This plastic can be manufactured by the Ziegler, Phillips or (gas phase) method.
This polymer differs from conventional high-density polymer in its average molecular weight, which is between 200,000 and 500,000 g/g-mol.
Another way to characterize it is by its flow rate, which is around 0.1 g/10 minutes, which is inversely proportional to the molecular weight, and for this reason it presents greater viscosity in processing. Its density is 0.944 - 0.954 g/cm3.
Properties
High molecular mass high density polyethylene has properties such as: good resistance to tearing, wide working temperature range (40o below zero to 120o), impermeability to water and does not keep odors.
As for its chemical resistance, it is very similar to that of high density polyethylene, but the higher molecular weight improves this behavior, implying longer exposure time in standardized tests, without fractures; although its structure and non-polar nature is the same.
Ultra High Molecular Mass Polyethylene
This type of polyethylene is of high density and high molecular weight; around 3 to 6 million grams per gram-mol, it is a semi-crystalline, whitish and really opaque industrial thermoplastic. Due to its high molecular weight, it has special properties.
It is a very difficult material to process due to its high molecular weight. It has a very low fluidity index, making it almost impossible to use it in plastic transformation methods such as blow molding, injection molding and extrusion.