Polyethylene was first discovered by accident in a laboratory in 1898. This is a running theme throughout the history of the plastics industry. It was not until 35 years later that the first commercially viable polyethylene was synthesized in 1933 by Imperial Chemical Industries (ICI). The long gap between the initial discovery of a polymer and the commercialization is also a recurring theme in the history of the plastics industry.
Polyethylene is the most commonly used plastic globally. According to Wikipedia, annual production is around 80 million metric tons or 176 billion pounds. It is used in many applications such as film that is used for everything from moisture barrier to grocery bags. It is also used for things like pick-up truck bed liners and tanks of all kinds. In recent years, polyethylene has been used for increasingly demanding applications like automotive fuel tanks, potable water pipe, artificial hip joints and even fiber for bulletproof vests.
Polyethylene’s use in these increasingly demanding applications has been made possible by innovations from the material manufacturers. Unlike TPO, these innovations have not happened at compounders but during the reaction of the polymer. These innovations have brought a dizzying array of new polyethylene materials to the market. A quick look at Matweb shows that there are currently 5534 different grades of polyethylene. I want to break down some of the different types that are now available.