Trash Particle Size Class Removal & Selectivity

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: Dust (under 500 µm), Medium Trash (500–1000 µm), Large Trash (over 1000 µm), Dust Remaining, Medium Trash Remaining, Large Trash Remaining, Waste Extracted and Good Fibre in the Waste.
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 Overall Particle Removal together with every supporting figure in one pass — no value is carried over from a previous entry.
4. The supporting outputs — Dust Removal, Medium Trash Removal, Large Trash Removal, Good Fibre Thrown Out, Actual Trash Removed and Selectivity (Trash per kg Lint Lost) — 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 Overall Particle Removal 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 — Particle Count Before, Particle Count After and Waste Stream. 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 Overall Particle Removal in the dark results panel — that is the headline figure, expressed in %.
4. Check the supporting rows underneath (Dust Removal, Medium Trash Removal, Large Trash Removal, Good Fibre Thrown Out, Actual Trash Removed and Selectivity (Trash per kg Lint Lost)) 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 Overall Particle Removal before a trial is booked, so machine time and material in Fiber Testing, Bale Management & Laboratory Sampling are committed against a calculated figure rather than an estimate.
• Costing and quotation — Overall Particle Removal 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 Dust (under 500 µm)) shows how much of the gap in Overall Particle Removal each variable explains.
• Teaching and study — the accepted ranges bracket normal Fiber Testing, Bale Management & Laboratory Sampling practice, so moving one variable at a time shows the shape of the relationship rather than a single answer.

Assumptions and limits

• Counts are not masses. One large trash particle can outweigh a thousand dust particles, so a high count-based removal figure and a high mass-based one are different claims and the two routinely disagree — quote which basis you mean. Dust removal is nearly always the worst of the three classes because the aerodynamic and mechanical mechanisms that strip seed coat and bark do very little to particles below half a millimetre, and those are the ones that carry into the card web and into the operators' air. Selectivity is the number to defend at a settings review: opening the grid bars or raising beater speed will improve every removal percentage on this page while quietly raising lint loss faster, and a line tuned only on cleaning efficiency will be losing saleable fibre. Sample the waste properly — a single grab from one drop point is not the line's waste composition.
• Every input is bounded to the range normal practice occupies (Dust (under 500 µm) 0 to 1000000 count, Medium Trash (500–1000 µm) 0 to 1000000 count and Large Trash (over 1000 µm) 0 to 1000000 count, 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