Compression Molding

Compression moulding generally uses a combination of heat and pressure to form moulded parts and is usually used with thermoset plastics or rubbers. Thermoset plastics cannot be reformed once heated.

The Compression Moulding process is as follows:

Material is placed in a heated mould and can be in the form of pellets, powder or preforms
The mould is then closed and pressure applied via a top force or plug member. This forces the material into contact with all the mould areas
Heat and pressure are maintained which will then result in cross-linking of the material
The form that is produced is demoulded once cooled.

Compression moulding is suitable for large, complex parts and usually has lower tooling costs than injection moulding.

Cycle times can be longer and waste material is generated.