Compression Moulding

Compression moulding is a method of molding in which the molding material, generally preheated, is first placed in an open, heated mold cavity. 
The mold is closed with a top force or plug member, pressure is applied to force the material into contact with all mold areas, while heat and pressure are maintained until the molding material has cured. 
The process employs thermosetting resins in a partially cured stage, either in the form of granules putty-like masses, or preforms. Compression moulding is a high-volume, high-pressure method suitable for molding complex, high-strength fiberglass reinforcements.