Shear and extensional flow of reinforced plastics in injection molding. I. Effects of temperature and shear rate with bulk molding compound

Abstract

Abstract Capillary flow studies on bulk molding compound (BMC) using an instrumented injection‐molding machine are reported. The significance of extensional flow effects with fiber‐reinforced materials is emphasized. The extensional flow behavior in converging dies is modeled, and a means of evaluating both extensional and shear viscosity from capillary flow data is proposed. Methods of correcting results for the effect of deformation heating are discussed. The shear and extensional flow behavior of BMC in the temperature region 18 to 58°C can be fitted to a simplified Arrhenius Law.