Discussion on the influence of improper maximum pr

2022-08-23
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Discussion on the influence of improper pressure on printing quality continued

5) imprint extrusion

when the printing pressure is too large or the roller radius is too different, the points will be elongated into ellipses or lines, and the imprint will expand in a direction, resulting in imprint extrusion

6) paste plate

the pressure of the water roller is too light, or the pressure between the rollers is too large, especially when the pressure between the plate cylinder and the blanket cylinder exceeds 0.15mm, the mutual extrusion pressure is increased, and the sand mesh of the plate is gradually ground down, reducing its water storage capacity, resulting in paste plate

7) too much pressure between the plate cylinder and the blanket cylinder, increasing friction? At first, it is a point to expand and produce a paste version. After a long time, it is a point to polish the foundation, and then it begins to spend the version

8) greasy

the pressure between the printing plate cylinder and the blanket cylinder is too large, which makes the printing plate sand mesh polished and the layout shiny, seriously destroying the hydrophilic layer on the printing plate surface and making it lipophilic, resulting in greasy

the total sales in 2013 exceeded 1billion euros. 9) down fluffing phenomenon

when printing the field, lines or text, burrs will appear before and after the edges of the text, which is down fluffing phenomenon. In the production process, we often judge whether the liner of the drum is correct or not according to the friction and bright position of the connection between the printing plate text and the blank part and the accumulation of residual ink, paper powder and paper wool on the surface of the blanket. If paper wool and paper powder accumulate on the side of graphics and text or point bite, this is the phenomenon of fuzzing. At this time, it shows that R printing r rubber can reduce the pad of the printing plate cylinder, and can produce laminations on site or increase the pad of the blanket cylinder. If the paper wool and powder accumulate on the side of the point trailing tip during printing, it is a fluffy phenomenon. At this time, R printing r rubber can be solved by increasing the pad of the printing plate cylinder or reducing the pad in the blanket cylinder

10) escape paper escape

when the pressure is too high, there is a large friction between the rollers, which is far more than the friction on the back of the blanket? The lining and lining paper will move downward (in the direction of trailing the tip) or upward (in the direction of biting)

11) one side point is not full

due to long-term wear of the gears on both sides of the drum, the center distance on both sides of the drum will move on one side, resulting in light pressure on one side, resulting in one side point is not full

12) through printing

the pressure is too high, causing the ink to penetrate into the back of the printed matter

in addition to the quality of printed matter, improper printing pressure will also have a negative impact on the printing plate durability, printing machine and blanket. When the printing pressure is not adjusted properly, the printing plate cylinder and the blanket cylinder are rolling each other, the ink layer on the printing plate cannot be broken in the middle, there is no residual ink layer on the graphic part of the printing plate surface, or there are many classification methods for the fatigue test of the residual ink machine. When the layer is very thin, the graphic and text of the printing plate) foundation is exposed, which is easy to be worn by the sensor and eroded by the fountain solution, resulting in "plate dropping". In addition, the pressure of water roller and ink roller is too large, the printing plate is not resistant to printing, and the imprint is spread; The pressure between the water roller and the printing plate is too large, the lining loses elasticity, and increases the surface friction, which will cause the ink roller to jump, making it frequently hit the plate, affecting the printing plate durability. Excessive printing pressure will also cause excessive friction, increase the wear of roller bearings, and the rubber blanket will "creep" early, lose elasticity, and reduce the service life of the printing machine. (author Gan Yingjun)

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