Process for producing corrugated multi-layer tubing having layers of differing plastic characteristics

(57) -- are a production method of summary polymer tubing (20), and resistant this tubing to osmosis by the organic matter material included in it -- the direction of outside at least one -- 延在する -- it has the domain limited by two or more annular upheaval parts. By this method, the polymer material which has the 1st external diameter and consists of at least three overlapping polymer materials is introduced into mold equipment, when a tubular polymer material comes out from suitable extrusion molding equipment. The mold surface of mold equipment has at least one domain fundamentally limited by the annular concave portion on the surface of a cylinder type (28). Once tubular material (20) is introduced, it will expand to the 2nd external diameter so that modification of tubular material (20) is possible and the mold surface may be contacted. The tubular material made wavelike exists in mold equipment after completion of an expansion stage.