- ~10
- roving bobbins from one 25 kg can
- 30–40
- cops from each bobbin
- 300–400
- cops from the one can
- 75–100k
- cops from one full 252-can creel
Arithmetic from published package sizes: a 6 × 16 inch roving bobbin holds 2–3 kg, and a cop weighs 55–110 g depending on count and ring. Your floor’s exact figure needs only those two numbers.
Where it is caught decides what it costs
- At the card — sliver, and it goes back into the line.
- At the speed frame — roving, most of which goes back in.
- At the winder — everything spent so far, plus splices, as hard waste that cannot be recycled.
Why the winder cannot close it
Winding already traces a bad cop to the spindle that spun it. It cannot say why. That spindle was fed by many bobbins, from many speed-frame positions, from many cans — and no record of which survives the doff.
The cheapest place to catch a fault is where there is only one of it.
The prize is attribution in hours rather than weeks, and knowing which few hundred cops to look at instead of all of them.