Combing Sequence
Mechanical arrangement of the feeding mechanism determines the volume of material presented to the circular comb during the nipper closure. In a system using backward feed, the fringe moves toward the comb while the nippers are moving toward the detaching rollers.
Fibre Path
Movement occurs when the nipper is in the rear position and the circular comb is already acting upon the tuft. This configuration ensures that the cotton undergoes a thorough cleaning action because the feed happens during the comb stroke.
Noil Extraction
Extraction levels increase because the fibres presented to the comb include those that might otherwise remain in the sliver. Using backward feed results in a higher percentage of waste than the alternative method.
Quality Tradeoff
Production of high quality fine yarns often relies on this specific feeding arrangement to remove the maximum amount of short fibres. While it reduces the overall yield of the machine, the resulting sliver has a much higher mean length and better parallelization. Spinners choose this setting when the raw material contains a high proportion of impurities that require aggressive removal.
The higher noil percentage is accepted as a cost for achieving the strength and appearance required for premium fabrics.
