Study on high-speed RTM to reduce the impregnation time of carbon/epoxy composites

Abstract

The resin transfer molding (RTM) process is widely used to fabricate carbon fiber reinforced composite structures. However, conventional RTM processes are limited with regard to producing larger structures due to impregnation time significantly increasing in proportion to the surface area of products. In this study, composite plate structures were fabricated using a new high-speed RTM process to reduce impregnation time. The key idea of this method is to change the resin flow direction from in-plane to through-thickness for the preform. Computational fluid dynamics (CFD) simulation was introduced to investigate the impregnation state of preform with respect to the number and size of vacuum gates. Impregnation tests, under conditions similar to those in the CFD simulation, were carried out, and the impregnation behaviors of the resin were compared with the simulation results. Finally, an optimization process was carried out to find the number of vacuum gates and permeability ratio that result in the minimum impregnation time. (C) 2014 Elsevier Ltd. All rights reserved.