Every automaker uses its share of plastics nowadays. But you wouldn’t know it from the outcome of this year’s Automotive Innovations competition sponsored by the Society of Plastics Engineers. The Chrysler Group won seven of 10 categories, including the Grand Award. Part of the reason comes down to the number of new models the company launched this year. “We had 10 launches, and that provided us with the opportunity to try different things,” says Susan Yester, senior manager for organic materials development in Chrysler’s Advanced Materials Group. But those new things didn’t necessarily have to be made from plastic. “We don’t have a materials bias,” Yester says, explaining that plastic was used in each of the winning parts because it offered advantages such as parts-consolidation, higher quality, weight savings, safety improvements or cost reduction. Here’s a look at Chrysler’s winning parts:
A Better Bumper
Blow-molded front and rear bumpers for the 2007 Jeep Wrangler won both the Grand Award and Exteriors Award. This thermoplastic polyolefin (TPO) bumper system, which combines fascia and beam functionality, replaces previous all-steel designs. By handling some of the structural chores, which include 5 mph impact and a 300 lb top load at 82C, the TPO bumper allowed Chrysler to go with a lighter steel cross-beam, resulting in a 9 percent weight reduction. Piece-part and assembly costs fell too, by 12 percent. ABC Group served as the system supplier for the project, helping with the design and handling not only of the molding but also the tooling and material development. Tim Chapman, vice president of the ABC’s Advanced Technology Group, says one of the key challenges was developing a TPO soft enough to help absorb impact energy yet stiff and strong enough to meet the loading requirements. Another challenge related to meeting European pedestrian safety requirements with the bumper – something Chrysler and ABC accomplished with a second, deeper bumper geometry for that market.
Window Regulator Needs No Rails
The winner in the Chassis-Hardware category was a rail-less window regulator with integrated drum housing for the 2007 Dodge Nitro SUV. This design, produced by Faurecia Interior Systems using polypropylene reinforced with commingled glass and thermoplastic filaments, represents the first integrated, cable-driven window regulator for door modules. And in another industry first, it features a robotically extruded thermoplastic seal to separate the “wet” and “dry” sides the system. Chrysler’s Yester notes that the part is a good example of the parts consolidation possible with innovative plastics designs and processing. The weight savings attributed to the system come to about 25 percent.
TPV Primary Seals
Primary door seals for the 2007 Dodge Ram took home the top honors in the Materials category. The seals represent the first use of a thermoplastic vulcanizate (TPV) in a primary body-mounted sealing application. These demanding dynamic seals have traditionally been made from a thermoset rubber, EPDM-sponge. Jyco Sealing Technologies served as the system supplier and also supplied the proprietary Jy-Flex TPV used in the seals. According to Shawn Jyawook, Jyco’s chief operating officer, the seals offered a 20 percent cost advantage over EPDM – mostly due to the increased manufacturing efficiencies and in-line secondary operations associated with thermoplastic extrusion.