CTP of the hottest computer direct plate making

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Computer to plate (CTP)

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 technology and plate making quality 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. However, since the direct plate making machine is still very expensive during this period, only small 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. It is reported that the United States printed 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 the direct plate making materials began to mature and develop. Therefore, a large number of investigations by GATF, the technical authority of China brush, have been carried out since, The number of CTP systems installed and expected to be installed in the world is as follows (including newspaper printing, which has also become the CTP system used in the material brush industry urgently needed by handheld terminal manufacturers, including a total of 8 opening, opposite opening, and full opening):

1995, 1996, 1997, 1998, 1999, 2000

311721 1686 31006200 12150

from this set of data, the application and popularity of CTP is growing at a rate of more than twice every year. During the three-year period from 1995 to 1998, the growth rate was as high as 10 times

ctp system can be popularized in the user group at such an amazing speed, 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 plate materials 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

American media commented that CTP is an inevitable technological revolution, and it will certainly replace the Phototypesetting Technology, just as the extension was replaced by the Phototypesetter five years ago

at the nexpo98 Exhibition hosted by the Newspaper Association of America in June 1998, a total of 11 manufacturers exhibited their CTP systems. 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

loading method

according to the degree of automation, the loading 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 according to the requirements of printing format and equipment × 84 Inches; Large format printing plate, size 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

major equipment suppliers

ctp equipment suppliers are mostly from the United States, as well as companies established 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. Creo company, Krause company, etc. provide special equipment for newspapers

basic working principle of CTP

CTP direct plate making machine is composed of accurate and complex optical system, circuit system and mechanical system

a single original laser generated by the laser is divided into multiple (usually beams) extremely fine laser beams by multiple optical fibers or a 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 LLL beams, the shorter the time to etch a printing plate. 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 has better physical properties and dimensional stability. The time 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 the 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 after heat treatment 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

development trend

ctp is surging. Since 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 is 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

As a development direction of China's printing and publishing industry, CTP system and technology 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 and high return technology intensive industry

ctp system requirements

when using the 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 the color prepress processing system and the improvement of the data transmission technology of the 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

kf 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. After exposure and development, the printing plate is sent to the KF plate with punching and bending function for online processing. The available plate is silverlith SDB of AGFA

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