Method for manufacturing sterile bags

Abstract

To provide a sterilization bag production method capable of producing, a sterilization bag which has great tearing opening property, and can maintain seal ability of its internal part.SOLUTION: A sterilization bag production method of the invention comprise: a slit formation step for, forming a plurality of slits in which, a lamination film is communicated with at least one lamination film, along a transport direction of a lamination film, out of two lamination films in which, a seal layer including at least one of low density polyethylene and linear low density polyethylene, and a substrate layer including high density polyethylene; a coating step for providing, a ventilation substrate on the surface on the seal layer side of the lamination film on which the slits are provided, so as to coat the slits; and a depositing step for, along the transport direction of the lamination film, overlapping the two lamination films so that the seal layer sides face each other, then depositing outer peripheral edge parts of the two lamination films while leaving an opening part where deposition is not performed, for forming a seal part.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing a sterile bag. [Background technology]

[0002] Sterilization bags are used as packaging for storing contents such as pharmaceuticals, medical supplies, various cosmetics, and food products. A sterilization bag is a bag-like body formed by layering laminates of multiple types of resin films and joining the outer edges by heat sealing or other methods. After the contents to be sterilized are placed inside the sterilization bag and sealed, the bag is sterilized using ethylene oxide (EO) gas or gamma ray sterilization before use.

[0003] As such a sterilization bag, for example, a sterilization packaging bag has been disclosed in which the packaging bag body is made of two types of heat-resistant synthetic resin films, and gaps or perforations are formed to connect the inside and outside of the packaging bag body, and these gaps or perforations are covered with a filter material which is made of a nonwoven fabric and a heat-resistant plastic film with many small holes protruding from it. (See, for example, Patent Document 1.) [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Utility Model Publication No. 4-21481 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] However, Patent Document 1 did not examine the tear-openability of sterilization packaging bags, and the sterilization packaging bags described in Patent Document 1 had the problem of being difficult to tear during use. Furthermore, it is important for sterilization packaging bags to be easy to tear during use while maintaining sealing properties so that the sterilized items remain in a sterilized state until use.

[0006] One aspect of the present invention aims to provide a method for manufacturing a sterile bag that can produce a sterile bag with high tear-openability and maintained internal sealability. [Means for solving the problem]

[0007] One embodiment of the method for manufacturing a sterile bag according to the present invention is: A slit forming step is performed in which a plurality of slits connecting the laminated films are formed in at least one of two laminated films, one of which is made by laminating a sealing layer containing at least one of low-density polyethylene and linear low-density polyethylene and a base layer containing high-density polyethylene, along the transport direction of the laminated film. A step of covering a breathable substrate, in which a breathable substrate is provided so as to cover the slit on the sealing layer side of the laminated film in which the slit is formed, A welding step is performed to overlap two of the laminated films so that their sealing layer sides face each other along the transport direction of the laminated film, and to weld the outer edges of the two laminated films together while leaving an unwelded opening to form a sealing portion. Includes. [Effects of the Invention]

[0008] One embodiment of the method for manufacturing a sterilization bag according to the present invention can produce a sterilization bag that is highly tear-openable and maintains internal sealing properties. [Brief explanation of the drawing]

[0009] [Figure 1] This is a plan view of a sterilization bag. [Figure 2] This is a view of the AA direction in Figure 1. [Figure 3] This is a schematic cross-sectional view showing an example of the structure of a laminated film. [Figure 4] This is a perspective view showing an example of a film extrusion molding apparatus for manufacturing each layer of a laminated film. [Figure 5] This is a plan view showing a breathable substrate. [Figure 6]It is a flowchart showing a method for manufacturing a sterilization bag according to an embodiment of the present invention. [Figure 7] It is a perspective view of a bag-making device for manufacturing a sterilization bag. [Figure 8] It is a plan view showing an example of a sterilization bag. [Figure 9] It is a cross-sectional view taken along the line B - B of FIG. 8. [Figure 10] It is a diagram showing the test results of the time and the amount of EO gas in Example 1 and Comparative Example 1.

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail. For ease of understanding of the description, the same reference numerals are given to the same components in each drawing, and duplicate descriptions are omitted. Also, the scales of the respective members in the drawings may be different from the actual ones. In this specification, "~" indicating a numerical range means including the numerical values described before and after it as the lower limit value and the upper limit value, unless otherwise specified.

[0011] In describing the method for manufacturing a sterilization bag according to an embodiment of the present invention, the configuration of the sterilization bag manufactured using the method for manufacturing a sterilization bag according to this embodiment will be described.

[0012] <Sterilization Bag> The sterilization bag will be described. FIG. 1 is a plan view of the sterilization bag, and FIG. 2 is a view taken along the line A - A of FIG. 1. As shown in FIGS. 1 and 2, the sterilization bag 1 includes a bag body 10 filled with a sterilization target and a breathable base material 20. In the sterilization bag 1, a sterilizing agent is supplied into the bag body 10, and the sterilization treatment of the sterilization target filled in the bag body 10 is performed.

[0013] In this embodiment, the objects to be sterilized include medical containers, medical devices, medical supplies, pharmaceuticals (medicines), nutritional agents, foods and drinks, cosmetics, and the like. Examples of medical containers include containers into which pharmaceuticals, cells, tissues, and cultures of animals and plants are introduced, and specific examples include ampoules, vials, syringes, and bags. Examples of medical devices and medical supplies include small medical instruments that can be distributed in a sterilization bag. Examples of small medical instruments include scalpels, knives, scissors, spoons, spatulas, forceps, catheters, syringes, injection needles, forceps, sutures, suture needles, bandages, gauze, lenses, gloves, and finger cots. Pharmaceuticals may be substances with high adsorption or permeability to general resins, such as nitroglycerin, albumin, vitamins, trace elements, radical scavengers, etc., or may be an aqueous solution containing edaravone, which is a pyrazolone derivative, or a pharmaceutically acceptable salt thereof. The pyrazolone derivative may have one or more substituents such as an alkyl group, an aromatic group, or a halogen atom on the carbon atom or nitrogen atom of pyrazolone. The pyrazolone derivative may form salts with organic acids, inorganic acids, etc. A plurality of objects to be sterilized of the same or different types may be simultaneously accommodated in the accommodation space.

[0014] The sterilizing agent is not particularly limited as long as it is a drug that can be used for sterilizing the object to be sterilized, such as a bactericide or a disinfectant, and those that can be filled into the accommodation space as a gas or vapor are preferred. The sterilizing agent preferably has appropriate permeability to the bag body 10 and preferably can diffuse to the outside through the bag body 10. Further, the sterilizing agent may be decomposed within the bag body 10. Examples of the sterilizing agent include hydrogen peroxide (H2O2), ethylene oxide (EO), ozone, and organic peroxides. Examples of the organic peroxide include organic peracids such as performic acid and peracetic acid. Other sterilizing agents include aldehyde-based sterilizing agents such as formaldehyde and chlorine-based sterilizing agents such as chlorine dioxide. Two or more of these sterilizing agents may be used in combination.

[0015] [Bag body] The bag body 10 is a packaging bag (pouch) formed from a pair of overlapping laminated films 100A and 100B. The bag body 10 has a seal portion 11 formed by overlapping the pair of laminated films 100A and 100B facing each other and welding their outer edges together, a storage chamber 12 defined by the pair of laminated films 100 and the seal portion 11, and an opening 13 where the outer edges of the pair of laminated films 100 are not welded together. The storage chamber 12 is a space for storing the object to be sterilized. The opening 13 is an unwelded gap between the opposing laminated films 100, and may be welded or otherwise sealed after the storage chamber 12 is filled with the object to be sterilized.

[0016] The bag body 10 is a three-sided bag, but the form of the bag body 10 is not particularly limited and can be applied to small bags such as four-sided bags, gusseted bags, self-standing bags, as well as large bags such as inner bags for bag-in-boxes and inner bags for drums.

[0017] The laminated film 100A has a plurality of slits (cuts) 101 that connect the laminated film 100A to its main surface. The slits 101 may be formed in the laminated film 100B, or in both the laminated film 100A and the laminated film 100B.

[0018] Multiple slits 101 may be formed in a single row on the main surface of the laminated film 100A to form a straight perforation, or multiple slits may be formed so that straight perforations are arranged in parallel. In Figure 1, multiple slits 101 are formed from one long side of the laminated film 100A to the other long side, but they may also be formed only in a part between the long sides of the laminated film 100A.

[0019] The length of the slit 101 and the spacing between adjacent slits 101 in the lengthwise or widthwise direction of the slit 101 may be set to any distance as appropriate, depending on the size or shape of the laminated film 100A or the slit 101, and the area in which the slit 101 is formed. For example, if the length of the slit 101 is approximately 1 mm, the spacing between slits 101 in the lengthwise direction may be approximately 2 mm, and the spacing between slits 101 in the widthwise direction may be approximately 5 mm.

[0020] (Laminated film) The laminated film 100 can be formed by overlapping and welding the seal layers of a laminated film, which has a seal layer mainly composed of at least one of low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE), and a base layer laminated to the seal layer and mainly composed of high-density polyethylene (HDPE), so that the seal layers face each other. The laminated film 100 may also have other layers besides the seal layer and the base layer. For example, it may include an intermediate layer between the seal layer and the base layer mainly composed of high-density polyethylene and low-density polyethylene. The laminated film 100 may have two or more of each of the seal layer, base layer, and intermediate layer.

[0021] The main component refers to a component whose content is 50 wt% or more, preferably 90 wt% or more, and more preferably 99 wt% or more.

[0022] Low-density polyethylene and linear low-density polyethylene have a density of 0.911 g / m³. 3 ~0.940g / m 3 This refers to polyethylene of a certain degree. High-density polyethylene has a density of 0.941 g / m³. 3 ~0.970g / m 3 It refers to polyethylene of a certain degree.

[0023] -Layer structure of laminated film- The layer structure of the laminated film 100 will now be described. Figure 3 is a schematic cross-sectional view showing an example of the structure of the laminated film 100. As shown in Figure 3, the laminated film 100A may be provided with a seal layer 110, an intermediate layer 120, and a base layer 130, laminated in this order from the seal layer 110 side.

[0024] (Seal layer) The sealing layer 110 preferably contains at least one of low-density polyethylene and linear low-density polyethylene as its main component, is substantially composed of at least one of low-density polyethylene and linear low-density polyethylene, and is preferably composed of at least one of low-density polyethylene and linear low-density polyethylene. The sealing layer 110 preferably contains low-density polyethylene in order to enable the bag body 10 to exhibit sealing properties.

[0025] The low-density polyethylene included in the seal layer 110 has a density of 0.911 g / m³. 3 ~0.925g / m 3 There are no particular limitations on the type of polyethylene; general low-density polyethylene can be used.

[0026] The linear low-density polyethylene contained in the seal layer 110 is typically copolymerized with α-olefins having 4 or more carbon atoms, and short-chain branching is introduced to create a linear molecular structure with fewer long-chain branches. Examples of α-olefins copolymerized with linear low-density polyethylene include 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene.

[0027] Examples of linear low-density polyethylene included in the seal layer 110 include resins polymerized using a Ziegler-Natta catalyst and resins polymerized using a single-site catalyst. Linear low-density polyethylene polymerized using a single-site catalyst is preferred because it has a narrow molecular weight distribution and excellent mechanical properties. Examples of single-site catalysts include metallocene catalysts. Examples of metallocene catalysts include catalysts containing a metallocene compound that includes a ligand having a cyclopentadienyl skeleton and in which the metal is zirconium, hafnium, etc.

[0028] Specific examples of linear low-density polyethylene included in the sealing layer 110 include the Harmolex® series manufactured by Nippon Polyethylene Co., Ltd. and the Nipolon® series manufactured by Tosoh Corporation.

[0029] The linear low-density polyethylene contained in the sealing layer 110 may be of one type or two or more types.

[0030] The flexural modulus of the linear low-density polyethylene contained in the seal layer 110 is preferably 200 MPa to 500 MPa, more preferably 300 MPa to 450 MPa, and even more preferably 360 MPa to 400 MPa. If the flexural modulus of the linear low-density polyethylene contained in the seal layer 110 is within the above preferred range, the seal layer 110 will have appropriate flexibility and will exhibit adhesion to the intermediate layer 120.

[0031] The flexural modulus can be measured using a method compliant with JIS K7171:2016 (ISO 178:2010).

[0032] The melt flow rate (MFR) of linear low-density polyethylene is preferably 0.1 g / 10 min to 10 g / 10 min, more preferably 0.5 g / 10 min to 5 g / 10 min, in the measurement (at 230 °C, 21 N load) based on JIS K 7210-1:2014 (ISO 1133-1:2011). If the MFR of linear low-density polyethylene is within the above preferred range, when forming the seal layer 110 by extrusion molding or the like, the extrudability is relatively stable and molding defects can be suppressed, so it becomes easier to stably form into a film shape, and the occurrence of molding defects such as burrs in the seal layer 110 during molding can be suppressed.

[0033] The melting point of linear low-density polyethylene is preferably 120 °C to 135 °C, more preferably 122 °C to 128 °C.

[0034] The density of linear low-density polyethylene is 3 ~0.940 g / cm 3 is preferable, and 3 ~0.930 g / cm 3 is more preferable.

[0035] The content of linear low-density polyethylene is preferably 80% by mass to 100% by mass, more preferably 85% by mass to 95% by mass. If the content of linear low-density polyethylene is within the above preferred range, the seal layer 110 has sufficient flexibility and can exhibit adhesiveness to the intermediate layer 120.

[0036] At least a part of the low-density polyethylene and linear low-density polyethylene contained in the seal layer 110 may be plant-derived polyethylene obtained by polymerizing ethylene produced from plants.

[0037] Also, at least a part of the low-density polyethylene and linear low-density polyethylene contained in the seal layer 110 may be recycled polyethylene obtained by recycling polyethylene products. The recycled polyethylene may be mechanically recycled polyethylene or chemically recycled polyethylene.

[0038] The thickness of the seal layer 110 is preferably 5 μm to 50 μm, more preferably 10 μm to 30 μm, and even more preferably 8 μm to 20 μm.

[0039] (Middle class) The intermediate layer 120 is provided between the seal layer 110 and the base layer 130, and mainly contains at least one of high-density polyethylene and low-density polyethylene, and may be substantially composed of at least one of high-density polyethylene and low-density polyethylene. The intermediate layer 120 preferably contains high-density polyethylene in order to exhibit tear-openability of the laminated negative film.

[0040] As the high-density polyethylene included in the intermediate layer 120, general high-density polyethylene can be used.

[0041] The low-density polyethylene used in the intermediate layer 120 is the same as that used in the sealing layer 110, so details are omitted.

[0042] At least a portion of the high-density polyethylene and low-density polyethylene contained in the intermediate layer 120 may be plant-derived polyethylene obtained by polymerizing ethylene produced from plants.

[0043] At least a portion of the high-density polyethylene and low-density polyethylene contained in the intermediate layer 120 may be recycled polyethylene obtained by recycling polyethylene products. The recycled polyethylene may be mechanically recycled polyethylene or chemically recycled polyethylene.

[0044] The thickness of the intermediate layer 120 is preferably 3 μm to 75 μm, more preferably 5 μm to 60 μm, and even more preferably 15 μm to 45 μm.

[0045] (base material layer) The base layer 130 is provided on the main surface of the base layer 130 and contains high-density polyethylene as its main component, and is substantially composed of high-density polyethylene, preferably composed of high-density polyethylene. The intermediate layer 120 is preferably made of high-density polyethylene in order to allow the bag body 10 to be opened by tearing. The high-density polyethylene used in the base layer 130 is the same as that used in the intermediate layer 120, so details are omitted.

[0046] The thickness of the base layer 130 is preferably 3 μm to 50 μm, more preferably 5 μm to 30 μm, and even more preferably 8 μm to 20 μm.

[0047] The laminated film 100A may have two or more layers of any of the sealing layer 110, the intermediate layer 120, and the base layer 130, or it may have other layers.

[0048] Laminated films 100A and 100B have three layers: a sealing layer 110, an intermediate layer 120, and a base layer 130. However, as described above, they may have multiple of any of these layers. For example, laminated film 100A may include five layers, with the sealing layer 110, intermediate layer 120, base layer 130, intermediate layer 120, and base layer 130 laminated in that order, or it may include seven layers, with the sealing layer 110, intermediate layer 120, base layer 130, intermediate layer 120, and base layer 130 laminated in that order.

[0049] Each layer constituting the laminated film 100, i.e., the sealing layer 110, the intermediate layer 120, and the base layer 130, etc., may contain various additives such as antioxidants, ultraviolet absorbers, antistatic agents, lubricants, and antiblocking agents, to the extent that safety and hygiene are not compromised, in order to improve the appearance of the container, stabilize its quality, and provide other necessary performance.

[0050] The method for forming each layer of the laminated film 100 is not particularly limited, but methods such as T-die molding and inflation molding can be used. When using the T-die molding method, after T-die molding, each layer of the laminated film 100 may be made into a film (sheet) and then rapidly cooled with a cooling roll. When continuously forming the films of each layer of the laminated film 100, it is preferable to wind up a long molded body of the films of each layer of the laminated film 100 after molding, as this improves productivity.

[0051] The laminated film 100 may have other layers laminated to it as needed, such as a heat seal layer and a substrate. That is, there may be an adhesive layer or an anchoring agent layer between each layer, or the layers may be laminated so that they are in direct contact with each other. Other layers may include a reinforcing layer, a gas barrier layer, a light shielding layer, a printing layer, etc., and one or more layers can be selected as appropriate. The heat seal layer is a layer used for heat sealing and is placed as the innermost layer in contact with the contents in the packaging material. Heat sealing is a method of bonding by melting the heat seal layer, but the sealing method is not particularly limited and examples include hot plate sealing, ultrasonic sealing, high-frequency sealing, and impulse sealing. The substrate may be the outermost surface of the laminate that is opposite to the heat seal layer, or it may be laminated inside the outermost surface of the other.

[0052] The total thickness of the laminated film 100 can be designed as appropriate, and from the viewpoint of balancing the required performance (e.g., transparency, flexibility, etc.) and cost (e.g., productivity, material costs, etc.), for example, 20 μm to 150 μm is preferred, 30 μm to 120 μm is more preferred, and 40 μm to 90 μm is even more preferred.

[0053] The ratio of the thicknesses of each layer, the sealing layer 110, the intermediate layer 120, and the base layer 130, is appropriately designed for the application of the container formed using the laminated film 100, for example, 1:1:1 to 1:5:1 is preferred, and 1:2:1 to 1:3:1 is more preferred.

[0054] The thicknesses of the sealing layer 110, the intermediate layer 120, and the substrate layer 130 may be, for example, 15 μm, 30 μm, and 15 μm, respectively.

[0055] The method for manufacturing the laminated film 100 is not particularly limited, and each layer constituting the laminated film 100 may be appropriately laminated by co-extrusion, extrusion lamination, dry lamination, or a combination of two or more of these methods.

[0056] When manufacturing the laminated film 100, if the laminated film 100 is laminated using a co-extrusion method, consisting of a seal layer 110, a base layer 130, and an intermediate layer 120, as shown in Figure 3, then these three layers can be laminated without an adhesive layer or anchoring agent layer in between.

[0057] Each of the layers, the seal layer 110, the intermediate layer 120, and the base layer 130, can be formed, for example, as shown in Figure 4, by extruding and uniaxially stretching the resin film 31 constituting each of the seal layer 110, the intermediate layer 120, or the base layer 130 using a film extrusion molding machine 30. The resin film 31 forming each of the seal layer 110, the intermediate layer 120, and the base layer 130 is then set into a laminating device (not shown) and fed out, and the seal layer 110, the intermediate layer 120, and the base layer 130 are bonded together. This forms a raw material roll of a long, continuous sheet of laminated film 100.

[0058] Furthermore, polyethylene, which serves as an interlayer adhesive layer, is extruded in a molten state and sandwiched between the resin films 31 that make up each layer of the sealing layer 110, the intermediate layer 120, or the base layer 130. As a result, the sealing layer 110, the intermediate layer 120, or the base layer 130 are bonded together via the adhesive layer, and a roll of laminated film 100 in the form of a long continuous sheet is laminated.

[0059] The laminated film 100 preferably has a tear strength of 26N or less in the transport direction (MD) during its formation, more preferably 20N or less, and even more preferably 16N or less. If the tear strength is 23N or less, the tear-openability of the bag body 10 can be improved.

[0060] When the laminated film 100 has a thickness of 15 mm, it is preferable that the tensile strength of the laminated film 100 in the transport direction (MD) during its formation is 21 N / 15 mm or more. Furthermore, it is preferable that the tensile strength of the laminated film 100 in the direction perpendicular to the transport direction (TD direction) during its formation is 15 N / 15 mm or more. The tensile strength is calculated using a laminated film with a width of 15 mm on each side, in accordance with JIS Z 0238.

[0061] Even when the laminated film 100 has a thickness of 5 mm, it is preferable that the tensile strength of the laminated film 100 in the MD direction at the time of formation of the laminated film 100 is 21 N / 15 mm or more, and the tensile strength of the laminated film 100 in the TD direction is 15 N / 15 mm or more.

[0062] When the laminated film 100 has a thickness of 15 mm, it is preferable that the tensile elongation of the laminated film 100 in the transport direction (MD) during its formation is 400% or more. Furthermore, it is preferable that the tensile elongation of the laminated film 100 in the direction perpendicular to the transport direction (TD direction) during its formation is 600% or more.

[0063] Even when the thickness of the laminated film 100 is 5 mm, it is preferable that the tensile elongation of the laminated film 100 in the transport direction during its formation is 400% or more, and the tensile elongation of the laminated film 100 in the TD direction is 600% or more.

[0064] [Breathable base material] As shown in Figures 1 and 2, the breathable substrate 20 is provided on the sealing layer side of the laminated film 100A so as to cover the slit 101 of the laminated film 100A with respect to one of the laminated films 100A.

[0065] As shown in Figure 5, the breathable substrate 20 has a plurality of cuts 21 on a side different from the sealing layer side of the laminated film 100A.

[0066] Preferably, the notch 21 is formed to correspond to the longitudinal direction of the breathable substrate 20.

[0067] The cut 21 may penetrate the breathable substrate 20, or it may only go partway through the breathable substrate 20.

[0068] Preferably, the cut 21 is formed with its longitudinal direction aligned with the transport direction of the laminated film 100.

[0069] The breathable substrate 20 can be any material that has multiple notches formed on its surface, for example, sterile paper can be used. Examples of sterile paper include kraft paper and glassine paper that allow water vapor and ethylene oxide to pass through but not bacteria, and specifically, sterile paper manufactured by Tokushu Paper Co., Ltd. and Tomoegawa Paper Co., Ltd.

[0070] It is preferable that the notch 21 is formed in the same orientation as the slit 101 of the laminated film 100.

[0071] The sterilization bag 1 may be equipped with an indicator in a portion of the interlayers of the laminated film 100 that constitutes the inside of the bag body 10. A commonly used indicator can be used as the indicator. When the object to be sterilized filled inside the bag body 10 is sterilized, the sterilizing agent supplied into the bag body 10 sterilizes the object filled inside the bag body 10, and then passes through the bag body 10, causing the indicator to change color, so that the sterilization status, such as whether sterilization is complete, can be confirmed from the outside.

[0072] When sterilization is performed, the sterilization bag 1 is placed in the sterilization chamber of the sterilization device, and the sterilizing agent present in the sterilization chamber enters the bag body 10 through the breathable substrate 20, sterilizing the items to be sterilized inside the bag body 10.

[0073] The sterilizing agent that passes through the breathable substrate 20 and enters the bag body 10 sterilizes the object to be sterilized, and then is released to the outside by permeating the laminated film 100 that makes up the bag body 10. If an indicator is provided in part of the interlayers of the laminated film 100 that makes up the bag body 10, the sterilizing agent that enters the bag body 10 will cause the indicator ink to change color and be released to the outside. Furthermore, since the laminated film 100 that makes up the bag body 10 is transparent, the color change of the indicator ink can be confirmed from the outside of the sterilization bag 1.

[0074] Thus, the sterilization bag 1 comprises a bag body 10 and a breathable base material 20. The bag body 10 is made of a laminated film in which a sealing layer containing at least one of low-density polyethylene and linear low-density polyethylene and a base material layer containing high-density polyethylene are laminated together. The bag body 10 can be made easy to tear by providing a base material layer containing high-density polyethylene on the surface (outside) and the airtightness of the containment chamber 12 can be maintained by providing a sealing layer containing low-density polyethylene on the back (outside). Therefore, by providing the bag body 10, the sterilization bag 1 can improve tearability and openability while maintaining the sealability of the containment chamber 12.

[0075] In other words, as described above, the sterilization bag 1 consists of a bag body 10 formed from a laminated film 100 and a breathable base material 20 that provides breathability. Regarding the composition of the laminated film 100, conventional sterilization bags generally consist of a laminated film in which the bag body has a heat-resistant material such as polyethylene tereoflate (PET) or nylon (Ny) on the surface layer and a sealant film such as L-LDPE, LDPE, or PP that provides sealing properties, from the viewpoint of sealability during bag making.

[0076] The inventors of the present invention, in developing a sterilization bag consisting of a bag body made of laminated film and a breathable base material made of paper and nonwoven fabric, focused on rationalizing the manufacturing process of the sterilization bag, reducing costs, and considering environmental considerations, by aiming to commercialize the product using a single material. The inventors of the present invention then discovered that in the manufacture of the sterilization bag 1, the laminated film 100 constituting the bag body 10 is made of polyethylene, and the breathable base material 20, which forms the breathable portion of the sterilization bag 1, is made of HDPE, thereby enabling the sterilization bag 1 to be made of a single material, polyethylene.

[0077] Furthermore, the inventors of the present invention have found that in the manufacture of the sterilization bag 1, the bag body 10 exhibits sealing properties, and that the laminated film 100 can be made easier to seal by forming the surface base layer with HDPE, the intermediate layer with HDPE or LDPE, and the sealing layer with LDPE or L-LDPE, thereby creating a temperature difference between the melting points of the base layer and the sealing layer.

[0078] Furthermore, while L-LDPE has high sealing strength, it has the property of being difficult to tear by hand. The inventors of this application focused on the fact that using LDPE for the sealing layer is advantageous when taking tearability into consideration, and found that if LDPE is used as the sealing layer for the laminated film 100, the bag body 10 can have sufficient sealing strength.

[0079] The sterilization bag 1 may include an intermediate layer 120 between the sealing layer 110 and the base material layer 130 of the laminated film 100. By including high-density polyethylene or low-density polyethylene in the intermediate layer 120, the bag body 10 can be made more torn or the airtightness of the containment chamber 12 can be improved. Thus, the sterilization bag 1 can be made more torn open and the sealing performance of the containment chamber 12 can be improved.

[0080] The sterilization bag 1 can contain high-density polyethylene in its intermediate layer 120. This allows the bag body 10 to be more reliably opened by tearing. Therefore, the sterilization bag 1 can be more reliably opened by tearing.

[0081] The sterilization bag 1 can include low-density polyethylene in its sealing layer 110. This allows the bag body 10 to further enhance the airtightness of the containment chamber 12. Therefore, the sterilization bag 1 can more reliably improve the sealing performance of the containment chamber 12.

[0082] The sterilization bag 1 allows the thickness of the laminated film 100 to be between 30 μm and 120 μm. This makes it possible to achieve both ease of tearing and sealing of the storage compartment 12 in the bag body 10, even when the laminated film 100 is thin. Thus, the sterilization bag 1 can maintain a balance between improved tearability and the maintenance of sealing of the storage compartment 12.

[0083] The sterilization bag 1 can have the longitudinal direction of the slit 101 formed in one of the laminated films 100A aligned with the transport direction of the laminated film 100A. By aligning the longitudinal direction of the slit 101 with the transport direction of the laminated film 100, it can be easily formed in the laminated film 100A when forming the bag body 10, thereby reducing deformation of the slit 101. Therefore, the sterilization bag 1 can maintain the sealing performance of the containment chamber 12 with greater precision.

[0084] The sterilization bag 1 may have a number of notches 21 formed in the breathable base material 20 on a side different from the sealing layer side of the laminated film 100, corresponding to the longitudinal direction of the slit 101. This allows the breathable base material 20 to have substantially uniform breathability across its entire surface. Therefore, the sterilization bag 1 can maintain the sealing performance of the containment chamber 12 with greater precision.

[0085] The sterilization bag 1 can use a strip of breathable sterile paper on a breathable base material 20. This allows the sterilization bag 1 to sterilize the air entering the containment chamber 12, thereby more reliably maintaining the sterile state of the objects to be sterilized contained in the containment chamber 12.

[0086] The sterilization bag 1 can be formed from a polyethylene resin breathable base material. As a result, the bag body 10 and the breathable base material 20 that make up the sterilization bag 1 can all be made from the same polyethylene material, thereby improving tear-openability, maintaining the sealing performance of the containment chamber 12, and providing excellent recyclability.

[0087] <Method for manufacturing sterilization bags> A method for manufacturing a sterilization bag according to an embodiment of the present invention will now be described. Figure 6 is a flowchart of the method for manufacturing a sterilization bag according to this embodiment. As shown in Figure 6, in the sterilization bag according to this embodiment, a slit 101 that connects the inside and outside is formed in one of two laminated films 100A, which consists of a seal layer 110, an intermediate layer 120, and a base layer 130, along the transport direction of the laminated film 100A (slit formation step: step S11).

[0088] Next, a breathable substrate 20 is provided on the side of the laminated film 100A facing the seal layer 110 so as to cover the slit 101 (breathable substrate coating step: step S12).

[0089] The breathable substrate 20 is joined to the seal layer 110 side of the laminated film 100A by a common joining method such as welding (heat sealing) so as to cover the slit 101.

[0090] Next, the two laminated films 100A and 100B are overlapped along the transport direction of the two laminated films 100A and 100B so that their sealing layer sides face each other, and the outer edges of the two laminated films 100A and 100B are welded together, leaving an unwelded opening, to form a sealed portion (welding process: step S13).

[0091] For example, as shown in Figure 7, two long, continuous sheets of laminated film raw material 41 are set in a roll state in the bag-making apparatus 40 and are fed along the flow direction by the feeding mechanism 42. The transport direction (MD direction) a1 of each laminated film 100 is the flow direction of the laminated film raw material 41.

[0092] At this time, the lower laminated film roll 41 may be transported in a folded state on one side in the width direction between the two laminated film rolls 41.

[0093] Next, in the heat-seal section 43, predetermined locations of the laminated film roll 41 are fused (heat-sealed) together, sealing three sides, and a sterilization bag 1 is formed in which a breathable base material 20 is provided on the sealing layer of one of the laminated films 100A. The lateral direction of the sterilization bag 1 is the direction of movement in the bag-making device 40.

[0094] The cutting section 44 cuts the sterilization bag 1 into individual pieces.

[0095] Subsequently, the sterilization bag 1 is placed into the containment chamber 12 through the opening 13 of the bag body 10, the opening 13 is heat-sealed, and then the sterilization bag 1 is placed in the sterilization chamber of the sterilization device. The sterilizing agent supplied into the sterilization chamber enters the bag body 10 through the breathable substrate 20 and sterilizes the items to be sterilized inside the bag body 10.

[0096] According to the method for manufacturing a sterilization bag of this embodiment, it is possible to manufacture a sterilization bag 1 that has high tearability and maintains internal sealing properties, as described above.

[0097] The method for manufacturing a sterilization bag according to this embodiment includes a slit formation step (step S11), so that a slit 101 can be formed in the laminated film 100A along the transport direction of the laminated film 100A. In the method for manufacturing a sterilization bag according to this embodiment, the slit 101 can be formed in advance on a flat area of ​​the bag body 10 without any steps, such as the surface of the laminated film 100A or laminated film 100B. Therefore, the sterilization bag can be manufactured productively without impairing its functionality as a sterilization bag 1, even without sealing and fusing the breathable base material 20 at the edge of the laminated film 100A or laminated film 100B.

[0098] For example, when manufacturing a sterilization bag by sealing a laminated film consisting of a three-layer structure of a sealing layer, an intermediate layer, and a base layer with a gas-permeable film such as sterilization paper, as shown in Figures 8 and 9, the sterilization bag 200 is manufactured by sealing the end 211A of one of the pair of laminated films 210A and the end 211B of the other laminated film 210B to the gas-permeable film 220. In such a sterilization bag 200, a step is created in the sealing portion between the laminated film 210A and the laminated film 210B due to the thickness of the gas-permeable film 220, making heat sealing difficult and resulting in poor production efficiency. Furthermore, if heat sealing is not performed sufficiently, the sterilization bag 200 may not be able to obtain sufficient sealing performance and strength.

[0099] Furthermore, when the laminated film 210 consists of a three-layer structure of a sealing layer, an intermediate layer, and a base layer, generally, low-density polyethylene or linear low-density polyethylene is used for the sealing layer, and high-density polyethylene is used for the intermediate layer and the base layer. When the laminated film 210 has such a layer structure, the difference in melting temperature between the high-density polyethylene constituting the base layer of the laminated film 210 and the low-density polyethylene or linear low-density polyethylene constituting the sealing layer is low, making it difficult to select optimal conditions for heat sealing, thus reducing the production efficiency of the sterilization bags 200.

[0100] The method for manufacturing a sterilization bag according to this embodiment includes a step of covering with a breathable substrate (step S12) and a welding step (step S13). Therefore, a breathable substrate 20 is provided on the side of the seal layer 110 of the laminated film 100A, which has a slit formed in it beforehand, so as to cover the slit 101, and the outer edges of the two laminated films 100A and 100B are welded together to form a bag. As a result, according to the method for manufacturing a sterilization bag according to this embodiment, welding can be performed on the seal portion 11 of the laminated film 100A and the laminated film 100B without creating a step, so that the function of the sterilization bag 1 is not impaired and the sterilization bag 1 can be manufactured with high productivity. Furthermore, according to the method for manufacturing a sterilization bag according to this embodiment, it is less likely that there will be areas in the seal portion 11 where the heat seal is insufficient, so the sterilization bag 1 has sufficient sealing ability and strength, and a highly reliable sterilization bag can be provided.

[0101] As described above, the sterilization bag 1 obtained by the method for manufacturing a sterilization bag according to the embodiment of the present invention has the above-mentioned characteristics and can therefore be suitably used as a bag for containing medical containers, medical devices, medical supplies, pharmaceuticals (drugs), nutritional supplements, food and beverages, cosmetics, etc., and for sterilization treatment.

[0102] As described above, embodiments have been explained, but these embodiments are presented as examples only, and the present invention is not limited by these embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, and modifications are possible without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Examples]

[0103] The embodiments will be described in more detail below with examples, but the embodiments are not limited to these examples.

[0104] <Example 1> [Preparation of sterilization bags] (Fabrication of laminated films) Low-density polyethylene (InnoPlus LD2426H, manufactured by PTT Global Chemical Public Company Limited) was used to form the sealing layer constituting the laminated film, and high-density polyethylene (InnoPlus HD3355F, manufactured by PTT Global Chemical Public Company Limited) was used to form the intermediate layer and the base layer. Using a T-die multilayer film manufacturing machine, the low-density polyethylene, high-density polyethylene, and high-density polyethylene were extruded by co-extrusion to produce a laminated film in which the sealing layer, intermediate layer, and base layer were laminated in this order. The thicknesses of the sealing layer, intermediate layer, and base layer were 15 μm, 30 μm, and 15 μm, respectively, to produce a laminated film with a thickness of 60 μm.

[0105] (Evaluation of laminated films) The prepared laminated film was cut to a predetermined size (15 mm wide x 100 mm long) to create rectangular test pieces 1. The laminated film was cut such that the shorter side of the test piece corresponded to the transport direction of the laminated film (MD direction), and the longer side of the test piece corresponded to the direction perpendicular to the transport direction of the laminated film (TD direction). In accordance with JIS K 7127, the tensile strength and tensile elongation of the prepared laminated film were measured to evaluate its tensile properties, and the tear strength was measured to evaluate its tearability.

[0106] -Measurement of tensile strength of laminated film- In accordance with JIS Z 0238, the tensile strength (unit: N / 15mm) of a 15mm wide laminated film in the short direction, i.e., the transport direction of the laminated film, was calculated to evaluate the tensile properties of the laminated film. Three test specimens were prepared for each thickness, and the average of the measured values ​​of the three specimens was used as the tensile strength of the specimen. A tensile strength of 21 N / 15mm or higher was evaluated as good tensile elongation. The measurement results of the tensile strength of the laminated film are shown in Table 1.

[0107] -Measurement of tensile elongation of laminated film- The tensile strength of the laminated film was evaluated by measuring the tensile elongation (in %) in the short direction, i.e., the direction of transport, of the laminated film using an autograph. Three test specimens were prepared for each thickness, and the average of the measurements of the three specimens was used as the tensile elongation for each specimen thickness. A tensile elongation of 400% or higher was considered good. The measurement results of the tensile elongation of the laminated film are shown in Table 1.

[0108] -Measurement of tear strength of laminated film- Tear strength (unit: N) was measured in accordance with JIS K 7128-2 (Elmendorf tear test). Seven layers of laminated film were stacked, and the tear strength (unit: N) in the short direction of the laminated film, i.e., the direction of transport of the laminated film, was measured to evaluate the tear-openability. Three test specimens were prepared, and the average value of the measurements of the three test specimens was used. If the tear strength was 26 N or less, the tear-openability was evaluated as good. The measurement results of the tear strength are shown in Table 1.

[0109] [Table 1]

[0110] (Making the bag itself) Of the prepared laminated films, five linear perforations were formed on one of the laminated films, with 1 mm long slits (cuts) spaced approximately 2 mm apart, and five of these linear perforations were arranged in parallel at intervals of approximately 5 mm. These linear perforations were formed so as to be approximately parallel to the shorter side of one of the laminated films. Subsequently, a rectangular piece of sterile paper (high-density polyethylene nonwoven fabric, "Tyvek 2FS", manufactured by DuPont) was heat-sealed to the surface on the sealing layer side. The sterile paper was positioned so that its long side aligned with the shorter side of the laminated film. Then, using one laminated film and the other laminated film, the innermost sealing layers were overlapped, and the outer circumference of the laminate was heat-sealed except for the opening (one side on the shorter side) to create a pouch, which is the bag body with outer dimensions of 300 mm x 360 mm.

[0111] (Preparation of sterile bags) After trimming the outer edge of the bag body to a seal width of 5 mm, the opening of the bag body was welded to create a sterile bag. Three sterile bags were made, and the average value of the three sterile bags was used.

[0112] [Evaluation of appearance after sterilization] Ethylene oxide (EO) gas was placed in the prepared sterilization bags as a sterilizer, and the amount of gas in the storage chamber was measured. Figure 10 shows the relationship between time and the amount of EO gas.

[0113] <Example 2> The procedure was the same as in Example 1, except that the sealing layer was formed using linear low-density polyethylene (InnoPlus LL7410D1, manufactured by PTT Global Chemical Public Company Limited). The measurement results of the tensile strength and tensile elongation of the fabricated laminated film are shown in Table 1.

[0114] <Comparative Example 1> In Example 1, the laminated film had no intermediate layer and consisted of a two-layer structure comprising a seal layer and a base layer. The thickness of the seal layer was 50 μm, and the seal layer was formed of PET with a thickness of 12 μm. "Tyvek® 1059B" was used as the sterile paper. Otherwise, the procedure was the same as in Example 1. The relationship between time and gas volume is shown in Figure 10.

[0115] As shown in Figure 10, in Example 1, the amount of EO gas in the containment chamber of the sterilization bag was approximately 1633 μg / g on day 0, and gradually decreased over time, remaining at approximately 373 μg / g on day 2 and approximately 170 μg / g on day 3. From day 2 onward, the amount of EO gas in the containment chamber of the sterilization bag hardly decreased and was approximately the same as in Comparative Example 1.

[0116] Therefore, the sterilization bag obtained in Example 1 can be opened by tearing while maintaining the seal of the containment chamber. Thus, when the sterilization bag obtained in Example 1 is used as a sterilization bag, it is easy to tear, and it can take in the sterilizing agent and hold it stably for a long period of time. Therefore, it can be said that the sterilization bag maintains its function as a sterilization bag while allowing the sterilization target to be easily removed and used. [Explanation of symbols]

[0117] 1 Sterilization bag 10 Bag body 11. Seal part 12 Confinement Rooms 13 Opening 20 Breathable base material 21 cuts 100, 100A, 100B laminated film 101 Slit 110 sealing layer 120 Middle Class 130 Base material layer

Claims

1. A slit forming step is performed in which a plurality of slits connecting the laminated films are formed in at least one of two laminated films, one of which is made by laminating a sealing layer containing at least one of low-density polyethylene and linear low-density polyethylene and a base layer containing high-density polyethylene, along the transport direction of the laminated film. A step of covering a breathable substrate, in which a breathable substrate is provided so as to cover the slit on the sealing layer side of the laminated film in which the slit is formed, A welding step is performed to overlap two of the laminated films so that their sealing layer sides face each other along the transport direction of the laminated film, and to weld the outer edges of the two laminated films together while leaving an unwelded opening to form a sealing portion. Includes, A method for manufacturing a sterilization bag, wherein the breathable substrate has a plurality of notches formed on a side of the laminated film different from the sealing layer side, corresponding to the longitudinal direction of the slit.

2. The method for manufacturing a sterilization bag according to claim 1, wherein the laminated film includes an intermediate layer between the sealing layer and the base material layer, the intermediate layer containing at least one of high-density polyethylene and low-density polyethylene.

3. The method for manufacturing a sterilization bag according to claim 2, wherein the intermediate layer comprises the high-density polyethylene.

4. The method for manufacturing a sterilization bag according to any one of claims 1 to 3, wherein the sealing layer comprises the low-density polyethylene.

5. A method for manufacturing a sterilization bag according to any one of claims 1 to 4, wherein the thickness of the laminated film is 30 μm to 120 μm.

6. A method for manufacturing a sterilization bag according to any one of claims 1 to 5, wherein the longitudinal direction of the slit is provided along the transport direction of the laminated film.

7. The method for manufacturing a sterilization bag according to any one of claims 1 to 6, wherein the breathable substrate is a strip-shaped breathable sterilization paper.

8. A method for manufacturing a sterilization bag according to any one of claims 1 to 7, wherein the object to be sterilized stored in the containment chamber defined by the laminated film and the sealing portion is a pharmaceutical product or a medical product.

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