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|1. (WO2017037912) METHOD FOR MANUFACTURING HOLLOW FIBER MEMBRANE AND NOZZLE FOR HOLLOW FIBER MEMBRANE SPINNING|
|Applicants:||MITSUBISHI CHEMICAL CORPORATION
|Title:||METHOD FOR MANUFACTURING HOLLOW FIBER MEMBRANE AND NOZZLE FOR HOLLOW FIBER MEMBRANE SPINNING|
The purpose of the present invention is to suppress detachment of membrane forming stock solution outside of a nozzle at a location of attachment covering the outer peripheral surface of a hollow porous base material and occurrences of trouble caused by the same in the manufacturing of a hollow fiber membrane. Provided is a method for manufacturing a hollow fiber membrane having a spinning step of applying a first membrane forming stock solution (3) and a second membrane forming stock solution (4) for forming a porous membrane layer to the outer peripheral surface of a hollow porous base material (2) using a nozzle (1) for hollow fiber membrane spinning and solidifying these membrane forming stock solutions, wherein a draft ratio (VB/VA), which is the ratio of feed velocity VB for hollow porous base material (2) fed out from a base material feed opening (7a) to linear velocity VA for the first membrane forming stock solution (3) and the second membrane forming stock solution (4) discharged from a membrane forming stock solution discharge opening (27a) of the nozzle (1) for hollow fiber membrane spinning, is set to 1 - 6.