Fiber bundle for artificial hair and method for producing fiber bundle for artificial hair

Abstract

Provided is a method for producing a fiber bundle for artificial hair. The method includes a first cutting process of cutting a first fiber strip obtained by arranging first fibers so that a cut part includes a first linear section extending linearly at an angle of >0 degrees and ≤60 degrees, and a second linear section extending linearly at an angle of ≤120 degrees relative to the first linear section, to form a first cut fiber strip; a second cutting process of cutting a second fiber strip obtained by arranging second fibers to form a second cut fiber strip; and a hackling process of gathering the first and second cut fiber strips in a bundle and hackling the bundle. A total length of the second cut fiber strip is shorter than a length of a shortest first fiber of the first cut fiber strip.

1 . A method for producing a fiber bundle for artificial hair, the method comprising:
 a first cutting process of cutting, at a middle section in a longitudinal direction, a first fiber strip obtained by arranging first fibers in a strip shape so that a cut part includes a first linear section extending linearly at an angle of more than 0 degrees and 60 degrees or less, relative to the longitudinal direction, and a second linear section extending linearly at an angle of 120 degrees or less relative to the first linear section, to form a first cut fiber strip;   a second cutting process of cutting, at a middle section in the longitudinal direction, a second fiber strip obtained by arranging second fibers in a strip shape to form a second cut fiber strip; and   a hackling process of gathering the first cut fiber strip and the second cut fiber strip in a bundle and hackling the bundle,   wherein in the second cutting process, the cutting is performed so that a total length of the second cut fiber strip is shorter than a length of a shortest first fiber of the first cut fiber strip.   
     
     
         2 . The method according to  claim 1 , wherein in the second cutting process, the cutting is performed so that most ends in the longitudinal direction of the second cut fiber strip include a third linear section extending linearly at an angle between 85 degrees and 95 degrees, both inclusive, relative to the longitudinal direction. 
     
     
         3 . The method according to  claim 2 , wherein in the first cutting process, the cutting is performed at least twice so that both ends in the longitudinal direction of the first cut fiber strip each include the first linear section and the second linear section, and
 in the second cutting process, the cutting is performed at least twice so that both ends in the longitudinal direction of the second cut fiber strip each include the third linear section.   
     
     
         4 . The method according to  claim 3 , wherein both the ends in the longitudinal direction of the first cut fiber strip include a first end and a second end, and
 the first linear section of the first end is aligned with the second linear section of the second end in the longitudinal direction.   
     
     
         5 . The method according to  claim 4 , wherein the first cut fiber strip has a recessed section formed by the first linear section and the second linear section, and
 a bottom of the recessed section of the first end is aligned with a bottom of the recessed section of the second end in the longitudinal direction.   
     
     
         6 . The method according to  claim 5 , wherein a depth of the recessed section of the first end is between 5 cm and 40 cm, both inclusive. 
     
     
         7 . The method according to  claim 1 , wherein the first cut fiber strip has a recessed section formed by the first linear section and the second linear section, and
 a depth of the recessed section is between 5 cm and 40 cm, both inclusive.   
     
     
         8 . The method according to  claim 1 , wherein in the hackling process, the first cut fiber strip and the second cut fiber strip are gathered in a bundle so that the second cut fiber strip is positioned inside both ends in the longitudinal direction of the first cut fiber strip. 
     
     
         9 . The method according to  claim 8 , wherein in the hackling process, the first cut fiber strip and the second cut fiber strip are stacked so that an overlapped region is formed at a central part in the longitudinal direction to form an in-progress fiber strip, and then the in-progress fiber strip is gathered in a bundle. 
     
     
         10 . The method according to  claim 1 , wherein the first cut fiber strip has a recessed section formed by the first linear section and the second linear section, and
 in the hackling process, the second cut fiber strip is gathered in a bundle so as to be positioned inside a bottom of the recessed section of the first cut fiber strip in the longitudinal direction.   
     
     
         11 . The method according to  claim 10 , wherein in the hackling process, the first cut fiber strip and the second cut fiber strip are stacked so that an overlapped region is formed at a central part in the longitudinal direction to form an in-progress fiber strip, and then the in-progress fiber strip is gathered in a bundle. 
     
     
         12 . The method according to  claim 11 , wherein in the in-progress fiber strip, a distance between an end in the longitudinal direction of the overlapped region and the bottom of the recessed section of the first cut fiber strip is 5 cm or more. 
     
     
         13 . The method according to  claim 1 , wherein a number of times of the hackling in the hackling process is between 3 and 20, both inclusive. 
     
     
         14 . A fiber bundle for artificial hair, the fiber bundle comprising:
 at least two types of fiber groups that are gathered in a bundle, wherein the two types of fiber groups include a first fiber group and a second fiber group, the first fiber group includes a plurality of first fibers, a difference between a longest first fiber and a shortest first fiber when 300 first fibers are randomly extracted is 3 cm or more, and an arithmetic mean length is between 10 cm and 180 cm, both inclusive, and   the second fiber group includes a plurality of second fibers, and the plurality of second fibers are shorter than a tenth length when 300 first fibers are randomly extracted and arranged in order from shortest to longest; and   a mixed region where the first fiber group and the second fiber group are mixed, and an exposed region where the first fiber group is exposed, wherein a length of the exposed region is between 0.8 times and 1.5 times, both inclusive, of a difference between the arithmetic mean length of the first fiber group and an arithmetic mean length of the second fiber group when 300 second fibers are randomly extracted.   
     
     
         15 . The fiber bundle for artificial hair according to  claim 14 , wherein the first fibers are different from the second fibers in at least one of color, material, or cross-sectional shape. 
     
     
         16 . The fiber bundle for artificial hair according to  claim 15 , wherein the first fibers are different in color from the second fibers. 
     
     
         17 . The fiber bundle for artificial hair according to  claim 14 , wherein a length of the mixed region is one-third or less of a length of the exposed region. 
     
     
         18 . The fiber bundle for artificial hair according to  claim 14 , wherein a number of the first fibers constituting the first fiber group is smaller than a number of the second fibers constituting the second fiber group.