Rate Dependent Adhesion Energy and Nonsteady Peeling of Inextensible Tapes

Elastomer based pressure sensitive adhesives used in various peeling applications are viscoelastic and expected to be rate sensitive. The effects of varying peel velocity on adhesion energy and its dependence on the peel angle and rate of peeling are investigated. Experiments are conducted on an adhesive tape using a displacement-controlled peel test configuration. By adjusting the peel arm length, the peel velocity can be continuously varied though the extremity of the film is displaced at a constant rate, which results in nonsteady peeling. Constant peel rate tests are performed over a wide range of peeling rates for a fixed peeling angle, which results in steady state peeling. Based upon the experimental data, a power law relation for the adhesive energy of a packaging tape and its dependence on the rate of peeling is presented. The applicability of the rate dependent law for adhesion energy based upon the steady state experiments to the nonsteady peeling process is critically examined.