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Polyethylene / Polythene

  • is the most common plastic.
  • the annual global production of polythene is approximately 80 million tonnes.
  • it is an ethane derived plastic.

Ethane isone of the byproducts of oil refining.
It can be isolated from natural gas,
It can be derived from plants.but most is made from petroleum or natural gas.

Ethene is one of the raw materials used to make polyethylene (abbreviated PE) (IUPAC name polyethene or poly(methylene)

Types of polythene

  • High-density polyethylene (HDPE)
  • Cross-linked polyethylene (PEX or XLPE)
  • Medium-density polyethylene (MDPE)
  • Linear low-density polyethylene (LLDPE)
  • Low-density polyethylene (LDPE)
  • Very-low-density polyethylene (VLDPE)

High-density polyethylene  HDPE Plastic code 2

Used to make supermarket type carrier bags, chemical drums, jerricans, carboys, toys, picnic ware, household and kitchenware, cable insulation, plastic milk cartons, juice bottles, shampoo bottles, and liquid detergent containers.

It is tough and can withstand exposure to sunlight and extremes of temperature.

Products made of HDPE are reusable.

Recycling

HDPE is the most commonly recycled plastic and is a relatively simple and cost-effective process to recycle HDPE plastic for secondary use.

Polythene bags can be recycled through the supermarket carrier bag recycling schemes. Sainsburys even print this fact on their packaging – I saw it on their grapes the other day.

If you don’t live near a supermarket (!) with a recycling scheme, then you can send the bags to this company who run a recycling scheme.

New technology allows HDPE to be recycled into new milk bottles.

LDPE (Low density polyethylene) plastic code 4

used to make soft clear bags for packing of vegetables some bread and frozen food bags, trash cans, and garbage can liners. Also used to make toys and clothes, dispensing bottles, wash bottles, tubing, molded laboratory equipment and corrosion-resistant work surfaces.

Parts that need to be weldable and machinable, parts that require flexibility, computer components, such as hard drives, screen cards and disk-drives are all made from LDPE.

It is considered less toxic than other plastics.

It is not commonly recycled yet but recycling possibilities are ever increasing.

Does Not Biodegrade…… or maybe it does

Polyethylene (PE) has been considered nonbiodegradable for decades. Although the biodegradation of PE by bacterial cultures has been occasionally described, valid evidence of PE biodegradation has remained limited in the literature. We found that waxworms, or Indian mealmoths (the larvae of Plodia interpunctella), were capable of chewing and eating PE films.