Hackling Yield Arithmetic between a Bale and a Finished Metre
Landed linen metre cost depends primarily on hackling line yield, where each percentage loss in combed sliver inflates yarn preparation costs down the loom.
Faller Bars
Pin Control
Metal combs occupy the drafting zone of a gill box to organize individual linen fibres before the spinning frame. Faller bars move in a cyclical path to pierce the untwisted sliver and regulate the distance between fibre ends. These components maintain a uniform density throughout the drawing operation.
Precision depends on the speed of the screw mechanism that drives each individual bar through the machine.
Operation Mechanics
Drafting rollers pull the fibre through the pinning array at a rate exceeding the delivery speed of the feed. Faller bars exert a resistance that holds back shorter fibres to prevent uneven drafting or thick spots in the roving. Mechanical timing ensures that the metal teeth retract from the sliver before the unit returns to the starting position.
Proper alignment of these needles reduces the breakage rate of high quality flax strands during processing. Frequent inspection of the tooth condition guards against snagging or fibre damage.
Quality Standard
Grade specifications for the finished yarn rely on the consistency achieved during this pinning sequence. Inspectors verify the draft ratio against the technical parameters listed in the mill production manual to confirm compliance with contract requirements. Divergence from the target alignment indicates a mechanical fault in the screw drive or a misalignment of the bars themselves.
Stability in this section dictates the uniformity of the final spun product.
Flax Fibre Non Cellulosic Content Impact on Hackling Yield
Non-cellulosic content above 3.5% lowers hackling line yield, increasing tow waste and landed line fibre cost per finished metre.