A customer has reported that during the process of using alkaline zinc plating additives, there is always yellowing in the low area of the test piece during the Hull cell plating experiment. What is the reason for this?
Based on on-site experience and the characteristics of the alkaline zinc plating additive BZ-513, Bigley Technology has analyzed the following three main reasons:
1. The coating is too thin. Check whether the zinc alkali concentration in the plating solution is within the process range. Generally, the zinc concentration in the BZ-513 plating solution should be between 8-12g/L, and the alkali concentration range should be controlled within the range of 110-130g/L. In addition, the temperature, current density, and electroplating time of the plating solution should also be controlled within the normal range to ensure good quality and sufficient thickness of the galvanized layer, so that the low areas of the coating will not turn yellow.
2. The plating solution additive is out of balance or the softener is insufficient. The imbalance of additives or insufficient softeners in the plating solution can lead to a decrease in dispersion and depth ability. Adjusting the proportion of brighteners or supplementing softeners appropriately can refine the crystallization of the coating and effectively improve the dispersion and depth ability of the plating solution. If additive BZ-513 is used correctly, the ratio of high and low areas of the coating can be tested between 1.2 and 1.6:1, so that there will be no yellowing of the low areas of the coating.
3. The influence of organic impurities or sodium carbonate in the plating solution. When the content of organic impurities or sodium carbonate in the plating solution is high, it will lead to a decrease in the upper limit of the current density of the plating solution. Under the same conditions, the coating will be relatively thin, and the coating is also prone to yellowing and embrittlement. Therefore, the plating solution should undergo regular impurity removal treatment to reduce the impact of organic impurities or sodium carbonate.
Therefore, in the process of using alkaline zinc plating additives, the low area of the plating solution is prone to yellowing during plating, and the above three points should be noted to reduce the occurrence of faults. If you are interested in alkaline zinc plating additives, please contact Bigley customer service for free samples and detailed technical information!
If you want to learn more about galvanizing, you can click to view the "Common problem".
