Adhesive behaviour of bonded paper layers: Mechanical testing and statistical modelling

In this study, an experimental methodology based on micromechanical testing inside a scanning electron microscope isproposed to characterise bonding of paper layers connected by wet pressing. The peeling force–displacement evolutionlaw that characterises the delamination of micromechanical double cantilever beam specimens of paper tissue have beenextracted from such peeling tests. It is observed that the force–displacement evolution curve achieves a steady-statevalue related to the effective adhesive energy of the interface. This behaviour is explained by examining the complex loadtransfer mechanism between the layers exerted by cellulose fibrils. A statistical approach is used for the computation ofthe effective adhesive energy. It is argued that the observed force–displacement evolution law may be satisfactorydescribed by a stochastic model that depends on the distribution function of the fibrils strength, and on two geometricaldistribution functions related to the in-plane and out-of-plane fibrils angles with respect to the undeformed interfaceconfiguration. Some applications of the proposed model are demonstrated on examples.