In the production process of the potassium chloride zinc plating brightener we used, after the plating solution is heavily treated, the workpiece coating is prone to appear black and gray, and the Hull cell test coupon is also gray,and after adding brightener, the coating will be bright. What is the reason?
According to the field experience and the characteristics of the product potassium chloride zinc plating brightener BZ-528, Bigolly Technology has made analysis, mainly for the following three reasons:
1. Hydrogen peroxide remains in the plating solution.The residual hydrogen peroxide will oxidize the brightener, resulting in insufficient concentration of the brightener. At this time, the zinc coating will become gray and not bright.In this case, the plating solution shall be heated to 60 ℃ and kept for 2 hours to completely remove the hydrogen peroxide in the plating solution.
2. The pH value of the plating solution is too high.Some customers forget to adjust the pH value of the bath back to the process range in the process of large-scale treatment of the bath, which leads to the high pH value of the bath and the blackening, roughness and looseness of the coating.In this case, 5%~10% hydrochloric acid solution shall be used, and the pH value of the plating solution shall be adjusted within the range of 4.6~5.4 under the condition of vigorous stirring.
3. The concentration of brightener in the plating solution is insufficient.The concentration of brightener in the bath is insufficient or absent after large treatment.At this time, the additive amount of brightener shall be determined by Hull cell test. After that, the plating bath shall be supplemented according to the additive amount, and the production can only be started after the product trial plating is normal.
Therefore, we should pay attention to the above three points after major treatment of the plating solution in the production process of using potassium chloride zinc plating brightener, and eliminate the fault in time to resume production.If you are interested in potassium chloride zinc plating brightener, please contact the Bigolly customer service for free samples and detailed technical information!
If you want to know more about zinc plating,you can click to view "Electroplating encyclopedia".