Five things to note when installing the air cylinder scraper filter (1) The air cylinder scraper filter must be installed flat. Before installing the air cylinder scraper filter, check whether there is a gap in the scraper blade. After the knife is installed, it must be carefully ground. If the cutting wire appears during the printing process, the machine must be stopped and carefully ground. In particular, after grinding the knife, dry the paper and the oil at the knife root with a dry cloth, and then dry with a soft cloth with a solvent. It is strictly prohibited to mix the oil of the knife into the ink.
(2) The environment must be governed and dust reduced in order to troubleshoot. The color printing environment should be kept as closed as possible. Air filters can be installed and the dust content can be checked. Otherwise, it is difficult to produce high-quality products.
(3) The knife wire caused by the printing plate cylinder generally appears in the shallow screen part, such as: the plate is rough, the gradient is excessively uneven, and the screen depth is not suitable. Metallographic sandpaper is generally used for graining. Pay attention to the uniform force when grinding. It is particularly serious to be returned to the platemaking factory for processing.
(4) Reduce ink viscosity. If the viscosity is too large, the printing ink dries too fast, which increases the friction between the printing plate cylinder and the scraper, making it difficult for the scraper to scrape off the printing ink and form a wire.
(5) If the knife wire is caused by ink, it is caused by impurities in the ink or uneven dissolution of the ink. Measures such as filtering the ink, re-selecting a solvent with a strong solubility, or changing the ink should be adopted. In addition, when the water enters, the stability system of the ink will be severely damaged, and it is easy to generate knife wire. Therefore, before the printing plate cylinder comes into contact with the ink, the printing plate cylinder must be wiped with a soft cloth with a solvent, and then immersed in the ink immediately. Do not directly contact the printing plate cylinder with water drops. Different types of ink tanks must be dried before they can be filled with ink.
Five countermeasures for cylinder scraper line mark treatment (1) Filter ink. The ink is circulated and filtered. The filter screen can be stainless steel mesh with 100 ~ 120 mesh.
(2) Add active moderator to eliminate active genes generated in printing. "CHY-1 Printing Auxiliary Agent" is a better active moderator. However, when using it, it is necessary to filter the ink and filter out the product after the active reaction. The effect is more significant.
(3) Sweep-type grinding. Use 50-mesh metallographic sandpaper to perform plate-scanning polishing on the plate cylinder, without stopping during processing. The basic operation is to select a palm-sized 50-mesh metallographic sandpaper (pay attention to the inspection to prevent powder from falling too easily and sticking to oil stains), and sweep back and forth in the axial direction of the rotating plate cylinder. The key to the operation lies in the speed of sandpaper sweeping back and forth and the position of the page sweeping.
(4) After washing the plate, apply 1 ﹟ metallographic sandpaper or 50-mesh metallographic sandpaper evenly with engine oil under high-speed motion, and then polish the plate. After grinding the plate, it must be cleaned. It is better to wash the plate with CHY-1 printing auxiliary and then apply the ink.
(5) The scraper should also be properly ground and adjusted. If filament-like spatula marks appear, the cause must be carefully analyzed. The main methods are: First, use 50-mesh metallographic sandpaper to lightly paste on the line mark. Note that the sandpaper cannot be pressed hard on the plate during grinding, but can only be lightly pressed. The printing speed is too slow to use this method; the second is to stop the grinding plate and the scraper in severe cases; the third is to filter the ink or use another bucket of ink, or even change another type of ink; the fourth is to improve the printing environment and increase the air humidity appropriately , Try to ensure the constant temperature, and reduce the dust; the fifth is to improve the static elimination function of the printing press and add certain antistatic agents and lubricants to the ink; the sixth is if there is a problem in the design and manufacture of the printing plate cylinder, it should be returned to the plate making factory Seventh, the use of quick-drying solvents for mild cutting; eighth, increasing the proportion of new ink.