Study of mechanical properties and performance of aging hemp fibers

International audience; The weathering of hemp fiber influences their appearance and mechanical properties. The aim of this study is to better understand the mechanism of aging of hemp fiber exposed to different conditions (moisture, heat and UV aging). A xenon aging test machine was used to simulate and accelerate the natural ageing. The influence of each aging condition on the mechanical properties of hemp fiber is investigated by micro tensile tests. The microstructures and water absorption of these natural fibers were analyzed by means of SEM and gravimetric methods. Humidity absorption of hemp fibers depends on the relative humidity, not concerning the temperature. Temperature accelerates the saturation of fibers. All aging process reduced the mechanical properties of hemp fibers. After 4 weeks exposure, fibers aged by UV has the worst mechanical properties compared to humidity and temperature aging.