Powder coatings have been widely used in modern painting industry. Like other polymer materials, powder coatings will also have a variety of irreversible damage phenomena with the passage of time, such as discoloration, loss of light, powder, cracking and so on. Therefore, the comprehensive and systematic detection of its performance is particularly important.

1. Impact resistance

Impact resistance refers to the degree of deformation of the film under the action of high-speed load, reflecting the elasticity of the film and the adhesion to the substrate. The state of the coating after being subjected to specific impact energy, such as cracking, falling off, etc., is detected by forward impact and recoil. The thickness of the film and substrate and the surface treatment will affect the impact strength results.

2. Resistance to moisture and heat

The moisture and heat resistance of the film reflects its stability in high temperature and high humidity environment, and is also an important index to evaluate its corrosion resistance. In order to ensure the accuracy of the determination, it is necessary to use a special temperature and humidity control box, as well as distilled water and metal plate samples to meet the specific requirements. By exposing the test plate to constant temperature and high humidity environment, and rating the damage degree of the coating appearance, the moisture and heat resistance of the coating film can be obtained.

Powder coating resistance test

3. Neutral salt spray resistance

The main purpose of this method is to evaluate the stability of the coating in the salt spray environment. First, it is necessary to prepare a certain concentration of sodium chloride solution, and ensure that the pH value of the solution is between 6.5 and 7.2. Using a salt spray test chamber, the test plate is exposed to a neutral salt spray, and then the coating is evaluated according to the degree of salt spray.

4. Resistance to liquid media

This test examines the resistance of the film or coated specimen to liquids and includes soaking, absorbent media and drop methods. Different test plate materials, such as tinplate, steel plate and aluminum plate, have their own specific specifications and pretreatment requirements to ensure the reliability of the test.

5. Water resistance test

Water resistance is the evaluation of the stability of the film in a water environment. This method includes the immersion test method and the immersion boiling test method, which requires the use of specific specifications of the bottom plate and ensure that the water used meets the standard requirements.

Powder coating resistance test

6. Resistance to artificial climate aging

This is a method to simulate the aging process of the coating in the natural environment by simulating natural climatic factors to accelerate the aging of the coating. Compared with natural weather exposure, the durability data of the coatings can be obtained more quickly and directly by artificial weathering tests.

The inspection of coating performance is not only the evaluation of its appearance and basic physical and chemical properties, but more importantly, the overall evaluation of its stability and durability in a specific environment. With the continuous progress of coating technology, the detection method of coating performance should also be continuously improved and updated to ensure the high quality and long life of coating products.