Main factors affecting printing quality
1. blocking. The blocking of dot will cause the transfer of ink to decrease, and the color of printed matter will change. In case of blocking, the printing plate shall be cleaned with solvent or special cleaning agent, and corresponding measures shall be taken for the causes of blocking.
2. the printing plate is worn. Plate wear will make the dot smaller and shallower, thus affecting the ink load of the dot. The result of plate wear is that the color is generally lighter. Sometimes the white version is worn out, resulting in insufficient ink on the white ink and insufficient hiding power for the substrate background color. At this time, the production should be stopped for version change, and the old version should be recoated. If the plate cylinder cannot be unplated due to the collapse of the transition screen wall, it must be remade.
3. the pattern color is inconsistent. When multiple patterns are arranged horizontally at the same time, the pattern colors at the left and right ends of the printing plate may be inconsistent. In the process of plate making, especially when the full plate is on the spot, the electric engraving is easy to change the dot size from left to right. Therefore, pay attention to check the printing effect difference between the left and right ends of the plate cylinder.
4. rationality of printing plate design. In the process of printing plate design, the influence of printing plate design on printing process and post press processing should be fully considered. For example, 80% and 5% of the colors in the dot jump area are prone to level merging, and change measures should be taken in advance.
5. printing environmental factors. If the room temperature of the printing workshop changes significantly, the flow state of the ink will change. Generally, the temperature and temperature of the production workshop shall be controlled at (23 ± 5) degrees Celsius and the humidity shall be 60% ± 5%. In addition, when using ink in winter, preheat it in advance to increase the fluidity of the ink.
6. printing conditions. When the layout is blown by irregular wind, the printing speed and drying speed change, which will lead to the color change of the printed matter. The above factors shall be fully considered in the printing process.