Application of the hottest UV ink in screen printi

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Application of UV ink in plate printing

the dryness of ink has a great impact on printing, especially in plate printing, the longer the ink lag time will make the imprinted ink layer thicker. Therefore, the good dryness of ink is of great significance to plate printing

I. The Influence of ink dryness on plate printing

the dryness of ink refers to the speed of ink drying, which mainly depends on the properties of binders in ink, as well as the properties of pigments and excipients in ink and the proportion of each component. The influence of ink drying speed on plate printing is mainly shown as follows:

1 Drying too fast. The viscosity of the ink increases, the particles become thicker, the imprint becomes shallow and weak, and it is easy to cause blockage. 2. Drying is too slow. The gloss of the imprint is poor, and the printed matter is easy to rub dirty, which is particularly detrimental to the post press operation (overprint time interval is too long, cutting waiting time is too long, etc.), thus reducing the production efficiency

from the above analysis, it can be seen that too fast drying mainly affects the printing adaptability, while too slow drying mainly affects the post printing. At the same time, it also reflects that the requirements for ink dryness are diametrically opposite between printing and post printing, that is, the safety protection device of the direct reading experimental machine has many ways to display in the brush, and the slower the drying speed of the ink, the better, so as to ensure good continuity and stable rheology of the ink; After printing, the faster the drying speed of the ink, the better, so as to facilitate the post printing operations. However, most of the inks used now are dried by oxidation conjunctiva, penetration, volatilization and other methods. Therefore, it is difficult to take into account the requirements of printing and post printing for ink dryness

II. Basic principle and characteristics of UV ink

uv ink fundamentally solves the different requirements for ink dryness after printing and printing with its unique drying method. The basic principle of its drying is: through the radiation of UV to the ink, it causes the photochemical reaction of the ink, so as to achieve the purpose of curing the ink. In the drying process of UV ink, there are two main chemical reactions that have embarked on a new journey of high-quality development:

1 Photochemical reaction: the photopolymerization initiator contained in the ink undergoes photochemical reaction to generate free radicals (forming fragments or other reactions) under ultraviolet radiation

2. Chain reaction: through photochemical reaction, free radicals with the ability to initiate chain reaction are generated, so that the unsaturated multi-functional prepolymer, multi-functional crosslinking agent and active diluent in the ink undergo chain reaction, and cross-linked with each other to form a three-dimensional structure of light cured product dry ink film. Therefore, the drying of UV ink mainly depends on its drying characteristics of light curing, so that the ink has different drying properties under the conditions of light (UV light) and no light, that is, when printing, the ink is not exposed to light, and the ink maintains stable rheological properties and has a good printing state; After printing, it is irradiated by ultraviolet light and dried rapidly, which can meet the post process operation and greatly improve the production efficiency. This fundamentally solves the different requirements for ink dryness after printing and printing, and greatly improves the drying adaptability of ink

III. types and characteristics of UV printing inks

uv printing inks have many kinds according to different uses. At present, there are mainly the following kinds of UV printing inks in China:

1 UV curable plastic ink

is suitable for all kinds of plastic films, such as pet, PC, PVC, artificial leather, nylon cloth, etc., and also suitable for all kinds of metal sheets, such as copper, aluminum, stainless steel and other substrates. It can be scrubbed with various solvents, and will not be blocked during printing. It has fast curing speed, good curing toughness, excellent adhesion fastness and bright colors

UV curing etching ink

using the expensive patterns of commodities, inserts, covers and high-end packaging boxes printed by this product, it has the etching effect of copper and silver plates, with clear layers, and the patterns are more expensive and bright, with excellent effect

3. UV curing anti etching ink

UV curing anti etching ink is adopted, which has no solvent allocation and pollution problems, simple printing, bright lines, strong corrosion resistance, and acid or alkali resistance according to different types

IV. problems that should be paid attention to when using UV ink

although UV ink has many advantages, in order to make it have better performance and good printing quality, in printing, we must also pay attention to the following problems:

1 Select the UV curing machine that matches the power and spectrum of the UV ink used to ensure the curing efficiency and effect

2. According to different inks, choose different mesh of silk to match it, otherwise it will also have a great impact on the printing effect. Generally, ink should not be diluted to avoid affecting its UV curing characteristics. If dilution is required, it must be adjusted with a matching special diluent

4. UV ink should be stored at low temperature and away from light as far as possible, so as to ensure the stability of its UV curing characteristics

to sum up, UV ink shows unparalleled advantages of other inks with its unique drying method, which fundamentally solves the different requirements for ink dryness after printing and printing. It creates conditions for the improvement of printing quality. With the continuous understanding of the properties of UV ink and the further improvement of the performance of UV ink, UV ink will be more widely used in plate printing

information source: printing industry

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