Thermoplastic film infusion process for long-fiber reinforced composites using thermally expandable elastomer tools

Thermoplastic film infusion process was investigated by using thermally expandable elastomer tools, which effectively compensated for the pressure loss caused by polymer infusion into porous fiber beds. In this process, the thermally expandable elastomer tool was incorporated in a fixed-volume mold with polymer-film and dry fabric layers, and upon heating, the polymer melt was forced to infuse into the dry fabric by the thermal expansion of the elastomer tool. The elastomer tool produced sufficiently high elastic force up to 7.5 MPa by the thermal expansion and sustained the mold pressure above 6.5 MPa during the resin impregnation in the flash-land compressing processing. Combining the D'Arcy's law and the compressibility of the elastomer tool and the elastic fiber bed, a film infusion model was developed to predict the resin infusion rate and impregnation pressure as a function of time during resin infusion.