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 sea-island composite fiber in which island components are interspersed in a sea component on a fiber cross-section, wherein the island components have a composite structure formed with two or more different polymers joined together, and the ratio (L/D) of the length (L) of the joint section of the island component and the diameter (D) of the composite island component is 0.1 to 10.0. The sea-island composite fiber has satisfactory high-order processability, and therefore can be produced with high productivity and quality using existing equipment, and thin fibers obtained by removing the sea component have functions of structure control while having an excellent tactile impression.

Abstract: A fiber material combines both stretchability and wear resistance, has a uniform and bump- and streak-free outer appearance, and has a smooth, delicate texture. The eccentric core-sheath composite fiber is characterized in that in the cross-section of a composite fiber composed of two different polymers, an A-component is completely covered by a B-component, a ratio S/D, or the minimum thickness S of the thickness of the B-component covering the A-component to a fiber diameter D, is 0.01 to 0.1, and a perimeter of a portion of fiber, where the thickness is 1.05 times or less the minimum thickness S, is at least one third of the perimeter of the fiber overall.

Abstract: Glossy fibers can be processed into woven or knitted fabric suitable for clothing applications while exhibiting a sense of deep, lustrous glossiness. The glossy fibers are characterized by having an average reflectance for the visible light region of 20% or greater, an average transmittance of 40% of less, and a contrastive glossiness of 3.0 or less.

Abstract: A fiber-filled material composed of batting and ticking made of synthetic fibers, wherein the batting made of synthetic fibers includes a bulky yarn in which (1) a fineness ratio of a sheath yarn to a core yarn (sheath/core) is 0.5-2.0, (2) entanglement points of the core yarn with the sheath yarn in a fiber axis direction are present at 1-30/mm, and (3) a radius of curvature of the sheath yarn forming loops is 2.0-30.0 mm.

Abstract: Provided is a liquid crystal polyester fiber having high strength, high elastic modulus, high abrasion resistance, excellent processability, and little thermal deformation at high temperature, and also provided is a production method thereof. A liquid crystal polyester fiber, characterized in that the peak half-value width of the endothermic peak (Tm1) observed when measuring by differential calorimetry under rising temperature conditions starting at 50° C. and increasing 20° C./min is 15° C. or higher, the polystyrene-converted weight-average molecular weight is between 250,000 and 2,000,000 inclusive, the peak temperature of the loss tangent (tan ?) is between 100° C. and 200° C. inclusive, and the peak value of the loss tangent (tan ?) is between 0.060 and 0.090 inclusive. A mesh fabric comprising the liquid crystal polyester fiber.

Abstract: A bulky yarn includes a sheath yarn having continuously formed loops without any breakages; and a core yarn that substantially fixes the sheath yarn by being interlaced with the sheath yarn, wherein a number of loops protruding from a yarn surface layer by not less than 3.0 mm is 1 to 30 loops/mm, an elastic modulus is not greater than 80 cN/dtex, and an extension recovery rate at a time of 10% extension recovery is not less than 50%.

Abstract: A composite spinneret that discharges a composite polymer composed of an island polymer and a sea polymer, the composite spinneret satisfying (1) and (2): (1) the composite spinneret comprises: a distribution device; a nozzle plate; a flow contraction plate; and (2) the nozzle plate has a nozzle hole collection including a plurality of discharge holes, and at least one sea-island discharge hole group including any of (i) to (v): (i) the sea discharge holes and the island discharge hole; (ii) the composite polymer discharge holes; (iii) the sea discharge holes and the composite polymer discharge holes; (iv) the island discharge holes and the composite polymer discharge holes; and (v) the sea discharge holes, the island discharge holes and the composite polymer discharge holes.

Abstract: An object of the present invention is to provide a bulky yarn made of synthetic fibers, which is suppressed in tanglement between filaments while having a loop shape in the surface layer thereof, and has a soft texture and is light and excellent in heat retention properties while being good in handleability in high-order processing. The present invention provides a bulky yarn made of synthetic fibers, including: a sheath yarn (1) having a three-dimensional crimped structure; and a core yarn (2) twisted with the sheath yarn (1) to fix the sheath yarn (1), wherein the sheath yarn (1) is not substantially broken and continuously forms loops.

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 sea-island composite fiber includes island component fibers having a circumscribed circle diameter of 10 to 1000 nm, a circumscribed circle diameter variation of 1 to 20%, a non-circularity of 1.2 to 5.0, and a non-circularity variation of 1 to 10%.

Abstract: A sea-island composite fiber includes two or more kinds of island components having different cross section shapes of which an irregularity difference is 0.2 or more in a same fiber cross section, wherein at least one kind of island component has an irregularity of 1.2 to 5.0 and an irregularity coefficient of variation of 1.0 to 10.0%.

Abstract: A sea-island composite fiber in which island components are interspersed in a sea component on a fiber cross-section, wherein the island components have a composite structure formed with two or more different polymers joined together, and the ratio (L/D) of the length (L) of the joint section of the island component and the diameter (D) of the composite island component is 0.1 to 10.0. The sea-island composite fiber has satisfactory high-order processability, and therefore can be produced with high productivity and quality using existing equipment, and thin fibers obtained by removing the sea component have functions of structure control while having an excellent tactile impression.

Abstract: Provided is a liquid crystal polyester fiber having high strength, high elastic modulus, high abrasion resistance, excellent processability, and little thermal deformation at high temperature, and also provided is a production method thereof. A liquid crystal polyester fiber, characterized in that the peak half-value width of the endothermic peak (Tm1) observed when measuring by differential calorimetry under rising temperature conditions starting at 50° C. and increasing 20° C./min is 15° C. or higher, the polystyrene-converted weight-average molecular weight is between 250,000 and 2,000,000 inclusive, the peak temperature of the loss tangent (tan ?) is between 100° C. and 200° C. inclusive, and the peak value of the loss tangent (tan ?) is between 0.060 and 0.090 inclusive. A mesh fabric comprising the liquid crystal polyester fiber.

Abstract: An islands-in-sea fiber includes island components and a sea component arranged to surround the island components, wherein the island components and the sea component are composed of at least two polymers and are provided on a fiber cross-section in a direction perpendicular to the fiber axis. The islands-in-sea fiber is a raw yarn for a combined filament yarn, which can be used to produce a cloth having good tension and drape and an excellent color-developing property. An islands-in-sea fiber in which at least two types of island components having different diameters are arranged on the same fiber cross section, the islands-in-sea fiber characterized in that at least one type of the island components have diameters of 10-1000 nm and have fluctuations in diameters of 1.0-20.0%.

Abstract: The fiber cross-section of an island-in-a-sea composite fiber perpendicular to the fiber axis, the island component and sea component are arranged such that the sea component surrounds the island components. The composite cross-section is very consistent, and the fiber has excellent post-processibility. The island-in-a-sea composite fiber wherein diameter of the island component is 10 to 1000 nm, variation of the island component diameter is 1.0 to 20.0%, modification ratio is 1.00 to 1.10, and variation of the modification ratio is 1.0 to 10.0%.

Abstract: A multicomponent fiber includes a sea component and an island component, wherein in cross-section observation of the multicomponent fiber, the multicomponent fiber includes a sea-island region with the plurality of island components arranged in the sea component; and one or more sea component regions formed only of the sea component between the sea-island region, and a width (H) of the sea component region is larger than a maximum value of a distance (W) between island components existing in the sea-island region and neighboring each other.

Abstract: A sea-island composite fiber includes two or more kinds of island components having different cross section shapes of which an irregularity difference is 0.2 or more in a same fiber cross section, wherein at least one kind of island component has an irregularity of 1.2 to 5.0 and an irregularity coefficient of variation of 1.0 to 10.0%.

Abstract: A sea-island composite fiber includes island component fibers having a circumscribed circle diameter of 10 to 1000 nm, a circumscribed circle diameter variation of 1 to 20%, a non-circularity of 1.2 to 5.0, and a non-circularity variation of 1 to 10%.

Abstract: A composite spinneret for discharging a composite polymer stream consisting of at least two or more component polymers, which includes a metering plate having multiple metering holes for metering respective component polymers, a distribution plate with multiple distribution holes formed in the distribution grooves for joining the polymer streams discharged from the metering holes, and a discharge plate.