Seam Sealing Tape Width, Overlap & Hydrostatic Resistance

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: Tape Width, Stitch Line Width, Sealed Seam Length per Garment, Hydrostatic Resistance per mm Overlap, Tape Own Hydrostatic Rating, Target Hydrostatic Head, Hot Air Nozzle Length and Sealing Speed.
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 Overlap Each Side together with every supporting figure in one pass — no value is carried over from a previous entry.
4. The supporting outputs — Hydrostatic Resistance Achieved, Margin Over Target Head, Tape Width for Target Head, Nozzle Dwell Time, Tape per Garment and Tape Area per Garment — 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 Overlap Each Side 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 — Seam & Tape and Performance & Line. 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 Overlap Each Side in the dark results panel — that is the headline figure, expressed in mm.
4. Check the supporting rows underneath (Hydrostatic Resistance Achieved, Margin Over Target Head, Tape Width for Target Head, Nozzle Dwell Time, Tape per Garment and Tape Area per Garment) 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 Overlap Each Side before a trial is booked, so machine time and material in Factory Physics & Assembly Logistics are committed against a calculated figure rather than an estimate.
• Costing and quotation — Overlap Each Side 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 Tape Width) shows how much of the gap in Overlap Each Side each variable explains.
• Teaching and study — the accepted ranges bracket normal Factory Physics & Assembly Logistics practice, so moving one variable at a time shows the shape of the relationship rather than a single answer.

Assumptions and limits

• Resistance is capped at the tape's own rating — no amount of overlap makes a seam better than the tape across it. The linear relation between overlap and head is a fit over the usable range and says nothing about a tape that has lifted at the edge, which is the actual failure mode; check peel and hydrostatic on aged and laundered seams, not just fresh ones.
• Every input is bounded to the range normal practice occupies (Tape Width 5 to 60 mm, Stitch Line Width 1 to 40 mm and Sealed Seam Length per Garment 0.1 to 40 m, 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