Polyethylene

Polyethylene is the most commonly produced form of plastic worldwide for a reason. Its variable crystalline structure makes it a very lightweight, durable thermoplastic. It is most commonly used in packaging, being used to make films, plastic bags, geomembranes, and various forms of plastic container, such as bottles, and freezer containers. Polyethylene is a very useful polymer as different forms prioritise different qualities. It can be both high density and low density, and different structures have different melting points, so you can prioritise cost effectiveness or temperature durability according to your business’ personal requirements.

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  Low Density Polyethylene, or LDPE is most popular for its lower melting point and good processability. It has very low water absorption, good chemical resistance to alcohols and low concentration acids and bases, and excellent electrical insulation properties. Its resistance is more limited to oxidising agents and halogenated hydrocarbons. However, it is flammable and is susceptible to stress cracking.

  LDPE is most commonly used for injection moulding, as well as for film and bubble film, and co-extrusion. LDPE is used in creating bottles and containers, tubing, especially for electrical components, plastic bags, and a variety of moulded laboratory equipment.

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  High Density Polyethylene, or HDPE is highly cost effective, as it can be manufactured at low temperatures. Despite this it has a fairly high melting point of 140 degrees Celsius. It is a stiff material with good low temperature resistance, as well as having good resistance to most solvents. It is also resistant to most alcohols, low concentration acids and bases, and most oils and greases. It lacks a high level of resistance to hydrocarbons. It is also susceptible to stress cracking and is less stiff than polypropylene.

  HDPE is most commonly used in packaging, such as crates, cartons, and industrial containers and cans for bulk usage. It has high tensile strength, making it useful in ropes and nets, and it is also used in consumer goods, such as bins, homeware, and toys. It can also be used in pipes, cables, and wiring.

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  Linear Low-Density Polyethylene, or LLDPE is very flexible, and possesses high impact strength. It makes a good barrier against both water and alcohol vapour and has excellent chemical resistance. It also has great stress crack and impact resistance.

  LLDPE is most commonly used in the blow moulding creation of films. This is usually in food packaging, to help keep foods fresher for longer. It can also be used in producing agricultural films, clothing packaging, stretch film, and general-purpose films.