In the production process of using decorative chrome plating additives, we often encounter gray and dull chrome plating and the phenomenon of blooming.However, after the chrome plating layer is removed, the surface of the nickel plating layer below is normal. What is the reason for this?
Bigolly Technology made an analysis based on the field experience and the characteristics of the product decorative chrome plating additive Cr-9, mainly for the following two reasons:
1. The chromium plating of the nickel plating layer is poor.If the nickel-plating additives used have poor cleaning properties, the surface of the workpiece is prone to residues of additives and cannot be cleaned properly, and the workpiece will appear flowery after chrome-plating.It is recommended to choose nickel plating additives with good chrome plating properties, such as Bigolly's Ni-301 nickel plating brightener. After the workpiece is plated with nickel layer, the water washing process should be strengthened to ensure that the workpiece is cleaned.
2. The surface of the workpiece has been passivated before chrome plating, mainly due to the passivation of the nickel layer surface caused by the washing time after the workpiece is electroplated with nickel.Therefore, after the workpiece is plated with the nickel layer, the washing time should be controlled to prevent the passivation of the coating, and the nickel activation process can also be added before the chrome plating to activate the nickel coating.
In addition, the residence time of each plating tank of some automatic lines cannot be adjusted, so that the workpiece stays in the washing tank after nickel plating for a long time, which is easy to cause the coating to bloom.At this time, 0.5~1g/L of sodium bicarbonate can be added to the washing tank to avoid passivation on the surface of the nickel layer.
Therefore, when we use decorative chrome plating additives, we choose a nickel-plating additive with good chrome-plating performance, and ensure that the workpiece surface is not passivated before chrome-plating, so as to avoid the phenomenon of graying and blooming after the workpiece is chrome-plated.If you are interested in chrome plating additives, please contact Bigolly customer service, you can get free samples and detailed technical information!
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