When using acid zinc brightener, if the coating in the low current density area is dull and lacks luster, it often takes a lot of time to deal with the fault, and it will also cause production suspension losses. Therefore, understanding the causes of such faults and taking preventive measures can help achieve good coating quality. In this article, let's first discuss one of the reasons, which is lead impurity contamination.
If the lead impurity content in the plating solution is 0.005g/L, the luster of the passivation film will be poor. When its content is greater than 0.01g/L, the coating in the low current density area of the part will be incomplete, or even no zinc layer will be deposited. As the lead impurities continue to accumulate in the bath solution, it becomes particularly difficult to deposit a galvanized layer on the substrate.
In severe cases, no coating can be obtained on the entire cathode. Even if high-current impact plating is used, the resulting coating will shine in 3% nitric acid and show black mottled spots. The main sources of lead impurities are impure zinc anodes and high impurity content in zinc chloride.
So, how can we determine whether the plating solution contains excessive lead impurities? When using potassium chloride zinc plating brightener, technicians in electroplating plants can take a small amount of plating solution, immerse activated zinc sheets in the plating solution for 2 to 3 minutes, and then take them out for observation. If there is a color of lead replacement on the surface of the zinc sheet, it indicates that there are many lead impurities in the original plating solution and it needs to be treated.
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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. 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.If you need our high-quality electroplating additives, please contact us. We can provide you samples for test, and also provide a series of services.
