Peeling of Flexible Laminates—Determination of Interlayer Adhesion of Backsheet Laminates Used for Photovoltaic Modules

Delamination is one of the most critical failure modes of a PV module during service lifetime. Delamination within a backsheet primarily imposes a safety risk, but may also accelerate various other PV module degradation modes. The main aim of this paper is to present a peel test set-up, which is more practical in sample preparation and execution than the width-tapered cantilever beam test and overcomes some issues of standard peel tests like the influence of sample geometry and energy dissipation through deformation on the peel test results. The best results with respect to accuracy and effort were achieved by using a 180° peel geometry where an additional adhesive tape is applied to the peel arm in order to avoid plastic deformation or breakage. The additional support of the adhesive tape leads to comparable peel strength values without any influence of the plastic deformation behavior of the peel arms with different thickness.