A nanofiber for a filter medium is provided that includes fiber-forming ingredients including polyacrylonitrile (PAN) and polyvinylidene fluoride (PVDF) and an emulsifying agent for improving the miscibility of the fiber-forming ingredients. The nanofiber has excellent mechanical strength and chemical resistance and, at the same time, significantly increased hydrophilicity without a separate surface modification/treatment to/on the nanofiber. A filter medium comprising said nanofiber can exhibit improved flux and filtration efficiency and excellent physical properties in a water treatment process in which a pressure equal to or more than a predetermined level is applied and which requires the filter medium to have high mechanical strength and in a water treatment process which requires chemical resistance as the liquid being filtered is strongly acidic or alkaline. Further, since the nanofiber has significantly superior spinnability, the mass productivity of the filter medium is significantly improved, and the unit costs of production can be reduced.

A nanofiber for a filter medium is provided that includes fiber-forming ingredients including polyacrylonitrile (PAN) and polyvinylidene fluoride (PVDF) and an emulsifying agent for improving the miscibility of the fiber-forming ingredients. The nanofiber has excellent mechanical strength and chemical resistance and, at the same time, significantly increased hydrophilicity without a separate surface modification/treatment to/on the nanofiber. A filter medium comprising said nanofiber can exhibit improved flux and filtration efficiency and excellent physical properties in a water treatment process in which a pressure equal to or more than a predetermined level is applied and which requires the filter medium to have high mechanical strength and in a water treatment process which requires chemical resistance as the liquid being filtered is strongly acidic or alkaline. Further, since the nanofiber has significantly superior spinnability, the mass productivity of the filter medium is significantly improved, and the unit costs of production can be reduced.

The provided articles and methods use a non-woven fibrous web containing 60-100 wt % of oxidized polyacrylonitrile fibers; and 0-40 wt % of reinforcing fibers having outer surfaces comprised of a polymer with a melting temperature of from 100 C. to 300 C. The non-woven fibrous web has an average bulk density of from 15 kg/m.sup.3 to 50 kg/m.sup.3, with the plurality of fibers substantially entangled along directions perpendicular to a major surface of the non-woven fibrous web. Optionally, the oxidized polyacrylonitrile fibers can have a crimped configuration. Advantageously, these articles can display a combination of low thermal conductivity, high tensile strength, and flame resistance.

A washable fire-resistant fabric and a method for making a washable fire-resistant fabric comprises a lightweight pliant non-woven batt blended from two or more types of fire-resistant organic fibers which are non-irritating to human skin. A method for stitch bonding a pliant batt of intertwined fire-resistant fibers to form a fabric which is durable and resistant to unraveling is also provided. The fabric has fire-resistant properties wherein the fabric prevents the ignition of articles made therefrom when exposed to high heat or flame sources and further insulates a wearer of the clothing from high heat or flame sources to prevent serious burns.

A sound absorbing body comprises a non-woven fabric or a non-woven fabric laminate, the non-woven fabric or the non-woven fabric laminate comprises a fiber that has an average fiber diameter of less than 3,000 nm, the non-woven fabric or the non-woven fabric laminate has a thickness of less than 10 mm, the non-woven fabric or the non-woven fabric laminate has a unit thickness flow resistance of greater than 4.0 E+06 Ns/m.sup.4 and less than 5.0 E+08 Ns/m.sup.4, and the non-woven fabric or the non-woven fabric laminate has a bulk density of greater than 70 kg/m.sup.3 and less than 750 kg/m.sup.3.

A sound absorbing body comprises a non-woven fabric or a non-woven fabric laminate, the non-woven fabric or the non-woven fabric laminate comprises a fiber that has an average fiber diameter of less than 3,000 nm, the non-woven fabric or the non-woven fabric laminate has a thickness of less than 10 mm, the non-woven fabric or the non-woven fabric laminate has a unit thickness flow resistance of greater than 4.0 E+06 Ns/m.sup.4 and less than 5.0 E+08 Ns/m.sup.4, and the non-woven fabric or the non-woven fabric laminate has a bulk density of greater than 70 kg/m.sup.3 and less than 750 kg/m.sup.3.

A fabrication method for a filter containing tragacanthin-polyvinyl alcohol (PVA) nanofibers includes obtaining a homogenous tragacanthin-PVA solution by obtaining a PVA solution by dissolving PVA in distilled water, and adding tragacanthin to the PVA solution. The method may further include obtaining a support layer by coating a stainless steel mesh with a thin layer of a hydrophobic polymer, coating a stainless steel mesh with the thin layer of the hydrophobic polymer comprising electrospinning a hydrophobic polymer solution onto the stainless steel mesh, and forming a tragacanthin-PVA nanofibrous web on the support layer by electrospinning the homogenous tragacanthin-PVA solution onto the support layer.

A method for producing a gas diffusion layer for a fuel cell, including providing a fiber composition which includes carbon fibers and/or precursors of carbon fibers and subjecting the fiber composition to a method for producing a fibrous web. The method further includes consolidating the fibrous web by exposure to aqueous fluid jets to form a nonwoven, water used by the aqueous fluid jets having a conductivity of at most 250 microsiemens/cm at 25 C. If the fiber composition includes precursors of carbon fibers, the nonwoven is subjected to pyrolysis at a temperature of at least 1000 C.

A method for producing a gas diffusion layer for a fuel cell, including providing a fiber composition which includes carbon fibers and/or precursors of carbon fibers and subjecting the fiber composition to a method for producing a fibrous web. The method further includes consolidating the fibrous web by exposure to aqueous fluid jets to form a nonwoven, water used by the aqueous fluid jets having a conductivity of at most 250 microsiemens/cm at 25 C. If the fiber composition includes precursors of carbon fibers, the nonwoven is subjected to pyrolysis at a temperature of at least 1000 C.

Provided is a fiber having superior bulkiness despite being a synthetic fiber, and wadding. The fiber contains inorganic particles having an average particle diameter of 1 m to 20 m within the fiber and fiber pores having a maximum width of 0.1 m to 5 m and maximum length of 1 m to 50 m are formed in fiber cross-sections in the axial direction of the fiber. The wadding contains a fiber A, and the content of fiber A in the wadding (100% by weight) is 50% by weight to 100% by weight, down power is 270 cm.sup.3/g to 400 cm.sup.3/g, and the fiber A contains inorganic particles having an average particle diameter of 1 m to 20 m within the fiber.