Common quality problems in carton printing and Solutions

Common quality problems in carton printing and Solutions

1、 Poor machine stamping related parts
Problem: when the plate cylinder head, the imprinting roller head, the transmission shaft, the gear and the important parts associated with the imprinting are worn or loose, the plate roller or the imprinting roller will produce the phenomenon of jumping or sliding during the imprinting process. Because of the unstable pressure, the contact between the plate and the board is abnormal, resulting in the paste or unclear local image and text imprinting on the printed surface of the board Question.
Methods: through careful observation and analysis, find out the exact location of the fault, take corresponding measures to deal with it, repair the worn and loose parts, and eliminate the fault phenomenon.
2、 Improper adjustment of pressure roller
Problem: the position of the pressure roller is too high or too low, so that the contact with the corrugated board is too tight or too loose, and the dirty version, paste version or local image and text imprint are not clear.
Methods: adjust the pressure roller to a proper position, so that the gap between the pressure roller and the roller is suitable for the thickness of the paperboard, so as to ensure the position of the printing plate and avoid the occurrence of the fault.
3、 Poor inking roller
Problem: when the ink roller head is loose, the ink roller body is bent, deformed or the surface is damaged, the layout will be dirty, the paste version or the local image and text will not be clear.
Methods: the causes should be found out, and the corresponding measures should be taken to deal with it, so as to maintain a uniform and appropriate contact condition between the ink roller and the printing plate. Only by replacing the damaged ink roller can the fault be eliminated.
4、 Uneven thickness of corrugated board
Problem: when the formed corrugated board surface has artificial damage dent marks, the paper surface in the dent part will also have quality defects with unclear marks. If the comprehensive increase of printing pressure is adopted to make up for it, it is easy to cause the quality problems of text and line layout.
Methods: in order to avoid the board paste, the corrugated board should be handled with care (the stacking height should be controlled) during the stacking and handling process, and the bad production habits such as throwing, smashing and pressing should not be used.
5、 Uneven plate thickness
Problem: when the thickness of rubber plate is uneven, the height difference will appear in the plate. Where the layout is high, it is easy to paste, and where the layout is low, it is easy to appear incomplete ink, resulting in unclear imprinting.
Methods: if the plate can be made into several small pieces by sporadic plate making, the same plate should be made separately, so that the thickness difference is relatively small. If the rubber plate has been made and there is a thickness difference, it can be made up by more adhesive layers on the back of the partial thin plate, so that the whole plate can maintain basically the same thickness, and ensure the printing pressure and the uniformity of the plate inking.
6、 Improper color sequence
Problem: if you arrange the pictures and texts with full layout in the first color group printing, when the corrugated board enters the next color group printing process, because the printing pictures and texts of the first color group of the board have a large amount of ink and slow drying speed, it is easy to transfer the imprint, resulting in the dirty layout.
Methods: to arrange the small area in the first color block printing and the large area in the subsequent color block printing can avoid the dirty printing caused by the transfer of imprinting.


Post time: Mar-05-2020

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