Polyethylene (PE) is a well-known thermoplastic polymer used in some sectors due to its low specific spend and some of its excellent characteristics. It also has a particularly economical price.
Polyethylene can be produced by extrusion, with a molecular weight of about 300,000 molecules per cubic cm, or by pressing, where the molecular weight can vary from 500,000 to even 1,000,000.
The best known brands (often in green color) are Polizene® and Polystone. Upon request, there are sheets of regenerated material with excellent characteristics and low prices.
Features and Types
Polyethylene is an insoluble material (therefore cannot be glued except by heat fusion), has excellent chemical resistance and is a good insulator. This technopolymer also offers excellent workability and a low specific weight; it is also suitable for contact with food. The operating temperatures are between -50 °C and + 80 °C. However, it has low general mechanical resistance (traction, bending, wear) and has limited resistance to atmospheric agents. It refuses adhesives and is therefore difficult to paint. Depending on the molecular density, PE is divided into three types:
PE300 polyethylene (molecular weight of about 300,000) is a high density material produced by extrusion, it is very elastic and has excellent sliding properties.
PE 500 (molecular weight of about 500,000) is a material produced by pressing and then grinding with better characteristics than PE 300: it is more elastic, has greater wear resistance and has excellent sliding properties.
PE 1000 (molecular weight approx. 1.00.000) is also produced by pressing and is more elastic than PE 500, thus offering even greater wear resistance and better sliding properties.
It is a very stable material to machining even if not suitable for very tight tolerances due to deviations due to thermal expansion. Depending on the type of processing, it is advisable to choose a higher molecular density, favoring PE 500 and PE 1000.
Very versatile plastic material used in many of the main areas: construction of machines in general, chain guide, sliding and various plates, tanks, chemical industry, construction of food machinery, pumps for food liquids. In the chemical industry because it is resistant to acids.
Extruded and Pressed in different molecular densities:
PE300, PE500 and PE1000
Extruded and Cast in different molecular densities:
PE300, PE500 and PE1000