Analysis of the printing process of the hottest an

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The anti-counterfeiting technology is applicable to the packaging and label anti-counterfeiting of securities, certificates, official documents, bills and all kinds of high-end commodities such as cigarettes, alcohol, food, drugs, cosmetics and so on. With the development of high technology and people's requirements for high-quality packaging and printing products, the packaging and printing industry has started a large-scale technological revolution in recent years. The combination of a variety of printing equipment and the mutual penetration of a variety of printing processes have made printing products more unpredictable and colorful. The products printed with these new technologies have set up layers of obstacles and resistance for those who try to be counterfeiters. Next, the author will briefly introduce the printing process of anti-counterfeiting labels

◆ combination of lithography + relief printing and multiple processes

generally, high-end packaging and decoration prints are mostly designed with large-area color blocks, multi-color sequence continuous tone pictures, complex lines, patterns, etc., which are difficult to print with a single printing method. If the combination of lithography and embossing is adopted, that is, the advantages of high pressure and uniform inking of relief printing machine are used to print field color blocks in a large area, and the advantages of flat and soft pressure of lithography printing machine are used to print four-color continuous and complex line parts. In this way, the advantages are enhanced and the disadvantages are avoided, and the effect is ideal. For some more demanding and complex prints, we can also use embossing, gravure printing, flat printing, embossing, gravure printing, silk screen printing and other printing processes. In a word, the more complex the printing process is and the more difficult the printing is, the better the anti-counterfeiting effect will be

◆ multicolor cross printing

multicolor cross printing is also called cross color printing, which is usually printed by relief printing machine. It is based on the requirements of printing products, after placing a partition in the ink tank, and then putting a variety of hue inks in different partitions. Under the action of the inking roller, the ink of adjacent parts is mixed and then transmitted to the printing plate. With this printing process, multiple colors can be printed at one time, and the middle transition is soft. Because it is difficult to see the placement distance of the ink tank partition from the print, it can also play a certain anti-counterfeiting role. If this process is used in large-area shading printing, its anti-counterfeiting effect will be more prominent

◆ gravure printing technology

this printing technology has raised graphics and texts on the printing plate, and the ink on the printed graphics and texts is also raised, and the graphics and texts have clear lines and clear layers, which can be felt by hand. This printing technology not only protects the paper, but also has anti-counterfeiting performance. Gravure printing technology is used for important securities

the types of gravure printing are divided into two categories according to the plate making methods: engraving gravure (including manual engraving gravure, mechanical engraving gravure) and corrosion gravure. (2) As the jaws of material testing machines are often used, engraving intaglio printing has a good anti-counterfeiting effect, which is generally combined with anti-counterfeiting ink technology. Some anti-counterfeiting inks have large pigment particles and need a thicker ink layer to reflect the printing effect, while gravure printing has a strong texture. The combination of the two can achieve the dual effect of anti-counterfeiting and decoration

gravure printing also often uses fluorescent ink, which not only ensures the micro convex feeling of gravure printing, but also ensures the use requirements of fluorescent ink, and the anti-counterfeiting functions of both are also guaranteed

◆ laser holographic iris printing

laser holographic iris printing uses laser holography to make a template in the shockproof chamber, and then transfers the pattern to a carrier through pressure. Under the irradiation of 45 degree point light source, its products can produce a rainbow like unique effect of color billows, and the image has a strong three-dimensional sense, which is favored by consumers. It is called the ink free color printing in the 21st century by some people of insight

at present, laser holographic iris printing mostly adopts two processes: cold press coating and direct hot stamping. Because the plate making process of this technology is complex and difficult, only a few domestic manufacturers can produce it, so the anti-counterfeiting effect is excellent. It should be particularly pointed out that holography uses a laser light source to simultaneously capture the amplitude information and phase information of the light wave of the scene in a very short time in the earthquake proof room, and uses the interference principle of light to form each particle of the scene to form all the information. In the process of plate making, the subtle air flow in the room can cause the color change of the hologram, so it is impossible to make two identical holograms in any case

◆ manual engraving and embossing

most packaging and decoration prints require key words such as trade names and patterns to be raised. These graphic bulges are mostly made into relief plates by chemical corrosion method, which are combined with gypsum gravure to complete embossing after being put on the machine. Although this method has the advantages of simple manufacturing process and short cycle, the embossing effect is poor and does not have anti-counterfeiting effect. So at present, Owens Corning announced 4 or 5 years ago that there would be no increase in production capacity by the end of 2015. Many printing plants use engraving embossing process. For manual engraving, copper plates with good texture should be selected. The graphics and texts (mainly patterns) required by users should be carved by carvers in layers with carving knives by hand skills. Generally, 3-4 levels can be carved. In particular, the chemical etching method can only make one level, and the dead corners of the edges cannot be made into a certain arc like manual carving to improve the embossing effect and prevent the paper from cracking. Because the skills of sculptors can not be mastered in a short time after the typhoon, and different sculptors have different carving styles, even the same sculptor cannot carve two identical templates. Therefore, the packaging prints stamped with such templates not only have good embossing effect, rich layers, high embossing rate, but also have strong anti-counterfeiting effect

◆ special gloss printing

special gloss printing is a popular new printing technology in the packaging and printing industry in recent years. At present, special gloss printing processes mainly include metal gloss printing, pearlescent printing, pearl gloss printing, refractive printing, variable gloss printing, laser holographic iris printing, Crystal Gloss printing, metal like etching printing and matte printing:

· metal gloss printing uses aluminum foil metal composite paper, with transparent ink and light weight, forming a special metal gloss effect on the print

· pearlescent printing is to apply silver paste first and then extremely transparent ink on the surface of the print. The silver flash reflects a pearlescent effect through the ink layer

· pearl gloss printing uses ink mixed with mica particles to produce a gloss effect similar to pearls and shellfish

· refractive printing is the unique effect of light refraction by using a refractive plate to imprint the pattern on the print through a certain pressure

· matte printing adopts matte ink printing or ordinary ink printing followed by matting film, which can produce hazy weak gloss characteristics, so it also has a relatively safe anti-counterfeiting effect

reprinted from: Chinese labels and stickers

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