The production cost of intaglio printing is high and the production cycle is long. If it is not used and stored properly, such as collision, corrosion, oxidation, etc., it will cause the printing plate to not be reused, which will affect the quality of printed products and the delivery time of products.
1. Before printing, the first step is to compare the gravure test sample provided by the plate making factory with the standard sample provided by the customer, and check whether the image and text content of the gravure plate drum match the printing effect. Before starting the machine, wipe off the rust proof oil on the plate drum, and then carefully inspect the layout for any bumps or sand leaks to prevent printing waste caused by accidental scratches on the plate drum.
2. When printing, the doctor blade should be installed according to the normal printing speed. Since the scraping blade holder can move back and forth to string ink, the intercepted scraping blade is generally 10~20mm longer than the plate cylinder to clean the ink and prevent the excess ink on both sides of the plate cylinder from printing on the substrate. Adjust the distance between the doctor blade and the support knife to 4~6mm, the support knife should be 10mm away from the tool holder, and the scraper pressure should be 2.5~4.0kg.
3. In the process of printing, if the light screen color (that is, the high gloss part of the ink) is difficult to transfer, the angle between the Doctor blade and the gravure can be appropriately reduced, the printing viscosity of the ink can be reduced, and the distance between the contact point of the plate cylinder and the imprint roller and the contact point of the plate cylinder and the Doctor blade can be shortened.
4. The version drum should be stored indoors, and a separate storage room should be established. The room should be kept dry and ventilated, with room temperature and humidity below 65%. Corrosive substances such as acid and alkali should not be placed near the version drum to prevent corrosion of the chromium plating layer.
5. After printing, thoroughly wipe the ink on the plate, both sides of the plate, and the printing plate plug with a solvent to avoid ink drying and clogging of the mesh holes, which may cause the next printing block and no ink application. If the ink on the shaft head dries up, it can also cause many inconveniences to the plate mounting process. During the printing process, the ink sheet and ink block are deposited in the ink tank, and finally clamped between the Doctor blade and the printing plate after the ink pump circulation, which will also cause printing faults such as "knife line", and even scratch the gravure plate in serious cases.
6. Due to the low production price of hollow concave printing cylinder, many printing manufacturers use hollow printing cylinder, but the accuracy of hollow printing cylinder registration is low, and the upper and lower plates are time-consuming and laborious. When disassembling the hollow cylinder shaft, a special wrench must be used to gently remove it. It is not allowed to directly hit the shaft head with blunt tools such as a hammer or copper rod to avoid deformation and misalignment of the positioning bolts near the shaft head under blunt impact. In addition, when installing the hollow plate drum or changing the plate shaft, it is necessary to evenly apply a layer of butter on the sealing sleeve or plastic pad to prevent ink from soaking and penetrating the inside of the printing plate for a long time, causing corrosion inside the plate drum.
7. During the process of handling the plate drum, it is best for the operator to wear gloves. After handling, the dirt on the surface of the printing plate should be immediately wiped off. After the surface of the printing plate is dry, it should be evenly coated with anti rust oil (such as engine oil or kerosene) for storage.
8. When changing or moving the plate, it is necessary to wear work clothes, and tools and objects (such as pens, printing sandpaper, or toothpicks) are not allowed to be placed in the top pocket. It is not advisable to wear a watch during operation, and clothes buttons and zippers should be checked frequently to prevent them from falling off, cracking, and scratching the image and text of the plate drum.