Composition and Method of "B-Staging" Prepreg Laminate Materials Prior to Final Composite Structures
Original Publication Date: 1984-Oct-01
Included in the Prior Art Database: 2005-Feb-05
Current B-staging methods consist of applying an epoxy resin-hardener-solvent solution onto fiber glass cloth and allowing the solvent to evaporate, leaving a contiguous resin-hardener-fiber glass cloth mixture. "B-stage" (i.e., resin cure level, cross-link density, etc.) is controlled by carefully balancing the heat and time used to evaporate the solvent for each particular batch. Instances exist, however, where hardener settles out, improper B-stage levels are attained, resulting in improper resin flow during subsequent composite lamination, etc., and/or inadequate final composite cure is attained. This composition and method of "B-staging" prepreg laminate materials, prior to final composite structures, uses actinic radiation to attain a precisely controlled state of B-stage for prepreg.