Types of
Thermoplastics

Polyethylene (PE)

• waxy, translucent
• specific gravity 0.94 to 0.96
• melting temperature 105°C to 137°C
• glass transition temperature -120°C to -125°C
• good electrical and chemical resistance
• good low temperature impact resistance
  
  Applications : packaging films, bottles, jerry cans, pipes, bottle crates
  
  
  an example of PE

• waxy, translucent
• specific gravity 0.89
• melting temperature 170°C to 176°C
• excellent chemical resistance
• good low temperature resistance
• reasonably stress bearing
• outstanding electrical insulation resistance
  
  Applications : biaxially oriented films, uniaxially oriented fibres, heater boxes for cars and trucks, luggage shells with integral hinges, bottle crates, chairs, straping tapes, housewares
  
  
  examples of PP

• transparent
• specific gravity 1.05
• glass transition temperature 100°C
• hard and brittle
• good electrical resistance
• low water absorption
• attack by aromatic solvents and chlorinated hydrocarbon
  
  Applications : decorative and commodity packaging e.g cosmetic, foodstuff, lighting fittings
  
  
  an example of PS

• transparent
• specific gravity 1.4
• melting temperature 212°C
• glass transition temperature 87°C
• good abrasion resistance
• good electrical resistance
• self extinguishing
  
  Applications : shower curtains, garden hose, wire and cable covering, simulated leather, packaging films and sheets, bottles, pipes and fittings
  
  
  examples of PVC

• transparent, tough
• T_m 220°C
• T_g 150°C
• exceptionally high impact strength
• chemical resistance not outstanding
• good electrical properties
  
  Applications : handles of electrical tools, street light globes, sunglass lenses, baby feed bottles, high voltage plugs and fittings, water pump impeller, aircraft fittings
  
  
  examples of PC

• hygroscopic (i.e water attractive)
• specific gravity 1.04 to 1.15
• T_m 225°C to 265°C
• T_g 40°C to 50°C
• good strength toughness
• excellent fatigue resistance
• excellent resistance to alkalies but attacked by acids
• poor dimensional stability
• low coefficient of friction
  
  Applications : hose connections, valve seats, gears, combs, textiles, brushes, tumblers, washers, radiator tanks, zip fasteners
  
  
  examples of Nylons

• good appearance
• specific gravity 1.42
• T_m 180°C to 200°C
• T_g -85°C
• excellent dynamic fatigue resistance
• less hygroscopic than nylon
• high stiffness and strength
• low coefficent of friction
  
  Applications : cams and gears, truck bearings, refrigerator door handles, window winding handles, pump impellers

• specific gravity 1.06
• excellent impact strength
• good dimensional stability
• excellent dielectric properties
• highly resistant to acids and basses
• high tensile strength and rigidity
  
  Applications : battery cases, computer modules, pumps, plumbing, car fascia panel

• highly crystalline 90% to 95%
• specific gravity 2.2
• T_m 327°C
• T_g 126°C
• very low dielectric loss
• very low coefficient of friction
• self distinguishing
• excellent weathering resistance
  
  Applications : gaskets and seals, coatings for frying pans, bearings and bushes, plumbing tapes, electrical insulation of heavy duty wires, slip joints

an examples of PET

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Types of Thermosetting plastics