Blood filter and method of filtration

Abstract

A filter material for filtering leucocytes from a fraction of or whole human blood, comprises a shape-sustaining laid textile web having a thickness of between about 2 millimeters to about 12 millimeters and a bulk density of about 0.05 to 0.4 g/cm.sup.3. The web has a plurality of interlocked, staple, textile fibers with average deniers between about 0.05 and 0.75 and average lengths between about 3 millimeters and 15 millimeters. The textile fibers are substantially uniformly distributed in the web so as to form a matrix of the textile fibers with spaces between adjacent interstices of interlocked fibers. A plurality of fibrillated particles of a polymeric material, e.g. a textile fiber material, having a surface area of between 5 and 60 square meters per gram are substantially disposed within the spaces of the matrix. The fibrillated particles have a plurality of fine fibrils which are interlocked with adjacent textile fibers of the spaces such that the fibrillated particles are not substantially displaced from the web during filtration of the blood. The weight ratio of the fibrillated particles to the textile fibers is between about 1:99 and 40:60.

Dependencies are inferred from the claim text.