Method and apparatus for treating styrene-acrylonitrile

Abstract

To provide a method for simply, flexibly and efficiently treating styrene-acrylonitrile.SOLUTION: The processing plant (1) comprises a processing screw machine (4) for processing the dewatered rubber (7) and the styrene-acrylonitrile, a dewatering screw machine (2) for dewatering the wet rubber (6) to provide the dewatered rubber (7), and a feed device (3) for feeding the dewatered rubber (7) to the processing screw machine (4). Since dewatering and processing are mechanically decoupled, a simple, flexible and efficient processing can be realized.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method and equipment for processing styrene-acrylonitrile. [Background technology]

[0002] Patent Document 1 discloses a method and equipment for processing styrene-acrylonitrile (SAN). The equipment includes an extruder that is formed, in succession in the conveying direction, with a first input zone, a preheating zone, a mechanical dehydration zone, a second input zone, a first degassing zone, a third input zone, a second degassing zone, and a discharge zone. In the first input zone, acrylonitrile-butadiene-styrene (ABS) and optional additives are fed to the extruder, heated in the preheating zone, and then dehydrated in the dehydration zone. In the second input zone, styrene-acrylonitrile is fed to the extruder. The mixture produced in the extruder is subsequently degassed in the degassing zone. In the third input zone, styrene-acrylonitrile and additives can be fed back to the extruder. The degassed mixture is discharged from the extruder in the discharge zone. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] WO 2022 / 229 347 A1 Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is to provide a method that allows for simple, flexible and efficient processing of styrene-acrylonitrile. [Means for solving the problem]

[0005] This object is achieved by a method having the features of claim 1. According to the invention, the dehydration of rubber, in particular acrylonitrile-butadiene-styrene (ABS), and the processing of styrene-acrylonitrile (SAN) are mechanically decoupled. The processing facility comprises a dehydration screw machine and at least one separate processing screw machine. The dehydration screw machine is for dehydrating wet rubber, and the at least one processing screw machine is for producing a mixture of dehydrated rubber and styrene-acrylonitrile and degassing the resulting mixture. Because the process steps of dehydration and processing, i.e., producing a mixture and degassing the resulting mixture, are mechanically separated between the dehydration screw machine and the at least one processing screw machine, these process steps can be carried out simply, flexibly, and efficiently. In particular, the dehydration screw machine can be configured and operated optimally for the dehydration process step, while the at least one processing screw machine can be configured and operated optimally for the processing process step.

[0006] Natural rubber and / or synthetic rubber, such as acrylonitrile butadiene styrene (ABS), can be used.

[0007] The dewatering screw machine comprises at least one dewatering shaft, preferably at least two dewatering shafts. During operation of the dewatering screw machine, at least one dewatering shaft rotates at a rotation speed n E In particular, the rotation speed n E is 40 rpm ≦ n E ≦600rpm, especially 50rpm≦n E ≦400rpm, especially 60rpm≦n E ≦300 rpm.

[0008] The dewatering screw machine can be configured as a single-shaft dewatering screw machine or a multi-shaft dewatering screw machine. Preferably, the dewatering screw machine is configured as a twin-shaft dewatering screw machine having two dewatering shafts, which may be co-rotating or counter-rotating. The dewatering shafts may be driven to rotate, and may be driven to rotate in the same direction or in opposite directions.

[0009] The wet rubber has a first moisture content W1 when fed to the dewatering screw machine, and the dewatered rubber has a second moisture content W2 when discharged from the dewatering screw machine. In particular, the relative moisture content change ΔW=(W1-W2) / W1 is 50%≦ΔW≦99%, in particular 60%≦ΔW≦95%, in particular 70%≦ΔW≦90%.

[0010] After being discharged from the dewatering screw machine, the dewatered rubber is fed to at least one processing screw machine. The dewatered rubber may be fed to one processing screw machine or to multiple processing screw machines. The multiple processing screw machines are arranged in parallel to each other so that the dewatered rubber can be distributed among the multiple processing screw machines. The processing facility includes a first feeding device for feeding the dewatered rubber to the at least one processing screw machine.

[0011] At least one processing screw machine, in particular each processing screw machine, is preferably configured as a multi-shaft processing screw machine. Each of the at least one processing screw machine has, in particular, at least two processing element shafts. The at least two processing element shafts can be or are, in particular, rotatably driven in the same direction. Preferably, at least one processing screw machine, in particular each processing screw machine, is configured as a co-rotating twin-shaft processing screw machine. Thus, each processing screw machine has exactly two processing element shafts that can be or are, rotatably driven in the same direction.

[0012] At least two processing element shafts rotate at a speed nA In particular, each rotation speed n A is 40 rpm ≦ n A ≦1200rpm, especially 100rpm≦n A ≦1000rpm, especially 200rpm≦n A ≦800 rpm.

[0013] The styrene-acrylonitrile can be fed to the at least one processing screw machine as bulk material and / or as a melt. Preferably, at least one additive is fed to the at least one processing screw machine and mixed with the dehydrated rubber and styrene-acrylonitrile to form a mixture.

[0014] For feeding the styrene-acrylonitrile to the at least one processing screw machine, the processing installation may comprise an associated second feeding device, which may in particular comprise a metering device and / or a feeding screw machine.

[0015] The method according to claim 2 ensures a simple, flexible and efficient processing of styrene-acrylonitrile. The dewatering screw machine is optimized for the dewatering process step, so that the wet rubber can be dewatered even at a high first moisture content W1 to the desired second moisture content W2.

[0016] The method according to claim 3 ensures simple, flexible and efficient processing of styrene-acrylonitrile. The dewatering screw machine is optimized for the dewatering process step, so that a low second moisture content W2 of the dewatered rubber can be achieved. Preferably, the second moisture content W2 is at most 12% by weight, in particular at most 6% by weight, in particular at most 5% by weight, in particular at most 2% by weight. The lower the second moisture content W2, the easier it is to degas the mixture produced using at least one processing screw machine.

[0017] The method according to claim 4 ensures a simple, flexible and efficient processing of styrene-acrylonitrile. KThus, the thermal energy of the dehydrated rubber is used for the processing of the styrene-acrylonitrile. The thermal energy has a positive effect on the viscosity of the styrene-acrylonitrile, resulting in improved mixing and homogenization of the styrene-acrylonitrile and the dehydrated rubber. If the styrene-acrylonitrile is supplied as a bulk material, for example as a powder and / or granules, the styrene-acrylonitrile can be plasticized more easily and quickly in at least one processing screw machine using thermal energy. If the styrene-acrylonitrile is supplied as a melt, the viscosity of the styrene-acrylonitrile melt is at least not impaired. Therefore, the temperature T K This ensures easy and efficient mixing and homogenization of the dehydrated rubber and styrene-acrylonitrile.

[0018] The method according to claim 5 ensures simple, flexible and efficient processing of styrene-acrylonitrile. Improved homogenization of the dehydrated rubber and styrene-acrylonitrile is achieved by feeding the dehydrated rubber to at least one processing screw machine upstream from the styrene-acrylonitrile source. If the styrene-acrylonitrile is fed as bulk material, e.g., as powder and / or granules, the styrene-acrylonitrile and the dehydrated rubber are plasticized or kneaded together in the at least one processing screw machine and homogenized in a simple and efficient manner. If the styrene-acrylonitrile is fed as a melt, the dehydrated rubber is kneaded in the styrene-acrylonitrile melt and simultaneously homogenized.

[0019] The method according to claim 6 ensures simple, flexible and efficient processing of styrene-acrylonitrile. By supplying styrene-acrylonitrile as a bulk material, for example as powder and / or granules, styrene-acrylonitrile and dehydrated rubber are plasticized or kneaded together in at least one processing screw machine and thereby homogenized. If styrene-acrylonitrile is supplied as a melt, the dehydrated rubber is directly kneaded in the styrene-acrylonitrile melt and simultaneously homogenized. This improves the processability of styrene-acrylonitrile.

[0020] The method according to claim 7 ensures simple, flexible, and efficient processing of styrene-acrylonitrile. Each seal is in particular a melt seal. Each seal of the at least one processing screw machine prevents water from escaping from the mixture during processing and prevents the generated water vapor from flowing back through the at least one processing screw machine in the direction opposite to the conveying direction. Preventing backflow prevents the supply of dehydrated rubber or styrene-acrylonitrile from being blocked. Preferably, the first feed point for the dehydrated rubber is located upstream of the second feed point for the styrene-acrylonitrile in the conveying direction. The styrene-acrylonitrile is fed to the at least one processing screw machine as a melt and / or as bulk material. The bulk material is plasticized into a melt in the at least one processing screw machine. Due to the temperature of the styrene-acrylonitrile melt, residual water contained in the dehydrated rubber is expelled as vapor. Each seal prevents this steam from flowing counter to the conveying direction in the at least one processing screw machine and in particular from interfering with the supply of dehydrated rubber.

[0021] A further object of the present invention is to create a processing facility that allows for simple, flexible and efficient processing of styrene-acrylonitrile.

[0022] This object is achieved by a treatment installation having the features of claim 8. The advantages of the treatment installation according to the invention correspond to the above-mentioned advantages of the method according to the invention. In particular, the method according to the invention can be developed using at least one feature described in connection with the treatment installation according to the invention.

[0023] The processing facility comprises a dewatering screw machine and at least one processing screw machine, so that the dewatering of the wet rubber and the processing of the dewatered rubber and styrene-acrylonitrile are mechanically decoupled and separated from each other. The dewatering screw machine is configured to dewater the wet rubber, while at least one processing screw machine, in particular each processing screw machine, can be configured to process the dewatered rubber and styrene-acrylonitrile. This improves the processing of styrene-acrylonitrile. In particular, a simple, flexible, and efficient processing is achieved.

[0024] The dewatering screw machine preferably comprises a housing and at least one dewatering shaft arranged in a corresponding housing bore of the housing. The at least one dewatering shaft is particularly configured with a double flight (double start screw shape). The dewatering screw machine preferably comprises at least two dewatering shafts, preferably exactly two dewatering shafts, arranged in corresponding housing bores of the housing. The two housing bores pass through each other and have a horizontal figure-eight shape in cross section. The dewatering screw machine is preferably configured as a co-rotating or counter-rotating multi-shaft dewatering screw machine.

[0025] Each processing screw machine preferably comprises a housing and at least two processing element shafts arranged in a housing bore corresponding to the housing. The at least two processing element shafts are in particular double-flighted. Each processing screw machine preferably comprises exactly two processing element shafts arranged in a housing bore corresponding to the housing. The two housing bores pass through each other and have a horizontal figure-eight cross section. Each processing screw machine is preferably configured as a co-rotating multi-shaft processing screw machine, in particular a twin-shaft processing screw machine.

[0026] At least one processing screw machine, in particular each processing screw machine, comprises at least one feed opening for feeding the dehydrated rubber and the styrene-acrylonitrile. Preferably, each of the at least one processing screw machine comprises a first feed opening for feeding the dehydrated rubber and a second feed opening for feeding the styrene-acrylonitrile. Preferably, the first feed opening is located upstream of the second feed opening in the conveying direction of the associated processing screw machine.

[0027] The feed device is for feeding the dewatered rubber to at least one processing screw machine. For this purpose, the dewatering screw machine opens into the feed device so that the dewatered rubber is fed to the feed device. The feed device in turn opens into the at least one processing screw machine, in particular into the first feed opening of the relevant processing screw machine.

[0028] The processing facility preferably comprises a first feeder for feeding the dehydrated rubber to at least one processing screw machine and at least one second feeder for feeding styrene-acrylonitrile to at least one processing screw machine. If the processing facility has a plurality of processing screw machines, the styrene-acrylonitrile can be fed to the plurality of processing screw machines by a common second feeder or by respective second feeders. Preferably, the first feeder opens in each case into a first feed port and at least one second feeder opens into at least one associated second feed port.

[0029] The processing equipment according to claim 9 ensures a simple, flexible and efficient processing of styrene-acrylonitrile. E / D E This ensures easy and efficient dewatering of wet rubber. E / D E The larger the value, the longer the length of at least one dewatering zone of the dewatering screw machine. This makes it possible to arbitrarily set the degree of dewatering of the wet rubber.

[0030] The processing equipment according to claim 10 ensures simple, flexible and efficient processing of styrene-acrylonitrile. At least one dewatering shaft is disposed in a corresponding housing bore of the housing of the dewatering screw machine. Ratio D E / d E The free volume or free cross-sectional area in at least one housing hole can be set using the ratio D. E / d E can be used to limit the mechanical energy input into the wet rubber. E / d E is preferably applied to at least one dewatering zone, in particular to each dewatering zone formed in the dewatering screw machine.

[0031] The processing equipment described in claim 11 ensures simple, flexible, and efficient processing of styrene-acrylonitrile. The dewatering screw machine preferably comprises multiple dewatering zones arranged consecutively in the conveying direction. The dewatering screw machine preferably comprises a housing and at least one dewatering shaft arranged in a corresponding housing bore of the housing. Each dewatering shaft preferably comprises at least one kneading element and / or at least one retaining element in each dewatering zone. Each dewatering shaft preferably comprises at least one kneading element in each dewatering zone and at least one retaining element arranged downstream of the at least one kneading element in the conveying direction. The at least one retaining element ensures that the wet rubber remains in the region of the at least one kneading element for a desired residence time, thereby being intensively mixed and kneaded by the at least one kneading element. As a result, water is squeezed out of the wet rubber. Each dewatering zone is preferably assigned at least one dewatering inlet formed in the housing. The at least one dewatering inlet is preferably arranged upstream of the at least one retaining element in the dewatering zone. A filter insert and / or a draining screw machine can be connected to the corresponding dewatering outlet to discharge the squeezed water. Each draining screw machine can be configured as, for example, a twin-shaft draining screw machine. Each twin-shaft draining screw machine can be configured to rotate in the same direction or in the opposite directions.

[0032] The processing facility according to claim 12 ensures simple, flexible, and efficient processing of styrene-acrylonitrile. The feeding device allows the dehydrated rubber to be fed directly from the dehydrating screw machine to at least one processing screw machine. For this purpose, the discharge outlet of the dehydrating screw machine is connected by the feeding device to a corresponding inlet of the at least one processing screw machine. The dehydrating screw machine may be directly connected to the at least one processing screw machine, for example, via at least one feed pipeline and / or at least one feed hopper. A buffer tank may be provided for temporarily storing or buffering the dehydrated rubber immediately before it is fed to the at least one processing screw machine. The dehydrated rubber may be fed to the at least one processing screw machine while being metered by a corresponding metering device and / or a corresponding feed screw machine.

[0033] The processing equipment according to claim 13 ensures a simple, flexible and efficient processing of styrene-acrylonitrile. A / D A The ratio L allows the desired homogenization of the dehydrated rubber and styrene-acrylonitrile and also allows for effective degassing of the resulting mixture. A / D A The smaller the value, the less mechanical complexity there is.

[0034] The processing installation according to claim 14 ensures a simple, flexible and efficient processing of styrene-acrylonitrile. The associated processing screw machine comprises a housing and at least two processing element shafts arranged in corresponding housing bores. The free volume or free cross-sectional area in the at least two housing bores is determined by the ratio D A / d A This free volume or free cross-sectional area can be used to achieve intensive mixing and homogenization of the dehydrated rubber and styrene-acrylonitrile. Furthermore, the free volume or free cross-sectional area can be used to limit the mechanical energy input and the shear forces that occur. The ratio D A / dA The larger the free volume or free cross-sectional area, the larger the free volume or cross-sectional area.

[0035] The processing equipment described in claim 15 ensures simple, flexible, and efficient processing of styrene-acrylonitrile. The dehydrated rubber is fed to each processing screw machine at a first feed point located upstream of the second feed point for styrene-acrylonitrile in the conveying direction, so that the dehydrated rubber can be processed directly together with styrene-acrylonitrile. If styrene-acrylonitrile is fed to the corresponding processing screw machine as a bulk material, e.g., powder and / or granules, the dehydrated rubber and the styrene-acrylonitrile bulk material can be plasticized or kneaded and homogenized together. If styrene-acrylonitrile is fed to the corresponding processing screw machine as a melt, the dehydrated rubber can be fed directly to the styrene-acrylonitrile melt. The dehydrated rubber is directly melted in the styrene-acrylonitrile melt and homogenized therewith.

[0036] The processing equipment according to claim 16 ensures simple, flexible, and efficient processing of styrene-acrylonitrile. A holding zone between the first inlet for feeding dehydrated rubber and the second inlet for feeding styrene-acrylonitrile prevents water from escaping during the processing of the dehydrated rubber and styrene-acrylonitrile and prevents generated water vapor from flowing back into the conveying direction in the associated processing screw machine and disrupting the supply of dehydrated rubber. Each processing screw machine has at least two processing element shafts. Each processing screw machine has at least one holding element per processing element shaft in the holding zone. The at least one holding element has a conveying direction opposite to the conveying direction of the corresponding processing screw machine. The at least one holding element per processing element shaft forms a seal in the holding zone, which prevents the backflow of the discharged water or resulting water vapor. The corresponding seal is, in particular, a melt seal.

[0037] The processing equipment described in claim 17 ensures simple, flexible, and efficient processing of styrene-acrylonitrile. Before the styrene-acrylonitrile is fed, the dehydrated rubber is again degassed in at least one first degassing zone arranged upstream of the second feed inlet in the conveying direction. The second residual moisture content W2 of the dehydrated rubber is again reduced in the at least one first degassing zone. For this purpose, at least one kneading element is arranged in the at least one first degassing zone, which intensively kneads the dehydrated rubber so that the second residual moisture content W2 is at least partially discharged in the form of steam. At least one first degassing zone is assigned to at least one degassing port formed in the housing of the associated processing screw machine. The steam is discharged from the housing through the at least one degassing port. The associated first degassing device may be connected to at least one degassing port. Preferably, the associated processing screw machine has at least two first degassing zones arranged in succession upstream of the second feed inlet in the conveying direction. Between the first degassing zones arranged in direct succession, a holding zone for forming a seal, in particular a fused seal, can be formed.

[0038] The processing equipment described in claim 18 ensures simple, flexible, and efficient processing of styrene-acrylonitrile. A mixture in the form of a melt is produced downstream of the second feed inlet from the dehydrated rubber and styrene-acrylonitrile. In at least one second degassing zone, the melt is intensively mixed and homogenized. This allows residual water and / or other volatile components to be removed from the melt. Each processing screw machine has at least two processing element shafts. At least one second degassing zone has at least one kneading element per processing element shaft. At least one second degassing zone is assigned to at least one second degassing opening formed in the housing of the corresponding processing screw machine. Residual water, residual water vapor, and / or other volatile components are removed from the at least one second degassing opening. Each of the at least one second degassing openings may be connected to a corresponding second degassing device. Preferably, at least two second degassing zones are arranged downstream of the second feed opening, and preferably two to four second degassing zones are arranged in succession. Between each immediately adjacent second degassing zone, a holding zone is formed, and a seal, in particular a melt seal, is formed. Preferably, each second degassing zone is assigned a second degassing opening. The second degassing device may in particular comprise a twin-shaft side degassing screw machine.

[0039] Further features, advantages and details of the invention are explained below with reference to several embodiments. [Brief explanation of the drawings]

[0040] [Figure 1] FIG. 1 is a partial cross-sectional plan view of a styrene-acrylonitrile processing facility according to a first embodiment, which includes a dehydration screw machine, a feeding device, and a processing screw machine. [Figure 2] 2 is a cross-sectional view of the processing facility of FIG. 1 taken along the section line II-II. [Figure 3] 3 is a cross-sectional view of the processing facility of FIG. 1 taken along the section line III-III. [Figure 4]3 is a cross-sectional view corresponding to FIG. 2 through a styrene-acrylonitrile processing facility according to a second embodiment. [Figure 5] 4 is a cross-sectional view corresponding to FIG. 3 through a processing installation according to a second embodiment.

[0041] A first embodiment of the present invention will be described below with reference to Figures 1 to 3. The treatment facility 1 shown in Figures 1 to 3 is for continuously treating styrene-acrylonitrile (SAN). To treat styrene-acrylonitrile, the treatment facility 1 includes a dehydration screw machine 2, a first supply device 3, a treatment screw machine 4, and a second supply device 5.

[0042] The dewatering screw machine 2 is for dewatering wet rubber 6 and supplying dewatered rubber 7. The dewatering screw machine 2 is configured as a co-rotating multi-shaft dewatering screw machine or a co-rotating twin-shaft dewatering screw machine. The dewatering screw machine 2 includes a housing 8 in which two housing holes 9 and 10 are formed, which are parallel to each other and penetrate each other. The housing holes 9 and 10 have a horizontal figure-eight shape in cross section.

[0043] The housing 8 includes a plurality of housing sections 12 to 17, which are arranged successively in the first conveying direction 11 and connected to each other to form the housing 8. The housing 8 further includes a discharge plate 18 that closes the housing 8 at the last housing section 17. The discharge plate 18 is connected to the last housing section 17. The discharge plate 18 includes a discharge port 19 for discharging the dewatered rubber 7.

[0044] A supply port 20 is formed in the first housing portion 12 in order to supply the wet rubber 6 to the dewatering screw machine 2. For supply, the dewatering screw machine 2 is provided with a supply hopper 21 that opens into the supply port 20.

[0045] Two dewatering shafts 22, 23 are disposed in the housing bores 9, 10 and can be rotated in the same direction about associated rotation axes 24, 25. For rotational drive, the dewatering screw machine 2 is provided with an electric drive motor 26 and a branch gear 28, with a coupling 27 disposed therebetween. The dewatering shafts 22, 23 are rotated in the same direction about the rotation axes 24, 25 by the drive motor 26 via the branch gear 28.

[0046] The dewatering screw machine 2 sequentially forms an intake zone 29, a first dewatering zone 30, a second dewatering zone 31, and a discharge zone 32 along a first conveying direction 11. In the intake zone 29, a supply port 20 is formed in the housing portion 12. The wet rubber 6 is supplied through a supply hopper 21. In the intake zone 29, the dewatering shafts 22, 23 have conveying elements 33, 33' or screw elements.

[0047] Alternatively, the wet rubber 6 may be supplied to the supply port 20 by a stuffing screw (forcing screw) arranged vertically or horizontally. In the case of a horizontal stuffing screw, the supply port 20 is formed in the lateral direction of the housing part 12.

[0048] In the intake zone 29, the wet rubber 6 is conveyed along the first conveying direction 11 to the first dewatering zone 30. In the first dewatering zone 30, the wet rubber 6 is dewatered. For this purpose, the dewatering shafts 22, 23 have kneading elements 34, 34' and holding elements 35, 35' arranged successively along the first conveying direction 11. The kneading elements 34, 34' in particular comprise kneading blocks with integrally interconnected kneading disks and / or individual kneading disks. The holding elements 35, 35' are configured as screw elements, and their conveying direction is opposite to the first conveying direction 11. The pitch of the holding elements 35, 35' can be used to adjust the retention effect and thereby the residence time of the wet rubber 6 in the first dewatering zone 30.

[0049] In the first dewatering zone 30, a first dewatering port 36 is formed in the housing 8. The squeezed water in the first dewatering zone 30 can flow out of the housing 8 through the first dewatering port 36. The first dewatering port 36 is arranged, for example, in the area of ​​the kneading elements 34, 34'. The dewatering screw machine 2 includes a first filter insert 37 arranged in the first dewatering port 36. The first filter insert 37 retains the wet rubber 6 but allows water to flow out. Instead of the first filter insert 37, a draining screw machine may be connected to the first dewatering port 36. The draining screw machine may be configured, for example, as a co-rotating or counter-rotating twin-shaft draining screw machine. The draining screw machine may also be connected laterally.

[0050] As a result of the conveying action of the conveying elements 33, 33', the wet rubber 6 is forced through the first dewatering zone 30 into the second dewatering zone 31. In the second dewatering zone 31, further dewatering of the wet rubber 6 takes place. In the second dewatering zone 31, the dewatering shafts 22, 23 have kneading elements 38, 38' and holding elements 39, 39', arranged in this order along the first conveying direction 11. The kneading elements 38, 38' in particular comprise kneading blocks with integrally interconnected kneading disks and / or individual kneading disks. The holding elements 39, 39' are configured as screw elements, and their conveying direction is opposite to the first conveying direction 11. The pitch of the holding elements 39, 39' can be used to adjust the retention effect and thereby the residence time of the wet rubber 6 in the second dewatering zone 31.

[0051] A second dewatering port 40 is formed in the second dewatering zone 31 of the housing 8 to discharge the squeezed water. The second dewatering port 40 is arranged in the area of ​​the kneading elements 38, 38'. The dewatering screw machine 2 includes a second filter insert 41 arranged in the second dewatering port 40. The second filter insert 41 holds back the wet rubber 6 but allows the squeezed water to be discharged. Instead of the second filter insert 41, a draining screw machine may be connected to the second dewatering port 40. The draining screw machine may be configured as, for example, a twin-shaft draining screw machine rotating in the same direction or in the opposite directions. The draining screw machine may also be connected laterally.

[0052] By dewatering the wet rubber 6 in the dewatering zones 30, 31, the dewatered rubber 7 is supplied to the discharge zone 32. In the discharge zone 32, the dewatering shafts 22, 23 have conveying elements 42, 42' or screw elements.

[0053] The dewatering shafts 22 and 23 are configured as double flights. The dewatering shafts 22 and 23 have a length L E Furthermore, the dewatering shafts 22 and 23 have an outer diameter D E and inner diameter d E It has.

[0054] Length L E and outer diameter D E The ratio is 16≦L E / D E ≦40, especially 18≦L E / D E ≦34, especially 20≦L E / D E ≦28.

[0055] Outer diameter D E and inner diameter d E The ratio is 1.22≦D E / d E ≦1.8, especially 1.4≦D E / d E ≦1.66, especially 1.5≦D E / d E ≦1.6.

[0056] The first supply device 3 is for supplying the dewatered rubber 7 to the treatment screw machine 4. The first supply device 3 includes a supply pipe 43. The supply pipe 43 connects the dewatering screw machine 2 and the treatment screw machine 4. For this purpose, the supply pipe 43 is connected to the discharge port 19.

[0057] The processing screw machine 4 is configured as a co-rotating multi-screw processing machine or a co-rotating twin-screw processing machine. The processing screw machine 4 includes a housing 44 in which two parallel, interpenetrating housing bores 45, 46 are formed. The housing bores 45, 46 have a horizontal figure-eight cross section. Two processing element shafts 47, 48 are disposed within the housing bores 45, 46 and can be driven to rotate in the same direction about corresponding rotation axes 49, 50. For rotational drive, the processing screw machine 4 includes an electric drive motor 51 and a branch gear 53 with a coupling 52 disposed between them. The processing element shafts 47, 48 are driven to rotate in the same direction about the rotation axes 49, 50 by the drive motor 51 via the branch gear 53.

[0058] The housing 44 includes a plurality of housing sections 54 to 62, which are arranged successively in the second conveying direction 63 and are interconnected to form the housing 44. The housing 44 includes a discharge plate 64 that is connected to the last housing section 62 and closes the housing 44. The discharge plate 64 includes a discharge port 65.

[0059] The processing screw machine 4 forms, in the second conveying direction 63, a first intake zone 66, a first degassing zone 67, a holding zone 68, a second intake zone 69, a melting zone 70, a second degassing zone 71, and a discharge zone 72 in this order.

[0060] In the first intake zone 66, the housing 44 has a first supply opening 73. The first supply opening 73 is for supplying the dewatered rubber 7. For this purpose, the supply pipe 43 opens into the first supply opening 73. In the first intake zone 66, the supplied dewatered rubber 7 is transported along the second conveying direction 63 to the first degassing zone 67. For this purpose, the processing element shafts 47, 48 of the first intake zone 66 have conveying elements 74, 74' or screw elements.

[0061] The first degassing zone 67 serves to reduce the moisture remaining in the dewatered rubber 7. For this purpose, the processing element shafts 47, 48 of the first degassing zone 67 are equipped with kneading elements 75, 75'. The kneading elements 75, 75' in particular comprise kneading blocks with integrally interconnected kneading disks and / or individual kneading disks. As a result of the intensive kneading of the dewatered rubber 7, water vapor is generated. To allow the water vapor to escape, the housing 44 is equipped with a first degassing opening 76 in the first degassing zone 67. The processing installation 1 is equipped with a first degassing device 77 connected to the first degassing opening 76. The first degassing device 77 is configured, for example, as a vacuum degassing dome.

[0062] The styrene-acrylonitrile is fed to the processing screw machine 4 as a styrene-acrylonitrile melt 78 (SAN melt) in a second intake zone 69. The holding zone 68, arranged upstream in the second conveying direction 63, is intended to form a melt seal 79 with the SAN melt 78. For this purpose, the processing element shafts 47, 48 of the holding zone 68 are provided with holding elements 80, 80'. The holding elements 80, 80' are configured as screw elements whose conveying direction faces the second conveying direction 63. The holding elements 80, 80' can also be used to adjust the residence time of the dewatered rubber 7 in the first degassing zone 67.

[0063] In the second intake zone 69, the housing 44 has a second supply inlet 81. The second supply inlet 81 is for supplying the SAN melt 78. The first supply inlet 73, the first degassing zone 67, and the holding zone 68 are therefore arranged upstream of the second supply inlet 81 in the second conveying direction 63. The dewatered rubber 7 is therefore supplied upstream of the SAN melt 78 in the second conveying direction 63. In the second intake zone 69, the processing element shafts 47, 48 are equipped with conveying elements 82, 82' or screw elements. The conveying elements 82, 82' are for transporting the dewatered rubber 7 and the SAN melt 78 to the melting zone 70.

[0064] The second supply device 5 is for supplying the SAN melt 78. The second supply device 5 includes a melt pump 83 and a supply pipe 84. The supply pipe 84 opens to a second supply port 81. The melt pump 83 is for transporting the SAN melt 78 to the second supply port 81 via the supply pipe 84. The SAN melt 78 is supplied from, for example, a manufacturing plant.

[0065] In the melting zone 70, the dewatered rubber 7 is kneaded in the SAN melt 78 and homogenized therewith. For this purpose, the processing element shafts 47, 48 of the melting zone 70 are provided with kneading elements 85, 85'. The kneading elements 85, 85' in particular comprise kneading blocks with integrally interconnected kneading discs and / or individual kneading discs.

[0066] A molten mixture 86 is produced from the dewatered rubber 7 and the SAN melt 78 in the melting zone 70 and conveyed to the second degassing zone 71. The second degassing zone 71 is located downstream of the second feed opening 81 in the second conveying direction 63. The molten mixture 86 is kneaded and homogenized in the second degassing zone 71. As a result, water vapor and / or other volatile components are released from the molten mixture 86. For the kneading and homogenization, the processing element shafts 47, 48 of the second degassing zone 71 are provided with kneading elements 87, 87'. The kneading elements 87, 87' may comprise, in particular, kneading blocks with integrally interconnected kneading disks and / or individual kneading disks. To discharge the water vapor and / or other volatile components, the housing 44 is provided with a second degassing opening 88 in the second degassing zone 71. The second degassing opening 88 is formed in the transverse direction of the housing 44 or the housing section 61.

[0067] The treatment facility 1 includes a second degassing device 89 for discharging water vapor and / or other volatile components from the second degassing zone 71. The second degassing device 89 includes a twin-shaft degassing screw machine 90. The degassing screw machine 90 includes a housing 91 having two parallel, interpenetrating housing bores 92, 93 formed therein. The housing bores 92, 93 have a horizontal, figure-8 cross section. Two screw shafts 94, 95 are disposed within the housing bores 92, 93 and are driven to rotate in the same direction about corresponding rotation axes 96, 97. For rotational drive, the degassing screw machine 90 includes an electric drive motor 98 and a branch gear 100, with a clutch 99 disposed therebetween. The screw shafts 94, 95 are driven to rotate in the same direction about the rotation axes 96, 97 by the drive motor 98 via the branch gear 100. The housing 91 includes a drain port 101 for discharging water vapor and / or other volatile components from the degassing screw machine 90. The second degassing device 89 may include a suction unit connected to the drain outlet 101 for sucking out water vapor and / or volatile components.

[0068] The housing 91 of the degassing screw machine 90 is connected to the housing 44 of the processing screw machine 4. The screw shafts 94, 95 extend into the second degassing port 88.

[0069] In the discharge zone 72, the homogenized and deaerated mixture 86 is discharged from the processing screw machine 4. For this purpose, the processing element shafts 47, 48 constitute conveying elements 102, 102' or screw elements in the discharge zone 72. The conveying elements 102, 102' convey the mixture 86 through the discharge opening 65.

[0070] The processing element shafts 47, 48 have a length L A Furthermore, the processing element shafts 47, 48 have an outer diameter D A and inner diameter d A It has.

[0071] Outer diameter D A Length L A The ratio is 20≦L A / D A ≦60, especially 28≦L A / D A ≦52, especially 36≦L A / D A ≦40.

[0072] Furthermore, the outer diameter D A Inner diameter d A The ratio is 1.22≦D A / d A ≦1.8, especially 1.4≦D A / d A ≦1.66, especially 1.5≦D A / d A ≦1.6.

[0073] The processing facility 1 may also include a melt pump and / or a filter device and / or a granulator (not shown in detail) located downstream of the processing screw machine 4. The granulator is intended to produce granules from the discharged mixture 86.

[0074] The operation of the processing equipment 1 is as follows.

[0075] The wet rubber 6 is supplied to the dewatering screw machine 2 through a supply hopper 21 and a supply port 20. The wet rubber 6 has a first moisture content W1. The first moisture content W1 is at least 20% by weight, particularly at least 30% by weight, particularly at least 40% by weight, and particularly at least 50% by weight.

[0076] The wet rubber 6 is, for example, natural rubber and / or synthetic rubber. Preferably, the wet rubber 6 is synthetic rubber, such as acrylonitrile butadiene styrene (ABS).

[0077] In the intake zone 29, the wet rubber 6 is conveyed to the first dewatering zone 30. In the first dewatering zone 30, the wet rubber 6 is kneaded by kneading elements 34, 34', and water is squeezed out of the wet rubber 6. The retaining elements 35, 35', on the one hand, adjust the residence time of the wet rubber 6 in the area of ​​the kneading elements 34, 34', and, on the other hand, prevent water from flowing downstream in the first conveying direction 11. The squeezed water flows out of the housing 8 of the dewatering screw machine 2 through a first dewatering port 36 and a first filter insert 37. The first filter insert 37 blocks the wet rubber 6.

[0078] The wet rubber 6 is pushed in the first conveying direction 11 into the second dewatering zone 31, where further dewatering takes place. The wet rubber 6 is kneaded by the kneading elements 38, 38', and further water is squeezed out. The retaining elements 39, 39', on the one hand, regulate the residence time of the wet rubber 6 in the region of the kneading elements 38, 38', and, on the other hand, prevent the squeezed water from flowing downstream in the first conveying direction 11. The squeezed water flows through the second dewatering opening 40 and the second filter insert 41 and is discharged from the housing 8. The second filter insert 41 holds back the wet rubber 6.

[0079] In this way, the wet rubber 6 is successively dewatered in the dewatering zones 30, 31, and the dewatered rubber 7 is present in the discharge zone 32. The dewatered rubber 7 has a second moisture content W2 lower than the first moisture content W1. The second moisture content W2 is at most 20% by weight, particularly at most 16% by weight, particularly at most 12% by weight, particularly at most 11% by weight, particularly at most 10% by weight, particularly at most 8% by weight, particularly at most 6% by weight, particularly at most 5% by weight, particularly at most 2% by weight.

[0080] The relative change in moisture content ΔW=(W1-W2) / W1 is in particular 50%≦ΔW≦99%, in particular 60%≦ΔW≦95%, in particular 70%≦ΔW≦90%.

[0081] The dewatering screw machine 2 rotates at a rotation speed n E It operates at a rotation speed of n E is 40 rpm ≦ n E ≦600rpm, especially 50rpm≦n E ≦400rpm, especially 60rpm≦n E ≦300 rpm.

[0082] The dehydrated rubber 7 is discharged from the discharge port 19 and supplied to the first supply device 3. The dehydrated rubber 7 flows through the supply pipe 43 from the discharge port 19 to the first supply port 73 of the treatment screw machine 4. The dehydrated rubber 7 is supplied from the first supply port 73 to the first intake zone 66 of the treatment screw machine 4. When supplied to the treatment screw machine 4, the dehydrated rubber 7 is heated to a temperature T K At temperature T K , 60℃≦T K ≦140℃, especially 70℃≦T K ≦130℃, especially 85℃≦T K ≦120℃, especially 100℃≦T K ≦110°C.

[0083] The dewatered rubber 7 is conveyed in the second conveying direction 63 by the conveying elements 74, 74' and sent to the first degassing zone 67. The dewatered rubber 7 is kneaded by the kneading elements 75, 75', and residual moisture is released as water vapor, further reducing the second moisture content W2. The released water vapor is discharged from the housing 44 through the first degassing port 76 by the first degassing device 77.

[0084] The SAN melt 78 is supplied to the second intake zone 69 of the processing screw machine 4 via a second supply port 81 by a melt pump 83 and a supply pipe 84. At least one additive may be mixed with the SAN melt 78 before the SAN melt 78 is supplied to the processing screw machine 4. In this manner, the dehydrated rubber 7 is supplied to the processing screw machine 4 upstream of the SAN melt 78 in the second conveying direction 63. A portion of the SAN melt 78 is conveyed by the retaining elements 80, 80' to the upstream retention zone 68 in the second conveying direction 63, where the SAN melt 78 forms a melt seal 79 in the housing bores 45, 46. The retaining elements 80, 80', on the one hand, make it possible to adjust the residence time of the dehydrated rubber 7 in the first degassing zone 67. On the other hand, additional water vapor generated in the second intake zone 69 and the melting zone 70 as a result of contact between the dehydrated rubber 7 and the hot SAN melt 78 cannot flow upstream in the second conveying direction 63. This is because the melt seal 79 formed in the retention zone 68 forms a barrier to water vapor. As a result of the high temperature SAN melt 78, residual water can again escape from the dehydrated rubber 7. Therefore, water vapor generated downstream from the retention zone 68 cannot enter the first degassing zone 67 and potentially enter the first intake zone 66 and disrupt the delivery of dehydrated rubber 7.

[0085] High temperature SAN melt 78 temperature T S is the temperature T of the dehydrated rubber 7 K On the one hand, this causes the residual water to evaporate from the dehydrated rubber 7. On the other hand, the heat of evaporation causes the temperature T SThe temperature T S low temperature T K ensures, on the one hand, the evaporation of residual water and, on the other hand, the temperature T S and temperature T K Avoid the adverse effects of excessively large temperature differences between

[0086] In the second intake zone 69, the dewatered rubber 7 and the SAN melt 78 are conveyed to the melting zone 70. In the melting zone 70, the dewatered rubber 7 is opened and kneaded in the SAN melt 78 by the kneading elements 85, 85'.

[0087] In the second degassing zone 71, the molten mixture 86 produced in the melting zone 70 is homogenized and degassed. The kneading by the kneading elements 87, 87' further expels water vapor and / or other volatile components from the mixture 86. The water vapor and / or other volatile components are expelled from the housing 44 through a second degassing port 88 by a second degassing device 89. The screw shafts 94, 95 rotate about rotation axes 96, 97 so that the mixture 86 does not leak out of the housing holes 45, 46. Meanwhile, the water vapor and / or other volatile components are sucked through the second degassing port 88, the housing holes 92, 93, and the drain port 101 by a suction device.

[0088] In the discharge zone 72, the homogenized and deaerated mixture 86 is discharged from the processing screw machine 4 through the discharge port 65. The discharged mixture 86 is then granulated by a granulator to produce granules.

[0089] The processing screw machine 4 operates at a rotation speed n A It operates at a rotation speed of n A is 40 rpm ≦ n A ≦1200rpm, especially 100rpm≦n A ≦1000rpm, especially 200rpm≦n A ≦800 rpm.

[0090] A second embodiment of the invention will now be described with reference to Figures 4 and 5. In contrast to the first embodiment, the treatment installation 1 comprises a first treatment screw machine 4 and a second treatment screw machine 4' arranged parallel to each other. The dewatered rubber 7 is fed by the dewatering screw machine 2 to the treatment screw machines 4, 4' in the manner described above.

[0091] In contrast to the first embodiment, the first supply device further includes a buffer tank 103, a first metering device 104, a second metering device 105, a supply hopper 109, and a supply screw machine 106. The supply piping 43 connects the discharge port 19 of the dewatering screw machine 2 to the buffer tank 103. The dewatered rubber 7 is temporarily stored and buffered in the buffer tank 103.

[0092] Starting from the buffer tank 103, the first feeding option will be described with reference to the first processing screw machine 4. The buffer tank 103 forms a first outlet opening 107. The first outlet opening 107 opens into a first metering device 104. The first metering device 104 is configured, for example, for the gravimetric or volumetric method. The first metering device 104 meters the dewatered rubber 7 into a feeding hopper 109, which feeds the dewatered rubber 7 into the first feeding opening 73 of the processing screw machine 4. For this purpose, the feeding hopper 109 is connected to the first processing screw machine 4 and opens into the first feeding opening 73.

[0093] Starting from the buffer tank 103, the second feeding option will be described with reference to the second processing screw machine 4'. The buffer tank 103 forms a second outlet opening 108. The second outlet opening 108 opens into a second metering device 105. The second metering device 105 is configured for gravimetric or volumetric metering. The second metering device 105 meters the dewatered rubber 7 and feeds it to the feeding screw machine 106. The feeding screw machine 106 can be configured with a single or twin screw. For example, the feeding screw machine 106 is configured as a twin-shaft side-feeding screw machine. The twin-shaft feeding screw machine 106 is particularly configured to rotate together.

[0094] The feed screw machine 106 includes a housing 110 having two parallel, interpenetrating housing bores 111, 112. The housing bores 111, 112 have a horizontal figure-eight cross section. Two screw shafts 113, 114 are disposed within the housing bores 111, 112 and can be driven to rotate in the same direction about corresponding rotation axes 115, 116. For rotational drive, the feed screw machine 106 includes an electric drive motor 117 and a branch gear 119 with a coupling 118 disposed therebetween. The screw shafts 113, 114 are driven to rotate in the same direction about the rotation axes 115, 116 by the drive motor 117 via the branch gear 119.

[0095] The housing 110 is connected to the housing 44, in particular to the first housing part 54 of the second processing screw machine 4'. The first feed opening 73 of the second processing screw machine 4' is formed laterally. The screw shafts 113, 114 extend into the first feed opening 73. The second metering device 105 measures the dewatered rubber 7 and feeds it to the feed opening 120 of the feed screw machine 106. The feed screw machine 106 transports the dewatered rubber 7 from the first feed opening 73 to the housing holes 45, 46 of the second processing screw machine 4' by means of the screw shafts 113, 114.

[0096] In contrast to the first embodiment, styrene-acrylonitrile is supplied to the processing screw machines 4, 4' as a styrene-acrylonitrile bulk material 121 (SAN bulk material). The SAN bulk material 121 is, for example, SAN powder and / or SAN granules. The SAN bulk material 121 may be mixed with at least one additive before being supplied to the first processing screw machine 4 and / or the second processing screw machine 4'.

[0097] The second feed device 5 has a metering device 122 and a feed hopper 123 for each processing screw machine 4, 4'. Each metering device 122 is configured for gravimetric or volumetric measurement. Each metering device 122 opens into a corresponding feed hopper 123. Each feed hopper 123 is connected to a corresponding second feed port 81. The SAN bulk material 121 is fed to the associated second feed port 81 of the processing screw machine 4, 4' by the corresponding metering device 122. A feed screw machine can be used to feed the SAN bulk material 121 instead of or in addition to each metering device 122. Each feed screw machine can be configured as a twin-screw side-feed screw machine. Each twin-screw feed screw machine can be configured to co-rotate in particular. The SAN bulk material 121 and the dewatered rubber 7 are plasticized or kneaded together in the associated melting zone 70 and thoroughly mixed. The temperature T of the dewatered rubber 7 is K The SAN bulk material 121 and / or the SAN melt 78 produced therefrom forms a seal, particularly a melt seal 79, in the retention zone 68.

[0098] For further structure and operation of the processing facility 1, please refer to the previous embodiments.

[0099] Generally, when a processing facility has multiple processing screw machines, the multiple processing screw machines may be identical and / or different in structure and / or operation method, and may be used to increase the production capacity of the dehydrated rubber and styrene-acrylonitrile mixture and / or to produce different mixtures of dehydrated rubber and styrene-acrylonitrile. [Explanation of symbols]

[0100] 1. Processing facilities 2. Dewatering screw machine 3 1st supply device 4. First processing screw machine 4' 2nd Processing Screw Machine 5 Second supply device 6. Wet rubber 7 Dehydrated rubber 8, 44, 91, 110 Housing 9, 10, 45, 46, 92, 93, 111, 112 Housing holes 11 First conveying direction 12, 13, 14, 15, 16, 17, 54, 55, 56, 57, 58, 59, 60, 61, 62 Housing part 18, 64 Discharge plate 19, 65 outlet 20, 120 supply port 21, 109, 123 Supply hopper 22, 23 Dehydration shaft 24, 25, 49, 50, 96, 97, 115, 116 Rotation axis 26, 51, 98, 117 Drive motor 27, 52, 118 Coupling 28, 53, 100, 119 Branch gear 29 Intake Zone 30 First Dewatering Zone 31 Second Dewatering Zone 32, 72 Discharge Zone 33, 33', 42, 42', 74, 74', 82, 82', 102, 102' Conveying elements 34, 34', 38, 38', 75, 75', 85, 85', 87, 87' kneading elements 35, 35', 39, 39', 80, 80' Retaining elements 36 1st dehydration port 37 First filter insert 40 2nd dehydration port 41 Second filter insert 43, 84 Supply piping 47, 48 Processing element shaft 63 Second conveying direction 66 First intake zone 67 First degassing zone 68 Retention Zone 69 Second intake zone 70 Melting Zone 71 Second degassing zone 73 1st supply port 76 First Vent 77 First Degasser 78 SAN Melt 79 Melt Seal 81 2nd supply port 83 Melt Pump 86 Molten Mixture 88 Second Vent 89 Second Degasser 90 Degassing Screw Machine 94, 95, 113, 114 Screw shaft 99 Clutch 101 Drain 103 Buffer Tank 104 1st weighing device 105 Second weighing device 106 Feeding Screw Machine 107 1st exit opening 108 Second exit opening 121 SAN bulk material 122 Weighing device

Claims

1. 1. A method for treating styrene-acrylonitrile, comprising: - providing a treatment installation (1) comprising a dewatering screw machine (2) and at least one treatment screw machine (4, 4'), -First moisture content W １ A step of supplying wet rubber (6) having the above formula to the dewatering screw machine (2), The wet rubber (6) is dewatered by the dewatering screw machine (2) to a second moisture content W ２ wherein the second moisture content W ２ <First moisture content W １ a process in which - Discharging the dewatered rubber (7) from the dewatering screw machine (2), - feeding said dehydrated rubber (7) and styrene-acrylonitrile (78, 121) into said at least one processing screw machine (4, 4'), - producing a mixture of said dehydrated rubber (7) and styrene-acrylonitrile (78, 121) by means of said at least one processing screw machine (4, 4'), and - degassing said mixture (86) produced by said at least one processing screw machine (4, 4'); A method comprising:

2. The first moisture content W １ 2. The method according to claim 1, wherein the % by weight of the polyisoprene is at least 20%, in particular at least 30%, in particular at least 40%, in particular at least 50% by weight.

3. Said second moisture content W ２ 3. The method according to claim 1 or 2, characterized in that the % by weight of the cellulose acetate solution is at most 20%, in particular at most 16%, in particular at most 11%, in particular at most 10%, in particular at most 8%.

4. The dehydrated rubber (7) is fed to the at least one processing screw machine (4, 4') at a temperature T Ｋ where 60° C.≦T Ｋ ≦140° C., particularly 70° C.≦T Ｋ ≦130°C, particularly 85°C≦T Ｋ ≦120°C, particularly 100°C≦T Ｋ 4. The method according to claim 1, wherein the temperature is ≦110° C.

5. 5. The method according to claim 1, wherein the dehydrated rubber (7) is fed to the at least one processing screw machine (4, 4') upstream of the styrene-acrylonitrile (78, 121) in the conveying direction (11).

6. said styrene-acrylonitrile (121) being fed as bulk material to said at least one processing screw machine (4, 4') and melted by said at least one processing screw machine (4, 4') to form a styrene-acrylonitrile melt; and / or 6. A method according to any one of claims 1 to 5, characterized in that the styrene-acrylonitrile (78) is fed to the at least one processing screw machine (4, 4') as a styrene-acrylonitrile melt.

7. 7. The method according to any one of claims 1 to 6, characterized in that in the at least one processing screw machine (4, 4'), a seal (79) is formed between the first feed point of the dehydrated rubber (7) and the second feed point of the styrene-acrylonitrile (78, 121).

8. A processing facility for processing styrene-acrylonitrile, comprising at least one processing screw machine (4, 4') for processing dehydrated rubber (7) and styrene-acrylonitrile (78, 121), a dehydration screw machine (2) for dehydrating the wet rubber (6) and supplying the dehydrated rubber (7); a feeding device (3) for feeding the dehydrated rubber (7) to the at least one processing screw machine (4, 4'); A processing facility comprising:

9. The dewatering screw machine (2) has a length L Ｅ and outer diameter D Ｅ and at least one dewatering shaft (22, 23) having a Ｅ / D Ｅ ≦40, and particularly 18≦L Ｅ / D Ｅ ≦34, and particularly 20≦L Ｅ / D Ｅ 9. Treatment installation according to claim 8, characterized in that ≦28.

10. The dewatering screw machine (2) has an outer diameter D Ｅ and inner diameter d Ｅ and at least one dewatering shaft (22, 23) having a Ｅ / d Ｅ ≦1.8, and in particular 1.4≦D Ｅ / d Ｅ ≦1.66, and in particular 1.5≦D Ｅ / d Ｅ 10. Treatment installation according to claim 8 or claim 9, characterized in that ≦1.

6.

11. 11. Treatment installation according to any one of claims 8 to 10, characterized in that the dewatering screw machine (2) comprises at least one dewatering zone (30, 31).

12. 12. Treatment installation according to any one of claims 8 to 11, characterized in that the feeding device (3) comprises at least one feeding pipe (43) and / or at least one feeding hopper (109) and / or a buffer tank (103) and / or at least one metering device (104, 105) and / or at least one feeding screw machine (106).

13. Each of said at least one processing screw machine (4, 4') has a length L Ａ and outer diameter D Ａ and at least two processing element shafts (47, 48) having a Ａ / D Ａ ≦60, particularly 28≦L Ａ / D Ａ ≦52, especially 36≦L Ａ / D Ａ 13. Treatment installation according to any one of claims 8 to 12, characterized in that ≦40.

14. Each of said at least one processing screw machine (4, 4') has an outer diameter D Ａ and inner diameter d Ａ and at least two processing element shafts (47, 48) having a Ａ / d Ａ ≦1.8, especially 1.4≦D Ａ / d Ａ ≦1.66, especially 1.5≦D Ａ / d Ａ 14. Treatment installation according to any one of claims 8 to 13, characterized in that ≦1.

6.

15. 15. The treatment facility according to claim 8, wherein each of the at least one treatment screw machines (4, 4') comprises a first supply port (73) for supplying the dehydrated rubber (7) and a second supply port (81) for supplying the styrene-acrylonitrile (78, 121), and the first supply port (73) is arranged upstream of the second supply port (81) in the conveying direction (63).

16. 16. The treatment installation according to claim 15, characterized in that each of the at least one treatment screw machine (4, 4') comprises at least one retention zone (68) arranged between the first feed opening (73) and the second feed opening (81) to form a seal (79).

17. 17. Treatment installation according to claim 15 or 16, characterized in that each of the at least one treatment screw machine (4, 4') comprises at least one first degassing zone (67) arranged between the first feed opening (73) and the second feed opening (81).

18. 18. Treatment installation according to any one of claims 15 to 17, characterized in that each of the at least one treatment screw machine (4, 4') comprises at least one second degassing zone (71) arranged downstream of the second feed opening (81) in the conveying direction (63).

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