1. Elasto-plastic approach for paper cockling phenomenon
- Author
-
Jari Hämäläinen, Jarmo Kouko, P. Lipponen, and Teemu Leppänen
- Subjects
Materials science ,elastoplasticity ,Mechanical Engineering ,Applied Mathematics ,paper ,Elasto plastic ,Mechanics ,finite element analysis ,Orthotropic material ,Condensed Matter Physics ,cockling ,Finite element method ,moisture gradient ,non-homogenous material ,Materials Science(all) ,Mechanics of Materials ,finite element ,Modeling and Simulation ,Modelling and Simulation ,General Materials Science ,Composite material ,Water content ,Moisture gradient - Abstract
Cockling of paper is a common problem occurring in the production, storage and end-use of paper. It is usually induced by a moisture content change. In many cases, cockling is an irreversible phenomenon; i.e. the initial shape is not obtained although the initial moisture content is restored. This kind of moisture content change occurs in copying machines and in the printing process, for example. In this paper, we present a continuum mechanical model, which is used to study the irreversible cockling of paper. In the model, paper is treated as an orthotropic elasto-plastic material and the model takes into account the small-scale variation of fibre orientation. The model is used to show the importance of the through-thickness moisture gradient on the cockling phenomenon during a cyclic moisture content change. The results suggest that the moisture gradient is a crucial factor for the irreversible cockling.
- Published
- 2008