UV Curing calculator

UV Cure Window Calculator

Every cured product has a process window — a band of line speeds (or doses, or temperatures) where the chemistry cures correctly without overcure damage. Outside that band, you get tacky parts on the slow side or substrate distortion / brittle film on the fast side. This calculator takes a current operating point against the validated min and max from your DOE or vendor data and shows whether you're inside the window plus the margin to either edge — clean enough to gate a process change.

What this calculator does

  • Check whether the current line speed (or any other process variable) sits inside the validated UV cure window — and how close it is to either limit.
  • Use it during process changes — new SKU, lamp swap, line speed adjustment — to confirm you're still inside the validated window before releasing the change.
  • Reports whether an operating point is inside the validated UV cure window and how much margin remains to the closest limit.

Formula used

  • Inside window = (window min ≤ operating point ≤ window max)
  • Margin = closest distance to either limit (negative = outside)

Inputs explained

  • Current operating point: Today's line speed (or other variable being checked) at the lamp.
  • Window minimum: Slowest validated speed before overcure damage (substrate burn, film embrittlement).
  • Window maximum: Fastest validated speed before undercure (tacky surface, weak bond, bleed-through).

How to use the result

  • Use it during change control: SKU intros, lamp swaps, belt-speed adjustments, and quarterly process audits where you need a documented in-window check.
  • Window edges come from your validation data, not from this calc. If the DOE only tested 22–48 ft/min, those are your defensible limits even if the chemistry technically allows wider — don't extrapolate. Also assumes the only variable changing is the one you entered; multi-factor drift (lamp aging + speed change at once) needs a re-validation, not a calc.

Common questions

  • How do I find my validated window? It comes out of a Design of Experiments (DOE) where you ran the line at multiple speeds (and ideally multiple doses) and inspected the cure for each cell. The slowest speed that still passed inspection is your minimum; the fastest is your maximum. If you've never done that DOE, the vendor data sheet is a starting point but should be tightened by a one-off DOE before claiming a hard window.
  • What margin should I leave before the limits? 10–15% of the window width is typical. With a 22–48 ft/min window (26 wide), that's 3–4 ft/min of buffer at each edge. Margin gives the line a chance to run through small disturbances without breaching the limit.
  • Operating point is outside but parts look fine — am I OK? No — you have an unvalidated state and a quality risk you can't quantify. 'Looks fine' on a UV part is not the same as 'cured correctly' (full cure depth and adhesion can fail invisibly). Either pull back into the window or run a focused re-validation to extend the window, then update this calc's inputs.
  • Can I use this for dose instead of speed? Yes — the window math is identical. Enter measured dose for the operating point and the validated min / max dose limits. The slug stays uv-cure-window because the principle is the same; just keep your unit usage consistent across the three inputs.

Last reviewed 2026-05-12.