October 17, 2011
We are running with plate and anilox sleeves but are getting a lot of uneven wear to our plates and uneven print densities across the web. Can you suggest what might be causing these issues?
Most sleeves are built up of a combination of an inner carbon fiber or fiberglass sleeve, a compressible inter-layer and a final aluminum shell if it is to become an anilox sleeve, or again carbon fiber or fiberglass if it is to be a plate sleeve. It is this very combination of materials that generally leads to the issues that you’re asking about and the real issue of run out, which can only be measured with a dial indicator when pressed against the outer surface of the coated anilox sleeve or the outer wall of the plate sleeve.
As each sleeve ages, the inner layers are prone to delamination caused by hardening, softening, shrinkage, bond failure, or contamination from water, solvents and inks. This results in loss of concentricity between the various layers that will cause run out and in turn can lead to premature damage of the printing plate, doctor blade and will be seen visually in the printed product as uneven color densities or variations in the overall print quality of the job you are running. Unfortunately this problem can occur within weeks or months of installation dependent on how the sleeve has been run and has been handled.
If the sleeve is dropped or knocked over, this can cause distortion and delamination within the sleeve, which will not only cause run out issues but may even prevent it being able to be slide onto the air mandrel. Again the only solution is to replace the sleeve.No Comments