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Common polishing technology to be used in the food and beverage industry

Sanitary stainless steel pipe with the food and drug safety in production.
The surface finish of the stainless steel pipeline system in the food and drug safety production has a very important role. Good surface finish with clean, reduce microbial breeding, corrosion resistant, removing metal impurities, etc. In order to improve the quality of the surface of the stainless steel pipeline system, namely, to improve the surface morphology and morphological structure, reduce the number of dielectric layers, common surface treatment methods are as follows:
1, Mechanical grinding and polishing (Mechanically Polished) short name MP. To improve the surface roughness in precision grinding way, can improve the surface texture, but does not improve the morphological structure and energy level and the number of dielectric layer.
2, Feather cloth polishing (Buffed Polished) referred to BP. Stainless steel industry is commonly used to improve the surface brightness, although Ra value may be better, but many crack was observed under the electron microscope, the actual surface area expansion, local have separated ferrite and martensite structure. Many impurities and surface inclusions granules. Due to the use of polishing paste, many impurity residues were stored in the sag, and gradually release the fluid, contaminated food.
3, Pickling and passivation (Pickled & Passivated/Chemically Polished) referred to as AP and CP. Pipe after pickling and passivation, not improve the surface roughness, but can remove surface residual particles, lower energy level, but will not reduce the amount of dielectric layer. In the stainless steel surface to form a chromium passivation layer, oxide oxidation protect stainless steel from corrosion.
4, Electrolytic polishing (company Polished) or EP. Through electrochemical polishing, can greatly improve the surface morphology and structure, reduce surface actual area is maximum. Surface is a layer of thick chromium oxide film, closed, energy to some of the normal levels of alloy, medium quantity will be reduced to a minimum at the same time. In order to achieve a perfect electric polishing results, mechanical lapping and polishing must be. It is important to note that the same Ra values do not represent the same surface treatment.