DETROIT — Rehau Inc. this year will begin molding one of the first all-thermoplastic front and rear bumpers made in North America, when production starts on a new vehicle for Mercedes-Benz AG.
The Leesburg, Va., injection molder was awarded the contract to make a variety of exterior parts for Mercedes's new sports utility vehicle. The light truck, which goes by the working title All Activity Vehicle, is scheduled to begin production in Vance, Ala., in July.
Mercedes asked Rehau to provide parts made exclusively from engineering thermoplastics, automotive product manager Roger Shoemaker said in a Feb. 24 interview at the Society of Automotive Engineers International Congress and Exposition in Detroit.
The company exhibited the vehicle's plastic frame at the show.
``They asked us to put our injection molding expertise to good advantage by producing light, durable plastic parts,'' Shoemaker said. ``We came up with some solutions that had worked for us in Europe but are fairly unique for North America.''
Among the vehicle's components are complete bumper systems made from polypropylene and other thermoplastic composites. The system includes an impact-absorbing inlay, ultrasonically welded to the fascia and snapped in place. Paint is applied through a robot-activated, flame-treatment process that eliminates the need for primer and reduces emissions.
The vehicle's rear pillars feature an acrylic material that is brought to a high-gloss finish through in-mold decoration.
The vehicle also includes an accelerator-pedal assembly made entirely from 35 percent glass-filled nylon 12, which Shoemaker said is unusual in North America. Rehau used dual injection molding to bond the upper and lower roof screen and window cowl screen, all of which use PP-based composites. The window cowl includes in-mold decorating featuring 2,100 pin-sized holes.
Body side moldings, wheel house covers, the radiator grille, the headlamp bezel and lift-gate handle also are made from plastic.
The parts will be produced at Rehau's Cullman, Ala., plant, which was expanded in January to 386,000 square feet. Shoemaker said that, not including equipment costs, the expansion cost $24 million.
To mold the part, the plant uses machines with clamping forces of 25-3,000 tons. The company did not disclose the number of presses there.
Mercedes expects to produce 65,000 sports utility vehicles during the first production year, Shoemaker said. Rehau will ship the parts about 50 miles to supply the Mercedes operation, he added.
Rehau is a subsidiary of Fraenkische Plastiks of Rehau, Germany. Shoemaker said some of the plastics technology has been used in Germany, where Mercedes is Rehau's largest automotive customer.
The company has nine plants in North America supplying automotive, furniture, construction, appliance and other markets.