Dot gain is a part of flexo printing, due to nature of the pressure sensitive process. Minimising and making Dot gains predictable are an essential task for any flexo printer.
Too great ink volume from the anilox.
Printing plate is too thick or swollen.
Mounting tape with wrong thickness or trapped air.
Printing pressure too high.
Inadequate ink setting.
Part of the press is damaged or worn-out.
Dirt on the impression or the printing plate cylinder.
Ink viscosity too low.
Use an anilox roller with a lower volume.
Use thinner plates. Replace the plate if there is residual solvent on the plate or it is swollen.
Change the mounting tape. Make sure that no air is trapped when mounting the plate. Remount plate.
Reduce the printing pressure (kiss print).
Use a metering system.
Check and replace damaged or worn parts (i.e. gears, mandrels, cylinders).
Clean the impression and printing plate cylinders.
Check, and maintain proper viscosity.
Helmut Mathes, troubleshooting defects supplied curtesey of Flexo & Gravure Int''l 2011
Flexo is a contact and pressure sensitive process. Increasing printing pressure, influences ink transfer and has a significant impact on print quality and performanceRead more
INK TRANSFER - ANILOX
The shape and consistency of anilox cells makes a huge impact on ink transfer and cleanliness of the inking process to the printing plate.Read more
Dried ink in anilox cells, can cause significant change in print densities. The FlexoStar laser can clean dried ink from even the smallest cells.Read more