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Nowadays different types of pipes, cables, plates and profiles are manufactured from different plastics. The most often applied include low and high density polyethylene and poIyvinyl chloride. Due to new areas of use, the need to alter or improve specific properties and reąuirements set for new products, it was necessary to introduce certain modifications. In recent years, microcellular extrusion technology became one of the most rapidly developing method of polymer processing. It was designed to obtain microcellular profiles and coatings with lower density, having no sinks on the extruder product surface and showing minimum contraction, with simultaneous retaining ofsimilar properties of products obtained in conventional extrusion. An extruder product obtained in the microcellular process has a regular microcellular intemal structure with closed pores and a smooth, hard topcoat. This type of product containing the blowing agent has Iow density, poor water absorptivity, poor corrosion and chemical resistance, and also Iow flammability. In this paper are presented characteristic of PVC microcellular extrusion process modified by special blowing agent and selected research results of course and effects of that process.
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