Much of Surat's grey fabric is woven on waterjet and airjet looms. Both are shuttleless — the weft is carried across by a jet, not a shuttle. The difference is whether the jet is water or air. That decides which yarns will run, how much power the loom takes and what upkeep it needs.
How the weft goes in
Waterjet
A nozzle shoots a thin stream of water that carries the weft through the shed. Every pick uses a little water, so the cloth comes off wet, and the loom needs a pump, filters and drainage.
Airjet
Compressed air from the main nozzle pushes the weft, and relay (sub) nozzles along the reed carry it across the full width. The air comes from a compressor — on an airjet, the compressor is part of the machine.
Which fabric on which loom
- Waterjet: the weft must not soak up water — polyester and nylon filament (FDY, DTY and so on). The usual choice for light to medium filament fabrics.
- Airjet: a wider range — filament plus spun yarn, viscose, cotton and blends. Viscose or spun weft absorbs water, so it doesn't fly well on a waterjet.
Pick range, width and design (dobby, jacquard) depend on the loom model — check with your loom's maker.
Output per shift
The formula is the same for both:
Airjets usually run at a higher RPM. The rough range seen in Surat: waterjets from a few hundred up to about 800–900 RPM, airjets often above that. Real figures change with model, width and quality — check with your loom's maker.
Example
The same 50-pick quality, 85% efficiency, 12-hour shifts, two shifts a day. Waterjet at 650 RPM, airjet at 850 RPM (both examples only).
- Picks per metre: 50 × 39.37 = 1,968.5
- Waterjet: 650 × 60 × 12 × 0.85 = 3,97,800 picks ÷ 1,968.5 = 202.08 m a shift, 404.17 m a day
- Airjet: 850 × 60 × 12 × 0.85 = 5,20,200 picks ÷ 1,968.5 = 264.26 m a shift, 528.52 m a day
Put your own loom's numbers into the Loom Production calculator — it also gives metres per day, per month and for the whole unit.
Power, water and air
On a waterjet, power goes to the loom motor and the water pump. On an airjet, a large share of the compressor is added to the loom motor — so an airjet's total load per loom is usually well above a waterjet's. More metres spread part of that cost, so compare ₹ per metre, not ₹ per day.
Example (for illustration only)
Say the waterjet's load is 2.5 kW and the airjet's, with its compressor share, 6 kW; power at ₹8 a unit (example rate), 24 hours:
- Waterjet: 2.5 × 24 × 8 = ₹480 a day ÷ 404.17 m = ₹1.19 a metre
- Airjet: 6 × 24 × 8 = ₹1,152 a day ÷ 528.52 m = ₹2.18 a metre
Enter your real kW and rate in Power cost per metre. The full working is in the loom power guide.
A waterjet needs a lot of clean water every day — filtering, softening and recycling, plus drying the cloth. An airjet needs dry, clean air — dryers, filters and a leak-free air line. For spun and viscose, the shed's humidity has to be controlled too.
| Waterjet | Airjet | |
|---|---|---|
| Weft | Polyester, nylon filament | Filament, spun, viscose, blends |
| Speed | Good | Usually higher |
| Power per loom | Lower | Higher (compressor) |
| Needs | Clean water, drainage | Compressed air, humidity |
| Watch | Rust, nozzles, pump, water | Nozzles, reed, compressor, leaks |
Maintenance
- Waterjet: water quality matters most — dirty water blocks nozzles and rusts parts. Clean filters, pumps and nozzles on a fixed day.
- Airjet: keep air pressure steady, hunt down leaks, service the compressor on time, keep nozzles and the profile reed clean.
Common mistakes
- Looking only at RPM. More RPM helps only if efficiency holds — if breaks rise, metres fall.
- Forgetting the compressor. Leave the compressor out of an airjet's power and the costing is wrong.
- Running any weft on a waterjet. A weft that soaks up water gives breaks and faulty cloth.
- Planning on brochure figures. Plan from a week of your own unit's actual metres.
- Ignoring water and drying costs. On a waterjet, the pump, filters and drainage are costs too.
To work out and raise real efficiency, read the loom efficiency guide.
In Loomiro
The loom master records each loom's type (waterjet, airjet or other) and RPM once. From the metres in Taka Entry, the Loom page shows each loom's efficiency with a 30-day chart, and the machine efficiency report puts every loom side by side — so you see which loom or quality is lagging. In Costing, the loom's kW and your power rate give each quality's power cost per metre.
The RPM, kW and rates here are examples only. Take your loom's figures from its maker's manual and your own power meter.