Braider Bobbin Depletion, Doff Interval & Effective Output

The formula

This is the expression the tool evaluates. Every term is named underneath, with the unit it must be supplied in.

How the result is derived

Step by step, from the values you type to the figure on screen.

1. The 8 inputs are read from the form on every keystroke: Bobbin Volume, Packing Density, Yarn Count, Carriers, Braid Angle, Take-Up Speed, Creel Change Time and Shift Length.
2. Each value is checked against the accepted range in the input table below. A value outside its range stops the calculation rather than producing a misleading figure — the results blank out and a message appears.
3. The validated values are substituted into the expression above, which resolves Run Before the Creel Is Empty together with every supporting figure in one pass — no value is carried over from a previous entry.
4. The supporting outputs — Yarn on One Bobbin, Length on One Bobbin, Draw per Carrier, Braid Made per Run, Output if It Never Stopped, Effective Output, Running Efficiency, Doffs per Shift and Yarn Loaded per Shift — come from the same pass, so they always describe the same case as the headline figure.
5. Results are rounded for display only. The full-precision value is used throughout the chain, so reading a rounded intermediate figure back into the tool by hand can shift the last digit.

What each input means

Where to read each value on the floor, the unit it must be in, and the range the tool accepts.

What the tool returns

The headline figure and every supporting value it is built from.

Worked example

The tool loads with this case already solved — the Run Before the Creel Is Empty shown above is its answer. Change one value and the difference from this baseline is the sensitivity of the result to that variable.

How to use it

1. Work through the input groups in order — The Bobbin, The Braid and The Stop. The defaults are a realistic case, so you can change one value at a time and watch what moves.
2. There is no calculate button. Every figure recalculates as you type or drag, which is what makes this usable for a what-if sweep rather than a single answer.
3. Read Run Before the Creel Is Empty in the dark results panel — that is the headline figure, expressed in min.
4. Check the supporting rows underneath (Yarn on One Bobbin, Length on One Bobbin, Draw per Carrier, Braid Made per Run, Output if It Never Stopped, Effective Output, Running Efficiency, Doffs per Shift and Yarn Loaded per Shift) before acting on the headline — they are where an implausible input usually shows itself first.
5. Reset to defaults returns every field to the reference case, which is the quickest way to check whether a surprising result came from the tool or from an input you had changed earlier.

Where this is used

• Process planning — establishing Run Before the Creel Is Empty before a trial is booked, so machine time and material in Narrow Fabrics, Tapes & 3D Weaving are committed against a calculated figure rather than an estimate.
• Costing and quotation — Run Before the Creel Is Empty is an input to the cost sheet, and quoting from a worked number rather than a remembered one is what keeps a margin intact.
• Troubleshooting — when the floor result drifts from plan, entering the measured values (starting with Bobbin Volume) shows how much of the gap in Run Before the Creel Is Empty each variable explains.
• Teaching and study — the accepted ranges bracket normal Narrow Fabrics, Tapes & 3D Weaving practice, so moving one variable at a time shows the shape of the relationship rather than a single answer.

Assumptions and limits

• Packing density is the input that decides the answer and the one nobody measures: a published bobbin volume is the space available, and how much yarn occupies it depends on the winding, the yarn and how hard it was laid on. Weigh a full bobbin and an empty one from the machine in question rather than taking a number from a handbook, because the difference between 0.45 and 0.65 g per ccm is a third of the run time. The model assumes every carrier carries a full bobbin of the same yarn and empties together, which is what a single-yarn braid does; a braid running two counts, or one where a broken end was replaced mid-run, empties unevenly and the first bobbin to run out sets the stop. Doffs per shift is left as a fraction on purpose - rounding it up assumes a change that starts before the shift ends also finishes inside it, and rounding it down hides a stop that has to happen. The change time should be measured from the last running minute to the next one, including threading and the restart, not from the operator arriving. Nothing here accounts for a bobbin taken off part-full at a shift change or a product change, which on a short-run job can matter more than depletion ever does.
• Every input is bounded to the range normal practice occupies (Bobbin Volume 20 to 2000000 ccm, Packing Density 0.15 to 1.2 g/ccm and Yarn Count 10 to 20000 tex, and so on for the rest). Those bounds are guard rails against typing errors, not a claim that the formula fails one unit outside them.
• The calculation is deterministic: the same inputs always give the same result. It carries no allowance for machine condition, operator skill, ambient conditions or lot-to-lot material variation unless an input above explicitly represents one.
• Nothing is sent anywhere. The maths runs in your browser, so the numbers you type never leave the page.

Questions people ask