fatherlarry
03-08-2002, 07:16 PM
Plastic body panels have tremendous advantages over their steel and aluminum counterparts. While metal panels are easily dented by minor impacts, plastic body panels are more resistant to damage. There are a number of plastic systems used for body panel applications. The three most important are SMC (Sheet Molding Compound - a thermoset polyester sheet), RIM-urethane (Reaction Injection Molding - also a thermoset system in which urethane resin is injected into the mold), and thermoplastic systems (including thermoplastic olefins, among others). All three systems use plastics reinforced with glass fiber, to add rigidity and structural support. The first use of plastic in body panels was in Chevrolet's Corvette (SMC), followed by Pontiac's Fiero (RIM). General Motor's Saturn line of cars is the first to use thermoplastics.