When replacing a new PS plate or using a PS plate produced by the same manufacturer with different batch numbers, the photosensitive speed will be different due to the different photosensitive liquid ratios, so the exposure time, developing time, and developer concentration must be changed accordingly. the
When using a developer, in order to achieve the ideal developing theater effect, it is best to use a developer that matches the PS plate, because the alkali resistance of the PS plate produced by different manufacturers is strong or weak. If the PS plate with weak alkali resistance is developed with a strong alkaline developer, the photosensitive layer that has not seen photodecomposition will be seriously affected. After development, the dots will become smaller and the image tone will be lost. the
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 durability of the PS plate. If the PS plate with strong alkali resistance is developed with a weak alkaline developer, the development will not be complete, and the printing plate will be dirty during printing. Due to the long development time, the aluminum plate base will also be corroded to a certain extent, which will affect the use effect of the PS plate.
Cleaning, cleaning, drying
The developed PS plate should be desmeared. Before desmearing, the PS plate needs to be blown dry first, because most of the besmeared parts are relatively close to the image or text, and as soon as the revision paste comes into contact with the PS plate, it will dissolve with the water on the surface of the plate base and spread to the surroundings. When removing dirt, dip a small amount of revision paste with the tip of a brush and gently wipe the place that needs to be repaired and remove it completely in the shortest time, then rinse with water immediately to avoid the revision paste drying up on the surface of the PS plate due to the long revision time.
It is easy to make the layout dirty if the revision time is too long. After repairing the dirt, wipe a layer of protective glue on 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 performance will be reduced, and the PS plate will be dirty during printing. The correct glue wiping method: use gauze dipped in an appropriate amount of glue to gently wipe a thin layer on the plate and spread evenly, so that all hydrophilic layers are protected. After wiping the glue, dry the PS plate and then protect it.
Protection method: Separate each two PS plates with a neutral moisture-proof paper, and store at 25°C. C, relative humidity is around 60.
If the printing quality is kept stable for a long time, printing workers must have the spirit of love and dedication, accumulate experience in work, find out a set of scientific and standardized data suitable for printing and proofing, and then be able to work with ease and adapt to the current needs of large-scale printing, which can not only improve work efficiency but also ensure product quality.