| 摘要 |
PROBLEM TO BE SOLVED: To provide a mixed fiber nonwoven fabric that is low in pressure loss and is excellent in collection efficiency, especially, a mixed fiber nonwoven fabric that is suitably used for an air filter.SOLUTION: The mixed fiber nonwoven fabric at least includes a thermoplastic resin fiber having a fiber diameter of 0.01-20 μm and a thermoplastic resin fiber having a fiber diameter of 70-120 μm, in which 7.0 or more pieces of the thermoplastic resin fibers having a fiber diameter of 70-120 μm are contained per 1 mm of a cross sectional length in a cross section in a thickness direction of the nonwoven fabric. At least the thermoplastic resin fibers having a fiber diameter of 0.01-20 μm and/or the thermoplastic resin fibers having a fiber diameter of 70-120 μm are electrification processed. The collection efficiency of 0.3-0.5 μm particles is at least 85% or more at a face wind speed of 4.5 m/min. The thickness is 0.3-1.0 mm and the bending resistance is 2.0 mN or more. The mixed fiber nonwoven fabric is made by a melt-blow method. |
