A fiber article includes a plurality of first fibers and a plurality of second fibers each having an outer diameter smaller than that of each of the first fibers, the plurality of second fibers being supported in a dispersed state by the first fibers. A ratio D1/D2 of an outer diameter D1 of the first fiber to an outer diameter D2 of the second fiber is set to a value in a range of 15.0 or greater to 1666.7 or less. The outer diameter D1 is set to a value in a range of 5.0 μm or greater to 50.0 μm or less, and the outer diameter D2 is set to a value in a range of 30.0 nm or greater to 1.0 μm or less.

A filter pad with a dry loft between approximately 0.15 and 0.5 inches includes at least a first fiber web comprising a plurality of oleophilic fibers, wherein the oleophilic fibers: have a linear density between approximately 2 and 9 denier; have a length between approximately 1 and 4 inches; and have been uploaded with flame resistant particles.

A filter medium for filtering matter from a fluid and the manufacture thereof are provided. In one exemplary embodiment, a method may be performed by a filter medium for filtering particulate matter from a fluid. Further, the filter medium may include a nonwoven sliver formed into a predetermined shape and composed of first synthetic staple fibers having a first denier, second synthetic staple fibers having a second denier, and third synthetic staple fibers having a third denier.

The filter medium for a filter of the present invention has a laminate structure in which a long-fiber non-woven fabric and a wet non-woven fabric are stacked, wherein the wet non-woven fabric comprises vinylon, polyester, and polyvinyl alcohol, is disposed on a most upstream side of air flow, has a surface located on the most upstream side of air flow, the surface having a surface roughness (SMD) not larger than 2.7 μm, and has a surface stacked on the long-fiber non-woven fabric, the surface having (a) a surface roughness (SMD) not smaller than 3.0 μm or (b) a rough texture (MMD) not lower than 0.02.

A filtration media with improved filtration, strength, tear resistance and air permeability in the form of a relatively thin and lightweight wet-laid fibrous web that has a wet Mullen ratio of 60% to 80% to ensure that the media is flexible enough to be formed into a fluted structure, and strong enough to retain the fluted structure when wound into a roll and to permit further processing without the media becoming too brittle. The filtration media comprises a blend of cellulose and synthetic fibers having a weight percent of 81 wt % to 87 wt % of a weight of the media and a resin binder having a weight of 13 wt % to 19 wt % (preferably about 16 wt %) of the weight of the media.

A filter medium comprising a first conductive fibrous substrate, a second conductive fibrous substrate spaced apart from the first conductive substrate and a third insulation substrate fitted between the first and the second substrates for electrically separating the first conductive substrate from the second conductive substrate. The first conductive fibrous substrate comprises a first layer with first fibers having a first average diameter; a second layer with second fibers having a second average diameter; and a third layer with third fibers having a third average diameter. The second layer comprises activated carbon in an amount sufficient to render the first fibrous substrate conductive. The present medium can be used in electrified filters for cabin air filtration for passenger cars and other vehicles. It can also be used for HVAC filtration for indoor air, and in portable air purification units and even in vacuum cleaners.

A depth filter with excellent filtration accuracy and pressure resistance performance even for fluids containing high density and high viscosity powder fine particles. A depth filter having a base material layer, a filtration layer, and a skin layer, in that order, wherein: the substrate layer and the skin layer are layers made by a nonwoven fabric being wound and thermally fused; the filtration layer is a laminate in which at least a nonwoven fabric and a net are laminated, being wound twice or more; and the nonwoven fabric contained in the filtration layer contains a mixed-fiber nonwoven fabric containing two or more types of fibers with mutually different average fiber diameters.

The present invention provides compositions comprising cellulose fibers and cellulose ester fibers and wet laid articles made from the compositions, as well as wet laid processes to produce these compositions. More specifically, the present invention provided compositions comprising cellulose fibers and cellulose acetate fibers and wet laid articles made from these compositions as well as wet laid processes to produce these compositions. The present invention also relates to developing a composition, process, wet laid product, or articles exhibiting any one of many the desired benefits. The Present invention also relates to a wet laid product having higher air permeability the same or lower pore size relative to a 100% cellulose comparative composition.

Systems and methods of filtering particulate matter from a fluid are provided. In one exemplary embodiment, a system for filtering particulate matter from a liquid comprises a filter having a filter housing, inlet and outlet ports, and compressible filter media with synthetic fibers. Further, the filter media is disposed in the housing between the inlet and outlet ports and is operable to filter particulate matter from the liquid. Also, a pressure difference between the inlet and outlet ports with the filter media disposed in the housing is no more than four pounds per square inch differential. In addition, the system includes a pump that is operationally coupled to the filter and operable to move the liquid through the filter media with a flux rate of at least eighteen gallons per minute per square foot of the filter media while operating at less than one electrical horsepower.

The present invention provides an electret fiber sheet having superior recovery of airflow volume by heat treatment and having high air permeability. The electret fiber sheet of the present invention is a nonwoven fabric formed from long fibers that are formed from a thermoplastic resin and have an average single fiber diameter of 0.1 to 8.0 μm, wherein a bulk density of the nonwoven fabric is 0.05 to 0.30 g/cm.sup.3 and the long fibers contain a crystal nucleating agent at 0.005 to 1.0% by mass.