A STUDY OF THE EFFECTS OF CONVERGENT FLOW FRONTS ON THE PROPERTIES OFFIBER-REINFORCED COMPOSITES PRODUCED BY RTM

The processing speed of resin transfer moulding (RTM) can be improved by using multiple injection ports. Out of necessity this results in th e convergence of resin flow fronts. Such convergence can result in the entrapment of voids within the composite leading to a degradation of mechanical properties. A series of carbon/epoxy plates of differing we ave styles were manufactured by RTM in a transparent mould with portin g arrangements designed to cause resin flows to converge. The plates w ere analysed to determine the effect of injection strategy, injection temperature and differences in weave style. Analysis was performed by qualitative ultrasound scanning, quantitative image analysis and inter laminar shear strength testing. It has been shown that there is a mark ed increase in voidage in the areas where hows meet and this is correl ated to a deterioration of mechanical properties. (C) 1997 Elsevier Sc ience Limited.