Frequent problems and solutions in baking process

The film-forming agent of the positive-image ps version photosensitive layer is made of cresol-formaldehyde resin and then changed from a linear shape to a bulk structure, which enhances the abrasion resistance of the graphic part, so the baking version can increase the resistance to printing. However, there are often problems with baking in actual work.

The printing plate is not faithfully reflecting the original tone level, but the rubber track. The rubber track is often caused by improper protection of the scratching agent. The rubber track left by the high concentration of the protective agent or uneven grinding will harden on the printing plate after baking and will not dissolve in the developer. Ink absorption. In this case, a slightly thicker alkaline solution than normal developer can be used again.

In the roasting plate, the high temperature causes the PS plate to deform and bend, often scraping the plate and giving a squeegee when the plate is sent. When printing, it is dirty, and when it is slightly stenciled, it can be removed with a dirt removing agent. Light red after baking. This light red color is due to a trace amount of photosensitive layer on the blank part of the plate, which has been changed after baking. If it is treated with developer, it will not get dirty. If the reddish remains on the plate after the treatment, it must be dirty. This condition can be treated with a dirt remover. Dark brown or dark brown after baking. Under normal circumstances, the photosensitive layer is reddish brown after baking. If the color is dark brown or dark brown, it indicates that the baking temperature is excessive or the time of the fine plate is too long. This version is over-baked version, any degree of photosensitive resin layer of carbonization, darkening and embrittlement, the result will reduce the PS version of the resistance to force.

After the baking version was dark green. This type of printing indicates that the baking temperature is low or the time is short, the photosensitive resin is not completely polymerized, and the wear resistance, corrosion resistance, solvent resistance, and ink affinity are not maximized, and the second baking is possible. Edition for best results.

Dirty after ps version is a common fault. There are several reasons for this situation. Before the baking plate, the dust, impurities, and the scratches were not completely cleaned. These dirt will be firmly adsorbed on the plate after baking, causing the plate to be dirty; insufficient exposure or incomplete development will result in incomplete decomposition of the non-graphic part of the photosensitive resin, the ink will be dirty when printing; wipe protection agent Improperly dirty. Ps version of baking protection agent is easy to precipitate, after placing the solute precipitated to the bottom of the bottle, the back of the protective solution is poured out thin, with this kind of protective agent to wipe the version will cause the layout to protect the touch too thin or leakage, resulting in PS version Dirty. Therefore, before use, be sure to shake it evenly and throw it out for use. And wipe the protective agent must be rubbed evenly; wipe the middle of the stop and did not wipe the glue in time, after the boot, there is no water roller, and the first ink roller causes the layout to appear. A lot of ink road. If this ink channel is washed with gasoline, the surface is clean, and it will be dirty when it is turned on. In this case, you can use a clean cloth to add some of the pine oil and scrub it slowly. After the ink channel is completely dissolved, wash it clean with clean water. That is to say, the original and the original traces of the traces were not removed; the protective agent was poor in performance and the roasting plate was dirty. The performance of the protective agent used in the ps version of the roasting plate directly affects the quality of the roasting plate. Many manufacturers are required to pay attention to whether the formulation is appropriate, whether the performance of the used drug is standard and whether the preparation method is appropriate. No matter which bad book goes wrong, it will lead to the problem of protective agent performance and cause no protective effect of the protective agent. In particular, when certain medicines are not available, and when they are replaced with drugs that are not commonly used, special attention must be paid to the quality of the protective agent. In order to prevent the loss of the plate, it can be tried first, and it can not be used, and it can be put into normal production after no problem. In order to obtain better printing quality, it is always at the same time as above. In the printing process, special attention must be paid to the control of the ph value of the fountain solution, and the ink-moisture balance should be mastered.