Optimizing Relay Nozzle Dynamics for High Hairiness Bast Fiber Shedding in Air Jet Looms
Optimizing relay nozzle pressure vectors, timing overlap, and reed profile clearance eliminates hairiness-induced stops in high-speed bast air-jet weaving.
Shed Opening Clearance
Gap Height
A geometric loom dimension defines the vertical distance between upper and lower warp sheets at the point of weft insertion. Air-jet and rapier looms processing heavy flax fabrics maintain specific shed opening clearance values to allow unhindered passage of the filling insertion element or air profile. Setting records attached to loom frames document harness stroke length, backrest position, drop wire height and shedding motion parameters.
Shift engineers verify these physical clearances during loom setup and style changes.
Motion Geometry
Flax warp yarns possess high hairiness and low elastic stretch compared to synthetic yarns, requiring clean shed division to prevent filling insertion errors. A larger shed opening clearance reduces warp yarn cling and allows the air-jet profile reed to pass without catching protruding flax fibres. Excessive shed opening height increases warp tension at peak harness lift, raising the rate of warp end breaks on brittle linen yarns.
Balancing harness stroke amplitude yields an open passage without straining warp yarns past their elastic limit.
Shaft Alignment
Factory loom specification sheets define target shed clearance dimensions for each fabric construction and yarn count. Digital loom sensors monitor harness shaft movement and signal deviations from configured geometry thresholds. Audit records log shed clearance verification alongside loom efficiency figures and cloth defect classifications to confirm stable processing conditions.