Plant-based porous extrudates with characterized microstructure for absorbent and material applications

Overview

SaniSOLE has developed large-scale porous structures based on plant proteins using extrusion as a thermal processing technique. The current focus is on porous absorbents for hygiene articles, with demonstrated correlations between microstructure and liquid absorption performance. The underlying models and characterization approach are applicable beyond a single product, enabling the design of porous plant-based materials for any application where porosity and a connected porous network are required. By linking processing parameters to material performance, the technology helps reduce research and industrial development time and resources.

Technical specifications

Core technology:

• Plant-protein-based porous extrudates produced via thermal extrusion
• Step-wise processing assessment with property-dependent gradients evaluated along the extrudate length and cross-section
• Microstructural characterization using scanning electron microscopy (SEM), 3D microtomography, and surface area analysis (BET)
• Processing window optimization supported by rheology and thermal analysis (TGA, DSC)
• Absorption performance evaluated through free swell capacity, retention, and absorption under load using industrial methods
• Microstructure freezing methods applied at the extruder exit to study plasticizing effects and prevent collapse of the cell structure

Planned capabilities:

• Advanced characterization including Circular Dichroism (CD), solid-state NMR, FTIR, and synchrotron experiments to evaluate protein crosslinking during processing
• Scalability assessment across extruder sizes from grams to kilogram-scale production
• Chromatography-based elemental analysis before and after extrusion

Technology readiness level

The porous extrudate technology has been developed and validated through over five years of research at KTH's department of Fibre and Polymer Technology. Microstructural and absorption characterization methods have been established and applied to identify processing conditions that yield the best-performing materials. The team has progressed toward commercialization through KTH Innovation's pre-incubator programs and received the Stora Ingenjörspriset Innovation award in 2022. Further validation is planned to deepen understanding of protein crosslinking behavior, confirm scalability across production scales, and broaden the structure-functionality correlations for diverse porous material applications.