A method and apparatus for manufacturing a carbon fiber. Pressure is applied to a filament to change a cross-sectional shape of the filament and create a plurality of distinct surfaces on the filament. The filament is converted into a graphitic carbon fiber having the plurality of distinct surfaces. A plurality of sizings is applied to the plurality of distinct surfaces of the graphitic carbon fiber in which the plurality of sizings includes at least two different sizings.

A method and apparatus for manufacturing a carbon fiber. Pressure is applied to a filament to change a cross-sectional shape of the filament and create a plurality of distinct surfaces on the filament. The filament is converted into a graphitic carbon fiber having the plurality of distinct surfaces. A plurality of sizings is applied to the plurality of distinct surfaces of the graphitic carbon fiber in which the plurality of sizings includes at least two different sizings.

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.

A manufacturing method and a manufacturing apparatus have high yields. The manufacturing method is a method for manufacturing a carbon fiber electrode substrate (3a) by feeding an oxidized fiber substrate (1a) through a carbonization furnace (102, 103) to carbonize the oxidized fiber substrate (1a). The method includes feeding, through the carbonization furnace (102, 103), a plurality of oxidized fiber substrates (1a) arranged in a thickness direction of the oxidized fiber substrates (1a).

A furnace for thermal treatment, in particular for carbonization and/or graphitization, of material, in particular fibers, in particular fibers of oxidized polyacrylonitrile PAN. During the thermal treatment, a pyrolysis gas is released from the material. The furnace includes a housing, a process space, which is located in the interior of the housing and is delimited by a process space housing and through which the material can be fed, a heating system for heating a process space atmosphere prevailing in the process space, and an extraction system for suctioning process space atmosphere laden with pyrolysis gas from the process space. The extraction system has at least one suction device having a suction channel, which is delimited by a channel wall and which is connected to the process space by means of a suction opening. The suction opening is arranged in a region of the process space in which, during operation of the furnace a temperature prevails at which no or only moderate chemical reactions occur between the pyrolysis gas and the process space housing and/or the channel wall.

A furnace for thermal treatment, in particular for carbonization and/or graphitization, of material, in particular fibers, in particular fibers of oxidized polyacrylonitrile PAN. During the thermal treatment, a pyrolysis gas is released from the material. The furnace includes a housing, a process space, which is located in the interior of the housing and is delimited by a process space housing and through which the material can be fed, a heating system for heating a process space atmosphere prevailing in the process space, and an extraction system for suctioning process space atmosphere laden with pyrolysis gas from the process space. The extraction system has at least one suction device having a suction channel, which is delimited by a channel wall and which is connected to the process space by means of a suction opening. The suction opening is arranged in a region of the process space in which, during operation of the furnace a temperature prevails at which no or only moderate chemical reactions occur between the pyrolysis gas and the process space housing and/or the channel wall.

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 %.

Efficient production of high quality oxidized fiber bundles and carbon fiber bundles is described, comprising a step for heat-treating aligned acryl based fiber bundles in an oxidizing atmosphere while turning them back on guide rollers installed on both ends outside the furnace body of a hot gas heating type oxidation furnace wherein: supply nozzles for supplying hot gas into a heat treatment chamber are installed at an end in the traveling direction of the acryl based fiber bundles; a fiber bundle traveling passage(s) exists above and/or below each nozzle; hot gas is supplied from the supply face(s) located above and/or below the acryl based fiber bundle; and the requirements (1) and (2) are satisfied where Vf and V are defined as described.

1.5 m/s≤Vf≤15 m/s   (1)

1.5 m/s≤V≤10 m/s   (2)

Systems and methods of production for consistently sized and shaped optically anisotropic mesophase pitch from vacuum residue, one method including supplying processed vacuum residue to an extruder; heating the processed vacuum residue throughout a horizontal profile of the extruder from an inlet to an outlet of the extruder; venting hydrocarbon off-gases from the extruder along the horizontal profile of the extruder from the inlet to the outlet of the extruder; and physically shaping the consistently sized and shaped mesophase pitch at the outlet of the extruder for production of carbon fibers.

Provided is a microwave treatment apparatus that can properly treat a treatment target using microwaves. The apparatus includes: a vessel 10 in which a treatment target 2 is arranged; a microwave irradiating unit 20 that irradiates an internal portion of the vessel 10 with microwaves; and heat generating member 30 that is provided inside the vessel 10 along the treatment target 2, generates heat by absorbing part of microwaves used for irradiation by the microwave irradiating unit 20, and transmits part of the microwaves. The microwave irradiating unit 20 irradiates a portion in which the heat generating member 30 is provided with microwaves, thereby heating the treatment target 2 from the outside through heat generation at the heat generating member 30, and directly heating the treatment target 2 with microwaves transmitted through the heat generating member 30.