Like the general printing ink composition, the aqueous ink is usually composed of a coloring agent, a binder, an auxiliary agent and the like. The colorant is a coloring substance of the aqueous ink, giving the ink a specific color. In the flexo printing, in order to make the imprint bright, the coloring agent generally uses a pigment with good chemical stability and high tinting strength; the binder is composed of water, a resin, an amine compound and other organic solvents. Resin is the most important component in water-based inks, usually using water-soluble acrylic resin. 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 China, because flexographic printing has only recently emerged, printers are accustomed to the control of traditional solvent-based inks. When controlling ink, they either use inertial thinking or do not know where to start. It is often a waste of manpower, material resources, and financial resources, and the loss is heavy. Therefore, for those engaged in flexo printing, it is especially important to understand the technical control indicators of ink. Article source address: http:// Vegan Lip Gloss,Lip Gloss,mua gloss,kit lip gloss Guangzhou Vast Internation Trade Co.,Ltd , https://www.tintsfeast.com