Abstract: A filtration material of the present invention comprises a bulky fiber sheet layer having a thickness of 0.5 mm or more, and a triboelectrically-charged nonwoven fabric layer in which two or more types of fibers different in constituent resin are mixed, wherein constituent fibers of the triboelectrically-charged nonwoven fabric layer penetrate into the bulky fiber sheet layer. A three-layer filtration material of the present invention comprises bulky fiber sheet layers having a thickness of 0.5 mm or more, and a triboelectrically-charged nonwoven fabric layer, which is located between the bulky fiber sheet layers, wherein the constituent fibers of the triboelectrically-charged nonwoven fabric layer penetrate into the bulky fiber sheet layers, and both bulky fiber sheet layers contain fibers having a limiting oxygen index of 20 or more, and have a mass per unit area 0.5 times or more than that of the triboelectrically-charged nonwoven fabric layer.

Abstract: A filtration material of the present invention comprises a bulky fiber sheet layer having a thickness of 0.5 mm or more, and a triboelectrically-charged nonwoven fabric layer in which two or more types of fibers different in constituent resin are mixed, wherein constituent fibers of the triboelectrically-charged nonwoven fabric layer penetrate into the bulky fiber sheet layer. A three-layer filtration material of the present invention comprises bulky fiber sheet layers having a thickness of 0.5 mm or more, and a triboelectrically-charged nonwoven fabric layer, which is located between the bulky fiber sheet layers, wherein the constituent fibers of the triboelectrically-charged nonwoven fabric layer penetrate into the bulky fiber sheet layers, and both bulky fiber sheet layers contain fibers having a limiting oxygen index of 20 or more, and have a mass per unit area 0.5 times or more than that of the triboelectrically-charged nonwoven fabric layer.

Abstract: The invention provides a filter element which has a reduced initial pressure loss, can reduce an energy cost and can secure a high air flow rate, a filter element which has an elongated gas removing service life and filtering service life while keeping a high gas removing performance and a high dust removing efficiency, a manufacturing method and a method of use of the same. In a filter element (10) in which a pleated composite substrate (11) obtained by lapping or laminating an nonwoven fabric sheet including a fiber constituted by a thermoplastic resin and a gas removal sheet is pleated, and a pleated shape of the pleated composite substrate (11) is held by a shape retaining member (12a), a thickness of the nonwoven fabric sheet is increased at least 5% when heated to 60 degree C.

Abstract: The invention provides a functional particle carried sheet constituted by a particle layer having a two-layer structure with a reduced pressure loss, in which a function of a functional particle is increased. The sheet is formed as a sharp shape in a peak portion and a trough portion of a pleat at a time of pleating process, the functional particle does not jump out of a base material, and the sheet has a good precision of a fold peak height, is easily manufactured, and can achieve a low cost.

Abstract: The invention provides a filter element which has a reduced initial pressure loss, can reduce an energy cost and can secure a high air flow rate, a filter element which has an elongated gas removing service life and filtering service life while keeping a high gas removing performance and a high dust removing efficiency, a manufacturing method and a method of use of the same. In a filter element (10) in which a pleated composite substrate (11) obtained by lapping or laminating an nonwoven fabric sheet including a fiber constituted by a thermoplastic resin and a gas removal sheet is pleated, and a pleated shape of the pleated composite substrate (11) is held by a shape retaining member (12a), a thickness of the nonwoven fabric sheet is increased at least 5% when heated to 60 degree C.