Improve the printing quality of offset printing products, in addition to high-quality paper, PS plate and other raw materials, accurate color reproduction of four-color color separation, non-color rendering, plate-making personnel to master the correct version of the PS plate exposure time, developer concentration and temperature, Monochrome, two-color and four-color offset masters adjust the amount of ink exactly to achieve the balance of ink and ink, accurate color, accurate overprinting, perfect reproduction of tone levels, clear and clean dots, and good overall results. The physical and chemical properties of the ink are determined. The quality of the printed product is good or bad. Only high-quality inks suitable for printability can print colorful and colorful worlds on glossy, white paper. Offset printing ink is a tree finger light fast drying type ink, which is composed of a colorant and a binder, an adjustability adjuster, a desiccant adjuster, and a print effect modifier. The role of pigments: 1. The ink is colored and the ink concentration is determined according to the amount. 2. Give the ink a certain thickness and other physical properties. 3. Maximize the ink's durability. 4. To a certain extent, the ink dryness is affected, and the oxidative conjunctiva type drying is the most significant. The role of the binder in the ink: 1. Give the ink a certain viscosity, viscosity, flowability and thixotropy. 2. Determine the type of ink drying and drying speed. 3. Determine the ink gloss, firmness and so on. We all know that different printing methods need to use different inks for printing. We need lead printing inks for printing in the printing process; offset printing inks are needed for offset printing; plastic printing inks are required for plastic printing. Because the materials used for printing and the printing materials are different, the substrates to which the inks are attached are different, so they require various types of inks with different suitability. For example, the inks used for offset and gravure are different because they are two completely different printing methods. The required viscosity and yield value of the ink are also different. However, where is the difference between various inks? It is on the ink binder. Therefore, different printing methods have different ink flow and drying performance forms. For example, lead printing needs infiltration and drying, offset inks need to be oxidized and conjunctiva dry, and plastic printing requires volatile drying and oxidative conjunctiva drying. Because plastic printing cannot penetrate and dry, plastic simply does not absorb a bit of ink. The color of the three inks is the same. The difference is in the link material in the ink. Offset four-color overprint printing is mainly used resin ink. Resin ink has the following characteristics: Ink fixation is faster. 2. Fast drying. 3. Ink luster, bright color. 4. Strong water resistance. 5. Printing performance is better. Resin ink type: 1. Dissolving resin binder, 2. Dispersion resin binder, 3. Colloidal resin binder, 4. Volatile resin binder. In the offset printing process, the single-color offset printing machine ink is a wet-dry printing, however, the four-color offset printing machine is a wet-on-wet printing. In the four-color overprinting, when a color is printed, the ink is still wet on the paper in a short time, and the ink immediately overprinted with another color is called “wet wetâ€. The properties of the ink, such as viscosity, dryness, fluidity, adhesion, thixotropy, and yield value, determine the color of the ink when wet and wet. Ink additives usually added to the ink have the following effects on the ink: 1. The addition of desiccant has a strong squeezing effect on the ink layer, usually adding about 1% of the dry oil content, and when using a desiccant, it is used now to avoid conjunctiva. Dry oil content in the ink can not exceed 2%, excessive easy to crystallize, the second color than the first color to put more, the winter temperature is lower than summer to put a little more. 2. The addition of the varnish increases the fluidity of the ink and improves the brushing properties, but reduces the concentration and viscosity of the ink, and also reduces the drying properties of the ink. 3. The addition of a detackifier reduces the viscosity of the ink while also increasing the plasticity of the ink. 4. Add dilute agent to dilute the original ink to meet the requirements of ink. 5. The addition of bright paste increases the brightness of the ink. Offset inks require the following features: First, the transparency of ink is high. When the ink is applied as a uniform film, the clearer the underlying color of the material of the ink film is required to be displayed, the higher the transparency of the ink is required. The color of ink on paper has three manifestations: 1. Reflected in the field and in the form of dots, the dot and field (ie, 100% dot) reflect the color of the sun's polychromatic light as a selective absorption and reflection. 2. The juxtaposition and overlap of monochrome dots indicate that two independent dots are juxtaposed or overlapped on the paper to present colors. 3. The juxtaposition of overlapping dots: that is, dots of two colors overlap on the paper to show colors. The yellow hue and the cyan color show green hue when overprinted. Second, the ink pigment particles require delicate. Especially for exquisite printed pictures, calendars, landscapes, and other high-precision prints, the fine particles of the ink are required, and the fine color particles can be printed with fine scale printing products. Third, require strong coloring offset printing ink. Coloring power is a quantity that represents the color intensity or concentration of an ink. The coloring power of an ink of the same color depends on: 1. The higher the degree of dispersion and dispersion of the pigment on the binder, the stronger the coloring power. 2. The higher the content and the content of the pigment, the stronger the coloring power. four. Offset printing inks require lightfastness. The color of the offset ink is required to have light resistance under the influence of sunlight and light, and the degree of discoloration and discoloration of the ink after being irradiated with light is as slow as possible. The printed products of outdoor advertisements are most likely to be faded and discolored after being exposed to the sun and wind. The two colors are yellow and red, and the two colors, cyan and black, are discolored and their fades are somewhat slow. It is important to solve the problems of fading and discoloration of the yellow and red colors, and it is crucial to improve the quality of printed products. Fives. Requires high color efficiency of offset inks. Color efficiency is a comprehensive index of ink color difference and gray scale. Offset printing ink requires the hue of the color to be positive and pure, non-colored. six. The chemical properties of offset inks are stable. The color of the ink will change under the effect of some chemicals, especially the acid, alkali, salt, oxidant will have a certain chemical reaction to the color material in the ink, and it is often easy to change color. Therefore, the offset ink is required to have good chemical stability. 1. Water resistance. Offset printing is a type of printing that uses water. Offset printing inks are water-resistant and demulsifying. 2. Acid and alkaline resistance. Offset water and water buckets should be filled with PS version wetting powder. Offset wetting powder has the following characteristics: 1. Can fully wet the PS plate and reduce the surface tension. Containing surfactant, wetting agent, surfactant CMC. 2. With the cleaning ability to add acid. 3. Has very good non-lipid capacity to add gum arabic. 4. To stabilize the pH value, place a buffering solvent. 5. Moisturizers can be added to suit changes in different climates. Therefore, the PS version of the wetting powder is a high-tech product with various chemical components and requires the ink to have stable chemical properties.
Source: China Business Forum