Best UV laser settings for marking plastics

UV Laser (355 nm)3 W–5 W UV

UV (355 nm) marks plastics by a cold photochemical process rather than heat, giving high-contrast marks with minimal melting — ideal on light plastics and where a heat-affected zone is unacceptable. These are gentle starting points; UV couples efficiently, so less is more.

Starting point — not a recipe. Run a material test on your own machine. Every laser, lens, gas supply, and material batch is different. These numbers exist to shrink your test, not replace it.

Recommended starting-point parameters

Power20–50%
Speed500–2,000 mm/s
Frequency30–80 kHz
Passes1–2
Line interval / hatch0.01–0.02 mm

Dialing it in

  • UV needs far less power than fiber on plastics — start low to avoid melting or foaming.
  • Different polymers (ABS vs PC vs PP) respond very differently; test per material.

The material-test workflow

The fastest way to a reliable cut is not a perfect chart — it's a tight test loop that you only run once per machine/material combination, then never repeat:

  1. 1Start from this baseline. Load the starting-point numbers above as the center of your test.
  2. 2Run a small array. Cut a grid that sweeps speed (and power, if cutting) ±20% around the baseline — typically 9–16 small squares.
  3. 3Judge the edge. Look for dross, burn-back, kerf width, and squareness. Pick the square that meets your part's requirement, not the prettiest one.
  4. 4Log it once. Save the winning parameters against this exact machine + material so the next job starts from your proven number — not a generic chart.

Stop re-running the same test square

CutLog gives you a starting point calibrated to your wattage and lens, then remembers every cut you log — so your machine builds its own proven library. Free to start.

Frequently asked questions

Why use a UV laser to mark plastic?

UV light marks via a cold photochemical reaction, producing crisp high-contrast marks with almost no heat-affected zone or melting, which fiber and CO₂ struggle with on many plastics.

Last reviewed 2026-06-28. Values are conservative starting points generalized across brands and published cutting charts; always verify on your own machine.