The present invention provides a carbon fiber, which has excellent tensile strength by having fewer internal defects while being a thick fiber having a single-fiber diameter of 6.0 μm or greater, and can provide the effects of reducing costs while increasing production amount to enhance the yieldability of the carbon fiber.

A method of producing a stabilized fiber, including performing a heat treatment on an acrylamide polymer fiber under an oxidizing atmosphere in a stabilization treatment temperature range of 200° C. to 500° C. while applying a tension of 0.07 mN/tex to 15 mN/tex.

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 and to a device for stabilizing precursor fibers for the production of carbon fibers. In the method, precursor fibers are first heated to a first temperature and held at the temperature for a predefined duration. Subsequently, the precursor fibers are heated to at least one second temperature, which is higher than the first temperature, and held at said temperature for a predefined duration. During each heating and between the heating steps, the precursor fibers are in a gas atmosphere having a negative pressure in the range between 12 mbar and 300 mbar and having an oxygen partial pressure of 2.5 to 63 mbar. The device has at least one evacuable, elongate vacuum chamber for feeding the precursor fibers through, at least two lock units and at least one heating unit. At least one lock unit is used for the sealed insertion of precursor fibers into the at least one vacuum chamber, while at least one other lock unit is used for the sealed removal of precursor fibers from the at least one vacuum chamber. The heating unit has at least two individually controllable heating elements, which are suitable for heating the at least one vacuum chamber to at least two different temperatures in heating zones which are adjacent in the longitudinal direction.

The present disclosure relates generally to carbon fibers having high tensile strength and modulus of elasticity, as well as a process for the manufacture of such carbon fiber. The process comprises spinning a polymer/solvent solution into a solvent/water bath in the range of 78%-85% solvent, thereby producing a dense fiber structure, and subsequently carbonizing the polymer precursor fiber at a lower than typical carbonization temperature to form carbon fibers.

A manufacturing method and an apparatus enable high productivity. A method for manufacturing an oxidized fiber bundle includes joining an upstream precursor fiber bundle and a downstream precursor fiber bundle together with a joining fiber bundle, and oxidizing the joined precursor fiber bundles by feeding the joined precursor fiber bundles through an oxidization furnace. The joining includes applying an oiling agent to a joint area of a joining target precursor fiber bundle before joining the joining target precursor fiber bundle and the joining fiber bundle together. A quantity of the oiling agent adhering to the joint area is 0.15 to 0.85 wt %.

The present invention addresses the problem of suitably improving a treatment agent for a carbon fiber precursor in terms of the heat resistance and the effect of suppressing fusion between fibers during the step of flame-resisting treatment. This treatment agent for a carbon fiber precursor is characterized by containing a lubricant, the lubricant comprising a specific sulfur-containing diester compound and a specific sulfur-containing monoester compound.

A process for the production of acrylic fibers, in particular a spinning process for obtaining precursor fibers of carbon fiber by the wet spinning of a polymer solution in an organic solvent and the relative apparatus.

The present invention provides a porous carbon fiber which has an excellent permeation amount and excellent pressure resistance, which is prevented from the occurrence of detachment or cracking at an interface, and which can exhibit excellent properties needed for use as a support for a fluid separation membrane. The present invention is a porous carbon fiber having a bicontinuous porous structure, wherein the average value R.sub.ave of the R value of the outer surface and the R value of the inside is 1.0 or more and 1.8 or less, the absolute value ΔR of the difference between the R value of the outer surface and the R value of the inside is 0.05 or less, and R value is a carbonization progression degree calculated from a Raman spectrum in accordance with the following formula:
R value=(intensity of scattering spectrum at 1360 cm.sup.−1)/(intensity of scattering spectrum at 1600 cm.sup.−1).

Hybrid carbon nanofiber (Cnf) products (e.g., mats, yarns, webs, etc.) and methods of fabricating the same are provided. The hybrid Cnf products are flexible and lightweight and have high thermal conductivity. An electrospinning process can be used to fabricate the hybrid Cnf products and can include preparation of an electrospinning solution, electrospinning, and carbonization (e.g., under a vacuum condition).