Thermoplastic moulding

Question 1

Describe blow moulding…

Answer 1

1) Plastic granules are fed into a hopper.
2) They are rotated past the heater by the archimedean scew, melting it.
3) The liquid plastic is fed into a mould
4) Air is ‘blown’ into the mould, forcing the liquid plastic against the mould sides; shaped
5) The mould is cooled, ‘split’ and the plastic product removed.

Question 2

Describe rotational moulding…

Answer 2

1) A set amount of plastic granules are measured into a mould.
2) The mould is placed into a heater and rotated so the melted plastics covers the side
3) The mould is air cooled and the product removed

Question 3

Describe injection moulding…

Answer 3

1. Granules of plastic powder are fed into a hopper along with any additives or pigments.
2. They are rotated past the heater by the archimedean screw, melting it.
3. The liquid is forced into a mould where it cools into the shape
4. The mould then opens and the unit is removed.