Thermoforming & Thermosetting polymers

• Thermoforming Polymers:

  Materials that can be heated and shaped repeatedly, and are able to be recycled.
• Examples of thermoforming:

  • Polypropylene(PP)
  • Polythene(PE)
  • Polystyrene(PS)
  • Polyvinyl Chloride(PVC)
• Polypropylene (PP):

  -Lightweight polymer that is strong and tough.

  -Good heat, chemical & fatigue resistance.

  -Used for buckets, bowls, crates, toys, bottle caps and car bumpers.
• Polythene (PE):

  -Tough and flexible.

  -Easily moulded

  -Used in carrier bags, bin liners and washing up bottles.
• Polystyrene (PS):

  -Lightweight, food safe & good impact strength

  -Available in opaque colours and transparent.

  -Used in disposable plastic cutlery, CD cases, smoke detector housings and plastic model assembly kits.
• Polyvinyl Chloride (PVC):

  -Rigid and dense

  -Good tensile strength

  -Used in water pipes, window frames, raincoats and flooring.
• Thermosetting Polymers:

  Materials that are cannot be reheated or reformed once they have been formed and cooles
• Melamine formaldehyde:

  -Excellent resistance to heat, moisture, scratching, and staining

  -Perfect for kitchen worktops and tableware.
• Epoxy resin:

  -Supplied in two parts, resin, and hardener

  -Creates a very strong adhesive with good chemical and heat resistance and excellent thermal insulation
• Urea formaldehyde:

  -Hard, stiff polymer with excellent electrical insulation properties

  -Suitable for switches, plugs, and electrical fittings
• Polyester resin:

  -Forms with a reaction of acids and alcohol

  -Commonly used in sheet moulding compound and toner of laser printers
• Sources of Polymers:

  Polymers can be made from natural and synthetic resources.

  Synthetic polymers:

  -Made from crude oil by scientists and engineers.

  Natural polymers:

  -Made using materials like silk, wool, cellulose, and proteins.
• Availability of polymers:

  Polymers are available in a variety of forms including sheet, film, bar, rod and tube.
• Properties of polymers:

  There are many different polymers and the selection of specific polymers for particular purposes can relate to cost, resistance to corrosion, strength, strength/weight ratio, conductivity, elasticity, stiffness or malleability.
• Differences between thermoforming and thermosetting polymers:

  Thermosetting polymer will strengthen when heated, and cannot be remoulded or heated after the initial forming.

  Thermoplastic can be reheated, remoulded and cooled as needed without causing a chemical change.