From a phone call and an email exchange with a flexo printer I propose a quick troubleshooting about printing white ink on transparent BOPP.
Have you ever experienced any troubles when printing in flexo? Here is a list of things you should avoid when approaching flexography in order to prevent from troubles in production.
Can you recognise the cause of dirty printing in highlights?It is important to understand wether the issue is related to dot dipping, thus plate-to-anilox ratio, wrong metering of the anilox surface or other causes.What is visible on the printed product is a generally a dirty aspect that forces to repeated stops for plate cleaning and
Do you know how to quickly convert your anilox rolls screen-count (cell count) and volume values between metric and imperial unit measurements? You can use these formulas: For volume: Volume in cm³/m² = Volume in BCM/in² x 1,55 (*)Volume in BCM/in² = Volume in cm³/m² ÷ 1,55 (*) 1,54899999999999 rounded to 1,55 For screen-count: Screen-count in c/cm = Screen-count in cpi ÷ 2,54Screen-count in cpi = Screen-count in c/cm x 2,54
Ink builds around small print elements like dots and small type creating hollow shapes like donuts. Inked dots perforate ink layers that were printed by previous printing groups. This happened on external print on plastic film, solvent based inks, flat-top plate, sequence YMCK. Combined action of excessive impression with high ink volume and low viscosity