METHOD OF MANUFACTURING MEMBRANE-TYPE TUBULAR FILTER ELEMENTS Russian patent published in 2003 - IPC

FIELD: chemical engineering. SUBSTANCE: manufacture of filter elements for ultra- and microfiltering of liquid mixtures for their concentration, separation, and purification of components consists in formation on open porous surface of liquid film from homogenous solution of 8-25 wt % fluoropolymer, 20-40 wt % nonsolvent, and, the rest, solvent, after which fluoropolymer is hardened to form selectively permeable membrane. Nonsolvent is selected from group including lower aliphatic alcohol, mixture of lower aliphatic alcohol with acetic acid, mixture of lower aliphatic alcohol with polyvinylpyrrolidone, and ternary mixture of lower aliphatic alcohol with acetic acid and polyvinylpyrrolidone. Substrate for membrane may be open-pore tubes from glass, carbon and organic plastic, ceramics or graphite, abc- plastic, and polyvinylchloride. EFFECT: enabled hydrophilization of membranes, enhanced their water permeability, and prevented pollution of filter elements. 2 cl, 1 tbl, 16 ex