Moulding

Question 1

rRotational moulding

Answer 1

1 - A pre-determined quantity of thermoplashic granules / powder are put into the mould
2. - Mould goes onto an oven + spun on two axes
3 - Thermoplastic is forced to the sides of the mould by centrifugal forces
4 - Removed from heater + still rotating until cool
5 - Removed from mould + flash removed

Question 2

Rotational moulding materials

Answer 2

• HDPE
• LDPE

Question 3

Rotational moulding products

Answer 3

• kayaks
• plastic safety barriers
• cones

Question 4

Extrusion

Answer 4

Granules of thermoplastic ore fed into the hopper
-Grannules feed along the archimedian screw post the heaters where they sofren
- Softened thermoplostic of forced through a die in a continuous length
- Product travels through water baths to cool
- Part is cur to the required length

Question 5

Extrusion materials

Answer 5

• PVC

Question 6

Extrusion products

Answer 6

• guttering
• window frames

Question 7

Extrusion blow moulding

Answer 7

• A parison of thermoplastic is extruded into the mould
  -Mould is closed + air is blown into the parison, blowing it up so that it fills the mould
• Allowed to cool, mould opened + the flash removed

Question 8

Extrusion blow moulding materials

Answer 8

• HDPE

Question 9

Extrusion blow moulding products

Answer 9

• gas containers
• bottles

Question 10

Compression moulding

Answer 10

A pre-determined quantity of materials in the form of o pre-form
- Placed into a heated mould
- Mould is closed with great heat † pressure.
- An irreversible reaction occurs
- Product is removed from mould + flash removed

Question 11

Compression moulding materials

Answer 11

• phenol formalahyde (Bakelite)
• urea formalde Hyde-UF

Question 12

Compression moulding products

Answer 12

• bowls
• plastic oven trays
• car parts