Electrolytic Degreasing Pre-Treatment

Electrolytic degreasing is the process of removing oil from the surface of parts in an alkaline solution with the parts as the anode or cathode, using stainless steel plate, nickel plate, nickel-plated steel plate or titanium plate as the second electrode, and removing oil from the surface of the parts under the action of direct current. Before using plating equipment for electroplating, metal workpieces need to undergo rigorous degreasing treatment to ensure the adhesion and durability of the plating layer.

Electrochemical degreasing solution is similar to alkaline chemical degreasing solution, but it mainly relies on electrolysis to strengthen the effect of degreasing, usually electrochemical degreasing is more effective than chemical degreasing, faster, more thorough degreasing.

Principle of oil removal electrochemical degreasing in addition to chemical degreasing saponification and emulsification, but also has an electrochemical effect. Under electrolytic conditions, the polarization of the electrode reduces the interfacial tension between the oil and the solution, the solution increases the wettability of the surface of the parts, so that the oil film and the adhesion between the metal is reduced, so that the oil is easy to strip and dispersed into the solution emulsified and removed. In electrochemical degreasing, whether the parts as the anode or cathode, there is a large amount of gas precipitation on its surface.

When the parts for the cathode (cathodic degreasing), the surface of the reduction reaction, precipitation of hydrogen; parts for the anode (anode degreasing), the surface of the oxidation reaction, precipitation of oxygen.

Oxygen or hydrogen released at the interface between the metal and the solution during electrolysis plays an emulsifying role in the solution. Because small bubbles are easily adsorbed on the surface of the oil film, with the increase and growth of bubbles, these bubbles tear the oil film into small oil droplets and bring them to the surface of the liquid, and at the same time play a stirring role in the solution, accelerating the speed of oil removal from the surface of the parts.