General Motors Corp. created a buzz Jan. 7 at the North American International Auto Show in Detroit when it introduced the Volt electric concept car, something executives maintain could make a difference in the way cars are powered in the coming decades.
The car also allowed GE Plastics to show off a whole new concept for the auto industry that could change the way car bodies are made within just a few years.
Nearly every exterior part of the Volt was made with GE thermoplastics, with the exception of the glass. GE's materials went inside as well - on the instrument panel, replacing the steel core in the steering wheel, on the door panel and in lighting.
The Volt was created to run solely on battery power. It can be plugged in to a standard outlet at home and run for up to 40 miles. It also could carry an on-board engine that could be run with gasoline, diesel or biofuel to create energy to supply the batteries with additional electricity.
To make the car a realistic concept, GM needed something light. By teaming with GE, GM shaved 60 pounds from the car.
The biggest potential game changer may be on the hood, where the plastics giant tested a new way to mold thermoplastics for large, horizontal surfaces.
GE married two sheets of its Xenoy iQ polycarbonate/polybutylene terephthalate with woven glass in a very low-compression molding process that could make it possible for thermoplastics to compete against thermoset composites on large parts like the hood.
The process will be ready to enter the market soon, Rob Butterfield, GE Plastics global market director of design and innovation, said at the auto show. ``We are looking at technology that is near-term,'' he said.
Thermoplastics typically cannot meet the structural requirements for large, horizontal panels like the hood, requiring automakers to use either steel or thermosets.
GE's solution for the Volt was to create an outer panel that meets the high-gloss aesthetics required for a carmaker, with a second layer that the company can shape to not only provide structural support, but also improve sound quality and provide ``bounce back'' zones that are required for European pedestrian safety standards.
The hood can be molded within a three-minute cycle, allowing the process to compete with thermoset compression molding, while the low pressure allows for less-expensive tooling and smaller presses, Butterfield said.
The year-long collaboration also allowed GM to tap into GE's environmental improvements. The Xenoy used in the body panels would use the plastic from 400 used water bottles, said Amanda Roble, executive director for GE Plastics' automotive business.
``They saw a way to unite their vision with our history of innovation and our Ecomagination initiatives,'' she said.
Uniting those visions put the car company's designers in close contact with plastics engineers for months.
They learned about the Lexan PC roof and rear deck lid, which also used a protective coating created by Exatec LLC of Wixom, Mich., a joint venture of GE and Bayer MaterialScience LLC. The PC, in turn, allowed GM designers to show off an interior that also was filled with plastic.
``One of our intentions was about getting light into the interior,'' said Wade Bryant, design manager of advanced interiors. ``From an interior designer's perspective, it's great just to be able to show off the interiors.
The Detroit carmaker also used coated Lexan on the doors to raise the exterior panels to a higher level - an auto style trend referred to as a ``high beltline'' - but also still keep the visibility of a standard door.
``This allows us to provide the best of both worlds,'' Bryant said.
And the car features GE materials beyond the exterior skin, including Xenoy energy absorbers under the bumper fascia, Lexan EXL resins used for the steering wheel and instrument panel and even the coating on the electrical wiring produced from Noryl GTX resins.
GM has not set any date for a potential production version of the Volt, though GE expects to have its new processes used on the concept car ready for the market within a few months. And for their part, GE engineers said now that GM designers have seen what their plastics can do on concept cars, they will put them into an increasing number of cars heading out to the general public.
``Our customers can bookshelf this technology and pull it out whenever they need it,'' Butterfield said. ``It's now part of their understanding of materials. They've put it into their palette.''