For a significantly increased feeding capacity when processing powdered material on twin screw extruders, Coperion GmbH, Stuttgart/Germany, formerly Werner & Pfleiderer, has developed the so called Feed Enhancement Technology (FET). The basic principle: The feeding zone is equipped with a porous, gas permeable wall section to which a vacuum is applied externally. Intermediate particle air is sucked out of the powdered bulk material through this section. This compacting of the loose material reliably raises the feeding capacity by a factor of two to three whilst maintaining unchanged high product quality.

FET is suitable not only for the feeding zone of the ZSK twin screw extruder, but also for the ZS-B twin screw side feeder that doses powder materials directly into the melt. A ZS-B twin screw side feeder with FET will be on show on the Coperion booth B33 in hall 14 at K 2010.

Amongst the most important advantages of FET for feed limited compounding processes are:
• Low investment cost, because a smaller compounding unit can provide the required
throughput,
• lower specific energy input,
• lower production costs through a move to non-compacted and therefore cheaper fillers,
• improved compound quality through gentler processing of sensitive products due to the
higher utilization of the available processing volume,
• reduced dust levels, because back venting is not necessary,
• improved process security through a larger processing window in respect of the feeding
zone limit.