Produced by General Motors from then GE Plastics’ (now SABIC Innovative Plastics) Noryl GTX 910 resin, the part’s use of an MPPE/PA copolymer eventually was adopted by 45 platforms and 20 million vehicles globally.
After the initial success, GM utilized the same material for the fenders on its 1987 model year Buick Reatta sports coupe, among other vehicles. From 1989-2005, GM’s Saturn passenger vehicles utilized thermoplastics for exterior vertical body panels. Such panels have since been carried beyond automotive to tractors and lawnmowers for home and agricultural use.
A team at GE worked for more than five years to develop a polymer that would fulfill GM’s requirements for a material that was high quality, lightweight, damage and corrosion resistant, and compatible with then current body-build practices and paint systems. GM’s own engineering group reviewed, tested, and rejected 160 different materials from 17 resin suppliers before settling on the MPPE/PA grade. Offering thermal stability that could endure online priming and painting, the material allowed the panels to be assembled to the body-in-white (BIW). In addition, the polymer alloy offered low-temperature impact strength, good thermal stability, broad chemical resistance, low mold shrinkage, low moisture absorption (vs. nylon alone), and good dimensional stability.
Making the switch from steel to thermoplastic enabled GM to reduce part weight 40% (4 lb (1.8 kg) compared to 7.3 lb (3.3 kg) in steel). GM’s Buick Factory 8 in Flint, MI molded the first fenders for the Buick LeSabre T-Type sports coupe utilizing molds from Delta Tooling (Auburn Hills, MI). Dave Malik, director-Front & Rear Closures, and Henry Brockman, lead engineer, both from GM, will accept the award on Nov. 12 at SPE’s annual Automotive Innovation Awards Gala at Burton Manor in Livonia, MI. —[email protected]