Dialysis machine.

Abstract

The invention relates to a filter device for material exchange; this device comprises a housing in the form of a tube section with a center of gravity and two end sections; within the housing is a hollow fiber bundle consisting of semi-permeable membranes; it also includes an end cap with first and second openings; where the housing and end cap form a primary sealing area which connects the housing and end cap in a leak-proof manner; where the primary sealing area is located further from the center of gravity of the housing relative to the opening; where a primary fluid gap is formed between the primary sealing area and the primary opening of the end cap, and through this primary fluid gap the primary opening is connected to the primary flow gap; where the housing and at least one end cap form a secondary sealing area;Here, the first and second sealing surfaces were not formed by means of a sealant;

Description

Technical field

[0001] The invention relates to a filter device for mass exchange, particularly for hemodialysis, comprising a tubular housing with a center of gravity and two housing ends, in which a hollow fiber bundle of semipermeable membranes is arranged, the fiber cavities of which form a first flow chamber, and the housing interior surrounding the hollow fiber bundle forming a second flow chamber, wherein the flow chambers at the housing ends are separated from each other by at least one flow chamber seal, the housing being provided at at least one end with at least one opening, the at least one opening being arranged closer to the center of gravity of the housing than the flow chamber seal, further comprising at least one end cap having a first and a second opening. The invention further relates to a method for manufacturing such a filter device. Background of the invention

[0002] Filter devices for mass transfer, particularly for hemodialysis, are known in the art. In filtration technology, and especially in hemodialysis, the use of semipermeable hollow fiber membranes as a separation medium has proven advantageous, as these are easy to manufacture and exhibit excellent separation characteristics. In hemodialysis, the use of polysulfone-based materials in combination with the addition of polyvinylpyrrollidone for the hollow fiber membranes has proven to be market-leading. Such a membrane is described in EP0168783A1. These membranes are bundled into hollow fiber bundles and inserted into a filter housing. Subsequently, a seal must be created between the two flow chambers. In the case of hemodialysis, the seal is located between the blood side and the dialysate side of the hemodialyzer.Accordingly, fluid inlets and outlets must be provided to supply the respective raw fluids to the filter and to discharge the processed fluids. In the case of hemodialysis, both fluids, separated by the semipermeable membrane or the hollow fiber membrane bundle, are passed in countercurrent flow, requiring a total of four fluid inlets per dialyzer. In the case of dead-end filtration, two fluid inlets may suffice.

[0003] Such a filter housing for dialysis is described in EP2326410A1. The design provides for the respective dialysis inlets and outlets on the tubular housing and the respective blood ports in separate components, the end caps. The end caps are then sealed against the filter housing using a separate elastomeric seal. All components are manufactured from thermoplastics using injection molding.

[0004] A simplified design is described in DE10147907 or US4724900, in which each end cap has one fluid inlet and outlet. This arrangement offers a significant simplification in production, as the respective production tools for the tubular housings are simplified. With these very large housing tools, complex components such as slides can thus be at least partially omitted. These components can be more easily accommodated in a smaller end cap tool. This also avoids the need for excessively large injection molding machines. In DE10147907, the respective fluid chambers are also at least partially connected to each other via sealing elastomeric components.

[0005] However, the use of sealing elastomeric components unfortunately leads to the formation of dead volumes, which hinders the efficiency of mass exchange. Dead volumes are particularly detrimental in the blood compartment, as blood that does not flow extracorporeally at all or flows at too low a velocity tends to cause platelet coagulation and thus can lead to a blockage of the dialyzer.

[0006] Furthermore, the need to use additional components is a disadvantage. Elastomeric components are also frequently problematic because the materials can have poor blood compatibility. For example, if these elastomeric components are made of EPDM, plasticizers can leach into the bloodstream. The same generally applies to filtration technology, as the transfer of substances into the filtrate is also detrimental in these applications.

[0007] Besides using elastomeric components as sealants, adhesives may also be used. However, such use of adhesives is technically very complex and, depending on the adhesive's reaction kinetics, also very time-consuming. Furthermore, undesirable components of the adhesive can migrate into the filtrate or the blood. Object of the invention

[0008] It is therefore an object of the invention to provide a filter device for mass exchange, particularly for hemodialysis, which prevents or at least mitigates the disadvantages of the prior art. In particular, it is an object of the invention to provide a filter device for mass exchange, especially for dialysis, that is particularly easy to manufacture and simultaneously reduces the adverse effects on a filtrate. In the case of a dialyzer, the aim is to reduce any adverse effects on the blood being purified. Summary of the invention

[0009] According to the invention, the problem according to a first aspect of the invention is solved by a filter device for mass exchange, in particular for hemodialysis, comprising a tubular housing with a center of gravity and with two housing ends, in which a hollow fiber bundle of semipermeable membranes is arranged, the fiber cavities of which form a first flow chamber and the housing interior surrounding the hollow fiber bundle forms a second flow chamber, wherein the flow chambers at the housing ends are separated from each other by at least one flow chamber seal, wherein the housing is provided at at least one end with at least one opening and the at least one opening is arranged closer to the center of gravity of the housing than the flow chamber seal, further comprising at least one end cap having a first and a second opening, wherein the housing and the at least one end cap have a first sealing surface,the housing and the end cap form a sealing connection, wherein the first sealing surface is located further from the center of gravity of the housing than the at least one opening, and wherein a first fluid space is formed between the first sealing surface and the first opening of the end cap, through which the first opening is fluidically connected to the first flow space, wherein the housing and the at least one end cap form a second sealing surface, which seals the housing and the end cap, and wherein the second sealing surface is arranged closer to the center of gravity of the housing than the flow space seal and the at least one opening, and wherein a second fluid space is formed between the first and second sealing surfaces and the second opening of the end cap, through which the second opening of the end cap is fluidically connected to the second flow space via the at least one opening.where the first and second sealing surfaces are not formed by a sealant.

[0010] This proposal proposes a particularly easy-to-manufacture filter device that requires no sealants such as elastomeric components or adhesives. This prevents or reduces dead volumes. When the filter device is used in hemodialysis, adverse effects on the blood are reduced. In particular, the tendency to become clogged due to platelet aggregation is minimized.

[0011] According to the invention, a filter device is proposed, characterized in that molecules of the housing are entangled with molecules of the end cap in the first and second sealing surfaces. This entanglement of the molecules ensures a particularly secure and long-term stable connection between the end cap and the housing. This entanglement of the housing molecules with the end cap molecules in the first and second sealing surfaces is achieved by ensuring that the respective surfaces melt during the connection of the housing to the end cap. The molten surfaces are then brought into contact with each other, thereby ensuring the entanglement of the molecules.

[0012] It has proven particularly advantageous if the melting points or glass transition points of the housing and end cap materials differ by less than 10°C, preferably less than 5°C, and most preferably less than 3°C. This allows for particularly safe connections that simultaneously minimize adverse effects on the filtrate or blood.

[0013] In one embodiment, the first sealing surface may be located further from the center of gravity of the housing than the at least one opening and the flow chamber seal. Such an arrangement is even more compact and features significantly reduced dead volumes.

[0014] Furthermore, in a particular embodiment, the tubular housing and the end cap can be made from the same material group. If both components are made from the same material group, the sealing process is significantly simplified. In particular, the entanglement of the molecules of the end cap and housing is facilitated when one material group is used for both components. A material group can refer, for example, to identical materials but with different colors. Different copolymer compositions can also be grouped together within a single material group.

[0015] According to the invention, the housing and end cap material comprises polypropylene or polypropylene copolymers or polycarbonate, in particular polypropylene or polypropylene copolymers. Both materials exhibit sufficiently high transparency and, as thermoplastic materials, are suitable for ensuring entanglement of the housing molecules with the end cap molecules. Polypropylene is particularly suitable because it is a very lightweight material and can be manufactured with very thin walls, less than 2 mm in the case of the housing. Accordingly, one embodiment of the invention is characterized in that the housing wall thickness is less than 2 mm. In another embodiment, the end cap wall thickness is also less than 2 mm, in particular less than 1.5 mm.In a particular embodiment, it may be provided that the wall thickness of the end cap is lower than the wall thickness of the housing, in which case a polypropylene-based material is preferably used for both components.

[0016] According to a further particular embodiment, the first sealing surface is equal to or larger, and in particular larger, than the cross-sectional area of ​​the tubular housing at the housing end. If the sealing surface is equal to the cross-sectional area of ​​the tubular housing at the housing end, a particularly good sealing effect is ensured by optimal utilization of the available sealing surface. In a preferred embodiment, it can also be provided that the sealing surface is larger than the cross-sectional area of ​​the tubular housing at the housing end. This can be ensured by designing the melting process in such a way that a larger quantity of material is melted and a compression is carried out during the subsequent joining process. Such a component has a bead-shaped sealing surface, which has a beneficial effect on the sealing effect.The bulge can also advantageously lead to a further reduction of any dead volume, which is particularly desirable in the case of hemodialysis.

[0017] Furthermore, in a preferred embodiment of the filter device, two end caps are provided at opposite ends of the tubular housing, and the housing is equipped with openings and flow chamber seals at both ends. The openings are positioned closer to the center of gravity of the housing than the flow chamber seals. The use of two filter caps at the two ends is particularly advantageous for hemodialysis, as it allows the blood and dialysate to flow in countercurrent flow. This results in particularly efficient blood purification.

[0018] Furthermore, the housing may be designed to have a multitude of openings at at least one end. In the case of hemodialysis, this ensures a particularly uniform dialysate flow, thus further improving the separation efficiency of uremotoxins. Simultaneously, the hydraulic pressure in the dialysate, and therefore the mechanical stress on the sealing surfaces, is reduced. This allows for a higher dialysate flow rate, which in turn has a positive effect on the separation efficiency of the filter device. Alternatively, the housing may be designed to have a multitude of openings at both ends.

[0019] A particular embodiment is characterized in that the filter device is a dialyzer and that the first openings of the end caps allow blood access and blood outlet, and that the second openings of the end caps allow dialysate access and dialysate outlet.

[0020] According to a further development of the invention, the tubular housing is designed without a dialyzer inlet and outlet. Such a housing is particularly cost-effective and can be manufactured using a simplified tool. Furthermore, this simplifies the use of a multi-cavity tool for the housing, resulting in cost and energy savings.

[0021] In a preferred embodiment, the material of the flow chamber seal comprises epoxy resin or polyurethane resin as the sealing material. Polyurethane is particularly preferred because it enables a particularly good seal when hollow fibers with an outer diameter of less than 300 µm are used. Polyurethane is also advantageous at packing densities of the hollow fiber bundles exceeding 60% due to its flow properties.

[0022] In a further embodiment, at least one energy direction sensor is arranged on the tubular housing section and / or on the end cap. Such an arrangement is preferred when the end cap and the housing are joined by ultrasonic welding. Such an energy direction sensor significantly increases the sealing effect of the joint and accelerates and simplifies the joining process.

[0023] Preferably, the material of the semipermeable membrane comprises polysulfone, polyethersulfone, polyvinylpyrrolidone, polymethyl methacrylate, polyamide, polyester, cellulose, or polyacrylonitrile. Particularly preferred is a material consisting predominantly of a mixture of polysulfone or polyethersulfone and polyvinylpyrrolidone. This means that the material consists of more than 50% by weight of this mixture. This mixture is particularly blood-compatible and thus further improves the properties of the filter device, especially the dialyzer.

[0024] According to a second aspect of the invention, the problem is solved by a method for manufacturing a filter device according to the first aspect of the invention, which is characterized in that the first and second sealing surfaces are each produced by melting and recooling the areas of the housing and the end cap facing the sealing surfaces in a sealingly connecting manner, and that an entanglement of molecules of the housing with molecules of the end cap is carried out.

[0025] In a further development of the process, it is provided that the sealing surfaces are produced by welding, in particular by hot-surface welding, laser welding, rotary welding, or ultrasonic welding, especially by hot-surface welding. These processes ensure reliable melting and joining of the components. In particular, it is ensured that the desired joining surface, especially a bead-shaped, particularly well-sealing joining surface, can be provided.

[0026] It is preferred to carry out the following process steps for the manufacture of a filter device when a hot-surface or mirror welding process is carried out: a) Providing the end cap b) Providing the tubular housing section c) Providing the mirror welding tool between the end cap and the housing section, wherein the mirror welding tool has a temperature above the melting point or glass transition point of the respective joining material at least at the provided at least 4 contact surfaces d) Bringing the mirror welding tool into contact with the contact surfaces of the end cap and the housing section to be welded e) Melting the contact surfaces f) Removing the mirror welding tool g) Welding the end cap and housing section by pressing the molten contact surfaces h) Cooling the molten contact surfaces below the melting point or glass transition point of the respective material.

[0027] According to a third aspect of the disclosure, it is provided that a mirror welding tool is suitable for providing a method according to the second aspect of the invention or for being used in a method according to the second aspect of the invention.

[0028] Such a mirror welding tool thus has 4 contact surfaces where, during the process according to the second aspect of the invention, the end cap and the tubular housing section simultaneously come into local contact and melt material.

[0029] In a preferred embodiment, the contact surface between the housing section to be melted and the mirror welding tool is designed such that the contact surfaces of the housing section or the end cap abut the tool at surfaces formed at angles other than 0° and 90° in the longitudinal direction of the (imaginary) housing section. Angles between 20° and 70° are preferred, more preferably between 30° and 60°, and even more preferably between 40° and 50°.

[0030] According to another embodiment, these contact surfaces are concave. Brief description of the drawings

[0031] Further details and advantages of the present invention will be explained in more detail with reference to an embodiment illustrated in the drawings. The drawings show: Fig. 1 a schematic representation of a raw-section-shaped housing Fig. 2 a schematic representation of an end cap Fig. 3a schematic representation of a filter device comprising a tubular housing and an end cap Fig. 3a an enlarged view of the Fig. 3 in the area of ​​a first sealing surface Fig. 4 A schematic representation of an arrangement consisting of a tubular housing, end cap and mirror welding tool during a heating phase of a mirror welding process. Fig. 5a Schematic representation of a section of a heating element or mirror welding tool with the associated housing section, representing a particular embodiment Fig. 5b Schematic representation of a section of a heating element or mirror welding tool with the associated end cap section, representing a particular embodiment Fig. 6a Schematic representation of a section of a heating element or mirror welding tool, depicting a particular embodiment Detailed description of an exemplary implementation

[0032] Fig. 1Figure 1 shows a tubular housing 2 of a filter device 1, which has a hollow fiber bundle 3 made of semipermeable membranes 4. At the ends, the tubular housing 2 has a flow chamber seal 8, which is shown here as concave towards the center of gravity S. The flow chamber seal 8 is made of polyurethane; an arrangement of epoxy resin or ceramic sealing material is also possible. If the filter device 1 is used for dialysis, polyurethane is preferred. The outer surface of the flow chamber seal 8 is designed such that the hollow fiber membranes 4 are open, forming a first flow chamber 6 that encompasses the interior of the hollow fiber membranes 4. The second flow chamber 7 is located in the housing 2 outside the hollow fiber membranes 4. Fig. 1The figure further shows openings 9 in the housing 2, which are arranged closer to the center of gravity S of the housing 2 than the flow chamber seal 8. If the filter device 1 is a dialyzer, dialysate can be supplied to or removed from the outer surface of the hollow fiber membrane 4 via these openings 9, so that an exchange of substances can take place between the blood side of the dialyzer, represented by the first flow chamber 6, and the dialysate, represented by the second flow chamber 7. In another embodiment, it is also possible to carry the blood in the second flow chamber 7 and the dialysate in the first flow chamber 6. The housing 2 further has a housing projection 2a, which is arranged closer to the center of gravity S of the housing 2 than the flow chamber seal 8 and the openings 9.

[0033] The Fig. 2Figure 1 shows an end cap 10 with a first opening 11 and a second opening 12. Threads 18 or devices for connecting fluid lines (not shown here) are provided on the outside of these openings 11 and 12.

[0034] The Fig. 3Figure 1 shows the assembly of the end cap 10 with the tubular housing 2. Both components are designed such that a first sealing surface 13 and a second sealing surface 14 are present. Fluid can enter the first flow chamber 6 through the first opening 11 or be discharged from the opening 11. The first sealing surface 13 prevents unwanted fluid transfer into the second flow chamber 7. Fluid can also enter the second flow chamber 7 through the second opening 12 or be discharged from the second opening 12. The first sealing surface 13 and the second sealing surface 14 prevent unwanted transfer of the second fluid into the first flow chamber 6. The projection 2a on the tubular housing 2 is shown, which, in this embodiment, forms the second sealing surface 14 together with the end cap 10.

[0035] In Fig. 3aAn enlarged view of the area of ​​the first sealing surface 13 is shown, wherein a first sealing surface 13 is formed that is larger than the cross-sectional area of ​​the tubular housing section 2 at the housing end. A bead 15 is formed. In this embodiment, this bead was produced by a mirror welding process, wherein the joining partners were joined with such pressure that an enlargement of the first sealing surface 13 occurred.

[0036] Fig. 4 Figure 1 schematically illustrates the joining process for forming the filter device 1 by joining the end cap 10 and the tubular housing section 2, where both joining partners are made of polypropylene. Other materials can also be used, in particular polycarbonate. Fig. 4Figure 1 shows the end cap 10, the tubular housing section 2, and a cross-section of a mirror welding tool 16. The tool provides a contact surface with those surfaces of the end cap 10 and the housing 2 that must be brought into contact to join the workpieces and form the first 13 and second 14 sealing surfaces. The illustration also shows tool heating 17, which ensures that the contact surfaces of the joining partners are heated above the melting point or glass transition point of the material. After the heating process, the joining partners can be moved further apart, allowing the mirror welding tool 16 to be removed. The joining partners are then joined to form the first 13 and second 14 sealing surfaces. In this embodiment, molecules of the end cap 10 and molecules of the tubular housing section 2 become intimately entangled.This creates the first 13 and second 14 sealing surfaces, which exhibit a particularly high degree of tightness.

[0037] Alternatively, the first 13 and second 14 sealing surfaces can also be provided by rotary welding or laser welding. Rotary welding is possible and preferred if the first 13 and second 14 sealing surfaces are arranged rotationally symmetrically. Ultrasonic welding is also possible, in which case at least one energy direction transmitter is preferably provided on the tubular housing section 2 and / or on the end cap 10.

[0038] The Fig. 5aThis represents a further preferred embodiment of the joining process for forming the filter device 1 by joining the end cap 10 and the tubular housing section 2, wherein the tubular housing section and the mirror welding tool 16 are shown in a section magnification. In this embodiment, the contact surface between the housing section 2 to be melted and the mirror welding tool 16 is designed such that the contact surface of the housing section 2 abuts the tool at a surface that is formed at an angle other than 0° and 90° in the longitudinal direction of the housing section. An angle between 20° and 70° is preferred, more preferably between 30° and 60°, and even more preferably between 40° and 50°. In the exemplary embodiment, an angle of 45° is specified.This design offers the advantage of precise control of the joining point, resulting in a particularly reliable and low-defect joint. Furthermore, the weld bead is especially small in this design, thus reducing potential constrictions of the fluid flow path during the separation process. In the case of a dialyzer, this is particularly relevant to the dialysate side.

[0039] The Fig. 5bThis represents a further preferred embodiment of the joining process for forming the filter device 1 by joining the end cap 10 and the tubular housing section 2, wherein the end cap and the mirror welding tool 16 are shown in a section magnification. In this embodiment, the contact surface between the part of the end cap 10 to be melted and the mirror welding tool 16 is designed such that the contact surface of the end cap 10 abuts the tool 16 at a surface that intersects the longitudinal direction of the (imaginary) filter device at an angle other than 0° and 90°. An angle between 20° and 70° is preferred, more preferably between 30° and 60°, and even more preferably between 40° and 50°. In the exemplary embodiment, an angle of 45° is specified. Such an embodiment has the advantage that precise control of the joining point is enabled, resulting in a particularly reliable and low-defect joint.Furthermore, in this design, the weld bead is particularly small, thus reducing potential constrictions of the fluid flow path during the separation process. In the case of a dialyzer, this is especially important on the blood side. The weld bead is designed to minimize dead volume in the blood chamber or even eliminate it entirely. A dead volume on the blood side can lead to excessive blood coagulation, resulting in progressive clogging of the dialyzer.

[0040] Another embodiment is described in the Fig. 6a shown, whereby this represents a further improved modification of the embodiment of Fig. 5aThis embodiment represents a contact surface between the housing section 2 to be melted and the mirror welding tool 16. The contact surface of the housing section 2 abuts the tool at a surface formed at an angle other than 0° and 90° in the longitudinal direction of the housing section, and this surface is concavely curved. Concave curvature means that the curvature extends into the welding tool. The radius of curvature must be adapted to the housing dimensions. In the case of a filter device the size of a dialyzer, preferred radii of curvature are between 1 mm and 10 mm, particularly between 2 mm and 8 mm, and more specifically between 3 mm and 6 mm. In this embodiment, a radius of 4.5 mm is specified.The concave curvature facilitates the precise engagement of the joining partner, even with increased tolerances of the joining partner, resulting in further enhanced product safety and weld quality. Increased tolerances occur particularly when a polyolefin, especially a polypropylene-based material, is used as the housing material. Fig. 6b The same applies to the joining of end cap 2. List of reference symbols:

[0041] 1 Filter device 2 Pipe section-shaped housing 2a Housing projection 3 Hollow fiber bundle 4 Semipermeable membrane 5 Housing interior 6 First flow chamber 7 Second flow chamber 8 Flow chamber seal 9 Openings 10 End cap 11 First opening 12 Second opening 13 First sealing surface 14 Second sealing surface 15 Bead 16 Mirror welding tool 17 Tool heater 18 Thread S Center of gravity K Contact surfaces

Claims

1. Filter device (1) for material exchange, more particularly for haemodialysis, comprising a • tubular housing (2) having a centre of gravity (S) and having two housing ends, in which housing there is arranged a hollow-fibre bundle (3) composed of semipermeable membranes (4), the fibre cavities of which hollow-fibre bundle form a first flow space (6), and the housing interior surrounding the hollow-fibre bundle (3) forms a second flow space (7), • wherein the flow spaces are separated from one another at the housing ends by at least one flow-space seal (8), • wherein the housing (2) is provided with at least one breach (9) at at least one end, and the at least one breach (9) is arranged closer to the centre of gravity (S) of the housing than is the flow-space seal (8), • furthermore comprising at least one end cap (10) having a first opening (11) and a second opening (12), wherein the housing (2) and the at least one end cap (10) form a first sealing surface (13), which sealingly connects housing (2) and end cap (10), and wherein the first sealing surface (13) is at a further distance from the centre of gravity (S) of the housing (2) than is the at least one breach (9), and • wherein a first fluid space is formed between the first sealing surface (13) and the first opening (11) of the end cap (10), via which first fluid space the first opening (11) is fluidically connected to the first flow space (6), • wherein the housing (2) and the at least one end cap (10) form a second sealing surface (14), which sealingly connects housing (2) and end cap (10), and the second sealing surface (14) is arranged closer to the centre of gravity (S) of the housing (2) than are the flow-space seal (8) and the at least one breach (9), • and wherein a second fluid space is formed between the first sealing surface (13) and second sealing surface (14) and the second opening (12) of the end cap, via which second fluid space the second opening (12) of the end cap (10) is fluidically connected to the second flow space through the at least one breach (9), • wherein the first sealing surface (13) and second sealing surface (14) are not formed by a sealant, • characterized in that the material of the housing (2) and of the end cap (10) comprises polypropylene or copolymers of polypropylene or polycarbonate, more particularly polypropylene or copolymers of polypropylene, and, in each of the first sealing surface (13) and second sealing surface (14), molecules of the housing are entangled with molecules of the end cap.

2. Filter device (1) according to Claim 1, characterized in that the first sealing surface (13) is at a further distance from the centre of gravity (S) of the housing (2) than are the at least one breach (9) and the flow-space seal (8).

3. Filter device (1) according to any one of the preceding claims, characterized in that the tubular housing (2) and the end cap (10) are formed from the same group of materials.

4. Filter device (1) according to any one of the preceding claims, characterized in that two end caps (10) are provided, at the opposite ends of the tubular housing (2), and the housing (2) is provided at both ends with breaches (9) and flow-space seals (8), and the breaches (9) are in each case arranged closer to the centre of gravity (S) of the housing (2) than are the flow-space seals (8).

5. Filter device (1) according to any one of the preceding claims, characterized in that the housing (2) has a multiplicity of breaches (9) at at least one end.

6. Filter device (1) according to Claim 4, characterized in that the filter device (1) is a dialyser, and in that the first openings (11) of the end caps allow an inflow of blood and an outflow of blood, and in that the second openings (12) of the end caps allow an inflow of dialysate and an outflow of dialysate.

7. Filter device (1) according to Claim 6, characterized in that the tubular housing (2) does not have a dialysate inlet or outlet.

8. Filter device (1) according to any one of the preceding claims, characterized in that the material of the semi-permeable membranes (4) comprises polysulfone, polyvinylpyrrolidone, polymethyl methacrylate, polyamide, polyester, cellulose or polyacrylonitrile.

9. Method for producing a filter device (1) according to any of the preceding claims, characterized in that the first sealing surface (13) and second sealing surface (14) are in each case produced by fusing and cooling of the regions of the housing (2) and of the end cap (10) that face the sealing surfaces (13, 14), with formation of a sealing connection, and in that an entanglement of molecules of the housing (2) with molecules of the end cap (10) is carried out, wherein the sealing surfaces (13, 14) are each produced by hot-surface welding.