Evaluation of Resin Impregnation Behavior in Thick FRP with Corner During VaRTM Process

Abstract

Vacuum assisted resin transfer molding (VaRTM) method is a manufacturing method for FRP, which is capable of producing relatively high quality parts at low cost. However, since resin impregnation behavior in the fibre preform during VaRTM process is still not understood exactly, there is a possibility of voids being remained after cure. The purpose of this study is to evaluate resin impregnation behavior in thick FRP with corner, which is said to be likely to contain voids, by focusing out-of-plane flow in the fibre preform attributed to distribution media (DM). However, our previous experiments show that when DM is placed on top of fibre preform, the flow front along the bottom surface becomes quite complicated, and thus the quantitative evaluation of resin impregnation behavior is of great difficulty. Therefore at first we evaluated the effect of permeability of DM (KDM) and the number of plies on the flow front shape by using a flat tool. It was found that when KDM is low or number of plies is small, the flow front along the bottom surface becomes relatively linear, while with higher KDM or larger number of plies, the flow front along the top surface becomes complicated. We evaluate resin impregnation behavior in thick FRP with corner by using mentioned DM with appropriately low KDM.