Precautions for ink scraper

1. Pressure
The factors that affect the pressure of the ink scraper are the size of the cylinder pressure, the difference in hard and soft blades, and the angle at which the ink scraper intersects with the printing plate. The larger the slope, the greater the pressure. Excessive pressure will reduce the ink transfer rate and cause significant wear on the printing plate and blades; Too little pressure can easily cause dirt or scraper lines, so it is important to control the pressure appropriately.
2. Sharpness of ink scraper
The sharpness of the knife depends on whether it is new, the angle of the blade when grinding, and the type of sandpaper (oilstone) used. The suitable sharpness of the knife should be to effectively scrape off the ink without generating any knife threads. Scrapers that are too sharp are often prone to generating blade marks and also wear out the printing plate. However, excessive use can cause blade wear and significantly reduce sharpness. So the blades also need to be replaced within a period of time.
3. The distance between the ink scraper and the printing plate
Reducing the distance between the scraper and the printing plate is beneficial for improving the ink transfer rate, but it is also prone to generating dirty plates; On the contrary, it will reduce the ink transfer rate.
4. Flatness of ink scraper
The flatness and warping of the ink scraper mainly depend on the installation method, and of course, it may also be related to the presence of foreign objects in the knife holder groove or on the blade or lining.
When the flatness of the ink scraper is poor, it can cause some water droplets like marks on the edges of the printing surface, or intermittent line marks from time to time. Some people may think that the ink is rough
5. Movement of ink scraper
When there are line marks in printing, one is causing plate damage, and the other is that the ink scraper is not sharp. However, another reason is that there are foreign objects sticking to the back of the blade. The solution is to move the ink scraper back and forth, up and down, in order to remove the adhesive. If it cannot be removed, the only option is to stop the machine and wipe the ink scraper.
Another challenge is related to the scraper, and many people misunderstand it as caused by ink. This refers to the occasional occurrence of dozens of irregular lines of varying lengths, which look like ink piles. Unlike scraper lines, they are not continuous, but sometimes absent. This is actually caused by the pressure of the scraper being too small or the scraper being not sharp enough.
The pressure, sharpness, and contact position with the plate making of the ink scraper all have an impact on the quality of printed products. Adjusting the ink scraper reasonably according to actual needs can solve many printing problems.