A nanofiber sheet includes: a substrate layer; and a nanofiber layer located on one surface side of the substrate layer and containing nanofibers of a polymer compound. A peripheral edge of the nanofiber layer has a thickness of from 0.1 to 10 μm. The nanofiber layer includes a gradation region having a thickness that gradually increases inward from the peripheral edge. The distance W1 between the peripheral edge of the nanofiber layer and a maximum thickness portion where the thickness becomes the greatest in the gradation region is at least 3 mm. A nanofiber sheet manufacturing method involves depositing nanofibers onto a collecting unit by moving at least either a nozzle or the collecting unit, to thereby manufacture a predetermined nanofiber sheet including a gradation region.

A nanofiber sheet includes: a substrate layer; and a nanofiber layer located on one surface side of the substrate layer and containing nanofibers of a polymer compound. A peripheral edge of the nanofiber layer has a thickness of from 0.1 to 10 μm. The nanofiber layer includes a gradation region having a thickness that gradually increases inward from the peripheral edge. The distance W1 between the peripheral edge of the nanofiber layer and a maximum thickness portion where the thickness becomes the greatest in the gradation region is at least 3 mm. A nanofiber sheet manufacturing method involves depositing nanofibers onto a collecting unit by moving at least either a nozzle or the collecting unit, to thereby manufacture a predetermined nanofiber sheet including a gradation region.

A spinning nozzle which has a perforated part in which ejection holes have been arranged in a density as high as 600-1,200 holes/mm.sup.2. This process for producing a fibrous bundle comprises ejecting a spinning dope having a viscosity as measured at 50° C. of 30-200 P from the ejection holes of the spinning nozzle to produce a fibrous bundle. This fibrous bundle has a single-fiber fineness of 0.005-0.01 dtex. By the wet-process direct spinning, a mass of nanofibers which are stably uniform and continuous can be produced at a high efficiency.

Methods for the preparation of carbon fiber from polyolefin fiber precursor, wherein the polyolefin fiber precursor is partially sulfonated and then carbonized to produce carbon fiber. Methods for producing hollow carbon fibers, wherein the hollow core is circular- or complex-shaped, are also described. Methods for producing carbon fibers possessing a circular- or complex-shaped outer surface, which may be solid or hollow, are also described.

In embodiments, the present invention provides a plurality of fine fiber strands made from a first polymer and a second polymer where the second polymer has a higher molecular weight than the first polymer. In preferred embodiments, the fine fiber strands have an average diameter of less than 2 micron, and the fine fiber strands have a length of at least 1 millimeter.

Disclosed are a polyurethane elastic fiber with a flame retardant function and a preparation method thereof. The polyurethane elastic fiber is prepared by using a polyether diol containing phosphorus elements or a polyester diol containing phosphorus elements as a raw material to react with 4,4′-diphenylmethane diisocyanate to prepare a prepolymer, extending the chain using an organic amine to obtain a polyurethane solution, and dry spinning with the polymer solution to prepare the polyurethane fiber. The limit oxygen index of the prepared polyurethane fiber was between 25% and 32%.

Disclosed are a polyurethane elastic fiber with a flame retardant function and a preparation method thereof. The polyurethane elastic fiber is prepared by using a polyether diol containing phosphorus elements or a polyester diol containing phosphorus elements as a raw material to react with 4,4′-diphenylmethane diisocyanate to prepare a prepolymer, extending the chain using an organic amine to obtain a polyurethane solution, and dry spinning with the polymer solution to prepare the polyurethane fiber. The limit oxygen index of the prepared polyurethane fiber was between 25% and 32%.

A process, for example a continuous process, for making an oral care article of manufacture containing a fibrous composition, for example a composite structure, and more particularly to a process for making an oral care article of manufacture containing a fibrous composition, such as a soluble fibrous composition, containing soluble filaments is provided.

The application relates to a method and apparatus for manufacturing a natural fiber based staple fibers. The application further relates to the staple fibers, staple fiber based raw wool and products comprising such. A method comprises providing a cellulose suspension (101, 310, 510) including water, refined cellulose fibrils and at least one rheology modifier, directing the cellulose suspension through a nozzle (102, 320, 520) onto a surface (300, 400, 500), drying the cellulose suspension onto the surface (103, 300, 400, 500) for forming a fiber (350, 550), and cutting the cellulose suspension on the surface for forming staple fibers (105).

The application relates to a method and apparatus for manufacturing a natural fiber based staple fibers. The application further relates to the staple fibers, staple fiber based raw wool and products comprising such. A method comprises providing a cellulose suspension (101, 310, 510) including water, refined cellulose fibrils and at least one rheology modifier, directing the cellulose suspension through a nozzle (102, 320, 520) onto a surface (300, 400, 500), drying the cellulose suspension onto the surface (103, 300, 400, 500) for forming a fiber (350, 550), and cutting the cellulose suspension on the surface for forming staple fibers (105).