Hermann Berstorff Maschinenbau Gmbh

Dietmar Anders

Jurgen Voigt

Wilhelm Brand

Manfred Dienst

Gerd Capelle

Adolf Herbert

Georg Reisswig

Heinrich Kruse

Gunter Meier

A screw- or worm-type degassing extrusion device wherein a pin region is provided to increase throughput of the mixture to be extruded, such increased throughput being maintained and utilized to provide an adequate pressure for, for example, a tool by locating the pin region immediately upstream of the degassing region and by increasing the diameter of the cylinder or barrel of the extrusion device in the degassing and discharge regions compared with its diameter in the pin region.

Degassing extrusion device

A filtering device for filtering solids from liquids or liquid-like materials comprising a housing within which a filter member is rotatably mounted. The filter member which is traversed radially by the material to be filtered, comprises an outer sleeve member, a fine filter sleeve, a support filter sleeve and an inner sleeve member or drum. The outer sleeve member includes bores which receive the material to be filtered and has an external surface which is cylindrical. The filtrate, that is to say, the liquid or liquid-like material, passes through the filter member into the interior of the drum and then travels axially along the drum to a discharge outlet. At least the fine filter sleeve and the support filter sleeve taper conically inwardly in a direction towards the outlet. The solid material remains in the bores. As the filter member rotates, these bores become aligned with back-rinsing bores of conduits formed in the housing and the solid material is forced into such conduits by the back-pressure set up by the liquid material in the filter member. The conduits are closable by means of slidably displaceable pistons located therein, the pistons and conduits having sealing means which co-operate in one position of the pistons.

Filtering device

An extrusion head for producing flat profiles such as tread strips for automotive vehicles from three or more different rubber or plastics materials is disclosed. The head comprises a fixed central portion and upper and lower portions pivotally connected thereto, and is fed with the different mixtures by a plurality of screw or worm extrusion devices. Between the upper and central portion and the central and lower portions of the head, insert members are located. In the upper and/or lower surface of each insert member, flow channels for the mixtures are defined, the flow channels each being bounded upwardly or downwardly as appropriate, by a plane surface of one of the portions of the head. The insert members are axially divided and are made in one piece. The flow channels each have a longitudinal axis of symmetry and such axes lie in a common vertical plane. Such an arrangement permits the profile to be changed merely by replacing one or both insert members, permits the worms or screws to be readily removed for cleaning purposes and also ensures that the flow rates in each of the flow channels is substantially constant, thereby avoiding problems of pre-vulcanization.

Extrusion head

A method of monitoring the production of extruded composite profiles by an extrusion head fed by a plurality of worm extruders in which, immediately after the profile has been extruded, it is monitored by spacing measurement devices which determine the spacing between the devices and the profile. The measured spacing is then transmitted to a regulator or governor and compared with a pre-selected value. The governor or regulator controls the worm speed of the individual extruders and, if the measured value differs from the pre-selected value, alters the worm speed of one or more of the individual extruders until the measured value is the same as the pre-selected value.

Method of monitoring the production of extruded profiles and an

In an extruder, for extruding thermoplastic synthetic material or rubber or for use for pressing water out of a material, a screw rotates in a cylindrical chamber and helical conveying lands provided on the screw are interrupted at positions at which pins project into the chamber thereby forming grooves to receive the pins. To sense breakage of a pin, for example caused by metal particles in the extrudate, signal-generating means are provided in a blind bore in each pin, receipt of a signal from the signal generating means causing the screw to be stopped from rotating thereby to prevent further damage.

Extruder

A device for monitoring the filling level of the degassing space in an extruder used for processing thermoplastic materials comprises a level detection orifice located in the degassing dome or jacket of the extruder which opening is connected to a conduit. The conduit leads through a regulator device to a gas source. Connected to the conduit, between the regulator device and the orifice, is a pressure sensor such as a pressure difference switch. If the level of molten material in the dome rises above a preselected level, it blocks the opening and produces a back-pressure in the conduit. The switch is automatically actuated by this back-pressure and produces a signal. Appropriate action can then be taken to prevent the further rise of the molten material in the dome and to prevent blockage of the degassing device.

Filling level monitoring device

The advantages of a twin-screw extruder, especially the good plasticizing and homogenizing effect, are to be retained in the present invention with a simultaneous, above-average degassing output of the extruder. This object is achieved by dividing the twin-screw extruder into two stages (a) the plasticizing and homogenizing stage with a high screw torque and (b) the degassing and discharging stage in which a large, free degassing volume is achieved by a reduction in the screw core, by an enlargement of the screw housing and by adapting the screw diameter to the respective housing diameters in the degassing and discharging stage.

Twin-screw degassing extruder for degassing thermoplastic materials or

A granulation apparatus in which a conical chamber having a downwardly and outwardly inclined wall is provided for collecting cut granules. The wall is covered with a flowing, circulating film of water, such film being of uniform thickness and circulating quickly. An annular water channel is provided around the cylindrical or conical chamber for collecting the granules, the annular channel being fed through a tangential water inlet. A flat, annular horizontal acceleration chamber is disposed in the upper region of the annular channel and communicates with the channel through an annular aperture formed in the upper radially outward region of the annular channel. At its radially inner periphery the acceleration chamber communicates with the chamber through an annular aperture. The disposition of the inlet, the channel and the acceleration chamber cause water flowing into the chamber to be subjected to centrifugal force whereby the film of water remains closely adjacent the wall and is of uniform thickness.

Apparatus for granulating plastics material or plastic compositions

A granulation apparatus which operates in the manner of a water-ring granulator comprises a perforated plate and rotatable cutter tool for granulating material fed through the plate. A recess is provided beneath the perforated plate which is concentric with, but inwardly of, a collection chamber for collecting the granulated material. The recess is dimensioned so as to have a cross-sectional area at least equal to the surface area of the plate.

Apparatus located at the output end of a screw extruder comprising a mandrel to rotate with said screw and a jacket coaxial with the mandrel and rotatable in an opposite direction of rotation to the mandrel at a speed which is steplessly adjustable. Sealing lips co-operating with abrasion rings are preferably provided on relatively moving surfaces of the jacket and stationary housings and temperature adjustment means can be provided in the jacket and the mandrel.

Apparatus for continuously processing rubber, elastomers, plastics and

A two-stage extruder having a first, vertical stage and a second, separately driven, horizontal stage, the two stages being off-set from one another and lying at tangents to one another in the region of a connecting passage. The first stage has a rotatable plasticizing member with kneading blades off-set from one another and located between conveying screw components of said member and cylindrical pins projecting into the working chamber of said first stage. A bearing is provided for the member at its upper end and a cylindrical sleeve surrounds the lower end of the member and can be turned to control the effective size of the connecting passage or to eject material through a second outlet.

Two-stage extruder

A filtering arrangement of thermoplastics extruding apparatus has a rotatable cylindrical screen unit through which material flows radially inwards and is discharged axially and an outlet aperture for impurities which are washed from the screening unit by reverse flow, i.e. radially outward flow, of part of the filtered material. The outlet aperture for the impurities is variable in cross-section by moving an arcuate segment about the axis of the cylinder to control the extent of reverse flow washing.

Filtering arrangement for thermoplastics materials

A kneading and mixing machine for plastic materials having a housing with a rotor rotatable therein to convey material from an inlet aperture fed by a feed hopper to an outlet passage and to plasticise the material during such conveying, and a throttling member in the form of a cylindrical sleeve concentrically surrounding the rotor within the housing having an aperture therein and being rotatable to alter the extent of the alignment of the aperture with the passage and thus the size of the effective output aperture of the machine. A discharge extruder may be fed via the aperture or the sleeve can be rotated to eject the output of the machine through a second outlet.

Kneading and mixing machine

In venting means for a screw extruder, particularly for thermo-plastics material, which venting means comprises a substantially vertical venting shaft communicating with the bore of a cylinder of the extruder and coupled to a low pressure source by a pipe, a pivotable flap which is moved from its normal position shown, when acted upon by plastics melt being extruded and rising in the shaft due to malfunction of the extruder, to cover the end of the pipe and prevent the melt passing into the pipe.

Venting means for screw extruders

In order to provide adaptability to a variety of material properties in a worm feed extruder for processing of synthetics or rubber, individual feed worm segments (7) and cylinder segments (10) surrounding the feed worm segments are provided at desired locations, the feed worm segments and cylinder segments being constructed divisible in the axial direction to enable these feed worm segments to be exchanged for feed worm segments of differing geometry. Removal of the cylinder (2, 3) or withdrawal of the feed worm (1) from the cylinder is thus avoided in the case where the feed worm is to be adapted to various material properties.

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Hanover, Germany

Dietmar Anders