| 摘要 |
PROBLEM TO BE SOLVED: To make rigidity more excellent than that of the conventional pipe, to decrease deformation in a cut face and to decrease deformation of the pipe caused by shrinkage. SOLUTION: In extrusion molding of a hollow molded article made of a thermoplastic resin, a mold 1 for shape molding and cooling in which the inner face is formed in a tapered shape so as to make the diameter larger toward the extrusion direction is used and the inner surface temp. of a parison 3 extruded from an extruder 2 is kept at least at its m.p. and a shape is molded by bringing the parison 3 into contact with the inner face of the mold 1 for shape molding and cooling by vacuum and it is drawn in biaxial directions. |
