Effect of molding parameters on compression molded sheet molding compounds parts

Abstract

A detailed experimental study was carried out to determine the effects of molding variables on the physical and mechanical properties of compression molded SMC (sheet molding compounds) parts. Simple compression tests using grease oil and mylar sheet as a lubricant at various temperatures were examined in characterizing the complex effect of SMC resin, fiberglass, and temperature on the flow stress of SMC. To investigate the effect of the molding parameters on the tensile and flexural properties of molded flat parts, two different mold temperatures and mold closing speeds were used for fabrication of test specimens under plane-strain conditions. Surface roughness, tensile and three-point bending tests were used in determining the surface qualities and the mechanical properties of the compression molded SMC parts. The fiber orientation and distribution in the molded parts were also investigated by taking photographs of burnt flat specimens and photographs using SEM (scanning electron microscope) of specimens of T-shaped cross-section. (C) 1997 Elsevier Science S.A.