Method of forming reinforced foam structure
AssigneeDetroit Gasket & Mfg. Co.
InventorRalph G. Doerfling
Life of this patent
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Abstract
A method of forming a reinforced foam structure or laminate wherein a low density, fast reacting liquid foamable resin is sprayed under pressure into a low density fiberglass mat to penetrate and wet the fibers. The foam then expands within the fiberglass mat, forming a low density foam sheet having fiberglass distributed substantially continuously therethrough. A support or cover sheet is preferably laminated to the foam-fiberglass sheet and the laminate is formed under heat and pressure in a die into a contoured shape, simultaneously curing the resin foam.
Claims1
A method of forming a contoured fiberglass reinforced thermosetting foam laminate, comprising the steps of:
- (a) laying a coherent mat of loosely woven glass fibers on a finish sheet wherein said finish sheet is a flexible woven sheet of absorbent fibers;
- (b) spraying a liquid low density foamable thermosetting resin reaction mixture into said fiberglass mat, from opposite said mat, under sufficient pressure to fully penetrate said mat of glass fibers and wet said finish sheet, said finish sheet sufficiently pervious to adsorb said liquid resin;
- (c) allowing said liquid thermosetting resin reaction mixture to foam and freely expand within said fiberglass mat for filling said mat and for temporarily bonding said finish sheet to said mat, and said thermosetting resin foam is an open cell relatively rigid polyurethane foam having a free blown density of less than about one pound per cubic foot;
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- (d) immediately placing said thermosetting foam-fiberglass mat and finish sheet laminate in a contoured die, prior to the curing of said foam, and forming said laminate under heat and pressure in said die into a permanently contoured shape and simultaneously permanently bonding said finish sheet to said contoured foam-fiberglass mat;
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- (e) including heating said finish sheet prior to overlying said fiberglass mat on said finish sheet to prevent soaking of said finish sheet with said liquid thermosetting resin, thereby limiting blowing of said thermosetting resin foam through said finish sheet during foaming of said thermosetting resin reaction mixture.
Dependencies are inferred from the claim text.