N. Pearce et al., A STUDY OF THE EFFECTS OF CONVERGENT FLOW FRONTS ON THE PROPERTIES OFFIBER-REINFORCED COMPOSITES PRODUCED BY RTM, Composites. Part A, Applied science and manufacturing, 29(1-2), 1998, pp. 141-152
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.