Real time 4D X-ray microtomography Imaging and analysis of water transport mechanisms in sustainable paper straws

Purpose and goal

At present, there are no quantitative experimental studies for liquid transport with relevant spatial and temporal resolution in cellulose fiber networks. This project aims to improve the understanding of the dynamic interplay between water transport processes and the cellulose fiber network. In this way, the proportion of sorption of water in pores and cell walls can be quantified and structural changes of the fibers and the fiber network can be monitored during the process. The goal is to create validated simulation models for the transport of water in cellulose fiber structures.

Expected results and effects

The project consortium consists of TetraPak, LU and RISE. The project will contribute valuable knowledge that will be used in the new development and the optimization of sustainable / environmental paper-based packaging materials. The results from the synchrotron experiments will identify the material structures and the water transport, calibrate material parameters, verify digital twins / calculation models and validate newly developed theory. This will lead to an increased understanding of the mechanical properties of paper straws and structural changes during water absorption.

Planned approach and implementation

Fiber-based strips with different material structures and behaviour will be imaged with X-ray tomography. This technology enables time-resolved dynamic studies with high resolution and in-situ studies of the water absorption processes in the fiber network structure. An experimental test environment will be developed, designed and built. At first, the sample environment will be used in a laboratory-based X-ray equipment for optimization and a beam line, e.g. ForMAX on MAXIV or TOMCAT on PSI in Switzerland. The analyzed and digitized structures will be modeled using digital twins.