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HOW-ARE-PLASTICS-MADE
August 24, 2021
How are plastics made?

Did you know that plastics are made from natural, organic materials like cellulose, coal, natural gas, salt and crude oil? The creation of plastic begins with the distillation of crude oil in an oil refinery, separating crude oil into groups of lighter components, called fractions.

Each fraction becomes a mixture of hydrocarbon chains (chemical compounds that are made of carbon and hydrogen). Each fracture differs in terms of the size and structure of their molecules. One of these fractions is called naphtha, which is the crucial compound for producing plastics. 

Two main ways used to produce plastic is polymerisation and polycondensation. Each requiring a specific stimulus. These are placed into a polymerisation reactor. Monomers; ethylene and propylene are linked together to form long polymer chains. Each polymer has its own properties, structure and size depending on the various types of basic monomers used.

The main ingredient of plastic is polymers. Plastic polymers make it possible to then be moulded, extruded, or pressed into solid objects. This creates adaptability and a wide range of other properties, allowing plastics to be lightweight, durable, flexible, and inexpensive to produce. 

With so many types of plastics, we can group them into two main polymer categories: 

  1. Thermoplastics (which soften on heating and then harden again on cooling).
  2. Thermosets (which never soften once they have been moulded).

EXAMPLES OF THERMOPLASTICS:

  • Acrylonitrile butadiene styrene (ABS)
  • Polycarbonate (PC)
  • Polyethylene (PE)
  • Polyethylene terephthalate (PET)
  • Polytetrafluoroethylene (PTFE)
  • Polyvinyl chloride (PVC)
  • Polymethyl methacrylate (PMMA)
  • Polypropylene (PP)
  • Polystyrene (PS)
  • Expanded Polystyrene (EPS) 

These are used to make products like sports equipment, toys, shampoo bottles, makeup packaging and bullet-proof vests. 

EXAMPLES OF THERMOSETS:

  • Epoxide (EP)
  • Phenol-formaldehyde (PF)
  • Polyurethane (PUR)
  • Unsaturated polyester resins (UP)

These are used to make products such as electrical housings and components, construction equipment panels, insulators, cell tower tops, circuit breakers, agricultural feeding troughs, heat shields, motor components, and disc brake pistons.

Plastic is used in almost everything that we touch. When you’re using your cell phone or laptop, watching TV, using public transport, in a train, plane or car, you are using plastic. When you go to the doctor or hospital, shop for clothing, shoes or groceries, it is plastics that you are using. Plastic is used to keep us and our wildlife safe and is even used in agricultural netting to produce healthy fruits and vegetables with little sun blemishes – whilst conserving natural resources like water.