PE
PE - polyethylene (polythene) is a thermoplastic, elastic, and nontoxic polymer. It features high flame resistance and burns without soot when ignited. It is not soluble in normal solvents at room temperature. It is chemically resistant to acids, alkalis, and salt solutions and is lightly permeable. Polyethylene's main features are its density and melting index. When the density increases, the impact resistance and transparency decrease, and there is a rise in melting temperature, density, strength, chemical resistance, and impermeability to gas and odour. When the polyethylene melting index decreases, its recyclability is impaired. However, it features better resistance to impact, chemicals, and wearing while enhancing sliding performance. The following modifications are made to improve polyethylene's characteristics:

LDPE
LDPE - low-density polyethylene (density 910 - 925 kg/m3) without extra polymerization. This polyethylene is viscous and soft.

MDPE
MDPE - medium density polyethylene (density 925 - 940 kg/m3) that combines the favoured characteristics of LDPE and HDPE.

HDPE
HDPE - high density polyethylene (density 940 - 970 kg/m3). It is one of the most practical and cheapest materials. It is highly solid and durable but has less elasticity than other polyethylenes.