Design and tech

• Polyethylene terephthalate

  PETE
• High density polyethylene

  HDPE
• Polyvinyl chloride

  PVC
• Low density polyethylene

  LDPE
• Polypropylene

  PP
• Polystyrene

  PS
• Thermoplastics

  • can be reshaped
  • expensive
  • recyclable
  • example - polythene
• Thermosetting plastics

  • can't be reshaped
  • cheap
  • not recyclable
  • example - Bakelite
• vacuum forming - a process in which a plastic sheet is heated and then shaped by a vacuum across a mould
• Vacuum forming advantages

  • quick production time
  • cost effective on a small scale
  • rapid prototyping
• vacuum forming disadvantages

  • inconsistent wall sizes
  • not cost effective on a large scale
  • limited detail and complexity
• vacuum forming examples

  • packaging trays
  • display sign holders
• Rotational moulding - A plastic material, usually in the form of powder, is placed in to a hollow mould to create hollow product such as kayaks and traffic cones
• Rotational moulding advantages

  • low tooling cost
  • easy to make complicated shapes
  • no size limit
  • environmentally friendly
• Rotational moulding disadvantages

  • less material options
  • high cost
  • high thermal stability