(1) Aluminum foil wrinkle
The factors are tension factor, equipment debugging factor, equipment + equipment maintenance factor, equipment aging factor and human factor.
Tension factors include the size of unwinding tension and winding tension, and balance problems.
If the unwinding tension is too small, the aluminum foil will fall off in the printing process; under the pressure of rubber drum and plate cylinder, it will deform and form dead folds, which will make the wrinkled Department unable to print ink.
If the unwinding tension is too large or the winding tension is too large, it will easily break the material. In the winding process of the aluminum foil products with active pleats, if the winding tension is too large, it will also produce shaking, leading to the release.
In aluminum foil printing, the aluminum foil at the unwinding position is wrinkled, that is, the aluminum foil is wrinkled between the unwinding position and the first color printing plate cylinder. This is because the material is not placed unevenly when the aluminum foil is applied, that is, the material is not level between the unwinding shaft and the aluminum foil roll, or the thickness of both sides of the material is not the same. At this time, the material should be adjusted to the level to make it consistent, and check whether there are bumps or dirt on each guide roller Clean away the object; grind the bruise with fine sandpaper.
In the process of feeding and discharging, if the two groups of printing guide rollers are not level, it will lead to wrinkle between colors in printing. Adjusting the printing guide roller to the level can solve the problem. If there is no wrinkling when feeding (aluminum foil into the plate cylinder), and the aluminum foil is wrinkled when it comes out of the plate cylinder, check whether the rubber roller is clean and level, and whether the rubber roller pressure is too large. If the above factors are excluded, the wrinkle phenomenon still exists, which may be caused by the corrosive solvent during cleaning and deformation of rubber roller.
(2) Uneven aluminum foil receiving roll
The phenomenon that aluminum foil swings left and right during winding up affects not only the neatness of the roll, but also the process of embossing and die cutting.
The solution is to determine which process the swing starts from, check whether the unwinding shaft and the unwinding coil are loose, and if so, tighten it and lock it. Sometimes, due to the long service time of the winding shaft, the deep groove will be grinded out, and the groove can be filed flat with a steel file, and the problem can be solved by locking the discharging machine with a spring on the discharging frame. If it is found that the discharging shaft is rolling in one direction, check all guide rollers, tighten the loose ones, and replace the bearing with necrosis.
(3) Relationship between printing objects
Because the flexographic materials used in printing are different, some corresponding values should also be changed. For example, when printing 520mm aluminum foil and 360mm aluminum foil, the tension is different from the pressure of rubber roller, and the printing method of beer label and chocolate packaging is also different. Therefore, different winding and unwinding tension and rubber roller pressure should be set according to the strength of different materials.
(4) Other topics
In the process of aluminum foil printing, it is easy to appear the phenomenon of printing ink, which is caused by the deformation of rubber roller caused by solvent cleaning for a long time, resulting in uneven surface. The solution is to take it off and re polish it on the grinder.
In the process of aluminum foil printing, there will be plate cylinder shaking or scraping ink. Should first check whether the version of the drum is installed or the plate cylinder groove is too large. If the printing plate is not installed properly, in the high-speed operation of the machine, because of the friction between the scraper and the plate cylinder, the scraper shakes in a certain part of the cylinder, so that the ink can not be wiped clean, and the quality of the printed product will be greatly reduced.
3. Operator's technical issues
In the printing process, the operator's technical level is the key factor affecting the whole printing process, so the operator should not only have excellent technical level, but also have certain professional ethics and professionalism.
The above are common problems in the process of aluminum foil printing. If you grasp these points, the problems of aluminum foil printing can be basically solved http://www.dgbpk.com/
Dongguan Beite packaging materials Co., Ltd
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