Electropolishing
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Electro polishing is a chemical surface finishing technique, by which metal is electrolytically removed, ion by ion from the surface of a metal object. The primary objective is to minimize mico-roughness, thus dramatically reducing the risk of dirt or product residues adhering and improving the cleanability of surfaces. Electro polishing is also used for debarring brightening and passivating.




Figure 1 :- ELECTROPOLISHING BY INDUCTION
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The work piece is connected to the positive terminal, while the negative terminal is connected to a suitable conductor. Both positive and negative terminal are submerged in the electrolyte, forming a complete electrical circuit. The current applied is direct (DC) current.
The quantity of metal removed from the work piece is proportional to the amount of current applied and the time. In the course of electropolishing, burrs and other projections become very high current density areas and are rapidly dissolved. The work piece is manipulated to control the amount of metal removal so that dimensional tolerances are maintained

REASON FOR ELECTROPOLISHING
Electropolishing produces excellent decorative finishes for the wide range of stainless steel automotive, appliance and household products. The surface produced combines attractive appearance with improved corrosion resistance.
Electropolishing improves corrosion resistance by reducing surface area, elimination occulision, reducing free iron, and producing and passivating film of a corrosion resistant chromium oxide. The special properties of the oxide layer are of great importance in semiconductor and pharmaceutical applications requiring clean, sanitary surface with little or no tendency to react with a liquid of gaseous chemical environment

 

Figure 2 :- EFFECT OF ELECTROPOLISHING ON SURFACE FINISH
---------------------------------------------------------------------------------------------------------------------------------------------------- Some steel products, such as textile rolls, are elecropolished prior to being plated to hard chrome. The smoothing and leveling effect of the electropolishing caused the chromium to deposit in a more regular fashion, improving the properties of the plate and strengthening the bond with the substrate steel.

Electropolishing also finds application in products requiring smooth, low-friction operation. Products such as powdered pharmaceutical, dyes and other dry chemicals are processed with minimal losses due to the low friction surface produced. A major application for electropolishing is in equipment for the manufacture and packaging of dairy, food and beverages and pharmaceutical products. The Processing equipment is regularly treated with “clean-in-place” chemicals to remove traces of products between batches and to maintain sanitary conditions. Electropolished stainless steel offers a surface which is readily cleaned by such process.

PROCESS STEP
1) Metal preparation: to remove surface oils, greases, oxides and other contaminants that interfere with the uniformity of electropolishing.
2) Electropolishing : to smooth, brighten and deburr the metal.
3) Post treatment : to remove residual electrolyte and by-products of the electropolishinbg reaction, and dry the metal to prevent staining


Figure 3 :- THE FOLLOWING SCHEMACTIC DAIGRAM SHOWS THE TYPICAL FLOW CHART
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METAL PREPARATION ELETROPOLISHING POST-TREATMENT
• CLEANING
• RINSING
• PICKLING
• RINSING
• ELECTROPOLISHING
• NEUTRALISATION/DRAGOUT
• RINSING
• NITRIC ACID
• RINSING
• HOT RINSING
• DRYING

 
Whats New
The Company POLIEREN, was Founded on 8th august, 2010,Specializes in electro Polishing, Fittings and Pipes. Polieren, operates to insure the quality, trust and commitement for electro polishing.
  


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