Scoring lines (flexography)

Surface damage to the anilox roller is caused by foreign particles being ground in. These particles cause scoring in the anilox roller. Since flexo printing does not use doctor blade oscillation, unlike gravure printing, foreign particles have the possibility of being trapped under the doctor blade tip and grinding into the surface of the anilox roller over a longer period of time. A distinction is made between cosmetic and heavy scoring. Cosmetic scoring is visible on the anilox roller, but only superficially and therefore does not pose a printing problem. This occurs mainly with a new anilox roller due to the last finishing with the first used doctor blade. Heavy scoring, however, has a noticeable indentation in Formeiner groove and causes printing problems. A renewal of the roller is the consequence.

Solutions to scoring lines:

• The ink should be checked for foreign particles and the ink filtration for blockages. If necessary, replace the paint. Magnetic colour filtration to filter out abrasive metal particles.
• Check for foreign particles under the doctor blade and remove them. Make sure the equipment is clean.
• Check the doctorblade and itschamber for excessive contact pressure. Excessive pressure can cause excessive wear and chipping of the docotr blade.
• When changing the anilox roller always change the doctor blade as well. Each doctor blade runs in with a specific anilox roller, so changing it will cause a different wear pattern and can lead to splintering.
• When changing the anilox roller for the first time, it is essential to clean the ink filters and replace the ink in the ink circuit, so residues from the newly ground in anilox roller and its loosened particles are completely removed.
  
  TKM recommends TKM Optiprint, TKM Protect coating, TKM PowerPrint and the ink filter TKM Magnet 8000 for metallic particles.