Filter material for filtering leucocytes from blood

摘要

A filter material for filtering leucocytes from a fraction of or whole human blood, comprises a web having a thickness of at least about 1 millimeter and a bulk density of about 0.05 to 0.4 g/cm3. The web has a plurality of interlocked matrix fibers distributed in the web to form a matrix thereof with spaces between adjacent interstices of interlocked fibers. The matrix fibers are composed mainly of about 1 to 3 micron diameter glass fibers, i.e. at least 75% of the weight of the web being the glass fibers. A plurality of fibrillated particles of textile fiber material, having a surface area of between 5 and 100 square meters per gram are disposed within the spaces of the matrix. The weight ratio of the fibrillated particles to the matrix fibers is between about 1:99 and 40:60. A thermoplastic binder is disposed at least at cross-over portions of the matrix fibers, with the amount of the binder being about 0.1% to 10% by weight of the web.