Numerous factors affecting the uniformity of coating in coating machines

After using the coating machine for a long time, some malfunctions may occur, and uneven weight distribution of the positive electrode plate is the most common situation, which can lead to the phenomenon of thick in the middle and thin on both sides, seriously affecting production progress. The many factors that affect the uniformity of coating generally include: material, viscosity of the slurry, uniformity of the slurry, and uniformity of the substrate thickness; In terms of equipment, the smoothness of the radial circle of the scraper and coating roller, the flatness of the axial direction, and the parallelism of the installation of the scraper and coating roller, etc.

If there are problems with the use of recycled materials during the initial batch production process, it is necessary to consider whether it is caused by uneven mixing of recycled materials. It is necessary to arrange for the re preparation of positive electrode slurry without recycled materials, conduct coating experiments, and check the results.

Measure the substrate aluminum foil used, with a uniform thickness.

Equipment. The coating machine is the most expensive and complex equipment in battery production, with high requirements for the processing accuracy and assembly accuracy of each component. General engineering personnel need years of exploration and experience to operate independently.

1、 If it is a densely packed small dot. There are two possibilities:

1. The air flow in the first few sections of the coating machine is too high, and the adhesive surface is not cured yet. Use strong wind to blow it up, which will definitely produce pitting.

Improvement method: If there is an air volume valve, control the air volume well. If not, check which section of the oven has a spot and turn off the fan in that section.

2. The materials used are not suitable for blowing hot air from the top first. It may be necessary to change the air duct of the previous sections and blow hot air from the bottom up.

2、 If it is larger, there are two situations:

1. The glue contains water, which will form pores after heating.

2. The temperature in the first few sections of the coating machine is too high, causing the adhesive to form a surface dry layer. After heating up again, the solvent will drill out the surface dry layer, resulting in a pore like pattern.

Improvement method: Reduce the temperature of the first few sections and let it gradually warm up.