Draft Variance
Bast stock optimization occurs during the hackling stage within the spinning mill when short tow separates from line flax. That mechanical sorting step shifts the proportion of staple lengths inside the processing batch. Workers measure this dispersion using comb sorters that group separated elements into fractions by millimeter length.
Jiangsu processing lines separate these segments before drafting frames draw the parallel ribbon into roving. Mill specifications demand tight control over short fraction ratios to prevent uneven twist propagation during ring spinning.
Fraction Standard
Document compliance depends on the technical sheet issued by the provincial inspection bureau after laboratory testing. Raw material standards distinguish between low grade tow containing excessive debris and high grade line flax intended for fine handkerchief counts. Buyers apply strict acceptance thresholds that penalize batches exceeding twenty percent short fractions by weight.
Mills enforce internal limits that sit well below those buyer ceilings to protect drawing frame performance. Exporters record these metric outcomes on the mill production certificate accompanying each shipping container.
Batch Uniformity
Roving tension depends heavily on stable distribution parameters across every delivery head. Uneven staple populations create drafting resistance fluctuations that snap fragile wet-spun strands during high speed traveler rotation. Finished yarn grading separates commercial weaving yarn from lower tier knitting yarn based on hairiness and breaking load consistency.
Fabric hand and drape originate directly from the regularity established when short fibers were extracted prior to carding.
