In the production process of using acid zinc plating brightener, sometimes such a phenomenon occurs: the current is not adjusted very much, and the coating is easy to burn. What should I do about this phenomenon?
Bigolly Technology made an analysis based on the field experience and the characteristics of the product acid zinc plating brightener BZ-528.The main reasons for this phenomenon are:
The zinc content in the acid zinc plating solution is low, the pH value is high or the acid zinc plating brightener content is low, which will lower the upper limit of the current density and cause the coating to be easily scorched.
When this kind of failure occurs, we must first measure the pH value of the plating solution. If the pH value is too high, an appropriate amount of hydrochloric acid can be used to lower the pH value.The zinc content in the plating solution can be determined by titration. If the zinc content in the plating solution is slightly low, the method of increasing the anode area and appropriately lowering the pH value of the plating solution can be used to gradually increase the zinc content. When the zinc content is too low, the zinc ion is supplemented by adding zinc chloride.
The concentration of acid zinc plating brightener in acid zinc bath can be confirmed by Hull cell experiment.When the concentration of brightener is low, the coating is rough, the range of current density is relatively narrow, and the color of the coating in the low current density area is dark. At this time, an appropriate amount of brightener is added to the plating solution, and the coating condition improves, and the problem is solved.
Therefore, we need to pay attention to the above 4 points in the production process of using acid zinc plating brightener, which can effectively avoid the phenomenon that the current is not adjusted well and the coating is easy to burn, and reduce the occurrence of failures.