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The factors affecting the printing quality of water-based inks are

Due to today's overall environmental protection and resource conservation, water-based inks have received widespread attention from inside and outside the industry due to their unique environmental performance, and have become the main direction of the current ink industry development. So, what are the factors affecting the printing quality of water-based inks?

Water-based ink

　　 Ink gloss:

　　 Ink glossiness mainly refers to the light emission ability of the ink sample formed at a certain angle. The factor that affects the ink gloss is mainly the conjunctiva produced by the link material after drying.

　　 The quality of the ink gloss directly affects the quality of the printed matter. Therefore, when the gloss of the ink itself can not meet the demand, people often take the method of covering the printed matter with plastic, plastic, film or varnish to improve the gloss.

　　 In this way, the gloss is improved, the printing process can also be increased, and the printing expenses will also increase. Therefore, if the gloss of the ink itself can meet the requirements, it must be both time and money saving.

　　Ink interface viscosity:

　　 The viscosity of the ink is directly related to the transferability of the ink and the suitability of the brush, and when printing with the same article, it will also form different influencing factors. At the same time, during the printing process of the ink, the difference in viscosity will also cause different changes in the surface tension, which directly affects the effect of the ink after printing.

　　 For water-based inks, people need to be able to take action on the gradation, dot expansion rate, and color intensity shown on the printed image. If the viscosity of the ink interface is relatively low, before the ink dries, it will expand accordingly, resulting in an unbalanced overall spreading effect of the ink, which reduces the gloss of the ink.

　　If the dots are not expanded, the balance of the ink itself will be destroyed accordingly, and the color will be distorted. If the viscosity of the ink is higher than the relevant standards, it will have a certain impact on the transfer of the ink, and it will also cause quality problems such as paste and dirty plates after the printing is formed.

Therefore, the control of ink viscosity should be formulated in accordance with the relevant national standards. Generally speaking, the viscosity is controlled at about 20", the general ink viscosity is controlled at 50"-65"/25 ℃, for high-grade ink, the viscosity is controlled at 25"-35"/25℃.

　　 Fineness analysis:

　　 Fineness refers to the particle size of the ink and the uniformity of the formation of dispersion. It is also an important standard for evaluating ink pastes, which will have a certain impact on printing quality.

In the production process of the color paste, in addition to adjusting the fineness of the ink through the decomposition machine, lubricant, etc., when necessary, it is also necessary to use a three-roller to color the pigment mixed in the color paste. Grinding, so as to maximize the details of the printed matter.

　　 And for the ink with relatively good fineness, the density performance is good, and it also has a good coloring rate. After printing such ink, the finished product quality will be relatively high. On the contrary, if the fineness is relatively large, it will hinder the printing work, make the edges of the printed pattern hairy, empty, and even cause paste.

　　 Therefore, for the fineness of the ink, it must also be able to make it under certain standards and be formulated in accordance with the relevant standards, so that it can avoid problems such as pigment agglomeration.

　 PH value is the pH:

The water-based ink is mainly presented with weak alkalinity. This is mainly because the acrylic resin in the ink will show acidity and it has the property of being insoluble in water. After adding ammonia-based substances to the ink, it will also react with water. A certain chemical reaction occurs, which causes the pH value to become larger and appear weakly alkaline.

At the same time, the size of the pH value has a great influence on the stability and dryness of the ink. If the pH value is too large, it means that the ink is more alkaline, and the alkaline resin dissolves relatively more, which also reduces the water ink itself. Some of the bubbles will appear during printing, which will affect the printing quality.

If the pH value is too low, it means that the ink is relatively weak in alkalinity, and some of the alkaline resin in the ink can not be dissolved, which makes the ink more viscous, the drying speed will be faster, and printing clogging and other problems occur. Therefore, the pH value of the ink is controlled. It should be kept stable between 8-9, so that it can ensure that the printing quality is in a high-quality state to meet people's demand for printed products.

　　The color rendering effect and color stability of water-based ink under different pH conditions, and the paper surface of different pH values is compared to analyze the printing effect. Through the study of the basic properties such as the solid content, viscosity, pH value of the water-based ink and the color density and color difference of the proofing spline, it is found that:

　　When the pH value of water-based ink is between 8.2-9.5, its solid content, surface tension and viscosity value are stable. The results of proofing on the surface of high-grade copy paper and corrugated paper show that the color density values of the ink on the two groups of paper surfaces are relatively stable and the fluctuation range is small, and the color density value of high-grade copy paper is greater than the color density of corrugated paper value.

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