TROY, MICH. — Plastic will make its way into more automotive window systems during the coming months and years.
The question is whether the material will be in the form of a thin barrier married to glass in the side and rear windows of a vehicle, or if those windows will switch to a coated polycarbonate.
Plastic-laminated glass already goes into front windshields worldwide. Some European automakers have adopted the material for other windows. The first major North American launch of laminated side windows could begin production by this summer.
Now Exatec LLC, a joint venture between Bayer Corp. and GE Plastics, is making a multi-million dollar investment to help make PC windows a commercially viable alternative.
"We're seeing interest globally," said Exatec President Cynthia Arnold at the Society of Plastic Engineers' Global Automotive Safety Conference, which was held Feb. 5 in Troy. SPE is based in Brookfield, Conn.
The company is installing plasma deposition technology at its Wixom, Mich., headquarters, which it will use to coat PC with an abrasion-resistant layer necessary for commercialization. Arnold would not give the exact cost of the project.
Both suppliers and automobile manufacturers have considered all-plastic windows in the past but with little success.
Polycarbonate now typically goes into only a few small windows on vehicles, such as a non-moving quarter panel on sport utility vehicles or minivans.
But PC still shows promise, Arnold said, especially for its ability to reduce vehicle weight. PC weighs half as much as a typical glass window.
Cutting pounds improves gasoline mileage and also helps lower the center of gravity in SUVs and minivans. A lower balance helps reduce the potential of a rollover crash.
About 90 percent of all fatalities from SUV crashes were linked to rollovers, Arnold said, compared to less than a quarter of the fatalities in passenger cars.
Exatec already has test vehicles using PC everywhere but the windshield, she said. The switch reduced the weight of a Dodge Caravan by 44 pounds.
Polycarbonate also offers additional protection during a crash, because the material will not shatter — unlike tempered safety glass — keeping crash victims inside the vehicle.
Exatec has worked with rescue personnel to ensure emergency crews can get through the systems using existing equipment.
Backers of plastic-laminated glass windows likewise point to their products' potential to keep passengers inside the vehicle but note it is far closer to market than polycarbonate.
"We've been producing laminated glass for 62 years," said Michael L. Sanders, automotive marketing manager for DuPont Automotive, which is a supplier of the plastic-enhanced product. "This is a proven technology. We're just moving it to another part of the vehicle."
Laminated glass will go onto rear and side windows on 1.5 million vehicles by 2002, up from 400,000 vehicles last year.
Either laminates or polycarbonate windows will aid vehicle safety by reducing the chance that someone will be ejected from a vehicle in a crash, said Brian O'Neill, president of the Insurance Institute for Highway Safety.
But so would consistent use of seat belts and even side air bags that inflate to form a barrier along the window.
"All of the above will help," O'Neill said.
Arnold said PC offers more advantages than laminated glass. PC windows are lighter, and the pure plastic program also allows molders to add brackets, make complex shapes and add color to spice up a vehicle's style, she said.
It will take time to bring polycarbonate up to speed for commercial applications, however. Full development programs with the plasma deposition technology in Wixom will not be up and running for another year.
The first focus will be on rear windows and nonfunctional side windows, typically found in SUVs and minivans.
"Technology can drive safety," she said.