Modelling and simulation of resin transfer moulding (RTM)—gate control, venting and dry spot prediction

Abstract

This work presents three simulation features developed in an existing mould filling simulation code for resin transfer moulding to address the processing issues encountered during manufacturing. They are gate control, venting, and dry spot formation. The first feature is achieved using numerical sensors, which simulate the sensors used in practice to control the process. This feature makes it possible to use the developed simulation code to design a control strategy to optimize mould filling time, or to reduce the injection pressure required. The second feature is developed to account for the presence of vents. With vent locations specified, simulation can be used to predict changes in the pressure distribution and mould filling pattern if the resin front is not directly connected to the vent. The third feature provides for the prediction of dry spot formation. The simulation code checks if air is trapped in the mould and keeps track of these trapped air pockets. It computes the location, size and the pressure of all dry spots formed in the filling process. The combination of these features enhances the ability of the code as a design tool. The gate control and dry spot prediction features can be used in conjunction to guide the design of optimal processing conditions. Controlled resin injection as a strategy is an indispensable way to prevent dry spot formation, and reduce operation costs. Similarly, venting and dry spot prediction can be used to detect possible flaws and to correct them before a prototype mould is constructed.