Evaluation of the influence of the material composition on the peel behavior of adhesive and cohesive peel systems using experimental fracture mechanics methods Bewertung des Einflusses der Materialzusammensetzung auf das Peelverhalten adhäsiver und kohäsiver Peelsysteme mit Hilfe experimenteller bruchmechanischer Methoden

The study focusses on a low-density polyethylene/isotactic polybutene-1 peel system with low-density polyethylene as matrix and isotactic polybutene-1 as peel component sealed against itself (cohesive peel system), and on an ethylene vinyl acetate/linear low-density polyethylene peel system with ethylene vinyl acetate as matrix and linear low-density polyethylene as peel component sealed against polyethylene terephthalate (adhesive peel system). Due to a new approach to estimate the true fracture surface using 3D reconstruction, it was possible to determine the true adhesive energy release rate, especially for cohesive peel systems. This enables a direct comparison of the fracture mechanics parameters determined from both types of peel systems. The results reveal that the recipe has a distinct influence on the peel behavior. An increasing amount of the used peel component leads in any case to a decrease of the peel force as well as of the energy release rate for both, sealed adhesive and cohesive peel systems. Using application engineering examples generalizable relationships between structure and properties of peel systems could be estimated and the structure sensitivity of the fracture mechanical parameters could be proven.