Weave Mechanism
Special loom shedding devices manipulate pairs of warp threads to twist around one another between picks, locking inserted filling yarns into position. Integrating a leno motion on shuttleless looms forms durable selvedges that prevent edge fraying on open-structure or heavy linen fabrics. One thread, termed the doup end, crosses over the stationary ground end on alternating picks to create a twisted binding loop.
This cross-weaving action locks the loose pick ends securely without requiring conventional closed selvedges.
Mechanical Execution
Mechanism types include mechanical doup harnesses or standalone electronic selvedge motions mounted beside main harness frames. High dynamic loads occur when twisting stiff flax warp threads, requiring smooth yarn guides and precise timing to avoid yarn chafing. Incorrect tension balance between doup and ground ends causes warp thread breakage or irregular selvedge thickness.
Electronic leno devices allow independent timing adjustments relative to the main shed opening, accommodating the low elasticity of flax yarn.
Edge Stability
Poorly bound selvedges unravel during subsequent continuous wet processing, causing machinery jams and fabric trim waste. Quality audits inspect selvedge integrity under lateral tension to verify structural performance. Proper setting of the leno motion guarantees edge stability throughout export roll slitting operations.
