Introduction to CTP technology of the hottest comp

2022-09-21
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Introduction to computer to plate (CTP) technology

Introduction to the development history of CTP technology CTP (computer to plate) technology appeared in the 1980s. This period is the initial stage of direct plate making technology research. Therefore, during this period, both the technology and the maximum weight of plate making quality lifting: 0.5T, are not very mature. In the 1990s, equipment manufacturers and printing manufacturers cooperated closely to accelerate the pace of research and development of this technology, and reached the level of maturity and industrial application during this period. As a result, 42 CTP systems were exhibited at the drupa printing exhibition in 1995. This move immediately attracted great attention from the printing industry to this technology. During, many large printing companies adopted CTP system to realize the direct plate making process, but the direct plate making machine is still very expensive during this period, which limits the use and promotion of this technology in small and medium-sized enterprises. From 1997 to 1998, the price of direct plate making machine decreased significantly, and direct plate making materials began to mature and develop, so a large number of small and medium-sized printing plants began to accept and use CTP technology. According to the situation of the printing factory, the developed machine format includes folio, 8 folio and 16 folio. According to statistics, by 1997, 65% of large printing plants (with more than 100 employees) in the United States had used CTP technology. According to the investigation of GATF, the authoritative organization of printing technology in the United States, the number of CTP systems installed and expected to be installed in the world during the period of (including the CTP systems used in newspaper printing industry, including 8 open, opposite open, and full power on): 1995, 1996, 1997, 1998, 1999, 2000, 3117216863100620021250 from this group of data, the application and popularization rate of CTP is growing at a rate of more than double every year. During the three-year period from 1995 to 1998, the growth rate was as high as 10 times. The reason why CTP system can be popularized in the user group at such an amazing speed is that in addition to its good plate making performance and the elimination of the advantages of film application, the expansion of the application scope of CTP technology is also one of the main reasons. At present, the direct plate making machine on the market can meet the needs of large format, small format printing size, single and double color printing and four-color color printing, newspaper printing and commercial printing. Therefore, it is very flexible to use. Moreover, in recent years, the development and improvement speed of plates is also very rapid. The price of CTP equipment has decreased significantly in five years, which has promoted the rise and development of the market. At present, 8 boot has been reduced from $400000 to $150000 - $200000 The power on model has also been reduced to about $400000. According to the evaluation of American public opinion, CTP is an inevitable technological revolution, which is bound to replace the Phototypesetting Technology, just like the situation that the electric extension was replaced by the Phototypesetter five years ago. In June, 1998, 11 manufacturers exhibited their CTP systems at the nexpo98 Exhibition hosted by the Newspaper Association of America. However, no influential manufacturer has introduced new laser imagesetters and related technologies. This fully shows that all manufacturers no longer hesitate about CTP technology and have entered the practical stage. Classification of CTP direct plate making machine at present, CTP direct plate making machine is generally divided into four categories: inner drum type, outer drum type, flat plate type and curve type. In these four types, the most commonly used are inner drum and outer drum; Flat type is mainly used for large format plates such as newspapers; Curvilinear form is rarely used. According to statistics, in 1997, among the 58 CTP machines provided by 29 manufacturers, there were 24 inner drum machines, 16 outer drum machines, 9 flat plate machines and 9 curve machines. In these forms, the external drum style gradually presents the mainstream trend. According to the degree of automation, the mounting method can be divided into manual and automatic. The machine with manual version is cheap, but it generally requires operation in the darkroom, so the efficiency is low; The automatic version of the equipment, high efficiency, but the price is more expensive, generally about 100000 dollars more expensive than the manual model. Moreover, the automatic equipment must use a whole box of printing plates with isolation paper when loading. The surface of the plate has a layer of anti light protective film, so it can be operated in the open room. With the help of the plate feeder, the protective film on the surface of the printing plate can be automatically peeled off to make the plate participate in plate making. The plate is fixed on the drum in two ways: full adsorption and middle adsorption, with clamps at the beginning and end. The full adsorption type has no limit on the size of the plate, while the plate used in the clip type must have a fixed size. 30% of CTP equipment is equipped with a punching device. Generally, the punching process is carried out after exposure, which can ensure the accurate positioning of the printing plate on the printing machine, reduce the pre press preparation time for the adjustment of the printing roller, and improve the printing quality, overprint and positioning accuracy. Printing size the printing plate used by CTP machine generally has a large format printing plate with a size of 66*84 inches according to the requirements of printing format and equipment; Large format printing plate, with the size of 55*67 inches; Medium format printing plate, with sizes of 41 inches, 32 inches and 22 inches; Small format printing plate, size less than 18 inches. Now the most used are medium and small format. The main suppliers of CTP equipment are mostly from the United States, as well as companies set up in the United States by Germany and Japan. The suppliers of large format equipment include Agfa, Barco, Creo, Heidelberg, Gerber, ECRM, Optronics, saiangel prepress, American screen, etc; Manufacturers of small and medium-sized formats include: printware, DuPont, etc. Providing equipment dedicated to newspapers is C. There is a product that can help mix stratolaunch. Joe ruddy, project director of stratolaunch, said that glass and nylon REO, Krause, etc. The basic working principle of CTP CTP direct plate making machine is composed of three parts: accurate and complex optical system, circuit system and mechanical system. The single original laser beam generated by the laser is divided into multiple (usually beams) extremely fine laser beams by multi-channel optical fibers or complex high-speed rotating optical beam splitting system. Each beam is modulated by the acoustooptic modulator according to the brightness and darkness of the image information in the computer, and then becomes a controlled beam. After focusing, hundreds of micro lasers are directly shot onto the surface of the printing plate for plate engraving. After scanning the plate, the latent image of the image is formed on the plate. After developing, the image information on the computer screen is restored on the printing plate for direct printing by the offset press. The diameter of each micro laser beam and the light intensity distribution shape of the beam determine the definition and resolution of the latent image formed on the printing plate. The smaller the spot of the low light beam, the closer the light intensity distribution of the beam is to the rectangle (ideal situation), the higher the definition of the latent image. The scanning accuracy depends on the mechanical and electronic control parts of the system. The number of laser microbeams determines the length of scanning time. The more the number of low light beams, the shorter the time to etch a printing plate is when the methods of measuring friction force or friction torque commonly used by friction and wear testing machines are mechanical method and electrical method. At present, the diameter of the beam has developed to 4.6 microns, which is equivalent to the printing accuracy of 600lpi. The number of beams can reach 500. The etching of a folio printing plate can be completed in 3 minutes. On the other hand, the higher the output power and energy density of the plate beam (the laser energy generated per unit area, in joules/square centimeter), the faster the etching speed is. However, too high power will also have a negative impact on shortening the working life of the laser and reducing the distribution quality of the beam. The light source of plate making machine includes: gas laser (argon ion laser 488nm, power: About 20MW); Solid state laser (FD YAG 532nm, above 100MW); Semiconductor laser (LD, infrared semiconductor laser in semiconductor laser has the advantages of low power and long life.) Direct plate making system is a comprehensive multidisciplinary technology industry, which includes precision machinery and optical technology, electronic technology, color digital image technology, computer and software technology, new printing plate and material technology, automation technology and network technology. It is another major technological revolution in the contemporary printing industry. The development trend of CTP is turbulent. From the end of the year, more than 300 patent articles have been published. In 1996, 55.3% of the 100 largest printing enterprises in the United States adopted CTP system, and 28.8% adopted color short edition digital printing system. Yangcheng Evening News in April, 1998, Agfa's flat CTP plate making machine and Fang's Optronics outer drum CTP were tried out in some sections of the "new Express". Since 1985, most newspapers in provinces and cities in Chinese Mainland and their printing plants have adopted Laser Phototypesetting and offset printing. The next technological transformation direction of these newspapers and printing houses with strong financial resources is direct plate making, color newspapers and periodicals, high-end color printing and packaging printing. It is required to expand the scanning format to folio (740*510), and the printing resistance of the plate can reach 300000 to 500000. For newspaper printing, CTP saves manpower, improves quality and reduces environmental pollution. Moreover, the streamlined and optimized process flow makes it easy to set up a continuous production line with a high degree of automation. In terms of newspapers, domestic national newspapers have a high degree of pre press digitalization and advanced technology and equipment. Compared with foreign newspapers, there is no obvious gap. The domestic newspaper industry is facing fierce competition. CTP system can save minutes of time for the whole publishing stream, so for the publication of evening newspapers in particular, the deadline can be postponed by minutes under the condition that the printing time remains unchanged, which is of great significance to the day. CTP system and technology, as a development direction of China's printing and publishing industry, has been included in the key scientific and technological projects of the national "Ninth Five Year Plan". It is a typical high-tech, high growth, high return technology intensive industry. Requirements of CTP system when using CTP system, first of all, we should pay attention to the interface technology with the front-end system, that is, the data exchange technology between color prepress processing systems and the perfection of data sharing technology of back-end equipment. For large capacity files, data exchange speed and data transmission speed are very important; Secondly, enterprises are required to establish a new set of electronic document management system and improve data storage and retrieval technology; Then, the requirements for color management technology and rip technology are also very important. Large capacity files require rip to have strong processing ability, so as to achieve efficient work efficiency. For the consistency of proofing and output, we need the participation of color management technology. When purchasing CTP, users need to make a detailed system demonstration and analysis according to their own needs before making a decision. The new technology system should not be required to match the old workflow, but should be comprehensively considered: comprehensive benefits, maintenance workload, consumable prices and supply sources; The system must be open, and the technology used may be upgraded. Performance description of CTP plate making machine for newspapers k&f company and Krause company: laserexpress direct plate making system is the fastest and most flexible CTP system at present. When the production speed is 1016dpi resolution, it can reach 200 single (or 200 double) printing plates/hour; At 1270dpi, it can reach 150 sheets/hour. The size of the printed version can take into account all the sizes of the current newspaper. Realize automatic loading and unloading, and automatic removal of plate liner. The exposed and developed plates are sent to the k&f plates with punching and bending functions for online processing. The plates that can be used are silverlith SDB silver salt diffusion plates of AGFA; Photopolymer CTP plates can also be used. Both plates are sensitive to 532nm wavelength, but they are far from high speed

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