The bad version of the fault is usually divided into two parts: plate damage and plate wear. The author summarizes the causes of the bad version and the corresponding solutions. Causes and solutions for plate breakage 1. The bending machine is faulty And bending machine when a failure occurs, it turns out slightly tilt the plate, resulting in positive and negative misregister time of printing. Our company has encountered such a problem. At the beginning, we did not seriously study it. We did not find the reason for the curved version. Instead, we used the method of palliative treatment by adding tape to the inner side of the corner of the plate. Correct the error on the overprint. Although this solves the problem of inaccurate overprinting, it causes the offset position of the plate cylinder to be consistent with the angle of the plate cylinder after the plate is loaded, so that the plate can not be closely attached to the surface of the plate cylinder, so the two are printed. When the printing was about 10,000 times, the printing plate began to rupture, so that the crack was dirty and transferred to the printed matter. At this time, we had to stop the plate change, otherwise the crack on the plate will become bigger and bigger, causing more serious problems. This kind of bad version caused by the problem of bending is often seen in newspaper printing . In addition to the inclination of the curved version, there is also a case where the bending angle is not accurate, and the latter case is more concealed, unlike the former, there will be no overprinting. It will be discovered and dealt with in time. For example, the inclination of the angle at the tip of the tip, the folding angle is too fast, the bending angle is shifted back, the layout becomes large, and the plate cylinder cannot be closely fitted. These conditions are easy to cause the plate to be damaged, so if the front and back are found to be overprinted, In case of inaccuracy, or if the plate and the roller are not tightly attached after the plate is installed, it is necessary to consider whether there is a problem with the bending machine and whether adjustment is needed. 2. The blank part of the printing plate that does not participate in printing is not on the fountain solution. Once we were printing on a narrow web, because the width of the paper was too narrow and the plate was blank, the dampening liquid nozzles at both ends of the plate were closed during printing (using a spray dampening method). ), after a period of printing, the machine made a loud "beep" sound. After the shutdown, it was found that the blank parts at the ends of several plates were broken at the tipping position. It was found through analysis that although the blank part on the printing plate was not watered and inked, the ink was covered by the squeezing roller and covered with the entire layout, and accumulated thicker without being taken away by the paper, and because the printing plate was The pressure between the rubber roller and the plate cylinder is running at high speed, and there is no dampening solution to remove the heat, so the temperature on both sides is getting higher and higher, the viscosity of the ink is getting bigger and bigger, and the plate is damaged soon. It is. Therefore, in the subsequent printing of similar orders, we will also open the dampening liquid nozzle in the blank part of the printing plate, only to reduce the amount of water. Of course, this form of order is very few after all, and it is basically not encountered in newspaper printing. 3. The cutting size of the blanket pad is incorrect or the position is running. The cutting size of the blanket pad is not correct, or the position is moved during installation, so that the pad is not neatly attached to the surface of the blanket cylinder, but a part of it is extended and inserted into the mounting groove of the blanket clip on the roller, so that This will cause the mounting groove edge to protrude, causing an additional impact on the printing plate during printing, making the plate easy to break. Therefore, if the plate breaks suddenly at the mouth or the tip of the plate, it is necessary to check whether the size of the blanket pad is appropriate. In fact, with the advancement of the manufacturing process of printing machinery and the improvement of the production precision of the drum, many printing presses can directly use the plastic film liner with higher hardness, which is directly attached to the blanket cylinder and does not need to be replaced frequently. Some presses do not even use pads, and directly mount the blanket on the blanket cylinder. Whether it is a paper liner or a plastic liner, just control the axial cutting width (greater than the maximum web width of about 20mm) before installation. When installing, first align the cornice (paper liner must be sprayed) Apply glue to the pad. Avoid padding when installing the blanket. After the pad is pressed against the rubber roller for one week, cut off the extra part of the pad along the edge of the groove. The problem is that the pad size is incorrect or the running position is installed. 4, the plate positioning hole is split In newspaper printing, we often encounter cracking of the plate at the positioning hole when loading or loading the plate. If the crack is located at the tipping position, the cracking of the crack is relatively small. If there are not many remaining sheets, the plate cracking does not affect the graphic part, and there is no significant impact on the quality of the printed product. We often insist on printing to avoid the waste caused by a shutdown and the impact on timeliness. However, if the plate is broken at the mouth of the mouth, it must be stopped immediately, otherwise the broken part will be impacted by the rubber roller and the rubber roller that is in contact with it, and will be torn quickly, and damage the rubber roller, blanket or even cause Broken paper, causing more serious problems. Economical Style Chafing Dish,Salt Stainless Steel Chafing Dish,Round Chafing Dish,Decorative Chafing Dishes Jiangmen Junerte Stainless Steel Kitchenware Co.,Ltd , https://www.jetkitchenwarejm.com
The bad version is coming, what should we do?
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