Leak test for the material selection of a bonded edge seal for fluid-filled façade elements

The fluidIGU research project is developing a bonded edge seal for fluid-filled insulating glazing. With the help of such façade elements, multifunctional building envelopes can be created and the energy efficiency of buildings can be increased. As a result of the hydrostatic pressure, a high mechanical force acts on the bonded edge seal in addition to typical loads in façades. The permanent contact with the fluid also causes strong effects of aging. A two-zone structure is used to distribute the stress over two functional zones. The first functional zone serves as a seal and separates the fluid from the second, load-bearing functional zone. The adhesive selection for both functional areas was carried out in an extensive test program, an essential part of which are the leak tests that are the subject of this article. Firstly, an overview of fluid-filled façade elements is given and the test program is introduced. Particular focus is given to the leak tests, for which a new test set-up was developed. Finally, a conclusion is drawn on applicability of the developed test methods for the assessment of adhesive performance in fluid-filled insulated glazing.