Hollow fiber membrane observation jig

Abstract

To provide a hollow fiber membrane observation tool capable of improving measurement accuracy of an outer diameter and an inner diameter of a hollow fiber membrane.SOLUTION: The jig body has a main surface and a first support hole that opens to the main surface and can accommodate the hollow fiber membrane. The first support hole has a first support hole inner peripheral surface, a first support hole bottom surface, and a first support hole enlarged surface. The first support hole enlarged surface is continuous with the main surface and an end portion of the first support hole inner peripheral surface on a side opposite to an end portion continuous with the first support hole bottom surface. An intersection line between a cross section passing through a center line of the first support hole and the first support hole enlarged diameter surface forms a shape that separates from the center line of the first support hole from the first support hole inner peripheral surface toward the main surface when viewed from a direction perpendicular to the cross section passing through the center line of the first support hole. An arithmetic average roughness of the first support hole bottom surface is not less than 1.1 μm.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to a hollow fiber membrane observation jig. [Background technology]

[0002] International Publication No. 2018 / 182027 (Patent Document 1) describes a method for measuring the porosity (air void ratio) of a hollow fiber membrane. According to this measurement method, a cross section of the hollow fiber membrane in a direction perpendicular to the longitudinal direction and in the thickness direction of the membrane is observed and photographed, and the outer diameter of the hollow fiber membrane is calculated. The density of the hollow fiber membrane is calculated using the calculated outer diameter and other values. The porosity is calculated using the density of the hollow fiber membrane. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 182027 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned Patent Document 1 does not describe in detail a method for measuring the outer diameter of a hollow fiber membrane. An object of the present disclosure is to provide a hollow fiber membrane observation jig that can improve the measurement accuracy of the outer diameter and inner diameter of a hollow fiber membrane. [Means for solving the problem]

[0005] The hollow fiber membrane observation jig according to the present disclosure supports a hollow fiber membrane in order to observe the first end face of the cylindrical hollow fiber membrane having an outer peripheral surface, an inner peripheral surface, a first end face, and a second end face. The hollow fiber membrane observation jig includes a jig body. The jig body has a main surface and a first support hole that opens into the main surface and is capable of accommodating a hollow fiber membrane. The first support hole has a first support hole inner peripheral surface, a first support hole bottom surface, and a first support hole expansion surface. The first support hole inner peripheral surface faces the outer peripheral surface when the hollow fiber membrane is accommodated. The first support hole bottom surface abuts against the second end face when the hollow fiber membrane is accommodated. The first support hole expansion surface is continuous with the main surface and with an end of the first support hole inner peripheral surface opposite the end that is continuous with the first support hole bottom surface. The intersection line between a cross section passing through the center line of the first support hole and the first support hole expansion surface has a shape that, when viewed from a direction perpendicular to the cross section passing through the center line of the first support hole, moves away from the center line of the first support hole from the inner peripheral surface of the first support hole toward the main surface. The arithmetic mean roughness of the bottom surface of the first support hole is 1.1 μm or more. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to provide a hollow fiber membrane observation jig that can improve the measurement accuracy of the outer diameter and inner diameter of a hollow fiber membrane. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic front view showing the configuration of a hollow fiber membrane cutting jig according to this embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a schematic cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a schematic front view showing the cutting unit in a state where it is placed at the preparation position. [Figure 5] FIG. 5 is a schematic front view showing a state in which the cutting unit is placed at the cutting position. [Figure 6] FIG. 6 is a schematic front view showing the configuration of a hollow fiber membrane cutting jig according to a modified example of this embodiment. [Figure 7]FIG. 7 is a plan view showing the configuration of the hollow fiber membrane observation jig according to this embodiment. [Figure 8] FIG. 8 is a schematic cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] FIG. 9 is an enlarged plan view showing the configuration of a hollow fiber membrane observation jig according to a first modified example of this embodiment. [Figure 10] FIG. 10 is an enlarged plan view showing the configuration of a hollow fiber membrane observation jig according to a second modified example of this embodiment. [Figure 11] FIG. 11 is a flow diagram that schematically shows a method for measuring the porosity of a hollow fiber membrane according to this embodiment. [Figure 12] FIG. 12 is a cross-sectional schematic diagram showing a state in which the cutting edges of the first plate blade portion and the second plate blade portion are in contact with the hollow fiber membrane simultaneously. [Figure 13] FIG. 13 is a cross-sectional view showing a process of imaging the cut surface of the hollow fiber membrane to be imaged. [Figure 14] FIG. 14 is an image showing a cross section of the hollow fiber membrane to be imaged according to Sample 1. As shown in FIG. [Figure 15] FIG. 15 is an image showing a cross section of the hollow fiber membrane to be imaged according to Sample 2. As shown in FIG. [Figure 16] FIG. 16 is an image showing a cross section of the hollow fiber membrane to be imaged according to Sample 3. In FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure will be listed and described.

[0009] (1) A hollow fiber membrane observation jig according to the present disclosure supports a hollow fiber membrane in order to observe the first end face of the cylindrical hollow fiber membrane having an outer peripheral surface, an inner peripheral surface, a first end face, and a second end face. The hollow fiber membrane observation jig includes a jig body. The jig body has a main surface and a first support hole that opens into the main surface and is capable of accommodating a hollow fiber membrane. The first support hole has a first support hole inner peripheral surface, a first support hole bottom surface, and a first support hole expansion surface. The first support hole inner peripheral surface faces the outer peripheral surface when the hollow fiber membrane is accommodated. The first support hole bottom surface abuts against the second end face when the hollow fiber membrane is accommodated. The first support hole expansion surface is continuous with the main surface and with an end of the first support hole inner peripheral surface opposite the end that is continuous with the first support hole bottom surface. The intersection of a cross section passing through the center line of the first support hole and the first support hole expansion surface, when viewed from a direction perpendicular to the cross section passing through the center line of the first support hole, forms a shape that moves away from the center line of the first support hole from the inner peripheral surface of the first support hole toward the main surface. The arithmetic mean roughness of the bottom surface of the first support hole is 1.1 μm or more. This improves the measurement accuracy of the outer diameter and inner diameter of the hollow fiber membrane.

[0010] (2) According to the hollow fiber membrane observation jig pertaining to (1) above, the jig body may include a first body member and a second body member. The first body member may have a main surface, a back surface parallel to the main surface, a first support hole inner circumferential surface, and a first support hole enlarged diameter surface. The first support hole inner circumferential surface may open to the back surface. The second body member may have a support surface abutting the back surface. When the back surface and the support surface abut, the portion of the support surface facing the internal space of the first support hole inner circumferential surface may form the first support hole bottom surface. This facilitates the manufacture of the hollow fiber membrane observation jig.

[0011] (3) According to the hollow fiber membrane observation jig of (2) above, the first body member and the second body member may be detachable between a state in which the back surface and the support surface are in contact with each other and a state in which the back surface and the support surface are spaced apart. This allows the hollow fiber membrane accommodated in the support hole to be easily removed by removing the first body member from the second body member.

[0012] (4) According to the hollow fiber membrane observation jig of (2) or (3) above, one or both of the first body member and the second body member may have a restricting protrusion. The restricting protrusion may restrict the first body member from moving relative to the second body member in a direction parallel to the back surface when the back surface and the support surface abut against each other. This prevents the hollow fiber membrane from moving relative to the second body member when observing the first end surface of the hollow fiber membrane.

[0013] (5) According to the hollow fiber membrane observation tool according to any one of (1) to (4) above, the arithmetic mean roughness of the main surface may be 1.1 μm or more, thereby reducing the intensity of light reflected by the main surface.

[0014] (6) According to the hollow fiber membrane observation tool according to any one of (1) to (5) above, in an environment where the hollow fiber membrane observation tool supports the hollow fiber membrane and images the first end face, the brightness of the hollow fiber membrane observation tool may be less than 50% of the brightness of the first end face, thereby improving the accuracy of detecting the shape of the first end face.

[0015] (7) According to any one of (1) to (6) above, the jig body may have a second support hole that opens to the main surface and is capable of accommodating a hollow fiber membrane. The second support hole may have a second support hole inner circumferential surface, a second support hole bottom surface, and a second support hole expansion surface. The second support hole inner circumferential surface may face the outer circumferential surface when a hollow fiber membrane is accommodated therein. The second support hole bottom surface may abut against the second end surface when a hollow fiber membrane is accommodated therein. The second support hole expansion surface may be continuous with an end of the second support hole inner circumferential surface opposite to the end that is continuous with the second support hole bottom surface, and with the main surface. The intersection line between a cross section passing through the center line of the second support hole and the second support hole expansion surface may be shaped so that it moves away from the center line of the second support hole from the second support hole inner circumferential surface toward the main surface, when viewed in a direction perpendicular to the cross section passing through the center line of the second support hole. The arithmetic mean roughness of the expanded diameter surface of the second support hole may be 1.1 μm or more. When the diameter of a circle inscribed in the inner circumferential surface of the first support hole as viewed along the center line of the first support hole is defined as the first diameter, and the diameter of a circle inscribed in the inner circumferential surface of the second support hole as viewed along the center line of the second support hole is defined as the second diameter, the first diameter and the second diameter may be different. This allows observation of multiple types of hollow fiber membranes with different outer diameters.

[0016] (8) In the hollow fiber membrane observation jig according to any one of (1) to (7) above, the arithmetic mean roughness of the expanded diameter surface of the first support hole may be smaller than the arithmetic mean roughness of the bottom surface of the first support hole, thereby preventing the expanded diameter surface of the first support hole from appearing excessively bright when viewed along the center line of the first support hole.

[0017] [Details of the embodiments of the present disclosure] Hereinafter, an embodiment of the present disclosure (also referred to as the present embodiment) will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0018] (Hollow fiber membrane cutting jig) As shown in Figures 1 and 2, the hollow fiber membrane cutting jig 100 has a support part 1 and a cutting part 2. The support part 1 supports the hollow fiber membrane 90. The cutting part 2 is movable relative to the support part 1. The hollow fiber membrane cutting jig 100 cuts the hollow fiber membrane 90 using the cutting part 2. Figure 2 shows the state in which the hollow fiber membrane 90 is supported. The hollow fiber membrane 90 has a cylindrical shape. The hollow fiber membrane 90 is formed from a porous resin. The hollow fiber membrane 90 is mainly composed of, for example, PTFE (polytetrafluoroethylene).

[0019] 2, the support part 1 has a first support member 10, a second support member 20, and a third support member 30. The first support member 10 is, for example, flat. The first support member 10 has a first support surface 11, a second support surface 12, and a first outer surface 13.

[0020] The first support surface 11 is a flat surface. The second support surface 12 is opposite the first support surface 11. The second support surface 12 is a flat surface. From another perspective, the first support surface 11 and the second support surface 12 are a pair of flat surfaces. The first support surface 11 and the second support surface 12 are parallel. In this specification, two surfaces being parallel means that the angle between the normals of the two surfaces is 3° or less.

[0021] The direction perpendicular to the first support surface 11 and the second support surface 12 is defined as a first direction 101. The first direction 101 is the direction from the second support surface 12 toward the first support surface 11. The first outer surface 13 is continuous with each of the first support surface 11 and the second support surface 12. When viewed from the first direction 101, the first outer surface 13 is annular.

[0022] The thickness of the first support member 10 in the first direction 101 (first thickness H1) is set in accordance with the length of the hollow fiber membrane 90 to be cut. The first thickness H1 is, for example, 7 mm.

[0023] The second support member 20 is disposed in a first direction 101 relative to the first support member 10. The second support member 20 is spaced apart from the first support member 10. A first gap 18 is formed between the first support member 10 and the second support member 20. The first gap 18 extends along a direction perpendicular to the first direction 101. The second support member 20 is flat. The second support member 20 has a third support surface 21, a fifth support surface 22, and a second outer surface 23.

[0024] The third support surface 21 is, for example, a flat surface. The second support member 20 is disposed so that the third support surface 21 is parallel to the first support surface 11 and faces the first support surface 11. The third support surface 21 is perpendicular to the first direction 101.

[0025] The fifth support surface 22 is opposite the third support surface 21. The fifth support surface 22 is a plane. The fifth support surface 22 is parallel to the third support surface 21. The second outer surface 23 is continuous with each of the third support surface 21 and the fifth support surface 22. When viewed from the first direction 101, the second outer surface 23 is annular.

[0026] The third support member 30 is disposed in a direction opposite to the first direction 101 relative to the first support member 10. From another perspective, the third support member 30, the first support member 10, and the second support member 20 are lined up in this order along the first direction 101. The third support member 30 is spaced apart from the first support member 10. The first support member 10, the second support member 20, and the third support member 30 may have the same shape as one another.

[0027] A second gap 19 is formed between the first support member 10 and the third support member 30. The second gap 19 extends in a direction perpendicular to the first direction 101. The third support member 30 has, for example, a flat plate shape. The third support member 30 has a fourth support surface 31, a sixth support surface 32, and a third outer surface 33.

[0028] The fourth support surface 31 is, for example, a flat surface. The third support member 30 is arranged so that the fourth support surface 31 is parallel to the second support surface 12 and faces the second support surface 12. The fourth support surface 31 is perpendicular to the first direction 101. The direction parallel to the first support surface 11, the second support surface 12, the third support surface 21, and the fourth support surface 31 is the direction perpendicular to the first direction 101.

[0029] The sixth support surface 32 is opposite the fourth support surface 31. The sixth support surface 32 is a plane. The sixth support surface 32 is parallel to the fourth support surface 31. The third outer surface 33 is continuous with each of the fourth support surface 31 and the sixth support surface 32. When viewed from the first direction 101, the third outer surface 33 is annular.

[0030] A through hole 7 is formed in the support part 1. A hollow fiber membrane 90 is disposed in the through hole 7. The through hole 7 penetrates the first support member 10, the second support member 20, and the third support member 30 along a first direction 101. Specifically, the through hole 7 penetrates each of the first support surface 11, the second support surface 12, the third support surface 21, the fourth support surface 31, the fifth support surface 22, and the sixth support surface 32. The through hole 7 is connected to each of the first gap 18 and the second gap 19.

[0031] The through hole 7 is made up of a plurality of holes. Specifically, the through hole 7 is made up of, for example, a first hole 71, a second hole 72, and a third hole 73. The first hole 71, the second hole 72, and the third hole 73 do not overlap each other when viewed from a first direction 101. The plurality of holes are lined up in a direction perpendicular to the first direction 101. The direction in which the plurality of holes are lined up is set as a second direction 102. The second direction 102 is the direction from the first hole 71 toward the third hole 73. In the second direction 102, the second hole 72 is provided between the first hole 71 and the third hole 73.

[0032] The first hole 71, the second hole 72, and the third hole 73 each penetrate the first support member 10, the second support member 20, and the third support member 30 along the first direction 101. When viewed in the first direction 101, the first hole 71, the second hole 72, and the third hole 73 each have, for example, a circular shape.

[0033] As shown in FIG. 3 , the inner diameter (fourth diameter D4) of the first hole 71, the inner diameter (fifth diameter D5) of the second hole 72, and the inner diameter (sixth diameter D6) of the third hole 73 are all different from one another. The first hole 71 has a first inner wall surface 61, a second inner wall surface 62, and a third inner wall surface 63. The first inner wall surface 61, the second inner wall surface 62, and the third inner wall surface 63 are formed by the first support member 10, the second support member 20, and the third support member 30, respectively. The central axes of the first inner wall surface 61, the second inner wall surface 62, and the third inner wall surface 63 may be, for example, collinear. The inner diameters of the first inner wall surface 61, the second inner wall surface 62, and the third inner wall surface 63 are the same. When viewed in the first direction 101, the first inner wall surface 61, the second inner wall surface 62, and the third inner wall surface 63, for example, overlap one another.

[0034] The configuration of each of the second hole 72 and the third hole 73 is substantially the same as the configuration of the first hole 71, except for the difference in inner diameter. The second hole 72 has a fourth inner wall surface 64, a fifth inner wall surface 65, and a sixth inner wall surface 66. The fourth inner wall surface 64, the fifth inner wall surface 65, and the sixth inner wall surface 66 correspond to the first inner wall surface 61, the second inner wall surface 62, and the third inner wall surface 63, respectively. The third hole 73 has a seventh inner wall surface 67, an eighth inner wall surface 68, and a ninth inner wall surface 69. The seventh inner wall surface 67, the eighth inner wall surface 68, and the ninth inner wall surface 69 correspond to the first inner wall surface 61, the second inner wall surface 62, and the third inner wall surface 63, respectively.

[0035] 1 and 2, a guide hole 8 is formed in the support part 1. The guide hole 8 guides the cutting part 2. A direction perpendicular to each of the first direction 101 and the second direction 102 and extending from the guide hole 8 toward the through hole 7 is defined as a third direction 103.

[0036] The guide hole 8 penetrates the first support member 10, the second support member 20, and the third support member 30 in the first direction 101. Specifically, the guide hole 8 penetrates each of the first support surface 11, the second support surface 12, the third support surface 21, the fourth support surface 31, the fifth support surface 22, and the sixth support surface 32. The guide hole 8 is connected to each of the first gap 18 and the second gap 19.

[0037] 1, the guide hole 8 extends along each of the second direction 102 and the third direction 103. When viewed in the first direction 101, the guide hole 8 is an elongated hole whose longitudinal direction is parallel to the second direction 102.

[0038] The second support member 20 is positioned so that the relative position of the second support member 20 with respect to the first support member 10 does not change. Similarly, the third support member 30 is positioned so that the relative position of the third support member 30 with respect to the first support member 10 does not change. Specifically, as shown in FIGS. 1 and 3, the support unit 1 has a plurality of fixing members 3. The plurality of fixing members 3 fix the first support member 10, the second support member 20, and the third support member 30.

[0039] Each of the multiple fixing members 3 is formed by, for example, a screw, a nut, and a spacer. A spacer is sandwiched between the first support member 10 and the second support member 20, and between the first support member 10 and the third support member 30. Screws are inserted into multiple fastening holes (not shown) provided in each of the first support member 10, the second support member 20, and the third support member 30, and into the spacers. The first support member 10, the second support member 20, and the third support member 30 are fixed together by attaching nuts to the screws. Note that the multiple fixing members 3 are not shown in FIG. 2.

[0040] As shown in FIG. 2, the cutting unit 2 has a first blade section 5, a second blade section 6, and a connecting section 9. The first blade section 5 is plate-shaped. The first blade section 5 is disposed between a first support member 10 and a second support member 20. In other words, the first blade section 5 is disposed inside the first gap 18.

[0041] The first plate blade unit 5 has a first plate blade surface 51 and a second plate blade surface 52. The first plate blade surface 51 and the second plate blade surface 52 are a pair of flat surfaces. The first plate blade unit 5 is disposed so that the first plate blade surface 51 abuts against the first support surface 11 and so that the second plate blade surface 52 abuts against the third support surface 21. From another perspective, the first support surface 11 and the third support surface 21 guide the first plate blade unit 5 so that it moves in a direction perpendicular to the first direction 101.

[0042] As shown in FIG. 4 , when viewed perpendicularly to the first plate blade surface 51, the first plate blade portion 5 has, for example, a rectangular shape. The first plate blade portion 5 has a first cutting edge 56 and a second cutting edge 57. When viewed perpendicularly to the first plate blade surface 51, the first cutting edge 56 forms one side of the first plate blade portion 5. For example, the cutting portion 2 is arranged so that the first cutting edge 56 faces the third direction 103. When viewed perpendicularly to the first plate blade surface 51, the second cutting edge 57 forms a side opposite to the side formed by the first cutting edge 56. For example, the cutting portion 2 is arranged so that the second cutting edge 57 faces the direction opposite to the third direction 103.

[0043] The shape of the second plate blade section 6 is substantially the same as the shape of the first plate blade section 5. The second plate blade section 6 is disposed between the first support member 10 and the third support member 30. In other words, the second plate blade section 6 is disposed within the second gap 19. The second plate blade section 6 has a third plate blade surface 53 and a fourth plate blade surface 54. The third plate blade surface 53 and the fourth plate blade surface 54 correspond to the first plate blade surface 51 and the second plate blade surface 52, respectively. The third plate blade surface 53 and the fourth plate blade surface 54 are a pair of flat surfaces. The second plate blade section 6 is disposed so that the third plate blade surface 53 and the second support surface 12 abut on each other, and the fourth plate blade surface 54 and the fourth support surface 31 abut on each other. From another perspective, the second support surface 12 and the fourth support surface 31 guide the second plate blade section 6 so that it moves in a direction perpendicular to the first direction 101.

[0044] The second plate blade portion 6 has a third cutting edge 58 and a fourth cutting edge 59. The third cutting edge 58 and the fourth cutting edge 59 correspond to the first cutting edge 56 and the second cutting edge 57, respectively. For ease of explanation, the second support member 20 is not shown in FIG. 4.

[0045] 2, the connecting portion 9 is fixed to the first blade portion 5 and the second blade portion 6. The connecting portion 9 connects the first blade portion 5 and the second blade portion 6. The connecting portion 9 extends along a first direction 101.

[0046] The connecting portion 9, the first blade portion 5, and the second blade portion 6 are configured to be movable as a unit. Specifically, the connecting portion 9 is formed by, for example, two screws, two nuts, and a plurality of spacers. Each of the first blade portion 5 and the second blade portion 6 has, for example, two fastening holes (not shown). A screw is inserted into each of the two fastening holes. A nut is attached to the screw. A spacer is sandwiched between the screw and the first blade portion 5 and between the second blade portion 6 and the nut.

[0047] The connecting portion 9 is housed so as to be movable along the guide hole 8. From another perspective, the guide hole 8 limits the movement of the cutting portion 2. Both ends of the connecting portion 9 are disposed outside the guide hole 8.

[0048] As shown in FIG. 4, the position of the cutting unit 2 where neither the first plate blade portion 5 nor the second plate blade portion 6 overlaps the through hole 7 when viewed from the first direction 101 is the standby position. As shown in FIG. 5, the position of the cutting unit 2 where both the first plate blade portion 5 and the second plate blade portion 6 overlap the through hole 7 is the cutting position. The direction from the cutting position toward the standby position is the same as the third direction 103. For ease of explanation, the second support member 20 is not shown in FIG. 5. FIG. 2 shows the state in which the cutting unit 2 is positioned at the standby position, and the positions of the first plate blade portion 5 and the second plate blade portion 6 when the cutting unit 2 is positioned at the cutting position are indicated by dashed lines.

[0049] 4 and 5, the cutting unit 2 is movable integrally between the preparation position and the cutting position in directions parallel to the first support surface 11, the second support surface 12, the third support surface 21, and the fourth support surface 31. Specifically, for example, the cutting unit 2 is movable integrally in the third direction 103 from the preparation position toward the cutting position.

[0050] When the cutting unit 2 is disposed in the preparation position, when the cutting unit 2 is disposed in the cutting position, and when the cutting unit 2 is moving between the preparation position and the cutting position, the first plate blade portion 5 and the second plate blade portion 6 do not protrude outside the support unit 1 when viewed from the first direction 101. From another perspective, the guide hole 8 limits the movement of the cutting unit 2 so that the first plate blade portion 5 and the second plate blade portion 6 do not protrude outside the support unit 1 when viewed from the first direction 101. Note that "outside the support unit 1 when viewed from the first direction 101" refers to the area formed by overlapping the outer area of ​​the first outer surface 13, the outer area of ​​the second outer surface 23, and the outer area of ​​the third outer surface 33 when viewed from the first direction 101.

[0051] When the cutting unit 2 is positioned in the preparation position, when the cutting unit 2 is positioned in the cutting position, and when the cutting unit 2 is moving between the preparation position and the cutting position, the cutting edges of the first plate blade unit 5 and the second plate blade unit 6 do not protrude inside the guide hole 8 when viewed from the first direction 101. From another perspective, the guide hole 8 limits the movement of the cutting unit 2 so that the cutting edges of the first plate blade unit 5 and the second plate blade unit 6 do not protrude inside the guide hole 8 when viewed from the first direction 101. This prevents the cutting edges of the cutting unit 2 from being exposed inside the guide hole 8.

[0052] The hollow fiber membrane cutting jig 100 places the cutting part 2 in a preparation position, accommodates the hollow fiber membrane 90 in the through hole 7, and moves the cutting part 2 to the cutting position, so that the cutting part 2 applies shear stress to the hollow fiber membrane 90 to cut the hollow fiber membrane 90.

[0053] (Modified example of hollow fiber membrane cutting jig) As shown in FIG. 6, the cutting unit 2 may be positionable in a second direction 102 or a direction opposite to the second direction 102 with respect to the cutting position (see FIG. 5). The position of the cutting unit shown in FIG. 6 is included in the preparation position. In this specification, the preparation position shown in FIG. 4 is referred to as the first position, and the preparation position shown in FIG. 6 is referred to as the second position. The second position is a position in the second direction 102 or a direction opposite to the second direction 102 with respect to the cutting position and the first position. When the third direction 103 is the direction of gravity, the cutting unit 2 being positionable in the second position allows the hollow fiber membrane 90 to be accommodated in the through-hole 7 even when the operator is not touching the cutting unit 2.

[0054] Although the above description has been given of a configuration in which the through-hole 7 is composed of three holes, there is no particular limitation on the number of holes in the through-hole 7. The number of holes in the through-hole 7 may be one, two, or four or more.

[0055] The first support member 10, the second support member 20, and the third support member 30 may be integral with each other. Specifically, for example, a connecting member (not shown) may be provided between the first support member 10 and the second support member 20, and between the second support member 20 and the third support member 30. The connecting member is continuous with each of the first support member 10, the second support member 20, and the third support member 30.

[0056] (Hollow fiber membrane observation jig) Next, the configuration of the hollow fiber membrane observation jig 200 will be described with reference to Figures 7 and 8. The hollow fiber membrane observation jig 200 supports a hollow fiber membrane. Specifically, the hollow fiber membrane observation jig 200 supports a hollow fiber membrane that has been cut using, for example, the hollow fiber membrane cutting jig 100 described above. In this specification, the hollow fiber membrane supported by the hollow fiber membrane observation jig 200 is also referred to as the hollow fiber membrane 95 to be imaged.

[0057] 8 shows a cross-sectional view of a hollow fiber membrane 95 to be imaged. The hollow fiber membrane 95 to be imaged has an outer peripheral surface 93, an inner peripheral surface 94, a first end face 91, and a second end face 92. The inner peripheral surface 94 is opposite the outer peripheral surface 93. The first end face 91 is continuous with both the outer peripheral surface 93 and the inner peripheral surface 94. The second end face 92 is opposite the first end face 91. The second end face 92 is continuous with both the outer peripheral surface 93 and the inner peripheral surface 94. The hollow fiber membrane observation jig 200 supports the hollow fiber membrane 95 to be imaged so that the first end face 91 of the hollow fiber membrane 95 can be observed.

[0058] 7 and 8, the hollow fiber membrane observation jig 200 has a jig body 4. The jig body 4 has a main surface 43, a main body bottom surface 44, a first support hole 14, a second support hole 24, and a third support hole 34.

[0059] The principal surface 43 is flat. The arithmetic mean roughness (Ra) of the principal surface 43 is, for example, 1.1 μm or more. The Ra of the principal surface 43 may be, for example, 1.5 μm or more, or 2 μm or more. The Ra of the principal surface 43 may be, for example, 20 μm or less, or 10 μm or less. The arithmetic mean roughness (Ra) is a surface texture parameter defined in JIS (Japanese Industrial Standards) B0601:2013.

[0060] In the jig body 4, the body bottom surface 44 is opposite to the main surface 43. The body bottom surface 44 is the surface that abuts against the imaging stand of the imaging device 300 described below. The body bottom surface 44 is flat. The body bottom surface 44 is parallel to the main surface 43. The direction that is perpendicular to the body bottom surface 44 and extends from the body bottom surface 44 toward the main surface 43 is defined as a fourth direction 104.

[0061] The first support hole 14 opens to the main surface 43. The first support hole 14 opens in a fourth direction 104. The first support hole 14 is capable of accommodating the hollow fiber membrane 95 to be imaged. The center line of the first support hole 14 is defined as a first center line O1. The first center line O1 is perpendicular to the bottom surface 44 of the main body.

[0062] The first support hole 14 has a first support hole bottom surface 15, a first support hole inner circumferential surface 16, and a first support hole expanded diameter surface 17. The first support hole inner circumferential surface 16 faces the outer circumferential surface 93 when the hollow fiber membrane 95 to be imaged is housed in the first support hole 14. When viewed along the first center line O1, the first support hole inner circumferential surface 16 is, for example, circular. The first center line O1 is the center line of the first support hole bottom surface 15. When viewed along the first center line O1, the diameter of the first support hole inner circumferential surface 16 is defined as a first diameter D1. The first diameter D1 is, for example, 3.5 mm.

[0063] The first support hole bottom surface 15 is continuous with the first support hole inner circumferential surface 16. The first support hole bottom surface 15 abuts against the second end surface 92 when the hollow fiber membrane 95 to be imaged is housed in the first support hole 14. The first support hole bottom surface 15 is parallel to the main surface 43. The first support hole bottom surface 15 is perpendicular to the first center line O1.

[0064] The Ra of first support hole bottom surface 15 is 1.1 μm or more. The Ra of first support hole bottom surface 15 may be, for example, 1.5 μm or more, or 2 μm or more. The Ra of first support hole bottom surface 15 may be, for example, 20 μm or less, or 10 μm or less.

[0065] The first support hole expansion surface 17 is continuous with the first support hole inner circumferential surface 16 and the main surface 43. Specifically, the first support hole expansion surface 17 is continuous with the end of the first support hole inner circumferential surface 16 opposite the end that is continuous with the first support hole bottom surface 15. When viewed along the first center line O1, the first support hole expansion surface 17 surrounds the hollow fiber membrane 95 to be imaged when the hollow fiber membrane 95 is accommodated in the first support hole 14. When viewed along the first center line O1, the first support hole expansion surface 17 is circular. The outer diameter (seventh diameter D7) of the first support hole expansion surface 17 is larger than the first diameter D1. The seventh diameter D7 is, for example, 8 mm.

[0066] As shown in FIG. 8 , the intersection of the cross section passing through the first center line O1 and the first support hole expansion surface 17, when viewed from a direction perpendicular to the cross section passing through the first center line O1, has a shape that gradually moves away from the center line of the first support hole 14 as it moves from the first support hole inner circumferential surface 16 toward the main surface 43. The intersection of the cross section passing through the first center line O1 and the first support hole expansion surface 17 is, for example, linear. The arithmetic mean roughness Ra of the first support hole expansion surface 17 is smaller than the arithmetic mean roughness Ra of the first support hole bottom surface 15. The arithmetic mean roughness of the first support hole expansion surface 17 is, for example, 1.0 μm or less.

[0067] The second support hole 24 opens to the main surface 43. The second support hole 24 is capable of accommodating the hollow fiber membrane 95 to be imaged. The second support hole 24 has a second support hole bottom surface 25, a second support hole inner circumferential surface 26, and a second support hole expanded diameter surface 27. The second support hole 24 and the first support hole 14 are substantially the same in other respects, except that the diameter of the second support hole inner circumferential surface 26 (second diameter D2) and the diameter of the first support hole inner circumferential surface 16 (first diameter D1) differ.

[0068] Specifically, the second support hole inner circumferential surface 26 faces the outer circumferential surface 93 when the hollow fiber membrane 95 to be imaged is accommodated in the second support hole 24. The second support hole bottom surface 25 abuts the second end surface 92 when the hollow fiber membrane 95 to be imaged is accommodated in the second support hole 24. The arithmetic mean roughness of the second support hole bottom surface 25 is 1.1 μm or more. The second support hole expanded diameter surface 27 is continuous with the end of the second support hole inner circumferential surface 26 opposite to the end that is continuous with the second support hole bottom surface 25 and with the main surface 43.

[0069] The intersection of a cross section passing through the center line (second center line O2) of the second support hole 24 and the second support hole expansion surface 27 has a shape that, when viewed from a direction perpendicular to the cross section passing through the second center line O2, becomes increasingly distant from the second center line O2 as it moves from the second support hole inner surface 26 toward the main surface 43.

[0070] The second diameter D2 is the diameter of the second support hole inner circumferential surface 26 when viewed along the second center line O2. The second diameter D2 is, for example, smaller than the first diameter D1. The outer diameter of the second support hole expanded diameter surface 27 (eighth diameter D8) is the same as the outer diameter of the first support hole expanded diameter surface 17 (seventh diameter D7).

[0071] The third support hole 34 has a third support hole bottom surface 35, a third support hole inner circumferential surface 36, and a third support hole expanded diameter surface 37. The third support hole 34 and the first support hole 14 are substantially the same in other respects, except that the diameter of the third support hole inner circumferential surface 36 (third diameter D3) and the diameter of the first support hole inner circumferential surface 16 (first diameter D1) are different.

[0072] The third support hole inner circumferential surface 36, the third support hole bottom surface 35, and the third support hole expansion surface 37 correspond to the first support hole inner circumferential surface 16, the first support hole bottom surface 15, and the first support hole expansion surface 17, respectively. The third diameter D3 is the diameter of the third support hole inner circumferential surface 36 when viewed along the center line (third center line O3) of the third support hole inner circumferential surface 36. The third diameter D3 is different from both the first diameter D1 and the second diameter D2. For example, the third diameter D3 is smaller than both the first diameter D1 and the second diameter D2. The outer diameter (ninth diameter D9) of the third support hole expansion surface 37 is the same as the outer diameter (seventh diameter D7) of the first support hole expansion surface 17.

[0073] The jig body 4 includes, for example, a first body member 41 and a second body member 42. From another perspective, the jig body 4 is formed, for example, from two separate components. The first body member 41 includes a main surface 43, a back surface 45, a first support hole inner circumferential surface 16, a first support hole expanded diameter surface 17, a second support hole inner circumferential surface 26, a second support hole expanded diameter surface 27, a third support hole inner circumferential surface 36, and a third support hole expanded diameter surface 37. The back surface 45 is flat. The back surface 45 is parallel to both the main surface 43 and the body bottom surface 44. The first support hole inner circumferential surface 16, the second support hole inner circumferential surface 26, and the third support hole inner circumferential surface 36 each open to the back surface 45.

[0074] The second main body member 42 has a support surface 46 and a main body bottom surface 44. The support surface 46 abuts against the back surface 45. A portion of the back surface 45 forms the first support hole bottom surface 15. Specifically, when the back surface 45 and the support surface 46 abut against each other, the portion of the support surface 46 that faces the internal space of the first support hole inner circumferential surface 16 forms the first support hole bottom surface 15. Similarly, portions of the back surface 45 form the second support hole bottom surface 25 and the third support hole bottom surface 35. The main body bottom surface 44 is opposite the support surface 46.

[0075] The second main body member 42 has, for example, a base 48 and a restricting protrusion 49. The base 48 has a support surface 46 and a main body bottom surface 44. The restricting protrusion 49 is provided on the base 48. The restricting protrusion 49 extends in a direction from the main body bottom surface 44 toward the support surface 46. When viewed in a direction perpendicular to the support surface 46, the restricting protrusion 49 has, for example, an annular shape. The restricting protrusion 49 surrounds, for example, the first main body member 41.

[0076] The restricting protrusion 49 restricts the first body member 41 from moving relatively to the second body member 42 in a direction parallel to the back surface 45 when the back surface 45 and the support surface 46 come into contact with each other. Specifically, for example, the restricting protrusion 49 restricts the first body member 41 from moving relatively to the second body member 42 by coming into contact with a side surface of the first body member 41. The first body member 41 is fitted into the restricting protrusion 49, for example.

[0077] The height W1 of the restricting protrusion 49 is smaller than the thickness (second thickness H2) of the first main body member 41. This prevents the restricting protrusion 49 from blocking light and creating a shadow on the hollow fiber membrane 95 to be imaged. The second thickness H2 is thicker than the thickness (first thickness H1, see FIG. 2) of the first support member 10. The length L1 of the first support hole inner circumferential surface 16 in the direction in which the first center line O1 extends is smaller than the first thickness H1.

[0078] The first body member 41 and the second body member 42 are detachable between, for example, a state in which the back surface 45 and the support surface 46 are in contact with each other and a state in which the back surface 45 and the support surface 46 are spaced apart from each other. From another perspective, the first body member 41 and the second body member 42 are not, for example, adhered or joined to each other.

[0079] In an environment in which the hollow fiber membrane observation jig 200 images the first end face 91 while supporting the hollow fiber membrane 95 to be imaged, the brightness of the hollow fiber membrane observation jig 200 is less than 50% of the brightness of the first end face 91. Specifically, for example, the hollow fiber membrane 95 to be imaged is placed inside one of the first support hole 14, the second support hole 24, and the third support hole 34 of the hollow fiber membrane observation jig 200. Below, a case in which the hollow fiber membrane 95 to be imaged is placed inside the first support hole 14 will be described.

[0080] The hollow fiber membrane observation jig 200 is placed on an imaging stage (not shown) of the imaging device 300 (see FIG. 13), which will be described later. The imaging device 300 irradiates the hollow fiber membrane 95 to be imaged and the hollow fiber membrane observation jig 200 with light along the direction in which the first center line O1 extends. With the hollow fiber membrane 95 and the hollow fiber membrane observation jig 200 irradiated with light, the imaging device 300 images the first end face 91 and the first support hole 14 as viewed along the first center line O1. In the captured image, the brightness of the first support hole 14 is less than 50% of the brightness of the first end face 91. The brightness value is expressed as L * a * b * L in color space * In the captured image, the brightness of the hollow fiber membrane observation jig 200 is 50 or less.

[0081] As the imaging device 300, for example, an FH-SM05R manufactured by OMRON Corporation is used. As imaging conditions, the field of view to be imaged includes the entire hollow fiber membrane 95 to be imaged, and is the inside of the area surrounded by the outer edge of the first support hole enlarged diameter surface 17. When the hollow fiber membrane 95 to be imaged is an extruded body described below, conditions of a shutter speed of 30,000 μs and a camera gain (brightness) of 0 are used. When the hollow fiber membrane 95 to be imaged is a dried body described below, conditions of a shutter speed of 8,000 μs and a camera gain of 0 are used. As an example of the intensity of the light source, 193 out of 256 levels is used when imaging either an extruded body or a dried body.

[0082] (Modified example of hollow fiber membrane observation jig) 9 and 10, the shape of the first support hole inner circumferential surface 16 when viewed along the first center line O1 is not limited to a circle. Specifically, when viewed along the first center line O1, the shape of the first support hole inner circumferential surface 16 may be, for example, a regular polygon or a star shape. Note that a star shape is a shape in which multiple ridges protrude toward the inside of the first support hole 14. The ridges support the hollow fiber membrane 95 to be imaged by abutting against the outer circumferential surface 93 of the hollow fiber membrane 95 to be imaged.

[0083] If the shape of first support hole inner surface 16 when viewed along first center line O1 is not circular, first center line O1 is defined as a straight line passing through the center of circle 99 inscribed in first support hole inner surface 16 when viewed perpendicular to first support hole bottom surface 15. First diameter D1 is defined as the diameter of circle 99 inscribed in first support hole inner surface 16 when viewed along first center line O1.

[0084] The intersection line between the cross section passing through the first center line O1 and the first support hole expansion surface 17 is not limited to being linear, for example. Specifically, the intersection line between the cross section passing through the first center line O1 and the first support hole expansion surface 17 may be an upwardly convex curved line or a downwardly convex curved line.

[0085] In the above, the second body member 42 has the restricting protrusion 49, but the first body member 41 may have the restricting protrusion 49. Both the first body member 41 and the second body member 42 may have the restricting protrusion 49.

[0086] The shape of the restricting protrusion 49 is not limited to annular. The restricting protrusion 49 may be formed by a plurality of pin-shaped protrusions. When the second body member 42 has the restricting protrusion 49, the first body member may be disposed between a plurality of pin-shaped protrusions. The restricting protrusion 49 may be formed by a single pin-shaped protrusion. When the second body member 42 has the restricting protrusion 49 which is a single pin-shaped protrusion, a recess may be provided on the back surface 45 of the first body member 41, and the restricting protrusion 49 may be inserted into the recess.

[0087] The first body member 41 and the second body member 42 may be fixed together. Specifically, for example, the back surface 45 of the first body member 41 and the support surface 46 of the second body member 42 may be bonded together with an adhesive. When the first body member 41 and the second body member 42 are fixed together, neither the first body member 41 nor the second body member 42 may have the restricting protrusion 49. The jig body 4 may be formed from a single part.

[0088] The number of support holes that the jig body 4 has is not limited to three. The number of support holes that the jig body 4 has may be one, two, or four or more.

[0089] (Method for measuring the porosity of hollow fiber membranes) Next, a method for measuring the porosity of the hollow fiber membrane 90 will be described. As shown in Fig. 11, the method for measuring the porosity of the hollow fiber membrane 90 includes a step (S10) of preparing a hollow fiber membrane, a step (S20) of cutting the hollow fiber membrane to form an imaged hollow fiber membrane, a step (S30) of imaging the cut surface of the imaged hollow fiber membrane, a step (S40) of measuring the outer diameter and inner diameter of the imaged hollow fiber membrane, and a step (S50) of calculating the porosity of the hollow fiber membrane.

[0090] First, a step (S10) of preparing a hollow fiber membrane is carried out. The hollow fiber membrane 90 is manufactured, for example, by the following steps: A composition containing a powdered resin and a liquid lubricant is extruded into a tubular shape. Hereinafter, the composition formed by extrusion will be referred to as an "extrudate." The powdered resin may be primarily composed of, for example, PTFE. The liquid lubricant may be any of various lubricants conventionally used in paste extrusion methods, such as petroleum-based solvents.

[0091] The extruded body is stretched in the axial direction while being heated. This causes the liquid lubricant to volatilize and the extruded body to become porous. The porous extruded body is then baked at a temperature equal to or higher than the melting point of the resin, thereby fixing the extruded body in its porous state. Hereinafter, the extruded body after the liquid lubricant has been volatilized by heating will be referred to as a "dried body." In the step (S10) of preparing a hollow fiber membrane, either the extruded body or the dried body described above is prepared as the hollow fiber membrane 90.

[0092] Next, a step (S20) of forming an imaged hollow fiber membrane by cutting the hollow fiber membrane is carried out. As shown in Figure 11, the step (S20) of forming an imaged hollow fiber membrane by cutting the hollow fiber membrane includes a step (S21) of placing the hollow fiber membrane in the through-hole and a step (S22) of cutting the hollow fiber membrane.

[0093] In the step (S21) of placing the hollow fiber membrane in the through hole, first, the cutting unit 2 is placed in the preparation position. The hollow fiber membrane 90 is inserted into the through hole 7 along a direction parallel to the first direction 101. Specifically, the hollow fiber membrane 90 is inserted into one of the first hole 71, the second hole 72, and the third hole 73. In this way, the hollow fiber membrane 90 is placed in the through hole 7. Below, the case where the hollow fiber membrane 90 is inserted into the first hole 71 will be described, but similar steps are also performed when the hollow fiber membrane 90 is inserted into the second hole 72 or the third hole 73.

[0094] Next, the step (S22) of cutting the hollow fiber membrane is performed. As shown in FIG. 12, the cutting unit 2 is moved integrally from the preparation position toward the cutting position along arrow A. This causes the cutting edges of the first plate blade unit 5 and the second plate blade unit 6 to simultaneously contact the hollow fiber membrane 90. The cutting unit 2 applies shear stress to the hollow fiber membrane 90. Specifically, the first cutting edge 56 of the first plate blade unit 5 applies shear stress to the portion of the hollow fiber membrane 90 located in the first gap 18. The third cutting edge 58 of the second plate blade unit 6 applies shear stress to the portion of the hollow fiber membrane 90 located in the second gap 19. The direction of arrow A is the third direction 103.

[0095] While the cutting section 2 applies shear stress to the hollow fiber membrane 90, the first inner wall surface 61, the second inner wall surface 62, and the third inner wall surface 63 each support the hollow fiber membrane 90. The portion of the hollow fiber membrane 90 in contact with the first plate blade section 5 receives a reaction force from each of the first support member 10 and the second support member 20. Similarly, the portion of the hollow fiber membrane 90 in contact with the second plate blade section 6 receives a reaction force from each of the first support member 10 and the third support member 30.

[0096] As the cutting unit 2 continues to move toward the cutting position, the hollow fiber membrane 90 is cut. As a result, the portion of the hollow fiber membrane 90 that was supported by the first support member 10 is cut out as the hollow fiber membrane 95 to be imaged. In this way, the hollow fiber membrane 95 to be imaged is formed. The hollow fiber membrane 95 to be imaged has the outer peripheral surface 93, inner peripheral surface 94, first end face 91, and second end face 92 described above. Each of the first end face 91 and the second end face 92 is a cut surface. The length of the hollow fiber membrane 95 to be imaged is approximately the same as the thickness (first thickness H1) of the first support member 10.

[0097] Next, a step (S30) of imaging the cut surface of the hollow fiber membrane to be imaged is performed. As shown in Fig. 13, the hollow fiber membrane 95 to be imaged is placed inside the support hole of the hollow fiber membrane observation jig 200. Specifically, the hollow fiber membrane 95 to be imaged is placed inside one of the first support hole 14, the second support hole 24, and the third support hole 34. Below, we will explain the case where the hollow fiber membrane 95 to be imaged is placed inside the first support hole 14, but similar steps are also performed when the hollow fiber membrane 90 is inserted into the second support hole 24 or the third support hole 34.

[0098] As shown in FIG. 13 , the second end surface 92 abuts against the first support hole bottom surface 15. The outer peripheral surface 93 faces the first support hole inner peripheral surface 16. The outer peripheral surface 93 may abut against the first support hole inner peripheral surface 16, or may be spaced apart from the first support hole inner peripheral surface 16. In the fourth direction 104, the first end surface 91 is located between the main surface 43 and the first support hole inner peripheral surface 16. When viewed along the first central axis, a portion of the first support hole bottom surface 15 is exposed from the hollow fiber membrane 90.

[0099] With the hollow fiber membrane 95 to be imaged disposed inside the first support hole 14, the first end face 91 is imaged using the imaging device 300. The imaging device 300 irradiates the hollow fiber membrane 95 to be imaged and the hollow fiber membrane observation jig 200 with light in the direction of arrow B. The direction of arrow B is along the first center line O1 and opposite to the fourth direction 104. With the hollow fiber membrane 90 and the hollow fiber membrane observation jig 200 irradiated with light, the imaging device 300 images the first end face 91 and the first support hole 14.

[0100] Next, a step (S40) of measuring the outer diameter and inner diameter of the hollow fiber membrane to be imaged is performed. The outer diameter and inner diameter of the hollow fiber membrane 90 are measured using the image of the imaged first end face 91. Specifically, the following image processing and calculations are performed on the imaged image.

[0101] The brightness of the brightest part in the captured image is set to 100%. The boundary between the part with a brightness of 50% or more and the part with a brightness of less than 50% is detected as the outer edge of the hollow fiber membrane 90. The outer edge of the hollow fiber membrane 90 includes the ridge line (outer diameter edge) between the outer peripheral surface 93 and the first end face 91 and the ridge line (inner diameter edge) between the inner peripheral surface 94 and the first end face 91. The outer diameter of the hollow fiber membrane 95 to be imaged is measured by approximating the outer edge to a circle and measuring the diameter of the circle. Similarly, the inner diameter of the hollow fiber membrane 95 to be imaged is measured by approximating the inner diameter edge to a circle and measuring the diameter of the circle. The outer diameter of the hollow fiber membrane 95 to be imaged is considered to be the outer diameter of the hollow fiber membrane 90. Similarly, the inner diameter of the hollow fiber membrane 95 to be imaged is considered to be the inner diameter of the hollow fiber membrane 90.

[0102] Next, a step (S50) of calculating the porosity of the hollow fiber membrane is performed. The cross-sectional area of ​​the hollow fiber membrane 90 is calculated using the outer diameter of the hollow fiber membrane 90 and the inner diameter of the hollow fiber membrane 90. Specifically, the cross-sectional area of ​​the hollow fiber membrane 90 is calculated using the following formula 1.

[0103] Cross-sectional area = π×{(outer diameter / 2) 2 -(inner diameter / 2) 2} ···(Formula 1) The hollow fiber membrane 90 is cut into lengths of, for example, 100 mm. The weight of the cut hollow fiber membrane 90 is measured. The density of the hollow fiber membrane 90 is calculated using the weight and length of the measured hollow fiber membrane 90 and the above-mentioned cross-sectional area. Specifically, the density of the hollow fiber membrane 90 is calculated using the following equation 2.

[0104] Density = weight / (cross-sectional area × length) (Equation 2) The porosity of the hollow fiber membrane 90 is calculated using the calculated density of the hollow fiber membrane 90 and the density (true density) of the material forming the hollow fiber membrane 90. Specifically, the porosity is calculated using the following equation 3. In this way, the porosity of the hollow fiber membrane 90 is measured.

[0105] Porosity = (1 - density of hollow fiber membrane / true density) × 100 (Equation 3) Next, the effects of the hollow fiber membrane observation jig 200 according to this embodiment will be described.

[0106] The hollow fiber membrane observation jig 200 according to this embodiment has a jig body 4. The jig body 4 has a main surface 43 and a first support hole 14 that opens to the main surface 43 and is capable of accommodating a hollow fiber membrane 90. When viewed from a direction perpendicular to the cross section passing through the first center line O1, the intersection line between the first support hole 14's center line (first center line O1) and the first support hole expanded diameter surface 17 has a shape that moves away from the first support hole inner circumferential surface 16 toward the main surface 43. The Ra of the first support hole bottom surface 15 is 1.1 μm or more.

[0107] When observing the first end face 91 of the hollow fiber membrane 90, if the periphery of the first end face 91 is excessively bright, it becomes difficult to accurately detect the outer edge of the first end face 91. In this case, the measurement accuracy of the outer diameter and inner diameter of the hollow fiber membrane 90 decreases. According to the hollow fiber membrane observation jig 200 of this embodiment, when observing the first end face 91 of the hollow fiber membrane 90 along the first center line O1, the first support hole expanded diameter surface 17 reflects light irradiated onto the first support hole expanded diameter surface 17 in a direction inclined with respect to the first center line O1. This prevents the first support hole expanded diameter surface 17 from becoming excessively bright when observing the first end face 91. Therefore, the outer diameter of the hollow fiber membrane 90 can be accurately measured. Furthermore, since the Ra of the first support hole bottom surface 15 is 1.1 μm or greater, light irradiated onto the first support hole bottom surface 15 is diffusely reflected. This prevents the first support hole bottom surface 15 from becoming excessively bright when observing the first end surface 91. Therefore, the inner diameter of the hollow fiber membrane 90 can be measured with high accuracy. As a result, the measurement accuracy of the outer diameter and inner diameter of the hollow fiber membrane 90 can be improved.

[0108] According to the hollow fiber membrane observation jig 200 of this embodiment, the jig body 4 has a first body member 41 and a second body member 42. The first body member 41 has a main surface 43, a back surface 45, and a first support hole inner circumferential surface 16. The second body member 42 has a support surface 46 that abuts against the back surface 45. When the back surface 45 and the support surface 46 abut, the portion of the support surface 46 that faces the internal space of the first support hole inner circumferential surface 16 forms the first support hole bottom surface 15. Therefore, in manufacturing the hollow fiber membrane observation jig 200, the support surface 46 can be processed to a predetermined surface roughness and then the first body member 41 and the second body member 42 can be combined to manufacture the hollow fiber membrane observation jig 200. This facilitates manufacturing of the hollow fiber membrane observation jig 200.

[0109] According to the hollow fiber membrane observation jig 200 of this embodiment, the first body member 41 and the second body member 42 are detachable between a state in which the back surface 45 and the support surface 46 are in contact with each other and a state in which they are spaced apart. Therefore, by removing the first body member 41 from the second body member 42, the hollow fiber membrane 90 housed in the support hole can be easily removed.

[0110] According to the hollow fiber membrane observation jig 200 of this embodiment, either or both of the first body member 41 and the second body member 42 have a restricting protrusion 49. The restricting protrusion 49 restricts the first body member 41 from moving relative to the second body member 42 in a direction parallel to the back surface 45 when the back surface 45 and the support surface 46 abut against each other. Therefore, when observing the first end surface 91 of the hollow fiber membrane 90, the hollow fiber membrane 90 can be prevented from moving relative to the second body member 42.

[0111] If the portion of the hollow fiber membrane observation jig 200 located around the first end face 91 is excessively bright, the difference in brightness between the first end face 91 and the hollow fiber membrane observation jig 200 becomes excessively small. In this case, the accuracy of detecting the shape of the first end face 91 decreases. According to the hollow fiber membrane observation jig 200 of this embodiment, the Ra of the main surface 43 is 1.1 μm or more. This makes it possible to reduce the intensity of light reflected by the main surface 43. This reduces the brightness of the portion of the hollow fiber membrane observation jig 200 located around the first end face 91. Therefore, the accuracy of detecting the shape of the first end face 91 can be improved.

[0112] According to the hollow fiber membrane observation tool 200 of this embodiment, in an environment in which the hollow fiber membrane 90 is supported by the hollow fiber membrane observation tool 200 and an image of the first end face 91 is captured, the brightness of the hollow fiber membrane observation tool 200 is less than 50% of the brightness of the first end face 91. Therefore, the difference in brightness between the first end face 91 and the hollow fiber membrane observation tool 200 is sufficiently large. This improves the accuracy of detecting the shape of the first end face 91.

[0113] According to the hollow fiber membrane observation jig 200 of this embodiment, the jig body 4 has a second support hole 24 capable of accommodating a hollow fiber membrane 90. The diameter (first diameter D1) of the inner circumferential surface 16 of the first support hole 14 as viewed along the center line of the first support hole 14 is different from the diameter (second diameter D2) of the inner circumferential surface 26 of the second support hole 24 as viewed along the center line of the second support hole 24. Therefore, the hollow fiber membrane 90 can be accommodated in a support hole that corresponds to the outer diameter of the hollow fiber membrane 90. This makes it possible to observe multiple types of hollow fiber membranes 90 with different outer diameters.

[0114] If light is diffusely reflected at the first support hole expanded diameter surface 17, the diffusely reflected light may cause the first support hole expanded diameter surface 17 to appear excessively bright when observing the first end face 91 along the first center line O1. According to the hollow fiber membrane observation jig 200 of this embodiment, the Ra of the first support hole expanded diameter surface 17 is smaller than the Ra of the first support hole bottom surface 15. This prevents light from being diffusely reflected at the first support hole expanded diameter surface 17. This prevents the first support hole expanded diameter surface 17 from appearing excessively bright when viewed along the first center line O1. [Example]

[0115] (Sample preparation) The effect of using the hollow fiber membrane cutting jig 100 according to this embodiment on the shape of the cut surface of the hollow fiber membrane 90 was investigated. Specifically, hollow fiber membranes 95 to be imaged according to Samples 1 and 2 were prepared. Sample 1 is a comparative example. Sample 2 is an example. In Sample 1, the hollow fiber membrane 95 to be imaged was prepared by cutting the hollow fiber membrane 90 with scissors. In Sample 2, the hollow fiber membrane 95 to be imaged was prepared by cutting the hollow fiber membrane 90 using the hollow fiber membrane cutting jig 100 according to this embodiment.

[0116] (Evaluation method) The shapes of the cut surfaces of the hollow fiber membranes 95 to be imaged for Samples 1 and 2 were observed. Specifically, the first end faces 91 were imaged while the hollow fiber membranes 95 to be imaged for Samples 1 and 2 were housed in the support holes of the hollow fiber membrane observation jig 200. The outer diameter and inner diameter of the hollow fiber membrane 90 were measured using the captured images.

[0117] (Evaluation results) 14, the cut surface of the photographed hollow fiber membrane 95 of Sample 1 was crushed in the vertical direction of the image. In Sample 1, the outer diameter of the hollow fiber membrane 90 was 2.23 mm. The inner diameter of the hollow fiber membrane 90 was 1.11 mm.

[0118] 15, the cross section of the hollow fiber membrane 95 to be imaged in Sample 2 was nearly circular. In Sample 2, the outer diameter of the hollow fiber membrane 90 was 2.41 mm. The inner diameter of the hollow fiber membrane 90 was 1.14 mm.

[0119] From the above, it was confirmed that when cutting the hollow fiber membrane 90 using the hollow fiber membrane cutting tool 100 of this embodiment, it is possible to prevent the cut surface from being crushed, compared to when cutting the hollow fiber membrane 90 using scissors. [Example]

[0120] (Sample preparation) The influence of the expanded diameter surface of the support hole of the hollow fiber membrane observation jig 200 on the shape detection of the cut surface of the hollow fiber membrane 90 was investigated. Specifically, hollow fiber membrane observation jig 200 according to Samples 2 and 3 were prepared. The hollow fiber membrane observation jig 200 according to Sample 2 is an example. The hollow fiber membrane observation jig 200 according to Sample 3 is a comparative example.

[0121] The hollow fiber membrane observation jig 200 of Sample 2 had a first support hole expanded diameter surface 17. In other words, the hollow fiber membrane observation jig 200 of Sample 2 was the hollow fiber membrane observation jig 200 according to the present embodiment described above. The hollow fiber membrane observation jig 200 of Sample 3 did not have a first support hole expanded diameter surface 17. From another perspective, the first support hole inner circumferential surface 16 was continuous with the main surface 43.

[0122] (Evaluation method) The first end face 91 of the hollow fiber membrane 90 was observed using the hollow fiber membrane observation jig 200 for samples 2 and 3. Specifically, an image of the first end face 91 was subjected to image processing, and the outer diameter edge and inner diameter edge of the first end face 91 were detected. The detection results from the image processing were compared with the positions of the outer diameter edge and inner diameter edge confirmed visually.

[0123] (Evaluation results) 15 and 16, the main surface 43 of Sample 3 was imaged brighter than the first support hole expansion surface 17 of Sample 2. In Sample 3, a discrepancy was confirmed between the position of the outer diameter edge detected by image processing and the position of the outer diameter edge confirmed by visual inspection. In Sample 2, the position of the outer diameter edge detected by image processing and the position of the outer diameter edge confirmed by visual inspection were almost the same.

[0124] From the above, it was confirmed that the outer diameter edge of the hollow fiber membrane 90 can be detected more accurately when using the hollow fiber membrane observation jig 200 of the example, compared to when using the hollow fiber membrane observation jig 200 of the comparative example. [Example]

[0125] The influence of the bottom surface of the support hole of the hollow fiber membrane observation jig 200 on shape detection of the cut surface of the hollow fiber membrane 90 was investigated. Specifically, hollow fiber membrane observation jigs 200 according to Samples 4 to 6 were prepared. Sample 4 is a comparative example. Samples 5 and 6 are examples.

[0126] In sample 4, the Ra of first support hole bottom surface 15 was 0.592 μm. In sample 5, the Ra of first support hole bottom surface 15 was 1.109 μm. In sample 6, the Ra of first support hole bottom surface 15 was 2.488 μm.

[0127] (Evaluation method) The first end face 91 of the hollow fiber membrane 90 was observed using the hollow fiber membrane observation jig 200 for samples 4 to 6. Specifically, an image of the first end face 91 was subjected to image processing, and the outer diameter edge and inner diameter edge of the first end face 91 were detected. The detection results from the image processing were compared with the positions of the outer diameter edge and inner diameter edge confirmed visually.

[0128] (Evaluation results) In sample 4, the first support hole bottom surface 15 was imaged relatively brightly, and part of the inner diameter edge could not be detected by image processing. Specifically, the inner diameter edge detected by image processing was interrupted. In samples 5 and 6, the first support hole bottom surface 15 was imaged relatively dark, and the position of the outer diameter edge detected by image processing and the position of the outer diameter edge confirmed visually were almost the same.

[0129] From the above, it was confirmed that the inner diameter edge of the hollow fiber membrane can be detected more accurately when using the hollow fiber membrane observation jig 200 of the example, compared to when using the hollow fiber membrane observation jig 200 of the comparative example.

[0130] The embodiments and examples disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims rather than the above-described embodiments, and it is intended to include any modifications within the scope of the claims that are equivalent in meaning to the claims. [Explanation of symbols]

[0131] 1 Support part 2 Cut section 3 Fixing member 4 Jig body 5 1st plate blade part 6 2nd plate blade part 7 Through holes 8 Guide hole 9 Connecting part 10 First support member 11 First support surface 12 Second support surface 13 First outer surface 14 1st support hole 15 Bottom of 1st support hole 16 Inner circumferential surface of first support hole 17 First support hole enlarged diameter surface 18 First Gap 19 Second Gap 20 Second support member 21 Third support surface 22 5th support surface 23 Second outer surface 24 2nd support hole 25 Bottom of second support hole 26 Inner circumferential surface of second support hole 27 2nd support hole enlarged diameter surface 30 third support member 31 4th support surface 32 6th support surface 33 Third outer surface 34 3rd support hole 35 Bottom of 3rd support hole 36 Inner circumferential surface of third support hole 37 3rd support hole enlarged diameter surface 41 first body member 42 second body member 43 Main Surface 44 Bottom of the main unit 45 Back side 46 Support surface 48 Base 49 Regulating protrusion 51 1st plate blade surface 52 2nd plate blade surface 53 3rd plate blade surface 54 4th plate blade surface 56 First cutting edge 57 Second cutting edge 58 Third cutting edge 59 4th cutting edge 61 First inner wall 62 Second inner wall 63 Third Inner Wall 64 4th inner wall 65 5th inner wall 66 6th inner wall 67 No. 7 Inner Wall 68 No. 8 Inner Wall 69 No. 9 Inner Wall 71 Hole 1 72 2nd hole 73 Hole 3 90 Hollow fiber membrane 91 1st end face 92 Second end face 93 Outer surface 94 Inner peripheral surface 95 Imaged hollow fiber membrane 99 yen 100 Hollow fiber membrane cutting jig 101 1st direction 102 Second direction 103 Third direction 104 4th direction 200 Hollow fiber membrane observation jig 300 Imaging device A,B arrows D1 1st diameter D2 2nd diameter D3 Third diameter D4 Fourth diameter D5 5th diameter D6 6th diameter D7 7th diameter D8 8th diameter D9 9th diameter H1 First thickness H2 Second thickness L1 length O1 1st center line O2 2nd center line O3 3rd center line W1 height

Claims

1. A hollow fiber membrane observation jig that supports a cylindrical hollow fiber membrane having an outer peripheral surface, an inner peripheral surface, a first end surface, and a second end surface, in order to observe the first end surface of the hollow fiber membrane, The hollow fiber membrane observation jig includes a jig body, the jig body has a main surface and a first support hole that opens to the main surface and can accommodate the hollow fiber membrane, the first support hole has a first support hole inner circumferential surface that faces the outer circumferential surface when the hollow fiber membrane is accommodated therein, a first support hole bottom surface that abuts against the second end surface when the hollow fiber membrane is accommodated therein, and a first support hole expanded diameter surface that is continuous with the main surface and an end of the first support hole inner circumferential surface opposite to the end that is continuous with the first support hole bottom surface, an intersection line between a cross section passing through a center line of the first support hole and the first support hole expansion surface has a shape that, when viewed in a direction perpendicular to the cross section passing through the center line of the first support hole, becomes more distant from the center line of the first support hole from the inner circumferential surface of the first support hole toward the main surface, The hollow fiber membrane observation jig, wherein the arithmetic mean roughness of the bottom surface of the first support hole is 1.1 μm or more.

2. The jig body includes a first body member and a second body member, the first body member has the main surface, a back surface parallel to the main surface, the first support hole inner circumferential surface, and the first support hole expanded diameter surface, an inner peripheral surface of the first support hole opens to the back surface, the second body member has a support surface that abuts against the back surface, 2. The hollow fiber membrane observation jig according to claim 1, wherein when the back surface and the support surface abut, the portion of the support surface that faces the internal space of the inner surface of the first support hole forms the bottom surface of the first support hole.

3. The hollow fiber membrane observation tool according to claim 2, wherein the first body member and the second body member are detachable between a state in which the back surface and the support surface are in contact with each other and a state in which the back surface and the support surface are spaced apart from each other.

4. A hollow fiber membrane observation jig as described in claim 2 or claim 3, wherein either or both of the first main body member and the second main body member have a regulating protrusion that regulates relative movement of the first main body member with respect to the second main body member in a direction parallel to the back surface when the back surface and the support surface abut.

5. The hollow fiber membrane observation jig according to claim 1 , wherein the arithmetic mean roughness of the main surface is 1.1 μm or more.

6. A hollow fiber membrane observation tool as described in any one of claims 1 to 3, wherein in an environment in which the hollow fiber membrane observation tool supports the hollow fiber membrane and images the first end face, the brightness of the hollow fiber membrane observation tool is less than 50% of the brightness of the first end face.

7. the jig body has a second support hole that opens to the main surface and is capable of accommodating the hollow fiber membrane; the second support hole has a second support hole inner circumferential surface that faces the outer circumferential surface when the hollow fiber membrane is accommodated therein, a second support hole bottom surface that abuts against the second end surface when the hollow fiber membrane is accommodated therein, and a second support hole enlarged diameter surface that is continuous with the main surface and an end of the second support hole inner circumferential surface opposite to the end that is continuous with the second support hole bottom surface, an intersection line between a cross section passing through a center line of the second support hole and the second support hole expansion surface has a shape that, when viewed in a direction perpendicular to the cross section passing through the center line of the second support hole, becomes more distant from the center line of the second support hole from the inner circumferential surface of the second support hole toward the main surface, the arithmetic mean roughness of the bottom surface of the second support hole is 1.1 μm or more; 4. A hollow fiber membrane observation jig according to claim 1, wherein the diameter of a circle inscribed in the inner surface of the first support hole when viewed along the center line of the first support hole is defined as a first diameter, and the diameter of a circle inscribed in the inner surface of the second support hole when viewed along the center line of the second support hole is defined as a second diameter, and the first diameter and the second diameter are different.

8. The hollow fiber membrane observation jig according to claim 1 , wherein the arithmetic mean roughness of the first support hole enlarged diameter surface is smaller than the arithmetic mean roughness of the first support hole bottom surface.

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