Unwanted ink transfer onto substrate, ink metering system out of adjustment or damaged.
Causes:
– Undissolved ink particles;
– Ink thrown off or dripping from anilox roll;
– Emulsification/water streaks;
– From metering system:
- Grooved wipe roll;
- Worn or warped doctor blade;
- Damaged or dirty anilox roll;
- Low ink flow;
Solutions:
– Filter particles out of ink, clean plates and anilox;
– Check ink pumps, hosing and blade housing for overflow or leaks. Increase viscosity, replace end seals or wipers;
– Check for water dropping onto the web;
– From metering system:
- Replace wipe roll;
- Reduce blade pressure or replace damaged blade;
- Clean or replace anilox roll;
- Increase ink flow across the press.