High-pressure microwave curing process for an epoxy-matrix/glass-fibre composite

The two main process parameters affecting the final mechanical properties of thermoset composites are the cure cycle and the reduction in void content. To effect the former, a conventional thermal process is used normally, with the cycle duration lasting a matter of hours. Recent work by the authors has indicated that this can be significantly shorter by using a microwave curing process. In order to apply the same microwave process industrially, reduction in void content must be accomplished. The conventional industrial practice is to use both a vacuum bagging application and an applied autoclave pressure. This paper describes how reduction in void content can be achieved for a microwave process by means of a high-pressure process that avoids the usage of a continued vacuum evacuation.