- 3 September 2007 -
Berstorff develops production method for natural fibre compounds

A twin-screw extruder concept for the production of natural fibre compounds has been developed by Berstorff, in cooperation with the bioprocess engineering department of Hannover University of Applied Sciences.

The natural fibres can be directly processed without any energy-intensive pre-drying. The patented Berstorff Multi-Process Elements (MPEs) used for this purpose are said to ensure particularly gentle and cost-effective incorporation of natural fibres and also allow the line to be tailored for the moisture content of the material to be processed – from wood flour or wood fibres up to flax and hemp.

The polymer is introduced into the feed zone by gravimetric metering systems and melted in the plasticizing section. Various additives are also fed into the feed section to improve the material properties. The natural fibres are supplied via downstream side feeders and gently incorporated into the melt by the MPEs. Several openings along the processing section serve to remove the moisture released from the natural fibres. After the fibres have been mixed in, the melt is degassed under vacuum to completely eliminate any moisture or low-molecular compounds. In a last step, the pressure required for further processing of the melt is built up.

Berstorff; www.berstorff.de
Hannover University of Applied Sciences; www.fh-hannover.de