The most popular four special printing methods to

2022-07-26
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Four special printing methods to meet the needs of special effects

(I) stereoscopic printing

when people observe objects, they can naturally produce a three-dimensional sense because there is a certain distance between people's two eyes. When observing objects, the left and right eyes observe from different angles, forming visual differences between the two eyes. When various images are reflected in the brain, they produce a sense of distance and three-dimensional sense

the above principle is used to observe a three-dimensional stereoscopic image on a two-dimensional plane image

the main process flow of stereoscopic printing is: modeling design and scenery selection → stereoscopic photography → color separation and plate making → printing → grating plate fitting → finished product

I. stereoscopic photography stereoscopic printing must first take stereoscopic photos as originals. Stereoscopic photography is different from general photography. It needs to accurately calculate the layout, distance angle, center point and grating plate spacing of the subject before shooting. Stereoscopic photography methods are divided into direct method and indirect method. The direct method is a method of photographing directly through the cylindrical grating plate. The camera moves within a certain field of view to continuously photograph the subject, and the effect is good. The indirect method is to take more than two pictures from a predetermined position, and then correctly combine them into a space. Compared with the direct method, the three-dimensional effect is good, but it is more cumbersome. Generally, it is not used

II. Color separation and plate making: a four-color printing plate is made by color separation and addition of the negative film of the stereogram. The plate making method is basically the same as the color separation and plate making process of lithography. In addition to manual revision, which is more demanding and difficult than that of ordinary printing, the cylindrical grating plate can quickly convert the collected experimental data into image information for amplification. Therefore, it is necessary to use a thin screen. At present, 120 lines/cm is usually used, which has no point interference and has the best effect. The line angle just used is different from that of general printing, because the grating plate is a parallel straight line, which is very easy to produce flashing halo with the eye. Therefore, the eye angle should be changed according to the grid spacing of the grating plate, especially to avoid 45 ° and 90 °

III. the printing process of stereoscopic printing is roughly the same as that of general printing. The accuracy of nesting rules is required to be high, and the error is generally no more than 0.01 mm. Otherwise, the clarity and stereoscopic sense of the image will be affected. Therefore, the paper used should also be coated paper with good texture

IV. grating plate fitting forming the fitting forming of cylindrical mirror grating plate and printed matter is the last key process of stereoscopic printing, which is directly related to the quality of stereoscopic pictures. The processing method is to install the grating mold on the injection molding machine, heat and dissolve the highly transparent thermoplastic material, press out the cylindrical grating plate, and at the same time, dissolve the printed matter with bright glue on the back of the grating plate. The grating lines must be accurately aligned with the corresponding lines on the printed matter. The distance between the cylindrical mirrors is 0.6 mm. The concave convex surface formed divides the image into countless pixels at an equal distance. The cylindrical mirror grating plate has 48 concave and convex surfaces per centimeter, and there are 8 pixels below each. The grating plays the role of mapping the pixels into the left and right eyes respectively, so you can see the stereoscopic image. Due to the different viewing angles of the left and right eyes, the corresponding images can be seen. The test results can be combined with the data situation output in Excel format to produce a three-dimensional sense

(II) foaming printing

foaming printing is a kind of printing process in which a special microsphere foaming ink is printed on the printing material. After it is heated in the drying channel, the ink is heated to foam and bulge, cooled and solidified into a floating text or pattern

the foaming agent in foaming ink is different, so the printing process used is also different, which can be divided into two processes: microsphere foaming and groove bottom foaming

1. Microspheres are the main component of microspheres foaming ink. They are synthesized from resin. They are spheres with a diameter of 5 ~ 80 microns and filled with low boiling point solvents. After the sphere is heated, the low boiling point solvent in the sphere vaporizes to increase the volume of the microspheres by 5 ~ 30 times. After the microspheres foaming ink is printed on the substrate, it is heated to 130 ℃ through the drying channel. Within a few seconds, the microspheres in the ink expand to form numerous small bubbles, making the ink layer form a convex shape

the silk printing method can be used for the foaming printing of microspheres, which can be heated and foamed after drying at low temperature

II. The foaming printing ink at the bottom of the ditch is mainly based on PVC resin, which dissolves the foaming agent in the liquid polymer. When the ink is heated, the foaming agent vaporizes, forming countless tiny pores in the ink layer to form a raised image. The foaming printing process at the bottom of the groove is relatively complex. When the paste ink is brushed and printed on the substrate, it can be rolled on the printing roller, embossing roller or embossing roller at the bottom of the groove, which can produce different shapes of convex patterns. This kind of foaming printing product has very fine pores, luster, light and soft, soft color, and good wear-resistant, pressure resistant and water-resistant characteristics. The height of pattern embossing depends on the pattern depth of the embossing roller

foaming printing has great practical value and can be used for braille printing. In books and periodicals, it can be used as book cover and binding materials, and can also print maps, which has a three-dimensional sense. On the packaging and decoration materials, a layer of artificial leather like film can be formed, which can be comparable with natural leather. The wallpaper made of embossing at the bottom of the ditch is a kind of cheap and good architectural decoration materials

(III) perfume printing

perfume printing is a kind of printing with special fragrance to increase the attraction to printing

at first, perfume was added to the printing ink for printing, or printed on paper with good absorption performance, and then printed or coated with transparent perfume ink. This method can not seal the perfume on the printing surface, and the fragrance will be very weak after 10 days; In addition, when printing, the fragrance is very strong. It is not suitable for human body to absorb this kind of air for a long time, and the perfume is also wasted. In order to keep the fragrance on the printed matter for a long time, it was invented in the early 1970s to seal the fragrance in the micro colloidal particles, and the colloidal particles were added to the ink for printing. When the rough measurement of cable fault entered a new stage, the fragrance was gradually released when the colloidal particles were damaged. The direct diameter of the micro colloidal particles was 10 ~ 30 microns, and the film thickness of the colloidal particles was about 1 micron. The film layer could keep the fragrance for a long time, and the fragrance would not be released during the operation. Generally, one year after printing, The fragrance remains unchanged. The manufacturing methods of micro colloidal particles include chemical, physicochemical and mechanical methods. Micro colloidal particles and organic solvents will penetrate through the film layer and dissolve the fragrance. Therefore, water-based ink must be used for fragrance printing. When using water-based ink, the moisture must be controlled. The smaller the permeability of the colloidal particles in the dry state, the greater the wetting. The drying of the water-based ink is slow. Therefore, a vacuum dryer should be used to reduce the leakage of the fragrance from the particles

the spice printing methods can be hole printing and photographical intaglio printing. The hole printing method is the simplest. The problems of hole printing are slow speed and poor nesting, which is suitable for printing small areas of printed matter. The Photographical gravure printing method is used. Because the water-based perfume gravure printing ink contains 10 ~ 30 μ m colloidal particles, it is easy to scrape off the ink of the graphic part during ink scraping, and it is also easy to damage the colloidal particles during ink scraping and embossing. The key lies in the flat pressing resistance of the colloidal particles. If it can reach 10 kg, it can meet the printing requirements

perfume printing is mainly used for packaging and decoration printing. The same fragrance as the food inside is printed on the food packaging. Various perfume and fragrances are printed on the cosmetics. Some flower fragrance is printed on the general instructions, postcards, calendars and New Year cards to promote the sale of goods

(IV) magnetic printing

magnetic printing is a method of printing with magnetic ink mixed with iron oxide powder. Magnetic printing is a unique recording medium produced by the combination of recording technology and printing technology. Its characteristic is that data can be written and read on the magnetic card, and words, patterns and photos can be seen visually

magnetic printed matter is formed by applying a magnetic layer on a paper or plastic sheet base, printing words or patterns on other parts, and displaying visual information corresponding to the service conditions

the film base of magnetic printing requires moderate toughness, uniform thickness, smooth surface, not easy to stretch or curl when temperature and humidity change, good water resistance and corrosion resistance, good printing and processing adaptability and low price. Commonly used materials include offset paper, coating paper, resin impregnated paper, PVC, pet and other plastic sheet substrates and their composites, with a thickness of 150 ~ 800 microns

the requirements for magnetic powder are large magnetic saturation, uniform particle size, good dispersion, stability and long aging. Commonly used are magnetite hematite and iron oxide attached to drill iron. Magnetic ink is composed of magnetic powder pigment, binder, desiccant, antioxidant, wetting agent and other additives. Add carbon black to black ink and other color pigments to color ink to obtain color

magnetic printing adopts silk screen printing or offset printing to obtain ribbon or graphic magnetic layer, which can form magnetic tape at the necessary place of the card, thus reducing the cost. The content of magnetic pigment in magnetic ink, the magnetism of PLA polyol as biological raw material of polyurethane, and the thickness of ink film after printing affect the magnetism

after the magnetic printing is printed, the transparent PVC sheets are laminated on both sides, pressed with a hot press, and die cut according to the specified size. In order to prevent forgery and tampering, magnetic printing has higher and higher security. Therefore, special materials or technologies are used in magnetic materials, printing and processing methods. For example, special plate making technologies and inks are used in printing, including fluorescent inks, thermal color changing inks, infrared absorbing inks, as well as topographical printing, microfilm printing, rainbow holography and other measures to prevent forgery

magnetic printing materials are widely used in finance, credit, communication, office and production management

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