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4 reasons why the coating of the workpiece is blistered and the adhesion is not good during the application of alkaline zinc plating additives

2021-07-30

In the process of using alkaline zinc plating additives, sometimes the coating of the workpiece is prone to blistering and poor adhesion, which seriously affects the quality of the coating. What causes this?

Based on the field experience and the characteristics of the alkaline zinc plating additive BZ-518, Bigley Technology has made an analysis, mainly for the following 4 reasons:

1. The pre-treatment is not good. The degreasing and activation ability of alkaline zinc plating solution is worse than that of cyanide zinc plating solution, so the requirements for pretreatment are relatively high. Incomplete degreasing or excessive acid corrosion will cause the coating to bubble.

2. The bath temperature is too low. The temperature of the plating solution is low, the conductivity is poor, the adsorption of additives is relatively strong, and the coating is easy to be mixed with additives, which leads to increased brittleness and bubbling.

3. The quality of alkaline zinc plating additives is not good. Some alkaline zinc-plating additives react incompletely during synthesis and may continue to polymerize during long-term storage or long-term use. Such alkaline zinc-plating additives may easily deform the crystal lattice and generate stress and cause the coating to bubble. Therefore, the additives should be of good quality, such as Bigley's alkaline zinc plating additive BZ-518.

4. Too many organic impurities in the plating solution. The decomposition products of additives and the introduction of grease will cause the coating to become brittle, blisters, and streaks. Therefore, in the production process, the plating solution should be treated with activated carbon or hydrogen peroxide, and then filtered.

Therefore, the above 4 points should be paid attention to in the process of using alkaline zinc plating additives to avoid blistering and poor adhesion in the coating of the workpiece and reduce the occurrence of failures. If you are interested in alkaline zinc plating additives, please contact Bigley customer service for free samples and detailed technical information!

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