Due to the timeliness of newspaper printing, standardized and digital production has always been difficult to achieve in newspaper printing plants. If newspaper printing can also form a set of standardized production mode like offset printing, not only can save time, but also contribute to the improvement of printing quality. The following is a discussion of the realization of the standardization and dataization of newspaper printing from several major links such as film output, spelling and printing, for your reference.
Standardization and dataization of film output
At present, the film output of most printing plants has formed a standardized and data-based production mode, but in actual work, due to the influence of factors such as personnel quality, equipment stability, management system, etc. The meaning of data. In the printing house, the film output is generally carried out according to the following procedure: First, turn on the phototypesetting machine and the filming machine, and after preheating for 30 minutes, output the 21-level gray ladder film. Then, use a dot density meter to check whether the dot value of each level on the film is within the specified range. If it is suitable, start normal operation; if it is not suitable, you need to readjust the development conditions and repeatedly output the 21-level gray ladder film. However, the daily output of the newspaper printing plant is quite large. The film output at the beginning is relatively normal. As the output of the film continues to increase, the concentration of the developer gradually decreases. Although the developer replenishing device is functioning, with the development As time goes on, the development quality of the film also decreases. Due to the heavy work tasks, in order to ensure that the tasks are completed on time, the operators often do not deal with them, or simply add a certain amount of developer to the developer tank and continue to work. Some operators will even increase the development and fixing temperature to speed up the development to complete production tasks on time.
Film is the basis of printing. If the quality of the film is not good, it is difficult to guarantee the final print quality. Judging from the situation described above, the main factor affecting the quality of the film output is the filming process. In most newspaper printing plants, due to heavy tasks and tight time, relatively speaking, the punching machine is always in an overloaded state. To this end, the printing plant should increase the number of punching machines according to its own actual situation to ensure the stability of the film quality.
Standardization and dataization of imposition and printing
Although many newspaper printing plants already use the CTP system at present, due to the high cost of CTP equipment and the high cost of plate materials, not all newspapers are printed using CTP plate making, and the conventional manual imposition and printing process still dominate.
The standardization and dataization of imposition is relatively easy to achieve. Just draw the standard imposition coordinates (table paper), and the imposition staff can construct according to the sample. However, for printing, the amount of tasks in the relative time is super saturated. In order to ensure the timeliness, the workshop had to sacrifice the quality at the expense of extending the exposure time on the one hand to achieve the purpose of removing dirt; on the other hand increasing the concentration of the developer and speeding up the development speed to increase the production speed. Therefore, small dots are seriously lost after printing, and dots below 5% cannot be exposed, resulting in a large area of ​​screen exclusion in many highlights during printing, which affects the quality of newspaper graphics.
In fact, the standardization and digitalization of printing are relatively easy to achieve. As long as the standard exposure time and development time are determined, the staff will strictly produce according to the requirements, and there will be no problem. However, due to the concentration of tasks in many newspaper printing plants, the equipment is often insufficient. To thoroughly realize the standardization and dataization of plate-making, plate-making equipment and operators must be added. This is a problem that most printing companies need to solve urgently. Now, many newspaper printing plants pay special attention to the investment of printing equipment and the cultivation of printing talents, but they are reluctant to invest more in the transformation of plate-making equipment and the introduction of plate-making talents. Over time, a situation of "excessive printing capacity and insufficient platemaking capacity" has formed. Therefore, even with advanced printing equipment, high-quality newspaper prints cannot be obtained in the end.
Standardization and digitalization of printing
The control of the printing process is the most complex and involving the most factors in the entire newspaper printing process. The performance and quality of the raw materials used, overprinting, printing pressure and printing environment will affect the standardization and dataization of the printing process.
1. Raw materials
In the production process, the same type of photosensitive material, PS plate, paper, ink and other raw materials should be used as much as possible to ensure the consistency of plate making and printing parameters and provide a data basis for color reproduction. At present, many newspaper printing companies have passed the ISO9000 quality system certification, and have carried out the material inspection as a daily task. Therefore, to ensure the publication timeliness and printing quality of newspaper printing, the incoming inspection of raw materials must be carried out in strict accordance with the regulations, and the quality should be controlled to prevent the occurrence of non-conforming products from the source.
2. Ink and fountain solution
The principle of offset printing is water-ink balance. Therefore, the control of water-ink balance is the basis of offset printing. Large amount of ink will inevitably require more water, otherwise it will paste the plate; small amount of ink will inevitably require less water, otherwise, the page will be gray. Therefore, mastering the appropriate amount of ink and water is the key to newspaper printing. How to balance ink and fountain solution? The author believes that we should start with the following points.
(1) Make a standard color header. When printing, use a densitometer to measure the density value of each primary color plate, and compare it with the density of the standard header, and make corresponding adjustments to ensure the consistency of the ink color of each newspaper header.
(2) Specify the density value of the version text. In the national standard for newspaper printing, the density value of the word "的" in Song No. 5 of the small book is used as the standard, and the standard density value is 0.25 ± 0.05.
(3) Divide the layout, and measure the density of the word "" in the same font size in different locations to keep it the same, so as to ensure the consistency of the ink color of the entire layout. For example, 4 open layouts are divided into 8 areas, and 8 open layouts are divided into 4 areas.
(4) According to the actual situation of the enterprise, stipulate the field density values ​​of standards Y, M, C, and K, and test them during the production process. As specified in national standards, the field density values ​​of Y, M, C, and K in newspaper printing are 0.60 to 0.80, 0.90 to 1.10, 1.0 to 1.20, and 1.0 to 1.30, respectively.
(5) Strictly control the proportion of fountain solution to ensure the consistency of fountain solution during printing.
(6) On the premise of ensuring no paste, print with the least amount of water supply. Once the amount of water is determined, it must be kept relatively stable.
3. Overprint
Whether overprinting is accurate is the most direct reflection of the quality of printing. Due to the high speed of newspaper printing, it is inevitable that there will be overprint errors, but there must be a standard. If it exceeds the standard range, it is a non-conforming product. According to national standards, the overprint error of the main body part should be within 0.5mm.
4. Printing pressure
Appropriate printing pressure is the prerequisite for ensuring smooth printing. If the pressure is too large, the dots will be deformed and the flat mesh will be uneven; if the pressure is too low, the dots will be imaginary and the texture will not be strong. Newspaper printing factories always use newsprint to print because of the single printed materials, and the standardization of printing pressure control is easy to achieve. Some old-fashioned printing machines used to measure pressure by pressing "fuses" and inserting "spacers". The current machine only needs to use a vernier caliper to measure the thickness of the paper and enter the data into the computer, which can automatically adjust the pressure.
5. Printing environment
Printing has relatively high requirements on ambient temperature and humidity. If the temperature and humidity are too high or too low, it will have a certain impact on the printability of paper and ink.
In addition, many advanced imported equipment have strict requirements on the ambient temperature and humidity. When the room temperature exceeds 30 ° C, the machine cannot start due to poor heat dissipation of the motor and electric cabinet. Therefore, the temperature in the workshop is generally controlled at 23 ± 5 ℃, and the relative humidity is controlled at 50% to 75%.
Only by strictly controlling newspapers in the above aspects can the standardization and dataization of newspaper printing be realized in actual production, and the quality of newspaper printing can be effectively improved.
SHANDONG CAIFENG INTERNATIONAL TRADING Co., Ltd. , https://www.zihcaifeng.com