Patent ID: 6406659
Filing Date: 2002-06-18
Classification: B29C

Abstract:
A method of molding a composite by flowing resin into a permeable preform contained in a molding apparatus comprising creating temporary resin flow channels on a surface of the preform, by placing a flexible impermeable membrane on portions of the preform, placing a spacer system over the flexible impermeable membrane, placing a second flexible impermeable membrane over the spacer system, and deforming the flexible impermeable membrane adjacent the preform into temporary resin flow channels by applying a higher pressure on the preform side of the flexible impermeable membrane than on the other side of the flexible impermeable membrane thereby creating a differential pressure which deforms the flexible impermeable membrane into the temporary resin flow channels, drawing a vacuum on the preform prior to flowing the resin into the preform, flowing the resin along the temporary resin flow channels and from the temporary resin flow channels into the preform, impregnating the preform with the resin, stopping the flow of the resin, removing the temporary resin flow channels, by returning the flexible impermeable membrane to a position flush with the surface of the preform by reversing the differential pressure, curing the resin in the preform and forming the composite, wherein deforming the flexible impermeable membrane into the temporary resin flow channels using the differential pressure comprises deforming the flexible impermeable membrane into a network of gaps in the spacer system adjacent to the flexible impermeable membrane, said flexible impermeable membrane deforming to take on the shape of a spacer system surface and thereby forming the temporary resin flow channels, and reversing the differential pressure to remove the temporary resin flow channels comprises applying a pressure to the spacer system greater than a pressure of the resin in the preform thereby removing the temporary resin flow channels and causing the impermeable flexible membrane to press evenly upon the surface of the permeable preform.