The mutual attraction of the contact parts of two different substances is a manifestation of molecular force. It only shows up when the molecules of the two substances are very close together. Two solids do not normally come into close contact, and the adhesion between them does not work; Liquids and solids come into close contact, and the adhesion between them ACTS. For example, there is adhesion between a coating and the object it is applied to.

The adhesion of paint film of internal and external wall renovation coating refers to the fastness of the paint film and the surface of the coated material. This binding force is formed by the interaction between the polar groups (such as hydroxyl or carboxyl groups) of the polymer in the paint film and the polar groups on the surface of the coating. Contamination or moisture on the surface of the coating; Paint film itself has greater shrinkage ability; During the curing process, the polymer crosslinked with each other and reduced the number of polar groups. These are the factors that cause the film adhesion to decline. The adhesion of paint film can only be measured by indirect means. At present, there are three main methods to determine the adhesion of paint film, namely, the comprehensive determination method represented by the grid method and the circle method, the peeling test method represented by the pull method and the test water test method with solvent and softener.

Internal and external wall renovation adhesion is not good coating will cause metope powder, peeling, bubbling, coating peeling phenomenon. There are other reasons for the decrease of adhesion caused by internal and external wall renovation: the low-molecular materials in the coating migrate to the surface of the coating and gather between the paint film and the surface of the coating, which weakens the force between the polar groups of the polymer in the paint film and the polar groups on the surface of the coating. Enhance the adhesion of coating to be able to extend the beautiful sex of metope, basically be the PH value that should measure good metope before doing coating, the base material processing that does metope, besmear brushs good moistureproof resist alkali primer, besmear brushs face paint again after primer is completely dry, in order to enhance the adhesion between each coating, achieve the effect that increases coating service fixed number of years.