodel PPA is used in fuel rails and other automotive applications, including solenoids, ABS motor endcaps and water pump housings.

The thermostat housing was designed and developed by the Powertrain Division of LDM Technologies, Inc. (formerly known as HPG) in Port Huron, MI.

--KC

For more information;

Circle 599 - BP Amoco Polymers or connect directly to their website via the
Online Reader Service Program at http://www.1rs.com/012df-599

Circle 589 - LDM Technologies or connect directly to http://www.1rs.com/012df-589