The invention is directed to carbon fibers having high tensile strength. The invention also provides a method and apparatus for making the carbon fibers. The method comprises advancing a precursor fiber through a plurality of passes through an oxidation oven, where stretching during the initial passes is minimized or eliminated entirely, or made negative, followed by controlled stretching over a series of passes, using rollers of increasing speed.

The invention is directed to carbon fibers having high tensile strength and modulus of elasticity. The invention also provides a method and apparatus for making the carbon fibers. The method comprises advancing a precursor fiber through an oxidation oven wherein the fiber is subjected to controlled stretching in an oxidizing atmosphere in which tension loads are distributed amongst a plurality of passes through the oxidation oven, which permits higher cumulative stretches to be achieved. The method also includes subjecting the fiber to controlled stretching in two or more of the passes that is sufficient to cause the fiber to undergo one or more transitions in each of the two or more passes. The invention is also directed to an oxidation oven having a plurality of cooperating drive rolls in series that can be driven independently of each other so that the amount of stretch applied to the oven in each of the plurality of passes can be independently controlled.

A method for producing microfibers includes the steps of (a) providing a base material; (b) forming the base material in a ring; (c) gripping opposing ends of the ring; (d) flipping one of the opposing ends relative to the other of the opposing ends, forming an upper portion and a lower portion; (e) folding the upper portion onto the lower portion; (f) stretching the folded upper and lower portions; and repeating steps (d)-(f) as desired. Different apparatuses for performing the method are also provided.

A polymeric fiber for use in gas separation is formed from a spin dope which includes solvent and non-solvent materials. The fiber is passed through a quench bath, and then a leach bath, in which the solvent and non-solvent are removed. The quench bath and the leach bath include sets of rollers which transport the fiber through the system. Each set of rollers in the leach bath operates at a speed which is greater than or equal to the speed of the rollers which are immediately upstream. Thus, the fiber is stretched, in different amounts, at the same time that the solvent and non-solvent are being removed, and while the fiber is still wet. The resulting fiber has been found to exhibit superior flux and selectivity properties.

The invention is directed to carbon fibers having high tensile strength and modulus of elasticity. The invention also provides a method and apparatus for making the carbon fibers. The method comprises advancing a precursor fiber through an oxidation oven wherein the fiber is subjected to controlled stretching in an oxidizing atmosphere in which tension loads are distributed amongst a plurality of passes through the oxidation oven, which permits higher cumulative stretches to be achieved. The method also includes subjecting the fiber to controlled stretching in two or more of the passes that is sufficient to cause the fiber to undergo one or more transitions in each of the two or more passes. The invention is also directed to an oxidation oven having a plurality of cooperating drive rolls in series that can be driven independently of each other so that the amount of stretch applied to the oven in each of the plurality of passes can be independently controlled.

The present disclosure relates to an elastic fiber, an elastic fiber covered yarn and reeling manufacturing methods thereof. The reeling manufacturing method of an elastic fiber includes: providing an elastic fiber material, the elastic fiber material having a core portion and a skin portion, the skin portion covering the core portion; performing a first extending, to have the elastic fiber material passing a first guiding roller, the speed of the first guiding roller being 500-1500 m/min; performing a second extending, to have the elastic fiber material passing a second guiding roller, the speed of the second guiding roller being 1200-2400 m/min; and performing a third extending, to have the elastic fiber material passing a third guiding roller, the speed of the third guiding roller is 1300-2600 m/min.

The present invention relates to a monofilament with a segmented pie structure formed by conjugated spinning of degradable polymers and non-degradable polymers, a hernia mesh having improved flexibility and biocompatibility, and a preparation method of the monofilament. More specifically, the hernia mesh of the present invention having improved flexibility and biocompatibility is prepared using the monofilament obtained by conjugated spinning of degradable polymers and non-degradable polymers into a segmented pie form, to control it to be gradually degraded in the body, whereby the stiffness of the early stage is removed, and thereby the foreign body sensation is also removed.

The invention is directed to carbon fibers having high tensile strength and modulus of elasticity. The invention also provides a method and apparatus for making the carbon fibers. The method comprises advancing a precursor fiber through an oxidation oven wherein the fiber is subjected to controlled stretching in an oxidizing atmosphere in which tension loads are distributed amongst a plurality of passes through the oxidation oven, which permits higher cumulative stretches to be achieved. The method also includes subjecting the fiber to controlled stretching in two or more of the passes that is sufficient to cause the fiber to undergo one or more transitions in each of the two or more passes. The invention is also directed to an oxidation oven having a plurality of cooperating drive rolls in series that can be driven independently of each other so that the amount of stretch applied to the oven in each of the plurality of passes can be independently controlled.

The invention is directed to carbon fibers having high tensile strength and modulus of elasticity. The invention also provides a method and apparatus for making the carbon fibers. The method comprises advancing a precursor fiber through an oxidation oven wherein the fiber is subjected to controlled stretching in an oxidizing atmosphere in which tension loads are distributed amongst a plurality of passes through the oxidation oven, which permits higher cumulative stretches to be achieved. The method also includes subjecting the fiber to controlled stretching in two or more of the passes that is sufficient to cause the fiber to undergo one or more transitions in each of the two or more passes. The invention is also directed to an oxidation oven having a plurality of cooperating drive rolls in series that can be driven independently of each other so that the amount of stretch applied to the oven in each of the plurality of passes can be independently controlled.

Provided are: acrylic fibers having 2-7% boiling water shrinkage and formed by the side-by-side conjugation of a copolymer A, which contains 5-10 mass % of an unsaturated monomer that can form a copolymer with acrylonitrile units, and a copolymer B, which contains 2-5 mass % of unsaturated monomer units that can form a copolymer with acrylonitrile units and 0.2-1.5 mass % of sulfonic acid group-containing monomer units; a method for manufacturing said fibers; a spun yarn containing said fibers; and a knitted fabric obtained from said spun yarn. The single fiber fineness of the heat-treated acrylic fibers is 1.7-6.6 dtex, the bulkiness is at least 380 cm3/g, the percentage of crimp is at least 15%, and the product (DKSDKE) of the knot strength (cN/dtex) and the knot elongation (%) is 10-25. The acrylic fibers have excellent crimp characteristics and anti-pilling properties.