Prevent ink spitting (flexography)
A tiresome issue in flexo printing is the spraying of ink over the anilox roller onto the respective substrate. Colloquially this problem is also called "ink splashing". This printing error occurs particularly frequent when processing UV ink, which has a viscosity up to five times higher than other printing inks. Due to the high viscosity, it can lead to back pressure. This lifts the squeegee slightly and causes the ink to splash. The viscosity can also be reduced by shear action (thixotropy) and can promote ink splashing after doctoring.
In the marked circles, the individual small splashes of ink can be seen very clearly.
But how can this problem be solved?
Our experience of the past year brings us to different solutions.
First of all, the anilox roller should be checked for damage or contamination. If there is damage, the anilox roller must be repaired or replaced. If the anilox roller is only dirty, we recommend cleaning it with our cleaning agent Enpurex and then checking to see if there is any improvement. If there is no improvement, we recommend checking the doctor blade. If the doctor blade has run in on the roller wheel, or the blade is too thin to withstand high viscosity, we recommend an upgrade to our TKM MeyerPrint Stable UV. This doctor blade is specially designed for UV coatings and to prevent ink splashes.