Intrinsic properties and color deployment of printing ink

In the preparation work before printing, whether it is a multi-color machine or a monochrome machine, ink color deployment is a high-tech work. Iron printing ink is a special offset printing ink. In order to meet the conditions of printing and high-temperature baking of metal printing, comprehensive consideration must be given to the choice of pigments and binders. If the operator does not understand the properties and color matching of the printing ink, the bright ink can not be mixed to achieve the desired appearance and quality.

The nature of Indian iron ink

Each color has three attributes of hue, lightness, and saturation. Hue can be expressed by the wavelength of light waves, that is, the wavelengths reflected by different colors are different. Brightness indicates the degree of lightness of the color, and lightness of the ink indicates the amount of light reflected by the ink. Saturation refers to the purity of the color. If an object has a high reflectance of light in a certain wavelength band in the spectrum and the reflectance of light in other wavelengths is low or absent, the purity of the color is high.

Ink ink pigments generally account for 1% to 35 of the ink composition. The amount of pigment determines the ink concentration, and also has a great influence on the relative density, transparency, heat resistance, and light resistance of the ink. In the ink color matching process, the ink should be selected according to elements such as the printing process, ink layer thickness, and the properties of the print, and the properties such as luster, hue, tinting power, hiding power and the like of the ink itself must also be considered.

1. Luster: refers to the ability of the ink to reflect light in the same direction after exposure to light, which directly affects the appearance of the print. It can be measured with a gloss meter or with the naked eye.

2. Hue: is the basic characteristics of color, color matchers must first consider whether the hue is the same. The detection method is: comparing the standard sample and the sample with the naked eye by scraping the paper or by simulating the method of printing iron, and observing whether the hue is consistent.

3. Covering power: refers to the ability of the ink to cover the background. The better the hiding power, the lower the transparency. The level of transparency directly affects the ink trapping efficiency and the degree of influence of the affected parts.

4. Coloring power: used to indicate the ink concentration. The determination method is as follows: a certain amount of ink is added with a certain amount of standard white ink to dilute, and compared with the standard sample. The strength of coloring reflects the relationship between the ink mixing degree and ink film thickness.

Luster, hue, hiding power can be identified by scraping paper scratching test, the specific operation is as follows: Put the standard ink in the upper left corner of the scraping paper, and put the color ink in the upper right corner, make the standard scraper and the scraping paper into a vertical angle force flattening Thinly applied part, gently compressing the thick part at an angle of inclination. After the surface of the ink is dried, the hue of the ink is observed in the thin portion, the difference in luster between the two inks is observed in the thick portion, and the hiding power (transparency) of the ink is identified in the black (real) portion. Normally, black or color inks use white scratch paper, and white ink uses black scratch paper. The color samples were observed under indirect indoor light sources during the day and under standard light sources at night.

Printing ink ink color matters needing attention

Avoid using too much color ink. Because the more ink, the farther away from the standard color, the worse the brightness, the worse the color gloss that is mixed out. At the same time, to use the same brand of ink, to avoid the production of iron in the printing, due to different manufacturers, different brands of ink mixed use escape color, transfer performance and other shortcomings.

The preparation of the primary color ink is divided into three kinds of monochromatic, intermediate and complex colors. Monochrome refers to the mixture of a primary color ink; inter-color is made of two primary color inks; complex color is made of three primary color inks. All inks formulated with diluting agents are called light-colored inks. The following three points should be taken into account when deploying: White ink is not needed as diluting agent; white ink is the main color when adding color, and appropriate color ink is added when color is selected; Accurate judgment, special color ink including gold / silver ink, pearl ink, luminous ink and so on. After the gold/silver ink is opened, it must be used in time, otherwise it will be easily oxidized and darkened. The commonly used gold ink is three kinds of gold, gold and red gold, the color is mainly based on gold powder, supplemented by color ink adjustment. There are also many kinds of silver inks. If a small amount of white ink is used, it will be silver white, and a small amount of yellow ink will be silvery yellow. Pearlescent ink consists of a pearlescent pigment and a bright varnish. Luminous ink is composed of phosphorescent pigment plus color ink and has the effect of nighttime light emission.

Tinplate has bright and dark surfaces depending on the thickness of the coating and the surface processing technology. For example, a high-transparency color ink can be selected bright tinplate prints to enhance the ink's metallic luster; while the dark side or rough surface of the tinplate can choose to cover the strong color ink, such as white ink, increase its adhesion strength.

Source: 21st Century Fine Chemicals Network