A Novel Method for the Manufacturing of Thick Composites

Abstract

Pre-catalyzing fabric method is a newly developed technique applied in manufacturing thick composites with hand layup process. By applying a peroxide catalyst to the fabric instead of mixing it into the bulk resin system, this technique can slow down the polymerization reaction rate and subsequently reduce the internal temperature of thick composites. In this study, two kinds of pre-catalyzing methods are developed: one uses polystyrene as the catalyst binder; another uses epoxy resin as the binder. The experimental results indicate that the pre-catalyzing method using polystyrene binder can eliminate the peak exothermic temperature, and the method using epoxy binder can limit this temperature to be below 39 C. The latter method has shorter curing time than the former one. The degree of cure for both methods can be more than 87% with low exothermic temperature after cure, and with this degree of cure, the laminate is rigid enough for further post cure. The degree of cure can be improved to be more than 97% by leaving the samples for more than five weeks in ambient temperature. Compared with the polystyrene binder which made the interlaminar shear strength decrease by 12.4%, the epoxy resin binder has the better characteristic, not to exhibit this decrease.