Improve the quality Of Table Game Of Cards Printing some experience

Improve the quality Of Table Game Of Cards Printing some experience

 

With the increasingly mature CTP technology, the fast publishing speed, good plate stability, high dot reduction and other characteristics greatly improve the plate quality. However, the current use of laser phototypesetter is still relatively common, how to improve the quality of printing under the existing process and equipment conditions, to maximize the restoration of the original information, to meet the higher and higher printing quality requirements, has become a topic in front of us. In this paper, combined with the work practice, talk about improving the quality of print and some experience.

 

First, strictly check the quality of plate making film

 

Check the work notice to ensure that the number of plate film is complete, the elements are correct; Check whether the film is peeling, scratches, creases, yellowing and darkening, and communicate with the previous process in time to deal with the problem as soon as possible. Use a clean, soft gauze dipped in alcohol to gently wipe the tape marks, debris, and dirt on the film to ensure that the film is clean.

 

Two, carefully clean the glass plate of the printing machine

 

The cleaning degree of the glass plate of the printing machine has a great impact on the quality of the printing. Even if it is a tiny hair, it may cause a batch of printing parts to be scrapped. Therefore, before printing, we must wipe the dust and fingerprints on the glass plate of the printing machine carefully. For stubborn dirt, such as tape printing and oil, we should wipe it repeatedly until it is completely removed. Because the glass plate is reflective, checking the glass plate from one direction often misses some dirt, so we should carefully check from multiple directions and angles to ensure that the glass plate is clean. In addition, after each printing plate, to re-check the glass plate there is no dirt, do not exist a lucky mind, otherwise, can not ensure the quality of the printing.

 

Three, the production of printing calipers to improve the accuracy

 

This unit uses Heidelberg CD-102 four-color offset press, the accuracy of printing requirements are: bite error ≤ 0.1mm, side gauge error ≤ 1.9mm. As the distance of 0.1mm is almost impossible to control with the naked eye, it is difficult to grasp with a scale. In order to reduce the error and improve the accuracy, using the abandoned PS version self-made printing caliper, its width and bite is consistent, length is equal to the width of the version, simple production, easy to operate, after use greatly improve the printing accuracy and efficiency. [next]

 

Four, accurately grasp the exposure time of printing

 

Take 3000W iodogallium light source as an example.

1. Determine the exposure time according to the thickness of photosensitive layer of PS plate. Under normal conditions (temperature 22±5℃, humidity 60%, developer concentration 14%), set the exposure time of 120s for PS plate with moderate sensitive layer thickness. But if the PS version of the sensitive layer is thick, such as fully open PS version than the normal exposure time increased by about 20%; If the photosensitive layer of PS version is thin, such as 920mm×760mm PS version, the exposure time should be reduced by about 15%.

 

2. Determine the exposure time according to the film dot size. Take the printing version of the city tourism map for example, the minimum dot of the map is 4%-5%, and the maximum dot is 50%-60%. Under normal conditions (temperature 22±5℃, humidity 60%, developer concentration 14%), the relationship between exposure time and dot percentage size is shown in the following table:

 

Generally, the exposure time should be controlled between 70s and 200s. If the exposure time is less than 70s, the page is easy to be stained. If the exposure time is greater than 200s, the dot is easy to lose, affecting the dot reducibility.

 

3. Determine the exposure time according to the film condition. If the film is old, yellow and dark, or has multiple splices, the exposure time should be increased appropriately, and the second exposure should be started if necessary.

 

4. Determine the exposure time according to the indoor temperature conditions. The best indoor operating temperature is 18℃-25℃. If the temperature exceeds 25℃, reduce the exposure time appropriately; If the temperature is below 18℃, the exposure time should be increased appropriately. In addition, the exposure time should be organically combined with other platemaking parameters, and the increase or decrease of exposure time should be based on the true reproduction of the original manuscript and the layout can not afford the bottom shadow as the principle.

 

5. Reasonable preparation of developer concentration

 

Taking Huaguang brand positive PS version developer as an example, the concentrated solution is prepared by strong alkali and weak acid salt. It has the advantages of fast developing speed, stable performance, good dot reduction and clean flushing. At room temperature (18℃-25℃), developer was prepared according to the concentration: water = 1:7; When the room temperature was higher than 25℃, the developer was prepared according to the concentrated solution: water = 1:8; When the room temperature is below 18℃, the developer is prepared according to the concentration: water = 1:6. Developer concentration should not be too high or too low, otherwise it will cause excessive destruction of dot reduction, or insufficient development of the background. Use a magnifying glass to observe the Photoshop version, as soon as you find even a slight shadow, immediately let off the developer and reformulate. [next]

 

Vi. Organic coordination of various platemaking parameters

 

The TUNG SHUNG 130 PSBN automatic plate printer is currently used for development. According to indoor environmental conditions, mainly temperature, dry humidity, cleanliness, exposure time, developer concentration, scientific and reasonable setting and adjustment of developing temperature and developing time. The relation between these platemaking parameters is not invariable, and should be coordinated according to specific conditions. For example, if the developing concentration is high, the developing time should be reduced accordingly; Exposure time is long, it is necessary to shorten the developing time; If the temperature is too low, the exposure time or development time should be increased. Adjust all kinds of platemaking parameters to clean the layout, the true reproduction of the original manuscript for the principle.

 

To sum up, every link of printing needs to be carefully mastered, not only need rich work experience, but also need a high degree of responsibility and dedication, so as to improve the quality of printing, to further improve the quality of printed products to lay a solid foundation.