Analysis of the current situation of gravure plate

2022-08-14
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Gravure plate making and printing status analysis (III)

II. Gravure printing

gravure printing is a printing method with excellent hierarchical performance, corresponding to a variety of substrates, seamless image printing, good printing quality stability and other advantages. In Europe and the United States, publishing and printing aiming at mass production are developed as the main body, while in Japan, packaging gravure printing is popularized as the center

packaging gravure uses paper, cellophane, plastic and plastic film as printing materials, with high printing quality and a wide selection of solvents according to the type of substrate. Therefore, compared with cheap flexographic printing, packaging gravure printing has been widely popularized in Japan. Japan's national gravure synergy Association, mainly composed of professional gravure companies, has more than 200 enterprise members, most of which are packaging gravure enterprises

publishing gravure printing has made great initial investment in environmental protection equipment such as printing machines, plate making equipment and solvent recovery. In Japan, there are about 60 publishing gravure presses mainly used by large companies. Its print level expressiveness is unmatched by other printing methods

(I) publishing gravure printing

although there are sheet fed gravure printing machines for the printing of art books in publishing gravure printing, the mainstream of publishing gravure printing is the high-speed Web rotary gravure printing machine suitable for mass printing. In the world, the high-speed wide width machine aiming at large quantities and low costs has made progress, with a maximum speed of 17 meters per second and a paper roll width of mm

in Japan, although 2450mm wide equipment has been introduced, compared with Europe and the United States, Japan's publishing market is small, and it is multi variety and small batch, so the mainstream width is 1900mm. Gravure printing and offset printing compete. The existing problems are to reduce costs, improve quality and take environmental countermeasures

1. Gravure printing system

the biggest feature of publishing gravure printing machine is that it can produce Folding stickers of various sizes and pages by changing the paper web and plate cylinder diameter. Gravure printing machines produced by Aruba (Germany) and Ceruti (Italy) occupy an absolute share of the market. Japanese manufacturers such as Toshiba machinery and Seiko are also producing

paper feeding section. Due to the high-speed printing, the high-speed pasting and receiving device synchronized with the speed of the paper roll is generally used

crew department. Gravure printing is to physically transfer the ink filled in the concave part of the plate cylinder to the substrate, and each color must be dried (mainly by hot air drying). Lechal can also be used as a health tracking equipment. A variety of inks can be used and printed on a variety of substrates. Gravure printing adopts a simple direct printing method, which has good stability and consistent printing quality. Tension control and printing registration become difficult due to the long paper route

folding machine. Folding machine is a model with adjustable size and number of pages. Different from the offset press, its plate cylinder diameter is variable, so the folding machine also needs to change the folding size accordingly. The printed paper tape is cut into narrow paper tape. By changing the position of the cutter, the size of the printing head and foot can be changed. By changing the phase between the teeth on the folding roller and the folding knife, the position of the folding is changed, and the size of the incision direction is changed. At this time, change the phase of the paper cutting roller to make the folding function fold out the book posts that are afraid of needing specifications

2. Environmental protection supporting equipment

solvent recovery device: a recovery device that uses activated carbon to absorb the solvent gas generated in production. Toluene solvent is not allowed to be discharged outdoors and must be 100% recycled. The recovered solvent will be reused by the device to reduce the use cost of the solvent

3. Air conditioning equipment

like offset printing, the control of temperature and humidity is very important for the environment of gravure printing workshop, especially when the temperature and humidity change sharply, it will inevitably have a great impact on the printing registration. From the perspective of solvent concentration, indoor ventilation management of gravure printing is necessary. The solvent recovery device can limit the emission of solvent gas near the unit. Considering the difference between the exhaust volume and the air supply volume, including air conditioning, it is necessary to implement the workshop design of overall ventilation and preventing the retention of solvent gas

4. The following auxiliary equipment is indispensable for today's high-speed gravure printing machine: ① overprint control device. Without it, gravure printing cannot be carried out now. ② Ink viscosity control device. A device that measures the viscosity of ink, adjusts the amount of solvent added, and automatically adjusts the viscosity. ③ Electrostatic printing device. A device that uses static electricity to help transfer ink. It is essential for engraving gravure and high-speed gravure. ④ Quality inspection device. Now the quality requirements have been improved, and even the products printed by the rotary machine should be checked one by one. The current inspection device can not detect the failure of the doctor blade mark, which needs to be developed

5. Ink

like offset printing, gravure printing also uses four-color ink for printing. It is very different from offset printing in that toluene solvent ink with low viscosity is used, so gravure printing does not have the problems of paper fracture caused by high viscosity of ink, such as producing offset printing with carbon fiber with low cost and high performance. Due to the use of low boiling point solvents under high-speed drying conditions, high-cost solvent recovery devices and explosion-proof devices are required. The disadvantage of gravure printing inks commonly used now is the use of organic solvents. The water-based and toluene free printing ink is important for both publishing gravure and packaging gravure, but in publishing gravure printing, because only toluene solvent is used, its recovery technology has been determined, and publishing gravure printing plants generally use a device to recover the evaporated solvent while adding water during operation. In order to recover completely and prevent solvent gas from being discharged outside the workshop, it goes without saying that it must also be prevented from leaking to the workplace. Therefore, the Countermeasures of completely sealing the part using solvent and realizing the complete recovery of solvent are being launched. The biggest remaining task is to reduce costs

6. Future trends

the future development is mainly determined by the publishing market and the postal advertising market. Gravure printing for large quantities of products can give full play to its strengths, but from the current situation in Japan, we cannot think that the market will expand on the whole. Therefore, while gravure printing competes for the market with offset printing, it should aim to fully reduce the cost, so that the printed matter can achieve rich level performance and high contrast

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