Prevention and cure of common defects of composite antirust pigment

2022-09-27

Only when you open the jar. When you open the barrel, you can see the appearance and stability of the paint. At this time, the disadvantages include floating water, caking, surface blistering, deterioration and mildew. The effect can be seen after painting. The disadvantages at this time include paint sagging, poor covering power, film surface shrinkage, uneven surface, lack of fullness and glossiness of external paint, etc. After a period of time, if the paint or paint quality is poor, there will be cracks, peeling, blistering, rust and other defects.

1. The main reasons for the blistering of the paint film are: the base material has oil dirt, rust particles, dust, etc.; The coating structure is not compact or there are too many hydrophilic substances in the paint, so water is easy to penetrate, resulting in air pressure, which makes the paint film rise. If there is too much foam, the whole coating will lose adhesion.

2. The main reasons for foam holes on the membrane surface are: improper selection and matching of defoamers; The defoamer is not evenly dispersed during the grouting and paint adjustment stage; The viscosity of rolling coating is too low, and the spray gun is not adjusted to a good place. There are bubble holes. The cavity is not covered with paint, water and oxygen are easy to invade, and corrosion occurs.

3. The main reason for coating shrinkage is that too much oil is used in the paint adjustment stage. Defoaming agent that is not easily dispersed in water; Materials with high surface tension such as lotion are not well distributed with other components; Poor fluidity of coating or oil stain of substrate; The dosage of defoamer and film forming agent is too large. There are many shrinkage holes, there is no paint at the hole, water and oxygen are easy to invade, rust is easy to come out and protect the air.

4. The main reasons for the hardness problem are related to the ceramic tile and dosage of the substrate, the oil absorption and dosage of the powder, and the environmental conditions during the film forming process, namely temperature and humidity. The film is too hard and flexible. Can not pass bending and impact resistance; The film is too soft, water penetration plasticized, and then retained corrosion effect is obvious.

5. The main reasons for poor water resistance (salt) are: poor quality of base material and insufficient dosage; Anti rust lotion does not rust; Because the surface tension of the coating is greater than that of the substrate, the adhesion between the primer and the substrate is poor; Poor quality of anti-rust materials; The paint color base is high; There are also fatal defects such as blistering and shrinkage. Some coatings cover the above shortcomings, so they are more resistant to water, salt water and even salt spray.

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