Abstract: This invention is an improvement in a process for making a thermosetting resin article.In the process of producing an article of thermosetting resin which comprises (a) impregnating a sheet having an open-cell structure with a curable thermosetting resin, (b) applying a layer of fibrous reinforcing material to at least one side of the impregnated sheet, (c) compressing the sheet and reinforcing layer to the extent that resin is expelled from the sheet into the fibrous reinforcing layer and (d) allowing the resin in the sheet and layer to cure while maintaining the compression, the improvement which comprises uniformly incorporating a gas release agent into the curable thermosetting resin to promote the expulsion of resin from the sheet into the reinforcing layer.The invention also includes an open-cell sheet impregnated with a mixture of a curable thermosetting resin, an effective curing agent for said resin, and a compatible gas release agent.

Abstract: This invention is an improvement in a process for making a thermosetting resin article.In the process of producing an article of thermosetting resin which comprises (a) impregnating a sheet having an open-cell structure with a curable thermosetting resin, (b) applying a layer of fibrous reinforcing material to at least one side of the impregnated sheet, (c) compressing the sheet and reinforcing layer to the extent that resin is expelled from the sheet into the fibrous reinforcing layer and (d) allowing the resin in the sheet and layer to cure while maintaining the compression, the improvement which comprises uniformly incorporating a gas release agent into the curable thermosetting resin to promote the expulsion of resin from the sheet into the reinforcing layer.The invention also includes an open-cell sheet impregnated with a mixture of a curable thermosetting resin, an effective curing agent for said resin, and a compatible gas release agent.