PRODUCTION OF PLASTIC CORRUGATED PIPE

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a plastic corrugated pipe of high commercial value which is free from deformation in a hollow crest part. SOLUTION: In the production of a plastic corrugated pipe by winding a molten plastic belt-shaped mold body 2 having a hollow crest part 2b on one side of a flat belt-shaped part onto the periphery of a mandrel 1 spirally so that the side fringe parts of the mold body 2 overlap each other, a shape-holding slider 7 for shape-holding the crest parts is fitted to the end of a support 7a and inserted into the crest part 2b and arranged, and the slider 7 is slid relatively so that the crest part 2b is spread from the inside by the slider 7 to be prevented from being curved inside to obtain a corrugated pipe P which keep its shape.