Abstract: A method and an apparatus for joining plastic brush bristles with plastic brush backs provides for heating the tips of brush bristle strands until they are soft and heating zones of the plastic brush backs to which the bristles will be mounted until they are soft. Thereafter, the soft tips of the bristles are brought into contact with the soft zones of the brush backs to fuse the bristles to the brush backs. In the particular structure and method of the machine of this invention, two relatively movable plates alternately clamp to and unclamp from indeterminant-length bristle strands to jog the strand ends into contact with the brush backs. One of the plates carries a cutting blade which cuts the strands into bristle lengths once their tips are fastened to the brush backs.

Abstract: A brush roundator comprises an endless conveyor for conveying brushes along a straight path in one direction. The brushes are mounted to the conveyor with their bristles extending outwardly away from the conveyor. A plurality of abrasion disc series, or groups, each including a plurality of abrasion discs arranged side-by-side in a line are positioned parallel to the conveyor and in the paths of the outer tips of the bristles. Each of the disc series is mounted on a frame whose position can be adjusted independently of the frames of the other series, both angularly and/or linearly. Each disc series includes a motor mounted on the frame to drive a first abrasion disc of the series and that disc has a gear thereon which meshes with a gear of an adjacent abrasion disc to rotate it in the opposite direction. This gear is linked to a gear of a next adjacent abrasion disc in a similar manner to rotate it in an opposite direction and so on.