A detailed elastic analysis of the flat punch (tack) test for pressure-sensitive adhesives

Abstract

Detailed finite element calculations are carried out in order to study the mechanical response of a compliant layer sandwiched between a rigid cylindrical flat punch and a rigid substrate. Two cases of practical interest are considered: one in which the layer is perfectly bonded to the punch and the substrate and one in which the interface between the punch and the layer is frictionless. The substrate is assumed to be perfectly bonded to the adhesive layer in both cases. Analytic expressions are obtained for the stresses away from the edges, and the effect of lateral constraint is examined. The compliances of the loading systems for both cases are obtained numerically, and accurate analytic expressions are determined based on these numeric results. The nature of the stress fields near the contact edge are explored, and their connections with the energy release rate are determined. The relevance of these calculations to two recent adhesion tests is discussed. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2769–2784, 2000

Using the simple compression test to determine Young’s modulus, Poisson’s ratio and the Coulomb friction coefficient

“…Similarly the boundary condition of r r = 0 at r = a will also be applied. Exact solutions for this type of problem for linear elasticity are discussed by Timoshenko and Goodier (1970) and lead to solutions in the form of Bessel functions in r. There are also some approximate solutions which follow this route (Lindsey et al, 1963;Kakavas and Blatz, 1991;Lin et al, 2000) for the fully constrained case and a comparison will be made in Section 5 with the results obtained here. Such results are, in effect, numerical and, as such, can more easily be derived using finite element analysis (FE).…”

Measurement of the mechanical properties of thin films mechanically confined within contacts

“…It can easily be recognized thatẼ 1 is in fact the so-called oedometric or longitudinal bulk modulus [15,16] of the layer, which corresponds to the elastic response of the constrained material under compression or extension, deformation in the lateral dimension being prevented. This finding is physically consistent with the expected deformation mode of a layer confined within a contact.…”

Morphology and elasticity of waterborne acrylic pressure-sensitive adhesives investigated with atomic force microscopy

“…PSAs are increasingly being used in more demanding applications that require enhanced performance characteristics [2]. Much progress has been made in understanding the mechanisms of tack and debonding in PSAs through a combination of modelling [3,4,5,6] and experiment [7,8,9,10,11,12]. This present work demonstrates a method to control the surface topography of a waterborne PSA.…”