DT

• Thermoforming polymers

  Thermoforming polymers can be heated and formed repeatedly. They are pliable and recyclable.
• Thermoforming polymer

  • Acrylic (PMMA)
  • High impact polystyrene (HIPS)
• Acrylic (PMMA)

  • Hard, brittle, shiny, available in a wide range of colours
  • Resists weather well, can be cut, folded and polished well, scratches easily, used for car lights, visors and baths
• High impact polystyrene (HIPS)

  • Rigid, cheap, available in a lot of colours
  • Can be cut and vacuum formed easily, food safe but toxic when burned, used for CD cases and yoghurt pots
• Thermosetting polymers

  Thermosetting polymers are brittle and can only be formed once. They are hard to recycle. They are good insulators and are resistant to heat and chemicals.
• Thermosetting polymer

  • Epoxy resin (ER)
  • Polyester resin (PR)
• Epoxy resin (ER)

  • Supplied as two parts, one resin and one hardener (see imogel - the resin and hardener combine to create an extra-strong adhesive)
  • Rigid and durable, strong, expensive and heat resistant, used to bond materials, waterproof coatings and lamination
• Polyester resin (PR)

  • A resin and a hardener, sets clear and smooth
  • Strong, heat resistant and good insulator
• Timber comes from trees. Trees have to grow to full maturity (between 25 and 100 years) before they can be cut down for wood.
• Hardwood

  • Ash
  • Beech
  • Mahogany
  • Oak
  • Balsa
• Ash

  • Pale coloured, narrow grain
  • Flexible and good for steam bending, tough, used for sports equipment
• Beech

  • Slight pink tint, close grain
  • Tough, durable and smooth to finish
• Mahogany

  • Dark-reddish colour, very close grain
  • Cuts and polishes easily, gives a fine finish, used for high-quality furniture
• Oak

  • Moderate-brown colour with unique and attractive grain markings
  • Tough and durable, polishes well, used for quality furniture
• Balsa

  • Pale and wide-spaced grain due to it being a fast-growing hardwood
  • Very soft and easy to form, often used to make models
• Softwood

  • Larch
  • Pine
  • Spruce
• Larch

  • Pale coloured with a contrasting darker grain, knotty
  • Durable, easy to machine, high sap content gives it good water resistance, used for exterior building and flooring
• Pine

  • Pale coloured with aesthetically pleasing grain
  • Lightweight, easy to form, used for construction and decking
• Spruce

  • Pale cream with an even grain
  • Easy to form, takes stain colour well, used for construction and furniture
• Manufactured board

  • Medium-density fibreboard (MDF)
  • Plywood
  • Chipboard
• Medium-density fibreboard (MDF)

  • Smooth, light brown, can be veneered
  • Smooth and easy to finish, absorbs moisture so not suitable for outdoor use, used for kitchens and flat pack furniture
• Plywood

  • Odd number of layers of veneer glued at 90 degree angles for strength, aesthetically pleasing outer layer
  • Easy to cut and finish, can be stained or painted, used for shelving, construction and toys
• Chipboard

  • Compacted wood chips, laminated with a variety of coverings, end cuts are difficult to finish
  • Strong but absorbent to water, used for veneered worktops and flooring
• Manufactured boards are usually made from timber waste and adhesive. To make them more aesthetically pleasing they are often veneered. They are cheap to buy.
• Metals are found naturally and are mined from the earth. Metals used in products are extracted from the natural ore using large heat furnaces.
• Ferrous metal

  • Low-carbon steel (mild steel)
  • Cast iron
  • High-carbon steel (tool steel)
• Low-carbon steel (mild steel)

  • An alloy that is grey and smooth, rusts if not protected
  • Ductile and tough, easy to form, braze and weld, versatile, useful for construction, nuts, bolts, bike frames
• Cast iron

  • Dull grey, rusts easily
  • Brittle, can be cast in a mould, used for manhole covers, pans and gates
• High-carbon steel (tool steel)

  • An alloy that is grey, smooth and does not rust easily
  • Hard-wearing, harder than low-carbon steel so less ductile but good for making tools, sharpens well
• Non-ferrous metal

  • Aluminium
  • Copper
  • Tin
  • Zinc
• Aluminium

  • Light grey with a matt finish
  • Lightweight but strong and ductile, used for drink cans, kitchen utensils and some parts in transport
• Copper

  • Rose coloured, polishes well but can oxidise to a green colour (verdigris)
  • Good electrical conductor, can be polished, welds easily, used for plumbing parts and electrical cable
• Tin

  • Silver coloured
  • Soft and malleable, easy to form, used to make food cans
• Zinc

  • Silvery blue with a matt finish
  • Brittle with average malleability and conductivity, often used to galvanise steel
• Copper oxidised to a green colour (verdigris)
• Alloy

  • Brass
  • Stainless steel
  • High-speed steel
• Brass

  • Non-ferrous metal that is gold coloured and darkens when oxidised with age
  • An alloy of copper and zinc, can be cast and machined, used for musical instruments and ornamental hardware
• Stainless steel

  • Ferrous metal that is silver when polished, resists rust
  • An alloy of chromium, nickel and manganese, hard and smooth, used for cutlery and sinks
• High-speed steel

  • Ferrous metal is dark grey when used for tool bits
  • Can be alloyed with a variety of materials for different properties, can withstand high temperatures used for drill bits and saw blades
• Most polymers are formed by processing crude oil. Rubber is a plastic that is found naturally.