Main Nozzle and Relay Nozzle System Design
topic
Air-jet loom main nozzles accelerate the weft yarn into the profiled reed channel using a convergent-divergent nozzle geometry at air pressures of 4 to 7 bar, with relay nozzles spaced at 60 to 100 millimetre intervals across the machine width firing sequentially as the weft progresses to maintain yarn velocity against aerodynamic drag, with nozzle timing, pressure, and number of active relays optimised for each weft yarn type and machine speed.
Role
Defines the air insertion performance that determines maximum machine speed and weft insertion reliability, with main nozzle geometry and relay nozzle pressure and timing sequence being the primary process variables governing the acceleration, transport velocity, and controlled deceleration of weft yarn across the fabric width that must be achieved without yarn breakage or short pick insertion.