Aseptic filling method and aseptic filling system

Abstract

Provided are an aseptic filling method and an aseptic filling system that achieve effective sterilization in a short time while avoiding or reducing the risk of bactericide remaining. The aseptic filling method is for filling a sterilized container with a content, the method comprising: a laser irradiation process for irradiating a container or an auxiliary container-shaped body with a CO2 laser beam to sterilize the container surface; and a filling process for filling the container with the content.

Description

Aseptic filling method and aseptic filling system

[0001] The present invention relates to an aseptic filling method and an aseptic filling system for filling a sterilized container with a content.

[0002] BACKGROUND ART Conventionally, aseptic filling methods for filling contents into sterilized containers have been known that include a sterilization treatment using a sterilizing agent such as hydrogen peroxide (see, for example, Patent Document 1).

[0003] JP 2010-202284 A

[0004] However, when using a disinfectant for sterilization, there is a concern that the disinfectant may remain in the molded container, and measures must be taken to reduce the risk of residue.

[0005] Therefore, the present invention aims to solve these problems and provide an aseptic filling method and aseptic filling system that has a simple configuration and achieves effective sterilization in a short period of time while avoiding or reducing the risk of residual disinfectant.

[0006] One aspect of the aseptic filling method of the present invention is an aseptic filling method for filling a content into a sterilized container, the method comprising: ２ The above-mentioned problem is solved by including a laser irradiation process in which a laser is irradiated to sterilize the container surface, and a filling process in which contents are filled into the container. Another aspect of the aseptic filling method of the present invention is an aseptic filling method for filling contents into sterilized containers, which solves the above-mentioned problem by including a laser irradiation process in which a laser of an infrared wavelength is irradiated onto the container or container preform to sterilize the container surface, and a filling process in which contents are filled into the container. One aspect of the aseptic filling system of the present invention is an aseptic filling system for filling contents into sterilized containers, which includes applying CO 2 to the container surface of the container or container preform. ２The above-mentioned problems are solved by including a laser irradiation means that irradiates a laser to sterilize the container surface, and a filling means that fills the container with contents. Another aspect of the aseptic filling system of the present invention is an aseptic filling system that fills contents into sterilized containers, which solves the above-mentioned problems by including a laser irradiation means that sterilizes the container surface by irradiating the container or container preform with a laser of an infrared wavelength, and a filling means that fills the container with contents.

[0007] In either of the above aseptic filling methods or aseptic filling systems, the laser irradiation treatment may be carried out on a path between an inlet of the container or container preform of aseptic filling equipment and a filling section where the filling treatment is carried out. In either of the above aseptic filling methods or aseptic filling systems, the laser irradiation treatment may be carried out by irradiating the outer surface of the container or container preform with CO 2 . ２ Laser irradiation and CO 2 irradiation on the inner surface of the container or container preform. ２ In one embodiment, the aseptic filling method further includes a container molding process in which a preform serving as the container preform is blow-molded to form a PET bottle serving as the container, and the laser irradiation process is performed on the preform. In one embodiment, the aseptic filling method further includes a heat treatment in which the preform is heated to a molding temperature during the container molding process, and the laser irradiation process is performed on the preform after the heat treatment. In one embodiment, the aseptic filling method further includes a heat treatment in which the preform is heated to a molding temperature during the container molding process, and the laser irradiation process is performed on the preform after the heat treatment. In one embodiment, the aseptic filling method further includes a heat treatment in which the preform is heated to a molding temperature during the container molding process, and the laser irradiation process is performed on the preform after the heat treatment. ２ The laser irradiation is performed by CO ２ In any of the above aseptic filling methods or aseptic filling systems, the laser irradiation treatment may be performed by applying CO 2 to the outer surface of the preform. ２ After the laser irradiation, the inner surface of the preform is subjected to CO ２In either of the aseptic filling method or the aseptic filling system, the laser irradiation treatment is performed by irradiating CO 2 diffused in a cone shape by an irradiation unit arranged outside the preform so as to face the opening of the preform. ２ In either the aseptic filling method or the aseptic filling system, the laser irradiation process may involve relatively moving at least one of the preform and the irradiating unit in the axial direction of the preform, while irradiating the inner surface of the preform with CO . ２ In either the aseptic filling method or the aseptic filling system, the laser irradiation process may include irradiating the CO ２ While changing the diffusion angle of the laser, CO ２ In either of the aseptic filling method or the aseptic filling system, the laser irradiation process may involve irradiating CO 2 through an irradiation unit disposed outside the preform so as to face the opening of the preform. ２ An irradiation spot is set so that the laser hits a partial area of ​​the inner surface of the preform, and CO is applied to the inner surface of the preform while rotating at least one of the preform or the irradiation unit around the axis of the preform. ２ In either of the aseptic filling method or aseptic filling system, the irradiation spot may include a part of the circumferential range of the preform from the center of the bottom of the preform to the tip of the opening side of the preform. In either of the aseptic filling method or aseptic filling system, the irradiation spot may be set to be elongated such that the vertical width in the axial direction of the preform is wider than the horizontal width in the circumferential direction of the preform. In either of the aseptic filling method or aseptic filling system, in the laser irradiation process, CO ２The laser is set to be irradiated in one direction, and at least one of the preform and the irradiating unit is rotated around the axis of the preform, and at least one of the preform and the irradiating unit is moved relatively in the axial direction of the preform, while CO is applied to the inner surface of the preform. ２ In either of the aseptic filling method or the aseptic filling system, a container forming process may be further included in which a sheet material container as the container preform is formed by shaping the sheet material as the container preform, and the laser irradiation process may be performed on the sheet material or the sheet material container. In either of the aseptic filling method or the aseptic filling system, the laser irradiation process may be performed on the sheet material before the container forming process. In either of the aseptic filling method or the aseptic filling system, the laser irradiation process may include CO ２ The laser irradiation spot is set to a horizontally elongated shape whose width in a direction perpendicular to the conveying direction is wider than the vertical width in the conveying direction of the sheet material, and the CO ２ Laser irradiation may also be used.

[0008] The present invention has a simple configuration that can achieve effective sterilization in a short time while avoiding or reducing the risk of residual sterilant.

[0009] 1 is an explanatory diagram showing an aseptic filling system according to one embodiment of the present invention. ２ 1 is an explanatory diagram showing an example of a laser irradiation mode. ２ 1 is an explanatory diagram showing an example of a laser irradiation mode. ２ The figure shows the results of a test to confirm the sterilization effect of laser irradiation. The figure shows the absorbance of spore-forming bacteria, mold, and PET resin with respect to the wavelength of light.

[0010] An aseptic filling system 10 according to one embodiment of the present invention will be described below with reference to the drawings. Note that the terms "upstream" and "downstream" used in this specification refer to the upstream and downstream sides in the conveying direction of the preforms P or containers.

[0011] First, the aseptic filling system 10 is configured as a so-called in-line blow type filling system that aseptically fills sterilized contents (particularly liquid contents) into sterilized containers, and as shown in Figure 1, it is equipped with an aseptic molding device 20 that aseptically molds containers, and a filling device 60 that aseptically fills the contents into the containers.

[0012] Each component of the aseptic filling system 10 will be described below with reference to the drawings.

[0013] First, the aseptic molding device 20 aseptically molds sterilized containers that have been subjected to a sterilization treatment, and as shown in Figure 1, it is equipped with an inlet section 21 into which preforms P as container preforms are introduced, a blow molding turret 22, an oven mechanism 30 that heats the preforms P in an oven area A1 set downstream of the inlet section 21, a preform transport mechanism 40 that transports the preforms P, and a container sterilization device 50 that sterilizes the preforms P.

[0014] As shown in FIG. 1, the inlet portion 21 is a portion for introducing the preforms P into the aseptic molding apparatus 20 (aseptic filling system 10).

[0015] 1, the blow molding turret 22 is disposed downstream of the oven area A1 and performs aseptic blow molding on the preforms P. Specifically, the blow molding turret 22 is configured as a turret equipped with a blow machine (not shown) that performs biaxial stretch blow molding of containers such as PET bottles by blowing aseptic air into the preforms P that have been heated to the molding temperature for aseptic blow molding.

[0016] The molding area A3, where the blow molding turret 22 is installed, is covered by a chamber and maintained at a sterile atmosphere and positive pressure by blowing sterile air passed through a HEPA filter from above using an FFU (Fan Filter Unit). Furthermore, the blow molding turret 22, blowing machine, and other equipment installed in the molding area A3 are sterilized down to the end of the blow piping. Preforms P, which have been sterilized only at the preform stage, are transported to the molding area A3 and aseptically blow-molded. This allows aseptic blow molding, in which blow molding is performed in a sterile environment, to be performed in the molding area A3. Therefore, it is not necessary to locally create a sterile air or sterilizing gas atmosphere near the transport path for transporting preforms P and blow-molded containers within the molding area A3, and it is also not necessary to sterilize the containers after blow molding.

[0017] The oven mechanism 30 performs a temperature raising process to raise the temperature of the preform P (of the body P1) to the molding temperature during aseptic blow molding in the blow molding turret 22, and has an oven chamber 31 with an oven area A1 inside, and a plurality of temperature raising heaters 32 configured as infrared heaters that raise the temperature of the preform P. Note that the oven mechanism 30 may be provided with a simple cover that surrounds the periphery of the oven instead of the oven chamber 31, or the oven chamber 31 may not be provided.

[0018] The body portion P1 of the preform P is a portion that is placed inside the mold during aseptic blow molding and is expanded within the mold, while the mouth portion P2 of the preform P is a portion that is placed outside the mold during aseptic blow molding and is not expanded.

[0019] As shown in FIG. 1, the transfer area A2 is an area downstream of the oven area A1 and upstream of the molding area A3, and is more contaminated than the molding area A3 but less contaminated than the oven area A1.

[0020] The preform conveying mechanism 40 conveys the preforms P inserted through the entrance 21 to the blow molding turret 22, and as shown in Figure 1, it is equipped with a conveying machine 41 that conveys the preforms P mainly in the oven area A1, and multiple turrets 42 that convey the preforms P removed from the oven area A1 toward the blow molding turret 22.

[0021] The turrets 42 transport the preforms P in the transfer area A2 and the molding area A3, and each turret 42 has a plurality of grippers that grip the outer periphery of the preforms P. It is desirable to sterilize the gripping portions of the grippers by UV irradiation or with a disinfectant.

[0022] The transport posture of the preform P by the preform transport mechanism 40 may be any posture, such as upright, inverted (i.e., downward facing with the mouth portion P2 of the preform P facing downward), or horizontal (i.e., horizontal facing with the mouth portion P2 of the preform P facing to the side).

[0023] The aseptic molding device 20 is configured to perform a sterilization process using a container sterilization device 50 or the like when the contents are filled in the filling device 60, so that the container is in a commercially sterile state (i.e., a state in which all microorganisms harmful to public health that may grow in the beverage under normal non-refrigerated storage and distribution conditions have been killed).

[0024] In this embodiment, the sterilization process by the container sterilization device 50 etc. is configured so that sterilization of the container is completed only by preform sterilization at the preform stage before the container is molded by aseptic blow molding, without performing sterilization at the container stage after aseptic blow molding (without requiring sterilization at the container stage) (more specifically, in this embodiment, sterilization is completed by the time of transfer area A2, and the sterilized preform P is transported to molding area A3). In other words, the container is configured so that the preform sterilization process at the preform stage alone will bring the container to a commercially sterile state, and in further other words, the preform sterilization process at the preform stage alone is capable of sterilizing the bacteria to be sterilized (on the entire outer surface including the inner and outer surfaces of the preform P) (bacteria that can grow in the contents to be filled into the container, such as mold, general bacteria, spore-forming bacteria, etc.). The bactericidal effect (D) is expressed by the formula: bactericidal effect (D) = LOG ((initial number of bacteria) / (surviving number of bacteria)). For example, if the number of bacteria is reduced from 100 to 10, then LOG (100 / 10) = 1D.

[0025] The container sterilization device 50 is configured to sterilize the inner surface (the inner surface of the body portion P1 and the mouth portion P2) and the outer surface (the outer surface of the body portion P1 and the mouth portion P2) of the preform P in an area (in this embodiment, the transfer area A2) downstream of the oven area A1 and upstream of the blow molding turret 22, and as shown in FIG. 1, CO ２ The apparatus includes a laser irradiator 51 as a laser irradiation means for irradiating a laser, and a heating means (in this embodiment, an oven mechanism 30) that is arranged upstream of or at the same location as the laser irradiator 51 and heats the area to be sterilized on the surface of the container. ２ A laser is a type of gas laser, and this CO ２ Carbon dioxide lasers use a mixture of carbon dioxide, nitrogen, and helium. A discharge current is passed through this gas mixture to produce a laser beam.

[0026] As shown in FIG. 1, the laser irradiator 51 is located in an area (transfer area A2 in this embodiment) downstream of the oven area A1 and upstream of the blow molding turret 22, and irradiates CO 2 onto the container surface of the preform P while it is being transported by the turret 42. ２ The laser irradiator 51 sterilizes the container surface of the preform P by irradiating it with a laser. The laser irradiator 51 includes a laser oscillator 51 a and a CO ２ The laser irradiator 51 has an irradiation section 51b that is made up of optical elements such as lenses, mirrors, beam expanders, and beam shapers for irradiating the laser. The laser irradiator 51 may be installed in the oven area A1 or on the upstream side of the oven area A1. Alternatively, the laser irradiator 51 may be installed on the downstream side of the blow molding turret 22 to irradiate the molded container with CO 2 . ２ Sterilization may be performed by irradiating with a laser.

[0027] The heating means is implemented before or simultaneously with the laser irradiation process by the laser irradiator 51 and heats the area to be sterilized on the container surface so that the area is heated during the laser irradiation process, and in this embodiment, the oven mechanism 30 described above functions as the heating means. Note that the specific form of the heating means is not limited to the above, and the heating means may also be constituted by a temperature raising heater or a supplier that supplies hot water, steam, hot air, etc., provided separately from the oven mechanism 30. In this case, the heating temperature of the area to be sterilized can be set appropriately to 60°C or higher, 80°C or higher, 100°C or higher, etc.

[0028] The filling device 60 is installed downstream of the aseptic molding device 20, and as shown in Figure 1, is equipped with a filling section 61 as a filling means for filling the contents into the container, and a capping section 62 located downstream of the filling section 61 for attaching a sterilized cap to the mouth of the container.

[0029] Each process in filling apparatus 60 is performed in a chamber whose interior is maintained in a sterile state. The sterile state of the containers is also maintained in the section in which the containers are transported between aseptic molding apparatus 20 and filling apparatus 60. In other words, the sterile state of the containers is maintained throughout the entire section from when the containers are aseptically blow-molded by blow molding turret 22 to when the contents are aseptically filled into the containers in filling section 61. In this embodiment, the entire section is covered by a chamber, thereby maintaining the sterile state of the containers throughout this section.

[0030] Next, a method for aseptic filling using the aseptic filling system 10 will be described below.

[0031] First, the aseptic filling method of this embodiment includes a heat treatment performed before or simultaneously with the laser irradiation treatment, and a CO 2 irradiation treatment performed on the container surface. ２ The process includes a laser irradiation process in which a laser is irradiated, a container molding process in which a container is formed by molding a container preform (in this embodiment, using the blow molding turret 22), and a filling process in which the contents are filled into the container by the filling section 61.

[0032] The laser irradiation process is carried out by a laser irradiator 51, which applies CO to the container surface (in this embodiment, the entire surface including the inner and outer surfaces of the preform P). ２ This involves irradiating a laser, and is carried out on the path between the inlet 21 of the container or preform (preliminary container molded body) P of the aseptic filling equipment and the filling section 61 where the filling process is carried out.

[0033] In the laser irradiation treatment, CO is applied to the outer surface of the container or container preform (in this embodiment, the outer surface of the preform P). ２ Laser irradiation and CO irradiation on the inner surface of the container or container preform (in this embodiment, the inner surface of the preform P) ２ Laser irradiation is carried out (individually).

[0034] CO on the inner surface of the preform P ２ Specific examples of laser irradiation include the following: In addition, the arrow indicated by the symbol Lc in FIGS. ２ 1 is a schematic diagram of a laser.

[0035] First, as shown in FIG. 2( a), CO 2 diffused in a cone shape by the irradiation unit 51 b arranged on the axis of the preform P outside the preform P so as to face the opening of the preform P. ２ It is conceivable to irradiate the inner surface of the preform P with a laser. ２ When irradiating the laser, CO ２ Since there is no need to insert the irradiation unit 51b into the preform P while irradiating the laser, irradiation can be completed in a short time. In the example shown in FIG. 2(a), the positional relationship between the irradiation unit 51b and the preform P can be determined by inserting the CO ２ Laser irradiation may be performed, and CO ２ 2A, irradiation may be performed so that the irradiation spot S is circular (full cone irradiation), or irradiation may be performed so that the irradiation spot S is annular (hollow cone irradiation). ２ While changing the divergence angle θ of the laser, ２ Laser irradiation may be performed, and CO ２ Laser irradiation may also be performed.

[0036] As shown in FIG. 2B, in the laser irradiation process, CO irradiated through an irradiation unit 51b arranged outside the preform P so as to face the opening of the preform P. ２ The irradiation spot S is set so that the laser hits a partial area of ​​the inner surface of the preform P, and while at least one of the preform P and the irradiation unit 51b is rotated around the axis of the preform P during irradiation (in the example shown in FIG. 2(b) , while the preform P is rotated without rotating the irradiation unit 51b), CO is applied to the inner surface of the preform P. ２ Laser irradiation may also be used.２ When irradiating the laser, CO ２ Since there is no need to insert the irradiation unit 51b into the preform P while irradiating the laser, irradiation can be completed in a short time. As shown in FIG. 2(b), the irradiation spot S may be set to include from the center of the bottom of the preform P to the tip of the opening side of the preform P in a partial range in the circumferential direction of the preform P. Also, as shown in FIG. 2(b), the irradiation spot S may be set to be elongated such that the vertical width in the axial direction of the preform P is wider than the horizontal width in the circumferential direction of the preform P. Also, specific shapes of the irradiation spot S may be rectangular, linear, elliptical, etc. In the example shown in FIG. 2(b), the positional relationship between the irradiation unit 51b and the preform P can be determined by CO 2 irradiation without moving both the irradiation unit 51b and the preform P in the axial direction of the preform P. ２ During the irradiation, at least one of the preform P and the irradiating section 51b may be moved relatively in the axial direction of the preform P to irradiate the preform P with a laser. ２ Laser irradiation may be performed. At this time, the irradiation spot S may be set to include a part of the area from the center of the bottom of the preform P to the tip of the opening side of the preform P in the axial direction of the preform P, and the entire area to be sterilized may be irradiated in multiple times.

[0037] As shown in FIG. 3A, in the laser irradiation process, CO ２ The laser is set to be irradiated in one direction (in the example shown in FIG. 3( a), a direction perpendicular to the axial direction of the preform P), and during irradiation, at least one of the preform P or the irradiating unit 51b is rotated around the axial line of the preform P (in the example shown in FIG. 3( a), the preform P is rotated without rotating the irradiating unit 51b), and at least one of the preform P or the irradiating unit 51b is moved relatively in the axial direction of the preform P (in the example shown in FIG. 3( a), the irradiating unit 51b is moved without moving the preform P), and CO is applied to the inner surface of the preform P. ２In the example shown in FIG. 3(a), CO 2 may be additionally irradiated from the irradiating portion 51b toward the bottom side of the preform P (the lower side in the example shown in FIG. 3). ２ Laser irradiation may also be used.

[0038] As shown in FIG. 3B, in the laser irradiation process, CO 2 is irradiated from the entire outer periphery of the tip of the irradiation part 51b disposed (inserted) in the preform P toward the outside in the radial direction (the direction perpendicular to the axial direction of the preform P). ２ The laser is set to be irradiated radially, and during irradiation, at least one of the preform P and the irradiating section 51b is moved relatively in the axial direction of the preform P (in the example shown in FIG. 3(b) , the preform P is not moved, but the irradiating section 51b is moved), and CO is applied to the inner surface of the preform P. ２ In the example shown in FIG. 3(b), CO 2 may be additionally irradiated from the irradiating portion 51b toward the bottom side of the preform P (the lower side in the example shown in FIG. 3). ２ Laser irradiation may also be used.

[0039] As shown in FIG. 3C, in the laser irradiation process, CO 2 is emitted from the tip of the irradiation section 51b arranged in the preform P. ２ The laser is set to be diffused (in all directions), and at the time of irradiation, at least one of the preform P and the irradiation unit 51b is moved relatively in the axial direction of the preform P (in the example shown in FIG. 3(c), the preform P is not moved, but the irradiation unit 51b is moved), and CO is applied to the inner surface of the preform P. ２ 3(c), at least one of the preform P and the irradiating section 51b may be rotated around the axis of the preform P.

[0040] As shown in FIG. 3( d ), the laser irradiation process is set so that the laser is diffused (in all directions) from the entire outer periphery of the elongated irradiation portion 51 b arranged in the preform P and extending along the axial direction of the preform P, and the CO ２3(d), the positional relationship between the irradiation unit 51b and the preform P is such that the CO ２ During the irradiation, at least one of the preform P and the irradiating section 51b is moved relatively in the axial direction of the preform P while CO ２ Laser irradiation may also be performed.

[0041] CO on the outer surface of the preform P ２ Regarding the specific mode of laser irradiation, an irradiation unit (CO 2 irradiating the inner surface of the preform P) is disposed outside the preform P. ２ The outer surface of the preform P is irradiated with CO by an irradiation unit (irradiation unit provided separately from or in the same as the irradiation unit 51b for irradiating the laser). ２ Anything that emits a laser may be used.

[0042] In addition, the CO ２ Laser irradiation and CO ２ Regarding the timing of laser irradiation, CO ２ After the laser irradiation, the inner surface of the preform P is ２ Alternatively, the outer surface of the preform P may be irradiated with CO ２ Before the laser irradiation, the inner surface of the preform P is irradiated with CO ２ Laser irradiation may be performed, and CO ２ Laser irradiation and CO irradiation on the inner surface of the preform P ２ Laser irradiation may be performed simultaneously.

[0043] In addition, in the laser irradiation process, CO ２ Laser irradiation output, irradiation time, and cumulative light amount (mJ / cm ２For example, the CO 2 relative to the mouth P2 of the preform (for both the inner and outer surfaces of the preform P, or for only the inner or outer surface of the preform P) may be varied. ２ The laser irradiation is performed on the body P1 of the preform. ２ The output may be higher and / or the irradiation time may be longer than that of laser irradiation. ２ Integrated light intensity of laser irradiation (mJ / cm ２ ) in the body P1 of the preform ２ Integrated light intensity of laser irradiation (mJ / cm ２ ) may be set to be larger than

[0044] In the laser irradiation process, CO with a wavelength in the 9 μm band (center wavelength 9.0 to 9.9 μm) ２ It is preferable to irradiate the substrate with a laser. In addition, in the laser irradiation process, CO ２ It is preferable to irradiate the container with a laser. This can significantly reduce the time required for the sterilization process of the container. The irradiation time here refers to the time required for the area to be sterilized to be exposed to CO ２ In addition, in the laser irradiation process, in order to obtain a good sterilization effect while avoiding damage to the container surface that is the irradiation target, the CO ２ The cumulative laser light intensity is 1600 mJ / cm ２ or more and 30,000 mJ / cm ２ CO ２ In the laser irradiation process, CO 2 is preferably used in either continuous wave or pulse wave form. ２ A laser may be irradiated.

[0045] The heat treatment is performed by heating the area to be sterilized on the container surface by laser irradiation treatment using a heating means, and in this embodiment, the preform P is heated to the molding temperature during the container molding treatment by an oven mechanism 30 as the heating means. Note that the heat treatment is preferably set so that the area to be sterilized on the container surface is heated to a temperature of 120°C or higher during the laser irradiation treatment performed on the preform P after the heat treatment.

[0046] Next, CO ２ A test conducted to confirm the sterilization effect of laser irradiation will be described with reference to FIG.

[0047] In this test, first, a 1.7 × 10 ３ cfu of spore-forming bacteria (Bacillus atrophaeus spores) and 1.2 × 10 ３ After attaching cfu of mold (Aspergillus niger conidia), the substrate was dried in a clean room to prepare a substrate inoculated with spore-forming bacteria and mold.

[0048] Then, the prepared substrate was subjected to CO 2 irradiation under the conditions shown in FIG. ２ After irradiating the substrate with a laser, the number of surviving bacteria on the substrate was measured by the following standard method. Measurement method of surviving bacteria count: The substrate, sterilized surfactant aqueous solution, and sterilized beads were placed in a sterilized test tube, and the test tube was sealed with a sterilized cap. The test tube was shaken to extract surviving bacteria in the surfactant aqueous solution, which were then suspended in a sterilized dilution solution, and the number of bacteria was measured on a standard agar medium by the membrane filtration method for each dilution ratio. The medium was cultured at 35°C for one week, and the number of colonies that appeared according to the dilution ratio was counted to determine the number of surviving bacteria. Note that the CO on the substrate surface was ２ The diameter of the laser irradiation spot was approximately 22 mm, and the "Φ5 output (W)" shown in Figure 4 was the output (W) of the laser oscillator during the test, measured as the output (W) of the portion irradiated onto a circular area with a diameter of 5 mm where the bacteria was inoculated. ２During laser irradiation, the irradiated area of ​​the substrate was heated by a heater so that it was 120°C. ２ The laser is continuous wave, and the output is adjusted by PWM control (frequency 5 kHz). ２ The laser is a pulse wave with a frequency of 1 kHz. ２ The wavelength of the laser is in the 9 μm band (9.3 μm), and the CO ２ The wavelength of the laser is in the 10 μm band (10.6 μm).

[0049] In this test, an optical system was configured using a laser oscillator, an irradiation lens as an irradiation unit, etc. The "Φ5 output (W)" was measured using a power meter (UP55N-300F-H12-D0) manufactured by Gentec.

[0050] From the results of the above tests, the following was found.

[0051] That is, CO ２ When the laser wavelength is in the 9 μm band, the irradiation time is in the range of 0.02 seconds or more and 0.05 seconds or less, and the irradiation energy is 1600 mJ / cm ２ or more (more preferably 3310 mJ / cm ２ It was found that a good sterilizing effect on mold can be obtained when the CO ２ When the laser wavelength is in the 9 μm band, the irradiation time is in the range of 0.05 seconds or more and 0.075 seconds or less, and the output is 3310 mJ / cm ２ or more (more preferably 3820 mJ / cm ２ It was found that a good sterilizing effect on mold can be obtained when the CO ２ When the laser wavelength is in the 9 μm band, the irradiation time is in the range of more than 0.075 seconds and less than 0.1 seconds, and the irradiation energy is 3820 mJ / cm ２ or more (more preferably 6621 mJ / cm ２ It was found that a good sterilizing effect on mold can be obtained when the CO ２When the laser wavelength is in the 9 μm band, the irradiation time is in the range of more than 0.1 seconds and less than 0.2 seconds, and the irradiation time is 6621 mJ / cm ２ or more (more preferably 7130 mJ / cm ２ It was found that a good sterilizing effect on mold can be obtained when the CO ２ When the laser wavelength is in the 9 μm band, the irradiation time is in the range of more than 0.2 seconds and less than 0.5 seconds, and the irradiation energy is 7130 mJ / cm ２ or more (more preferably 7894 mJ / cm ２ It was found that a good sterilizing effect on mold can be obtained when the CO ２ When the laser wavelength is in the 9 μm band, the irradiation time is in the range of more than 0.5 seconds and less than 1.0 seconds, and the output is 7894 mJ / cm ２ or more (more preferably 10186 mJ / cm ２ It was found that a good sterilizing effect on mold can be obtained when the CO ２ When the laser wavelength is in the 10 μm band, the irradiation time is in the range of 0.05 seconds or more and 1.0 seconds or less, and the output is 5093 mJ / cm ２ or more (more preferably 10200 mJ / cm ２ It was found that a good sterilizing effect on mold can be obtained when the CO ２ When the laser wavelength is in the 9 μm band and the substrate is heated, the irradiation time is in the range of 0.005 seconds or more and 0.01 seconds or less, and the irradiation intensity is 400 mJ / cm ２ or more (more preferably 662 mJ / cm ２ It was found that a good sterilizing effect on mold can be obtained when the CO ２ When the laser wavelength is in the 9 μm band and the substrate is heated, the irradiation time is in the range of 0.01 seconds or more and 0.03 seconds or less, and the output is 662 mJ / cm ２ or more (more preferably 1986 mJ / cm ２ It was found that a good sterilizing effect on mold can be obtained when the CO ２ When the laser wavelength is in the 9 μm band and the substrate is heated, the irradiation time is in the range of 0.03 seconds or more and 0.05 seconds or less, and the output is 1986 mJ / cm ２or more (more preferably 3310 mJ / cm ２ Therefore, even if the irradiation time is set to 1 second or less (0.025 seconds or more without heating the substrate, and 0.005 seconds or more with heating the substrate), a good sterilization effect on mold can be obtained. ２ It was found that mold can be sterilized by appropriately setting the laser output.

[0052] Also, CO ２ When the laser wavelength is in the 9 μm band, the irradiation time is in the range of 0.05 seconds or more and 0.075 seconds or less, and the output is 4966 mJ / cm ２ It was found that a good bactericidal effect against spore-forming bacteria was obtained when the CO ２ When the laser wavelength is in the 9 μm band, the irradiation time is in the range of more than 0.075 seconds and less than 0.1 seconds, and the irradiation energy is 4966 mJ / cm ２ or more (more preferably 6621 mJ / cm ２ It was found that a good bactericidal effect against spore-forming bacteria was obtained when the CO ２ When the laser wavelength is in the 9 μm band, the irradiation time is in the range of more than 0.1 seconds and less than 1.0 seconds, and the irradiation time is 6621 mJ / cm ２ or more (more preferably 10186 mJ / cm ２ It was found that a good bactericidal effect against spore-forming bacteria was obtained when the CO ２ When the laser wavelength is in the 10 μm band, the irradiation time is in the range of 0.05 seconds or more and 1.0 seconds or less, and the output is 7639 mJ / cm ２ Therefore, even if the irradiation time is set to 1 second or less (0.05 seconds or more), a good sterilization effect on spore-forming bacteria can be obtained. ２ It was found that spore-forming bacteria can be sterilized by appropriately setting the laser output.

[0053] Furthermore, a comparison between A-7 and A-9 revealed that the sterilization effect against spore-forming bacteria was improved when the substrate was heated.

[0054] It was also found that whether the wave was continuous or pulsed did not have a significant effect on the sterilization effect.

[0055] Also, CO ２ It was found that the higher the laser output (Φ5 output) and the shorter the irradiation time, the smaller the integrated light dose required for sterilization.

[0056] In addition, CO ２ The mechanism by which lasers exert the excellent sterilization effect described above is not entirely clear. However, the absorbance of spore-forming bacteria (Bacillus atrophaeus), mold (Aspergillus niger), and PET resin against the wavelength of light shown in Figure 5 indicates that CO ２ In the wavelength band of the laser, especially in the 9 μm band, spore-forming bacteria, mold, and PET resin all show high absorbance. ２ It is believed that the excellent sterilizing effect is achieved because the PET resin is heated by absorbing the laser light, destroying the DNA, and indirectly heating the bacteria cells as well. The absorbance was measured using a Fourier transform infrared spectrophotometer (JASCO Corporation, FT / IR6700) using the Kbr tablet method.

[0057] In this embodiment, the CO ２ By including the laser irradiation process of irradiating a laser, the surface of the container can be sterilized satisfactorily in a short time.

[0058] Also, CO ２ By adopting sterilization by laser irradiation, sterilization using a disinfectant is not required, or even if sterilization using a disinfectant is used in addition, the amount of disinfectant used can be reduced, thereby reducing the risk of disinfectant remaining in the molded container.

[0059] In addition, the present invention further includes a heating process that is carried out before or simultaneously with the laser irradiation process, and in this heating process, the sterilization effect of the sterilization area on the container surface can be further improved by heating the sterilization area on the container surface using the laser irradiation process.

[0060] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design modifications can be made without departing from the scope of the present invention as set forth in the claims. Furthermore, the configurations of the above-described embodiments and the modified examples described below can be arbitrarily combined to configure the aseptic filling method and aseptic filling system 10.

[0061] Furthermore, in the above-described embodiment, the aseptic filling method (aseptic filling system 10) has been described as being configured to sterilize the container surface of the preform P, which is a preformed container body, but the specific aspects of the aseptic filling method (aseptic filling system 10) are not limited to the above, and the container surface of the container after molding may also be sterilized.

[0062] Furthermore, in the above-described embodiment, the container preform is the preform P, and the container is a PET bottle. However, the specific aspects of the container preform and the container are not limited to this. For example, the container may be a resin-coated can or a painted can. The container preform may be a sheet material (for example, a sheet material in which the surface of a paper base material is coated with a synthetic resin, or a sheet material formed as a resin film), and the container may be a sheet material container (for example, a paper pack or a pouch) obtained by molding the sheet material. In this case, too, the laser irradiation treatment is performed on the sheet material or the like as the container preform or the sheet material container or the like as the container. In this case, the laser irradiation treatment may be performed using CO ２ The laser irradiation spot is set to a horizontally elongated shape in which the width in a direction perpendicular to the conveying direction is wider than the vertical width in the conveying direction of the sheet material as the container preform, and CO ２ A laser may be irradiated.

[0063] In addition, when the container surface is made of (or coated with) synthetic resin such as PET (polyethylene terephthalate), PP (polypropylene), or PE (polyethylene), CO ２ To avoid damage to the container surface caused by the laser, CO ２ The cumulative laser light intensity is 30,000 mJ / cm２ CO ２ Preferably, a laser is used.

[0064] Furthermore, in the above-described embodiment, the container sterilization apparatus 50 has been described as including the laser irradiator 51, etc., but the container sterilization apparatus 50 may also include other sterilization devices as components thereof, such as a sterilization device that sterilizes by supplying a sterilizing fluid such as hydrogen peroxide (aqueous hydrogen peroxide solution), peracetic acid (aqueous peracetic acid solution), or water (hot water, steam) to the container surface of a container or container preform, a sterilization device that sterilizes by irradiating the container surface with UV light or an electron beam, or a dust remover that removes dust adhering to the preform P. Note that when water (hot water, steam) is used as the sterilizing fluid, the risk of the sterilant remaining in the molded container can be eliminated.

[0065] In the above-described embodiment, the laser irradiation process uses CO 2 having a wavelength in the 9 μm band (central wavelength of 9.0 to 9.9 μm, such as 9.3 μm or 9.6 μm). ２ Although the description has been given assuming that a laser is used for irradiation, other wavelengths, for example, CO in the 10 μm band (central wavelengths of 10.2 μm, 10.6 μm, etc., central wavelengths of 10.0 to 10.9 μm) may also be used. ２ Laser irradiation may also be used.

[0066] In the above-described embodiment, the CO 2 is applied to the entire container surface, including the inner and outer surfaces, of the container or container preform in the laser irradiation treatment. ２ Although the description has been given assuming that a laser is irradiated, it is also possible to irradiate only a portion of the container surface (for example, only the inner surface, only the outer surface, only the inner surface of the mouth, etc.) with CO . ２ Laser irradiation may also be used.

[0067] In the above-described embodiment, CO ２ Although the explanation has been given of sterilizing the container surface by irradiating it with a laser, ２ Instead of a laser, a laser with an infrared wavelength (specifically, a laser with a wavelength of 0.78 μm to 1000 μm, including a laser with a near-infrared wavelength, a mid-infrared wavelength, and a far-infrared wavelength) may be used to sterilize the container surface. ２In addition to lasers, diode lasers, fiber lasers, YAG lasers, YVO ４ Known lasers such as IR lasers and CO lasers may also be used. Compared to known infrared lamps and heaters, infrared wavelength lasers have high directivity and can irradiate the target area with infrared rays in a concentrated manner, resulting in high energy efficiency. In addition, the output rises quickly when irradiation starts, enabling short-term ON-OFF control. Specific aspects of the aseptic filling method and system using infrared wavelength lasers are described in detail in the CO ２ The CO laser described above is used except that a laser of infrared wavelength is used instead of the laser. ２ Since it is exactly the same as the aseptic filling method and system using a laser, ２ "CO" in the explanation of the aseptic filling method and system using a laser ２ By replacing "laser" with "laser of infrared wavelength," specific explanation will be omitted.

[0068] The above-mentioned aseptic filling method and system using an infrared wavelength laser can also be described as, but are not limited to, the following supplementary notes. (Supplementary Note 1) An aseptic filling method for filling a sterilized container with contents, comprising: a laser irradiation process for irradiating the container or container preform with an infrared wavelength laser to sterilize the container surface; and a filling process for filling the container with contents. (Supplementary Note 2) The aseptic filling method according to Supplementary Note 1, wherein the laser irradiation process is carried out on a path between an inlet of the container or container preform of aseptic filling equipment and a filling section where the filling process is carried out. (Supplementary Note 3) The aseptic filling method according to Supplementary Note 1 or Supplementary Note 2, wherein the laser irradiation process involves irradiating the outer surface of the container or container preform with an infrared wavelength laser and irradiating the inner surface of the container or container preform with an infrared wavelength laser. (Appendix 4) The aseptic filling method according to any one of Appendices 1 to 3, further comprising a container molding process in which a preform serving as a container preform is blow-molded to form a PET bottle serving as the container, and the laser irradiation process is performed on the preform. (Appendix 5) The aseptic filling method according to Appendices 4, further comprising a heat treatment in which the preform is heated to a molding temperature during the container molding process, and the laser irradiation process is performed on the preform after the heat treatment. (Appendix 6) The aseptic filling method according to Appendices 4 or 5, characterized in that, in the laser irradiation process, the infrared wavelength laser irradiation on the mouth portion of the preform has a higher output and / or a longer irradiation time than the infrared wavelength laser irradiation on the body portion of the preform. (Appendix 7) The aseptic filling method according to any one of Appendices 4 to 6, characterized in that, in the laser irradiation process, the infrared wavelength laser is irradiated on the outer surface of the preform, and then the infrared wavelength laser is irradiated on the inner surface of the preform.(Appendix 8) The aseptic filling method according to any one of Appendices 4 to 7, characterized in that in the laser irradiation process, the inner surface of the preform is irradiated with a laser of an infrared wavelength diffused in a cone shape by an irradiation unit arranged outside the preform so as to face the opening of the preform. (Appendix 9) The aseptic filling method according to Appendices 8, characterized in that in the laser irradiation process, the inner surface of the preform is irradiated with a laser of an infrared wavelength while at least one of the preform and the irradiation unit is moved relatively in the axial direction of the preform. (Appendix 10) The aseptic filling method according to Appendices 8 or 9, characterized in that in the laser irradiation process, the inner surface of the preform is irradiated with a laser of an infrared wavelength while changing the diffusion angle of the laser of the infrared wavelength emitted by the irradiation unit. (Appendix 11) The aseptic filling method according to any one of Appendices 4 to 7, characterized in that in the laser irradiation process, an irradiation spot is set so that an infrared wavelength laser irradiated through an irradiation unit arranged outside the preform so as to face the opening of the preform hits a partial area of ​​the inner surface of the preform, and the infrared wavelength laser is irradiated onto the inner surface of the preform while at least one of the preform or the irradiation unit is rotated around the axis of the preform. (Appendix 12) The aseptic filling method according to Appendices 11, characterized in that the irradiation spot is set to include from the center of the bottom of the preform to the tip of the opening side of the preform in a partial range in the circumferential direction of the preform. (Appendix 13) The aseptic filling method according to Appendices 11 or 12, characterized in that the irradiation spot is set to be elongated such that its vertical width in the axial direction of the preform is wider than its horizontal width in the circumferential direction of the preform.(Appendix 14) The aseptic filling method according to any one of Appendices 4 to 7, characterized in that in the laser irradiation treatment, an irradiation unit arranged inside the preform is set to irradiate an infrared wavelength laser in one direction, and at least one of the preform or the irradiation unit is rotated about the axis of the preform and at least one of the preform or the irradiation unit is moved relatively in the axial direction of the preform while irradiating the inner surface of the preform with the infrared wavelength laser. (Appendix 15) The aseptic filling method according to any one of Appendices 1 to 3, characterized in that it further includes a container forming treatment in which a sheet material container as the container is formed by shaping a sheet material as the container preform, and the laser irradiation treatment is performed on the sheet material or the sheet material container. (Appendix 16) The aseptic filling method according to Appendices 15, characterized in that the laser irradiation treatment is performed on the sheet material before the container forming treatment. (Appendix 17) The aseptic filling method according to appendix 16, characterized in that in the laser irradiation process, an irradiation spot of an infrared wavelength laser is set to be horizontally elongated with a width in a direction perpendicular to the conveying direction of the sheet material being wider than a length in the conveying direction of the sheet material, and the infrared wavelength laser is irradiated onto the sheet material while conveying the sheet material. (Appendix 18) An aseptic filling system for filling contents into sterilized containers, comprising: laser irradiation means for sterilizing the container surface by irradiating the container surface of the container or container preform with an infrared wavelength laser, and filling means for filling the container with contents.

[0069] DESCRIPTION OF SYMBOLS 10: Aseptic filling system 20: Aseptic molding device 21: Inlet section 22: Blow molding turret 30: Oven mechanism 31: Oven chamber 32: Heating heater 40: Preform conveying mechanism 41: Conveyor 42: Turret 50: Container sterilization device 51: Laser irradiator (laser irradiation means) 51a: Laser oscillator 51b: Irradiation section 60: Filling device 61: Filling section 62: Capping section P: Preform (preliminary container molded body) P1: Body section of preform P2: Mouth section of preform A1: Oven area A2: Transfer area A3: Molding area Lc: CO ２ laser

Claims

1. A sterile filling method for filling a sterilized container with contents, comprising: irradiating the container or a preform of the container with a CO ２ laser to sterilize the surface of the container (laser irradiation treatment); and filling the container with the contents (filling treatment). The sterile filling method is characterized by including these steps.

2. The aseptic filling method according to claim 1, wherein the laser irradiation treatment is performed on a path between an inlet portion of the container or the preform of the aseptic filling facility and a filling portion where the filling treatment is performed.

3. In the laser irradiation treatment, CO laser irradiation is performed on the outer surface of the container or the preform of the container, ２ and CO laser irradiation is performed on the inner surface of the container or the preform of the container. ２ The aseptic filling method according to claim 1, characterized in that 4. The aseptic filling method according to claim 1, further comprising a container forming process of forming a PET bottle as the container by blow molding a preform as the preform of the container, wherein the laser irradiation treatment is performed on the preform.

5. The aseptic filling method according to claim 4, further comprising a heat treatment of heating the preform to a forming temperature during the container forming process, wherein the laser irradiation treatment is performed on the preform after the heat treatment.

6. In the laser irradiation treatment, the CO for the mouth part of the preform ２ laser irradiation is the CO for the body part of the preform ２ The aseptic filling method according to claim 4, characterized in that the output is higher and / or the irradiation time is longer than the CO laser irradiation for the body part of the preform.

7. In the laser irradiation treatment, after performing CO laser irradiation on the outer surface of the preform, CO laser irradiation is performed on the inner surface of the preform. The aseptic filling method according to claim 4, characterized in that. ２ After performing CO laser irradiation on the outer surface of the preform, CO laser irradiation is performed on the inner surface of the preform. ２ The aseptic filling method according to claim 4, characterized in that CO laser irradiation is performed on the inner surface of the preform after performing CO laser irradiation on the outer surface of the preform.

8. In the laser irradiation treatment, a CO laser diffused in a conical shape is irradiated onto the inner surface of the preform by an irradiation unit disposed outside the preform so as to face the opening of the preform. ２ The aseptic filling method according to claim 4, wherein in the laser irradiation treatment, a CO laser diffused in a conical shape is irradiated onto the inner surface of the preform by an irradiation unit disposed outside the preform so as to face the opening of the preform.

9. In the laser irradiation treatment, while relatively moving at least one of the preform or the irradiation unit in the axial direction of the preform, a CO ２ laser is irradiated onto the inner surface of the preform. The aseptic filling method according to claim 8, characterized in that.

10. In the laser irradiation treatment, while changing the diffusion angle of the CO ２ laser by the irradiation unit, irradiate the inner surface of the preform with the CO ２ laser. The aseptic filling method according to claim 8, characterized in that.

11. In the laser irradiation treatment, the CO laser is irradiated through an irradiation unit disposed outside the preform so as to face the opening of the preform. ２ The irradiation spot is set so that the laser hits a partial region of the inner surface of the preform, and while rotating at least one of the preform or the irradiation unit around the axis of the preform, the inner surface of the preform is irradiated with the CO laser. ２ The aseptic filling method according to claim 4, characterized in that the inner surface of the preform is irradiated with a CO laser.

12. The aseptic filling method according to claim 11, wherein the irradiation spot is set to include from the center of the bottom of the preform to the tip of the opening side of the preform in a partial range in the circumferential direction of the preform.

13. The aseptic filling method according to claim 11, wherein the irradiation spot is set in a vertically long shape in which the vertical width in the axial direction of the preform is wider than the horizontal width in the circumferential direction of the preform.

14. In the laser irradiation treatment, the irradiation unit disposed in the preform is set to irradiate the CO ２ laser in one direction, and at least one of the preform or the irradiation unit is rotated about the axis of the preform, and while at least one of the preform or the irradiation unit is relatively moved in the axial direction of the preform, the inner surface of the preform is irradiated with the CO ２ laser. The aseptic filling method according to claim 4, characterized in that.

15. The aseptic filling method according to claim 1, further comprising a container forming process of forming a sheet material container as the container by forming a sheet material as the preform of the container, wherein the laser irradiation treatment is performed on the sheet material or the sheet material container.

16. The aseptic filling method according to claim 15, wherein the laser irradiation treatment is performed on the sheet material before the container forming process.

17. In the laser irradiation treatment, CO ２ The irradiation spot of the laser is set to be horizontally long with a width in the direction orthogonal to the conveyance direction being wider than the vertical width in the conveyance direction of the sheet material, and while conveying the sheet material, CO ２ The aseptic filling method according to claim 15, wherein the sheet material is irradiated with a laser.

18. A sterile filling system for filling a sterilized container with a content, wherein a CO ２ laser irradiation means for irradiating a surface of the container or a preformed container with a CO laser to sterilize the container surface, and a filling means for filling the content into the container. A sterile filling system characterized by including these components.

19. An aseptic filling method of filling a sterilized container with a content, comprising: a laser irradiation treatment of irradiating the container or the preform of the container with a laser having an infrared wavelength to sterilize the container surface; and a filling treatment of filling the container with the content.

20. An aseptic filling system for filling a sterilized container with a content, comprising: laser irradiation means for irradiating the surface of the container of the container or the preform of the container with a laser having an infrared wavelength to sterilize the container surface; and filling means for filling the container with the content.

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