Process for preparing thermoset composite articles

Abstract

A process for preparing thermoset composite articles under relatively mild conditions includes exposing a laminate containing a partially-cured thermosettable resin and a fibrous substrate to an elevated temperature which increases over time, the elevated temperature being below the glass transition temperature of the resin but sufficient to promote further curing and increase the glass transition temperature thereof to the ultimate glass transition temperature of the resin. The temperature of exposure is generally increased at a rate which maintains the temperature within about 20.degree. C. below the glass transition temperature of the thermoset-table resin, so that cure of the resin proceeds in the glassy state. The pressure during the process is generally maintained below about 50 psi and is preferably atmospheric pressure. The process enables the production of thermoset composite articles suitable for high-performance applications without lengthy autoclave treatments.

Dependencies are inferred from the claim text.