Construction techniques for thermosetting polymers

Question 1

Compression moulding

Answer 1

Plastic is forced into a mould whilst hot which forms into the mould shape. The pressure from the insertion forms the shape and then is ejected when the shape is set

Question 2

Transfer moulding

Answer 2

Similar to comp moulding but the polymerisation doesnt happen in the mould, it happens in an adajcent cavity and then transferred into the mould whilst soft.

Question 3

Hand Lay-up

Answer 3

This is when fibres are placed into a mould and then a resin is applied ontop. If the finished product requires thicker areas, more fibres and resin is applied to strengthen the final product. This is how fibreglass or CPFR is made.

Question 4

Vaccum Lay-up

Answer 4

This usually uses a material called pre-preg, a cloth of fibres such as carbon that has partially set epoxy resin. Prepreg is like stickers, it gets cut and then stuck into a mould. Then a bag is fitted over the prepreg and put into a vacuum chamber which puts even pressure over the prepreg and also sets it with 190 deg C air.