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Recent trends in automotive interior trim include part consolidation, elimination of painting and lower gloss, all of which require better molding materials, be it general purpose or high heat grades. These requirements, larger and more complex parts and uniform surface appearance, have led the plastics industry to respond with softer flowing grades. These grades provide longer flow length, and better pick up of the mold surface details for the final appearance. To produce a softer flowing polymer, the polymer viscosity is reduced through material structure engineering. At the same time that these soft flow polymers provided the needed moldability it was found that molding could be accomplished at lower melt and mold temperatures while still achieving the desired surface appearance. Lower molding temperatures make it possible to shorten the cooling cycle and possibly the total cycle time.

This paper discusses the effect of various individual and combinations of thermal Stabilizers and their effect on polymer properties. We will show the effect on initial molded properties with various stabilizers, and how the proper balance of stabilization can enhance the long term heat aged properties on both ASTM test specimens and also on actual large molded part performance. Physical Properties investigated are those of Izod, multi-axial impact, tensile and flexural properties over a range of aging times and temperatures.

Elastomeric alloys (EAs) have found many under-the-hood automotive applications, replacing conventional thermoset rubbers. The clean air duct on an automobile engine has historically been a thermoset material such as CR, EPDM, nitrile or epichlorohydrin rubber. EAs have a highly suitable aggregate of performance properties for this application. This paper will give in detail the requirements for the automotive clean air duct and how EAs meet them. It will also discuss the proper design of these ducts with EAs. These designs incorporate the flexibility of blow molding in improving part performance and tooling costs, lowering part weight and reducing overall part cost relative to clean air ducts from conventional thermoset rubbers.

The cadmium and lead salts (along with organic colorants) especially pigments used for coloration of thermo-plastic polymers, have been regarded as technological and functional necessities in nearly every sphere of our daily lives. They also greatly influence our mood and thus contribute enormously to the very quality of the lives we lead. At the same time, we have come to realize that our achievements and continuing technological progress are only worthwhile provided they pose no hazard to the environment as well as human life. The regulatory agencies, corporate laboratories, customers, consumers and employees alike have identified problems with lead and cadmium colorants. To meet these challenges, a color chemist must become familiar not only with what pigments are available, but how they differ from one another. The use of environmentally safer colorants are a trend for the 1990's. Monsanto has been exploring alternates to cadmium pigments in their resins for several years.