EP2700456A1 - Arrangement and method for the sorting of plastic material - Google Patents

Abstract

The device has first and second sorting apparatuses (S1) whose outlet openings receive a major fraction (H1) and a minor fraction (N1) and are connected to inlet openings of second and third sorting apparatuses (S2, S3). An outlet opening of the first sorting apparatus for receiving another minor fraction (N2) is connected to the inlet opening of the first sorting apparatus. The outlet opening of the third sorting apparatus for receiving another major fraction (H3) is connected to the inlet opening of the first sorting apparatus. An independent claim is also included for a method for obtaining material from a mixed fraction.

Description

The present invention relates to an arrangement and a method for sorting plastic material such as polyethylene terephthalate, polyethylene or polypropylene.

Nowadays, many everyday items such as bottles, films or other packaging are made of plastic materials. By way of example, reference is made to PET bottles which are produced from polyethylene terephthalate (PET). Here, a polyethylene terephthalate prepolymer is prepared from the monomers terephthalic acid and ethylene glycol via a melt polycondensation and then raised in a solid phase post-condensation (SSP) to the desired molecular weight. The production of PET is known and, for example, in Handbook Modern Polymers (Scheirs / Long (ed.), Wiley 2003, especially pp. 31-104 and 143-186) ) described in detail.

Especially for environmental reasons, the recycling of such plastic materials is nowadays carried out on a large scale. PET is very well suited for recycling as it can be re-processed several times. Recycling cycles have been established involving the collection of used PET bottles, their separation from other refuse and reprocessing. The plastic material is ground into flakes and separated from foreign substances. Typically, the molecular weight of the resulting PET flakes must be increased again in an SSP reaction to compensate for material degradation occurring during use and recycling as described above.

For the recyclability of the plastic material, it is important to recover the same in a pure form. In addition to the separation the plastic material of foreign matter, it is also necessary to separate different colored fractions of the plastic material precisely from each other.

A separation can be achieved with the help of known sorting machines in principle. Thus, the company Bühler Sortex Ltd. Sorting machines known with which particles can be separated, inter alia, based on different staining. These sorting machines are for example in the US 4,203,522 . US 4,513,868 . US 4,699,273 . US 5, -538.142 . WO 98/18573 . EP-0 838 274 A2 or WO 2010/073004 A1 described.

In these sorting machines, the particulate product to be separated from a metering system is introduced continuously and uniformly via a chute into the actual sorting station, which passes through the particles in free fall. For example, in the sorting station, the particles are visually inspected. For this purpose, the particles are charged with suitable electromagnetic radiation, the radiation reflected by the particles or, alternatively, the transmission radiation passing through the particles is detected and evaluated in a data processing system. Depending on the nature of the received signal corresponding to a particle, the particle then falls into a first container, or it is activated by the signal, a separator such as a blow-out system, which deflects the corresponding particle with a blast of air from a nozzle and transferred to a second container ,

These sorting machines, which were originally developed for foods such as rice, are very efficient and can achieve throughput rates of up to 32 t / h, depending on the product to be separated. When separating plastic particles with these Sorting machines achieved throughput rates of 0.5 to 12 t / h.

It has been found that with the known sorting machines, a degree of purity required for various applications of recycled plastic can not be achieved or an excessively high, economically disadvantageous scrap is generated.

It was therefore the object of the present invention to provide an arrangement and a method for even more efficient separation of plastic particles.

The present object is achieved by an arrangement and a method according to the independent claims.

More particularly, the present invention relates to an assembly for obtaining a material from a mixed fraction comprising particles of the desired material and particles of at least one other material having different optical properties than the desired material, comprising a first sorter having at least two discrete particle exit orifices therethrough characterized in that at least two further sorting devices with at least two outlet openings for separate particles of the first sorting device are connected, wherein an outlet opening of the first sorting device for receiving a main fraction is connected to the inlet opening of a first further sorting device, an outlet opening of the first sorting device for receiving a secondary fraction is connected to the inlet opening of a second further sorting device, an outlet opening of a first further sorting device ng for receiving a secondary fraction is connected to the inlet opening of the first sorting device, and an outlet opening of a second further sorting device for receiving a main fraction is connected to the inlet opening of the first sorting device.

1. a) Abtrennung von Teilchen des weiteren Materials von Teilchen des gewünschten Materials in einer ersten Sortiereinrichtung unter Erhalt einer Hauptfraktion und einer Nebenfraktion;
2. b) Überführung der Hauptfraktion in eine erste weitere Sortiereinrichtung und Überführung der Nebenfraktion in eine zweite weitere Sortiereinrichtung;
3. c) Abtrennung von Teilchen des weiteren Materials von Teilchen des gewünschten Materials in einer ersten weiteren Sortiereinrichtung unter Erhalt einer zweiten Hauptfraktion und einer zweiten Nebenfraktion;
4. d) Abtrennung von Teilchen des weiteren Materials von Teilchen des gewünschten Materials in einer zweiten weiteren Sortiereinrichtung unter Erhalt einer dritten Hauptfraktion und einer dritten Nebenfraktion;
5. e) Rückführung der zweiten Nebenfraktion und der dritten Hauptfraktion in die Mischfraktion oder direkte Überführung dieser Fraktionen in die erste Sortiereinrichtung.

The present invention further relates to a process for obtaining a material from a mixed fraction comprising particles of the desired material and particles of at least one other material having different optical properties than the desired material, preferably in an arrangement as described above, comprising the steps:

1. a) separating particles of the further material from particles of the desired material in a first sorter to obtain a main fraction and a minor fraction;
2. b) transfer of the main fraction into a first further sorting device and transfer of the secondary fraction into a second further sorting device;
3. c) separating particles of the further material from particles of the desired material in a first further sorting means to obtain a second main fraction and a second minor fraction;
4. d) separating particles of the further material from particles of the desired material in a second further sorting means to obtain a third main fraction and a third minor fraction;
5. e) recycling of the second secondary fraction and of the third main fraction into the mixed fraction or direct transfer of these fractions into the first sorting device.

According to the present invention, "downstream" is understood to mean that a sorting device is operatively following another sorting device in such a way that it receives and further processes a fraction of the particles separated from the other sorting device. The two sorting facilities may in this case be arranged one above the other or next to one another, or the one sorting device may be arranged in front of or behind the other sorting device.

According to the present invention, the term "main fraction" is understood to mean a particle stream leaving a sorter, in which the desired particles are enriched in comparison to the mixing fraction introduced into the sorter, i. the particle stream has a smaller amount of particles of at least one other material. For example, the major fraction may comprise 95% of desired material and 3% of undesired material, starting from a mixed fraction of 70% desired material and 30% undesired material.

According to the present invention, by "minor fraction" is meant a particle stream leaving a sorter in which the desired particles are depleted as compared to the mixed fraction introduced into the sorter, i. the particle stream has a smaller amount of particles of the desired material. However, it is possible that the majority of the minor fraction particles are particles of the desired material. For example, the minor fraction may comprise 60% of desired material and 40% of undesired material, starting from a mixed fraction of 70% of desired material and 30% of undesired material.

According to the invention, the purity of the main fraction ultimately removed from the assembly as a desired product is increased efficiently and economically by separating off secondary fractions, mainly comprising particles of at least one further material, in a plurality of sorting devices arranged serially one behind the other. Through the multiple separation the purity of the main fraction is increased. At the same time, however, the secondary fractions obtained in this way are not discarded, but subjected to further separation processes, with uniform guidance of the various sorting devices being ensured by the guidance of the particle streams according to the invention. In this way, the yield of main fraction can be increased because the desired material present in the secondary fractions is not discarded, but is returned to the process cycle and can be removed as the desired product.

Fig. 1a

eine schematische Darstellung einer erfindungsgemäss verwendbaren Sortiereinrichtung

Fig. 1b

eine detaillierte Darstellung einer erfindungsgemäss verwendbaren Sortiereinrichtung

Fig. 2

eine erste Ausführungsform der vorliegenden Erfindung

Fig. 3

eine zweite Ausführungsform der vorliegenden Erfindung

Fig. 4

eine dritte Ausführungsform der vorliegenden Erfindung

Fig. 5

eine vierte Ausführungsform der vorliegenden Erfindung

Fig. 6

eine nicht erfindungsgemässe Ausführungsform einer Sortieranordnung

The present invention will be explained in more detail below by way of non-limiting examples and figures. Show it:

Fig. 1a

a schematic representation of a usable according to the invention sorting device

Fig. 1b

a detailed view of a usable according to the invention sorting device

Fig. 2

a first embodiment of the present invention

Fig. 3

A second embodiment of the present invention

Fig. 4

A third embodiment of the present invention

Fig. 5

A fourth embodiment of the present invention

Fig. 6

a not inventive embodiment of a sorting arrangement

In Fig. 1a the functional principle of a sorting device which can be used according to the invention is shown. However, the present invention is not limited to such a sorting device. In principle, any means of efficiently separating particles by their optical properties can be used.

In the Fig. 1a The inlet region has at least one inlet opening for receiving a mixed fraction to be separated (for example a cyclone (centrifugal separator) with downstream lock) and at least one accelerating device for accelerating the particles of the mixed fraction.

In the inlet region 1, additional units such as a buffer space for intermediate storage of the introduced mixed fraction and a metering device can be arranged. Metering devices for sorting devices are well known and serve to introduce a uniform particle flow of certain quantity into the accelerator device. Exemplary here are a vibrating trough, a screw conveyor, a conveyor belt (such as in the WO 98/18573 described) or an opening with adjustable cross section called. According to one embodiment of the present invention, however, an acceleration device may be provided as a belt machine, which at the same time fulfills the function of a metering device. In other words, in this embodiment, the dosing device and the accelerator device are the same device.

In the acceleration device, the particles to be separated are acted upon at a fixed speed, with which they subsequently pass through the detection region 2 in free fall as a uniform product flow. Acceleration devices for sorting devices are well known. Exemplary here are an inclined channel, a slide, a conveyor belt (for example, as in the WO 98/18573 described by 60 ° inclined conveyor belt) or a drop distance called. The accelerated particles enter the detection area 2. In the detection area 2, the particles are exposed to electromagnetic radiation from at least one radiation source 2a. Depending on the optical property to be determined, these may be radiation sources which emit light in the wavelength range from 10 to 10000 nm, ie in the visible range of the electromagnetic spectrum, in the ultraviolet (UV) range of the electromagnetic spectrum or in the infrared (IR). Emit area of the electromagnetic spectrum or in several of these areas. Suitable radiation sources for sorting devices are well known. By way of example, mention may be made of halogen lamps which emit a broad spectrum of electromagnetic radiation from the visible range to the near infrared range (SWIR), ie over a wavelength range from 400 to 2000 nm. Several radiation sources with different emission spectra can also be combined with one another.

The electromagnetic radiation reflected by the particles, or alternatively the transmission radiation passing through the particles, is detected by means of at least one detector 2c. Suitable detectors for sorting devices are well known. Examples include camera units with detectors for visible light or detectors for SWIR light such as InGaAs detectors and optionally with beam splitters such as prisms or mirrors. It is in this regard on the content of WO 2010/073004 reference, the contents of which are hereby incorporated by reference. Depending on the application, one or more identical or different such detectors 2c may be present in the sorting device S.

According to a preferred embodiment, a filter between radiation source 2a and detector 2c may be arranged so that only selective radiation to the detector 2c passes and is detected by this. Suitable filters are well known to those skilled in the art.

The particles then leave the detection area 2 through a product passage 2b (a suitable opening), while the at least one detector 2c forwards the detected radiation in the form of a signal to a data processing installation 3. In the data processing system 3, the incoming signal is evaluated and converted into a separation command. Suitable data processing systems for sorting devices are well known. Depending on the degree of coloration of the particles, for example, a certain threshold of radiation reflected by the particle is exceeded and the particle is classified as unsuitable. The data processing system 3 then generates a disconnect command and thus triggers the function of a deflection device 4a.

The deflection device 4 a is arranged in the separation region 4. The particles passing through the product passage 2b enter the separation area and pass the deflection device. If no separation command is triggered, the deflection device remains inoperative, and the particles pass without web change directly into the outlet opening 5 for a main fraction, which mainly comprises particles of the desired material. If, on the other hand, a separation command has been triggered, the deflection device 4a receives the corresponding command from the data processing system 3 and deflects the particles passing through the deflection device 4a, so that it passes into the outlet opening 6 for a minor fraction, which mainly comprises particles of the further material.

The deflection device 4a may be a mechanical or pneumatic device. Preferably, a used pneumatic deflecting device. This includes, for example, an elongated tube having a plurality of separately operable air nozzles mounted along the tube. Compressed air is passed through the pipe. Upon receipt of a disconnect command, an appropriate nozzle is activated and delivers an air blast onto the passing particulate, which is thereby deflected as desired.

The sorting devices which can be used according to the invention thus have two outlet openings. The outlet opening 5 for receiving the main fraction, i. of the particle stream in which the desired particles are enriched as compared to the mixing fraction introduced into the sorter is thus operatively connected to the product passage 2b (ie, there is no direct connection between product passage 2b and exit orifice 5) from the product passage 2b get into this outlet opening 5 when the deflection device 4a is inactive. For example, the outlet opening 5 for receiving the main fraction can be arranged directly below the product passage 2b in its free fall line, so that the particles in free fall pass directly from the product passage 2b into this outlet opening 5.

The outlet port 6 for receiving the minor fraction, ie the particle stream in which the desired particles are depleted compared to the mixed fraction introduced into the sorter, is thus operatively connected to the product passage 2b (ie there is no direct connection between product passage 2b and outlet opening 6), that the particles from the product passage 2b only reach this outlet opening 6 when the deflection device 4a is active and directs the particles into the outlet opening 6. For example, the outlet opening 6 for receiving the secondary fraction be arranged below the product passage 2b offset from the free fall line of the same, so that the particles do not enter this exit opening 6 in free fall from the product passage 2b. Rather, the outlet opening 6 is in this case in a path, which occupy the particles when they are deflected by the deflection device 4a from the path of free fall.

The sorting devices present in the arrangement according to the invention are all constructed according to the above principle, but may possibly differ in details, for example in the type and number of radiation sources used, detectors, acceleration devices, etc.

According to the invention, all sorting devices present in the arrangement are preferably constructed identically.

In Fig. 1b is shown a detailed representation of an inventively usable sorting device. This is a schematic representation of a commercially available sorting device (Sortex A Buhler Sortex Ltd.). The sorting device has a metering funnel 1a, in which the material to be separated is filled and brought uniformly onto a vibrating trough 1b. With the help of the vibrating channel 1b, the material is conveyed to an approximately 60 ° inclined channel 1c and accelerated there. The particles pass through a detection area in free fall, in which a total of 4 radiation sources 2a and a total of 4 detectors (cameras) 2c) are arranged. A high-speed ejector 4a occupies the falling particles depending on the receipt of a cut command from a (in Fig. 1b not shown) data processing device with an air blast and drives the otherwise into the outlet opening 5 for the main fraction falling particles into the outlet opening 6 for the minor fraction.

According to the present invention, an even more efficient and economical purification of plastic material can be achieved with an arrangement as shown schematically in one of the FIGS. 2 to 5 is shown. The present invention is not limited to the embodiments shown there, but which are currently most preferred considering all aspects such as efficiency, cost, complexity, etc.

In Fig. 2 the basic principle of the present invention is explained. In a first sorter S1, the mixed fraction M containing the desired material is separated into a first main fraction H1 and a first minor fraction N1. The construction of the first sorting device S1 corresponds to the structure of FIG Fig. 1 shown sorting device S, wherein identical reference numerals in the figures have the same meaning.

The first main fraction H1 is now subjected to an additional purification in a first further sorting device S2. The structure of the first further sorting device S2 corresponds to the structure of FIG Fig. 1 shown sorting device S, wherein identical reference numerals in the figures have the same meaning.

The transfer of the particles from one sorting device to another sorting device can be carried out in a known manner, for example by means of a tube through which the particles can be conveyed by means of a gas, or by means of a conveyor belt, a screw conveyor or a vibrating trough. In the transfer of the particles from one sorting device to another sorting device should basically any risk of contamination is excluded as far as possible.

In the first further sorting device S2, an analogous second separation of undesirable particles in the form of a second secondary fraction N2 from the main fraction H1, as described above, takes place. The further purified main fraction H2 can be taken as the desired product P of the arrangement according to the invention.

The second secondary fraction N2 obtained in the first further sorting device S2 is not discarded as waste. After all, these are particles which, in the first separation process, were accepted in the device S1 and assigned to the main fraction H1. Rather, the second secondary fraction N2 is returned to the first sorting device S1.

According to the present invention, it is possible for the second secondary fraction N2 to be combined with the mixed fraction M before it enters the first sorting device S1, ie the feeds of the mixed fraction M and the second minor fraction N2 should unite before entering the first sorting device S1 , According to the invention, however, both fractions (mixed fraction M and second minor fraction N2) are preferably combined in a buffer space in the inlet region 1 of the first sorting device S1. In this case, the mixed fraction M and the second secondary fraction N2 are passed through separate inlet openings (for example, cyclones (centrifugal separator) with downstream locks) in the corresponding buffer space, where they unite and are guided together in the other sections of the sorter S1.

Also, the first secondary fraction N1 obtained in the first sorting device S1 is not discarded as waste. Rather, the first secondary fraction N1 is transferred to the second further sorting device S3. The construction of the second further sorting device S3 corresponds to the structure of FIG Fig. 1 shown sorting device S, wherein identical reference numerals in the figures have the same meaning.

The first secondary fraction N1 is subjected to a purification in the second further sorting device S3. The purification is carried out as described above by separating a third secondary fraction N3 from the first secondary fraction N1. However, the purified third main fraction H3 thus obtained is not pure enough to be taken as the desired product of the arrangement according to the invention. The third main fraction H3 is therefore returned to the first sorter S1.

According to the present invention, it is possible for the third main fraction H3 to be combined with the mixed fraction M before it enters the first sorting device S1, ie the feeds of the mixed fraction M and the third main fraction H3 should unite before entering the first sorting device S1 , For example, the feeds of the mixed fraction M, the second secondary fraction N2 and the third main fraction H3 combine at a location in front of the inlet opening of the first sorter S1. According to the invention, however, all fractions (mixed fraction M, second minor fraction N2 and third main fraction H3) are preferably combined in a buffer space in the inlet region 1 of the first sorting device S1. In this case, the mixed fraction M, second secondary fraction N2 and third main fraction H3 through separate inlet openings (for example, cyclones (centrifugal) with downstream locks) in the corresponding buffer space directed, where they unite and are led together in the other sections of the sorter S1.

The third secondary fraction N3 accumulating in the second further sorting device S3 is so strongly purified of the desired product that its further processing is no longer worthwhile. It is discarded as waste W.

By the arrangement according to Fig. 2 On the one hand, a higher purity of the main fraction H2 taken off as product is achieved, since this is obtained after two separate removal (and not just one-time separation as in the prior art) of unwanted particles. On the other hand, the process operated with this arrangement is more economical because the minor fractions N1 and N2 are not discarded as waste, but are recycled to the process loop for reworking. Only the depleted third minor fraction N3 obtained after two-part separation treatment is discarded as waste W. In this way, significantly less waste accumulates in the arrangement according to the invention and more precious plastic material is obtained for further processing.

An even further purification of the desired product P can be carried out with an arrangement according to the in Fig. 3 be achieved embodiment shown. In contrast to the embodiment according to Fig. 2 the second main fraction H2 is not taken from the arrangement as a desired product, but supplied to a third further sorting device S4. The transfer of the particles from one sorting device to another sorting device can also be carried out in the embodiment according to FIG Fig. 3 carried out in a known manner, for example by means of a tube through which the particles can be conveyed by means of a gas, or by means of a conveyor belt, a screw conveyor or a Vibrating chute. When transferring the particles from one sorting device to another sorting device, basically any risk of contamination should be excluded as far as possible.

In the third further sorting device S4, an analogous third separation of undesired particles in the form of a fourth secondary fraction N4, as described above, takes place. The further purified fourth main fraction H4 can be taken as the desired product P of the arrangement according to the invention.

The fourth secondary fraction N4 obtained in the third further sorting device S4 is not discarded as waste. After all, these are particles which were accepted in the previous separation processes in the device S1 and S2 and the main fraction H1 or H2 were assigned. Rather, the fourth secondary fraction N4 is returned to the first further sorting device S2.

According to the present invention, it is possible for the fourth secondary fraction N4 to be combined with the first main fraction H1 prior to its entry into the first further sorting device S2, ie the feeds of the first main fraction H1 and the fourth minor fraction N4 are to occur before entry into the first combine further sorting device S2. According to the invention, however, both fractions (first main fraction H1 and fourth minor fraction N4) are preferably combined in a buffer space in the inlet region 1 of the first further sorting device S2. In this case, the first main fraction H1 and fourth minor fraction N4 through separate inlet openings (for example, cyclones (centrifugal) with downstream locks) are directed into the corresponding buffer space where they unite and be performed together in the other sections of the first further sorting device S2.

An alternative embodiment of the arrangement according to Fig. 3 is in Fig. 4 shown. Here, the fourth secondary fraction N4 is not returned to the first further sorting device S2, but into the second further sorting device S3. This leads to an even higher purity of the resulting product P, since even in two separation processes accepted particles are not fed into the path of the main fraction, but are subjected to reprocessing in at least four sorting devices (S3, S1, S2 and S4) before they can get into the fraction of the desired product P. With regard to the transfer of the particles from one sorting device to another sorting device as well as the introduction of the fractions into the respective sorting devices, reference is made to the above explanations of the variants according to FIG Fig. 2 and 3 directed.

Another alternative embodiment of the arrangement according to Fig. 3 is in Fig. 5 shown. Here, the fourth secondary fraction N4 is not returned to the first further sorting device S2 or to the second further sorting device S3, but to the first sorting device S1. This also leads to an even higher purity of the resulting product P, since even in two separation processes accepted particles are not fed into the path of the main fraction, but are subjected to reprocessing in at least three sorting devices (S1, S2 and S4) before they are introduced into the fraction of the desired product P can get. With regard to the transfer of the particles from one sorting device to another sorting device as well as the introduction of the fractions into the respective sorting devices, reference is made to the above explanations of the variants according to FIG Fig. 2 and 3 directed.

In Fig. 6 a non-inventive embodiment of a sorting arrangement is shown. The embodiment according to Fig. 6 differs from the inventive embodiment according to Fig. 3 in that the outlet opening of the first further sorting device (S2) for receiving a minor fraction (N2) is not connected to the inlet opening of the first sorting device (S1), and in that the outlet opening of the third further sorting device (S4) is also used to receive a minor fraction (N4 ) is not connected to the inlet opening of the first further sorting device (S2). Rather, in the embodiment according to Fig. 6 the outlet openings of the sorting devices (S1, S2, S4), which serve to receive secondary fractions (N1, N2, N4), are connected to the inlet opening of the second further sorting device (S3). All secondary fractions are thus transferred to the second further sorting device (S3). The minor fraction (n3) of the second further sorter (S3) is discarded as waste (W), while the main fraction (H3) of the second further sorter (S3) is returned to the first sorter (S1).

As will be shown below with reference to the examples and comparative examples with the embodiment not according to the invention Fig. 6 Compared to an embodiment according to the invention, a poorer sorting and hence a greater loss of the desired product are obtained.

With the inventive arrangement, any type of plastic material can be cleaned. Thus, the present invention can be used for the purification of PET or polyamide material after SSP reaction. The sorting devices have to be modified if necessary, as described in the pending patent application PCT / GB2012 / 000377 is described.

The relevant content of this application is hereby incorporated by reference.

However, the preferred use of the arrangement according to the invention and of the method according to the invention consists in the recycling of plastic material. The mixed fraction is therefore particularly preferably a Kunststoffmahlgut of polyethylene (PE), polypropylene (PP) or polyethylene terephthalate (PET) or mixtures thereof used, which is obtained from containers, films, etc. from these materials as described above. Most preferably, the present invention operates PET recycling, i. the mixed fraction M comprises PET as the main component.

According to the invention, it is preferred that the millbase has been comminuted such that 90% or more of the particles of the mixed fraction M have a particle size of more than 2 mm, preferably between 2.5 mm and 20 mm, and particularly preferably between 2.5 mm and 16 mm have.

It is further preferred according to the invention that the mixed fraction M consists of 50 to 90% particles of the desired material and 10 to 50% particles of at least one further material.

With the present invention, a very efficient purification can be carried out to a degree that the main fraction H2, H4 removed from the assembly as desired product P is less than 1000 ppm, preferably less than 500 ppm and more preferably less than 200 ppm of particles of the corresponding minor fraction N2 , N4 are included.

Furthermore, the purification with the present invention is very economically feasible. In the end, as waste W discarded minor fraction N3 are less than 40%, preferably less than 30%, and more preferably less than 25% particles of the desired material. As a result of the repeated treatment of the fractions, a large part of the particles of the desired material are ultimately obtained as product P.

With the arrangement of the present invention, analog throughput rates can be achieved as in the conventional sorters described above, i. about 0.5 to 12 t / h.

• Die Trennung klarer PET-Flakes von gefärbten PET-Flakes jeglicher Farbtönung mit Hilfe einer Detektion im sichtbaren Bereich des elektromagnetischen Spektrums
• Die Trennung gefärbter PET-Flakes jeglicher Farbtönung von klaren und/oder hellblauen PET-Flakes mit Hilfe einer Detektion im sichtbaren Bereich des elektromagnetischen Spektrums
• Die Trennung brauner PET-Flakes von klaren und/oder gefärbten PET-Flakes jeglicher Farbtönung ausser Braun mit Hilfe einer Detektion im sichtbaren Bereich des elektromagnetischen Spektrums
• Die Trennung von PET-Flakes von Flakes aus anderem Kunststoffmaterial (z.B. PE, PP, PVC (Polyvinylchlorid), PS (Polystyrol), PC (Polycarbonat) oder PLA (Polymilchsäure)) mit Hilfe einer Detektion im IR-Bereich des elektromagnetischen Spektrums
• Die Trennung von PE-Flakes von PP-Flakes mit Hilfe einer Detektion im IR-Bereich des elektromagnetischen Spektrums.

With the present invention, complicated separation operations can be performed. Examples include:

• The separation of clear PET flakes from colored PET flakes of any hue by detection in the visible region of the electromagnetic spectrum
• The separation of colored PET flakes of any hue of clear and / or light blue PET flakes by means of detection in the visible region of the electromagnetic spectrum
• The separation of brown PET flakes from clear and / or colored PET flakes of any hue other than brown by means of detection in the visible region of the electromagnetic spectrum
• The separation of PET flakes from flakes of other plastic material (eg PE, PP, PVC (polyvinyl chloride), PS (polystyrene), PC (polycarbonate) or PLA (polylactic acid)) by means of a detection in the IR range of the electromagnetic spectrum
• The separation of PE flakes from PP flakes by means of a detection in the IR range of the electromagnetic spectrum.

example 1

1000kg / h PET flakes consisting of 80% clear flakes and 20% colored flakes were sorted according to a FIG. 3 fed. The returns resulted in a throughput of the sorting device (S1) of 1950 kg / h with a 19.4% color content. With a sorting efficiency of 88% and a rejection rate of 60%, a main fraction of 1119 kg / h with 4.2% color content and a secondary fraction of 832 kg / h with 40% color content resulted.

The sorter (S2) had a flow rate of 1213 kg / h with a 4.1% color content. With a 90% grading efficiency and a 90% rejection rate, a major fraction of 762 kg / hr with 0.66% color fraction and a minor fraction of 451 kg / hr with 10% color fraction resulted.

In the sorter (S4), the flow rate was 762 kg / h. With a 95% sorting efficiency and 95% rejection rate, the main fraction was 667 kg / h with 0.038% color content and a minor fraction of 95 kg / h with 5% color content.

In the sorter (S3), the flow rate was 832 kg / h. With a 60% sorting efficiency and 40% rejection rate, the main fraction was 499 kg / h with 26.7% color content and a minor fraction of 333 kg / h with 60% color content.

The total loss of clear flakes was thus 133 kg / h or 16.6% of the supplied clear flakes.

Comparative Example 1

1000 kg / h PET flakes consisting of 80% clear flakes and 20% colored flakes were sorted according to a FIG. 6 fed.

As a result of the returns, the throughput of the sorting device (S1) was 1679 kg / h with 18.3% color content.

With a sorting efficiency of 88% and a false reject rate of 60%, a main fraction of 1003 kg / h with 3.7% color fraction and a minor fraction of 677 kg / h with 40% color fraction resulted.

In the sorter (S2), the flow rate was 1003 kg / h. With a 90% grading efficiency and 90% rejection rate, the main fraction was 671 kg / hr with 0.55% color fraction and a minor fraction of 332 kg / hr with 10% color fraction.

In the sorter (S4), the flow rate was 671 kg / h. With a 95% sorting efficiency and a 95% rejection rate, the main fraction was 601 kg / h with 0.032% color content and a secondary fraction of 70 kg / h with 5% color content.

The sorter (S3) had a throughput of 1079 kg / h with 28.5% color content. With a grading efficiency of 65% and a rejection rate of 50%, the main fraction was 680 kg / h with 15.8% color content and a secondary fraction of 399 kg / h with 50% color content. The loss of clear flakes was thus 199 kg / h or 24.9% of the supplied clear flakes.

Here, the advantage of the inventive arrangement shows the significantly lower loss of good product (clear flakes). This is mainly a consequence of the lower throughput and the higher color content in sorting in sorting device (S3).

Example 2

1000 kg / h PET flakes consisting of 80% clear flakes and 20% colored flakes were sorted according to a FIG. 3 fed.

The returns resulted in a throughput of sorting equipment (S1) of 2004 kg / h with 17.9% paint content. With a grading efficiency of 90% and a rejection rate of 65%, a main fraction of 1083 kg / h with 3.3% color content and a secondary fraction of 921 kg / h with 35% color fraction resulted.

The sorter (S2) had a throughput of 1159 kg / h with a 3.4% color content. With a 92% sorting efficiency and 92% rejection rate, the main fraction was 712 kg / h with 0.44% color content and a minor fraction of 447 kg / h with 8% color content.

In the sorter (S4), the flow rate was 712 kg / h. With a 97% sorting efficiency and 96% rejection rate, the main fraction was 636 kg / h with 0.015% color content and a minor fraction of 76 kg / h with 4% color content.

In the sorter (S3), the flow rate was 921 kg / h. With a sorting efficiency of 62% and a rejection rate of 45%, a main fraction of 558 kg / h resulted with 22% color content and a minor fraction of 363 kg / h with 55% color content. The loss of clear flakes was thus 164 kg / h or 20.5% of the supplied clear flakes.

Here is another advantage of the flexibility of the inventive arrangement. With still less good product loss, the good product quality can be significantly improved.

Example 3

1000 kg / h PET flakes consisting of 70% clear flakes and 30% colored flakes were sorted according to a FIG. 3 fed.

The returns resulted in a throughput of the sorter (S1) of 2227 kg / h with a 28.8% paint content. With a grading efficiency of 85% and a false reject rate of 55%, the main fraction was 1017 kg / h with 9.4% color content and a secondary fraction of 1210 kg / h with 45% color fraction.

The sorter (S2) had a flow rate of 1161 kg / h with a 9.1% color content. With a 90% grading efficiency and 80% rejection rate, the main fraction was 683 kg / h with 1.55% color and a minor fraction of 478 kg / h with 20% color.

In the sorter (S4), the flow rate was 683 kg / h. With a 95% sorting efficiency and a rejection rate of 93%, the main fraction was 539 kg / h with 0.098% color content and an auxiliary fraction of 144 kg / h with 7% color content.

In the sorter (S3), the flow rate was 1210 kg / h. With a sorting efficiency of 55% and a rejection rate of 35%, a main fraction of 749 kg / h with 32.7% color fraction and a minor fraction of 461 kg / h with 65% color fraction resulted.

The loss of clear flakes was thus 161 kg / h or 23% of the supplied clear flakes.

Comparative Example 2

1000kg / h PET flakes consisting of 70% clear flakes and 30% colored flakes were sorted according to a FIG. 6 fed.

As a result of the returns, the throughput of the sorter (S1) was 1838 kg / h with 27.2% color content. With a grading efficiency of 85% and a rejection rate of 55%, the main fraction was 894 kg / h with 8.4% color content and a minor fraction of 944 kg / h with 45% color content.

In the sorter (S2), the flow rate was 894 kg / h. With a grading efficiency of 90% and a rejection rate of 80%, the main fraction was 557 kg / h with 1.35% color content and a minor fraction of 337kg / h with 20% color fraction.

In the sorter (S4), the flow rate was 557 kg / h. With a sorting efficiency of 95% and a rejection rate of 93%, a main fraction of 455 kg / h resulted with 0.082% color content and a secondary fraction of 102 kg / h with 7% color content.

The sorter (S3) had a throughput of 1383 kg / h with a 36% color content. With a sorting efficiency of 60% and a rejection rate of 45%, a main fraction of 838 kg / h with 23.8% color fraction and a minor fraction of 545 kg / h with 55% color fraction resulted.

The loss of clear flakes was thus 245 kg / h or 35% of the supplied clear flakes.

The advantage of the inventive arrangement with significantly lower loss of clear flakes is even more pronounced at higher input concentration.

Claims (19)

An arrangement for obtaining a material from a mixed fraction (M) comprising particles of the desired material and particles of at least one other material having different optical properties than the desired material, comprising a first sorter (S1) having at least two exit openings (5, 6) for Particles separated from each other, characterized in that at least two further sorting devices (S2, S3) with at least two outlet openings (5.6) for separate particles of the first sorting device (S1) are connected downstream, wherein an outlet opening (5) of the first sorting device (S1) for receiving a main fraction (H1) is connected to the inlet opening of a first further sorting device (S2), - An outlet opening (6) of the first sorting device (S1) for receiving a secondary fraction (N1) with the inlet opening of a second further sorting device (S3) is connected - An outlet opening (6) of a first further sorting device (S2) for receiving a secondary fraction (N2) with the inlet opening of the first sorting device (S1) is connected, and - An outlet opening (5) of a second further sorting device (S3) for receiving a main fraction (H3) with the inlet opening of the first sorting device (S1) is connected. Arrangement according to claim 1, characterized in that three further sorting devices (S2, S3, S4) of the first sorting device (S1) are connected downstream, wherein an exit opening (5) of the first further sorting device (S2) for receiving a main fraction (H2) with the inlet opening of the third further sorting device (S4) and an outlet opening (6) of the third further sorting device (S4) for receiving a minor fraction (N4) is connected to the inlet opening of the first further sorting device (S2). Arrangement according to claim 1, characterized in that three further sorting devices (S2, S3, S4) of the first sorting device (S1) are connected downstream, wherein an outlet opening (5) of the first further sorting device (S2) for receiving a main fraction (H2) with the Inlet opening of the third further sorting device (S4) and an outlet opening (6) of the third further sorting device (S4) for receiving a minor fraction (N4) is connected to the inlet opening of the second further sorting device (S3). Arrangement according to claim 1, characterized in that three further sorting devices (S2, S3, S4) of the first sorting device (S1) are connected downstream, wherein an outlet opening (5) of the first further sorting device (S2) for receiving a main fraction (H2) with the Inlet opening of the third further sorting device (S4) and an outlet opening (6) of the third further sorting device (S4) for receiving a secondary fraction (N4) is connected to the inlet opening of the first sorting device (S1). Arrangement according to one of claims 1 to 4, characterized in that the first sorting device (S1) and the at least two further sorting devices (S2, S3, S4) comprise: An inlet region (1) having at least one inlet opening for receiving the mixed fraction and an accelerating device for accelerating the particles of the mixed fraction, a detection region (2) having at least one radiation source (2a), at least one detector (2c) for detecting the radiation reflected by the particles and a data processing system (3) for evaluating the detected radiation, - A separation region (4) for separating the particles of the desired material of particles of the further material with a deflection device (4a) for the selective deflection of the particles of the further material on the basis of the detected radiation. Arrangement according to claim 5, characterized in that one or more or all sorting devices (S1, S2, S3, S4) have a buffer space between the inlet opening and accelerating device. Arrangement according to claim 5 or 6, characterized in that one or more or all sorting devices (S1, S2, S3, S4) have a metering device between the inlet opening and accelerating device. Arrangement according to one of claims 5 to 7, characterized in that one or more or all sorting means (S1, S2, S3, S4) comprise a filter between the radiation source and the detector. A process for obtaining a material from a mixed fraction (M), which particles of the desired material and particles of at least one other material with other optical properties as the desired material, preferably in an arrangement according to one of claims 1 to 8, comprising the steps: a) separation of particles of the further material from particles of the desired material in a first sorter (S1) to obtain a main fraction (H1) and a minor fraction (N1); b) transfer of the main fraction (H1) into a first further sorting device (S2) and transfer of the secondary fraction (N1) into a second further sorting device (S3); c) separating particles of the further material from particles of the desired material in a first further sorting device (S2) to obtain a second main fraction (H2) and a second secondary fraction (N2); d) separating particles of the further material from particles of the desired material in a second further sorting device (S3) to obtain a third main fraction (H3) and a third minor fraction (N3); e) recycling the second secondary fraction (N2) and the third main fraction (H3) into the mixed fraction (M) or direct transfer of these fractions (N2, H3) into the first sorting device (S1). A method according to claim 9, characterized in that the second main fraction (H2) is removed as the desired product. A method according to claim 9, characterized in that the second main fraction (H2) in a third further sorting device (S4) transferred and there particles of the further material of particles of the desired material to obtain a fourth major fraction (H4) and a fourth minor fraction (N4), the fourth major fraction (H4) being taken out as the desired product. A method according to claim 11, characterized in that the fourth secondary fraction (N4) either the first main fraction (H1) supplied and transferred with this or directly into the first further sorting device (S2). A method according to claim 11, characterized in that the fourth secondary fraction (N4) either the first secondary fraction (N1) and fed with this or directly into the second further sorting device (S3) is transferred. A method according to claim 11, characterized in that the fourth secondary fraction (N4) is either fed to the mixed fraction (M) and transferred with this or directly into the first sorting device (S1). Method according to one of claims 9 to 14, characterized in that the mixing fraction (M) comprises Kunststoffmahlgut, which in particular selected from the group of Mahlgütern of containers or films of polyethylene, polypropylene, polyethylene terephthalate, or mixtures thereof. A method according to any one of claims 9 to 15, characterized in that 90% or more of the particles of the mixed fraction (M) have a particle size of more than 2 mm, preferably between 2.5 mm and 20mm, and more preferably 2.5 mm and 16 mm have. Method according to one of claims 9 to 16, characterized in that the mixing fraction (M) consists of 50 to 90% particles of the desired material and 10 to 50% particles of at least one further material. Process according to one of Claims 9 to 17, characterized in that less than 1000 ppm, preferably less than 500 ppm and particularly preferably less than 200 ppm particles of the secondary fraction (N2) are present in the main fraction (H2, H4) taken off as the desired product (P) , N4) are included. Use of an assembly according to any one of claims 1 to 8 for obtaining a material from a mixed fraction (M) comprising particles of the desired material and particles of at least one other material having different optical properties than the desired material.

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