ASTM D4541 describes a procedure for evaluating the adhesion of coating systems on metal substrates. In fact, by using a portable adhesion Tester, it is possible to measure this property. Additionally, the peel strength of coatings on hard substrates such as plastics and wood can be characterized by this test protocol. However, for concrete, ASTM D7234 is required. Finally, the standard can be used as a complementary method to accelerated aging testing to assess the evolution of this property over time.
Measuring the Peel Strength of Coatings Using a Portable Adhesion Tester
ASTM D4541 Adhesion Test The purpose of ASTM D4541 is to provide guidelines for the preparation, testing and evaluation of results of coating systems to evaluate the tensile strength of samples. In fact, the adhesion ability of coated samples can be assessed by two testing protocols. Protocol 1 is used to determine the maximum force that can be applied to the sample area before the loading fixture separates from the sample.
ASTM D4541 Adhesion Test On the other hand, Protocol 2 is used to demonstrate the integrity of the coating specimen under the minimum load standard. More specifically, the test involves monitoring and gradually increasing the force exerted by the test equipment on a loading fixture that has been secured to the sample using an adhesive. The latter is increased until the restraint between the grips and the specimen fails, or until the specified force is reached or the maximum pull of the apparatus is reached.
ASTM D4541 typical test parameters
The number of samples required is three, and the typical parameters of the test are shown in Table 1.
Table 1: Typical Test Parameters
| parameter | Specification |
| pull rate | 1 MPa/s (150 psi/s) or less |
| Test duration | The selected rate is less than 100 seconds |
