| 摘要 |
PROBLEM TO BE SOLVED: To draw even a thermoplastic tube having a plurality of through-holes while holding the outer diameter thereof and the inner diameter of the through- holes highly accurately. SOLUTION: The leading end part of a thermoplastic tube 1 having through- holes is finely drawn. A draw-molding method of the thermoplastic tube 1 has a process for inserting cores 2, 3, 4 having outer diameters smaller than the diameters of the through-holes and longer than the leading end part of the tube 1 after draw-molding, a process for heating a cylindrical molding die 5 having a conical introducing port through which the tube 1 passes to constant temp., a process for passing the leading end part of the tube 1 through the min. inner diameter part of the heated molding die 5 to finely draw the same so that the outer diameter of the leading diameter part of the tube becomes the inner diameter of the min. inner diameter part 7 and a process for cooling at least the leading end part of the tube drawn up to the inner diameter dimension.
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