Some problems and handling in the use of gravure printing presses
The gravure printing machine will have the defects of overprinting error in use. The phenomenon is that in the multi-color overprinting process, each color cannot be completely overlapped, and there is a certain error. The problem with such a problem is generally due to the following two factors: The first is the equipment factor.
The accuracy and performance of the entire equipment, the tension control of the overprint, the heating air supply system, the embossing rubber roller, the plate roller, the plate shaft, the guide roller and other systems, which determine the temperature, pressure, parallelism, and extension during overprinting. Long-term rate, take-up, etc., and the color system itself limits its accuracy. The increment of the plate roller is not suitable, and the longitudinal color registration is liable to be inaccurate, the rubber of the platen roller is deformed, and the elasticity is insufficient. Keep the pressure roller in good condition. The second is the operating process
The tension setting is unreasonable, the tension is too small, the substrate is slack, and the vertical and horizontal color registration are not accurate; the tension is too large, the lateral contraction of the substrate and the longitudinal color registration are unstable, and accordingly the tension is adjusted accordingly. The temperature is not suitable, especially if the oven temperature is too high, the temperature of the chill roll is too high to deform the film, and the temperature of the preheating box should be appropriately increased for a film that is not flat. The air volume in the oven is unbalanced, causing the film to shake in the oven, and the anemometer is used to measure the amount of air in and out and to control it. The plate roller is not properly installed. If the eccentricity is generated, the ink on the plug must be cleaned before the plate roller is installed. The countermeasures for such problems are mainly that the tool must be smooth and careful when loading the knife. Before the tool is installed, it is necessary to check whether the blade has a gap. After the knife is loaded, it must be carefully ground. If there is a wire in the printing process, it must be stopped and carefully ground. It is strictly forbidden to mix the oil of the knife into the ink. The environment must be managed to reduce dust in order to troubleshoot. The color printing environment should be kept as closed as possible, and the air filter can be installed and checked for dust content. Otherwise, it is difficult to produce high quality products. The wire caused by the plate roll generally appears in the shallow part of the mesh, such as rough plate, excessive gradual unevenness, and unsuitable mesh depth. Generally, it should be processed by grinding with metallographic sandpaper. Pay attention to the uniform force when grinding the plate, especially if it is serious, return it to the plate making factory. Reducing the viscosity of the ink, such as too much viscosity, the plate ink drying too fast, relatively increasing the friction between the plate roller and the blade, making it difficult for the blade to scrape the blade formed by the plate ink. If the wire is caused by ink, it is generally caused by garbage or uneven ink dissolution. Filter ink or re-select solvent or ink change.