Aseptic filling method and aseptic filling system

Abstract

To provide an aseptic filling method and aseptic filling system which can realize effective sterilization in a short time while avoiding or reducing residual risk of fungicide.SOLUTION: An aseptic filling method for filling a content in a sterilized container includes a laser irradiation process of irradiating the container or a container preforming body with CO2 laser to sterilize a container surface, and a filling process of filling the content in the container.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[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). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-202284 Summary of the Invention [Problem to be solved by the invention]

[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. [Means for solving the problem]

[0006] One aspect of the aseptic filling method of the present invention is an aseptic filling method for filling contents into a sterilized container, which solves the above-mentioned problem by including a laser irradiation process in which a CO2 laser is irradiated onto the container or container preform to sterilize the container surface, and a filling process in which the 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 a sterilized container, which solves the above-mentioned problem by including a laser irradiation process in which an infrared wavelength laser is irradiated onto the container or container preform to sterilize the container surface, and a filling process in which the contents are filled into the container. Furthermore, one aspect of the aseptic filling system of the present invention is an aseptic filling system for filling contents into sterilized containers, which solves the above-mentioned problem by including a laser irradiation means for irradiating the container surface of the container or container preform with a CO2 laser to sterilize the container surface, and a filling means for filling the contents into the container. Another aspect of the aseptic filling system of the present invention is an aseptic filling system for filling contents into a sterilized container, which solves the above-mentioned problem by including a laser irradiation means for irradiating the container surface of the container or container preform with an infrared wavelength laser to sterilize the container surface, and a filling means for filling the contents into the container.

[0007] In any of the above aseptic filling methods or aseptic filling systems, the laser irradiation process may be carried out on a path between an inlet portion of the container or container preform of the aseptic filling equipment and a filling section where the filling process is carried out. In either of the above-mentioned aseptic filling methods or aseptic filling systems, the laser irradiation process may involve CO2 laser irradiation on the outer surface of the container or container preform, and CO2 laser irradiation on the inner surface of the container or container preform. Either of the above aseptic filling methods or aseptic filling systems may further include 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 may be performed on the preform. Either of the above aseptic filling methods or aseptic filling systems may further include a heat treatment for heating the preform to the molding temperature during the container molding process, and the laser irradiation treatment may be performed on the preform after the heat treatment. In either of the above aseptic filling methods or aseptic filling systems, the laser irradiation process may involve CO2 laser irradiation on the mouth portion of the preform at a higher output and / or a longer irradiation time than CO2 laser irradiation on the body portion of the preform. In either the aseptic filling method or the aseptic filling system, the laser irradiation process may involve irradiating the outer surface of the preform with a CO2 laser, and then irradiating the inner surface of the preform with a CO2 laser. In either of the above-mentioned aseptic filling methods or aseptic filling systems, the laser irradiation process may involve irradiating the inner surface of the preform with a CO2 laser beam diffused in a cone shape by an irradiation unit arranged outside the preform so as to face the opening of the preform. In either of the above-mentioned aseptic filling methods or aseptic filling systems, the laser irradiation process may involve irradiating the inner surface of the preform with a CO2 laser while moving at least one of the preform or the irradiation unit relatively in the axial direction of the preform. In either the aseptic filling method or the aseptic filling system, the laser irradiation process may involve irradiating the inner surface of the preform with a CO2 laser while changing the diffusion angle of the CO2 laser irradiated by the irradiation unit. In either of the above-mentioned aseptic filling methods or aseptic filling systems, the laser irradiation process may involve setting an irradiation spot so that a CO2 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 irradiating the CO2 laser onto the inner surface of the preform while rotating at least one of the preform or the irradiation unit around the axis of the preform. In either of the above aseptic filling methods or aseptic filling systems, the irradiation spot may include a portion of the circumferential range of the preform from the center of the bottom of the preform to the tip of the preform on the opening side. In either the aseptic filling method or the aseptic filling system, the irradiation spot may be set to have an elongated shape with a vertical width in the axial direction of the preform greater than a horizontal width in the circumferential direction of the preform. In either of the above aseptic filling methods or aseptic filling systems, the laser irradiation process may be set so that a CO2 laser is irradiated in one direction by an irradiation unit arranged inside the preform, and the CO2 laser may be irradiated onto the inner surface of the preform while rotating at least one of the preform or the irradiation unit around the axis of the preform and moving at least one of the preform or the irradiation unit relatively in the axial direction of the preform. Either of the above aseptic filling methods or aseptic filling systems may further include a container forming process in which a sheet material serving as the container preform is shaped to form a sheet material container as the container, 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 aseptic filling system described above, the laser irradiation process may be performed on the sheet material before the container forming process. In either of the above-mentioned aseptic filling methods or aseptic filling systems, in the laser irradiation process, the CO2 laser irradiation spot may be 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 CO2 laser may be irradiated onto the sheet material while the sheet material is being conveyed. [Effects of the Invention]

[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. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram showing an aseptic filling system according to one embodiment of the present invention. [Figure 2] FIG. 1 is an explanatory diagram showing an example of a CO2 laser irradiation mode. [Figure 3] FIG. 1 is an explanatory diagram showing an example of a CO2 laser irradiation mode. [Figure 4] An explanatory diagram showing the results of a test to confirm the sterilization effect of CO2 laser irradiation. [Figure 5] A graph showing the absorbance of spore-forming bacteria, mold, and PET resin versus light wavelength. DETAILED DESCRIPTION OF THE INVENTION

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

[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 the 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 conveying mechanism 40 that conveys 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] As shown in FIG. 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 sterile air into a preform P that has been heated to the molding temperature during sterile blow molding.

[0016] The molding area A3 where the blow molding turret 22 is installed is covered by a chamber, and a sterile atmosphere and positive pressure are maintained by blowing sterile air that has passed through a HEPA filter from above using an FFU (Fan Filter Unit). In addition, the blow molding turret 22, blow machine, and other equipment installed in the molding area A3 are sterilized down to the ends of the blow piping. Preforms P, which have been sterilized only at the preform stage, are transported to molding area A3 and aseptically blow molded. As a result, aseptic blow molding, which is blow molding performed under sterile conditions, is performed in molding area A3, which eliminates the need to locally create an atmosphere of sterile air or sterilizing gas near the transport path when transporting preforms P or containers after blow molding within molding area A3, and also eliminates the need to sterilize the containers after blow molding.

[0017] The oven mechanism 30 performs a heating process to raise the temperature of the preform P (its 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 multiple heating heaters 32 configured as infrared heaters that raise the temperature of the preform P. The oven mechanism 30 may be provided with a simple cover surrounding 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 the 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 the 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 preforms P from the outer periphery. 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., a downward position with the mouth portion P2 of the preform P facing downward), or horizontal (i.e., a horizontal position 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 containers are 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 formed 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 configured to be able to sterilize the bacteria to be sterilized (bacteria that can grow in the contents to be filled into the container, such as mold, general bacteria, spore-forming bacteria, etc.) (on the entire outer surface including the inner and outer surfaces of the preform P). 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 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 Figure 1, it is equipped with a laser irradiator 51 as a laser irradiation means that irradiates a CO2 laser onto the container surface of the container or preform P, and a heating means (in this embodiment, an oven mechanism 30) that is arranged upstream of or in the same location as the laser irradiator 51 and heats the area of ​​the container surface to be sterilized. A CO2 laser is a type of gas laser, and this CO2 (carbon dioxide) laser uses a gas mixture of carbon dioxide, nitrogen, and helium. A discharge current is passed through this mixed gas to produce a laser beam.

[0026] As shown in FIG. 1, the laser irradiator 51 sterilizes the container surface of the preform P by irradiating it with a CO2 laser in an area downstream of the oven area A1 and upstream of the blow molding turret 22 (in this embodiment, the transfer area A2) while the preform P is being transported by the turret 42. The laser irradiator 51 has a laser oscillator 51a and an irradiation section 51b made up of optical elements such as a lens, a mirror, a beam expander, and a beam shaper for irradiating the CO2 laser oscillated by the laser oscillator 51a. The laser irradiator 51 may be installed in the oven area A1 or upstream of the oven area A1. Alternatively, the laser irradiator 51 may be installed downstream of the blow molding turret 22, and the molded containers may be sterilized by being irradiated with a CO2 laser.

[0027] The heating means is performed 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.In this embodiment, the above-mentioned oven mechanism 30 functions as the heating means. The specific embodiment of the heating means is not limited to the above, and the heating means may be constituted by a heating 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 step in the filling device 60 is carried out in a chamber whose interior is maintained in a sterile state. In addition, the sterile state of the container is maintained even in the section where the container is transported between the aseptic molding device 20 and the filling device 60. In other words, the sterile state of the container is maintained throughout the entire section from when the container is aseptically blow-molded by the blow molding turret 22 to when the contents are aseptically filled into the container in the filling section 61. In this embodiment, the sterile state of the container is maintained throughout the entire section by covering the above-mentioned entire section with a chamber.

[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 heating process carried out before or simultaneously with the laser irradiation process, a laser irradiation process in which a CO2 laser is irradiated onto the container surface, 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 involves irradiating the container surface (in this embodiment, the entire surface including the inner and outer surfaces of the preform P) with a CO2 laser using a laser irradiator 51, and is carried out on the path between the inlet section 21 of the container or preform (container preform) P of the aseptic filling equipment and the filling section 61 where the filling process is carried out.

[0033] In the laser irradiation process, CO2 laser irradiation is performed (individually) on the outer surface of the container or container preform (in this embodiment, the outer surface of the preform P), and CO2 laser irradiation is performed on the inner surface of the container or container preform (in this embodiment, the inner surface of the preform P).

[0034] The following are examples of CO2 laser irradiation of the inner surface of the preform P. Note that the arrow indicated by the symbol Lc in Figures 2 and 3 is a schematic representation of the CO2 laser.

[0035] First, as shown in FIG. 2(a), it is conceivable to irradiate the inner surface of the preform P with a conically diffused CO2 laser by an irradiation unit 51b arranged on the axis of the preform P outside the preform P so as to face the opening of the preform P. When irradiating with a CO2 laser in this manner, the entire area to be sterilized on the inner surface of the preform P is irradiated with the CO2 laser without the need to insert the irradiation section 51b into the preform P, so irradiation can be completed in a short time. In the example shown in Figure 2(a), with regard to the positional relationship between the irradiation unit 51b and the preform P, the CO2 laser may be irradiated without moving either the irradiation unit 51b or the preform P, or the CO2 laser may be irradiated while moving at least one of the preform P or the irradiation unit 51b relatively in the axial direction of the preform. In the example shown in FIG. 2(a), irradiation may be performed so that the irradiation spot S has a circular shape (full cone irradiation), or irradiation may be performed so that the irradiation spot S has an annular shape (hollow cone irradiation). In the example shown in FIG. 2(a), the CO2 laser may be irradiated while changing the diffusion angle θ of the CO2 laser by the irradiation unit 51b, or the CO2 laser may be irradiated without changing the diffusion angle θ.

[0036] Furthermore, as shown in FIG. 2(b), in the laser irradiation process, an irradiation spot S is set so that the CO2 laser irradiated through an irradiation unit 51b arranged outside the preform P so as to face the opening of the preform P hits a partial area of ​​the inner surface of the preform P, and the CO2 laser may be irradiated onto the inner surface of the preform P while rotating at least one of the preform P or the irradiation unit 51b around the axis of the preform P during irradiation (in the example shown in FIG. 2(b), the preform P is rotated without rotating the irradiation unit 51b). When irradiating with a CO2 laser in this manner, the entire area to be sterilized on the inner surface of the preform P is irradiated with the CO2 laser without the need to insert the irradiation section 51b into the preform P, so irradiation can be completed in a short time. As shown in FIG. 2(b), the irradiation spot S may be set in a partial range in the circumferential direction of the preform P so as to include the area from the center of the bottom of the preform P to the tip of the preform P on the opening side. Furthermore, as shown in FIG. 2(b), the irradiation spot S may be set to have an elongated shape in which the vertical width in the axial direction of the preform P is greater than the horizontal width in the circumferential direction of the preform P. The specific shape of the irradiation spot S may be rectangular, linear, elliptical, or the like. 2(b), with regard to the positional relationship between the irradiation unit 51b and the preform P, the CO2 laser may be irradiated without moving both the irradiation unit 51b and the preform P in the axial direction of the preform P, or the CO2 laser may be irradiated by relatively moving at least one of the preform P or the irradiation unit 51b in the axial direction of the preform P during irradiation. In this case, 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 passes.

[0037] Furthermore, as shown in FIG. 3(a), in the laser irradiation process, the CO2 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) by the irradiation unit 51b arranged inside the preform P, and during irradiation, at least one of the preform P or the irradiation 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 irradiation unit 51b), and the CO2 laser may be irradiated onto the inner surface of the preform P while at least one of the preform P or the irradiation unit 51b is moved relatively in the axial direction of the preform P (in the example shown in FIG. 3(a), the irradiation unit 51b is moved without moving the preform P). In the example shown in FIG. 3(a), the CO 2 laser may be additionally irradiated from the irradiating section 51b toward the bottom side of the preform P (the lower side in the example shown in FIG. 3).

[0038] Furthermore, as shown in Figure 3(b), in the laser irradiation process, the CO2 laser is set to be irradiated radially outward from the entire outer periphery of the tip of the irradiation section 51b arranged (inserted) within the preform P in the radial direction (direction perpendicular to the axial direction of the preform P), and during irradiation, the CO2 laser may be irradiated onto the inner surface of the preform P while at least one of the preform P or the irradiation section 51b is moved relatively in the axial direction of the preform P (in the example shown in Figure 3(b), the irradiation section 51b is moved without moving the preform P). In the example shown in FIG. 3(b), the CO 2 laser may be additionally irradiated from the irradiating section 51b toward the bottom side of the preform P (the lower side in the example shown in FIG. 3).

[0039] Furthermore, as shown in Figure 3(c), in the laser irradiation process, the CO2 laser may be set to diffuse (in all directions) from the tip of the irradiation section 51b arranged inside the preform P, and during irradiation, the CO2 laser may be irradiated onto the inner surface of the preform P while moving at least one of the preform P or the irradiation section 51b relatively in the axial direction of the preform P (in the example shown in Figure 3(c), the preform P is not moved, but the irradiation section 51b is moved). In the example shown in FIG. 3(c), at least one of the preform P and the irradiation section 51b may be rotated around the axis of the preform P.

[0040] Furthermore, as shown in FIG. 3(d), in the laser irradiation process, the CO2 laser may be irradiated onto the inner surface of the preform P by setting it to diffuse (in all directions) from the entire outer periphery of the elongated irradiation section 51b that is arranged inside the preform P and extends along the axial direction of the preform P. In the example shown in Figure 3(d), with regard to the positional relationship between the irradiation unit 51b and the preform P, the CO2 laser may be irradiated without moving either the irradiation unit 51b or the preform P during irradiation, or the CO2 laser may be irradiated while moving at least one of the preform P or the irradiation unit 51b relatively in the axial direction of the preform P during irradiation.

[0041] As for the specific manner of CO2 laser irradiation on the outer surface of the preform P, any manner is acceptable as long as the CO2 laser is irradiated onto the outer surface of the preform P by an irradiation unit arranged outside the preform P (an irradiation unit provided separately from or in the same place as the irradiation unit 51b for irradiating the inner surface of the preform P with CO2 laser).

[0042] Furthermore, with regard to the timing of CO2 laser irradiation on the inner surface of the preform P and CO2 laser irradiation on the outer surface of the preform P, the CO2 laser may be irradiated on the inner surface of the preform P after the CO2 laser is irradiated on the outer surface of the preform P, or conversely, the CO2 laser may be irradiated on the inner surface of the preform P before the CO2 laser is irradiated on the outer surface of the preform P, or the CO2 laser irradiation on the outer surface of the preform P and the CO2 laser irradiation on the inner surface of the preform P may be performed simultaneously.

[0043] In addition, in the laser irradiation process, the output, irradiation time, and integrated light amount (mJ / cm) of CO2 laser irradiation were determined for each part of the container surface of the preform P. 2 ) may be varied. For example, the CO2 laser irradiation on the mouth portion P2 of the preform (for both the inner and outer surfaces of the preform P, or only the inner or outer surface of the preform P) may have a higher output and / or a longer irradiation time than the CO2 laser irradiation on the body portion P1 of the preform. In addition, the integrated light amount (mJ / cm2) of the CO2 laser irradiation on the mouth portion P2 of the preform may be 2 ) is the cumulative light amount (mJ / cm ) of the CO laser irradiation on the body P1 of the preform. 2 ) may be larger than

[0044] In the laser irradiation process, it is preferable to irradiate with a CO2 laser having a wavelength in the 9 μm band (center wavelength of 9.0 to 9.9 μm). In addition, it is preferable to irradiate the CO2 laser for a time of 1 second or less during the laser irradiation process. This significantly reduces the time required for the container sterilization process. The irradiation time here refers to the time the area to be sterilized receives the CO2 laser light. 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 integrated light intensity of the CO2 laser on the sterilization target area of ​​the container surface is set to 1600 mJ / cm 2 or more and 30,000mJ / cm2 It is preferable to irradiate with a CO2 laser so that the following occurs: In addition, in the laser irradiation process, the CO2 laser may be irradiated in either a continuous wave or pulse wave form.

[0045] The heating process involves heating the area of ​​the container surface to be sterilized by laser irradiation using a heating means, and in this embodiment, the preform P is heated to the molding temperature during the container molding process using an oven mechanism 30 as the heating means. 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 carried out on the preform P after the heat treatment.

[0046] Next, a test conducted to confirm the sterilization effect of CO2 laser irradiation will be explained with reference to FIG.

[0047] In this test, 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] The prepared substrate was irradiated with a CO2 laser under the conditions shown in Figure 4, and the number of surviving bacteria on the substrate was then measured using the following standard method. Method for measuring surviving bacterial count: After placing the above substrate, sterilized surfactant aqueous solution, and sterilized beads in a sterilized test tube, the test tube was sealed with a sterilized cap, and 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 counted on a standard agar medium at each dilution ratio using the membrane filtration method. The medium was stored 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. The CO2 laser irradiation spot diameter on the substrate surface was approximately 22 mm, and the "Φ5 output (W)" shown in Figure 4 was the measured output (W) of the laser oscillator during the test that was irradiated onto a circular area with a diameter of 5 mm where the bacteria had been inoculated. In addition, the substrates A-9 to A-12 were heated by a heater so that the irradiated area of ​​the substrate was heated to 120°C during CO2 laser irradiation. The CO2 laser irradiated in A-1 to A-12 is a continuous wave, and the output is adjusted by PWM control (frequency 5 kHz). The CO2 laser irradiated in B-1 to B-3 and C-1 to C-7 is a pulse wave, and the frequency is 1 kHz. The wavelength of the CO2 laser irradiated at A-1 to 12 and B-1 to 3 is in the 9 μm band (9.3 μm), and the wavelength of the CO2 laser irradiated at C-1 to 7 is in the 10 μm band (10.6 μm).

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

[0050] The results of the above tests revealed the following:

[0051] That is, when the wavelength of the CO2 laser 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 output is 1600 mJ / cm 2 or more (more preferably 3310 mJ / cm 2 It was found that when the concentration of the solution is 100% or more, a good bactericidal effect on mold can be obtained. In addition, when the wavelength of the CO2 laser 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 when the concentration of the solution is 100% or more, a good bactericidal effect on mold can be obtained. In addition, when the wavelength of the CO2 laser 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 output is 3820 mJ / cm 2 or more (more preferably 6621 mJ / cm 2 It was found that when the concentration of the solution is 100% or more, a good bactericidal effect on mold can be obtained. In addition, when the wavelength of the CO2 laser 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 output is 6621 mJ / cm 2 or more (more preferably 7130 mJ / cm 2 It was found that when the concentration of the solution is 100% or more, a good bactericidal effect on mold can be obtained. In addition, when the wavelength of the CO2 laser 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 output is 7130 mJ / cm 2 or more (more preferably 7894 mJ / cm 2 It was found that when the concentration of the solution is 100% or more, a good bactericidal effect on mold can be obtained. In addition, when the wavelength of the CO2 laser 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 when the concentration of the solution is 100% or more, a good bactericidal effect on mold can be obtained. In addition, when the wavelength of the CO2 laser 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 when the concentration of the solution is 100% or more, a good bactericidal effect on mold can be obtained. In addition, when the wavelength of the CO2 laser 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 laser output is 400 mJ / cm 2 or more (more preferably 662 mJ / cm 2 It was found that when the concentration of the solution is 100% or more, a good bactericidal effect on mold can be obtained. In addition, when the wavelength of the CO2 laser 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 2or more (more preferably 1986 mJ / cm 2 It was found that when the concentration of the solution is 100% or more, a good bactericidal effect on mold can be obtained. In addition, when the wavelength of the CO2 laser is in the 9 μm band and the substrate is heated, the irradiation time is between 0.03 seconds and 0.05 seconds, and the output is 1986 mJ / cm 2 or more (more preferably 3310 mJ / cm 2 It was found that when the concentration of the solution is 100% or more, a good bactericidal effect on mold can be obtained. Therefore, it was found that even if the irradiation time was set to 1 second or less (0.025 seconds or more without substrate heating, 0.005 seconds or more with substrate heating), mold could be sterilized by appropriately setting the output of the CO2 laser.

[0052] In addition, when the wavelength of the CO2 laser 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 when the above conditions are met, a good bactericidal effect against spore-forming bacteria can be obtained. In addition, when the wavelength of the CO2 laser 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 radiation intensity is 4966 mJ / cm 2 or more (more preferably 6621 mJ / cm 2 It was found that when the concentration of the solution is 100% or more, a good bactericidal effect against spore-forming bacteria can be obtained. In addition, when the wavelength of the CO2 laser 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 output is 6621 mJ / cm 2 or more (more preferably 10186 mJ / cm 2 It was found that when the concentration of the solution is 100% or more, a good bactericidal effect against spore-forming bacteria can be obtained. In addition, when the wavelength of the CO2 laser 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 It was found that when the above conditions are met, a good bactericidal effect against spore-forming bacteria can be obtained. Therefore, it was found that even if the irradiation time was set to 1 second or less (0.05 seconds or more), it was possible to sterilize spore-forming bacteria by appropriately setting the output of the CO2 laser.

[0053] Furthermore, a comparison of A-7 and A-9 revealed that the bactericidal effect on 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] It was also found that the higher the CO2 laser output (Φ5 output) and the shorter the irradiation time, the smaller the cumulative light intensity needed for sterilization.

[0056] Although the mechanism by which CO2 lasers exert the excellent sterilization effect described above is not entirely clear, Figure 5 shows the absorbance of spore-forming bacteria (Bacillus atrophaeus), mold (Aspergillus niger), and PET resin at different wavelengths of light. The spore-forming bacteria, mold, and PET resin all exhibit high absorbance in the CO2 laser wavelength range, particularly in the 9 μm band. The bacteria absorb the CO2 laser light and are directly heated, destroying their DNA. The PET resin is also heated by the laser light, indirectly heating the bacteria, which is thought to result in an excellent sterilization effect. Absorbance was measured using a Fourier transform infrared spectrophotometer (JASCO Corporation FT / IR6700) using the KBR tablet method.

[0057] In this embodiment obtained in this way, the surface of the container can be sterilized well in a short time by having a laser irradiation process in which a CO2 laser is irradiated onto the surface of the container.

[0058] Furthermore, by adopting sterilization by CO2 laser irradiation, sterilization with a disinfectant is not required, or even if disinfection with 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 container preform, 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 described as being the preform P, and the container as being a PET bottle, but the specific aspects of the container preform and the container are not limited to this, and for example, the container may be a resin-coated can or a painted can, or 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 as well, the laser irradiation treatment is performed on a sheet material or the like serving as a container preform or a sheet material container or the like serving as a container. In this case, in the laser irradiation process, the CO2 laser irradiation spot may be 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 serving as the container preform, and the CO2 laser may be irradiated onto the sheet material while the sheet material is being conveyed.

[0063] In addition, if the container surface is made of (or coated with) synthetic resin such as PET (polyethylene terephthalate), PP (polypropylene), or PE (polyethylene), the cumulative light intensity of the CO2 laser on the area to be sterilized on the container surface must be 30,000 mJ / cm2 to prevent damage to the container surface by the CO2 laser. 2 It is preferable to irradiate with a CO2 laser so that the following occurs:

[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 processors as components thereof, such as a sterilization processor 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 a container preform, a sterilization processor 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] Furthermore, in the above-described embodiment, the laser irradiation process is described as irradiating a CO2 laser 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), but it is also possible to irradiate a CO2 laser having another wavelength, for example, a 10 μm band (central wavelength of 10.0 to 10.9 μm, such as 10.2 μm or 10.6 μm).

[0066] In addition, in the above-described embodiment, the CO2 laser is irradiated onto the entire container surface of the container or container preform, including the inner and outer surfaces, during the laser irradiation process. However, the CO2 laser may be irradiated onto 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.).

[0067] In the above-described embodiment, the container surface is sterilized by irradiating it with a CO2 laser, but instead of a CO2 laser, the container surface may be sterilized by irradiating it with an infrared wavelength laser (specifically, a laser with a wavelength of 0.78 μm to 1000 μm, including lasers with near-infrared wavelengths, mid-infrared wavelengths, and far-infrared wavelengths). In addition to the CO2 laser, known lasers such as a diode laser, fiber laser, YAG laser, YVO4 laser, and CO laser may also be used. Compared to known infrared lamps and heaters, infrared wavelength lasers have high directionality and can irradiate infrared rays intensively on the area to be sterilized, making them highly energy efficient. They also have the advantage of having a fast output rise when irradiation begins, allowing for short-term ON-OFF control. The specific aspects of the aseptic filling method and system using an infrared wavelength laser are exactly the same as the aseptic filling method and system using a CO2 laser described above, except that an infrared wavelength laser is used instead of a CO2 laser. Therefore, the specific explanation will be omitted by replacing "CO2 laser" in the explanation of the aseptic filling method and system using a CO2 laser described above with "infrared wavelength laser."

[0068] Furthermore, the above-mentioned aseptic filling method and system using an infrared wavelength laser can also be described as follows, but is not limited to the following: (Appendix 1) 1. An aseptic filling method for filling a sterilized container with a content, comprising: a laser irradiation treatment in which the container or container preform is irradiated with a laser having an infrared wavelength to sterilize the container surface; a filling process for filling the container with a content; A method for aseptic filling, comprising: (Appendix 2) The aseptic filling method described in Appendix 1, characterized in that the laser irradiation process is performed on the path between the inlet of the container or container preform of the aseptic filling equipment and the filling section where the filling process is performed. (Appendix 3) The aseptic filling method according to claim 1 or 2, characterized in that the laser irradiation treatment involves irradiating the outer surface of the container or container preform with a laser of an infrared wavelength, and irradiating the inner surface of the container or container preform with a laser of an infrared wavelength. (Appendix 4) The method further includes a container molding process of blow molding the preform as the container preform to form a PET bottle as the container, 4. The aseptic filling method according to any one of claims 1 to 3, wherein the laser irradiation treatment is performed on the preform. (Appendix 5) The method further includes a heat treatment for heating the preform to a molding temperature during the container molding treatment, 5. The aseptic filling method according to claim 4, wherein the laser irradiation treatment is performed on the preform after the heat treatment. (Appendix 6) The aseptic filling method according to claim 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) 7. A method for aseptic filling according to any one of claims 4 to 6, characterized in that the laser irradiation process involves irradiating the outer surface of the preform with a laser of an infrared wavelength, and then irradiating the inner surface of the preform with a laser of an infrared wavelength. (Appendix 8) The aseptic filling method according to any one of appendices 4 to 7, characterized in that in the laser irradiation process, a laser beam of infrared wavelength diffused in a cone shape is irradiated onto the inner surface of the preform by an irradiation unit arranged outside the preform so as to face the opening of the preform. (Appendix 9) The aseptic filling method described in Appendix 8, characterized in that in the laser irradiation process, an infrared wavelength laser is irradiated onto the inner surface of the preform 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 described in Appendix 8 or Appendix 9, characterized in that the laser irradiation process irradiates the inner surface of the preform with an infrared wavelength laser while changing the diffusion angle of the infrared wavelength laser by the irradiation unit. (Appendix 11) The aseptic filling method according to any one of Supplementary Notes 4 to 7, characterized in that in the laser irradiation process, an irradiation spot is set so that an infrared wavelength laser is irradiated through an irradiation unit arranged outside the preform so as to face the opening of the preform and 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 rotating at least one of the preform or the irradiation unit around the axis of the preform. (Appendix 12) The aseptic filling method described in Appendix 11, characterized in that the irradiation spot is set to include a portion 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. (Appendix 13) The aseptic filling method described in Appendix 11 or Appendix 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 Supplementary Notes 4 to 7, characterized in that in the laser irradiation process, 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 around 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 infrared wavelength laser onto the inner surface of the preform. (Appendix 15) The method further includes a container forming process of forming a sheet material container as the container by forming the sheet material as the container preform, 4. The aseptic filling method according to any one of claims 1 to 3, wherein the laser irradiation treatment is performed on the sheet material or the sheet material container. (Appendix 16) 16. The aseptic filling method according to claim 15, wherein the laser irradiation treatment is performed on the sheet material before the container forming treatment. (Appendix 17) The aseptic filling method described in Appendix 16, characterized in that in the laser irradiation process, the irradiation spot of the infrared wavelength laser is set to a horizontally elongated shape whose width in a direction perpendicular to the conveying direction of the sheet material is wider than its vertical width in the conveying direction of the sheet material, and the infrared wavelength laser is irradiated onto the sheet material while the sheet material is being conveyed. (Appendix 18) An aseptic filling system for filling a sterilized container with a content, a laser irradiation means for sterilizing the container surface by irradiating the container surface or the container preform with a laser having an infrared wavelength; a filling means for filling the container with a content; An aseptic filling system comprising: [Explanation of symbols]

[0069] 10. Aseptic Filling System 20... Aseptic molding equipment 21 Entrance 22 Blow molding turret 30 Oven mechanism 31 Oven chamber 32 Heating heater 40 Preform transport mechanism 41 Conveyor 42 Turret 50... Container sterilizer 51 Laser irradiator (laser irradiation means) 51a Laser oscillator 51b... Irradiation section 60... Filling equipment 61 Filling section 62 Capping section P ··· Preform (preformed container) P1: Body of the preform P2: Mouth of preform A1 Oven area A2 Transfer area A3: Molding area Lc...CO2 laser

Claims

1. 1. An aseptic filling method for filling a sterilized container with a content, comprising: CO ２ a laser irradiation process for sterilizing the container surface by irradiating the container with a laser; a filling process for filling the container with a content; A method for aseptic filling, comprising:

2. The aseptic filling method according to claim 1, characterized in that the laser irradiation treatment is carried out on a path between an inlet of the container or container preform of an aseptic filling equipment and a filling section where the filling treatment is carried out.

3. In the laser irradiation treatment, CO ２ Laser irradiation and CO 2 irradiation on the inner surface of the container or container preform. ２ 2. The aseptic filling method according to claim 1, further comprising the step of irradiating the container with a laser.

4. The method further includes a container molding process of blow molding the preform as the container preform to form a PET bottle as the container, 2. The aseptic filling method according to claim 1, wherein the laser irradiation treatment is performed on the preform.

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

6. In the laser irradiation treatment, CO ２ After the laser irradiation, the inner surface of the preform is subjected to CO ２ 5. The aseptic filling method according to claim 4, further comprising the step of irradiating the container with a laser.

7. In the laser irradiation process, CO diffused in a cone shape is emitted by an irradiation unit arranged outside the preform so as to face the opening of the preform. ２ 5. The aseptic filling method according to claim 4, wherein the inner surface of the preform is irradiated with a laser.

8. In the laser irradiation process, at least one of the preform and the irradiation unit is moved relatively in the axial direction of the preform, and CO ２ 8. The aseptic filling method according to claim 7, further comprising irradiating a laser.

9. In the laser irradiation process, the CO ２ While changing the diffusion angle of the laser, CO ２ 8. The aseptic filling method according to claim 7, further comprising irradiating a laser.

10. In the laser irradiation process, CO irradiated through an irradiation unit arranged 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 5. The aseptic filling method according to claim 4, further comprising irradiating a laser.

11. The aseptic filling method according to claim 10, wherein the irradiation spot is set to 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.

12. 11. The aseptic filling method according to claim 10, wherein the irradiation spot is set to have an elongated shape whose vertical width in the axial direction of the preform is greater than its horizontal width in the circumferential direction of the preform.

13. In the laser irradiation process, CO ２ The 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 5. The aseptic filling method according to claim 4, further comprising irradiating a laser.

14. The method further includes a container forming process of forming a sheet material container as the container by forming the sheet material as the container preform, 2. The aseptic filling method according to claim 1, wherein the laser irradiation treatment is performed on the sheet material or the sheet material container.

15. 15. The aseptic filling method according to claim 14, wherein the laser irradiation treatment is performed on the sheet material before the container forming treatment.

16. In the laser irradiation process, 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 15. The aseptic filling method according to claim 14, wherein a laser is irradiated.

17. An aseptic filling system for filling a sterilized container with a content, The container surface of the container or container preform is subjected to CO ２ a laser irradiation means for sterilizing the surface of the container by irradiating the surface with a laser; a filling means for filling the container with a content; An aseptic filling system comprising:

18. 1. An aseptic filling method for filling a sterilized container with a content, comprising: a laser irradiation treatment in which the container or container preform is irradiated with a laser having an infrared wavelength to sterilize the container surface; a filling process for filling the container with a content; A method for aseptic filling, comprising:

19. An aseptic filling system for filling a sterilized container with a content, a laser irradiation means for sterilizing the container surface by irradiating the container surface or the container preform with a laser having an infrared wavelength; a filling means for filling the container with a content; An aseptic filling system comprising:

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