Oxidation, coloring and sealing treatment are traditional surface treatment processes of aluminum profile, which make aluminum profile perishable and poorly durable especially in the environment of acid rain and ocean.Therefore, people have tried to improve the decoration of aluminum profile and extend durable years by means of coating since 1970s. At present, electrophoresis paint, powder paint and fluorocarbon paint have been successfully industrialized. Since electrophoresis paint is a type of water-based paint, aluminum profile can be directly electrophoresed after watering pretreatment. Electrophoresis coverage has a high transparency, and it’s highly decorative and is able to highlight metallic luster of aluminum profile. It is now widely used by architectural aluminum profile.
The electrophoretic coating method is suitable for the production process of a large number of assembly lines. The update period of Shenzhen aluminum profile in the electrophoresis groove should be within 3 months. Take an annual output of 300000 rims electrophoresis production line as an example.It is vital to manage bath scientifically, to test all kinds of numbers of the bath regularly, and to adjust or replace the bath according to the test results. Generally, the bath is tested as the following frequency : electrophoresis liquid, ultrafiltrate and ultrafiltration cleaning fluid, Yin (Yang) pole fluid, loop lotion, PH of ion cleaning solution, solid content and electric conductivity should be tested once a day; the content of the acrylic, organic solvents and test chamber should be tested twice a week. Aluminum processing manufacturer should manage the quality of paint film by checking the uniformity of the coating and film thickness frequently.There should not be pinhole, wrinkle, sagging, or orange skin,and physical and chemical indexes such as adhesion of the coating and its corrosion resistance ought to be tested regularly. In general, each batch should be tested within the inspection period according to the standard of the manufacturer. The advantages of the aluminum window of the insulation door and window technology are light weight, high strength and wear resistance, which is easy to become aluminum window parts of all kinds of complex shapes by extrusion. Aluminum can be electroplated or covered by other surfaces, making aluminum more durable and reduce maintenance costs.
Advantages of electrophoresis paint:
1、High utilization rate. Because it has a low viscosity and less workpiece as well as the electrophoretic workpiece can be washed, the utilization rate of electrophoretic coating can reach over 95% with a recycling device.
2、High safety and environmental protection. Electrophoresis coating is water diluted and has a low solids and low solvent content which are fairly environmentally friendly.In addition, the danger of fire is relieved and the workers’ health is also guaranteed.
3、Excellent coating quality. Acrylic resin with amino resin’s solidification ensures a high decorative level and high corrosion resistance of coating. At the same time,it effectively highlights the aluminum metallic texture, due to the highly transparent resin, to obtain decorative effect such as inferior smooth, sand surface and pearl surface if necessary.
Compared with usual electrolytic shading process, it has the characteristics of time and manpower saving. The electrophoresis coating has no need to seal the hole, and the aluminum profile avoids the defects caused by the crack of the sealing hole. The thickness of the film can be controlled freely, and it is usually controlled at 7μm and 12μm at home and abroad.
It is key to develop the aluminum profile processing technology and improve the qualification rate of electrophoretic material. The high cost of electrophoretic profiles is due to low qualified rate. If the qualified rate is less than 80%, there will be no profit or even loss. To the contrary, it is profitable with a qualified rate more than 90%. Therefore, this is an essential factor for the development of electrophoresis technology. The high transparency of electrophoretic paint causes the casting shrinkage cavity, and some flaws are revealed such as the black color, black line, coarse grain caused by molds extrusion, collision scratches, combination of the coarse crystal line, black and white spot;broken flower, marking and water mark caused in oxidation coloring process;dust, burr and nodular caused by environmental conditions and a low swimming through rate, surface of Yin and Yang and a high rate of porosity caused by electrophoresis. Comprehensive technical level of aluminum processing must be systematically improved.
