Synchrotron‑based investigation of sulfur homogeneity for strong packaging papers

At Mid Sweden University, we are conducting advanced research to enhance the strength and sustainability of packaging papers by optimizing the sulfonation process in chemithermomechanical pulps (CTMP). A uniform distribution of sulfonated lignin within and between fibers is essential for improving fiber bonding and mechanical properties. However, achieving consistent sulfonation is challenging due to wood chip size, density, and composition variations. This project aims to refine impregnation techniques to ensure consistent fiber softening while minimizing pulp production's chemical usage and energy consumption.

We are utilizing high-resolution X-ray fluorescence (XRF) analysis at leading synchrotron facilities, including Diamond Light Source in the UK and Elettra in Italy. Unlike traditional in-house XRF, which has limited spatial resolution, synchrotron-based XRF offers exceptional precision in mapping sulfur distribution at the micro level. By comparing sulfur homogeneity across different sulfite treatments and wood mixtures, we aim to develop more efficient pulping strategies that enhance fiber quality, reduce refining energy, and improve overall process efficiency.

This research aligns with global initiatives to replace fossil-based packaging with renewable, high-performance fiber materials. Our findings will support advancements in CTMP-based packaging and contribute to industrial innovation by optimizing pulping technologies. Supported by the Åforsk Foundation, this project fosters collaboration between academia and industry, driving sustainable solutions for the future of packaging.