GE’s Lexan* EXL Resin Featured in New Cadillac DTS Instrument Panel

BERGEN OP ZOOM, THE NETHERLANDS. — May 10, 2006 — To create an innovative instrument panel (IP) incorporating the passenger air bag system for GM’s upcoming Cadillac DTS model, Lear Corporation, a Fortune 500 supplier of integrated automotive interiors, took an innovative approach. The company’s design, featuring an IP Active Upper, or “topper,” instead of the traditional air bag door, required several critical material properties. To enable the topper to rapidly lift up above the inflating air bag while avoiding the safety hazard of fragmentation, especially at low temperatures, the material had to be highly ductile. To prevent degradation from temperature extremes over the life of the vehicle, the material needed to resist environmental aging. Finally, it had to offer design flexibility to accommodate the limited space offered by the Cadillac’s aggressive windshield rake angle.

GM and Lear selected GE’s Lexan* EXL 1414H resin, a polycarbonate (PC)-siloxane copolymer, to produce a topper, offering seamless appearance for better interior appearance harmony, high performance, and consumer safety. As an added benefit, the GE material eliminated the need for the addition of several metal components through part consolidation.

“We created a great IP design but needed to find the right material for it,” said Bob Morris, vice president of Integration for Lear’s GM Division. “GE not only provided the best resin, but also worked with us to fine-tune the design to achieve excellent aesthetics, safety, and performance for the IP topper, while avoiding costs through part consolidation.”

GE technical experts provided finite element analysis (FEA) and deployment simulations of Lear’s CAD design using Lexan EXL resin data, and assistance with the entire molding process. Together, the close work between GE and Lear helped take an innovative design and make it successful.

Lear is also using GE’s Lexan EXL 1414H resin to mold the IP topper for the upcoming 2006 GM Buick Lucerne.

Inflation without Fragmentation

GE’s Lexan EXL resin allowed Lear to incorporate a dual-depth passenger air bag system into the IP design without the risk of fragmentation, breakage, or sharp edges that can occur during an inflation when traditional materials are used. The low-temperature ductility of the GE resin, down to –40 C, helps ensure consumer safety vs. similar PCs or lesser-performing resins currently on the market. The material met the requirements of low-temperature ductility performance, resisting embrittlement before and after heat aging (400 hours at 102 C). GE’s Lexan EXL resin retains 90 percent of impact strength after heat aging.

After the air bag deployment is completed, the excellent elasticity and ductility of Lexan EXL resin allow the IP topper to limit its upward travel enough to avoid headform intrusion into the opening space, which may help to protect the passenger’s head in secondary impacts.

The durability of GE’s Lexan EXL resin at cold temperatures makes the material an attractive option for components in the air bag deployment area. The material’s design flexibility also offers Lear the potential to eliminate metal reinforcement parts in these and future systems for further cost reductions.

According to Bob Nelson, GE’s market director, Automotive, the versatility of the Lexan EXL resin is a prime example of why major manufacturers like Lear depend on GE innovation. “Our materials offer an unbeatable combination of performance, flexibility, and value. Together with our global technical resources, GE materials help customers deliver winning products and with our Lexan EXL resin, increased safety for consumers.”

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