Cosmetic brush and method for manufacturing same

Abstract

Provided is a cosmetic brush having bristles that easily go between thin eyelashes and easily catch eyelashes when rolling up, and a manufacturing method of the same. A cosmetic brush includes an applying portion formed into a substantially columnar shape as a whole in which bristles are spread radially from a core wire portion evenly in a circumferential direction of the core wire portion and continued in a helicoidal fashion in an axial direction of the core wire portion, and tip ends of the bristles are uniformly bent at substantially the same angle forward or rearward in the axial direction of the core wire portion, and tapered toward tip ends.

1 - 6 . (canceled) 
     
     
         7 . A manufacturing method of a cosmetic brush, comprising:
 a forming step of forming a cosmetic brush before main machining including a straight core wire portion formed of a pair of core wires and a substantially columnar applying portion having bristles spread radially from twisted portions of the core wires and continued in a helicoidal fashion by pinching a number of bristles with predetermined lengths arranged in parallel in the form of a belt by the pair of metal core wires and helically twisting the core wires;   a trimming step of forming an external shape of the applying portion by trimming tip ends of the bristles constituting the applying portion; and   a grinding step of machining tip end portions of the bristles constituting the applying portion into predetermined shapes by grinding the tip end portions, wherein   in the grinding step,   the cosmetic brush before main machining is held on a flat grinding surface of a disk-shaped grind stone so that the core wire portion of the cosmetic brush before main machining is orthogonal to a radial direction of the grind stone, and   while the cosmetic brush before main machining is rotated around its central axis, a side surface of the applying portion of the cosmetic brush before main machining is relatively pressed against a grinding surface of the rotating disk-shaped grind stone, whereby bending the tip end portions of the bristles while grinding them.   
     
     
         8 . The manufacturing method of a cosmetic brush according to  claim 7 , wherein
 in the trimming step, the external shape of the applying portion is formed into a substantially truncated cone shape or a substantially inverted truncated cone shape, and   in the grinding step, while the cosmetic brush before main machining is rotated around its central axis, the cosmetic brush is inclined so that a ridge line of the substantially truncated cone shape or substantially inverted truncated cone shape of the applying portion becomes parallel to the grinding surface of the rotating disk-shaped grind stone, and a side surface of the applying portion is relatively pressed against the grinding surface.   
     
     
         9 . The manufacturing method of a cosmetic brush according to  claim 7 , wherein
 in the grinding step, two or more cosmetic brushes before main machining are arranged at even intervals in a circumferential direction of the disk-shaped grind stone and machined simultaneously.   
     
     
         10 . The manufacturing method of a cosmetic brush according to  claim 7 , wherein
 in the grinding step, two or more cosmetic brushes before main machining are arranged parallel to each other in a radial direction and machined simultaneously.   
     
     
         11 . The manufacturing method of a cosmetic brush according to  claim 7 , wherein
 in the grinding step, the cosmetic brush before main machining is arranged at a position close to the outer edge of the disk-shaped grind stone and machined.   
     
     
         12 . The manufacturing method of a cosmetic brush according to  claim 7 , wherein
 in the trimming step, a rotational speed of the cosmetic brush before main machining is slower than a rotational speed of the disk-shaped grind stone.   
     
     
         13 . The manufacturing method of a cosmetic brush according to  claim 7 , wherein
 in the trimming step, a reduced-diameter portion is formed in a part of the applying portion by trimming tip ends of the bristles constituting the applying portion, and a diameter of the reduced-diameter portion is smaller than a diameter of other parts of the applying portion.   
     
     
         14 . The manufacturing method of a cosmetic brush according to  claim 7 , wherein
 in the trimming step, the external shape of the applying portion is formed into a bullet shape by trimming the tip ends of the bristles constituting the applying portion.