What Is HDPE Plastic?

By Eric Dontigney; Updated April 24, 2017
HDPE plastics are used to make milk jugs and other food packaging.

HDPE (high-density polyethylene) plastic is a linear polymer (a polymer that does not branch or cross-link) generated from ethylene using a catalyzing process.

Applications

Applications

HDPE plastic has several applications, including packaging for foods (milk and snacks, for example) and cleaners. It is also used for pipe fittings, trays and hinges.

Processing

Injection molding machine

High-density polyethylene plastics are suitable for several manufacturing processes including injection molding, extrusion molding and blow molding.

Characteristics

HDPE plastic pipes

HDPE plastic is resistant to acids, bases, alcohol and vegetable oils, as well as being impact resistant. It is also resistant to sustained heat of about 110 degrees Celsius.

Disadvantages

HDPE does not biodegrade in landfill settings

High-density polyethylene plastics have poor resistance to UV (ultraviolet) light. HDPE does not biodegrade in landfill settings, nor can it be composted.

Recycling

Recycling

HDPE is a recyclable material and is falls under No. 2 of the plastic resin code. Recycled HDPE is used in pallets, drainage pipes and packaging.