Characterization of new generations of out-of-autoclave prepregs (OoA)

Abstract

New generations of out-of-autoclave prepregs, also known as VBP (vacuum bag only) are achieving a high maturity level that would allow the composite manufacturing with autoclave quality. These materials are characterized by its capability to allow air evacuation and minimize the presence of defects before its complete polymerization. To do this, it is necessary to control the factors which govern the phenomena that occur within it, such as compression, resin flow and void growth processes. Additionally, it should be considered fibers and resins properties, and curing cycle parameters such as temperature, vacuum quality and duration. In this work we have studied comparatively conventional and OoA prepregs.To do this, several panels have been laminated using hand lay-up method and cured only using vacuum bag and without autoclave pressure. Then, the panels have been characterized by optic microscopy, ultrasonic inspection and mechanical standarized tests. The results show that out-of-autoclave prepregs are achieving similar qualities to the conventional prepregs. Having completed this stage, new research and developments should be focused on, among other issues,  guaranteeing manufacturing processes robustness and optimization of bigger structures with complex geometries