Berstorff

Plastics Engineering, August, 2007

In cooperation with the bioprocess engineering department of Hanover University of Applied Sciences, Berstorff has developed a new twin-screw extruder concept for the production of natural fibre compounds. These natural fibres can be directly processed without the need for predrying.

Patented Multi-Process-Elements (MPE) allow the line to be tailored to the moisture content of the material to be processed--from wood flour or wood fibres to flax and hemp. The direct processing of fibres without pre-drying also eliminates any risk of explosion.

Natural fibres are supplied via downstream side feeders and gently incorporated into the melt by means of the MPEs. Several openings arranged along the processing section serve to remove the moisture released from the fibres. After they have been mixed in, the melt is degassed under vacuum to completely eliminate any moisture or low-molecular components. In a last step, the pressure required for further processing of the melt is built up.

In order to open up new fields of application for these materials, Berstorff has carried out several test series at its process laboratory in Hanover in close cooperation with the University.