| 摘要 |
PURPOSE:To enhance the cleaning efficiency and to prolong the service life by successively decreasing the average film diameter in each layer extending from the air inlet side to air outlet side of a multilayer fiber sheet obtained by laminating >= 2 layers of an fiber agglomerate having a different average fiber diameter for each layer. CONSTITUTION:The multilayer fiber sheet is obtained by laminating at least two layers in the thickness direction of a fiber agglomerate having a different average fiber diameter for each layer, and the average fiber diameter of each layer extending from the air inlet side to air outlet side is successively decreased. A nonwoven fabric by the entangled water current method known as the water jet method is used for a clean layer 1 to further enhance the collection efficiency. Consequently, although the laminated structure obtained by needling the combination with other senior fibers is entangled and furnished by needling, the efficiency in collecting dust, etc., is excellent. |
