Western European polyethylene production sites in

Depending on the physico-chemical properties of the product, different types of polyethylene are distinguished. The different product types require different production processes where the main distinction is the density of the final product. 

Low density polyethylene is the oldest type of polyethylene. It is produced in a high pressure process. It is a soft, tough and flexible kind of polyethylene due to its highly branched molecular structure. The typical density of LDPE lies between 915 and 935 kg/m. When it is deformed, it can recover its original shape due to its natural elasticity. The high pressure polyethylene shows a higher melt flow index (MFI) and therefore, processes easier than most other types of polyethylene. 

It is used for strong, supple items like lids. It has been used as an insulation material for a long time. Nowadays, the most popular application is film, some examples being carrier bags, packaging material and agricultural film covers. 

Caused by its high crystallinity, high density polyethylene is the most rigid and least bendable amongst the different types of polyethylene. HDPE has hardly any side branches. Therefore, the density is always higher than 940 kg/m. The rigid and somewhat hard character is useful for a wide range of applications. 

This is the youngest of all the PE types. It looks similar to HDPE but has lower crystallinity due to a larger number of short chain branches. Therefore, it also has a lower density (normally lower than 940 kg/m ). However, PE with densities between 930 and 940 kg/m is often called MDPE or medium density polyethylene. 

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Table 3.2 Main Western European polyethylene production sites in 2001...

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