There are two reasons. One is that the coating itself has poor brightness. The other is that you didn't properly control the operation time of the trivalent chromium chromate zinc passivation solution.
The zinc coating itself has poor brightness
Since the passivation film layer is formed on the basis of the galvanized layer, if the foundation is poor, it will affect the appearance of the subsequent passivation film layer. What factors can affect the brightness of the galvanized layer? Many people instinctively think that it is due to insufficient brightening agent. This conclusion may hold true in alkaline galvanizing processes, but it may not be the case in potassium chloride galvanizing processes. For example, some electroplating factories have already added a lot of potassium chloride galvanizing brightening agents, but the coating is still not bright enough. At this time, the reason cannot be attributed to insufficient dosage, but rather the proportion of the brightening agent may be out of balance.
There are three other reasons that can cause the insufficient brightness of the coating:
① The contents of potassium chloride and zinc chloride are too low
② Iron and other heavy metal impurities contaminate the plating solution
③ Organic impurities contaminate the plating solution
It can be seen that the poor brightness of the coating is mainly caused by the poor production management of the electroplating factory. How to solve this problem? Exploring by oneself requires time cost, and when the production machines stop, it will also bring huge financial losses. Therefore, one can cooperate with the qualified chromic zinc passivation liquid manufacturer, such as Bigely, and follow the guidance of their engineers to learn to control the production factors before and after the passivation process, so as to avoid unnecessary detours.
About us
Guangdong Bigely Technology Co., Ltd. ,founded in 2003, is a high-tech enterprise integrating R & D，production, sales and service, specializing in the production of electroplating chemicals. As a fast growing electroplating chemicals supplier in China, Bigely has over 20 years' experience in electroplating additives production and own production base of 5000 square meters. We can produce 15,000 tons of electroplating additives every year, which can fully meet the needs of customers.
If you need our high-quality electroplating additives, please contact us. We can provide you samples for test, and also provide a series of services.
