Loom State Greige Thread Density Verification Basics
Verifying off-loom thread density after four hours of tension-free conditioning prevents bulk specification disputes and costly finished cloth rejections.
Fell Position
Weaving Geometry
Boundary lines where the newly inserted pick meets the previously woven cloth define the active front of textile formation. Maintaining a stable fell position is essential for ensuring uniform pick spacing across the entire length of the fabric.
Tension Adjustment
Variations in warp yarn tension during loom stoppages and restarts shift the boundary line away from its neutral point. When the warp tension drops, the fell position moves toward the reed, which reduces the effective beat-up force on the inserted yarn. Correcting this balance requires automatic tension sensors to regulate the let-off and take-up motions dynamically, preventing any slippage that might occur during long periods of machine inactivity.
Defect Prevention
Incorrect alignment at restart causes fabric faults known as set marks or starting marks. When the fell position is not returned to its precise coordinates after a pick repair, the reed either over-beats the yarn or leaves a gap, which alters the physical structure of the weave. Automated control systems track this alignment to eliminate these cosmetic defects.
Sensor Calibration
Modern high-speed looms employ optical or mechanical sensors to monitor the fabric front in real time. These sensors measure the position relative to a fixed datum point on the loom frame, sending instantaneous corrections to the drive motors. Without this measurement, fine apparel fabrics can exhibit visible quality irregularities that cause rejection during final inspection.