Front and rear racks on the Sportsman 700 Twin all-terrain vehicle (ATV) from Polaris Industries Inc., Medina, Minn. (www.polarisindustries.com), must carry heavy loads at temperatures down to -25°F. Instead of forging, welding, and painting steel racks, Polaris engineers selected Celstran long-fiber-reinforced thermoplastic (LFRT) from Ticona, Summit, N.J. (www.ticona-us.com), for a molded part with high impact and flexural strength in the cold.
The injection-molded racks are made of Celstran PP FG40 02 LFRT, which contains 40% long-glass fibers in a polypropylene matrix. This grade has a notched Izod impact strength of 5.1 and 6.7 ft-lb/in. at 70°C and -40°C, respectively. The resin resists creep and wear. High UV and chemical resistance ensures that it weathers well and doesn't corrode. "The racks have the fatigue resistance to flex when carrying sandbags and other substantial loads as the ATV traverses rough terrain," says Scott Ostroski, a Polaris spokesman. "The racks weigh less than if they were made of steel, and molding them was much faster than forming them from steel. Also, the racks need no secondary steps after processing," he adds.
