Flow characterisation of sheet moulding compounds (SMC)

摘要

The compression moulding flow of SMC has been investigated by squeeze flow testing between parallel circular plates at room temperature and a modestly elevated temperature of 30 deg C. A model based on the upper bound theory was abopted to characterise the squeeze flow of SMC. The present results indicate that the squeeze flow of SMC at 30 deg C is predominantly extensional with shear becoming significant at very small plate separations. Measurements of the pressure distribution across the plate also indicate that the flow is predominantly extensional. The presence of edge effects due to fibre length is also evident. The strong dependence of the compresson moulding flow characteristics of SMC with temperature is demonstrated by the different behaviour of SMC tested at room temperature.