Experimental analysis of mold filling in vacuum assisted compression resin transfer molding

Abstract

Vacuum-assisted compression resin transfer molding, a flexible resin transfer molding process, has been developed to reduce a cycling period in the present study. The vacuum-assisted compression resin transfer molding utilizes an extra elastic film placed between the upper mold and the mold cavity compared with resin transfer molding. Through the stretchable film, the state of the fabric stack is under control. During resin injection, a loose fiber stack is present and then resin is easily introduced into the cavity. Once enough amount of resin is injected, a compression pressure is applied on the film that compacts the preform and drives the resin through the preform. Prior to vacuum-assisted compression resin transfer molding experiment, a compression test is performed to understand the variation of the preform thickness at various loads. Through observing vacuum-assisted compression resin transfer molding experiments, some experimental shortcomings are inevitable including the edge effect and excess of injected resin. More resin leads to a longer injection and compression phase and more wastes. At all events, vacuum-assisted compression resin transfer molding is a feasible process and can be expected to fabricate a better part quality. It also reduces the mold filling time/injection pressure and cleaning mold time compared with resin transfer molding.