Natural fibre-reinforced biopolymers as construction materials - new discoveries

Originally coming from aerospace technology, fibre reinforced plastics (FRP ) are successfully used for various applications because of their excellent specific properties, e.g. high strength and stiffness, low weight and the potential of optimisation by orientating (esp. continuous) fibres along the load paths. In order to successfully meet the environmental problems of these classic c omposites, the DLR Institute of Structural Mechanics developed an innovativ e idea in 1989: By embedding natural and near natural reinforcing fibres, e .g. flax, hemp, ramie, cellulose etc., into a biopolymeric matrix from cell ulose, starch or lactic acid derivatives, etc. (thermoplastics as well as t hermosets), new fibre reinforced materials, called biocomposites. were crea ted and are still being developed. In terms of mechanical properties being comparable to glass fibre reinforced plastics (GFRP), latest developments o n new fibre/matrix combinations and environmentally compatible flame retard ants enable biocomposites to replace GFRP in most cases. Biocomposites are designed to meet the processing requirements for commonly used manufacturin g techniques, e.g, pressing, injection moulding, filament winding, BMC, SMC etc. Apart from anisotropic and specially tailored lightweight structural parts with continuous fibre reinforcements, biocomposites are very well suited fo r panelling elements in cars, railways and aeroplanes, etc., using differen t kinds of nonwovens from single fibres (needlefelt nonwovens, fleeces, etc .) to be easily adapted to the usually curved shapes of panellings, fairing s, etc.