Process Metric
Fiber weight losses measured during the mechanical opening of combed flax are recorded as a proportion of total raw input. A high carding waste fraction suggests that the scutched flax contains a large volume of short fibers, shives, or poorly separated bast bundles. This value is recorded on mill run sheets to evaluate the processing behavior of the shipment.
Operational Variable
Adjustment of the carding cylinder speed and worker-stripper clearances directly influences the separation of valuable long fiber from trash. When the carding waste fraction increases beyond the historical baseline, it usually points to excessive pin action or fiber damage occurring during the initial opening. Technicians adjust the feed roller tension to minimize fiber breakage while maintaining the necessary cleaning action.
Material Standard
Yarn spinners use incoming fiber grades to predict processing losses and establish cost structures for each yarn lot. The carding waste fraction determines the yield of carded sliver and determines whether the flax lot is suitable for wet spinning or must be redirected to coarser dry-spinning lines. Contractual agreements between flax mills and spinners specify a maximum allowable loss rate, which typically ranges from fifteen to twenty-five percent depending on the fiber origin.
Standardized weighing of the collected drops from the under-card grids verifies that the material remains within these agreed boundaries before final invoicing.
