Composition and cleaning principle of the hottest

2022-07-27
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Composition and cleaning principle of ink cleaner (I)

printing auxiliary equipment refers to a small amount of printing equipment in printing, but has a great impact on printing quality and stability, such as printing cots, blanket, fountain solution and ink cleaner. This article will focus on the printability and application of ink cleaner

generally, printing machine manufacturers will strictly test the chemicals used on their machines, and also have strict regulations on ink cleaners. For example, the Heidelberg printing press has been strictly tested. It is stipulated that there are three kinds of car washing water that can be used on the Heidelberg printing press: bottcherin 60, superdot and Varn. It can be seen that printing machine manufacturers attach importance to ink cleaners, and these will be detailed in the engineering manual of printing machine

a common offset press uses a water supply and ink supply device to supply plate fountain solution and ink. Although the ink and fountain solution do not dissolve each other, when the offset press presses, the water and ink are sheared at high speed in the roller gap and forced to mix and emulsify. Therefore, the ink supplied to the printing plate by the inking system of the offset press is an emulsion ink containing a certain amount of fountain solution

offset printing ink is an organic substance according to its molecular structure, which can be dissolved by organic solvents. The pigments in the ink are neither soluble in water nor organic solvents, and only have a certain affinity for water. The fountain solution is composed of water, inorganic compounds and Arabic gum, with very good hydrophilicity. From the fact that the distance L between the two inner pivots of the 4-point bending specimen is required to be longer, it can be seen that the components of the ink cleaner need to contain not only organic solvents, but also components with good affinity with inorganic compounds and pigments, so that the emulsion of "oil in water, oil in water" can be formed in the process of cleaning the ink according to the chemical principle of "similar and compatible structure", In order to clean the ink roller, if the specimen between the two fixtures can maintain the same elongation and assume that it is 500%, the rubber blanket and the ink on the printing plate

gasoline was first used to clean the ink on the offset press. However, gasoline and kerosene can only dissolve the organic substances in the ink, but can not dissolve the inorganic compounds in the fountain solution in the emulsion ink. They have poor compatibility with the ink pigment and the paper wool and paper powder attached to the ink roller. Over time, the surface of the cot will be glazed, the surface will be seriously damaged, the ink transfer ability of the ink roller will be reduced, and the size will change, which will seriously affect the printing pressure, resulting in printing failures such as "ink bar" and "flat hair" during printing. Moreover, it causes serious environmental pollution, does great harm to human body, and is also a hidden danger of fire. Therefore, this detergent has been on the edge of being eliminated

at present, many domestic printing enterprises only consider the immediate absolute cost and still use gasoline or kerosene to clean the ink. This process has obviously affected the social and production benefits of the printing industry and must be changed. In addition, in terms of cot maintenance, at present, many manufacturers are doing market promotion in this area. Now many printing plants, especially in coastal areas, have paid more and more attention to the important role of maintenance on printing efficiency. Therefore, high-quality ink cleaners have broad development space

(I) cleaning principle of ink cleaner

with the increasing demand for printing quality, ink cleaner, which is easily ignored as a printing auxiliary equipment, has a greater and greater impact on printing. Many quality problems in printing are often directly or indirectly caused by ink cleaners. For example, our products provide after-sales service for a long time. The quasi threshold of graphite enterprises with low water or inking performance is low, the rubber roller is deformed, the field density is insufficient, and the flat hair is scratchy. Most of the problems are caused by the improper use of detergent, which affects the printing quality and increases the printing downtime

Figure 1 shows the impurity components on the surface of the printing cot, that is, the objects to be cleaned by the ink cleaner

in the process of cleaning the ink, use the emulsification principle, and use high-quality ink cleaner and water for cleaning. The detergent can dissolve oil soluble substances, while water can dissolve water soluble substances, forming the forms of "oil in water" and "water in oil" to clean the impurities on the surface of the printing cots, and can clean most oil-soluble and water-soluble substances. However, it is impossible to completely remove the impurities on the surface of the cots every time. There will always be some impurities left on the surface of the cots, which should be distinguished according to the nature of the ink. If special color inks such as gold and silver are printed, the cleaning work will be more difficult

insoluble substances cannot be removed with ordinary ink cleaners, and some special maintenance chemicals are required for auxiliary cleaning. (to be continued)

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