Method for the preparation of carbon fiber from fiber precursor, wherein the fiber precursor is subjected to a magnetic field of at least 3 Tesla during a carbonization process. The carbonization process is generally conducted at a temperature of at least 400° C. and less than 2200° C., wherein, in particular embodiments, the carbonization process includes a low temperature carbonization step conducted at a temperature of at least or above 400° C. or 500° C. and less than or up to 1000° C., 1100° C., or 1200° C., followed by a high temperature carbonization step conducted at a temperature of at least or above 1200° C. In particular embodiments, particularly in the case of a polyacrylonitrile (PAN) fiber precursor, the resulting carbon fiber may possess a minimum tensile strength of at least 600 ksi, a tensile modulus of at least 30 Msi, and an ultimate elongation of at least 1.5%.

In a method of making a carbon fiber, carbon nanotubes (CNT) are mixed into a solution including polyacrylonitrile (PAN) so as to form a CNT/PAN mixture. At least one PAN/CNT fiber is formed from the mixture. A first predetermined electrical current is applied to the PAN/CNT fiber until the PAN/CNT fiber is a stabilized PAN/CNT fiber. A heatable fabric that includes a plurality of fibers that each have an axis. Each of the plurality of fibers includes polyacrylonitrile and carbon nanotubes dispersed in the polyacrylonitrile in a predetermined weight percent thereof and aligned along the axes of the plurality of fibers. The plurality of fibers are woven into a fabric. A current source is configured to apply an electrical current through the plurality of fibers, thereby causing the fibers to generate heat.

A method for producing polyacrylonitrile (PAN) fiber, the method comprising: (i) mixing PAN with an ionic liquid in which the PAN is soluble to produce a PAN composite melt in which the PAN is dissolved in the ionic liquid; (ii) melt spinning the PAN composite melt to produce the PAN fiber; and (iii) washing the PAN fiber with a solvent in which the ionic liquid is soluble to substantially remove the ionic liquid from the PAN fiber. Also described herein is a method for producing carbon fiber from the PAN fiber as produced above, the method comprising oxidatively stabilizing the PAN fiber produced in step (iii), followed by carbonizing the stabilized PAN fiber to produce the carbon fiber. The initially produced PAN fiber, stabilized PAN fiber, resulting carbon fiber, and articles made thereof are also described.

The present disclosure relates to the production of polyacrylonitrile-based polymers with high conversion by a process comprising reacting acrylonitrile with at least one comonomer in the presence of a radical initiator in a liquid medium, wherein the radical initiator is present in an amount of from about 0.6 wt % to about 1.8 wt %, relative to the amount of acrylonitrile, and wherein no chain transfer agent is present. The polyacrylonitrile-based polymers produced may be used for producing carbon fiber, typically carbon fiber used in manufacturing composite materials.

A method and precursor for making carbon fibers and the like comprising carbon black modified with at least one cyclic compound promoter. A source of the carbon black may be recycled materials such as recycled tires or recycled plastics. The carbon black is modified by attaching at least one cyclic compound promoter to the outer periphery of the carbon black.

A method for manufacturing a precursor fiber bundle provides precursor fiber bundles used in manufacturing carbon fiber bundles allowing high productivity and having high tensile strength with less yarn bundle divides in the fiber bundles. The method for manufacturing a precursor fiber bundle includes spinning by extruding a spinning solution through a spinneret to produce a coagulated fiber bundle, and interlacing the coagulated fiber bundle by applying a fluid onto the coagulated fiber bundle. The interlacing includes applying the fluid (18) under a pressure in a range of 0.01 to 0.05 MPa onto the coagulated fiber bundle (14) with a moisture content in a range of 25 to 50% under a tension of 0.02 g/dtex or less.

The present invention is a method for producing carbon fiber, characterized by using a carbon-fiber precursor produced from a polymer having a narrow molecular weight distribution and by applying only a small amount of a smoothing agent, composed of a specific component, to the carbon fiber surface immediately before winding of carbon fiber. According to the present invention, it is possible to stably produce carbon fiber, which has excellent dispersibility and do not deteriorate in quality and quality even when a sizing agent is not attached to the carbon fiber surface. In addition, the produced carbon fiber is suitable for use in a composite material which is produced by high-temperature processing using a thermoplastic resin.

The present disclosure relates to a process for producing one or more carbon fiber precursor fibers, particularly by spinning a polymer solution, wherein the polymer has a polydispersity (PDI) of less than or equal to 2, in a coagulation bath with a jet stretch of about 5 to about 60. The one or more carbon fiber precursor fibers produced may be used for producing carbon fiber, typically carbon fiber used in manufacturing composite materials.

Provided herein is a method for producing an acrylonitrile based fiber bundle by dry-jet wet spinning technique that serves to allow a high-grade, high-quality acrylonitrile based fiber bundle to be produced stably even if the traveling speed of the coagulated fibers is increased or the number of spinneret discharge holes is maximized in an attempt to enhance the production efficiency. The production method for an acrylonitrile based fiber bundle is characterized by first extruding a spinning dope solution through a plurality of discharge holes in a spinneret, then allowing the spinning dope solution to run downward into a coagulation bath liquid stored in a coagulation bath to form coagulated fibers, turning the coagulated fibers upward on a direction changing guide part located in the coagulation bath liquid below the spinneret, and pulling them out of the coagulation bath liquid, wherein certain requirements are met.

A method of producing a carbon fiber bundle suppresses penetration of a process oil agent into the fiber surface layer and suppresses adhesion between fibers and the generation of surface voids, and also provides a carbon fiber bundle. The carbon fiber bundle is characterized by having a crystallite size of 3.0 nm or less as measured by wide-angle X-ray diffraction, containing a point where the Si/C ratio is 10 or more as calculated by SIMS (secondary ion mass spectrometry) in the region ranging from 0 to 10 nm in depth from the fiber surface, and also showing a Si/C ratio of 1.0 or less as calculated by SIMS at a depth of 10 nm from the fiber surface.