PERMEATION PREVENTIVE METHOD FOR ORGANIC SOLVENT INTO SYNTHETIC RESIN PIPE

摘要

PROBLEM TO BE SOLVED: To easily and surely prevent an organic solvent from permeating into a synthetic resin pipe by a method wherein at least on one of the external surface, the internal surface and the inside of the synthetic resin pipe, at least one layer of a gas non-permeable resin layer is formed by fusing, or by injection-molding at the same time with an injection molding of the synthetic resin pipe. SOLUTION: For example, a gas non-permeable resin layer 2 is formed on the external surface of a polyethylene resin pipe 1 for water supply to constitute this synthetic resin pipe. The gas non-permeable resin layer 2 comprises an ethylenevinylalcohol copolymerized resin. In order to form the gas non-permeable resin layer 2 on the external surface of the polyethylene resin pipe 1, a film made of a gas non-permeable resin is wound around the external surface of the polyethylene resin pipe 1, and the film is fused, or at the time of injection molding of the polyethylene resin pipe 1, a mouthpiece for injection molding is formed into a structure of a plurality of layers, and the gas non-permeable resin is injected at the same time with an injection of the polyethylene resin. The gas non-permeable resin layer 2 may be formed on the internal surface of the polyethylene resin pipe 1, or in the inside of the polyethylene resin pipe 1.