Poor ink adhesion is a major problem in the printing process of film-based self-adhesive materials. In the self-adhesive label printing industry, workers generally use 3M tape for ink adhesion testing. Use test tape to stick to the test section, cover the entire test area, grasp the end of the tape with your hand, and quickly remove the tape. Alkali resistance of pigments: Pigments are materials that impart color characteristics to the ink and meet the color requirements of printing. Since the resin of the aqueous ink is mostly alkali-soluble, the viscosity and pH of the ink are precisely controlled, and the pH is generally controlled between 8.0 and 9.5. When the pH is higher than 9.5, the alkalinity is too strong, the viscosity of the ink will decrease, the monotonic speed will be slow, and the water resistance will be deteriorated; when the pH is lower than 8.0, the alkalinity will be too weak, and the viscosity of the ink will rise. The ink is easy to monotonous and will form defects such as dirty plate, paste and blistering. Therefore, pigments with excellent alkali resistance must be used when selecting pigments. Relative density of pigments: When the relative densities of pigments for aqueous inks are very different from each other, pigments with relatively low density are simply floating on them. For example, ink-green inks are often co-colored with pigments such as carbon black and phthalocyanine blue lead chrome. The phenomenon of floating color, hair flowering, sedimentation, etc.; when the relative density of the pigment is too large, the stability of the aqueous ink is damaged due to its simple deposition and agglomeration, such as iron red, chrome yellow, etc., often because the agglomeration cannot be stirred. In terms of drying, evaporation of water is an important factor, especially on non-absorbent materials, which can use an energy to evaporate the solvent. The humidity of water is a factor between the surface tension of water and the body to be printed. Water naturally forms a minimum surface area that is not adjacent to the boundary of the body to be wetted. The drying of the aqueous ink absorbs both the printed body and the non-absorbed ink. It is clear that the ink is not absorbed by the printed body such as the plastic film. Article source address: http:// Desktop Shelves and Office Shelves Desktop Shelve,Office Shelves,Shelf To Put On Desk,Expandable Desk Shelf ROYALWIND IMPORT&EXPORT CO.,LTD , https://www.hoombest.com
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