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Three Reasons for Inconsistent Color of Aluminum Profile Oxidation Coloring

First. Reasons for anodic oxidation

1, the principle of oxidation dyeing: after dyeing, it must go through the sealing treatment, fixing the dye in the film hole, and increasing the corrosion resistance and wear resistance of the oxide film.

2, anodic oxidation process on the influence of dyeing: oxidation tank liquid temperature on dyeing is very significant, too low temperature or too high temperature is not conducive to dyeing control, oxidation tank temperature change should be within 2 ℃ appropriate; current density is too large, in the case of a certain film thickness, we must correspondingly shorten the electrolysis time of aluminum products in the tank; film thickness is too low, dyeing is easy to appear uneven phenomenon, while in the requirement of dyeing When the dark color (such as black) is required, because the film thickness is not enough, the amount of dye deposition is limited and the required color depth cannot be reached; in a word, anodic oxidation, as the pre-process of dyeing, is the basis of dyeing.

Second, The reason for dyeing

1. It is very necessary to set up pure water cleaning before dyeing tank and to monitor the water quality.

2、In order to effectively prevent the tank solution from getting moldy, before preparing the tank solution, you can disinfect the tank with bleach and phenol. When preparing the bath, adding anti-mildew agent can effectively extend the use time of the dyeing solution. After preparing the bath, it should be stored for several hours before it can be put into use.

3、Dyeing process control
For different color requirements, the dyeing temperature can be adjusted appropriately to avoid the dyeing time being too long or too short. The actual dyeing power of the dyeing tank should be tested periodically in comparison. To ensure stable dyeing power, the tank solution can be partially replaced after a period of production. Dyeing time is too long, or no matter how long dyeing can not get the required color depth, at this time we have to consider whether the oxide film is too thin or the dye concentration is too low. Stable ph value is very important for dyeing, in order to strengthen the stability of ph value, add buffer solution when preparing the tank solution, and also strengthen the water washing before dyeing to avoid bringing acidic substances.

4、Wash after dyeing
After dyeing, the aluminum products should be washed to remove the floating color attached to the surface of the aluminum products, at this time, we should pay attention to the water quality of the washing tank, because the combination of dye molecules and oxide film is reversible, when there are more impurity ions in the water, it will prompt the separation of dye molecules and oxide film into the water, at this time, it shows fading, this fading is often uneven, which eventually leads to color difference on the same material.

Third, The reason for sealing hole: sealing hole treatment is an indispensable part of anodic oxidation, after oxidation dyeing, the only way to ensure the original color of the dyed film is to carry out sealing hole treatment, sealing hole process can be a variety of steam sealing hole, hot water sealing hole, medium temperature sealing hole are good choices, some dyes can also choose cold sealing hole process.

Yan yifan

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