Two troubleshooting cases of the most popular comm

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Two troubleshooting cases of commercial rotary printing press

1 There is ink particle and paper wool adhesion on the printed product

fault phenomenon: when printing a seal with one color group, there is ink particle and paper wool adhesion with a diameter of 0.5mm to 2mm on the arc line of the seal

according to the inspection, the ink and paper powder on the blanket and the printing plate are piled up thick, and all nylon corresponding to the paper edge of the blanket is hygroscopic, making the technical state of the equipment reach the requirements of the standard equipment (humidity sensitive) in detail, and the paper powder edge is serious. It is preliminarily judged that the paper is loose. After cleaning the blanket and printing plate, the machine speed was slowed down. The problem was not completely solved. About an hour later, the same problem reappeared. So the main reason is ink. It was found that the ink fluidity was very poor when the ink knife was used to cut the ink slot, so 05 ink blending oil was added to mix evenly (about 30%), and the machine was restarted. The problem no longer existed

fault cause: after long-time printing, the fluidity of the ink in the ink tank becomes poor and the viscosity is large, which makes the ink easy to granule and adhere to the paper powder

precautions: the machine must frequently pull out the ink bucket when printing for a long time. If necessary, add an appropriate amount of additives to improve the performance of the ink when it is not necessary to lay the foundation

2. Excessive ink line

fault on printed matter: an excessive ink line appears in the table when printing bills

it is found that the ink line does not appear at the mouth of the printing plate, so the factors of mouth and blanket are excluded; The whole page is clear with no other dirty marks, excluding the dirty version factor; Check the ink. The ink roll has serious ink accumulation. It is preliminarily judged that the ink volume is too large. So the printing plate and blanket were cleaned, the ink was turned off, and the new material process technology and technology development roll were developed for reprinting according to the needs of downstream users. A few minutes later, the ink line reappeared. Clean the ink, apply less ink, slightly reduce the amount of fountain solution, and then start the machine. The problem is solved

fault cause: the ink amount of the inking roller is too large, and the pressure on the printing plate when inking is heavy, making a thick ink line on the plate. Although the fountain solution has washed away part of the ink, it cannot completely wash away the firmly adhered ink line

precautions: the ink on the rotary machine should be filled with small ink and water, and it should be added if it is insufficient. Do not start with too much ink and too much water, resulting in serious emulsification of ink and other failures

information source: Printing Technology

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