The ink in the screen printing is printed on the substrate by the leakage of the printing plate into the printing material. The printing process and the ink properties are different from those of the gravure or flexographic printing. Some of the main causes of the failure are caused by the ink. The solutions are listed below. (1) blocking network After the machine is shut down for a period of time, the printing plate is re-started, the plate mesh is clogged, the ink can not be leaked, and the graphic is not printed; sometimes after printing for a period of time, some of the mesh holes are blocked, so that the printed image is defective. These blocking phenomena are caused by the ink drying too fast, so that the ink is dried on the plate during shutdown or during printing, blocking the mesh. Should be stopped immediately, use a solvent, cleaning agent or pore-forming agent (a liquid composed of several solvents, which has a good dissolution and cleaning effect on the general mesh ink), remove the blockage, and then add appropriate in the ink. Slow drying or slow drying solvents reduce their dryness and print. (2) Printed text found defects One situation is a slight blockage of the net, because it is slight, not easy to detect, and the quality of the printed matter is detected. The printing inspection in progress should be strengthened. Once found, immediately add an appropriate amount of slow drying solvent or slow drying diluent to the ink. In another case, the ink is mixed with impurities or dried ink, which blocks the mesh. The impurities or ink should be removed immediately, and the plate should be cleaned before printing. (3) The edges of the printed graphic are rough and bluish The solvent of the ink evaporates faster. After printing for a long time, the viscosity of the ink becomes larger due to the decrease of the solvent component, or the ink itself is too sticky, so that the ink has a drawing phenomenon when the screen is scraped and the screen is lifted. After the ink filament breaks, it is retracted onto the print to make the edge of the print rough. Add appropriate amount of de-adhesive or slow-drying solvent to reduce the viscosity of the ink, no drawing phenomenon, and the edge of the blot will not be rough. (4) Small prints, enlarged graphics and paste The flowability of the ink is too large, and there is a large expansion after being printed on the substrate, so that the fine dotted lines are enlarged and even thickened. This drawback can be improved by adding a thickener to thicken the ink and reduce flow expandability. (5) The edge of the printed graphic is obviously zigzag The mesh screen of the mesh printing is thicker than other printed dots, and the flowability of the ink is too poor. The ink leaking on the substrate surface is in the shape of a mesh, and the edge of the graphic is obviously zigzag. . This problem can be solved by adding an appropriate amount of leveling agent to increase the flowability of the ink. (6) Ink drawing, affecting printing quality In the ink with acrylate as the main component, the solvent volatilization is reduced to a certain extent during the printing process, and when the printing plate is separated from the ink layer of the substrate, many inks are drawn into a filament and then broken, and the filament ink is obtained. Staining the blank portion of the substrate and the underside of the plate seriously affects the print quality. Always pay attention to adding appropriate amount of solvent to avoid the occurrence of wire drawing. Article source address: http:// Self-Inking Stamp Ink,Self Inking Stamp Ink,Black Stamp Ink,Office Stamp Refill Ink Huhua Stationary Co., Ltd , https://www.huhuastamp.com
April 25, 2023