COMPRESSION MOULDING
DESCRIPTION
Compound or blend is placed in mould and heated under pressure. When reaction
is complete, product is cooled and ejected.
APPLICATIONS
Electrical switch and fuse boxes. Domestic electrical equipment microwave containers and tableware. Business
machine housings. Gas and electricity meter housing. Dish aerials.
NOTABLE POINTS
Original process for 'Bakelite'. Slow process and wasteful for 'flash'. Whilst moulds are simpler than for injection moulding, they must still be made from tool steel.
INJECTION MOULDING
DESCRIPTION
Basically the process used for thermoplastics, modified to avoid hardening of the plastic in the machine.
APPLICATIONS
Electrical switch and fuse boxes. Domestic electrical equipment microwave containers and tableware. Business machine housings. Gas and electricity meter housing. Dish aerials.
NOTABLE POINTS
Can produce more accurate mouldings with better control on material usage. More suited to longer runs.
PRESS MOULDING
DESCRIPTION
Material is charged to a large press with flat platens, generally in the form of a 'pre-preg'. Heat and pressure are applied to react the mixture and convert it into the finished plastic.
APPLICATIONS
Large mouldings. Some sheet products.
NOTABLE POINTS
As with compression moulding, a rather slow process.