CTP plate is widely used in the printing field, mainly consists of two parts: photographic material and plate base, which is the support body of coated photographic layer.

Aluminum plate base used to support the plate generally have to make the surface treatment, the surface treatment of aluminum plate is the most commonly used method of electrolytic sand mesh, the specific process is degreasing - washing - electrolytic roughening - washing - anodic oxidation - washing - drying, of which electrolytic roughening is the most critical step of electrolytic sanding, the effect of roughening directly determines the sanding of the good and bad, the electrolysis temperature of 35-40 ° C, electrolysis time of 20-40 s.

Oxidation is an anodic oxidation of the aluminum plate, the formation of the composition of the surface of the plate as the aluminum oxide film structure (aluminum oxide). Aluminum oxide film structure (including thick and loose porous layer and thin and dense barrier layer), to achieve the hydrophilic function of the aluminum plate and to ensure the stability of the coated photographic materials, oxidation liquid temperature of 30-40 ℃, oxidation time of 25-30s.