DE102022114272A1 - Coating of hollow fiber membranes in medical technology II - Google Patents

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), comprising the steps: providing the hollow fiber membrane (1) with a coating side (30) to be coated and one opposite thereto Secondary side (40), providing the coating material (B) and applying the coating material (B) to the coating side (30), or only to this. The hollow fiber membrane (1) has a longitudinal direction (L) with two first and second ends (10, 20) opposite one another in the longitudinal direction (L). Furthermore, the hollow fiber membrane (1) is arranged in a housing (50).

Description

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 preamble or generic terms of these claims.

With ECLS (extracorporeal lung support), oxygen is supplied to the blood flowing extracorporeally in a gas exchange device (ECMO = extracorporeal membrane oxygenation) and/or CO ₂ is removed (ECCO2R = extracorporeal CO ₂ removal) depending on the blood flow speed. The procedure represents an advantageous alternative and/or supplement to conventional mechanical ventilation for the patient in many respects.

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

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

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 with the features of claim 15 and by means of the dialyzer with the features of claim 16. In addition, it is solved by a device with the features of claim 17.

The method according to the invention for coating a, preferably porous and/or hydrophilic, hollow fiber membrane with a coating material includes providing at least one hollow fiber membrane with a coating side to be coated and a secondary side opposite this, as well as providing the coating material.

Furthermore, the method includes applying the coating material to exactly 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 may be suitable and applied to reduce the passage of plasma through the pores of the hollow fiber membrane in use.

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

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. H. not in 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 made.

If we are talking about a hollow fiber membrane here, what has been said in this regard also applies in some embodiments to a large number of mostly parallel hollow fiber membranes, which, for. B. bundled, for example in a common housing, for example the filter housing, for example as in 2 B the US 10,583,458 B2 shown in section. They can be coated simultaneously using the present invention.

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

The hollow fiber membrane according to the invention was coated using the method according to the invention.

The gas exchanger, blood filter or dialyzer according to the invention has a hollow fiber membrane according to the invention. The coating side may be the blood side in these or any other embodiments.

The device according to the invention for coating a hollow fiber membrane is configured to carry out the method according to the invention.

Embodiments according to the invention may have some, some or all of the following features in any combination, unless this is technically impossible for those skilled in the art.

In all of the following statements, the use of the expression “may be” or “may have” etc. is synonymous with “is preferably” or “preferably has” etc. and is intended to explain embodiments according to the invention.

Whenever numerical words are mentioned herein, the person skilled in the art understands these as indicating a numerically lower limit. Unless this leads to a contradiction that is recognizable to the expert, the expert therefore always reads “at least one” or “at least one” when “a” or “an” is stated. This understanding is also included in the present invention, as is the interpretation that a numerical word such as “a” can alternatively be meant as “exactly a”, wherever this is technically possible for a person skilled in the art. Both are encompassed by the present invention and apply to all number words used herein.

Whenever spatial information is used herein, such as: B. "above", "below", "left" or "right" is mentioned, the expert understands this to mean 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 bottom of the figure than “top.”

Advantageous further developments of the present invention are the subject of subclaims and embodiments.

If an embodiment is mentioned herein, it represents an exemplary embodiment according to the invention, which is not to be understood as limiting.

If it is disclosed herein that the object according to the invention has one or more features in a specific embodiment, it is also disclosed here that the object according to the invention expressly does not have exactly this or these features in other embodiments also according to the invention, e.g. B. in the sense of a disclaimer. For each embodiment mentioned herein, the opposite embodiment, for example formulated as a negation, is also disclosed.

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 steps that can be carried out automatically, in any combination or corresponding devices, which are preferably based on the name of the respective method step (e.g. “determination” 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 be connected to it in a signal connection, to be controlled accordingly.

When speaking of programmed or configured herein, 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.

In some embodiments of the method, the coating material is applied to the coating side of the hollow fiber membrane simultaneously or overlapping in time from both the first and second ends. This means that during the coating, in which the coating material, which in order to be able to coat the coating side, i.e. the inner surface of the hollow fibers closed except for their end faces, must always be introduced into the hollow fiber from one end, here from both ends is introduced into the hollow fiber. The introduction of coating material can be started at the same time from both the first end and the second end. However, it can also be provided to initially start inserting from one end in order to later start inserting from the other end. What is relevant is that there is at least one point in time during the coating at which the coating takes place from both ends simultaneously.

Such a simultaneous or overlapping introduction of coating material from both ends can contribute particularly advantageously to avoiding gas inclusions in the membrane.

For this purpose, as with one-sided introduction, a certain minimum pressure must be used to overcome the flow resistance for coating the coating side with the coating material, which is preferably less than 1 bar, particularly preferably less than 0.5 bar, in order to avoid damage. In the compartment on the coating side of the hollow fiber membrane, i.e. H. Air located 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 ventilation connections, as described herein.

If the measured pressure or the pressure required to further introduce coating material into the hollow fibers increases suddenly, this may be an indication that the two are moving towards each other from the first end or the second end of the hollow fiber membrane The corresponding fronts of the coating material have “hit” within the hollow fibers and the coating side of the hollow fiber membrane is therefore completely coated.

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

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

The depth of penetration of the coating material into the pores can alternatively or additionally also 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.

In some embodiments, during the application of the coating material, the pressure which prevails 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.

If several inlet lines are provided for the coating material, in some embodiments the pressure prevailing in each of the inlet lines is measured. In certain embodiments, provision can be made to monitor these pressures and to regulate or control the coating process accordingly or, for example. B. to end, too, since in some embodiments z. B. the increase in pressure can say something about the depth at which the coating material has already penetrated into the pores of the hollow fiber membrane.

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

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.

In some embodiments, the first ventilation connection and/or the second ventilation connection are not closed, but are at most throttled, for example by means of a throttle, preferably whose passage area can be changed. This preferably applies to the entire duration of the procedure, or at least to a large part of it, e.g. B. for at least 70%, 80%, 90% or more of the duration of the step of applying the coating material to the coating side.

If this refers to a “passage area”, e.g. B. in connection with the ventilation connections, the throttle, through openings, etc., other terms such as cross section, cross section area, passage cross section, opening cross section, etc. are also included.

In some embodiments, the first ventilation port and/or the second ventilation port are a dialysis fluid inlet line or dialysate outlet line, or a respective port therefor.

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).

In some embodiments, the closure device has a passage opening to the atmosphere or to an exterior of the housing through which gas can escape, the passage opening preferably being or comprising a capillary. Capillaries can have different diameters. The smaller the diameter of the capillary, the more delayed concentration compensation takes place between the compartment on the secondary side of the hollow fiber membrane on the one hand and the surroundings of the housing, i.e. H. for example the atmosphere, on the other hand. A preferred diameter of the capillary, or of all capillaries arranged in parallel at these points, is preferably less than 1 mm, particularly preferably less than 0.7 mm, very particularly preferably less than 0.5 mm.

In some embodiments, the present invention includes enabling the air to flow out through a closure device, which is not impermeable at least in sections, but rather z. B. has gas-permeable gauze. Includes e.g. B. a screw-on or attachable lid, which at least in sections has such gauze over which an exchange between inside and outside, based on the housing, can take place.

In some embodiments, the present invention includes enabling the outflow of air by means of a closure device, which is or comprises a type of stopper, which in turn consists wholly or partly of an air-permeable material, e.g. B. made of foam with pores.

In some embodiments, the closure device has or includes a check valve. The check valve can be or will be integrated into the closure device. It functions as a pressure relief valve, which opens to the surroundings of the housing when there is excess pressure in the compartment of the secondary side, so that the saturated air can 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.

In certain embodiments, the check valve can simultaneously prevent air from flowing in via the ventilation connections from the surroundings of the housing into the compartment on the secondary side of the hollow fiber membrane.

In some embodiments, the through opening of the closure device has or has 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.

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

In some embodiments of the method according to the invention, the pressure which prevails 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.

The volume adjacent to or surrounding the side of the hollow fiber membrane that is not to be coated, also referred to herein as the secondary side, is in some embodiments preferably fluidly connected to an exterior of the housing or the dialyzer, e.g. B. by means of the housing. The housing can have ventilation connections, as described herein.

Solvent filtered from the coating material by means of capillary forces evaporates in the compartment on the secondary side until the atmosphere therein is saturated. The resulting solvent concentration in this compartment will attempt to balance itself with the environment according to the principle of osmosis. If the hollow fiber membrane is impermeable to the solvent on its coating side through the coating material, only the ambient air or atmosphere in the opposite direction is available to balance the concentration.

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 are dangerous to the patient.

Venting gas along the secondary side of the hollow fiber membrane serves to immediately remove substances or products of the coating process from the side of the hollow fiber membrane facing the secondary side from the housing. These substances, for example solvent residues, which should no longer be present in the housing during later use of the hollow fiber membrane, can in this way be partially or completely removed from the housing, which can shorten the time required for subsequent priming or rinsing.

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.

The control device can cause all or substantially all of the method steps to be carried out. The method according to the invention can be carried out essentially or completely by the control device. It can be partially carried out by the control device, in particular those steps which do not require or involve human intervention and/or provision can be carried out by the control device. The control device can serve as a pure control device or as a regulating device.

Since the coating material becomes more and more viscous as the solvent evaporates, it can be advantageous to influence the speed at which the pressure equalization described above takes place. For this reason, the invention includes varying the size of the ventilation connections for this purpose, for example through different configurations of the closure device, for example as described herein, for example by using a check valve or a throttle.

The present invention also includes influencing the penetration depth of the coating material into the pores of the hollow fiber membrane by varying the size of the ventilation connections.

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

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

In some embodiments, the hollow fiber membrane consists of polysulfone, polyvinylpyrrolidone or a mixture thereof, or has at least one of these materials or the mixture, in particular before being coated.

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

Some or all embodiments according to the invention may have one, more or all of the advantages mentioned above and/or below.

In recent years, CO ₂ elimination from the blood has increasingly come into focus, not least due to the Covid19 pandemic and the increasing importance of COPD. When using a hollow fiber membrane coated according to the invention, the blood flow can be achieved in an ultra-low flow process of e.g. B. less than 1000 ml/min or even less than 500 ml/min, but is not limited to this, so that compared to standard treatment (low-flow ECMO), treatment is “minimally invasive” because it uses a smaller catheter for vascular access than with ECMO, which is also used for dialysis (e.g. Shaldon catheter (11 - 13.5 Fr).

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 who suffer from an acute exacerbation, i.e. a significant worsening of the clinical picture of their disease. The present invention and its benefits can thus benefit a variety of patients.

State-of-the-art gas exchangers can be used to treat these patients. Gas exchangers are usually manufactured in much smaller quantities than dialyzers. Their production therefore only has a low degree of automation. For this reason, gas exchangers are comparatively expensive to manufacture. An advantage of the present invention can therefore be that the coating process can be automated, i.e. in particular without human intervention. This can help save time and costs.

A further advantage may be that a large number of coated dialyzers according to the invention can be produced, since several modules can be coated at the same time using the present invention. Since this can speed up the production of dialyzers suitable for gas exchange, this can also help save time and costs.

During the coating of the coating side of the hollow fiber membrane, the air located there is displaced towards the secondary side via the hollow fiber membrane. If flow from the secondary side out of the housing were prevented, air pockets could occur in the hollow fiber membrane, which could be dangerous for a patient during later treatment using the coated hollow fiber membrane. This can advantageously be prevented or at least reduced with the present invention. This can contribute to increased patient safety.

A further advantage of the present invention can be that solvent from the coating material, which filters through the hollow fiber membrane towards the secondary side and evaporates there when coating the coating side, can escape from the housing. This means that solvent residues that would otherwise remain in the dialyzer housing can be removed be avoided. This can also help to increase patient safety and optimize the quality of the coating.

All of the advantages that can be achieved with the methods according to the invention can also be achieved undiminished with the devices according to the invention in certain embodiments according to the invention, and vice versa.

• 1 zeigt einen beispielhaften Ablauf eines erfindungsgemäßen Verfahrens zum Beschichten einer, vorzugsweise porösen und/oder hydrophilen, Hohlfasermembran mit einem Beschichtungsmaterial in einer beispielhaften Ausführungsform;
• 2 zeigt eine beispielhafte Anordnung zum Ausführen des erfindungsgemäßen Verfahrens in einer Ausführungsform unter Verwendung einer erfindungsgemäßen Vorrichtung in einer ersten beispielhaften Ausführungsform;
• 2a zeigt das Diagramm eines beispielhaften Verlaufs von Druck über der Zeit, wie er innerhalb einer ersten oder zweiten Zulaufleitung stattfinden könnte;
• 2b zeigt das Diagramm der 2a mit Kennzeichnung des Zeitpunkts t_B, wenn die Hohlfasern der Hohlfasermembran beschichtet sind;
• 3 zeigt eine beispielhafte Anordnung zum Ausführen des erfindungsgemäßen Verfahrens in einer Ausführungsform unter Verwendung einer erfindungsgemäßen Vorrichtung in einer zweiten beispielhaften Ausführungsform;
• 4 zeigt eine weitere beispielhafte Anordnung zum Ausführen des erfindungsgemäßen Verfahrens in einer weiteren Ausführungsform unter Verwendung einer erfindungsgemäßen Vorrichtung in einer dritten beispielhaften Ausführungsform; und
• 5 zeigt eine weitere beispielhafte Anordnung zum Ausführen des erfindungsgemäßen Verfahrens in einer weiteren Ausführungsform unter Verwendung einer erfindungsgemäßen Vorrichtung in einer vierten beispielhaften Ausführungsform.

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

• 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;
• 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;
• 2a shows the diagram of an exemplary course of pressure over time as it could take place within a first or second inlet line;
• 2 B shows the diagram of the 2a with identification of the time t _B when the hollow fibers of the hollow fiber membrane are coated;
• 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;
• 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
• 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.

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 embodiment.

Reference is made to the reference numbers of the device 100 and components in the following figures.

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

The hollow fiber membrane 1, which can consist of or have 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.

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

Applying 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 method step M3. It should be noted that the terms “side” and “end” of the hollow fiber membrane 1 have different meanings, as explained herein, and are therefore not to be equated.

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

Since the hollow fiber membrane 1 can have a large number of hollow fibers, the “coating side 30” is distributed over the large number of hollow fibers or is composed of their insides. It also applies to the “secondary side 40” that it reflects a large number of outer sides of the hollow fibers or even makes up or co-limits the space that is delimited by it.

The compartment of the secondary side 40 may in some embodiments have a first ventilation port 85 and a second ventilation 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 ventilation ports 85, 95, e.g. B. in a schematically shown section like that of 3 .

In the optional process step M4, during the application of the coating material B, e.g. B. one of the two ends 10 or 20 or starting from both ends 10, 20, the pressure P1, P2, which prevails 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.

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.

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.

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 one another in the longitudinal direction L.

The hollow fiber membrane 1 is fluidly 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 in fluid communication with a container 103 for a coating material B, which can be or include 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 fluidly connected to them.

A pressure P1 prevailing in the first inlet line 80 can be measured by means of a suitable pressure gauge PS1 intended for this purpose, and a pressure P2 prevailing in the second inlet line 90 can be measured by means of a suitable pressure meter PS2 intended for this purpose (see also 2a and 2 B) . In certain embodiments it can be provided that the determined pressures P1, P2 (in 2 not shown) to store and/or process further.

The coating material B finds its way along the coating side of the hollow membrane fiber 1 and through the filter housing 50 towards the opposite end 10, 20 and remains fully or partially adhered as a coating to the coating side 30 of the hollow fiber membrane 1.

The housing 50 has in the example of 2 on its upper cross section there is also a first ventilation connection 85 and a second ventilation connection 95, via which passive gas, in particular air saturated with solvent, e.g. B. into the atmosphere, flows out or can be derived.

The arrangement in the upper cross section of the housing 50 and the fluidic connection of the ventilation connections 85, 95 with the compartment of the secondary side of the hollow fiber membrane can advantageously contribute to the passive escape of the gas.

The possibility of passive ventilation (in the 2 represented by small circles) can serve to avoid negative pressure, which could make it more difficult for coating material B to flow in the direction of the hollow fiber membrane 1.

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 underneath it. This can involve controlling or regulating the introduction of the coating material B, venting the gas or controlling and/or regulating a throttle 97 (not shown here, see 5 ), in particular as described herein, be or include.

2a shows the diagram of an exemplary course of pressure P1, P2 (y-axis, p) over time (x-axis, t), as it could take place within a first or second inlet line 80, 90. Reference numbers are used 2 referred.

It can be seen from the diagram that the pressure P1, P2 shows a uniform course when the coating material B is fed. This period is marked by a double arrow and two dashed lines.

2 B shows the diagram of the 2a with identification of the time t _B when the hollow fibers of the hollow fiber membrane 1 are coated.

If the printing effort increases suddenly, as in the example 2 B shown at time t _B , this may be an indication that the two fronts of the coating material B extending 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. In this alternative, the time at which the fibers of the hollow fiber membrane 1 are actually completely coated could advantageously be determined. A further supply of coating material B would result in a larger ßeren penetration depth of the coating material B into the pores of the hollow fiber membrane 1.

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 embodiment. The comments on the 3 until 5 are not limited to the fact that the coating is carried out from only one end 10 or 20 or from both ends 10, 20 at the same time.

Please refer to the reference numbers and the description 2 Reference is made and in the following only focused on the differences to this as far as the device 100 is concerned.

In contrast to 2 is in the example 3 only the housing 50 with the hollow fiber membrane 1 is shown. The other components shown are the 2 (Inlet lines 80, 90, container 103, conveyor 105, etc.) were in 3 and the following figures are omitted to increase clarity. The hollow fiber membrane 1 is represented schematically in a very simplified manner only by means of the oblique line within the housing 50. Coating side 30 and secondary side 40 are also marked.

The housing 50 has in its upper cross section a first ventilation connection 85 and a second ventilation connection 95, which are fluidly connected to the compartment of the secondary side 40. The ventilation connections 85, 95 are each closed by means of a closure device 60.

In the closure device 60 of the first ventilation connection 85, a through opening 61 is arranged in the form of a capillary, by means of which the compartment of the secondary side 40 of the hollow fiber membrane 1 with the environment, i.e. H. the atmosphere, is fluidly connected. Through this passage opening, the air saturated with solvent can escape from the compartment towards the environment. This is shown using small circles.

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.

Reference is made to the reference numbers and statements 2 and 3 Reference is made and the following only focuses on the differences to these.

In the example, in the closure device 60 of the first ventilation connection 85 4 a check valve 63 is arranged, by means of which the compartment of the secondary side 40 of the hollow fiber membrane 1 can be or can be closed off from the environment, ie the atmosphere.

The check valve 63 functions as a pressure relief valve, which opens to the surroundings of the housing when there is excess pressure in the compartment of the secondary side so that the air saturated with solvent can escape into the ambient air via the check valve. In some embodiments, a minimal excess pressure from the gas may be sufficient to open the check valve.

The check valve can simultaneously prevent air from flowing in via the first ventilation port 85 from the surroundings of the housing into the compartment on the secondary side of the hollow fiber membrane.

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.

Reference is made to the statements in the preceding figures and only the differences to these are discussed below.

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

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

In some embodiments it can also be provided that the compartment of the secondary side 40 of the hollow fiber membrane 1 is exposed to the environment, i.e. H. the atmosphere, to be fluidically separated by means of the throttle 97.

Reference symbol list

1

Hollow fiber membrane

10

first ending

20

second ending

30

Coating side

40

Secondary side

50

Housing; Filter housing

60

Closure device

61

Passage opening

63

check valve

80

first inlet line

85

first ventilation connection

90

second inlet line

95

second ventilation connection

97

throttle

100

contraption

101

Control device

103

Container for coating material

105

funding

b

Coating material

L

Longitudinal direction

M1 to M4

Procedural steps

PS1

Pressure gauge

PS2

Pressure gauge

P1

first printing; Pressure in the first inlet line

P2

second printing; Pressure in the second inlet line

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 10583458 B2 [0010]
• DE 10034098 C2 [0060]

Claims (18)

Method for coating a, preferably porous and/or hydrophilic, hollow fiber membrane (1) with a coating material (B), with the steps: - Providing the hollow fiber membrane (1) with a coating side (30) to be coated and a secondary side (40) opposite this; - 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, the hollow fiber membrane (1) having a longitudinal direction (L) with two first and second ends (10) opposite one another in the longitudinal direction (L). , 20); and wherein the hollow fiber membrane (1) is in a housing (50), such as a filter housing, e.g. B. a dialyzer is arranged. Procedure according to Claim 1 , wherein the coating material (B) is or comprises a solution, preferably a silicone solution. Method according to one of the preceding claims, wherein the application of the coating material (B) to the coating side (30) of the hollow fiber membrane (1) takes place simultaneously or overlapping in time from both the first and second ends (10, 20). Procedure according to Claim 3 , wherein during the application of the coating material (B) from both ends (10, 20) the pressure (P1, P2) which is in at least one feed line (80, 90) for supplying coating material (B) to the coating side (30). Hollow fiber membrane (1) prevails, is measured. Method according to one of the preceding claims, wherein the housing has a first vent port (85) and a second vent port (95), respectively, wherein gas is allowed to exit the housing during coating via the first vent port (85) or the second vent port (95). to flow out. Procedure according to Claim 5 , wherein the first vent port (85) and/or the second vent port (95) in the upper half of the cross section of the housing is in fluid communication with the atmosphere or an exterior of the housing. Procedure according to Claim 5 or 6 , wherein the first ventilation connection (85) and / or the second ventilation connection (95) is not closed, but rather throttled, for example by means of a throttle (97) or by means of one or more capillaries. Procedure according to one of the Claims 5 until 7 , wherein the first ventilation connection (85) and / or the second ventilation connection (95) are a dialysis fluid inlet line or dialysate outlet line or a connection therefor. Procedure according to one of the Claims 7 or 8th , wherein the at least one capillary has a diameter of at most 1 mm, particularly preferably less than 0.7 mm, very particularly preferably less than 0.5 mm. Procedure according to one of the Claims 5 until 9 , wherein the first ventilation connection (85) and / or the second ventilation connection (95) has a closure device (60) for partially closing its passage area. Procedure 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. Procedure according to Claim 10 or 11 , wherein the closure device (60) has or includes a check valve (63). Procedure according to one of the Claims 10 until 12 , wherein the closure device (60) has or has a passage surface that can be adjusted and/or changed by means of a throttle (97). Method according to one of the preceding claims, wherein during the application of the coating material the pressure (D1, D2) which prevails 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 regulated. Hollow fiber membrane (1), coated using the method according to one of the preceding claims. Gas exchanger or dialyzer, with a hollow fiber membrane (1). Claim 15 . Device (100) for coating a hollow fiber membrane (1), configured to carry out the method according to one of Claims 1 until 14 . Device (100) after 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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