FILTER MEMBRANE COMPRISING TWO ADSORBENTS

Description

State of the art

[0001] The invention relates to a method for producing a filter device according to the preamble of claim 1, a filter device according to the preamble of claim 7 and a method with a filter device according to claim 2

[0002] A filter device is already known which is intended for stabilizing a liquid, in particular beverages, which comprises at least one filter unit, in particular a membrane filter unit, which has at least one filter element and at least one integrated stabilizing means.

[0003] WO 99 / 60090 A1 proposes adding a PVPP-containing slurry to a beer-containing tank to clarify the beer. The clarified beer is then transferred to a filter tank.

[0004] For beverage clarification, WO 2008 / 097154 A1 proposes equipping a separation matrix in the form of beads, a membrane, or a filter with PVPP. According to EP 2 022 555 A1, hollow-fiber membranes are manufactured with a hydrophobic and a hydrophilic polymer. One possible hydrophilic polymer is PVP, which acts as a pore-forming agent.

[0005] Further hollow-fiber membranes made of a polymer material are known from EP 1 627 941 A1. The polymer material may contain small amounts of PVP.

[0006] WO 2006 / 135966 A1 proposes using a polymer mixture comprising a hydrophobic, non-crosslinkable component and a crosslinkable component in the production of porous polymer membranes. PVP is mentioned as one of the crosslinkable components.

[0007] EP 0 806 474 A1 describes a process for beer stabilization in which, among other things, PVPP is used.

[0008] The object of the invention is in particular to provide a generic device with improved properties with regard to the stabilization of liquids. Advantages of the invention

[0009] The invention relates to a method for producing a filter device according to claim 1 and to a filter device obtainable by this method according to claim 10.

[0010] According to the latter aspect, the invention relates to a filter device which is intended for stabilizing a liquid, in particular beverages, with at least one, in particular at least several, filter units, in particular a membrane filter unit, which has at least one filter element and at least one integrated stabilizing means.

[0011] It is proposed that the filter unit have at least one additional integrated stabilizing agent. By using multiple stabilizing agents, more and, in particular, different substances dissolved in the liquid, which form turbidity, particularly during storage and / or transport, can be separated from the liquid. In particular, multiple stabilization principles can be utilized, resulting in more efficient and purer stabilization. Advantageously, when using a filter device with at least one stabilizing agent, there are up to 3% fewer turbidity-active substances in the liquid compared to a filter device without a stabilizing agent.Another advantage is that, compared to a filter device without a stabilizing agent, when using a filter device with at least one stabilizer and at least one further stabilizer, there are up to 6% fewer cloud-active substances in the liquid. Furthermore, the storage stability of the liquid can be improved. Compared to a filter device without a stabilizer, a storage stability up to five times longer can be achieved, with the first cloudiness only appearing after up to 6 months of storage. A combination of filtration and stabilization is particularly interesting for the brewing and beverage industry, as only one system needs to be invested in, which can reduce costs. Overall, the stabilization of the liquid can therefore be improved.

[0012] In this context, a "filter device" is understood to mean at least one part, in particular a subassembly of a filter, in particular a filter module, a filter device, and / or a filter system. The filter device is preferably intended for stabilizing beverages, such as drinking water, juices, spirits, in particular beer, wine, and / or whiskey. Furthermore, the filter device could alternatively or additionally be used for refining, wastewater treatment, and / or in medical technology, in particular for hemodialysis. In particular, the filter device can also comprise the entire filter, in particular the entire filter module, the entire filter device, and / or the entire filter system. Advantageously, the filter device can comprise further parts and subassemblies, in particular these, preferably in addition to forming the filter, the filter device, and / or the filter system.

[0013] The term "stabilization of a liquid" is to be understood in particular as meaning the separation of substances dissolved in a liquid, in particular organic and / or turbidity-active substances, such as tannins, phenols, proteins, peptides and / or other turbid substances, from the liquid by means of liquid chromatography, in particular by applying various mechanical, chemical and / or physical separation principles.

[0014] A "filter unit" is understood, in particular, to be a unit designed to receive a liquid with a substance dissolved therein and to separate the substance from the liquid at least partially, in particular at least to a large extent, and particularly preferably completely. The filter unit advantageously receives the separated substance and allows the liquid to pass through. The filter unit is designed, in particular, for microfiltration, preferably for ultrafiltration, and particularly preferably for nanofiltration. The filter unit has, in particular, at least one liquid channel for conducting the liquid. The filter element has, in particular, a partially permeable, in particular porous, structure, which preferably at least partially forms a membrane.The filter element preferably delimits the liquid channel in at least one direction, in particular in a circumferential direction of the liquid channel. Advantageously, the filter unit is designed as a hollow fiber, the casing of which is preferably formed by the filter element. Particularly preferably, the filter unit forms a cross-flow filtration unit, in which, in particular, the liquid channel runs longitudinally to the filter element, wherein, in particular in an operating state, a liquid flowing in the liquid channel penetrates the filter element transversely to the liquid channel.

[0015] The filter element is in particular food-safe, in particular components of the filter element, preferably precursors of the filter element and / or the components formed by these precursors, comply with the guideline of the Federal Environment Agency for the hygienic assessment of organic materials in contact with drinking water (KTW) and / or the guideline on contact with food of the US Food and Drug Administration (FDA).

[0016] The filter element has, in particular, pores with an average pore size of at least 0.004 µm, preferably of at least 0.01 µm, and particularly preferably 0.1 µm, and / or in particular of at most 10 µm, preferably of at most 5 µm, and particularly preferably of at most 2 µm. The filter element can, in particular, be designed asymmetrically, specifically having a pore gradient, preferably along a wall thickness. The filter element can preferably have a support structure designed to bear at least a dead weight of the filter element, and in particular a separation structure designed at least to filter and / or stabilize the liquid.

[0017] An "integrated stabilizing means" is to be understood in particular as a stabilizing means which is at least partially formed integrally with the filter unit and is in particular connected integrally with the filter element and / or at least partially forms the latter.

[0018] In this context, "at least partially integral" should be understood in particular to mean that at least one component of at least one object, in particular the object itself, is formed in one piece with at least one component of at least one further object, in particular the further object itself. "Integral" in this context should be understood in particular to mean at least materially connected, for example, by a welding process, an adhesive process, an injection molding process, and / or another process deemed appropriate by a person skilled in the art. Advantageously, "integral" should also be understood to mean one piece. "One-piece" should be understood in particular to mean formed in one piece.Preferably, this one piece is produced from a single blank, a mass and / or a casting, preferably in an injection molding process, in particular a single-component and / or multi-component injection molding process, and particularly preferably in a spinning process, in particular a wet spinning process, such as reactive spinning, in which the filter unit with integrated stabilizing agents is produced in particular in a phase inversion process.

[0019] The term "a stabilizing agent" is to be understood in particular as meaning a substance which is intended to advantageously selectively separate and in particular to absorb at least one substance dissolved in the liquid by at least one preferably chemical separation principle, preferably by ion exchange and / or by adsorption.

[0020] The stabilizing agent and the further stabilizing agent are in particular different from one another and differ from one another in particular at least partially by a separation principle and / or a substance, in particular a precursor, which forms the respective stabilizing agent.

[0021] In a further aspect of the invention, it is proposed that the filter device comprises at least a first precursor, which is intended to at least partially form the filter element, and the same first precursor is intended to at least partially form the stabilizing agent. This enables efficient integration of the stabilizing agent, since the material which, in particular, at least partially forms the filter element during production, is used to form the stabilizing agent. Furthermore, manufacturing costs and, in particular, material costs can be reduced. In particular, the stabilizing agent can be distributed particularly homogeneously in the filter element, in particular in a layer of the filter element and particularly preferably on a surface of the filter element, whereby a uniform or targeted effectiveness can be achieved."A precursor" is to be understood in particular as a starting material intended to form, in particular with itself and / or with another substance, preferably another precursor, an end product, such as a substance, an element, or a unit, preferably by polymerization, in particular cross-linking. Designations such as first, second, or third element, substance, precursor, and / or unit serve in particular merely for identification and / or differentiation and are preferably not intended to specify a sequence, especially during production. In particular, "the same precursor" is to be understood as a single, identical amount of the precursor added once, especially in a single process step.The term "a precursor at least partially forms the filter element" is to be understood in particular as meaning that the precursor, particularly during production of the filter unit, at least partially influences and / or at least partially forms a shape, a feel, a structure, in particular a porosity of the filter element and / or a membrane of the filter element. Preferably, the same first precursor is a pore former of the filter element. Furthermore, the same first precursor is particularly intended to at least partially form the filter element, wherein the same first precursor preferably polymerizes, in particular cross-links, with itself and / or with at least one further precursor, preferably at least partially forming it. "Cross-linked" is to be understood in particular as polymerized, and advantageously polymerized with at least one, preferably at least several, nodes and / or intersection points.Furthermore, the same first precursor is intended, in particular, to functionalize the filter element. In particular, a non-crosslinked precursor, in particular a residual non-crosslinked amount of the precursor, is oxidatively cleaved during a manufacturing process, in particular during a post-treatment, and rinsed with water.

[0022] The crosslinking can, in particular, occur at least partially via a heterocyclic part of the first precursor and / or an aliphatic chain part of the first precursor. In particular, the first precursor can at least partially form the separating structure, in particular through the crosslinking, wherein the support structure is preferably substantially free of the first precursor, in particular through a leaching process.

[0023] It is further proposed that the stabilizing agent be designed to absorb a substance, preferably at least one tanning agent and / or a phenol, which is dissolved in the liquid, and that the further stabilizing agent be designed to absorb another substance, preferably a protein and / or a peptide, which is dissolved in the liquid and which is different from the substance. This can further improve the stabilization of the liquid, since different substances can be specifically and selectively separated from the liquid using the various stabilizing agents.

[0024] It is conceivable that the filter device is intended for single use, wherein a stabilizing agent of the filter unit is not regenerable; however, this reduces the service life of the filter device. In order to extend the service life of the filter device, in particular through multiple use, and in particular to save material costs, it is preferably proposed that the filter unit comprise at least one, in particular at least several, preferably at least two, and particularly preferably exactly two, chemically regenerable stabilizing agents, in particular the aforementioned stabilizing agent and / or the aforementioned further stabilizing agent. "Chemically regenerable" is to be understood in particular to mean that the filter unit can be regenerated by a chemical reaction.In particular, the stabilizing agent, in particular the aforementioned stabilizing agent, is chemically regenerable using an acid and / or an alkali, preferably a sodium hydroxide solution. Furthermore, the stabilizing agent, in particular the aforementioned further stabilizing agent, is chemically regenerable using a salt solution, preferably a sodium chloride solution.

[0025] It is further proposed that the filter unit comprise at least one stabilizing agent, in particular the aforementioned stabilizing agent, which is an adsorbent. This allows a substance dissolved in a liquid to be separated from the liquid in a simple manner. In particular, the substance is deposited in the filter unit at the interface between the solid and liquid phases, where it can be removed particularly advantageously to regenerate the stabilizer. "An adsorbent" is to be understood in particular as a stabilizing agent that preferably uses van der Waals interactions as a separation principle and is particularly intended to adsorb a substance dissolved in the liquid.

[0026] It is also proposed that the filter unit comprise at least one stabilizing agent, in particular the aforementioned further stabilizing agent, which is an ion exchanger. This allows a substance dissolved in a liquid to be separated from the liquid in a particularly simple manner. "An ion exchanger" is understood to mean, in particular, a stabilizing agent that preferably uses Coulomb interactions as a separation principle and is particularly intended to exchange ions with a substance dissolved in the liquid, in particular the substance itself. The ion exchanger can advantageously be designed as a cation exchanger and / or anion exchanger.

[0027] It is further proposed that the same first precursor be used to hydrophilically functionalize the filter element. This can improve the penetration of the filter element by the liquid transverse to the flow direction. Optimal mass transfer during filtration can be ensured. In particular, retentate circulation can be improved.

[0028] According to the invention, the first precursor comprises at least polyvinylpyrrolidone (PVP). Furthermore, the first precursor can comprise, in particular, pore-forming agents, preferably hydrophilic pore-forming agents, such as polyvinyl acetate, polyvinylpyrrolidone, polyethylene glycol, copolymers of vinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, polyethylene glycol esters, and / or benzophenone acrylate. This can further improve environmental and / or health compatibility.

[0029] It is further proposed that the filter device optionally comprise a second precursor, which is intended to at least partially form a stabilizing agent, in particular the stabilizing agent already mentioned. This allows various properties of the stabilizing agent to be adjusted, in particular depending on a concentration ratio of the first precursor and the second precursor. In particular, the second precursor is different from the first precursor. Preferably, a ratio, in particular a weight and / or volume ratio, of the first precursor and the second precursor is between 80% to 20% and 55% to 45%, preferably between 70% to 30% and 60% to 40%. Particularly preferably, the ratio is 65% to 35%.

[0030] Furthermore, it is proposed that the second precursor comprise at least vinyl acetate (VA). This advantageously allows a strength, a charge, and in particular an adsorption behavior of the stabilizing agent to be adjusted particularly advantageously. Preferably, the second precursor at least partially forms the filter element. In particular, the second precursor is cross-linked with the first precursor in an operating state of the filter device. In particular, a mixing ratio of both precursors, preferably of the first and second precursors, can be adjusted to adjust the desired properties of the stabilizing agent.

[0031] The filter device according to the invention has a third precursor which comprises polysulfone (PS), polyethersulfone (PES) and / or polyvinylidene fluoride (PVDF) and which is intended to at least partially form the filter unit.

[0032] Furthermore, the third precursor can comprise polyetherimide, polyimide, polyamide, polyamideimide, polyether, polyetherketone and / or polyetheretherketone. In particular, the second precursor and / or the third precursor can be intended to at least partially, in particular at least to a large extent, form the support structure of the filter element. In particular, the second precursor and / or the third precursor is intended to be hydrophilically crosslinked with the first precursor, in particular by covalent and / or ionic crosslinking, in particular crosslinking, with the first precursor. In particular, during production of the filter device, the first precursor, the second precursor and / or the third precursor can be a component of a lumen fluid and / or a polymer solution.

[0033] This can further improve health compatibility.

[0034] In a preferred embodiment of the invention, it is proposed that the filter unit comprise at least one stabilizing agent, in particular the aforementioned stabilizing agent, which is at least partially formed from at least one cross-linked precursor, in particular the same first precursor. This allows the stabilizing agent to be formed particularly cost-effectively. In particular, an oxidation-resistant and alkali-insoluble stabilizing agent can be formed. In particular, the first precursor, cross-linked with the second precursor, forms the stabilizing agent at least partially, preferably completely.

[0035] In particular, to support cross-linking, the filter device can comprise further precursors, such as, in particular, hydrophobic pore formers, preferably block copolymers with a hydrophobic portion and a hydrophilic portion, copolymers of vinylpyrrolidone with vinyl acetate (PVP / VA), polyethylene glycol-co-propylene glycol, particularly known under the brand name (Poloxamer 477), and copolymers with acrylate and acrylamide groups. Furthermore, further precursors, in particular cross-linkable hydrophilic polymers or oligomers, especially those that can be cross-linked without light irradiation, such as benzophenone methacrylate or polyvinyl alcohol (PVA), are conceivable.

[0036] In a particularly preferred embodiment of the invention, it is proposed that the filter unit comprise at least one, in particular at least several, preferably at least two, and particularly preferably exactly two, stabilizing agents designed as adsorbents, in particular the aforementioned stabilizing agent and / or the aforementioned further stabilizing agent, which comprises at least one cross-linked polyvinylpyrrolidone (PVPP), a xerogel, a silica gel, a zeolite, a bentonite, and / or a mixture of these types. This can further improve stabilization.

[0037] The filter unit can, in particular, comprise a stabilizing agent configured as an ion exchanger, in particular the additional stabilizing agent already mentioned, which comprises at least one functionalized hydrophilic polymer, a functionalized silica gel, a functionalized cellulose, or a functionalized dextran. The function of the stabilizing agent as an anion and / or cation exchanger depends in particular on the functionalization. In particular, ammonium groups, especially quaternary ammonium groups, diethylaminoethyl (DEAE), trimethylhydroxypropyl (QA), quaternary aminoethyl (QAE), quaternary aminomethyl (Q), triethylaminomethyl (TEAE), triethylaminopropyl (TEAP), and polyethyleneimine (PEI) can be used to functionalize the stabilizing agent as an anion exchanger.In particular, to functionalize the stabilizing agent as a cation exchanger, carboxyl groups, sulfate groups, in particular sulfonate (S), sulfoethyl (SE), sulfopropyl (SP), phosphate groups, in particular orthophosphate (P), methacrylate, and / or carboxymethyl (CM) can be used. To further improve environmental and / or health compatibility, it is proposed that the filter unit comprise a stabilizing agent configured as an ion exchanger, which comprises at least one functionalized agarose. In particular, the agarose is configured as a cross-linked agarose, specifically as Sepharose, preferably Sepharose beads, also known as Sepharose beads. Particularly preferably, the agarose is functionalized by means of an ammonium group, preferably a quaternary ammonium group, and particularly preferably diethylaminoethyl (DEAE). The further stabilizing agent is preferably configured as an anion exchanger.

[0038] Furthermore, the invention is based on a method for producing a filter device which is intended for stabilizing a liquid, in particular beverages, and having a filter unit, wherein at least partially a filter element of the filter unit is formed from at least a first precursor.

[0039] It is proposed that an integrated stabilizing agent of the filter unit be formed at least partially from the same first precursor. This can improve the stabilization of liquids. Furthermore, efficient integration of the stabilizing agent can be achieved and manufacturing costs, and in particular material costs, can be reduced. In particular, the first precursor is dissolved in a solvent in one process step, preferably a quantity of the precursor, preferably together with other substances, other precursors, which are provided in particular for forming the filter unit.

[0040] The solvent may in particular comprise N-methylpyrrolidone (NMP), dimethyl sulfoxide, chloroform, methylene chloride, dimethylformamide and / or dimethylacetamide.

[0041] It is further proposed that the filter unit be formed at least partially by a further stabilizing agent and / or at least a fourth precursor, in particular of the further stabilizing agent. This allows a filter unit with multiple stabilizing agents to be formed in a simple manner.

[0042] In particular, the filter unit is formed by phase inversion using the first precursor and in particular by means of the further substance, in particular a further precursor. Furthermore, an activator is proposed, by which the formation of at least one stabilizing agent is initiated at least by the same first precursor. This allows a targeted formation of the stabilizing agent. "An activator" is to be understood in particular as a substance which is intended to react with at least one substance, in particular the same first precursor, in a cross-linking manner, preferably by irradiation with light, in particular UV light. The activator can in particular be a radical initiator, such as peroxide, tert-butyl peroxypivalate and / or H 2 O 2 / CuCl 2.Furthermore, the activator can in particular be a photoactivator, such as 4,4'-diazidostilbene-2,2'-disodium sulfonate.

[0043] Furthermore, the photoactivator can be 2,4-diethyl-9H-thioxanthen-9-one and / or phenylbis(2,3,6-trimethylbenzoyl)phosphine oxide.

[0044] In particular, during production of the filter device, the irradiation with light can take place within and / or immediately after a spinneret, for example by means of a light guide arranged in the spinneret. Advantageously, targeted irradiation of an inner surface of the filter element, in particular the separating structure, can take place. Furthermore, during production of the filter element, at least one production parameter, in particular several production parameters, such as a temperature, a pH value, a concentration of the activator, in particular of the radical initiator and / or the photoactivator, as well as an intensity and / or wavelength of a light irradiation can be varied and controlled in particular by means of a control and / or regulating unit.In particular, a temperature during production may be at least 20°C, preferably at least 50°C and particularly preferably at least 70°C and / or at most 130°C, preferably at most 100°C and particularly preferably at most 90°C.

[0045] In particular, to protect the filter element from radicals and / or light radiation, it can be provided with a reflection and / or absorption layer, for example, using light-absorbing substances such as soot and / or radical scavengers, such as dialkyldithiocarbamates. Alternatively or in addition to light irradiation, irradiation with ionizing radiation is also conceivable.

[0046] It is further proposed that the stabilizing agent is formed by reactive spinning, wherein the same first precursor is radically polymerized.

[0047] Furthermore, the invention is based on a method with a filter device intended for stabilizing a liquid, in particular beverages, having a filter unit. The filter unit stabilizes a liquid in one method step using at least one integrated stabilizing agent of the filter unit, and the integrated stabilizing agent is regenerated in a further method step. This allows continuous operation with regenerable stabilizing agent to be achieved. Drawings

[0048] Further advantages will become apparent from the following description of the drawings. The drawings illustrate an exemplary embodiment of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

[0049] They show: Fig. 1 shows a filter module with a filter device with several filter units in an exploded view, Fig. 2 shows one of the filter units in a sectional view, Fig. 3 shows a schematic process sequence for producing the filter unit, Fig. 4 shows a device for producing the filter device, Fig. 5 shows a device for producing the filter device with a spinneret and Fig. 6 shows a schematic process sequence for regenerating stabilizers. Description of the embodiment

[0050] Figure 1shows a filter module 24 with a filter device. The filter device is intended for stabilizing a liquid. In the present case, the filter device is intended for stabilizing beverages, such as drinking water, juices, spirits, in particular beer, wine, and / or whiskey. However, the filter device can also be used for stabilizing other liquids. The filter device stabilizes the liquids by separating, in at least one operating state, organic substances dissolved in the liquid, such as tannins, phenols, proteins, peptides, and / or other turbid substances, from the liquid.

[0051] The filter device has a housing 26. The housing 26 has a housing base 28. The housing 26 also has two end caps 30, 32. The end caps 30, 32 seal the housing base 28 in a liquid-tight manner. A first end cap 30 has a liquid inlet. A second end cap 32 has a liquid outlet. The housing base 28 forms a cylindrical shell. The housing base 28 defines a cavity 34. The end caps each have two connections. One connection each serves to connect to a liquid circuit for the liquid to be stabilized. Another connection each serves to discharge the stabilized liquid.

[0052] The filter device has at least one filter unit 10 (cf. Figure 2). In the present case, the filter device has a plurality of filter units 10. The filter units 10 are arranged in the cavity 34. For better clarity, they are arranged parallel to one another and bundled. The filter units 10 are provided with a seal in end regions which, in an assembled state, are at least partially arranged in the end cap. In an assembled state, the seal seals an intermediate space between the end cap and the filter units. This prevents mixing of a liquid to be stabilized with an already stabilized liquid. The seal is formed from a resin, in particular a potting resin. The filter units 10 are designed to be at least substantially equivalent to one another, in particular apart from manufacturing and / or assembly tolerances. Therefore, only one filter unit 10 will be described in more detail below.In the present case, the filter unit 10 is designed as a membrane filter unit. The filter unit 10 has a fluid channel 36 for conducting the fluid.

[0053] The filter unit 10 has a filter element 12. The filter element 12 forms a membrane. The filter element 12 has a porous structure that is partially permeable to the liquid. The porous structure at least partially forms the membrane. The filter element 12 delimits the liquid channel 36 in at least one direction. The filter element 12 delimits the liquid channel 36 in a circumferential direction of the liquid channel 36.

[0054] The filter unit 10 is formed as a hollow fiber. The filter unit 10 has a casing. The casing is formed by the filter element 12. The filter unit 10 is designed as a cross-flow filtration unit. The liquid channel 36 runs longitudinally to the filter element 12. A liquid flowing in the liquid channel 36 during operation penetrates the filter element 12 transversely to the liquid channel 36. The filter unit is formed at least partially from polysulfone, polyethersulfone, or polyvinylidene fluoride.

[0055] In particular, the filter unit 10 can be designed as a capillary membrane. The filter unit can, in particular, have an outer diameter of at most 10 mm, preferably at most 5 mm, and particularly preferably at most 3 mm, and / or at least 0.1 mm, preferably at least 0.3 mm, and particularly preferably at least 0.5 mm. Alternatively, the filter unit 10 can be designed as a flat membrane.

[0056] The filter device has a first precursor 18. The first precursor 18 comprises at least polyvinylpyrrolidone. In the present case, the first precursor 18 is polyvinylpyrrolidone. The first precursor 18 is intended to at least partially form the filter element 12. The same first precursor 18 is a pore former of the filter element 12. Furthermore, the same first precursor 18 is intended to functionalize the filter element 12. The same first precursor 18 is intended to make the filter element 12 hydrophilic. Furthermore, the same first precursor 18 is intended to at least partially form the stabilizing agent 14.

[0057] Furthermore, the filter device comprises at least one second precursor 20. The second precursor 20 at least partially forms the filter element 12. The second precursor 20 is intended to at least partially form the stabilizing agent 14. The second precursor 20 comprises at least vinyl acetate. In the present case, the further precursor 20 is vinyl acetate.

[0058] The first precursor 18 is intended to polymerize and, in particular, to crosslink with itself and / or with at least the second precursor 20. A ratio, in particular a weight and / or volume ratio, of the first precursor 18 and the second precursor 20 is 65% to 35%.

[0059] The filter device further comprises at least a third precursor 21. The third precursor 21 comprises polysulfone (PS), polyethersulfone (PES), and / or polyvinylidene fluoride (PVDF). In the present case, the third precursor is polyethersulfone. The third precursor 21 is intended to at least partially form the filter unit 12.

[0060] Furthermore, the filter unit 10 has at least one integrated stabilizing means 14. The stabilizing means 14 is at least partially formed integrally with the filter unit 10. The stabilizing means 14 is formed integrally with the filter element 12.

[0061] The stabilizing agent 14 is intended to selectively separate, and in particular to absorb, at least one substance dissolved in the liquid. The substance separated from the liquid by the stabilizing agent 14 is a tanning agent and / or a phenol.

[0062] The stabilizing agent 14 is chemically regenerable. The stabilizing agent 14 is chemically regenerable using an alkali. The alkali is a sodium hydroxide solution. However, it is also conceivable that the stabilizing agent 14 is chemically regenerable using another alkali, in particular an acid.

[0063] The stabilizing agent 14 is an adsorbent. The stabilizing agent 14 comprises a cross-linked polyvinylpyrrolidone. Alternatively or additionally, however, the filter unit 10 could also comprise a stabilizing agent 14 which is an adsorbent comprising a xerogel, a silica gel, a zeolite, a bentonite, and / or a mixture of these types.

[0064] Furthermore, the filter unit 10 has at least one further integrated stabilizing agent 16. The stabilizing agent 14 and the further stabilizing agent 16 are designed differently from one another. The further stabilizing agent 16 is intended to selectively separate, and in particular to absorb, at least one substance dissolved in the liquid. The substance separated from the liquid by the further stabilizing agent 16 is a protein and / or a peptide.

[0065] The additional stabilizing agent 16 is chemically regenerable. The additional stabilizing agent 16 is chemically regenerable using a salt solution, preferably a sodium chloride solution.

[0066] The stabilizing agent 14 and the additional stabilizing agent 16 differ from each other in their separation principle. The additional stabilizing agent 16 is an ion exchanger. The additional stabilizing agent 16 is designed as an anion exchanger. However, it is also conceivable that the additional stabilizing agent 16 could be designed as a cation exchanger.

[0067] The stabilizing agent 14 and the further stabilizing agent 16 differ from one another by a substance, in particular a fourth precursor 22, from which the stabilizing agents 14, 16 are formed. The further stabilizing agent 16 comprises a functionalized agarose. The agarose is formed as a cross-linked agarose. The agarose further forms Sepharose beads. Additionally or alternatively, the further stabilizing agent 16 could comprise a functionalized hydrophilic polymer, a functionalized silica gel, a functionalized cellulose, and a functionalized dextran. In the present case, the agarose is functionalized by means of an ammonium group, preferably a quaternary ammonium group, and particularly preferably diethylaminoethyl (DEAE). The further stabilizing agent 16 is formed as an anion exchanger.In particular, the further stabilizing agent 16 can preferably also be designed as a cation exchanger, depending on a functionalization. To functionalize the further stabilizing agent 16 as an anion exchanger, in particular ammonium groups, in particular quaternary ammonium groups, diethylaminoethyl (DEAE), trimethylhydroxypropyl (QA), quaternary aminoethyl (QAE), quaternary aminomethyl (Q), triethylaminomethyl (TEAE), triethylaminopropyl (TEAP), and polyethyleneimine (PEI) can be used. In particular, to functionalize the further stabilizing agent 16 as a cation exchanger, carboxyl groups, sulfate groups, in particular sulfonate (S), sulfoethyl (SE), sulfopropyl (SP), phosphate groups, in particular orthophosphate (P), methacrylate, and / or carboxymethyl (CM) can be used.

[0068] In Figure 3 A method for manufacturing the filter device is shown schematically. Figures 4 and 5an associated device for producing the filter device is shown schematically. In a method step 38, a polymer solution 46, in particular a polymer suspension, is produced. At least one precursor is dissolved in a suitable solvent, in particular a solvent mixture. In the present case, the first precursor 18 is dissolved in the solvent. Furthermore, the second precursor 20 is dissolved in the solvent. Furthermore, the third precursor 21 is dissolved in the solvent. Furthermore, the further stabilizing agent 16 is added in particulate form to the solution and in particular dissolved. However, it is also conceivable that a fourth precursor 22, which is intended to form the further stabilizing agent 16, is dissolved in the solvent. A polymer solution 46 is formed which in particular comprises the further stabilizing agent 16 in particulate form.

[0069] In a further method step 40, a spinning dope jet 50 is spun from the polymer solution 46 using a spinneret 48. The spinneret 48 has two separate channels 52, 54. The channels 52, 54 open together to an outlet opening 56 of the spinneret 48. The polymer solution 46 is pumped into an outer channel 52 of the spinneret 48. A lumen fluid 58 is pumped into an inner channel 54 of the spinneret 48. The lumen fluid 58 is a liquid in which the components used to produce the filter unit 10 are not soluble. In the present case, water, for example, can be used as the lumen fluid 58. This creates the spinning dope jet 50, which forms the filter unit 10 through at least one post-treatment. The lumen fluid 58 forms the fluid channel 38 of the filter unit 10.

[0070] Alternatively or additionally, the lumen fluid 58 can comprise water-based solvents, particularly organic solvents. Typically, the polymer solution 48 and the lumen fluid 58 are subsequently separated from one another by phase inversion in a precipitation bath 60, thus forming the filter unit 10. In the present case, however, the filter unit is additionally formed by reactive spinning in a further process step 42. For this purpose, an activator 25 is added to the polymer solution 46 before spinning. The activator 25 is intended to trigger a radical polymerization. The activator 25 can, in particular, be a radical initiator, such as peroxide or tert-butyl peroxypivalate. In the present case, the activator 25 is a photoactivator, such as 4,4'-diazidostilbene-2,2'-disodium sulfonate. The photoactivator is activated by irradiation with light, particularly UV light.For this purpose, a light source 62 can be used, which is integrated directly into the spinneret, in particular by means of a light guide. In the present case, the light source 62 is a UV lamp. Due to the radical polymerization, the first precursor 18 not only forms the filter element 12, but simultaneously forms the stabilizing agent 14 through cross-linking with the second and in particular the third precursor 20, 21. In this process, the stabilizing agent 14 is at least partially formed from the same first precursor 18 and the filter element 12 is formed simultaneously. Furthermore, the filter unit 10 is also at least partially formed as a result.

[0071] It is conceivable that a light guide can be provided with a pointed edge in order to improve the homogeneity of the irradiation. As an alternative to a design of the light source as a UV lamp, designs as an LED, as a gas discharge lamp, in particular a deuterium lamp, as a vapor lamp, as a laser and / or as a gas discharge lamp, in particular a fluorescent tube, are possible. The light source preferably has a radiation spectrum and preferably an intensity maximum of the radiation spectrum with a wavelength of at most 390 nm, advantageously of at most 315 nm, more advantageously of at most 280 nm, preferably of at most 200 nm and particularly preferably of at most 121 nm, and / or in particular of at least 10 nm, advantageously of at least 100 nm, more advantageously of at least 200 nm, preferably of at least 280 nm and particularly preferably of at least 315 nm.

[0072] In particular, in the case that the filter unit 10 is designed as a flat membrane, the spinning solution jet 50 can be extruded onto a particularly coarse-pored support material or placed on a roller for introduction into the precipitation bath 60.

[0073] In a further process step, the polymer solution 46 and the lumen fluid 58 are separated from each other by phase inversion in the precipitation bath 60.

[0074] Furthermore, a further process step is conceivable in which a non-crosslinked portion of the first precursor is removed from the filter element 12. For this purpose, the filter element 12 can be cleaved, in particular oxidatively, preferably using sodium chloride or hydrogen peroxide, and rinsed, in particular, with water.

[0075] In Figure 6A process sequence with a filter device is shown schematically. For this purpose, in a process step 64, a liquid is stabilized by means of the stabilizing agents 14, 16 of the filter units 10. If the stabilizing agents 14, 16 lose their effectiveness, the filter units 10 must be replaced with new filter units if the stabilizing agents 14, 16 are not regenerable. In the present case, the stabilizing agents 14, 16 are regenerable. In a further process step 66, the filter units 10 are placed in a salt solution, an alkali and / or an acid for regeneration, particularly depending on the stabilizing agents 14, 16. In a further process step, the regenerated stabilizing agents 14, 16 can be used again to stabilize the liquid.To enable continuous stabilization of the liquid, a portion of the filter unit 10 is used to stabilize the liquid, while simultaneously regenerating another portion of the filter unit 10. Process steps 64, 66, and 68 are partially performed simultaneously.

Claims

1. A method for producing a filter device, in particular for stabilizing beverages, with at least one filter unit (10) which has at least one filter element (12), wherein the filter element (12) is at least partially formed of a first and a third precursor (18; 21), wherein the first and third precursors (18; 21) are dissolved in a solvent to form a polymer solution (46); wherein the filter unit (10) is formed as a hollow fibre by means of reactive spinning; wherein the first precursor (18) comprises at least polyvinylpyrrolidone and at least partially forms an integrated stabilizing means (14) of the filter unit (10), which is formed integrally with the filter element (12), wherein the formation of the stabilizing means (14, 16) by at least the first precursor (18) is initiated by an activator (25) in the form of a radical initiator which is added to the polymer solution (46) before reactive spinning, wherein the first precursor is radically cross-linked and at least partially forms the filter element (12); wherein the third precursor (21) comprises polysulphone, polyethersulphone and / or polyvinylidene fluoride; and wherein optionally a second precursor (20) is provided in the polymer solution, to at least partially form a stabilizing means (14, 16).

2. The method according to claim 1, wherein the first precursor (18) hydrophilically functionalizes the filter element (12).

3. The method according to any one of claims 1 and 2, wherein the second precursor (20) comprises at least vinyl acetate.

4. Method according to any one of claims 1 to 3, wherein the second precursor (20) is intended to at least partially form a stabilizing means (14, 16).

5. The method according to any one of claims 1 to 4, wherein the stabilizing means (14, 16) is an adsorbent.

6. The method according to any one of claims 1 to 5, wherein the filter unit (10) has at least one stabilizing means (14, 16) which is an ion exchanger.

7. A filter device, obtainable by a method according to any one of claims 1 to 6, wherein the filter device has at least one filter unit (10) configured as a hollow fibre with at least one filter element (12), wherein the filter element (12) has an integrated stabilizing means (14) which is formed from a first precursor at least partially and integrally with the filter element (12), wherein the filter element (12) has a further integrated stabilizing means (16) and is at least partially formed by a third precursor and the further stabilizing means (16); wherein the first precursor (18) comprises at least polyvinylpyrrolidone and wherein the third precursor (21) comprises polysulfone, polyethersulphone and / or polyvinylidene fluoride.

8. The filter device according to claim 7, wherein the filter element has a chemically regenerable stabilizing means (14, 16).

9. The filter device according to claim 7 or 8, wherein the filter unit (10) is at least partially formed by a further stabilizing means (14, 16) and / or a further precursor (22).

10. The filter device according to any one of claims 7 to 9, wherein the filter unit (10) has at least one stabilizing means (14, 16), configured as an adsorbent, which comprises at least one cross-linked polyvinylpyrrolidone, a xerogel, a silica gel, a zeolite, a bentonite and / or a mixture of this type.

11. The filter device according to any one of claims 7 to 10, wherein the filter unit (10) has a stabilizing means (14, 16), configured as an ion exchanger, which comprises at least one functionalized agarose.

12. A method with a filter device, in particular according to any one of claims 7 to 11, which is used to stabilize a liquid, in particular of beverages, with a filter unit (10), in particular a membrane filter unit, wherein the filter unit (10), in one method step, stabilizes a liquid by means of at least one integrated stabilizing means (14, 16) of the filter unit (10) and, in a further method step, the integrated stabilizing means (14, 16) is regenerated.