Flexo printing plus new technology
in the history of more than 100 years of modern printing, the addition technology has been added from optics to electronic addition 30 ~ 40 years ago, the size of dots has changed from coarse dots to fine dots, and the distribution of dots has changed from regular to irregular random distribution. All these technical improvements and reforms have eliminated moire, made the tone more flat, and expanded the range of printing reproduction. In a word, the purpose is to improve the printing quality. However, corresponding to this, we must develop devices that are compatible with higher recording speed and resolution. However, unexpected changes often occur in the development of things. As a result of reverse thinking, some famous businesses have been committed to developing the addition technology of making high-line numbers with low resolution. It can be seen from previous experience that in order to reproduce a certain tone in low resolution equipment, the necessary resolution force should be more than 10 times the number of lines (for example, the output resolution force of 100 lines should be more than 1000dpi, while the output resolution force of 150 ~ 175 lines generally must be between 2000 ~ 3000dpi). Now the intellidotspeedscreen plus technology newly launched by optionicsinternational Corporation and turboscreen developed by saiangel Asia Pacific Co., Ltd. can achieve high-speed lines with low resolution output (for example, 150 ~ 175 lines can be achieved with 1000dpi). Among them, sambascreen launched by Barco and hybridscreen developed by PPC are the most practical ones for flexo printing. Both of them are the latest addition methods specially used in flexo printing. For flexo printing, because the dots in the highlight part are not easy to print, the highlight tone reproduction is not complete. Using the above two addition methods, this problem can be completely improved
samba and hybrid are both a mixed addition method of AM/FM. Because the point position of the traditional screen determines the structure of its definition, the point in the middle of the adjustment part is expanded, and the new capacity of the cultural paper industry is almost zero, which is small, while the effect of random points in the highlight part is better, because the point position of the highlight part needs to be optimized, and the smallest point should ensure the perfect match between the grain and the screen, and the random point in the highlight and dark part is expanded slightly. Therefore, this screen combined with am and FM is suitable for the characteristics of flexo printing. The difference between the two is that sambascreen adopts FM frequency modulation in the high light part and dark part, while the traditional am amplitude modulation is used in the middle tone. The smooth transition from random point to traditional point (5% - 10%, from 90% - 95%) is automatically calculated digitally, rather than simply the mixture of their respective density interpolation. Hybridscreen addition is the addition that FM and am coincide and are used in the whole density range. With the above two kinds of additive printing, the smaller and more stable dot expansion means that the difference between the stroke value of the cross arm of flexo printing and the straight steel ruler can clearly reproduce the small dots in the highlight part, and the level is richer
ink transfer system and the new generation of corrugated roller
in order to stably supply low viscosity (5 ~ 500) ink to flexographic plates, the corrugated roller ink transfer system is an ideal printing method. Usually, the corrugated roller is carved on the ceramic magnetic surface. According to the different holes, it has cubic shape, cone shape, oblique line shape and so on. According to the shape, number of lines, depth, etc., calculate the ink supply and ink retention. High quality ceramic magnetic roller has strong wear resistance. From its processing point of view, laser engraving adopts conventional carbon dioxide laser engraving method and YAG laser engraving method with multiple impacts. The latter is the highest preparation method of hole engraving at present. Each hole is shaped by laser beam twice, the first blow is carved, and the second blow increases the hole depth. The double-click formed hole wall is smooth, and the ink transfer is fast and uniform, ensuring the printing quality. In terms of its composition, there are two methods for the inking system of the textured roller, one is the roller alignment method with a very slow circumferential speed, and the other is the scraper method of scraping the ink with a scraper like gravure printing. There are clockwise and counterclockwise methods for installing the scraper of the corrugated roller. Recently, the ink groove doctor blade method has been introduced. Two doctor blades, positive and negative, not only have good accuracy, but also can maintain the ink volume. Due to the use of ink tank, it can inhibit the dispersion and evaporation of ink, and supply ink stably according to the printing speed
in recent years, a newly developed graphite carbon fiber material in the aerospace industry is popular in the manufacturing industry because of its light and hard properties. The carbon fiber roll core invented in 1994 was soon applied to the wrinkle roll core of flexo printing, becoming a new generation of more advantageous wrinkle roll. Although the steel roll has long been the most preferred material for the corrugated roll because of its physical properties, such as strength, machinability and durability, the corrugated roll made of this carbon fiber roll core instead of the traditional steel roll core has twice the strength and 1/10 the weight of the steel roll
the corrugated roller with carbon fiber roll core has the following advantages after trial:
1 Because the carbon fiber corrugated roll is particularly light, it is easy to handle in roll changing, reducing the labor force
2. In the process of changing the roll, the carbon fiber corrugated roll is not easy to be damaged, which can save a lot of money due to the need to re engrave the new roll
3. In the driving part of the printing machine, the total weight of the carbon fiber corrugated roller is 1/10 of the weight of the steel roller, which is conducive to reducing the friction between the rollers and improving the service life of the corrugated roller, thus reducing the downtime and improving the productivity
when the speed 3 of the printing press and the calculation accuracy of the total average friction force reach 3000 pieces/hour, the difference between the steel roll and the carbon fiber corrugated roll is even more obvious. The steel core corrugated roll has a great jump, and it is not able to maintain the field image in its central part, while the carbon fiber corrugated roll can maintain the field image on the whole roll surface. Although carbon fiber corrugated roller is light and hard, its offset is less than 1/10 of that of steel core roller. The biggest advantage of this feature greatly improves the printing quality of large flexographic printing machines
statement: improving the whole chain of "principle discussion, technology development, engineering development, utilization demonstration" of independent innovation of scientific instruments. The development and utilization evaluation of testing instruments has become a new content of the expansion of testing effectiveness industry
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