Jacquard Harness Tie Configurations and Structural Repeat Fundamentals
Jacquard repeat limits scale with hook count and warp density, where systematic harness casting-out maintains uniform cord pull angles across the comber board.
Drop Threads
Structural Void
Missing yarns in the longitudinal direction of a textile indicate a failure in the warp supply during the production cycle. These drop threads occur when a single strand breaks and the stop motion fails to halt the machinery. Empty channels then appear in the finished linen where the yarn should have provided coverage.
Detection Method
Optical sensors mounted on the machine frame monitor the presence of every yarn as it travels toward the interlacing zone. When drop threads escape this initial check, they are identified during the final inspection under high intensity lighting. The absence of a yarn disrupts the uniformity of the cloth.
Identification requires the inspector to mark the start and end of the missing section.
Mill Rectification
Corrections for these voids require manual intervention by skilled menders who reintroduce the missing strand into the finished piece using a specialized needle. Because the manual repair of drop threads is time consuming, mills prefer to invest in laser based detection systems that offer higher sensitivity. Such technology ensures the loom stops the moment a break is sensed, which prevents the defect from extending over several meters of cloth.
Efficient mending restores the commercial value of the roll.