High-density Polyethylene: How it’s made, Properties, Uses and The Olden Days.

Resin Code Identification, HDPE, 2

How is it made?

The uncomplicated version would be: high-density polyethylene occurs after the polymerisation of Ethylene. In other words, the monomer Ethylene is multiplied into a polymer through a mechanism called gas-phase polymerisation.


It is a light and versatile material. Similar to PET, HDPE - as is commonly known - is transparent, resistant to most solvents and acts as a good barrier from the outside elements. It has a reasonable higher tensile strength – stretchability characteristic. Plus its good chemical resistance which makes it a fan favourite for household and industrial chemicals.

Pigmented bottles tend to have a better crack resistance.

Common Uses

It’s another of our favourites for bottles for milk, water, juice, cosmetics, shampoo, washing-up/dishwashing liquid, laundry detergent and household cleaners. We also fancy it for bags for groceries and cereal box films/liners.

HDPE can be used for wire and cable insulation/covering, extruded pipe and conduit and wood-polymer composite (WPCs).

According to the American Chemistry Council, HDPE’s products second life is almost identical to its first. Including bottles for shampoo, conditioner, household cleaners, motor oil and antifreeze bottles. Plastic lumber, fencing and picnic tables, pipes, flower pots, film and sheet.

The olden days

1958 is the year that Karl Ziegler, member of the now called Max Planck Society in Germany, along with his associate Heinz Martin, and Erhard Holzkamp and Heinz Breil, graduate students discovered what we called HDPE.