Pad-Dry-Cure Thermal Load & Pick-Up Sensitivity

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 11 inputs are read from the form on every keystroke: Fabric GSM, Working Width, Line Speed, Wet Pick-Up, Fabric Inlet Temperature, Cure Temperature, Specific Heat of Water, Latent Heat of Evaporation, Specific Heat of Fabric, Oven Thermal Efficiency and Energy Cost.
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 Burner Duty Required together with every supporting figure in one pass — no value is carried over from a previous entry.
4. The supporting outputs — Fabric Throughput, Water to Evaporate, Heating the Water, Boiling the Water, Heating the Cloth, Latent Share of Useful Heat, Useful Heat, Fuel Energy Required, Energy per kg of Fabric, Energy per kg of Water, Energy Cost and Saved by 5 Points Less Pick-Up — 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 Burner Duty Required 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, Temperatures and Thermal Constants & Cost. 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 Burner Duty Required in the dark results panel — that is the headline figure, expressed in kW.
4. Check the supporting rows underneath (Fabric Throughput, Water to Evaporate, Heating the Water, Boiling the Water, Heating the Cloth, Latent Share of Useful Heat, Useful Heat, Fuel Energy Required, Energy per kg of Fabric, Energy per kg of Water, Energy Cost and Saved by 5 Points Less Pick-Up) 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 Burner Duty Required before a trial is booked, so machine time and material in Finishing, Coating, Lamination & Functional Performance are committed against a calculated figure rather than an estimate.
• Costing and quotation — Burner Duty Required 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 Fabric GSM) shows how much of the gap in Burner Duty Required each variable explains.
• Teaching and study — the accepted ranges bracket normal Finishing, Coating, Lamination & Functional Performance practice, so moving one variable at a time shows the shape of the relationship rather than a single answer.

Assumptions and limits

• The balance is steady-state and counts only what leaves in the fabric and the vapour; it does not model the air actually moved through the oven, which is where a badly set exhaust throws away far more than any of these terms. Energy per kilogram of water is the number to benchmark against, and a well-run stenter sits near 3,000 to 3,500 kJ per kilogram evaporated - a figure well above that points at exhaust humidity rather than at anything in this calculation, because an oven exhausting drier air than it needs to is heating fresh air for no purpose. Oven efficiency is therefore doing a great deal of work as a single input and should be measured rather than assumed. Cure is treated as a temperature to reach rather than a time to hold, so a resin needing dwell at temperature will need a longer oven than the heat balance alone suggests. The pick-up sensitivity assumes the same efficiency at the lower loading, which is slightly conservative: a stenter with less water to remove usually runs at a better exhaust setting as well, so the real saving tends to exceed the figure shown.
• Every input is bounded to the range normal practice occupies (Fabric GSM 20 to 900 g/m2, Working Width 0.3 to 6 m and Line Speed 1 to 200 m/min, 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