DETROIT — Delphi Automotive Systems' much-heralded Super Plug plastic door module has had a brush with kryptonite.
When the Super Plug was introduced in 1995, it was lauded for its invention and awarded with several top industry honors. Now, its producer, Delphi, says it plans a retrenchment to a metal-and-plastic hybrid for its next generation of door modules.
``It seems better to use different types of materials than to stay with all plastic,'' said Gary Nordberg, manager of modular doors for Delphi, based in Troy, Mich. ``We want the steel in the modules for product integrity and side-impact safety. We've learned more over time.''
Nordberg made his comment during the Society of Automotive Engineers' SAE '99 conference, held March 1-4 in Detroit.
The Super Plug caught the plastics industry's attention as the first one-piece interior door module made entirely of composite thermoplastics.
The supplier claimed that the module consolidated as many as 61 parts by eliminating fasteners and screws. The module provided a carrier to hold other door parts, such as window regulator plates, wire harnesses and speaker mounts.
Delphi worked on development with General Motors Corp., which at the time owned the supplier, and GE Plastics, which provided the special glass-reinforced polycarbonate/polyester blend used to make the door panel.
Now, Delphi plans to shy away from engineered resins and move to commodity materials like polypropylene and polyester on future programs, said Becky Farless, Delphi engineering group manager for modular door systems.
``We've made a shift to more-standard material,'' Farless said. ``It helps us find it globally and at a good price.''
Even as the supplier moves away from Super Plug, Delphi has launched a new door-module business. The company, spun off from GM in February, was just awarded new contracts worth about $558 million with truck makers Navistar International Corp. of Chicago and MAN of Grosspetersdorf, Austria, and several major carmakers.
Those programs, which will include a metal-and-plastic door module, will start within the next eight months, Nordberg said. Delphi will mold, stamp and assemble the modules at plants worldwide, including facilities in Columbus, Ohio, and Adrian, Mich.
The new modules will eliminate as much as 70 percent of the fasteners and components of a conventional door system, Nordberg said.
The firm will use a combination of injection and compression molding to make the thermoplastic components of the modular door carrier. Then glass and latching subsystems are added into the door before wiring and other components are attached, Farless said. The entire piece slips into the door cavity on an assembly line.
The Super Plug is used on several current car models, including the Chevrolet Malibu and several GM minivans, including the Chevrolet Venture, Pontiac Trans Sport and Oldsmobile Silhouette.
Interior-systems supplier Lear Corp. also has been developing a plastic door module that it introduced as a concept in 1997. Lear officials were unavailable for comment to discuss the progress of its One-Step Door Module.