Pull-off forces for adhesive tapes

Abstract

An analysis is given of the force F required to pull an adhesive tape of unit width away from a rigid substrate in terms of the strength Ga of adhesion, the tensile modulus E of the tape, and its thickness t. Measurements are reported for several commercial adhesive tapes and compared with the predictions of the theory. Excellent agreement is obtained, suggesting that the theory is basically correct. Attention is drawn to the unusual form of the dependence of the failure force F upon the work Ga of detachment and the resistance Et of the tape to stretching in this case: F4 ∝ EtG. Even though the tape is assumed to be linearly elastic, the markedly nonlinear (cubic) relation between force F and displacement δ of the tape away from the substrate leads to this unusual result. Differences observed in Ga from pull-off and from 90° peeling experiments are tentatively attributed to additional energy losses in the latter case due to the severe bending deformations imposed on the tape as it is peeled away.