The three main types of polyethylene (PE) are low density PE (LDPE), linear low density PE (LLDPE) and high density PE (HDPE).
HDPE is a thermosetting white solid whose molecular chains are comparatively straight and closely aligned. It is resistant to most chemicals, insoluble in organic solvents and has high impact and tensile strength.
LLDPE is a thermosetting, translucent white solid whose chains are comparatively straight and closely aligned, and has a lower density than HDPE.
LDPE is a thermosetting white solid which has highly branched and widely spaced molecular chains.
End uses of HDPE include blow-moulding applications such as bottles, packaging containers, drums, fuel tanks for automobiles, toys and house wares. Injection-moulded articles made from HDPE include crates, pallets, packaging containers and caps, paint cans, house wares and toys.
LLDPE’s short chain branching gives it higher tensile strength, puncture and anti-tear properties, making it particularly suitable for high strength film applications.
LDPE is used mainly in film applications for both packaging and non-packaging uses. Other markets include extrusion coatings, sheathing in cables and injection moulding applications.