THE CONTINUOUS CURING PROCESS FOR THERMOSET POLYMER COMPOSITES .1. MODELING AND DEMONSTRATION

This paper presents a new manufacturing method, continuous curing, that is specifically engineered for extremely thick parts made from thermosetting polymer matrix composites. In this process, matrix curing takes place continuously as the precursor material is being laid down. The energy for curing is obtained from the exothermic curing reaction through controlled heat release; once started, the process is self-sustaining. Thermal spiking, an unavoidable feature of autoclave curing, can be completely eliminated in continuous curing by manipulating the process parameters. In addition, manufacturing times are reduced by an order of magnitude or more. A simple analytical model is presented first to show the inherent features of continuous curing. Next, a detailed thermo-chemical process model is developed and numerical results are obtained for a glass/polyester composite. The process is demonstrated by curing a 100 mm thick graphite/epoxy laminate. Finally, thermal spiking behavior and manufacturing times are compared for conventional autoclave curing and continuous curing.