Electropolishing Process Requirements
Electropolishing is accomplished in a series of wet processing steps using specially designed tanks, similar to electroplating or anodizing. The parts to be polished are mounted on a rack or jig which is moved from tank to tank. The three major process steps of the electropolishing system are:
Preclean: To remove all oils, lubricants, shop dirt, scale, oxides, and other contaminants from the surface. Suitable methods include vapor degreasing, solvent immersion, alkaline and/or acid soak cleaning, spray washing, abrasive blasting, wire brushing, and other types of mechanical finishing steps.
Electropolish: To smooth, brighten, deburr, passivate, improve surface profile, hygienically clean, reduce friction, increase corrosion resistance. To remove and recover electropolishing solution.
Post Treatment: To remove chemical residues or byproducts of electropolishing. The process is comparable to any metal finishing operation such as plating or anodizing. Each of the major process steps may require more than one tank to achieve the desired results. Details of the system vary on a case-by-case basis.
Electropolishing systems require rinse water to remove solution from the parts after each chemical operation. These rinses usually go to drain, and are subject to Federal, State, and Local regulations affecting discharge to public sewer treatment systems. Most modern electropolishing systems now incorporate evaporative recovery and/or multiple rinse technologies to minimize the amount of rinse water used. MCP can furnish simple waste treatment packages guaranteed to meet the current restrictions.
Electropolishing baths generate both hydrogen and oxygen gases, producing an acid mist which must be ventilated to meet OSHA requirements. Other solutions in the line, such as cleaners and acid pickles, may also require ventilation to meet these regulations. MCP can furnish installed ventilation systems constructed entirely of PVC which meet or exceed such regulations.