Wednesday, 8 July 2020
ENGINEERING CONCEPTS

Classification and materials used for plastic

Main Topics

Classification of plastic is determined by two variants :

Thermoplastics: Plastics that are repeatedly molded and re shaped By application of heating and cooling cycle under pressure.

Example: Polypropylene, polyethylene, polyvinyl chloride. Out of total plastics 85 % of plastics are Thermoplastics other 10-15% is Thermo set plastics.

Below fig shows Thermo plastics:Plastic

Thermoset plastics:

Plastics ones shaped by application of heat and pressure. Do not have versatility of repeat process ability.

Example: Phenol formaldehyde.

Thermosetting plastics

Plastic materials:

Polypropylene:

Common general plastics excellent flex resistance integral in product such as cases, powder boxes, Tiffin boxes.

Polyethylene:

  1. LDPE: Carry bags,milk packets,shampoo sachets.
  2. HDPE: Plastic crates,petrol cans,Jerry cans,pipes,fuel tanks.
  3. POLY VINYL CHLORIDE: Good electrical properties,good out door weather resistance.

Polystyrene:

  • GPPS: Highly transparent low cost case of molding,crystal clear, coloured.
  • HIPS: High impact strength of good toughness compared to GDPS.

Example: Bath Room cabinets.

ABS{Acrylonitrile Butadiene styrene}

  • High impact strength.
  • High surface gloss unlimited color ability.
  • Computer monitor,Telephone body,AC,Mixer,Washing machine.