Ink scraping is not clean plagued many flexible packaging plant at home, cause there are ten reasons scraping clean, covered up spare it! 1. Ink viscosity is too high When the viscosity of the ink increases, its surface tension also increases accordingly, and the mutual force also increases, so that the blade will increase the impact force of the ink on the blade during the contact with the ink, destroying its equilibrium point, resulting in The squeegee cannot completely scrape off the ink on the plate roller, which directly affects the quality of the product. 2. The pressure of the scraper is too small Under normal circumstances, the blade pressure is often set very small when the machine is turned on. As the machine speed increases, the impact force of the ink on the plate roller on the blade will increase with the increase of the speed of the machine, destroying the original balance point, directly Cause scraping not clean. 3. The ink enters the water or the use time is too long After the ink is used for a long time, on the one hand, the pigment in the ink will be continuously precipitated during the long-term circulation process, causing the composition of the ink to change. On the other hand, the water vapor in the air will solidify due to the volatilization of the solvent and enter the ink In the same way, the composition of the ink is also changed. Therefore, the overall performance of the ink is changed, and the scraping performance of the ink is greatly reduced, which directly increases the difficulty of scraping the scraper, resulting in unclean scraping. 4. The solvent dries too quickly or slowly The mixed solvent dries too fast, in addition to increasing the viscosity of the ink in a short time, it will also cause the ink to adhere to the vacant part of the plate roller. Because the solvent volatilizes too quickly, the ink adhering to the plate roller will be gelled. When the plate roller passes through the doctor blade, due to the high adhesion of the gelled ink, the doctor blade cannot scrape off the plate roller when it runs for a week, so it is directly brought to the printing substrate, resulting in unclean scraping. . The solvent itself evaporates very slowly, causing part of the ink on the plate roller to not dry on the surface of the plate roller in a timely manner. Its state is similar to the ink with dots, so that when the printing substrate passes through the plate roller, the ink on the plate roller is easy. Transferred to the printing substrate, resulting in unclean scratches. 5. The use time of the plate roller is too long Due to the long-term use, the surface of the plate roller will be worn due to the force of the scraper, and its surface will become smoother and smoother, causing the affinity of the ink and the plate roller to become stronger and stronger, which directly increases the difficulty of scraping the scraper, causing scraping. Produce cleanly. 6. The scraper assembly is too soft and the angle is too flat When the doctor blade is too soft and the angle is too flat, due to the effect of air pressure, the doctor blade will bend on the surface of the plate roller, that is, the ink scraping point will be bent, resulting in the ink scraping method is not a " point " relationship, but a " face " relationship. In this way, the ink on the vacant part of the plate roller, that is, the part without dots, cannot be effectively scraped off, resulting in unclean scraping. 7. The roller assembly is not concentric The phenomenon that the rollers are assembled out of concentricity, under normal circumstances, the beating within 10 filaments will not affect the color registration and product quality. When the plate roller runs from the long side of the elliptical diameter to the side of the short elliptical diameter, the distance becomes longer instantaneously, because the blade is an external force acting on the plate roller, there is a time difference during the conversion process, forming a period Time, that is, the pressure of the blade is relatively reduced in an instant, so that the pressure of the blade is tightened and loosened within one plate circumference due to the jumping of the plate roller, thereby causing a local phenomenon of unclean scraping. 8. The problem of solvent A. Since the solvent is added to the ink, it will directly damage the overall performance of the ink, resulting in unscratching. B. Improper solvent proportioning will directly cause the ink to dry quickly or slowly, resulting in unscratching. C. The solvent itself has impurities, such as low purity and high water content. 9. The ink does not circulate On the one hand, non-circulating ink makes the viscosity difficult to control. On the other hand, due to the thixotropic nature of the ink, the performance of the ink will be reduced when it is not circulated. In addition, the ink surface in the ink tank will be crusted because it is not circulated. , Directly increase the chance of crust dry ink sticking to the plate roller, causing the phenomenon of unclean scraping. 10. The problem of stirring ink sticks Since the convex part of the surface of the ink stir stick adheres more or less to some ink after use, as the number of uses increases, the amount of ink also increases. When the solvent is completely evaporated, dry ink remains. In the following process, the ink in the ink tank cannot completely wet the dry ink on the convex part of the surface of the ink stirring rod, causing the gelled ink to be transferred to the surface of the plate roller during the operation of the ink stirring rod. Due to the strong adhesion, the doctor blade can not scrape the plate roller down for one week, so it can be directly brought to the printing substrate, resulting in the occurrence of unclean scratches. This phenomenon is especially obvious in the dot-free part. Bucket Hats Hun Yuan Ya Lian Wan Jia Dian Zi Shang Wu You Xian Ze Ren Gong Si , https://www.ylwjastragalus.com