When processing aluminum alloy products on the surface of aluminum radiators, there is always a common problem - flow marks on the surface of the workpiece. The reasons for its occurrence are quite complex, possibly related to impurities, pH, water washing, etc. In addition, there are many other common problems. Next, the author will integrate some common reasons.

1. Insufficient thickness of the anodic oxide film leads to color inconsistency in the later surface treatment. Check whether the anodizing process is standardized and whether factors such as temperature, voltage, and conductivity are stable. If there are any abnormalities, please adjust the specifications accordingly. If there are no abnormalities, the oxidation time can be appropriately extended to ensure that the film thickness reaches the corresponding thickness. Moreover, it is important to pay attention to whether there are residual acids in the membrane pores after oxidation, otherwise staining, blooming, and whitening may occur. If necessary, HT400 surface conditioner can be added to remove the residual acids.

2. The pH value of the dye solution is too high, resulting in color fading or inability to seal the product in the later stage. Both high and low levels can affect the pH value, and glacial acetic acid can be used to adjust it to the standard value.

3. Improper selection of dyes results in a lack of necessary elements in the dyeing bath of the workpiece, and uneven coloring of the aluminum radiator. Select appropriate dyes and replace the original coloring tank.

4. The oxidized product is left in the air for too long, causing the oxidation film pores to combine with air moisture and impurities, causing blockage, and the newly generated oxidation film is more prone to coloring. After product oxidation, coloring and related sealing treatment should be carried out as soon as possible.

5. The water washing is not clean, and there is residual liquid on the surface. Water washing takes up many steps in the oxidation process, and qualified water washing can reduce many oxidation problems. If necessary, HT60 chemical polishing and punching agent can be added during polishing to directly control the acid solution, achieving the effect of reducing the difficulty of water washing.

6. Alkali wash flow marks, alkali corrosion marks caused by the flow of alkaline solution on the aluminum surface, and localized corrosion of aluminum workpieces by alkaline solution. Shorten the time for transferring the alkaline washing tank to water washing and reduce the temperature of the alkaline washing solution; Reduce the corrosiveness of alkaline cleaning solution;

7. Unreasonable setting and operational issues with hanging tools. Before loading and hanging oxidation products into the tank, check whether the hanging position is correct and operate according to the post standard process.; The characteristics of aluminum radiators are that when coloring, the products are squeezed and stacked against each other. After oxidation, the products should be directly colored with the hanging fixture as soon as possible to avoid damaging the coloring film when the products overlap and shake in the basket after unloading.

8. There is dust adhered to the surface of the oxide layer, and when the dust impurities block the interaction between the tank liquid and the oxide layer for treatment. Clean the surface of the product with water to remove dust;

9. There are insoluble impurities in the dye. Replace the dye without impurities, or filter the color solution to remove insoluble impurities;

10. The dye concentration in the coloring solution is too low. Add dyes appropriately, and the mass concentration of the dye should be determined based on the dye used and the coloring depth, generally ranging from 0.5 to 5.0 g/L. When coloring light, the mass concentration of the dye is 0.5~1.0g/L; When dark colored, it is 5-10g/L, while when black colored, it can reach 10-15g/L. In some cases, extending the coloring treatment time can be used to allow dye molecules to fully penetrate deep into the pores of the oxide film, increasing color depth and facilitating color fixation and uniformity. This can be compared to the color card provided by the pigment supplier;

11. If the coloring treatment time for aluminum radiators is short, extend the coloring time appropriately. If the coloring time is short, the color will be light and easy to fade; If the coloring time is too long, the color is too deep, and the surface is prone to blooming and fading, so time control is also very important;

12. If there are too many impurities in the sealing groove and there is a quality issue with the sealing agent, try replacing it with another aluminum surface treatment additive manufacturer;

13. After anodizing of aluminum, do not directly put it into the drying channel. It should be hung and dried for about 30 minutes before entering low temperature (60-80 ℃) for 1-2 hours. The time can be adjusted appropriately according to the size and complexity of the workpiece.

If conditions permit, after anodizing, use a hair dryer to blow off the surface moisture, which must be blown at room temperature and cannot be heated.

These are common reasons, and the control is not very complex. The key lies in whether the production personnel can strictly follow the production standards for operation.