Relay Nozzle Systems and Air Timing Sequence
topic
Relay nozzles spaced at 60 to 100 millimetre intervals across the reed width each fire a supplementary air blast timed to arrive just ahead of the yarn tip as it passes their position, maintaining yarn velocity that would otherwise decelerate from air resistance and gravity across the wide shed, with electronic control of each relay nozzle's opening duration and timing from a solenoid valve that is individually programmed to the optimal setting for each yarn type and loom speed in a precisely sequenced cascade that maintains yarn tip velocity from selvedge to selvedge.
Role
Maintains yarn insertion velocity across the full shed width by compensating for the air resistance deceleration that would cause yarn tip stall in the shed without relay assistance, with relay nozzle timing optimisation being one of the most technically demanding and quality-critical setup tasks in air-jet loom operation, where incorrect timing causes late yarn tip arrival at the receiving selvedge, incomplete pick insertion, and weft short pick defects that are among the most common fabric faults in air-jet weaving.