Hot metal spraying dust pollution is not a matter of tolerance and must be taken seriously!

       Thermal spraying refers to heating and melting the coating material, atomizing it into extremely fine particles with a high-speed airflow, and spraying it onto the surface of the workpiece at a high speed to form a coating. According to the need to select different layer removal materials, one or several properties of wear resistance, corrosion resistance, oxidation resistance, heat resistance, etc. can be obtained.



Some common thermal spray processes include plasma arc spray, combustion spray, electric arc spray, wire flame spray, high velocity oxy-fuel spray, cold spray and powder flame spray.



Thermal metal spraying is used across a wide range of industries and metalworking pervasive applications including automotive, agricultural, aerospace, gas turbine, gas or petrochemical.



/ Thermal metal spray dust characteristics /



Processes and consumable materials by which pollutants or smoke are generated. The particle size can range from over 50 µm to well below 1 µm with high dust and smoke generation rates. Contaminants from arc electrospray have a high percentage of particulates and higher smoke generation rates compared to other processes.



In addition, when these materials are exposed to high temperature, complex metal compounds such as hexavalent chromium, the resulting particles can also be ground, especially metal sprays are utilized.



/ Hot metal spray dust hazards /



The material used in thermal spraying is thermal spraying powder. A large amount of smoke and dust is generated during thermal spraying, which includes smoke and dust. The particles with a diameter of less than 0.1 μm are called smoke, and the particles with a diameter of between 0.1 μm and 10 μm are called dust.



The temperature of thermal spraying is very high, the temperature of flame spraying is above 3000 degrees Celsius, the temperature of arc spraying is above 6000 degrees Celsius, and the plasma temperature is even higher than tens of thousands of degrees. Such a high temperature causes the evaporation of metal elements, the metal vapor condenses rapidly in the air, and oxidizes to form thermal spray dust of different particle sizes. The smoke and dust stay in the air for a long time, and float in the air of the working environment in the form of aerosol.

The degree of harm of metal fume to the human body depends on the physical and chemical properties of the fume, the amount of fume inhaled by the human body, the intrusion route of the fume, and the location where the fume settles. Which can cause asthma, bronchitis and other respiratory diseases (as shown below).