Flexo printing technology control related to all aspects of the production process, as long as the rational choice from the plate to the plate-making process technology design; from the selection of ink and reasonable adjustment to the printing process of technical aspects, a comprehensive technical checks And control, so that the production process can not only effectively avoid this or that the occurrence of quality problems, but also better improve the quality of the product printing to meet the requirements of users.
Each set of a pack to pay attention to adjust the appropriate pressure. In addition, the printing process should also pay attention to the ink, substrates and printing layout characteristics, to grasp the appropriate, constant printing speed, in order to maintain the same batch of printing ink consistent. The printing area is relatively small, the use of good performance of the ink and the substrate material is also a good product, may be appropriate to use a higher speed for printing. On the contrary, it should be appropriate to reduce the speed of printing in order to obtain a saturated printing ink quality effect.
Reasonable Selection of Flexible Plate Printing Plate
Flexible version is different from the offset printing process of the plate, the plate is more soft, prone to elastic deformation when pressed, and different thickness, hardness of the plate printing adaptability is also very different. The thinner the media, the greater the hardness, the smaller the coefficient of deformation, so the more conducive to improving the quality of printing. Therefore, when the printing of high cable cable boxes, color boxes and other relatively fine color products, the use of the thickness of 2.84mm flexographic printing effect is better, and printed corrugated cardboard or other material uneven substrate, it should be used thicker Plate, otherwise, because the plate relief height is shallow, the blank sheet is easy to appear from the dirty ills. The use of large thickness of the plate printing, compression can be used to overcome the thickness of the substrate difference or poor gloss defects, so that the surface of the substrate surface can also be relatively uniform ink, is conducive to improving the product's printing quality The Resin flexible version, with solid and liquid resin version of the points, due to material properties, the production process is different, plate prices and printing effects are also some differences, the use of the actual situation should be based on the choice of production.
Solid resin version is the use of rough semi-finished plate, directly through the copy exposure, washing (development), drying or after the second exposure, it becomes a finished version, with plate-making convenience, fast features. Solid resin thickness is relatively uniform, its expansion and contraction ratio than the rubber version and liquid resin version is much smaller. Because the plate has a good surface with good ink resistance, high resistance to India and other characteristics, and the plate tolerance is better, can reproduce the fine high-light outlets and small text, lines, etc., but the plate is more expensive.
General solid version is more suitable for printing high-grade, fine pre-printed paper box paper, box and other packaging products. Also from the cost point of view, the number of products printed to be larger to be cost-effective. The liquid photosensitive resin is a liquid photosensitive resin as the material, to go through the pavement, the back mask exposure, positive exposure, the back of the full exposure, recovery of unhardened resin, development, drying and then exposure process, plate length is relatively long , Generally takes about 1 hour, but its raw material cost is about half of the solid resin version. In addition, because the thickness of the liquid plate thickness is not as high as the solid version, and the deformation coefficient is relatively large, the printing quality effect is not as good as the solid version. Therefore, generally suitable for printing a small number, as well as relatively simple layout of the product.
Water-based ink is used correctly for technical control
Ink is one of the important raw materials for printing, and it is also a major factor affecting the quality of printed products. Proper use of ink, in fact, is to control the quality of the ink. Fineness of good water-based ink, its pigments, filler particles on the relatively small, good color effect, the relative amount of ink when printing less, you can get more satisfactory color effects. Control the flexographic water-based ink fineness, you can use fineness scraper for testing, the general flexo water-based ink fineness within 20μm is appropriate, the lower the value of the ink color concentration is stronger, with the relative amount of ink can be reduced , You can get the ideal color, printing is not easy to paste paste and other ills.
Viscosity is also one of the main indicators of water-based ink, the impact of the quality of printed products, if the viscosity is too high, ink leveling is not good, affecting the uniform coating of ink, and prone to dirty version, paste version and other ills. On the contrary, if the viscosity is too low, the printing color quality is not good. Usually high-grade water-based ink viscosity should generally be controlled in about 20 seconds, its strong coloring, bright colors. Adjust the viscosity of water-based ink can be controlled by the ink temperature and diluent dosage, so that the viscosity of ink to meet the requirements of printing.
Water-based ink viscosity detection, the general use of viscosity paint 4 cup full of ink, then from the release of the hole to the flow of finished glass in the ink time is the test results. In addition to the fineness and viscosity, the pH value of the water-based ink is also an important control index that can not be ignored, and the change in the pH value changes the viscosity of the ink. Usually the pH value of water-based ink is controlled in the range of 8.5-9.5, when the ink printing performance is relatively good, the printing quality is also relatively stable. When the ph value is higher than 9.5, due to the alkaline alkaline light, its viscosity will drop, drying speed becomes slow, water resistance is also worse. When the ph value is less than 8.5, due to the weak alkaline of the ink, its viscosity is high, the ink prone to dry phenomenon, so that the plate or anilox roller clogging, resulting in dirty plate.
Therefore, the printing process should pay attention to the control of the value of ph. Generally use ph-value stabilizer to adjust the pH of the ink, the use of the discretion of the ph value of the stabilizer added to the ink evenly or directly into the circulating ink pump

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