Coating for hollow-fiber membranes in medical engineering ii

Abstract

The present invention relates to a method for coating a preferably porous and / or hydrophilic hollow-fiber membrane (1) with a coating material (B), the method comprising the steps of: providing the hollow-fiber membrane (1) that has a coating side (30) to be coated and an oppositely facing secondary side (40), providing the coating material (B) and applying the coating material (B) to the coating side (30), or exclusively to the latter. The hollow-fiber membrane (1) has a longitudinal direction (L) with two first and second ends (10, 20) opposite to each other in the longitudinal direction. The hollow-fiber membrane (1) is arranged in a housing (50).

Description

[0001] Description

[0002] Coating of hollow fiber membranes in medical technology II

[0003] The present invention relates to a method for coating a preferably porous and / or hydrophilic hollow fiber membrane with a coating material according to claim 1, a hollow fiber membrane according to claim 15, a dialyzer according to claim 16 and a device according to claim 17 or according to the respective preambles or generic terms of these claims.

[0004] In ECLS (extracorporeal ventilation support), oxygen is added (ECMO = extracorporeal membrane oxygenation) and / or CO2 is removed (ECCO2R = extracorporeal CO2 removal) from the blood flowing extracorporeally in a gas exchange device, depending on the blood flow rate. The procedure represents a beneficial alternative and / or supplement to conventional mechanical ventilation for the patient in many respects.

[0005] An object of the present invention is to provide a method for producing a hollow fiber membrane suitable for this treatment method.

[0006] Furthermore, a membrane, in particular a hollow fiber membrane, a dialyzer and a device are to be specified.

[0007] The object of the invention is achieved by means of the method for coating a preferably porous and / or hydrophilic hollow fiber membrane with a coating material having the features of claim 1, by means of the hollow fiber membrane having the features of claim 15, and by means of the dialyzer having the features of claim 16. Furthermore, it is achieved by a device having the features of claim 17.

[0008] The method according to the invention for coating a preferably porous and / or hydrophilic hollow fiber membrane with a coating material comprises the provision of at least one hollow fiber membrane with a coating side to be coated and a secondary side opposite thereto, and the provision of the coating material.

[0009] Furthermore, the method comprises applying the coating material to precisely one or at least one side of the hollow fiber membrane, namely the coating side, or only to this side, not also to the secondary side. The coating material can be suitable and applied to reduce the permeation of blood plasma through the pores of the hollow fiber membrane during subsequent use.

[0010] The hollow fiber membrane has a longitudinal direction with two longitudinally opposite ends, referred to herein as the first and second ends, respectively.

[0011] The hollow fiber membrane is arranged in a housing, for example, a filter housing. The hollow fiber membrane can be connected to the housing, for example, at one end, at both ends, or only partially at one or both ends, i.e., not across the entire width of the hollow fiber membrane. Connecting elements can be arranged between the hollow fiber membrane and the housing, via which the connection can be established.

[0012] When referring to a hollow-fiber membrane, the above statements also apply in some embodiments to a plurality of hollow-fiber membranes, mostly running parallel to one another, which are bundled, for example, in a common housing, such as the filter housing, as shown in section in Fig. 2B of US Pat. No. 10,583,458 B2. They can be coated simultaneously using the present invention.

[0013] If several hollow fibers or hollow fiber membranes are present, the coating side can correspond to the side facing the inner lumen of the hollow fiber, the secondary side would be the outer surface of the hollow fibers, alternatively the entire space within the housing, which is formed or (co-)limited by the housing inner walls and the outer surfaces of the hollow fibers.

[0014] The hollow fiber membrane according to the invention was coated by the method according to the invention.

[0015] The gas exchanger, blood filter, or dialyzer according to the invention comprises a hollow fiber membrane according to the invention. In these or any other embodiments, the coating side can be the blood side.

[0016] The device according to the invention for coating a hollow fiber membrane is configured to carry out the method according to the invention. Embodiments of the invention may comprise some, some, or all of the following features in any combination, unless this is recognizably technically impossible for a person skilled in the art.

[0017] In all the following statements, the use of the expression "may be" or "may have" etc. is to be understood as synonymous with "is preferably" or "preferably has" etc. and is intended to explain embodiments of the invention.

[0018] Whenever numerical words are mentioned herein, the person skilled in the art will understand this as indicating a numerical lower limit. Unless this leads to a contradiction recognizable to the person skilled in the art, the person skilled in the art will therefore always read the reference to "a" or "an" as "at least one" or "at least one". This understanding is also encompassed by the present invention, as is the interpretation that a numerical word such as "a" can alternatively be meant as "exactly one", wherever this is recognizably technically possible for the person skilled in the art. Both are encompassed by the present invention and apply to all numerical words used herein.

[0019] Whenever reference is made herein to spatial information such as "top," "bottom," "left," or "right," the skilled person will understand this to refer to the arrangement in the figures attached here and / or in the state of use. "Bottom" is closer to the center of the earth or the lower edge of the figure than "top."

[0020] Advantageous further developments of the present invention are the subject of subclaims and

[0021] Embodiments. When reference is made herein to an embodiment, it represents an exemplary embodiment of the invention and is not to be construed as limiting.

[0022] If it is disclosed herein that the subject matter according to the invention has one or more features in a particular embodiment, it is also disclosed herein that the subject matter according to the invention expressly does not have precisely this or these features in other, likewise inventive embodiments, e.g., by way of a disclaimer. For each embodiment mentioned herein, the opposite embodiment, for example, formulated as a negation, is also disclosed.

[0023] If method steps are mentioned or disclosed herein, the device according to the invention is configured in some embodiments to carry out one, several or all of these method steps, in particular if these are automatically performable steps, in any combination or to control corresponding devices, which are preferably based on the name of the respective method step (e.g. "determining" as a method step and "device for determining" for the device, etc.) and which can also be part of the device(s) according to the invention or can be connected thereto in a signal connection.

[0024] When reference is made herein to "programmed" or "configured," these terms may be interchangeable in some embodiments. In some embodiments of the method according to the invention, the coating material is or comprises a solution, preferably a silicone solution.

[0025] In some embodiments of the method, the coating material is applied to the coating side of the hollow fiber membrane simultaneously or with an overlapping time from both the first and the second end. This means that during the coating process, during which the coating material, which in order to coat the coating side, i.e. the inner surface of the hollow fibers which are closed except for their end faces, always has to be introduced into the hollow fiber starting from one end, in this case it is introduced into the hollow fiber from both ends. The introduction of coating material can begin simultaneously from both the first and the second end. However, it is also possible to begin introduction from one end first in order to start introduction from the other end later.What is relevant is that there is at least one point in time during the coating process at which the coating is carried out simultaneously from both ends.

[0026] Such simultaneous or temporally overlapping introduction of coating material from both ends can be particularly advantageous in preventing gas inclusions in the membrane.

[0027] For this purpose, as with one-sided introduction, a certain minimum pressure must be applied to overcome the flow resistance for coating the coating side with the coating material, which pressure is preferably below 1 bar, particularly preferably below 0.5 bar, in order to avoid damage. Air located in the compartment on the coating side of the hollow fiber membrane, i.e. inside the fibers, escapes via the membrane into the compartment on the secondary side of the hollow fiber membrane and can escape from there to the outside via the completely open or partially open vent connections, as described herein.

[0028] If the measured pressure or the pressure required to further introduce coating material into the hollow fibers increases abruptly, this may be an indication that the two fronts of the coating material moving towards each other from the first end or from the second end of the hollow fiber membrane have "met" within the hollow fibers and thus the coating side of the hollow fiber membrane is completely coated.

[0029] In such embodiments, the coating material can advantageously be supplied to the hollow fiber membrane with less pressure since it only has to overcome part of the distance within the hollow fiber membrane.

[0030] In fact, by further applying pressure and applying additional coating material in certain embodiments, the depth of penetration of the solution into the pores can be regulated, which is also encompassed by the invention.

[0031] The penetration depth of the coating material into the pores can alternatively or additionally be determined or co-determined, for example, via the pore size of the hollow fiber membrane and / or by means of the solvent concentration of the coating material.

[0032] In some embodiments, during the application of the coating material, the pressure prevailing in at least one feed line for supplying coating material to the coating side of the hollow fiber membrane is measured from one or both ends.

[0033] If multiple supply lines are provided for the coating material (in the sense of being present), in some embodiments the prevailing pressure is measured in each of the supply lines. In certain embodiments, it may be possible to monitor these pressures and to regulate, control, or, for example, terminate the coating process accordingly. This is also because, in some embodiments, the pressure increase can provide information about the depth to which the coating material has already penetrated into the pores of the hollow-fiber membrane.

[0034] If the housing has a first vent port or a second vent port, then in some embodiments of the method, gas can be allowed to flow out of the housing via the first vent port or the second vent port during coating. The gas can, for example, be solvent filtered through the hollow fiber membrane and evaporated.

[0035] In some embodiments, the first vent port and / or the second vent port in the upper half of the cross-section of the housing are in fluid communication with the atmosphere or an exterior of the housing.

[0036] In some embodiments, the first vent port and / or the second vent port are not closed, but at most throttled, for example by means of a throttle whose passage area is preferably variable. This preferably applies for the entire duration of the process, or at least for a large part thereof, e.g., for at least 70%, 80%, 90%, or more of the duration of the step of applying the coating material to the coating side.

[0037] When reference is made here to a "passage area", e.g. in connection with the ventilation connections, the throttle, passage openings, etc., this also includes other terms such as cross-section, cross-sectional area, passage cross-section, opening cross-section, etc.

[0038] In some embodiments, the first venting port and / or the second venting port are a dialysis fluid supply line or

[0039] Dialysate drain line, or a connection for each.

[0040] In some embodiments, the first ventilation connection and / or the second ventilation connection have a closure device for partially closing their (respective) passage area (alternatively: its passage cross-section).

[0041] In some embodiments, the closure device has a through-opening to the atmosphere or to an exterior of the housing through which gas can escape, wherein the through-opening is preferably or comprises a capillary. Capillaries can have different diameters. The smaller the diameter of the capillary, the more delayed the concentration equilibration between the compartment on the secondary side of the hollow-fiber membrane on the one hand and the environment of the housing, e.g., the atmosphere, on the other hand. A preferred diameter of the capillary, or of all capillaries arranged in parallel at this point, is preferably less than 1 mm, more preferably less than 0.7 mm, most preferably less than 0.5 mm.

[0042] In some embodiments, the present invention encompasses enabling the outflow of air through a closure device that is not impermeable, at least in sections, but instead comprises, for example, gas-permeable gauze. This includes, for example, a screw-on or attachable lid that, at least in sections, comprises such gauze, through which an exchange between the inside and outside of the housing can take place.

[0043] In some embodiments, the present invention encompasses enabling the outflow of air by means of a closure device which is or comprises a type of plug which in turn consists entirely or partially of an air-permeable material, e.g. of foam with pores.

[0044] In some embodiments, the closure device has or includes a check valve. The check valve can be or become integrated into the closure device. It functions as a pressure relief valve which opens to the environment of the housing when there is excess pressure in the compartment of the secondary side, thus allowing the saturated air to escape into the ambient air via the check valve. In some embodiments, a minimal excess pressure may be sufficient to open the check valve. Below this pressure, the check valve can close the housing in its area.

[0045] In certain embodiments, the check valve can simultaneously prevent air from flowing through the ventilation ports from the surroundings of the housing into the compartment on the secondary side of the hollow fiber membrane.

[0046] In some embodiments, the passage opening of the closure device has or includes a passage area that can be adjusted and / or changed by means of a throttle. The throttle can be or will be integrated into the closure device.

[0047] In some embodiments, the pressure relief of the compartment on the secondary side of the hollow fiber membrane can be continuously controlled by means of the throttle.

[0048] In some embodiments of the method according to the invention, the pressure prevailing in at least one feed line for supplying coating material to the coating side of the hollow fiber membrane is regulated and / or monitored during the application of the coating material. In some embodiments, the at least one hollow fiber membrane is arranged in the housing, or filter housing, of a dialyzer.

[0049] In some embodiments, the volume adjacent to or surrounding the side of the hollow fiber membrane not to be coated, also referred to herein as the secondary side, is preferably fluidically connected to an exterior of the housing or the dialyzer, e.g., via the housing. The housing may have ventilation connections, as described herein.

[0050] Solvent filtered from the coating material by capillary action evaporates in the compartment on the secondary side until the atmosphere there is saturated. The resulting solvent concentration in this compartment will attempt to equalize with the surroundings according to the principle of osmosis. If the hollow-fiber membrane is impermeable to the solvent on its coating side due to the coating material, only the ambient air or atmosphere is available in the opposite direction to create concentration equilibrium.

[0051] In some embodiments, this possibility of passive or active ventilation can serve to avoid air inclusions in the hollow fiber membrane or its coating, which could prove to be extremely disadvantageous during subsequent treatment of a patient because they could be hazardous to the patient.

[0052] Venting gas along the secondary side of the

[0053] Hollow fiber membranes are used for the immediate removal of substances or coating process products from the secondary side of the hollow fiber membrane from the housing. These substances, such as solvent residues, which should no longer be present in the housing during later use of the hollow fiber membrane, can be partially or completely removed from the housing in this way, which can shorten subsequent priming or rinsing.

[0054] In some embodiments of the device according to the invention, it has a control device for controlling or regulating the introduction of the coating material, the escape of the gas and / or the throttle, in particular as described herein.

[0055] The control device can initiate the execution of all or substantially all method steps. The method according to the invention can be executed substantially or entirely by the control device. It can be executed partially by the control device; in particular, those steps which do not require or involve human intervention and / or provision can be executed by the control device. The control device can serve as a pure control device or also as a regulating device.

[0056] Since the coating material becomes increasingly viscous with increasing evaporation of the solvent, it may be advantageous to influence the speed at which the pressure equalization described above takes place. For this reason, the invention encompasses varying the size of the venting connections for this purpose, for example, by various configurations of the closure device, for example as described herein, for example by using a check valve or a throttle.

[0057] It is also encompassed by the present invention to influence the penetration depth of the coating material into the pores of the hollow fiber membrane by varying the size of the ventilation connections.

[0058] In some embodiments, the dialyzer according to the invention is designed for use in dialysis, hemodialysis, hemofiltration or hemodiafiltration, in particular for acute, chronic renal replacement therapy or for continuous renal replacement therapy (CKRT = continuous kidney replacement therapy).

[0059] In some embodiments, no pump is used to introduce the coating material into or onto the hollow fiber membrane, but in others, it is.

[0060] In some embodiments, the hollow fiber membrane consists of polysulfone, polyvinylpyrrolidone or a mixture thereof, or comprises at least one of these materials or the mixture, in particular before its coating.

[0061] In some embodiments, the hollow fiber membrane is designed as in DE 100 34 098 C2, the disclosure of which is hereby incorporated by reference in its entirety.

[0062] Some or all embodiments of the invention may have one, several, or all of the advantages mentioned above and / or below. In recent years, not least due to the Covid-19 pandemic and the ever-increasing significance of COPD, there has been increasing focus on CCj elimination from the blood. When using a hollow fiber membrane coated according to the invention in an ultra-low-flow procedure, the blood flow can be, for example, less than 1000 ml / min or even less than 500 ml / min, but is not limited to this, so that treatment can be "minimally invasive" compared to standard treatment (low-flow ECMO), as it can be carried out using a smaller catheter for vascular access than with ECMO, such as the one used for dialysis (e.g., Shaldon catheter (11-13.5 Fr).

[0063] The field of application of the present invention can therefore be, in particular, the treatment of patients with chronic obstructive pulmonary disease (COPD), including those suffering from an acute exacerbation, i.e., a significant worsening of the clinical picture of their disease. The present invention and its advantages can thus benefit a wide range of patients.

[0064] State-of-the-art gas exchangers can be used to treat these patients. Gas exchangers are usually produced in much smaller quantities than dialyzers. Their production therefore has only a low degree of automation. For this reason, gas exchangers are comparatively expensive to manufacture. One advantage of the present invention can therefore be that the coating process can be automated, i.e. in particular can be carried out without human intervention. This can help to save time and costs. A further advantage can be that a large number of coated dialyzers according to the invention can be produced, since several modules can be coated simultaneously using the present invention. Since this can accelerate the production of dialyzers suitable for gas exchange, this can also help to save time and costs.

[0065] During coating of the coated side of the hollow fiber membrane, the air located there is displaced via the hollow fiber membrane toward the secondary side. If outflow from the secondary side out of the housing were prevented, air pockets could form in the hollow fiber membrane, which could be dangerous for a patient during subsequent treatment using the coated hollow fiber membrane. With the present invention, this can be advantageously prevented or at least reduced. This can contribute to increased patient safety.

[0066] A further advantage of the present invention may be that solvent from the coating material, which filters through the hollow fiber membrane toward the secondary side and evaporates there during coating of the coating side, can escape from the housing. This avoids solvent residues that would otherwise remain in the dialyzer housing. This can also advantageously contribute to increasing patient safety and optimizing the quality of the coating.

[0067] All advantages achievable with the methods according to the invention can also be achieved without reduction with the devices according to the invention in certain embodiments of the invention, and vice versa.

[0068] The present invention is described below purely by way of example with reference to the accompanying figures. In them, identical reference numerals designate identical or similar components. The following applies:

[0069] Fig. 1 shows an exemplary sequence of a method according to the invention for coating a preferably porous and / or hydrophilic hollow fiber membrane with a coating material in an exemplary embodiment;

[0070] Fig. 2 shows an exemplary arrangement for carrying out the method according to the invention in one embodiment using a device according to the invention in a first exemplary embodiment;

[0071] Fig . 2a shows the diagram of an exemplary course of pressure over time as it could take place within a first or second inlet line ;

[0072] Fig. 2b shows the diagram of Fig. 2a with the time tß marked when the hollow fibers of the hollow fiber membrane are coated;

[0073] Fig. 3 shows an exemplary arrangement for carrying out the method according to the invention in one embodiment using a device according to the invention in a second exemplary embodiment;

[0074] Fig. 4 shows a further exemplary arrangement for carrying out the method according to the invention in a further embodiment using a device according to the invention in a third exemplary embodiment; and

[0075] Fig. 5 shows a further exemplary arrangement for carrying out the method according to the invention in a further embodiment using a device according to the invention in a fourth exemplary embodiment.

[0076] Fig. 1 shows an exemplary sequence of a method according to the invention for coating a preferably porous and / or hydrophilic hollow fiber membrane 1 with a coating material B in an exemplary

[0077] Implementation form.

[0078] Reference is made to the reference numerals of the device 100 and components in the following figures.

[0079] Method step M1 represents a provision of the hollow fiber membrane 1. The hollow fiber membrane 1 can be arranged in a housing 50, such as a filter housing, for example of a dialyzer, for example as shown in the following figures.

[0080] The hollow fiber membrane 1 , which may consist of or comprise a plurality of hollow fibers, has a longitudinal direction L with two first and second ends 10 , 20 opposite one another in the longitudinal direction L.

[0081] Method step M2 represents providing the coating material B. The coating material B can be or comprise a solution, preferably a silicone solution.

[0082] The application of the coating material B to exactly one or at least one side of the hollow fiber membrane 1, which serves as the coating side 30, is represented in process step M3. It should be noted here that the terms "side" and "end" of the hollow fiber membrane 1 have different meanings, as explained herein, and are therefore not equivalent.

[0083] The volume adjacent to the secondary side 40 of the hollow fiber membrane 1 that is not to be coated is preferably fluidically connected to an exterior of a housing 50, e.g. the filter housing, or a dialyzer, wherein this connection can also be restricted or interrupted, for example as described herein.

[0084] Since the hollow fiber membrane 1 can comprise a plurality of hollow fibers, the "coating side 30" is distributed over the plurality of hollow fibers or is composed of their inner sides. Likewise, the "secondary side 40" reflects a plurality of outer sides of the hollow fibers or even constitutes or co-delimits the space defined by them.

[0085] In some embodiments, the secondary side compartment 40 may have a first vent port 85 and a second vent port 95. These are arranged in particular in the upper half of the housing cross-section, which is in fluid communication with the first and second vent ports 85, 95, e.g., in a section shown only schematically, such as that in Fig. 3.

[0086] In the optional process step M4, during the application of the coating material B, e.g. starting from one of the two ends 10 or 20 or from both ends 10, 20, the pressure Pl, P2 prevailing in at least one feed line 80, 90 for supplying coating material B to the coating side 30 of the hollow fiber membrane 1 is measured.

[0087] Further process steps before and / or after the process step of applying coating material B are conceivable, such as steaming, moistening, drying, sterilizing, ... of the hollow fiber membrane 1.

[0088] Fig. 2 shows an exemplary arrangement for carrying out the method according to the invention in one embodiment using a device 100 according to the invention in a first exemplary embodiment.

[0089] At least one, preferably porous and / or hydrophilic, hollow-fiber membrane 1 is arranged in a housing 50, here a filter housing. It has a longitudinal direction L with two ends 10, 20 opposite each other in the longitudinal direction L.

[0090] The hollow fiber membrane 1 is fluidically connected at its first end 10 to a first inlet line 80 and at its second end 20 to a second inlet line 90. The first and second inlet lines 80, 90 are fluidically connected to a container 103 for a coating material B, which may be or comprise silicone or a silicone solution. At least one conveying means 105 can be provided for conveying the coating material B within the first and second inlet lines 80, 90 in or on these lines, or fluidically connected to them.

[0091] A pressure PI prevailing in the first inlet line 80 can be measured by means of a suitable pressure gauge PS1 provided for this purpose, and a pressure P2 prevailing in the second inlet line 90 can be measured by means of a suitable pressure gauge PS2 provided for this purpose (see also Fig. 2a and Fig. 2b). In certain embodiments, it can be provided to store and / or further process the determined pressures PI, P2 (not shown in Fig. 2).

[0092] The coating material B finds its way along the coating side 30 of the hollow fiber membrane 1 and through the filter housing 50 in the direction of the respective opposite end 10, 20 and remains as a coating wholly or partially adhered to the coating side 30 of the hollow fiber membrane 1.

[0093] In the example of Fig. 2, the housing 50 further comprises a first vent port 85 and a second vent port 95 at its upper cross section, through which gas, in particular gas saturated with solvent, can flow out or be discharged, e.g., into the atmosphere. The arrangement in the upper cross section of the housing 50 and the fluidic connection of the vent ports 85, 95 to the compartment of the secondary side of the hollow fiber membrane can advantageously contribute to the passive escape of the gas.

[0094] The possibility of passive venting (in Fig. 2 shown by small circles) can serve to avoid negative pressure, which could make it difficult for coating material B to flow towards the hollow fiber membrane 1.

[0095] In a very simplified schematic, a control device 101 for carrying out the method and / or for controlling and / or regulating the device 100 is arranged below it. This can be or include controlling or regulating the introduction of the coating material B, the venting of the gas, or controlling and / or regulating a throttle 97 (not shown here, see Fig. 5), in particular as described herein.

[0096] Fig. 2a shows a diagram of an exemplary curve of pressure Pl, P2 (y-axis, p) over time (x-axis, t), as it could occur within a first or second inlet line 80, 90. Reference is made to the reference symbols in Fig. 2.

[0097] The diagram shows that the pressure P1, P2 exhibits a uniform curve during the application of the coating material B. This period is indicated by a double arrow and two dashed lines. Fig. 2b shows the diagram of Fig. 2a, indicating the time tß when the hollow fibers of the hollow fiber membrane 1 are coated.

[0098] If the pressure application increases abruptly, as shown in the example of Fig. 2b at time tß, this may be an indication that the two fronts of the coating material B emanating from the ends 10, 20 have "met" within the hollow fibers and thus the coating side 30 of the hollow fiber membrane 1 is completely coated. Advantageously, this alternative could determine the time at which the fibers of the hollow fiber membrane 1 are actually completely coated. A further supply of coating material B would lead to a greater penetration depth of the coating material B into the pores of the hollow fiber membrane 1.

[0099] Fig. 3 shows a further exemplary arrangement for carrying out the method according to the invention in one embodiment using a device 100 according to the invention in a further exemplary

[0100] Embodiment. The explanations for Figs. 3 to 5 are not limited to the coating being carried out from only one end 10 or 20 or from both ends 10, 20 simultaneously.

[0101] Reference is made to the reference numerals and the description of Fig. 2 and in the following only the differences therefrom as far as the device 100 is concerned are concerned.

[0102] In contrast to Fig. 2, in the example of Fig. 3, only the housing 50 with the hollow fiber membrane 1 is shown. The other components shown in Fig. 2 (feed lines 80, 90, container 103, conveying means 105, etc.) have been omitted from Fig. 3 and the following figures to increase clarity. The hollow fiber membrane 1 is represented schematically in a highly simplified manner only by the oblique line within the housing 50. The coating side 30 and the secondary side 40 are also marked.

[0103] The housing 50 has a first vent port 85 and a second vent port 95 in its upper cross-section, which are fluidically connected to the compartment of the secondary side 40. The vent ports 85, 95 are each closed by a closure device 60.

[0104] A through-opening 61 in the form of a capillary is arranged in the closure device 60 of the first vent port 85, by means of which the compartment of the secondary side 40 of the hollow-fiber membrane 1 is fluidically connected to the environment, i.e., the atmosphere. Through this through-opening, the solvent-saturated air can escape from the compartment toward the environment. This is represented by small circles.

[0105] Fig. 4 shows an exemplary arrangement for carrying out the method according to the invention in one embodiment using a device 100 according to the invention in a third exemplary embodiment.

[0106] Reference is made to the reference numerals and designs of Fig. 2 and Fig. 3, and only the differences therefrom will be discussed below. In the example of Fig. 4, a check valve 63 is arranged in the closure device 60 of the first vent port 85, by means of which the compartment of the secondary side 40 of the hollow fiber membrane 1 can be or be sealed off from the environment, i.e., the atmosphere.

[0107] The check valve 63 acts as a pressure relief valve which opens to the environment of the housing when there is an overpressure in the compartment of the secondary side 40, so that the air saturated with solvent can escape through the check valve into the ambient air. To open the check valve 63, in some

[0108] In some embodiments, a minimal overpressure from the gas is sufficient.

[0109] The check valve can simultaneously prevent air from flowing through the first vent port 85 from the surroundings of the housing into the compartment on the secondary side of the hollow fiber membrane.

[0110] Fig. 5 shows an exemplary arrangement for carrying out the method according to the invention in one embodiment using a device 100 according to the invention in a fourth exemplary embodiment.

[0111] Reference is made to the explanations of the preceding figures and only the differences from these are discussed below.

[0112] In the example of Fig. 5, a throttle 97 is arranged on the closure device 60 of the first ventilation connection 85, by means of which the passage area of ​​the ventilation connection 85 can be adjusted and / or changed.

[0113] In certain embodiments, the pressure relief of the compartment on the secondary side of the hollow fiber membrane can be continuously controlled by means of the throttle 97.

[0114] In some embodiments, it may further be provided to fluidically separate the compartment of the secondary side 40 of the hollow fiber membrane 1 from the environment, i.e. the atmosphere, by means of the throttle 97.

[0115] List of reference symbols

[0116] Hollow fiber membrane

[0117] 10 first end

[0118] 20 second end

[0119] 30 coating side

[0120] 40 Secondary page

[0121] 50 housings; filter housings

[0122] 60 locking device

[0123] 61 Passage opening

[0124] 63 Check valve

[0125] 80 first inlet line

[0126] 85 first ventilation connection

[0127] 90 second supply line

[0128] 95 second ventilation connection

[0129] 97 Thrush

[0130] 100 device

[0131] 101 Control device

[0132] 103 Containers for coating material

[0133] 105 funding

[0134] B Coating material

[0135] L longitudinal direction

[0136] Ml to M4 process steps

[0137] PS I pressure gauge

[0138] PS2 pressure gauge

[0139] PI first pressure; pressure in first inlet line

[0140] P2 second pressure; pressure in second supply line

Claims

Claims 1. Method for coating a, preferably porous and / or hydrophilic, hollow fiber membrane (1) with a coating material (B) , comprising the steps: Providing the hollow fiber membrane (1) with a coating side (30) to be coated and a secondary side (40) opposite it; Providing the coating material (B); and Applying the coating material (B) to the coating side (30) of the hollow fiber membrane (1) or only to this side, wherein the hollow fiber membrane (1) has a longitudinal direction (L) with two first and second ends (10, 20) opposite each other in the longitudinal direction (L); and wherein the hollow fiber membrane (1) is arranged in a housing (50), such as a filter housing, e.g. of a dialyzer.

2. The method of claim 1, wherein the coating material (B) is or comprises a solution, preferably a silicone solution.

3. Method according to any of the preceding claims, wherein the application of the coating material (B) to the coating side (30) of the hollow fiber membrane (1) The process is carried out simultaneously or overlapping in time from both the first and the second end (10, 20). A method according to claim 3, wherein, during the application of the coating material (B) from both ends (10, 20), the pressure (Pl, P2) prevailing in at least one supply line (80, 90) for supplying coating material (B) to the coating side (30) of the hollow fiber membrane (1) is measured. A method according to any of the preceding claims, wherein the housing has a first vent connection (85) or a second vent connection (95), wherein gas is allowed to flow out of the housing during coating via the first vent connection (85) or the second vent connection (95). A method according to claim 5, wherein the first vent connection (85) and / or the second vent connection (95) is in fluid communication with the atmosphere or an exterior of the housing in the upper half of the cross-section of the housing.A method according to claim 5 or 6, wherein the first ventilation port (85) and / or the second ventilation port (95) is not closed, but at most throttled, for example by means of a throttle (97) or by means of one or more capillaries. A method according to any one of claims 5 to 7, wherein the first ventilation port (85) and / or the second ventilation port (95) is a. Dialysis fluid inlet or dialysate outlet, or a connection therefor, are respectively. A method according to claim 7 or 8, wherein the at least one capillary has a diameter of at most 1 mm, particularly preferably less than 0.7 mm, most preferably less than 0.5 mm. A method according to any one of claims 5 to 9, wherein the first vent port (85) and / or the second vent port (95) has a closure device (60) for partially closing its passage area. A method according to claim 10, wherein the closure device (60) has a through-opening (61) to the atmosphere or to an exterior of the housing through which gas can escape, the through-opening preferably being or comprising a capillary. A method according to claim 10 or 11, wherein the closure device (60) is or comprises a check valve (63).Method according to one of claims 10 to 12, wherein the closure device (60) has, is or comprises a passage surface that can be adjusted and / or changed by means of a throttle (97).

14. Method according to one of the preceding claims, wherein during the application of the coating material (B) the pressure (D1, D2 ) prevailing in at least one supply line (80, 90) for supplying coating material (B) to the coating side (30) of the hollow fiber membrane (1) is regulated.

15. Hollow fiber membrane (1) , coated by the method according to any of the preceding claims.

16. Gas exchanger or dialyzer, comprising a hollow fiber membrane (1) according to claim 15.

17. Device (100) for coating a hollow fiber membrane (1) , configured to carry out the method according to any one of claims 1 to 14.

18. Device (100) according to claim 17, comprising a control device (101) for controlling or regulating the introduction of the coating material (B), the gas and / or the throttle (97).

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