FILTER MEDIUM FOR AIR FILTER, FILTER PACK, AIR FILTER UNIT, AND METHOD FOR MANUFACTURING FILTER MEDIUM FOR AIR FILTER

• Main Authors: KIYOTANI HIDEYUKI, NIINUMA HITOSHI, KOBAYASHI MAKOTO, SHIBUYA YOSHIYUKI, YAMAMOTO SEIGO, TSUTSUMI OSAMU, INUI KUNIHIKO, CHAEN SHINICHI
• Format: Patent
• Language: English; Japanese
• Published: 29.10.2015
• Subjects: PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; TRANSPORTING

PROBLEM TO BE SOLVED: To provide a filter medium for an air filter that has substantially improved a dust collecting volume while keeping high collection efficiency, a filter pack, an air filter unit, and a method for manufacturing such a filter medium for an air filter.SOLUTION: A filter medium for an air filter includes a first porous membrane and a second porous membrane mainly made of fluorine resin. The second porous membrane is disposed further downstream side of an air flow than the first porous membrane. A dust collecting volume of poly-α-olefin particles in the first porous membrane at the time when air containing poly-α-olefin particles with the volume median diameter of 0.25 μm is ventilated at a flow rate of 5.3 cm/sec continuously, and the pressure loss is increased by 250 Pa is larger than that in the second porous membrane. The filter medium for an air filter is characterized by the fact that the pressure loss is less than 200 Pa, the collection efficiency of NaCl particles with a particle diameter of 0.3 μm is 99.97% or more, and the dust collecting volume of poly-α-olefin particles with the volume median diameter of 0.25 μm is 25 g/mor more. 【課題】高い捕集効率を維持しながら、保塵量が大幅に向上したエアフィルタ用濾材、フィルタパック、エアフィルタユニット、および、そのようなエアフィルタ用濾材の製造方法を提供する。【解決手段】本発明のエアフィルタ用濾材は、主としてフッ素樹脂からなる第１の多孔膜および第２の多孔膜を備える。第２の多孔膜は、第１の多孔膜よりも気流の下流側に配される。第１の多孔膜は、個数中位径０．２５μｍのポリアルファオレフィン粒子を含む空気を流速５．３ｃｍ／秒で連続通風し圧力損失が２５０Ｐａ上昇したときのポリアルファオレフィン粒子の保塵量が第２の多孔膜よりも大きい。エアフィルタ用濾材は、圧力損失が２００Ｐａ未満であり、粒径０．３μｍのＮａＣｌ粒子の捕集効率が９９．９７％以上であり、個数中位径０．２５μｍのポリアルファオレフィン粒子の保塵量が２５ｇ／ｍ２以上であることを特徴とする。【選択図】図１