It would be to easy to say good old fashioned “elbow grease” was the solution ie : manual scrubbing of the anilox, but to some extend there is some truth in this statement. Manual scrubbing with the right type of brush, in combination with the appropriate cleaning solution, can and will help to get an anilox roll clean. If you note, I did say “will help” but the truth is that while manual cleaning does just that it is not efficient, is hugely labor intensive, and absolutely cannot get into the bottom of the individual cells where the real hardening of the ink and coating is taking place.
The solution has to be and is mechanical cleaning, but before you say eureka there are several options to consider.
These include Ultrasonics- this method can only be done off press and uses sound waves to implode microscopic air bubbles in a tank of heated liquid which very quickly and efficiently can clean all sizes of rolls. This method is very effective and generally only needs short cleaning times for most rolls.
Media Blasting- this process uses an abrasive medium that is blasted at the roll surface, and again is done off press. Rotational speed, dwell time, air pressure, traverse speeds need to be carefully monitored at all times.
Baking soda cleaning- Similar to the media blasting but utilizes baking soda as the cleaning media but can be done off and on press. Same consideration needs to be made to speeds, rotational, traverse and blast pressure as media blasting.
Cyrogenic cleaning- A very environmentally friendly process that uses dry ice pellets to remove the contamination from the roll surface and cell structure, but cannot reach into the smaller cell engravings. Air velocity is a serious consideration. Can be done off and on press.
Laser cleaning – A very high tech cleaning method that can be done off and on press, thermally ablates material from engraving but can be slow.