Bond failure refers to poor bonding between the sealant and the substrate, resulting in poor sealing effect. Usually manifested as the peeling of the substrate and the sealant.

Cause Analysis:

1. Application problems　

1. Improper cleaning method of substrate surface and inappropriate solvent used for cleaning;

2. The surface cleaning of the substrate does not meet the requirements of the sealant application, and the surface of the substrate is not volatilized and dried when the sealant is applied;

3. The primer used is improper or the primer has expired before use;

4. Excessive primer on the surface of the substrate, and the surface of the substrate is not volatilized and dried when the sealant is applied;

5. The sealant in the interface is not fully compacted during the application of the sealant;

6. The contact area between the sealant and the substrate is too small to ensure the adhesion between the sealant and the substrate (unreasonable interface design);

7. The sealant is affected by external influences during the curing process, such as wind load, thermal expansion and contraction of the substrate, etc.;

8. During construction, the ambient temperature is lower than 5°C, causing condensation and dark dew on the surface of the substrate.

Applicability issues

1. The stone curtain wall has not been tested for pollution, and it is impossible to determine whether the sealant will contaminate the substrate;

2. The use of acid glue for metal and stone curtain walls will cause a chemical reaction between the glue and the substrate;

3. The use of acid glue for the adhesion of glass and aluminum profiles in the glass curtain wall, and the use of acid glue for the adhesion of the coated glass coating surface will cause the adhesion to fail;

4. There is no compatibility test or adhesion test before the start of construction, and the adhesion of the sealant and the substrate cannot be guaranteed. Chemically incompatible assembly accessories (such as: sealing strips, spacer strips, gasket strips, fixing blocks, etc.) contact with the sealant will cause the sealant to discolor or lose the adhesion between the sealant and the substrate.