Preparation and processing of preserved natural fibres

The conventional production of natural fibres on the basis of field drying and retting of fibre straw is connected to a higher weather risk under German weather conditions. At the Leibniz Institute of Agricultural Engineering a weather-independent post harvest technique on the basis of chopping hemp with a forage harvester followed by anaerobic storage is under investigation. As a further advantage of this novel processing technology, the whole plant material is processed to semi products for plastic reinforcement or final products like insulation materials and fibre boards.

A pilot plant with a processing capacity of 1t per hour wet preserved hemp has been put into operation at the ATB in March 2007. The production of (intermediate) fibrous materials is realised by means of a twin screw extruder as well as a disc mill (Fig. 1). Because of the specific particle morphology and the requested particle characterization the ongoing research focuses e.g. relevant established and innovative methods. One of the investigated methods is based on the image analysis system “Fibreshape^©”. Key aspects are the optimisation of sample preparation and the purposeful analysis of resulting fibre/particle properties.