Is steel auto frame plastics' next target?

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The auto industry has used structural plastics for years, in door panels, trunks, exterior fascia and a range of other parts.

But Magna International Inc. believes the industry may be nearing a new turning point, where thermoplastic composites could take over from steel in major parts of the car.

“This is moving from body structure to the full frame,” said William Harney, executive director of research and development for Magna's exteriors and interiors group, during a media event at Magna's Novi seating division facility Feb. 16.

The press event focused on new technology.

Auto industry watchers and insiders have predicted that plastics could win more business as carmakers try to shave weight off vehicles and meet increasing fuel economy requirements in the United States.

However, Magna, headquartered in Aurora, Ontario, has developed an advanced composites research team that is looking at opportunities to move beyond typical targets for material replacement. It also has a partnership with Natural Resources Council Canada to support research projects. That partnership includes a composites research center in Concord, Ontario, that will study lightweight and bio-based composites.

The potential for such applications has grown in conjunction with advancements in thermoplastic molding technology, Harney said.

In-line compounding gained wide acceptance in the auto industry since it first debuted, but early parts married glass with polypropylene. The low melt temperature of PP limited its use in structural parts, since standard auto production puts the frame through a high-temperature process for corrosion resistance.

The ability to combine in-line compounding with high-temperature resins such as nylon, however, would create thermoplastic composites that can withstand the high temperatures of an electrocoat process, expanding the range of places where it can be used, Harney said.

The composites center also is looking into carbon-fiber processing, thermoset composites and a variety of other future structural plastic parts.

Meanwhile Magna is marketing a new plastic part to North American automakers: an “active grille” that is placed at the front of the car, in front of the radiator, and has plastic louvers that open and close based on the need for engine cooling.

When the engine does not require cool air, the company said, the louvers are closed, improving airflow and fuel economy.

Active grilles already are used in Europe and on one model of General Motors Co.'s Chevrolet Cruze, the Cruze Eco, which places the shutter system behind the lower grille.