Upper Layer Force
The tensile load acting on the upper layer of warp yarns when the loom shed is fully open determines the clearance for the weft insertion carrier. In linen weaving, the top shed line tension must be carefully regulated to prevent the upper yarns from sagging into the path of the rapier or shuttle. This tension is adjusted by changing the height of the back rest or the timing of the harness frames.
Mill operators monitor this force using tension sensors during the start-up of a new linen fabric run.
Yarn Damage
High tension in the upper warp layer can lead to fiber abrasion and yarn breaks as the yarns are stretched to their mechanical limits. Conversely, if the top shed line tension is too low, the loose warp yarns may catch on the weft insertion element, causing cloth defects or machine stops. Achieving the optimal tension balance is essential for preventing friction damage to the delicate flax fibers.
Loom technicians document the measured tension values in the loom setting sheet to maintain consistent quality across different production runs, enabling quick adjustments during shift handovers to ensure stable operations.
Weaving Clearance
Adequate tension in the top layer ensures a wide, clean opening for the passage of the weft yarn carrier. This setting is verified against the mill’s standard operating procedure for high-speed rapier looms. Proper clearance reduces the risk of yarn snagging and fabric damage.
