Process flow of etching products

Etching process flow

Different kinds of metals have different etching processes, However, the general process is as follows: metal etching → oil removal → water washing → etching → water washing → drying → screen printing → thousand drying → water immersion for 2~3min → etching pattern text → water washing → deinking → water washing → acid washing → water washing → electrolytic polishing → water washing → dyeing or electroplating → water washing → hot water washing → drying → soft cloth polishing (polishing) → transparent paint spraying → drying → inspection → finished product packaging.

Etching pretreatment

The process before metal etching is pre-treatment, which is the key process to ensure the good adhesion between the screen printing ink and the metal mask. Therefore, the oil stain and oxide film on the metal etching surface must be completely removed. The oil removal scheme shall be determined according to the oil contamination of the workpiece. It is better to conduct electrolytic oil removal before screen printing to ensure the effect of oil removal. In addition to the oxide film, the best etching solution shall be selected according to the type of metal and the film thickness to ensure that the surface is clean. Before screen printing, it should be dried. If there is moisture, it will also affect the adhesion of the ink, and affect the effect of subsequent pattern etching or even the distortion, affecting the decorative effect.

Screen printing.

For screen printing, the standard pattern screen shall be made according to the printing needs. In the process of decoration, the screen printing mainly plays a protective role, while the number of times when applying photosensitive adhesive should be more to make a thicker screen, so as to make the covering performance good and the etched pattern clear. Under the action of light, the adhesive film of the layout will produce photochemical reaction, making the photosynthetic part cross-linked into an insoluble adhesive film. However, due to the water melting of the photosynthetic part, the screen space will be exposed. Therefore, the screen layout coated with the adhesive film is engraved with a screen pattern matching the black and white positive film.

Fix the screen plate with pattern on the screen printer, use alkali soluble acid-resistant ink, print the required pattern on the metal plate, and then etch it after drying.

Post-etching treatment

The screen printing ink must be removed after etching. General acid-resistant ink is easily soluble in alkali. Immerse the etching plate in 40~60g/L sodium hydroxide solution at 50~80 ℃ for several minutes to remove the ink. After stripping, if high brightness is required, polishing can be carried out, and then dyeing can be carried out. After dyeing, transparent varnish can be sprayed to prevent discoloration and increase wear and corrosion resistance. For some metals that have good corrosion resistance and do not stain, they can also be painted without transparent paint, depending on the actual needs.