D.W. Coffin. Developing a deeper understanding of the constitutive behavior of paper. In Advances in Pulp and Paper Research, Oxford 2009, Trans. of the XIVth Fund. Res. Symp. Oxford, 2009, (S.J. I’Anson, ed.), pp 841–875, FRC, Manchester, 2018.
A constitutive equation for the mechanical behavior of paper is presented. Since the initial work in the late 1940’s rheology studies of paper seem to come in waves and the results have not always been viewed favorably. With the benefit of fifty years of literature and the relative speed of modern computing, a more robust constitutive model is certainly within reach. The presented model captures the essence of the mechanical response and links the stress-strain curve to relaxation and creep in a reasonable manner. Experimental results are provided to illustrate the important components of the behavior and the model can easily be generalized to include more subtle features.