Production of improved preimpregnated material comprising a particulate thermosetting resin suitable for use in the formation of a substantially void-free fiber-reinforced composite article

Abstract From the Canadian patent

Abstract of the Disclosure, An improved multifilamentary fibrous material is formed having solid particles of a matrix-forming thermosetting resin substantially uniformly dispersed among adjoining filaments in the absence of fusion bonding. The thermosetting resin particles initially are dispersed in an aqueous medium containing an effective amount of a dissolved polymeric binding agent and the viscosity of the medium subsequently is substantially increased to at least 50,000 cps. to form a gelled impregnation bath having a plastic flow characteristic with shear-thinning behavior wherein the thermosetting resin particles are substantially uniformly suspended. The resulting impregnation bath …