PS Plate Making Process
At present, one main type of the PS plates is the positive PS plate, which the aluminum base plate of 0.1-0.5 mm is used as a support. After the surface roughening treatment such as electrolytic oxidation, the surface of the aluminum base plate is formed a multi-grain layer and then it will be coated with a diazo photosensitive resin layer.
The specific PS plate making process is as the following:
1. Unwind. The aluminum coil features light weight, small flexibility, stable size. And it is easy to get fine and uniform grain. After being anodized, the aluminum base plate has strong hydrophilicity, corrosion resistance and abrasion resistance, which shows excellent good printability.
2. Degrease. During the rolling process, storage and transportation, the aluminum plate will be coated with oil to prevent rusting. In order to achieve the desired effect of electrolytic oxidation, the oil stains on the surface of the aluminum plate must be removed.
3. Electrolysis. The electrolytic method is used to roughen the aluminum plate. The aluminum plate continuously electrolyzes in dilute hydrochloric acid to form rough grain by making use of the alternating current.
4. Anodization. It is to improve the hardness, corrosion resistance and chemical stability of the base plate, which contributes to better printing resistance of the PS plate.
5. Coating. A layer of photosensitive material is attached to the the oxide film of the aluminum plate to make a PS plate for offset printing.
6. Cutting. It takes large sheets from the intermediate product store and converts them into a finished product of a given size. The cutting is done by large cutting machines which make guillotine cuts across the complete width or length of the sheets, sometimes followed by drilling to create registration holes.
Original source: https://www.hm-alu.com/a/ps-plate-making-process.html
Tags:ps plate making process positive ps plate ps plate for offset printing