HDPE (high-density polyethylene) is polyethylene with little branching in its polymer chains, which produces a higher density (0.94 – 0.97 g/cm³). Because of its higher density, HDPE is harder and more rigid than LDPE. It is more resistant to high temperatures and extremely resistant to chemicals, which is why it is used for all kinds of bottles (shampoo, beverages, cleaning products etc.) as well as canisters, drinks crates and piping.
Polyethylene, a type of polyolefin, is a thermoplastic produced through the addition polymerisation of ethylene. It has a waxy feel and before dyeing has a dull, milky colour. Polyethylene burns with a bright flame and forms drips, producing a smell similar to a candle flame.