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Field cracking in some instrument panels (IP) manufactured with a competitive grade of polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) material was observed in high temperature/high humidity geographies. OEMs and tier molders are: 1) questioning the thermal and hydrolytic stability of the various suppliers' PC/ABS resins, and 2) converting to grades with advantaged stability. A study was undertaken to compare the thermal and hydrolytic stability of two suppliers' high flow PC/ABS resins. Materials were aged at 90C/95% relative humidity up to 1000 hours. Samples were tested to compare the retention of properties. This paper will discuss the experimental procedures, resulting data, and the common factor in the PC/ABS resins showing the best stability.

The QUESTRA* Crystalline Polymer product family, based on syndiotactic polystyrene (SPS), has been improved to meet the needs of the automotive connector and light socket applications in a very cost effective manner. In this paper, the attributes of two new SPS formulations, SPS/polyamide (PA) blends and low gas SPS formulations, are compared to existing SPS formulations and competitive resins. It is shown that the SPS/PA blends have significantly improved strength and ductility over existing SPS formulations. This improves the SPS formulation technology to include the full range of strength and ductility options the designer of automotive connectors needs to achieve the terminal retention forces and latch deflection distances necessary for the smaller connectors like the .64 mm terminal systems that the automotive industry is migrating towards.

An advanced high flow PCABS was developed for improving the efficiency of injection molding processes and cycle times. Proprietary technology was used to develop this new blend while maintaining key properties (heat resistance and impact) necessary to meet end use part requirements. Significant rheological improvements in melt flow rate (MFR) and flow capabilities throughout the entire viscosity versus shear rate range were obtained. These improvements allowed for lower cooling times (21-27% reduction) and injection pressures. Molders using this resin have the potential to improve cycle times, improve processes, and save money. This paper will document cycle time and process improvements in automotive instrument panel applications with the new high flow PCABS blend, PULSE*2000EZ.

The passing of the federal regulation for head impact protection for upper interior components (FMVSS 201U) has led to the use of a variety of foam materials in interior trim pillar and headliner reinforcement applications. Polyurethane foams and expanded bead foams are some of the commonly used foams in these applications. However, the low energy absorption efficiency (35% - 55%) of the current foams requires the use of 20 mm - 40 mm of packaging space to integrate the countermeasures that make it possible to meet the regulations. A newly developed high efficiency olefin based foam is able to meet the performance requirements at a reduced packaging space. A combination of physical structure and superior mechanical properties provides the much needed higher efficiency (80% - 90%) of the olefinic foam. This paper discusses the foam architecture and performance benefits for many interior applications, such as energy absorbing countermeasures in pillar trim, headliners, and door panels.

The major element of contact between the occupant, the vehicle and the road surface is the automobile seat. Flexible polyurethane foams are the material of choice for this application, not only because of the economies offered by large-scale molding operations, but also because the cushioning characteristics of the foam/seat assembly can be adjusted. The automotive original equipment manufacturers (OEM’s) worldwide are looking for optimization of the balance between foam weight and foam specifications, with more emphasis than ever on comfort and durability. This goes with specific requirements for the various foam pads, i.e., front cushion, rear cushion, front backrest and rear backrest. Commercially useful foams can be made from a variety of polyurethane molding chemistries.