Positive doctor blade lines (gravure print)
Positive doctor blades usually move with the oscillation of the blade. Clearly visible and continuous in engraved and non-engraved areas. This problem usually comes from contamination of ink or equipment such as ink tanks, attachments and outdated filters. Incorrect finishing in copper or chrome can be a reason, but also damage to the doctor blade bevel.
Solutions to positive doctor blade lines:
- Check the paint for impurities and foreign particles, as well as clogged filters. Use a clean ink tray before starting printing and replace the ink if necessary.
- Check the doctor bevel for damage and replace the doctor blade.
- Check doctor bevel for dirt and remove the bevel with a doctor blade and carefully polish the printing cylinder with fine sandpaper.
- Check the gravure cylinder for correct roughness values in the chrome and copper, if necessary polish or replace the cylinder.
TKM recommends TKM CeraPrint