The use of shrinkage and leveling agents in coatings

Paint, commonly referred to as paint, is applied to the surface of an object to form a layer of adhesive, strong, solid film that serves a protective and decorative purpose. Shrinkage is a small circular pit that appears on the coating film and is one of the common problems in coating application. It is generally prevented by using leveling agents.

After the coating construction is completed, it enters the leveling stage, and the wet film gradually dries and shrinks. At this time, small holes of different sizes often appear, which are called shrinkage holes. It leads to obvious defects on the surface of the paint film, seriously affecting its luster and stain resistance, and significantly reducing its aesthetics and practicality.

Root cause:

The surface tension of the coating is uneven. Under the action of tension difference, the coating flows from low surface tension to high surface tension, resulting in uneven appearance of the coating and the formation of shrinkage cavities.

Influencing factors:

1. Poor degreasing before painting treatment

2. The coating itself contains low surface tension droplets

3. Poor construction environment, contamination of coatings, and formation of low surface tension zones by pollutants

4. Poor resin dissolution in coatings

5. Improper selection of defoamers, etc

Adverse effects:

1. Appearance: Ugly, poor painting effect, difficult to pass inspection

2. Practicality: Shrinkage reduces the sealing performance of the coating, allowing water to enter and exit freely, and the waterproof performance is almost lost. Adequate moisture greatly increases the possibility of mold growth, foaming, peeling, and alkali leaching, which accelerates the aging of the coating.