Abstract: A spinneret includes: a plate including a plurality of nozzle holes formed therein. In the plates, the plurality of nozzle holes are formed in a substantially rectangular area on a principal surface, the rectangular area includes a non-forming zone that intersects with nozzle hole rows, the non-forming zone continuously extending from one long side of the rectangle to the other long side, and the non-forming zone including no nozzle holes, in nozzle hole rows with which the non-forming zone intersects out of the nozzle hole rows, in each of the nozzle hole rows, the nozzle hole is not formed on a part where the non-forming zone intersects with a position of the regular interval at which the nozzle holes are aligned, and the nozzle hole corresponding to number of the unformed nozzle holes is additionally formed in a short side direction of the nozzle hole row.

Abstract: A pack for spinning is provided with a kneading part disposed on a spinneret. The kneading part includes: an introduction plate including a plurality of first introduction holes for introducing a melted polymer; and a plurality of kneading units including a supply plate including a plurality of independent supply grooves into which the polymer introduced from the introduction holes flows and one or more supply holes disposed in each of the supply grooves, and a converging plate including a plurality of converging grooves in which a plurality of grooves into which the polymer supplied from the supply holes flows are intersected and a plurality of second introduction holes disposed in each of the converging grooves.

Abstract: An object of the present invention is to provide a ligand-immobilized sea-island composite fiber in which generation of fine particles due to peeling of a sea component from an island component and generation of fine particles due to destruction of a fragile sea component are both suppressed. The present invention provides a sea-island composite fiber comprising a sea component and island components, in which a value (L/S) obtained by dividing the average total length (L) of the perimeter of all island components in a cross section perpendicular to the fiber axis by the average cross-sectional area (S) of the cross section is from 1.0 to 50.0 ?m?1, a distance from the surface to the outermost island component is 1.9 ?m or less, and an amino group-containing compound is covalently bonded to a polymer constituting the sea component at a charge density of 0.1 ?mol or more and less than 500 ?mol per 1 gram dry weight.

Abstract: An object of the present invention is to provide a ligand-immobilized sea-island composite fiber in which generation of fine particles due to peeling of a sea component from an island component and generation of fine particles due to destruction of a fragile sea component are both suppressed. The present invention provides a sea-island composite fiber comprising a sea component and island components, in which a value (L/S) obtained by dividing the average total length (L) of the perimeter of all island components in a cross section perpendicular to the fiber axis by the average cross-sectional area (S) of the cross section is from 1.0 to 50.0 ?m?1, a distance from the surface to the outermost island component is 1.9 ?m or less, and an amino group-containing compound is covalently bonded to a polymer constituting the sea component at a charge density of 0.1 ?mol or more and less than 500 ?mol per 1 gram dry weight.

Abstract: A spinneret includes: a plate including a plurality of nozzle holes formed therein. In the plates, the plurality of nozzle holes are formed in a substantially rectangular area on a principal surface, the rectangular area includes a non-forming zone that intersects with nozzle hole rows, the non-forming zone continuously extending from one long side of the rectangle to the other long side, and the non-forming zone including no nozzle holes, in nozzle hole rows with which the non-forming zone intersects out of the nozzle hole rows, in each of the nozzle hole rows, the nozzle hole is not formed on a part where the non-forming zone intersects with a position of the regular interval at which the nozzle holes are aligned, and the nozzle hole corresponding to number of the unformed nozzle holes is additionally formed in a short side direction of the nozzle hole row.

Abstract: A core-sheath conjugated fiber includes two kinds of polymer, wherein the core-sheath conjugated fiber is characterized in that the core component has projected shapes having projections and grooves alternately in a cross section in a direction perpendicular to the fiber axis, the projections are formed continuously in the direction of the fiber axis, and the height (H) of the projections, the width (WA) at the tip of the projections, and the width (WB) of the bottom surface satisfy the formulas at the same time: 1.0?H/(WA)1/2?3.0??(1) 0.7?WB/WA?3.0??(2).

Abstract: A conductive composite fiber is formed from a polymer containing conductive carbon black in a polyamide resin as a conductive layer and thermoplastic resin as a nonconductive layer that is exposed in three or more locations on the outside surface of the fiber in a cross section, the coefficient of variation in the surface area of each conductive layer in a fiber cross section is 10% or less, and the average value of the area specific resistance is 4 log (?·cm). The variation in the fiber surface specific resistance is suppressed and the variation in the exposed surface area of each conductive layer polymer in a fiber cross section is suppressed by exposure of the conductive layer in three or more locations on the fiber surface, crimping of the original yarn is suppressed by equal disposition, and antistatic performance for woven and knitted fabrics and carpets is improved.

Abstract: A pack for spinning is provided with a kneading part disposed on a spinneret. The kneading part includes: an introduction plate including a plurality of first introduction holes for introducing a melted polymer; and a plurality of kneading units including a supply plate including a plurality of independent supply grooves into which the polymer introduced from the introduction holes flows and one or more supply holes disposed in each of the supply grooves, and a converging plate including a plurality of converging grooves in which a plurality of grooves into which the polymer supplied from the supply holes flows are intersected and a plurality of second introduction holes disposed in each of the converging grooves.

Abstract: A core-sheath conjugated fiber includes two kinds of polymer, wherein the core-sheath conjugated fiber is characterized in that the core component has projected shapes having projections and grooves alternately in a cross section in a direction perpendicular to the fiber axis, the projections are formed continuously in the direction of the fiber axis, and the height (H) of the projections, the width (WA) at the tip of the projections, and the width (WB) of the bottom surface satisfy the formulas at the same time: 1.0?H/(WA)1/2?3.0??(1) 0.7?WB/WA?3.0??(2).