Common problems and solutions in the process of th

2022-07-24
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The film-forming agent for the photosensitive layer of positive pattern PS plate is made of cresol formaldehyde resin after baking, which changes from linear structure to body structure, enhancing the wear resistance of the graphic part. Therefore, the baking plate can improve the printing resistance. But there are often some problems in the actual work

when printing, the printing plate does not faithfully reflect the tone level of the original, but the glue channel. The glue track is often caused by improper wiping of protective agent. Due to the high concentration of protective agent or uneven wiping of prototype models or flame retardant materials in functional materials with required specific strength, the glue track is hardened and fixed on the printing plate after baking, and is difficult to dissolve in the developer, resulting in non ink absorption. In this case, it can be displayed again with alkaline injection slightly thicker than normal developer

during baking, the high temperature causes the PS plate to deform and bend. It is often scratched during plate delivery, resulting in scratches. When printing, it is dirty. If the slight scratches do not damage the image and text points, it can be removed with dirt remover. Light red after baking. This kind of light red is due to the fact that there is a small amount of photosensitive layer in the blank part of the layout, which becomes after baking. If the developer is used to dispose of it, it will not get dirty. If the light red color is still left on the layout of the ultra light fabric made of Tenax carbon fiber, such as various electrical protection fabrics of the power link, it will certainly get dirty. This condition can be treated with dirt remover. Dark brown or dark brown after baking. Normally, the photosensitive layer is reddish brown after baking. If the color is dark brown or dark brown, it means that the baking temperature is too high or the finishing time is too long. This type of plate belongs to the over baked version. The resin of the photosensitive layer is carbonized to varying degrees, darkened and brittle, which will reduce the printing resistance of the PS version

dark green after baking. This kind of plate color indicates that the baking plate temperature is low or the time is short, the photosensitive resin is not fully polymerized, and its wear resistance, corrosion resistance, solubility and ink affinity have not been improved to the maximum. At this time, the second baking plate can be carried out to achieve the best effect

It is a common fault that the

ps plate gets dirty after baking. There are several reasons for this. The dust, impurities and dirt removal scratches on the plate before baking were not thoroughly cleaned in time. After baking, these dirt will be firmly adsorbed on the plate, causing dirty on the printing plate; Insufficient exposure or incomplete development will cause insufficient decomposition of photosensitive resin in non graphic parts, and ink absorption and dirt during printing; Brush the protective agent improperly and get dirty. PS plate baking protectant is easy to precipitate. After placing, the solute precipitates to the bottom of the bottle, and the protective solution poured out from the back is thin. Wiping the plate with this protectant will cause the plate protection to be too thin or have glue leakage, resulting in dirty PS plate. Therefore, it must be shaken evenly before use, and poured out for use. In addition, when wiping the protective agent, it must wipe the "simple operation faults and solutions" of Kesheng sharing tensile machine: evenly wipe; The printing machine stopped halfway and did not wipe the glue in time. After the machine was started, it did not discharge the water roller first, but first dropped the ink roller, resulting in a large number of ink tracks on the layout. If the ink duct is washed with gasoline, the surface will be clean and dirty once it is turned on. In this case, wipe it slowly with a clean cloth and a little turpentine. After all the ink ducts are dissolved, wash it with clean water in time, that is, restore it as before, and there is no dirt; Poor performance of protective agent, dirty baking version. The performance of the protective agent used for PS plate baking directly affects the quality of the baking plate. Many manufacturers prepare their own products. They should pay attention to whether the formula is appropriate, whether the performance of the drugs used is standard, and whether the preparation method is appropriate. No matter which bad book goes wrong, it will lead to the performance problem of the protective agent, resulting in the unprotected effect of the protective agent. In particular, when some drugs are not available and are replaced by drugs that are not commonly used, special attention should be paid to whether the quality of protective agents is reliable. In order to prevent the loss of plates, you can try them out first without getting dirty. If there is no problem, you can put them into normal production. In order to obtain better printing quality, in addition to the above conditions, pay special attention to the control of the pH value of the fountain solution during the printing process, and master the balance of water and ink

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