| 摘要 |
Provided are a method and device for manufacturing a brush unit for a rotary toothbrush having a roller-shaped rotating brush containing a plurality of layers of substantially discoidal brush units obtained by radially joining strands made of a synthetic resin such as nylon, wherein the defective count is low and producibility is high. A device for manufacturing a brush unit, a plurality of said units being layered to form a rotating brush, wherein said device and method for manufacturing a brush unit for a rotating brush are characterized by comprising: a base provided with an insertion hole through which is passed a strand cluster obtained by bundling together a plurality of strands; a strand payout section for paying out the strand cluster from a payout device provided with a ring cutter and holding the strand cluster as protruding by a fixed amount outward from the insertion hole in the base; and an ultrasonic welding machine provided with a horn, at the distal end of which the protruding tip of the strand cluster is pushed radially open and the middle portion of the strand cluster is welded, the center part of the welded middle portion being sandwiched between the ring cutter and the distal end of the horn and cut off to form an axial hole while at the same time the brush unit is separated from the strand cluster. |
