| 摘要 |
PROBLEM TO BE SOLVED: To stably obtain a uniform polyolefin porous hollow fiber membrane having no drawing unevenness from a hollow fiber having a large outer diameter and large membrane thickness by increasing hollow fiber grip of cold drawing rollers to suppress hollow fiber slipping on the roller surface of the cold drawing rollers. SOLUTION: This membrane is obtained by using an apparatus for producing a porous hollow fiber membrane having a heat treating part 10 heat-treating a hollow fiber 11, a cold drawing part 20 cold-drawing the heat treated hollow fiber 11 and a hot drawing part hot-drawing the cold-drawn hollow fiber 11 wherein the cold drawing part 20 comprises a cold drawing roller having multiple feed rollers 21 and multiple take up rollers 22, the feed roller 21 is set to form the sum of contact angles of the hollow fiber with the roller surface of each feed rollers to be >=720 deg. and the take up roller is set to form the sum of contact angle of the hollow fiber 11 with the roller surface of each take up rollers to be >=720 deg..
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