Effect of two stage pressure molding on surface quality of sheet molding compounds

摘要

AbstractThe goal of this work was to investigate the effect of two stage pressure molding on the compression molding of a sheet molding compound (SMC). It has been shown in previous studies that a rapid drop in pressure during SMC curing significantly reduced severity of sink marks. This study concentrated on a method of predicting the optimum time during curing to release pressure by examining material behavior through process data from in‐mold sersors. A simple control scheme was them applied for automatic pressure release at the optimum time corresponding with the peak of the material expansion and the onset of the reaction exother