The viscosity of the ink is easy to cause the problem of plate fog, flying ink, and the impact on the color, transfer rate and color saturation of the gravure products. The editor has organized the following 6 major problems and treatment measures! First, the version fog problem: In the plastic gravure printing, the non-printing surface of the printing plate cylinder is often stuck with a hazy ink, and the transfer to the printing substrate often shows a sheet or line-shaped stained plate, which is a dirty plate, also called Foggy version. The cause of the staining problem is not only related to the ink formulation itself, the pressure and contact angle of the doctor blade, and the quality of the printing plate, but also related to the printing viscosity of the ink. If the printing viscosity of the ink is too high, the viscosity of the ink will increase. Under the high-speed movement of the printing plate, the ink will produce a great impact on the doctor blade. In this way, it is difficult for the squeegee to scrape off the non-graphic part of the ink smoothly, resulting in plate contamination. If the pigment in the ink is unevenly distributed in the ink system, or the resin in the ink fails to wrap the pigment particles well, the pigment particles will re-aggregate. These larger particles, which form the human pigment group, are very easy to form linear or strip-shaped cutting lines during printing. Generally, the lower the viscosity of the printing ink, the less prone to fouling problems Edition, so in the actual printing of the printing ink pay special attention to account for half of the changes, to adjust the printing viscosity, high embankment package bag printing quality. 2. The flying ink problem of high-speed printing: When the gravure printing speed exceeds 20m / min or more, if the domestic chlorinated polylactone resin with a wide molecular weight distribution is used in the gravure ink, the viscosity of the printing ink is too low, which may cause the problem of " flying ink " . The reason for this is that the viscosity of the printing ink is too low. The cohesion of the ink is greatly reduced. When the ink is transferred to the printed composite film , the low molecular weight resin is easily separated, and small " ink dots " can be seen in the blank part of the printed product . To solve the " flying ink " problem, it can be solved from the following two aspects: one is to use chlorinated polypropylene resin with a narrow molecular weight distribution; the other is to appropriately increase the printing viscosity of the ink according to the printing situation. Third, the impact on color, transfer rate and color saturation: The gravure ink is transferred to the printing substrate by the ink of the indented dots of the intaglio, and the volume of the printed dots is relatively fixed relatively. As the printing viscosity of the ink increases, the viscosity of the ink also increases, and the more ink transferred from the dots, the higher the color density and saturation of the printed matter, but there are certain limits. When the viscosity of the ink continues to increase to a certain degree, the transfer rate of the ink also increases synchronously. If the viscosity of the ink continues to rise, the viscosity of the ink becomes stronger and stronger, and the ink becomes difficult to enter. In the dots, the ink in the dots is getting less and less, and the transfer rate of the ink starts to decline gradually. The color density of the printed matter also began to decline. Ink manufacturers recommend that the printing viscosity of gravure ink is generally 13 to 22 seconds , which is only an empirical value. In the actual printing process, in order to achieve a good printing transfer effect. Carefully choose the printing viscosity. Fourth, the impact on printing speed: The printing speed of existing domestic gravure printing machines ( including imported machines and domestic machines ) ranges from 30m / min to 300m / min . The printing speed of general printing machines is 80-200m / min . In actual printing, it is necessary to choose according to the printing speed of the printing machine. When the printing speed increases, its printing viscosity value will decrease. Of course the most suitable printing viscosity. It is also affected by other factors: 1. Even at the same printing speed, due to the difference in ink formulation design, the printing viscosity will be different. Therefore, in the actual printing process, it must be adjusted according to the effect of printing. 2. Influenced by seasonal temperature: The viscosity of the same printing ink is different in summer and winter, and ink manufacturers have been working hard to reduce the influence of temperature on ink viscosity. 3. The most suitable ink printing viscosity should also be selected according to the actual conditions of the printing plate cylinder. Fifth, the impact on the gloss of the printed crystal: The lower the viscosity of the gravure ink ( that is, adding more solvent to the original ink ) , the content of resin and pigment in the printing ink is reduced, and the ink is not easy to form a smooth ink layer after being transferred to the printing substrate and dried. The white flower phenomenon directly leads to the lack of glossiness of the printed matter. Therefore, in order to obtain excellent gloss, it is necessary to ensure that the printing ink has a suitable resin and pigment content. 6. Static problems: Under normal circumstances, OPP printing ink itself has limited antistatic ability, which is more likely to generate static electricity than polyamide type surface printing ink and polyurethane system ink. For OPP inks, the higher the viscosity of the printing ink, the less likely to cause static electricity. Under normal temperature conditions, the viscosity of the printing ink is more than 16 seconds (3 # Chaen Cup ) Static electricity generally does not occur; if If the printing viscosity is lower than 16 seconds / 3 # cup, whiskers, stripes, edge repulsion and other failures will easily occur. If the viscosity of the printing ink is already 15 seconds / 3 cups, we recommend not to use the method of increasing the viscosity of the printing ink as much as possible, because increasing the printing viscosity of the ink will not only increase the printing cost but also cause difficulties in printing transfer, and it is easy to produce stains. Printing failure. According to the specific situation of generating static electricity, other methods for eliminating static electricity can be adopted, for example, the ratio of diluted solvent can be changed. Add 5 % isopropyl alcohol ( a polar solvent, good conductivity ) or add a small amount of antistatic agent as appropriate to achieve the purpose of eliminating static. Custom Aluminum Instrument Case,Instrument Box For Power,Medical Instrument Box,Aluminum Tools Case Changzhou Junye Aluminum Case Co., Ltd , https://www.junye-box.com