The series entitled “Labelprinting – experience gained in practice” looks at everyday challenges encountered in labelprinting and how to overcome them. In this issue we take a look at “Ink spitting”.
Definition of problem:
Fine ink splashing across the entire printing width (in machine direction), which is also visible on the surface of the anilox roller.
Possible solutions:
- Reduce the press speed
- Increase or reduce the pressure of the squeegee knife
- Make the squeegee angle flatter
- Turn the anilox roller around 180°
- Clean the anilox roller thoroughly
- Reduce the ink viscosity using additives
- Add an antistatic additive to the ink (3 - 5 %)
- Check that the squeegee system has been assembled correctly
- Use a different type of squeegee
- Change the ink series (the concentration of the ink pigment could be too high)
- Insufficient surface finishing used in the production of the anilox roller. In this case, the manufacturer must modify the anilox roller
- Use an anilox roller with a different cell geometry
- Use special Gallus squeegee designed to prevent ink spitting (only suitable for chambered doctor blade systems) Gallus order numbers: EM 280: 185714 / EM 410 S: 1070404/ EM 510 S: 1070403 / RCS 330: 185715 / RCS 430: 189326