ICNF 2015 - 2nd International Conference on Natural Fibers
Aart van Vuure
The Composite Materials Group (CMG) of the Department of Materials Engineering of KU Leuven (Belgium) pays considerable attention to natural fibres and bio-based composites. Currently about 10 of its members (around 35 in total) work on this theme. Focal points are fibre structure-property relations, physical-chemical-(micro)-mechanical analysis of interfaces and processing related issues such as fibre extraction and low twist preforming. Recently much attention goes to durability of bio-composites including improving moisture resistance and improving internal fibre strength. Fully bio-based composites have been developed with a gluten matrix. Main projects center around performance of bamboo, flax and hemp fibres.
The keynote lecture will present some of our research highlights. KU Leuven has a unique process to extract high quality bamboo fibres. Currently, research is ongoing to produce a continuous unidirectional tape from these fibres. Extracted bamboo fibres have a lignin rich surface, which means that their moisture resistance is decent, e.g. compared to flax fibres. Treatments are developed for flax fibres, which have high pectin content in their middle lamellae, which is most likely detrimental for mechanical performance and moisture resistance.
To optimize fibre-matrix interfacial strength, an integrated physical-chemical-micromechanical approach is used. Particularly, suitable thermoplastic matrices have been selected with this approach. Improving interface quality is also a key element in improving natural fibre composite durability. Flax fibre composites appear to have similar fatigue characteristics as glass fibre composites. Work on natural fibre composites with a gluten matrix has lead to well impregnated composites by employing a wet route for the powdery bio-polymer.