News & Knowhow

Reasons for chattermarks Chattermarks occur diagonally to the web running direction. Chattermarks are often a problem of worn bearings or gears, especially when the stripes are in line with the drive system. Other reasons may be the ink system, inclu...

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 This problem usually comes from contamination of ink or equipment such as ink tanks, attachments and outdated fi...

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 h...

The paint collects around the closing doctor blade and its surroundings. Due to its design, the doctor blade is subjected to dynamic pressure because the lamella surface lies within the chamber and bends inwards. If the doctor blade is too stiff, or ...

The main reason for squeezed edges is too much pressure of the printing plate onto the anilox roller and the substrate. This results in the flexible image carrier squeezing the screen dot to be printed onto the substrate and creating a squeezed edge ...

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 po...

Tone value increase is a printing error between the master and the printout. This results in a darker and sometimes blurred image. The reasons can be many and varied, for example the pressure of the printing plate on the substrate, as well as an inco...

Damage to the doctor blade is usually caused by poorly finished or damaged impression cylinder edges. While soft wear on the doctor blade bevel is normal, edge break-outs describe severe damage (as shown in the picture). This damage can lead to furth...

The smearing, which also bleeds from the printed area into the unprinted area, is often a sign of poor colour tolerance to moisture or an incorrect drying time of the ink. In some cases, a too flat doctor blade setting can lead to bleeding. Solutions...

Extractors are strips that smear out of the printed area. This is usually caused by dirt that accumulates on the upper side of the doctor bevel. This is favoured by a too low doctor blade angle or a too flexible setting. These impurities are often ca...