Analysis of resin transfer moulding process with controlled multiple gates resin injection

In resin transfer moulding, increase of fibre volume fraction decelerates the resin flow. For fast resin flow without increasing injection pressure, resin can be injected using multiple injection gates. However, with improper injection schemes, the resin front becomes complicated and numerous air bubbles may form where the flow fronts merge. In this study, two different multiple gate injection schemes were investigated. One is to open the gates in a sequential manner as the resin front advances. The other is to control the resin injection pressure as a function of time. Mould filling was simulated numerically using the Control Volume Finite Element Method (CVFEM). Experiments were performed to verify the simulation results. The resin front shapes observed from the experiments were compared with the numerical results. Close agreements were found. The controlled multiple gate injection methods were proven to reduce the injection time by a big margin as well as to prevent the formation of air bubbles due to air entrapment.