Packaging method and apparatus

Abstract

The present disclosure relates to methods and apparatus for packaging hollow fiber membranes in a diffusion and / or filtration device, such as an ultrafilter or a capillary dialyzer.

Description

Technical Field

[0001] This disclosure relates to methods and apparatus for encapsulating hollow fiber membranes in diffusion and / or filtration devices, such as ultrafiltration or capillary dialyzers. Background Technology

[0002] Diffusion and / or filtration devices, including hollow fiber membranes, are widely used for the separation or purification of liquids. Examples include: ultrafiltration devices for water purification; plasma filters for separating plasma from blood; capillary dialyzers for blood purification in patients with renal insufficiency, i.e., for patients treated by hemodialysis, hemodialysis filtration, or hemofiltration; and so on. A variety of different models of diffusion and / or filtration devices including hollow fiber membranes are commercially available.

[0003] These devices typically include a housing comprising a tubular portion with end caps covering the opening of that tubular portion. The hollow fiber membrane bundle is disposed within the housing in such a manner that a seal is formed between a first flow space created by fiber cavities and a second flow space surrounding the membrane on the outside. This seal is typically provided by end-wall devices within the housing, which is formed of a polymer block in which the ends of the hollow fiber membrane are embedded.

[0004] GB2016358A describes a method for encapsulating the ends of a hollow fiber bundle in a hollow fiber dialyzer. The method includes: inserting the (hollow fiber) bundle into a tubular housing; sealing the ends of the housing with a sealing member; providing a curable liquid sealant within the housing; rotating the housing to cause the sealant itself to disperse around the ends of the hollow fibers, allowing the sealant to solidify; and subsequently removing the sealing member and cutting through the ends of the fibers and sealant, or alternatively cutting through the sealing member without removing it.

[0005] WO1984 / 002486A1 discloses another method for manufacturing a hollow fiber separator, the method comprising the step of forming an integral structure including: at least one tubular outer shell portion; and an elongated chamber portion extending elongated relative to the tubular outer shell portion and communicating with the outer shell portion near its opposite end. An orifice is provided in the central region of the elongated chamber. Hollow fibers for diffusion are introduced into the outer shell and the ends of the outer shell portion are closed. This structure rotates on an axis between the ends, and an encapsulating compound is added to the chamber portion through the orifice. The encapsulating compound migrates radially outward through the chamber to the closed end of the outer shell portion to encapsulate the ends of the hollow fibers within the encapsulating compound. After the encapsulating compound has cured, the ends of the tubular outer shell portion are laterally cut to expose the openings in the hollow fibers, and a manifold end cap member is applied to the cut ends of the tubular outer shell portion.

[0006] EP3620228A1 discloses a method for manufacturing a filtration and / or diffusion device comprising a hollow fiber membrane bundle housed in a tubular housing. The method includes sealing the ends of the fibers and the nozzle of the tubular housing with a thermoplastic resin.

[0007] CA1245166A discloses a blow-molded side port for a hollow fiber separator. The side port is made of plastic and defines an outwardly extending annular shoulder to receive and house an annular connector seal of a mating connector. A first annular groove surrounding the side port is proportionally sized to receive a retaining member from the mating connector, and a second annular groove surrounding the side port, positioned between the first annular groove and the shoulder, reinforces the side port. The depth of the second groove is less than that of the first groove to avoid a noticeable locking structure between the side port and the mating connector when the retaining member extends into the second groove.

[0008] EP3479890A1 discloses a hollow fiber membrane having a tubular body, a cap, a hollow fiber membrane, and an end seal, wherein at least the liquid contact portion of the end seal is sealed with cured epoxy resin.

[0009] Polyurethane resins are commonly used as encapsulating compounds or curable liquid sealants. Isocyanates and polyols are metered into a mixer, such as a mixing head, and the reaction mixture is introduced into the housing of a diffusion and / or filtration device via a disposable manifold. Because small amounts of polyurethane resin remain in the mixing unit and on the surface of the manifold, forming scale as the resin cures, it is necessary to periodically flush the mixing unit and replace the disposable manifold.

[0010] One object of this disclosure is to provide a more efficient packaging method that generates less waste. Summary of the Invention

[0011] This disclosure provides methods and apparatus for encapsulating hollow fiber membranes in diffusion and / or filtration devices.

[0012] The isocyanate component and the polyol component are metered into the tubular fluid port of the housing of the diffusion and / or filtration device and mixed in a recess provided on the inner wall of the fluid port to form a reactive polyurethane mixture.

[0013] The diffusion and / or filtration device rotates about a central axis perpendicular to the longitudinal axis of the housing, thereby conveying a reactive polyurethane mixture toward one end of the housing, where the polyurethane mixture condenses and forms an end wall.

[0014] The device disclosed includes two capillaries angled relative to each other, with the nozzles of the capillaries spaced apart. One capillary is connected to a reservoir containing an isocyanate component, and the other capillary is connected to a reservoir containing a polyol component. Each of the two capillaries is also connected to a metering device for metering the desired amounts of the polyol component and the isocyanate component into the fluid port of the housing of the diffusion and / or filtration device, respectively.

[0015] This disclosure also provides a tubular housing for a diffusion and / or filtration device, wherein two tubular fluid ports are located on the outer wall of the tubular housing at equidistant distances from the nozzle of the tubular housing, and the inner wall surface of each tubular fluid port is characterized by a recess. This recess is used to form a reactive polyurethane mixture from a first liquid flow of an isocyanate component and a second liquid flow of a polyol component. Attached Figure Description

[0016] Figure 1 This is a schematic front view of a tubular fluid port of the present disclosure, characterized by a recess on its inner wall surface and two capillaries for quantitatively dispensing polyurethane components into the tubular fluid port.

[0017] Figure 2 This is a schematic side view of a tubular fluid port of the present disclosure, characterized by a recess on its inner wall surface and a capillary for quantitatively dispensing polyurethane components into the tubular fluid port.

[0018] Figure 3 This is a schematic perspective view of a tubular fluid port disclosed herein, characterized by a recess on its inner wall surface;

[0019] Figure 4 This is a schematic longitudinal sectional view of the housing of the filtration and / or diffusion device of this disclosure. Detailed Implementation

[0020] This disclosure provides methods and apparatus for encapsulating hollow fiber membranes in diffusion and / or filtration devices.

[0021] This disclosure provides a method for encapsulating a hollow fiber membrane in a diffusion and / or filtration device, the diffusion and / or filtration device comprising a tubular housing in which a hollow fiber membrane bundle is disposed, and at least one tubular fluid port located on the outer wall surface of the tubular housing.

[0022] The method includes the following steps:

[0023] a) The polyol component and the isocyanate component are simultaneously but separately metered into a recess located on the inner wall of at least one tubular fluid port;

[0024] b) Allows the polyol component to mix with the isocyanate component in the recess to form a polyurethane reaction mixture;

[0025] c) Causing the polyurethane reaction mixture to flow toward the nozzle of the tubular housing, which is sealed by the encapsulation cap; and embedding the ends of the hollow fiber bundles into the polyurethane reaction mixture; and

[0026] d) Allows the polyurethane reaction mixture to cure and form a solid encapsulation area at the nozzle of a sealed tubular shell.

[0027] In the method disclosed herein, the polyol component and the isocyanate component are simultaneously but separately metered into the tubular fluid port (commonly referred to as the "Hansen" connector) of the housing of the diffusion and / or filtration device, and mixed in a recess provided on the inner wall of the tubular fluid port.

[0028] Apart from the inner wall of the tubular fluid port, no parts of the metering device come into contact with the mixture. Therefore, no parts of the metering device are susceptible to contamination by polyurethane residues. A separate mixing unit, such as a rotary mixer, is no longer necessary. Consequently, cleaning of the mixing unit (which involves rinsing) is not required. Furthermore, disposable manifolds are not used in this encapsulation method.

[0029] In one embodiment of the method, the polyol component and the isocyanate component are separately and quantitatively dispensed into the tubular fluid port via two capillaries. These capillaries do not contact each other or the inner wall of the tubular fluid port.

[0030] In one embodiment of the method, fluids flowing from two capillaries form two liquid jets that meet in a recess provided on the inner wall of the tubular fluid port.

[0031] Two liquid jets are directed toward each other. In one embodiment, the capillary forms an angle in the range of 5° to 30°, for example 10° to 25°, or 15° to 20°. In another embodiment, the liquid jet forms an angle in the range of 15° to 45°, for example 15° to 30°, or 15° to 25° with the inner wall surface of the tubular fluid port.

[0032] Generally, the volumetric flow rates of the liquid in the two capillaries are not the same. The volumetric flow rate must be adjusted according to the stoichiometry of the polyurethane to be produced. In an exemplary embodiment, the volume ratio of the polyol component to the isocyanate component is 100:(66±5). Therefore, the volumetric flow rate of the isocyanate component must reach approximately 2 / 3 of the volumetric flow rate of the isocyanate component.

[0033] In one embodiment, the recess has a cylindrical cross-section. In a further embodiment, the recess is conical. In another embodiment, the recess has a spherical segment, such as a hemispherical shape. In yet another embodiment, the recess has a polygonal cross-section, such as a rectangular or hexagonal cross-section. In other words, the shape of the recess is selected from the group consisting of cylinders, cones, spherical segments, polygonal prisms, and polygonal pyramids.

[0034] In a further embodiment, the longitudinal axis of the recess forms an acute angle with the inner wall surface of the tubular fluid port, for example, in the range of 30° to 60°, such as 45°. The longitudinal axis of the recess is a central axis that passes through the center of the bottom of the recess and the center of the nozzle of the recess; and the aforementioned acute angle causes the longitudinal axis to tilt toward the nozzle of the tubular fluid port away from the housing.

[0035] In one embodiment, the diameter of the nozzle of the recess is in the range of 3 mm to 9 mm, for example, 5 mm to 7 mm. In one embodiment, the depth of the recess, measured horizontally from the inner wall surface of the tubular fluid port, is in the range of 0.5 mm to 2.0 mm, for example, 1.0 mm to 1.9 mm, for example, 1.5 mm to 1.8 mm.

[0036] In one particular embodiment, the recess is conical, with a mouth diameter of 6 mm and a depth of 1.8 mm.

[0037] The polyurethane reaction mixture is induced to flow toward the nozzle of the tubular housing, which is sealed by a cap. The reaction mixture accumulates at the sealed end, embedding at the end of the hollow fiber bundle. In one embodiment of the method, the polyurethane reaction mixture is induced to flow toward the nozzle of the tubular housing by centrifugal force generated by rotating the housing about an axis perpendicular to the longitudinal axis of the housing. In a further embodiment, the housing is rotated about an axis extending through the center of the housing.

[0038] In another embodiment of the method, the polyol component and the isocyanate component are simultaneously but separately metered into two recesses located on the inner walls of two tubular fluid ports situated on the outer surface of a tubular housing at equidistant points from the nozzles of the housing. These components mix within the recesses to form a polyurethane reaction mixture, which is then induced to flow through the respective tubular ports toward the opposing nozzles of the tubular housing, which are sealed by the encapsulation cap. In this embodiment, the tubular housing rotates about its central axis, i.e., an axis perpendicular to its longitudinal axis and extending through its center.

[0039] In one embodiment of the method, the mixing of components in the recess is assisted by ultrasound. In one embodiment, an ultrasonic sonotrode contacts the outside of the tubular fluid port near the bottom of the recess, and ultrasound (e.g., ultrasound in the frequency range of 30 kHz to 50 kHz) is continuously applied during the metered liquid dispensing.

[0040] This disclosure also provides an apparatus for encapsulating a hollow fiber membrane in a diffusion and / or filtration device. This apparatus can be used to perform the encapsulation method of this disclosure.

[0041] The device disclosed includes two capillaries angled relative to each other, with their nozzles spaced apart. One capillary is connected to a reservoir containing an isocyanate component, and the other capillary is connected to a reservoir containing a polyol component. Each of the two capillaries is also connected to a metering device for metering the desired amounts of the polyol component and the isocyanate component into tubular fluid ports on the housing of the diffusion and / or filtration device, respectively.

[0042] In one embodiment of the device, the two capillaries are formed at an angle ranging from 5° to 30°, for example from 10° to 25°, or from 15° to 20°.

[0043] In one embodiment of the device, the inner diameter of the capillary is in the range of 0.5 mm to 2.0 mm, for example, 0.8 mm to 1.8 mm, or 1.3 mm to 1.7 mm. In one embodiment, the two capillary tubes have the same inner diameter. In another embodiment, the inner diameters of the capillary tubes are different. In a particular embodiment, the inner diameter of the capillary tube connected to the reservoir containing the polyol component is larger than the inner diameter of the capillary tube connected to the reservoir containing the isocyanate component. This takes into account the fact that the volumetric flow rate of the polyol component is generally greater than that of the isocyanate component.

[0044] Each of the two capillaries is connected to a metering device for quantitatively dispensing a desired amount of liquid into the tubular fluid port of the filtration and / or diffusion device. In one embodiment of the device, the metering device is a metering pump. Examples of suitable metering pumps include plunger pumps, diaphragm pumps, peristaltic pumps, and gear pumps. In one embodiment of the device, the metering pump is a piston pump. In a particular embodiment, the piston is actuated by a pneumatic cylinder. In another embodiment, the piston is actuated by a linear motor. Compared to a pneumatic cylinder, a linear motor allows for much lower start-up, acceleration, and damping phases in the liquid jet.

[0045] This disclosure also provides a tubular housing for a diffusion and / or filtration device, characterized in that two tubular fluid ports are located on the outer wall of the tubular housing at equidistant distances from the nozzle of the tubular housing, and the inner wall surface of each tubular fluid port is characterized by a recess. The recess is used to form a reactive polyurethane mixture from a first liquid flow of an isocyanate component and a second liquid flow of a polyol component.

[0046] The tubular housing is typically made by injection molding from a thermoplastic polymer, such as polyester (e.g., polycarbonate or PETG) or polyolefin (e.g., polypropylene). In one embodiment, a recess is introduced into the wall of the tubular fluid port of the housing during the manufacturing of the housing by injection molding. In another embodiment, the recess is introduced after the housing has been manufactured by injection molding, for example by drilling, milling, embossing, or thermoforming.

[0047] The two aforementioned devices are used when the polyol component and the isocyanate component are simultaneously and quantitatively added into the two tubular fluid ports of the tubular shell.

[0048] Exemplary embodiments of the apparatus and methods disclosed herein are shown in the accompanying drawings and described below. It should be understood that the features described above and below are not limited to the specified combinations, but can be used in other combinations or on their own without departing from the scope of the invention.

[0049] Figure 1 This is a schematic front view of the tubular fluid port 10 of this disclosure, characterized by a recess 11 on its inner wall surface. A first capillary 20 for metering polyol component 23 into the tubular fluid port 10 is connected to a metering device 21 and a reservoir 22 for the polyol component. A second capillary 30 for metering isocyanate component 33 into the tubular fluid port 10 is connected to a metering device 31 and a reservoir 32 for the isocyanate component. As shown, a jet 23 of the polyol component is ejected from the first capillary 20; while a jet 33 of the isocyanate component is ejected from the second capillary 30. The jets 23 and 33 meet in the recess 11 in the wall of the tubular fluid port 10 and form a reaction mixture, which produces polyurethane. The reaction mixture flows through the tubular fluid port 10 into the housing of a filtration and / or diffusion device and is conveyed towards one end of the housing by centrifugal force.

[0050] Figure 2This is a schematic side view of the tubular fluid port 10 of this disclosure, characterized by a recess 11 on its inner wall surface. A capillary 30 for metering isocyanate component 33 into the tubular fluid port 10 is connected to a metering device 31 and a reservoir 32 for the isocyanate component. As shown, a jet 33 of the isocyanate component is ejected from the capillary 30. The jet 33 of the isocyanate component is guided into the recess 11, where it mixes with a jet of polyol component (not shown).

[0051] Figure 3 This is a schematic perspective view of the tubular fluid port 10 of the present disclosure, characterized by a tapered recess 11 on its inner wall surface.

[0052] Figure 4 This is a schematic longitudinal sectional view of the tubular housing 40 of the filtration and / or diffusion device of this disclosure. The housing 40 is characterized by two tubular fluid ports 41 and 43, each characterized by recesses 42 and 44 on its inner wall surface. The fluid ports 41 and 43 are located near opposite ends of the housing 40, equidistant from the center of the housing 40. Both fluid ports 41 and 43 are also located equidistant from the nozzle of the tubular housing 40. In the embodiment shown in the figure, the fluid ports 41 and 43 are located on the same side of the housing 40, and the longitudinal axes of the fluid ports 41 and 43 lie in a common plane. A hollow fiber membrane bundle 45 is disposed inside the housing 40, and the nozzle of the housing 40 is sealed by encapsulation caps 47 and 49. During the encapsulation process of this disclosure, a polyol component and an isocyanate component are metered into the recesses 42 and 44 of the tubular fluid ports 41 and 43, where the polyol component and the isocyanate component mix and form a polyurethane reaction mixture. As shown in the figure, the outer casing 40 rotates about a central axis perpendicular to its longitudinal axis. A polyurethane reaction mixture flows into the casing 40 and is conveyed towards the ends of the casing 40 by centrifugal force. The polyurethane reaction mixture solidifies and cures at the nozzle of the casing, forming end walls 46, 48 made of polyurethane. Encapsulation caps 47, 49 are then removed, and the ends of the hollow fiber membrane bundle 45 are cut off to reopen the hollow fiber membrane.

[0053] List of reference numerals in the attached diagram:

[0054] 10 tubular fluid ports

[0055] 11 recesses

[0056] 20 First capillary

[0057] 21 Metering device

[0058] 22 Polyol Component Storage Container

[0059] 23 Polyol Component Jet

[0060] 30 Second capillary

[0061] 31 Metering device

[0062] 32 Isocyanate component storage container

[0063] 33 Isocyanate component jet

[0064] 40 Tubular outer shell

[0065] 41 Tubular fluid port

[0066] 42 recess

[0067] 43 Tubular fluid port

[0068] 44 recess

[0069] 45 Hollow fiber membrane bundles

[0070] 46-end wall / package area

[0071] 47 package cap

[0072] 48 end walls / package area

[0073] 49 package cap

Claims

1. A method for encapsulating a hollow fiber membrane in a diffusion and / or filtration device, the diffusion and / or filtration device comprising: A tubular outer shell (40) in which a hollow fiber membrane bundle (45) is disposed; The method includes at least one tubular fluid port (10, 41, 43) located on the outer wall surface of the tubular housing (40), and comprises the following steps: a) The polyol component (23) and the isocyanate component (33) are simultaneously but separately metered into the recesses (11, 42, 44) provided on the inner wall of the at least one tubular fluid port (10, 41, 43); b) Allow the polyol component (23) and the isocyanate component (33) to mix in the recesses (11, 42, 44) to form a polyurethane reaction mixture; c) Causing the polyurethane reaction mixture to flow toward the nozzle of the tubular housing (40) which is sealed by the encapsulation caps (47, 49); and embedding the end of the hollow fiber membrane bundle (45) into the polyurethane reaction mixture; and d) Allow the polyurethane reaction mixture to cure and form a solid encapsulation area (46, 48) that seals the mouth of the tubular housing (40).

2. The method according to claim 1, wherein, The process of causing the polyurethane reaction mixture to flow toward the nozzle of the tubular housing (40) includes rotating the tubular housing (40) about an axis perpendicular to the longitudinal axis of the tubular housing (40).

3. The method according to claim 2, wherein, The tubular housing (40) rotates about an axis that extends through the center of the tubular housing (40).

4. The method according to any one of claims 1 to 3, wherein, The recesses (11, 42, 44) are conical in shape.

5. The method according to claim 4, wherein, The diameter of the mouth of the recess (11, 42, 44) is in the range of 5 mm to 7 mm.

6. An apparatus for encapsulating a hollow fiber membrane in a diffusion and / or filtration device, the apparatus comprising two capillaries (20, 30) angled relative to each other, the nozzles of the capillaries (20, 30) being spaced apart from each other; one capillary (30) being connected to a reservoir (32) containing an isocyanate component and to a metering device (31) for metering a desired amount of the isocyanate component into a tubular fluid port (10, 41, 43) of a tubular housing (40) of the diffusion and / or filtration device; the other capillary (20) being connected to a reservoir (22) containing a polyol component and to a metering device (21) for metering a desired amount of the polyol component into the tubular fluid port (10, 41, 43) of the tubular housing (40) of the diffusion and / or filtration device.

7. The apparatus according to claim 6, wherein, The two capillaries (20, 30) form an angle in the range of 5° to 30°.

8. The apparatus according to claim 6 or 7, wherein, The inner diameter of the capillaries (20, 30) is in the range of 0.5 mm to 2.0 mm.

9. The apparatus according to claim 6 or 7, wherein, The metering devices (21, 31) are metering pumps.

10. The apparatus according to claim 9, wherein, The metering pump is a piston pump.

11. The apparatus according to claim 10, wherein, The piston is actuated by a pneumatic cylinder.

12. The apparatus according to claim 10, wherein, The piston is actuated by a linear motor.

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