FILTRATION MEMBRANE AND PROCESS FOR PRODUCING THE MEMBRANE

摘要

A fillration membrane, especially adapted for use in hemofiltration as well as filtration of infusion solutions. The membrane, in the form of a hollow fiber, is made of a polymer which is soluble in a polar, non-protonic organic solvent. The most preferred polymer for the membrane material is polyamide. Characterizing for the membrane is high ultrafiltration rates (permeabilities to water) of up to 500 x 10-4 m1/sec. x cm2 x atm., and impermeability to albumin (Mw 68,000). The membrane is prepared by extruding a polymer solution with a center liquid under conditions such that the volume of polymer solution to volume of center liquid ratio is within the range of from 2:1 to 4:1. Simultaneously, the inner diameter to wall thickness ratio of the hollow fiber is preferably correlated to the polymer concentration and is set to 150:75 to 280:75 at a polymer concentration of 5 - 20%. The most preferred such correlation is 220:75 at a polymer concentration of 11%.