Contact moulding is the main technique for fabrication used in the reinforced plastic industry. The contact moulding process requires a single faced mould or tooling. It can be either male or female depending on which face of the moulding requires the moulded finish. They can vary in size from small, easily handled moulds to huge moulds weighing many tonnes requiring mechanical handling equipment. They can be of single section design or multiple sections.
Production moulds are generally made from GRP and are manufactured to be rigid to maintain dimension stability. They are usually made off a timber pattern or plug.
The pattern is generally hand crafted from timber with the finished applied at the final stage. The finish can be as diverse as is practical to cover the pattern, from a high gloss 'class a' to leather grain or sand effect. Increasingly the use of CNC routing machines to produce the pattern are being adopted.
Direct from cad the data is sent to the CNC router to machine an oversize pattern, the surface is then hand completed to the required finish.
Slightly different materials are used to manufacture the mould, to achieve the required stiffness and a durable mould face. Once the mould is released from the pattern it is cleaned and prepared with release agents ready for production. A well designed, produced and looked after mould should be able to produce several thousand mouldings before it requires replacing.