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HDPE | High Density Polyethyelene


HDPE

High Density Polyethylene (HDPE)
A linear polymer, High Density Polyethylene (HDPE) is prepared from ethylene by a catalytic process. The absence of branching results in a more closely packed structure with a higher density and somewhat higher chemical resistance than LDPE. High Density Polyethylene is also somewhat harder and more opaque and it can withstand rather higher temperatures (120° Celsius for short periods, 110° Celsius continuously). High density polyethylene lends itself particularly well to blow molding. (Source: Dynalab Corporation).

Advantages of HDPE

Impact, and wear resistant. Flexible, can have very high elongation before breaking. Generally good chemical resistance.

  • Food Contact Acceptable
  • Processability, Good
  • Copolymer
  • ESCR, High (Stress Crack Resist.)
  • Antioxidant
  • Density, Low
  • Density, High
  • Impact Resistance, Good
  • Toughness, Good

Disadvantages of HDPE

Sensitive to thick sections in your part. It may have voids, bubbles or sink. Poor dimensional accuracy. Low mechanical and thermal properties. Price is low to very low.

  • High thermal expansion
  • Poor weathering resistance
  • Subject to stress cracking
  • Difficult to bond
  • Flammable
  • Poor temperature capability
  • Low strength/stiffness

Background

After its experimental preparation in the 1930s the application in high frequency radar cables during World War II gave impetus to its commercial production. Today Polyethylene (PE) is one of the most widely used plastics with production in the billions of pounds each year.