A separator for blood components comprises a cylindrical housing with ports for blood introduction and exit, packed with at least two layers of fibrous aggregate in series, the layer on the inlet side having a bulk density of 0.16-0.21  g/cm3 and that on the outlet side having a bulk density of 0.21-0.23 g/cm3. The inlet side layer may comprise two successive layers  of fibrous aggregate having respectively bulk densities of 0.16-0.19 and 0.19-0.21 g/cm3. The wt. ratio of the layers is pref. 75:25-60:40. The separator is packed with 0.04-0.09 g fibrous aggregate per 1 ml of blood to be treated. The fibre is pref. short fibres and may be natural cotton, polyester, polyamide, polyacrylonitrile or cellulose acetate. Pref. is defatted, bleached Egyptian cotton. - The removal of leucocytes and platelets from blood.  (0/3) EPAB- EP-312595 B An apparatus for separating white blood cells and blood platelets from blood, comprising: a tubular housing (14) having at one end thereof a blood inlet (10) and at another end thereof a blood outlet (12); a plurality of layers 916, 18) of staple fibres of bleached Egyptian cotton capable of sequestering white blood cells and blood platelets packed in said housing in the direction of flow of blood through said housing between said blood inlet and outlet; said layers of fibres comprising a blood inlet side fibre layer (16) adjacent said blood inlet (10) and a blood outlet side fibre layer (18) adjacent said blood outlet (12), characterised in that the fibres of both said blood inlet side fibre layer (16) and blood outlet side fibre layer (18) are substantially the same except for their respective bulk densities, said blood inlet side fibre layer (16) having a bulk density of not less than 0.16 g/cm3 and not more than 0.21 g/cm3, and said blood outlet side fibre layer (18) having a bulk density of not less than 0.21 g/cm3 and not more than 0.23 g/cm3. said plurality of layers of fibres being packed in a ratio in the range of 0.04 to 0.09 g per ml of the flow volume of blood under treatment by said apparatus; and the ratio by weight of said blood inlet side fibre layer (16) to said blood outlet side fibre layer (18) is in the range of 75:25 to 60:40. - (Dwg.1/3) - EP-312595 B An apparatus for separating white blood cells and blood platelets from blood, comprising: a tubular housing (14) having at one end thereof a blood inlet (10) and at another end thereof a blood outlet (12); a plurality of layers 916, 18) of staple fibres of bleached Egyptian cotton capable of sequestering white blood cells and blood platelets packed in said housing in the direction of flow of blood through said housing between said blood inlet and outlet; said layers of fibres comprising a blood inlet side fibre layer (16) adjacent said blood inlet (10) and a blood outlet side fibre layer (18) adjacent said blood outlet (12), characterised in that the fibres of both said blood inlet side fibre layer (16) and blood outlet side fibre layer (18) are substantially the same except for their respective bulk densities, said blood inlet side fibre layer (16) having a bulk density of not less than 0.16 g/cm3 and not more than 0.21 g/cm3, and said blood outlet side fibre layer (18) having a bulk density of not less than 0.21 g/cm3 and not more than 0.23 g/cm3. said plurality of layers of fibres being packed in a ratio in the range of 0.04 to 0.09 g per ml of the flow volume of blood under treatment by said apparatus; and the ratio by weight of said blood inlet side fibre layer (16) to said blood outlet side fibre layer (18) is in the range of 75:25 to 60:40. ((Dwg.1/3)) USAB- US4936993 A White blood cells (WBC) and blood platelets (BP) are sepd. - from B using a tubular housing having an inlet and an outlet and packed with numerous layers of staple fibres of bleached Egyptian cotton able to sequester the WBC and BP. - The packing is at a rate of 0.04-0.09 g/ml B flow and is in direction of flow of B between the inlet and outlet. The fibre layer on the inlet side has a bulk density 0.16-0.21 g/cm3 and the layer on the outlet side 0.21-0.23 g/cm3. The wt. ratio of the fibre layer on the