Water-based ink is a Newtonian fluid, so the stability of the ink is poor, mainly in the following three aspects: 1, the precipitation of ink pigments, the ink in the ink tank should be uniformly stirred before use, and the ink in the ink tank should be stirred frequently during printing to prevent the precipitation of ink pigments, resulting in the color and standard of the printed matter. certain differences. An effective way is to use a fully enclosed scraper to keep the ink in a state of stirring and flowing under the operation of the ink pump. 2, During storage and use, due to the stabilizer in the ink composition, resulting inPHvalue decreases. During use, the stabilizer of the water-based ink volatilizes, so that the ink tends to be weakly alkaline, resulting in an increase in its surface tension and a decrease in the adhesion to the surface of the printing plate, which affects the transfer performance and drying speed (the more the ink tends to be alkaline, The drying speed is accelerated), which will cause incomplete printing images and texts during the printing process, especially when printing the screen version, the printing dots are lost or the screen version is blocked because the ink dries too fast. 3, Due to the volatilization of water during use, the viscosity of the ink increases and the flow performance is weakened. The ink supply method of some printing equipment is a single-squeegee system, which requires the ink to have a certain viscosity and fluidity, so that it is within a more suitable range. When the ink is in use and the fluidity exceeds the requirements of printing use, the transfer performance of the ink will be affected, and the surface printing of the printed matter will appear to have some problems.”Chromatic aberration”.
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