Bubble development in a polymeric resin under vacuum

Understanding the gas diffusion and evaporation behavior in a polymeric resin under vacuum is of great importance because many types of polymer and composite products are manufactured by applying a vacuum to the production system. This article proposes a theoretical model that can describe bubble growth under vacuum by combining the mechanisms of gas diffusion and evaporation. To confirm such a model, we carried out experimental analyses including evaporation experiments with a bell jar or a tube as well as vacuum‐assisted resin transfer molding (VARTM). Particularly in the VARTM process, it was identified that many bubbles were nucleated and grew at the fiber‐matrix interface due to the applied vacuum pressure. Those results suggest that more attention should be paid to vacuum‐assisted material processing to prevent bubbles from existing in the final products. POLYM. ENG. SCI., 2012.