Spinning Measure
Direct length per unit mass quantifies linear density during yarn formation. The metric Nm count calculates how many thousand meters of dry flax yarn sit inside a single kilogram. Chinese mills record this numerical value on the production sheet immediately after drafting and before packaging.
Higher digits mean finer strands destined for delicate summer apparel while lower numbers indicate heavier twine intended for sturdy household textiles. Factory testing protocols separate loose fibre fineness from twisted yarn specifications by drawing skeins under standard atmospheric humidity. Technicians measure mass on calibrated scales to establish precise commercial yields before export documents leave the office.
Buyers set minimum thresholds in the purchase contract to reject substandard deliveries at the loading dock. Mills rely on internal tolerances to monitor drafting machine wear over prolonged shifts.
Drafting Limit
Mechanical tension applied during drawing frames determines maximum attainable fineness without breakage. Natural flax staple length varies widely across harvests and dictates how much stretch machinery tolerates. Excessive drafting speed pulls individual cells apart and ruins linear regularity along the entire bobbin.
Operators adjust roller settings whenever raw material batches change from dew retted crops to water retted alternatives.
Commercial Yield
Contractual settlement relies on moisture corrected mass rather than raw weight measured on the shop floor. Standard conditioning ovens remove residual humidity so technicians calculate dry weight accurately. Final payment adjustments apply when conditioned results deviate from agreed specifications.