Open source Monte carlo simulation platform for particle level simulation of light scattering from generated paper structures

Abstract

The Kubelka-Munk model and extensions thereof are extensively used in product development, thanks to their simplicity and the fact that they are invertible. However, their explanative power is limited to distinguishing processes that aect scat- tering properties from those that aect absorption properties, an example being the frequently observed decrease of the scattering coecient with calendering. Better under- standing of how internal structural changes aect the optical properties requires mod- elling the composite structure of a paper layer. We propose a modular object-oriented Open Source Monte Carlo simulation platform, Open PaperOpt, which allows dierent geometrical representations of the inner paper structure. The proposed le formats open for a standardisation that facilitates data exchange between dierent simulation tools and measuring instruments, and supports a broad dissemination of the simulation software. We applied the model to the analysis of the eect of calendering on the optical proper- ties of uncoated paper. The simulation results agreed well with reectance measurements and indicate that the light scattering decrease due to calendering can be explained by a change in pore size and shape.