Determining Flax Staple Profile Using Manual Comb Sorting
Manual comb sorting by ISO 2370 isolates technical flax bundle length profiles to prevent drafting waves, control short fibre content, and enforce purchase contracts.
Floating Fibre Waves
Drafting Irregularity
Roller draft defects describe the periodic mass variations that occur in yarn when uncontrolled fibers move erratically in the drafting zone of a spinning frame. These deviations, known as floating fibre waves, arise because fibers that are shorter than the distance between rollers are not gripped by either set of rolls. This freedom allows the short strands to cluster and accelerate through the drafting zone together.
Flow Behavior
Control of these uncontrolled fibers relies on the use of drafting gills, aprons, or thick liquids during wet spinning to provide frictional resistance. When the drafting tension fluctuates, floating fibre waves occur as a succession of heavy and light sections in the sliver. This cyclical fault cannot be corrected in subsequent processes and remains visible as a thick and thin pattern in the finished cloth.
Mill technicians analyze the yarn spectrogram to identify the characteristic wavelength of these waves, which corresponds to the mechanical geometry of the drafting zone.
Weft Appearance
Visual quality in woven fabrics deteriorates when periodic yarn faults are spaced at intervals that align with the cloth width. This alignment produces an undesired patterning or barry effect across the fabric surface. The issue becomes critical in plain-weave linen shirts where high-density weaving makes mass deviations highly visible.