MIXED-FIBER NON-WOVEN FABRIC, LAMINATE SHEET, FILTER, AND METHOD FOR PRODUCING MIXED-FIBER NON-WOVEN FABRIC

摘要

Provided are a mixed-fiber nonwoven fabric exhibiting a low pressure drop and an excellent collection efficiency, in particular, a mixed-fiber nonwoven fabric suitable for air filters and a filter medium using the mixed-fiber nonwoven fabric. The nonwoven fabric comprises at least two types of fibers having different melting points, which fibers are low melting point fibers made of a polyolefin resin component A, and high melting point fibers made of a high melting point resin component B having a higher melting point than that of the polyolefin resin component A. The number average fiber diameter of the high melting point fibers is larger than that of the low melting point fibers. At least one high melting point fiber having a fiber diameter of 20 µm to 100 µm is present per 1.00 mm of the length of the cross section of the nonwoven fabric. The number average fiber diameter of all fibers constituting the nonwoven fabric falls within the range of 0.3 µm to 10 µm.