Fiber Separation
Separated flax fibres emerge from mechanical breaking machines as combings tow, a short waste fraction containing broken shives and residual short filaments. Machinery captures this discarded material during initial carding passes in Chinese spinning mills before long-line preparation. Operatives collect the mass for lower-grade yarn spinning operations, diverting it from premium warp production lines.
Low tensile strength and high trash content restrict its utility to heavy weft yarns and rough canvas goods.
Trash Classification
Sorting protocols categorize combings tow by measuring extraneous woody debris percentages against clean cellulose weight. Laboratory technicians burn small samples to determine ash residues, establishing baseline purity grades for domestic mill accountants. Buyers reject lots exceeding specified foreign matter limits because excessive shives snap during high-speed draft rolling.
Mills maintain distinct documentation for this secondary material, separating waste ledger entries from long-line inventory records.
Export Valuation
Overseas buyers negotiate combings tow purchases based on staple length distribution curves rather than single maximum measurements. Chinese export agents quote prices per metric ton according to regional moisture regain standards established by provincial inspection bureaus. Final trade settlements depend upon independent laboratory certificates verifying contamination levels prior to maritime container loading.
Ocean freight documentation identifies the cargo strictly as short-staple flax waste rather than processed textile yarn.
