Zinc Spraying Machine Process

Temperature

When the temperature of the cast pipe coming out of the annealing furnace is as low as 200℃, it can be sprayed on the finishing line zinc spraying machine. The zinc spraying temperature of cast iron pipes should not be too high. If the temperature is too high, the zinc coating will easily turn yellow. When the temperature is too low, the adhesion between the coating and the outer wall of the pipe will be affected, and the adhesion and deposition rate will be reduced.

Material

Using the electrospray zinc process, the purity (mass fraction) of the zinc wire is not less than 99%, or the use of aluminum wire can be changed to copper wire (bronze, copper, brass). After spraying, it can also be sprayed with primer and then painted to meet the requirements of heavy anti-corrosion.

coating method

The zinc coating adopts the thermal spray zinc process. The pipe diameter of 80-1000mm is generally sprayed on one side with double spray guns, and the pipe diameter above 1000mm is generally sprayed with four spray guns on both sides. When spraying, a low-voltage high-current power supply is used to heat the zinc wire to a molten state, and with the help of compressed air, the molten zinc is atomized and sprayed onto the pipe wall in microdroplets.

Coating Requirements

The zinc coating shall cover the entire outer wall of the cast tube, without defects such as exposed spots and weak adhesion. The average weight per unit area of the zinc coating shall not be less than 130g/square meter, and the local minimum value shall not be less than 110g/square meter.