2. Thermoplastic polymers
Properties
Examples of use
Low-density polyethylene (LDPE)
Soft and flexible. Not very strong
Carrier bags, detergent bottles, packaging
High-density polyethylene (HDPE)
Strong
Bowls, buckets, milk crates
Polypropylene (PP)
Can be bent or flexed many times without breaking. High impact strength for a polymer
Lunch boxes, plastic chairs, children’s toys
High-impact polystyrene (HIPS)
Light but strong
Vacuum-formed packaging and casings
Acrylic (polymethyl methacrylate – PMMA)
It can be transparent, like glass, or coloured with pigments. Hard wearing and will not shatter on impact
Plastic windows, bath tubs, display sign
Polyvinyl chloride (PVC)
Stiff and hard wearing
Pipes, coverings for electric cables, floor and wall coverings, packaging
© Nelson Thornes 2011

3. Thermosetting polymers
Properties
Examples of uses
Epoxy resins
Good resistance to chemicals and wear. Strong when reinforced
Adhesives, printed circuit boards
Melamine formald- hyde
Good strength. Resistant to scratches
Laminates for work surfaces, plastic plates
Urea formald- hyde
Good strength, but brittle – it will break rather than change shape
Electrical fittings, light sockets, switches, plugs
© Nelson Thornes 2011

4. Types of metal Metal Alloy or pure metal? Ferrous or non- ferrous
Properties
Typical uses
Mild steel
Alloy (Iron with –0.35% carbon
Ferrous
Strong, cheap, needs to be protected from rusting
Building frames, car bodies
High speed steel
Alloy (Iron with % carbon)
Very hard and strong
Tools
Stainless steel
Alloy (Iron with chrome and nickel)
Hard, tough, resistant to corrosion
Sinks, knives and forks, dishes
© Nelson Thornes 2011

5. Types of metal Metal Alloy or pure metal? Ferrous or non- ferrous
Properties
Typical uses
Aluminium
Pure metal
Non- ferrous
Lightweight, strong for its weight, easier to shape than steel
Cooking pans, aircraft frames, drinks cans
Copper
Expensive, easier to shape than iron. Electricity flows through it really well
Pipes and plumbing fittings, electrical wires
Zinc
Corrosion resistant. Zinc has a lower melting point than many metals, so it is easier to mould
Camera bodies, handles for car doors
Brass
Alloy (65% copper and 35% zinc)
Strong, good corrosion resistance
Castings and ornaments, door knobs
© Nelson Thornes 2011 5