Carbon fiber and method of forming the same are provided. The method modifies proportion of a finishing oil to control a relation between a surface tension and a particle size of the finishing oil, and thus penetration of the finishing oil into an interior of the carbon fiber is avoided. Therefore, the carbon fiber can have both low oil residues and a high strength.

The invention relates to a method for thermally stabilizing melt-spun PAN precursors. For this purpose, the invention provides a continuous method for producing a thermally stabilized multifilament thread made of a meltable copolymer of polyacrylonitrile (PAN), wherein a pre-stabilized multifilament thread is thermally stabilized and in the process at least temporarily stretched. The invention additionally relates to a thermally stabilized multifilament thread which can be obtained according to a corresponding method and to a carbon fiber which is made of the correspondingly thermally stabilized multifilament thread.

A multi-end monofilament production apparatus includes the following sequential process units along monofilaments flow direction: a vertical spinning machine comprising a spinneret and a distribution plate below the spinneret; a water bath for quenching spun monofilaments; a vacuum jet device for transferring monofilaments from the water bath; a steam jet able to provide superheated steam at a temperature within the range between 300 C. and 380 C. and at a pressure within the range between 4 bars and 5 bars; a drawing unit; and a monofilament winder for winding monofilaments at a speed exceeding 500 m/min. The present invention further proposes a method for multi-end monofilament yarn production.

A method for manufacturing a nylon 66 hollow fiber includes steps as follows. A plurality of nylon 66 particles are provided. A melting step is provided, wherein the nylon 66 particles are melted so as to form a spun liquid. A fiber spitting step is provided, wherein the spun liquid goes through a hollow spinneret plate so as to form hollow nascent fibers. An evacuating step is provided, wherein the hollow nascent fibers are preliminarily solidified so as to form hollow half-solidified fibers. A cooling step is provided, wherein the hollow half-solidified fibers are cooled and solidified so as to form solidified fibers. A collecting and oiling step is provided. A drawing step is provided. A winding step is provided so as to obtain the nylon 66 hollow fiber.

A carbon fiber precursor fiber bundle which permits easy bundling of a plurality of small tows into one bundle, is provided with a dividing capability to divide into the original small tows spontaneously at the time of firing, and is suitable for obtaining a carbon fiber that is excellent in productivity and quality. A carbon fiber precursor fiber bundle that has a degree of intermingle of 1 m.sup.1 or less between small tows, consists of substantially straight fibers without imparted crimp, a tow of which straight fibers has a moisture content of less than 10% by mass when housed in a container, and has a widthwise dividing capability to maintain a form of a single aggregate of tows when housed in a container, taken out from the container and guided into a firing step, and to divide into a plurality of small tows in the firing step by the tension generated in the firing step.

The present invention discloses a method for preparing a PET/PTT parallel complex filament with high self-crimpiness, wherein PET and PTT are sliced, dried and crystallized, and then fused separately and subjected to extrusion molding through a parallel-type spinneret plate; oil is applied after cooling; then level 1-3 drafting and heat setting treatment are adopted; and during drafting, a total drafting rate is controlled to be 3 to 3.5, wherein the level-1 drafting rate is 2.8 to 3.0 at a temperature controlled to be 75 to 80? C., according to the method for preparing the PET/PTT parallel complex filament with high self-crimpiness, methods like multi-level drafting for increasing the drafting rate are adopted, and the effects of improving the fiber strength, moderately lowering the breaking elongation, and greatly improving the self-crimpiness are achieved.

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 drawing device for drawing a drawable material, the drawing device comprising at least a pair of tapered rollers each having a taper ratio in a range of 0.035 to 0.50, wherein the taper ratio is represented by ()/2L, where denotes a maximum diameter of the roller, denotes a minimum diameter of the roller, and L denotes a length of a tapered portion of the roller.

A method for forming porous fibers is provided. The fibers are formed from a thermoplastic composition containing a continuous phase, which includes a matrix polymer, and a nanoinclusion additive that is at least partially incompatible with the matrix polymer so that it becomes dispersed within the continuous phase as discrete nano-scale phase domains. The method includes traversing a bundle of the fibers through a multi-stage drawing system that includes at least a first fluidic drawing stage and a second fluidic drawing stage. The first drawing stage employs a first fluidic medium having a first temperature and the second drawing stage employs a second fluidic medium having a second temperature. The first and second temperatures are both lower than the melting temperature of the matrix polymer, and the first temperature is greater than the second temperature.

The present invention provides a continuous method for the production of at least one polymeric yarn comprising the steps of: mixing a polymer with a first solvent generating a mixture; homogenizing the mixture; rendering the mixture inert; dosing the mixture to an extruder; immersing the mixture in a quenching bath (30), wherein an air gap is maintained before the mixture achieves the surface of the liquid of the quenching bath (30) forming at least one polymeric yarn; drawing at least once the at least one polymeric yarn; washing the polymeric yarn with a second solvent that is more volatile than the first solvent; heating the at least one polymeric yarn; drawing at room temperature, at least once, the at least one polymeric yarn; and heat drawing, at least once, the at least one polymeric yarn, wherein the mixture comprises: a polymer comprising ultra-high molecular weight polyethylene, comprising an intrinsic viscosity of from 5 dL/g to 40 dL/g, and a polydispersity index of from 2 to 10; and a first solvent capable of dissolving the polymer under the process conditions, and comprising a dynamic viscosity, measured at a temperature of 37.8? C., according to ASTM D-445, greater than 10 cP. The present invention further provides a continuous system for the production of at least one polymeric yarn, comprising: means for mixing the polymer with a first solvent generating a mixture; means for homogenizing the mixture; means for rendering the mixture inert; means for dosing the mixture to an extruder; means for immersing the mixture in a quenching bath (30), wherein an air gap is maintained before the mixture achieves the surface of the liquid of the quenching bath (30) forming at least one polymeric yarn; means for drawing at least once the at least one polymeric yarn; means for washing for washing the at least one polymeric yarn with a second solvent that is more volatile than the first solvent; means for heating the at least one polymeric yarn; means for drawing at room temperature at least once the at least one polymeric yarn; and means for heat drawing at least once the at least one polymeric yarn, wherein the mixture comprises: a polymer comprising ultra-high molecular weight polyethylene, comprising an intrinsic viscosity of from 5 dL/g to 40 dL/g, and a polydispersity index of from 2 to 10; and a first solvent capable of dissolving the polymer under the process conditions and comprising a dynamic viscosity, as measured at a temperature of 37.8? C. according to the ASTM standard D-445, greater than 10 cP. Further, the present invention provides a polymeric yarn made according to the above stated method.