Treatment of ghost trouble of Mitsubishi 3F offset

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Handling of "ghost" fault of Mitsubishi 3F offset press

the problem of "Jinan gold test cantilever impact testing machine experimental method; ghost" is often encountered in the printing process. At this time, the film and printing plate have been made, and the revision is unrealistic. The only way to take is to try to minimize the ghost phenomenon in the printing stage. The following will introduce how to minimize the ghost fault in combination with Mitsubishi 3F offset press

1. Cause

the picture we want to print is shown in Figure 1. Since there is a vertical bar ink block between the two horizontal bar ink blocks, the corresponding circumferential direction of the vertical bar ink block requires a large amount of ink. However, in high-speed printing, if sufficient ink cannot be added to the inking roller in time, or the ink volume of the horizontal bar corresponding to the vertical bar is less than that of other parts, it is easy to produce the ghost of ink shortage

2. Troubleshooting

although the following methods can not completely eliminate the ghost, they can reduce its 6 biological tribology to an almost invisible level

(1) adjust the ink supply system. As the layout with vertical bar requires a large amount of ink, we can increase the ink amount of the ink key corresponding to the vertical bar to supplement the vertical marking amount of the swing rod of the ink supply impact tester in this part as much as possible. However, due to the axial movement of the inking roller, in order to ensure the uniform ink color of the entire horizontal bar, the ink volume should be reduced on both sides of the corresponding parts of the vertical bar, as shown in Figure 2. This ink amount plus string 5 Electronic balance: used to calculate the ink quantity from the mass movement, which can basically ensure the uniformity of the horizontal ink quantity

(2) control the fountain method. Mitsubishi 3F offset printing machine has three ways to moisten the plate. The three modes can be switched at any time on the remote control console. In case of ghost, the moistening form shown in Figure 3 is generally adopted. In this way, since the transfer roller 2 is separated from the inking roller 5 and the inking roller 6, the ink retained on the inking roller 1 cannot be transferred, so these excess ink can be used as a supplement to the ink deficient part of the plate, so as to reduce the ghost. The fountain method has the lowest number of revolutions of the bucket roll and the small degree of ink emulsification

(3) adjust the water supply. We know that the ink water balance is a relative balance in the printing process. The ink water balance can be achieved when the content of fountain solution in the ink is between 15% and 26%. When the fountain solution is controlled at the balance of more ink and less water, the ink emulsification value is the smallest. Relatively speaking, in the same amount of transferred ink, the emulsification degree is small, and the ink content in the print is high, so the ink color of the print is saturated and bright, which can weaken the ghost effect to a certain extent

through the joint action of the above three methods, the influence of ghost fault in the printing process can be basically reduced to very small, so as to improve the quality of printing products. This method is very effective in practical operation, and high quality products can be printed directly without changing the design and process of printing products

source: keyin media -- printing technology

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