This test method follows a procedure for evaluating the pull-off strength (commonly referred to as adhesion) of a coating by determining either, the greatest perpendicular force (in tension) that a surface area can bear before a plug of material is detached, or whether the surface remains intact at a prescribed force (pass/fail). Failure occurs along the weakest plane within the system comprised of the test fixture, adhesive coating system and substrate. The force per unit area required to reach a failure point as well as the mode of failure are reported. The nature of the failure is qualified in accordance with the percent of adhesive and cohesive failures and the actual interfaces and layers involved. The pull-off strength is computed based on the maximum indicated load, the instrument calibration data and the original surface area stressed.
- Coated flat panel, typically 4”x4”
Charter Coating’s Pull-Off Adhesion Tester