A retaining material that can sufficiently maintain the function of retaining a pollution control element in a pollution control device at high temperature. In one aspect, the retaining material has a mat shape and contains inorganic fiber material, with the retaining material containing: a surface layer containing inorganic colloid particles; and an internal region positioned further to the inside than the surface layer, impregnated with inorganic colloid particles and organic binder; wherein the surface layer contains inorganic colloid particles at a higher concentration than the internal region; and the amount of inorganic colloid particles in the internal region is 1 mass % to 10 mass % based on the total mass of the retaining material.

A retaining material that can sufficiently maintain the function of retaining a pollution control element in a pollution control device at high temperature. In one aspect, the retaining material has a mat shape and contains inorganic fiber material, with the retaining material containing: a surface layer containing inorganic colloid particles; and an internal region positioned further to the inside than the surface layer, impregnated with inorganic colloid particles and organic binder; wherein the surface layer contains inorganic colloid particles at a higher concentration than the internal region; and the amount of inorganic colloid particles in the internal region is 1 mass % to 10 mass % based on the total mass of the retaining material.

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. A filter element of the present invention comprises the filtration material in a pleated state.

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. A filter element of the present invention comprises the filtration material in a pleated state.

Filter element for air conditioning unit comprising a textile substrate selected from woven fabric and nonwoven fabric, and a composition comprising graphene, in which said graphene is in the form of nano-platelets and is present in an amount from 2 to 20 g of graphene per square meter of textile substrate and is dispersed in a binding agent and applied uniformly on all said textile substrate by means of impregnation.

Filter element for air conditioning unit comprising a textile substrate selected from woven fabric and nonwoven fabric, and a composition comprising graphene, in which said graphene is in the form of nano-platelets and is present in an amount from 2 to 20 g of graphene per square meter of textile substrate and is dispersed in a binding agent and applied uniformly on all said textile substrate by means of impregnation.

A fiber sheet is densely charged with electric charge and provides an electret fiber sheet that has excellent dust collecting performance. The electret fiber sheet is an electret fiber sheet in which averages of a* values and b* values satisfy all requirements of the following (a) to (c): (a) 10average of (a* values)40; (b) 25average of (b* values)0; and (c) 5average of [(a* values)+(b* values)]40; wherein a* and b* are values measured by a spectrophotometer when a red positive charge toner and a blue negative charge toner are attached.

A fiber sheet is densely charged with electric charge and provides an electret fiber sheet that has excellent dust collecting performance. The electret fiber sheet is an electret fiber sheet in which averages of a* values and b* values satisfy all requirements of the following (a) to (c): (a) 10average of (a* values)40; (b) 25average of (b* values)0; and (c) 5average of [(a* values)+(b* values)]40; wherein a* and b* are values measured by a spectrophotometer when a red positive charge toner and a blue negative charge toner are attached.

An air filter medium includes a fluororesin porous membrane and a supporting member stacked on top of each other. The air filter medium has a permeability ratio (permeability after disinfection treatment/permeability before disinfection treatment) of 5.0 or less, the permeability ratio being a ratio of permeabilities of the air filter media before and after the disinfection treatment of the fluororesin porous membrane as determined using NaCl particles having a particle size of 0.1 ?m, and a pressure loss ratio (pressure loss after disinfection treatment/pressure loss before disinfection treatment) of 0.83 or more and 1.15 or less, the pressure loss ratio being a ratio of pressure losses of the air filter media before and after the disinfection treatment of the fluororesin porous membrane.

A floor cleaner with an air inlet, an air outlet, a suction motor, and a filter. The filter includes a first media layer, a second media layer, an end cap, and an annular cap. The first media layer and the second media layer extend along a filter axis between the end cap and the annular cap. The filter is compressible along the filter axis between the end cap and the annular cap.