After the invention of the method of chemical modification of natural polymers in the XVIII century, the industry of plastics masses began to develop. In recent years, hundreds of new polymers have been synthesized on a global scale. The synthesis of polymers with new chemical properties shows high level of development of the chemical industry.

As a result of the processing of polymers a finished product is obtained. The final result of the processing of polymers is an obtainment of products conforming to operating conditions.

Plastic masses are chemical products composed of high molecular compounds, and long-chain polymers. At the current stage production of plastic masses is increasing every year, and in recent years its production has reached 250 million tons. High-quality and low-cost of plastic-based products expand their field of use.

One of the important achievements of modern chemical science is obtainment of new natural polymer materials replacing existing materials and their application in different fields of industry. Plastic masses are easily formed, incredible, resistant to a number of corrosive environments, are well-painted with satisfactory appearance. One ton of plastic mass replaces 3-4 tons of non-ferrous metal, which shows its cost-efficiency.

Plastic masses are divided into the following groups subject to their fields of application:

• high dielectric properties
• shock-proof
• resistant to corrosive environments
• heat and frost-resistant
• flexible
• easily formed etc.

The main raw material for the production of polyethylene is ethylene. At present, in the polyethylene industry there are high, low and medium-pressure polymerization methods.

Polyethylene is processed by extrusion, pressurized casting and pressing methods.

The method of extrusion is used in the production of products of various length and with different cross sections. Alloys of polymer materials undergo shaping process and processed by extrusion method for the obtainment of a finished product. The essence of the polymer extrusion method consists of the transportation of screw corners along the screwed channel formed between the inner surfaces of the cylinder. The process of transformation is an intense deformation of the material which causes formation of pressure in the screw channel. Various processes take place during the transportation of the polymer - mixing of the components due to the deformation of the material, heating of the material by means of the cylinder, transformation of deformation into heat, transfer of the polymer material from solid state into fluid, ousting of moisture and gaseous components. Extrusion method enables to get films, layers, pipes. Extrusion process is carried out mainly in an extruder. The extruder is equipped with a shaping head. In the extruder a polymer material is, firstly, turns into plastic and then transfers into alloy and reshapes.