METHOD OF MANUFACTURING ASYMMETRIC MICROPOROUS HOLLOW FIBERS AND ASYMMETRIC MICROPOROUS HOLLOW FIBERS Russian patent published in 1997 - IPC

FIELD: synthetic fibers production. SUBSTANCE: invention concerns separation processes including transfer, for example, dialysis, ultra filtration, chemifiltration, blood separation, and water filtration. Solution containing 11-25% of polysulfone and 0.1-5% of polyvinylpyrrolidone in proton solvent with viscosity 700-3500 cP is shaped through inner annular charge and filters. Simultaneously, 60-85% of isopropyl alcohol aqueous solution is passed through inner pipe. The two solutions are introduced first into a gas medium and then into hardening bath. Shaped fibers are withdrawn and wound with speed 90-150% of shaping speed. Ratio of areas of cross-sections of inner annular charge and inner pipe is at least 5:1. Hardening bath is placed at distance at least 1 m from die. EFFECT: manufactured fibers possess strength high enough to be wound with speed at least 75 m/min. 33 cl, 3 dwg, 8 tbl