Author: The Galaxy UV imitation metal etching printing, also known as matte or matte printing, is printed on a substrate with metallic mirror gloss (such as gold and silver cardboard) after a layer of uneven translucent ink, after passing through ultraviolet light (UV) After curing, it can produce the effect of etching or frosting similar to the shiny metal surface. Imitation metal etching ink printed products have obvious etching effect, full ink film, strong three-dimensional sense, and make the packaged products fully upscale, has been widely used in packaging color printing industry such as cigarette labels, wine labels, cosmetics, health care products and so on. It can also be used for greeting cards, calendars, name tags, tags, advertisements, and for use. It can also be used for the printing of greeting cards, calendars, famous brands, tags, advertisements, art paintings, etc .; UV imprinting remembers that the screen printing ink can also produce a suede and matt effect, which can make the printed products soft, solemn, elegant, luxurious, and reach the general The effect of ink is difficult to achieve, for which it has been rapidly promoted and applied. 1. UV curing ink The ink filaments of this ink are short and thick, and the diameter of the additive particles is about 15 to 30 μm. After printing, due to the roughness of the ink film surface, under light, the reflection is diffuse reflection, and the film surface gloss is dark. Where there is no film surface with metallic luster, under light, the reflection is regular reflection, and the gloss is stronger, so the place with the film surface is dark and concave, and the place without the film surface is bright and convex, the effect of the two is diametrically opposite. In order to reflect the inherent luster of the substrate, the ink should be transparent, and the hiding power ink should not be used. UV imitation metal etching ink is generally a variety of materials such as photosensitive resin stirred into a light-colored transparent paste; can also be used to make color etching ink. Its components are as follows. UV etching ink: main agent (silicone 15 ~ 30μm); connecting material (photocurable resin or prepolymer, crosslinking agent, photosensitizer, polymerization inhibitor). Second, the main points of UV imitation metal etching ink screen printing 1. Quality control of plate making operation (1) The screen mesh and the thickness of the photoresist film have a certain thickness of the etching ink. If the screen mesh with too high mesh is selected, due to the small mesh opening, the ink will not pass easily or pass very little during printing, making the ink uneven and appear The whitening phenomenon leads to poor etching effect. If a screen with a too low mesh number is selected, the mesh is too large and the amount of ink transmission is too large, which causes paste and affects the printing effect. · Frosted coarse grains: 100 ~ 180 mesh screen; photosensitive adhesive film thickness below 10μm. · Frosted mid-grain (or ice-flower mid-flower): 150 ~ 250 mesh wire mesh; photosensitive film thickness 12 ~ 14μm. · Frosted text (or ice flower floret): 200 ~ 300 mesh screen; photosensitive film thickness 14 ~ 16μm. (2) Because the imitation metal etching ink has a certain thickness, the aluminum alloy screen frame and screen printing machine are used for printing in order to prevent the screen deformation from making the pattern overprint difficult. (3) Stretching net operation Oblique stretch type is used to stretch the net to reduce the serration as much as possible and improve the precision of plate making. (4) Measurement of tension The magnitude of tension is directly related to the flatness and printing quality of the photosensitive film coated by the doctor blade. If the tension is too high, the screen becomes brittle, the reaction force against the scraper during printing is large, and it is easy to tear the strong screen; the tension is too low, the screen is soft, and the necessary resilience to the scraper during printing cannot be generated, and the dots or Printing blind spots. Only a moderate tension can ensure the dimensional accuracy of printing and printing, so that the overprint is accurate, and the screen has good resilience, the dots are clear and resistant to printing, and it is not easy to break under normal conditions. (5) When making screen plates, use solvent-resistant or water-resistant photoresist, developed with water, no pollution, and made of solvent-resistant photoresist, which can be reused after printing and stripping. (6) Due to the thick photoresist film, the screen needs a longer exposure time to completely harden the photoresist layer, and at the same time, the development time is appropriately extended to make the obvious impact more adequate. It is best to perform double exposure to fully cure the photosensitive film and enhance the screen printing durability. 2. Quality control of printing operations Metal imitation etching ink should be fully stirred before printing to use. During the printing process, it should also be stirred in time to prevent unevenness of the ink layer or no ink drop. Similar to ordinary screen printing ink, metal imitation etching ink can be printed by screen printing machine or manual printing. Considering the characteristics of the etching ink itself, such as the ink itself is thick, the printing resistance is large, the pattern registration requirements are high, and the printing ink layer requires uniformity, etc., so it is generally appropriate to use a screen printing machine for printing. At the same time, we should pay attention to adjust the printing pressure, scraping angle, screen height, etc. to control the printing quality and prevent premature screen damage. (1) Use of additives · When imitation metal etching ink is printed first, do not add other solvents at will. Only when the ink leakage can not continue during the printing process, you can add a small amount of thinner to stir and then print. Excessive addition of thinner or insufficient stirring will greatly affect its metal texture, and it will also affect its firmness and dryness on the aluminum gold film. Therefore, when the ink is compounded, various additional materials must be stirred evenly. In order to reduce the leveling of the ink on the film surface after printing, no or less dilution or leveling agent is used in the formulation to promote the formation of the rough film surface. · Use special thinner or industrial alcohol for dilution and cleaning. (2) Scraper selection UV ink cannot use squeegee made of polyurethane. Special rubber squeegee should be used. · Scraping strip: its hardness should not be too high, generally 65 Shore hardness. The shape of the scraper: the substrate is flat, and a right-angle scraper should be used; when the substrate is convex, a conical scraper should be used; · The length of the squeegee is generally wider than the printed image, so that when the ink is pushed back, there will be no residual film on both sides. The quality of scraper pressure control is also an important factor that cannot be ignored. Because the ink filament is short and thick, and the pressure is small, the ink will not pass through the mesh smoothly; if the pressure is large, the amount of ink passing through the mesh will be too much. Both will affect the printing quality and the printing effect of imitation metal etching. The pressure of the squeegee should be controlled to be slightly higher than the pressure of printing ordinary color ink. · The pressure should be the same during printing, to avoid the thickness of the ink layer that is etched by the metal imitation due to the different pressure, affecting the uniformity of the rough surface. (3) During the printing process, the wet state of the imitation metal etching ink should be maintained to ensure the complete consistency of the printed products. The degree of wetting is determined based on user experience. When the ink is dry, add special thinner in time, and continue to use after stirring. (4) The drying of the imitation metal etching ink should be selected within the range of 80W ~ 6.4kW of the purple lamp power of the UV light curing machine according to the thickness of the ink and the speed of the light curing machine. The light curing machine must be equipped with a cooling device to avoid thermal deformation failure of the composite paper when passing through the light curing machine. GlazeKing Ceramics TechnologyCo.,Ltd. , http://www.maglazekingceramics.com