| 摘要 |
<p>Extruded pipe, fitting or shaped part from the plastic for construction of conduits for liquid, paste-like and gaseous media manufactured by die casting or blowing contains a tubular body executed, at least, of three layers. Internal (2), middle (4) and external (3) layers of pipe, fitting or shaped part consist of polymeric material with random copolymer of polypropylene as basic material. The composite material of middle (4) layer contains 50-90 per cent by weight of random copolymer of polypropylene with specific characteristics, 10-50 per cent by weight of fiberglass, glass beads or powdered glass, or the mixture of these materials and binding additive for connecting the polymeric matrix with the filler. Into amorphous areas of partially crystalline polymeric material of inner layer (2) contacting with the transported medium additives are introduced against aggressive media, in particular, oxidizing and reducing atmospheres. Into the amorphous areas of polymeric material of the middle layer (4) the fillers and additives are introduced as barrier material for decreasing the migration of additives from inner layer (2) into outer layer (3) of pipe.</p> |
