HOLLOW FIBER DEGATING MODULE AND INKJET PRINTER

Abstract

Hollow fiber degassing module (1) comprising a hollow fiber membrane bundle (3) obtained by bundling a plurality of hollow fiber membranes (2) in a cylindrical shape, and a cylindrical body (5) which accommodates the hollow fiber membrane bundle (3) and extends in an axial direction and degasses a liquid by supplying the liquid to the outside of the hollow fiber membranes (2) and depressurizing the inside of the hollow fiber membranes (2), wherein a side wall of the cylindrical body (5) is provided with an outlet opening (5d) which releases the degassed liquid, characterized in that the hollow fiber membrane bundle (3) in a reference cross-section (A) that is perpendicular to the axial direction (L) of the cylindrical body (5) and runs through the outlet opening (5d), is eccentric to the opposite side of the outlet opening (5d).

Description

Technical field

[0001] The present invention relates to a hollow fiber degassing module that degasses a liquid and to an inkjet printer that contains the hollow fiber degassing module.

[0002] An inkjet printer is a printing machine that uses a system in which ink droplets are sprayed directly onto a printing medium. In such an inkjet printer, there is a possibility that gas dissolved in the ink may escape due to pressure changes within an ink reservoir during printing, potentially blocking a nozzle. This can result in a noticeable deterioration in print quality. This risk becomes particularly pronounced with prolonged use and high-speed operation. To address this issue, degassing is effective in removing dissolved gas and bubbles from the ink.As a method for effectively degassing the ink, WO 2007 / 063720A1 proposes a method of continuous degassing of the ink by fitting a hollow fiber degassing module which uses a hollow fiber membrane at an ink passage extending from an ink storage section to an inkjet head.

[0003] The hollow fiber degassing module shown in WO 2007 / 063 720 A1 is an external flow-through type hollow fiber degassing module. A hollow fiber membrane bundle, obtained by bundling multiple hollow fiber membranes, is housed within a cylindrical body. Ink is then supplied to the outside of the hollow fiber membrane, and the inside of the membrane is depressurized to allow the ink to degas. The degassed ink is discharged through a discharge port formed in a side wall of the cylindrical body.

[0004] A degassing device with the features of the preamble of claim 1 is known from US patent 2011 / 0146891A1.

[0005] Furthermore, a hollow fiber membrane module for filtering raw water is known from JP 2004 - 50 023 A. Summary of the invention: Technical problem

[0006] To integrate such a hollow fiber degassing module into an inkjet printer, low pressure drop and a long service life are required. Therefore, if the hollow fiber degassing module is designed as an external flow-through type, it is possible to suppress the pressure drop, thus keeping it low. However, the inventors have found that when degassing ink using the known hollow fiber degassing module, liquid can leak from the module before the end of the hollow fiber membrane's service life is reached.

[0007] In this process, the inventors, as a result of careful investigation of the known hollow fiber degassing module, found that part of the hollow fiber membranes forming the hollow fiber membrane bundle can be drawn into the outlet opening and easily cut by the ink flow if the ink flow rate is increased or the ink viscosity is increased.

[0008] One aspect of the invention is to propose a hollow fiber degassing module and an inkjet printer, both of which operate at low pressure and can extend service life. Solution to the problem

[0009] A hollow fiber degassing module according to the invention has the features of claim 1 and comprises a hollow fiber membrane bundle obtained by bundling a plurality of hollow fiber membranes in a cylindrical shape and a cylindrical body that accommodates the hollow fiber membrane bundle and extends in an axial direction and degasses a liquid by supplying the liquid to the outside of the hollow fiber membrane and depressurizing the inside of the hollow fiber membrane, wherein a side wall of the cylindrical body is provided with an outlet opening that releases the degassed liquid, and the hollow fiber membrane bundle is eccentric in a reference cross-section that is perpendicular to the axial direction of the cylindrical body and passes through the outlet opening.

[0010] The hollow fiber degassing module according to one aspect of the invention is of the external flow type, in which a liquid is supplied to the outside of the hollow fiber membrane, and the inside of the hollow fiber membrane is depressurized to degas the liquid. This allows for the damping of the liquid's pressure drop, thus minimizing it. Furthermore, the hollow fiber membrane bundle is eccentric in the reference cross-section, which is perpendicular to the axial direction of the cylinder body and passes through the outlet opening. This prevents the hollow fiber membrane, which forms the hollow fiber membrane bundle, from being drawn towards the outlet opening by the liquid flow. Consequently, it is possible to prevent liquid leakage resulting from the hollow fiber membrane being ruptured, thus extending the service life of the hollow fiber degassing module.

[0011] Furthermore, if a gap between the cylindrical body and the hollow fiber membrane bundle near the outlet opening in the reference cross-section is designated by G and an inner diameter of the cylindrical body is designated by D, a relationship of G ≥ 0.08D can be satisfied.

[0012] Furthermore, a gap between the cylindrical body and the hollow fiber membrane bundle near the outlet opening in the reference cross-section can be 2.5 mm or more.

[0013] According to the invention, the hollow fiber membrane bundle is eccentric to the opposite side of the outlet opening in the reference cross-section, which is perpendicular to the axial direction of the cylindrical body and passes through the outlet opening.

[0014] An inkjet printer according to one aspect of the invention is an inkjet printer in which ink stored in an ink storage section is supplied to an inkjet head through an ink passage and the aforementioned hollow fiber degassing module is attached to the ink passage.

[0015] In the inkjet printer according to one aspect of the invention, it is possible, because the hollow fiber degassing module is attached to the ink passage, to suppress the pressure loss of the ink in the ink passage in order to be low and to degas the ink for a long period of time. Advantageous effects of the invention

[0016] According to one aspect of the invention, the pressure loss is low and the service life can be extended. Brief description of the drawings Fig. Figure 1 is a schematic configuration diagram of an inkjet printer according to an exemplary embodiment. Fig. Figure 2 is a schematic sectional view of a hollow fiber degassing module according to an exemplary embodiment. Fig. Figure 3 is a partially enlarged view of a hollow fiber membrane bundle located in Fig. 2 is shown, where Fig. 3(a) shows a membrane bundle end section of the hollow fiber membrane bundle and Fig. 3(b) shows the other membrane bundle end section of the hollow fiber membrane bundle. Fig. 4 is a sectional view along a line IV-IV, which is in Fig. 2 is shown. Fig. 5 is a diagram showing a reference cross-section A, which is in Fig. 2 is shown. Description of the exemplary implementations

[0017] A hollow fiber degassing module and an inkjet printer of an exemplary embodiment are described in detail below with reference to the drawings. The hollow fiber degassing module of the exemplary embodiment is obtained by applying a hollow fiber degassing module according to the invention to a hollow fiber degassing module for degassing ink. Furthermore, the same or corresponding parts are designated by the same reference numerals in all drawings, and redundant descriptions are avoided.

[0018] Fig. Figure 1 is a schematic configuration diagram of an inkjet printer according to an exemplary embodiment. As shown in Fig. As shown in Figure 1, an inkjet printer 11 according to an embodiment mainly comprises an ink storage section 12, which is an ink tank for storing ink, an inkjet head 13, which directly sprays droplet-shaped ink onto a printing medium, a first ink supply line 14, to which ink is supplied from the ink storage section 12, a second ink supply line 15, which supplies ink to the inkjet head 13, a hollow fiber degassing module 1 according to the embodiment, which is attached to the first ink supply line 14 and the second ink supply line 15 and degasses ink, a suction pump 16, which is used for vacuum suction operation, and an inlet line 17, which connects the suction pump 16 and the hollow fiber degassing module 1.Furthermore, the first ink supply line 14 and the second ink supply line 15 are ink passages that extend from the ink storage section 12 to the inkjet head 13.

[0019] Fig. Figure 2 is a schematic sectional view of the hollow fiber degassing module according to the exemplary embodiment. Fig. 3 is a partially enlarged view of the in Fig. 2 hollow fiber membrane bundles shown. Fig. 4 is a sectional view along a line IV-IV, which is in Fig. 2 is shown. Fig. 5 is a diagram showing a reference cross-section A, which is in Fig. 2 is shown. As in Fig. As shown in Figures 1 to 5, the hollow fiber degassing module 1 has a hollow fiber membrane bundle 3 in which a plurality of hollow fiber membranes 2 are bundled in a cylindrical shape, and a housing 4 which accommodates the hollow fiber membrane bundle 3. The hollow fiber degassing module 1 degasses ink by supplying the ink to the outside of the hollow fiber membrane 2 and reducing the pressure on the inside of the hollow fiber membrane 2.

[0020] The hollow fiber membrane 2 is a hollow, fibrous membrane that allows the passage of gas but not the passage of liquid. The material, membrane shape, and membrane type of the hollow fiber membrane 2 are not particularly restricted. Examples of materials for the hollow fiber membrane 2 include polyolefin-based resins such as polypropylene and poly(4-methylpentene-1), silicon-based resins such as polydimethylsiloxane and a copolymer thereof, and fluorine-based resins such as PTFE and vinylidene fluoride. Examples of membrane shapes (sidewall shapes) for the hollow fiber membrane 2 include a porous membrane, a microporous membrane, and a homogeneous membrane that has no porosity (nonporous membrane).The membrane type of hollow fiber membrane 2, for example, is a symmetrical membrane (homogeneous membrane) with a homogeneous chemical or physical structure across the entire membrane, or an asymmetrical membrane (heterogeneous membrane) in which the chemical or physical structures of the membrane vary depending on the membrane segment. The asymmetrical membrane (heterogeneous membrane) is a membrane that has a non-porous dense layer and porosity. In this case, the dense layer can be located anywhere within the membrane, such as on a surface layer or on the inner surface of the porous membrane. The heterogeneous membrane includes composite membranes with varying chemical structures and multilayer membranes, such as three-layer structures.Because a heterogeneous membrane, especially one using poly(4-methylpentene-1) resin, has a dense layer for blocking a liquid, it is particularly desirable for degassing liquids other than water, such as ink. In the case of a hollow fiber used for external flow, it is desirable for the dense layer to be formed on the outer surface of the hollow fiber.

[0021] The hollow fiber membrane bundle 3 can, for example, be formed from a hollow fiber membrane sheet (not shown) in which a plurality of hollow fiber membranes 2 are woven in the form of a woven reed. In this case, for example, the hollow fiber membrane sheet is wound around a cylindrical temporary core to be bundled into a cylindrical shape, with both end sections of the bundled hollow fiber membrane sheet being fixed, and the temporary core being removed from the hollow fiber membrane sheet, whose two end sections are fixed. Consequently, the hollow fiber degassing module 1 without a central tube can be manufactured as a membrane bundle hollow section 3c arranged radially in the center of the hollow fiber membrane bundle 3. In this case, the hollow fiber membrane bundle 3 is formed, for example, by the hollow fiber membrane sheet, which has thirty to ninety hollow fiber membranes 2 per inch.Consequently, even if the central tube is not arranged in the center of the hollow fiber membrane bundle 3c in the radial direction, the ink can flow without any diversion.

[0022] The housing 4 comprises a cylindrical body 5, a first cover section 6 and a second cover section 7.

[0023] The cylindrical body 5 is a component that houses the hollow fiber membrane bundle 3. The cylindrical body 5 is shaped cylindrically and extends in the axial direction L, with both end sections of the cylindrical body 5 being open. The first cover section 6 is attached to one opening end section 5a, which is an opening end section of the cylindrical body 5. Furthermore, the second cover section 7 is attached to the other opening end section 5b, which is the other opening end section of the cylindrical body 5. The first cover section 6 and the second cover section 7 can be attached to the cylindrical body 5 by, for example, screws, fitting, gluing, or the like.

[0024] The first cover section 6 is conical in shape, decreasing in diameter as it extends away from the cylindrical body 5. A front end section of the first cover section 6 is provided with a supply opening 6a, which feeds ink into the first cover section 6. The supply opening 6a is cylindrical and is located on a central axis of the cylindrical body 5. A connecting section 6b, separately connected to the first ink supply line 14, extends from the supply opening 6a along the axial direction L. The connecting section 6b is cylindrical. Furthermore, the inner circumferential surface of the connecting section 6b is provided with an internal thread 6c into which the first ink supply line 14 is screwed.Furthermore, the connection between the connecting section 6b and the first ink supply line 14 is not limited to screws, but can, for example, be fitted.

[0025] The second cover section 7 is conically shaped to decrease in diameter as it extends away from the cylindrical body 5. A front end section of the second cover section 7 is provided with an inlet opening 7a, which draws gas from the inside of the housing 4. The inlet opening 7a is cylindrical and is located on the central axis of the cylindrical body 5. A connecting section 7b, which is detachably connected to the inlet line 17, extends from the inlet opening 7a along the axial direction L. The connecting section 7b is cylindrical. Furthermore, the inner circumferential surface of the connecting section 7b is provided with an internal thread 7c into which the inlet line 17 is screwed. The connection between the connecting section 7b and the inlet line 17 is not limited to screws and can, for example, be a fitted connection.

[0026] A side wall 5c of the cylindrical body 5 is provided with an outlet opening 5d, which discharges the ink from the inside of the housing 4. The outlet opening 5d is cylindrical. The outlet opening 5d is located near the other opening end section 5b in relation to the center in the axial direction L of the cylindrical body 5. A connecting section 5e, which is detachably connected to the second ink supply line 15, extends from the outlet opening 5d in a direction perpendicular to the axial direction L. The connecting section 5e is cylindrical in shape. Furthermore, the inner circumferential surface of the connecting section 5e is provided with an internal thread 5f into which the second ink supply line 15 is screwed. The connection between the outlet opening 5d and the second ink supply line 15 is not limited to screws and can, for example, be a fitting.

[0027] The cylindrical body 5, the first lid section 6, and the second lid section 7 are, as desired, made of resin for ease of manufacturing. In this case, the cylindrical body 5, the first lid section 6, and the second lid section 7 can be formed by injection molding. Furthermore, taking into account UV-cured ink, which is hardened by irradiation with UV rays, the cylindrical body 5, the first lid section 6, and the second lid section 7 are, as desired, finished in a color that prevents the penetration of UV rays, for example, black.

[0028] Furthermore, one membrane bundle end section 3a of the hollow fiber membrane bundle 3 is attached to an opening end section 5a of the cylindrical body 5 by a sealing section 8. The other membrane bundle end section 3b of the hollow fiber membrane bundle 3 is also attached to the other end section 5b of the cylindrical body 5 by a sealing section 9.

[0029] The sealing section 8 is made of resin. Examples of resins used in the sealing section 8 include epoxy resin, urethane resin, UV-curing resin, and polyolefin resins such as polyethylene and polypropylene. The sealing section 8 is filled over an entire area that differs from the membrane bundle hollow section 3c in a cross-section perpendicular to the axial direction L of the cylindrical body 5. This means that the sealing section 8 is located only between the hollow fiber membranes 2, within the hollow fiber membranes 2, and between the hollow fiber membrane bundle 3 and the inner wall of the cylindrical body 5 (see figure). Fig. 3(a)) is filled. Furthermore, the sealing section 8 is provided with a connecting opening 8a, which connects the membrane bundle hollow section 3c to the outside of the cylindrical body 5. For this reason, the ink, which is supplied from the supply opening 6a into the first cover section 6, is supplied into the cylindrical body 5 only via the connecting opening 8a and directed to the outside of the hollow fiber membrane 2 inside the cylindrical body 5.

[0030] Sealing section 9 is made of the same resin as sealing section 8. Sealing section 9 is filled over the entire area that differs from the inside of the hollow fiber membrane 2 in a cross-section perpendicular to the axial direction L of the cylindrical body 5. This means that sealing section 9 is not filled into the hollow fiber membrane 2 but only between the hollow fiber membranes 2, between the hollow fiber membrane bundle 3 and the inner wall of the cylindrical body 5, and into the membrane bundle hollow section 3c (see figure). Fig.3(b)). For this reason, it is possible to prevent the ink supplied to the cylindrical body 5 from flowing beyond the sealing section 9 to the second lid section 7. Furthermore, the inside of the hollow fiber membrane 2 is connected to the inside of the second lid section 7. For this reason, the interior of the hollow fiber membrane 2 is depressurized when air is drawn in through the inlet opening 7a by the suction pump 16.

[0031] Furthermore, the hollow fiber membrane bundle 3 is eccentric in the reference cross-section A perpendicular to the axial direction L of the cylindrical body 5 and passes through the outlet opening 5d. In particular, the sealing section 8 fixes one membrane bundle end section 3a of the hollow fiber membrane bundle 3 to the cylindrical body 5 such that the central axis of this membrane bundle end section 3a coincides with the central axis of the cylindrical body 5. Meanwhile, the sealing section 9 fixes the other membrane bundle end section 3b of the hollow fiber membrane bundle 3 to the cylindrical body 5 such that the central axis of this other membrane bundle end section 3b is eccentric with respect to the central axis of the cylindrical body 5. The eccentric position is not particularly limited.For example, to prevent fiber breakage due to contact between the edge section of the outlet opening 5d and the hollow fiber membrane, it is desirable that the central axis of the other membrane bundle end section 3b in the sealing section 9 be eccentric to the central axis of the cylindrical body 5 on the opposite side of the outlet opening 5d. Consequently, in the reference cross-section A, the hollow fiber membrane bundle 3 is eccentric to the opposite side of the outlet opening 5d. Furthermore, the reference cross-section A can be any cross-section at any position, as long as it is perpendicular to the axial direction L of the cylindrical body 5 and passes through the outlet opening 5d. For example, the outlet opening 5d has a predetermined length in the axial direction L, but the reference cross-section A can be any cross-section that passes through the outlet opening 5d at any position in the axial direction L.

[0032] Here, in the reference cross-section A, a gap between the cylindrical body 5 and the hollow fiber membrane bundle 3 near the outlet opening 5d is designated by G, and an inner diameter of the cylindrical body 5 is designated by D. Furthermore, the gap G is a dimension of a gap between the cylindrical body 5 and the hollow fiber membrane bundle 3 near the outlet opening 5d. In this case, it is desirable to specify the position of the hollow fiber membrane bundle 3 relative to the cylindrical body 5 such that the relationship of the following equation (1) is satisfied. G≥0.08D

[0033] Furthermore, in the reference cross-section A, the gap G between the cylindrical body 5 and the hollow fiber membrane bundle 3 near the outlet opening 5d is preferably 2.5 mm or more. Because the gap is 2.5 mm or more, it is possible to prevent fiber breakage due to contact between the edge section of the outlet opening 5d and the hollow fiber membrane, and to increase the flow rate of the fluid, such as ink, flowing within the housing. However, the gap G is preferably more than 4.0 mm or less to ensure a sufficient membrane area.

[0034] Furthermore, the ratio between the inner diameter D of the cylindrical body 5 and the length of the hollow fiber membrane bundle 3 in the axial direction L is preferably 1:1 to 1:6.

[0035] Next, an ink degassing process using the hollow fiber degassing module 1 is described.

[0036] The ink supplied from the ink reservoir section 12 to the first ink supply line 14 is fed from the supply opening 6a into the first cover section 6. The ink supplied to the first cover section 6 is fed to the membrane bundle hollow section 3c through the connecting port 8a. The ink supplied to the membrane bundle hollow section 3c passes through a gap between the hollow fiber membranes 2 that form the hollow fiber membrane bundle 3 and flows radially towards the outside of the cylindrical body 5. That is, the ink supplied to the membrane bundle hollow section 3c is fed to the outside of the hollow fiber membrane 2 in the cylindrical body 5. At this time, when the suction pump 16 is operated, drawing air from inside the housing 4 through the inlet opening 7a, the interior of the hollow fiber membrane 2 is depressurized.Then, when ink flows between the hollow fiber membranes 2, dissolved gas and air bubbles from the ink are drawn into the hollow fiber membranes 2. Consequently, the ink is degassed.

[0037] The degassed ink then flows from outlet 5d into the second ink supply line 15, from where it is fed into the inkjet head 13. At this time, each hollow fiber membrane 2, forming the hollow fiber membrane bundle 3, is drawn towards outlet 5d by the flow of ink from outlet 5d to the second ink supply line 15. However, because the hollow fiber membrane bundle 3 is eccentric in the reference cross-section A, the hollow fiber membrane 2 is not easily drawn towards outlet 5d.

[0038] In this way, the hollow fiber degassing module 1, according to the exemplary embodiment, is of an external flow type that degasses the ink by supplying the ink to the outside of the hollow fiber membrane 2 and rendering the inside of the hollow fiber membrane 2 pressureless. For this reason, it is possible to reduce the pressure drop of the ink to a low level. Accordingly, even if, for example, the hollow fiber degassing module 1 is mounted in the inkjet printer 11, which supplies the ink from the ink reservoir section 12 to the inkjet head 13 by the weight of the ink itself, the ink can be adequately supplied to the inkjet head 13.

[0039] Furthermore, the hollow fiber membrane bundle 3 is eccentric in the reference cross-section A perpendicular to the axial direction L of the cylindrical body 5, which passes through the outlet opening 5d. For this reason, it is possible to prevent the hollow fiber membrane 2, which forms the hollow fiber membrane bundle 3, from being drawn into the outlet opening 5d by the ink flow. Because it is possible to prevent liquid leakage resulting from the rupture of the hollow fiber membrane 2, it is consequently possible to extend the service life of the hollow fiber degassing module 1. Because the hollow fiber membrane bundle 3 is eccentric to the opposite side of the outlet opening 4a in the reference cross-section A, it is possible in this case to prevent fiber breakage resulting from contact between the edge section of the outlet opening 4a and the hollow fiber membrane 2.

[0040] Furthermore, because the gap G between the cylindrical body 5 and the hollow fiber membrane bundle 3 near the outlet opening 5d and the inner diameter D of the cylindrical body 5 have a relationship of G ≥ 0.08D, it is possible to adequately prevent the hollow fiber membrane 2 from being drawn into the outlet opening 5d by the flow of ink.

[0041] Furthermore, because the gap G between the cylindrical body 5 and the hollow fiber membrane bundle 3 near the outlet opening 5d is set to 2.5 mm or more, it is possible to adequately prevent the hollow fiber membrane 2 from being drawn into the outlet opening 5d along with the flow of ink.

[0042] Furthermore, because the hollow fiber degassing module 1 in the inkjet printer 11 according to the exemplary embodiment is attached to the ink passage including the first ink supply line 14 and the second ink supply line 15, the pressure drop of the ink in the ink passage can be low and the ink can be degassed for a long period of time. Consequently, if, for example, the inkjet printer 11 supplies the ink from the ink storage section 12 to the inkjet head 13 by the weight of the ink itself, it is possible to supply the ink adequately to the inkjet head 13.

[0043] While the preferred embodiment of the invention has been described, the invention is not limited to the embodiment described above. For example, the relationship between the gap G and the inner diameter D, as well as the dimension of the gap G, are precisely described in the embodiment described above, but the invention is not limited to this relationship and dimension. Furthermore, the embodiment described above includes a case in which the membrane bundle hollow section 3c is not provided with the central tube, but the membrane bundle hollow section 3c may be provided with the central tube. The embodiment described above also includes a case in which the ink is a liquid to be degassed, but the liquid to be degassed may be a liquid different from the ink. Reference symbol list:

[0044] 1: Hollow fiber degassing module, 2: Hollow fiber membrane, 3: Hollow fiber membrane bundle, 3a: One membrane bundle end section, 3b: Other membrane bundle end section, 3c: Membrane bundle hollow section, 4: Housing, 4a: Outlet opening, 5: Cylindrical body, 5a: One opening end section, 5b: Other opening end section, 5c: Side wall, 5d: Outlet opening, 5e: Connecting section, 5f: Internal thread, 6: First cover section, 6a: Supply opening, 6b: Connecting section, 6c: Internal thread, 7: Second cover section, 7a: Inlet opening, 7b: Connecting section, 7c: Internal thread, 8: Sealing section, 8a: Connecting opening, 9: Sealing section, 11: Inkjet printer, 12: Ink reservoir section, 13: Inkjet printhead, 14: First ink supply line, 15: Second Ink supply line, 16: Suction pump, 17: Inlet line, A: Reference cross-section, D: Inner diameter, G: Gap, L: Axial direction.

Claims

[1] Hollow fiber degassing module (1) comprising a hollow fiber membrane bundle (3) obtained by bundling a plurality of hollow fiber membranes (2) in a cylindrical shape, and a cylindrical body (5) which accommodates the hollow fiber membrane bundle (3) and extends in an axial direction and degasses a liquid by supplying the liquid to the outside of the hollow fiber membranes (2) and depressurizing the inside of the hollow fiber membranes (2), wherein a side wall of the cylindrical body (5) is provided with an outlet opening (5d) which releases the degassed liquid, characterized by , that the hollow fiber membrane bundle (3) in a reference cross-section (A) that is perpendicular to the axial direction (L) of the cylindrical body (5) and runs through the outlet opening (5d), is eccentric to the opposite side of the outlet opening (5d). [2] Hollow fiber degassing module (1) according to claim 1, wherein, if a gap (G) between the cylindrical body (5) and the hollow fiber membrane bundle (3) in the vicinity of the outlet opening (5d) in the reference cross-section (A) is designated by G and an inner diameter (D) of the cylindrical body is designated by D, a relationship of G ≥ 0.08D is satisfied. [3] Hollow fiber degassing module (1) according to claim 1 or 2, wherein a gap (G) between the cylindrical body (5) and the hollow fiber membrane bundle (3) in the vicinity of the outlet opening (5d) is 2.5 mm or more in the reference cross-section. [4] Inkjet printer (11) in which ink stored in an ink storage section (12) is supplied through an ink passage (14, 15) to an inkjet head (13), wherein the hollow fiber degassing module (1) according to one of claims 1 to 3 is attached to the ink passage (14, 15).

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