EFFECT OF MOLDING PARAMETERS ON COMPRESSION MOLDED SHEET MOLDING COMPOUNDS PARTS

A detailed experimental study was carried out to determine the effects of molding variables on the physical and mechanical properties of com pression molded SMC (sheet molding compounds) parts. Simple compressio n tests using grease oil and mylar sheet as a lubricant at various tem peratures were examined in characterizing the complex effect of SMC re sin, fiberglass, and temperature on the flow stress of SMC. To investi gate the effect of the molding parameters on the tensile and flexural properties of molded flat parts, two different mold temperatures and m old closing speeds were used for fabrication of test specimens under p lane-strain conditions. Surface roughness, tensile and three-point ben ding tests were used in determining the surface qualities and the mech anical properties of the compression molded SMC parts. The fiber orien tation 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.