Abstract: A back-pressure bearing arrangement for a twin-screw extrusion device which prevents any back-pressure forces from affecting a gear arrangement used for driving the screws. By disposing the back-pressure bearings between the gear arrangement and the housing of the extrusion device and by providing a bearing plate, which is supported by adjustment bolts or tension rods, the bearings are frictionally disconnected from the gear arrangement housing and the back-pressure forces of the screw shafts are effectively prevented from adversely affecting the gear arrangement.

Abstract: A calendering apparatus is disclosed which includes means for replacing a desired take-up roller from a take-up roller train. Displaceable, bifurcated carrier means are disposed on the embossing means forming part of the calender apparatus, which carriers can accommodate individual take-up rollers. The rollers are then moved out of the train by such carriers. The embossing means are also displaceable into a position in a lifting mechanism which can be used to collect the roller from the carrier.

Abstract: An apparatus for reducing wastage during the start-up phase of extrusion device used to produce extruded profiles such as tread strips for vehicle tires from a plurality of mixtures. Each of a plurality of extruders extrudes one component of the profile and is provided with its own drive motor. The outlets from the extruders communicate with a template member having flow channels formed therein which communicate with the outlet ends of the extruders and which lead into a common extrusion port. Pressure sensors are positioned adjacent to the outlet of each extruder. These pressure sensors and the drive motors for each extruder are operatively connected to a control device which has stored therein predetermined desired pressure levels for each extruder. The drive motors for the several extruders are actuated and the pressure of each is monitored and compared with the predetermined desired pressure for each extruder.

Abstract: A filter changing apparatus for use in an extrusion press, comprising a frame, filter support members hydraulically displaceable in the frame, in a direction which is substantially at right angles to the flow of material through the press and filters disposed in each of the filter support members, at least one of the filter support members being detachably mounted in the frame, and a support member for discharging residues of rubber or thermoplastics material from the extrusion press, the support member being detachably mountable in the frame in place of the at least one detachably mounted filter support member, the support member having associated therewith a discharge plate for displacing residual material in the extrusion press to a discharge station.

Abstract: An apparatus for measuring the material pressure in a twin-screw extrusion device, wherein adjustment bolts are employed as deformation components for returning the axial back-pressure of the screws to the housing of the extrusion device, the deformation components having strain gauges affixed thereto.

Abstract: An apparatus for monitoring the production of elongate profiles which are formed from one or more mixtures of rubber or thermoplastics material in an extrusion head which is fed by one or more extrusion devices. The profile passes through a cooling zone in which longitudinal shrinkage of the profile occurs. The actual shrinkage is monitored and compared with desired shrinkage by a control device which controls the drive means for the extrusion devices. The profile also passes over a weighing device which determines the weight per unit length thereof, with the weighing device also being operatively connected to the regulating or control means. If a deviation from the desired shrinkage in the zone or station is ascertained, the regulating device sets a new, corrected, desired weight per unit length value to be achieved at the weighing device. To achieve this desired weight per unit length, the drives for the extrusion devices are each adjusted by a uniform amount by the regulating or control device.

Abstract: A pin-barrel extrusion device having a barrel temperature control means between the outer and inner hollow cylinders of the barrel and an apparatus for adjusting the radial depth of penetration of the pins into the inner hollow cylinder is disclosed in which problems due to different rates of thermal expansion of the cylinders in the axial direction are obviated or at least minimized. This is achieved by locating the pins in guide sleeves, which sleeves are detachably mounted in a bore formed in the inner cylinder and pass through aligned bores in the outer cylinder. The outer cylinder bores have a diameter larger than that of the sleeves so that an annular gap is defined between the bores and the cylinder. This provides room for movement of the sleeve if the inner cylinder on which it is mounted expands at a different rate to that of the outer cylinder.

Abstract: An extrusion apparatus for the production of mixtures of molten synthetic material includes a gear pump which is provided in the flow of molten material. The gear pump comprises a housing and two meshing gear pump wheels. The line joining the centers of the two wheels extends at right angles to the central longitudinal axis of the hollow cylinder. Outlet and inlet openings are formed in the cylinder of the extrusion apparatus which lead directly into the gear pump housing into regions which are, respectively, upstream and downstream of the gear wheels. The major surfaces of the gear wheels are disposed horizontally relative to the central longitudinal axis of the hollow cylinder.

Abstract: A method for monitoring deviations in the dimensions of profile strips during production is disclosed, as is an apparatus suitable for carrying out the method. The profile strip is formed from one or more rubber or thermoplastics material mixtures which are fed from one or more extrusion devices through nozzles into a common nozzle in an extrusion head. Pressure and temperature measuring means measure the extrusion pressure and temperature of each mixture. The profile strip thus produced then passes over weighing device which measures its weight per unit length. The measured value is transmitted to a regulating or control device and compared with a desired weight per unit length.

Abstract: An extrusion head comprising at least one fixed head portion and at least one displaceable head portion pivotable into and out of an operative position includes means for filtering material being extruded and means for effecting change-over of the filter. The means for effecting the change-over includes at least two perforated plates displaceable on guide means in a direction generally at right angles to that of the extruded material. The at least one pivotable head portion includes a pressure surface which, in the operative position, abuts against the perforated plates thereby retaining the plates in position and sealing them against leakage of the extruded material.

Abstract: A method particularly suitable of monitoring the production of elongate profiles which are formed from one or more mixtures of rubber or thermoplastic material in an extrusion head which is fed by one or more extrusion devices is disclosed as in an apparatus which is particularly suitable for carrying out such a method. During production, the strip passes through a cooling path or station in which longitudinal shrinkage thereof occurs. The desired shrinkge is known and the actual shrinkage is monitored by suitable means. These means are operatively connected to a regulating or control device. When leaving the head, the profile passes over a weighing device which determines the weight per unit length thereof. The weighing device is also operatively connected to the regulating or control device. If a deviation from the desired shrinkage in the zone or station is ascertained, the regulating device sets a new, corrected, desired weight per unit length value to be achieved at the weighing device.

Abstract: An apparatus for granulating thermoplastics materials comprising a nozzle plate and a cutter device in which the spacing between these integers can be pre-set and accurately maintained. This is achieved by isolating the component parts of the granulation apparatus, particularly a housing for the cutter device, which is subjected to variable thermal expansion, from the components which locate the cutter device in front of the nozzle plate.

Abstract: An apparatus for the clearance-free mounting of at least one of the rollers in the support column of a calender. The mounting is for producing plastics material films achieved by means of a roller bearing which is divided into three, a central section or ring and two laterally outer sections or rings in a direction transverse to the major axis of the roller journalled to rotate therein. Each bearing ring or section comprises an inner ring portion, at least one row of cylinder rollers, an outer ring portion and a bearing body portion. Pressure applicator means are provided for displacing the central section relative to the two laterally outer sections or rings in a direction towards and away from the roller journalled therein so as to eliminate play within the bearing. To eliminate the play between the bearing body and the calender support column, an additional pressure applicator means is provided which is incorporated in the calender support column.

Abstract: A method of reducing wastage during the start-up phase of an extrusion device used to produce extruded profiles such as tread strips for vehicle tires from a plurality of mixtures is disclosed. The extrusion device comprises a plurality of extruders each extruding a component of the profile and each extruder has its own drive means. The outlets from the extruders communicate with a template member having flow channels formed therein which lead into a common extrusion port. The drive means are actuated simultaneously and the pressure of each of the components is monitored in the outlet region of each extruder. These pressures are compared with a pre-determined desired pressure by a control device, which device switches-off the appropriate drive means as each desired pressure is attained. When all desired pressures have been attained, all of the drive means are re-actuated simultaneously by the control device.

Abstract: A method for monitoring deviations in the dimensions of profile strips during production is disclosed, as is an apparatus suitable for carrying out the method. The profile strip is formed from one or more rubber or thermoplastic material mixtures which are fed from one or more extrusion devices through nozzles into a common nozzle in an extrusion head. Pressure and temperature measuring means measure the extrusion pressure and temperature of each mixture. The profile strip thus produced then passes over weighing device which measures its weight per unit length. The measured value is transmitted to a regulating or control device and compared with a desired weight per unit length.

Abstract: When longitudinally stretching thermoplastics films in a stretching zone comprising at least one roll by the application of a stretching force thereto, width contraction of the film generally occurs. In the present invention, this is prevented by the improvement of directing compressed air against the film while it is passing over at least one of the rolls and is being stretched longitudinally. The compressed air emerges from nozzles distributed over the entire length of the rolls and retains the film in position on the roll or rolls, thereby preventing its width from contracting. The improved apparatus suitable for carrying out the improved method comprises nozzle means disposed adjacent to and directed towards the film located on the roll means and compressed-air supply means communicating with the nozzle means.

Abstract: An embossing calender arrangement for thermoplastics material films which can be used for embossing either the top side or the underside of a film as desired comprises an embossing calender, the rollers of which are rotatably mounted in a frame. The frame, together with the calender is displaceable to and from a pivoting position by being suitably mounted and, when in such pivoting position, is pivotable.

Abstract: An extrusion head is provided for extruding flat profiles for producing tread strip portions of vehicle tires from mixtures of rubber or plastics materials, which permits one of the constituents such as the tread strip mixture to be changed without adversely affecting the other constituent parts of the mixture, such as the lateral rubber strip mixtures and the base rubber layer. This is achieved by suitably deflecting the flow channels for the lateral rubber layers in a front template. The flow channel for the lateral strips enters the template below the flow channel for the tread strip but discharges alongside the lateral edges of the tread strip. The head comprises a fixed central portion and pivotable upper and lower portions, the flow channels for the constituents of the mixture being defined by channels formed in insert members located between the head portions.

Abstract: A device for enabling the changeover of the shell or casing or a roller in a calender, the ends of the roller being journalled to rotate in bearings, means being provided for retaining the journal at one end in a desired position while the bearing body surrounding the roller bearing at the other end is removed. A yoke-shaped hinged support member is provided with means for removing the bearing body and is pivotally mounted at one of its ends so as to be pivotable into a position, after the bearing body has been removed to reveal the free annular space around the roller bearing through which the roller casing can be removed and interchanged.

Abstract: An extrusion device comprises feed means and extrusion means. The feed means comprises a feed hopper having a feed aperture formed therein, said feed aperture feeding material into a hollow barrel in which a single screw rotates. The single screw conveys the material to the extrusion device. The extrusion device comprises twin screws rotating in a further barrel. The two barrels are co-axial with one another and are in series with one another. The diameter of the single screw is at least twice the diameter of each of the twin screws.