High quality PS version will coexist with CTP version

With the launch of CTP equipment and various CTP plates on the market, it is undoubtedly a challenge to the original prepress technology and the original PS plate printing technology. CTP plate will replace the existing PS version? How will the PS version develop in the future? This is a concern for the printing industry and the printing industry.

- Review of the PS version process

Before the PS version has not been asked before the offset printing is mostly using the gravure or gravure or flat-panel version, to the laser phototypesetting, electronic color era, flat concave and flat version is hindered the development of printing technology, so the PS version appeared to show it with The traditional media has obvious advantages compared to the traditional media. Here are some points to restate:

The 1PS version changed the original gravure plate, gravure plate or protein plate that was ready to use to a plate that could be pre-produced and could be stored for a long period of time. This greatly saved the time of plate making and shortened the time needed for original plate work to more than one hour. Completed in minutes.

2 It has changed the phenomenon of hand-manufactured plates, and the good weatherability of PS plates has made it easy to realize the mechanical operation of printing and developing.

3 The quality of the printing plate has been significantly improved. The resolution of the photosensitive material and the reproducibility of the dot are unmatched by the old plate material.

4 It has been possible to change a large number of plate editions in the past when offset printing was used in long-term printing. It is possible to print tens of thousands of pages, hundreds of thousands of printings, and even hundreds of thousands of copies per PS plate.

From the early 1970s to the end of the 20th century, China developed the PS version for nearly 30 years. Specifically, it was divided into two stages.

The first phase of the slow development period (1970-1985): In 1975, our country successfully studied and completed the first single-sheet PS version production workshop. The reason for the slow pace of development was the delay in accepting new technologies under the circumstances. In 1979, the National Offset Printing Conference held by the China Printing Technology Association was to promote printing technology. Through these powerful technical extension efforts, the demand for PS editions by printing companies has reached an imminent point for a period of time. Although the PS editions are within the scope of fine chemical technology, the printing industry had to first launch their own products, since 1982. The “Intermediate Test Project” for the continuous production of the PS version of the reel aluminum version undertaken by the Institute of Printing Science and Technology of China and the production of six PS-version production lines for single-sheet PS from some manufacturers are all important products in this situation. The measures played a positive role in starting the PS version and satisfying domestic requirements.

The second period of rapid development (1985-2000): In 1985, the completion of PS production line for continuous production of the first aluminum reel made in China, and the subsequent introduction of second-hand production lines for the second film factory, making the PS version The production has grown rapidly. The number of manufacturers has increased year by year and the output has been expanding year by year. By 1990, the sales volume of domestic PS versions had approached 10 million square meters. In the 10 years of the 1990s, with the popularity of pre-press color publishing systems and the rapid increase in the number of rubber transfer machines and multi-color offset presses, many manufacturers have been encouraged to build PS production lines. As a result, by the end of the 20th century, there were nearly 30 domestic manufacturers with annual production of over one million square meters, and the country’s total production capacity reached a considerable level. According to the PS version manufacturers' own declaration, the statistics of the relevant departments show that the total production capacity of the 32 domestic manufacturers of the PS version is now over 80 million square meters, and last year it has produced about 45 million square meters. This does not include the number of domestic manufacturers that have the ability to produce PS versions. Hundreds of recycled PS plates.

Before the 1990s, China's single-sheet PS plate production line accounted for roughly half of the total output. Now, more than 20 PS plate production lines are mostly reel-type production lines. This shows that both in terms of output and technically, it has reached a certain level.

Second, the status of the PS version of the analysis

After long-term development, the relationship between supply and demand for the domestic PS version has basically reached equilibrium. Specifically, the PS version of the general quality has a slight surplus, while the high-end PS version is still somewhat inadequate. Some special performance and special specifications of the material still need to be imported. There is still a certain gap between China's and developed countries in terms of manufacturing technology and performance of the PS version.

(a) In manufacturing technology:

Although China now has a production capacity of 80 million square meters or more, it is completed by dozens of production companies and a total of I Division. Most of the manufacturers are not large-scale, fast, and have incomplete specifications. In general, the production line speed is At around 6 m/min, advanced companies can reach 10 m/min to 15 m/min, and the highest speed for introducing production lines is 25 m/min. Secondly, there is still a large gap in the level of white chemicals. The process control of each link still requires an experienced manual Song operation in order to maintain the stability of the product.

The main raw material for the production of the PS plate is still insufficient in quality. Although after several years of efforts, several major aluminum plate plants have made the products considerably improved. However, to truly meet the PS plate plant's requirements for the quality of the plate base, it is necessary to The stability of the quality of batches makes great efforts. Aluminum plate base is one of the basic factors for manufacturing high-quality PS plates. Some manufacturers do not hesitate to import plates to meet production requirements in order to achieve high yields and good product quality. In terms of chemical materials, it is not enough. Photosensitive materials and film-forming resins are mostly small workshop-type production equipment. They have not yet been scaled up. Their quality is difficult to achieve to an ideal level, which has a certain impact on the quality of the PS plate.

(B) The current PS version of the product quality

PS version manufacturers have done a lot of work in strengthening enterprise management. The quality of the PS version has gradually become stable. The PS version professional committee of the China Printing and Equipment and Equipment Industry Association has been tracking the quality of the PS version for many years, and conducts a nationwide inspection every two years. For the PS version quality has played a positive role.

(III) Analysis from the use of performance

On the whole, with the shortening of the publishing cycle and the speed of printing presses, the quality requirements for the PS version are becoming more and more stringent. The biggest requirement for users is that they are stable in quality, easy to operate, and difficult to produce waste. From this perspective, the following aspects of the quality of the plate still need further improvement.

(1) Stability of Plates

It is not too difficult for most PS manufacturers to produce a good quality PS version. However, it is not easy to maintain consistent performance for a long time, especially in microscopic performance. In last year's PS version testing activities, we had selected a foreign model of PS to compare with its 1998 test data and found that the two test results are strikingly similar. In particular, the thickness of the photosensitive layer and the thickness of the oxide film and their deviation from the same version have almost no change, which indicates that the control of the product quality is very strict, and users are certainly more assured when using this type of material. Now we have mentioned The stability problem is not an issue that cannot be used, but whether it can give the operator greater convenience and reliability when all can be used.

(2) Exposure and development conditions

Foreign high-quality PS plates generally have a short printing time and strong adaptability to the developer. That is, the developed thicker, lighter, newer, or old-fashioned point can produce a printing plate that conforms to the requirements of the publicity. Users have a sense of fulfillment. Most domestic PS versions do not yet have this capability, and there is less room for selection during printing. Taking the positive example as an example, less exposure may result in a lack of darker levels, and exposure to a little more will cause the loss of small outlets. This phenomenon has little effect on general prints but will affect fine products. Now.

(3) Zhenning adhesion layer

With the development of printing technology and the improvement of printing quality, fine prints all hope to solve the problem of evenness of large-area plain printing. Applying a vacuum adhesive layer makes the film more closely to the printing plate when vacuum is applied to the printing process. It is good to prevent the phenomenon of different shades of system from being published. This is where domestic PS editions need attention.

(4) Printing performance of printing plates

A few days ago, people were not too strict about the number of printing plates. However, they paid more attention to the ink receptivity of printing plates. A good PS version may use 4-5 sheets of paper to achieve ink enrichment, and the poor PS version may use 10 sheets of paper, this micro-performance is also the content of the plate industry to improve. Of course, there are not enough PS plates to be manufactured. In the process of transport, storage, and use of the PS plates, they also need to cooperate. Even if the PS plates are not used according to the operating procedures, it is not enough. There are now offset printing plate production standards. As a result, the overall level of the current PS version can be further improved by the combination of manufacturing and use of the PS version.

Third, the prediction of the future development of the PS version

The use of CTP technology and the use of CTP plates is an impact on conventional PS plates. This shock is normal and gratifying. Because it is now possible to come up with a variety of reasons to explain that using CTP technology is much more advanced than using conventional methods to make PS plates, such as:

(1) Improve the speed of plate making

CTP technology can scan and image directly on the printing plate through the laser light source, eliminating the middle part of the film, eliminating the printing process and saving the time of plate making. The laser scanning time is also much simpler than the conventional printing method. Now many laser platemaking machines can easily output 20-30 sheets per hour, which is unmatched by conventional printing technology.

(2) Improve plate quality and printing quality

The biggest difference between the exposure process of the CTP system and the PS plate is that it does not require a powerful UV light source like the PS plate, which avoids the exposure process and scattered and refracted light. Most laser light sources use a certain range of wavelengths of light, so the light energy concentration, and because the output resolution of the direct plate-making machine can be very high, and CTP plate regardless of the thermal plate, photosensitive resin plate or silver salt version have a very good outlets Reducibility provides good conditions for improving print quality.

(3) Conducive to environmental protection

Since the adoption of the PS version, people have got rid of the pollution of dichromate in the plate making industry, and silver salt pollution is inevitable. The CTP technology has saved the scanning process of the film and naturally reduced the use of silver salt.

The emergence of CTP plates does provide a broad prospect for people to choose photosensitive materials. Many photosensitive resins and thermal resins have excellent environmental performance. In terms of thermal ablation plates, the ignition residue is very good. Excluding, the concentration of the developer used in the post-treatment of some photosensitive resins is also gradually reduced, which is advantageous for protecting the environment.

(4) Helps to get rid of darkroom operation

Prepress System Processing During photolithography or electronic color separation, people cannot get out of the darkroom operating environment. The arrival of digital information and the emergence of CTP technology can make the prepress system work in white light or yellow light. Now there are many models of far-infrared laser plate making and UV and violet laser platemaking machines. The production of CTP plates can be carried out under a light source similar to the original drying plate version of PS. This will help the conventional PS plate to be enhanced and then reach the laser. The purpose of the plate.

The above analysis does not involve the superiority of CTP technology in terms of input and output information. It can be seen from the use of CTP plate material that its technological advancement is multifaceted. The application of it to China will rise rapidly and gradually form a climax, among which newspaper printing and new printing companies will choose this technology. The current promotion of CTP technology is a long-term process. The main reason is that our country has a vast territory and the printing industry runs through all departments. For enterprises that already have an image-setter output function, the current selection of conventional plate-making methods may be more economical. .

Therefore, people's demand for CTP plates is urgent, and the total volume will not be high at once. Imagine if China's plate material has changed from the PS version to the CTP version one-tenth, its number must be more than 4 million square meters. This quantity is very impressive.

Therefore, the recent PS version is still the main plate of offset printing, and it will not be eliminated at present. In particular, in the process of rising printing capacity in recent years, the sales volume of the PS version will increase. However, in today's highly developed science and technology, the promotion of a new technology will no longer take decades, as it used to. There should be a sober understanding of the plate industry, and the PS version is the main force today. It cannot be forever. Is the main force, with the promotion of CTP technology, the share of the PS version of the market, some will give way to the CTP plate, after a period of time after preparation, the CTP plate will become the main plate of offset printing.