Nanofiber filter media ribbons are flexible elongate strips of polymeric material having a surface on which is formed an array of nanofibers. Ribbons are formable into woven or non-woven mats. The array of nanofibers can be configured to filter a predetermined contaminant from a fluid stream passing through the mats. Filter ribbons are formable by applying a moldable polymer to a first angular location of a rotating cylindrical roll having an array of nanoholes formed in a circumferential surface thereof so that the polymer covers the surface of the roll and infiltrates the nanoholes; cooling the polymer while rotating the polymer-covered roll to a second angular position; and removing the cooled polymer from the roll as an elongate film having an array of nanofibers formed on a surface thereof by the polymer that infiltrated the nanoholes.

Provided is a conductive nonwoven fabric, including a meltblown nonwoven fabric made from a melt liquid-crystal-forming wholly aromatic polyester having a melt viscosity at 310 C. of less than or equal to 20 Pa.Math.s and satisfying (A) an average fiber diameter from 0.1 m to 5 m, (B) two or less film-like objects existing per 1 mm.sup.2 of the nonwoven fabric, (C) a breaking length in a warp direction of greater than or equal to 10 km and a breaking length in a weft direction of greater than or equal to 6 km, (D) a basis weight from 1.0 g/m.sup.2 to 15 g/m.sup.2, (E) a thickness from 5 m to 50 m, and (F) an air permeability of less than or equal to 300 cc/cm.sup.2/second, and a metal coating film formed on the meltblown nonwoven fabric.

Provided is a conductive nonwoven fabric, including a meltblown nonwoven fabric made from a melt liquid-crystal-forming wholly aromatic polyester having a melt viscosity at 310 C. of less than or equal to 20 Pa.Math.s and satisfying (A) an average fiber diameter from 0.1 m to 5 m, (B) two or less film-like objects existing per 1 mm.sup.2 of the nonwoven fabric, (C) a breaking length in a warp direction of greater than or equal to 10 km and a breaking length in a weft direction of greater than or equal to 6 km, (D) a basis weight from 1.0 g/m.sup.2 to 15 g/m.sup.2, (E) a thickness from 5 m to 50 m, and (F) an air permeability of less than or equal to 300 cc/cm.sup.2/second, and a metal coating film formed on the meltblown nonwoven fabric.

A non-woven fiber article for use in a food, medical, or pharmaceutical production environment including a melt-spun polymer fiber is provided having a cross-section and a length and a detectable particulate present in an amount of 20 to 80 weight percent loadings of metal or 10 to 80 weight percent loadings of radiopaque particles to render the polymer fiber detectable by magnetic or X-ray detection, alone or in combination with a secondary functional particulate distributed with the polymer fiber to render the polymer fiber chemically responsive to a chemical reactant, change in pH or temperature. The detectable particulate and the secondary functional particulate are each independently present in a core, a sheath, or both portions of polymer matrix. A process of detecting a fabric made from such a fiber. The fabric article passes through detector. A signal is collected from the detector indicative of the presence of the fabric article.

Provided is a melt-blown nonwoven fabric including a propylenic polymer that shows at least one peak top at a position of a molecular weight of 20,000 or higher and at least one peak top at a position of a molecular weight of less than 20,000 in a discharge curve obtained by gel permeation chromatography, that has an intrinsic viscosity [] of from 0.35 dl/g to 0.50 dl/g.

Nonwoven multilayer structures having at least two nanofiber layers are described herein. The nonwoven multilayer structure may have two nanofibers layers that have different properties from each other, such as fiber diameter. One nanofiber layer may be produced by an electrospinning process, while another nanofiber layer may be produced by a melt blown process.

Provided is a nonwoven fabric and a laminated nonwoven fabric suitable as the skin material of a composite sound-absorbing material. The nonwoven fabric and laminated nonwoven fabric are easily formable, thin, and lightweight and excel in form stability, and can nevertheless be controlled within a given range of aeration after being formed into shape. A nonwoven fabric having a laminate structure in which at least one ultra-fine fiber layer (M) having an average fiber diameter of 0.3 to 7 m (inclusive) and a basis weight of 1 g/m.sup.2 to 40 g/m.sup.2 (inclusive) and at least one continuous filament layer (S) having an average fiber diameter of 10 to 30 m (inclusive) are integrated together by partial thermocompression bonding.

Provided is a nonwoven fabric and a laminated nonwoven fabric suitable as the skin material of a composite sound-absorbing material. The nonwoven fabric and laminated nonwoven fabric are easily formable, thin, and lightweight and excel in form stability, and can nevertheless be controlled within a given range of aeration after being formed into shape. A nonwoven fabric having a laminate structure in which at least one ultra-fine fiber layer (M) having an average fiber diameter of 0.3 to 7 m (inclusive) and a basis weight of 1 g/m.sup.2 to 40 g/m.sup.2 (inclusive) and at least one continuous filament layer (S) having an average fiber diameter of 10 to 30 m (inclusive) are integrated together by partial thermocompression bonding.

A nanofiber nonwoven product is disclosed which comprises a polyamide with a relative viscosity from 2 to 330, spun into nanofibers with an average diameter of less than 1000 nanometers (1 micron). In general, the inventive products are prepared by: (a) providing a polyamide composition, wherein the polyamide has a relative viscosity from 2 to 330; (b) melt spinning the polyamide composition into a plurality of nanofibers having an average fiber diameter of less than 1 micron, followed by (c) forming the nanofibers into the product.

A nanofiber nonwoven product is disclosed which comprises a polyamide with a relative viscosity from 2 to 330, spun into nanofibers with an average diameter of less than 1000 nanometers (1 micron). In general, the inventive products are prepared by: (a) providing a polyamide composition, wherein the polyamide has a relative viscosity from 2 to 330; (b) melt spinning the polyamide composition into a plurality of nanofibers having an average fiber diameter of less than 1 micron, followed by (c) forming the nanofibers into the product.