New analysis of peeling data from paper

Abstract

Peel force measurements are used routinely in the adhesive industry to characterize the performance of pressure sensitive adhesive (PSA) tapes. Indeed the art of PSA formulation involves balancing “the peel,” a measure of adhesion, with shear tests, a measure of the cohesive strength of the PSA [1]. In many cases peeling is done from stainless steel, silicon, or glass and one usually observes either separation at the PSA/solid interface or cohesive failure within the adhesive layer. There had been many experimental and theoretical analyses of peeling from hard surfaces. Simple semi-empirical models can account for peel angle [2], peel rate and the contribution of thermodynamic work of adhesion [3, 4]. On the other hand, there are no fundamental models relating PSA material properties to peeling behavior because of the complexity of PSA deformation at the peel front. Our interests have focused on PSA peeling from paper. This is a more complicated system because paper surfaces are not uniform and because failure often occurs within the paper substrate. The overall goal of our work is to understand the links between paper properties and peeling behavior. The objective of this note is to introduce a new method of analysis of peeling data from paper. We anticipate that this analysis would also be relevant to peeling from skin and other weak substrates. Fig. 1 shows the peeling behavior for a PSA tape (3M No. 9974B) on newsprint. The peel angle was 180 degrees and the other experimental details were described previously [5]. At a low peel rate the tape cleanly separates from the paper (i.e. interfacial failure) and the peel force quickly achieves a steady-state value. The higher peel rate experiment shows more complicated behavior. After climbing to a peak value, the peel