Yarn Count and Sizing Chemistry in Warp Preparation
Warp sizing requires matching yarn packing factor to polymer viscosity, adjusting squeeze nip pressure for precise solids add-on, and maintaining elongation.
Wet Pickup
Fiber Moisture Retention
The retention of liquid mass within flax roving directly before mechanical drawing determines wet pickup ratios across Chinese spinning mills. Measured as a percentage increase over dry weight, the value dictates the lubrication level required to prevent filament breakage during high speed drafting frames. Supervisors record these exact masses on the daily mill processing log alongside atmospheric humidity indices.
Natural pectin removal depends entirely on maintaining this moisture boundary throughout the pre-spinning preparation hall.
Liquor Application Rate
Water spray nozzles deposit exact liquid volumes onto the sliver before the material enters the gill box rollers. Excess fluid causes sliver compaction on the metal pins, while insufficient dampening generates static electricity that scatters short fibers across the workshop floor. Technicians calibrate the metered valves against the linear density of the incoming flax ribbon rather than relying on standard machine settings.
Process Verification
Quality inspectors compare laboratory oven dry weights against conditioned sample masses to calculate the final retention percentage before authorizing the yarn for spinning frames. Exceeding the upper moisture limit risks fungal growth during subsequent storage periods in humid warehouse environments. Mill acceptance criteria remain stricter than general buyer tolerances because excess water distorts the final yarn count calculations.