METHOD FOR STERILIZING BLOW MOLDING MACHINE, AND BLOW MOLDING MACHINE

Abstract

A blow molding machine is subjected to a sterilizing treatment in a simple manner. A liquid sterilizer is filled into preforms of at least the same number as the number of spindles. In a heating unit that heats the preforms to a molding temperature, some of the liquid sterilizer is caused to diffuse, and blow air is blasted into preforms in which the liquid sterilizer remains to cause the liquid sterilizer to diffuse in a molding unit, and molded bottles are discharged.

Claims

1. A blow molding machine in which a heating unit that has a travelling device which causes preforms and bottles to travel from supply of the preforms until molding of the bottles and that heats the preforms to a blow molding temperature from an upstream side toward a downstream side in the travelling device, and a molding unit that blow molds the preforms into the bottles by means of blow air are provided in that order, wherein a liquid sterilizer filling unit that fills a liquid sterilizer into the preforms of at least a same number as a number of spindles that hold the preforms in the heating unit is provided upstream of the heating unit, and a discharging device that discharges the bottles is provided downstream of the molding unit so that the bottles that are molded from the preforms in which the liquid sterilizer is filled and used to sterilize the blow molding machine are not used as a product.

2. The blow molding machine according to claim 1, wherein: an inspection device that inspects whether or not the preform in which the liquid sterilizer is filled is being held by the spindle is provided.

3. The blow molding machine according to claim 2, wherein: a supply apparatus that, in a case where the spindle that does not hold the preform in which the liquid sterilizer is filled is identified by the inspection device, supplies the preform in which the liquid sterilizer is filled to the spindle is provided.

4. The blow molding machine according to claim 1, wherein: the spindle is provided in a manner so that a gap is formed between the spindle and the preform when the spindle holds the preform.

5. The blow molding machine according to claim 1, wherein: in the molding unit that comprises a blow nozzle to which a valve block is joined that butts against a mouth portion of the preform, and an extension rod that is guided by a hole provided in the blow nozzle and inserted into the preform, a valve block is provided and the blow air that is supplied from the valve block to the blow nozzle is blown into the preform, the preform is molded into the bottle, the blow air in which the liquid sterilizer inside the bottle diffuses passes through the valve block from the blow nozzle, and the liquid sterilizer is caused to diffuse inside the molding unit of the blow molding machine.

6. The blow molding machine according to claim 5, wherein a valve block that causes the blow air in which the liquid sterilizer is diffused to flow backward to an aseptic filter of a compressed air supplying apparatus that supplies the blow air is provided.

7. The blow molding machine according to claim 2, wherein: the spindle is provided in a manner so that a gap is formed between the spindle and the preform when the spindle holds the preform.

8. The blow molding machine according to claim 3, wherein: the spindle is provided in a manner so that a gap is formed between the spindle and the preform when the spindle holds the preform.

9. The blow molding machine according to claim 2, wherein: in the molding unit that comprises a blow nozzle to which a valve block is joined that butts against a mouth portion of the preform, and an extension rod that is guided by a hole provided in the blow nozzle and inserted into the preform, a valve block is provided and the blow air that is supplied from the valve block to the blow nozzle is blown into the preform, the preform is molded into the bottle, the blow air in which the liquid sterilizer inside the bottle diffuses passes through the valve block from the blow nozzle, and the liquid sterilizer is caused to diffuse inside the molding unit of the blow molding machine.

10. The blow molding machine according to claim 3, wherein: in the molding unit that comprises a blow nozzle to which a valve block is joined that butts against a mouth portion of the preform, and an extension rod that is guided by a hole provided in the blow nozzle and inserted into the preform, a valve block is provided and the blow air that is supplied from the valve block to the blow nozzle is blown into the preform, the preform is molded into the bottle, the blow air in which the liquid sterilizer inside the bottle diffuses passes through the valve block from the blow nozzle, and the liquid sterilizer is caused to diffuse inside the molding unit of the blow molding machine.

11. The blow molding machine according to claim 4, wherein: in the molding unit that comprises a blow nozzle to which a valve block is joined that butts against a mouth portion of the preform, and an extension rod that is guided by a hole provided in the blow nozzle and inserted into the preform, a valve block is provided and the blow air that is supplied from the valve block to the blow nozzle is blown into the preform, the preform is molded into the bottle, the blow air in which the liquid sterilizer inside the bottle diffuses passes through the valve block from the blow nozzle, and the liquid sterilizer is caused to diffuse inside the molding unit of the blow molding machine.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0036] FIG. 1 is a plan view illustrating an outline of a blow molding machine according to an embodiment of the present invention.

[0037] FIGS. 2 (A)-2 (D) are multiple views illustrating each process of a method for sterilizing a blow molding machine according to an embodiment of the present invention, in which (A) illustrates a process of filling a liquid sterilizer into a preform, (B) illustrates a process of heating a preform in which the liquid sterilizer has been filled, (C) illustrates a process of blow molding a preform in which the liquid sterilizer remains, and (D) illustrates a process of taking out a bottle that is blow molded.

[0038] FIG. 3 is a partial cross-sectional view illustrating a state in which a preform is held by a spindle according to an embodiment of the present invention.

[0039] FIG. 4 is a cross-sectional view illustrating an overview of a heating unit of a blow molding machine according to an embodiment of the present invention.

[0040] FIG. 5 is a cross-sectional view illustrating an overview of a molding unit of a blow molding machine according to an embodiment of the present invention.

[0041] FIG. 6 is a schematic diagram illustrating conduits of a valve block of a blow molding machine according to an embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

[0042] In the following, modes for carrying out the present invention will be described with reference to the drawings.

[0043] First, referring to FIG. 1, an overview of a blow molding machine in which a liquid sterilizer filling unit for filling a liquid sterilizer into preforms supplied from a preform supplying apparatus, a heating unit for heating preforms in which the liquid sterilizer has been filled to a temperature at which the preforms are to be molded into bottles, and a molding unit for blow molding the heated preforms into bottles are provided will be described. In addition, the details of a process for sterilizing the blow molding machine will be described with reference to FIG. 2, FIG. 3, FIG. 4, FIG. 5 and FIG. 6. According to this embodiment, a blow molding machine can be simply and easily sterilized, and an aseptic condition can be easily obtained inside an aseptic filling machine in which the blow molding machine is installed, before operation of the aseptic filling machine.

[0044] (Overview of Blow Molding Machine)

[0045] By filling a liquid sterilizer S into a preform 1 illustrated FIG. 2(A), and molding the preform 1 into a bottle 2 illustrated in FIG. 2(D), the blow molding machine of the present invention can sterilize locations which directly or indirectly contact the inner surface of preforms in a heating unit 16 and a molding unit 23 constituting parts of the blow molding machine. Further, by installing the blow molding machine in an aseptic filling machine, the blow molding machine can be sterilized before operation of the aseptic filling machine and, during operation of the aseptic filling machine, the aseptic condition of sterilized preforms 1 can be maintained and aseptic bottles 2 can be molded.

[0046] As illustrated in FIG. 1, preforms 1 are supplied by a preform supplying apparatus 3. The liquid sterilizer S is filled into the supplied preforms 1 at a liquid sterilizer filling unit 10. The number of the preforms 1 to be filled is the same as or greater than the number of spindles 15 of the heating unit 16. All of the spindles 15 must hold a preform 1 in which the liquid sterilizer S has been filled, and an inspection device 61 is provided that includes a photoelectric sensor for inspecting whether all of the spindles 15 hold a preform 1 in which the liquid sterilizer S has been filled, and a proximity sensor that confirms positional information of the spindles 15. The positional information of the spindles 15 can be identified at all times with these sensors. Further, it is not necessary to limit the sensors to these sensors. The preforms 1 in which the liquid sterilizer S has been filled are heated to a molding temperature by the heating unit 16. The liquid sterilizer S diffuses as a result of the heating, and locations facing the inner surface of the preform 1 of the spindle 15 are sterilized by the diffused liquid sterilizer S. The heated preform 1 in which the liquid sterilizer S remains is conveyed to the molding unit 23, at which high-pressure blow air is blasted into the preform 1 in which the liquid sterilizer S remains, and the liquid sterilizer S diffuses into the blow air. The blow air in which the liquid sterilizer S has diffused spurts out into the molding unit 23, and as a result the inside of the molding unit 23 is sterilized by the liquid sterilizer S diffused in the molding unit 23. The molded bottle 2 is discharged to outside of the aseptic filling machine by a discharging device 29, and is not used as a product.

[0047] The heating unit 16 constituting a part of the blow molding machine may be shielded by a heating unit chamber 17, and the molding unit 23 machine may be shielded by a molding unit chamber 25. Before operating the aseptic filling machine in which the blow molding machine is installed, the inside of the heating unit chamber 17 and the molding unit chamber 25 may be sterilized, and thereafter aseptic air may be supplied into the heating unit chamber 17 and into the molding unit chamber 25, and the inside of the chambers may thus be kept at a positive pressure. Thereby, when the aseptic filling machine operates, aseptic bottles 2 are obtained in a state in which the aseptic condition of the sterilized preforms 1 has been maintained.

[0048] (Details of Method for Sterilizing Blow Molding Machine, and Blow Molding Machine)

[0049] First, by means of the preform supplying apparatus 3 illustrated in FIG. 1, the preform 1 illustrated in FIG. 2 (A) is conveyed continuously by a preform supplying conveyor 4 at a desired speed to the liquid sterilizer filling unit 10 for the preform 1.

[0050] The preform 1 in the present embodiment is a bottomed cylindrical body having a test tube shape, and the preform 1 is formed with a mouth portion 1a like that of the bottle 2 shown in FIG. 2 (D) when performing initial molding thereof. A male thread is formed at the mouth portion 1a concurrently with molding of the preform 1. Further, a support ring 1b for conveyance is formed at a lower part of the mouth portion 1a in the preform 1. The preform 1 or the bottle 2 travels through the inside of the blow molding machine while being gripped by a gripper 6 through the support ring 1b. The preform 1 is molded by injection molding, compression molding or the like. The material of the preform 1 is composed of a thermoplastic resin such as polyethylene terephthalate, polyethylene naphthalate, polypropylene or polyethylene, and may be a simple substance or a mixture of these thermoplastic resins, and may include recycled thermoplastic resin. Further, to impart a barrier property, a thermoplastic resin such as an ethylene-vinyl alcohol-copolymer or polyamide having an aromatic amine such as meta-xylene diamine as a monomer may be included as a layer or as a mixture.

[0051] Further, with regard to the preform 1 that is used for sterilizing the blow molding machine, because it is not necessary to use a preform 1 that is to be used during operation of the aseptic filling machine, a preform 1 which is rejected because a defect is found during an inspection when manufacturing the preform 1, or an inexpensive preform of a different shape to the preforms 1 that are used during operation of the aseptic filling machine may be used as the preform 1 for sterilizing the blow molding machine. In order to raise the temperature of the preform 1 in the heating unit 16 and improve the sterilizing effect, a preform 1 to which a black pigment such as carbon is added may be used.

[0052] The preform 1 is transferred from the preform supplying conveyor 4 to a wheel of the liquid sterilizer filling unit 10 by being gripped by the gripper 6 that is provided at regular intervals on the wheel of the liquid sterilizer filling unit 10. As illustrated in FIG. 2(A), at the wheel, a given quantity of the liquid sterilizer S is filled into the preform 1 by a liquid sterilizer filling nozzle 32 that is provided in the liquid sterilizer filling unit 10.

[0053] A liquid containing hydrogen peroxide is preferable as the liquid sterilizer S, and in addition to hydrogen peroxide, the liquid sterilizer S may contain one or more compounds that have a sterilizing effect such as organic acids such as peracetic acid and acetic acid, chlorine compounds such as sodium hypochlorite, alkaline compounds such as sodium hydroxide and potassium hydroxide, nitric acid, ozone, or acid water. Further, the sterilizer S may contain an additive agent such as a cationic surface active agent, a non-ionic surface active agent or a phosphate compound. In addition, as a solvent, the sterilizer S may contain one or more kinds of substance among water, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol and butyl alcohol, ketones such as acetone, methyl ethyl ketone and acetylacetone, and glycol ether and the like.

[0054] The concentration of the hydrogen peroxide solution is preferably in the range of 0.1 mass % to 35 mass %, and more preferably is in the range of 1 mass % to 5 mass %. If the concentration is less than 0.1 mass %, the sterilizing power will be poor, and if the concentration is more than 35 mass % there is a risk that the hydrogen peroxide solution will cause packing used in the blow molding machine to deteriorate.

[0055] Preferably, the liquid sterilizer S contains ethanol as a solvent. By containing ethanol as a solvent, the liquid sterilizer S can be caused to diffuse with favorable efficiency inside the blow molding machine.

[0056] The amount of the liquid sterilizer S to be filled into the preform 1 is in the range of 0.01 ml to 10 ml per preform, and preferably is in the range of 0.1 ml to 3 ml. This is because, if the amount less than 0.01 ml, the sterilization capability will be insufficient, while if the amount is more than 10 ml, some of the liquid sterilizer S may remain inside the bottle 2 after molding, thus constituting a waste thereof.

[0057] A plurality of the liquid sterilizer filling nozzles 32 and the grippers 6 are provided at fixed intervals on the wheel of the liquid sterilizer filling unit 10. The preform 1 is gripped by the gripper 6 and conveyed at a constant speed on the wheel, and the liquid sterilizer filling nozzle 32 that rotates in synchronization therewith is inserted into the preform 1 and fills a predetermined amount of the liquid sterilizer S into the preform 1. Alternatively, a fixed nozzle of the liquid sterilizer filling nozzle 32 may be provided on the wheel, and may quantitatively fill the liquid sterilizer S into the preform 1 that is conveyed at a constant speed, and may quantitatively cause the liquid sterilizer S to adhere to the outer surface of the preform 1. It is also possible to adjust the filling amount of the liquid sterilizer S by adjusting the conveying speed. Although it is desirable that the liquid sterilizer filling nozzle 32 is provided in this manner in the blow molding machine, the liquid sterilizer S may be filled manually into the preforms 1 of a number greater than or equal to the number of the spindles 15, and the preforms 1 that are manually filled may then be supplied to the heating unit 16.

[0058] The preform 1 in which the liquid sterilizer S has been filled is conveyed from a preform sterilization wheel 9 inside a preform sterilizing unit 7 that includes a sterilizer gas blowing nozzle 11 that blows a gas or mist of the sterilizer or a mixture of these at the preform 1 to sterilize the preform 1 during operation of the aseptic filling machine to a wheel 14 via an air blowing wheel 12 that includes an air blowing nozzle 13 that blows air at the preform 1 at which a gas or mist of the sterilizer or a mixture of these is blowed. The liquid sterilizer filling unit 10 and the preform sterilizing unit 7 are shielded by a preform sterilizing unit chamber 8.

[0059] As illustrated in FIG. 1, a blower 30 for removing excess gas or mist of the sterilizer or a mixture of these blown at the preform 1 during operation of the aseptic filling machine is provided in the preform sterilizing unit 7. Further, a filter 31 for detoxifying the sterilizer is also provided. In some cases the liquid sterilizer S evaporates when the liquid sterilizer S is being filled into the preform 1, therefore when filling the liquid sterilizer S into the preform 1, the blower 30 may be driven to perform evacuation thereof.

[0060] The preform 1 in which the liquid sterilizer S has been filled that is conveyed by the wheel 14 is released from the gripper 6, and as illustrated in FIG. 2(B), the spindle 15 is inserted into the mouth portion 1a of the preform 1 and conveyed to inside of the heating unit 16 by an endless chain 18.

[0061] As illustrated in FIG. 1, the heating unit 16 includes at least a heater 20 for heating the preform 1, a reflector plate 21 for reflecting the heat of the heater 20 to efficiently heat the preform 1, the spindles 15 for holding and rotating the preforms 1, the endless chain 18 for moving the spindles 15 and on which the spindles 15 are provided at regular intervals, and pulleys 19a and 19b for rotating the endless chain 18. Further, to prevent the heat of the heater 20 from conducting to outside of the heating unit 16 for preforms, a heat insulating material 33 may be provided on the outer side of the heater 20.

[0062] As illustrated in FIG. 4, a motor or an operation transmitting device or the like as a driving apparatus for driving the heating unit 16 having the aforementioned equipment is provided in a heating drive unit 34. Since the equipment of the heating drive unit 34 requires a lubricant, and contamination is accumulated, it is difficult to maintain the aseptic condition. Therefore, the heating unit 16 and the heating drive unit 34 are isolated from each other, and the outside of the heating unit 16 may be shielded by the heating unit chamber 17.

[0063] The heater 20 is preferably a halogen lamp that emits infrared rays. A plurality of halogen lamps as the heater 20 are provided in parallel to be perpendicular to the axial direction of the preform 1. The preform 1 in which the liquid sterilizer S has been filled is heated by near-infrared rays, infrared rays, or far-infrared rays emitted from the halogen lamps of the heater 20. The heating temperature of the plurality of halogen lamps that are provided is controlled, and a temperature difference may be provided with respect to the heating temperature in the axial direction of the preform 1. Further, a plurality of units of halogen lamps are provided with respect to the moving direction of the preform 1 as shown in FIG. 1. Although in FIG. 1, six units are provided in each row so that a total of 12 units are provided, the number of units can be arbitrarily decided. The temperature of these halogen lamp units is controlled, and may be set to be a high temperature at the initial stage of heating, and to a low temperature at the final stage of heating.

[0064] As illustrated in FIG. 2(B), the preform 1 that is conveyed to the heating unit 16 is heated by the heater 20 to a temperature suitable for subsequent blow molding by infrared heating or another heating device. The aforementioned temperature is preferably in the range from 90° C. to 140° C. Note that, although during operation of the aseptic filling machine the temperature of the mouth portion 1a of the preform 1 is suppressed to a temperature of not more than 70° C. to prevent deformation and the like, in the case of sterilizing the blow molding machine, because the bottle 2 that is blow molded from the preform 1 that is used will be discarded from the aseptic filling machine, the temperature may be higher than or equal to 70° C. Further, to enhance the sterilizing effect of the liquid sterilizer S with respect to the spindles 15 or the heating unit 16, the heating time period of the preform 1, the output of the heater 20, the frequency of a blower 37 and the like may be adjusted and the preform 1 may be heated under temperature conditions at which the liquid sterilizer S is easily activated that are different conditions from the conditions for heating the preform 1 during operation of the aseptic filling machine. In order to prevent overheating of the mouth portion 1a of the preform 1, as illustrated in FIG. 4, a mouth portion protection member 35 which is formed as a surface perpendicular to the axial direction of the preform 1 or as a surface that is joined to the aforementioned surface and has an upward angle from the aforementioned surface is provided below the support ring 1b of the preform 1. The mouth portion protection member 35 is arranged so as to prevent the infrared rays or the like emitted from the heater 20 from reaching the mouth portion 1a of the preform 1 more than necessary, and cooling water that is supplied to the mouth portion protection member 35 during operation of the aseptic filling machine need not be supplied in the case of sterilizing the blow molding machine.

[0065] Although the preform 1 is heated by infrared rays or the like emitted from the heater 20, infrared rays or the like that arrive at the rear of the preform 1 without being absorbed by the preform 1 do not contribute to heating. Therefore, as illustrated in FIG. 4, by providing the reflector plate 21 at the rear of the preform 1, infrared rays or the like that arrive at the rear of the preform 1 are reflected, and thus heating of the preform 1 can be efficiently performed. The reflector plate 21 that is used is obtained by vapor-depositing or plating gold, silver, or aluminum or the like on a metal. Any kind of object may be used as long as it can reflect infrared rays and the like. The reflector plate 21 may have a flat surface, a curved surface, or a combination of a flat surface and a curved surface. The reflector plate 21 may be provided not only at the rear of the preform 1, but also at the rear of the heater 20, so as to reflect infrared rays or the like emitted to the rear of the heater 20.

[0066] As illustrated in FIG. 2 (B), the spindle 15 is inserted into the mouth portion 1a of the preform 1, and the preform 1 is conveyed through the inside of the heating unit 16 while rotating. As illustrated in FIG. 3, when the lower part of the spindle 15 is inserted into the mouth portion 1a, the preform 1 is held by the spindle 15 by elastic deformation of elastic bodies 36 such as rubber or springs. The spindles 15 are provided at regular intervals on the endless chain 18. The endless chain 18 is rotated by the pulleys 19a and 19b.

[0067] The temperature of the preform 1 in which the liquid sterilizer S has been filled is raised by heat of the heater 20 in the heating unit 16. The liquid sterilizer S inside the preform 1 is heated by heat conducted from the preform 1, and some of the liquid sterilizer S evaporates. As illustrated in FIG. 3, the evaporated activated liquid sterilizer S flows toward a gap between the mouth portion 1a of the preform 1 and the spindle 15. Locations at which the spindle 15 contacts the preform 1, particularly locations around the elastic bodies 36 are appropriately sterilized by the liquid sterilizer S that evaporates and diffuses from the preform 1. In addition, the liquid sterilizer S diffuses inside the heating unit 16, and the equipment inside the heating unit 16 as well as the inside of the heating unit chamber 17 that shields the heating unit 16 are sterilized by the liquid sterilizer S that diffuses inside the heating unit 16.

[0068] To maintain the aseptic condition inside the heating unit chamber 17 that is sterilized, aseptic air may be supplied into the heating unit chamber 17. As illustrated in FIG. 4, the blower 37 and an aseptic filter 38 are provided at a lower part of the heating unit 16, and air is blown by the blower 37 through the aseptic filter 38 and the resultant aseptic air is supplied from the lower part of the heating unit 16. Further, an exhaust device 40 may be provided at an upper part of the heating unit 16, and the inside of the heating unit chamber 17 may be kept in an appropriate positive pressure state by aseptic air. Further, the aseptic air may be heated by a heating device 39 provided between the blower 37 and the aseptic filter 38. By supplying heated aseptic air into the heating unit chamber 17 after the liquid sterilizer S is diffused therein, sterilizer that remains inside the heating unit chamber 17 is activated and the sterilizing effect increases.

[0069] The preforms 1 in which the liquid sterilizer S has been filled must be supplied in at least the same number as the number of the spindles 15. This is to ensure that all of the spindles 15 that contact a preform 1 are reliably sterilized. The greater the number of preforms 1 in which the liquid sterilizer S is filled that are supplied is, the greater the sterilizing effect will be because the amount of the liquid sterilizer S that diffuses inside the heating unit 16 will increase, and preferably the number of preforms 1 is not more than five times the number of spindles 15 because in such a case a sufficient sterilizing effect is obtained and there is a risk that the preforms 1 and the liquid sterilizer S will be wasted if the number of preforms 1 is greater than five times the number of spindles 15.

[0070] The preforms 1 in which the liquid sterilizer S has been filled must be held by all of the spindles 15. Therefore, the inspection device 61 is provided that includes a proximity sensor and a photoelectric sensor to inspect that all of the spindles 15 hold a preform 1. The proximity sensor is used for checking the origin of the spindles 15, and detects the origin upon the spindle 15 completing one full circuit during operation. The photoelectric sensor checks whether or not the preform 1 is held by the spindle 15. It is not necessary to limit the detection method to this method. Although the inspection device 61 is provided at a position that is before the heater 20 on the downstream side of the pulley 19a, the inspection device 61 may be provided at a position that is before the pulley 19a on the downstream side of the heater 20.

[0071] In a case where a spindle 15 that does not hold a preform 1 in which the liquid sterilizer S has been filled is found by the inspection device 61, an alarm or error message may be displayed. Thereafter, a preform 1 in which the liquid sterilizer S has been filled is supplied to the spindle 15 that does not hold a preform 1 in which the liquid sterilizer S has been filled, to thereby cause the spindle 15 to hold the preform 1 in which the liquid sterilizer S has been filled. A supply apparatus is provided that supplies a preform 1 in which the liquid sterilizer S has been filled to a spindle 15 that does not hold a preform 1 in which the liquid sterilizer S has been filled. In a case where a spindle 15 that does not hold a preform 1 in which the liquid sterilizer S has been filled is detected by the inspection device 61, the supply apparatus supplies a preform 1 to the liquid sterilizer filling unit 10 at a timing that causes the spindle 15 in question to hold the preform 1 in which the liquid sterilizer S has been filled. The supply apparatus is an apparatus that supplies a preform 1 to the liquid sterilizer filling unit 10 upon receiving a signal from the inspection device 61.

[0072] Although some of the liquid sterilizer S that is filled into the preform 1 evaporates and diffuses in the heating unit 16, the preform 1 is gripped by the gripper 6 of a wheel 22 from the endless chain 18 in a state in which some of the liquid sterilizer S remains in the preform 1, and is conveyed by the wheel 22. The preform 1 in which the liquid sterilizer S remains is conveyed by the wheel 22 to the molding unit 23.

[0073] As illustrated in FIG. 5, the molding unit 23 includes a mold 26, a blow nozzle 41, a valve block 42, an extension rod 43 and the like. As illustrated in FIG. 2(C), the mold 26 is composed of split molds 26a and 26b and a bottom mold 26c. A motor, a hydraulic apparatus, an operation transmitting device, an air cylinder or the like is required in order to drive the molding unit 23, and is provided in a mold driving unit 44. Since the equipment of the mold driving unit 44 requires a lubricant, and contamination is accumulated, it is difficult to maintain the aseptic condition. Therefore, the molding unit 23 and the mold driving unit 44 are isolated from each other. The mold 26 is provided at fixed intervals at the periphery of a molding unit wheel 24, and molds the preform 1 by opening and closing in synchrony with rotation of the molding unit wheel 24.

[0074] As illustrated in FIG. 5, the molding unit 23 may be shielded by the molding unit chamber 25. Further, the molding unit chamber 25 is composed of a movable unit 45 that holds the molding unit 23, and isolates the molding unit 23 from the mold driving unit 44, and fixed unit 46 that shields the molding unit 23 from the outside. The movable unit 45 rotates around a rotary pipe 47 as a central axis. The molding unit 23 held by the movable unit 45 also rotates, and accompanying the rotation, as illustrated in FIG. 2(C), the preform 1 in which the liquid sterilizer S remains is blow molded into the bottle 2.

[0075] As illustrated in FIG. 2(C), by closing the split molds 26a and 26b and the bottom mold 26c of the mold 26 of the molding unit wheel 24, the preform 1 is passed from the wheel 22 to the molding unit wheel 24. Thereafter, the blow nozzle 41 is joined to the mouth portion 1a of the preform 1, the extension rod 43 is guided by the hole provided in the blow nozzle 41 to be inserted into the preform 1, and simultaneously, an intermediate pressure air P1 and a high pressure air P2 are sequentially fed into the preform 1 by the operation of an electromagnetic valve of the valve block 42, and the preform 1 is molded into the bottle 2. The term “intermediate pressure air P1” refers to air with a pressure in the range of 1 MPa to 2.5 MPa, and the term “high pressure air P2” refers to air with a pressure in the range of 2.5 MPa to 4 MPa. As illustrated in FIG. 5, blow air is supplied by a high-pressure-air supply apparatus 51, and the high pressure air is sterilized by an aseptic filter 52 to become aseptic high pressure air. The intermediate pressure air P1 may be obtained by decreasing the pressure of the high pressure air P2.

[0076] The extension rod 43 penetrates downward through the inside of the blow nozzle 41 and enters into the preform 1. The extension rod 43 butts against and stretches the base of the preform 1 while penetrating through the inside of the preform 1, and stretches the base of the preform 1 until reaching the bottom mold 23c. At such time, the tip of the extension rod 43 is sterilized when the tip of the extension rod 43 contacts the liquid sterilizer S remaining inside the preform 1.

[0077] Subsequently, as illustrated in FIG. 6, a valve for the intermediate pressure air P1 of the valve block 42 opens and the intermediate pressure air P1 is blasted into the preform 1, and furthermore, the valve for the intermediate pressure air P1 closes, a valve for the high pressure air P2 opens, and the high pressure air P2 is blasted into the preform 1 to expand the preform 1 in the lateral direction to be molded into the shape of the mold 26.

[0078] After molding is completed, the valve for the high pressure air P2 illustrated in FIG. 6 is closed, and concurrently with the extension rod 43 being lifted, a mold unit release valve 48 in which a silencer is provided that is illustrated in FIG. 6 is opened. The liquid sterilizer S remaining in the preform 1 that is pressurized by the high pressure air P2 all at once becomes gas or mist and diffuses into the molding unit 23 from the mold unit release valve 48. The diffused liquid sterilizer S sterilizes the equipment such as the mold 26, the blow nozzle 41, the valve block 42 and the extension rod 43 of the molding unit 23 and also the inside of the molding unit chamber 25. To improve the sterilizing effect of the molding unit 23, conditions such as the pressure of the high pressure air P1 and P2, the insertion time period and speed of the extension rod 43, the opening and closing time periods and timings of an exhaust valve (not illustrated) and the like may be adjusted to conditions that are different from the molding conditions during operation of the aseptic filling machine.

[0079] As illustrated in FIG. 5, the intermediate pressure air P1 and high pressure air P2 required for molding the preform 1 into the bottle 2 are supplied by a hose provided inside the rotary pipe 47 from an upper part of the blow molding machine. The rotary pipe 47 and the fixed unit 46 are joined by a rotary joint 49, enabling rotation of the rotary pipe 47. The intermediate pressure air P1 and the high pressure air P2 are introduced into a high pressure air manifold 50 from a hose inside the rotary pipe 47 that passes through the aseptic atmosphere inside the molding unit chamber 25. The intermediate pressure air P1 and the high pressure air P2 are sterilized as a result of high pressure air supplied from the high-pressure-air supply apparatus 51 passing through the aseptic filter 52. An exhaust valve 53 is provided between the high-pressure-air supply apparatus 51 and the aseptic filter 52. Because the intermediate pressure air P1 and the high pressure air P2 is supplied from the high pressure air manifold 50 to the valve block 42 held by the movable unit 45, the high pressure air manifold 50 is configured to be rotatable.

[0080] As a result of the liquid sterilizer S diffusing inside the molding unit chamber 25, equipment that is exposed inside the molding unit chamber 25 is sterilized. However, there is a risk that the blow nozzle 41, the valve block 42, and conduits for blow air which are unexposed will not be sterilized. After molding of the preform 1 is completed, by opening the exhaust valve 53 equipped with a silencer, the valve for the intermediate pressure air P1 and the valve for the high pressure air P2 of the valve block 42, as well as a valve for return air AR at the same time, the high pressure air P2 in which the liquid sterilizer S is diffused can be caused to reach the exhaust valve 53 via the respective valves from the conduits of the valve block 42. By means of this operation, the conduits for blow air and the valve block 42 can all be sterilized. The conduit for return air AR (air recycling) is a conduit that returns a part of the high pressure air P2 remaining in the bottle 2 after molding is completed to a part of the intermediate pressure air P1 during operation of the aseptic filling machine. The high pressure air P2 in which the liquid sterilizer S is diffused can sterilize the aseptic filter 52 by being caused to reach the exhaust valve 53.

[0081] As illustrated in FIG. 2(D), the mold 26 opens and the molded bottle 2 is gripped by the gripper 6 of the wheel 27 and taken out from the mold 26 and conveyed to a wheel 28 that is outside the molding unit chamber 25. The bottles 2 that are molded from the preforms 1 in which the liquid sterilizer S is filled and used to sterilize the blow molding machine are discharged to outside of the aseptic filling machine by the discharging device 29 provided in the wheel 28, and are not used as products.

[0082] Sterilization at the molding unit 23 is performed by molding the preforms 1 in which the liquid sterilizer S has been filled, into the bottles 2. That is, sterilization is performed by repeating opening and closing of the mold 26 accompanying rotation of the molding unit wheel 24 with respect to the preforms 1 in which the liquid sterilizer S has been filled that are of the same number as the number of the spindles 15, lowering and lifting of the extension rod 43, blowing of the intermediate pressure air P1 and the high pressure air P2 into the preform 1, and diffusion of the liquid sterilizer S into the molding unit 23 and the blow air conduits by control of the valve block 42 after molding is completed. Because the number of the preforms 1 in which the liquid sterilizer S has been filled that are supplied is equal to or greater than the number of spindles 15, it is possible for sterilization in the molding unit 23 to be performed accompanying molding of one bottle 2 or a plurality of bottles 2 in one mold 26. This is because the number of molds 26 is less than the number of spindles 15. The number of the preforms 1 in which the liquid sterilizer S remains that are supplied to one mold is preferably three or more, and it is good for the number to be not more than 100. If the number of the preforms 1 is less than three, it may result in defective sterilization, while if the number of the preforms 1 is more than 100, there is a risk that the liquid sterilizer S will remain inside the molding unit chamber 25. Therefore, after performing sterilization treatment of the blow molding machine, it is preferable to perform blow molding using preforms 1 in which the liquid sterilizer S has not been filled, to thereby remove any remaining liquid sterilizer S. Alternatively, it is good to confirm that the liquid sterilizer S has been removed and that blow molding is being performed as normal. Whether or not the liquid sterilizer S has been removed can be confirmed by filling water into a molded bottle, and measuring the amount of the liquid sterilizer S in the water, for example, in a case where the liquid sterilizer S contains hydrogen peroxide, measuring the amount of hydrogen peroxide, and it can be confirmed that the liquid sterilizer S has been removed if the measured value is equal to or less than a reference value. Further, whether or not blow molding is being performed as normal can be confirmed by measuring the overall height, capacity and wall thickness distribution and the like of the molded bottle 2, and checking whether or not the measured values conform with reference values.

[0083] To maintain the aseptic condition inside the sterilized molding unit chamber 25, aseptic air is supplied into the molding unit chamber 25. As illustrated in FIG. 5, a blower 54 and an aseptic filter 55 are provided at an upper part of the molding unit chamber 25, and aseptic air obtained by passing air through the aseptic filter 55 by means of the blower 54 is supplied from the upper part of the molding unit chamber 25. Further, an device may be provided in the molding unit chamber 25, and the inside of the molding unit chamber 25 may be kept in an appropriate positive pressure state by the aseptic air. Further, aseptic air may be heated by a heating apparatus 56 provided between the blower 54 and the aseptic filter 55. By supplying heated aseptic air into the molding unit chamber 25 after the liquid sterilizer S diffuses therein, the liquid sterilizer S remaining inside the molding unit chamber 25 is activated and the sterilizing effect increases.

[0084] Because the extension rod 43 and the mold 26 are exposed inside the molding unit chamber 25, the extension rod 43 and the mold 26 are sterilized by the liquid sterilizer S that diffuses in the molding unit 23. As illustrated in FIG. 5, the extension rod 43 is held by an extension rod holding member 59. The operations to lift up and to lower the extension rod 43 are performed by operating the extension rod holding member 59. The extension rod holding member 59 is operated upward and downward by movement of an extension rod holding member movement shaft 60. The extension rod holding member 59 is operated by rotating the extension rod holding member movement shaft 60 by means of a servomotor provided in the mold driving unit 44, or by coupling the extension rod holding member movement shaft 60 to a pneumatic cylinder.

[0085] As illustrated in FIG. 5, the inside of the molding unit chamber 25 is maintained in an aseptic atmosphere during operation of the aseptic filling machine. The mold driving unit 44 that is outside the molding unit chamber 25 is provided in a non-aseptic atmosphere. The aseptic atmosphere and the non-aseptic atmosphere are isolated from each other by sealing the lower part of the movable unit 45 with a liquid seal apparatus 57 provided at the lower part of the movable unit 45. Although the liquid may be a liquid such as water, the liquid preferably includes a sterilizer such as peracetic acid (a concentration in the range of 100 ppm to 3000 ppm is preferable as the concentration contained in the liquid), or hydrogen peroxide (preferably contained in the liquid in an amount within the range of 1 mass % to 40 mass %). An end face of the movable unit 45 immersed in the liquid of the liquid seal apparatus 57 is provided so as not to contact a bottom part of the liquid seal apparatus 57. The liquid contacts with both surfaces of the movable unit 45 that are immersed. However, in a case where the inside of the molding unit chamber 25 is at a positive pressure because of the supply of the aseptic air, the height of the liquid level of the liquid on the non-aseptic atmosphere side of the liquid seal apparatus 57 is higher than the liquid level of the liquid on the aseptic atmosphere side. Further, in order to prevent the aseptic atmosphere and the non-aseptic atmosphere from communicating with each other if the liquid volume decreases, a liquid level gage may be provided in the liquid seal apparatus 57 so as to constantly monitor the liquid level. In addition, if a large amount of the liquid flows into the liquid seal apparatus 57 and overflows from the liquid seal apparatus 57, the liquid will flow out into the aseptic atmosphere. To prevent this, the height of the wall surface on the non-aseptic atmosphere side of the liquid seal apparatus 57 may be made lower than the height of the wall surface on the aseptic atmosphere side, so that liquid that overflows is stored in a liquid reservoir tank 58, and is discharged from a bottom part of the liquid reservoir tank 58. When sterilizing the blow molding machine, it is necessary to isolate the aseptic atmosphere and the non-aseptic atmosphere from each other by means of the liquid seal apparatus 57.

[0086] Note that, in the process of blow molding the preform 1 illustrated in FIG. 2 (C), it is possible to blast the blow air into the preform 1 not only to cause the preform 1 to expand, but also to break or damage the preform 1. For example, this can be achieved by supplying an increased amount of the liquid sterilizer S into the preform 1, or by blasting the blow air into the preform 1 more rapidly or under higher pressure. If the preform 1 is broken in the course of expansion in this way, the liquid sterilizer S remaining inside the preform 1 is dispersed and scattered inside the mold 26 and adheres to the inner surface of the mold 26. In this way, the preform 1 may be caused to break during the process of expanding the preform 1, to thereby cause the liquid sterilizer S to diffuse inside the molding unit 23.

[0087] During operation of the aseptic filling machine, when molding of the bottles 2 is being performed by the blow molding machine, some kind of failure may occur in the blow molding machine. At such time, an operator stops the blow molding machine, and inspects or cleans the inside of the molding unit chamber 25 or the heating unit chamber 17 surrounding the blow molding machine. When the blow molding machine is opened, bacteria or the like from a person or the external environment enter into the blow molding machine, and the bacteria or the like that enter adhere to the spindles 15 of the heating unit 16, and the blow nozzle 41, the valve block 42 or the extension rod 43 of the molding unit 23 or the like, and the adhered bacteria or the like move to the inner surface of the preforms 1 or the bottles 2 and consequently aseptic packaged products can no longer be made. Therefore, when resuming operation of the aseptic filling machine it is necessary to sterilize the blow molding machine by utilizing the method for sterilizing a blow molding machine of the invention of the present application.

[0088] During operation of an aseptic filling machine in which the blow molding machine of the present invention is installed, each bottle 2 molded by the blow molding machine is conveyed to an inspection unit chamber via the wheel 28. Each bottle 2 that is inspected in the inspection unit chamber and determined as not having a defect is conveyed to the filling unit chamber, filled with sterilized content, and the bottle 2 in which the content is filled is sealed with a sterilized cap and then discharged to a non-aseptic atmosphere as an aseptic product. The bottle 2 is inspected for foreign matter, discoloration, flaws and the like at the body part, the upper surface of the mouth portion 1a, the support ring 1b and the bottom part, and when it is determined to exceed the limit, the bottle 2 is discharged. Further, after the molded bottle 2 is inspected in the inspection unit chamber, the bottle 2 may be sterilized again before the filling unit.

[0089] The inside of the inspection unit chamber that shields the inspection unit, and the inside of the filling unit chamber that shields the filling unit and a sealing unit are also sterilized before operation of the aseptic filling machine, and by the inside of each chamber being kept at a positive pressure by the aseptic air, the aseptic condition inside each chamber is maintained. With respect to the pressure that is kept at a positive pressure, the pressure in the filling unit chamber is set as the highest pressure, and the pressure is set progressively lower in the chambers upstream from the filling unit chamber, namely, in the order of the inspection unit chamber and the molding unit chamber 25. The aseptic air is also supplied during operation into the heating unit chamber 17, which is upstream of the molding unit chamber 25, to maintain the aseptic condition. The pressure in the heating unit chamber 17 is set to a lower pressure than the pressure in the molding unit chamber 25. For example, the pressure in the filling unit chamber is set in the range of 30 Pa to 150 Pa, the pressure in the inspection unit chamber is set in the range of 30 Pa to 50 Pa, the pressure in the molding unit chamber 25 is set in the range of 20 Pa to 30 Pa, and the pressure in the heating unit chamber 17 is set in the range of 0 Pa to 20 Pa. Further, the pressure in an outlet chamber that is downstream of the sealing unit and into which products are discharged and the aseptic products are placed on a conveyor to be discharged to outside of the aseptic filling machine, is set in the range of 0 Pa to 20 Pa.

[0090] Although the present invention is configured as described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the gist of the present invention. For example, as the form of the blow molding machine, a linear-type blow molding machine may be used instead of the aforementioned wheel-type blow molding machine.

REFERENCE SIGNS LIST

[0091] 1 preform [0092] 2 bottle [0093] 10 liquid sterilizer filling unit [0094] 15 spindle [0095] 16 heating unit [0096] 17 heating unit chamber [0097] 23 molding unit [0098] 25 molding unit chamber [0099] 32 liquid sterilizer filling nozzle [0100] 41 blow nozzle [0101] 42 valve block [0102] 43 extension rod [0103] S liquid sterilizer