Proper Attention to Ink Raising Treatment
The ink raising treatment of PS plates enhances the photosensitive properties of the coating, protects the image areas, and enables quicker inking during printing and proofing. The developer ink used in this process also acts as a light shield to prevent light exposure in the image areas, thereby extending the lifespan of the printing plate. Ink raising also helps improve the print durability. Therefore, unless the plate is urgently needed for immediate printing, ink raising should always be performed. During operation, ensure the developer ink is applied evenly, and the plate surface must be clean and free of dirt.
Proper Attention to Plate Supply
After fixing, the PS plate should be cleaned and dried before being baked. Baking helps stabilize the coating developed by the alkaline solution by evaporating the residual alkaline substances. A properly baked PS plate will have better ink affinity in image areas, faster inking, and improved durability. When handling baked plates, ensure they are cooled before ink raising, with a certain amount of moisture retained. If necessary, apply two thin layers of gum solution to help prevent over-inking.
Proper Maintenance of Environment and Equipment
1. The plate exposure room must be kept clean, especially the exposure glass, which should be wiped clean before use. The developing machine should be regularly cleaned and maintained.
2. Light sources and illumination levels must be checked regularly. Ensure the electrical voltage is stable at 380V (within the range of 360V–400V).
3. PS plates must be stored in a cool, dry, and dark place—ideally an air-conditioned darkroom. Avoid placing them near water sources. During handling, do not bend or scratch the plates. Avoid touching the plate surface with oily or developer-contaminated hands.
Proper Attention to Phosphoric Acid Treatment
For manually developed plates, a 2%–3% phosphoric acid solution should be used for post-treatment. After development, the exposed areas of the photosensitive layer are removed by the developer, while the unexposed image areas remain intact and still photosensitive. The acid treatment neutralizes the alkaline surface and stabilizes the image areas. During operation, do not apply phosphoric acid immediately after development—rinse the plate with clean water to remove any remaining developer before treatment.
Proper Attention to De-staining Treatment
After development, a wet de-staining process is commonly used. Although effective, it may cause stains due to incomplete development. The best method is to apply a thin layer of gum solution, allow it to dry slightly, and then perform the de-staining. This improves cleaning results and helps prevent surface contamination.
Proper Attention to Gum Coating and Exposure
When applying gum solution, ensure it is spread thinly and evenly to protect the plate surface. In actual production, this step is often neglected—gum is applied unevenly, too thick, or not at all, which may lead to localized damage to the plate.
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