How to improve printing quality

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How to improve the printing quality

printing is the process of transferring the original image and text to the PS plate. It is a bridge between plate making and printing. The environment section is very important in the whole printing quality management. How to improve the printing quality, reduce waste and reduce costs, according to their own practice, from the following aspects to talk about the experience. 1、 Be highly dedicated and professional

1 The plate printing operator shall master the performance and technical parameters of the plate printing machine, cherish the equipment, and maintain the equipment frequently to ensure the normal operation of the plate printing machine

2. Keep the environment clean, keep the indoor temperature and humidity, carefully check the original before printing, and analyze and deal with those that do not meet the printing requirements according to the specific conditions to avoid unnecessary waste. What are the common abnormalities in the operation of the two spring torsion tester of the printing machine? Wipe the surface glass

3. Check whether the specifications and dimensions of the original version meet the requirements of the operation voucher by referring to the process sheet; Whether the mouth, band mark, color mark and platform mark are complete. 2、 Quality of the original version 4. The fluctuation range of the power supply voltage shall not exceed 10% of the rated voltage

1 First, check the density of the original. The field density of the normal original is about 3.0. At this time, the point, text, line and other densities meet the requirements of printing. As long as normal exposure and development are performed. However, in actual production, it is often encountered that the density of some originals is low or high, so it should be handled according to different situations. a. During the exposure process of the original with low image and text density, due to the low density, light is easy to pass through the edge of the point, so that the part of the photosensitive layer that should not have seen light decomposition occurs light decomposition. After development, the point becomes gray and smaller, and the text and lines will become lighter accordingly. On the machine, the ink color is not saturated, which reduces the printing resistance and does not achieve the desired effect. For this type of original to take less exposure, less development. b. For the original with high image and text density (the density of the blank part is greater than 0.05), there is a layer of fog on the surface of the original, and there is also a layer of fog on the edges of the corresponding points and lines. This layer of fog blocks the passage of light when printing, so that the light of the photosensitive layer in the fog area at the edge of the points is not completely decomposed. After developing, the dot is enlarged, especially the enlargement rate of the dark tone part of the image is increased. When printing, the dark tone is merged and pasted, which also can not achieve the ideal effect. For this kind of original, we should adopt the method of multi exposure and multi development

2. Because of the revision of some pictures and texts, there are more "open skylights" in the original version, which makes it difficult to print. The edge of the tape is too close to the image, which will easily make the image weak. Because the overlap of the film base will cause static electricity, the middle interlayer is easy to absorb some dust, small sand particles, etc., which will also make the image weak. In addition, some parts of the original image are folded into horseshoe pits. After exposure, this part also has the image weak phenomenon. In view of the above phenomena, the printing operator is required to find and solve them in time

3. Some books and periodicals are full of private banter [Mu Xi] so that they can express their opinions quickly? (1) Nora's life? The following is the main content of this article: 1. The main contents of this article are as follows:? The position of the valve shall be adjusted? Qiuwei

III. control of printing signal strip the printing operator shall conduct a matching test on exposure and development before working every day to determine the exposure time, development time and developer concentration suitable for printing and proofing. Methods: first, ensure that the temperature and concentration of the developer meet the development requirements. Then take a small PS plate and put the print signal bar on it for exposure test. Before the test, it is necessary to consider the different service objects for printing, and the exposure time test should also be adjusted to varying degrees

a. proofing: after the signal bar is exposed and developed, half of the level 4 gray scale is required to be dried off, and the small points of 2 are dried up. The point of 50 is basically accurate, and the point of 80 cannot be shrunk down, and the edge of the points is clear and tidy

b. printing plate: after the signal strip is exposed and developed, the level 4 gray scale shall be dried off for 1.5, and the top 2 points shall be dried off. The 50 and 80 points sharing weal and woe shall be restored basically accurately, and the point edges shall also be clear and tidy. The reason why the drying printing plate is inconsistent with the proofing plate is mainly to solve the difference in mechanical performance between the proofing machine and the printing machine, so as to ensure that the printing and proofing samples are basically consistent in terms of tone, hue and saturation

IV. understand the performance indicators of the PS version, correctly use the PS version. When replacing a new PS version or using a PS version produced by the same manufacturer with different batch numbers, the photosensitive speed will be different due to different proportion of photosensitive solution, so the exposure time, development time and concentration of the developing solution should be changed accordingly. When using the developer, in order to achieve the ideal development effect, it is best to use the developer matching the PS version, because the PS version produced by different manufacturers has strong or weak alkali resistance. If the PS version with weak alkali resistance is developed with the strong alkaline developer, the photosensitive layer without photodegradation will be seriously affected, and the dot will become smaller and the image tone will be lost after development. When the developer concentration is too high, it will not only corrode the photosensitive layer, but also destroy the oxide film of the printing plate, which will affect the lipophilic performance of the printing plate and reduce the printing resistance of the PS plate. If the PS plate with strong alkali resistance is developed with weak alkaline developer, the development will be incomplete, the printing plate will be dirty during printing, and the aluminum plate base will also be corroded due to the long development time, which will affect the use effect of the PS plate

v. dirt removal, glue wiping and drying the developed PS plate. Even if the shrinkage of the same material in different batches produced by one factory is not the same, dirt removal is required. Before removing dirt, it is necessary to dry the PS version first, because most of the dirt removal parts are close to the image or text. Once the revision paste contacts with the PS version, it will dissolve with the surface of the base and spread around, which is very easy to erode the image or text, making the edge of the image empty, the lines of the text shallow or the pen broken. When removing dirt, dip a small amount of revision paste with the tip of a brush to gently wipe the dirty area to be repaired and completely remove it in the shortest time, and then rinse it immediately with water to avoid the revision paste drying up on the surface of the PS plate due to the long revision time. In addition, too long revision time is easy to make the layout dirty. After the cleaning, a layer of protective glue shall be applied to the PS plate in time. If the glue is not applied in time, the hydrophilic layer of the PS plate will be oxidized, the hydrophilic property will be reduced, and the PS plate will be dirty during printing. Correct glue wiping method: gently wipe a thin layer on the layout with a sand cloth dipped in an appropriate amount of glue and apply it evenly to protect all hydrophilic layers. After wiping the glue, blow the PS version dry and protect it

protection method: each two PS plates shall be separated by a neutral moisture-proof paper, and the storage temperature shall be 25. C, and the relative humidity is about 60

if the printing quality is in a stable state for a long time, the printing staff must have the spirit of love and dedication, constantly accumulate experience in work, find out a set of scientific standardized data suitable for printing and proofing, and be able to work with ease, adapt to the current needs of large-scale printing plate drying, and improve work efficiency and ensure product quality


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