1, the difference between the proofing version and the upper version In fact, for proofing and printing, two different versions should be printed. For proofing, from the standpoint of the structure of the proofer itself, it generally belongs to a platform type. The pressure of proofing is lower than the printing pressure, and the speed is slower than the printing speed. At the same time, the dot gain caused by proofing is small, and when printing is required, 2% to 3% of the dots are reserved, and 98% of the dots cannot be pasted. For printing, because the printing pressure is high and the printing speed is high, the printing ink is softer than the proofing ink (small in viscosity), which easily causes dot gains, and it can increase up to 30% to 40%, so the same plate is used for proofing. And the effect of printing is not the same, and this contradiction has not been solved for a long time. Therefore, when printing the printing plate, it is required to retain 4% to 5% of the outlets, and 96% of the outlets are not pasted, leaving room for the expansion of printing points caused by printing, and the printed products are easily accessible to proofs. 2ã€Dying phenomenon when printing In the event of loss of outlets, one should first look at the degree of restoration of the film itself, such as whether the 50% of the dots on the film are square, and whether 4% to 5% of the outlets are complete. In short, check the quality of the photocopied film, and then judge according to it. Whether the outlet is lost during the printing process. Because of the problem of printing operations, missing dots often appear. This has a direct relationship with exposure time, development time, developer temperature, and concentration. Excessive exposure and excessive developer concentration can cause dots on the layout to be lost or text strokes to become thinner. Strictly speaking, the printing staff should control the exposure and development through the printing test strip and the gray ladder, and test out their own test data. 3, the layout of virtual The reason for prosecution of false printings may be related to the printing film. If the film is exposed when the film is output, it will cause the printing dots on the printing film to become imaginary, and the printed version will naturally become imaginary. From the operation of the printing plate, it may be due to foreign matter or dirt attached to the glass or film of the platen; or the pad of the printing machine is not suitable; or the vacuum is not true, so that the film and the plate are closely attached. Insufficient; improperly printed copy film; before exposure (drilling) or after exposure to pre-developed lighting is too strong and so on, all may cause the direct printing surface to be ridiculous; and the developer temperature is too high, the concentration is too high, the development time is too long. Excessive development caused by too much developer replenisher is also the reason why the layout can't be ignored. At this point, the glass or film should be cleaned with a cleaning agent; the liner should be leveled; the tape should be separated from the image by 3mm, and the film should be in close contact with the plate; in safe light, such as a fade-resistant fluorescent light, yellow light Fluorescent lamps equipped with safety lamp shades are used for operations; for unsuitable development problems, they should be performed according to standards. 4, uneven development Inhomogeneous development or poor development, often caused by the decrease in the activity of the developer, which is mainly reflected in several aspects: the developer solution is not timely; the development time is too short; the developer temperature is too low; backwashing fluid, etc. At this time, in addition to standardizing the development conditions, the developer should be replenished in a timely manner. In addition, the dirty spots or foreign materials on the plate may also hinder the development. This requires the staff to regularly check the developing machine and the printing machine, and perform a timely cleaning of the machine. 5, the layout of the dirty There are different conditions on the layout, and there are different causes. The layout is dirty, which may be underexposure. There are two possibilities. One is that the transparency of the film is not good or the film is out of date; the second is that the exposure light source is used for a long time and there is an aging phenomenon. If you encounter the first situation, you can only re-film; if it is the problem of exposure light source, you should use the gray ladder ruler to adjust the exposure time, or directly change the exposure light source. Of course, the poor development may also cause the layout to be dirty. At this time, it is necessary to check out the specific causes of the poor development and timely adjust to the standard conditions. In production, spotted dirt is sometimes encountered. Analysis, the "culprit" really a lot. For example, there are dirty spots on the glass of a printing machine, and there are dust or dirt on the film. 2 When the collage printing film is used, the adhesive tape on the film is printed and the tape marks are left on the printing plate surface; Adhesion caused by poor development of blisters (developer nozzle holes due to clogging and foaming); 4 due to hands in the printing operation is not clean, leaving fingerprints on the layout; 5 protective glue glue thin; 6 protective glue is not dry and heavy Stacked and stored, making the plates stick together, causing the protective rubber layer to peel off when taken; 7 After plate making, the plates are kept under high temperature and high humidity conditions. Should be "differentiated" for different reasons. Among them, the upper part of the viscera caused by the tape adhesive and the tape marking is the most common. First, it should be prevented. Thin and clean scotch tape should be used as far as possible when the imposition is made. If the tape adhesive is applied to the printing plate, it should be gently. Wipe away and develop. When doing the printing, it is necessary to fully evacuation, to minimize the air layer around the make-up tape and the original film, and to minimize the possibility of light interference. If there is tape marking on the plate after exposure, remove the dirt by hand or remove the dirt by double exposure. For other aspects of the removal of dirt can be used in addition to dirty agent, plate knife, pumice stone in addition to dirty, you can also use the diffuser film to remove dirt or dirty dirty cover except dirty. 6, printing plate bad ink If it is not caused by the sensitizer of the photosensitive material, it should be based on the relationship between the printing force of the printing plate, the exposure time and the concentration of the developer. If the exposure time is too long or the concentration of the developer is too large, the printing plate is likely to have poor ink application. Because the exposed photosensitive layer of the PS plate is not absolutely soluble or absolutely insoluble, but is in between the two, the control is not good, it will make the photosensitive layer of the plate dissolved, not dissolved, and deinked. The rate is higher and the ink is bad. In addition, if a protective glue is not desirable, the glue is too thick, and the glue is not evenly coated by hand; 2 the drying temperature of the printing plate is too high or too low, which results in poor ink absorption or poor film-forming performance; 3 After printing, the plate contacts Strong light; 4 plate plate after printing in a high temperature and humidity environment, will cause the decline in ink. At this time, the protective glue specified in the plate should be used, the glue should be diluted appropriately, and the drying temperature should be reasonably determined. Generally, it should be 60. C; Appropriate to prevent light after gluing, and store plate-making plates in a qualified environment. If the printing plate is found to be poorly inked during the printing process, it should be checked whether it is the amount of glue in the fountain solution or whether it has been washed with water after using the cleaning agent. 7, printing plate resistance to print force reduction The main cause of the decrease of printing plate resistance to printing force is the printing operation and printing. In the aspect of printing: 1 Runout occurs before exposure or before development; 2 Density of film is not high enough; 3 Due to high developer temperature and concentration, long development time or oversupply caused excessive development; 4 Strong acids, strong bases, organic solvents , In addition to dirty liquid and other agents attached to the plate; 5 with plate cleaning agent too many times, etc., these will affect the printing plate's resistance to printing. In terms of printing, if the printing pressure is too high or the paper powder is too much, and strong plate cleaners and roller cleaners are used in UV printing, it will inevitably cause a decrease in the resistance force. In particular, it should be pointed out here that in order to prevent running out of light, a yellow safety light is used for ordinary PS plates to fully shield harmful light. 8, there is a bright blue plate on the sun In the production, a version of the sun out, whether it is because of the issue of pre-production plate, or the exposure of the sun exposure and development time matching conditions are not suitable, the sunburned version of the bottom blue. The "secret" of the appearance of the bottom blue is: 1 when the plate is made, the coarse sand is coarse, and the current of electrolytic oxidation does not match; 2 the underexposure or the concentration of the developer during the printing is insufficient, or the matching of these two conditions is not appropriate. The phenomenon of bottom blue caused headaches for many operators. This problem has occurred. More development is not possible, and less development is not possible. If you develop more, the dots you need to keep will be reduced or lost; if you do not develop it, the entire layout will be affected. Under the moderate conditions of exposure and development, if there is a background blue, it will be necessary to repair the dirt. However, once the dirt is repaired, there will be a watermark on the layout, and the watermark plate will be printed on the machine, and the watermark will be printed around. To get dirty, if you finish repairing this area with dirty liquid, you will get another dirty, and if you are stuck in the picture, text, or mesh, the plate will not work at all. To solve this problem, it is necessary to apply a thin layer of glue before going dirty, and high-quality prints cannot use this version.