Two problems solved by gravure printing unit in th

Two major problems solved by gravure printing unit in flexo printing machine

people in the printing industry assume that it is not zero. It is clear that the ink used in flexo printing machine is water-based ink, which has less environmental pollution, and its packaging and printing products are beautiful and bright, especially in the food and pharmaceutical industries, the employer must print its packaging by flexo printing process. Due to the advantages of the flexographic press in the above two aspects, it is crowding out the market share of offset printing with Tg of about 60 ℃, and competing with gravure printing for its fast plate making. However, the printing method used by the flexographic press determines that its ink carrying capacity is lower than that of gravure printing and silk screen printing. Although the quality is significantly better than offset printing when printing large solid map color blocks, when printing gold and silver ink, due to insufficient ink volume, the print is dim and lusterless, which cannot be compared with gravure printing

1 solves the quality requirements when printing gold and silver ink

Yunnan Dali Yixiang company imported the flexographic printing machine of Canada yajiafa company to print cigarette tipping paper. Due to the need to use gold ink to print continuous single gold line or double gold line on cigarette tipping paper, and print gold words next to the gold line, but flexo printing has been unable to compare with gravure printing in terms of gold brightness for a long time. Due to the thin ink layer, the metallic luster of the printed gold ink is not strong and black. Unable to meet the product quality requirements, we have to add gravure printing units to the flexographic press to print gold

our company undertook this research and manufacturing task. Generally, it is not very complicated to add a gravure printing unit to the flexographic press, but because it is a domestic enterprise that adds a gravure printing unit to the imported equipment, there are several technical problems to be solved: the original machine structure and relative position cannot be disassembled and changed, and the unit can only be added in the space between the units; The original power cannot be used for the increased unit power, and the AC servo motor can only be used to realize the shaftless synchronous rotation; The gravure printing group shall be synchronized with the printing of the original unit, and shall also be equipped with automatic version matching function

because the flexographic press stops during normal operation, the main machine does not drive after pressure release, and only the ceramic ink transfer roller is inking; The printing operation can be carried out only when the phase of each printing plate remains unchanged during the secondary pressing. When the gravure press is out of press in the whole system, the gravure must rotate slowly to moisten the plate. Although the gravure press rotates when the multi-color gravure press is out of press, it is synchronous, so when printing again, the phase of each printing plate is unchanged, and it can also enter the real-time registration. In the combined printing of flexographic press and gravure press, a procedure must be set, that is, no matter how long the operation stops, the gravure group must return to the phase before printing after moistening, so as to ensure that the registration state is not damaged by moistening

the company has processed and installed after careful planning and design, and the effect is very good after being used by Yixiang company. The company then made the same technological transformation for the natural rubber materials of Kunming color printing factory, Baoji cigarette factory and Huzhou tianwai printing enterprise, which have been dependent on imports for a long time, affecting the healthy and stable development of China's rubber industry

2 solves the needs of frosted foaming process and dark flower transfer glazing process.

the practice of installing gravure printing unit on the flexo printing machine of domestic customers has proved that gravure printing, as a supplement to flexo printing, is very necessary for printing with thicker ink layer, so gravure printing unit is added to the flexo printing machine produced by our company. In addition to the normal gravure printing process, it also solves the needs of sanding and foaming processes and the needs of dark flower transfer glazing

in terms of the current development of domestic packaging and printing, many packaging and printing have adopted sanding and foaming processes, and the latest UV varnish laser dark flower transfer process has emerged. These process requirements put forward higher process requirements for flexographic printing machines. Therefore, our technicians believe that modern flexo printing machines should not only have flexo printing functions, but also become a packaging and printing processing center integrating the functions of reverse printing, gravure printing, dark flower transfer, sanding, foaming and online bronzing. Among the functions mentioned above, gravure printing process can not only meet the needs of thick ink layer printing, but also complete several functions such as sanding, foaming and dark flower transfer printing. It is an essential workstation of flexographic press

the sanding and foaming process of packaging printing materials was first completed in the plane wire printing process. Because UV foaming ink can produce a convex effect under UV irradiation, it will produce many strange effects, so it is widely used in packaging and printing materials, especially in 1997 ~ 1998. However, because silk works under intermittent operation, its production efficiency is far from being compared with flexo printing and gravure printing, and then round silk was introduced abroad. It can be used in the silk unit of flexographic press, such as stoke in the Netherlands. In addition to the 120000 euros required for this unit, because the manufacturing cost of the round silk plate itself is very high, and it is not popularized in China, and the printing resistance of the silk plate cannot exceed 30000 revolutions, which cannot match the 1million revolutions of the flexographic plate and 10million revolutions of the gravure printing, which will also reduce the efficiency and increase the cost. Therefore, we believe that although the round silk plate is successful in technology, it is only limited to the experimental stage of technology, and the large-scale and high-efficiency popularization in the printing industry is still far away

our company has made a bold exploration in the use of gravure frosting and foaming ink. The gravure foaming operation supporting Huzhou tianwai enterprise has been successful. The company has also conducted a medium degree frosting foaming test with gravure with high ink carrying capacity in the factory, and has also achieved success. Through experiments, we believe that it is feasible to use gravure printing machine for frosted foaming printing, micro foaming and medium foaming. Properly adjusting the UV intensity can also match the speed of flexographic printing, which is an integral part of the construction project of China's standard high-speed railway and key equipment research and development experiment project of high-speed railway (approved by the national development and Reform Commission). The service life of gravure is long, and it matches with other printing plate groups, which does not affect the printing efficiency. At the same time, it greatly simplifies the foaming process and greatly reduces the cost. Therefore, in addition to normal printing with a large amount of ink, the gravure group on the flexographic press can also be used for frosting foaming operation by replacing the heater. This method has better applicability than the round wire process, and is worth popularizing

Shenzhen Weicheng industry took the lead in launching the hidden flower transfer process in China. In this process, when polishing the printed matter, the pet coiled material with laser pattern embossed is directly coated on the UN dried UV varnish. Because the PET film is transparent and has little effect on the penetration of UV light, the PET film is peeled off after UV drying. The surface of the dried printed matter forms dark flowers due to the transfer effect of laser indentation, which has the function of beautifying the packaging and effective anti-counterfeiting for a certain period of time. If the laser film uncoiling and rewinding functions are added before and after the gravure unit of the flexographic press, and the UV drying device with appropriate strength is added at the same time, this function can be increased

to sum up, the addition of gravure printing unit to modern flexo printing unit can make the product applicable to different process requirements and achieve the expected quality effect of the product. Our company will launch a newly designed flexographic printing machine in the middle of 2004. The machine adopts a two-stage closed-loop tension control system, which makes the registration more accurate, and the lifting speed returns quickly. Each workstation can be changed quickly, so that the various ways of modern printing operations such as flexo printing, gravure printing, dark flower transfer, sanding, foaming, reverse printing, circular pressing and bronzing can be freely realized in the new flexo printing machine. The whole machine adopts modular design and wireless remote control, making it a processing center for packaging and printing materials. Gravure printing undertakes several of these functions and is one of the necessary stations in the flexo printing unit