Chattermarks (gravure print)

Stripes that appear at right angles to the web run direction. Depending on the press speed, these stripes can change. The reason is a brief loss of contact between the doctor blade bevel and the impression cylinder. A common cause is poorly balanced cylinders, an excessively stiff doctor blade or damaged bearings.

Solutions to negative doctor blade lines:

• Check the machine bearings for wear and damage.
• Ink build-up pressure can lift the doctor blade bevel, so check the doctor blade angle and setting, flatten the angle and/or use a softer padding.
• Check the doctor blade oscillation for interruptions, especially at dead centre. Oscillation should always be even and between 10 to 30 mm lateral movement.
• Check the doctor blade pressure, as excessive pressure can bend the doctor blade bevel. Reduce the pressure as much as necessary.
  
  TKM recommends TKM OptiPrint and TKM PowerPrint