How to Recognize Chill Roll Marks on Film
Chill roll marks are impressions or gloss differences on the film that repeat according to the chill roll circumference, and the ink layer is often still intact. If the repeat length matches the chill roll, do not wash the printing plate. Dirt spots on the roll, uneven temperature, or excessive pressure can press ring-like marks into the film surface.
Chill roll marks are indentations or gloss differences on film that repeat according to the chill roll circumference; the ink layer is often still intact. If the repeat length matches the chill roll, do not wash the printing plate. Dirt spots on the roll, uneven temperature, or too much pressure can press ring-like marks into the film surface.
Separate from printing defects
Printing defects change the ink in halftone dots or solid areas. Chill roll marks change the film surface more: under side light you can see a series of ovals or an indentation, while viewed straight on the color is almost the same. They also appear on blank film. If the blank areas have the same periodicity, you can rule out the printing plate.
Circumference is still calculated as chill roll diameter × 3.1416. The film stretches slightly, so a difference of a few millimeters is acceptable. If it matches the printing plate rather than the chill roll, go back to the plate and anilox roller.
What problem on the roll
| Appearance of mark | Blank film | Check first |
|---|---|---|
| Equally spaced indentations, ink still present | Also present | Dirty or raised roll surface |
| A hazy band repeating at roll circumference | Different gloss | Temperature and pressure |
| Missing ink only in the pattern | None | Not the chill roll, return to printing |
Do this first this round
- Check under side light whether the blank film has the same periodicity.
- If yes, measure the circumference and match only against the chill roll.
- After cleaning the roll surface or reducing pressure, check whether the next repeat is still there; do not touch the printing plate.
