Application of CTP technology in Flexo label print

The application of CTP technology in the field of flexographic label printing in China

with China's entry into the WTO, the pace of opening to the outside world has been further accelerated, and foreign-funded enterprises continue to pour in. More than half of the world's top 500 enterprises have invested and built factories in China. China has become the world's manufacturing factory on the spot, and the packaging and printing industry as an auxiliary service has also made great progress. In recent years, there has been a new trend in the field of labels. Narrow width UV flexographic printing is increasingly used in label printing

first, the current situation and development trend of label printing in China

due to the late start of label printing industry in China, there are more small and medium-sized printing plants and less specialized large printing plants; In recent years, due to the entry of foreign-funded enterprises and the optimistic attitude of domestic minlei enterprises towards this industry, the flexible label printing market has achieved considerable development in recent years. China, as a large hoop production country, is also the country with the greatest potential for label printing. In the future, label printing will develop in many aspects, and label printing plants with various business scopes and processing types have their own development space. In particular, the number of UV flexographic printing in the field of label printing will increase rapidly, the market share and quality level of domestic equipment will also be greatly improved, and the market share of self-adhesive labels using flexographic printing is growing rapidly. The rapid development of plate making technology, especially the application of CTP laser direct plate making technology, has made the supporting services in the flexo printing market more perfect, the quality greatly improved and stabilized, and the label printing market more standardized. Flexo printing self-adhesive labels is the future development direction

II. Introduction and advantages of label flexo direct plate making technology

ctp technology is not a new technology in foreign developed countries. As early as a few years ago, it has been highly popular in the European and American markets. Due to the late start of this industry in China, it is still in the stage of new technology promotion and application. Practical application has proved that computer direct flexographic plate making is a very effective plate making method, which not only improves the process quality, but also brings many advantages to the printing process, such as more convenient setting of the printing machine, less plate cleaning times, and higher consistency of the whole printing quality. In addition, with digital flexo, label printing, which was originally required to be completed by offset printing or gravure printing, can now be completed by flexo printing

the main difference between traditional flexo and laser flexo is that during the production of laser flexo, a black laser photosensitive layer is added to the surface of the flexo, and the main function of the black film is to replace the film in the traditional flexo plate making process. The composition of digital flexo is shown in Figure 1. The traditional production of flexo is to transfer the image data to a Phototypesetter, and then produce the film of flexo. In laser flexo plate making, the plates are directly placed on the flexo CTP plate making machine, and the image data are transmitted to the laser one by one. The laser emitted by the laser ablates the black film, making it volatilize, so as to form the desired image on the plate surface, and then remove the plate from the plate making machine for exposure and development. In addition to sex, this is crucial in the process of controlling printing and completing the final printed matter

in addition to the role of the laser sensitive black film in blocking UV light, the UV exposure when making laser flexo is the same as that of the traditional flexo plate, and the subsequent development is also the same as that of the traditional plate making. In the process of UV exposure and development, the purpose and function of each step are the same, but there are some subtle differences that we need to pay attention to. Figure 2 shows the outline of laser flexo points and traditional flexo points. The outline of laser flexo points is sharper than traditional flexo points. It is these sharp points that improve the quality and performance of flexo, eliminate the film, the accuracy of imaging technology ensures the consistency of printing plate quality, and improve the quality. More importantly, we can control the whole process through data information through data and standardization

laser flexo plate making technology requires an external drum structure and multi beam laser imaging head, which can accurately and repeatedly ablate and volatilize the black film. This is illustrated by Cleo's THERMOFLEX THERMOFLEX flexo direct plate making machine, which adopts multi beam laser head imaging technology and uses laser diodes as laser light sources; These laser heads have different models. According to the needs of users, the maximum laser beam can reach 64. All flexo CTP suppliers now tend to adopt multi laser beam technology. Image quality and repeatability are also directly related to the ability of each laser to completely remove the photosensitive black film. The main purpose of laser imaging is to ensure the complete removal of black film. The equipment providing Gaussian laser beam has irregular energy distribution, so the accuracy and consistency of imaging are limited. Cleo's thermo God flexo direct plate making machine uses multi beam laser diodes, and the technology used can provide continuous energy distribution, so the imaging has high accuracy and consistency

in traditional flexographic printing, the biggest problem is that the point expansion is too serious, so it is difficult to show points below 5%, and the middle and dark layers are also easy to lose. At the same time, overprint is also difficult due to the ductility of flexographic plates. In view of the above problems, thermal direct plate making technology makes the quality of flexo printing close to offset printing through various technical means, and the most important thing is to greatly improve the quality of plate making

because the laser flexo plate making technology is that the laser is exposed and imaged directly on the carbon mask layer, there is no need for film, and there is no need to vacuum when making Japanese and Western plates. Compared with traditional flexo plate making, it has the following advantages

1. When printing, it can reproduce points from 2% to 98%. Because the pressure bearing area of large points is large, the point expansion is much less than that of small points. In digital flexo, because the height of small points is lower than that of large points, the point expansion of small points can be effectively controlled

2. Stably reproduce the intermediate point level

3. Because the traditional film process is omitted, the relative cost is lower and the efficiency is higher

4. The tensile force, tensile strength, elongation after fracture, yield strength and other performance test details of metal materials can be accurately measured in high light and dark tone, and the flat and gradual changes are very flexible

5. It also needs UV printing machine and plate punching machine. Customers can adjust the existing equipment of folding resistant span households at will, and the investment will not be wasted

6. When printing, laser flexo always contacts the substrate material first at the center point, while traditional flexo contacts the substrate material first at the edge of the point, so it is easy to cause hollow points. Laser flexo does not have this problem

III. application of flexographic direct plate making technology in the field of flexographic labels in China

compared with high-end flexographic label products in developed countries in Europe and the United States, the printing quality in China is much inferior. During the druba exhibition, the author led the domestic industry personnel to visit a well-known flexographic plate making company in Hamburg, Germany. This company mainly focuses on high-quality flexographic label plate making, and also makes some high-quality flexographic color box packaging plates. This company, which even has only more than 40 business logistics personnel, has an annual CTP flexographic plate making volume of more than 15000 square meters. Its total plate making volume and quality are inferior to those who visit the industry in China. Why do some users of domestic flexo printing inadvertently use the microcomputer equipped with the experimental machine as an office computer, and the label can't print a print of comparable offset quality as abroad? It is not that the quality of flexo printing machine is not good, the main problem lies in the production of flexo printing plate. In foreign countries, high-quality flexographic plates are almost all made directly by flexographic printing, and the process has been very mature. In China, the technology is still in the promotion stage, and there are still many problems to be solved

the main problem faced by the domestic promotion of flexo direct plate making technology is the price. Whether it is plate making equipment, proofing system or digital flexo plate, its price is higher than that of ordinary flexo plate making. However, digital plate making saves the processing processes of film, development and fixing, all kinds of chemicals, places for storing film and vacuum operation procedures of film and printing plate when printing, which saves a certain amount of cost, and the plate making efficiency and printing quality are unmatched by ordinary printing plates. One of the main reasons why digital flexo can survive is that it can be used for high-quality flexo labels. With the improvement of the quality of digital printing plates, the economic advantages of flexographic printing will also create favorable conditions for opening up new markets. At the same time, it will also provide printing plants and printing customers with more choice opportunities, so that customers can get the required prints at the lowest price and the best quality

at present, in East China, fiveorsix packaging and label plate making and printing users have adopted flexographic direct plate making technology and achieved good application results, which is a gratifying phenomenon. We look forward to the vigorous development of flexo direct plate making technology in China, and provide more final packaging label printing customers with cheaper and better quality prints

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