Feeding device and method for feeding granulate and screwing material into a plastic extruder

Abstract

The invention relates to a method for feeding granulate and comminuted material, in particular flocculent material, into a plastic extruder, comprising the following working steps: conveying the granulate and comminuted material to a feed opening of the plastic extruder by means of a conveying device, the comminuted material and / or granulate being compacted by means of a compacting device during the conveying; and adjusting the compaction device as a function of at least one first parameter which characterizes the compaction of the granular material and / or comminuted material in the conveying device.

Description

Technical Field

[0001] The present invention relates to a feeding device and method for feeding granules and crushed materials into a plastic extruder, wherein the granules and / or crushed materials are conveyed to the feed opening of the plastic extruder by means of a conveying device, and during conveying, the crushed materials and / or granules are compacted by means of a compaction device. Background Technology

[0002] In many devices used for manufacturing film webs, especially in the form of cast roll extrusion facilities, strips are produced by longitudinally cutting the film webs. Here, film webs are particularly plastic film webs. These strips are primarily edge strips, which are considered waste due to the process. To be fed into the extruder, these strips are first pulverized in a pulverizer, particularly into small flakes, commonly referred to as flocculent material. A feeding device is provided for feeding into the extruder. Preferably, fresh granules are fed simultaneously, so that the flocculent material and granules are co-melted in the extruder and conveyed to the extrusion facility as plastic melt. However, alternatively, it can be specified that only waste generated during plastic film production, such as edge strips, waste rolls, or even used film, is pulverized and conveyed to the extruder. These pulverized film wastes can be returned to the extruder individually or in combination with fresh granules. This process can particularly be part of a recycling and granulation facility.

[0003] The plastic extruder must continuously supply sufficient plastic material through the feeding device during the extrusion process, that is, supply the amount of plastic material necessary for the extrusion process.

[0004] Document WO 2021 / 074184 A1 relates to a feeding device for feeding flocculent and granular materials into an extruder, having a conveying device with a discharge side section for granular materials, by means of which the granular materials can be conveyed to form a column of granular materials, wherein the section is connected to a feed opening of the extruder and has a funnel with a hopper outlet for conveying the flocculent materials, wherein a conveying screw for conveying the flocculent materials is provided in the funnel, the conveying screw extending through the hopper outlet and into the section, wherein the flocculent materials can be conveyed within the column of granular materials, wherein the conveying screw is designed to: also convey a portion of the granular materials and / or compact the flocculent materials by means of a compaction device.

[0005] Document WO 2019 / 224261 A1 relates to a system for suctioning and crushing at least one strip of material opposite to a transport line, the strip being produced by at least one longitudinal cutting of a film web, the strip being able to be drawn from the film web via the transport line, the system having a crusher for crushing the strip and means for providing a volumetric flow to transport the strip from the film web to the crusher, wherein the means for providing the volumetric flow includes a first suction device, the first suction device—viewed along the transport direction of the strip—connected to the transport line before the crusher. Summary of the Invention

[0006] The object of this invention is to provide an improved method and an improved feeding device for feeding granular and / or pulverized materials into a plastic extruder. In particular, the object of this invention is to ensure an adequate supply of plastic material to the plastic extruder.

[0007] The objective is achieved through the independent claims. Advantageous designs are claimed in the dependent claims.

[0008] A first aspect of the present invention is a method for feeding granular and / or pulverized material, particularly flocculent material, into a plastic extruder, comprising the following steps:

[0009] • Granular and / or crushed material is conveyed to the feed opening of a plastic extruder by means of a conveying device, wherein during conveying, the crushed and / or granular material is compacted by means of a compaction device; and

[0010] • The compaction device is adjusted according to at least one first parameter, the first parameter being a characterization of the compaction of granular and / or crushed material in the conveying equipment.

[0011] A second aspect of the invention relates to a feeding device for a plastic extruder, comprising:

[0012] • Conveying equipment used to convey granular and / or crushed materials, especially flocculent materials, to the feed opening of a plastic extruder;

[0013] • Compacting devices for compacting crushed and / or granular materials during conveying; and

[0014] • A control device having a mechanism for adjusting the compaction device according to at least one parameter, the parameter being characterized in the compaction of crushed and / or granular material in the conveying equipment.

[0015] A third aspect of the invention relates to a feeding device for a plastic extruder, comprising:

[0016] • A conveying device for conveying granular and crushed materials, especially flocculent materials, to the feed opening of a plastic extruder, wherein the granular material can form a column of granules in the area of ​​the outlet of the conveying device;

[0017] • Funnels for containing crushed materials, especially flocculent materials; and

[0018] • As a conveying screw of the compaction device, the conveying screw is arranged inside the funnel and extends into the conveying equipment through the neck of the conveying screw in such a way that the crushed material can be conveyed within the column of granules when the conveying screw rotates, wherein a pipe section is arranged at the outlet, in the region of the pipe section the conveying screw has a diameter that ensures that not only the crushed material but also the granules are conveyed to the feed opening.

[0019] The present invention is based on the following concept: to operate and construct the feed device in such a way as to improve the supply of plastic material having a mixture of granules and pulverized material to the extruder.

[0020] In equipment used for manufacturing film webs, after the film strips are separated from the qualified film in the return system, the film strips, and if necessary, other plastic waste, are pulverized into a powder, particularly a flocculent powder, in a mill. This powder is then conveyed to a feeding device. The feeding device, by means of a compaction device (typically a conveying screw), returns the powder to the plastic extruder. Equipment used for processing film waste and used film for recycling granulation facilities operates in a similar manner.

[0021] The inventors have confirmed that the operating speed of the compaction unit, typically the rotational speed of the conveying screw of the compaction unit, has a significant impact on the operation of the plastic extruder. If the operating speed of the compaction unit is too low, the intake zone of the extruder screw will not be adequately filled with material due to the low bulk density of the pulverized material. This results in a decrease in the delivery rate of the plastic extruder compared to the granulated material, and the extruder begins to pulsate. Pulsation, as defined herein, means fluctuations in the discharge rate of the plastic extruder when the extruder screw speed is constant.

[0022] This leads to variations in the thickness and / or profile of extruded products, as well as instability in facility operation.

[0023] This invention addresses the issue of a compaction device compacting plastic material in a conveying device in such a way that sufficient plastic material is fed into a plastic extruder. For this purpose, the compaction device is adjusted according to at least one first parameter, which characterizes the compaction of granular and / or pulverized material, i.e., the plastic material fed to the plastic extruder.

[0024] By adjusting the compaction device to depend on the compaction of the plastic material, it is possible to ensure that sufficient mass of plastic material is contained in the provided volume of plastic material to guarantee the stable operation of the extruder.

[0025] Specifically, by better regulating the compaction of the pulverized material in the suction zone of the plastic extruder, the delivery rate of the plastic extruder is increased, and discharge fluctuations are reduced. By reducing discharge fluctuations, the thickness fluctuations of the extruded plastic products, particularly films, are also reduced, thereby improving the overall operational stability of the facility. Discharge fluctuations, for example, lead to unstable edge strips in films. The melt quality in the plastic extruder is also improved due to its more stable operation. Furthermore, during startup, this invention reduces the time required to obtain qualified products.

[0026] Furthermore, it is possible to generally increase the proportion of shredded material in the plastic material supplied to the plastic extruder. In this way, it is possible to bring additional shredded material back into the plastic extruder from other plastic waste, such as waste rolls and edge strips from the winding machine, in addition to the film strips generated during the production of plastic products, especially films.

[0027] Preferably, a so-called PID controller is used to regulate the compaction device. More preferably, the compaction device has a conveyor screw or a feed screw. More preferably, the conveyor screw is operated by a motor, and the speed of the motor at the output shaft is further preferably regulated in accordance with the invention. More preferably, the output shaft is connected to the shaft of the compaction device, particularly the shaft of the conveyor screw. Preferably, the speed of the compaction device shaft is regulated as an absolute value or as a factor, the factor indicating the ratio of the compaction device shaft speed to the extruder screw speed.

[0028] According to the invention, adequate compaction of the plastic material in the region of the feed opening of the plastic extruder or in the suction region of the extruder screw is also ensured by the following: the conveying screw of the compaction device has a sufficiently large diameter relative to the inner diameter of the pipe section at the outlet of the conveying equipment, said diameter ensuring that not only pulverized material but also granular material is conveyed to the feed opening of the plastic extruder. A suitable plastic screw geometry is advantageous for sufficiently high compaction at the feed opening or in the suction region.

[0029] In an advantageous design of the method, at least one first parameter characterizing the compaction of pulverized and / or granular materials is selected from the following group of parameters:

[0030] • The torque applied to the compaction device;

[0031] • Motor parameters, especially the motor speed and / or motor current and / or motor load of the compaction device;

[0032] • Forces acting on the compaction device, especially forces acting on the conveying screw;

[0033] • The pressure within the compacted plastic material.

[0034] The parameters can be determined very easily.

[0035] In another advantageous design of the method, the compaction device is also adjusted according to at least one second parameter, which characterizes the operation of the plastic extruder and is selected from the following group of parameters:

[0036] • The conveying speed of the plastic extruder;

[0037] • Throughput or gravity parameters of the plastic extruder;

[0038] • The melt pressure in a plastic extruder, especially the constant melt pressure;

[0039] • Melt temperature in a plastic extruder;

[0040] • Motor parameters, especially the motor speed and / or motor current and / or motor load of the plastic extruder;

[0041] • Temperature in the plastic extruder;

[0042] • Heating power of the plastic extruder;

[0043] • The torque applied to the shaft of the plastic extruder, especially the extruder screw;

[0044] • Forces acting on the shaft of the plastic extruder, especially forces acting on the extruder screw;

[0045] • The rotational speed of the shaft of the plastic extruder, especially the rotational speed of the extruder screw.

[0046] In particular, consideration of the rotational speed of the extruder screw or shaft of the plastic extruder provides the following advantages: even when the shaft speed of the plastic extruder varies, the compaction remains essentially constant.

[0047] In another advantageous design of the method, the compaction device is also adjusted according to the rotational speed of the plastic extruder shaft, particularly the extruder screw, and at least one first parameter changes the factor between the rotational speed of the compaction device and the rotational speed of the plastic extruder shaft.

[0048] This enables exceptionally stable operation of the plastic extruder because the compaction unit's rotational speed responds to changes in the extruder's shaft speed without time delay. Conversely, if regulation is only achieved via a PID control loop, a time delay in the compaction unit's response results in system overshoot.

[0049] In another advantageous design scheme, the method also includes the following steps:

[0050] • Select at least one first parameter based on the operating mode of the plastic extruder; and / or

[0051] • Change at least one adjustment parameter of the adjustment circuit according to the operating mode of the plastic extruder, wherein the adjustment circuit adjusts the compaction device.

[0052] The selection of the first parameter and the adjustment of the parameter according to the operating mode take into account the different operating characteristics of each operating mode. This also enables more stable operation of the plastic extruder.

[0053] In another advantageous design of the method, at least a distinction is made between a production mode and an operating mode, wherein a lower reaction rate is set in the production mode and a higher reaction rate is set in the operating mode.

[0054] The operating mode for the purposes of this invention is particularly the process of upgrading a facility to a production mode and / or the process of switching operation from a first production mode to a second production mode.

[0055] The lower response speed of the control loop in production mode is used because the large control steps resulting from high response speeds do not produce stable operation due to permanent fluctuations in extruder operating parameters. Conversely, in start-up mode, rapid control is required, i.e., a higher response speed, to react to relatively large changes that occur during operation. Other examples of start-up mode include switching the feed of crushed material on and off and changes in extruder speed.

[0056] Preferably, the response speed can be achieved by adjusting the parameters of the PID controller and / or by smoothing at least one input signal, particularly at least one first parameter and / or at least one second parameter.

[0057] In another advantageous design of the method, the granules form a column of granules in a conveying device, and the crushed material is contained in a hopper, wherein the compaction device is a conveying screw arranged inside the hopper and extending into the conveying device through the neck of the hopper in such a way that the crushed material is conveyed within the granule column as the conveying screw rotates, wherein the rotational speed of the conveying screw is adjusted.

[0058] The design is particularly suitable for feeding and compacting plastic materials into plastic extruders.

[0059] In an advantageous design of the feeding device, the diameter of the conveying screw in the pipe section region is at most 30% smaller than the inner diameter of the pipe section, preferably at most 25% smaller, more preferably at most 10% smaller, and most preferably at most 5% smaller.

[0060] This enables exceptionally good transport of plastic materials via the conveyor screw. In particular, it allows for the transport of not only shredded materials but also granular materials.

[0061] In another advantageous design of the feeding device, the diameter of the conveying screw increases in the region of the funnel, following the shape of the funnel.

[0062] This improves the intake of crushed material from the funnel into the conveying equipment. Preferably, the area of ​​the conveying screw that increases in size according to the shape of the funnel is configured as a plastic, sleeved scraper.

[0063] In another advantageous design of the feeding device, at least one, and in particular two, obstacles are arranged on the inner side of the funnel, which are at least substantially perpendicular to the blade orientation of the conveying screw.

[0064] This also improves the intake of the crushed material into the conveying screw by preventing the crushed material from rotating with the conveying screw in the hopper. Preferably, the feeding device is also equipped with a deionization tube through which the crushed material passes before being collected in the hopper. This reduces the electrostatic charge on the crushed material. Furthermore, the hopper is preferably equipped with an air nozzle to prevent the crushed material from hanging on the wall.

[0065] In another advantageous design, the blades of the conveying screw are spaced one to thirty millimeters apart from at least one obstacle. This prevents the formation of a crushed material zone that rotates with the conveying screw between the obstacle and the conveying screw.

[0066] The features and advantages described above with respect to the first aspect of the invention also apply to the second and third aspects of the invention, and vice versa. Attached Figure Description

[0067] Other features and advantages will become apparent from the following description with reference to the accompanying drawings. Wherein:

[0068] Figure 1 A cross-sectional view of a first embodiment of a feeding device arranged at a plastic extruder is shown;

[0069] Figure 2 A cross-sectional view showing a portion of a second embodiment of the feed device;

[0070] Figure 3a Showing according to Figure 1 A detailed view of section A of the first embodiment, showing the transport screw.

[0071] Figure 3b Showing according to Figure 1 A detailed view of section A of the second embodiment of the transport screw;

[0072] Figure 4 Show Figure 1An enlarged view of the conveying screw and pipe section in section A;

[0073] Figure 5 A block diagram showing an embodiment of a method for feeding granules and pulverized material into a plastic extruder; and

[0074] Figure 6 A circuit diagram showing one embodiment of the regulating circuit for regulating the compaction device is provided. Detailed Implementation

[0075] Figure 1 An embodiment of a feeding device 11 is shown, which is arranged at a plastic extruder 1 to feed plastic material into the feed opening 2 of the plastic extruder 1. The feeding device 11 has a funnel 9 that tapers toward the plastic extruder 1 and continues in a neck 10.

[0076] The conveying screw 4 extends through the neck 10 within the funnel 9, and together with the motor 18 that drives the conveying screw 4, forms a compaction device. During operation, the conveying screw 4 rotates in the direction of arrow 17.

[0077] The conveying screw 4 includes a helix 16, the various elements of which are visible in the cross-sectional view. These elements form blades that extend axially outward from the conveying screw 4 to the funnel 9 and its neck 10.

[0078] exist Figure 1 In the process, crushed material (not shown), particularly so-called flocculent material, can be conveyed from above to hopper 9. During operation, the crushed material is transported through neck 2 by the rotation of conveying screw 4.

[0079] Furthermore, the feeding device 1 has a conveying device 3 that extends from the pipe section 14 to the feed opening 2 of the extruder 1. Figure 1 The upper part of the conveying device 3 conveys the granular material, which, as indicated by the arrow, flows into the funnel-shaped section of the conveying device 3. In the lower part of the conveying device 3 above the outlet 13, the granular material preferably forms a column of granules.

[0080] The crushed material is conveyed from the funnel 9 through its neck 10 and through the granule column by means of the conveying screw 4 towards the outlet 13 of the conveying device 3. Through the outlet 13, the crushed material and granules flow together through the tube section 14 to the feed opening 2 of the plastic extruder 1, entering the suction zone (not shown in the figure) of the extruder screw 8. Here, the plastic material, particularly the crushed material and / or granules, is compacted in the tube section 14 by means of the conveying screw 4. In the extruder 1, the plastic material is drawn from the suction zone... Figure 1 The material is transported to the right, where it gradually melts and mixes.

[0081] Preferably, the conveying screw 4 has an agitator 19 in the region of the funnel 9, which supports the conveying of the pulverized material. More preferably, an air nozzle is present in the region of the funnel 9 to prevent the pulverized material from depositing on the walls of the funnel 9. Furthermore, a deionization device may be present to reduce the electrostatic charge on the pulverized material.

[0082] Figure 2 A second embodiment of the upper part of the conveying device 3 for the feeding device 11 is shown.

[0083] Here, the helix 16 of the conveying screw 4 has a widened portion in the region of the funnel 9 that follows the shape of the funnel 9. Preferably, the widened portion is configured as a steel or plastic extension of the helix 16.

[0084] Furthermore, preferably, at least one obstruction 15, in particular in the form of a rod, is arranged on the inner wall of the funnel 9, which prevents or at least reduces the rotation of the crushed material in the funnel 9 as the conveying screw 4 rotates.

[0085] exist Figure 2 In the middle, the spiral 16 of the conveying screw 4 extends to the inner wall of the neck 10 of the funnel 9.

[0086] Figure 3a and 3b Showing according to Figure 1 Two embodiments of the conveying screw 4 in section A of the middle section.

[0087] exist Figure 3a In this configuration, the spiral 16 has a relatively small diameter D relative to the inner diameter I of the tube segment 14. Thus, the main crushed material 6 is conveyed through the column of particles. Figure 3a In the lower region, the crushed material 6 is even squeezed outward in the tube section 14 by the rotation of the conveying screw 4 and forms a widening section 7, thereby preventing the granular material 5 from subsequently flowing in through the feed opening (not shown) of the extruder.

[0088] On the contrary, Figure 3b In this configuration, the conveying screw 4 has a larger diameter D relative to the inner diameter I of the pipe section 14. This ensures that not only the crushed material 6 but also the granular material 5 is conveyed by the conveying screw 4 towards the feed opening (not shown) through the outlet 13 of the conveying device 3. Furthermore, according to... Figure 3b The conveying screw 4 in this embodiment has a double helix 16. This reduces the lateral force acting on the conveying screw 4 and also improves the compaction caused by the rotating conveying screw 4.

[0089] exist Figure 4 The diameter D of the conveying screw 4 is shown, and this diameter is predetermined by the helix 16. Additionally, the pipe section 14 is also shown. Figure 1The inner diameter I in region A.

[0090] By adjusting the ratio of the diameter D of the conveying screw 4 to the inner diameter I of the tube section 14, the conveying and compaction of plastic material into the feed opening (not shown) of the plastic extruder 1 can be affected.

[0091] Figure 5 A block diagram illustrating an embodiment of a method 100 for feeding granules 5 and pulverized material 6 into a plastic extruder 1 is shown. Preferably, method 100 is performed using a feeding device 11, as described in [the relevant section on...] Figures 1 to 4 The embodiments are illustrated below.

[0092] In the first working step 101 of method 100, the granules 5 and the crushed material 6 are conveyed to the feed opening 2 of the plastic extruder 1 by means of the conveying device 3. Here, the granules 5 flow through the upper part of the conveying device 3 by gravity and enter the lower funnel-shaped section of the conveying device 3, where they form a column of granules.

[0093] The crushed material 6, preferably configured as a so-called flocculent material, flows into the hopper 9, particularly through a deionization device. From there, the granules are also conveyed by means of a conveying screw 4 through the neck 10 of the hopper 9 into the funnel-shaped area of ​​the conveying device 3, and there are also conveyed by means of the conveying screw 4 through the granule column. From there, the granules 5 and the crushed material 6 reach the feed opening 2 of the plastic extruder 1 through the outlet 13 and the pipe section 14 of the conveying device 3, and then enter the suction area (not shown in the figure) of the extruder screw 8. Here, the granules 5 and the crushed material 6 are also driven by gravity. Additionally, the granules and the crushed material are conveyed by the rotation of the conveying screw 4, which also extends in the pipe section 14.

[0094] Based on the ratio of the diameter of the conveying screw 4 to the inner diameter I of the pipe section 14, it basically only conveys the crushed material 6 or conveys both the crushed material 6 and the granular material 5.

[0095] Depending on the rotational speed of the conveying screw 4, the granules 5 and crushed material 6 are compacted to varying degrees in the region of the tube section 14 and in the suction zone of the extruder screw 8. Here, the conveying screw 4 may cooperate with the motor 18 that drives the conveying screw to act as a compaction device.

[0096] In the second working step 102, the first parameter M is preferably selected according to the operating mode of the plastic extruder 1.

[0097] Alternatively or additionally, in the third working step 103, the value of at least one adjusting parameter N4 of the adjusting circuit is changed according to the operating mode of the plastic extruder 1, the adjusting circuit adjusting the compaction device 4.

[0098] Finally, in the fourth working step 104, the rotational speed N4 of the conveying screw 4 is adjusted according to at least one first parameter M, which characterizes the compaction of the granules 5 and / or crushed material 6 in the conveying device 3. The first parameter M is preferably the torque applied to the conveying screw 4. This torque is preferably determined either by means of a torque sensor in the region of the shaft of the conveying screw 4 or by means of a torque sensor in the region of the motor 18. More preferably, the torque is determined indirectly by means of the motor parameters of the motor 18, particularly the rotational speed and / or motor current and / or motor load, the force acting on the conveying screw 4, or the pressure of the compacted plastic material.

[0099] Preferably, a PID controller is used to regulate the rotational speed of the conveying screw 4. The response speed of the PID controller is then adjusted in the third operating step 103 according to the operating mode. It is particularly preferable to distinguish between a production mode and a start-up mode, wherein a lower response speed is set in the production mode and a higher response speed is set in the start-up mode.

[0100] It is also possible to set the response speed by smoothing the input signal of the regulator, that is, in particular the torque M as the first parameter.

[0101] Preferably, in working step 104, the rotational speed N4 of the conveying screw 4 is further adjusted according to a second parameter N8, the second parameter being characterized by the operation of the plastic extruder 1 and selected from the following parameter group:

[0102] • The conveying speed of plastic extruder 1;

[0103] • The throughput or gravity parameters of plastic extruder 1;

[0104] • Melt pressure in plastic extruder 1;

[0105] • Melt temperature in plastic extruder 1;

[0106] • Motor parameters of the motor of plastic extruder 1, especially speed and / or motor current and / or motor load;

[0107] • The temperature in plastic extruder 1;

[0108] • Heating power of plastic extruder 1;

[0109] • The torque applied to the shaft 8 of the plastic extruder 1, particularly to the extruder screw;

[0110] • Forces acting on the shaft 8 of the plastic extruder 1, particularly forces acting on the extruder screw;

[0111] • The rotational speed of the shaft 8 of the plastic extruder 1, especially the rotational speed of the extruder screw.

[0112] If the rotational speed N4 of the conveyor screw 4 is adjusted according to the rotational speed N8 of the extruder screw 8, then the corresponding value of the torque M at the conveyor screw 4 preferably changes the factor N4:N8 between the rotational speed of the conveyor screw 4 and the rotational speed of the extruder screw 8. This ensures that the rotational speed N4 of the conveyor screw 4 responds immediately, i.e., without delay, to changes in the rotational speed of the extruder screw 8. Therefore, when the conveying rate of the extruder screw 8 is high, in addition to the adjustment depending on the torque, the rotational speed N4 of the conveyor screw 4 also increases proportionally.

[0113] Preferably, the rotational speed N4 of the conveying screw 4 is adjusted such that the throughput through the plastic extruder 1 fluctuates by only one to two percent. However, at the same time, the rotational speed N8 of the extruder screw 8 should also fluctuate by a maximum of + / - one revolution per minute.

[0114] Figure 6 An embodiment of an adjustment diagram is shown for adjusting the rotational speed N4 of the conveying screw 4 according to a first input parameter M.

[0115] Therefore, the feeding device 11 preferably has a control device 12, which has a mechanism for adjusting the compaction device 4. The mechanism for use in this invention can be constructed in both hardware and software, and in particular has a digital processing unit, particularly a microprocessor unit (CPU), and / or one or more programs or program modules, preferably connected to a storage and bus system for data and / or signals. The CPU can be configured to: process instructions implemented as a program stored in the storage system, detect input signals from the data bus, and / or output output signals to the data bus. The storage system can have one or more, particularly different, storage media, particularly optical, magnetic solid and / or other non-volatile media. The program can be created such that it embodies or is capable of executing the methods described herein, allowing the CPU to perform the steps of such methods. Preferably, the control device is computer-implemented.

[0116] As the first input parameter to the control device 12, the torque M applied to the conveying screw 4 is adjusted. More preferably, as the second input parameter, the rotational speed N8 of the extruder screw 8 of the extruder 1 is adjusted in the control device 12. There, the target rotational speed N4 of the conveying screw 4 is determined by means of a factor N4:N8, which describes the speed ratio between the conveying screw 4 and the extruder screw 8, and also depends on the torque M applied to the conveying screw 4.

[0117] It should be noted that the embodiments are merely examples and should not be construed as limiting the scope, application, or structure of protection in any way. Rather, the foregoing description provides guidance to those skilled in the art for implementing at least one embodiment, wherein various modifications can be made, particularly concerning the function and arrangement of the described components, without departing from the scope of protection derived from the claims and their equivalent features.

[0118] List of reference numerals

[0119] 1. Plastic extruder

[0120] 2. Feed opening

[0121] 3 Conveying equipment

[0122] 4. Compaction device / Conveying screw

[0123] 5. Granular material

[0124] 6. Crushed material

[0125] 7. Widening section

[0126] 8. Extruder screw

[0127] 9 Funnel

[0128] 10 Neck

[0129] 11 Feeding equipment

[0130] 12 Control mechanism

[0131] 13 Exports

[0132] 14 Pipeline Sections

[0133] 15 Obstacles

[0134] 16 spirals

[0135] 17. Direction of rotation

[0136] 18 motors

[0137] 19. Mixer

Claims

1. A method (100) for feeding granular material (5) and / or crushed material (6), particularly flocculent material, into a plastic extruder (1), the method comprising the following operational steps: The granules (5) and / or the crushed material (6) are conveyed (101) to the feed opening (2) of the plastic extruder (1) by means of a conveying device (3), wherein, during conveying, the crushed material (6) and / or the granules (5) are compacted by means of a compaction device (4); and The compaction device (4) is adjusted (104) according to at least one first parameter (M), the first parameter (M) characterizing the compaction of the granular material (5) and / or the crushed material (6) in the conveying device (3).

2. The method (100) according to claim 1, wherein the at least one first parameter (M) characterizing the compaction of the pulverized material (5) and / or the granular material (6) is selected from the group consisting of: • The torque applied to the compaction device (4), particularly to the conveying screw; • The motor parameters of the motor of the compaction device (4), especially the speed and / or motor current and / or motor load; • The force acting on the compaction device (4), especially the force acting on the conveying screw; • The pressure within the compacted plastic material.

3. The method (100) according to claim 1 or 2, wherein the compaction device (4) is further adjusted according to at least one second parameter (N8), the second parameter characterizing the operation of the plastic extruder (1) and selected from the group consisting of: • The conveying rate of the plastic extruder (1); • The throughput or gravity parameters of the plastic extruder (1); • The melt pressure in the plastic extruder (1); • The melt temperature in the plastic extruder (1); • The motor parameters of the motor of the plastic extruder (1), especially the speed and / or motor current and / or motor load; • The temperature in the plastic extruder (1); • The heating power of the plastic extruder (1); • The torque applied to the shaft (8) of the plastic extruder (1), particularly to the extruder screw; • The force acting on the shaft (8) of the plastic extruder (1), especially the force acting on the extruder screw; • The rotational speed of the shaft (8) of the plastic extruder (1), especially the rotational speed of the extruder screw.

4. The method (100) according to any one of the preceding claims, wherein the compaction device (4) is further adjusted according to the rotational speed of the shaft (8) of the plastic extruder (1), in particular the rotational speed of the extruder screw, and the at least one first parameter (M) changes the factor (N4:N8) between the rotational speed (N4) of the compaction device (4) and the rotational speed (N8) of the shaft (8) of the plastic extruder (1).

5. The method (100) according to any one of the preceding claims further comprises the following working steps: Select (102) at least one first parameter (M) according to the operating mode of the plastic extruder (1); and / or The value of at least one adjustment parameter (N4) of the adjustment circuit (103) is changed according to the operating mode of the plastic extruder (1), and the adjustment circuit adjusts the compaction device (4).

6. The method (100) according to claim 5, wherein at least a distinction is made between a production mode and an operating mode, wherein a lower reaction rate is set in the production mode and a higher reaction rate is set in the operating mode.

7. The method (100) according to any one of the preceding claims, wherein the granules (5) form a column of granules in the conveying device and the crushed material (6) is contained in a funnel (9), wherein the compaction device (3) has a conveying screw (4) arranged inside the funnel (9) and extending into the conveying device (3) through the neck (10) of the funnel in such a way that the crushed material is conveyed in the column of granules as the conveying screw (4) rotates, wherein the rotational speed of the conveying screw (4) is adjusted.

8. A feeding device (11) for a plastic extruder (1), the feeding device comprising: Conveying equipment (3) for conveying granular material (5) and / or crushed material (6), especially flocculent material, to the feed opening (2) of the plastic extruder (1); A compaction device (4) for compacting the crushed material (5) and / or the granular material (6) during conveying; and A control device (12) having a mechanism for adjusting the compaction device (4) according to at least one first parameter (M), the first parameter being a characterization of the compaction of the crushed material (4) and / or the granular material (5) in the conveying equipment (3).

9. The feed device (11) according to claim 8 further comprises: A funnel (9) for containing the pulverized material (5); The granules (6) are able to form a column of granules in the conveying device (3), and the compaction device (4) is a conveying screw arranged inside the funnel (9) and extending into the conveying device (4) through the neck (10) of the funnel in such a way that the crushed material (6) can be conveyed in the column of granules (5) when the conveying screw (4) rotates.

10. A feeding device (11) for a plastic extruder (1), particularly the feeding device according to claim 8, comprising: A conveying device (4) for conveying granules (5) and crushed materials (6), particularly flocculent materials, to the feed opening (2) of the plastic extruder (1), wherein the granules (5) are capable of forming a column of granules in the area of ​​the outlet (13) of the conveying device (3); A funnel (9) for receiving the crushed material (6); and A conveying screw (4) is arranged inside the funnel (9) and extends into the conveying device (3) through the neck (10) of the funnel in such a way that the crushed material (5) can be conveyed within the granular column when the conveying screw (4) rotates, wherein a pipe section (14) is arranged at the outlet (13), and the conveying screw (4) has a diameter (D) in the region of the pipe section (14) that ensures that not only the crushed material (6) but also the granular material (5) is conveyed to the feed opening (2) and compacted.

11. The feeding device (11) according to claim 10, wherein in the region of the pipe section (14), the diameter (D) of the conveying screw is at most 30% smaller than the inner diameter (I) of the pipe section (14), preferably at most 25% smaller, more preferably at most 10% smaller, and most preferably at most 5% smaller.

12. The feeding device (11) according to any one of claims 7 to 11, wherein at least one unique, particularly two obstacles (15) are arranged inside the funnel (9), the obstacles being oriented at least substantially perpendicular to the blades (16) of the conveying screw (4).

13. The feeding device (11) according to claim 12, wherein the blades (16) of the conveying screw (4) are spaced 3 to 6 mm apart from the at least one obstacle (15).

14. A plastic extruder (1) having a feeding device (11) according to any one of claims 8 to 13.

15. A cast roll extrusion facility or blown film extrusion facility, having a feeding device (11) according to any one of claims 8 to 13 or an extruder (1) according to claim 14.

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