Assessment system to characterise and compare different hemp varieties based on a developed lab-scaled decortication system

With superior quality, hemp fibres are being more and more widely used for a large number of traditional and innovative industrial applications. The quality of the final products is strongly influenced and determined by the quality of the fibres, which in turn is subjected to agronomic factors, such as genotypes (hemp accessions), growing conditions, harvesting and processing. To improve hemp productivity and raw material quality for end-user requirements and advance scientific understanding of gene-to-trait relationships in this crop, characterisation and comparison of hemp samples of different varieties are important research tasks, which are normally carried out on small samples and require accurate and reproducible measurements. Decortication, the mechanical processing of stems to separate bast fibres from shives, plays a very central role in the whole natural fibre production chain. In the frame of the MultiHemp project (http://multihemp.eu/) a partially automated lab-scaled decortication process was designed and developed. The energy consumption during decortication was investigated to characterise and compare different hemp varieties. In order to calibrate the breaking unit a method was developed, and the process stability was analysed. Furthermore a new characterisation value, a so-called κ-number was introduced and a model of an assessment system was established for a more objective and reproducible evaluation of hemp varieties. Finally the assessment system was tested on three hemp varieties (Fédora 17, Futura 75 and Tygra) cultivated in the frame of a large Multihemp trial.