Calibrating Flax Fibre Intake Standards for Dry Spinning
Dry spinning flax intake standards require strict bundle fineness under 2.2 tex, residual shive below 0.8 percent, and 11 percent target moisture regain.
Gill Box Pinning
Drawing Specification
Selection and density of needles mounted on the faller bars in a drafting system control the alignment of flax slivers during preparation for spinning. This setup, known as gill box pinning, must match the micronaire and average staple length of the combed flax. Proper execution of this layout is specified on the mill production card before each run of sliver preparation begins.
Mechanical Action
Needles penetrate the moving fibre bundle to hold the shorter fibres while the longer ones are pulled forward by the drawing rollers. This action parallelizes the strands and removes small tangles or remaining pieces of shive. Incorrect pin density can cause fiber damage or result in uneven drafting that compromises yarn strength.
Yarn Quality
Spinning factories adjust the needle arrangement on the faller bars to control the hairiness of the final linen yarn. When the gill box pinning is too loose, the fibres are not fully straightened, resulting in a fuzzy yarn surface that creates friction during fabric production. Finer pinning patterns are reserved for high-quality yarn batches destined for luxury table linens or lightweight apparel.
By optimizing the needle pattern, the mill minimizes yarn breakages and improves the efficiency of the winding department.