Method and device for sterilizing preform

Abstract

Provided are a preform sterilization method and device with which it is possible to reduce hydrogen peroxide remaining during preform sterilization. In the present invention, a sterilizing agent containing at least 30% by mass or less of hydrogen peroxide and a solvent having a boiling point of 85 DEG C or less is gasified, the sterilizing agent gas is blown to a preform, hot air is blown or not blown to the preform to which the sterilizing agent has been blown, and the preform is heated to a temperature at which the preform can be molded. Furthermore, after irradiating the preform with light including ultraviolet rays, a sterilizing agent gas is blown to the preform, and the preform is heated to a temperature at which the preform can be molded.

Description

[0001] This application is a divisional application of the Chinese invention application “Method and device for sterilizing preforms” with application number 201780039181.0 and application date on June 21, 2017. Technical Field

[0002] The present invention relates to a method and device for sterilizing preforms. Background Art

[0003] In the past, the following sterilization method has been proposed: a sterilizing agent is applied to a preform while the preform is continuously advanced, the preform is directly introduced into a heating furnace in this state, the preform is heated in the heating furnace to a temperature for forming into a container, and the sterilizing agent applied to the preform is simultaneously dried and activated by this heating (Patent Documents 1, 2, and 3).

[0004] In addition, the following beverage filling method has been proposed: preheating a preform, blowing hydrogen peroxide mist or gas onto the preheated preform, further heating the preform to a molding temperature, molding the preform that has reached the molding temperature into a bottle in a blow molding mold that is also continuously moving, removing the bottle from the blow molding mold, and then filling the bottle with a beverage and sealing it with a cap (Patent Documents 4 and 5).

[0005] The sterilizer used in the above-mentioned prior art is hydrogen peroxide. On the other hand, there are also proposals for using a sterilizer prepared by dissolving hydrogen peroxide in a solvent having a boiling point of less than 100°C, or a sterilizer containing ethanol with a hydrogen peroxide concentration of 25% by mass, in polyethylene terephthalate (PET) preforms and bottles (Patent Documents 6 and 7).

[0006] On the other hand, regarding the sterilization of preforms, sterilization by light without using hydrogen peroxide has also been proposed (see Patent Document 8).

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application No. 2001-510104

[0010] Patent Document 2: Japanese Patent Application Laid-Open No. 2008-183899

[0011] Patent Document 3: Japanese Patent Application No. 2008-546605

[0012] Patent Document 4: Japanese Patent Application Laid-Open No. 2013-35561

[0013] Patent Document 5: Japanese Patent Application Laid-Open No. 2013-35562

[0014] Patent Document 6: International Publication No. WO2013 / 0099789

[0015] Patent Document 7: Japanese Patent Application Laid-Open No. 7-315345

[0016] Patent Document 8: Japanese Patent Application Laid-Open No. 2016-55915 Summary of the Invention

[0017] Problems to be solved by the invention

[0018] Conventional aseptic bottle filling machines mold preforms into bottles and sterilize the formed bottles. However, this requires large amounts of sterilizing agents and results in excessively large equipment. Consequently, aseptic filling machines that sterilize the preforms at the preform stage are gaining popularity. Consequently, proposals for preform sterilization, such as those described in the aforementioned patent documents, have been proposed. Patent Documents 1, 2, and 3 propose methods in which hydrogen peroxide, a sterilizing agent, is sprayed onto the preforms and then the preforms are directly introduced into a heating furnace for heating.

[0019] The prior art for sterilizing preforms mentioned above involves performing the sterilization treatment at the preform stage before bottle molding. The hydrogen peroxide attached to the preform for sterilization is decomposed or volatilized by heating the preform in an oven. However, some of it remains in the preform. The preform is then blow-molded into a bottle, and while this blow-molding process further reduces the amount of hydrogen peroxide, it may still remain on the inner surface of the bottle. Furthermore, the bottle is rinsed with sterile water and sterile air before being filled with a beverage, further reducing residual hydrogen peroxide. However, there is a concern that some of the hydrogen peroxide that remains in the bottle may transfer into the beverage being filled. Therefore, when sterilizing preforms, it is necessary to minimize the amount of hydrogen peroxide remaining in the preform.

[0020] Furthermore, the hydrogen peroxide sprayed onto the preform surface must form a uniform coating. If the hydrogen peroxide sprayed onto the preform surface forms an uneven coating, temperature differences will occur across the preform when the preform is heated in the furnace due to differences in the hydrogen peroxide's heat of vaporization. This can result in poor molding, such as whitening, deformation, and uneven molding of the finished bottle. Furthermore, if the hydrogen peroxide concentration on the preform surface is low or if certain areas of the preform surface are not covered with hydrogen peroxide, there is a concern that sterilization will be inadequate.

[0021] As in Patent Document 6, it is also proposed to add a solvent with a boiling point lower than that of water to hydrogen peroxide as a sterilizing agent. However, a step of removing the sterilizing agent after spraying is required, which has the disadvantage of increasing the number of steps compared to the method of directly introducing the sterilizing agent into a heating furnace.

[0022] The sterilized preform is molded into a bottle, which is then filled with the sterilized beverage under a sterile atmosphere to produce a finished product. However, if the mouth of the preform shrinks or deforms during bottle molding, bacteria can enter the product from outside, potentially compromising the sterility of the beverage. Therefore, to prevent shrinkage and deformation of the preform's mouth, the mouth temperature must be maintained below 70°C. This limits heating of the mouth, so to sterilize the mouth, a sterilant containing excess hydrogen peroxide must be applied or sprayed over the entire preform, exceeding the amount required to sterilize the body and bottom of the preform. This results in a high level of residual hydrogen peroxide.

[0023] Methods for sterilizing preforms without using hydrogen peroxide have also been proposed, but the sterilization is insufficient. A method for sterilizing preforms that uses hydrogen peroxide and has high sterilization performance and low residual hydrogen peroxide is being sought.

[0024] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method and apparatus for sterilizing preforms that can reduce residual hydrogen peroxide during preform sterilization.

[0025] Solutions to the problem

[0026] The preform sterilization method of the present invention includes a gas sterilizer blowing step of vaporizing a sterilizer containing at least 30 mass % or less of hydrogen peroxide and a solvent having a boiling point of 85° C. or less and blowing the sterilizer onto the preform.

[0027] Furthermore, the preform sterilization method of the present invention preferably includes a heating step of heating the preform to which the sterilizer gas has been blown to a temperature suitable for molding into a bottle.

[0028] Furthermore, in the preform sterilization method of the present invention, it is preferred that the sterilizer is a solution containing 0.5% by mass to 30% by mass of a hydrogen peroxide component.

[0029] Furthermore, in the preform sterilization method of the present invention, it is preferred that the solvent is ethanol.

[0030] Furthermore, in the preform sterilization method of the present invention, it is preferred that the sterilizer is a solution containing 0.5% to 30% by mass of a hydrogen peroxide component and 14% to 99% by mass of the ethanol.

[0031] Furthermore, the preform sterilization method of the present invention preferably further comprises a light irradiation step of irradiating at least the opening of the preform with light containing ultraviolet rays.

[0032] The preform sterilization method of the present invention comprises: a light irradiation step, in which light containing ultraviolet rays is irradiated on at least the mouth of the preform; and a sterilizing agent gas blowing step, in which a sterilizing agent containing at least hydrogen peroxide is vaporized and the sterilizing agent gas is blown toward the above-mentioned preform.

[0033] Furthermore, in the preform sterilization method of the present invention, it is preferable that the sterilizer gas is formed by spraying the sterilizer into a vaporization section to vaporize the sterilizer, and blowing the sterilizer gas toward the preform from a nozzle of the vaporization section.

[0034] Furthermore, in the preform sterilization method of the present invention, it is preferable that one or more nozzles are positioned opposite to a travel path of the preform, and the sterilizing agent gas is blown toward the preform from the nozzles.

[0035] Furthermore, in the preform sterilization method of the present invention, the sterilant gas is preferably divided into a plurality of flow paths within the nozzle, with one flow path directed toward the mouth of the preform and another flow path directed toward the outer surface of the preform.

[0036] Furthermore, in the preform sterilization method of the present invention, it is preferable that, after blowing the sterilant gas toward the preform, air is blown toward the sterilant gas blowing portion in the preform.

[0037] Furthermore, in the preform sterilization method of the present invention, it is preferable that the air is hot air.

[0038] Furthermore, in the preform sterilization method of the present invention, it is preferable that the light containing ultraviolet rays is irradiated by a xenon flash lamp.

[0039] Furthermore, in the preform sterilization method of the present invention, it is preferable that the light containing ultraviolet rays is concentratedly irradiated onto the mouth portion of the preform.

[0040] The preform sterilization device of the present invention is provided with: a moving mechanism for moving the preform from the supply of the preform to the molding of the bottle; a nozzle in the moving mechanism for blowing sterilant gas toward the preform; and a lamp for irradiating light containing ultraviolet rays to at least the mouth of the preform.

[0041] In the preform sterilization apparatus of the present invention, the nozzle is preferably a nozzle for blowing sterilant gas toward the preform, and the sterilant gas contains at least 30% by mass or less of hydrogen peroxide and a solvent having a boiling point of 85° C. or less.

[0042] Furthermore, in the preform sterilization apparatus of the present invention, it is preferable that the sterilizer is a solution containing 0.5% to 30% by mass of a hydrogen peroxide component and 14% to 99% by mass of ethanol.

[0043] Furthermore, in the preform sterilization apparatus of the present invention, it is preferable that an air nozzle for blowing air toward the preform is provided on the downstream side of the travel mechanism with respect to the nozzle.

[0044] Furthermore, in the preform sterilizing apparatus of the present invention, it is preferred that the air nozzle has a slit-shaped blowing port for blowing the air toward the opening of the preform, and the blowing port extends in the traveling direction of the preform.

[0045] Furthermore, in the preform sterilization apparatus of the present invention, it is preferable that the nozzle is disposed at a front end portion of a vaporization section that vaporizes the sterilizing agent by spraying.

[0046] In addition, in the sterilization device for preforms of the present invention, the above-mentioned nozzle for conveying the above-mentioned sterilant gas is preferably divided into multiple pipelines, so that the discharge port of one pipeline is opposite to the opening of the above-mentioned preform, and the other pipeline is extended toward the outer surface of the above-mentioned preform, and its discharge port is opposite to the outer surface of the above-mentioned preform.

[0047] Furthermore, in the preform sterilization apparatus of the present invention, it is preferable that the lamp that irradiates light including ultraviolet rays is a xenon flash lamp.

[0048] Furthermore, in the preform sterilization apparatus of the present invention, it is preferable that a reflecting plate is provided on the opposite side of the preform from the lamp irradiating the light.

[0049] Furthermore, in the preform sterilization apparatus of the present invention, it is preferable that the reflecting plate is provided so as to cover the mouth portion of the preform.

[0050] Effects of the Invention

[0051] According to the present invention, since the method for sterilizing preforms includes a sterilizer gas blowing step of vaporizing a sterilizer containing at least 30% by mass or less of hydrogen peroxide and a solvent having a boiling point of 85°C or less, and blowing the sterilizer gas toward the preform, even with a sterilizer having a low hydrogen peroxide concentration of 30% by mass or less, sufficient sterilizing power can be obtained by using a solvent having a boiling point of 85°C or less, thereby reducing the amount of hydrogen peroxide remaining in the preform. As a result, the amount of hydrogen peroxide remaining in the bottle formed by blow-molding the preform can be reduced.

[0052] Furthermore, according to the present invention, the sterilization effect is enhanced by providing a light irradiation step of irradiating the preform with light including ultraviolet rays. This allows the concentration of hydrogen peroxide, which is a sterilizing agent component of the sterilizer, to be reduced, resulting in a reduction in the amount of residual hydrogen peroxide in the preform.

[0053] Furthermore, according to the present invention, by intensively irradiating the mouth of the preform with ultraviolet light, the mouth of the preform, which is the most difficult to sterilize, can be effectively sterilized. Consequently, the concentration and amount of hydrogen peroxide in the sterilizing agent sprayed onto the entire preform can be further reduced, resulting in less residual hydrogen peroxide in the preform. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a schematic plan view showing a portion of an aseptic filling device incorporating the preform sterilization device of the present invention, specifically, the portion up to bottle molding.

[0055] Figure 2 A method for sterilizing a preform according to an embodiment of the present invention is shown, wherein (A), (B), (C), and (D) respectively represent a sterilizing gas blowing step, an air blowing step, a light irradiation step, and a heating step for the preform.

[0056] Figure 3 (E), (F), (G), and (H) respectively represent the preform molding process, bottle taking-out process, content filling process, and sealing process.

[0057] Figure 4 It is a vertical cross-sectional view showing an example of a gas generator for generating sterilant gas.

[0058] Figure 5 This is a vertical cross-sectional view showing a sterilant gas blowing nozzle incorporated in the preform sterilization apparatus of the present invention.

[0059] Figure 6 The air nozzle incorporated in the preform sterilization apparatus of the present invention is shown, with (A) being a plan view thereof and (B) being a vertical cross-sectional view.

[0060] Figure 7 This is an explanatory diagram showing a modified example of the process of blowing air onto the preform.

[0061] Figure 8 This is an explanatory diagram showing another modified example of the process of blowing air onto the preform.

[0062] Figure 9 This is an explanatory diagram showing still another modified example of the process of blowing air onto the preform.

[0063] Figure 10This is an explanatory diagram showing a modified example of the step of heating the preform to the molding temperature.

[0064] Figure 11 This is an explanatory diagram showing a modified example of the process after heating the preform to the molding temperature.

[0065] Figure 12 This is a schematic plan view showing a portion of an aseptic filling device incorporating the preform sterilization device of the present invention, specifically, the portion up to bottle molding.

[0066] Explanation of symbols

[0067] 1…Preform

[0068] 2…bottles

[0069] 6… Sterilant gas blowing nozzle

[0070] 6a, 6b…nozzles

[0071] 9…Gasification Department

[0072] 23…Umbrella-shaped parts

[0073] 24…Gas outlet

[0074] 37…Air nozzle

[0075] 37a…Air outlet

[0076] G…Gas

[0077] P…Air

[0078] L…Light DETAILED DESCRIPTION

[0079] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

[0080] (Implementation 1)

[0081] First pass Figure 1 、 Figure 2 and Figure 3 The process and apparatus from preform sterilization to bottle molding are described, followed by a detailed description of the preform sterilization method and apparatus. According to this first embodiment, sterilizing the preform can produce a sterilized preform, and the amount of hydrogen peroxide remaining in the bottle molded from the preform can be reduced.

[0082] (Overview of Method and Apparatus)

[0083] like Figure 1As shown, the preform 1 is supplied from the preform supply device 11 and is conveyed into the cavity 28 a by the preform conveyor 14 .

[0084] The preform 1 is delivered to the sterilant gas blowing wheel 15, as shown in FIG. Figure 2 As shown in FIG. 2 (A), the sterilizer gas G is blown toward the preform 1 by the sterilizer gas blowing nozzle 6 (sterilizer gas blowing step).

[0085] Then, the preform 1 is handed over to the air blowing and light irradiation wheel 16, as shown in FIG. Figure 2 As shown in FIG. 1 (B), air P is blown by the air nozzle 37 .

[0086] Furthermore, Figure 2 As shown in FIG. 5 (C), the preform 1 is irradiated with light L containing ultraviolet rays emitted from the lamp 30a provided in the light irradiation device 30 (light irradiation step).

[0087] In the light irradiation step of the preform 1, the preform 1 and the lamp 30a may be moved in parallel, or the lamp 30a may be inserted into the preform 1. Since the main purpose is to sterilize the mouth 2a, the insertion distance may be such that the lamp 30a is inserted to the same horizontal position as the clamp 13, but it may also be inserted to the bottom of the preform 1. A short insertion distance has the advantage of a compact apparatus even at high speeds.

[0088] Blowing the sterilant gas G onto the preform 1 (sterilizer gas blowing step) (A) is essential, but blowing the air P (B) and irradiating the preform 1 with light L (C) (light irradiation step) are optional. However, it is ideal to perform both steps. Furthermore, blowing the sterilizer gas G and blowing the air P onto the preform 1 are performed sequentially, but light irradiation (C) can be performed at any stage.

[0089] That is, in the sterilizing gas blowing wheel 15, the light irradiation device 30 can be installed upstream or downstream of the nozzle 6, or downstream of the air nozzle 37. Furthermore, it can be installed in multiple locations among the three locations mentioned above. In addition, the blowing (A) of the sterilizing gas G, the blowing (B) of the air P, and the irradiation (C) of the light L can be performed by a single wheel, or they can be performed by separate wheels.

[0090] The preform 1 that has completed the sterilization process is released from the gripper 13 that has been gripped during the wheel transport, and is transported to the heating furnace 25 by the heating furnace transport wheel 17 .

[0091] The preform 1 placed in the heating furnace 25 is as follows Figure 2 As shown in (D), the infrared heater 18a and other heating means are used to heat the mold to a temperature suitable for subsequent blow molding. The temperature is about 90°C to 130°C.

[0092] In order to prevent deformation and the like, the temperature of the mouth portion 2a of the preform 1 is suppressed to 70°C or lower.

[0093] In addition, the preform 1 is as Figure 2 As shown in (D), a shaft 29 is inserted into the mouth 2a, and the preform is transported while rotating in the heating furnace 25. By inserting a mandrel instead of the shaft 29 into the preform 1, the preform 1 can also be rotated and transported in an inverted state.

[0094] The heated preform 1 is released from the shaft 29 and is gripped by the clamp 13 of the wheel 19 of the blow molding machine 12 and is transported to the molding wheel 20 of the blow molding machine through the wheel 19. Figure 3 As shown in (E), the bottle 2 is blow-molded. A plurality of molds 4 and blow nozzles 5 are arranged around the molding wheel 20, and rotate around the wheel 20 at a constant speed along with the rotation of the wheel 20. When the heated preform 1 arrives, the mold 4 clamps the preform 1. The blow nozzle 5 is inserted into the preform 1, and air or other gas is blown into the preform 1 from the blow nozzle 5, thereby forming the bottle 2 in the mold 4. Figure 3 As shown in FIG. 1 (F), the bottle 2 after molding is gripped by the clamp 13 provided on the wheel 21 and is taken out from the mold 4 .

[0095] The bottle 2 is visually inspected by an inspection device 27 provided on the wheel 21. The inspection device 27 is a well-known device, and therefore its details are omitted.

[0096] The inspected bottles 2 are transported by wheels 22 to the filling station.

[0097] The filling part is located in a sterilized chamber, such as Figure 3 As shown in (G), the filling nozzle 10 is used to fill the sterilized contents into the sterilized bottle 2 under a sterile atmosphere. Figure 3 The filled bottle 2 shown in (H) is sealed with a sterilized cap 3. The filling unit is a well-known device, and its details are omitted.

[0098] (Details of the method and apparatus)

[0099] The preform 1 in the present invention is a test tube-shaped cylindrical body with a bottom, which is given Figure 3The same mouth portion 2a as the bottle 2 shown in (H) of FIG. An external thread is formed on the mouth portion 2a at the same time as the preform 1 is formed. The preform 1 is formed by injection molding, compression molding, etc. The material of the preform 1 includes thermoplastic resins such as polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyethylene, etc., and these resins can be monomers or mixtures, and can also include recycled thermoplastic resins. In addition, in order to impart barrier properties, thermoplastic resins such as ethylene-vinyl alcohol copolymers and polyamides with aromatic amines such as o-xylylenediamine as monomers can be made into layers or included in the form of a mixture.

[0100] The sterilizer contains at least 30% by mass or less of hydrogen peroxide and a solvent with a boiling point of 85°C or less. If the hydrogen peroxide content exceeds 30% by mass, the amount of residual hydrogen peroxide after bottle molding will be excessive. Currently, hydrogen peroxide containing 35% by mass of hydrogen peroxide is commonly used as a sterilizer. Including a solvent with a boiling point of 85°C or less as a component of the sterilizer lowers the condensation temperature of the vaporized sterilizer and makes the condensed mist finer. This increases the sterilization effect of the sterilizer gas G on the surface of the preform 1 and the sterilization effect of the condensed mist. Therefore, even with a reduced hydrogen peroxide content, a sufficient sterilization effect can be achieved.

[0101] The sterilizer contains at least 30% by mass or less of hydrogen peroxide and a solvent having a boiling point of 85°C or less. Therefore, compared with sterilizers that have only contained hydrogen peroxide and water so far, after the sterilizer gas G is blown to the preform 1, the contact angle of the sterilizer mist, that is, the droplets, formed on the surface of the preform 1 is small, and even if the droplets have the same weight, the coverage area becomes larger. Therefore, it is also believed that when the hydrogen peroxide in the above-mentioned droplets decomposes, a greater sterilization effect will be exerted.

[0102] The hydrogen peroxide content of the disinfectant is more preferably 0.5% to 30% by mass. A content of less than 0.5% by mass may result in insufficient bactericidal activity. Setting the content to 30% by mass or less can further reduce the amount of residual hydrogen peroxide. Furthermore, a hydrogen peroxide content of 20% by mass or less is more preferred. This can further reduce the amount of residual hydrogen peroxide, although this varies depending on the type and amount of the solvent with a boiling point of 85°C or less.

[0103] Solvents with a boiling point of 85°C or less include methanol, ethanol, isopropyl alcohol, and acetone. These can be used alone or in combination. The disinfectant component other than hydrogen peroxide and solvents with a boiling point of 85°C or less is water, and when these are mixed, the composition must be uniform. Solvents with a boiling point of 85°C or less, particularly ethanol, are suitable from a safety perspective.

[0104] The best disinfectant is a solution containing 0.5% to 30% hydrogen peroxide and 14% to 99% ethanol. If the ethanol content is less than 14%, the residual hydrogen peroxide content cannot be sufficiently reduced.

[0105] Fungicides such as Figure 4 As shown, the sterilant gas generator 7 is used for vaporization. The sterilant gas generator 7 includes: a sterilant supply section 8 which is a two-fluid spray nozzle that supplies the sterilant in the form of drops; and a vaporization section 9 that heats the sterilant supplied from the sterilant supply section 8 to a temperature below the decomposition temperature of hydrogen peroxide to vaporize it. The sterilant supply section 8 introduces sterilant and compressed air from the sterilant supply path 8a and the compressed air supply path 8b, respectively, and sprays the sterilant into the vaporization section 9. The vaporization section 9 is a tube with a heater 9a sandwiched between the inner and outer walls, and heats the sterilant blown into the tube to vaporize it. The vaporized sterilant gas is ejected from the sterilant gas blowing nozzle 6 to the vaporization section 9. The vaporization section 9 can also be heated by induction heating instead of the heater 9a.

[0106] The operating conditions of the sterilant supply unit 8 include adjusting the compressed air pressure within a range of, for example, 0.05 MPa to 0.6 MPa. The sterilant can be dropped by gravity or pressure can be applied. Furthermore, the sprayed sterilant is vaporized by heating the inner surface of the vaporization unit 9 to 140°C to 450°C.

[0107] The sterilant gas G is blown as Figure 2 As shown in FIG. 1 (A), the sterilizer gas is blown from the sterilizer gas blowing nozzle 6 toward the preform 1 (sterilizer gas blowing step).

[0108] Sterilizer gas G is blown from the sterilizer gas blowing nozzle 6 toward the preform 1. Figure 5 As shown, the sterilant gas G may be divided into two parts and flowed in the sterilant gas blowing nozzle 6, one part of which is blown from the nozzle 6a toward the interior of the preform 1, and the other part of which is blown from the sterilant gas blowing port 24 provided in the nozzle 6b toward the outer surface of the preform 1. After the sterilant gas G exits the sterilant gas blowing nozzle 6, it may flow into the interior of the preform 1 as a gas, or may condense into mist, or may become a mixture thereof, or may be blown toward the outer surface of the preform 1.

[0109] It should be noted that, for the sterilant gas blowing nozzle 6, nozzles 6a, 6b, condensation of the sterilant containing hydrogen peroxide in the nozzles 6a, 6b can be prevented by supplying hot air as sterile air from the middle of the nozzles 6a, 6b. Alternatively, an electric belt heater can be wound around the nozzles 6a, 6b to prevent condensation.

[0110] In addition, the flow path of the sterilant gas G ejected into the interior of the preform 1 is covered by the umbrella-shaped member 23. The sterilant gas G and mist flowing into the preform 1 overflow from the mouth 2a of the preform 1. However, the flow path of the overflowing sterilant gas G and the like may collide with the umbrella-shaped member 23 and be guided to the annular groove 23a provided on the inner surface of the umbrella-shaped member 23, thereby changing the flow path toward the outer surface of the preform 1 and being blown toward the outer surface of the preform 1.

[0111] In this manner, the sterilizing agent gas G, mist, or a mixture thereof is blown toward the inner and outer surfaces of the preform 1 , thereby sterilizing or damaging microorganisms attached to the surface of the preform 1 .

[0112] It should be noted that in Figure 2 Immediately before the sterilizing gas G shown in (A) is blown onto the preform 1, hot air or the like may be blown onto the preform 1 to preheat the preform 1. This preheating can further enhance the sterilization effect of the preform 1.

[0113] Furthermore, not only one sterilizer gas blowing nozzle 6 but a plurality of sterilizer gas blowing nozzles 6 may be arranged along the travel path of the preform 1 , and the sterilizer gas G may be blown toward the preform 1 from the sterilizer gas blowing nozzle 6 .

[0114] The preform 1 blown with the sterilant gas can be Figure 2 As shown in FIG. 1 (B), the material is gripped and transported by the clamp 13 and air P is blown from the air nozzle 37.

[0115] The blowing of air P activates hydrogen peroxide adhering to the surface of the preform 1, sterilizing microorganisms on the inner and outer surfaces of the preform 1. Furthermore, the blowing of air P rapidly removes the sterilant adhering to the surface of the preform 1. The sterilant adhering to the surface of the preform 1 is removed from the preform 1 by the blowing of air P before it is placed in the heating furnace 25, thereby preventing damage to various components within the blow molding machine 12, such as sealing components, caused by hydrogen peroxide. Furthermore, the occurrence of defects such as whitening, deformation, and uneven molding of the bottle caused by the adhesion of sterilant to the preform 1 is prevented.

[0116] The air P can be at room temperature, but heating it to hot air P promotes the decomposition of hydrogen peroxide, improving the sterilization effect and reducing residual hydrogen peroxide. The ideal temperature for heating the air P when blowing it onto the preform is 40°C to 140°C. Temperatures below 40°C are less effective, while temperatures exceeding 70°C can cause problems such as deformation of the mouth 2a of the preform 1. Therefore, a temperature between 40°C and 70°C is appropriate.

[0117] like Figure 2As shown in FIG. 1 (B), the air P is blown out from a slit-shaped air outlet 37 a formed in a box-shaped manifold 37 b serving as a main body of the air nozzle 37 .

[0118] Furthermore, if Figure 6 As shown in (A), the air nozzle 37 has a box-shaped manifold 37b that is bent along the arc of the wheel 16, and a slit-shaped air outlet 37a is provided on the bottom surface of the manifold 37b. The air nozzle 37 is arranged on the wheel 16 so that the air outlet 37a extends along the travel path of the preform 1 in the wheel 16. Figure 6 As shown in (B), the manifold 37b is connected to a blower 32, a sterilizing filter 33, and an electric heater 34. The external air introduced by the blower 32 is sterilized by the sterilizing filter 33, heated by the electric heater 34, and becomes hot air P and is sent to the air nozzle 37.

[0119] The air supplied to the air nozzle 37 can be not the air from the blower 32, but the air obtained by sterilizing the compressed air with higher propulsion force through a sterile filter. In addition, the high-pressure air used for blow molding in the blow molding machine 12 can be recovered and reused.

[0120] like Figure 6 As shown in (B), the air P supplied to the manifold 37b of the air nozzle 37 is ejected from the air blowing outlet 37a and blown toward the preform 1 moving upward at the mouth 2a below the air blowing outlet 37a. A part of the air P flows into the interior of the preform 1, and the other part flows along the outer surface of the preform 1.

[0121] like Figure 7 As shown, sterilized air P can be blown from a cylindrical air blowing nozzle 38 toward the preform 1. Furthermore, a suction pipe 39 can be disposed near the air blowing nozzle 38 to suck in foreign matter such as dust that is discharged from the preform 1 when the air P is blown from the air blowing nozzle 38 into the preform 1. By collecting foreign matter with the suction pipe 39, it is possible to prevent the foreign matter from being mixed into other preforms 1 or subsequently formed bottles 2.

[0122] In addition, if Figure 8 As shown, the air blowing nozzle 38 can be arranged upward, the preform 1 can be placed in an inverted state, and sterilized air P can be blown from the air blowing nozzle 38 into the mouth 2a of the downward-facing preform 1. As a result, foreign matter in the preform 1 falls outside the preform 1 due to the wind pressure of the air P blown from the air blowing nozzle 38 and the weight of the foreign matter.

[0123] In addition, the supply of air P can be utilized Figure 9 The air nozzle 40 shown in FIG. Figure 5 The sterilant gas blowing nozzle 6 shown has the same structure. Figure 9 In the figure, nozzles 40a and 40b represent multiple branching nozzles for delivering air P. The outlet of one nozzle 40a of the multiple nozzles 40a and 40b faces the opening of the mouth portion 2a of the preform 1. Air P is blown from the outlet of nozzle 40a toward the preform 1 and flows into the interior of the preform 1. This activates hydrogen peroxide adhering to the inner surface of the preform 1, and removes excess hydrogen peroxide.

[0124] The umbrella-shaped member 41 covers the periphery of the nozzle 40a's outlet. An annular groove 41a with a substantially semicircular cross-section is formed on the lower surface of the umbrella-shaped member 41. Air P entering the preform 1 through the nozzle 40a's outlet fills the preform 1 and then overflows from the mouth 2a of the preform 1. This overflowing air P is guided by the lower surface of the umbrella-shaped member 41 and the annular groove 41a toward the outer surface of the preform 1, where it flows along the outer surface. Consequently, the air P exiting the nozzle 40a is also blown toward the outer surface of the preform 1.

[0125] Furthermore, another nozzle 40b extends in a generally U-shape along the outer surface of the preform 1, with its outlet 42 facing the outer surface of the preform 1. Air P is also blown from the outlet 42 of the nozzle 40b toward the outer surface of the preform 1, contacting the outer surface of the preform 1. Thus, the air P from the nozzle 40b merges with the air P escaping from the mouth 2a of the preform 1, activating the hydrogen peroxide adhering to the outer surface of the preform 1 and removing the excess hydrogen peroxide.

[0126] After the blowing of the air P is completed, sometimes Figure 2 As in (C), the preform 1 is irradiated with light L containing ultraviolet rays (light irradiation step). This step may be before or after the blowing of the sterilizing gas G. Here, instead of irradiating the light L containing ultraviolet rays, at least the mouth of the preform 1 may be irradiated with an electron beam.

[0127] Ultraviolet light is a type of electromagnetic wave with a wavelength of 100 to 380 nm. Light L containing any of these wavelengths, particularly UV-C, with wavelengths of 100 to 280 nm, is effective for sterilization. Furthermore, the wavelength of 253.7 nm is the most effective for sterilization, and including this wavelength is optimal.

[0128] The light irradiation device 30 emitting ultraviolet rays of 100nm to 380nm includes low-pressure mercury lamps, high-pressure mercury lamps, xenon flash lamps, etc. In particular, the light emitted from a xenon flash lamp (wavelength: 100-950nm) with xenon gas sealed inside has a high sterilization effect, so the irradiation device including this lamp is the most suitable.

[0129] The sterilization effect of light is proportional to the average irradiation dose per unit area and the irradiation time. However, xenon flash lamp light has a higher sterilization effect than light emitted by low-pressure mercury lamps and high-pressure mercury lamps, so a shorter irradiation time is sufficient, thus preventing the temperature of the preform 1 from rising.

[0130] Figure 2 The reflective plate 31 shown in (C) has the purpose of effectively irradiating the preform 1 with the light L emitted by the lamp 30a. Therefore, the preform 1 is arranged on the opposite side relative to the lamp 30a. The reflective plate 31 can be a flat surface, a curved surface, or a combination of multiple surfaces of any shape. The reflective plate can be any reflective plate as long as it can reflect the light L. For example, it can be formed of resin or metal and its surface can be smoothed; or it can be coated, plated with metal, or vapor-deposited with metal, metal oxide, etc. to make it smooth; or a combination of these can be performed.

[0131] like Figure 2 As shown in (C), the irradiation of light L is not limited to the mouth portion 2a, and can be performed on any portion of the preform 1. By irradiation with light L, sterilization of the irradiated portion is promoted.

[0132] However, if the mouth 2a is deformed by heating, Figure 2 The sterility of the product filled with contents, as shown in (H), is compromised. Therefore, when using hot air as the air P, the amount blown to the outer surface is reduced, and the heating temperature in the heating furnace 25 used for blow molding is lowered. As a result, there is a possibility of insufficient sterilization of the mouth 2a. Therefore, by concentrating the irradiation of light L on the mouth 2a, the mouth 2a can be effectively sterilized, thereby preventing poor sterilization of the mouth 2a.

[0133] In this case, it is particularly preferred that Figure 2 As shown in FIG. 3 (C), a lamp 30a is provided above the mouth 2a, and a reflector 31 is provided to surround the lamp 30a. By adopting such a device, the inner and outer surfaces of the mouth 2a can be effectively irradiated with light L.

[0134] Next, the preform 1 is transported to the heating furnace using the heating furnace transport wheel 17. Figure 2 As shown in (D), the preform 1 is heated to a temperature suitable for subsequent blow molding by using an infrared heater 18a and other heating mechanisms. Figure 2As shown in (D), a shaft 29 is inserted into the mouth 2a of the preform 1. The preform 1 is suspended in an upright (or inverted) position, rotating along with the shaft 29 and placed into the heating furnace 25 via an endless chain 18. The endless chain 18 is rotated by pulleys 26a and 26b, with shafts 29 mounted at regular intervals. This heating decomposes any hydrogen peroxide remaining in the preform 1, further promoting sterilization. This can also reduce residual hydrogen peroxide.

[0135] like Figure 10 As shown, when the lower portion of the shaft 29 is inserted into the mouth 2a thereof, the preform 1 is supported by the shaft 29 due to the elastic deformation of the elastic body 29b. Furthermore, when the umbrella-shaped member 29a is provided, the mouth 2a of the preform 1 is simultaneously covered by the umbrella-shaped member 29a.

[0136] In this case, a gap is formed between the inner surface of the mouth 2a of the preform 1 and the lower part of the shaft 29 and between the outer surface of the mouth 2a of the preform 1 and the umbrella-shaped part 29a, so that the air in the preform 1 heated by the heat from the infrared heater 18a becomes hot air, and flows from the inside of the preform 1 to the outside of the preform 1 in the above-mentioned gap, while heating the mouth 2a of the preform 1.

[0137] The mouth portion 2a of the preform 1 must be prevented from being deformed by the heat applied during the preform 1 stage in order to prevent the sealing of the bottle 2 from being impaired when the bottle 2 is subsequently sealed with the cap 3.

[0138] The hot air flowing through the gap heats the mouth 2a, but only to a temperature below 70°C where the mouth 2a does not deform. The heating of the mouth 2a activates the trace amount of hydrogen peroxide remaining in the mouth 2a, sometimes also moderately sterilizing the mouth 2a.

[0139] In addition, if Figure 11 As shown, the heated preform 1 is released from the shaft 29, handed over to the clamp 13, and sterile air Q is blown from the mouth 2a side and blown to the Figure 3 The mold 4 as a blow molding mold shown in (E) is transported. By blowing the sterile air Q, the preform 1 is supplied to the mold 4 while maintaining sterility.

[0140] The sterile air Q may be hot air. The hot air is blown to prevent the temperature of the preform 1 from decreasing.

[0141] In addition, if Figure 11As shown, at the part where the heating of the preform 1 is completed and the preform 1 is facing the mold 4, a cover 43 is sometimes provided in a tunnel shape so as to surround the travel path of the preform 1. The ceiling portion of the tunnel-shaped cover 43 that covers the mouth 2a of the preform 1 from above is formed in the shape of a roof with an inclined surface. In addition, nozzles 43a that blow sterile air Q toward the mouth 2a of the preform 1 are provided in the ceiling portion in the shape of a row of tubes or a slit. As a result, sterile air Q is effectively supplied to the preform 1, and the preform 1 maintains sterility and travels while in the chamber 28b. In the case where the molding machine is set in a sterilized chamber, the tunnel-shaped cover 43 is not required.

[0142] The heated preform 1 is as Figure 3 As shown in (E), the bottle 2 is blow-molded in the mold 4. The mold 4, which serves as a blow-molding mold, moves continuously at the same speed as the moving speed of the preform 1 and becomes a closed mold state. After the preform 1 is blow-molded in the mold 4, it becomes an open mold state. The preform 1 is installed in the mold 4, and while the extension rod is inserted into the preform 1 from the center hole of the blow nozzle 5, blowing air is blown into the inside of the preform 1. The blowing air must be sterile air that has been sterilized by a sterilizing filter, etc. Through the extension rod and the blowing air, the preform 1 expands into the shape of the mold 4 and becomes a bottle 2. The bottle 2 is gripped by the clamp 13 and transported to the inspection device 27 by the wheel 21.

[0143] Although not shown in the drawings, the inspection device 27 may include, for example, a light source and a camera for inspecting whether the top surface of the mouth portion 2a of the bottle 2 after molding is smooth.

[0144] If the inspected bottles 2 are unqualified, they are removed from the conveying path by a rejection device (not shown), and only qualified bottles are conveyed to the wheel 22 .

[0145] The bottles 2 that pass the inspection are transported by wheels 22 to the filling device.

[0146] like Figure 1 As shown, the wheels 15 and 16 are surrounded by a chamber 28a. The chamber 28a is connected to an exhaust mechanism comprising a filter 36 and a blower 35 for filtering the air within the chamber 28a. Consequently, the remaining sterilant gas blown from the sterilant gas blowing nozzle 6 is removed by the filter 36 of the exhaust mechanism and discharged outside the chamber 28a. This prevents the hydrogen peroxide in the sterilant from flowing into the adjacent heating furnace 25 or blow molding machine 12. Ideally, the amount of air supplied to and exhausted from the chamber 28a is adjusted so that the pressure within the chamber 28a is negative, below atmospheric pressure.

[0147] In addition, if Figure 1As shown, the heating furnace 25 and the blow molding machine 12 are surrounded by a chamber 28b. Ideally, the chamber 28b is adjusted to a positive pressure by supplying sterilized air. The sterilized air can be obtained by sterilizing air obtained by a blower by passing it through a sterilizing filter or the like.

[0148] In addition, if Figure 1 As shown, wheel 22 is surrounded by chamber 28c. It is desirable to also supply sterile air to chamber 28c. The pressure in chamber 28c is preferably adjusted to a level between the sterile air supply pressure of the filling section, which is used to fill the contents in the next step, and the pressure in chamber 28b.

[0149] By supplying sterile air, chambers 28b and 28c are maintained at a positive pressure, thereby maintaining the sterile state achieved by the pre-operation sterilization process within the chambers and preventing the influx of bacteria from outside. The pre-operation sterilization process can be accomplished by, for example, sterilizing the interior of chambers 28a, 28b, and 28c with hydrogen peroxide gas at a concentration of 10 mg / L or less. Alternatively, the areas where the preform 1 and bottle 2 come into contact can be irradiated with ultraviolet light. Alternatively, a solution containing 1% by mass of ethanol and hydrogen peroxide can be sprayed onto areas where the preform 1 and bottle 2, such as the mold 4, blow nozzle 5, and clamp 13, come into contact.

[0150] Example

[0151] Hereinafter, the first embodiment of the present invention will be described with reference to examples.

[0152] (Operation Method) A 20g preform 1 for a 500ml bottle made of polyethylene terephthalate was used. 10 tacks were applied to the inner surface of the preform 1 at three locations, namely, the mouth, the center of the body, and the bottom, for a total of nine locations. 3 , 10 4 , 10 5 After the B. atrophaeus spores are formed, the mold-carrying preform 1 is dried naturally.

[0153] Next, use Figure 2 A light irradiation device 30, as shown in FIG. 3 , including a lamp 30a and a reflector 31 surrounding the lamp 30a in a dome shape, irradiates the inner and outer surfaces of the mouth portion 2a of the preform 1 with concentrated light L. A xenon lamp (arc length 500 mm) manufactured by Econos Japan Co., Ltd. was used as the lamp, and pulse waves of approximately 0.2 seconds per pulse were continuously applied six times (light irradiation step).

[0154] Next, use Figure 2The sterilizing gas blowing nozzle 6 shown in (A) blows the sterilizing gas G to the preform 1 with bacteria. Figure 4 The sterilant gas generator 7 supplies 0.5 MPa compressed air and 10-60 ml / min of sterilant to generate the sterilant gas at a surface temperature of the vaporization section 9 of 300° C. The sterilant gas G is blown toward the preforms 1 (sterilant gas blowing step).

[0155] Furthermore, using Figure 2 The air nozzle 37 shown in FIG. 1 (B) blows air at a flow rate of 600 L / min from the air outlet 37a toward the preform 1 for about 1.2 seconds, and the air P is also heated to 70°C during this time.

[0156] Then, if Figure 2 As shown in (D), the preform 1 is heated in the heating furnace 25 until the outer surface temperature of the main body of the preform 1 reaches 120°C. Figure 3 As shown in FIG. 1 (E), the preform 1 is molded into a 500 ml bottle using a mold 4 .

[0157] (Method for measuring bactericidal effect)

[0158] The molded bottle is filled with 100 ml of SCD broth under a sterile atmosphere. After sealing with a sterile cap, the bottle is shaken to ensure the culture medium contacts the entire inner surface of the bottle. The bottle is then incubated at 35°C for one week. If the bottle is turbid, it is not sterilized; if it is not turbid, it is sterilized.

[0159] (Method for determining residual hydrogen peroxide in bottles)

[0160] The molded bottle was filled with 500 ml of pure water and sealed, and the concentration of hydrogen peroxide in the filled pure water was measured using a SUPER ORITECTOR MODEL 5 manufactured by Chiyoda Corporation.

[0161] (Examples, Comparative Examples and Results)

[0162] Table 1 shows examples and comparative examples in which the same procedures as described in the operating method were performed. These examples and comparative examples show the composition of the sterilizing agent, the presence or absence of air heating and irradiation with ultraviolet light, and other operating conditions, as well as the sterilizing effects and residual hydrogen peroxide in the bottles.

[0163]

[0164] In the table, "○" indicates that all bacteria were killed in the measurement of the bactericidal effect.

[0165] According to the above-described embodiment, by using a sterilizer containing 30% by mass or less hydrogen peroxide and containing ethanol with a boiling point of 85°C or less as a solvent, preforms 1 can be sterilized, and residual hydrogen peroxide in bottles 2 molded from the preforms 1 can be reduced. If the hydrogen peroxide content exceeds 30% by mass, sterilization is possible even when ethanol is included, but residual hydrogen peroxide increases. Even if the hydrogen peroxide content is 30% by mass or less, sterilization is insufficient when ethanol is not included. Furthermore, under conditions where the hydrogen peroxide content is 5% by mass or less, ethanol is included, and ambient temperature air is blown, preforms 1 can be sterilized, and residual hydrogen peroxide in bottles 2 molded from the preforms 1 can be reduced.

[0166] Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

[0167] (Implementation Method 2)

[0168] The second embodiment of the present invention differs from the first embodiment in that, after the sterilant gas blowing step, a heating step is performed instead of blowing air onto the preform 1. According to the second embodiment, by sterilizing the preform, a sterilized preform can be easily obtained, and the amount of hydrogen peroxide remaining in the bottle formed from the preform can be reduced.

[0169] (Overview of Method and Apparatus)

[0170] like Figure 12 As shown, the preform 1 is supplied from the preform supply device 11 and is conveyed into the sterilizer blowing chamber 28 a by the preform supply conveyor 14 .

[0171] The preform 1 is delivered to the sterilant blowing wheel 15, as shown in FIG. Figure 2 As shown in (C), the preform 1 is irradiated with light containing ultraviolet rays emitted from the lamp 30a provided in the light irradiation device 30 (light irradiation step). The light irradiation step is performed in the same manner as in the first embodiment.

[0172] Blowing sterilant gas onto the preform 1 (sterilizer gas blowing step) is essential, but irradiation with light (light irradiation step) is optional. Blowing sterilant gas onto the preform 1 (sterilizer gas blowing step) and heating the preform 1 to a temperature sufficient for molding the preform 1 into a bottle 2 (heating step) are performed sequentially, but irradiation with light onto the preform 1 (light irradiation step) can be performed at any stage.

[0173] That is, the light irradiation device 30 may be installed upstream of the nozzle 6 in the sterilizing gas blowing wheel 15, or may be installed on the wheel 16 after the sterilizing gas is blown. Alternatively, it may be installed on the wheel 19 that transports the preforms 1 after heating. Furthermore, it may be installed in multiple of these three locations.

[0174] The preform 1 to which the sterilizing gas has been blown is released by the gripper 13 gripped during the wheel transport and is transported to the heating furnace 25 by the heating furnace transport wheel 17 .

[0175] The preform 1 placed in the heating furnace 25 is as follows Figure 2 As shown in (D), the preform 1 is heated to a temperature suitable for subsequent blow molding using infrared heater 18a and other heating mechanisms (heating process). This temperature is approximately 90°C to 130°C. The sterilizing agent blown onto the preform 1 is activated by the heating (heating process), sterilizing bacteria and the like adhering to the surface of the preform 1. Furthermore, the remaining sterilizing agent is volatilized by the heating.

[0176] In order to prevent deformation and the like, the mouth portion 1 a of the preform 1 is kept at a temperature of 70° C. or lower.

[0177] The steps of heating the preform 1, blow molding the heated preform into a bottle, inspecting the molded bottle, filling the inspected bottle with the content, and sealing the filled bottle are the same as those in the first embodiment.

[0178] (Details of the method and apparatus)

[0179] The preform 1 and the sterilizer in the second embodiment of the present invention are the same as those in the first embodiment. Figure 4 The sterilant gas generator shown generates the gas in the same manner as in the first embodiment.

[0180] For blowing sterilant gas, such as Figure 2 As shown in (A), the sterilizing gas is blown from the sterilizing gas blowing nozzle 6 to the preform 1 (sterilizing gas blowing process). The sterilizing gas is blown to the preform 1 in the same manner as in the first embodiment. Figure 2 Immediately before the sterilizing gas shown in (A) is blown onto the preform 1, hot air or the like may be blown onto the preform 1 to preheat the preform 1. This preheating can further enhance the sterilization effect of the preform 1.

[0181] Before the sterilizing gas is blown to the preform 1, Figure 2As shown in (C), sometimes at least the mouth portion 1a of the preform 1 is irradiated with light containing ultraviolet rays (light irradiation step). This step can be performed after blowing the sterilant gas. Here, instead of irradiating at least the mouth portion of the preform 1 with an electron beam, the light containing ultraviolet rays can also be irradiated. The light irradiation device 30 containing ultraviolet rays and the irradiation light is also the same as in the first embodiment.

[0182] like Figure 2 As shown in (C), the irradiation of light is not limited to the mouth portion 1a, but can be performed on any portion of the preform 1. The irradiation of light promotes sterilization of the irradiated portion.

[0183] However, if the mouth 1a is deformed by heating, in order not to damage Figure 3 The sterility of the product filled with contents, as shown in (H), is improved by lowering the heating temperature in the heating furnace 25 used for blow molding. As a result, the mouth 1a may be insufficiently sterilized. Therefore, by concentrating the light irradiation on the mouth 1a, the sterilization effect of the mouth 1a can be improved, preventing poor sterilization of the mouth 1a.

[0184] In this case, it is particularly preferred that Figure 2 As shown in FIG. 3 (C), a lamp 30a is provided on the upper portion of the mouth 1a, and a reflector 31 is provided to surround the lamp 30a. By adopting such a device, the inner and outer surfaces of the mouth 1a can be effectively irradiated with light.

[0185] Next, the preform 1 is transported to the heating furnace by the heating furnace transport wheel 17. Figure 2 As shown in (D), the preform 1 is heated to a temperature suitable for subsequent blow molding by using an infrared heater 18a and other heating mechanisms. Figure 2 As shown in (C), by inserting shaft 29 into the mouth 1a of preform 1, preform 1 is suspended in an upright position (or inverted position) and rotated together with shaft 29, and is placed into heating furnace 25 via endless chain 18. Endless chain 18 is rotated by pulleys 26a and 26b and is mounted on shafts 29 at regular intervals. This heating decomposes hydrogen peroxide, a component of the sterilizing agent, adhering to the surface of preform 1, sterilizing bacteria and the like adhering to the surface of preform 1. In addition, the remaining hydrogen peroxide and other components of the sterilizing agent are volatilized by heating.

[0186] The infrared heater 18a is preferably a halogen lamp that emits infrared rays. As the infrared heater 18a, a plurality of halogen lamps are arranged in parallel perpendicularly to the axial direction of the preform 1. The preform 1 is heated by the near-infrared rays, infrared rays, and far-infrared rays emitted from the halogen lamps. The plurality of halogen lamps are arranged to control the heating temperature, and a temperature difference can be set for the heating temperature in the axial direction of the preform 1. In addition, a plurality of halogen lamp units are arranged in parallel with the moving direction of the preform 1. The number of units can be set arbitrarily. The heating temperature of the halogen lamp unit is also controlled, and the initial heating stage of the preform 1 can be set to a high temperature and the final heating stage can be set to a low temperature.

[0187] The preform 1 is heated by the infrared rays and the like emitted from the infrared heater 18a, but the infrared rays and the like that are not absorbed by the preform 1 and reach the rear of the preform 1 do not contribute to the heating. Therefore, by providing a reflector behind the preform 1, the infrared rays and the like that reach the rear of the preform 1 are reflected, thereby enabling the preform 1 to be heated effectively. The reflector is a reflector made by evaporating or plating a metal with gold, silver, or aluminum. Any reflector can be used as long as it can reflect infrared rays and the like. The reflector can be a flat surface, a curved surface, or a combination of a flat surface and a curved surface. The reflector can be provided not only behind the preform 1, but also behind the infrared heater 18a, thereby reflecting the infrared rays and the like that are emitted to the rear of the infrared heater 18a.

[0188] like Figure 10 As shown, when the lower portion of the shaft 29 is inserted into the mouth 1a thereof, the preform 1 is supported by the shaft 29 due to the elastic deformation of the elastic body 29b. Furthermore, when the umbrella-shaped member 29a is provided, the mouth 2a of the preform 1 is simultaneously covered by the umbrella-shaped member 29a.

[0189] In this case, a gap is formed between the inner surface of the mouth 1a of the preform 1 and the lower part of the shaft 29 and between the outer surface of the mouth 1a of the preform 1 and the umbrella-shaped part 29a. Therefore, the vaporized air containing hydrogen peroxide as a component of the sterilizer in the preform 1 heated by the heat from the infrared heater 18a becomes hot air and flows from the inside of the preform 1 to the outside of the preform 1 in the above-mentioned gap, during which the mouth 1a of the preform 1 is heated and the hydrogen peroxide sterilizes the outer surface of the mouth 1a.

[0190] The mouth 1a of the preform 1 must be protected from deformation by the heat applied to the preform 1 in order to prevent the seal of the bottle 2 from being compromised when the bottle 2 is subsequently sealed with the cap 3. The hot air flowing through the gap heats the mouth 1a, but the temperature of the mouth 1a is kept below approximately 70°C. If the mouth 1a reaches 70°C or higher, deformation may occur.

[0191] Sometimes the heated preform 1 is released from the shaft 29, handed over to the clamp 13 of the wheel 19, and sterile air is blown from the mouth 1a side and blown to the Figure 3 The mold 4 as a blow molding mold shown in (E) is transported. By blowing the sterile air, the preform 1 is kept sterile and supplied to the mold 4. By heating the sterile air, the preform 1 can be supplied to the mold 4 without lowering its temperature.

[0192] In addition, if Figure 2 As shown in (C), the wheel 19 may be irradiated with light containing ultraviolet rays.

[0193] The heated preform 1 is molded in the same manner as in the first embodiment. The molded bottle 2 is gripped by the gripper 13 and conveyed by the wheel 21 to the inspection device 27. The inspection device 27 is not shown, but may include, for example, a light source and a camera for inspecting whether the top surface of the mouth 1a of the molded bottle 2 is smooth. If a bottle 2 fails the inspection, it is removed from the conveyance path by a rejection device (not shown), and only qualified bottles are conveyed to the wheel 22. Bottles 2 that pass the inspection are conveyed by the wheel 22 to the filling device.

[0194] like Figure 12 As shown, the wheels 15 and 16 are shielded by a sterilant blowing chamber 28a. The sterilant blowing chamber 28a is connected to an exhaust mechanism including a filter 36 and a blower 35 for filtering the air in the sterilant blowing chamber 28a. As a result, the remaining sterilant gas blown from the sterilant gas blowing nozzle 6 is removed by the filter 36 of the exhaust mechanism and discharged outside the sterilant blowing chamber 28a. Therefore, hydrogen peroxide in the sterilant can be prevented from flowing into the adjacent heating furnace 25 and blow molding machine 12. It is ideal to adjust the amount of supply and exhaust in the sterilant blowing chamber 28a so that the pressure in the sterilant blowing chamber 28a is lower than atmospheric pressure.

[0195] In addition, if Figure 12 As shown, the heating furnace 25 is shielded by the heating section chamber 28b, and the blow molding machine 12 is shielded by the molding section chamber 28c. Before operation, sterilizing agent gas or mist or a mixture thereof is blown into the heating section chamber 28b and the molding section chamber 28c, and sterilization is performed by further blowing sterile hot air. During operation, sterile air is supplied to the heating section chamber 28b and the molding section chamber 28c, and the pressure in the heating section chamber 28b and the molding section chamber 28c is adjusted to become positive pressure, thereby maintaining the sterility of the heating section chamber 28b and the molding section chamber 28c. Sterile air can be obtained by sterilizing the air obtained by the blower through a sterilizing filter or the like.

[0196] In the heating section chamber 28b, since the infrared heater 18a is used for heating, an upward airflow is generated. Compared with flowing the sterile air from the top to the bottom, when the sterile air is flowing in the same direction as the upward airflow, turbulence is not generated in the heating section chamber 28b, and the sterile air can be smoothly flowed. Therefore, the sterile air is blown into the heating section chamber 28b from the bottom to the top. The sterile air blown in from the bottom flows toward the outside and inside of the infrared heater 18a and the reflector.

[0197] The sterile air flowing from the bottom to the top of the heating chamber 28b contains components of the sterilant volatilized from the preforms 1. To maintain appropriate pressure within the heating chamber 28b and exhaust the sterilant components, an exhaust system is installed above the heating chamber 28b. The exhaust system includes a filter and a blower for filtering the air. Hydrogen peroxide, a component of the sterilant, is decomposed and discharged by the filter.

[0198] The filling section and the filling section chamber of the shielding sealing section are also sterilized before work, and sterile air is used to maintain the positive pressure in the chamber to maintain the sterility in the chamber. As for the pressure maintained at positive pressure, the filling section chamber is taken as the highest pressure, and the pressure is set to lower and lower as the molding section chamber 28c and the heating section chamber 28b are closer to the upstream. For example, the pressure in the filling section chamber is set to 30Pa~150Pa, the pressure in the molding section chamber 28c is set to 20Pa~30Pa, and the pressure in the heating section chamber 28b is set to 0Pa~20Pa. In addition, the outlet chamber where the products downstream of the sealing section are discharged, the sterile products are placed on the conveyor belt and discharged to the outside of the aseptic filling machine is set to 0Pa~20Pa.

[0199] To maintain a positive pressure in each chamber, a sterile air supply device is provided in each chamber, but this need not be provided in all chambers. For example, sterile air flowing from the filling chamber into the forming chamber 28c can be used to maintain a positive pressure in the forming chamber 28c. Furthermore, to maintain an appropriate pressure within the chamber, an exhaust device can be provided in each chamber. This device does not need to be provided in all chambers. For example, an exhaust device provided in the heating chamber 28b can be used to maintain an appropriate pressure in the forming chamber 28c.

[0200] In order to ensure the sterility of the molding chamber 28c, the interior of the molding chamber 28c is sterilized before operation. However, in order to prevent the deterioration of the inspection equipment by the sterilizer, the camera, lamp, etc. as the inspection equipment may be sealed.

[0201] Hereinafter, the second embodiment of the present invention will be described with reference to examples.

[0202] (How to operate)

[0203] A 20g preform 1 for a 500ml bottle made of polyethylene terephthalate was used. 10 adhesives were applied to 9 locations in total, namely, the mouth, the center of the body, and the bottom of the inner surface of the preform 1. 3 , 10 4 , 10 5 After the B. atrophaeus spores are formed, the mold-carrying preform 1 is dried naturally.

[0204] Next, use Figure 2 A light irradiation device 30, as shown in FIG. 3 , equipped with a xenon flash lamp 30a and a reflector 31 surrounding the lamp 30a in a dome shape, irradiates the inner and outer surfaces of the mouth portion 1a of the preform 1 with concentrated light. A xenon lamp (arc length 500 mm) manufactured by Econos Japan Co., Ltd. was used, and six pulses of approximately 0.2 seconds each were continuously irradiated (light irradiation step).

[0205] Next, use Figure 2 The sterilizing gas blowing nozzle 6 shown in (A) blows the sterilizing gas to the preform 1 with bacteria for 2 seconds (sterilizing gas blowing step). Figure 4 The sterilant gas generator 7 shown above supplies 0.5 MPa compressed air and sterilant at 10 ml / min, and generates sterilant at a surface temperature of the vaporization section 9 of 300°C.

[0206] Then, if Figure 2 As shown in (D) of FIG. 2 , the preform 1 is heated in the heating furnace 25 until the outer surface temperature of the main body of the preform 1 reaches 120° C. (heating step). Figure 3 As shown in FIG. 8 (E), the preform 1 is molded into a 500 ml bottle 2 using a mold 4 .

[0207] (Method for measuring bactericidal effect)

[0208] The molded bottle 2 was filled with 100 ml of SCD broth under a sterile atmosphere and sealed with a sterilized cap. The sealed bottle 2 was vibrated to allow the culture to contact the entire inner surface of the bottle 2. The bottle was then incubated at 35°C for one week. If the culture was turbid, sterilization was not possible; if it was not turbid, sterilization was achieved.

[0209] (Method for determining residual hydrogen peroxide in bottles)

[0210] The molded bottle 2 was filled with 500 ml of pure water and sealed, and the concentration of hydrogen peroxide in the filled pure water was measured using a SUPER ORITECTOR MODEL 5 manufactured by Chiyoda Corporation.

[0211] (Examples, Comparative Examples and Results)

[0212] Table 2 shows examples and comparative examples in which the same procedures as those described in the operating method were performed. The examples and comparative examples show the composition of the disinfectant, the operating conditions such as the presence or absence of light irradiation including ultraviolet light, the disinfection effects, and the residual hydrogen peroxide in the bottles.

[0213]

[0214] In the table, "○" indicates that all bacteria were killed in the measurement of the bactericidal effect.

[0215] According to the above-described embodiment, by using a sterilizer containing 30% by mass or less hydrogen peroxide and including ethanol with a boiling point of 85°C or less as a solvent, preforms 1 can be sterilized, and residual hydrogen peroxide in bottles 2 molded from the preforms 1 can be reduced. If the hydrogen peroxide content exceeds 30% by mass, sterilization is still possible even when ethanol is included, but residual hydrogen peroxide increases. Even if the hydrogen peroxide content is 30% by mass or less, sterilization is insufficient without the presence of ethanol. Furthermore, even if the hydrogen peroxide content is 5% by mass or less, the preforms 1 can be sterilized, and residual hydrogen peroxide in bottles 2 molded from the preforms 1 can be reduced.

[0216] Hereinafter, a third embodiment of the present invention will be described with reference to the drawings.

[0217] (Implementation 3)

[0218] The third embodiment of the present invention differs from the first embodiment in that the sterilizing agent blown onto the preform 1 contains hydrogen peroxide but does not necessarily contain a solvent, and that the preform 1 must be irradiated with light containing ultraviolet light. According to this third embodiment, sterilizing the preform can easily produce a sterilized preform, and the amount of hydrogen peroxide remaining in bottles formed from the sterilized preform can be reduced.

[0219] (Overview of Method and Apparatus)

[0220] like Figure 1 As shown, the aseptic filling device assembled with the preform sterilization device of the present embodiment comprises: a preform supply device 11, a preform conveyor belt 14 for transporting the preform 1 supplied by the preform supply device 11, a heating furnace 25 for heating the preform 1, and a blow molding machine 12 for forming a bottle from the preform 1 heated by the heating furnace 25.

[0221] (Overview of the process of aseptic filling equipment)

[0222] The preform 1 is held by a clamp 13 and is transferred to a wheel 15 which is continuous with a preform conveyor 14. The wheel 15 is moved forward while the preform 1 is being conveyed. Figure 2 As shown in (C), light L containing ultraviolet rays is irradiated (light irradiation step).

[0223] Furthermore, if Figure 2 As shown in FIG. 1A , the sterilizer gas G is blown toward the preform 1 by the sterilizer gas blowing nozzle 6 via the wheel 15 (sterilizer gas blowing step).

[0224] The preform 1 is then handed over to the wheel 16 as Figure 2 As shown in FIG. 1 (B), air P is blown by the air nozzle 37 .

[0225] Irradiation with light L (light irradiation step) and blowing of sterilant gas G onto the preform 1 (sterilizer gas blowing step) are essential, but blowing of air P (B) is not necessary. However, it is ideal to perform both steps. Furthermore, blowing of sterilant gas G (A) and blowing of air P (B) onto the preform 1 are performed sequentially, but light irradiation (C) can be performed at any stage.

[0226] That is, in wheel 15, the light irradiation device 30 may be located upstream or downstream of the nozzle 6. Furthermore, in wheel 16, it may be located downstream of the air blowing (C). Furthermore, irradiation (A) of light L, blowing (B) of sterilant gas G, and blowing (C) of air P may be performed by a single wheel, or they may be performed by separate wheels.

[0227] The preform 1 that has completed the sterilization process is released from the gripper 13 that has been gripped during the wheel transport, and is transported to the heating furnace 25 by the heating furnace transport wheel 17 .

[0228] The steps of heating the preform 1, blow molding the heated preform into a bottle, inspecting the molded bottle, filling the inspected bottle with the content, and sealing the filled bottle are the same as those in the first embodiment.

[0229] (Details of the preform sterilization method and apparatus)

[0230] In round 15, if Figure 2 As in (C), the preform 1 is irradiated with light L containing ultraviolet rays (light irradiation step). This step may be performed in multiple steps. That is, it may be performed before the sterilant gas G is blown onto the preform 1 (A), or it may be performed after the air P is blown (B). The light irradiated onto the preform 1 and the light irradiation device 30 in this third embodiment are the same as those in the first embodiment.

[0231] If the mouth 2a is deformed by heating, in order not to damage Figure 3To ensure the sterility of a beverage-filled product such as that shown in FIG. 1 (H), when hot air is used as the air P, deformation of the mouth 2a is prevented by reducing the amount of air blown toward the outer surface and lowering the heating temperature in the heating furnace 25 used for blow molding. Consequently, sterilization of the mouth 2a is sometimes insufficient. To prevent this, excessive sterilization of the mouth 2a has been performed by blowing sterilizer excessively. Therefore, by providing a reflector 31 in the light irradiation device 30, the irradiation of the light L is concentrated on the mouth 2a, effectively sterilizing the mouth 2a. Furthermore, even if the amount of sterilizer blown is reduced, poor sterilization of the mouth 2a can be prevented.

[0232] In this case, it is particularly appropriate if Figure 2 As in the light irradiation device 30 of (C), a lamp 30a is provided on the upper portion of the mouth 2a, and a reflector 31 is provided so as to surround the lamp 30a. By adopting such a device, the inner and outer surfaces of the mouth 2a can be effectively irradiated with light L.

[0233] The disinfectant in Embodiment 3 contains at least hydrogen peroxide. A suitable content range is 0.5% to 65% by mass. A content less than 0.5% by mass may result in insufficient bactericidal activity, while a content exceeding 65% by mass may lead to safety and handling difficulties. Furthermore, a content of 0.5% to 40% by mass is more suitable. A content of 40% or less by mass facilitates handling and results in a low concentration, thereby reducing the amount of residual disinfectant after sterilization.

[0234] The bactericide includes water and may also include one or more of alcohols such as methanol, ethanol, isopropyl alcohol, n-propyl alcohol, and butanol, ketones such as acetone, methyl ethyl ketone, and acetylacetone, and glycol ethers.

[0235] Furthermore, the bactericide may contain compounds having a bactericidal effect such as peracetic acid, acetic acid, chlorine compounds, ozone, and other additives such as cationic surfactants, nonionic surfactants, and phosphoric acid compounds.

[0236] The bactericide is similar to the first embodiment, using Figure 4 The sterilant gas generator 7 shown is used to gasify the preform. The blowing amount of the sterilant gas G is arbitrary and is determined by the amount of sterilant supplied by the sterilant gas generator and the blowing time. Multiple sterilant gas generators can be provided. The blowing amount varies depending on the size of the preform. In terms of the amount of hydrogen peroxide, 1×10 -3 g / mm 2 ~1g / mm 2 The range is appropriate. -3 g / mm 2 When the sterilization rate exceeds 1g / mm, the sterilization rate becomes insufficient. 2 , the amount of residual hydrogen peroxide in the preform 1 increases.

[0237] The sterilizer gas G is blown toward the preform 1 from the sterilizer gas blowing nozzle 6 , and the blowing of the sterilizer gas is the same as that in the first embodiment.

[0238] It should be noted that in Figure 2 Immediately before the sterilizing gas G shown in (A) is blown onto the preform 1, hot air or the like may be blown onto the preform 1 to preheat the preform. This preheating can further enhance the sterilization effect of the preform.

[0239] The preform 1 blown with the sterilizing agent can be Figure 2 As shown in FIG. 1 (B), the material is gripped and transported by the clamp 13 and air P is blown from the air nozzle 37.

[0240] The blowing of air P activates hydrogen peroxide adhering to the surface of the preform 1, sterilizing microorganisms on the inner and outer surfaces of the preform 1. Furthermore, the blowing of air P rapidly removes the sterilant adhering to the surface of the preform 1. The sterilant adhering to the surface of the preform 1 is removed from the preform 1 by the blowing of air P before it is placed in the heating furnace 25, thereby preventing damage to various components within the blow molding machine 12, such as sealing components, caused by hydrogen peroxide. Furthermore, the occurrence of defects such as whitening, deformation, and uneven molding of the bottle caused by the adhesion of sterilant to the preform 1 is prevented.

[0241] The air P can be at room temperature, but heating it to hot air promotes the decomposition of hydrogen peroxide, improving the sterilization effect and reducing residual hydrogen peroxide. The ideal temperature for heating the air is 40°C to 140°C when blown onto the preform. Temperatures below 40°C are less effective, while temperatures exceeding 70°C can cause problems such as deformation of the mouth 2a of the preform 1. Therefore, a temperature of 140°C or less is appropriate.

[0242] like Figure 2 As shown in FIG. 1 (B), the air P is blown out from a slit-shaped blowout port 37 a formed in a box-shaped manifold 37 b serving as a main body of the air nozzle 37 .

[0243] Furthermore, if Figure 6 As shown in (A), the air nozzle 37 has a box-shaped manifold 37b that is bent along the arc of the wheel 16, and a slit-shaped blowing port 37a on the bottom surface of the manifold 37b. The air nozzle 37 is arranged on the wheel 16 so that the blowing port 37a extends along the travel path of the preform 1 in the wheel 16. Figure 6As shown in (B), the manifold 37b is connected to a blower 32, a HEPA filter 33, and an electric heater 34. The external air introduced by the blower 32 passes through the HEPA filter 33 for sterilization, is heated by the electric heater 34, becomes hot air P, and is sent to the air nozzle 37.

[0244] The air supplied to the air nozzle 37 may not be the air from the blower 32, but may be obtained by sterilizing the compressed air having a higher propulsion force through a sterilizing filter.

[0245] like Figure 6 As shown in (B), the air P supplied to the manifold 37b of the air nozzle 37 is ejected from the blowing outlet 37a and blown toward the preform 1 moving upward at the mouth 2a below the blowing outlet 37a. A part of the air P flows into the interior of the preform 1, and the other part flows along the outer surface of the preform 1.

[0246] In addition, similarly to the first embodiment, Figure 7 、 Figure 8 The cylindrical blowing nozzle 38 shown in FIG. Figure 9 The air nozzle 40 shown blows sterilized air P toward the preform 1 .

[0247] Next, the preform 1 is transported to the heating furnace 25 by the heating furnace transport wheel 17. Figure 2 As shown in (D), the preform 1 is heated to a temperature suitable for subsequent blow molding using an infrared heater 18a and other heating mechanisms. Heating is performed in the same manner as in Embodiment 1. This heating may decompose hydrogen peroxide remaining in the preform 1, thereby promoting sterilization. Alternatively, this may reduce the amount of residual hydrogen peroxide.

[0248] Sometimes the heated preform 1 is released from the shaft 29 and is handed over to the clamp 13, such as Figure 11 As shown, sterile air Q is blown from the mouth 2a side and toward Figure 3 The mold 4 as a blow molding mold shown in (E) is transported. By blowing the sterile air Q, the preform 1 is supplied to the mold 4 while maintaining sterility.

[0249] The sterile air Q may be hot air. The hot air is blown to prevent the temperature of the preform 1 from decreasing.

[0250] like Figure 3As shown in FIG. 1 (E), the heated preform 1 is blow-molded into a bottle 2 within the mold 4, similar to the first embodiment. The molded bottle 2 is gripped by the clamp 13 and conveyed by the wheel 21 to the inspection device 27. The inspection device 27 is not shown, but may include, for example, a light source and a camera for inspecting whether the top surface of the mouth 2a of the molded bottle 2 is smooth. Bottles 2 that fail the inspection are removed from the conveyor path by a rejection device (not shown), and only qualified bottles are conveyed to the wheel 22. Bottles 2 that pass the inspection are conveyed by the wheel 22 to the filling device.

[0251] like Figure 1 As shown, the wheels 15 and 16 are surrounded by a chamber 28a. The chamber 28a is connected to an exhaust mechanism comprising a filter 36 and a blower 35 for filtering the air within the chamber 28a. As a result, the remaining sterilant ejected from the sterilant gas blowing nozzle 6 is removed by the filter 36 of the exhaust mechanism and discharged outside the chamber 28a. This prevents the hydrogen peroxide in the sterilant from flowing into the adjacent heating furnace 25 or blow molding machine 12. Ideally, the amount of air supplied to and exhausted from the chamber 28a is adjusted so that the pressure within the chamber 28a is negative, below atmospheric pressure.

[0252] In addition, if Figure 1 As shown, the heating furnace 25 and the blow molding machine 12 are surrounded by a chamber 28b. For the chamber 28b, it is ideal to supply air obtained by a blower with air sterilized by passing it through a HEPA filter or the like, thereby adjusting the chamber 28b to a positive pressure.

[0253] In addition, if Figure 1 As shown, the wheel 22 is surrounded by a chamber 28c. Ideally, the chamber 28c is also supplied with sterile air, and the sterile air supply pressure is preferably adjusted to between the sterile air supply pressure of the filling device for filling the contents in the next step and the pressure of the chamber 28b.

[0254] By supplying sterile air, chambers 28b and 28c are maintained at a positive pressure, thereby maintaining the sterility achieved by the pre-operation sterilization process within the chambers and preventing the influx of bacteria from outside. The pre-operation sterilization process can be accomplished by, for example, sterilizing the interior of chambers 28a, 28b, and 28c with hydrogen peroxide gas at a concentration of 10 mg / L or less. Alternatively, the areas where the preform 1 and bottle 2 come into contact can be irradiated with ultraviolet light. Alternatively, a solution containing 1% by mass of ethanol and hydrogen peroxide can be sprayed onto areas where the mold 4, blow nozzle 5, and fixture 13, etc., come into contact with the materials.

[0255] The present invention is configured as described above, but is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention.

Claims

1. A method for sterilizing a preform, comprising: a light irradiation step comprising: a lamp provided above the mouth of the preform; and a dome-shaped reflector having a plurality of surfaces surrounding the lamp and an opening capable of irradiating the inner and outer surfaces of the opening of the mouth of the preform with light containing ultraviolet rays, wherein at least the inner and outer surfaces of the mouth of the preform are irradiated with the light containing ultraviolet rays; a step of vaporizing a sterilizing agent containing at least hydrogen peroxide; and a sterilizing gas blowing step of blowing the sterilizing gas toward the preform, in, The light irradiation step is performed before the sterilant gas blowing step. After the sterilizer gas blowing step, the preform is conveyed to a heating furnace where the preform is heated to a temperature suitable for blow molding.

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