Modelling the interfacial peeling of pressure-sensitive adhesives

Peel tests were performed using specimens which consisted of a polyester backing membrane supporting an acrylic pressure-sensitive adhesive adhered to a polyethylene substrate. Interfacial separation of the PSA from the polyethylene substrate was observed. Finite element (FE) peeling simulations were conducted which modelled the backing-membrane as an elasto-plastic power-law material, the adhesive as a viscoelastic material and the interfacial properties with a cohesive zone model (CZM). The material properties of the backing membrane and the pressure-sensitive adhesive were measured from tensile and stress relaxation experiments. The cohesive zone parameters were calculated analytically from the peel test data, as well as being measured directly from independent poker-chip probe tack tests. The numerical results from the CZM/FE simulations and the experimental values of the peel forces as a function of the peel angle were found to be in good agreement.