Some customers reported that in the production process of using alkaline galvanizing brightener, the appearance of the coating after the workpiece is galvanized is good, but the coating has foaming phenomenon after baking, what is the reason for this?
Bigolly Technology made an analysis based on the field experience and the characteristics of the product alkaline galvanizing brightener BZ-515, mainly including the following 4 points:
1. Poor pretreatment.The putty pre-treated on the workpiece is not cleaned, resulting in poor adhesion between the galvanized layer and the substrate. During baking, the expansion coefficient of the coating and the substrate is different, and blistering will occur.
2. Improper control of bath operating conditions.In the galvanizing process, when the operating conditions are not controlled properly, such as the temperature is too low or the current density is too high, the coating is easily mixed with organic impurities, so that the coating is prone to foaming after baking.
3. The influence of metal impurities in the plating solution.When the content of metal impurities such as copper and lead in the plating solution is high, the galvanized layer is easily mixed with impurities such as copper and lead, resulting in poor adhesion between the coating and the substrate, and the coating is prone to blistering after baking.
4. The influence of post-galvanizing treatment.After the workpiece is galvanized, improper operation during bright dipping and passivation, or incomplete cleaning will cause the bright dipping solution or passivation solution to remain in the coating, and the coating is prone to foaming after baking.In addition, the temperature of the workpiece should be strictly controlled during baking and aging, otherwise the galvanized layer is prone to foaming.
Therefore, in the production process of using alkaline galvanized brightener, we should pay attention to the above four points, which can effectively prevent the workpiece from foaming after baking and reduce the occurrence of failures.If you are interested in alkaline galvanizing brightener, please contact Bigolly customer service, you can get free samples and detailed technical information!
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