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.
