| 摘要 |
The purpose of the present invention is to control cracking of a porous hollow yarn membrane, even one produced under a high spinning speed. The method for producing a porous hollow yarn membrane of the present invention comprises a spinning and coagulation step wherein the membrane-producing liquor branches into multiple currents that merge back together; the membrane-producing liquid that has formed multiple merging sites is fed to a spinning nozzle (10); inside the spinning nozzle (10) the membrane-producing liquor branches, merges annularly, and then is extruded annularly; and the membrane-producing liquor is coagulated with a coagulating bath. The ratio (t/T) of the time t found by the formula t = V/Q (where V is the volume (cm3) of the liquor flow path, from the point where the first merging site is formed in the membrane-forming liquor to the point where the membrane-forming liquor that has branched merges inside the spinning nozzle, and Q is the amount extruded per time (cm3/second) of membrane-forming liquor from the spinning nozzle (10)) and the viscoelastic relaxation time T of the membrane-forming liquor is less than 1. Moreover, spinning device (1) is used for the production method. |
