Fibre Alignment
Graded flax roving emerges during the drafting sequence inside the preparatory spinning hall as line sliver, an intermediate strand of parallel parallelized bast fibres prepared for wet or dry drawing frames. Carded tow produces a shorter and more irregular ribbon, whereas continuous long-line preparation yields parallel fibre bundles free from root ends. Jiangsu spinning mills reject lots containing excessive neps or twisted sections before the drawing heads press the material into uniform slivers.
Drafting Tolerances
Technical inspectors measure linear density in grams per meter on the delivery apron, rejecting batches exceeding the mill tolerance threshold. Variations in humidity inside the preparation room alter moisture regain, shifting the measured mass per unit length independently of actual fibre volume. Operators adjust gill box pin densities to control draft ratios and eliminate periodic faults before the roving reaches the final spinning frames.
Export Classification
Commercial contracts separate export-grade line sliver from domestic tow supplies based on tensile strength and extraction cleanliness. Buyers specify maximum acceptable hairiness values and residual pectin content within the accompanying technical certificate supplied with each pallet. Chinese customs inspectors verify bale markings against accompanying phytosanitary documents before approving outbound shipments destined for European spinning mills.
