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As petroleum prices experience record volatility, automotive OEMs are seeking advanced materials that permit the development of more light weight, fuel efficient vehicles. Thermoplastics are a natural solution since they provide the combination of structural properties with lower material density, along with ease of forming geometrically complicated parts with rapid cycles and with minimal finishing operations. However, new automotive applications are becoming increasingly demanding with regard to chemical exposure, environmental exposure, thermal environment, and load bearing requirements. Addressing these challenges requires a thorough understanding of the application in order to identify appropriate thermoplastic resins and to develop novel resin technologies to extend the performance of structural engineering thermoplastics.

The use of injection molded long glass fiber composites to replace metal in automotive components continues to find success. This paper will discuss the use of these composites to replace steel in running boards, a very demanding application. The success of an injection molded-in-color composite running board on a 2004 mid size SUV has opened the door to realize the benefits of composites in these large exterior parts. These benefits include significant weight reduction, corrosion resistance, scratch and mar resistance, design flexibility, and cost out opportunities. 40% long glass fiber polypropylene was formulated to meet the rigorous structural and aesthetic requirements demanded by global OEM manufacturers for these large structural parts.

Thermoplastic polyesters are widely used in the automotive industry and are the material of choice for many types of electrical and electronic components due to their excellent balance of mechanical and electrical properties. Under certain conditions including elevated temperatures and the presence of high humidity, thermoplastic polyesters such as polybutylene terephthalate (PBT) have the potential to suffer hydrolytic attack. Recognizing the need for standardization, USCAR USCAR (The United States Council for Automotive Research) established component level testing guidelines specific to connectors. In response, many companies developed HR (hydrolysis resistant) PBT resins to help manufactures meet these requirements. As with many additive technologies in plastics, there are trade-offs. In this case, hydrolysis resistance was often improved at the expense of melt viscosity stability and high flow during the injection molding process.