METHOD FOR JOINING BRAIDS USED FOR BRAID-REINFORCED HOLLOW FIBER MEMBRANE AND METHOD FOR PRODUCING BRAID-REINFORCED POROUS HOLLOW FIBER MEMBRANE

摘要

A method for joining braids that are used for a braid-reinforced hollow fiber membrane, produced by the method inserting a core material into the hollow parts of ends of two braids to be joined to connect the two braids, covering the joint part with a heat-shrinkable tube, and shrinking the heat-shrinkable tube by heating at 120 to 160° C., thereby joining the braid ends together, and that can exhibit sufficient joint strength when load is applied during spinning, or when a porous hollow fiber membrane is used as a treatment membrane for water purification treatment, sewage and waste water treatment, etc. A braid-reinforced porous hollow fiber membrane is produced by allowing braids whose ends are joined by the above method to pass through the inner nozzle of a double annular spinning nozzle, applying a membrane-forming dope discharged from the outer nozzle of the double annular spinning nozzle to the outer surfaces of the joined braids passing through the inner nozzle of the double annular spinning nozzle for impregnation, then coagulating the braids in a coagulating liquid, and winding the braids on a bobbin.