Coperion Gmbh

Hans-Joachim Sämann

Werner Wiedmann

Sören Welb

Jürgen Strecker

Peter Munkes

Michael Ahlgrimm

Peter Heidemeyer

Klaus Kapfer

In a processing plant for producing plastics material granulate, the start-up takes place in such a way that a screw machine is firstly driven by means of a drive device and then plastics material to be processed is fed by means of a metering device into the screw machine. At least one conveying position of the plastics material in the screw machine is determined by means of a control device by evaluating at least one measuring signal. Depending on the conveying position determined, a granulating device is activated and put into operation. The method according to the invention allows a direct start-up of the processing plant without the use of a start-up valve. This ensures an easy and safe start-up of the processing plant.

Method for starting up a processing plant for producing plastics material granulate and processing plant for producing plastics material granulate

In a screw machine, to extend the material to be prepared with the latter, at least one processing element is configured as an extension-kneading element, the crest region of which has a reduced thickness compared to a flank region and, with adjacent processing elements, forms an extension channel for the material in the region between the triangles, which tapers in cross section in the flow direction of the material. Because of the tapering of the extension channel, the material is accelerated in the flow direction thereof and extended, so that high-molecular particles in the material are divided and the latter is therefore homogenized.

Screw machine with at least one extension-kneading element in a flow direction

An extruder with a housing comprising parallel, partially inter-engaging bores and screws disposed therein is used when applying a method of feeding powdery bulk materials into such an extruder. A solid transport of powdery bulk material takes place in an inlet zone disposed downstream of a feed opening wherein said inlet zone is partially filled. The inlet zone is provided with at least one gas-permeable wall portion wherein a layer of bulk material is created on said wall portion, thereby preventing bulk material from passing through, The gas-permeable wall portion is connected to a vacuum source and to a pressure gas source. Furthermore, the gas-permeable wall portion has an inner wall which is set back with respect to the wall of the bores, thereby forming a gap with a partially annular cross section wherein a layer of the bulk material is formed in the gap.

Extruder having a set back gas-permeable wall portion

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Bietigheim-Bissingen, Germany

Hans-Joachim Sämann