4, polishing: to overcome the aluminum material surface defects and improve surface finish. Polishing and chemical mechanical polishing polishing points. It is the use of
mechanical polishing cloth polishing wheel machine, multi-chemical polishing is carried out in an acidic solution, such as 15% sulfuric acid, 10% nitric acid, the temperature of 90-100
degrees, time of 2-3 minutes.
5, oxide: aluminum surface polished has a residual soap polishing, wipe application boards yarn dipped in gasoline and chemical degreasing, then immersed in a nitric acid
solution (1 to 1 ratio of nitric acid and water), removed after 10 minutes, and then into the oxidation tank electrochemical oxidation. Oxidizing liquid formula: nitrate 160-200 g / ml,
temperature of 10-20 degrees, 30 minutes. Good sufficiently washed with water dried aluminum oxide, formed on the surface layer of uniform porosity in the oxide layer, i.e., oxide film, to
avoid dirt contamination. Good aluminum oxide immediately print the best, if not immediately printed, soft paper application septum wrapped or dried directly on the shelves, storage time
should not exceed one week. The surface of the aluminum oxide layer can absorb dye, water and other salts, it is not something with greasy hands or contact surface when printing. When the ink
is printed onto the oxide layer, namely the ink penetrate pores. Heating the next step is to accelerate the ink to penetrate pores until all the pores in the surface of the ink-covered been
filled so far. Few printed ink surface diffusion or non-proliferation, to ensure good text, graphics precision and clarity.
6, closed: its role is firmly sealed in the ink within the pores, and never rise overflow or diffusion. No ink coverage to complement the site is closed to fill the role of
the oxide film is also the gap, making it impervious to enhance corrosion resistance surface. Generally use nickel sulfate solution for blocking. Recipe: Chinese NICKEL 10-12 ml, temperature
80-90 degrees, 10-15 minutes. Hand or other things and then sealing with oil contact surface with the general cleaning agents can be washed off.
Silk screen printing ink (paint)