Height Settings
Vertical displacement of the heald frames during a shed opening determines the clearance for weft insertion. Harness frame lift is adjusted to accommodate the specific thickness of linen yarns used in a particular weave. If the lift is insufficient, the rapier will strike the warp yarns and cause a machine stop.
Loom Timing
Coordination between the harness movement and the reed motion is the most critical aspect of loom setup. A larger harness frame lift provides more space for the weft carrier but increases the tension on the warp yarns. Technicians must find the balance that allows for clean yarn passage without causing excessive fiber fatigue.
High-speed looms require very precise timing to ensure the shed is fully open at the moment of insertion.
Mechanical Clearance
Clearance between the top and bottom layers of the warp sheet must be maintained throughout the entire width of the loom. Adjusting the harness frame lift involves moving the eccentric cams or changing the digital parameters on a computerized dobby. Linen mills use specific lift profiles for different fabric weights to optimize the weaving efficiency.
Proper lift settings prevent the occurrence of skipped picks or yarn entanglements in the finished cloth.
