Where a Spinning Mill Loses Money: Spindle Hours, Power per Kg and Waste (India)

A mid-size Indian spinning mill rarely loses money in one dramatic breakdown. It loses it a few minutes at a time, in thousands of places: frames waiting for the doffing gang, frames starved of roving, spindles idle behind an end break, an extra point of comber noil, and power that keeps flowing while output dips. On a 25,000-spindle ring mill, these floor-level leaks can plausibly add up to ₹40–50 lakh a year before you touch cotton price or tariff, and they are the part of the loss you can actually manage.

By the Mama Editorial Team. This is an owner's overview for ring and open-end mills in Coimbatore, Tiruppur, Dindigul and Rajapalayam, in Gujarat's Saurashtra and Ahmedabad belts, and in Punjab. Every figure is linked to its source. Where a number is our assumption, we say so, so you can swap in your own.

Key takeaways

• Count your losses in spindle-hours, not in hours. A 25,000-spindle mill has 6 lakh spindle-hours a day. A 1,200-spindle frame that waits six minutes for a doff costs 120 spindle-hours, and nobody writes it down.
• Power is among the biggest costs after cotton, and partly controllable. SIMA (September 2022) put the average at about 5 units of electricity per kg of yarn. Humidification, compressors and lighting keep running when frames stop, so lost output pushes up kWh per kg.
• The doffing gang and the roving trolley are usually bigger leaks than end breaks. End breaks cost you piecing labour, pneumafil waste and quality. Stopped frames cost you whole production.
• Waste is money on a scale. Comber noil is a setting, not a fixed fact. A Rieter customer case from Brazil describes a mill that switches between 14% and 24% noil by product. One extra point across your combed line is good fibre sold as waste.
• Cotton price swings dwarf everything else, and cameras do nothing for them. In January–May 2022, cotton rose about 53% while yarn rose only 21%, and ICICIdirect estimated that smaller mills buying at those prices were losing ₹50–60 per kg. That is a buying and hedging problem, not a floor problem.

Why mid-size mills feel this harder

Tamil Nadu's textile department says on its (undated) website that the state has 55% of India's spinning mills, 43% of its installed spindles and 60% of its rotors. It also says the state's yarn productivity is lower than the rest of the country, mainly because of old machinery. SIMA made the same point on 14 December 2024: of 46 million working spindles in India, 19 million are in Tamil Nadu, and over 12 million of those are more than 15 years old.

Old frames have no auto-doffer, no spindle monitoring and patchy machine data. Supervisors manage by walking the alleys and reading a handwritten register, and that is where minutes vanish.

The six places the money goes

1. Doffing delays

A ring frame stops completely for every doff. If the doffing gang is on another frame, at tea, or short-staffed after a festival, the full frame waits. Doff waits are seldom logged, because the frame "was being doffed". Without auto-doffers this is often the largest controllable loss of running time, and it is visible: a full frame, stopped, with no one at it.

2. Stopped frames: roving shortage, count change, maintenance

Frames also stop for upstream reasons. Speed frames fall behind and the ring frame creel runs out of roving. A count change takes longer than the plan allowed. A fitter is called and arrives late. A 2019 study of two mills in Ethiopia, measured against SITRA norms (Wagaye and Walle, IJTEP), found that power interruption and roving shortage accounted for 23% and 9% of total downtime, and named count change, with planned and cleaning stoppages, among the causes of low machine productivity. Those mills were not Indian, but the mechanism is the same in Coimbatore. The general method for costing a changeover is in our changeover time cost calculator.

3. End breaks and piecing labour

SITRA's 2010 norms, as cited in the same paper, set an end-break standard of about 8–10 breaks per 100 spindle-hours for counts from 16s to 40s. The Ethiopian mills studied ran about 12–19. Every break idles one spindle until a tenter pieces it, sends fibre into the pneumafil, and adds a patrol load. A mill running well above the norm needs more tenters for the same output.

4. Power per kg

SIMA's 5 units per kg is an average; yours depends on count, speed, humidification and motor age. What matters is that much of the load (humidification, compressors, lighting, suction) does not fall when output falls. A shift with three frames down still pays for the full air-conditioning of the ring room. Power cost is set in your tariff, but power per kg is set on the floor. Tariffs move too: when Tamil Nadu revised tariffs in 2022, SIMA estimated a net rise of about ₹1 per unit, or ₹1.2 crore a year for a 25,000-spindle mill. For the idle-load side of the bill, see Idle Machines, Lights and Compressors.

5. Waste: comber noil, pneumafil, sweepings

Comber noil is a quality decision that becomes a cost decision. Too little and the yarn fails the buyer's spec. Too much and you are selling good fibre as noil at a fraction of its value. The 14–24% working range in that vendor case from one Brazilian mill shows how wide the lever is. Pneumafil waste rises with end breaks.

6. Cotton price and labour availability

These two forces sit mostly outside the floor. The government's MSP for medium-staple seed cotton for 2026-27 is ₹8,267 per quintal, ₹557 up on the year. That sets the floor that kapas prices start from. In March 2022, Shankar-6 was set to touch ₹1 lakh a candy; by May, cotton had crossed ₹1.15 lakh. On labour, the Coimbatore, Tiruppur and Dindigul mills depend heavily on migrant workers, and a 2018 report already called the shortage a crisis. Where the floor connects to both is spindle utilisation: a mill that runs fewer spindle-hours spreads its cotton risk and its fixed labour over fewer kilos.

A worked ₹ example: a 25,000-spindle ring mill on 40s combed

Every input below is an assumption unless it is linked. Replace each one with your own register.

Four honest caveats.

• The doff wait and stopped-frame figures are illustrations, not industry statistics. Measure a week before you believe either.
• The assumed 90 seconds per break is mostly patrol wait; the paper above timed the piecing itself at 5–7 seconds. The end-break line looks small because each break idles only one spindle. The real cost of high breaks is the tenters you need, the pneumafil waste and the yarn faults that follow. It is not the idle time.
• The power row is the biggest, but it is not all controllable. Part of a bad kWh/kg is the tariff, the count mix and the age of the motors. The controllable part is the fixed load you keep running while output is down.
• The ₹46 contribution and ₹290 realisation are assumptions. In a 2022-type cotton spike, contribution can turn negative, and then lost spindle-hours stop being the main problem.

The pattern holds: floor leaks run to tens of lakhs a year, the power ratio to about a crore, cotton swings to crores. Manage the first two daily and the third at the purchase desk. For a quick cross-check, OEE Explained for Indian Factories shows how availability losses like these flow through to output.

What cameras can and cannot see in a spinning mill

What a camera sees well

• A full frame stopped with no one at it. Doff waits and unattended stops are the clearest, highest-value signal in the mill.
• The doffing gang's route. Where the gang is, and how long the gap is between a frame stopping and the gang arriving. This is counted as a group, not as named people.
• Empty creels and roving trolleys. A ring frame waiting for roving, or a speed frame with no full bobbins staged, is visible from the alley.
• Count-change duration, from the last doff of the old count to the first running frame on the new one.
• Waste bags and sweepings piling up, and whether the pneumafil and waste room are being cleared on schedule.
• Lights, fans and suction in a section with no production during a stoppage or a short shift.

What a camera cannot see

• Individual end breaks across 25,000 spindles. A spindle is too small and too numerous for ceiling video to count breaks reliably. That is the job of spindle-monitoring sensors on the frame.
• Yarn quality. Count CV, hairiness, imperfections and strength come from the lab, not from video.
• kWh, humidity and noil percentage. These need meters, hygrometers and a scale.
• Whether a running frame is running well. A frame with many down ends still looks like a frame with spindles turning. Motion is not output.

Lint is the other limit: fly settles on lenses and humid ring rooms fog glass. Plan cleaning and housings before analytics. Textile Factory Cameras: What Tirupur's Lint and Dye Houses Do to Them covers the hardware side.

People questions need care. Footage of identifiable workers is personal data. Put up a clear notice before cameras go live (template here), and keep the analysis on frames, gangs and flows, not on named individuals. Women can work night shifts with written consent and prescribed safeguards: transport, lighting, emergency numbers, POSH compliance and, under the Central Rules, CCTV along the way to washrooms and facilities. Your state's rules may add more. Tamil Nadu's conditions are covered in Women on the Night Shift in Tamil Nadu.

Where Mama fits

Mama reads the cameras a mill already has, or a few it adds, and every morning sends the owner a short plain-language note. The note says which frames stood idle and for how long, how long count changes took, where the doffing gang was the bottleneck, and which sections ran their load while production was down. It watches machines and flows, counts people only in aggregate, and does not replace your spindle monitoring, lab or meters. Mama can draw a camera plan for your frames and doffing routes. Leave an email or phone in the form below.

FAQ

What is a good end-break rate for a ring spinning mill? SITRA's 2010 norms, as cited in a 2019 study (Wagaye and Walle, IJTEP), put the standard at about 8–10 breaks per 100 spindle-hours for counts from 16s to 40s. Your target depends on count, fibre and speed. If you are well above it, look at piecing practice, travellers and roving quality before you add tenters.

How much power does a spinning mill use per kg of yarn? In 2022, SIMA used an average of about 5 units per kg. Track kWh per kg every day, not just the monthly bill, because a fall in output raises the ratio even when the meter looks normal.

Can cameras count end breaks on ring frames? Not reliably across a whole mill; spindles are too small and too many. Use spindle-monitoring sensors for breaks, and cameras for stopped frames, doff waits, roving shortages and count-change time.

What does one idle spindle cost per year? At the SITRA production norm for 40s (as cited above) and an assumed contribution of ₹46 per kg, one spindle idle around the clock for a year costs about ₹5,000 in lost contribution. Spread across the illustrative 3.6% leak on a 25,000-spindle mill, that comes to about ₹180 per installed spindle a year. Use your own contribution figure.

Should a mill worry more about cotton prices or floor losses? Both, but in different places. Cotton risk sits with buying and stock policy. Floor losses sit with the shift in-charge and are recovered daily.