1. The influence of ink viscosity. The ink viscosity should match the printing speed. For high-speed printing, the viscosity of the ink should be controlled between 12-15 seconds (3 × chaen cup); for medium speed printing, the viscosity of the ink should be controlled between 16-18 seconds (3 × chaen cup). The viscosity of the ink is too high, and the adhesion to the printing plate cylinder is too strong, which is not conducive to the scraping knife to clean the redundant ink in the layout, and the probability of knife line in printed matter is high. During the printing process, the ink viscosity should be measured and controlled regularly, usually every 20-30 minutes. 2. The influence of ink dryness, ink drying too fast, prone to skin phenomenon, if the crust is not dissolved in the process of ink circulation, once touching the blade, it will adhere to the edge or bottom of the knife, resulting in printed product knife line. If the ink circulation system is open ink tank, it is more likely to occur ink crust, caking phenomenon. In order to reduce the occurrence of such knife line failure, the ink in the ink tank should be stirred frequently; appropriate amount of slow drying agent should be added as required; if possible, a sealing cover can be added to effectively control and reduce the knife line fault of printed matter. 3. The influence of ink fineness on gravure printing ink is mainly composed of pigments, binders and additives. If the pigment is not fully grinded, the particles are coarse and insoluble in the binder and solvent, and stay at the edge of the squeegee during printing, it will lead to small and irregular knife lines. The fineness of pigment particles has a direct impact on the frequency of knife line. For example, the pigment particles used in blue ink have high hardness, and it is difficult to achieve a very fine particle size even after full grinding. In the printing process, it is easy to damage the doctor blade or affect the scraping effect. When printing blue ink, knife line failure often occurs. 4. The influence of ink activity in the ink production process, generally add a certain amount of activator. The plate cylinder also has a certain activity after chromium plating. If the activity of the ink and plate cylinder is too high, the active substance will adhere firmly to the cylinder during printing, and it is difficult for the scraper to clean it, thus forming a knife line. At this time, the plate cylinder is cleaned to remove the active substances on its surface, and the active retarder is added to the ink to eliminate the knife line. 5. The influence of the quality of ink, ink storage time is too long, the solvent balance changes, resulting in ink solubility reduction; or ink deployment, improper use, causing chemical reactions, will make the ink precipitation. In the printing process, the deposit in the ink is easy to accumulate on the blade edge, causing knife line, so the ink needs to be replaced.
Dongguan Beite packaging materials Co., Ltd. - located in Dongguan City, the world's manufacturing city, is a subsidiary of Beite packaging (China) Co., Ltd., with a plant area of 6000 square meters. It is a flexible packaging enterprise integrating R & D, production and sales. It has a complete set of domestic advanced production equipment, a scientific and humanized management system and a group of experienced technical personnel For backing, to provide customers with quality products and first-class service.
The company produces composite bags, roll film, fruit bags, aluminum foil bags, suction mouth bags, self-supporting bags, zipper bags, anti-static bags, special-shaped bags, etc., which are suitable for the internal and external packaging of food, daily chemicals, electronics, toys, medicine, cosmetics, industrial products and other industries.
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