How to apply powder coatings

Pre-washing the surface of metals

Electrostatic powder coating can be applied on metal surfaces such as iron, galvanized, aluminum. In general, the metal surface must be thoroughly washed using appropriate chemicals before spraying and be free of pollutants such as fat, oil, dust, metal rust, rubber and plastic particles, after pre-washing and pre-heating, the metal surface should be coated immediately to prevent premature rusting, depending on the type of metal used, several methods of washing and surface preparation can be used:

• Chromate solution
• Phosphate solution
• Degreasing solution
• Laundry

 

It should be noted that the pH of the solutions and the amount of water should be checked daily so that the process of underlaying parts can be done in the best possible way.

 

Electrostatic coating spraying

Generally, there are two methods for electrostatic coating spraying:

• Corona
• Tribe

 

which is the most common method of spraying corona system powder coating in such a way that the electrostatic particles are charged (negative) and the object connected to the earth (positive) is free of charge, and thus, after spraying, the electrostatic coating sticks to the object.

 Heating powder coating

Electrostatic powder coating is cured when it passes through the furnace and forms a uniform coating, the required time and temperature should be proportional to the type of piece and its thickness and the characteristics of the desired color. Generally, 13 minutes at 200 degrees Celsius is recommended, during the preparation of a surface, apart from substructure and improvement, other points should also be considered. These points include:

 

1. The dust that is on the surface
2. The quality of water used for washing
3. How is the base surface pure metal or alloy?
4. What kind of metal compounds with or without iron
5. The type of cast metal, machined sheet, coil, sheet or a combination of these states
6. Weight, dimensions and appearance of the piece
7. Maintenance system control

 

Production and collection: Rangin Kimia Industrial Complex

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