Totally bio-based, high-performance wood fibre biocomposites

VTT has developed totally bio-based and compostable PLA – wood fibre com-posite material to be utilised in industrial applications. The usability of the mate-rial has been demonstrated in several processing methods and products. A large-scale injection moulding chair demo was carried out together with a de-sign company KO-HO to demonstrate the usability of the material in industrial scale. Adhesion between PLA and wood-based fibres was improved with bio-based additives and chemo-mechanical treatments providing improved ductility, tensile strength and stiffness. Especially epoxy functional polyunsaturated vege-table oils was shown to act as a combined reactive plasticiser-coupling agent in bleached softwood kraft pulp reinforced PLA composites. The material was also shown to be applicable for novel light-weight structures, contributing towards decreased ecological footprint with savings in materials, energy and costs. In thermoplastic extrusion foaming process, wood fibre reinforced PLA was demonstrated to provide a promising alternative in formation of a closed-cell structure with low density. Furthermore, the material was shown to be suitable for production of thermoformable sheets produced by film extrusion. The ex-truded sheets can be utilised e.g. in light-weight honeycomb structures. The developments can open new business opportunities together with contribution to more sustainable world.