KREYENBORG offers the following extruder feeding systems:
Precise feeding devices
Extruder feeding systems enable precise and controlled material feeding into the extruder, in particular by evenly feeding of light and poorly flowing materials such as regrind, powder or pellets, to ensure efficient and high-quality processing.
Densifier
The Densifier (type KWS) is used to feed extruders with products that do not flow optimally, such as regrind, punching grids, powder, agglomerate, film flakes and fibers.

Feeding | the material to be processed is transported into the receiving hopper of the Densifier |
Filling level | monitored with a level-indicator |
Loosening | if necessary, the material is loosened up in the bin by means of special agitators and scrapers |
Pre-compaction | the material is pre-compacted via the densifying screw |
Extruder feeder | by pre-compacting the material and feeding it into the extruder at a constant pressure, the extruder is fed with the largest possible amount of material |
Throughput | 100 – 4,000 kg/h (film flakes) 200 – 9,000 kg/h (powder) |
Options
Lifting system | The densifiers may be equipped with a hydraulically-operated lifting system with manually operated pump. This device ensures the quick and easy lifting and swinging away of the aggregates from the extruder for easier cleaning and maintenance. |
Coating | special coatings of the bin and of the densifying screw for products that tend to stick |
Special Feed Hopper
A Special Feed Hopper is used for the direct refeeding of edge-trims or production waste into the production extruder. Free-flowing granulate (virgin material) can be added to the recycled material (film flakes, regrind).

Direct refeeding | no additional thermal stress of the material is caused, absent intermediate granulation, by direct refeeding |
Feeding | At the end of the film line, the edge trims are ground and fed into the special feed hopper. Simultaneously, granulate can be conveyed into the same hopper over a second inlet pipe. |
Mixing | regrinds of edge trims/production waste and granules can be mixed by means of a screw |
Extruder feeder | an adjustable feeding screw ensures constant feeding of the extruder |
Throughput | 100 – 1,000 kg/h |