Thermoplstics - Properties

Question 1

Low density polythene (LDPE)

Answer 1

Wide range of colours
Tough
Good chemical resistance
Good electrical insulator
Flexible, soft
Fades unless light stabilised
Attracts dust unless anti-static
Service temp 60C

Question 2

High density polythene (HDPE)

Answer 2

Wide range of colours
Fairly stiff and hard
Stiffness and softening point both is crease with density
Can be sterilised
Good chemical resistance
Fades unless light stabilises
Service temp 80C

Question 3

Rigid PVC

Answer 3

Wide range of colours
Stiff, hard
Tough at room temp
Can be used outside if suitably stabilised
Light weight
Very good acid and alkali resistance
Particularly good for fabricating

Question 4

Plasticised PVC

Answer 4

Wide range of colours
Soft, flexible
Good electrical conducted

Question 5

Polystyrene

Answer 5

Stiff, hard
Wide range of colours
Can be made impact resistant

Question 6

Expanded polystyrene

Answer 6

Very buoyant
Light weight
Absorbs shocks
Very good sound and heat insulator
Crumbles easily
Burns readily unless flame proofed

Question 7

Acrylic

Answer 7

Stiff, hard, glass-clear
Very durable outdoors
Easily machined, cemented and polished
Good electrical conductor
Food safe
Ten times more impact resistant than glass
Splinters easily
Scratches easily

Question 8

Polypropylene

Answer 8

Very light, floats
Very good chemical resistance
Hard
Can be sterilised
Impact resistant even at low temps
Service temp 100C
Rigid
Good mechanical and electrical properties

Question 9

Nylon

Answer 9

Hard, tough, rigid, creep resistant
Good bearing surface
Self-lubricating
Resistant to oils, fuels and chemicals
Good fatigue resistant
High melting point
Very resilient
Wear and friction resistant

Question 10

Cellulose acetate

Answer 10

Tough
Can be made flexible
Hard, stiff
Resilient
Light weight