At present, there are four ways to use water-based ink printing equipment in the corrugated box industry, and their characteristics are different. One is the chain-type single-machine printing method. This printing method can only print without slotting and die cutting. The second is the commonly used production method of printing slotting and round die cutting. This method uses inking printing. After slotting or die cutting, it only needs to be bonded (nail box) to form. The third is to use a full-automatic printing tank, folding bonding (nail box) production method, this machine uses a lower ink printing system for folding molding, which belongs to a disposable molding machine. The fourth is the currently more advanced printing and round die cutting method. It is characterized by multi-color printing and high equipment accuracy. The printed products can achieve the color printing effect, especially suitable for the sales of color carton package. The common characteristics of the above several methods are the use of ink printing. The printing principle and equipment structure are basically the same, but the number of colors, the number of screen lines and the process equipment are different. The printing process is affected and restricted by many aspects and factors, and many problems can be solved by simple adjustment by the operator. Only through the coordination of all aspects, try to reduce and avoid some unnecessary problems in production. Slotting knife and longitudinal compression line are inaccurate, resulting in inaccurate printing position Cause Analysis: Because the slotting and crimping lines are not adjusted according to the size requirements of the process drawings, the length or width of the cardboard is manufactured with a deviation in size, which ultimately affects the inaccurate printing position. solution: First, the slotting or crimping size should be adjusted according to the manufacturing size of the drawing, and the required position is accurate. Then, the position of the printing plate should be readjusted according to the exact size position to check the deviation of the slotting or crimping wheel due to wear. The position of the printing plate is not correct, causing the readjustment of the printing plate Cause Analysis: Due to the unclear color registration and local printing plate position labeling, the error in typesetting is large, and the printing position is obviously deviated in actual production. The current printing equipment is basically cylinder printing, and the layout is on a flat surface, which will inevitably produce longitudinal position errors, and also cause shrinkage problems due to the size of the printing pressure. solution: First of all, when making a 1: 1 ink drawing, it should be drawn according to the normal percentage shrinkage. When typesetting, adjust the printing plate strictly according to the position of the ink drawing. When the precision of color registration is very high, the "cross-hair" typesetting method should be used. The cross-hair of the printing plate and the ink drawing are aligned. If necessary, the deviation can be checked with a magnifying glass. Printing ghosting and white leak problems Original group analysis: These two problems often occur in the production process. Ghosting around printed patterns or text is caused by excessive pressure between the anilox roller and the printing plate; ghosting at the front edge of the printing is caused by excessive pressure between the printing cylinder and the platen roller. Large area printing through bottom and white leakage are caused by insufficient pressure of printing roller and impression roller. These two problems are caused by opposing pressures. solution: Printing ghosting problem should adjust the gap and pressure between the anilox, roller and plate roller, commonly known as the upper pressure. Ghosting is caused by the excessive pressure, and the anilox roller squeezes the printing plate (referring to the flexographic plate) deformation. Therefore, the gap between the two rollers should be increased to reduce the pressure. For the printing leakage problem, the gap and pressure between the plate roller and the impression roller should be adjusted, commonly known as down pressure. Because the gap between the plate roller and the impression roller is too large, it will be unrealistic when printing in a large area, which requires increasing downforce. In addition, the unevenness of the printing plate, plate lining, plate hardness and other quality will affect the above problems, and should be adjusted locally. Multicolor printing overprint is not allowed Cause Analysis: The problem of inaccurate overprinting is common in the printing industry. Because it is composed of many factors, it is not easy to solve. First of all, the accuracy of the position and accuracy of the plate roller of the multi-color printing and slotting machine itself is a direct factor. The second is the adjustment of the feed roller and the traction roller, the use of the traction belt, and the arrangement of the printing plates; the accuracy of the clam and the problem of warpage of the cardboard will cause the problem of overprinting. solution: Because overprinting is composed of multi-color printing, it is inevitable that the position of the plate roller on the printing and grooving machine of various colors is relatively not; First of all, since the start of printing has an impact on the thickness of the cardboard, the plate roller part of each color should be slightly larger than the previous pressure, so that the pressure applied to all colors is equal. Secondly, the front and rear of each print have a paper feed roller and a pulling roller. The adjustment of these two rollers is very important, especially when the width of the cardboard is too narrow, you should pay more attention to adjust the gap and position. In case of local color registration, two traction belts should be added to the edge of each printing plate to ensure that the cardboard is smooth and excessive during the printing process. In addition, due to the different degree of warpage of corrugated cardboard, it has an absolute impact on overprinting. If necessary, the cardboard should be replaced again, but it must be flat. [next] Printing colors are inconsistent Cause Analysis: Inconsistent printing color refers to the unevenness of the overall printed board along the machine's longitudinal or transverse direction after printing. The reason for this problem is mainly due to the different colors of both ends of the horizontal printing, one side is lighter and the other side is darker. Also, the circulation of the ink system is unfavorable, the flow of ink is insufficient, and the transfer of the ink transfer roller is uneven. solution: The uneven lateral color is caused by the gap between the rubber roller and the anilox roller, the anilox roller and the plate roller, so to adjust the gap between the three rollers, the two ends must be kept parallel. Because the printing slotting machine is centered, such as the production of narrow cardboards, the rubber roller and anilox roller will wear faster, and the two ends will wear less. The result after printing is different. Obviously inconsistent, you need to repair or replace a certain roller. The uneven color in the longitudinal direction is caused by too little ink flow and insufficient ink supply. Therefore, the amount of ink needs to be increased a little, and the machine runs idly, so that the amount of ink is fully circulated before production, which can reduce the occurrence of problems in this regard. Crush the corrugation when feeding or printing Cause Analysis: This is caused by two aspects. One is that the gap between the paper feed roller (referring to the printing and grooving machine) is too small, which is lower than the thickness of the original cardboard, and the corrugation is crushed before printing; the other is that the pressure of the printing roller is too large during the printing , Causing the corrugation of the printed part to collapse obviously. solution: The gap of the paper feed roller should be determined according to the thickness of the corrugated cardboard, which is basically 0.5mm lower than the thickness of the original cardboard. If the gap is too small, the corrugation is destroyed, and various physical strengths will be affected after the corrugated carton is formed; if the gap is too large, the cardboard cannot travel at a uniform speed, causing the printing position to fail; Pay attention to adjust the gap between the printing roller and the impression roller during printing. At present, most of the corrugated carton printing uses flexographic printing, and the printing method uses light pressure. Both kiss printing, the pressure must not be too large. If the pressure is too high, the corrugation of the printing part will be crushed, which will affect the performance of the carton. Therefore, the adjustment of the gap between the plate roller and the impression roller is very important, and there is no obvious depression in the printing part of the hand. Corrugated box manufacturing process must not damage the corrugated box. It is different from the general carton sales and packaging, because the force formed by the corrugated box is multi-faceted. Once the UV-shaped corrugated board is destroyed, the corrugated box is meaningless. In summary, these printing problems are only the most common problems. Others, such as blurred printing, distortion and distortion, excessive printing traces after printing (commonly known as dirty printing), streaks appear in the print, and the ink color does not achieve the desired effect, etc. There are many analyses. But in addition to objective factors, such as printing plate materials, plate liners, inks, and even the quality of corrugated cardboard, all directly affect the printing effect of corrugated boxes. Therefore, high-quality raw materials should be selected to ensure the high quality of printing. If you want to solve the various problems in the printing process, you must rely on operators who have practical experience. First of all, they must have a certain level of theoretical knowledge. For example, they must understand the principles and process regulations of printing equipment and manufacturing processes, and fully master the printing system. The relationship between the rubber roller, the ink transfer roller (anilox roller), the plate roller and the impression roller, how to be proficient when a certain problem occurs; the correct adjustment of the corresponding part can be quickly solved. Secondly, we should be good at summarizing in actual operation, which parts to adjust under what circumstances, and require accurate, which is not easy for ordinary operators to do. As an excellent car stopper, you must be good at finding problems and solving problems in time, so that production efficiency can be improved. All in all, printing problems can not be separated from the above-mentioned conditions. As long as the printing principle is fully understood, the printing problems will be solved. 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Common Problems and Solutions in the Ink Printing Process of Corrugated Box