How to distinguish between aluminum oxide dyeing and electrolytic coloring

The dyeing solution is generally easy to wash down with the corresponding solvent (such as: water, ethyl acetate, acetone, benzene, alcohol, gasoline, etc.), and is easy to be oxidized and faded by strong oxidants (such as potassium permanganate solution, 84 disinfectant, etc.), and even the color can be smoked off by sulfur fumigation; Electrolytic coloring is generally not easy to wash off, resistant to strong oxidants, resistant to sulfur fumigation, but often not resistant to strong acids.

Sometimes burning is also a good solution.

Concept of electrolytic coloring.

The so-called electrolytic coloring refers to the anodizing of aluminum and its alloys, alternating current electrolysis in an aqueous solution containing metal salts, and electrodepositing metals, metal oxides or metal compounds at the bottom of the porous layer of the anodized film, which presents various colors due to the scattering of light by electrodeposited substances, and this coloring method is called electrolytic coloring method or secondary electrolytic coloring method [1].

Classification of electrolytic coloring methods.

Electrolytic coloring methods can be divided into the following types according to their electrolyte composition, properties and process implementation methods:

a.Monometallic salt coloring solution bPolymetallic salt colorant cTwo coloring solutions are colored continuously dThree-groove three-stage coloring.

In electrolytic coloring, nickel salts and stannous salts are easily deposited at the bottom of the oxide film pores, while copper salts and zinc salts are easily deposited on the surface of the pores.

Anodizing chemical dyeing is the use of the porosity and chemical activity of the oxide film layer to adsorb various pigments to make the oxide film colored, according to the coloring mechanism and process, it can be divided into organic dye coloring, inorganic dye coloring, color paste printing, color matching dyeing and achromatic dyeing.

The resulting color is single and uniform.

Summary. Hello, common problems and solutions of aluminum oxide dyeingCommon problems and solutions of aluminum oxide dyeing.

1. The dyeing is not colored, 1. The thickness of the anodized film is insufficient. The solution is to check whether the anodizing process is standardized, to see whether the temperature, voltage, conductivity and other factors are stable, if there is any abnormality, please adjust the specification accordingly, if there is no abnormality, the oxidation time can be appropriately extended to ensure that the film thickness is up to standard.

2. If the pH value of the dye solution is too high, at this time, the pH value can be adjusted to the standard value with glacial acetic acid.

3. After oxidation, the workpiece is placed in the sink for too long. Timely dyeing is advocated, and if this has already happened, the workpiece can be placed in an anodizing tank or a nitric acid neutralization tank for proper activation treatment before dyeing, and the effect will be very good. 4. Improper selection of dyes.

Choose the right dye.

5. The dye has been decomposed or mildewed, and the dye needs to be replaced at this time

6. The oxidation temperature is too low, resulting in a dense film. The oxidation temperature can be increased appropriately.

Aluminum oxide staining problems.

Hello, common problems and solutions of aluminum oxide dyeingCommon problems and solutions of aluminum oxide dyeing.

1. The dyeing is not colored, 1. The thickness of the anodized film is insufficient. The solution is to check whether the anodizing process is standardized, to see whether the temperature, voltage, conductivity and other factors are stable, if there is any abnormality, please adjust the specification accordingly, if there is no exception, the oxidation time can be appropriately extended to ensure that the film thickness is up to standard. 2. If the pH value of the dyeing solution is too high, at this time, the pH value can be adjusted to the standard value with glacial acetic acid.

3. After oxidation, the workpiece is placed in the sink for too long. Timely dyeing is advocated, and if this has already happened, the workpiece can be placed in an anodizing tank or a nitric acid neutralization tank for proper activation treatment before dyeing, and the effect will be very good. 4. Improper selection of dyes.

Choose the right dye. 5. The dye has been decomposed or mildewed, and the dye needs to be replaced at this time6. The oxidation temperature is too low, resulting in a dense film.

The oxidation temperature can be increased appropriately.

All of these factors can lead to this failure, and can be eliminated with careful detection and accurate judgment.

Have a great day! Happy every day

The aluminium products in the store are colorful, some are golden, some are turquoise, and some are bright red ......These colors are not painted like paint, but are adsorbed and colored by the adsorption of alumina.

Aluminum oxidizes rapidly in the air, forming a dense oxide film on the surface to protect the aluminum inside from further oxidation. However, the film formed by natural oxidation is generally only a few microns thick, which is not resistant to friction and cannot be used for coloring.

To carry out the oxidation coloring of aluminum, the first thing is to make a thicker oxide film on the surface of aluminum, the practice is to use 1 4 sulfuric acid as an electrolyte, aluminum products for the anode, carbon rod for the cathode for electrolysis, about half an hour, the surface of the aluminum products to generate a thicker oxide film, up to tens of microns, there are many pores in it, can adsorb color molecules. After the aluminum product is soaked in the dyeing solution, the color is absorbed by the oxide film, and the aluminum product shows color. Finally, the dyed aluminum products are put into the sealing solution and heated to close the pores, so that the color of the surface of the aluminum products will be maintained for a long time.

As can be seen from the production process described above, the oxidation coloring treatment of aluminum products has two functions, one is to thicken the oxide film and increase wear resistance, and the other is to be bright and beautiful after coloring.

Electrolytic coloring film refers to an oxide film based on the transparent anodic oxide film of primary electrolysis of sulfuric acid and electrolytically colored by DC or AC in a solution containing metal salts, which is also called a secondary electrolytic film in Japan. It means that anodizing is called primary electrolysis, while electrolytic coloring is called secondary electrolysis. Polychromatic technology, which is beginning to be popularized in industry, can obtain multiple colors in one electrolytic coloring tank.

This is a new type of electrolytic coloring method that uses the effect of interfering light, and it is also called the triple electrolysis method in Japan because of the addition of electrolytic adjustment before electrolytic coloring.

The weather resistance, lightfastness and service life of electrolytic coloring film are much better than that of dyed film, and its energy consumption and coloring cost are much lower than that of the overall coloring film, which has been widely used in the coloring of architectural aluminum profiles. In the 60s of the 20th century, after the advent and industrialization of Japan's Asada method, AC electrolytic coloring technology took the lead with its good oxide film performance, convenient industrial control and low operating cost, and became the preferred coloring method for anodizing film of architectural aluminum profiles. The electrolytic coloring technology has been continuously developed and improved through the test of industrial practice, the coloring power supply is updated, the composition of the bath liquid is stable, the process is more mature, the cost is decreasing, and the scale is expanding day by day.

Electrolytic coloring technology has made great progress in theory and practice, especially in the anodizing electrolytic coloring project, today's industrialization process is not the same as the early literature patents, and there have been several kinds of aluminum anodized film electrolytic coloring summary monographs published abroad.