Patent ID: 6939490

Claim:
A rapid resin or pitch infiltration molding process for a mold, said process comprising the steps: providing a mold containing locating means for positioning a porous body within the mold insert cavity in a position that brings about unidirectional flow of the molten resin or pitch through the thickness of the porous body; heating said mold to a temperature above a melting point of the resin or pitch to be infiltrated into the preform; preheating a porous preform to a temperature above a melting point of the resin or pitch to be infiltrated into the preform; placing the preheated preform into said mold; injecting a high melting point, high viscosity, molten resin or pitch into said mold to effect a unidirectional impregnation through the thickness of the preform via a pressure gradient in the mold, wherein said pressure gradient is provided by steps or protusions in the mold; permitting the resin- or pitch-infiltrated preform to cool below the melting point of the resin or pitch; and removing the impregnated preform from the mold.