Adhesion test requirements for polyurea coating and its testing equipment

Adhesion testing can be used for quality control purposes, but more typically to follow Hengye standards and customer specifications. Unless otherwise specified, SSPC-PA 14 requires that a polyurea coating be tested either on the structure itself or on a representative sample of the substrate to be coated. The purpose of the test is "to confirm the quality of the applied coating and to recommend operating parameters for overall surface preparation and surface coating".

Due to the inherent adhesion and tensile strength properties of polyurea coatings, SSPC-PA 14 requires higher adhesion pullout strengths than other thick or elastic coating types. When testing for adhesion on steel substrates according to ASTM D 4541 Standards D & E, SSPC-PA 14 specifies that the pull force required three times should be at least 6.8 megapascal pressure [MPa] for each adhesion value (1000 lb per square inch [psi]), unless otherwise specified.

In addition, the SSPC–PA 14 standard requires that when testing polyurea coating adhesion on concrete (as described in ASTM D7234), each of the three pulls needs to be able to break the cohesion of the concrete matrix, while the polyurea coating Still adhered to the concrete. On request, a 20mm size nail capable of a maximum pullout force of 20MPa (3000psi) is recommended for testing the adhesion of most polyurea coatings, regardless of the composition of the substrate.

PosiTest AT pull-off adhesion Testers (both manual and automated) accurately test the bond strength of polyurea coatings applied to any rigid substrate.

The picture below shows the manual and automatic models of the PosiTest AT pull-off adhesion Tester:

Defelsko PosiTest AT Manual Pull-Off Adhesion Tester

Defelsko PosiTest AT Automatic Pull-Off Adhesion Tester