Continuous separation of synthetic resin mixtures

Abstract

An apparatus (100) for separating a synthetic resin mixture (111) is described, the apparatus (100) comprising: i) a feed zone (110) configured to feed the synthetic resin mixture (111) in an at least partially molten state; ii) a centrifugation zone (120) coupled to the feed zone (110) and configured to separate the at least partially melted synthetic resin mixture (111) by centrifugation into a first synthetic resin fraction (112) and a second synthetic resin fraction (113), the first synthetic resin fraction (112) being different from the second synthetic resin fraction (113); and iii) a discharge zone (130) coupled to the centrifugation zone (120) and configured to provide the separated first synthetic resin fraction (112) and the separated second synthetic resin fraction (113). The device (100) is set to operate in continuous mode.

Description

[Technical Field]

[0001] The present invention relates to an apparatus for separating (molten) synthetic resin mixtures, which comprises a feed zone, a centrifugal separation zone and a discharge zone. The present invention further relates to a method for separating (molten) synthetic resin mixtures. Thus, the present invention can relate to the technical field of separating synthetic resin fractions from synthetic resin mixtures. [Background technology]

[0002] Recycling of plastics is a hot topic of great economic and environmental importance. Numerous methods are being developed and used worldwide. A particular challenge here is how to efficiently recycle plastic mixtures, since different plastics may require different recycling processes depending on their properties. This is especially true for unsortable plastic mixtures, such as multilayer films. In these cases, special technological developments may be required not only to achieve complete separation but also to make this possible within cost-effective limits. In Europe, approximately 17.8 Mt of used packaging materials were collected in 2018, of which only 7.5 Mt were recycled. This offers a potential of over 10 Mt / a for new separation methods.

[0003] Current research activities in the field of recycling are directed toward the reprocessing of material streams. For example, multi-sensor-assisted sorting systems using artificial intelligence, or so-called tracking systems, are being investigated. The goal of these studies is to generate pure material streams that can then be reintroduced into the cycle via traditional recycling routes. However, these approaches can have significant drawbacks: they often do not work with material composites such as multilayer films or polymer alloys. New processing concepts may be needed to make this quantitatively large waste category usable as materials again.

[0004] The separation method differs from existing recycling methods in one important respect: the separation of the synthetic resin mixture is carried out in the molten state of the polymers. Scientific literature has shown that the separation of two different polymers in a melt-like state in a centrifuge works because of the different physical properties (especially density) of the fractions in the centrifugal field. Such methods can be carried out discontinuously or batchwise: a batch of the synthetic resin mixture is fed into the centrifuge and then melted by increasing the temperature or applying heat. Subsequent use of the centrifuge allows for density separation of the synthetic resin fractions of the synthetic resin mixture. These fractions are then cooled and removed, and the centrifuge is ready for another batch of synthetic resin mixture.

[0005] However, this method can have the disadvantages of being relatively time consuming, generating a large amount of waste of synthetic resin mixture, and allowing only low throughput. Summary of the Invention

[0006] There may be a need to enable separation of synthetic resin mixtures efficiently, reliably, and at high throughput.

[0007] An apparatus and a method are provided according to the independent claims. Advantageous embodiments are set forth in the dependent claims.

[0008] According to a first aspect of the present invention, an apparatus for separating an (at least partially molten) synthetic resin mixture is described, the apparatus comprising: i) a feed zone (e.g., a continuous conveying device such as a screw conveyor) configured to feed a synthetic resin mixture in an (at least partially) molten state; ii) a centrifugation zone (an elongated tubular centrifuge) connected to the feed zone (e.g. connected via a flange) and configured to separate the at least partially dissolved synthetic resin mixture by centrifugation into a synthetic resin fraction and at least one other synthetic resin fraction (based on different physical properties, in particular density difference, viscosity difference, etc.), where the synthetic resin fraction is different (in particular chemically or physically different, more in particular at least specific density different) from the at least one other synthetic resin fraction (e.g. polyethylene and polyester); iii) a discharge area (e.g., a sieve plate or a transverse opening in the wall of the centrifuge) coupled to the centrifugation area and configured to provide the separated (at least partially dissolved, substantially liquid) synthetic resin fraction and at least one other separated (at least partially dissolved, substantially liquid) synthetic resin fraction(s).

[0009] In this case, the equipment is preferably set up to operate in continuous mode (and therefore not in discontinuous or batchwise operation).

[0010] According to a second aspect of the present invention, a method (e.g., for separating a synthetic resin mixture using an apparatus as described above) is described, the method comprising: i) at least partially melting the synthetic resin mixture; ii) centrifuging the at least partially dissolved synthetic resin mixture, thereby separating the dissolved synthetic resin mixture into a synthetic resin fraction and at least one other synthetic resin fraction, Separating these synthetic resin fractions, which are (physically and / or chemically) distinct from one another; iii) recovering the separated synthetic resin fraction and at least one other separated synthetic resin fraction.

[0011] In this case, the method can be carried out continuously.

[0012] In the context of this specification, the term "synthetic resin blend" may refer to a material containing at least two synthetic resins or synthetic resin fractions. For example, a synthetic resin blend may contain polyethylene and polystyrene. In one example, the synthetic resins (fractions) cannot be sorted or manually separated. An example of such a blend may be a multilayer film or a polymer alloy. In this context, the term "synthetic resin" may refer to a synthetic substance (particularly a material) that consists essentially of (particularly carbon-based) macromolecules, i.e., polymers. Colloquially, synthetic resins may also be referred to as plastics. In this context, synthetic resins may include thermoplastics, thermoset plastics, and elastomers. Specific examples include polyethylene terephthalate (PET), polypropylene (PP), high-density polyethylene (HDPE) or low-density polyethylene (LDPE), polystyrene (PS), and polyvinyl chloride (PVC). In one example, a synthetic resin blend may contain only one type of synthetic resin (e.g., PE), but this can be separated into two or more synthetic resin fractions (e.g., LDPE and HDPE).

[0013] In the context of this specification, the term "at least partially melted" may in particular refer to a molten state.

[0014] In the context of this specification, the term "feed zone" may particularly refer to a device suitable for continuously feeding the molten synthetic resin mixture to the centrifuge zone. In a simple embodiment, the feed zone can be the inlet zone (upstream in the process direction) of the centrifuge zone. In a more complex embodiment, the feed zone can have a conveying device capable of transporting the molten synthetic resin mixture by a continuous flow. In one example, the feed zone is a separate device connected to the centrifuge zone.

[0015] In the context of this specification, the term "centrifugation zone" may refer in particular to a device suitable for exerting centrifugal force on a material to be centrifuged, in particular a synthetic resin mixture. Preferably, the centrifugation zone is suitable for receiving the (at least partially dissolved) synthetic resin mixture and centrifuging it by rotation. The rotation (uniform circular motion) of the material to be centrifuged results in a material separation that can be utilized in particular to separate the synthetic resin mixture into synthetic resin fractions. The centrifugation zone may comprise a centrifuge device including one side wall (e.g., when formed as a tube) or multiple side walls (e.g., when formed as a square) that define an interior space capable of accommodating the material to be centrifuged. The centrifugation zone is preferably coupled to an inlet zone and a discharge zone, which allows for continuous supply and discharge of the material flow. Rotation of the centrifugation zone can be achieved by a drive, e.g., a motor. Corresponding coupling of the drive and the centrifugation device can be achieved, for example, via the discharge zone. In a preferred embodiment, the centrifugation zone is configured and suitable for operation in a furnace.

[0016] In the context of this specification, the term "discharge area" may particularly refer to a device suitable for continuously discharging or leading off (dissolved) synthetic resin fractions from the centrifugation area. In a simple embodiment, the discharge area can be the outlet area (downstream in the process direction) of the centrifugation device. In a more complex embodiment, the discharge area can have openings configured so that different synthetic resin fractions can be discharged separately through different openings (e.g., in terms of location or size). In one embodiment, the centrifugation device can be elongated and can be provided with openings downstream in the process direction and perpendicular to its main elongated extension (e.g., at the bottom of the tube), for example as a sieve plate. In another embodiment, the discharge area can be part of the centrifugation device or centrifugation area, for example, openings can be provided in the side walls of the centrifugation device.

[0017] According to an exemplary embodiment, the invention can be based on the idea that efficient and reliable separation of a synthetic resin mixture is achieved when the molten synthetic resin mixture is continuously fed into a centrifugal separation zone and, downstream in the process direction, various continuously separated (molten) synthetic resin fractions are drawn off and provided.

[0018] A continuously operating centrifugal separation zone (with additional structures) can make it possible to separate the mixed synthetic resin fractions into pure material streams. Unseparated material streams that are currently discarded can be separated using the presented method and reintroduced into the material cycle and reused separately in the future. Previous batch approaches work reliably, but have drawbacks in terms of throughput and therefore economy.

[0019] However, the inventors have surprisingly realised that a significantly higher throughput is possible with (substantially) the same reliability in a continuous mode, in which the synthetic resin mixture is fed to the centrifuge already in a molten state and the molten separated synthetic resin fractions are continuously withdrawn.

[0020] Illustrative Embodiments According to one embodiment, the device further comprises a heating device, in particular a furnace. In one example, the centrifugal separation zone is at least partially (in particular completely) arranged within the furnace. This has the advantage that a desired temperature can be directly (and uniformly) provided to the centrifugal separation zone or the at least partially melted synthetic resin mixture. In particular, this allows the (at least partially melted) synthetic resin mixture to be kept within a specific temperature range. This may also have the advantage that the synthetic resin mixture does not harden or cool down too quickly. In one embodiment, the inlet zone and / or outlet zone are arranged outside the furnace. In another example, the inlet zone and / or outlet zone are at least partially arranged within the furnace.

[0021] In one embodiment, the heating device is configured to heat the centrifuge, the gas and / or the synthetic resin compound within the centrifuge, hi another embodiment, the heating device can be an energy source in the vicinity of the centrifuge, for example, sunlight, an incineration facility, etc.

[0022] In another example, the heating device can be designed as an induction heating device for eddy current heating of an iron-containing induction centrifuge.

[0023] According to another embodiment, the heating device is configured to provide a temperature in the centrifugal separation zone such that the molten state of the molten plastic mixture is maintained. This temperature can be, for example, 150° C. or higher, in particular 300° C. or higher. The heating device can provide or maintain a temperature in the ambient environment, in the air, or in the plastic melt.

[0024] This may have the advantage that an individual temperature can be set depending on which synthetic resin mixture is used and to what extent it is to be dissolved during centrifugation.

[0025] The term "temperature" can refer to room temperature, wall temperature, or the thermal energy supply, in particular to heat the melt sufficiently or to compensate for heat losses in the supplied mass flow of synthetic resin mixture that may already be present as (partially) molten material. In another example, a source of thermal energy from the surroundings can be used, for example by combustion gases from non-recyclable materials in the surroundings.

[0026] According to another embodiment, the device further comprises a heating device configured to heat at least a portion of the side wall of the centrifuge area. It has been found that materials in the outer areas of the centrifuge or near the side wall tend to cool (and thereby harden) more quickly. This can be effectively and precisely prevented by additionally or alternatively heating the corresponding side wall area.

[0027] According to another embodiment, the apparatus includes a drive (e.g., a motor) configured to drive (or enable rotation of) the centrifuge region. In one embodiment, the drive can be coupled to the centrifuge region by a drive shaft. In another example, the drive shaft passes at least partially through the discharge region. In one example, the drive is located outside the furnace, and in another example, the drive is located inside the furnace.

[0028] According to another embodiment, the device comprises a cooling device, in particular associated with the connection area between the centrifugal separation area and the drive device (in particular via the discharge area). In particular, when using the above-mentioned furnaces, the temperature can be critical for the drive device. A corresponding cooling device (for example using a cooling liquid) can enable efficient and reliable operation.

[0029] According to another embodiment, the feeding zone is provided with a conveying device, in particular an extruder (for example, a single- or twin-screw extruder, a co-rotating or counter-rotating extruder, etc.), which extruder is configured to continuously add the at least partially melted synthetic resin mixture to the centrifugal zone. In this context, a conveying device may refer to a device suitable for transporting the (at least partially melted) synthetic resin mixture to the centrifugal zone. A screw conveyor may be suitable for this. In another example, a conveyor belt may also be used (which is suitable for at least a portion of the synthetic resin melt). The conveying device is considered to be part of the feeding zone and can lead to the interior of the centrifugal zone via a transition zone.

[0030] According to another embodiment, the centrifugation zone is elongated with a main direction of extension (H). In that case, a process direction (P) extends along this length, and the substance flow (molten synthetic resin mixture) is transported through the centrifugation zone along this process direction. This has the advantage that the synthetic resin fraction can be separated particularly efficiently and reliably along this transport length (see Figures 16 and 17). In one embodiment, the centrifugation zone or centrifuge device is formed as an elongated container, with one or more side walls defining an interior space (for the centrifuged substance). The container can be formed, for example, round (tubular) or rectangular in cross section. In this context, the term "elongated" may in particular refer to an object, such as a container, having a main direction or main direction of extension along which this object (this container) extends.

[0031] In certain embodiments, the centrifuge can have a rotation speed ranging up to 3000 rpm. The container can be approximately 1 meter long and 10 cm in diameter at lab scale. In one example, the rotation speed can be adjusted for a particular synthetic resin mixture, and then reused for similar applications.

[0032] According to another embodiment, the discharge area comprises: The separator has a first opening for discharging the synthetic resin fraction and / or a second opening for discharging at least one other second synthetic resin fraction. This has the advantage that the synthetic resin fraction can be discharged directly from the centrifugation area (e.g., via the side wall and / or bottom area) without substantially any additional auxiliary means. The openings can preferably be oriented towards a collecting device. For example, each opening can lead to a separate collecting device, thereby providing separated synthetic resin fractions. Furthermore, the openings can be provided with an outflow device (e.g., a groove) for guiding the (continuous) melted synthetic resin fraction flow.

[0033] According to another embodiment, the discharge area with the first and / or second (or at least one other) opening is arranged perpendicular to the main extension direction of the elongated centrifugation area. During centrifugation, the molten synthetic resin mixture moves through the centrifugation area along the process direction. Since the separation of the synthetic resin fraction can be most reliable downstream in the process direction, it may be efficient to provide the openings in this end or bottom area of ​​the centrifugal separator. For example, the openings can be arranged in an area arranged perpendicular to the process direction (material flow). In the case of an elongated container, this can be, for example, a plate with at least two openings, such as a sieve plate (see FIGS. 12 and 13). In one example, the axis of the holes is parallel to the process direction and / or parallel to the rotation axis of the centrifuge.

[0034] According to another embodiment, the discharge area with the first and / or second opening is arranged (substantially) parallel to the main direction of extension of the elongated centrifugation area. This example may particularly refer to an embodiment in which the opening is associated with or formed in a boundary surface (particularly a side wall) of the centrifugation area (particularly an elongated container). Additionally, side walls, in particular bottom surfaces, that are not arranged parallel to the main direction of extension of the container may also be relevant here. The openings can be assigned to the discharge area, and thus this or several discharge (partial) areas can be present in the side walls of the container. In one example, one discharge area or several of these discharge (partial) areas are arranged in the end region of the centrifugation area (see FIG. 14). In another embodiment, the discharge area / opening or several (or several) discharge (partial) areas / openings are formed along the longitudinal extension (main direction) of the elongated container, in particular associated with the side walls (see FIG. 5).

[0035] According to another embodiment, the centrifugal separation zone comprises at least one discharge zone having at least one opening in its side wall through which at least one synthetic resin fraction can be separated.

[0036] According to another embodiment, the centrifugation area (or elongated container) comprises, along the main direction of extension (H), a discharge area having a plurality of openings in the side wall through which a plurality of different synthetic resin fractions can be separated and / or discharged.

[0037] According to another embodiment, the discharge area has three or more, in particular five or more, more in particular ten or more openings. It is also possible to provide several discharge (partial) areas (for example three or more, in particular five or more, more in particular ten or more), each having one or more openings. In particular, the device is configured to discharge a separate / different synthetic resin fraction at each opening. This can allow for efficient separation and sorting.

[0038] Surprisingly, the inventors have realised that separating / directing the (at least partially dissolved) synthetic resin fraction along the process direction (or along the elongated centrifugation container, in particular via the side wall) can enable a particularly efficient and reliable separation.

[0039] According to another embodiment, the synthetic resin mixture comprises a multilayer film and / or a polymer alloy. Such unsortable mixtures are largely impossible to separate using conventional methods, and the described apparatus may be particularly useful for these materials.

[0040] According to another embodiment, the synthetic resin mixture comprises at least one synthetic resin from the group consisting of polyethylene, PE, polystyrene, PS, polyester, PE, polypropylene, PP, polyamide, PA, polyvinyl chloride, PVC, polylactic acid, and PLA. Therefore, synthetic resins of particular economic importance and widespread use may be suitable for the described separation. Any of these examples may be a synthetic resin fraction. Furthermore, however, two or more of these synthetic resins may together form one synthetic resin fraction.

[0041] According to another embodiment, the device further comprises an electromagnetic device configured to (directly, selectively) provide one or more electromagnetic fields in the centrifuge zone. This may have the advantage that other efficient (e.g., magnetic) separation mechanisms can be used. In one example, electromagnetic fields are used directly in the centrifuge zone, for example, by an induction device (see also Figures 6 and 7). In another example, magnetic separation can also be performed on synthetic resin mixtures or synthetic resin fractions. In one embodiment, alternating poles can be used.

[0042] In one example, a DC magnetic field (with north and south poles) can deflect electrically charged (Coulomb-charged) synthetic resin particles in a rotating material flow (Stoffstrom), and the deflection in the magnetic field (Lorentz force = q*(vxB)) can vary depending on the charge (height).

[0043] In one example, a magnetic field is induced, which allows the separation of differently charged synthetic resins. In one embodiment, the rotational motion can be adjusted to achieve a separation based on the action of different forces on charged synthetic resin particles of different electronegativity at the top / bottom of the centrifugation zone (two separation stages).

[0044] In another example, magnetic separation can occur during rotation, so that another force (electrostatic / electrodynamic) is applied synchronously with the rotation, thereby increasing the centrifugal force (one separation stage).

[0045] According to another embodiment, the device is further configured to provide fractional crystallization (by temperature gradient) within the centrifugal zone, which has the advantage that certain synthetic resin substances or synthetic resin fractions will (at least partially) crystallize, while other synthetic resin fractions will not, thereby allowing a particularly efficient separation.

[0046] According to another embodiment, the method comprises moving (continuously) the synthetic resin mixture (transporting) perpendicularly to the direction of gravity (G), in this embodiment the process direction extends horizontally or along the x- or y-axis, in other words transversely or substantially parallel or tangential to the surface of the earth.

[0047] According to another embodiment, the method comprises moving (continuously) the synthetic resin mixture (substantially) parallel to the direction of gravity (G), in this embodiment the process direction extends vertically or along the Z axis, in other words from top to bottom or bottom to top, or normal to the earth's surface.

[0048] Depending on the space conditions or the desired result, different modes of operation may be particularly advantageous. However, in one example, the process direction (or centrifugation area) can also be tilted or pivoted, for example, in the range of 1 to 89° relative to the direction of gravity (0° and 90° can be referred to as vertical and horizontal).

[0049] According to another embodiment, the method further comprises discharging at least one synthetic resin fraction from the elongated centrifugation region transversely to the main extension direction (of the elongated container), in particular through at least one opening in each of the side walls of the centrifugation region.

[0050] According to another embodiment, the method comprises subjecting at least one already separated synthetic resin fraction to a further separation step, in particular centrifuging the separated synthetic resin fraction again, thereby further separating the separated synthetic resin fraction into a further first synthetic resin fraction and a further second synthetic resin fraction.

[0051] Further centrifugation steps can be carried out by equivalent (or identical) equipment. The further centrifugation steps can follow the described separation method continuously or can be carried out batchwise. In one example, the at least one separated synthetic resin fraction is at least partially (still) molten when fed to the further centrifugation step. In another example, the at least one separated synthetic resin fraction is cold and needs to be (at least partially) thawed again before being sent to the further centrifugation step.

[0052] In another embodiment, the volumetric flow rates (of the separated synthetic resin fractions) are allocated in the (respective) discharge areas according to the fractions. In particular, the device comprises a sensor device configured to determine characteristic quantities of the separated synthetic resin fractions being discharged. For example, a scale or other sensor device can determine the density of the fractions, and one or more dividers can additionally control the discharge volumetric flow rates depending on the detected characteristic quantities (color, density, etc.).

[0053] In one example, the synthetic resin fraction is discharged in two or more discharge areas. These subfractions can be collected in separate stages.

[0054] In one example, when feeding the synthetic resin (into the inlet region), care is taken to ensure that the synthetic resin fractions to be separated are mixed as homogeneously as possible (for example, a multilayer film of constant composition or a mixture of known starting fractions as an auxiliary separator).

[0055] It should be noted that embodiments of the present invention have been described with respect to different subject matters. In particular, some embodiments have been described with respect to method claims, while other embodiments have been described with respect to apparatus claims. However, from the above and following description, those skilled in the art will appreciate that, unless otherwise specified, any combination of features belonging to one type of subject matter, as well as any combination of features relating to different subject matters, is also considered to be disclosed by this specification. This is particularly true between features of method claims and features of apparatus claims.

[0056] The above-defined and further aspects of the present invention will become apparent from and be elucidated with reference to the exemplary embodiments described below, with which the present invention will be explained in more detail, but to which the present invention is not limited. [Brief explanation of the drawings]

[0057] [Figure 1] 1 illustrates an apparatus according to an exemplary embodiment of the present invention. [Figure 2] 1 illustrates an apparatus according to an exemplary embodiment of the present invention. [Figure 3] 1 illustrates an apparatus with a transport device according to an exemplary embodiment of the present invention; [Figure 4] FIG. 1 illustrates an apparatus with a furnace according to an exemplary embodiment of the present invention. [Figure 5] 1 illustrates an apparatus with lateral discharge areas according to an exemplary embodiment of the present invention. [Figure 6] 1 illustrates an apparatus including an electromagnetic device according to an exemplary embodiment of the present invention. [Figure 7] 1 illustrates an apparatus including an electromagnetic device according to an exemplary embodiment of the present invention. [Figure 8] Figure 8a shows a tubular centrifugation region and Figure 8b shows a feed region according to an exemplary embodiment of the present invention. [Figure 9]Figure 9a shows a tubular centrifugation region, Figure 9b shows a feed region according to an exemplary embodiment of the invention, and Figure 9c shows a tubular centrifugation region with a lateral discharge region according to an exemplary embodiment of the invention. [Figure 10] FIG. 1 illustrates a feed region according to an exemplary embodiment of the present invention. [Figure 11] FIG. 1 illustrates a feed region according to an exemplary embodiment of the present invention. [Figure 12] FIG. 10 illustrates a discharge area according to an exemplary embodiment of the present invention. [Figure 13] FIG. 10 illustrates a discharge area according to an exemplary embodiment of the present invention. [Figure 14] The tubular centrifugation region is shown. [Figure 15] 15b shows the bonded region (cooled) according to an exemplary embodiment of the present invention. [Figure 16] 1 illustrates the separation of a synthetic resin mixture into various synthetic resin fractions according to an exemplary embodiment of the present invention. [Figure 17] 1 illustrates the separation of a synthetic resin mixture into various synthetic resin fractions according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0058] The illustrations in the drawings are schematic. It should be noted that in different figures, similar or identical elements or features are provided with the same reference signs, or with reference signs that differ only within the scope of the corresponding reference signs and initial digits. To avoid unnecessary repetition, elements or features that have already been described with reference to the previous embodiments will not be described again in the remainder of this specification.

[0059] Additionally, as shown in the figures, spatially relative terms such as "front" and "back," "top" and "bottom," "left" and "right" are used to describe the relationship of one element to another. Thus, the spatially relative terms may refer to orientations when used that are different from the orientations depicted in the figures. It should be apparent that these spatially relative terms are for ease of explanation only, and that the orientations depicted in the figures are not necessarily limiting, as a device according to an embodiment of the present invention, particularly when used, may assume orientations other than those depicted in the figures.

[0060] FIG. 1 illustrates an apparatus 100 for separating a synthetic resin mixture melt 111 according to an exemplary embodiment of the present invention.

[0061] The apparatus 100 has a feed zone 110, here realized as an opening in the process direction P upstream of a centrifugation zone 120, configured to feed the at least partially molten synthetic resin mixture 111. The centrifugation zone 120, here a tubular centrifuge, separates the at least partially molten synthetic resin mixture 111 by centrifugal force (rotation is indicated diagrammatically by arrows) into a first synthetic resin fraction 112 and a second synthetic resin fraction 113 (the first synthetic resin fraction 112 is different from the second synthetic resin fraction 113, e.g., polyethylene and polylactic acid). In this example, a discharge zone 130 is shown downstream in the process direction P as an opening of the centrifugation zone 120. The separated synthetic resin fractions 112, 113 can be removed from the apparatus 100 via the discharge zone 130 and provided. Preferably, the illustrated apparatus 100 is configured to operate in a continuous mode, i.e., to continuously feed, centrifuge, and discharge the melt 111.

[0062] FIG. 2 shows an apparatus 100 for separating a synthetic resin mixture melt according to another exemplary embodiment of the present invention. Here, three zones are designed as separate units: i) a feed zone 110, ii) a centrifugation zone 120, and iii) a discharge zone 130. The feed zone 110 has a smaller diameter inlet than the centrifugation zone 120 connected downstream in the process direction P (see FIGS. 8 to 11 for details). Downstream of the centrifugation zone 120 in the process direction P is also connected the discharge zone 130. In this example, the connections between the zones 110, 120, and 130 are realized via flanges. As shown in the following FIGS. 12 and 13, the discharge zone 130 is designed as a sieve plate 131. Additionally, a drive shaft 148 for the centrifuge 120 is visible, which can be connected to a drive unit 140 (see FIGS. 4 and 5).

[0063] 3 shows an apparatus 100 with a conveying device 114 according to an exemplary embodiment of the invention. The centrifugal separation zone 120 is connected to a feeding zone 110 with a conveying device 114 for continuously providing the molten synthetic resin mixture. In this embodiment, the conveying device 114 is designed as an extruder (screw conveyor).

[0064] 4 shows the apparatus 100 with an oven 150 according to an exemplary embodiment of the present invention. In this preferred embodiment, the centrifugation region 120 is located within the oven 150. The oven 150 provides the temperature to the centrifugation region 120 so that the synthetic resin mixture remains substantially (at least partially) molten and does not cool / harden during centrifugation. In this example, the feed region 110 and the discharge region 130 are located outside the oven 150. Furthermore, in this example, a drive unit 140 is shown, which is implemented as an electric motor. A drive shaft (not shown in detail) is connected to the centrifuge 120 via the discharge region 130, enabling its rotation.

[0065] FIG. 5 shows an apparatus 100 with multiple lateral discharge areas 130 according to an exemplary embodiment of the invention. In this embodiment, the apparatus 100 comprises multiple discharge areas 130 arranged side by side. On the one hand, the synthetic resin fraction can be separated downstream in the process direction P via a sieve plate 131. The drive 140 described above enables the rotation of the centrifuge 120 by means of a drive shaft (attached at reference number 145). Discharge areas 130 are also formed as openings 125 in the side wall of the centrifuge at the centrifugation area 120. Each of the multiple discharge areas 130 is provided with a collector 170 below it. In continuous mode, each of the multiple discharge areas 130 allows the discharge of a specific synthetic resin fraction in its respective area B1-B5, so that a different synthetic resin fraction is found in each collector 170.

[0066] 6 and 7 each show an apparatus 100 including an electromagnetic device 160 according to an exemplary embodiment of the invention.

[0067] 6, the electromagnetic device 160 is here designed as an inductive device (coil) around the centrifugation region 120. In this way, it is possible to electromagnetically influence the molten synthetic resin mixture 111 in the centrifugation region 120 in specific areas, and thus to carry out, for example, fractional crystallization or magnetic separation (in the case of synthetic resins of different electronegativity).

[0068] Figure 7 shows the device 100 according to Figure 6 in more detail. In particular, an electromagnetic device 160 is able to generate different electromagnetic fields (shown diagrammatically) in different areas of the centrifuge 120. The coils here indicate precise heating to achieve precise temperature control of the process or melt. The symbols "+ / -" exemplarily represent additionally applicable (electro)magnetic fields.

[0069] 8-11 each illustrate a feed region 110 according to an exemplary embodiment of the present invention.

[0070] In this embodiment, in Fig. 8a, the feed area 110 has a feed line with a cross-sectional area much smaller than that of the centrifugation area 120, which feed line leads to the centrifugation area 120 via an end cover. The corresponding discharge area 130 is implemented as a simple sieve plate 131, through which the drive shaft 148 of the centrifuge 120 passes. Fig. 8b shows a detailed view of the feed area 110.

[0071] In this embodiment, in Fig. 9a, the supply area 110 has a conical transition area between the supply line, which has a smaller cross-sectional area, and the centrifugal separation area 120, which has a larger cross-sectional area. The corresponding discharge area 130 has an additional drive docking device (shown here exemplarily in the form of a gear) to allow drive "from the outside" and thereby avoid the need to insert the drive shaft through the sieve plate. Fig. 9b shows a detailed view of the supply area 110, and Fig. 9c shows a detailed view of the discharge area 130.

[0072] Figure 10 shows the transition between the introduction device 115 of the feeding device 110 and the centrifugation zone 120. The introduction device 115 is designed as a funnel, which allows the molten synthetic resin mixture 111 to be introduced into the area of ​​reduced cross section of the feeding device 110. The transition from the non-rotating extruder to the rotating centrifugation zone 120 takes place here, and a seal is provided. Reference numeral 116 denotes the connection (here a flange) between the feeding device 110 and the centrifugation device in the centrifugation zone 120, and reference numeral 117 denotes a fixing part (e.g. a ball bearing ring). Figure 10b shows a detailed view of the introduction device 115.

[0073] Figures 11a and 11b show again the feeding device 110 according to Figure 10a in another view.

[0074] 12 and 13 each illustrate a discharge area 130 according to an exemplary embodiment of the present invention.

[0075] 12a, in this embodiment the discharge area 130 has a sieve plate 131 provided with openings 135a and 135b for discharging the synthetic resin fraction. The aforementioned drive shaft 148 of the drive device 140 (not shown here, see Figures 4 and 5) passes through the sieve plate 131.

[0076] Figure 12b shows a schematic diagram of the distribution of apertures 135a and 135b (here at a constant angular distance and at two different radial distances from the axis of rotation). Besides the apertures for separation, other apertures are provided for mounting purposes.

[0077] 13a and 13b show another view of sieve plate 131 and openings 135a and 135b.

[0078] Figure 14a shows a tubular centrifugation zone 120 with a lateral discharge zone according to an exemplary embodiment of the invention. Upstream in the process direction P, the centrifugation zone 120 has a connection zone 121 for a feed device, and downstream in the process direction, the centrifugation zone 120 has a connection zone 122 for a discharge device. In the latter connection zone 122 (see Figure 14b), openings 125a, 125b are provided in the side walls of the centrifugation zone 120, which can be assigned to the discharge zone. These openings 125a, 125b allow the discharge of specific synthetic resin fractions.

[0079] Figure 15 shows a coupling area 145 according to an exemplary embodiment of the invention. The coupling area 145 between the drive device and the centrifugal zone (via the discharge zone), for example by the drive shaft 148, can be thermally problematic for the drive device. In the embodiment shown in Figure 15b, this problem can be overcome by a cooling device 146, here realized by a coolant flow.

[0080] FIG. 16 shows the separation of a synthetic resin mixture 111 into different synthetic resin fractions 112, 113 according to an exemplary embodiment of the present invention before and after centrifugation.

[0081] In FIG. 16a, a synthetic resin mixture 111 is specifically shown having a first synthetic resin fraction 112 (white) and a second synthetic resin fraction (black).

[0082] In FIG. 16b, a view into the centrifugal separation region 120 shows that the (molten) synthetic resin mixture 111 is deposited on the sidewall after a short spinning time.

[0083] In FIG. 16c, a view of the centrifuged region 120 after a longer spinning time shows that the synthetic resin fractions 112, 113 have separated into a white outer region 112 and a black inner region 113.

[0084] FIG. 17 illustrates the separation of a synthetic resin mixture into different synthetic resin fractions 112, 113 according to an exemplary embodiment of the present invention.

[0085] 17a shows a schematic diagram of the mixture separation profile of the synthetic resin fractions 112 and 113 (here PLA and HDPE) along the length of the (tubular) centrifugation zone 120. In this example, a lab scale has been chosen.

[0086] Figure 17b shows corresponding images (related to the view in Figure 17a) of the synthetic resin mixture 111 at various positions within the elongated centrifugal field 120. A clear separation of the synthetic resin fractions 112, 113 downstream in the process direction P can be achieved.

[0087] FIG. 17c shows in cross section the mixture separation at the marked position in the centrifugation zone 120 at a specific time, where the ninth opening from the left in FIG. 17b represents the discharge (partial) zone, through which the outer ring portion (= the higher or highest density portion) can be (continuously) separated from the substance flow and discharged. This is ideally done until this fraction is no longer in the substance flow. (Note: Density: HDPA<1 g / cm 3 , PLA>1.2g / cm 3 ). (Other possible items) (Item 1) An apparatus (100) for separating a synthetic resin mixture (111), said apparatus (100) comprising: a supply area (110) configured to supply said synthetic resin mixture (111) in an at least partially molten state; a centrifugation zone (120) coupled to said feed zone (110) and configured to separate said at least partially dissolved synthetic resin mixture (111) by centrifugation into a synthetic resin fraction (112) and at least one other synthetic resin fraction (113); a centrifugation zone in which the synthetic resin fraction (112) is different from the at least one other synthetic resin fraction (113); a discharge area (130) coupled to the centrifugal separation area (120) and configured to provide the separated synthetic resin fraction (112) and at least one other separated synthetic resin fraction (113); The device (100) is configured to operate in a continuous mode. (Item 2) The apparatus further comprises a heating device, in particular a furnace (150), for heating the centrifugal separation zone (120), the centrifugal separation zone (120) being at least partially disposed within the furnace (150). Item 1. The device (100) according to item 1. (Item 3) the heating device (150) is configured to provide a temperature within the centrifugal separation zone (120) such that the at least partially melted synthetic resin mixture (111) remains in a molten state. Item 3. The device (100) according to item 2. (Item 4) the feeding zone (110) comprises a conveying device (114), in particular an extruder, configured to continuously feed the at least partially melted synthetic resin mixture (111) into the centrifugal separation zone (120); 4. The device (100) according to any one of items 1 to 3. (Item 5) the centrifugal separation area (120) is elongated with a main direction of extension (H), in particular as an elongated container, more particularly tubular; 5. The device (100) according to any one of items 1 to 4. (Item 6) The discharge area (130) has first openings (125a, 135a) for discharging the synthetic resin fraction (112); and a second opening (125b, 135b) for discharging the at least one other synthetic resin fraction (113). 6. The device (100) according to any one of items 1 to 5. (Item 7) the interface of the discharge area (130) with the first opening (135a) and / or the second opening (135b) is arranged substantially perpendicular to the main direction of extension (H) of the elongated centrifugal separation area (120), In particular, the discharge area (130) has a sieve plate (131) at the end area of ​​the elongated container (120) in the process direction (P). Item 5 and 6. The device (100) according to item 5 and item 6. (Item 8) the discharge area (130) having the first opening (125a) and / or the second opening (125b) is arranged substantially parallel to the main direction of extension (H) of the elongated centrifugal separation area (120), In particular, the discharge area (130) is formed in a boundary surface, in particular a side wall, of the elongated container (120). Item 5 and 6. The device (100) according to item 5 and item 6. (Item 9) the discharge area (130), in particular a plurality of discharge areas (130), having at least one opening (125a, 125b) is formed in the side wall of the centrifugal separation area (120), At least one synthetic resin fraction (112, 113) can be separated through the at least one opening (125a, 125b), 9. The device (100) according to any one of items 1 to 8. (Item 10) the centrifugal separation zone (120) comprises, along the main extension direction (H) in the process direction (P), a discharge zone (130), in particular a plurality of discharge zones (130), with a plurality of openings (125a, 125b) through which a plurality of different synthetic resin fractions (112, 113) can be separated and / or discharged; The plurality of different synthetic resin fractions includes the synthetic resin fraction (112) and at least one other synthetic resin fraction (113). Item 10. The device (100) according to item 9. (Item 11) the discharge area (130) has three or more, in particular five or more, more in particular ten or more openings (125a, 125b, 135a, 135b); the device (100) is configured to discharge a different synthetic resin fraction (112, 113) at each opening (125a, 125b, 135a, 135b); The device (100) according to any one of items 6 to 10. (Item 12) the synthetic resin mixture (111) comprises a multilayer film material, and / or The synthetic resin mixture (111) comprises at least one of the following synthetic resins: polyethylene, PE, polystyrene, PS, polyester, PE, polypropylene, PP, polyamide, PA, polyvinyl chloride, PVC, polylactic acid, PLA; 12. The device (100) according to any one of items 1 to 11. (Item 13) an electromagnetic device (160) configured to provide an electromagnetic field within said centrifugal field (120); 13. The device (100) of any one of items 1 to 12, further comprising: (Item 14) 14. The apparatus (100) of any one of items 1 to 13, further configured to provide fractional crystallization within the centrifugation zone (120). (Item 15) At least partially melting the synthetic resin mixture (111); centrifuging the at least partially dissolved synthetic resin mixture (111), thereby separating the at least partially dissolved synthetic resin mixture (111) into a synthetic resin fraction (112) and at least one other synthetic resin fraction (113), separating said synthetic resin fraction (112) from said at least one other synthetic resin fraction (113); and discharging the separated synthetic resin fraction (112) and the separated at least one further synthetic resin fraction (113), The method is carried out continuously. (Item 16) The centrifugation is performed in an elongated centrifugation region (120), and the method comprises: continuously moving the synthetic resin mixture (111) in a process direction (P) substantially perpendicular to the direction of gravity (G); or 16. The method according to item 15, comprising continuously moving the synthetic resin mixture (111) in a process direction (P) parallel to the direction of gravity (G). (Item 17) Discharging at least one synthetic resin fraction (112, 113) from said elongated centrifugal zone (120) transversely to the main direction of extension (H), in particular through at least one opening (125a, 125b) respectively in the side wall of said centrifugal zone (120). Item 17. The method of item 16, further comprising: (Item 18) further comprising subjecting at least one separated synthetic resin fraction (112, 113) to a further separation step; In particular, the method according to any one of items 15 to 17, further comprising centrifuging the at least one separated synthetic resin fraction (112, 113), thereby separating the separated synthetic resin fraction (112, 113), 18. The method according to any one of items 15 to 17. [Explanation of symbols]

[0088] 100 devices 110 Supply area 111 Synthetic resin mixture, melted 112 First Synthetic Resin Fraction 113 Second Synthetic Resin Fraction 114 Conveying equipment, extruders 115 Introduction device, funnel 116 Flange 117 Fixing devices (in the supply area) 120 Centrifugal Region 121 Combined Area Supply 122 Combined Area Discharge 125 Lateral opening (in the wall of a centrifuge) 130 Emission area 131 sieve plate 135 drainage opening (e.g., in the cribriform plate) 140 Drive device, motor 145 Combined area 146 Cooling device 147 Fixing part (in the discharge area) 148 Drive shaft 150 furnace 160 Electromagnetic devices 170 Collection Device P process direction B1, B2, B3, B4, B5 fraction area

Claims

1. 1. An apparatus for separating a synthetic resin mixture, said apparatus comprising: a supply region configured to supply the synthetic resin mixture in an at least partially molten state; a centrifugation zone coupled to said feed zone and configured to separate said at least partially dissolved synthetic resin mixture into a synthetic resin fraction and at least one other synthetic resin fraction by centrifugation; a centrifugation zone, wherein the synthetic resin fraction is different from the at least one other synthetic resin fraction; a discharge region coupled to the centrifugation region and configured to provide the separated synthetic resin fraction and the separated at least one other synthetic resin fraction; The apparatus is configured to operate in a continuous mode.

2. a heating device, in particular a furnace, for heating the centrifugal separation zone, the centrifugal separation zone being at least partially arranged in the furnace; 10. The apparatus of claim 1.

3. the heating device is configured to provide a temperature within the centrifugal zone such that the at least partially melted synthetic resin mixture is maintained in a molten state.

3. The apparatus of claim 2.

4. the feeding zone comprises a conveying device, in particular an extruder, configured to continuously feed the at least partially melted synthetic resin mixture into the centrifugal separation zone; 10. The apparatus of claim 1.

5. the centrifugal separation area is elongated with a main direction of extension, in particular as an elongated container, more particularly tubular; 10. The apparatus of claim 1.

6. The discharge area includes a first opening for discharging the synthetic resin fraction; a second opening for discharging the at least one other synthetic resin fraction.

6. The apparatus of claim 5.

7. an interface of the discharge area with the first opening and / or the second opening is arranged substantially perpendicular to the main direction of extension of the elongated centrifugal separation area, In particular, the discharge area has a sieve plate at the end area of ​​the elongated container in the process direction.

7. The apparatus of claim 6.

8. the discharge area with the first opening and / or the second opening is arranged substantially parallel to the main direction of extension of the elongated centrifugal separation area, In particular, the discharge area is formed in a boundary surface, in particular a side wall, of the elongated container.

7. The apparatus of claim 6.

9. the discharge area with at least one opening, in particular a plurality of discharge areas, is formed in a side wall of the centrifugal separation area, At least one synthetic resin fraction can be separated through the at least one opening.

10. The apparatus of claim 1.

10. the centrifugal separation zone comprises, along its main extension in the process direction, a discharge zone with a plurality of openings, in particular a plurality of discharge zones, through which a plurality of different synthetic resin fractions can be separated and / or discharged, The plurality of different synthetic resin fractions includes the synthetic resin fraction and at least one other synthetic resin fraction.

10. The apparatus of claim 9.

11. the discharge area has three or more openings, in particular five or more openings, more in particular ten or more openings; the device being configured to discharge a different synthetic resin fraction at each opening; 7. The apparatus of claim 6.

12. the synthetic resin mixture comprises a multilayer film material; and / or The synthetic resin mixture comprises at least one of the following synthetic resins: polyethylene, PE, polystyrene, PS, polyester, PE, polypropylene, PP, polyamide, PA, polyvinyl chloride, PVC, polylactic acid, PLA; 10. The apparatus of claim 1.

13. an electromagnetic device configured to provide an electromagnetic field within the centrifuge region; The apparatus of claim 1 further comprising:

14. 14. The apparatus of any one of claims 1 to 13, further configured to provide fractional crystallization within the centrifugal zone.

15. at least partially melting the synthetic resin mixture; centrifuging the at least partially dissolved synthetic resin mixture, thereby separating the at least partially dissolved synthetic resin mixture into a synthetic resin fraction and at least one other synthetic resin fraction; separating, wherein the synthetic resin fraction is different from the at least one other synthetic resin fraction; and discharging the separated synthetic resin fraction and the separated at least one other synthetic resin fraction, The method is carried out continuously.

16. The centrifugation is performed in an elongated centrifugation region, and the method comprises: continuously moving the synthetic resin mixture in a process direction substantially perpendicular to the direction of gravity; or 16. The method of claim 15, comprising continuously moving the synthetic resin mixture in a process direction parallel to the direction of gravity.

17. Discharging at least one synthetic resin fraction from the elongated centrifugal separation zone transversely to the main direction of extension, in particular through at least one opening in each of the side walls of the centrifugal separation zone.

17. The method of claim 16, further comprising:

18. further comprising subjecting the at least one separated synthetic resin fraction to a further separation step; In particular, the method comprises centrifuging the at least one separated synthetic resin fraction, in particular according to any one of claims 15 to 17, thereby separating the separated synthetic resin fraction, The method according to any one of claims 15 to 17.

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