Hemp yarn reinforced composites – II. Tensile properties

Whereas the first paper is addressing the characteristics of textile hemp yarn, this second paper is addressing the tensile properties of aligned hemp yarn composites under influence of a number of experimental variables: hemp yarn type, fibre volume fraction, thermoplastic matrix type, process temperature, conditioning humidity, and loading direction relative to the fibre direction. Altogether, the results show that aligned hemp yarn composites demonstrate the good potential of plant fibres as reinforcement in composites for structural components. The tensile performance of the hemp yarn composites is excellent. As an example, a fibre volume fraction of 0.48 results in a stiffness of 28 GPa and an ultimate stress of 280 MPa. It is demonstrated that the influence of experimental variables is well understood and can be quantitatively described.