摘要 |
PROBLEM TO BE SOLVED: To prevent the dimensional change of a tube in the diameter direction thereof caused by the buckling of the tube in a method for winding the tube after extrusion molding around a winding member to heat-treat the same. SOLUTION: A tube 2 after extrusion molding is wound around a winding member 1 having a plurality of tube engaging parts 3 so as to be linearly held between the tube engaging parts 3 and heat-treated in such a state that the interior of the wound tube 2 is always opened to the outside.
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