POLYETHYLENE

Polyethylene has an high chemical resistance to chemical agents, it has good electrical properties and it presents slow water absorption. PE is usually used at a temperature between -40° C and + 80° C. Polyethylene resists to water, oil, alcohol, alkalis, saline solutions as well as to acids.
Under 60 ° C, PE is insoluble in all organic solvents. The use of certain types of high density PE is permitted for the production of fuel oil containers and fuel tanks. PE is odorless, tasteless and physiologically harmless and it is suitable for food industry. PE is easily weldable with traditional welding systems. Due to the non-polarity and poor adhesiveness, the PE presents difficulties in bonding and decorations. The PE surfaces can be printed, painted or glued using contact adhesives only after a plasma oxidative pretreatment, or with a luminescent discharge, an oxidizing flame, ozone or in a chromic acid solution. When machining PE be carefull that material does not overheat.

Main features

Commercial polyethylene is generally the extruded or pressed type. Good chemical properties, high workability, in relation to poor hardness, and cheapness are its main qualities.

  • Good chemical resistance typical of polyolefin materials.
  • Resistance to impacts, good at low temperatures.
  • Low specific weight.
  • FDA - ECC 90/128 food compatibility (only for the colored types, the data must be confirmed from time to time).

Applications

  • Mechanical: the low coefficient of friction and non-hygroscopicity make it suitable for bearings or other mechanical parts with low loads even if they work in water.
  • Alimentary: physiologically inert it is approved for use in contact with food by various Bodies, it is a material widely used for this characteristic in the construction of food machines, pumps for food liquids, etc.
  • Electrical: excellent dielectric characteristics and stability to bad weather make it increasingly used in this sector
  • Chemical: due to its high chemical resistance to acids and alkalis it is used for components in the chemical industry.

Applications

Sectors: mechanical, chemical, electrical, advertising, food as semi-finished products for working with tools, such as solid rounds, perforated rounds, tubes and plates. We get equipment for the chemical industry, bins and containers, coatings for hoppers and slides, components for pumps, sliding elements, rollers, gears, sliding guides and cutting boards.

Defects

  • Low general mechanical strength (traction, bending, wear, etc.)
  • Compared to higher molecular weights, it is less resistant to wear, repeated impact and internal stresses
  • Limited dimensional stability of details
  • Difficult to paint, glue and weld at high frequency
  • Limited resistance to atmospheric agents