Industrial Hemp Transformation for Composite Applications: Influence of Processing Parameters on the Fibre Properties

The main objective of this collaborative work is to characterize the influence of the processing stages of industrial hemp on the fibre properties. Transformation processes well suited for composite reinforcing textiles are considered. The work focuses on the different stages along the transformation chain of hemp, from the straw retting to the preform manufacturing. The main highlight is the predominant influence of retting on the tensile properties of individual fibres after their mechanical extraction from the stalks. Regarding the secondary processing, different technologies such as spinning, and use of natural binder systems are also proposed to produce yarns and woven fabrics. The effect on these secondary processing technologies and their parameters on the fibre properties are also characterised. The results show that the first steps of processing (retting and decortication) have the greatest impact on the tensile strength of hemp fibres.