Development of Plastic Lamp Housings

New housing materials have been developed for exterior automotive lamps, to replace the traditionally used die cast zinc and stamped steel or aluminum. Polyester premix was introduced into production by General Motors for rear lamp housings in the 1967 model year, and fiber glass reinforced polypropylene in the 1969 model year. The developmental programs which led to the approval of these new housing materials are briefly outlined. The functional requirements of this application and the comparative performances in functional tests of the metal and plastic materials are reviewed. The material physical property requirements for this application and the comparative properties of steel, aluminum, die cast zinc, polyester premix, fiber glass reinforced polypropylene, and talc-filled polypropylene are also discussed.