Abstract: 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/mm2. 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.

Abstract: 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/mm2. 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.

Abstract: 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/mm2. 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.

Abstract: A carbon fiber bundle having high total fineness and extremely fine single fiber fineness is provided. The carbon fiber bundle includes continuous single fibers and satisfying the following (1) to (4): (1) a fineness of the single fiber is 0.0035-0.056 dtex; (2) a number of the single fibers in one carbon fiber bundle is 300-2500 thousand; (3) a strand strength of the carbon fiber bundle is 3000-10000 MPa; and (4) a strand elastic modulus of the carbon fiber bundle is 200-400 GPa.

Abstract: 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/mm2. 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.

Abstract: An acrylic fiber having an irregular form section and a ramie-like feeling, wherein the section of the fiber has unmethodical surface unevenness and has at least two concave parts which has a ratio of the length l of a perpendicular from a tangental line between adjacent convex parts of said unevenness to the deepest part of the concave part to the diameter D.sub.1 of a circumscribed circle: l/D.sub.1 of 0.05 or more, and the surface of said fiber is covered with many discontinuous creases having an average width of 1.mu. or more provided along the lengthwise direction of the fiber, and process for producing the same.