Calculating Raw Fibre Yield and Net Yarn Conversion Costs
Raw fiber yield calculations require converting gross lot weight to dry commercial mass under ISO 6741 and deducting mechanical waste extractions.
Comber Noil Extraction
Fibre Fraction
Selective removal of short fibres happens during the high precision refinement of cotton or wool to produce high quality yarns. The comber noil extraction process identifies fibres below a specific length threshold and separates them from the long staples that continue to the next production stage. This action results in a cleaner, stronger and more uniform yarn suitable for fine fabrics.
Waste Efficiency
Recovery rates vary according to the end use requirements where finer yarns demand higher levels of short fibre removal. When comber noil extraction occurs, it generates a reusable byproduct known as comber noil, which finds use in coarser spinning or hygienic padding. Mills calculate the extraction percentage by comparing the mass of removed fibres to the mass of the input sliver.
Tuning Procedure
Mechanical settings on the comber dictate the separation point by adjusting the index time or the top comb position. Increasing the comber noil extraction level improves the strength of the final product while reducing the total mass of the output. Technicians adjust these parameters carefully to maintain a profit margin between raw material cost and the high price of premium yarn.
Verification Standard
Sampling intervals confirm that the machine produces a consistent volume of waste throughout the daily shift. An unstable comber noil extraction rate leads to yarn count variations and inconsistent dyeing outcomes across different batches. Periodic measurement verifies the alignment of the needles and the accuracy of the extraction cycle.