Blowroom Mass-Flow & Waste Balance

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: Bale Feed Rate, Lint Price, Bale Opener & Pre-Cleaner, Fine Cleaner Droppings, Filter & Condenser Dust, Invisible Loss, Good Fibre in Droppings and Recovery Achievable by Reprocessing.
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 Line Yield to Card together with every supporting figure in one pass — no value is carried over from a previous entry.
4. The supporting outputs — Delivered to Card, Total Waste Extracted, Good Fibre in the Waste, Actual Trash Removed, Reclaimable by Reprocessing and Annual Value of the Reclaim — 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 Line Yield to Card 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 — Line Feed, Waste by Extraction Point and Waste Composition. 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 Line Yield to Card in the dark results panel — that is the headline figure, expressed in %.
4. Check the supporting rows underneath (Delivered to Card, Total Waste Extracted, Good Fibre in the Waste, Actual Trash Removed, Reclaimable by Reprocessing and Annual Value of the Reclaim) 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 Line Yield to Card before a trial is booked, so machine time and material in Blowroom, Carding, Drawing & Roving Control are committed against a calculated figure rather than an estimate.
• Costing and quotation — Line Yield to Card 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 Bale Feed Rate) shows how much of the gap in Line Yield to Card each variable explains.
• Teaching and study — the accepted ranges bracket normal Blowroom, Carding, Drawing & Roving Control practice, so moving one variable at a time shows the shape of the relationship rather than a single answer.

Assumptions and limits

• Invisible loss is the entry that closes the books and the one with no scale under it — it is inferred as the difference between what was fed and what was collected, so every weighing error in the other four terms accumulates there. An invisible loss above about 1% usually means a leaking duct, an uncounted droppings point or a moisture change between bale store and card, not fibre that vanished. Waste percentages are meaningful only against a stated trash content in the mixing: a 4.9% total on a 6% trash cotton is a different line from the same 4.9% on a 2.5% cotton, and comparing the two is the most common mistake made with this figure. The reclaim value assumes reprocessed fibre re-enters at full lint price, which it does not — recovered blowroom droppings are shorter and dirtier than the original, so they belong in a coarser count, and the honest figure sits below what is printed here.
• Every input is bounded to the range normal practice occupies (Bale Feed Rate 1 to 100000 kg/h, Lint Price 0 to 1000 currency/kg and Bale Opener & Pre-Cleaner 0 to 30 %, 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