Dialysis Device

Abstract

The present invention relates to a filter device for material exchange, the filter device comprises a pipe cross-section shaped housing having a center of gravity and two housing ends, in which a hollow fiber bundle made of a semipermeable membrane is arranged, the filter device further comprises an end cap having a first and a second opening, the housing and the end cap form a first sealing area connecting the housing and the end cap in a sealing manner, the first sealing area being at a greater distance from the center of gravity of the housing than the bore, a first fluid space is formed between the first sealing area and the first opening of the end cap, through which the first opening is connected to the first flow space, the housing and one end cap form a second sealing area, the first and second sealing areas are not formed by a sealant.

Description

[Technical field]

[0001] The invention relates to a filter device for mass exchange, more particularly hemodialysis, comprising a pipe-section-shaped housing having a center of gravity and two housing ends, in which a hollow fiber bundle made of a semipermeable membrane is arranged, the fiber cavities of the hollow fiber bundle forming a first flow space and the housing interior surrounding the hollow fiber bundle forming a second flow space, the flow spaces being separated from each other at the housing ends by at least one flow space seal, the housing being provided with at least one hole at at least one end, the at least one hole being located closer to the center of gravity of the housing than the flow space seal, further comprising at least one end cap with first and second openings.The invention further relates to a method for producing such a filter device. [Background technology]

[0002] Filter devices for material exchange, more specifically for hemodialysis, are known in the prior art. In filtration techniques, more specifically for hemodialysis, the use of semipermeable hollow fiber membranes as separation media has been found to be advantageous since they are simple to produce and exhibit excellent separation properties. In hemodialysis, the use of polysulfone-based materials associated with the addition of polyvinylpyrrolidone to hollow fiber membranes has proven to be market-dominant. Such membranes are described in EP 0 168 783 A1. These membranes are gathered to form a hollow fiber bundle and fitted into a filter housing. Afterwards, sealing of the two flow spaces must be performed. In the case of hemodialysis, the sealing is performed between the blood side and the dialysate side of the hemodialysis device. Fluid inlets and outlets must therefore be generated to be able to provide the filter with the respective live fluid and to remove the process fluid. In the case of hemodialysis, the two fluids separated by the semipermeable membrane or hollow fiber membrane bundle are guided past each other in countercurrent, thus requiring a total of four fluid inlets per dialyzer. In the case of dead-end filtration, two fluid inlets are believed to be sufficient.

[0003] Such a filter housing for dialysis is described in EP 2 326 410 A1, where the respective dialysate inlets and outlets are provided on a pipe cross-section housing and the respective blood inlets are arranged in separate components, namely end caps. The end caps are then provided with individual elastomeric seals and sealed from the filter housing. All components are produced from thermoplastic materials in an injection moulding process.

[0004] A simplified arrangement is described in DE10147907, where one fluid inlet and one fluid outlet are provided per end cap in such an arrangement. Such an arrangement represents a substantial simplification in terms of production, since the respective production moulds for the pipe cross-section housings are simplified. With these very large production moulds it is therefore possible to at least partially dispense with complex additions, such as sliders for example, which can be more easily accommodated by the smaller end cap moulds. In addition to this it is therefore possible to avoid the use of excessively large injection moulding machines. Also in DE10147907 the respective fluid spaces are at least partially connected to one another through sealing elastomer components.

[0005] However, the use of sealing elastomeric components disadvantageously leads to the formation of dead volumes, which inhibit the efficiency of mass exchange, especially in the blood compartment, since blood flowing outside the body with too low a flow rate or not flowing at all has a tendency towards platelet coagulation and thus can cause clogging of the dialysis machine.

[0006] Moreover, having to use an additional component is disadvantageous. In addition, an elastomeric component is often disadvantageous since the material may exhibit poor hemocompatibility; if this elastomeric component is made of, for example, EPDM, plasticizers may leak into the blood. The same applies generally to filtration techniques, since migration of substances into the filtrate is also disadvantageous in these applications.

[0007] Besides the use of elastomer components as sealants, it is also possible to use adhesives. The use of such adhesives is very complicated in terms of production and also very time-consuming, depending on the reaction kinetics of the adhesive. In addition, adverse components of the adhesive can pass into the filtrate or blood. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] EP0168783A1 [Patent Document 2] EP2326410A1 [Patent Document 3] DE10147907 Summary of the Invention [Problem to be solved by the invention]

[0009] It is therefore an object of the present invention to provide a filter device for substance exchange, more specifically for hemodialysis, which avoids or at least reduces the disadvantages of the prior art. In particular, it is an object of the present invention to provide a particularly easy-to-produce filter device for substance exchange, more specifically for dialysis, which at the same time reduces the adverse effects on the filtrate. In the case of a dialysis device, the adverse effects on the blood to be purified are reduced. [Means for solving the problem]

[0010] According to the invention, that object is achieved according to a first aspect of the invention by a filter device for mass exchange, more particularly hemodialysis, the filter device comprising a pipe cross-section shaped housing having a centre of gravity and having two housing ends, in which a hollow fibre bundle made of a semipermeable membrane is arranged, the fibre cavity of said hollow fibre bundle forming a first flow space and the housing interior surrounding said hollow fibre bundle forming a second flow space, the flow spaces being separated from each other at the housing ends by at least one flow space seal, the housing being provided with at least one hole at at least one end, the at least one hole being arranged closer to the centre of gravity of the housing than the flow space seal, the filter device further comprising at least one end cap having a first and a second opening, the housing and the at least one end cap being arranged in a closed position with respect to the housing and the at least one end cap. the housing and the at least one end cap form a first seal area sealingly connecting the housing and the end cap, the first seal area being at a greater distance from the center of gravity of the housing than the at least one hole, a first fluid space being formed between the first seal area and the first opening of the end cap, through which the first opening is fluidly connected to the first flow space; the housing and the at least one end cap form a second seal area sealingly connecting the housing and the end cap, the second seal area being disposed closer to the center of gravity of the housing than the flow space seal and the at least one hole, a second fluid space being formed between the first and second seal areas and the second opening of the end cap, through which the second opening of the end cap is fluidly connected to the second fluid space through the at least one hole, and the first and second seal areas are not formed by a sealant.

[0011] What is proposed is therefore a particularly easy to produce filter device that operates without the use of elastomeric components or sealants such as adhesives. This prevents or reduces dead volumes. The adverse effects on the blood are reduced when the filter device is operated in hemodialysis. The tendency towards clogging due to platelet aggregation is particularly reduced.

[0012] According to one development of the invention, a filter device is proposed, characterized in that the molecules of the housing are entangled with the molecules of the end cap in both the first and second sealing zones. The entanglement of the molecules ensures a particularly reliable and long-term stable connection of the end cap to the housing. The entanglement of the molecules of the housing with the molecules of the end cap in the first and second sealing zones is achieved by ensuring melting of the respective faces during the connection of the housing to the end cap. The melted faces then come into contact with each other, thereby ensuring the entanglement of the molecules.

[0013] It has been found to be particularly advantageous when the melting points or glass transition points of the materials of the housing and the end cap differ by less than 10° C., preferably less than 5° C., particularly preferably less than 3° C. A particularly secure connection is then possible which at the same time minimizes adverse effects on the filtrate and blood.

[0014] In one embodiment, it can be provided that the first sealing area is at a greater distance from the center of gravity of the housing than the at least one aperture and the flow space seal, such an arrangement being even more compact and in particular having a reduced dead volume.

[0015] Furthermore, in certain embodiments, it can be provided that the pipe cross-section housing and the end cap are formed from the same family of materials. When both components are made from one family of materials, the process of sealing is substantially easier. The molecular intertwining of the end cap and the housing is easier, especially when one family of materials is used for both components. "Family of materials" means, for example, the same material but in different shades. Different copolymer compositions can also be included under one family of materials.

[0016] According to one development of the invention, the material of the housing and the end cap comprises polypropylene or a copolymer of polypropylene or a polycarbonate, more particularly polypropylene or a copolymer of polypropylene. Both materials are suitable as thermoplastic materials, exhibiting a sufficiently high transparency and ensuring the intertwining of the molecules of the housing with those of the end cap. In particular polypropylene is particularly highly suitable, since it is a particularly light material and at the same time can be produced with a particularly low wall thickness of less than 2 mm in the case of the housing. Thus, one embodiment of the present invention is characterized in that the wall thickness of the housing is less than 2 mm. In yet another embodiment, the wall thickness of the end cap is also less than 2 mm, more particularly less than 1.5 mm. Thus, in a particular embodiment, it can be provided that the wall thickness of the end cap is smaller than the wall thickness of the housing, in which case preference is given to using a polypropylene-based material for both components.

[0017] According to yet another particular embodiment, the first sealing area is equal to or larger than, more particularly larger than, the cross-sectional area of ​​the pipe section housing at the housing end. If the sealing area is equal to the cross-sectional area of ​​the pipe section housing at the housing end, a particularly good sealing effect is ensured through optimal utilization of the possible sealing area. In a preferred embodiment, it can also be provided that the sealing area is larger than the cross-sectional area of ​​the pipe section housing at the housing end. This can be ensured by configuring the melting process so that a relatively large amount of material is melted and squeezing takes place in a subsequent joining process. Such components have a bead-like sealing area, which has an advantageous effect on the sealing effect. The beads can advantageously also lead to a further reduction in the possible dead volume, which is particularly desirable, especially in the case of hemodialysis.

[0018] Furthermore, in a preferred embodiment of the filter device, there are two end caps at both ends of the pipe cross-sectional housing, the housing is provided with a hole and a flow space seal at both ends, the hole being located in each case closer to the center of gravity of the housing than the flow space seal. The use of two filter caps at the two ends is particularly advantageous for hemodialysis, since blood and dialysis fluid can thereby be guided in counterflow. This leads to particularly efficient blood purification.

[0019] It can further be provided that the housing has a large number of holes at least at one end. In the case of hemodialysis, this result allows a particularly uniform dialysate flow rate. The separation efficiency for uremic toxins is thus further improved. At the same time, the hydraulic pressure in the dialysate and therefore the mechanical load on the sealing area is reduced. That is, a relatively high dialysate flow rate can also be achieved, which in turn has a favorable effect on the separation efficiency of the filter device. It can also be provided that the housing has a large number of holes at both ends.

[0020] Certain embodiments are characterized in that the filter device is a dialysis machine, a first opening in the end cap allows blood to flow in and blood to flow out, and a second opening in the end cap allows dialysate to flow in and dialysate to flow out.

[0021] According to one development of the invention, the pipe cross-section housing has no dialysate inlet and outlet. Such a housing is possible in a particularly cost-effective manner and with the aid of a simplified mold. Furthermore, it is thereby possible to provide a multi-cavity mold for the housing in a particularly simplified manner, which leads to further cost and savings.

[0022] In a preferred embodiment, the material of the flow space seal comprises an epoxy resin or a polyurethane resin as sealing material. Polyurethane is particularly preferred since it allows a particularly good seal when hollow fibers with an outer diameter of less than 300 μm are used. Also in the case of hollow fiber bundles with a packing density of more than 60%, the material polyurethane is advantageous due to its flow properties.

[0023] In yet another embodiment, at least one energy director is disposed on the pipe-shaped housing section and / or on the end cap, respectively. Such an arrangement is preferred when the end cap and the housing are connected by ultrasonic bonding. Such an energy director significantly increases the sealing effect of the bond, making the bonding process quicker and simpler.

[0024] Preferably, the material of the semipermeable membrane comprises polysulfone, polyethersulfone, polyvinylpyrrolidone, polymethylmethacrylate, polyamide, polyester, cellulose or polyacrylonitrile. Particular preference is given to materials that are mainly composed of polysulfone or a mixture of polyethersulfone and polyvinylpyrrolidone. This means that the material is composed of said mixture to an extent of more than 50% by weight. Said mixture is particularly hemocompatible and therefore further improves the properties of the filter device, more particularly the dialysis machine.

[0025] According to a second aspect of the invention, the object is achieved by a method for producing a filter device according to the first aspect of the invention, characterized in that the first and second sealing areas are produced by melting and cooling of the areas of the housing and the end cap facing the sealing areas in each case with the formation of a sealed connection, and in that entanglement of the molecules of the housing with the molecules of the end cap is carried out.

[0026] In one development of the method, the sealing zone is in each case produced by welding, more particularly by hot surface welding, laser beam welding, spin welding or ultrasonic welding, more particularly by hot surface welding. These methods ensure reliable melting and joining of the components. In particular, what is guaranteed is that a desired joining zone can be provided, more particularly a bead-like and particularly efficiently sealing joining zone.

[0027] When the hot surface welding or hot plate welding method is carried out, preference is given to carrying out the following method steps for producing the filter device:

[0028] a) providing an end cap; b) providing a pipe-shaped housing section; c) applying a hot plate welding tool between the end cap and the housing section, the hot plate welding tool having a temperature higher than the melting point or glass transition point of the particular joining material at least in at least four intended contact areas; d) contacting a hot plate welding tool with the contact areas of the end cap and the housing section to be welded; e) melting the contact area; f) removing the hot plate welding tool; g) welding the end cap and the housing section together by pressing the molten contact areas; h) cooling the molten contact area below the melting point or glass transition point of the particular material.

[0029] According to a third aspect of the invention there is provided a hot plate welding tool suitable for providing or for use in a method according to the second aspect of the invention.

[0030] Such a hot plate welding tool has namely four contact areas where there is simultaneous local contact and material melting of the end cap and the pipe-like housing section during the performance of the method according to the second aspect of the invention.

[0031] In a preferred embodiment, the contact area between the housing section to be melted and the hot plate welding tool is designed in such a way that the contact area of ​​the housing section or the end cap strikes the tool with surfaces formed at different angles between 0° and 90° in the longitudinal direction of the (assumed) housing section, with angles between 20° and 70° being preferred, angles between 30° and 60° being more preferred, angles between 40° and 50° being even more preferred.

[0032] According to yet another embodiment, these contact areas are concave.

[0033] Further details and advantages of the invention will be elucidated more particularly on the basis of the exemplary embodiments depicted in the drawings. [Brief description of the drawings]

[0034] [Figure 1] FIG. 2 is a schematic diagram of a pipe cross-section housing. [Diagram 2] FIG. 2 is a schematic diagram of an end cap. [Diagram 3] FIG. 1 is a schematic diagram of a filter device with a pipe cross-section housing and end caps. [Figure 3a] FIG. 4 is an enlarged view of FIG. 3 in the region of the first sealing area; [Figure 4] FIG. 2 is a schematic diagram of the arrangement of the pipe-shaped housing, end caps, and hot plate welding tool during the heating phase of the hot plate welding process. [Figure 5a] 1 is a schematic diagram of a cross-section of a hot plate welding tool with associated housing sections illustrating certain embodiments. [Figure 5b] 1 is a schematic diagram of a cross section of a hot plate welding tool with associated end cap sections illustrating certain embodiments. [Figure 6a] 1 is a schematic diagram of a cross section of a hot plate welding tool illustrating certain embodiments. [Figure 6b] 1 is a schematic diagram of a cross section of a hot plate welding tool with associated end cap sections illustrating certain embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] FIG. 1 shows a pipe-section-shaped housing 2 of a filter device 1 with a hollow fiber bundle 3 composed of a semipermeable membrane 4. At the end, the pipe-section-shaped housing 2 is provided with a flow space seal 8, which here draws concavely towards the center of gravity S. The flow space seal 8 is made of polyurethane, the arrangement of an epoxy resin or a ceramic sealing material being likewise possible. Polyurethane is preferred if the filter device 1 is used for dialysis. The outer surface of the flow space seal 8 is configured such that the hollow fiber membranes 4 open out, thus forming a first flow space 6 with the interior of the hollow fiber membranes 4. A second flow space 7 is located in the housing 2 outside the hollow fiber membranes 4. FIG. 1 shows a further hole 9 in the housing 2, which is arranged closer to the center of gravity S of the housing 2 than the flow space seal 8. If the filter device 1 is a dialysis device, the dialysate can be supplied to or removed from the outer surface of the hollow fiber membranes 4 through this hole 9, so that a substance exchange can take place between the blood side of the dialysis device represented by the first flow space 6 and the dialysate represented by the second flow space 7. In another embodiment, it is also possible to induce blood in the second flow space 7 and dialysate in the first flow space 6. The housing 2 further comprises a housing protrusion 2a arranged closer to the center of gravity S of the housing 2 than the flow space seal 8 and the hole 9.

[0036] 2 shows an end cap 10 having a first opening 11 and a second opening 12. Provided on the outside of said openings 11 and 12 are threads 18 or a device for fluid line connection, not shown here.

[0037] 3 shows the assembly of the end cap 10 with the pipe-section-shaped housing 2. The two components are designed such that there is a first sealing area 13 and a second sealing area 14. Through the first opening 11, the fluid can then enter the first flow space 6 or be removed from the opening 11, and the first sealing area 13 prevents the unwanted movement of the fluid into the second flow space 7. Through the second opening 12, the fluid can then enter the second flow space 7 or be removed from the second opening 12, and the first sealing area 13 and the second sealing area 14 prevent the unwanted movement of the second fluid into the first flow space 6. Shown on the pipe-shaped housing 2 is a protrusion 2a which in this exemplary embodiment forms the second sealing area 14 together with the end cap 10.

[0038] 3a is an enlarged view of the area of ​​the first sealing area 13, which is formed larger than the cross-sectional area of ​​the pipe-section housing 2 at the housing end. Formed is a bead 15, which in this exemplary embodiment was produced by a hot plate welding method, the joining partners being joined under such pressure that an expansion of the first sealing area 13 occurs.

[0039] FIG. 4 shows diagrammatically the joining step in the formation of the filter device 1 by joining of an end cap 10 with a pipe-shaped housing section 2, the two joining partners being made of polypropylene. Other materials are possible, in particular also polycarbonate. FIG. 4 shows a cross section of the end cap 10, the pipe-shaped housing section 2 and the hot plate welding tool 16. The tool provides a contact area of ​​the area of ​​the end cap 10 and the housing 2 that must be brought into contact to join the workpieces in order to form the first sealing area 13 and the second sealing area 14. In the depicted one, the tool heating element 17 is also depicted, which ensures the heating of the contact area of ​​the joining partners above the melting point or glass transition point of the material. After the heating step, the joining partners can be moved further apart so that the hot plate welding tool 16 can be removed. The joining partners are then joined so that the first sealing area 13 and the second sealing area 14 are formed. In this exemplary embodiment, the molecules of the end cap 10 are intimately entangled with the molecules of the pipe-shaped housing section 2. This results in the first sealing area 13 and the second sealing area 14 exhibiting a particularly high leak-tightness.

[0040] Alternatively, the first sealing area 13 and the second sealing area 14 can also be provided by spin welding or laser beam welding. Spin welding is possible and preferred when the first sealing area 13 and the second sealing area 14 are arranged with rotational symmetry. Ultrasonic welding is likewise possible, in which case at least one energy inductor will preferably be provided on the pipe-shaped housing section 2 and / or on the end cap 10, respectively.

[0041] FIG. 5a illustrates yet another preferred embodiment of the joining step in the formation of a filter device 1 by joining an end cap 10 with a tubular housing section 2, depicting the tubular housing section and the hot plate welding tool 16 in enlarged cross section. In this embodiment, the contact area between the housing section 2 to be melted and the hot plate welding tool 16 is designed in such a way that the contact area of ​​the housing section 2 hits the tool with a surface formed at different angles from 0° to 90° in the longitudinal direction of the housing section. Angles between 20° and 70° are preferred, angles between 30° and 60° are more preferred, angles between 40° and 50° are more preferred. In an exemplary embodiment, an angle of 45° is shown. Such an embodiment has the advantage of allowing a precise control of the joining point, i.e. resulting in a particularly secure joint that is less susceptible to mismatching. Furthermore, the weld bead is particularly small with such a design, i.e. reducing the possibility of narrowing of the fluid flow path in the separation step. In the case of a dialysis device, this is particularly relevant for the dialysate side.

[0042] FIG. 5b illustrates yet another preferred embodiment of the joining step in the formation of the filter device 1 by joining the end cap 10 with the pipe-like housing section 2, depicting the end cap and the hot plate welding tool 16 in enlarged cross section. In this embodiment, the contact area between the part of the end cap 10 to be melted and the hot plate welding tool 16 is designed in such a way that the contact area of ​​the end cap 10 hits the tool 16 at different angles, between 0° and 90°, in the (assumed) longitudinal direction of the filter device. Angles between 20° and 70° are preferred, angles between 30° and 60° are more preferred, angles between 40° and 50° are more preferred. In an exemplary embodiment, an angle of 45° is shown. Such an embodiment has the advantage of allowing a precise control of the joining point, i.e. resulting in a particularly reliable joint that is less susceptible to mismatching. Furthermore, the weld bead is particularly small with such a design, i.e. reducing the possibility of narrowing of the fluid flow path in the separation step. In the case of a dialysis device, this is particularly relevant also for the blood side. The weld bead is designed so that as little dead volume as possible is formed in the blood space, or even to prevent dead volume altogether, which may lead to excessively strong clotting of the blood, i.e. increased clogging of the dialysis machine.

[0043] Yet another embodiment is depicted in FIG. 6a, which depicts a further improved embodiment of FIG. 5a. In this embodiment, the contact area between the housing section 2 to be melted and the hot plate welding tool 16 is designed in such a way that the contact area of ​​the housing section 2 hits the tool with a surface formed at different angles from 0° to 90° in the longitudinal direction of the housing section, this surface having a concave curvature. Concave curvature shall be understood to mean that the curvature projects into the hot plate welding tool. The radius of curvature must be adapted to the housing dimensions. In the case of filter devices of the size of a dialysis machine, the preferred radius of curvature is between 1 mm and 10 mm, in particular between 2 mm and 8 mm, more particularly between 3 mm and 6 mm. In this embodiment, a radius of 4.5 mm is shown. The concave curvature facilitates the exact acceptance of the joining partner with even increased tolerances of the joining partner, i.e. resulting in even increased product reliability and weld quality. The increased tolerances arise in particular when the housing material used is a polyolefin, in particular a polypropylene-based material. FIG. 6b applies correspondingly to the joining of end cap 2.

[0044] List of References 1. Filter Device 2 Pipe cross-sectional shape housing 2a Housing protrusion 3 Hollow fiber bundle 4 Semi-permeable membrane 5 Inside the housing 6 First flow space 7 Second flow space 8 Flow space seal 9 holes 10 End cap 11 First opening 12 Second opening 13 First sealed area 14 Second Sealed Area 15 Beads 16 Hot plate welding tool 17 Tool Heating Elements 18 Threads S center of gravity K Contact area

Claims

1. A filter device for substance exchange, more particularly for hemodialysis, comprising: a pipe-section shaped housing having a center of gravity and two housing ends, in which a hollow fiber bundle made of a semipermeable membrane is disposed, the fiber cavity of the hollow fiber bundle forming a first flow space and the housing interior surrounding the hollow fiber bundle forming a second flow space; Equipped with the flow spaces are separated from one another at the housing ends by at least one flow space seal; the housing is provided with at least one aperture at at least one end, the at least one aperture being located closer to the center of gravity of the housing than the flow space seal; at least one end cap having a first and a second opening; Further comprising: the housing and the at least one end cap form a first sealing area sealingly connecting the housing and the end cap, the first sealing area being at a greater distance from the center of gravity of the housing than the at least one aperture; a first fluid space is formed between the first sealing area and the first opening of the end cap, the first opening being fluidly connected to the first flow space through the first fluid space; the housing and the at least one end cap form a second sealing area sealingly connecting the housing and the end cap, the second sealing area being located closer to the center of gravity of the housing than the flow space seal and the at least one aperture; a second fluid space is formed between the first and second sealing areas and the second opening of the end cap, through which the second opening of the end cap is fluidly connected to the second flow space through the at least one hole; The first and second sealing areas are not formed by a sealant; A filter device comprising:

2. 2. The filter device of claim 1, wherein the molecules of the housing are entangled with the molecules of the end cap in both the first and second sealing areas.

3. 2. The filter device of claim 1, wherein the first sealing area is at a greater distance from the center of gravity of the housing than the at least one hole and the flow space seal.

4. 10. The filter device of claim 1, wherein the pipe cross-sectional housing and the end caps are formed from the same group of materials.

5. 10. The filter device of claim 1, wherein the material of the housing and the end caps comprises polypropylene or a copolymer of polypropylene, or polycarbonate, more specifically, polypropylene or a copolymer of polypropylene.

6. 2. The filter device of claim 1, wherein the first sealing area is equal to or greater than, and more specifically greater than, a cross-sectional area of ​​the pipe-profile housing at the housing end.

7. 2. The filter device according to claim 1, characterized in that there are two end caps at both ends of the pipe cross-sectional shaped housing, the housing being provided with holes and flow space seals at both ends, the holes being in each case located closer to the center of gravity of the housing than the flow space seals.

8. 10. The filter device of claim 1, wherein the housing has a number of holes in at least one end.

9. the filter device is a dialysis machine; the first opening in the end cap allows blood inflow and blood outflow; the second opening in the end cap allows for dialysate inflow and dialysate outflow.

8. A filter device according to claim 7.

10. The film device of claim 9 , wherein the pipe cross-sectional shaped housing does not have a dialysate inlet or outlet.

11. 10. The filter device of claim 1, wherein the material of the semi-permeable membrane comprises polysulfone, polyvinylpyrrolidone, polymethylmethacrylate, polyamide, polyester, cellulose, or polyacrylonitrile.

12. A method for producing a filter device according to any one of claims 1 to 11, comprising the steps of: said first and second sealing areas being in each case produced by melting and cooling of areas of said housing and of said end cap facing said sealing areas by formation of a sealed connection, entanglement of the housing molecules with the end cap molecules is performed; A method comprising:

13. 13. The method according to claim 12, characterized in that the sealed area is produced by welding, more particularly by hot surface welding, laser beam welding, spin welding or ultrasonic welding, more particularly by hot surface welding in each case.

14. A hot plate welding tool for carrying out the method of claim 12.

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