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During the application of zincate zinc plating brightener, what are the factors that lead to poor adhesion of the galvanized layer?

2021-07-30

A customer consulted that in the production process of using zincate zinc plating brightener, the bonding force of the galvanized layer of the workpiece is always relatively poor, which seriously affects the quality of the galvanized layer of the workpiece. So, what are the factors that lead to the poor adhesion of the galvanized layer of the workpiece?

Bigley Technology has made an analysis based on the field experience and the characteristics of the zincate zinc plating brightener BZ-515. There are many factors that affect the adhesion of the galvanized layer, which may be caused by one cause or multiple Causes, the more common influencing factors are the following 5:

1. Degreasing of the workpiece is not clean. The bath of zincate zinc plating is alkaline. When the workpiece is not clean due to the pre-treatment degreasing, when the workpiece with oily dirt on the surface enters the plating tank, the oily dirt will interact with the alkaline substance before the zinc ion Preemptively discharge and deposit, the zinc layer will be deposited on the oil film, resulting in poor adhesion of the galvanized layer.

2. The workpiece stays in the cleaning water or air for a long time before galvanizing. Sometimes due to the shutdown of the production line, the workpiece stays in the cleaning water or air for a long time, resulting in passivation of the workpiece surface, which affects the bonding force of the workpiece galvanized layer.

Zincate zinc plating brightener

3. Too much brightener in the plating solution. The brightness of zincate galvanized layer will be worse than that of potassium chloride galvanized layer. Some people will add extra brightener during production to increase the brightness of galvanized layer, but this will not only fail to achieve the desired effect , It will also seriously affect the bonding force of the galvanized layer. Therefore, Bigley recommends to customers that the supplement of brightener should be supplemented in strict accordance with the consumption, and the principle of adding less and adding more frequently.

4. There is greasy dirt on the surface of the plating solution. After the zincate bath is produced for a period of time, a layer of floating oil formed by the decomposition products of oil stains and brighteners will be suspended on the surface of the plating bath. After the workpiece enters the tank, it will be surrounded by this layer of floating oil, which will cause the galvanized layer to be damaged. Peeling.

5. The thickness of the galvanized layer is too thick. When the thickness of the galvanized layer is too thick, the internal stress and brittleness of the coating will increase, and the workpiece will appear blistering and peeling at the edge. Generally, the thickness of the galvanized layer of the zincate galvanizing process should be controlled within 20μm.

Therefore, in the production process of using zincate zinc plating brightener, we should pay attention to the above 5 points to avoid the poor bonding force of the galvanized layer of the workpiece and affect the quality of the galvanized layer. If you are interested in zincate zinc plating brightener, please contact Bigley customer service to get free samples and detailed technical information!

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