The most popular gravure printing cigarette packag

2022-07-30
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Gravure printing cigarette packs comprehensively consider various process parameters

gravure printing accounts for nearly 30% of the cigarette pack printing market because of its high saturation, high contrast, high brightness, strong consistency and high printing plate resistance. The gravure cigarette package printing process is relatively mature. The reason why it is relatively mature is that firstly, there are many kinds of gravure printing inks and papers, and the plate making manufacturers have not developed a complete set of gray balance parameters and printing characteristic curves for each printing manufacturer; Second, plate making factories often evaluate the plate making quality by proofing samples, but the actual printing conditions are quite different from the proofing process conditions. Due to the fact that gravure cigarette packs are mostly on the ground, color blocks and lines, the requirements for color management in plate making are relatively lax, and the control of gravure printing process is easier than offset printing and flexo printing. The in-depth understanding of the gravure plate making process by the cigarette package printing plant will help to improve the success rate of the cigarette plate. Specifically:

1 Gravure plates express the levels through the size and depth of holes. In order to improve the ink transfer rate, field plates usually use 37 ° flattened diamond points. Only when the angle of the engraving needle is 1 can intensive energy conversion be carried out by 30 °, and the number of lines added is 70 ~ 75 lines/cm; When carving small characters, the angle of the carving needle is 110 °, and the number of lines added is 80 lines/cm

artificial organs use plastic 2 For field, small (anti white) text or products with the same color of lighter lines, if you want to ensure the hole depth of the field during plate making, the clarity of the text will be affected; When printing, the angle of the scraper is also different for the field and point. The scraper angle is large, the text and point are clear, but the field ink layer is thin and the gloss is poor. On the contrary, the scraper angle is small, the text and point are fuzzy, and the field ink layer is thick and the gloss is high; In addition, for the layered version, in order to improve the ink transfer rate, a large proportion of slow drying agent is used, while a large proportion of fast drying agent is used for field printing. Therefore, separate plate making should be considered

3. After the printing plate is made, carefully check its concentricity, balance, increasing amount, etc., so as not to affect the printing overprint. Cigarette packs have requirements for friction resistance and high temperature resistance of printing ink (no color fading for 0.5 seconds at 150 ~ 160 ° C). There are usually two solutions, one is to choose high temperature resistant ink (nitrocellulose resin has become the preferred binder because it meets this requirement and is cheap); Second, high temperature resistant varnish is selected, and water-based varnish is often used for cigarette package printing (compared with solvent based varnish, the amount of water-based varnish is small, and the residual taste of ethanol solvent is much lighter than that of ethyl acetate)

at the same time, gravure printing ink should have high fluidity, good scraping characteristics, good transfer and dryness. The use of solvents in printing is to adjust the viscosity and dryness of the ink. Due to the different solubility and volatilization rate of various solvents (ethyl acetate volatilization rate> toluene> ethanol> isopropanol), mixed solvents are often used. During printing, as the solvent volatilizes continuously, the balance of the mixed solvent is broken. At this time, printing problems are easy to occur, and new solvents need to be added continuously. In addition, the requirements for solvent residue in cigarette packs are usually not higher than 30mg/m2. For the failures in the gravure printing of cigarette packets, the user must also understand these problems, and comprehensively consider the factors such as the same ink, printing plate, printing machine, doctor blade, printing environment, solvent, paper, etc., and analyze the specific problems

reprinted from: Guangdong Printing

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