Japan Lindeco LPM300 self-adhesive printing machine is a relatively high-end model of self-adhesive printing machine, which can meet the quality requirements of most domestic self-adhesive printing jobs. The following is the analysis and solution of the inaccurate overprinting problems encountered by this model in daily production from the following aspects. First, the problem of the printing plate Anyone who is familiar with printing knows that the quality of the printing plate will have a great impact on the subsequent printing work. It is no exception for self-adhesive printing mainly based on relief printing. Since the resin plate used for sticker printing has two exposure methods of flat exposure and circular exposure, if used improperly, it will cause overprint errors in the printing process. This phenomenon of inaccurate overprinting is mainly manifested in that one color and the other color of the live part can be applied on one side, and the other side cannot be overprinted or both sides cannot be overprinted (that is, the so-called short version). The usual solution to this problem is to check the film. If the film has errors, it needs to be reissued; if the film has no errors, it should be remade. Second, the error of the previous version is large Since the resin plates used for self-adhesive printing are all pasted on the plate cylinder by hand, if the person who makes the plate is unskilled, it is easy to cause errors in the plate. In this case, the plate cylinder can be removed (the plate cylinder of the LPM300 machine can be removed). Use a magnifying glass to check whether the plate is slanted. If it is, you need to re-plate. There is also a possibility that the position of the printing plate is not correct, because the LPM300 machine plate cylinder has a positioning groove, and the gripper of the plate must be placed about 3 mm below the longitude of the positioning groove when the plate is released. If it is too far or too far back, it will affect the step size of the paper during the printing process. Cause the printing plate to twist the paper and affect the overprint. The author had a similar situation in the process of printing once. Overprinting left and right when printing, adjusting many places is useless. Finally, I found that the position of the previous version is above the meridian where the positioning groove is located. It seems that the simpler the error, the less likely it is to be discovered, and I hope everyone will pay attention. 3. The plate cylinder is not in place This is the same as the second reason, which is also a "low-level error", because the LPM300 machine has a positioning groove on the plate cylinder, and a pin in the relative position of the machine. When placing the plate cylinder in the machine, the pin must be stuck in the positioning groove. If the position is deviated, it will cause the plate cylinder to not be positioned. If displacement occurs during printing, overprinting cannot be guaranteed. This kind of problem was caused by someone in the actual printing process, and I would like to remind everyone here. Fourth, the paper is not correct This is the most troublesome problem that every worker who has operated the LPM300 machine has encountered. Since the LPM300 model does not have an automatic correction function, the paper feed is completely controlled by the platen roller and platen roller on the machine. This makes the printing operation difficult. If the paper goes wrong, not only can the overprint not be guaranteed, but it may also cause the paper to break and get caught in the unit unit. In case of misfeeding, the paper must be repositioned first. Keep the position of the paper in front and back of the machine consistent (for example, 180mm wide paper needs to be positioned at 90mm around the zero scale of the front and back of the machine), then turn on the air pump, press the front and back pressure rollers to start the paper, by slowly adjusting Press the position of the roller to straighten the paper. If the paper deviates from the center by 2 to 3 mm, it is normal. The key is to make the paper run smoothly. After the paper is running smoothly, you can print normally. Paper misalignment may also be caused by uneven paper cuts and different tensions on both sides of the paper. The way to judge these two situations is: if the paper runs smoothly while the paper is moving but the edge of the paper has a certain swing, it means that the paper is not cut smoothly. Generally, the paper has certain errors in slitting, so the edge of the paper will have a certain swing when the paper is fed. When the amplitude of the swing is small, it will not cause too much impact on the overprint of the live parts, but if the slitting error is too large, the amplitude of the swing of the edge of the paper during paper feeding will also increase, thereby affecting the overprint. If the tension on both sides of the paper is not stable, the phenomenon is that the paper always runs in one direction when the paper is fed. If this situation is not serious, it can be adjusted by adjusting the position of the pressure roller, but if it is too serious, you can only change the paper. [next] 5. Improper position and pressure of the platen roller There is a white rubber pressure roller in front of each unit of LPM300 machine, which plays the role of adjusting the tension of the paper and limiting the position of the paper. If these platen rollers have one or more improper positions and pressure, it will affect the paper feed and result in overprinting. This phenomenon is mainly manifested as one or two sets of printed graphics and text. But there is no problem with the previous version. If you encounter this kind of problem, you need to check the platen roller in front of the problematic unit to see if the up and down position is different from the other groups, and whether the pressure on both sides of this group of platen rollers is different. If the above phenomenon occurs, you need to carefully adjust until the upper and lower positions of this group of platen rollers are similar to those of other units, and the pressure on both sides is the same. Of course, there may also be problems with the position and pressure of the platen rollers of other units, which may affect the units behind or in front. If the problem cannot be solved after adjusting the platen roller of the problematic unit, then you need to check the position and pressure of the platen roller in front of each group in turn until the problem is solved. Six, unit unit oblique If there is a set of overprint oblique and there is no problem on the plate, and also check and adjust all the platen roller problems, but still can not be solved, it may be that the unit unit is oblique. The possibility of encountering this kind of problem is extremely small packaging of washing supplies, which is almost impossible to happen with the new machine. This may happen if it is an old machine that has been used for many years. This situation is very similar to the misregistration caused by improper position and pressure of the platen roller mentioned above. If this happens, you can only find professional maintenance personnel to solve it. Because the position of the adjustment unit unit requires many years of experience and special tools, it is difficult for ordinary units and individuals to do. The above analyzes the causes and solutions of several common overprinting inaccuracies on the LPM300 printing machine. I hope it will be helpful to everyone's daily production work. At the same time, I hope you can sum up more experience in daily production. , Better serve our label production. We are manufacturer and supplier of Stainless Steel Flour Sifter,Manual Sieve Cup,Stainless Steel Flour Sifter,Powder Sugar Manual Sieve Cup,Flour Strainer. And we located in Jiangmen, Guangdong, China. If any interested, please contact us for free. Flour Sifter,Manual Sieve Cup,Stainless Steel Flour Sifter,Powder Sugar Manual Sieve Cup,Flour Strainer Jiangmen Xinhui Zhancha Metal Products Co,. Ltd. , https://www.zckitchenware.com