Current situation and development direction of hea

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The current situation and development direction of domestic thermal CTP

with the increasing development of digitalization and networking technology, prepress technology is springing up, showing infinite vitality. It can be seen that laser, infrared laser, violet laser, CTCP and inkjet technology are emerging in endlessly; A hundred schools of thought contend in silver salt version, thermal version and photopolymer version. With the passage of time, the debate between silver salt version and thermal version seems to have lost its necessity. The comparison between thermal technology and violet laser technology has attracted more and more attention. There is no doubt that thermal CTP technology has been proved to be the most successful plate making technology, and has been selected by printers all over the world. In the market, there are more than 15 kinds of thermal plates for users (see the attached table, performance list of some thermal CTP plates). According to imaging technology and washing equipment, there are negative plates that need to be preheated, positive plates that need not be preheated, plates that need not be processed, etc. This colorful coexistence of various plates is of great benefit to users. Because more choices mean lower prices, more stable supply, better plate characteristics and better services. Since China introduced the first thermal plate making machine (liaomei, trendsetter3244) in 1999, it has developed rapidly. According to the author's incomplete statistics, the number of thermal plate making machines has exceeded 30, most of which were installed after the Fifth Beijing International Printing Exhibition in May 2001, which has a great relationship with the exhibition of Huaguang brand TN thermal plate at this exhibition and its official introduction to the market. Due to the light weight and high elastic strength of special glass fibers, the versions currently used in China include Huaguang brand, KPG ditp, TN thermal version and Electra 830. From the perspective of plate making process, more than 90% of the plate punching machines are equipped with preheating equipment, and the plates used are negative plates that need preheating treatment, such as TN and ditp. The other 10% use positive plates that do not need preheating. This paper tries to analyze the current situation and development direction from the perspective of technology

first, the negative plate to be preheated is the mainstream of current thermal CTP technology. The concept of thermal negative plate and positive plate follows the classification method of Conventional PS plate, that is, the coating exposed part of the plate that is ink friendly (image) is negative plate, and the coating exposed part that is hydrophilic (non image) is positive plate. Looking at the thermal CTP plates on the market, it is not difficult to see that the currently preheated thermal negative plates can meet today's increasingly demanding printing reproduction and printing requirements, and provide durable high-resolution images. This is because the preheating thermosensitive negative plate generates images through chemical reaction in the thermosensitive coating containing catalyst through infrared energy, and further crosslinks and solidifies during the preheating process of washing. Its advantages are: (1) extremely high resolution; (2) Great flushing tolerance; (3) High stability and printing resistance; (4) The non image area can be completely removed, avoiding the dirt caused by the plate edge and the plate holder of the plate making machine; (5) The structure of the plate is relatively simple, it is easy to control the quality in production, and the stability of the product is good. There are two disadvantages of this plate: (1) the development process is complex and needs preheating, which is not suitable for the development requirements of the printing industry pursuing high speed; (2) It needs to be operated under the yellow light. The author believes that the above two unfavorable factors are acceptable for the current printing level. The development of printing industry is to strive for high speed while pursuing high quality and low consumption. CTP technology is developed under this situation. Compared with the traditional process, the thermal CTP technology is undoubtedly a technological revolution in terms of quality, cost and speed. Compared with the plate without preheating, the preheating time of 1 minute longer for the preheated thermal plate should be acceptable. With the technological progress of plate making equipment (high-power, double laser head), the improvement of developing equipment (integrated washing machine), the improvement of plate sensitivity (reduction of preheating temperature, shortening of time), etc., the plate making speed of preheated CTP plate can be comparable to that of CTP of any technology, which can not only meet the needs of commercial printing, but also meet the requirements of high timeliness newspaper industry. In May, 2001, the thermalnews newspaper plate exhibited by KPG company in the Fifth Beijing International Printing Exhibition is a kind of negative thermal version that needs to be preheated. This kind of plate, together with creos' latest trendsetter news system of Citex company if the oil pipe breaks, is completely suitable for the needs of the newspaper industry, and has the advantages of reducing consumables, simple washing, high printing resistance (200000 prints of the non baked version), etc. In terms of the operating environment, for most printers, especially users who are used to using color separation film and PS version, they often want to operate CTP plate in the previously familiar environment, so the operation under the yellow light of negative plate that needs to be preheated should be accepted. It is worth noting that users have paid more attention to the plate than to CTP technology and equipment. The price of CTP plate, printing and coating, safe operation light, printing resistance, resolution, ease of operation and so on are the key issues affecting the development of CTP technology. TN thermal plate is the only localized plate in the domestic market. With low price, excellent performance and perfect after-sales service, it has been recognized by domestic users, and some products have been exported to foreign countries. In addition, TND developer and tndm860 plate punching machine supporting TN plate have also been put on the market, providing users with as perfect a technological process as possible. We believe that the thermosensitive CTP plates that need to be preheated in recent years will have greater development in China. 2、 The non preheated positive plate needs to be further stabilized and improved. From the perspective of plate making process, the non preheated positive plate has more development potential than the preheated negative plate. This kind of plate uses the energy of infrared ray to promote the chemical or physical changes of the plate coating, so that the decomposition speed of the image area is higher than that of the non image area, and the image area is removed through development, so as to form a printing plate. It has the following advantages: (1) without preheating, the development process is close to the traditional positive PS version, which is easy for users to accept; (2) Plate making time is short, which meets the needs of today's printing; (3) It can be operated in the open room, which is conducive to environmental protection and the health of operators. Due to technical reasons, there are still many disadvantages: (1) the resolution is not high. When outputting high resolution, some points near the non image area will be removed according to the reaction principle; (2) The tolerance of development is small, and the difference of dissolution rate between image area and non image area in developer is small; (3) The printing resistance is low, and there is no auxiliary reaction to solidify the image in the process of image generation; (4) The edge of the plate and the dirt caused by manual plate delivery may cause residual dirt on the printed page; (5) Short storage period, which is caused by poor thermal stability; (6) The structure and production process of plates are complex, which is easy to cause poor stability of products. Plates are generally completed by multi-layer coating, and special treatment is required before leaving the factory. In terms of the domestic plate market, there are few types of non preheating positive plates. Only two foreign companies have this product, and similar products of other companies are basically not promoted to the Chinese market. This is not only related to the sales strategy of each company, but also related to the shortage of plates mentioned above. The author understands that some users who currently use the positive version have deliberately switched to the negative version. We are looking forward to the improvement of the performance of positive plates and the listing of such domestic plates. Nowadays, improving the performance of the positive plate has become the direction of efforts of major plate production companies. The three-dimensional three-dimensional structure that realizes printing, such as domestic erjiao and Beijing Normal University, is actively accelerating the process of shape preserving units in the process of high temperature and high vacuum crosslinking. With the improvement of the performance of positive plates, more and more users will use positive plates. 3、 Non processing thermal plates are the development direction of thermal technology. Preheating negative thermal plates and non preheating positive thermal plates also need chemical development processing in the process of plate making. In terms of the development of technology, it is not a perfect result. Non processing plates have attracted great attention of the printing industry because they do not need development, open room operation, are conducive to environmental protection, and can be realized in machine-made plates, and have been put into development and research. At present, products have come out, but most of them do not have the ability to commercialize. With the further maturity of technology and the improvement of plate making equipment, the heat sensitive technology without treatment is bound to become the replacement product of CTP. Generally speaking, the heat sensitive plate without treatment is made by using thermal ablation, thermally induced phase change and other technologies. The imaging principle of thermal ablation technology is to use high-power laser to chemically change one to several layers of coating on polyester or metal plate base, that is, ablation. After removing the ablation products, a printing plate can be formed without development treatment. This technology has the following advantages: (1) no development processing is required, and the plate making process is reduced; (2) It is a printing plate that can realize the characteristics of "water free Printing CTP"; (3) It can be applied in the field of machine-made edition. At present, most Di printing machines use this technology. There are still some shortcomings in this technology: (1) the residue generated in the imaging process of the plate will affect the transmission of the laser beam or stick to the printing plate, and ultimately affect the printing quality. (2) The process of plate is complex, and special metal deposition device is needed to realize multi-layer coating; (3) The price of plate is high, which is difficult for users to accept; (4) Plate making equipment has poor versatility, which requires not only large laser power, but also a residue collection system. At present, the market of Di printing machine is not very good, which is largely related to the lack of thermal ablation technology. Major plate production companies are improving the shortcomings of thermal ablation technology through various technologies, such as changing the composition of plates, using new reaction mechanisms, new imaging materials, etc. The development prospect of thermal ablation technology is not very clear. At present, only products of companies such as Agfa and pressek have been preliminarily recognized in the market. Thermal ablation technology realizes the wet free development process, but there is also a dry process - the process of removing residues, which is not a real untreated plate in a sense. At drupa '2000 printing exhibition, Asahi company exhibited phase change CTP plates, which led to a new wave of research on untreated plates. The imaging principle of phase change technology is: using the plate coating under the irradiation of laser, physical or chemical changes occur, which causes the hydrophilic and lipophilic properties of the plate to change, that is, the exposed part changes from hydrophilic phase to lipophilic phase (negative image) or lipophilic phase to hydrophilic phase (positive image). The exposed plate can be directly printed on the machine without any treatment. Nowadays, all major companies focus on the research of thermal phase change ctp1, carefully browsing the operating instructions and the related operation, use and protection technology of the experimental machine. In the past two years, dozens of relevant patents have appeared one after another. The rapid development speed and wide application of technology are exciting. Domestic units, such as second glue and Printing Institute, have also begun to study this aspect. Although the product is still in the beta test stage, and there is a certain distance from commercialization, in the near future, the untreated plate will certainly become the mainstream of the market, and the digital printing machine based on this technology will replace the existing printing machine. Conclusion CTP technology is a revolutionary new technology in the field of printing, which will replace the traditional printing process. From the perspective of the world, the development is extremely uneven. Europe, America, Japan and other countries are developing rapidly. Although China has made some progress recently (more than 60 CTP plate making machines have been installed), the development speed is far behind that of Europe, America, Japan and other developed countries. At present, the obstacles restricting the development speed still come from the price of plates and equipment. We are looking forward to the upgrading of thermal CTP plates and domestic silver

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