The Modelling of Mold Filling in Resin Transfer Molding

The resin transfer moulding process (RTM) allows the industrial production of large FRP parts. In this technique layers of reinforcements (mats, woven rovings) are inserted into the mold cavity and resin is injected to fill the closed mold applying external pressure. Due to the strong interdependence between mold design, filling behavior and part quality it is most important to control the cavity pressure as the major influencing process parameter. A simple model is proposed to represent the pressure distribution during mold filling. It is based on Darcy's law for flow of liquids through a porous media and can be applied to single type or combinations of different reinforcements.