Surface pretreatment method for anti-rust materials

1) Surface Cleaning. For metal powder coating processing, the cleaning method must be selected based on the nature of the surface to be protected against rust and the current conditions. Generally, commonly used methods include solvent cleaning, chemical treatment cleaning, and mechanical abrasion cleaning.

2) Surface dry. After cleaning, the surface can be dried using filtered dry compressed air, or dried with a dryer at 120-170°C, or dried with a clean cloth.

2. Rust Inhibitor Coating Methods

1. Immersion Coating Method

The clean metal parts are immersed into liquid rust-preventive oil until an adequate oil film thickness is achieved on the metal surface. After that, they are removed and drained to complete the dipping process. This method is mostly suitable for large quantities of metal products and components, such as bearings, measuring tools, cutting tools, hardware, standard parts, and auto and agricultural machinery components. It can also be used for individual large pieces. It is not suitable for products with a coated surface.

2. Brush Coating Method

Apply rust-proof oil with a brush and coat it onto the clean surface of metal parts. Dongguan metal powder coating processing uses this method for all products, especially for those with coated surfaces or areas prone to oil, brush coating is more suitable for local rust prevention. For example, large machinery and equipment can be brushed with oil. For products with complex structures, pipes, and numerous holes, it should be combined with other methods. During the brushing process, the coating should not be too thick, and it should be brushed evenly in both directions to avoid the formation of oxygen concentration cells on the metal surface due to uneven coating thickness, which can lead to corrosion at the thicker areas. Prevent corrosion caused by missed brushing.

3. Spray Coating Method

During the powder coating process for hardware, high-pressure air sprays rust-proof oil onto the clean surface of metal components. This method is suitable for coating large flat surfaces, pillars, precision product surfaces, and exposed surfaces of large machinery and equipment. During the spraying process, select the spray gun based on the oil's viscosity, control the appropriate pressure, ensuring a uniform oil mist without stringy oil or intermittent patterns. Additionally, control the oil temperature and spraying distance, extending the coating in a specific direction onto the surface of the components.