Executive Summary Bulk Molding Compound (BMC) and Sheet Molding Compound (SMC) materials are used for a wide range of automotive and truck parts, from headlamp housings to under-the-hood electrical and heat-shielding components to exterior body parts and interior structural and cosmetic components. Thermoset compounds are used because of their high thermal stability, low coefficient of thermal expansion (comparable to steel), high impact strength, relatively low weight, and their receptiveness to paint. Many of these parts are used where a Class A surface finish is required, as these materials can endure the required paint and bake cycles of the automotive industry. |