During the production process of potassium salt zinc plating brighteners, excessively high pH levels can easily lead to coating defects. So why does the pH tend to rise too high? Or rather, why does the pH consistently show a slow upward trend? There are three reasons.
①Cathodic hydrogen evolution is the primary cause of the increase in pH value.
During the electroplating process, although the cathode current efficiency exceeds 95%, a small portion of the current is still consumed by hydrogen evolution, causing the pH value to rise.
② Dissolution of steel components
When using potassium salt zinc plating brighteners, the plating bath pH should be maintained between 4.5 and 5.5, exhibiting weak acidity. While the plating solution has limited dissolution effect on steel components, complex-shaped parts undergo chemical dissolution in low current density zones due to insufficient zinc deposition. This process reduces hydrogen ions to hydrogen gas, elevating the solution's pH. This phenomenon occurs more readily during barrel plating.
③ Chemical dissolution of zinc anodes
The anode current efficiency of potassium chloride galvanizing exceeds 100%. Why does this occur? This is because the anode is constantly in a state of chemical dissolution. Although this reaction process is very weak, chemical dissolution becomes more pronounced when the plating tank is idle for extended periods, especially with zinc anodes of lower purity, where chemical dissolution occurs more rapidly.
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Guangdong Bigely Technology Co., Ltd. ,founded in 2003, is a high-tech enterprise integrating R & D，production, sales and service, specializing in the production of electroplating additives/electroplating chemicals. As a famous electroplating additives source manufacturer in China, Bigely has over 20 years' experience in electroplating additives production and own production base of 5000 square meters. We can produce 15,000 tons of electroplating additives every year, which can fully meet the needs of customers.
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