What's the step before the metal surface etching processing?

What's the step before the metal surface etching processing?

1. Oil on the surface

After the metal workpiece is processed, transported, and inventory, the surface is stained with different processing oil or rust -proof oil, etc., and it must be completely cleaned. Not good, the paint film is soaked in the etching solution to bubble or break, causing the surface that should not be etched to be corroded and damaged. In addition, if the surface of the etched part is not cleaned, the oil stains will affect the contact between the etching solution and the metal, so that the etching part is unevenly dissolved, and even some places cannot dissolve and affect the etching effect and quality. The method of removing oil can choose the method of removing oil according to the surface oil pollution. For details, you can refer to the content of the oil removal part of the second chapter.

2. Surface rust removal, film removal

Rust and oil are generally dirty on the metal surface. This is because the metal surface is in contact with oxygen, sulfur, and moisture in the air during processing, transportation or storage, and it is easy to generate oxide or rust layers. If the rust layer or membrane layer is completely removed before etching, it will affect the effect and quality of the etching. The quality of the protective layer of the etching site is not guaranteed. The surface of the etching site cannot be fully exposed to the etching solution due to the obstacles of the oxidation film, which affects the speed of the metal dissolution and the uniformity of the etching surface. If there is a thick rust or thicker oxide film on the surface, it is used to be soaked or soaked in alkaline fluid. The electrolytic method is relatively thorough and can be selected according to the situation. In the case of thinner membrane layers or rust layers, weaker erosion or brief electrolyte can be considered.

3. Surface polishing

The smoothness of the smoothness of the metal etching surface has a greater effect on etching. When the surface is rough, the corrosion -resistant glue not required for etching is difficult to remove. Due to the rough surface of the etched part, the eclipotic traces are rough and uneven. Therefore Before etching, the metal surface should be polished. You can formulate polishing schemes and selection methods according to the situation and product requirements. For details, you can refer to the polishing part of the second chapter.

4. Apply corrosion protection layer

The etching metal decorative parts generally split the carved part and does not require the etching part. For example, if a metal plaque is to be etched. If the text needs to be protruding, the glyphs of the text should be protected by corrosion -resistant protective paint and corroded to dissolve the text without text. If you want to engrave the text on the metal board, the text is concave. The font should be revealed, and the non -text part is protected with a corrosion -resistant protective layer before putting it into the etching solution.

Correct protective materials generally use organic coatings or inks with corrosion -resistant solution corrosion. The selected corrosion protection coating should be completely dissolved with some solvent, because the coating must be dissolved after etching. Therefore, the selected corrosion -resistant protective coatings must be an organic coating that can be cleared with solvent or chemical solution after etching in chemical etching. The coatings used in electrolytic etching must also have good insulation performance.