Device and method for continuously separating plastic mixture

Abstract

The invention relates to a device (100) for separating a plastic mixture (111), comprising: i) a feed region (110), which is designed to feed a plastic mixture (111) in an at least partially molten state; ii) a centrifugation zone (120) coupled to the feed zone (110) and configured for separating, by centrifugation, the at least partially molten plastic mixture (111) into a first plastic fraction (112) and a second plastic fraction (113), where the first plastic fraction (112) is different from the second plastic fraction (113); and iii) a discharge region (130) coupled to the centrifugal region (120) and configured to provide a separated first plastic fraction (112) and a separated second plastic fraction (113). The device (100) is configured to operate in a continuous mode.

Description

Technical Field

[0001] The present invention relates to an apparatus for separating (molten) plastic mixtures, which apparatus comprises a feed region, a centrifugal region and a discharge region. The present invention also relates to a method for separating (molten) plastic mixtures. The present invention can accordingly relate to the technical field of separating plastic fractions from plastic mixtures. Background Art

[0002] The recycling of plastics is a current topic and has significant economic and environmental-technical importance. A variety of methods are used and developed worldwide. Here, a particular problem lies in the efficient recycling of plastic mixtures, since different plastics require different preparation processes depending on their properties. This is especially the case when it comes to inseparable plastic mixtures, such as multi-layer films. Here, special technical improvements are required in order to achieve not only a clean separation, but also a clean separation within the scope of cost-technical economy. In Europe, approximately 17.8 Mt of used packaging was collected in 2018, but only 7.5 Mt of it was recycled. Therefore, there is a potential of more than 10 Mt / a for new separation methods.

[0003] Current research in the field of recycling is proceeding in the direction of the preparation of material flows; for example, multi-sensor-based sorting systems with artificial intelligence or so-called tracking systems are being investigated. The aim of these studies is to produce pure material flows in order to subsequently recycle them via traditional recycling paths. However, these methods can have significant disadvantages: they fail in most cases in the case of material connections, such as in the case of multi-layer films or polymer alloys. In order to be able to reuse this large quantity of waste categories, new design concepts for treatment are required.

[0004] Separation methods differ significantly from existing recycling methods: the separation of plastic mixtures takes place in the molten state of the polymers. Scientific work has shown that due to the different physical properties (especially density) of the fractions in the centrifugal field, a sorting operation of two different polymers in the molten state is carried out in a centrifuge. This method works intermittently or batchwise: a batch of plastic mixture is added to the centrifuge and then melted by increasing the temperature or supplying heat. Subsequently, the centrifuge is used to achieve a density separation of the plastic fractions of the plastic mixture. Then these plastic fractions are cooled, removed, and the centrifuge is prepared for another batch of plastic mixture.

[0005] However, this method can have the following disadvantages: the method is relatively time-consuming and only a small production capacity can be achieved in the case of large quantities of waste plastic mixtures. Summary of the Invention

[0006] There will be a need to allow the separation of plastic mixtures in an efficient and reliable manner and with high throughput.

[0007] An apparatus and a method according to the independent claims are provided. Advantageous embodiments are introduced by the dependent claims.

[0008] According to a first aspect of the present invention, an apparatus for separating (at least partially molten) plastic mixtures is introduced. The apparatus comprises:

[0009] i) a feeding area (e.g., a continuous feeding device such as a feeding screw), which is configured to feed the plastic mixture in a (at least partially) molten state;

[0010] ii) a centrifugal area (e.g., an elongated tubular centrifuge), the centrifugal area being coupled to the feeding area (e.g., by a flange connection), and the centrifugal area being configured to separate the at least partially molten plastic mixture into one plastic fraction and at least one other plastic fraction (based on different physical properties, especially density differences, viscosity differences, etc.) by centrifugation,

[0011] wherein the plastic fraction is different from the at least one other plastic fraction (especially chemically or physically different, further especially different at least in specific density) (e.g., polyethylene and polyester); and

[0012] iii) a discharge area (e.g., a sieve plate or a lateral opening in the centrifuge wall), the discharge area being coupled to the centrifugal area and being configured to provide the separated (at least partially molten, substantially liquid) plastic fraction and the separated at least one (or more) other plastic fraction (at least partially molten, substantially liquid).

[0013] In this case, the apparatus is preferably configured to operate in a continuous mode (thus, not in a discontinuous batch mode).

[0014] According to a second aspect of the present invention, a method (for separating plastic mixtures, e.g., by means of the apparatus described above) is introduced, the method comprising:

[0015] i) at least partially melting the plastic mixture;

[0016] centrifuging the at least partially molten plastic mixture and thereby separating the molten plastic mixture into one plastic fraction and at least one other plastic fraction,

[0017] wherein the plastic fractions are different from each other (physically and / or chemically); and

[0018] iii) discharging the separated plastic fractions and the separated at least one other plastic fraction.

[0019] This method can run continuously here.

[0020] In the context of this document, the term "plastic mixture" can refer to a material having at least two types of plastics or plastic fractions. For example, a plastic mixture can have polyethylene and polystyrene. In one example, the plastic (fraction) is inseparable or not manually separable. Examples of such mixtures can be multilayer films or polymer alloys. The term "plastic" in this document can denote a synthetic material (especially a raw material) substantially composed of macromolecules (especially carbon-based), i.e., composed of polymers. Popularly speaking, plastics can also be called plastics. In this context, plastics can include thermoplastics, thermosets, and elastomers. Specific examples can include: polyethylene terephthalate (PET), polypropylene (PP), high-density polyethylene (HDPE) or low-density polyethylene (LDPE), polystyrene (PS), polyvinyl chloride (PVC). In one example, a plastic mixture can have only one plastic (e.g., PE), but it can be separated into two or more plastic fractions (e.g., LDPE and HDPE).

[0021] In the context of this document, the term "at least partially melted" can especially refer to a state similar to melting.

[0022] In the context of this document, the term "feed area" can especially refer to a device suitable for supplying a continuously melted plastic mixture to the centrifugation area. In a simple embodiment, the feed area can be the inlet area (upstream in the process direction) of the centrifugation device. In a more complex embodiment, the feed area can have a feeding device that can feed the melted plastic mixture by means of a continuous flow. In one example, the feed area is a separate device connected to the centrifugation device.

[0023] In the context of this document, the term "centrifugation area" can especially refer to a device suitable for applying centrifugal force to the material to be centrifuged (especially a plastic mixture). Preferably, the centrifugation area is suitable for accommodating (at least partially melted) plastic mixture and centrifuging it by rotation. The rotation of the material to be centrifuged (uniform circular motion) causes material separation, and the material separation can especially be used to separate a plastic mixture into plastic fractions. The centrifugation area can have a centrifugation device that has one (e.g., in the design of a tube) or more (e.g., in an angular design) side walls that define an inner cavity, and then the material to be centrifuged can be accommodated in this inner cavity. The centrifugation area is preferably connected to the feed area and the discharge area so as to enable continuous feeding and discharging of the material flow. The rotation of the centrifugation area can be achieved by a driving device, such as a motor. The corresponding connection of the driving device to the centrifugation device can be achieved, for example, through the discharge area. In a preferred embodiment, the centrifugation area is configured and suitable for operating in a furnace.

[0024] In the context of the present text, the term "discharge region" can in particular refer to a device adapted to continuously discharge (molten) plastic fractions from the centrifugation region. In a simple embodiment, the discharge region can be the outlet region of the centrifugation device (downstream in the process direction). In a more complex embodiment, the discharge region can have openings configured such that different plastic fractions can be discharged separately from one another through different (e.g., with respect to position or size) openings. In one embodiment, the centrifugation device can be configured elongate, wherein openings can be provided downstream in the process direction and perpendicular to the elongate main extension direction (e.g., the bottom of a tube), for example as a sieve plate. In another embodiment, the discharge region can be part of the centrifugation device or part of the centrifugation region, wherein, for example, the openings can be provided in the side wall of the centrifugation device.

[0025] According to an exemplary embodiment, the present invention can be based on the idea that when a continuously molten plastic mixture is fed to the centrifugation region, a highly efficient and reliable separation of the plastic mixture with high throughput is achieved, and continuously separated, different (molten) plastic fractions are discharged and provided downstream in the process direction.

[0026] A continuously operating centrifugation region (with additional structures) can achieve separating the mixed plastic fractions into pure material streams. The currently still discharged unseparated material stream can in the future be re-introduced into the material cycle due to separation by means of the method described and utilized separately. Although the current batch method operates reliably, it has disadvantages related to throughput and thus economic efficiency.

[0027] The inventors have now surprisingly recognized that significantly higher throughput can be achieved with continuous operation with (substantially) the same reliability, in which the plastic mixture is fed to the centrifuge in a molten state and the molten separated plastic fractions are continuously discharged.

[0028] Exemplary embodiment

[0029] According to one embodiment, the device further comprises:

[0030] Heating device, in particular a furnace. In one example, the centrifugation area is at least partially (in particular completely) located inside the furnace. This can have the advantage that the desired temperature can be provided directly (and uniformly) at the centrifugation area or at the at least partially molten plastic mixture. In particular, the (at least partially molten) plastic mixture can thus be kept within a defined temperature range. This in turn can have the advantage that the plastic mixture does not harden or cool down too quickly. In one embodiment, the feed area and / or the discharge area are arranged outside the furnace. In another example, the feed area and / or the discharge area are at least partially arranged inside the furnace.

[0031] In one embodiment, the heating device is configured to heat the centrifuge, the gas inside the centrifuge, and / or the plastic material. In another embodiment, the heating device can also be an energy source around the centrifuge, such as solar energy, a combustion device, etc.

[0032] In another example, the heating device can be implemented as an induction heating device for eddy current heating of an iron-containing inductive centrifuge.

[0033] According to another embodiment, the heating device is arranged to provide a temperature in the centrifugation area in such a way that the molten state of the molten plastic mixture is maintained. The relevant temperature can be, for example, 150 °C or higher, in particular 300 °C or higher. The heating device can provide or maintain this temperature to the surroundings, the air, or the molten plastic.

[0034] This can have the advantage that the individual temperature can be determined depending on which plastic mixture is used or to what extent it should be melted during centrifugation.

[0035] The term "temperature" can be room temperature, wall temperature, or heat energy supply, in particular for sufficiently heating the melt or for compensating for heat losses in the supplied mass flow of the plastic mixture that may already be present as (part of) the melt. In another example, a heat energy source can be utilized in the environment, for example, combustion gases from non-recyclable materials are utilized in the environment.

[0036] According to another embodiment, the device further has: a heating device configured to heat at least a part of the side wall of the centrifugation area. It has been found that materials in the outer area of the centrifuge or near the side wall tend to cool down (and thus harden) more quickly. This can be efficiently and specifically suppressed by additionally or alternatively heating the corresponding side wall area.

[0037] According to another embodiment, the device includes a drive device (such as a motor) configured to drive the centrifugal region (or achieve rotation). In one embodiment, the drive device can be coupled to the centrifugal region by means of a drive shaft. In another example, the drive shaft at least partially extends through the discharge region. In one example, the drive device is arranged outside the furnace, and in another example, the drive device is arranged inside the furnace.

[0038] According to another embodiment, the device has a cooling device, particularly associated with the coupling region (particularly via the discharge region) between the centrifugal region and the drive device. Especially when using the above-mentioned furnace, the temperature of the drive device can become crucial. The corresponding cooling device (such as by means of a coolant) enables efficient and reliable operation.

[0039] According to another embodiment, the feeding region has a feeding device, particularly an extruder (such as a single-screw or twin-screw extruder, co-rotating or counter-rotating extruder, etc.), which is arranged to continuously add at least partially molten plastic mixture into the centrifugal region. Herein, the feeding device can refer to a device suitable for feeding (at least partially molten) plastic mixture into the centrifugal region. A feeding worm can be suitable for this. In another example, a conveyor belt (which is suitable for at least partial plastic melt) can also be used. The feeding device can be regarded as part of the feeding region and leads into the interior of the centrifugal region through a transition region.

[0040] According to another embodiment, the centrifugal region is designed to be elongated in the main extension direction (H). Then the process direction (P) can extend along this length, where the material flow (molten plastic mixture) is fed through the centrifugal region along this process direction. This can have the advantage that the plastic fractions can be separated particularly efficiently and reliably along the feeding length (see Figure 16 and Figure 17 ). In one embodiment, the centrifugal region or the centrifugal device is designed as an elongated container, where one side wall or multiple side walls define the (centrifuged material) internal space. The cross-section of the container can be designed, for example, as circular (tubular) or (rectangular) angular. Herein, the term "elongated" can particularly relate to an object, such as a container, having a preferred direction or main extension direction, and the object (the container) extends along the preferred direction or main extension direction.

[0041] In a special embodiment, the centrifuge can have a rotational speed in the range up to 3000 revolutions per minute. The container can have a length of approximately 1 m and a diameter of 10 cm on a laboratory scale. In one example, the rotational speed can be adjusted for a specific plastic mixture and then reused for similar applications.

[0042] According to another embodiment, the discharge region has:

[0043] A first opening for discharging a plastic fraction and / or a second opening for discharging at least one other second plastic fraction. This can have the advantage that the plastic fraction can be discharged directly from the centrifugation region (e.g., via the sidewall and / or the bottom region) substantially without other additives. The openings can preferably be oriented towards the collection device. For example, each opening can lead to an independent collection device, thereby providing independent plastic fractions. In addition, these openings can be provided with discharge devices (such as troughs) to conduct (continuous) streams of molten plastic fractions.

[0044] According to another embodiment, the discharge region having the first opening and / or the second (or at least one other) opening is arranged perpendicular to the main extension direction of the elongated centrifugation region. The molten plastic mixture moves through the centrifugation region along the process direction during centrifugation. Downstream in the process direction, the separation of the plastic fractions can be the most reliable, such that the openings can be applied efficiently in this end region or bottom region of the centrifuge device. For example, the openings can be arranged in a region arranged perpendicular to the process direction (material flow). In the case of an elongated container, for example, this can be a plate having at least two openings, such as a sieve plate (see Figure 12 and Figure 13 ). In one example, the axes of the holes are parallel to the process direction and / or parallel to the rotation axis of the centrifuge.

[0045] According to another embodiment, the discharge region having the first opening and / or the second opening is arranged (substantially) parallel to the main extension direction of the elongated centrifugation region. This example can particularly relate to an embodiment in which the openings are associated with or formed in the boundary surface (especially the sidewall) of the centrifugation region (especially of an elongated container). Here, it can also additionally relate to the sidewall, especially the bottom surface, which is not arranged parallel to the main extension direction of the container. The openings can correspond to the discharge region, such that this or these discharge (sub) regions can be located on the container sidewall. In one example, one or more such discharge (sub) regions are located at the end of the centrifugation region 14 (see Figure 14 ). In another embodiment, one discharge region / opening or multiple discharge (sub) regions / openings are formed along the longitudinal extension (main extension direction) of the elongated container, especially in association with the sidewall (see Figure 5 ).

[0046] According to another embodiment, the centrifugation region has at least one discharge region having at least one opening in the sidewall through which at least one plastic fraction can be separated out.

[0047] According to another embodiment, the centrifugation zone (or the elongated container) has a discharge zone along the main extension direction (H) with a plurality of openings in the side wall, through which a plurality of different plastic fractions can be separated and / or discharged.

[0048] According to another embodiment, the discharge zone has three or more, in particular five or more, further in particular ten or more openings. It is also possible to provide a plurality of discharge (sub) zones (for example three or more, in particular five or more, further in particular ten or more), each of which has one or more openings. In particular, the device is configured to discharge other / different plastic fractions at each opening. This enables highly efficient separation and sorting.

[0049] The inventors have unexpectedly recognized that separating / discharging (at least partially melted) plastic fractions along the process direction (or along the elongated centrifugation container, in particular through the side wall) enables particularly efficient and reliable separation.

[0050] According to another embodiment, the plastic mixture has a multilayer film and / or a polymer alloy. Such inseparable mixtures can hardly be separated by conventional methods, and the device described may be particularly helpful for these materials.

[0051] According to another embodiment, the plastic mixture has at least one of the following plastics: polyethylene, PE, polystyrene, PS, polyester, PE, polypropylene, PP, polyamide, PA, polyvinyl chloride, PVC, polylactic acid (polylactylide), PLA. Thus, plastics that are particularly important economically and widely used are suitable for the separation described. Each of these examples can be a plastic fraction. In addition, however, two or more of these plastics can also together form a plastic fraction.

[0052] According to another embodiment, the device further has: an electromagnetic device configured to provide one or more electromagnetic fields (directly, selectively) within the centrifugation zone. This can have the advantage that other highly efficient separation mechanisms can be used (for example in a magnetic force manner). In one example, for example, by means of an induction device (also see Figure 6 and Figure 7 ), the electromagnetic field is used directly in the centrifugation zone. In another example, magnetic separation can also be performed with respect to the plastic mixture or the plastic fractions. In one embodiment, transformable magnetic poles can be used.

[0053] In one example, a direct current magnetic field (with a north pole and a south pole) can deflect charged (Coulomb charge) plastic particles of the plastic in the rotating material flow, where different charges (heights) can produce different deflections in the magnetic field (Lorentz force = q*(vxB)).

[0054] In one example, an (electric) magnetic field is induced such that plastics with different charges can be separated. In one embodiment, the rotational movement can be adjusted in order to remove and separate (two separation steps) based on different force actions on charged plastic particles with different electronegativities at the top / bottom of the centrifugal region.

[0055] In another example, magnetic separation can be successful during rotation. Thus, additional (electrostatic / electrodynamic) forces are applied synchronously with the rotation, and thereby the centrifugal force is amplified (separation step).

[0056] According to another embodiment, the device is further configured to: provide fractional crystallization (by temperature gradient) within the centrifugal region. This can have the advantage that specific plastic materials or plastic fractions can be separated with particular high efficiency by causing specific plastic materials or plastic fractions to (at least partially) crystallize while other plastic fractions do not crystallize.

[0057] According to another embodiment, the method includes:

[0058] continuously moving (feeding) the plastic mixture perpendicular to the direction of gravity (G). In this embodiment, the process direction extends in the horizontal direction or along the x-axis or y-axis, in other words: laterally or substantially parallel or tangential to the earth's surface.

[0059] According to another embodiment, the method includes:

[0060] continuously moving (feeding) the plastic mixture (substantially) parallel to the direction of gravity (G). In this embodiment, the process direction extends in the vertical direction or along the z-axis, in other words: from top to bottom, or from bottom to top, or perpendicular to the earth's surface.

[0061] Depending on the circumstances of the space or the desired result, different operating modes can be particularly advantageous. But in one example, the process direction (or the centrifugal region) can also be designed to be inclined or pivotable, for example in the range of 1 - 89° with respect to the direction of gravity (0° and 90° correspond to the names of vertical and horizontal).

[0062] According to another embodiment, the method further includes: discharging at least one plastic fraction laterally from the elongated centrifugal region relative to the main extension direction (of the elongated container), in particular through at least one opening in the side wall of the centrifugal region.

[0063] According to another embodiment, the method includes: providing at least one already separated plastic fraction to another separation step, in particular including: centrifuging the separated plastic fraction again, and further separating the separated plastic fraction into other first plastic fractions and other second plastic fractions.

[0064] Another centrifugation step can be carried out by equivalent (or identical) devices. The said another centrifugation step can be carried out continuously immediately after the said separation method or in batches. In one example, when at least one separated plastic fraction is fed into another centrifugation step, it is at least partially melted (still in the molten state). In another example, at least one separated plastic fraction is cooled and must be melted again (at least partially) before being fed into another centrifugation step.

[0065] In another embodiment, the volume flow (separated plastic fraction) is distributed in the (corresponding) discharge area in relation to the fraction. In particular, the device has a sensor device which is configured to determine characteristic quantity values of the discharged separated plastic fraction. For example, a scale or other sensor device can determine the density of the fraction, and one or more switches can additionally adjust the supply volume flow according to the detected characteristic quantity values (color, density, etc.).

[0066] In one example, the plastic fraction is discharged at two or more discharge nozzles. These sub-fractions can be combined in a further step.

[0067] In one example, when supplying plastic (into the feed area), attention is paid to the as-uniform-as-possible mixing of the plastic fractions to be separated (for example, a multi-layer film with a constant composition, or a mixture of known input fractions as an auxiliary separator).

[0068] It should be noted that: Embodiments of the present invention have been introduced with reference to various items. In particular, some embodiments have been introduced with reference to method claims, while other embodiments have been introduced with reference to apparatus claims. However, those skilled in the art will understand from the foregoing description and the following description that, unless otherwise indicated, any combination of features relating to different subject matters is also considered to be disclosed herein, in addition to any combination of features belonging to one type of subject matter. This particularly also applies to the features between method claims and apparatus claims.

[0069] The above and other aspects of the present invention will become apparent from the examples of the embodiments described below and will be explained with reference to the examples of the embodiments. The present invention will be described in detail below with reference to the embodiments, but the present invention is not limited to these embodiments. Description of the Drawings

[0070] Figure 1 and Figure 2 respectively show apparatuses according to exemplary embodiments of the present invention.

[0071] Figure 3 Shows an apparatus having a feeding device according to an exemplary embodiment of the present invention.

[0072] Figure 4 Shows an apparatus having a furnace according to an exemplary embodiment of the present invention.

[0073] Figure 5 Shows an apparatus having a lateral discharge area according to an exemplary embodiment of the present invention.

[0074] Figure 6 and Figure 7 Shows an apparatus having an electromagnetic device according to an exemplary embodiment of the present invention, respectively.

[0075] Figure 8 b, Figure 9 b and Figure 10 and Figure 11 Show a feeding area according to an exemplary embodiment of the present invention, respectively.

[0076] Figure 12 and Figure 13 Show a discharge area according to an exemplary embodiment of the present invention, respectively.

[0077] Figure 8 a, Figure 9 a and Figure 14 Show a tubular centrifugal area; Figure 9 c shows a tubular centrifugal area having a lateral discharge area according to an exemplary embodiment of the present invention.

[0078] Figure 15 Show a coupling area according to an exemplary embodiment of the present invention ( Figure 15 b is a cooled coupling area).

[0079] Figure 16 and Figure 17 Show the separation of a plastic mixture into different plastic fractions according to an exemplary embodiment of the present invention, respectively. Detailed Description

[0080] The illustrations in the drawings are schematic. It should be noted that in different drawings, similar or identical elements or features will be represented by the same reference numerals or reference numerals that differ only in the first digit from the corresponding reference numerals. To avoid unnecessary repetition, elements or features already described with respect to the previously introduced embodiments will not be elaborated in the subsequent part of the specification.

[0081] In addition, spatial relative terms, such as "front" and "rear", "top", "bottom", "left" and "right", etc., are used to introduce the relationship between one element and another, as shown in the accompanying drawings. Therefore, spatial relative terms different from the orientation shown in the accompanying drawings can be used. Obviously, these spatial relative terms are only for the convenience of introduction and reference to the orientation shown in the accompanying drawings, and are not necessarily restrictive, because the device according to the embodiments of the present invention can adopt orientations other than those shown in the accompanying drawings, especially during application.

[0082] Figure 1 A device 100 for separating a molten plastic mixture 111 according to an exemplary embodiment of the present invention is shown.

[0083] The device 100 has a feed area 110, which is realized here as an opening upstream of the centrifugal area 120 along the process direction P, and the centrifugal area is configured to supply the plastic mixture 111 in at least a partially molten state. The centrifugal area 120 (here a tubular centrifuge) separates the at least partially molten plastic mixture 111 into a first plastic fraction 112 and a second plastic fraction 113 (wherein the first plastic fraction 112 is different from the second plastic fraction 113, for example polyethylene and polylactic acid) by means of centrifugal force (rotation schematically shown by the arrow). In this example, the discharge area 130 is shown as an opening of the centrifugal area 120 downstream in the process direction P. The separated plastic fractions 112, 113 can be removed from and provided by the device 100 through the discharge area 130. Preferably, the device 100 is designed to operate in a continuous mode, that is, continuously supply, centrifuge, and discharge the melt 111.

[0084] Figure 2 A device 100 for separating a molten plastic mixture according to another exemplary embodiment of the present invention is shown. Here, each of the three areas: i) the feed area 110, ii) the centrifugal area 120, iii) the discharge area 130 is constructed as a separate device. The feed area 110 has an inlet (see the details in Figures 8 to 11 ), and the inlet has a smaller diameter than the centrifugal area 120 connected downstream in the process direction P. The discharge area 130 is connected downstream of the centrifugal area 120 in the process direction P. In this example, the connections between the areas 110, 120, 130 are realized by flanges respectively. As shown in Figure 12 and Figure 13 below, the discharge area 130 is constructed here as a sieve plate 131. In addition, the drive shaft 148 for the centrifuge 120 can be seen, and the drive shaft 148 can be connected to the drive device 140 (see Figure 4 and Figure 5 ).

[0085] Figure 3 Device 100 is shown having a feeding device 114 according to an exemplary embodiment of the present invention. The centrifugation area 120 is connected to the feeding area 110, which includes a feeding device 114 for continuously supplying a molten plastic mixture. In this embodiment, the feeding device 114 is configured as an extruder (feeding screw).

[0086] Figure 4 Device 100 is shown having a furnace 150 according to an exemplary embodiment of the present invention. In this preferred exemplary embodiment, the centrifugation area 120 is placed inside the furnace 150. The furnace 150 provides a temperature to the centrifugation area 120 so that the plastic mixture remains substantially (at least partially) molten during centrifugation and does not cool / harden. In this example, the feeding area 110 and the discharge area 130 are arranged outside the furnace 150. In addition, a drive device 140 is shown in this example, which is implemented as an electric motor. The drive shaft (not shown in detail) is connected to the centrifuge 120 through the discharge area 130 and enables the rotation of the centrifuge 120.

[0087] Figure 5 Device 100 is shown having a plurality of lateral discharge areas 130 according to an exemplary embodiment of the present invention. In this embodiment, the device 100 has a plurality of discharge areas 130 arranged side by side. On the one hand, the plastic fractions downstream in the process direction P can be separated by the sieve plate 131. The above drive device 140 can enable the rotation of the centrifuge 120 by means of a drive shaft (supported by the reference numeral 145). In the side wall of the centrifugation device, in the centrifugation area 120, the discharge area 130 is again configured as an opening 125. In each of the plurality of discharge areas 130, a collection device 170 is provided. In continuous mode, each of the plurality of discharge areas 130 should be able to discharge a specific plastic fraction in its corresponding area B1 to B5, so that different plastic fractions can be recovered in each collection device 170.

[0088] Figure 6 and Figure 7 Device 100 is shown respectively having an electromagnetic device 160 according to an exemplary embodiment of the present invention.

[0089] Figure 6 : The electromagnetic device 160 is designed here as an induction device (coil) surrounding the centrifugation area 120. In this way, within a specific range, an electromagnetic influence can be exerted on the molten plastic mixture 111 in the centrifugation area 120, for example, thus fraction crystallization or magnetic separation (for plastics with different electronegativities) can be carried out.

[0090] Figure 7 is shown in further detail according to Figure 6Device 100. In particular, the electromagnetic device 160 can generate different electromagnetic fields (schematically shown) in different regions of the centrifuge 120. Here, the coil is a suggestion for targeted heating in order to thus achieve targeted temperature control of the process or the melt. The symbol "+ / -" schematically represents the (electrical) magnetic field, and these magnetic fields can additionally be applied.

[0091] Figures 8 to 11 The feeding area 110 according to an exemplary embodiment of the present invention is shown respectively.

[0092] Figure 8 a: In this embodiment, the feeding area 110 has a feeding pipe whose cross-section is significantly smaller than that of the centrifugal area 120, and the feeding pipe leads into the centrifugal area through the end cover of the centrifugal area 120. The corresponding discharge area 130 is implemented as a simple sieve plate 131, and the drive shaft 148 for the centrifuge 120 extends through the sieve plate 131. Figure 8 b is a detail view of the feeding area 110.

[0093] Figure 9 a: In this embodiment, the feeding area 110 has a conical transition area between the feeding pipe with a smaller cross-section and the centrifugal area 120 with a larger cross-section. The corresponding discharge area 130 has additional drive docking devices (exemplarily shown here in the form of gears) in order to achieve "external" drive, so that the drive shaft does not have to pass through the sieve plate. Figure 9 b is a detail view of the feeding area 110, Figure 9 c is a detail view of the discharge area 130.

[0094] Figure 10 The transition of the feeding device 115 of the feeding device 110 to the centrifugal area 120 is shown. The feeding device 115 is configured as a funnel through which the molten plastic mixture 111 can be introduced into the area of the feeding device 110 with a small cross-section. Here, it transitions from a non-rotating extruder to the rotating centrifugal area 120, where a seal is provided. The reference numeral 116 represents the connection (here a flange) between the feeding device 110 and the centrifugal device in the centrifugal area 120, and the reference numeral 117 represents the fixing member (such as a ball bearing ring). Figure 10 b shows a detail view of the feeding device 115.

[0095] Figure 11 a and Figure 11 b again shows the feeding device 110 according to Figure 10 a in a different view.

[0096] Figure 12 and Figure 13The discharge region 130 according to an exemplary embodiment of the present invention is shown respectively.

[0097] Figure 12 a: In this embodiment, the discharge region 130 has a sieve plate 131, in which openings 135a and 135b for discharging plastic fractions are provided. The above-mentioned drive shaft 148 of the drive device 140 (not shown here, see Figure 4 and Figure 5 ) extends through the sieve plate 131.

[0098] Figure 12 b shows a schematic diagram of the distribution of the openings 135a and 135b (at a constant angular interval and two different radial distances from the rotation axis here). In addition to the openings for separation, other openings for fixing purposes are provided.

[0099] Figure 13 Figs. 13a and 13b show other views of the sieve plate 131 and the openings 135a and 135b.

[0100] Figure 14 Fig. 20a shows a tubular centrifugal region 120 with a lateral discharge region according to an exemplary embodiment of the present invention. Upstream in the process direction P, the centrifugal region 120 has a connection region 121 for a feeding device, while downstream in the process direction P, the centrifugal region 120 has a connection region 122 for a discharging device. In the connection region 122 of the discharging device (see Figure 14 b), openings 125a, 125b are provided in the side wall of the centrifugal region 120, and these openings can be assigned to the discharge region. These openings 125a, 125b can achieve the discharge of specific plastic fractions.

[0101] Figure 15 Fig. 26 shows a connection region 145 according to an exemplary embodiment of the present invention. The connection region 145 between the drive device and the centrifugal region (on the discharge region), for example, by means of the drive shaft 148, may be technically challenging in terms of heat for the drive device. In the shown embodiment Figure 15 b, this problem can be overcome by means of a cooling device 146, which is achieved by means of a coolant flow here.

[0102] Figure 16 Fig. 32 shows the separation of a plastic mixture 111 into different plastic fractions 112, 113 before and after centrifugation according to an exemplary embodiment of the present invention.

[0103] Figure 16 a: Intuitively shown, the plastic mixture 111 has a first plastic fraction 112 (white) and a second plastic fraction (black).

[0104] Figure 16 b: As viewed in the direction of the centrifugal region 120, the (molten) plastic mixture 111 is positioned on the side wall after a very short rotation time.

[0105] Figure 16 c: As viewed in the direction of the centrifugal region 120 after a longer rotation time, the plastic fractions 112, 113 have separated into a white outer region 112 and a black inner region 113.

[0106] Figure 17 The separation of a plastic mixture into different plastic fractions 112, 113 according to an exemplary embodiment of the present invention is shown.

[0107] Figure 17 The figure in a schematically shows the separation process of the plastic fractions 112 and 113 (here PLA and HDPE) along the length of the (tubular) centrifugal region 120. In this embodiment, a laboratory scale is selected.

[0108] Figure 17 b shows corresponding photographs of the plastic mixture 111 at different positions within the elongated centrifugal region 120 (compared with the Figure 17 chart in a). A clear separation of the plastic fractions 112, 113 can be achieved downstream in the process direction P.

[0109] Figure 17 c shows the remixing or separation at a marked position in the centrifugal region 120 at a specific point in time in cross-section, where Figure 17 the ninth opening from the left in b shows the discharge (sub) region through which the outer ring fraction (the outer ring fraction having a higher or the highest density) can be discharged (continuously) from the material flow. Ideally, this is only done for as long as this fraction no longer appears in the material flow. (Hint: Density: HDPA < 1 g / cm 3 , PLA > 1.2 g / cm 3 )

[0110] Reference numerals

[0111] 100 Device

[0112] 110 Feeding area

[0113] 111 Molten plastic mixture

[0114] 112 First plastic fraction

[0115] 113 Second plastic fraction

[0116] 114 Feeding device, extruder

[0117] 115 Feeding device, funnel

[0118] 116 flange

[0119] 117 fixing device (in the feeding area)

[0120] 120 centrifugal area

[0121] 121 feeding connection area

[0122] 122 discharging connection area

[0123] 125 lateral opening (in the centrifuge wall)

[0124] 130 discharging area

[0125] 131 sieve plate

[0126] 135 through hole (e.g., in the sieve plate)

[0127] 140 driving device, motor

[0128] 145 connection area

[0129] 146 cooling device

[0130] 147 fixing part (in the discharging area)

[0131] 148 drive shaft

[0132] 150 furnace

[0133] 160 electromagnetic device

[0134] 170 collection device

[0135] P process direction

[0136] B1, B2, B3, B4, B5 fraction areas

Claims

1. An apparatus (100) for separating a plastic mixture (111), the apparatus (100) having: A feeding area (110) configured to feed the plastic mixture (111) in at least a partially molten state; A centrifugation zone (120) that is coupled to the feed zone (110) and that is configured to separate at least a partially molten plastic mixture (111) into one plastic fraction (112) and at least one other plastic fraction (113) by centrifugation, wherein, The plastic fraction (112) is different from the at least one other plastic fraction (113); And A discharge area (130) connected to the centrifugal area (120) and configured to provide the separated plastic fraction (112) and the separated at least one other plastic fraction (113); Wherein the apparatus (100) is configured to operate in a continuous mode.

2. The apparatus (100) according to claim 1, further having: Heating device, in particular furnace (150), for heating the centrifugation zone (120), wherein, The centrifugal area (120) is at least partially arranged within the furnace (150).

3. The apparatus (100) according to claim 2, Among them, The heating device (150) is configured to provide a temperature within the centrifugal area (120) such that the molten state of the at least partially molten plastic mixture (111) is maintained.

4. The apparatus (100) according to any one of the preceding claims, Among them, The feeding area (110) has a feeding device (114), particularly an extruder, configured to continuously feed the at least partially molten plastic mixture (111) to the centrifugal area (120).

5. The apparatus (100) according to any one of the preceding claims, Among them, The centrifugal area (120) is elongately configured with a main extension direction (H), particularly configured as an elongate container, and further particularly configured as tubular.

6. The device (100) according to any one of the preceding claims, wherein, The discharge area (130) has: A first opening (125a, 135a) for discharging the plastic fraction (112), and A second opening (125b, 135b) for discharging the at least one other plastic fraction (113).

7. The apparatus (100) according to claims 5 and 6, Among them, The boundary surface of the discharge area (130) having the first opening (135a) and / or the second opening (135b) is arranged substantially perpendicular to the main extension direction (H) of the elongate centrifugal area (120), In particular, the discharge area (130) has a sieve plate (131) in the end area of the elongate container (120) relative to the process direction (P).

8. The apparatus (100) according to claims 5 and 6, Among them, The discharge area (130) having the first opening (125a) and / or the second opening (125b) is arranged substantially parallel to the main extension direction (H) of the elongate centrifugal area (120), In particular, the discharge area (130) is configured in the boundary surface, particularly the side wall, of the elongate container (120).

9. The apparatus (100) according to any one of the preceding claims, Among them, The discharge area (130), particularly a plurality of discharge areas (130), forms at least one opening (125a, 125b) in the side wall of the centrifugal area (120), At least one plastic fraction (112, 113) can be separated through the at least one opening (125a, 125b).

10. The apparatus (100) according to claim 9, Among them, The centrifugal region (120) has a discharge region (130), particularly a plurality of discharge regions (130), along a main extension direction (H) in the process direction (P), and the discharge regions have a plurality of openings (125a, 125b), and through the openings (125a, 125b), a plurality of different plastic fractions (112, 113) can be separated and / or discharged, wherein the plurality of different plastic fractions include the plastic fraction (112) and the at least one other plastic fraction (113).

11. The apparatus (100) according to any one of the preceding claims 6 to 10, Among them, The discharge region (130) has three or more, particularly five or more, and further particularly ten or more openings (125a, 125b, 135a, 135b), and The apparatus (100) is configured to discharge different plastic fractions (112, 113) at each opening (125a, 125b, 135a, 135b).

12. The apparatus (100) according to any one of the preceding claims, Among them, The plastic mixture (111) has a multi-layer film material; and / or The plastic mixture (111) has at least one of the following plastics: polyethylene, PE, polystyrene, PS, polyester, PE, polypropylene, PP, polyamide, PA, polyvinyl chloride, PVC, polylactic acid, PLA.

13. The apparatus (100) according to any one of the preceding claims further comprises: An electromagnetic device (160) configured to provide an electromagnetic field within the centrifugal region (120).

14. The apparatus (100) according to any one of the preceding claims, and the apparatus is further configured to provide fraction crystallization within the centrifugal region (120).

15. A method comprising: At least partially melting a plastic mixture (111); Centrifuging the at least partially melted plastic mixture (111) and separating the at least partially melted plastic mixture (111) into a plastic fraction (112) and at least one other plastic fraction (113) therein, wherein the plastic fraction (112) is different from the at least one other plastic fraction (113); and Discharging the separated plastic fraction (112) and the separated at least one other plastic fraction (113); wherein the method runs continuously.

16. The method according to claim 15, wherein, The centrifuging is carried out in an elongated centrifugal region (120), and the method comprises: Moving the plastic mixture (111) continuously in a process direction (P) substantially perpendicular to the gravity direction (G); or Moving the plastic mixture (111) continuously in a process direction (P) parallel to the gravity direction (G).

17. The method according to claim 16, the method further comprises: At least one plastic fraction (112, 113) is discharged laterally from the elongated centrifugation zone (120) relative to the main extension direction (H), in particular laterally through at least one opening (125a, 125b) in the side wall of the centrifugation zone (120).

18. The method according to any one of claims 15 to 17, further comprising: providing at least one separated plastic fraction (112, 113) to another separation step, The method particularly comprises: In particular, according to the method of any one of claims 15 to 17, centrifuging the at least one separated plastic fraction (112, 113) and separating the separated plastic fraction (112, 113) therein.

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