Air-Jet Spinning
Air-jet spinning has no mechanical speed limit. It has an air bill instead.
— kWh/kg
The running cost that defines the process
Specific air power is a system figure, not a compressor nameplate: it should include the dryer, the receiver losses and the distribution leakage, which together commonly add 20 to 30% to the compressor-only value. Leakage in particular is chronic in textile plants and can reach a third of total generation, so a measured plant figure will be worse than a catalogue one. Air per position is the manufacturer design value at the stated nozzle pressure and assumes correct nozzle condition; worn nozzles pass more air and spin worse. Production excludes piecing, doffing and lot changes beyond the efficiency term entered. The fibre-length to nozzle-bore ratio is reported as a configuration check rather than a performance prediction - the relationship between the two is empirical and machine-specific.
Air-Jet & Vortex Spinning Production, Air Demand & Energy per Kilogram — free, with the formula and a worked example, at Textile School.