What does the waterway of printing machinery mean? Thank you for your questions.

As we all know, in the use of offset press, the adjustment and use of water roller and its related institutions is very important to the printing process. Next, taking the waterway of J2 108 offset press as an example, we will introduce some common faults and maintenance of the waterway system popular in domestic offset presses, and the problems that are easy to appear and matters needing attention. 1. When replacing a new dampening form roller, you can usually use the old version to correct the dampening form roller pressure. In order to avoid polluting the dampening form roller, you should first clean the ink with gasoline. If a new printing plate is used, or the water roller pressure is found to be inaccurate in the printing process, and it is necessary to correct it, first wipe the printing plate glue and dry the fan to protect the printing plate. Then select the blank parts at both ends of the printing plate, or measure the blank parts at the tail end with steel sheets, and insert as few times as possible to prevent the printing plate from being scratched and stained with ink, and clean the inserted parts with fountain solution and Arabic gum solution to maintain its proper hydrophilicity. 2. The total thickness of the printing plate pad should meet the standard, so as not to affect the contact pressure between the water roller and the printing plate when changing plates. If it is necessary to change the thickness of the printing plate gasket, the possible pressure change between them should be predicted and corrected. 3. Pay attention to protect the cleanliness of the water roller and the printing plate when adjusting and installing the water roller. Don't pinch the water roller with your fingers at the same time to avoid polluting the water roller flannel sleeve. 4. Before installing the water roller, the new water roller flannel or new water roller flannel should be soaked with water or fountain solution in advance, and the fluff should be wiped off to prevent the fluff from falling on the printing plate and ink roller during printing, which will affect the product quality. At the same time, in terms of pressure control, the general wet water roller is slightly smaller than the wet water roller. 5. When adjusting the contact pressure between the water roller and the water channeling roller, we must pay attention to the symmetry of the eccentric bearing direction, that is, the eccentricity of both ends should be adjusted in the same direction, otherwise the water will not be parallel to the printing plate cylinder and the water channeling roller, and the flannel sleeve on the water channeling roller will be easily pushed into a spiral shape by the axial force, and the water delivery will be uneven. If the eccentric direction of the water roller is asymmetric, it will also lead to the phenomenon that the pressure of the water roller is light at both ends and heavy in the middle. Therefore, when testing the pressure of the water roller, we can measure several places, both ends and the middle, to prevent the water roller from being uneven or eccentric. 6, feng shui roller neck or bearing has been seriously worn, or water roller with ball bearing, its bearing has been damaged, should be repaired or replaced in time, so as to avoid inaccurate pressure control. 7. No obvious axial movement of the dampening roller is allowed, otherwise the layout may be damaged. 8. Grasp the contact pressure between the water rollers (1). The pressure between the two water rollers and the printing plate should be light on the top and heavy on the bottom. (2) The pressure between the two dampening rollers and the channeling roller should also be lighter at the top and heavier at the bottom. (3) The pressure between the dampening form roller and the printing plate is slightly greater than that of the channeling roller. (4) The pressure of water conveying roller and water channeling roller is equal to or slightly less than that of water contact roller and water channeling roller. 1. dampening roller 1 failure caused by improper contact pressure. If the contact pressure between the dampening roller and the printing plate is too high, the printing plate will be subjected to excessive friction, so that the graphic part of the layout will be quickly worn and the sand holes will be smoothed, resulting in the phenomenon of "pattern plate". Due to excessive pressure, the dampening form roller will jump when it contacts the printing plate, which makes the jumping part easy to get dirty, and the falling part of the graphic part (especially the flat screen) will cause it. 2. If the contact pressure between the dampening roller and the printing plate is too light, and the layout is not adequately supplied with water, the imprint will be thick, diffuse and even dirty. At the same time, due to uneven sheet piling of the dampening form roller, uneven water supply for the layout will be caused. 3. If the contact pressure between the dampening rollers is too high, the water will be squeezed at a certain point of the dampening rollers, resulting in poor water supply and affecting the normal water delivery of the two dampening rollers. In particular, the excessive contact pressure of the dampening form roller will not only lead to poor water flow, but also make the dampening form roller ineffective, which will easily lead to dirty printing plates. 4. The contact pressure between dampening roller and channeling roller is too small. Due to poor contact, the dampening roller lacks normal water source and cannot supply water to the printing plate normally, resulting in the printing plate hanging dirty. At the same time, the dampening roller lacks water film protection and is quickly polluted by ink, thus losing its water supply function. The contaminated ink spreads and causes the channeling roller and bucket roller to be contaminated by ink, thus affecting the water supply performance of the wetting roller. Second, there are many reasons for uneven water delivery. In addition to the improper pressure adjustment of the above-mentioned water roller, there are several common reasons as follows: 1. The diameter of the roller core of the water roller is not equal or the water roller is not round; 2. When sewing the water roller, the two ends are tight and the middle is loose, or the two ends are loose and the middle is tight; 3. The thickness of water roller is uneven or the roller is low in use; 4. Ink layer is formed on the surface of the water roller, which has poor water absorption; 5. After long-term use, the fluff of the water roller is polished; 6. There is too much ink on the surface of the bucket roller and the water channeling roller; (1) The linear velocities of the plate cylinder and the water channeling roller are not equal; (2) There are too many ink spots on the dampening roller or water transfer roller; (3) The surface of the bucket is too smooth to form ink; (4) When the downtime is long, the ink of the water channeling roller and the water bucket roller is lost or dried to form a thin oil film, and the oil mist in the workshop environment is on the roller; (5) There is no proper amount of hydrophilic glue in the plating solution; (6) others. Correct according to different reasons, and clean the ink stains on the roller before reprinting.