Carbon fiber bundle

Abstract

A carbon fiber bundle may have a total fineness of 2 g/m or more and a variation rate of a thickness of the fiber bundle of 30% or less in a width direction of the fiber bundle. A manufacturing method of a carbon fiber bundle may include applying a sizing agent to the carbonized fiber bundle, drying the carbonized fiber bundle, then passing the carbonized fiber bundle such that one surface of the carbonized fiber bundle in the width direction and one opposite surface thereof are alternately brought into contact with two or more parallel rods, and winding the carbonized fiber bundle on a bobbin.

1 . A carbon fiber bundle, having
 a total fineness of 2 g/m or more, and   a variation rate of a thickness of the fiber bundle in a width direction of the fiber bundle of 30% or less.   
     
     
         2 . The carbon fiber bundle of  claim 1 , wherein the number of single fibers is 20,000 or more. 
     
     
         3 . The carbon fiber bundle of  claim 1 , wherein a fiber of the fiber bundle has an average thickness in a range of from 0.18 to 0.28 mm. 
     
     
         4 . The carbon fiber bundle of  claim 1 , having a variation rate of a width in a length direction of the fiber bundle of 13% or less. 
     
     
         5 . The carbon fiber bundle of  claim 1 , having a width in a range of from 13 to 18 mm. 
     
     
         6 . The carbon fiber bundle of  claim 1 , having a flatness, which is width/average thickness, in a range of from 60 to 70. 
     
     
         7 . The carbon fiber bundle of  claim 1 , wherein a cantilever value of the carbon fiber bundle is in a range of from 210 to 250 mm and a stickability is 0.18 m or less. 
     
     
         8 . The carbon fiber bundle of  claim 1 , wherein an adhesion amount of a sizing agent is in a range of from 0% to 20% by mass. 
     
     
         9 . The carbon fiber bundle of  claim 1 , having a fiber-fiber dynamic friction coefficient of 0.2 or less. 
     
     
         10 . The carbon fiber bundle of  claim 1 , having a fiber-metal dynamic friction coefficient of 0.18 or less. 
     
     
         11 . A manufacturing method of a carbon fiber bundle, the method comprising:
 in an averaging member having two or more parallel rods arranged between a sizing agent dryer and a winder or a transfer device, passing a carbonized fiber bundle through the averaging member such that each of a surface A of the carbonized fiber bundle and a surface B of the carbonized fiber bundle opposite side to the surface A comes into contact with the rods at least once.   
     
     
         12 . The method of  claim 11 , wherein a distance between adjacent rods of the parallel rods is in a range of from 15 to 50 mm. 
     
     
         13 . The method of  claim 11 , wherein, in the passing the carbonized fiber bundle, the carbonized fiber bundle is passed such that the carbonized fiber bundle is brought into contact with the parallel rods in a state in which a surface direction of a carbon fiber bundle in contact with a roller one before the parallel rods is twisted by 90°. 
     
     
         14 . The method of  claim 11 , wherein, in the passing the carbonized fiber bundle, the carbonized fiber bundle is passed such that a maximum width of the carbonized fiber bundle in contact with the parallel rods is in a range of from 5% to 20% wide with respect to a width of a carbon fiber bundle in contact with a roller one before the parallel rods. 
     
     
         15 . The method of  claim 13 , wherein the roller is located upstream of the parallel rods in a traveling direction of the carbonized fiber bundle, and
 wherein a length direction of the roller and a length direction of the parallel rods are substantially perpendicular to each other.   
     
     
         16 . The method of  claim 13 , wherein a distance from a center of the roller to a center of the parallel rods is in a range of from 200 to 1,500 mm at a position where the distance is shortest. 
     
     
         17 . The method of  claim 11 , wherein, in the passing the carbonized fiber bundle, the carbonized fiber bundle is flat, and the carbonized fiber bundle is passed through the averaging member such that one surface A of the carbonized fiber bundle is brought into contact with the parallel rods located upstream in a traveling direction of the carbonized fiber bundle and then the other surface B of the carbonized fiber bundle is brought into contact with the parallel rods located downstream in the traveling direction of the carbonized fiber bundle. 
     
     
         18 . The method of  claim 11 , the method further comprising:
 before the passing of the carbonized fiber bundle, changing a direction of a surface of the carbonized fiber bundle with a length direction of the carbonized fiber bundle as an axis.   
     
     
         19 . The method of  claim 18 , wherein in changing the direction of the surface, the surface of the carbonized fiber bundle is tilted in a width direction in a range of from 30° to 150° with the length direction of the carbonized fiber bundle as the axis. 
     
     
         20 . The method of  claim 18 , wherein the changing of the direction of the surface is performed between a roller located upstream of the two or more parallel rods in the traveling direction of the carbonized fiber bundle, and the parallel rods located most upstream among the two or more parallel rods. 
     
     
         21 . (canceled)