Insertion Defect
Loom mechanics determine whether flax yarn survives the passage across a wide carriage without snapping or catching on adjacent hooks. Weft insertion failure occurs when a pick leaves the guiding shuttle or projectile prematurely and leaves a gap in the woven structure. Mill operators record this anomaly in the daily weaving register alongside warp breakage rates and loom speed adjustments.
Production supervisors inspect the grey cloth for missing picks before the fabric moves to the finishing department for bleaching and dyeing. Fabric grading standards penalize this structural fault heavily because unanchored yarn ends compromise the tensile strength of the linen sheet.
Shuttle Calibration
Air jet velocity and projectile braking forces require constant monitoring during high speed production shifts. Loom calibration parameters must match the stiffness and hairiness of wet spun flax yarn to prevent flight deviations across the shed. Mechanical wear on the gripper jaws reduces holding tension during the transfer cycle.
Technicians adjust the pick timing wheels to correct the timing of yarn release. Loose tension settings cause the yarn to oscillate inside the channel and drop before reaching the far selvedge.
Quality Threshold
Buyer contracts specify the maximum allowable linear density of structural defects per hundred meters of finished fabric. Exporters reject linen bolts containing clustered insertion faults because automated apparel cutting tables cannot compensate for missing horizontal yarns. Laboratory tensile tests confirm that a single uncorrected gap weakens the surrounding warp threads under stress.
Export compliance documents separate acceptable minor blemishes from structural failures that disqualify the batch from premium linen grades.
