Abstract
When liquid packaging board is made aseptic in the filling machine the unsealed edges of the board are exposed to hydrogen peroxide. A high level of liquid penetration may lead to aesthetic as well as functional defects. To be able to make a priori predictions of the edge wicking properties of a certain paperboard material is therefore of great interest to paper industry as well as to packaging manufacturers. In this paper a multi-scale framework is proposed that allows for detailed simulation of the edge wicking process. On the fiber micro-scale virtual paper models are generated based on input from tomographic and SEM images. A pore morphology method is used to calculate capillary pressure curves, and on the active pores one-phase flow simulations are performed for relative permeabilities. The results as functions of saturation and porosity are stored in a database. The database is used as input for two-phase flow simulations on the paper macro-scale. The resulting fluid penetration is validated against pressurized edge wick measurements on paper lab sheets with very good agreement. The proposed multi-scale approach can be used to increase the understanding of how edge wicking in paperboard packages depends on the micro-structure.
Acknowledgement
This work is part of the ISOP (Innovative Simulation of Paper) project which is performed by a consortium consisting of Albany International, Eka Chemicals, Stora Enso, Tetra Pak, Fraunhofer ITWM and Fraunhofer-Chalmers Centre.
Authors and Afillations
- A. Mark, Fraunhofer-Chalmers Centre
- A. Berce, Fraunhofer-Chalmers Centre
- R. Sandboge, Fraunhofer-Chalmers Centre
- F. Edelvik, Fraunhofer-Chalmers Centre
- E. Glatt, Fraunhofer ITWM
- S. Rief, Fraunhofer ITWM
- A. Wiegmann, Fraunhofer ITWM
- M. Fredlund, Stora Enso
- J. Amini, Stora Enso
- M. Rentzhog, Stora Enso
- R. Lai, Eka Chemicals
- L, Martinsson, Albany International
- U. Nyman, Tetra Pak
- J. Tryding, Tetra Pak