What is the process of thermal spraying zinc wire?

       What is the process of thermal spraying zinc wire?

The whole construction process of thermal spraying zinc wire anticorrosion is divided into 4 kinds of surface treatment, zinc spraying and sealing treatment quality inspection.

Surface Treatment of Thermal Spray Zinc Wire



The quality of surface treatment directly affects the quality and protection period of electroplating, so it is necessary to do a good job of pretreatment at the base level first. According to the process requirements, the standard of rust removal and rust removal on the surface of the base layer is in accordance with the Sa3 grade standard of "Steel Surface Corrosion Grade and Rust Removal Grade before Coating" (GB8923-88). The specific quality requirements of this standard are: very thorough spraying, oxidation Accessories such as leather, oil, corrosion, dirt, paint, etc., showing a uniform metallic color, should be sprayed.



Sandblasting of thermal sprayed zinc wire



During the construction process, the following equipment and measures are used: air compressor, air tank, oil-water separator, air filter, sand tank, tape, sand spray gun, wear-resistant ceramic port. The abrasive is river sand with high hardness and an angle of 0.5-2mm. The sand is dry, the water content is less than 1%, and there is no impurities. The nozzle uses an expanded L-shaped ceramic mouth. During the expansion-compression-expansion stage, the airflow leaving the dune will reach supersonic speed, which greatly increases the kinetic energy of the injected abrasive, further activates and electrifies the surface of the body, and increases the bonding strength of the coating. The process of removing rust is to compress the air into the gas tank, pass through the oil-water separator and air filter to make it clean and dry, free of grease, and then enter the sandbox, press the sandpaper to the spray gun through the tape, and spray the metal gas. According to the above equipment conditions, the surface treatment can reach the Sa3 standard, and the surface roughness is 40um-60um. At this time, the electrode potential and activation degree of the metal surface and the adhesion of the coating reach the optimal parameters.



Zinc spraying of thermal spray zinc wire



The sandblasting of thermal spray zinc wire should be completed within 2-3 hours. After sandblasting, the electrode potential value of the substrate surface is greater than the electrode potential value before treatment, so the substrate surface reaches the minimum value of the electrode potential. At this time, the activation degree of the substrate surface reaches the maximum parameter, and the bonding strength of the electrode potential coating on the substrate surface is the highest, 2- Within 3 hours, the electrode potential on the substrate surface was basically stable. Over time, the electrode potential value of the surface will increase, the activation strength will weaken, and the bonding strength of the coating and the gas will decrease. This is because the thickness of the surface oxide film is generated within 2-3 hours when the sprayed particles hit the surface, and the thin oxide film is easily broken into high-speed sprayed particles. After 2-3 hours, the oxide film plays the role of separating electroplating and gas, destroying the adhesion of electroplating and gas. The spraying equipment uses domestic spray guns (generally use the portable spray gun for medium smoke produced by Shanghai Spraying Machinery Factory).