Process of making a carbon fiber precursor fiber bundle
AssigneeMitsubishi Rayon Co., Ltd.
InventorsKatsuhiko Ikeda, Atsushi Kawamura
Life of this patent
Estimating the term…
Abstract
A production method for a carbon fiber precursor fiber bundle and a production apparatus of the carbon fiber precursor fiber bundle. A carbon fiber precursor fiber bundle that has a degree of intermingle of 1 m−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.
Claims11
A production method of a carbon fiber precursor fiber bundle, characterized by comprising:
- a coagulation step of forming swollen yarn by extruding an organic solvent solution of an acrylonitrile-based polymer into an aqueous solution of dimethylacetamide from a spinning nozzle having a nozzle hole diameter of 45 μm or more and 75 μm or less and the number of holes of 50,000 or more at a coagulated yarn take-up speed/extrusion linear speed ratio of 0.8 or less;
- a wet heat drawing step of wet heat drawing the swollen yarn;
- an oiling agent imparting step of imparting a first oiling agent to the wet heat drawn yarn by guiding the heat wet drawn yarn into a first oil bath, and subsequently imparting a second oiling agent in a second oil bath after once squeezing the yarn by use of two or more guides;
- a small tow production step of obtaining a small tow by drying, densifying and secondarily drawing the yarn imparted with the first and second oiling agents so as to have a total drawing magnification of 5 or more and 10 or less;
- and
- an aggregate-of-tows production step of obtaining an aggregate of tows by feeding a plurality of the small tows so as to be in parallel and so that side ends of the small tows adjacent to each other are in contact with each other into an intermingling device that comprises a yarn channel having a flat rectangular section and a plurality of air jet holes which are disposed with a predetermined interval along the long side direction of the flat rectangle and which open into the yarn channel, and by jetting out air from the air jet holes to intermingle the adjacent small tows with each other.
A production method of a carbon fiber precursor fiber bundle, characterized by comprising a step of obtaining a single aggregate of tows by disposing a plurality of small tows of carbon fiber precursor fiber so as to be in parallel and so that side ends of the small tows adjacent to each other are in contact with each other, and by intermingling the adjacent small tows with each other by air flow.
Dependencies are inferred from the claim text.