The most important step in the entire finishing process is the surface preparation of metals and the cleaning process. This is because the appearance and acceptance of the article depend primarily on a sound finish achieved with a clean and active substrate. The desired surface finish is achieved through the following methods:
1. Deburring & descaling: This is done by filing, tumbling and blasting with sand, grit or vapor. This is then followed by pickling process where the component is immersed in acid to remove rust, scale, workshop soil &oil, grease, tarnish, light oxides, dirt and any other material. These should be removed to ensure strong adherence of electrodeposited metal to the piece.
2. Polishing – It is done after the surface has been subjected to grinding or wire brushing. This method alters the surface of the metal through the use of a variety of abrasives: coarse, medium, fine and so on. This operation smoothens the surface of the metal.
3. Buffing – It further smoothens the metal surface and improves its appearance by the application of very fine abrasives to produce different types of finishes (e. g., satin, brushed, mirror finish, etc.)
4. Electrolytic cleaning – this process is performed on the metal surface prior to electroplating. It is more efficient than soak cleaning and considerably minimizes chemical attack on the metal surface.
5. Ultrasonic cleaning – the use of high-frequency waves called ultrasonic waves enhance cleaning efficiency of components with cavities and intricate shapes.
6. Electroplating – Electroplating is a process of coating an object, usually metallic, with one or more relatively thin layer of some other metal like copper, chrome, nickel, etc. by means of electrochemical process. The electroplating process is essentially preceeded by the ultrasonic cleaning process to achieve high quality of surface finish.
7. Electrophoretic Lacquering – The process relies on the migration and deposition of charged particles from a solution (lacquer) onto an opposite-polarity substrate (work piece) under the application of an external power supply. Lacquer coating may be applied by any route from a simple dipping to the more sophisticated electrophoretic method. Some installations replace electroplating completely by using lacquering direct onto base metals to produce replacements for electroplating.
8. Powder Coating – Powder coating is the technique of applying dry paint to a part. The finish is the same as a 2-pack wet paint. In powder coating, the powdered paint is electrostatically charged and sprayed onto the part. The part is then placed in an oven and the powder particles melt and coalesce to form a continuous film.
Our finishing section is equipped with following machines:
Vertical Belt grinder : 3
Buffing m/c : 20
Ultrasonic cleaning : 1
Electroplating plant : 1
Powder Coating Plant : 1
Electrophoretic Lacquering : 1