ENGINEERING CONCEPTS

Classification and materials used for plastic

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 Thermoset 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.