Notes from last lesson
 plastic is known as polymers are made from crude oil which is non renewable. which is made from monomers joint together to make polymers

there are two type of plastics:
thermoplastics and thermosetting
thermoplastics go soft when heated and thermosetting are heated and moulded once.

plastics:

• Are good electrical and thermal insulators
• Have a good strength to weight ratio
• Generally good resistance to atmostperic and chemical erosion 
• Have a low melting point
• Are light weight
• They are available in wide range of colours and transparency.

Fillers are added to polymer powder to give the material some bulk
Flame retardant is to reduce the risk of catching fire
Anti static reduces the effects of static charges
plasticisers make the plastic less brittle
stabilisers reduce the effects of ultra violet light.

types of plastic:
PMMA: Acrylic.