Spinneret arrangement

Abstract

The application relates to a spinneret arrangement for the defect-free mounting of a spinneret unit, and to the use of the spinneret arrangement in the production of hollow fibre membranes.

Description

Fresenius Medical Care Germany GmbH SPINNING NOZZLE ARRANGEMENT

[0001] The present invention relates to a spinneret arrangement for the production of hollow fiber membranes. In particular, the invention relates to a spinneret arrangement for the extrusion of a spun yarn in a manufacturing process for hollow fiber membranes. Furthermore, the invention relates to the use of a spinneret arrangement for the production of a hollow fiber membrane.

[0002] Spindle nozzles for the production of hollow fiber membranes are used particularly in the manufacture of hollow fiber membranes for use in extracorporeal blood treatment procedures and water purification. The production of such hollow fiber membranes typically involves the preparation of one or more spinning compounds, consisting of a polymer solution. These compounds are extruded into a filament, which is then precipitated into a hollow fiber membrane by targeted contact with a non-solvent. The extrusion of the spinning compound into a filament occurs via a spinnel nozzle, through which the polymer spinning compound is co-extruded together with a coagulation fluid. The spinning compound is extruded into a hollow filament, the cavity of which contains the coagulation fluid. The extruded filament is then drawn downwards in the direction of gravity, guided through a precipitation gap, and introduced into a precipitation bath.By introducing the spun yarn into the precipitation bath, the yarn precipitates, thus fixing the pore structure of the spun yarn formed by coagulation after extrusion. The resulting hollow fiber membrane is rinsed, dried, and possibly modified in further processing steps before finally being prepared for the construction of filter modules.

[0003] Spindle nozzles made of metal, such as steel or titanium, are predominantly used for extruding one or more spinning masses and the coagulation fluid. In state-of-the-art processes, a large number of such spindle nozzles are arranged in a spinning block, allowing a swarm of filaments to be extruded simultaneously and precipitated into hollow fiber membranes. Depending on the manufacturer, individual spindle nozzle holders are used to accommodate these nozzles within a spinning block. The integration of metal spindle nozzles into spindle nozzle holders and corresponding spinning blocks is a process employed by Fresenius Medical Care Germany. GmbH This is generally unproblematic, as spinnerets and spinneret holders made of metal are robust against mechanical stresses. Furthermore, when using metal for the spinneret, spinneret holder, and spinneret block, no significant thermally induced material stresses occur, even when the extrusion of the spinning mass is carried out at higher temperatures. Generally, the temperature of the spinneret and spinneret block can vary between 0 and 150°C, depending on the desired type of hollow fiber membrane.

[0004] In addition to metal spinnerets used in large-scale production, spinnerets made of semiconductor materials are also used for the production of hollow fiber membranes. The design of such spinnerets is described, for example, in EP 2 112256 A1 and WO 2018 / 206675 A1. These types of spinnerets can be manufactured with superior precision. Furthermore, such spinnerets can be fabricated using microstructuring techniques, thus enabling the creation of structures that cannot be achieved with metal spinnerets. Therefore, the use of semiconductor material spinnerets is preferred in certain manufacturing processes for hollow fiber membranes.

[0005] The semiconductor material used in these spinnerets has the disadvantage of being brittle, and when installed in standard spinneret holders and spinning blocks, it can be damaged even during the spinning process. The pressure of the spinning mass and coagulation fluids used in the spinning process alone can compress the semiconductor spinneret in a standard spinneret holder to such an extent that material damage occurs. As a result, material particles can enter the spinneret's fluid channels, rendering it unusable. Furthermore, spinnerets made of semiconductor material differ significantly in their external dimensions from the metal spinnerets used in hollow fiber membrane production. Manufacturing semiconductor spinnerets with the same dimensions as metal spinnerets is not technologically or economically viable.Therefore, using the semiconductor spinneret in membrane production would require the conversion / purchase of all spinnerets. Fresenius Medical Care Germany. GmbH TASK

[0006] In light of the aforementioned disadvantages, the task is therefore to provide a suitable spinneret holder that does not damage the spinneret, for example, during assembly of the spinneret holder and spinneret, nor does it cause damage during the ongoing spinning process. Furthermore, for economic reasons, it is also necessary to provide such a spinneret holder and spinneret assembly in a form that can be installed in already used spinning blocks. SUMMARY

[0007] The problem is solved by a spinning arrangement or the use of a spinning arrangement having the features of claims 1 and 12. Claims 2 to 11 represent preferred embodiments. BRIEF DESCRIPTION OF THE FIGURES

[0008] They show, in schematic representation: Fig. 1 shows a cross-section through a spinneret assembly, Fig. 2 shows a view of the upper adapter part, with the lower side of the adapter part facing upwards. Fig. 3 shows a view of the lower adapter part, DETAILED DESCRIPTION

[0009] The invention is described in the attached claims. The invention is explained below with reference to Figures 1 to 3. However, the invention is not limited to Fresenius Medical Center Germany. GmbH The specific embodiments are limited to those shown in Figures 1 to 3. In a first aspect, the invention relates to a spinneret arrangement 100 for the production of hollow fiber membranes, comprising a spinneret holder 200, a spinneret receiving area 250 for receiving a spinneret unit 500, a spinneret unit 500 for spinning one or more spinning masses with a coagulation fluid, a spinneret 501 for extruding a hollow spinning thread, wherein the spinneret unit 500 is mounted in the spinneret receiving area 250, and one or more elastomeric sealing elements (600) for fluid-tight mounting of the spinneret unit 500 in the spinneret receiving area 250.

[0010] An embodiment of the first aspect of the invention is shown in Fig. 1. Fig. 1 shows a cross-sectional view of a spinneret assembly 100 consisting of a spinneret holder 200, sealing elements 600, and a spinneret unit 500. The spinneret unit 500 is located in a spinneret receiving area 250 inside the spinneret holder 200. As shown in Fig. 1, the spinneret holder 200 can be circular, i.e., rotationally symmetrical about a central longitudinal axis A. The spinneret holder 200 is designed such that it enables the spinning of one or more spinning masses via the spinneret 501 of the spinneret unit 500 with a coagulation fluid. In particular, one or more spinning masses are extruded with the coagulation fluid to form a spinning thread, which is discharged from the spinneret assembly 100 and fed to further process steps of hollow fiber membrane production.The spinneret unit 500, comprising the spinneret 501, is designed as a separate unit that is inserted into the spinneret receiving area 250. Elastomeric sealing elements 600 seal the spinning mass and the coagulation fluid from the spinneret unit 500. The sealing elements 600 seal the spinneret unit from the spinneret holder 200 and support the spinneret unit 500 in the spinneret receiving area. The spinneret unit is fixed in the spinneret receiving area 250 by the elastomeric sealing elements 600, so that the spinneret unit 500 is held stably in the spinneret receiving area against the pressures of the inflowing one or more spinning masses and the coagulation fluid. This is achieved by pressing the sealing elements 600 together. GmbH Spindle nozzle receiving area 250, wherein the sealing elements 600 are in contact with the spinneret holder 200 and the spinneret unit 250.

[0011] The described spinneret arrangement has the advantage that manufacturing inaccuracies in the spinneret holder are compensated for by the elastomeric sealing elements in the spinneret assembly's mounting. The spinneret assembly is therefore protected by the elastomeric sealing elements within the spinneret holder and is less likely to be damaged. In particular, the spinneret assembly can be mounted via the elastomeric sealing elements in such a way that the spinneret assembly and the spinneret holder are in contact without contact. Furthermore, any potential differences in thermal expansion between the spinneret assembly and the spinneret holder can be compensated for by the elastomeric sealing elements.Furthermore, the storage of the spinneret in the spinneret holder can be designed in such a way that the spinneret holder can be manufactured with the usual external dimensions and thus be inserted into existing spinning blocks.

[0012] According to the present application, a "spinner assembly" is understood to be a technically functional unit that can be used in the production of hollow fiber membranes. One or more spinning masses and a coagulation fluid are fed to a spinneret via the spinneret assembly and extruded through the spinneret to form a filament. The individual components of the spinneret assembly according to the invention are named in claim 1.

[0013] According to the present application, a “spinner holder” is understood to be a device that can accommodate a spinneret unit as a separate unit, so that the spinning masses supplied to the spinneret, as part of the spinneret unit, and the coagulation fluid can be extruded through the spinneret.

[0014] According to the present application, a "spinner mounting area" is understood to be a cavity in the spinneret holder which is configured by its shape to accommodate a spinneret unit.

[0015] According to the present application, a "spinning nozzle unit" is understood to be a technical construction unit comprising a spinning nozzle and several feed channels for supplying one or more spinning masses and the coagulation fluid to the spinning nozzle. Fresenius Medical Care Germany GmbH The spinneret unit preferably has a rectangular, and in particular a square, plate, which may consist of one or more layers containing structures that form the feed channels. Furthermore, the spinneret unit is preferably manufactured using a microstructuring technique. In its rectangular plate form, the spinneret unit preferably has a thickness of 0.2 mm to 4 mm and an edge length of 0.5 mm to 25 mm.

[0016] For the purposes of this application, a "spinner" is understood to be a structural unit comprising a central coagulation fluid bore 502 for conveying a coagulation fluid and one or more annular gaps arranged concentrically to the central coagulation fluid bore 502, as well as a structure of fluid channels through which the one or more spinning materials are supplied to the one or more annular gaps, so that the one or more spinning materials can be extruded with the coagulation fluid to form a filament. The spinneret is part of the spinneret assembly. The aforementioned fluid channels and the one or more annular gaps are in fluid communication with the supply channels of the spinneret assembly. The height of the spinneret can be from 0.2 to 4 mm.

[0017] For the purposes of this application, "fluid-tight" means a seal between the spinneret unit and another component of the spinneret assembly that is sufficiently tight to prevent the extrusion of the one or more spinning materials and the coagulation fluid under the pressure conditions of the extrusion of these materials. Pressures of 20, 30, or 40 bar can occur during regular operation; therefore, a leak test is performed at test pressures up to 80 bar.

[0018] The "spinning masses" mentioned are, in the context of the claimed spinneret arrangement, polymer solutions. In preferred manufacturing processes for hollow fiber membranes in which the claimed spinneret arrangement is used, the spinning mass is a polymer solution comprising polysulfone, polyvinylpyrrolidone, and an aprotic polar solvent, e.g., dimethyl sulfoxide, dimethylacetamide, or N-methylpyrrolidone. However, the use of the spinneret arrangement according to the present application is not limited to the spinning mass components mentioned here as examples. Fresenius Medical Gare Germany GmbH

[0019] One embodiment of the first aspect of the invention is characterized in that the spinneret holder has, or in particular consists of, an upper adapter part 300 and a lower adapter part 400, wherein the upper and lower adapter parts 300, 400 are positively joined and form the spinneret receiving area (250). Due to the two-part design of the spinneret holder consisting of two adapter parts, the spinneret unit and the sealing elements can be inserted between the two adapter parts. By assembling the adapter parts with the inserted spinneret unit and sealing elements, the spinneret unit is mounted in the receiving area. The adapter parts are assembled in such a way that the sealing elements press the spinneret unit into the spinneret receiving area and thus secure it. The adapter parts can be fixed against each other in the assembled position by welding or bonding.In one embodiment according to Fig. 1, the spinneret holder consists of the upper and the lower adapter part.

[0020] The terms "upper" and "lower" define a spatial arrangement of the adapter parts, which, in the manufacturing process of hollow fiber membranes, correspond to the extrusion direction of the filament extruded through the spinneret. In the production of hollow fiber membranes, the extruded filament is drawn off from "top" in the direction of gravity towards "bottom" and introduced into a precipitation bath.

[0021] Fig. 2 shows a view of an upper adapter part 300, looking down at the underside of the adapter part. The upper adapter part is rotationally symmetrical about a central axis A. The upper adapter part 300 has a cylindrical recess 305. Fig. 3 shows a view of a lower adapter part, looking down at the top of the adapter part. In this view, the lower adapter part 400 has a substantially cylindrical shape. The outer diameter of the lower adapter part is dimensioned such that the lower adapter part 400 can be positively inserted into the cylindrical recess 305 of the upper adapter part. A view of the assembled adapter parts is shown in Fig. 1.

[0022] Due to the two-part design of the spinneret holder according to an upper and a lower adapter part.

[0023] One embodiment of the first aspect is characterized in that a central coagulation fluid port 301 is located on the upper adapter part 300 for inlet and Fresenius Medical Gare Germany GmbH The device is designed to allow the passage of a coagulation fluid into the spinneret receiving area 250 and a central spinning orifice 401 on the lower adapter part 400 for the outlet and passage of a filament extruded through the spinneret 501. The central coagulation fluid port 301 on the upper adapter part 300 can be formed into a projecting nozzle 304, which has a channel 304A leading from the central coagulation fluid port 301 into the spinneret receiving area 250. One or more sealing elements 600 seal between the upper adapter part 400 and the spinneret unit 500. The coagulation fluid flowing into the receiving area is thus guided through the central coagulation fluid bore 502 of the spinneret 501. In the spinneret, the coagulation fluid and the one or more spinning materials are combined and extruded as filament.The spinneret unit 500 is additionally sealed against the lower adapter part 400 by one or more sealing elements 600.

[0024] Another embodiment of the first aspect is characterized in that one or more lateral spinning mass openings 302A, 302B and one or more spinning mass channels 303A, 303B are arranged on the upper and / or lower adapter part 300, 400 for the inlet and feeding of one or more spinning masses into the spinneret receiving area 250. The one or more spinning masses are introduced into the spinneret receiving area and fed to the spinneret unit via the lateral spinning mass openings 302A, 302B and spinning mass channels 303A, 303B. The spinning mass entering the spinneret unit is sealed against the coagulation fluid entering through the coagulation fluid port 301 by means of one or more elastomeric sealing elements 600 between the spinneret unit 500 and the upper adapter part 300, and between the spinneret unit 500 and the lower adapter part 400. Additionally, the entering spinning mass is also sealed against the extruded yarn.The one or more spinning masses are thus fed to the one or more feed channels 504A, 504B of the spinneret unit.

[0025] In order to interact in the arrangement of the upper and lower adapter parts 300, 400 and one or more sealing elements 600 described above, the spinneret unit 500 has a central coagulation fluid bore 502 for passing a coagulation fluid through the spinneret 501. Furthermore, Fresenius Medical Care Germany GmbH Spindle nozzle assembly 100 has one or more inlet openings 503A, 503B and feed channels 504A, 504B, which are arranged on the spinneret unit 500 to convey one or more spinning masses to the spinneret 501.

[0026] Another embodiment of the first aspect is characterized in that the spinneret unit is mounted by the one or more elastomeric sealing elements 600, 601, 602 in such a way that the one or more spinning masses and the coagulation fluid are fluid-tightly separated from each other in the spinneret receiving area (250).

[0027] Another embodiment of the first aspect is characterized in that the one or more sealing elements 600 comprise at least one first sealing ring 601 and at least one second sealing ring 602, and the spinneret unit 500 is sealed against the upper adapter part 300 by the at least one first sealing ring 601, and / or the spinneret unit 500 is sealed against the lower adapter part 400 by the at least one second sealing ring 602. Preferably, the underside of the upper adapter part 300, as shown in Fig. 2, has a central circular groove 307, which is rotationally symmetrical to the coagulation fluid port 301 and the nozzle 304. The at least one first sealing ring 601 is recessed in the groove 307 and is held in position by the groove 307. More preferably, the lower adapter part has on its upper side, as shown in Fig.3, a circular recess 402 concentric to the central spinning opening 401 in which the at least one second sealing ring 602 is embedded and held in its position. As shown in Fig. 3, in this embodiment the at least one first sealing ring 601 and the at least one second sealing ring 602 fix the spinneret unit 500 in the spinneret receiving area 250 in the assembled state of the upper and lower adapter parts 300, 400. Preferably, the spinneret unit is supported in the spinneret receiving area 250 by the at least first and second sealing rings 601, 602 such that the spinneret unit does not contact any parts of the upper and lower adapter parts 300, 400.

[0028] Another embodiment of the first aspect is characterized in that the spinneret unit (500) and / or the spinneret (501) comprise or consist of a semiconductor material, in particular silicon, gallium arsenide or germanium. Fresenius Medical Care Germany GmbH Preferably, the spinneret unit (500) and spinneret (501) are designed as an integral component made of silicon.

[0029] Another embodiment of the first aspect is characterized in that the spinneret receiving area 250 is formed at least in part by a recess 306 in the upper adapter part, into which the spinneret unit 500 is inserted. Preferably, the recess 306 is substantially circular. To accommodate a spinneret unit formed as a rectangular or square plate, the circular recess 306 can have further structural features 308A, 308B, e.g., semicircular extensions of the circular recess, so that the spinneret unit is positioned correctly. In particular, the preferably rectangular or square spinneret unit can be positioned such that the inlet opening 503A, 503B of the spinneret unit is opposite the spinning mass inlets 309A, 309B.In other embodiments, however, the number of inlet openings and spinning mass inlets can be increased; for example, spinning mass inlets can also be present. According to this embodiment, the lateral spinning mass openings 302A, 302B, the one or more spinning mass channels 303A, 303B, and the one or more spinning mass inlets 309A, 309B are formed on the upper adapter part 300. It is also possible to arrange the spinning mass openings vertically, particularly when several different spinning masses are provided. In this embodiment, the central circular groove 307 forms a recess for receiving the spinneret unit 306. In one embodiment, the recess for receiving the spinneret unit 306 forms a recess in the cylindrical recess 305 for receiving the lower adapter part. This embodiment is shown in Fig. 2.The central circular groove therefore has a smaller diameter than the recess for receiving the spinneret unit 306, which in turn has a smaller diameter than the cylindrical recess 305 for receiving the lower adapter part.

[0030] In a second aspect, the invention relates to the use of the spinning arrangement according to an embodiment of the first aspect in the production of hollow fiber membranes. Fresenius Medical Gare Germany GmbH

[0031] Reference symbol list 100 spinning arrangement 200 spinneret holders 250 spinneret intake area 300 upper adapter part 301 Coagulation fluid sports 302A, 302B lateral spinning mass openings 303A, 303B Spinning mass channels 304 nozzles on the upper adapter part 305 cylindrical recess 306 Recess for receiving the spinneret unit 307 central circular groove 308A, 308B Structural forms 308A, 308B for receiving the spinneret unit 309A, 309B Spin mass inlets 400 lower adapter part 401 central spinning opening on the lower adapter part 402 circular depression 500 spinneret unit 501 Spin nozzle 502 Coagulation fluid borehole 503A, 503B Inlet openings 504A, 504B feed channels 600 elastomeric sealing elements 601 first sealing ring 602 second sealing ring

Claims

Fresenius Medical Gare Germany GmbH REQUIREMENTS 1. Spindle assembly (100) for the production of hollow fiber membranes, comprising a spinnel holder (200) comprising a spinneret receiving area (250) for receiving a spinneret unit (500), a spinneret unit (500) for spinning one or more spinning masses with a coagulation fluid comprising a spinneret (501) for extruding a hollow spinning thread, wherein the spinneret unit is mounted in the spinneret receiving area, one or more elastomeric sealing elements (600) for fluid-tight mounting of the spinneret unit in the spinneret receiving area.

2. Spindle nozzle arrangement (100) according to claim 1, characterized in that the spindle nozzle holder has an upper adapter part (300) and a lower adapter part (400), further characterized in that the upper and lower adapter parts (300, 400) are positively joined together and form the spindle nozzle receiving area (250).

3. Spindle nozzle arrangement (100) according to claim 2, characterized in that a central coagulation fluid port (301) is arranged on the upper adapter part (300) for the inlet and passage of a coagulation fluid into the spindle nozzle receiving area (250) and a central spinning opening (401) is arranged on the lower adapter part (400) for the outlet and passage of a filament extruded through the spinneret (501).

4. Spindle nozzle arrangement (100) according to claim 2 or 3, characterized in that one or more lateral spinning mass openings (302A, 302B), one or more spinning mass channels (303A, 303B) and one or more spinning mass inlets (309A, 309B) are provided on the upper and / or lower adapter part (300, 400) for the inlet and Fresenius Medical Gare Germany GmbH Feeding one or more spinning masses into the spinneret receiving area (250) are arranged.

5. Spindle nozzle assembly (100) according to one of claims 1 to 4, characterized in that the spinneret unit (500) has a central coagulation fluid bore (502) for passing a coagulation fluid through the spinneret (501).

6. Spindle nozzle assembly (100) according to one of claims 1 to 5, characterized in that one or more inlet openings (503A, 503B) and feed channels (504A, 504B) are arranged on the spinneret unit (500) to guide one or more spinning masses to the spinneret (501).

7. Spindle nozzle arrangement (100) according to one of claims 1 to 6, characterized in that the spinnel nozzle unit is mounted by the one or more elastomeric sealing elements (600) in such a way that the one or more spinning masses and the coagulation fluid are fluid-tightly separated from each other in the spinnel nozzle receiving area (250).

8. Spindle nozzle assembly (100) according to claim 7, characterized in that the one or more sealing elements (600) comprise at least one first sealing ring (601) and at least one second sealing ring (602) and the spindle nozzle unit (500) is sealed against the upper adapter part (300) by the at least one first sealing ring (601), and / or the spindle nozzle unit (500) is sealed against the lower adapter part (400) by the at least one second further sealing ring (602).

9. Spindle nozzle assembly (100) according to any one of claims 1 to 7, characterized in that the spinneret unit (500) and / or the spinneret (501) comprises or consists of a semiconductor material, in particular silicon. Fresenius Medical Care Germany GmbH 10. Spindle nozzle assembly (100) according to claim 8, characterized in that spinneret unit (500) and spinneret (501) form an integral component made of a semiconductor material, in particular silicon.

11. Spindle nozzle arrangement (100) according to one of claims 1 to 10, characterized in that the spindle nozzle receiving area (250) is formed at least in part by a recess in the upper adapter part into which the spinnel nozzle unit is inserted.

12. Use of a spinneret arrangement according to any one of claims 1 to 11 in the manufacture of hollow fiber membranes.

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