Adhesion Promoters: Optimizing Coating Performance
Types of Adhesion Promoters
Selecting the Right Adhesion Promoter
Methods to Test Paint Adhesion
Methods to Test Paint Adhesion
When testing and evaluating, a new adhesion promoter can be fastidious. It is possible to focus on critical points to reduce the time and material spent on the study keeping a high pertinence of results.
Cross-cut test: Gloss evaluation (ISO 2409)
It is an ISO test method where a pattern is cut into the film and sometimes removed by a normalized adhesive tape. A specific cutting tool can be used for this test.
Cross-cut Test for Adhesion Promoters
Tensile method: Pull-off test for adhesion (ISO 4624)
The pull-off method is the most widely used procedure. As a preparation for the test, a stud, normally made of steel, is glued with the coating. It is then subjected to axial tension until detachment of the paint film occurs. The result, i.e., the adhesion strength, is the maximum tensile stress that is possible at the interface.
Pull-off Test for Adhesion Promoters
Knife cutting method
Film separation is obtained using a sharp knife, pushed along the interface with an exactly measured force. Although this seems to be a simple test method, the process of detachment is complicated. It comprises both shear and tensile stresses, which finally cause disbanding of the film.
However, various other test methods also exist and can be used when necessary. There are so many different paint systems and applications that it would be unrealistic to look for a unique adhesion test method, such as:
- Peel test
- Blister test
- Scratch test
- Indentation debonding
- Impact test
- Conical mandrel bend test
- Ultrasonic pulse-echo system