PE belongs to the group of olefin plastics.
PE is made according to two methods, resulting in a product with either high density (HDPE) or low density (LDPE). The HD type is most common, as the mechanical properties improve with increasing molecular weight. The natural colour is white/colourless, while the options for colouring are unlimited. Polyethylene can be obtained as a “regenerated”, reused material.
Advantages
The electrical properties of PE are good, as is its impact toughness. It is resistant to acids and alkalis, as well as weak solvents. The material tolerates cold and is not sensitive to moisture. Polyethylene can be used in contact with foods.
Limitations
The mechanical properties are greatly dependent on temperature. The coefficient of expansion and moulding shrinkage are high. Polyethylene does not tolerate UV radiation unless it is coloured black. Oxidising acids and halogens damage the plastic. The material is difficult to bond and mark with text without prior surface treatment.
Uses
Polyethylene is used for instance for slide strips, bearings, pump housings, companion flanges, buckets and bins, bottles, cable insulation, pipes, packaging film and petrol tanks.
Identification
PE burns with a bright, non-sooting flame, blue at the core and yellow at the tip. Drips and has a paraffin odour.
