Printing tools are the most important part of any printing process and gravure cylinders are no exception either. As the most dimensionally stable among all of the printing tools, its life is longer. But it can be increased further, if only defined housekeeping measures are in place and are followed strictly.
The improper placing of doctor blades can cause streaking, hazing, drag outs, ink bleeding, blade chatter and ink spitting which causes a great deal of impact on printing cylinders and thus affects the print quality. Though incorrect finish of cylinder surfaces can directly contribute in producing undesirable quality initially but inadequate housekeeping definitely shortens the life of gravure cylinders.
As a cylinder maker, we need to ensure the roughness of the polished chrome surface and its pattern. But after printing the first run successfully and before using the set of cylinders second time on the machine it is extremely important how they are stored. White is a very abrasive ink which leads very quickly to an excessive wear of blade and chrome surface. Right choice of white ink supplier & brand and type of doctor blade gives you longer runs.
Another significantly important area is the adequate cleaning of the cylinders. Ultrasonic cleaning and spray wash equipments for the cleaning of gravure cylinders are available now and both technologies can be used for removing residues of printing inks from the cells of gravure cylinders, ink trays, doctor blades and other printing press components.
Due to the micro crack structure of the hard chrome and the fact that the solvents used in cleaning cylinders after printing may attract moisture, oxidation of the copper takes place under the chrome layer. Sometime you will see this by looking at the color of the exposed copper.
A very thin wipe of light oil or jelly and then wrap the cylinder in a plastic film protects the surface and thus keeps it in a good condition till the time you open it again for rerun. Cylinders must be dry and clean all times during storage.