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

Purpose and goal:

The aim of this project was to investigate the possibility of using time-resolved synchrotron imaging at TOMCAT, PSI, and ForMAX, MAX IV, to increase the knowledge of liquid absorption in cellulose fiber networks. We studied different types of liquids´ impact and interaction with paper fiber networks. The outcome shows that synchrotron light tomography measurements with high spatial and time resolution are a suitable technique to study the different liquid transport mechanisms, swelling and pore structure changes in cellulose-based materials in real time.

Expected results and effects:

Measurement data from the time-resolved synchrotron based tomography experiments show how the liquid front moves in the fiber material and how the dimensions of the paper fiber network change over time due to liquid absorption. Furthermore, the measurement data shows how the liquid spread and the transport speed are affected by the type of liquid used.

The measurement results will be used in ongoing research projects for the development of physically based material models for liquid transport in paper fiber networks to develop the future fiber-based packaging. Approach and implementation:

Dynamic imaging of liquid absorption was carried out at TOMCAT (PSI) and ForMAX (MAX IV). Materials from paper straws were used in the experiments, interacting with different types of liquids. The measurements at both synchrotron light facilities were carried out by personnel from Tetra Pak, Lunds Universitet and RISE together with the radiation tube experts Schlepütz ( TOMCAT) and McDonald (ForMAX).

New test setups were developed for in-situ wetting of the sample material. Data analysis and evaluation are ongoing to extract quantitative information from the measurements.