Test tool, leak test device, and leak test method

Abstract

This test tool is used for leak testing on a bag-shaped container having a port protruding from the surface thereof. The test tool is provided with a pair of holding plates that sandwich and hold the bag-shaped container. At least one of the pair of holding plates has a slit which allows the port to pass therethrough from an end edge of the holding plate.

Description

Inspection tool, leak inspection device, and leak inspection method

[0001] The technology of the present disclosure relates to an inspection tool, a leak inspection device, and a leak inspection method.

[0002] For example, as a quality inspection of a bag-shaped container that stores a fluid, a leak inspection for inspecting a leak in the bag-shaped container is known. The leak inspection is performed, for example, by sandwiching a bag-shaped container pressurized by enclosing air between a pair of holding plates and measuring the pressure drop of the bag-shaped container in that state. As described in Japanese Patent No. 6718781, a port for taking in and out the fluid may be provided on the surface of the bag-shaped container. When such a port protrudes from the surface, interference between the pair of holding plates and the port may hinder appropriate pressurization by the pair of holding plates or may prevent the distance between the pair of holding plates from being narrowed.

[0003] Japanese Patent No. 6718781 discloses an inspection tool used for a leak inspection for inspecting the presence or absence of a leak in a bag-shaped container having such a port protruding from the surface, the inspection tool having a pair of holding plates that sandwich both sides of the bag-shaped container, and at least one of the holding plates having a hole for inserting the port. In the inspection tool described in Japanese Patent No. 6718781, since a hole for inserting the port is provided in the holding plate, when the bag-shaped container is sandwiched between the pair of holding plates, the protruding port enters the hole, so that interference between the port and the holding plate is suppressed.

[0004] When installing the bag-shaped container in the inspection tool described in Japanese Patent No. 6718781, the bag-shaped container is inserted between the pair of holding plates, and the port is aligned with the hole in the holding plate with the bag-shaped container inserted between the pair of holding plates. However, when the distance between the pair of holding plates is narrow, it may take time to align the port and the hole. For example, when extending the hand from the end of the holding plate to align the port of the bag-shaped container with a hole near the center of the holding plate, it is difficult to reach the hand if the distance between the pair of holding plates is narrow. Such a problem becomes more prominent as the planar sizes of the bag-shaped container and the holding plate are larger.

[0005] The technology disclosed herein provides an inspection tool for leak testing, an inspection tool, a leak testing apparatus, and a leak testing method that offer improved workability in the process of installing a bag-shaped container with a port between a pair of retaining plates compared to conventional methods.

[0006] The inspection tool relating to the technology of this disclosure is an inspection tool used for leak testing of a bag-shaped container having a port protruding from its surface, and comprises a pair of holding plates that clamp and hold the bag-shaped container, and at least one of the pair of holding plates has a slit that allows the port to enter from the edge of the holding plate.

[0007] The slit may be formed by cutting out a portion of the retaining plate.

[0008] The retaining plate may have multiple slits formed in it.

[0009] A slit may be formed in a portion of each of the pair of retaining plates, and the pair of retaining plates may be arranged so that the edges of the retaining plates at the slits face in the same direction.

[0010] A wider section may be provided in part of the slit, which is relatively wider than the other parts.

[0011] In a retaining plate with a slit formed therein, a reinforcing member that straddles the slit may be provided.

[0012] In the retaining plate, reinforcing ribs may be provided on the surface opposite to the surface in contact with the bag-shaped container, in areas other than the slits.

[0013] At least one of the pair of retaining plates is composed of a plurality of divided plates, and the slit may be formed by the gap between adjacent divided plates.

[0014] There are three or more dividing plates, and at least two of the dividing plates are movable plates that can slide in a first direction intersecting the direction in which the slit extends, and the position of the slit in the first direction can be changed according to the position of the two movable plates.

[0015] On the surface of the retaining plate that comes into contact with the bag-shaped container, the corners defining the slits may be rounded with a radius of 2 mm or more.

[0016] The pair of retaining plates have a variable distance between their opposing surfaces that sandwich the bag-shaped container, and the adjustable distance range may be set with a lower limit of 30 mm or less and an upper limit of 100 mm or more.

[0017] The leak testing device relating to the technology disclosed herein comprises one of the above-mentioned testing tools, a compressed air supply device for supplying gas to a bag-shaped container, and a measuring unit for measuring the pressure drop of the bag-shaped container.

[0018] The leak inspection method relating to the technology of this disclosure is a leak inspection method using any of the inspection tools described above, and includes aligning the port of the bag-shaped container with the position of the slit, placing the bag-shaped container between a pair of retaining plates, pressurizing the bag-shaped container by supplying gas, pressing the pressurized bag-shaped container with the pair of retaining plates, and measuring the pressure drop of the bag-shaped container.

[0019] The technology of this disclosure provides an inspection tool, a leak inspection device, and a leak inspection method that offer improved workability in the process of installing a bag-shaped container with a port between a pair of retaining plates, compared to conventional methods.

[0020] This figure shows an overview of the leak inspection device. This figure shows the state of the leak inspection device when a plastic bag is installed. This figure shows a plastic bag in an unfolded state. This figure shows the process of transitioning a plastic bag from a folded state to an unfolded state. This figure shows multiple types of plastic bags. This figure shows a leak inspection method. This is an exploded perspective view of the inspection tool 30. This is a plan view of one of the holding plates. This is a plan view of the other holding plate. This figure shows the rounded processing of the corners defining the slits. This figure shows the adjustable spacing between a pair of holding plates. This is a flowchart showing the procedure for the leak inspection method. This figure shows how to use the slits when installing a plastic bag. This figure shows how to fill in unused slits. This figure shows the inspection tool of the second embodiment. This is an exploded perspective view of the inspection tool of the second embodiment. This figure shows how to change the position of the slits in the second embodiment. This figure shows an embodiment with multiple holding parts.

[0021] [First Embodiment] Figures 1 and 2 show an overview of a leak inspection device 20 equipped with an inspection tool 30. The inspection tool 30 is an example of an "inspection tool" according to the technology of this disclosure, and the leak inspection device 20 is an example of a "leak inspection device" according to the technology of this disclosure. The leak inspection device 20 is a device for performing leak inspection of a plastic bag 10. The plastic bag 10 is a container for holding fluid and is an example of a "bag-shaped container" according to the technology of this disclosure. Leak inspection is one of the quality inspections for checking the airtightness of the plastic bag 10, for example, and detects fluid leaks caused by minute voids or welding defects.

[0022] As shown in Figures 3 and 4, the plastic bag 10 is used, for example, in bioprocess applications such as the manufacture of biopharmaceuticals and vaccines. The plastic bag 10 contains process solutions used in each step of the bioprocess. Process solutions are examples of fluids, such as cell suspensions used in cell culture, culture media, culture medium additives, and buffers. In bioprocesses, it is important to prevent contamination in order to ensure the quality of the product, so the plastic bag 10 is for single use.

[0023] As shown in Figure 3, the plastic bag 10 has a three-dimensional storage space inside for containing the process solution. For example, when unfolded, the plastic bag 10 is approximately rectangular in shape and has a front surface 10F, a back surface 10B, a top surface 10U, a bottom surface 10L, and two sides 10S. For example, the top surface 10U and the bottom surface 10L are provided with ports 12, which are openings for supplying and discharging the process solution to and from the plastic bag 10. The ports 12 have ring-shaped opening edges that protrude from the surfaces of the top surface 10U and the bottom surface 10L. For example, there are three ports 12 on the top surface 10U and three on the bottom surface 10L. For example, tubes 11 are connected to such ports 12. The tubes 11 function as conduits connecting the plastic bag 10 to, for example, a device that supplies the process solution to the plastic bag 10 or a device that discharges the process solution from the plastic bag 10. Note that the location and number of ports 12 shown in Figure 3 are just an example and can be changed as appropriate.

[0024] Such a plastic bag 10 is formed, for example, by sealing four plastic sheets together by heat welding. The four sheets consist of two sheets that mainly constitute the top surface 10U and the bottom surface 10L, respectively, and two sheets that mainly constitute the left and right sides 10S.

[0025] As shown in Figure 4, the plastic bag 10 changes from a folded state to an unfolded state in which the sheets are unfolded and a three-dimensional storage space is formed inside. In Figure 4, the upper section shows the plastic bag 10 in its folded state. In the folded state, the four sheets are stacked on top of each other and have a nearly flat shape. In the folded state, the two sheets that make up the top surface 10U and the bottom surface 10L are arranged facing each other, and the sheets that make up the left and right sides 10S are arranged between them, folded inward in a valley fold.

[0026] By blowing gas into the folded plastic bag 10, for example, through the port 12, it unfolds into an unfolded state with a three-dimensional (in this example, rectangular) storage space inside. The middle section shows the state after gas injection begins from the folded state, and the bag has slightly expanded. The bottom section shows the state as gas injection progresses further, and the bag is closer to the unfolded state. Further gas injection results in the unfolded state shown in Figure 3.

[0027] The sheet constituting the plastic bag 10 is, for example, a sheet made of multiple laminated resin layers. The multiple resin layers include, for example, a polyethylene (PE) layer and a polyethylene terephthalate (PET) layer. Furthermore, the resin layers may also include nylon (ONY) resin and ethylene-vinyl alcohol copolymer (EVOH) resin.

[0028] Furthermore, as shown in Figure 5, the plastic bags 10 come in various sizes with different capacities. For example, capacities range from about 1 L for small bags to about 2000 L for large bags. When processing relatively large volumes of process solutions, such as in bioprocesses involving cell perfusion culture, a capacity of 50 L or more is preferable. More preferably, a capacity of 100 L to 1000 L is preferred. Figure 5 shows the plastic bag 10 in a folded state. The plastic bag 10 shown in Figure 5(A) has a capacity of about 1000 L, and in this case, as an example, the length (Y direction) is about 2100 mm and the width (X direction) is about 1100 mm. The plastic bag 10 shown in Figure 5(B) has a capacity of about 500 L, and in this case, as an example, the length is about 1700 mm and the width is about 850 mm. The plastic bag 10 shown in Figure 5(C) has a capacity of approximately 200L. In this case, for example, the length is approximately 1300mm and the width is approximately 700mm.

[0029] Since the plastic bag 10 has a relatively large capacity, the thickness of each sheet is preferably 120 μm or more, and as an example, it is about 180 μm to 350 μm. If the sheet thickness is thin, the water vapor permeability will be high. The reason why a thickness of 120 μm or more is preferred is to ensure the water vapor permeability required in bioprocessing. When the plastic bag 10 is constructed from sheets, there is a tendency for water vapor to permeate through the sheets to be high. In bioprocessing, changes in the concentration of the aqueous solution, which is the contents, due to water evaporation can be a problem, and therefore, there is a high need to suppress water vapor evaporation, making water vapor permeability important. By making the sheet thickness 120 μm or more, the water vapor permeability required in bioprocessing can be ensured. Furthermore, in such a plastic bag 10 for bioprocessing, airtightness is important, and leak testing as a quality inspection is particularly important.

[0030] In Figures 1 and 2, the leak inspection device 20 is, as an example, composed of an inspection tool 30, a leak tester 21, and a control device 22. The inspection tool 30 is a tool that pressurizes a plastic bag 10 by supplying air inside it. The inspection tool 30 includes a holding part 33 that holds the plastic bag 10 by clamping it, and a frame 34 that supports the holding part 33. The holding part 33 is composed of a pair of holding plates 31 and 32. The holding plates 31 and 32 are arranged opposite each other, and press the plastic bag 10 by clamping it from above and below (the Z direction in Figures 1 and 2) with their respective opposing surfaces. In the vertical direction, the holding plate 31 is positioned above and contacts the upper surface of the folded plastic bag 10. The holding plate 32 is positioned below and contacts the lower surface of the folded plastic bag 10.

[0031] In the inspection device 30, the distance in the Z direction between the pair of retaining plates 31 and 32, that is, the distance between the opposing surfaces of each retaining plate 31 and retaining plate 32, is variable. Figure 1 shows the state of the retaining part 33 when a pressurized plastic bag 10 is pressed, and Figure 2 shows the state of the retaining part 33 when the plastic bag 10 is attached to or detached from the retaining part 33. Hereinafter, the state of the retaining part 33 shown in Figure 1 will be referred to as the pressed state, and the state of the retaining part 33 shown in Figure 2 will be referred to as the attached / detached state. In the pressed state, the distance between the opposing surfaces of the retaining plates 31 and 32 is, for example, about 10 mm to 30 mm. On the other hand, in the attached / detached state, the distance between the opposing surfaces of the retaining plates 31 and 32 is, for example, about 150 mm to 250 mm.

[0032] As shown in Figure 2, when the plastic bag 10 is installed in the holding section 33, for example, it is installed with the tube 11 connected to the port 12. Since the port 12 and tube 11 protrude from the surface of the plastic bag 10, slits 36 are provided in the holding plates 31 and 32. The slits 36 are openings to suppress interference between the port 12 and the tube 11 connected to the port 12 and the holding plate 31 or 32. The port 12 can be inserted into the slits 36, and the tube 11 can be routed to the outside of the holding section 33 through the slits 36. When the operator S, who performs the leak inspection, installs the plastic bag 10 in the holding section 33, the positions of the port 12 and tube 11 are aligned with the positions of the slits 36, the port 12 is inserted into the slits 36, and the tube 11 is brought out to the outside of the holding section 33. The configuration of the inspection tool 30, including the slits 36 and the holding section 33, will be described later.

[0033] The leak tester 21 is, for example, a pressure drop type measuring instrument that measures the pressure drop of the plastic bag 10 when the plastic bag 10 is pressed by the holding part 33. If there is no leak in the plastic bag 10, there is almost no pressure drop, and if there is a leak, the pressure drop becomes significant. This allows for inspection of whether or not there is a leak in the plastic bag 10.

[0034] The control device 22 controls the leak tester 21 and the inspection tool 30. For example, the control device 22 inputs a command to start the leak test to the leak tester 21 and acquires data such as measured values ​​from the leak tester 21. The control device 22 also outputs a drive signal to an electric actuator for controlling the spacing between the holding plates 31 and 32 of the inspection tool 30. The control device 22 is composed of, for example, a personal computer. However, the control device 22 may also be composed of a PLC (Programmable Logic Controller) or the like.

[0035] Figure 6 shows a schematic of a pressure drop type leak test. A compressed air supply device 24 is connected to the leak tester 21 via a pipeline. The compressed air supply device 24 supplies compressed air to pressurize the plastic bag 10. The leak tester 21 is connected, for example, to a part of the tube 11 of the plastic bag 10, and the compressed air generated by the compressed air supply device 24 is supplied to the plastic bag 10 via the leak tester 21 and the tube 11. An antibacterial and disinfectant filter 26 is provided upstream of the leak tester 21 to filter the compressed air for antibacterial and disinfection purposes. Furthermore, a hollow fiber filter 27 is provided downstream of the leak tester 21. The hollow fiber filter 27 is also provided for antibacterial and disinfection of the compressed air. In this way, by doubling the filters, contamination of the plastic bag 10 during inspection is minimized. The leak tester 21 is, as an example, a direct pressure type. The leak tester 21 can set the pressure inside the container to be tested for leaks to, for example, between 3 kPa and 100 kPa. In leak testing of the plastic bag 10, for example, a range of 3 kPa to 15 kPa is used.

[0036] The leak tester 21 has an adjustment function that adjusts the pressure inside the plastic bag 10 to a preset pressure value, and a measurement function that measures the change in pressure drop inside the plastic bag 10 over time after pressurization is stopped. The leak tester 21 determines that there is a leak, for example, if the pressure drop after a preset time has elapsed is greater than a threshold.

[0037] Graphs C1 to C3 in Figure 6 show examples of changes in pressure drop over time. Graph C1 is an example of a plastic bag 10 without leakage, while graphs C2 and C3 are examples of plastic bags 10 where leakage occurs due to the formation of micropores with a diameter of approximately 100 μm. In graph C1, where there is no leakage, there is no pressure drop. The inspection conditions for graphs C1 to C3 are common, for example, that the pressure value applied to the plastic bag 10 is 10 kPa. In graphs C1 and C2, the distance between the retaining plates 31 and 32 of the retaining part 33 that presses the plastic bag 10 is 30 mm. In graph C3, the distance between the retaining plates 31 and 32 is 10 mm. As shown in graph C3, when the distance between the retaining plates 31 and 32 is small, the pressing force applied to the plastic bag 10 is larger, so the amount of pressure drop per unit time (i.e., the slope of the graph) is larger than in graph C2. Therefore, by narrowing the distance between the retaining plates 31 and 32, the throughput of leak testing can be improved.

[0038] The ejector 28 is a vacuum ejector and is an example of an exhaust device that exhausts compressed air from a pressurized plastic bag 10 for leak testing. The ejector 28 is connected to both the supply line for supplying compressed air from the compressed air supply device 24 and the exhaust line from the plastic bag 10. As is well known, the ejector 28 has a nozzle that injects compressed air taken in from the compressed air supply device 24 and a diffuser that discharges the compressed air injected by the nozzle to the outside. By injecting compressed air from the nozzle towards the diffuser, the ejector 28 creates a vacuum inside with a high-speed flow of compressed air. This draws in air from the plastic bag 10 and discharges the drawn-in air from the diffuser together with the compressed air. By using such an ejector 28, it is possible to exhaust the plastic bag 10 in a short time.

[0039] Valve 29 is a valve for switching between an open state and a closed state for the supply line to the ejector 28 and the exhaust line, respectively. Valve 29 may be a solenoid valve or a manual valve. Although the example was explained using an ejector 28 as the exhaust device, a vacuum pump may be used instead of the ejector 28. However, using the ejector 28 allows for space savings compared to using a vacuum pump.

[0040] For example, the leak tester 21 may be an ATEQ F600. For example, the antibacterial / sterilizing filter 26 may be a combination of three filters manufactured by SMC: HF2-BFA40-04 (filtration degree 5 μm), HF2-BFB40-04 (filtration degree 0.1 μm), and HF2-BFD40-04 (filtration degree 0.01 μm). For example, the hollow fiber filter 27 may be an SMC SFD102-F02.

[0041] As shown in Figure 7, the inspection tool 30 includes a holding section 33 containing a pair of holding plates 31 and 32, as well as clamping members 37 and a linear guide 38. The clamping members 37 are members that clamp the holding plates 31 and 32 to prevent the gap between them from widening due to the pressure from the plastic bag 10 when the plastic bag 10 is pressed. As an example, the clamping members 37 are attached in two places on each side of the holding plates 31 and 32.

[0042] The linear guide 38 is a member that guides the vertical movement of the retaining plate 31. The linear guide 38 has a rod-shaped guide member, the rod-shaped guide 38A, whose longitudinal direction is aligned with the vertical direction, and a block 38B that moves relative to the rod-shaped guide 38A. The block 38B is fixed to the retaining plate 32 via an L-shaped bracket 42. The upper end of the rod-shaped guide 38A is fixed to the retaining plate 31. Reference numeral 31A indicates the portion of the retaining plate 31 to which the rod-shaped guide 38A is connected. The retaining plate 32 to which the block 38B is fixed is fixed to a frame 34 (see Figures 1 and 2). As the rod-shaped guide 38A moves vertically relative to the block 38B, the retaining plate 31 moves up and down, and the distance between the retaining plate 31 and the retaining plate 32 changes. The linear guide 38 is driven by an electric actuator, such as a motor (not shown), as an example. The linear guide 38 and the electric actuator constitute the lifting mechanism for the retaining plate 31. The lifting mechanism is driven and controlled via an electric actuator, for example, by a control device 22. Alternatively, an actuator such as an air cylinder may be used instead of an electric actuator. Of course, the linear guide 38 may also be operated manually. Furthermore, the form of the linear guide 38 is just an example, and various forms can be used, such as a form having a guide rail with a substantially rectangular cross-section instead of a rod-shaped guide 38A.

[0043] Furthermore, the rod-shaped guide 38A and the retaining plate 31 are connected by a floating joint (not shown). The floating joint reduces the stress applied to the retaining plate 31 when the retaining plate 31 deforms due to pressure from the plastic bag 10. When the retaining plate 31 presses against the plastic bag 10, the retaining plate 31 deforms so that its center becomes convex outward due to the pressure from the plastic bag 10. In this case, if the rod-shaped guide 38A is rigidly fixed at the end of the retaining plate 31, the stress applied to the end of the retaining plate 31 will be large. Therefore, the floating joint reduces the stress applied to the end of the retaining plate 31 by slightly rotating the end of the retaining plate 31 in the direction of the applied force.

[0044] As also shown in FIGS. 8 and 9, the holding plates 31 and 32 are, as an example, substantially rectangular in planar shape and have projecting portions in the width direction (X direction in the drawing) at the four corners. The sizes of the holding plates 31 and 32 in the longitudinal direction and the width direction are such that they can cover the entire plastic bag 10. In order to inspect the 1000 L plastic bag 10 shown in FIG. 5, the planar sizes of the holding plates 31 and 32 are, for example, about 2200 mm in the longitudinal direction and about 1200 mm in the width direction. The holding plates 31 and 32 are, as an example, made of lightweight aluminum and have a thickness of about 20 mm. Also, in the holding plates 31 and 32, for example, an alumite treatment is applied to the contact surfaces that contact the plastic bag 10. Further, the holding plates 31 and 32 may be made of, for example, a honeycomb plate in which a honeycomb-shaped core material is sandwiched between surface plates from both sides. Thereby, lightweight and highly rigid holding plates 31 and 32 can be obtained.

[0045] The slits 36 formed in the holding plates 31 and 32 respectively are slits through which the port 12 of the plastic bag 10 can enter from the edge of the holding plate 31 or the holding plate 32. The slit 36 is formed by cutting out a part of the holding plate 31 or the holding plate 32. One end of the slit in the longitudinal direction (Y direction in the drawing) reaches the respective edges of the holding plate 31 or 32 and is an open end. The other end in the longitudinal direction is located in the middle of the longitudinal direction of the holding plate 31. The position of the other end is, as an example, near the center in the longitudinal direction of the holding plates 31 and 32. The size of the slit 36 in the longitudinal direction and the position of the holding plate 31 or the holding plate 32 in the width direction are determined according to the position of the port 12 of the plastic bag 10 to be inspected.

[0046] In this example, a plurality of slits 36 are provided in each of the holding plates 31 and 32. This is for making one inspection tool 30 compatible with a plurality of types of plastic bags 10. As shown in FIG. 5, the plastic bags 10 have a plurality of sizes, and the positions of the respective ports 12 are different. A plurality of slits 36 are provided so that one inspection tool 30 can inspect such a plurality of types of plastic bags 10. In this example, the number of slits 36 provided in each of the holding plates 31 and 32 is two, and they are the same number. Of course, the number of slits 36 in each may be different.

[0047] Also, the pair of holding plates 31 and 32 are arranged in a posture such that the end portions on the edge side of the holding plate 31 or 32 in each slit 36 face in the same direction. That is, each slit 36 of the holding plates 31 and 32 has one end in the longitudinal direction open and the other end closed. The open ends of the slits 36 of the holding plates 31 and 32 face in the same direction. Thereby, the operator S can access both slits 36 of the holding plates 31 and 32 from the same direction.

[0048] Also, a wide portion 36A having a relatively wider width than other portions is provided in a part of the slit 36. A tube 11 is inserted into the slit 36, but a member larger than the diameter of the tube 11, such as a connector, may be attached to the end of the tube 11 of the plastic bag 10. The wide portion 36A is provided to allow a member larger than the diameter of such a tube 11 to pass through.

[0049] In the retaining plates 31 and 32, which have slits 36 formed therein, a reinforcing member 44 is provided that straddles the slits 36. The reinforcing member 44 is a prismatic member whose longitudinal direction extends in the X direction, which is perpendicular to the longitudinal direction (i.e., the Y direction) of the slits 36. As an example, the reinforcing member 44 has a length that spans multiple slits 36. The reinforcing member 44 is provided near the open end of the slits 36. The reinforcing member 44 compensates for the reduced rigidity in the retaining plate 31 or the retaining plate 32 due to the slits 36 and suppresses deformation such as deflection of the retaining plate 31 or the retaining plate 32.

[0050] Furthermore, on the retaining plates 31 and 32, reinforcing ribs 46 are provided on the surfaces opposite to the surfaces in contact with the plastic bag 10, in portions other than the slits 36. Multiple ribs 46 are provided along the longitudinal and width directions of the retaining plates 31 and 32, respectively, and are arranged in a grid pattern by the intersection of multiple ribs 46. In this embodiment, ribs 46 are also provided between multiple slits 36. It is preferable that the ribs 46 be made of hollow material to reduce weight.

[0051] Furthermore, as shown in Figure 10, the corner 36B defining the slit 36 ​​on the surface of the retaining plate 31 that contacts the plastic bag 10 is rounded with a radius of 5 mm (indicated as R5 in Figure 10). This suppresses scratches on the plastic bag 10. The rounding does not have to be with a radius of 5 mm. The rounding can be 5 mm or more or less, and can be appropriately determined depending on the material of the plastic bag 10, etc. However, in order to obtain an effective effect in suppressing scratches, a radius of 2 mm or more is preferable.

[0052] As described above, the distance between the opposing surfaces of the pair of retaining plates 31 and 32 that sandwich the plastic bag 10 is variable. As shown in Figure 11, the adjustable distance range is, for example, a maximum distance D1 of 250 mm and a minimum distance D2 of 2 mm. When attaching or detaching the plastic bag 10, it is preferable that the distance between the retaining plates 31 and 32 be at least 150 mm to 200 mm. Furthermore, when the plastic bag 10 is pressed during inspection, it is preferable that the distance between the retaining plates 31 and 32 be narrowed to about 10 mm to 30 mm.

[0053] In inspection, a narrower gap allows for a smaller volume of the plastic bag 10 during inspection, which may be preferable if the leak test needs to be completed quickly. The gap for inspection also needs to be determined considering the thickness of the plastic bag 10. Therefore, depending on the thickness of the plastic bag 10, it may be better to narrow the gap between the retaining plates 31 and 32 to about 2 mm as described above. Of course, it may be possible to narrow it even further to about 1 mm. When attaching and detaching the plastic bag 10, a wider gap between the retaining plates 31 and 32 is preferable. However, if the gap is too wide, the stroke length of the linear guide 38 will be required, so the upper limit of the gap between the retaining plates 31 and 32 can be appropriately determined within a range of about 300 mm, taking into consideration the balance between the two.

[0054] Thus, the adjustable distance between the opposing surfaces of the retaining plate 31 and the retaining plate 32 is determined according to the requirements for inspection and attachment / detachment, but it is preferable to set the lower limit to 30 mm or less and the upper limit to 100 mm or more.

[0055] The operation of the leak inspection device 20 with the above configuration will be explained with reference to the flowchart shown in Figure 12. To start a leak inspection, first, as shown in step ST11, the pair of retaining plates 31 and 32 are set to the attachment / detachment spacing shown in Figures 2 and 11(A). In this state, as shown in step ST12, the operator S aligns the port 12 of the plastic bag 10 with the position of the slit 36 ​​and places the plastic bag 10 between the pair of retaining plates 31 and 32. In the plastic bag 10 to be inspected, a portion of the tube 11 connected to the port 12 is connected to the leak tester 21. The remaining tube 11 is airtightly sealed using, for example, a clamp that shields the flow path by sandwiching a portion of the tube 11, or a sealing cap attached to the open side of the tube 11.

[0056] In this installation process, as shown in Figure 13, worker S inserts the tube 11 into the slit 36 ​​from the inside of the retaining plate 31 at the open end of the slit 36, passes the tube 11 through the slit 36, and removes the tube 11 to the outside of the retaining part 33. As shown in Figures 13(A) and 13(B), worker S places the folded plastic bag 10 between the retaining plate 31 and the retaining plate 32, removing the tube 11 one by one to match the insertion state of the folded plastic bag 10. In addition to removing the tube 11 from the slit 36 ​​to the outside of the retaining plate 31, worker S adjusts the position of the plastic bag 10 so that the port 12 aligns with the position of the slit 36. Because worker S can easily reach the open end of the slit 36 ​​and the port 12 can be moved along the slit 36 ​​in the longitudinal direction, it is easy to align the port 12 with the position of the slit 36.

[0057] Figure 13 shows how to align the slit 36 ​​on the retaining plate 31 with the port 12 and tube 11 of the plastic bag 10, but the same applies to the retaining plate 32.

[0058] After the plastic bag 10 is placed in the holding section 33 in this manner, the pair of holding plates 31 and 32 are set to the pressing distance shown in Figures 1 and 11(B), as shown in step ST13. Since the position of the port 12 protruding from the surface of the plastic bag 10 is aligned with the position of the slit 36, the port 12 enters the slit 36. Also, the tube 11 is brought out to the outside of the holding section 33 through the slit 36. Therefore, the port 12 and tube 11 do not interfere with the holding plate 31 or the holding plate 32. As a result, the stress on the plastic bag 10 caused by the port 12 or tube 11 is suppressed by the pressure on the port 12 or tube 11 from the holding plate 31 or the holding plate 32.

[0059] In this state, as shown in step ST14, the plastic bag 10 is pressurized by supplying compressed air. When the plastic bag 10 is pressurized, it comes into contact with both the pair of retaining plates 31 and 32, and as shown in step ST15, the plastic bag 10 is pressed by the pair of retaining plates 31 and 32. Then, as shown in step ST16, the pressure drop of the plastic bag 10 is measured after the pressurization is stopped. Based on this measurement result, it is determined whether or not there is a leak in the plastic bag 10.

[0060] In the above embodiment, an example was described in which slits 36 are provided on both the retaining plate 31 and the retaining plate 32, but the slits 36 may be provided on only one of the retaining plate 31 or the retaining plate 32.

[0061] Furthermore, in the above embodiment, the installation of the plastic bag 10 is performed with the tube 11 attached to the port 12, but the installation may also be performed with the tube 11 not attached to the port 12. In this case, a sealing cap is attached to the port 12.

[0062] As described above, the inspection tool 30 according to the technology of this disclosure is an inspection tool used for leak testing of a plastic bag 10 (an example of a bag-shaped container) having a port 12 protruding from its surface, and comprises a pair of holding plates 31 and 32 that sandwich and hold the plastic bag 10, and at least one of the pair of holding plates 31 and 32 has a slit 36 ​​that allows the port 12 to enter from the edge of the holding plate 31 or 32.

[0063] Unlike conventional technologies where the retaining plate has a circular hole sized to match the port, the slit 36 ​​has an elongated shape with an open end on the edge side of the retaining plate 31 and retaining plate 32. Therefore, for an operator S working on the edge side of the retaining plate 31 and retaining plate 32, it is easy to reach the open end of the slit 36, making it easy to align the port 12 with the position of the slit 36. As shown in Figure 13, the port 12 can be inserted into the edge of the slit 36 ​​from the side of the retaining plate 31 and retaining plate 32 where the plastic bag 10 is inserted, and the port 12 can be moved along the longitudinal direction of the slit 36 ​​in accordance with the insertion state of the plastic bag 10. Therefore, even when the distance between the pair of retaining plates 31 and retaining plate 32 is narrow, good workability can be ensured when installing the plastic bag 10 with the port 12 between the pair of retaining plates 31 and retaining plate 32. Furthermore, as in the above embodiment, even when the tube 11 is attached to the port 12, it is easy to reach the open end of the slit 36, making it easier to pass the tube 11 through the slit 36, thus improving workability compared to the conventional circular hole.

[0064] Furthermore, even when a reinforcing member 44 is provided so as to straddle the slit 36 ​​at the open end of the slit 36, as in the above embodiment, it is still easy to reach the open end of the slit 36, making it easier to align the port 12 and tube 11 with the slit 36. Therefore, the effect of improving the workability of the installation work of the plastic bag 10 with the port 12 can be obtained.

[0065] In other words, even when the reinforcing member 44 is provided, as shown in Figures 10 and 11, the thickness of the slit 36 ​​is ensured to be such that it corresponds to the thickness of the retaining plate 31 or retaining plate 32, so that it is possible to insert the port 12, to which the tube 11 is not attached, from the edge of the slit 36. Furthermore, even when the tube 11 is attached to the port 12, the tube 11 can be passed under the reinforcing member 44, and the tube 11 can be passed through the slit 36 ​​from near the open end of the slit 36 ​​and moved along the slit 36. This makes it easier to remove the tube 11 from the inside to the outside of the retaining plate 31 or retaining plate 32.

[0066] In the above embodiment, the slit 36 ​​is formed by cutting out a part of the retaining plate 31 or the retaining plate 32. Therefore, the structure is simple.

[0067] In the above embodiment, the retaining plate 31 or retaining plate 32 has multiple slits 36 formed therein. Having multiple slits 36 makes it possible to use the inspection tool 30 to inspect multiple types of plastic bags 10 with different port positions 12, thus improving the usability of the inspection tool 30.

[0068] In the above embodiment, a slit 36 ​​is formed in a part of each of the pair of retaining plates 31 and 32, and the pair of retaining plates 31 and 32 are arranged so that the edges of the retaining plates 31 and 32 in the respective slits 36 face in the same direction. Because the edges of the retaining plates 31 and 32 in the slits 36 face in the same direction, the workability is improved when inserting the port 12 of the plastic bag 10 into both slits 36 of the pair of retaining plates 31 and 32.

[0069] In the above embodiment, a wide portion 36A is provided in a part of the slit 36, which is relatively wider than the other parts. For example, a long object such as a tube 11 may be attached to the plastic bag 10, or a member larger than the diameter of the tube 11 may be attached to the end of the tube 11. Even in this case, if a wide portion 36A is provided, it is easier to pass the tube 11 through the slit 36 ​​and easier to remove the tube 11 to the outside of the holding plate 31, thereby improving the work efficiency of the installation work of the plastic bag 10.

[0070] In the above embodiment, a reinforcing member 44 is provided that straddles the slit 36 ​​in the retaining plates 31 and 32, which have a slit 36 ​​formed therein. Since force is applied to the retaining plates 31 and 32 from the pressurized plastic bag 10, the rigidity of the portion where the slit 36 ​​is formed decreases and it becomes easily deformed. When the retaining plates 31 and 32 deform, a change in the volume of the plastic bag 10 occurs, which may reduce the accuracy of the pressure drop measurement. By providing the reinforcing member 44 that straddles the slit 36, it is possible to suppress the decrease in measurement accuracy caused by the deformation of the retaining plates 31 and 32.

[0071] In the above embodiment, reinforcing members 44 are provided on both the retaining plate 31 and the retaining plate 32. However, if a slit 36 ​​is provided on one of the retaining plates 31 or 32, the reinforcing member 44 may be provided only on the retaining plate having the slit 36.

[0072] Furthermore, from the viewpoint of ensuring rigidity, it is preferable that the reinforcing member 44 be fixed to the retaining plate 31 or retaining plate 32 in a way that prevents it from being detached. However, the reinforcing member 44 may be detachable if the necessary rigidity of the retaining plate 31 or retaining plate 32 is ensured.

[0073] Furthermore, in the above embodiment, the retaining plates 31 and 32 are provided with reinforcing ribs 46 on the surface opposite to the surface in contact with the plastic bag 10, in portions other than the slits 36. This suppresses deformation of the retaining plates 31 and 32 compared to the case where there are no ribs 46. In addition, in the above embodiment, ribs 46 are also provided between the multiple slits 36, so the effect of suppressing deformation is greater compared to the case where there are no ribs 46 between the slits 36. Note that if one of the retaining plates 31 and 32 is provided with slits 36, the ribs 46 may be provided only on the retaining plate having the slits 36, similar to the reinforcing member 44.

[0074] Furthermore, in the above embodiment, the corners 36B that define the slit 36 ​​on the surfaces of the retaining plates 31 and 32 that come into contact with the plastic bag 10 are rounded to a radius of 2 mm or more. This prevents the plastic bag 10 from being scratched by being pressed against the corners 36B.

[0075] Furthermore, in the above embodiment, the distance between the opposing surfaces of the pair of retaining plates 31 and 32 that sandwich the plastic bag 10 is variable, and the adjustable distance range is set from a lower limit of 30 mm or less to an upper limit of 100 mm or more. By making the distance between the retaining plates 31 and 32 adjustable in a range of at least 30 mm to 100 mm, the following advantages are obtained. That is, by setting the lower limit to 30 mm or less, the necessary spacing during inspection can be secured. On the other hand, by setting the upper limit to 100 mm or more, good workability during the installation work of placing the plastic bag 10 between the pair of retaining plates can be ensured to a minimum. More preferably, the lower limit is set to about 2 mm and the upper limit to about 250 mm.

[0076] (Modification) Also, as in the above embodiment, even if there are multiple slits 36 in the retaining plate 31 or retaining plate 32, if there is only one type of plastic bag 10 to be inspected, only one slit 36 ​​is used and the other slits 36 may be unnecessary. In such cases, as shown in Figure 14, the unused slits 36 may be blocked with an embedding member 51. The embedding member 51 has a shape that matches the shape of the slit 36 ​​and has a fitting portion that fits into the slit 36. By providing the embedding member 51 in the unused slits 36, the reduction in rigidity of the retaining plate 31 due to the slits 36 can be suppressed. The embedding member 51 is fixed to the retaining plate 31, for example, with screws.

[0077] The embedding member 51 may be fixed to the holding plate 31 in a way that prevents it from being detached, or it may be fixed in a way that allows it to be detached. For example, if there is only one type of plastic bag 10 to be inspected, it is preferable that the embedding member 51 be fixed in a way that prevents it from being detached. On the other hand, if there are multiple plastic bags 10 to be inspected, the embedding member 51 may be made detachable so that the embedding member 51 can selectively close the unused slits 36 according to the plastic bag 10 to be inspected.

[0078] [Second Embodiment] In the first embodiment, the slit 36 ​​is formed by cutting out a part of the retaining plate 31 or the retaining plate 32, but the slit is not limited to this form. For example, it may be a slit 66 as shown in Figures 15 to 17 of the second embodiment. In the second embodiment, at least one of the pair of retaining plates is made up of divided plates, and the slit is formed by the gap between adjacent divided plates.

[0079] The holding portion 63 of the second embodiment is composed of a pair of holding plates 61 and 62. The holding plate 61 is composed of a plurality of divided plates 61A and 61B. For example, the divided plate 61A is relatively wide, and the divided plate 61B is relatively narrow. There are a plurality of divided plates 61B, each of which is a movable plate that can slide in the width direction (i.e., the X direction) intersecting the longitudinal direction (i.e., the Y direction) of the slit 66. The position of the slit 66 in the X direction can be changed according to the positions of the plurality of divided plates 61B. Here, the longitudinal direction is an example of the "direction in which the slit 66 extends", and the width direction is an example of the "first direction". Preferably, the divided plates 61A and 61B are composed of, for example, lightweight and highly rigid honeycomb plates.

[0080] The sliding of the divided plates 61B is achieved, for example, by a linear guide 71. The linear guide 71 consists of a guide rail 71A extending in the sliding direction (i.e., the X direction) and a carriage 71B that is movable along the guide rail 71A. Each divided plate 61B is fixed to the carriage 71B. As the carriage 71B moves along the guide rail 71A, the divided plates 61B slide in conjunction with the movement of the carriage 71B.

[0081] As shown in Figure 16, the linear guide 71 is fixed to a support member 72 that extends in the X direction. Both ends of the support member 72 are fixed to the columns that make up the frame 34. Similarly, the retaining plate 62 is composed of multiple divided plates 62A and 62B, with the divided plate 62B being the movable plate. The other configurations are the same as those of the retaining plate 61.

[0082] As shown in Figure 17, the position of the slit 66 can be changed according to the type of plastic bag 10 by sliding the dividing plate 61B. Figure 17(A) is an example of holding a relatively large plastic bag 10, and Figure 17(B) is an example of holding a relatively small plastic bag 10. Since the position of the port 12 differs in each plastic bag 10, the position of the slit 66 is changed by sliding the dividing plate 61B.

[0083] In the second embodiment, the retaining plate 61 is composed of three or more divided plates 61A and 61B, and furthermore, at least two of the divided plates 61B are movable plates that can slide in the width direction (an example of a first direction) intersecting the direction in which the slit 66 extends. Furthermore, the position of the slit 66 in the first direction can be changed according to the positions of the two movable plates, which are the divided plates 61B. Therefore, it is possible to change the position of the slit 66 to match plastic bags 10 with different port 12 positions. The same effect as the retaining plate 61 can be obtained with the retaining plate 62.

[0084] Furthermore, although the second embodiment shows an example where the dividing plate 61B is a movable plate, the dividing plate 61B may not be movable and the position of the slit 66 may be fixed. In this case, the position of the slit 66 cannot be changed. However, unlike the slit 36 ​​in the first embodiment, since the slit 66 is formed to both ends in the longitudinal direction of the retaining plate 61, the plastic bag 10 can be installed from either side in the longitudinal direction of the retaining plate 61.

[0085] In the embodiments described above, an inspection tool 30 having one holding portion 33 or holding portion 63 was shown as an example. However, as shown in Figure 18, the inspection tool 30 may have two or more holding portions 33 or holding portions 63. This makes it possible to perform leak inspections of multiple plastic bags 10 in parallel.

[0086] Furthermore, although a plastic bag 10 was described as an example of a bag-shaped container in the above embodiment, the technology of this disclosure is not limited to a plastic bag 10 and can be applied to bag-shaped containers of different shapes or materials. For example, in the above embodiment, a gusseted bag with a gusset (also called a 3D (dimension) bag, etc.) was described as an example of a plastic bag 10, but it can also be applied to bags without a gusset (also called a 2D bag, etc., as opposed to a 3D bag).

[0087] The above embodiments further disclose the following: [Appendix 1] An inspection tool used for leak testing of a bag-shaped container having a port protruding from its surface, comprising a pair of holding plates that clamp and hold the bag-shaped container, wherein at least one of the pair of holding plates has a slit into which the port can enter from the edge of the holding plate. [Appendix 2] The inspection tool according to Appendix 1, wherein the slit is formed by cutting out a part of the holding plate. [Appendix 3] The inspection tool according to Appendix 2, wherein a plurality of slits are formed in the holding plate. [Appendix 4] The inspection tool according to Appendix 2 or Appendix 3, wherein a slit is formed in a part of each of the pair of holding plates, and the pair of holding plates are arranged in such a position that the edges of the holding plates on the edge side of each slit face in the same direction. [Appendix 5] The inspection tool according to any one of Appendix 1 to Appendix 4, wherein a wide portion is provided in a part of the slit that is relatively wider than the other parts. [Addendum 6] An inspection tool according to any one of Addendum 1 to 5, wherein a reinforcing member is provided across the slit in a retaining plate having a slit formed therein. [Addendum 7] An inspection tool according to any one of Addendum 1 to 6, wherein a reinforcing rib is provided on the surface opposite to the surface in contact with the bag-shaped container, in a portion other than the slit in the retaining plate. [Addendum 8] An inspection tool according to any one of Addendum 1 to 7, wherein at least one of a pair of retaining plates is composed of a plurality of divided plates, and the slit is formed by the gap between adjacent divided plates. [Addendum 9] An inspection tool according to Addendum 8, wherein there are three or more divided plates, and at least two of the divided plates are movable plates that can slide in a first direction intersecting the direction in which the slit extends, and the position of the slit in the first direction can be changed according to the position of the two movable plates. [Note 10] The inspection tool described in any one of Notes 1 to 9, wherein the corners defining the slits on the surface of the retaining plate that comes into contact with the bag-shaped container are rounded to a radius of 2 mm or more.[Note 11] An inspection tool according to any one of Note 1 to Note 10, wherein the distance between the opposing surfaces of the pair of holding plates that sandwich the bag-shaped container is variable, and the adjustable distance range is set with a lower limit of 30 mm or less and an upper limit of 100 mm or more. [Note 12] A leak inspection device comprising the inspection tool according to any one of Note 1 to Note 11, a compressed air supply device for supplying gas to the bag-shaped container, and a measuring unit for measuring the pressure drop of the bag-shaped container. [Note 13] A leak inspection method using the inspection tool according to any one of Note 1 to Note 11, comprising: aligning the port of the bag-shaped container with the position of the slit and placing the bag-shaped container between the pair of holding plates; pressurizing the bag-shaped container by supplying gas; pressing the pressurized bag-shaped container with the pair of holding plates; and measuring the pressure drop of the bag-shaped container.

[0088] The descriptions and illustrations presented above are detailed explanations of the technical aspects of this disclosure and are merely examples of the technical aspects. For example, the above descriptions of the structure, function, operation, and effect are examples of the structure, function, operation, and effect of the technical aspects of this disclosure. Therefore, it goes without saying that you may delete unnecessary parts, add new elements, or replace elements in the descriptions and illustrations presented above, as long as you do not deviate from the essence of the technical aspects of this disclosure. Furthermore, in order to avoid confusion and facilitate understanding of the technical aspects of this disclosure, explanations of common technical knowledge and the like that do not require special explanation to enable the implementation of the technical aspects of this disclosure have been omitted from the descriptions and illustrations presented above.

[0089] In this specification, "A and / or B" is synonymous with "at least one of A and B." That is, "A and / or B" means that it may be A alone, or B alone, or a combination of A and B. Furthermore, in this specification, the same concept as "A and / or B" applies when expressing three or more things linked by "and / or."

[0090] The disclosure of Japanese Patent Application No. 2024-192444, filed on 31 October 2024, is incorporated herein by reference in its entirety. Furthermore, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated as being incorporated by reference.

Claims

1. An inspection tool used for leak testing of a bag-shaped container having a port protruding from its surface, comprising a pair of holding plates that clamp and hold the bag-shaped container, wherein at least one of the pair of holding plates has a slit that allows the port to enter from the edge of the holding plate.

2. The inspection tool according to claim 1, wherein the slit is formed by cutting out a part of the retaining plate.

3. The inspection tool according to claim 2, wherein the retaining plate has a plurality of slits formed therein.

4. The inspection tool according to claim 2, wherein the slit is formed in a part of each of the pair of retaining plates, and the pair of retaining plates are arranged in such a position that the edges of the retaining plates on the edge side of each slit face in the same direction.

5. The inspection tool according to claim 1, wherein a part of the slit is provided with a wide portion that is relatively wider than the other parts.

6. The inspection tool according to claim 1, wherein a reinforcing member is provided that straddles the slit in the retaining plate in which the slit is formed.

7. The inspection tool according to claim 1, wherein the retaining plate is provided with reinforcing ribs on the surface opposite to the surface in contact with the bag-shaped container, in a portion other than the slit.

8. The inspection tool according to claim 1, wherein at least one of the pair of holding plates is composed of a plurality of divided plates, and the slit is formed by the gap between adjacent divided plates.

9. The inspection tool according to claim 8, wherein there are three or more of the dividing plates, and at least two of the dividing plates are movable plates that can slide in a first direction intersecting the direction in which the slit extends, and the position of the slit in the first direction can be changed according to the positions of the two movable plates.

10. The inspection tool according to claim 1, wherein the corners defining the slit on the surface of the retaining plate that contacts the bag-shaped container are rounded with a radius of 2 mm or more.

11. The inspection tool according to claim 1, wherein the pair of holding plates have a variable distance between their opposing surfaces that sandwich the bag-shaped container, and the adjustable distance range is set to a lower limit of 30 mm or less and an upper limit of 100 mm or more.

12. A leak inspection device comprising: an inspection tool according to claim 1; a compressed air supply device for supplying gas to the bag-shaped container; and a measuring unit for measuring the pressure drop of the bag-shaped container.

13. A leak inspection method using the inspection tool described in claim 1, comprising: aligning the port of the bag-shaped container with the position of the slit and placing the bag-shaped container between the pair of retaining plates; pressurizing the bag-shaped container by supplying gas; pressing the pressurized bag-shaped container with the pair of retaining plates; and measuring the pressure drop of the bag-shaped container.

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