Modeling of In-Mold Coating for Resin Transfer Molding

摘要

Closed mold reactive liquid composite molding processes such as resin transfer molding (RTM) and any of its variations such as vacuum-assisted resin transfer molding (VARTM), Seemann Composite Resin Infusion Molding Process (SCRIMP), etc. are environmentally friendly alternatives to open mold processes, which have been traditionally employed to form large composite parts. However, in most cases, in order to improve and/or protect the part surfaces, gel coating is required. The gel coat is applied with the mold open, which releases harmful volatile organic compounds (VOC) to the environment, partially compromising the benefits of the closed mold processes. In-mold coating (IMC) is an attractive alternative to gel coating to eliminate VOC. IMC is a coating operation performed by injecting a coating material onto the surface of the substrate with the mold closed. The coating flows by compressing the substrate under pressure. In the present work, we develop mathematical models to predict the filling and packing stages of IMC for RTM parts. These models include the effect of the compressibility of the substrate and mold. The deflection of a mold during the IMC filling influences the IMC flow behavior.