Method and apparatus for making bristle subassemblies

A continuous method for making a bristle subassembly comprising the steps of

• (a) continuously forming a wrap of polymeric filaments by wrapping at least one filament around the axis of a four sided mandrel having a moving endless cable support on each corner, said endless cable support runs along one corner along the length of the mandrel protruding outward from the intersection of the two side planes of the mandrel which form the corner of the mandrel and runs in an opposite direction in a recessed channel in the mandrel located on a diagonal side of the mandrel from said corner and does not protrude into the plane of the mandrel side and moves the wrap of filaments along a substantial length of the mandrel;
• (b) feeding pairs of base strings of a polymeric monofilament outside of the wrap of polymeric filaments onto each side of the mandrel while the wraps are being moved substantially the length of the mandrel;
• (c) bonding the base strings and the polymeric filaments of the wrap together by simultaneously pressing the base strings in contact with the polymeric filaments of the wrap and applying energy to the base strings and polymeric filaments of the wrap;
• and
• (d) cutting the polymeric filaments of the wrap at a point downstream of where the filaments of the wrap are bonded with the base strings to form bristle subassemblies having at least one row of filament segments connected between two base strings,
• wherein in step (c) the bonding of the base strings and polymeric filaments of the wrap together includes moving the base strings and polymeric filaments of the wrap under a wave energy source which is an ultrasonic horn positioned adjacent to the mandrel and defines an opening sufficient to allow passage of the base strings and the filaments of the wrap and maintains the base strings in contact with the filaments of the wrap and does not allow the base strings to reposition itself and sufficient wave energy is applied to partially melt at least one of the base strings and the filaments of the wrap.

A continuous method for making a yarn string comprising the steps of

• (a) continuously forming a wrap of yarn by wrapping at least one yarn end around the axis of at least a three sided mandrel having a moving cable support on each corner running substantially the length of the mandrel on the exterior corner of the mandrel and returning along a continuous exposed recessed channel in a diagonal opposing face of the mandrel in an opposite direction, said cable support being capable of supporting and moving the wrap of yam along substantially the length of the mandrel;
• (b) feeding at least one base string outside of the wrap of yarn to a selected portion of the mandrel as required to form the subassembly while the wrap of yarn is being moved substantially the length of the mandrel;
• (c) bonding the base string and the wrap of yarn together by simultaneously pressing the base string in contact with the wrap of yarn such that the yarn bundle is compressed and applying energy to the base string and the wrap of yarn;
• and
• (d) cutting the wrap of yarn at a point downstream of where the wrap of yarn is bonded with the base string to form at least one bristle subassembly having at least one row of filament segments connected to at least one yarn string.