When coloring inks, you should generally pay attention to the following issues:
1. Carefully observe the color samples, pay particular attention to the printed substrate, and select the ink from the rough and smooth reflection of the substrate. For example, inks are printed on smooth, highly reflective aluminum plates or cans. Choosing high transparency inks will help enhance the metallic luster of the ink.
2. When selecting inks for color matching, avoid mixing too much ink as much as possible. Use inks that are close to standard colors and made from a single pigment. The more color inks are used for color matching, the farther from the standard color, the worse the brightness and the higher the degree of matteness of the mixed colors. It is not possible to modulate the primary colors by color matching.
3, pay special attention to the coloring of ink. If the selected ink concentration is not high enough, the standard color concentration cannot be achieved regardless of how the ink is dispensed.
4, need to add white. When black ink is used, special attention should be paid to the accuracy of the added weight and weighing. In all inks, the hiding power of black ink is extremely strong, and adding too much will not only dilute the color, but also will prevent the reflection of the substrate. However, for the printing of rugged substrates such as nylon or paperboard, it is best to print a white layer that serves as the background color in order to ensure the appearance of the print. Due to the strong coloring power of black ink, adding too much carelessly to the black ink requires adding a large amount of other color inks to adjust the color and cause waste. So pay special attention.
5, the production of light-colored ink, the degree of transparency should be judged from the ink film should be how much white ink or varnish (diluent) to add color. It is absolutely not allowed to use solvents to dilute the color. Excessive solvent addition will not only affect the printing performance, but will also destroy the structure of the ink, resulting in separation of the pigment from the resin oil, and often or greatly reducing the ink luster.
6, improve the printing ink film gloss method:
1) Add appropriate amount of varnish within the allowable range of color density.
2) Apply a coat of varnish or varnish to the surface of the printing ink film.
3) Increase the transparency of the ink, such as the use of a high transparency of the high-gloss ink or adding a suitable amount of varnish, using the smooth reflection to increase the gloss of the reflective substrate.
4) Prevent the adsorption of the substrate surface and reasonably improve the smoothness of the printed surface of the substrate.
5) Pay attention to the temperature of the printing environment. In the case of high humidity, low humidity, and high temperature, when the plastic gravure printing is performed, the solvent vaporizes quickly (usually the surface of the ink film is dried within 1 minute), absorbing the heat around the ink film and causing rapid condensation of water vapor in the air. , Make the surface of printing ink film form fog, make the ink layer luster. During the rainy season, special attention must be given to controlling the temperature and humidity of the printing environment to ensure good printing results.
7, fluorescent ink can not be mixed with a large number of non-fluorescent ink color, otherwise it will lose the ink fluorescence effect. If the tension is too large, when the screen is printed, it is more laborious to scrape the ink and it is easy to tear the screen plate. If the tension is too small, the springback force during the printing is small, and the springback effect cannot be achieved. It is easy to paste lines.
Source: 21st Century Fine Chemicals Network
