Plastic Processes (K)

Question 1

Explain the process of vacuum forming -

Answer 1

• sheets of thermoplastics heats around a moulds
• mould needs draft angles and air holes and rounded corners
• ideal for batch and mass production.

Question 2

Explain the process of calendaring_

Answer 2

• Heated rollers squash and stretch polymer pellets to make thinner (continuous production)

Question 3

Explain the process of line bending-

Answer 3

• Thermoplastic sheeting is heated along a line
• (one off and batch production) →schools

Question 4

Explain the process of injection moulding _

Answer 4

• Complex 3D shapes → made quickly for mass/ continuous production
• tooling and set up costs are high

Question 5

Explain the process of blow moulding -

Answer 5

• Parison stretched to fit a mould, using hot air
• high set up costs → ideal for mass and contentious production of thin walled components
  -( plastic bottles)

Question 6

• Explain the process of rotational moulding -

Answer 6

• Mould filled with thermoplastic granules or powder and is then continuously rotated though heating and cooling chambers
  -( mass/ batch production )

Question 7

Explain the process of extrusion -

Answer 7

• Same as injection moulding but - melted polymer goes through a die
• ( continuous production)

Question 8

Explain the process of compression moulding

Answer 8

• Polymer slug is placed in the lower mould and pressed into shape
• (large-scale batch production)

Question 9

Explain the process of lamination ( lay -up )

Answer 9

• (Fibre reinforced composite) FRC sheets are rolled into a mould and resin cast over the top