JP7090436B2 - Hollow fiber membrane module and its manufacturing method, and molding mold for the potting part of the hollow fiber membrane module - Google Patents

Description

The present invention relates to a hollow fiber membrane module, a method for manufacturing the same, and a mold for molding a potting portion of the hollow fiber membrane module.

Conventionally, a hollow fiber membrane type blood purifier (referred to as a "hollow fiber membrane module" in the present specification) is used for extracorporeal circulation type blood purification therapy such as hemodialysis, blood filtration, plasma separation, and plasma component fractionation. Various types have been developed and are used in many blood purification therapies using membrane separation technology.

In a hollow fiber membrane module, generally, a bundle of hollow fiber membranes is loaded into a cylindrical main body container provided with a port on the side, and the hollow fiber membrane bundle is bonded and fixed to the main body container with a potting material such as urethane. , Consists of a module configured by attaching headers to both ends of the body container. In hemodialysis using this hollow fiber membrane module, dialysate flows into the port on the inlet side and flows out from the outlet port to circulate in the main body container, and blood flows from the header on the blood inlet side to the hollow fiber membrane. It is done by inflowing and circulating toward the blood outlet side header.

When performing such hemodialysis, it is necessary to seal the liquid tightly so that the liquid does not leak from the joint portion between the header and the main body container. For example, the contact portion between the potting portion and the inner surface of the header. (For example, see Patent Document 1).

International Publication No. 2013/146663

However, if the potting portion and the abutting portion on the inner surface of the header are not completely abutted, the liquid may be incompletely sealed, and for example, blood may leak to the outside of the sealing portion and stay in the closed space. Then, residual blood may be left and solid matter may move into the patient's body when the blood is returned.

On the other hand, if the header is pushed deeper into the container in order to obtain complete sealing performance (sealing ability) in the sealing portion, the resin in the potting portion cracks, and on the contrary, sufficient sealing performance is obtained. It may disappear.

Therefore, the present invention relates to a hollow fiber membrane module and a manufacturing method thereof in which the resin cracking of the potting portion is suppressed and sufficient sealing performance of the hollow fiber membrane module is ensured, and a mold for molding the potting portion of the hollow fiber membrane module. The challenge is to provide.

The hollow fiber membrane module according to one aspect of the present invention is
A cylindrical container with one end and the other end open,
A bundle of hollow fiber membranes loaded in the tubular container,
A potting part that embeds and fixes a bundle of hollow fiber membranes at both ends of a tubular container,
Headers with nozzles that serve as fluid inlets and outlets, which are provided at both ends of the tubular container,
A fixing part where the header and the tubular container are fixed to each other,
A contact portion where the inner contact surface of the header and the potting portion are in contact with each other to hermetically seal the inner space of the header.
Equipped with
Among the potting portions, the angle of the side wall of the outer peripheral portion of the surface of the potting protrusion protruding from the end of the container is smaller than 90 degrees.

According to this aspect, even if the header is pushed too much toward the tubular container, the resin cracking of the potting portion is suppressed, and it becomes easy to secure sufficient sealing property of the hollow fiber membrane module.

In the hollow fiber membrane module of the above aspect, the angle of the side wall of the outer peripheral portion of the surface of the potting portion may be 45 degrees or more and 85 degrees or less.

In the hollow fiber membrane module of the above aspect, the height of the potting portion may be 0.4 mm or more and 3 mm or less.

In the hollow fiber membrane module of the above aspect, it is preferable that the difference in height of the outer peripheral portion of the surface of the potting portion in the entire circumferential direction is 0.05 mm or more and 0.5 mm or less.

In the hollow fiber membrane module of the above aspect, the outer peripheral root portion of the side wall of the surface outer wall portion of the potting portion may be at the boundary between the potting portion and the tubular container.

In the hollow fiber membrane module of the above aspect, the outer peripheral root portion of the side wall of the surface outer wall portion of the potting portion may be in contact with the open end surface of the tubular container.

The method for manufacturing a hollow fiber membrane module according to one aspect of the present invention is as follows.
A cylindrical container with one end and the other end open,
A bundle of hollow fiber membranes loaded in the tubular container,
A potting part that embeds and fixes a bundle of hollow fiber membranes at both ends of a tubular container,
A method for manufacturing a hollow fiber membrane module, which is provided at both ends of a tubular container and has a header having a nozzle portion that serves as an inlet / outlet for a fluid.
Among the potting portions, a step of forming the potting portion in which the angle of the side wall of the outer peripheral portion of the surface of the potting protrusion protruding from the end of the container is smaller than 90 degrees in a state of being in contact with the header.
The process of bringing the inner contact surface of the header into contact with the potting protrusion so that the internal space of the header is hermetically sealed, and
It is characterized by including a fixing step of fixing the header and the tubular container to each other.

The method for manufacturing the hollow fiber membrane module according to the above aspect is as follows.
The process of loading a bundle of hollow fiber membranes into a tubular container,
The process of attaching the molding mold of the potting part to the open end face of the cylindrical container,
The process of potting resin on the end face of the opening by centrifugal molding,
After the resin has hardened, the molding mold is removed, the potting part is cut, and the end face of the bundle of hollow fiber membranes is opened.
May further be included.

In the method for manufacturing a hollow fiber membrane module according to the above aspect, ultrasonic welding may be performed in the fixing step.

In the method for manufacturing a hollow fiber membrane module according to the above aspect, laser welding may be performed in the fixing step.

In the method for manufacturing a hollow fiber membrane module according to the above aspect, screwing may be performed in the fixing step.

The molding mold according to one aspect of the present invention is
A cylindrical container with one end and the other end open,
A bundle of hollow fiber membranes loaded in the tubular container,
A potting part that embeds and fixes a bundle of hollow fiber membranes at both ends of a tubular container,
A mold for molding a potting portion used for manufacturing a hollow fiber membrane module provided with a header having nozzle portions serving as an inlet / outlet for a fluid provided at both ends of a tubular container.
It has a tapered structure smaller than 90 degrees for forming the potting portion in a structure in which the angle of the side wall of the outer peripheral portion of the surface of the potting portion is maintained to be smaller than 90 degrees in the state of being in contact with the header. be.

According to the present invention, a hollow fiber membrane module and a manufacturing method thereof, in which resin cracking of the potting portion is suppressed and sufficient sealing performance of the hollow fiber membrane module is ensured, and a mold for molding the potting portion of the hollow fiber membrane module. Can be provided.

It is a schematic diagram of the vertical cross section which shows an example of the structure of the hollow fiber membrane module. It is an enlarged cross-sectional view which shows the joint part and its periphery at the time of the start of welding of a header and a tubular container by an ultrasonic horn. It is sectional drawing which shows the state when the header and the tubular container were ultrasonically welded. It is an enlarged sectional view which shows the joint part in a state where a header and a tubular container are welded, and the periphery thereof. (A) State before pushing the header when the angle α of the side wall of the potting protrusion is less than 90 degrees and the outer peripheral root of the side wall of the outer wall of the surface of the potting part is at the boundary between the potting part and the cylindrical container. It is a vertical cross-sectional view which shows a part of the said header, a cylindrical container, and a potting part in (B), and (B) is a vertical cross-sectional view in the state after pushing in. (A) In the state before pushing the header when the angle α of the side wall of the potting protrusion is less than 90 degrees and the outer peripheral root of the side wall of the surface outer wall of the potting is in contact with the open end surface of the tubular container. It is a vertical sectional view which shows a part of the said header, a cylindrical container, and a potting part, and (B) is a vertical sectional view in the state after pushing in the header. Partial vertical cross-sectional view of the header, the tubular container, and the potting portion, showing from before pushing to after pushing along the time series of (A) to (C) for explaining that the cracking of the potting portion is suppressed. Is. It is the schematic which shows the manufacturing method of the hollow fiber membrane module in the order of (A)-(E). It is a graph which shows the value of the urethane height and the urethane height difference in Comparative Example 2 (when the angle of the side wall of the potting protrusion is 90 degrees) and the result (presence or absence of urethane cracking) in that case. It is a graph which shows the value of the urethane height and the urethane height difference in Example 1 of the present invention (when the angle of the side wall of the potting protrusion is 70 degrees) and the result (presence or absence of urethane cracking) in that case. It is a graph which shows the value of the urethane height and the urethane height difference in Example 2 of the present invention (when the angle of the side wall of the potting protrusion is 80 degrees) and the result (presence or absence of urethane cracking) in that case. It is a partial cross-sectional view which shows the state before (A) the header is pushed and (B) after the header is pushed in the case where the cut surface of a potting part is asymmetrical, as a comparative example. It is a partial cross-sectional view showing another example in which the cut surface of a potting portion is asymmetrical. It is a partial cross-sectional view which shows the state which the header is tilted with respect to a potting part or a cylindrical container as a comparative example. It is a partial cross-sectional view which shows the case where the shape of a header is asymmetrical left and right as a comparative example. It is a partial cross-sectional view which shows the case where the center of a header and the center of a tubular container are deviated from each other as a comparative example. The header and the tubular shape are shown as Comparative Example 1 along the time series of (A) to (C) from before pushing the potting having the same structure as before in which the angle α of the side wall of the potting portion is 90 to after pushing. It is a partial vertical sectional view of a container and a potting part. It is a figure explaining the potting protrusion, the height (urethane height) and the like in Comparative Example 2 and Examples 1 and 2. It is a figure explaining the height difference (urethane height difference) of the potting protrusion in Comparative Example 2 and Examples 1 and 2. It is a figure explaining the case where the urethane height when there is a difference in urethane height is measured at a plurality of points at equal intervals over the outer circumference of the urethane. (A) In the case where the side wall of the potting protrusion is conical, and (B) in the partial vertical cross-sectional view of the header, the tubular container, and the potting part when the side wall of the potting protrusion is curved outward. be.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The same elements are designated by the same reference numerals, and duplicate description will be omitted. In addition, the positional relationship such as up, down, left, and right shall be based on the positional relationship shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios in the drawings are not limited to the ratios shown. Further, the following embodiments are examples for explaining the present invention, and the present invention is not limited to this embodiment.

<Structure of hollow fiber membrane module>
First, the configuration of the hollow fiber membrane module according to the present embodiment will be described. FIG. 1 is a schematic cross-sectional view showing an example of the configuration of the hollow fiber membrane module 1 (however, only the cross section is shown).

The hollow fiber membrane module 1 includes a tubular container 2, a hollow fiber membrane bundle 3, a potting portion 4, a header 5, and the like.

The tubular container 2 is formed in a cylindrical shape, and both end portions 2a in the longitudinal direction (the central axis P direction of the cylinder) are open. The hollow fiber membrane bundle 3 is housed inside the tubular container 2. For example, two ports 10 that serve as inlets and outlets for fluids are formed on the side surfaces of the tubular container 2.

The hollow fiber membrane bundle 3 is a bundle of a large number of hollow fiber membranes, and is housed in the tubular container 2 along the longitudinal direction. The hollow fiber membrane bundle 3 functions as a separation membrane, and can separate the components of the fluid to be separated between the inner region and the outer region of each hollow fiber membrane.

The potting portion 4 is made of a potting resin, embeds both end portions 3a of the hollow fiber membrane bundle 3 inside both end portions 2a of the tubular container 2, and the hollow fiber membrane bundle 3 is embedded in both end portions of the tubular container 2. It is fixed to 2a. The outer peripheral portion of the potting portion 4 is a portion 4a composed of only the potting resin, and the inside thereof is a portion 4b in which the potting resin has entered the gap between the hollow fiber membranes of the hollow fiber membrane bundle 3. Examples of the potting resin include, but are not limited to, polyurethane resin, epoxy resin, silicon resin and the like.

The header 5 is provided at the openings of both end portions 2a of the tubular container 2 as a lid material for both end portions 2a. The header 5 has a tubular nozzle portion 20 that serves as an inlet / outlet for fluid on the central axis P, a plate-shaped top plate portion 21 that extends radially from the nozzle portion 20, and a tubular container 2 side from the outer peripheral edge of the top plate portion 21. It has a header projecting portion 22 as a side wall portion projecting toward.

The nozzle portion 20 has a screw structure for connecting an external tube. The top plate portion 21 faces the end portion 3a of the hollow fiber membrane bundle 3 and has an inner surface 21a whose diameter gradually increases toward the end portion 2a of the tubular container 2 from the nozzle portion 20 (see FIG. 4). ). A space 23 through which the fluid flowing in from the nozzle portion 20 or the fluid flowing out from the nozzle portion 20 passes is formed between the inner surface 21a of the header 5 and the end portion 3a of the hollow fiber membrane bundle 3.

The header protrusion 22 has a cylindrical shape with the central axis P as the axis. As shown in FIG. 4, the header protruding portion 22 is provided with a base portion 30, a middle stage portion 31, and a tip portion 32 in this order from the top plate portion 21 toward the cylindrical container 2. The base portion 30, the middle stage portion 31, and the tip portion 32 have different radial thicknesses from each other, the thickness of the base portion 30 is the largest, the thickness of the middle stage portion 31 is the largest, and the thickness of the tip portion 32 is the smallest.

The base portion 30 is a portion continuous from the top plate portion 21. An annular flat surface 40 perpendicular to the central axis P is formed between the inner surface 21a of the top plate portion 21 and the first inner peripheral surface 30a of the base portion 30.

The middle portion 31 has a second inner peripheral surface 31a. The tip portion 32 has a third inner peripheral surface 32a having the same inner diameter as the second inner peripheral surface 31a, and an outer peripheral surface 32b having a constant outer diameter smaller than the outer peripheral surface 31b of the middle stage portion 31. is doing. An annular flat surface (step portion) 42 perpendicular to the central axis P is formed between the outer peripheral surface 31b of the middle stage portion 31 and the outer peripheral surface 32b of the tip portion 32.

The end portion 2a of the tubular container 2 has a so-called bifurcated structure. The end portion 2a has an inner protruding portion 50 and an outer protruding portion 51 that doubly project to the header 5 side in a cylindrical shape. The inner protrusion 50 and the outer protrusion 51 each have a cylindrical shape with the central axis P as the axis, and are arranged concentrically. The inner protruding portion 50 is longer than the outer protruding portion 51 and protrudes toward the header 5 side (outside in the central axis P direction). The inner peripheral surface 50a of the inner protruding portion 50 constitutes the inner peripheral surface of the tubular container 2.

The outer protruding portion 51 is formed by a flange portion having a shape that protrudes radially outward from the outer surface of the tubular container 2 and is further bent from the outer edge toward the end portion 2a side (the nearest header 5 side). Further, an annular recess 52 forming a coupling structure is formed between the inner protrusion 50 and the outer protrusion 51 so that a part of the header 5 (tip portion 32) is fitted (the tip portion 32) is fitted (the tip portion 32). See Figure 4).

<Joining structure of header and tubular container>
The header 5 and the tubular container 2 are welded by ultrasonic welding with the header protruding portion 22 inserted between the inner protruding portion 50 and the outer protruding portion 51 of the tubular container 2. The inner protruding portion 50 faces the middle stage portion 31 and the tip portion 32 of the header protruding portion 22, and the outer protruding portion 51 faces the tip portion 32.

As for the method of fixing the header 5 and the tubular container 2, there are a method of applying ultrasonic vibration to perform welding, a method of applying laser light to perform welding, a method of screwing with a screw, and the like (with a screw). For the method of screwing, see, for example, column 16, FIG. 10, etc. of JP-A-52-13871). The following description will be given by taking ultrasonic welding as an example.

The header 5 and the tubular container 2 are the primary welding portion 71 between the vicinity of the tip portion of the inner protrusion 50 and the middle stage portion 31 of the header protrusion 22, and the two between the inner protrusion 50 and the tip portion 32. It is welded by the welding portion 70 including the next welding portion 72. As described above, by providing the welding portions at at least two places to perform double welding, the liquid leakage suppressing effect and the withstand voltage strength can be further improved.

The primary welded portion 71 is formed, for example, over the end surface (upper end surface in FIG. 4) of the inner protruding portion 50 and the outer peripheral surface 50b. In FIG. 4, for convenience, the primary welded portion 71 is represented by a broken line and its boundary line is clearly shown. However, in the case of welding in which the contact portion is melted and adhered, the boundary is ambiguous and the boundary is welded. The fact is that it fluctuates from time to time.

The secondary welded portion 72 is formed in the vicinity of the tip of the tip portion 32 of the header protruding portion 22 (a position closer to the tip than the center in the longitudinal direction of the tip portion 32), and the secondary welded portion 72 is larger than the above-mentioned primary welded portion 71. It is arranged on the outer side in the radial direction of the tubular container 2 (see FIG. 4 and the like). The secondary welded portion 72 is separated from the primary welded portion 71, and a space (a space in which the header protruding portion 22 and the inner protruding portion 50 are not in contact between the secondary welded portion 72 and the primary welded portion 71). (Indicated by reference numeral 75) is formed in FIG.

In order to weld at the positions of the primary welding portion 71 and the secondary welding portion 72, at least one of the header protruding portion 22 or the inner protruding portion 50 of the portion to be the primary welding portion 71 and the secondary welding portion 72 , A joint for welding is provided in advance.

Further, at least one of the primary welded portion 71 and the secondary welded portion 72 is continuously formed over the entire circumference of the header protruding portion 22 in the circumferential direction, and the other is formed intermittently, for example. There is. More preferably, both the primary welded portion 71 and the secondary welded portion 72 are continuously formed over the entire circumference.

Further, in the present embodiment, a share joint is adopted as a joint design of the primary welding portion 71 and the secondary welding portion 72 for welding the header 5 and the tubular container 2.

A slope 5c is formed in a portion of the header 5 of the primary welding portion 71 that comes into contact with the end portion 2a of the tubular container 2 (see FIG. 2). The inclination angle of the slope 5c with respect to the plane perpendicular to the central axis P is preferably 20 to 45 °, and even more preferably 30 to 45 ° within that range. In this specification, this angle is referred to as a "main welding angle". When the main welding angle of the slope 5c is formed in this range, the slip of the end portion 2a of the tubular container 2 can be suppressed.

<Arrangement of potting part>
As shown in FIG. 4, a potting portion cut surface 4S formed by cutting both ends of the potting portion in the radial direction is formed on the end surface of the potting portion 4. The potting portion 4 protrudes outward (header 5 side) in the central axis P direction from the inner protruding portion 50 of the tubular container 2. The cutting surface 4S of the potting portion is in contact with the flat surface (inner contact surface) 40 of the inner surface of the header 5 in a state where a predetermined pressure is applied. As a result, it is possible to prevent the fluid from easily entering the gap between the header protruding portion 22 and the end portion 2a of the tubular container 2, and it is possible to improve the sealing force between the header 5 and the tubular container 2. An annular flat surface (inner contact surface) 40 perpendicular to the central axis P of the header 5 and an annular flat surface portion of the cut surface 4S of the potting portion 4 that abuts against the flat surface 40. Then, a contact portion T for liquid-tightly sealing the inner space of the header 5 is formed (see FIG. 4). It should be noted that the above-mentioned "predetermined pressure" includes an extremely small amount of pressure, and the "contact" referred to in the present specification includes not only a state in which the potting portion 4 is deformed by the action of pressure but also a pressure. It also includes a state in which the pressure is very small and is in contact with almost no deformation.

The raw materials of the tubular container 2 and the header 5 are not particularly limited and are selected from various thermoplastic resins. For example, in the case of crystalline resin, a copolymer of ethylene and α-olefin, a polyethylene resin such as low-density polyethylene and high-density polyethylene, a polymer of propylene alone, a polymer of propylene and ethylene, or a copolymer of propylene and ethylene. Polyethylene-based resins such as copolymers with other α-olefins can be mentioned. On the other hand, examples of the amorphous resin include resins such as polyester, polycarbonate, polystyrene, styrene-butadiene copolymer (SBS), and acrylonitrile-butadiene-styrene copolymer (ABS), and these may be used alone. It may be used well or as a mixture. Among the above, the suitable resin in the present embodiment is a polypropylene-based resin, in which a random copolymer of propylene and ethylene is preferable from the viewpoint of rigidity and heat resistance, and propylene having an ethylene content adjusted to 1 to 8% by mass. And ethylene random copolymers are more preferred.

<Structure of the outer peripheral surface of the potting part>
The portion of the potting portion 4 that protrudes outward from the end portion (end surface of the open end) 2a of the tubular container 2 in the direction of the central axis P is referred to as a “potting protrusion portion” in the present specification, and is referred to as a reference numeral 4P in the drawing. Indicated by. In the present embodiment, the potting protrusion 4P has a thin annular shape having a substantially trapezoidal cross section, and the surface of the annular portion around the hollow fiber membrane bundle 3 is configured to abut on the flat surface 40 of the header 5. There is. In the present specification, the portion of the potting protrusion 4P where the surface is exposed, that is, the annular flat surface facing the flat surface 40 of the header 5 and the side wall around the annular flat surface are combined to form a “surface”. It is called "outer peripheral portion" and is indicated by reference numeral 4r.

The angle of the side wall 4W of the outer peripheral portion 4r of the surface of the potting protrusion 4P is indicated by reference numeral α1 when the header 5 is in contact with the surface outer peripheral portion 4r, and is indicated by reference numeral α2 in the state after the header 5 is in contact with the header 5 (FIG. 4, etc.). reference). As shown in the figure, the angles α1 and α2 are the angles of the side wall 4W with respect to the plane perpendicular to the central axis P in the vertical cross section of the potting portion 4, and if it is smaller than 90 degrees, the potting protrusion 4P is the side wall thereof. The taper shape becomes thinner as the 4W approaches the nozzle portion 20 of the header 5. In the present embodiment, the potting protrusion 4P is formed so that the angle α2 of the side wall 4W is smaller than 90 degrees (see FIG. 4 and the like). When the angle α2 of the side wall 4W of the surface outer peripheral portion 4r of the potting protrusion 4P is less than 90 degrees, it is possible to suppress cracking in the potting portion 4 even if the header 5 is pushed too much (FIGS. 5 and 5). 6). In FIGS. 5 to 19, in order to show the state of the potting portion 4 in an easy-to-understand manner, a part of the header 5 and a part of the tubular container 2 are shown in a simplified rectangular shape or the like. Further, in FIGS. 12 to 17, "'" is added to the reference numeral (for example, the potting portion 4') to indicate that it is a comparative example.

It is considered that the fact that the cracking of the potting portion 4 is suppressed when the angle α2 of the side wall 4W is less than 90 degrees can be explained as follows. That is, when the flat surface (step portion) 40 of the header 5 is applied to and pushed into the potting portion 4 when the angle of the side wall 4W is less than 90 degrees (see FIG. 7A), the outer peripheral portion of the surface of the potting protrusion 4P. Of 4r, a force for compressing the potting protrusion 4P while bringing the upper surface portion 4Pu near the header 5 and the outer peripheral root portion 4Pd near the end portion 2a of the tubular container 2 close to each other ( The compressive force) acts (see FIG. 7 (B)) and does not cause cracks in the potting portion 4 (see FIG. 7 (C)). The suitable range of the angle α2 of the side wall 4W is not particularly limited, but a suitable example from the viewpoint of suppressing cracking of the potting portion 4 is 45 degrees or more and 85 degrees or less.

The height H of the potting protrusion 4P is also not particularly limited and may take various values. However, a preferable example from the viewpoint of suppressing cracking of the potting portion 4 is 0.4 mm or more and 3 mm or less. The range of is suitable.

It is most preferable that there is no difference (height difference) ΔH in the height H (see FIG. 18) of the outer peripheral portion 4r of the surface of the potting protrusion 4P in the entire circumferential direction, and even if there is a difference, it may be within a predetermined range. preferable. When the difference is within a predetermined range, even when the potting portion 4 is pushed by the header 5, stress is less likely to be applied partially and the potting portion 4 is less likely to be cracked, and the internal space of the header 5 is hermetically sealed. It is preferable to the above. As an example, the potting protrusion 4P in which the difference ΔH between the height H1 at the highest point and the height H2 at the lowest point of the outer peripheral portion 4r of the surface is generated is shown in the figure (see FIG. 19). When ΔH is present, the ΔH is preferably in the range of 0.05 mm or more and 0.5 mm or less as an example (see FIG. 19).

In the hollow fiber membrane module 1, it is most preferable that the center of the header 5 and the center of the tubular container 2 coincide with the central axis P, respectively, and the center of the header 5 and the center of the tubular container 2 are deviated from each other. Even if it is, it is preferable that the deviation amount is within a predetermined range, for example, within a range of 0.1 mm or more and 1.0 mm or less in the horizontal direction. For example, if the shape of the header 5 is asymmetrical (see FIG. 15), or if the header 5 is attached in a misaligned state (see FIG. 16), the center of the header 5 and the center of the tubular container 2 are aligned. Although they may be misaligned with each other, even if there is a misalignment between them, if it is within a predetermined range, cracking of the potting portion 4 is suppressed and the internal space of the header 5 is hermetically sealed. It is possible to secure a sufficient sealing force for the header.

The outer peripheral root portion 4Pd of the side wall 4W of the surface outer peripheral portion 4r of the potting portion 4 can take various positions depending on the shape of the potting portion 4, the structure of the cylindrical container 2, and the position thereof is particularly limited. There is no such thing. To give a specific example, for example, the potting portion 4 may be formed so that the outer peripheral root portion 4Pd is located at the boundary between the potting portion 4 and the tubular container 2 (see FIG. 5). In such a case, the stress in the outer peripheral direction (outward in the radial direction) acting on the upper surface portion 4Pu of the potting protrusion 4P is suppressed, and the effect of suppressing the cracking of the potting portion 4 is exhibited. Alternatively, the potting portion 4 may be formed so that the outer peripheral root portion 4Pd is located on the open end of the tubular container 2 and is in contact with the end portion 2a (see FIG. 6). In this case, from the inner peripheral surface near the end 2a of the tubular container 2 acting on the outer peripheral root portion 4Pd of the potting protrusion 4P toward the center in the radial direction and downward (lower in the drawing, that is, the longitudinal length of the hollow fiber membrane module 1). The stress on the central portion 1c in the direction facing the direction) is suppressed, and the effect of suppressing the cracking of the potting portion 4 is exhibited.

If the cutting accuracy and molding accuracy of the potting portion 4 are inferior, the contact portion T of the potting portion 4 becomes asymmetric (see FIGS. 12 and 13), and if the header 5 is slightly tilted (see FIG. 14), partial stress occurs. May cause cracks in the potting portion 4 due to excessive action, which may be unfavorable for liquid-tightly sealing the internal space of the header 5, but when the angle α2 of the side wall 4W is less than 90 degrees. In some cases, it exerts the effect of suppressing cracking of the potting portion 4.

<Manufacturing method of hollow fiber membrane module>
First, a hollow fiber membrane bundle 3 longer than the required length is finally prepared, and the hollow fiber membrane bundle 3 is loaded into the tubular container 2 and accommodated (see FIG. 8A). Next, the molding mold 100 of the potting portion 4 is attached to the end portion 2a of the tubular container 2 (see FIG. 8B).

In the present embodiment, the potting portion 4 is molded so that the angle α2 of the side wall 4W of the outer peripheral portion 4r of the surface outer peripheral portion 4r of the potting protruding portion 4P protruding from the end portion 2a of the tubular container 2 of the potting portion 4 is smaller than 90 degrees. do. This can be achieved, for example, by using a molding die 100 having a taper structure smaller than 90 degrees for forming the angle α2 of the side wall 4W smaller than 90 degrees. At the time of molding, the molding mold 100 is attached to the open end surface of the end portion 2a of the tubular container 2, and the resin is potted in the tubular container 2 by centrifugal molding (see FIG. 8C). After the resin has hardened, the molding die 100 is removed (see FIG. 8D), and the unnecessary portion of the potting portion 4 (both ends 3a of the hollow fiber membrane bundle 3) is cut in a cross section perpendicular to the central axis P. Then, the cut surface 4S of the potting portion is formed, and the end surface of the hollow fiber membrane bundle 3 is opened (see FIG. 8E).

Next, the header 5 is welded to the tubular container 2. For example, as shown in FIG. 3, the header protrusion 22 of the header 5 is inserted between the inner protrusion 50 and the outer protrusion 51 of the tubular container 2, and the cutting portion cutting surface 4S of the potting portion is the flat surface 40 of the inner surface of the header 5. Is in contact with. In this state, the ultrasonic horn 90 comes into contact with the top plate portion 21 of the header 5 from the outside. Then, when the ultrasonic horn 90 oscillates ultrasonic vibration toward the header 5 while pressing the header 5 from the outside in the central axis P direction toward the tubular container 2, ultrasonic welding (mechanical vibration of electrical energy) occurs. A technology that generates strong frictional heat on the joint surface of two parts to be welded by converting it into energy and applying pressure at the same time to melt and join the plastic), the secondary welded part 72, the primary The welded portion 71 is welded. In the above example, the flat surface 40 of the inner surface of the header 5 is in contact with the cutting surface 4S of the potting portion, but the outer peripheral portion 4r of the surface of the potting protrusion 4P in the contact portion T needs to be a cut surface. Instead, it may be directly formed by the molding mold 100.

The frequency, pressure, amplitude, and time are important for the ultrasonic vibration oscillated by the ultrasonic horn 90. For example, the frequency is 15 kHz, 20 kHz, 30 kHz, 40 kHz, 50 kHz, 70 kHz, the amplitude is 20 to 125 μm, the pressure is 50 N to 3000 N, the time is 0.1 to 1 second, and the like is particularly limited as long as it is sufficient for welding. However, depending on the situation, ultrasonic vibration having a relatively low frequency (for example, a low frequency of about 15 kHz when an ultrasonic wave having a frequency of about 20 kHz is generally used) may be used. In such a case, the ultrasonic vibration easily reaches a position away from the ultrasonic horn 90. Amplitude, pressure, and time may increase some or all of these values if you want to strengthen the welding. If the ultrasonic vibration is too strong and the tubular container 2 or the header 5 is damaged, some or all of these values may be reduced or a high frequency one may be adopted.

The speed at which the header 5 and the tubular container 2 are pushed in by ultrasonic welding is 0.5 to 10 mm / sec, preferably 1 to 3 mm / sec. The slower the speed, the more the amount of melting due to the frictional heat at the welded portion increases and the bonding strength increases, but if it is too slow, the frictional heat becomes excessive and carbonization may occur.

As described above, the hollow fiber membrane module 1 in which the header 5 and the tubular container 2 are welded at at least two places is completed (see FIG. 1). According to the present embodiment, the header 5 and the tubular container 2 are welded in two regions of the secondary welded portion 72 and the primary welded portion 71, so that the bonding strength is increased and the hollow fiber membrane is formed. The overall withstand voltage strength of the module 1 is improved. Therefore, the withstand voltage is unlikely to be insufficient, and liquid leakage is unlikely to occur.

For example, when the hollow fiber membrane module 1 is used, a fluid such as blood flows into the header 5 from the nozzle portion 20, passes through each hollow fiber membrane of the hollow fiber membrane bundle 3, and is discharged from the nozzle portion 20 of the opposite header 5. At that time, a predetermined component of the fluid is separated to the outside through the side wall of the hollow fiber membrane. With the continuous use of the hollow fiber membrane module 1, clogging of the hollow fiber membrane progresses, and the internal pressure of the hollow fiber membrane module 1 rises. If the pressure of the fluid in the header 5 rises more than a certain amount, the fluid may infiltrate from between the potting portion 4 and the inner surface of the header 5 to the outside. In this regard, according to the hollow fiber membrane module 1 of the present embodiment, (1) even if a part of the primary welded portion 71 is damaged, the secondary welded portion 72 is present, so that fluid leakage is unlikely to occur, and further. (2) Generally, it can be said that the pressure resistance strength increases as the welding area increases, but in the present embodiment, the welding area is increased by forming two welding portions, a primary welding portion 71 and a secondary welding portion 72. , It is possible to improve the pressure resistance. As a result, the header 5 is less likely to come off from the tubular container 2, and the pressure resistance of the hollow fiber membrane module 1 can be improved.

According to the hollow fiber membrane module 1 of the present embodiment, the angle α2 of the side wall 4W of the outer peripheral portion 4r of the surface outer peripheral portion 4r in the potting protrusion 4P of the potting portion 4 is set to less than 90 degrees, so that the header 5 is pushed in or over-pushed. At that time, it is possible to suppress the occurrence of resin cracking in the potting portion 4. According to this, it is easy to secure sufficient sealing performance (sealing ability) of the hollow fiber membrane module 1.

Although the above-described embodiment is an example of a preferred embodiment of the present invention, the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the description has been made while showing a form in which the angle α2 of the side wall 4W of the side wall 4W of the surface outer peripheral portion 4r in the potting protrusion 4P of the potting portion 4 is set to less than 90 degrees. It is not always the case that 4W is uniformly inclined like a cone. In addition, for example, as a result of forming a shape in the potting step, or as a result of pushing the header 5, the side wall 4W of the potting protrusion 4P may have a curved shape that bulges outward, in which case the header. A line connecting the outermost peripheral header contact 4Pup in contact with 5 and the outermost peripheral root point 4Pdp at the outer peripheral root portion can be drawn, and the angle can be determined by the inclination of the line (see FIG. 21). The point is, regardless of whether the surface of the side wall 4W has a shape bulging outward or not, if the angle α2 is less than 90 degrees and the structure is such that resin cracking of the potting portion 4 is unlikely to occur, the hollow fiber It is advantageous in that it becomes easy to secure sufficient sealing performance of the membrane module 1.

Further, the structure of the hollow fiber membrane module 1 shown in the above-described embodiment is only a suitable example, for example, the structure of the header protrusion 22 of the header 5, the inner protrusion 50 and the outer protrusion 51 of the tubular container 2. The structure and the like are not limited to those described above. Further, the overall structure of the tubular container 2 and the header 5 is not limited to that described above. Further, the use of the hollow fiber membrane module 1 is not limited to the treatment of liquids such as blood, and may be used for the treatment of gases.

Further, in the above-described embodiment, the hollow fiber membrane module 1 in which the header 5 and the tubular container 2 are welded by ultrasonic welding has been described as an example, but this fixes the header 5 and the tubular container 2. It is only a suitable example of the form to be used. As described above, in addition to ultrasonic welding, laser light, screwing, or the like can be used as a fixing means or in a fixing step to form a fixing portion between the header 5 and the tubular container 2.

[Comparative Example 1]
When the potting portion 4 having the same structure as before in which the angle of the side wall 4W is 90 degrees is pushed in by the header 5 (see FIG. 17A), (i) the outer peripheral root portion 4Pd of the potting protrusion 4P has a cylinder. Stress acts from the inner peripheral surface near the end 2a of the shape container 2 toward the center in the radial direction and downward (the lower side in the figure, that is, the side facing the center portion 1c in the longitudinal direction of the hollow fiber membrane module 1). , (Ii) It was confirmed that stress in the outer peripheral direction (outward in the radial direction) acts on the upper surface portion 4Pu of the potting protrusion 4P (see FIG. 17B). Further, the upper surface portion 4Pu of the potting protrusion 4P is deformed so as to protrude outward in the radial direction while being compressed, and as a result, (iii) stress acts from the upper surface portion 4Pu of the potting protrusion 4P toward the outer peripheral root portion 4Pd. , It was confirmed that resin cracks may occur in the potting portion 4 (see FIG. 17 (C)).

[Comparative Example 2]
When the angle of the side wall 4W is 90 degrees, it is investigated whether or not the potting portion 4 is cracked when the "urethane height" and the "urethane height difference" of the polyurethane resin potting protrusion 4P take various values. rice field. Here, the "urethane height" refers to a distance H parallel to the central axis P from the end surface of the end portion 2a of the tubular container 2 to the potting protrusion 4P with which the header 5 abuts (see FIG. 18). .. As shown in FIG. 18, the urethane height H is not the height after the header 5 abuts and is compressed, but the height before the header 5 abuts. The "urethane height difference" means the difference obtained by subtracting the minimum height H2 from the maximum height H1 of the urethane height with which the header 5 abuts (urethane height difference ΔH = H1-H2) (see FIG. 19).

Table 1 shows the results of whether or not the potting portion 4 cracked (urethane cracks) occurred when the urethane height H and the urethane height difference ΔH had various values, and FIG. 9 shows the results in a graph. Shown in. After the header 5 is brought into contact with the potting portion 4, if urethane cracking occurs, it is "cracked", and if it does not occur, it is "OK", which is shown in the result column in Table 1. From the above, it was obtained that when the angle of the side wall 4W is 90 degrees, the higher the urethane height and the larger the urethane height difference, the more likely the urethane cracks occur. Here, for the measurement of the urethane height, a two-dimensional high-speed dimension measuring instrument TM-3000 series (controller unit TM-3000, head unit TM-065R) manufactured by KEYENCE Corporation was used.

The urethane height H when there is a difference in urethane height is a value obtained by measuring heights of 248 points at equal intervals over the outer circumference and averaging them (see FIG. 20). Here, the first point when measuring at equal intervals is a position that overlaps with the center line in the longitudinal direction of the port 10 when the cutting surface 4S of the potting portion is viewed from above vertically.

[Example 1]
When the angle α2 of the side wall 4W is 70 degrees, the presence or absence of cracks in the potting portion 4 when the “urethane height” and the “urethane height difference” of the polyurethane resin potting protrusion 4P take various values is determined. Examined.

Table 2 shows the results of whether or not the potting portion 4 cracked (urethane cracks) occurred when the urethane height and the urethane height difference were various values, and FIG. 10 shows the results in a graph. .. From the above, it was obtained that when the angle of the side wall 4W is 70 degrees and the urethane height and the urethane height difference are the values shown in Table 2, urethane cracking does not occur.

[Example 2]
When the angle α2 of the side wall 4W is 80 degrees, the presence or absence of cracks in the potting portion 4 when the “urethane height” and the “urethane height difference” of the polyurethane resin potting protrusion 4P take various values is determined. Examined.

Table 3 shows the results of whether or not the potting portion 4 cracked (urethane cracks) occurred when the urethane height and the urethane height difference were various values, and FIG. 11 shows the results in a graph. .. From the above, it was obtained that when the angle of the side wall 4W is 80 degrees and the urethane height and the urethane height difference are the values shown in Table 3, urethane cracking does not occur.

The present invention is suitable for application to a hollow fiber membrane module that requires a liquid sealing property.

1 ... Hollow fiber membrane module, 2 ... Cylindrical container (container), 2a ... End, 3 ... Hollow fiber membrane bundle, 4 ... Potting part, 4P ... Potting protrusion, 4Pd ... Outer peripheral root part, 4Pu ... Top surface part, 4r ... Surface outer peripheral part, 4W ... Side wall, 5 ... Header, 20 ... Nozzle part, 40 ... Header flat surface (inner contact surface), 70 ... Welding part (fixed part), 100 ... Molding mold, T ... Contacting part, α1, α2 ... Angle (on the side wall of the outer wall of the surface of the potting part), H ... Height of the potting protruding part 4P, ΔH ... Difference in height H in the entire circumference of the outer peripheral part of the surface of the potting protruding part (. Height difference), P ... Central axis

Claims (12)

Hollow fiber membrane module
A cylindrical container with one end and the other end open,
A bundle of hollow fiber membranes loaded in the tubular container,
A potting portion in which the bundle of hollow fiber membranes is embedded and fixed at both ends of the tubular container, and a potting portion.
A header provided at both ends of the tubular container and having nozzles serving as fluid inlets and outlets, and a header.
A fixing portion in which the header and the tubular container are fixed to each other,
An abutting portion where the inner abutting surface of the header and the potting portion abut and liquid-tightly seal the inner space of the header.
Equipped with
Among the potting portions, the angle of the side wall of the outer peripheral portion of the surface of the potting protrusion protruding from the end of the container is smaller than 90 degrees.
The inner contact surface, which is an annular flat surface perpendicular to the central axis of the tubular container of the header, and the annular flat surface portion of the potting portion, which faces the inner contact surface and abuts. , A hollow fiber membrane module characterized in that the contact portion for liquid-tightly sealing the inner space of the header is formed . The hollow fiber membrane module according to claim 1, wherein the angle of the side wall of the outer peripheral portion of the surface of the potting protrusion is 45 degrees or more and 85 degrees or less. The hollow fiber membrane module according to claim 1 or 2, wherein the height of the potting protrusion is 0.4 mm or more and 3 mm or less. The hollow fiber according to any one of claims 1 to 3, wherein the difference in height of the potting protrusion in the entire circumferential direction of the outer peripheral portion of the surface is 0.05 mm or more and 0.5 mm or less. Membrane module. The hollow fiber membrane according to any one of claims 1 to 4, wherein the outer peripheral root portion of the side wall of the surface outer peripheral portion of the potting protrusion is located at the boundary between the potting portion and the tubular container. module. The hollow fiber membrane according to any one of claims 1 to 4, wherein the outer peripheral root portion of the side wall of the surface outer peripheral portion of the potting protrusion is in contact with the open end surface of the end portion of the tubular container. module. A cylindrical container with one end and the other end open,
A bundle of hollow fiber membranes loaded in the tubular container,
A potting portion in which the bundle of hollow fiber membranes is embedded and fixed at both ends of the tubular container, and a potting portion.
A method for manufacturing a hollow fiber membrane module, which is provided at both ends of the tubular container and includes a header having nozzle portions serving as an inlet / outlet for a fluid.
Among the potting portions, a step of forming the potting portion in which the angle of the side wall of the outer peripheral portion of the surface of the potting protrusion protruding from the end of the container is smaller than 90 degrees in a state of being in contact with the header.
The inner contact surface, which is an annular flat surface perpendicular to the central axis of the tubular container of the header, and the annular flat surface portion of the potting portion, which faces the inner contact surface and abuts. , The step of forming the contact portion for liquid-tightly sealing the inner space of the header, and
A step of bringing the inner contact surface of the header into contact with the potting protrusion so that the internal space of the header is hermetically sealed.
It comprises a fixing step of fixing the header and the tubular container to each other.
A method for manufacturing a hollow fiber membrane module. The step of loading the bundle of the hollow fiber membrane into the tubular container, and
The step of mounting the molding mold of the potting portion on the open end face of the tubular container, and
The process of potting the resin on the open end face by centrifugal molding,
After the resin is cured, the molding mold is removed, the potting portion is cut, and the end face of the bundle of the hollow fiber membranes is opened.
7. The method for manufacturing a hollow fiber membrane module according to claim 7. The method for manufacturing a hollow fiber membrane module according to claim 7 or 8, wherein ultrasonic welding is performed in the fixing step. The method for manufacturing a hollow fiber membrane module according to claim 7 or 8, wherein laser welding is performed in the fixing step. The method for manufacturing a hollow fiber membrane module according to claim 7 or 8, wherein screwing is performed in the fixing step. A cylindrical container with one end and the other end open,
A bundle of hollow fiber membranes loaded in the tubular container,
A potting portion in which the bundle of hollow fiber membranes is embedded and fixed at both ends of the tubular container, and a potting portion.
A mold for molding the potting portion, which is used for manufacturing a hollow fiber membrane module provided with headers having nozzle portions serving as fluid inlets and outlets provided at both ends of the tubular container.
A structure having a taper smaller than 90 degrees for forming the potting portion in a structure in which the angle of the side wall of the outer peripheral portion of the surface of the potting portion is maintained to be smaller than 90 degrees in a state of being in contact with the header.
A structure for forming an annular flat surface portion of the header facing the inner contact surface, which is an annular flat surface, in the potting portion.
Mold for molding.

Images