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

Main material :  rubber, silicone , plastic.

Compression molding is one of the oldest manufacturing technique for rubber molding. The process parameters includes molding time, temperature, and pressure. Usually, a 300-400 ton clamp pressure is used. The typical mold is shaped like a clam shell. The molding press looked a lot like a ladle filled vertical press used for casting aluminum. The bottom of the mold was always the cavity. Compression molding used preforms made by an extruder/wink cutter or a roller die/die cutter. Wink meaning that 2 blades meet on center to cut the extrudate to length. For example; Molding water bottles used die cut sheets from a roller die. The sheet was 3 inch by 6 inch. The first sheet was placed- one below a core and one sheet of equal size above the core, and then the top of the mold lowered by hand or by hoist to near shut.