By: Rhoda Miel
October 28, 2013
DÜSSELDORF, GERMANY — Sabic Innovative Plastics has spent more than 10 years working to convince the auto industry to use more polycarbonate as a glass replacement for car windows.
Its Exatec LLC unit developed glazing technology to protect the plastic and ensure PC will meet safety and performance requirements. It has won some success in sunroof systems, especially in Europe, but now is making its debut on side windows, appearing on Volkswagen AG's XL1 high-efficiency hybrid car.
The XL1 was exhibited at K 2013, held Oct. 16-23 in Düsseldorf.
The hybrid uses plastics extensively, with carbon fiber used for its body and lithium-ion battery pack providing support for the electric drive. It is going into limited production at this point, with each one made at VW's Osnabrück, Germany, plant. The plug-in electric engine is supported by a diesel hybrid engine, with the two systems capable of going 100 kilometers on less than 1 liter of fuel.
The unconventional design has a streamlined shape to improve the car's aerodynamics. The driver's and passenger's seats are slightly off-center from each other to allow for a narrower car body.
The two-seat vehicle is the first vehicle to feature advanced plasma coating on two-component injection molded PC windows, Sabic said. Volkswagen said the side windows are 33 percent lighter than conventional glass, but the driver and passenger can still roll down the small windows — making them the first PC roll-down, moving windows used in the auto industry. The XL1 also uses Sabic's Lexan PC in the rear quarter windows.
Sabic has made a long-term commitment to developing PC as a real alternative for the auto industry globally. Its Exatec facility in Wixom, Mich., has full-production prototyping capabilities with molding and glazing operations.
"We're passionate about glazing in cars because of what it can do with polycarbonate in parts integration," said Scott Fallon, general manager for automotive at Sabic.
The auto industry is now beginning to catch on, thanks to demands for improved fuel economy in North America and reduced emissions in Europe.
"The challenges within the industry are all pointing things in our favor now," he said.
While the XL1 is a limited-production vehicle, it still is an important vehicle for Volkswagen, capable of bringing together multiple technologies. It is an icon for the carmaker, and Lexan and Exatec are a prominent part of it — right down to having the Exatec logo on the side windows.
Exatec will produce the windows and ship them to Germany for assembly.
"The plasma-coated windows from Sabic are one of many distinguishing features on the XL1 that help us lighten the vehicle to reduce energy consumption," said Ulrich Hackenberg, member of the board for Volkswagen's passenger-car group.
In addition to the XL1, Sabic also is showcasing a concept for an all-thermoplastic liftgate, which would come in at 30 percent lighter than a conventional tailgate. The concept would use Stamax long-glass-fiber-reinforced polypropylene or Vertron long-glass-fiber-reinforced polybutylene terephthalate for structural components, Noryl GTX for the outer layer and Lexan PC with Exatec coating to replace the glass.
The total weight savings adds up to 12 kilograms (26½ pounds).
"The real benefit is in system integration," Fallon said. "We didn't just replace metal, we showed what the whole system can do."