About Harboro Rubber Engineering in Rubber      Contents      Introduction      Uses of Rubber      Processing Rubber          Compounding          Mixing          Pre-Forming          Moulding              Compression              Transfer Injection              Direct Injection          Finishing      Designing With Rubber      Selecting / Specifying Rubber      Quality In Rubber      Rubber Directory      Health & Safety      Measuring Properties      Glossary of Terms      Request A Copy Contact Information

Compression A piece of uncured rubber of the correct size is placed between two halves of a heated mould. The mould is closed in a press under a pressure of around one ton/sq in and the rubber is forced into the exact shape of the cavity. The rubber gains heat by conduction from the mould surfaces and "cures". When the rubber has had sufficient time to cure, the mould can be opened and the part removed. Compression moulding is a relatively simple process and is often used for components required in fairly low quantities. It is also the most economic method for parts with simple shapes. Parts moulded by this method will always have some flash because the mould surfaces are held apart by the necessary excess rubber in the "blank".