Arrangement and method for upgrading plastics

Abstract

Arrangement (1) for upgrading used plastics (6), with a first compounding device (2) for the production of a recyclate (7), with a sensor device (4) for detecting physical properties of the recycled material (7), with an evaluation device (5) for evaluating the physical properties and defining corrective actions (14) on the recycled material (7) after detecting a deviation, wherein the corrective actions (14) include the variable addition of additives and the variable addition of virgin material, and with a second compounding device (3) for producing a corrected recyclate (17) from the recyclate (7).

Description

[0001] The invention relates to an arrangement for upgrading used plastics, comprising a first compounding device for producing a recyclate, a sensor device for detecting the physical properties of the recyclate, and an evaluation device for assessing the properties and defining corrective measures for the recyclate. The invention also relates to a method for upgrading used plastics using this arrangement. State of the art

[0002] For reasons of resource conservation, environmental protection, and waste recycling, plastic components are often recycled and processed to manufacture new plastic products. Upcycling used plastic is a well-known practice, used to enhance its properties and to produce high-quality products from it.

[0003] For example, the publication EP 1 484 146 B1, which probably represents the closest prior art, describes a system for recycling a used plastic material as a resin material. The system includes means for regenerating and / or restoring a desired property, means for measuring a physical property of the regenerated plastic, and means for displaying the measured physical property for quality assurance.

[0004] US patent 7,137,802 B2 discloses a device for processing thermoplastic synthetic material, which is processed successively in a first and then in a second container. A temperature sensor is provided to prevent overheating.

[0005] WO 2018 / 140 884 A1 discloses a process for processing colored PET bottles, in which, after grinding the bottles and washing the resulting material, impurities are detected and removed by various detection devices. Several formulations are proposed, in which both clear and colored PET material can be processed with the addition of color additives. Disclosure of the invention

[0006] An arrangement for upgrading used plastics with the features of claim 1 and a method for upgrading used plastics with the features of claim 8 are proposed. Preferred or advantageous embodiments of the invention will become apparent from the dependent claims of the following description and / or the accompanying figures.

[0007] The system is designed for upgrading used plastics. It includes a first compounding unit configured to produce a recyclate. A recyclate is, for example, a processed plastic or a processed molding compound with defined properties. In particular, the used plastic was already processed into a product before being reprocessed into the recyclate.

[0008] The first compounding device is designed to perform compounding operations on the used plastics and, in particular, to produce the recyclate. Specifically, during the compounding operations, the used plastics are conveyed, melted, dispersed, mixed, degassed, and pressurized to obtain the recyclate as the end product of the compounding process.

[0009] The arrangement includes a sensor device configured to detect the physical properties of the recycled material. The sensor device can comprise at least one, preferably several, measuring probes. The at least one measuring probe is, for example, configured as an online rheometer, a spectroscopic probe, a microwave measuring device, and / or an ultrasonic sensor.

[0010] For example, the physical properties of the recyclate that can be measured include spectrometric absorption, electromagnetic properties, permeability, and / or acoustic damping behavior. Optionally, the sensor device can also be configured to measure the mass pressure and / or mass temperature of the recyclate being produced and / or already produced in the first compounding device.

[0011] The arrangement includes an evaluation unit designed to assess the physical properties of the recycled material. For this purpose, the sensor unit transmits the detected physical properties, particularly as sensor data, to the evaluation unit.

[0012] The evaluation unit is trained to define necessary corrective measures for the recycled material.

[0013] According to the invention, the arrangement comprises a second compounding device. The second compounding device is configured to produce a corrected, and in particular, re-upgraded recyclate from the recyclate. Preferably, the second compounding device is configured to compound the recyclate produced by the first compounding device again, and in particular a second time. In particular, the second compounding device is configured to perform some or all of the compounding operations that the first compounding device can also perform. For example, the first compounding device and / or the second compounding device are configured as a single-screw extruder, a twin-screw extruder, a planetary roller extruder, or a kneader.

[0014] The advantage lies in the fact that the recyclate produced in the first compounding unit is inspected for the desired physical properties and can then be reprocessed using the second compounding unit. In particular, a two-stage compounding process can be provided, in which the used plastics are upgraded twice, enabling the production of even higher-quality recyclates. This is because, especially during use, products made from used plastics are exposed to various environmental influences, which can lead to plastic degradation and negative effects on the product's physical properties. The provided system overcomes the uncertainty regarding the subsequent material properties of the recyclates that arises from material degradation.Specifically, corrected recyclates can be provided that possess the required physical properties, enabling the production of high-quality plastic parts. In a preferred embodiment of the invention, the evaluation unit is configured to evaluate the physical properties of the recyclate as material property values. Preferably, the evaluation unit is configured to calculate further parameters from these material property values. These further parameters include, in particular, melt viscosity, molecular weight, additives such as fibers and / or other additives and their proportions in the recyclate, and / or impurities such as foreign substances and / or other types of plastic and their proportions in the recyclate.

[0015] The invention provides that the evaluation unit is configured to assess whether the other parameters are the same or different and whether they are set to a target value. Preferably, the target values ​​for the corresponding parameters are stored in the evaluation unit. In particular, the target values ​​are based on empirical data from the production of recycled materials that possess the necessary physical properties.

[0016] The evaluation unit is designed to define corrective measures in the event of a deviation. Preferably, the corrective measures can be implemented in the second compounding device, particularly during and / or during compounding operations on the recycled material. According to the invention, the corrective measures include the variable addition of additives, e.g., peroxides, as well as the variable addition of virgin material, especially plastic granules. In further embodiments, the removal of at least one unsuitable material stream, e.g., air, moisture, and / or solvents, is also possible.

[0017] In one possible embodiment of the invention, the arrangement comprises a first control device and a second control device. Preferably, the first control device is configured to control the first compounding device to perform the compounding operations. Preferably, the second control device is configured to control the second compounding device to perform the compounding operations. In particular, the second control device is configured to control the second compounding device to perform corrective measures. For example, the second compounding device can be controlled to adapt and / or modify the compounding operations performed in the second compounding device according to the corrective measures.

[0018] Particularly preferred within the scope of the invention is that the evaluation unit, the sensor unit, and the two control units are arranged in a measurement and control loop for the first and second compounding devices and / or jointly form the measurement and control loop. Preferably, the first control unit, particularly within the measurement and control loop, is configured to feed back evaluations from the evaluation unit to the first compounding device and to control compounding operations based on these evaluations. In particular, the compounding operations are modifiable and / or adaptable according to the deviations.

[0019] Another object of the invention is a method for upgrading used plastics with the arrangement according to the previous description and / or according to one of claims 1 to 7.

[0020] As part of the process, the recycled material, in particular from the used plastic, is manufactured. The physical properties of the recycled material are recorded and evaluated. Furthermore, necessary corrective measures are defined and implemented on the recycled material as part of the process.

[0021] Preferably, in this process, the first compounding device and the first control device are provided for the production of the recyclate. Preferably, the first compounding device performs the compounding operations to produce the recyclate from the used plastics. In particular, the first compounding device is controlled by the first control device to execute the compounding operations.

[0022] Preferably, a sensor device is provided for measuring the physical properties of the recyclate. In particular, the recyclate, in its molten state, is continuously fed to the sensor device for measuring its physical properties.

[0023] Optionally, the evaluation unit is provided as part of the procedure to evaluate the physical properties and define the necessary corrective measures.

[0024] In one possible process step, the evaluation unit assesses the physical properties as material property values ​​and calculates the other determining variables from these material property values. Preferably, target values ​​for the determining variables are stored in the evaluation unit.

[0025] Another possible procedural step involves the evaluation unit assessing whether there is agreement or deviation between the determined variables and the target variables. If a deviation is identified, the evaluation unit defines corrective measures, particularly to rectify the deviations.

[0026] In a further preferred process step, the second compounding device and the second control unit are provided. Preferably, the corrective measures are carried out on the recycled material using the second compounding device. The second compounding device is preferably controlled by the second control unit to perform the corrective measures on the recycled material. Specifically, the second compounding device produces the corrected, and in particular, the re-upgraded, recycled material.

[0027] Further features, advantages, and effects of the invention will become apparent from the following description of preferred embodiments of the invention. These include: Fig. 1. An arrangement for upgrading used plastics

[0028] Corresponding or identical parts are each provided with the same reference symbols in the figures.

[0029] In the Fig. Figure 1 shows an arrangement for upgrading used plastics 6. The used plastics 6 are plastics that have already been processed into a product.

[0030] The arrangement 1 comprises a first compounding device 2, a first control device 12, a second compounding device 3, a second control device 13, a sensor device 4 and an evaluation device 5.

[0031] In the first compounding device 2, a recycled material 7 is produced from the used plastic 6. Recycled materials 7 are defined as processed plastics in the form of a molding compound. The processing of the used plastics in the first compounding device 2 is carried out by compounding operations such as conveying, melting, dispersing, mixing, degassing, and pressurizing the used plastics 6. The aim is to process the used plastics 6 in such a way that the resulting recycled materials 7, i.e., the material stream at point 7, exhibit defined physical properties, such as melt pressure, melt temperature, spectrometric absorption capacity, electromagnetic properties, permeability, and / or acoustic damping behavior. The first control device 12 controls the first compounding device 2 to perform the compounding operations and thereby upgrade the used plastics 6 to the recycled material 7.

[0032] However, the products manufactured from the plastics 6 can degrade through use and environmental influences, which can negatively affect the product's physical properties. The degree of degradation can affect the recyclate 7 produced in the first compounding device 2, so that its physical properties, which the recyclate 7 is intended to acquire through the compounding operations, may deviate from the desired physical properties.

[0033] To detect any deviations, the sensor device 4 and the evaluation device 5 are provided. The sensor device 4 comprises several measuring probes, e.g., an online rheometer, a spectroscopic probe, a microwave measuring device, and / or an ultrasonic measuring head, for recording the physical properties of the recyclate 7. This is continuously supplied to the sensor device 4 as a molding compound.

[0034] The sensor unit 4 detects the physical properties of the recycled material 7 and transmits these as sensor signals 8 to the evaluation unit 5. The evaluation unit 5 evaluates the sensor signals 8, based on the detected properties, as material property values ​​9. From the material property values ​​9, the evaluation unit 5 calculates further parameters 10, such as the melt viscosity and / or molecular weight of the recycled material 7, additives such as fibers and / or other additives and their proportions in the recycled material 7, and / or impurities from foreign substances and / or other types of plastic and their proportions in the recycled material 7.

[0035] The evaluation unit 5 contains target variables 11 for the determining variables 10, which are based primarily on empirical data. The evaluation unit 5 compares the determining variables 10 with the target variables 11 and evaluates whether there is agreement or a deviation between them.

[0036] When the evaluation unit 5 evaluates the deviation, it defines corresponding corrective actions 14 and transmits them to the second control unit 13. The second control unit 13 then controls the second compounding unit 3 to carry out the corrective actions 14, in particular by adjusting and / or modifying its compounding operations. For example, additives such as peroxides or virgin material are added to the recyclate 7 compounded again in the second compounding unit 3, or material streams characterized as unsuitable can be removed from the recyclate 7. The corrective actions 14 are intended to further improve the physical properties of the recyclate 7 so that the corrected recyclate 17 is produced as a final product that has the necessary physical properties to manufacture high-quality plastic parts.

[0037] The two control units 12, 13, the sensor unit 4 and the evaluation unit 5 form a control loop 15 for the first and second compounding devices 2, 3. Within the control loop 15, feedback takes place between the evaluation unit 5 and the first control unit 12. As a result of the feedback, the control unit 12 reacts to the evaluations of the evaluation unit 5 and, if necessary, controls the first compounding device 2 to perform modified and / or adapted compounding operations in the production of the recyclate 7.

Claims

[1] Arrangement (1) for upgrading used plastics (6), with a first compounding device (2) for the production of a recyclate (7), with a sensor device (4) for detecting physical properties of the recycled material (7), with an evaluation device (5) for evaluating the physical properties and defining corrective actions (14) on the recycled material (7) after detecting a deviation, wherein the corrective actions (14) include the variable addition of additives and the variable addition of virgin material, and with a second compounding device (3) for producing a corrected recyclate (17) from the recyclate (7). [2] Arrangement (1) according to claim 1, characterized by, that the evaluation device (5) is designed to evaluate the physical properties of the recyclate (7) as material property values ​​(9) and to calculate further determining variables (10) from the material property values ​​(9). [3] Arrangement (1) according to claim 2, characterized by , that the evaluation unit (5) is designed to evaluate a match or deviation between the determining variables (10) and stored target variables (11) and, in the case of a deviation, to define the corrective measures (14). [4] Arrangement (1) according to any one of the preceding claims, characterized by, that the arrangement (1) comprises a first control device (12) wherein the first control device (12) is configured to control the first compounding device (2) to perform compounding operations and / or that the arrangement (1) comprises a second control device (13) wherein the second control device (13) is configured to control the second compounding device (3) to carry out the corrective measures (14) on the recycled material (7). [5] Arrangement (1) according to claim 4, characterized by , that the evaluation unit (4), the sensor unit (4) and the two control units (12, 13) form a measurement and control loop (15) for the first and second compounding device (2, 3), wherein the first control unit (12) is configured to feed back evaluations of the evaluation unit (4) to the first compounding device (2) and to control compounding operations (16) based on the evaluations. [6] Arrangement (1) according to any one of claims 2 to 5, characterized by , that the physical properties include pressure, temperature, spectrometric absorption capacity, electromagnetic properties, permeability and / or acoustic damping behavior of the recyclate (7) and / or that the further determining parameters (10) include a melt viscosity, a molecular weight, additives and their proportions and / or impurities and their proportions of the recyclate (7). [7] Arrangement (1) according to any one of the preceding claims, characterized by , that the corrective measures (14) include the removal of at least one unsuitable material stream. [8] Method for upgrading used plastics (6) with the arrangement (1) according to one of the preceding claims, where a recycled material (7) is produced, wherein the physical properties of the recycled material (7) are recorded, wherein the physical properties are evaluated, wherein corrective actions (14) are defined on the recycled material (7), wherein the corrective actions (14) are defined and carried out when the deviation has been evaluated, and wherein the corrective actions (14) are carried out on the recycled material (7), wherein the corrective actions (14) include the variable addition of additives and the variable addition of virgin material. [9] Method according to claim 8, characterized by , that the physical properties of the recyclate (7) are evaluated as material property values ​​(9), that further determining variables (10) are calculated from the material property values ​​(9), and that a match or deviation between the determining variables (10) and stored target variables (11) is evaluated.

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