A method for manufacturing a brushing part including the following steps: providing the support, pierced with through-holes, passing through the channel formed by the support; forming the tuft of bristles, by assembling a plurality of bristles by one end opposite the free end, so as to form a base of the tuft, so that a diameter of a section of the tuft, in a plane transverse to a direction of extension of the tuft, is greater than a diameter of a through-hole; merging the ends forming the base of the at least one tuft so that an extension of the merged zone in a direction transverse to the direction of extension of the at least one tuft is greater than an extension of the base in the transverse direction before the merging step; inserting the one tuft by force into one of the holes of the channel of the support, depositing glue and filling with resin.

A method for manufacturing a brushing part including the following steps: providing the support, pierced with through-holes, passing through the channel formed by the support; forming the tuft of bristles, by assembling a plurality of bristles by one end opposite the free end, so as to form a base of the tuft, so that a diameter of a section of the tuft, in a plane transverse to a direction of extension of the tuft, is greater than a diameter of a through-hole; merging the ends forming the base of the at least one tuft so that an extension of the merged zone in a direction transverse to the direction of extension of the at least one tuft is greater than an extension of the base in the transverse direction before the merging step; inserting the one tuft by force into one of the holes of the channel of the support, depositing glue and filling with resin.

An apparatus for manufacturing an individual brush unit constituting a rotary brush by being stacked in multiple layers, includes an anvil having an insertion hole through which a filament group passes, a filament feeding unit which feeds the filament group from a feeder including a ring cutter on a tip and holds the filament group while a predetermined amount of the filament group protrudes outward from the insertion hole of the anvil, and an ultrasonic welder including a horn having a horn tip portion which pushes and radially expands a protruding tip of the filament group and welds a central part of the expanded filament group, to form the individual brush unit. A core of the welded central part is sandwiched between the ring cutter and the horn tip portion and is cut out, to simultaneously form a shaft hole and separate the individual brush unit from the filament group.