Plastics

Question 1

What are the properties of THERMOSETTING plastics?

Answer 1

• Not remouldable.
• Not recyclable.
• Self colouring and can be painted post production.
• Does not melt.

Question 2

Give examples of THERMOSETTING plastics.

Answer 2

Urea formaldehyde:

• Used for electrical fittings.
• Hard and durable.
• Insulating.
• Does not melt.
• Compression moulded.

Phenol formaldehyde:

• Used for sauce pan handles.
• Black.
• Compression moulded.

Melamine formaldehyde:

• Used for heat resistant surfaces, school desks and kitchen work surfaces.
• Calandered.

Polyester resin:

• Plastic component of GRP.

Epoxy resin.

Question 3

Give examples of ELASTOMERS.

Answer 3

TPE (Thermo plastic elastomer):

• Ergonomic.
• Overmoulded over objects.
• Toothbrush handles.
• Electric drills.
• Injection moulded.

LSR (Liquid silicon rubber):

• Cook wear.
• Teats off of baby bottles.

Question 4

Give examples of BIODEGRADABLE POLYMERS.

Answer 4

Bio-batch additive:

• 1% will render the majority of the polymers. Makes it 100% bio-degradable.
• Used for: LDPE, HDPE, PP, PET, polystyrene and even PVC (Within 1-5 years).

Biopol polylactide (PLA):

• Used for medical implants (eg, screws, pins, plates etc).
• Breaks down after 6 months.
• Often used in place of ABS.
• Can be soft.
• Cellulose based (Organic and abundant polymer).

Lactel:

• Plastic capsules on tablets.
• Absorbable and water soluble.
• Breaks down in minutes.

Question 5

What are the properties of THERMO plastics?

Answer 5

• Remouldable.
• Recyclable.
• Self coloured and self finishing.
• Oil based.

Question 6

Give examples of THERMO plastics.

Answer 6

ABS:

• Hard.
• Shiney.
• Colourful and not clear.
• Injections moulded.
• Used for mice, remote controls etc.

PET:

• Clear.
• Extremely strong - even when thing.
• Crinkly.
• Cheap feel.
• Non-toxic.
• Blow moulded.
• Used for bottles and food containers.

PMMA Acrylic:

• Optically clearer than glass.
• Available in many colours.
• Hard.
• Scratches easily.
• Injection moulded.
• Used for headlight lens and shop signs.

Polypropylene:

• Expensive compared to other plastics such as ABS.
• Extremely durable.
• Has an integeral hinge.
• Used for sandwich boxes.

HIPS (High impact polystyrene):

• Used for cheap toys and calculator cases.

Expanded polystyrene:

• Used for insulation.

LDPE (Low density polyethylene):

• Soft and flexable.
• Stretchy and strong.
• Can be printed on.
• Bio-degradable.
• Calandered.
• Used for toothpaste tubes and carrier bags.

HDPE (High density polyethylene):

• Poor mans PP.
• Blow moulded.
• Used for washing up bowls and milk bottles.

Nylon:

• Self lubricating.
• Used for clothes, bearings and gears.

UPVC:

• Hard.
• Cheap.
• Used for window frames, gutters and pipes.

PVC:

• Can be clear.
• Calandered.
• Used for packaging, tape and hose pipes.

Polystyrene:

• Vacuum formed.
• Ised for disposable food contains and yoghurt pots.

Question 7

Give examples of ADDITIVES.

Answer 7

Plasticizer