How do you calculate UV ink cure speed?

First find required dwell as dose divided by web irradiance, then convert the cure-zone length to feet and divide by dwell, times 60. With a 0.375-second dwell and an 8-inch zone that yields about 106.7 ft/min.

What limits how fast I can run a UV press?

The ink's dose requirement and your delivered irradiance. The web must spend enough time in the cure zone to accumulate full dose, so higher irradiance or a longer cure zone lets you run faster.

How does cure-zone length affect press speed?

Speed scales directly with cure-zone length: doubling the illuminated length (by adding a lamp) roughly doubles the achievable speed at the same dose and irradiance, because the ink gets its dose over a longer travel.

What is a good press speed margin?

Run 10-20% below the calculated maximum to cover irradiance dips across the web width and lamp output decay. The 106.7 ft/min example would prudently be capped nearer 90-95 ft/min in production.

Why does my ink under-cure at high speed even though the lamp is on full?

At high speed the web dwell in the cure zone drops below what full dose requires. The lamp being on does not matter if the ink passes through too fast to absorb its target dose.

Press speed vs dwell time, how are they related?

They are inverses through the cure-zone length. Dwell is how long a point on the web sits under the lamp; speed is cure-zone length divided by dwell. Shorter required dwell means higher achievable speed.

UV Curing calculator

UV Ink Cure Speed Calculator

The UV Ink Press Cure Speed calculator tells a press operator the fastest web speed at which a UV ink or coating still receives its full cure dose. Print and converting engineers use it to balance throughput against cure quality on flexo, offset and screen lines. It matters because press speed, cure-zone length and irradiance are locked together: the ink needs a fixed dose, the cure zone gives it a fixed window, and the only free variable is how fast the web can move through that window. Push past this speed and the ink under-cures, showing up as poor rub resistance, odor or migration; run slower and you leave throughput on the table.

What this calculator does

Solve for the press speed (fpm) at which a UV ink film hits target dose, with a margin for ink film thickness and pigment loading variation.
Use it during press makeready and SKU changeover to dial in a starting cure speed instead of running blind off the operator's last memory.
It computes required dwell from dose over web irradiance, then converts the cure-zone length and that dwell into a maximum press speed in feet per minute.

Formula used

Required dwell (sec) = ink target dose ÷ measured irradiance at the web
Press speed (ft/min) = (cure-zone length ÷ 12) ÷ required dwell × 60

Inputs explained

Ink target cure dose:
Lamp cure-zone length:
Measured irradiance at the web:

How to use the result

Use it when qualifying a new ink, changing lamp power or adding a lamp module, or setting the speed ceiling for a job.
It gives the theoretical speed at full dose; real presses need a margin for irradiance non-uniformity across the web and lamp aging, so run below this number and verify with a cure test.

Common questions

How do you calculate UV ink cure speed? First find required dwell as dose divided by web irradiance, then convert the cure-zone length to feet and divide by dwell, times 60. With a 0.375-second dwell and an 8-inch zone that yields about 106.7 ft/min.
What limits how fast I can run a UV press? The ink's dose requirement and your delivered irradiance. The web must spend enough time in the cure zone to accumulate full dose, so higher irradiance or a longer cure zone lets you run faster.
How does cure-zone length affect press speed? Speed scales directly with cure-zone length: doubling the illuminated length (by adding a lamp) roughly doubles the achievable speed at the same dose and irradiance, because the ink gets its dose over a longer travel.
What is a good press speed margin? Run 10-20% below the calculated maximum to cover irradiance dips across the web width and lamp output decay. The 106.7 ft/min example would prudently be capped nearer 90-95 ft/min in production.
Why does my ink under-cure at high speed even though the lamp is on full? At high speed the web dwell in the cure zone drops below what full dose requires. The lamp being on does not matter if the ink passes through too fast to absorb its target dose.

Last reviewed 2026-05-12.