How to solve the ink roller hardness control of sheet-fed printing press

What needs special mention here is the ink roller hardness control of the printing press. Increasing the ink roller hardness of the printing press will cause the following problems during the printing process.

① Too many tonal values ​​increase;

â‘¡ The edge of the outlet is irregular;

â‘¢ The density of the dots is not uniform;

â‘£Ghosting of outlets;

⑤Rough grainy mesh area;

â‘¥ The field effect is poor;

⑦ Increased mechanical ghosts;

⑧Color is difficult to control during operation.

These are the problems we hope to rule out completely. However, the fundamental solution is to make the ink roller clean, with good ink affinity and soft surface. Every printing press manufacturer and ink roller manufacturer has their own ideas and suggestions. For commercial printing companies, if they want to be able to print both high-end paper (coated paper) and ordinary paper (non-coated paper) on their printing presses, then they should pay attention to the printing machine manufacturer's ink roller Recommended hardness value (Shore hardness). Some manufacturers will give different hardness values ​​according to the different functions and positions of the ink rollers, while other manufacturers will make all the ink rollers use the same hardness. After you have determined the correct ink roller hardness of the printing press, you must try to maintain this hardness index.

Since the rollers will harden under ultraviolet, high temperature and ozone environments, keep the rollers away from sunlight and store them in a dark environment, keeping them away from heat sources and motors.

It is wise to maintain the softness of the ink roller at least once a week using a decalcification solution or a cleaning solution made up of hot water and 15% acetic acid to wash away any calcium build-up on the ink roller. In addition, at weekends, use a commercially available ink cleaner to perform a gentle cleaning operation to keep the ink roller clean throughout the weekend. When you go to work on Monday, you need to apply more ink cleaner to the roller and rinse it. As far as possible, do not use irritating chemical solvents on the ink roller, and never use a steel wire cleaning pad to scrub on the ink roller. The ideal situation is to remove the ink roller from the printing machine for manual cleaning every quarter, and also to clean all the ink roller support parts and the side wall panel of the printing machine. It may take some time and effort to do this, but why not eliminate white circles and improve print quality?