Aisin claims a world first with a new plastic belt-driven sunroof that will make sunroofs lighter, more durable and less costly. The company says the new design has been enabled with DuPont materials and delivers 40 percent cost savings, reduces component weight 45 percent and cuts parts by 33 percent.

Aisin says the design uses DuPont(TM) Hytrel(R) polyester elastomer, Zytel(R) high-performance PPA, Rynite(R) PET, Delrin(R) acetyl and Zytel(R) PA66. This patented design, appearing on the Toyota Opa in 2003, received an achievement award in the body interior category of the SPE Automotive Division Innovation Awards program. Aisin says that this application is expected to be on more imported vehicles as well as on some U.S. automakers' vehicles within the next few years.

The new Aisin system uses a Hytrel(R) belt with moulded-in teeth to engage a drive gear made of Delrin(R), reducing friction and noise for much smoother operation than traditional metal cable and steel gear-based systems. The older system requires plastic flocking on the cable to help reduce friction and noise, adding cost and complexity.

The company says that Hytrel(R) increases drive belt durability through exceptional wear resistance and flexibility combined with high strength and dimensional stability, even when exposed to moisture and temperatures over 120 degrees Celsius. Delrin(R) and Hytrel(R) lower friction, helping to increase the transmission efficiency of torque by 30 percent, making it possible to use a more compact, lightweight electric motor that also consumes less energy. In operation, the sunroof features an electronic stop versus a mechanical stop that further improves motor reliability, according to Aisin.

Aisin says its design significantly reduces system complexity by integrating the front shoe of Rynite(R) and the functional slider bracket of mineral and glass-reinforced Zytel(R) high-performance PPA. This eliminates several heavier metal components that require riveting for assembly. The outstanding dimensional stability and strength of Zytel(R) high-performance PPA used in this crucial bracket also help improve durability. The linkage and Zytel(R) PA66 rear shoe also are integrated, further reducing assembly complexity.

Suggested further reading: Global market review for vehicle sunroofs: forecasts to 2005