JP2015123578A - Preform sterilization method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heat a preform to a blow molding temperature easily and quickly and to sterilize the preform.SOLUTION: A preform 1 is sterilized by spraying super heated steam at 200°C-500°C made from water, at least inside the preform. Then, hot air H at 80°C-120°C is blown inside the preform to heat inside the preform. Thereafter, the preform is introduced to a heating furnace to heat the preform from the outside, and the temperature of the preform is risen to a blow molding temperature to sterilize the preform.

Description

  The present invention relates to a method for sterilizing a preform for making a container such as a bottle.

  Conventionally, a PET (polyethylene terephthalate) preform is being transported and a sterilizing gas such as hydrogen peroxide is sprayed onto the preform to sterilize it, and the preform is formed into a bottle by a blow molding machine. Aseptic filling method as an in-line system has been proposed (see Patent Document 1, for example).

  In addition, the vaporized germicide is attached to the preform, and the remaining germicide is discharged by a flame with a burner (see, for example, Patent Document 2), or vapor of germicide is sprayed on the preform, There has also been proposed a method in which a preform is heated and then blow-molded (see, for example, Patent Document 3).

  On the other hand, as a method of sterilizing a preform without using a sterilizing agent, a method has been proposed in which superheated steam is blown into the preform to sterilize the preform (for example, refer to Patent Document 4).

JP 2001-212874 A Japanese Patent No. 3780165 JP 2008-183899 A JP 2013-216092 A

  The conventional method of sterilizing a preform using a sterilizing agent has a problem that the sterilizing agent remains in the preform. Further, when the preform is blow-molded after sterilization, there is a problem that each part of the molding machine is easily corroded by the germicide remaining on the preform.

  According to the method of sterilizing the inside of the preform with superheated steam, the problem of the sterilizing agent remaining is solved, but there is a problem that the sterilizing effect tends to be lower than when sterilizing with the sterilizing agent.

  An object of the present invention is to further enhance the sterilizing effect when the preform is sterilized using superheated steam.

  In order to solve the above problems, the present invention employs the following configuration.

  That is, the invention according to claim 1 sterilizes the inner surface of the preform by spraying at least the inner surface of the preform (1) with superheated steam (S) of 200 ° C. to 500 ° C. made from water. (1) Hot air (H) of 80 ° C. to 120 ° C. is blown into the interior to heat the preform (1) from the inner surface, and then the preform (1) is introduced into the heating furnace (23a). A preform sterilization method is employed in which the preform (1) is heated to the blow molding temperature while being heated from the outer surface thereof.

  As described in claim 2, in the preform sterilization method according to claim 1, the warm air (H) can be blown into the preform (1) for 0.5 second to 2 seconds. .

  As described in claim 3, in the preform sterilization method according to claim 1, the superheated steam (S) can be generated by inductively heating water.

  According to the present invention, at least the inner surface of the preform (1) is sprayed with superheated steam (S) made from water at a temperature of 200 ° C. to 500 ° C. to sterilize the inner surface of the preform, and then in the preform (1). The preform (1) is heated from the inner surface by blowing hot air (H) at 80 ° C. to 120 ° C. into the furnace, and then the preform (1) is introduced into the heating furnace (23a). Is heated from the outer surface, and the preform (1) is sterilized by raising the temperature to the blow molding temperature, so that the superheated steam (S), hot air (H) and heating furnace (23a) The preform (1) can be sterilized by the three parties, and the sterilizing effect can be enhanced by about 2D compared with the conventional superheated steam (S) and the heating furnace (23a). The bactericidal effect of It has become possible formation. In addition, the amount of superheated steam (S) used can be reduced. Further, after blowing warm air (H) into the preform (1), the preform (1) is introduced into the heating furnace (23a), and the preform (1) is heated from the outside. (1) can be heated from the inner and outer surfaces, and therefore the preform (1) can be efficiently heated to the molding temperature.

It is explanatory drawing from the sterilization process of a preform to a blow molding process. It is explanatory drawing after a blow molding to a capping process. It is a schematic plan view of the content filling apparatus for enforcing the sterilization method which concerns on this invention.

  Hereinafter, an embodiment of the present invention will be described.

  This preform sterilization method can be incorporated into an in-line system as shown in FIGS. 1 to 3, thereby enabling mass production of aseptic packaging.

  In this in-line system, the preform 1 is continuously conveyed at a desired speed, and is formed into a sterile package through the steps shown in FIGS.

  First, as shown in FIG. 1 (A), the sterilization of the preform 1 is performed on the inner and outer surfaces of the entire preform including the mouth portion 1a of the preform 1 from an atmospheric pressure of 200 ° C. to 500 ° C. made from water. This is done by blowing high pressure superheated steam S.

  The temperature of the superheated steam sprayed on the preform is desirably 200 ° C to 500 ° C, and more desirably 250 ° C to 400 ° C. If it is the temperature range of 200 degreeC-500 degreeC, the microbe adhering to the surface of a preform can be disinfected in a short time by exposing only the surface of a preform to high temperature. When the temperature of the superheated steam S is less than 200 ° C., it is necessary to spray for a long time for sterilization, the PET itself constituting the preform becomes high temperature, and the deformation of the preform increases. Moreover, when it exceeds 500 degreeC, the temperature of PET itself which comprises a preform will rise even for a short time, and it will become easy to produce a deformation | transformation in a preform.

  The pressure of the superheated steam sprayed on the preform is higher than atmospheric pressure, desirably higher than 0.1 MPa and lower than 0.3 MPa. If it is in the vicinity of 0.1 MPa, even if the superheated steam comes into contact with the preform and the temperature drops, the possibility of dew condensation is low. If the pressure is higher than 0.3 MPa, the heated steam is sprayed on the preform. There is a possibility of condensation on the surface of the preform. When dew condensation occurs, there is a possibility that whitening or the like may occur on the surface of the bottle when blow molding is performed later on the bottle or the like.

  The sterilization of the preform is indispensable for the inner surface of the preform, but the outer surface can be performed by heating for blow molding described later, or a desired sterilization process is added after the blow molding. It is also possible to do this.

  The preform 1 is formed as a bottomed tubular body having a test tube shape by injection molding of PET. The preform 1 is later formed as a bottle 2 which is a container as shown in FIG. 2E, and a mouth 1a similar to that in the bottle 2 is provided at the beginning of the forming. A male screw is formed on the outer peripheral surface of the mouth portion 1 a simultaneously with the molding of the preform 1. This male screw can be screwed with the female screw of the cap 4 that covers the mouth of the bottle 2 as shown in FIG. A support ring 5 is formed below the male screw 3 at the mouth of the bottle 2.

  The superheated steam S can be obtained by using a commercially available superheated steam generator (not shown). Specifically, a superheated steam generator having a trade name UPSS manufactured by Tokuden Corporation can be used. This is made by inserting an induction heating coil in the center of the spiral of a water pipe made of a spirally wound conductor. It guides water into the water pipe and applies an alternating voltage to the induction heating coil. It is supposed to be. It is also possible to energize the AC voltage by converting the frequency with an inverter. By applying the AC voltage, the induction heating coil generates an alternating magnetic flux, an induction current flows through the water pipe, and the water pipe generates heat. The water flowing inside is heated by this heat generation of the water passage pipe to become saturated steam, further becomes superheated steam S, and is taken out of the water passage pipe.

  In addition, it is also possible to make a heating effect further by making an induction heating coil into a conductive tube and letting water flow through this.

  As the superheated steam S, one having a pressure of about 0.1 MPa and a temperature of 200 ° C. to 500 ° C. can be obtained. By adopting the induction heating method, water can be turned into superheated steam at 200 ° C. or more in a short time from the start of energization.

  In FIG. 1 (A), the code | symbol 7 shows a cylindrical nozzle. This cylindrical nozzle 7 hangs down from the end of a conduit connected to the end of the water flow pipe of the superheated steam generator.

  The preform 1 is conveyed in one direction directly below the circular opening 7a in the cylindrical nozzle 7 in an upright state with the mouth portion 1a facing up. The conveyance method may be a continuous conveyance method in which the preform 1 is continuously run, or an intermittent conveyance method in which the preform 1 is temporarily stopped immediately below the opening 7 a of the cylindrical nozzle 7. The preform 1 can be conveyed by holding the support ring 5 by a gripper (not shown).

  Moreover, in FIG. 1 (A), the code | symbol 9 shows a slit-shaped nozzle. The slit nozzle 9 is connected to the tip of a branch pipe branched from the conduit of the superheated steam generator, and is arranged so that the slit extending in the longitudinal direction of the preform 1 faces the side surface of the preform 1. Desirably, the slit-shaped nozzles 9 are paired so as to be opposed to each other so as to sandwich the preform 1 from its side surface, and the preform 1 is conveyed while being rotated around its axis. Although it is possible to carry the preform 1 without rotating it, a plurality of pairs of slit-like nozzles 9 are arranged in that case.

  In the illustrated example, the nozzle is a slit-like nozzle, but a circular nozzle such as the above-described cylindrical nozzle may be disposed opposite to the side surface or the bottom surface of the preform 1.

  When the preform 1 is sterilized, the superheated steam S is constantly supplied from the superheated steam generator to the cylindrical nozzle 7 and the slit nozzle 9, and is directed toward the preform 1 from the opening of the cylindrical nozzle 7 and the slit of the slit nozzle 9. Erupt. The nozzle diameter, angle, preform axis, and the like are arbitrary, and are preset so that the jetted superheated steam S contacts the entire inner surface of the preform 1.

  As a result, the superheated steam S ejected from the opening of the cylindrical nozzle 7 enters the preform 1 from the mouth 1a of the preform 1, contacts the entire inner surface of the preform 1, and adheres to the inner surface of the preform 1. Disinfects general bacteria, molds and yeasts. Moreover, since this sterilization can be achieved by blowing superheated steam S toward the inside of the preform for a short time, excessive heating from the inside of the mouth portion 1a of the preform 1 is prevented. Deformation of the mouth 1a is reliably avoided.

  Moreover, the superheated steam S ejected from the slit-like nozzle 9 comes into contact with the entire outer surface including the mouth portion 1a of the preform 1 that rotates about the shaft core and is sterilized by heating. Thereby, the general bacteria, molds and yeasts attached to the outer surface of the preform 1 are sterilized. Further, this sterilization can be achieved by spraying the superheated steam S toward the outer surface of the preform 1 for a short time, so that excessive heating from the outside in the mouth portion 1a of the preform 1 is prevented. The deformation of the mouth 1a is reliably avoided.

  In the illustrated example, the preform 1 is in an upright state when the superheated steam S is sprayed, but may be in an inverted state.

  Further, the inner and outer surfaces of the preform 1 can be sterilized by shifting in time by shifting the installation locations of the cylindrical nozzle 7 and the slit nozzle 9 with respect to each other.

  As shown in FIG. 1B, hot air H having a predetermined temperature is blown into the preform 1 sterilized by the superheated steam S.

  When the preform 1 sterilized by the superheated steam S reaches the lower part of the hot air nozzle 8, the hot air nozzle 8 for supplying the hot air H into the preform 1 is disposed in the conveyance path of the preform 1. Hot air H is blown from the hot air nozzle 8. Thereby, the preform 1 is heated from the inner surface side.

  The temperature of the hot air H is desirably 80 ° C to 120 ° C. If it is less than 80 ° C., heating is insufficient, and if it is higher than 120 ° C., the preform may be deformed.

  As shown in FIG. 1C, the preform 1 heated from the inside by the hot air H is heated from the outside by the heater 10.

  The conveyance path of the preform 1 extends into the heating furnace 23a (see FIG. 3). In the heating furnace 23a, the heater 10 is disposed in a wall shape along the conveyance path. The preform 1 is heated while traveling by the heater 10. The preform 1 is uniformly heated from about 90 ° C. to about 130 ° C. by this heating, and is brought into a heating state suitable for blow molding.

  As described above, the preform is heated from the inside by the hot air H, and subsequently heated from the outside by the heater 10, so that the preform 1 is efficiently heated to the blow molding temperature. Further, the preform is efficiently sterilized by heating from the inside and outside.

  When the preform 1 is heated by the heater 10, it is suspended in an upright state by inserting a spindle 11 into its mouth 1 a, and is uniformly heated by the heater 10 by rotating together with the spindle 11. .

  The preform 1 sterilized by heating and brought to a temperature suitable for blow molding is subjected to blow molding as shown in FIG. 1 (D) and formed into a bottle 2 as a container.

  The mold 12 that is a blow mold is continuously clamped with the preform 1 while continuously running at the same speed as the preform 1, and the mold 12 is blow-molded with respect to the preform 1 in the mold 12. After the process is performed, the mold is opened.

  The preform 1 is heated almost uniformly in the heating step shown in FIG. 1C so that the entire temperature rises to a temperature range suitable for molding. As shown in D), the entire spindle 11 is mounted in the mold 12. The blow nozzle 13 is inserted into the preform 1 through the upper part of the mold 12 and the spindle 11 in the mouth 1 a of the preform 1.

  While the mold 12 is traveling, for example, primary blow air and secondary blow air are sequentially blown into the preform 1 from the blow nozzle 13 so that the preform 1 is finally finished in the cavity C of the mold 12. It expands to the bottle 2 of the molded product.

  When the bottle 2 is molded in the mold 12 as described above, the mold 12 is opened while traveling, and the finished product of the bottle 2 is taken out of the mold 12 as shown in FIG. .

  While the bottle 2 continuously runs after molding, as shown in FIG. 2 (F), the desired content a such as mineral water, catechin-containing tea beverage, carbonated beverage or the like is fed from the filling nozzle 14 to the bottle 2. As shown in FIG. 2 (G), the inside is sealed with a cap 4 which is a lid.

  In addition, you may make it improve a bactericidal effect by performing external surface sterilization of the bottle 2 by spraying of the vapor | steam containing disinfectants, such as hydrogen peroxide, electron beam irradiation, etc. after the said blow molding. When the inner surface of the bottle is sterilized by spraying with hydrogen peroxide, it is necessary to reduce the concentration of hydrogen peroxide as much as possible to reduce the residual hydrogen peroxide in the bottle.

  Thus, the bottle 2 made into a package is collected and carried out to the market.

  A filling apparatus for carrying out the filling method is configured as shown in FIG. 3, for example.

  As shown in FIG. 3, the filling apparatus includes a preform feeder 15 for sequentially supplying a bottomed cylindrical preform 1 having a mouth 1a (see FIG. 1A) at a predetermined interval, and blow molding. A machine 16 and a filling machine 17 that fills and seals the molded bottle 2 with the content a.

  Between the preform feeder 15 and the filling machine 17, a mold 12 having a preform conveying means for conveying the preform 1 on the first conveying path and a cavity C of the finished product shape of the bottle 2 (see FIG. 1 (D)) is connected to the second conveying path, and the mold conveying means for conveying the second conveying path on the second conveying path connected to the first conveying path and the bottle 2 formed by the mold 4 to the second conveying path. And a bottle transport means for transporting on the third transport path.

  The first conveying path of the preform conveying means, the second conveying path of the mold conveying means, and the third conveying path of the bottle conveying means communicate with each other, and the preform 1 is placed on these conveying paths. And a gripper (not shown) that conveys the bottle 2 while holding it.

  The preform conveying means includes a preform conveyor 18 that sequentially supplies the preform 1 at a predetermined interval on the first conveying path. Further, a row of wheels 19, 20, 21, and 22 that receive and transport the preform 1 from the end of the preform conveyor 18, and a conveyor 23 that receives the preform 1 from the wheel 22 and travels.

  A cylindrical nozzle 7 and a slit-like nozzle 9 for injecting the superheated steam S toward the preform 1 are provided slightly upstream from the location where the preform conveyor 18 in the preform feeder 15 is connected to the wheel 19. . Superheated steam S is sprayed from these nozzles 7 and 9 toward the preform 1 before heating (see FIG. 1A). Thereby, the inner and outer surfaces of the preform 1 are uniformly heat sterilized.

  These nozzles 7 and 9 can also be installed at a fixed position on the outer periphery of the wheel 22 before the preform 1 reaches the conveyor 23, for example.

  A hot air nozzle 8 is disposed at a predetermined location around the wheel 22. Hot air H is constantly blown out from the hot air nozzle 8 toward the preform 1. When the preform 1 passes directly below the warm air nozzle 8, the warm air H is blown into the preform 1, whereby the preform 1 is heated from the inner surface side.

  The conveyor 23 has an endless transport chain extending in the horizontal direction, and the endless transport chain is drawn into the heating furnace 23a. A large number of spindles 11 shown in FIG. 1C are attached to the endless transport chain at a constant pitch. Each spindle 11 can rotate while traveling along with the traveling of the endless conveyance chain. As shown in FIG. 1 (C), the spindle 11 is inserted into the preform 1 sent from the wheel 22 side to the conveyor 23 through its mouth 1a, and is held on the spindle 11 in an upright state.

  The preform 1 is received by the conveyor 23 through a row of the preform conveyor 18 and the wheels 19, 20, 21, and 22, and reciprocates by the conveyor 23 in the heating furnace 23 a. A heater 10 (see FIG. 1C) is stretched around the inner wall surface of the heating furnace 23 a, and the preform 1 conveyed by the conveyor 23 is heated by the heater 10. The preform 1 rotates along with the rotation of the spindle 11 while traveling on the conveyor 23, and is uniformly heated by the heater 10.

  Since the preform 1 has already been heated from the inside by the hot air H, it is heated to the molding temperature efficiently by being heated from the outside by the heater 10 and is also sterilized efficiently.

  The blow molding machine 16 receives a preform 1 heated by the heating furnace 23a of the preform supply machine 15 and sets a plurality of molds 12 and blow nozzles 13 (see FIG. 1D) for thermoforming the bottle 2 into the preform 12. Prepare.

  In the blow molding machine 16, the second conveyance path of the mold conveyance means passes. This second transport path is constituted by a row of wheels 24, 25, 26, 21, 27. The wheel 21 is shared between the row of the wheels 24, 25, 26, 21, 27 and the row of the wheels 19, 20, 21, 22 of the preform conveying means.

  A plurality of molds 12 and blow nozzles 13 are arranged around the wheel 25, and turn around the wheel 25 at a constant speed as the wheel 25 rotates.

  When the gripper (not shown) of the wheel 24 receives the preform 1 heated by the heating furnace 23a of the preform feeder 15 together with the spindle 11 and passes it to the mold 12 around the wheel 25, the split mold 12 is closed. The preform 1 is gripped as shown in FIG. The preform 1 in the mold 12 is formed into a finished product of the bottle 2 by being blown with the high pressure air for blow molding from the blow nozzle 13 while turning around the wheel 25 together with the mold 12 and the blow nozzle 13. The As shown in FIGS. 1B and 1C, the preform 1 is uniformly blown to the blow molding temperature by the hot air H and the heater 10, and thus is smoothly blow molded.

  When the preform 1 comes into close contact with the cavity C of the mold 12 to form the bottle 2, the mold 12 is opened when it comes into contact with the wheel 26, and the bottle 2 and the spindle 11 are released. Then, the bottle 2 is received from the spindle 11 by a gripper (not shown) of the wheel 26.

  On the other hand, the spindle 11 that has released the bottle 2 returns to the conveyor 23 via the wheel 24 and continues to hold and carry another preform 1.

  The bottle 2 that comes out of the blow molding machine 16 and reaches the wheel 26 is inspected for molding defects or the like by an inspection device 28 arranged on the outer periphery of the wheel 26.

  Although not shown, the inspection device 28 includes a bottle body inspection means for determining the quality of the body of the bottle 2, a support ring inspection means for determining the quality of the support ring 5 of the bottle 2, and a top surface of the neck of the bottle 2. A bottle neck top surface inspecting unit for determining pass / fail and a bottle bottom inspecting unit for determining the quality of the bottom of the bottle 2 are provided.

  The bottle body inspection means, the support ring inspection means, and the bottle neck top surface inspection means are arranged along the outer periphery of the wheel 26.

  The bottle body inspection means, the support ring inspection means, and the bottle neck top surface inspection means are not shown in the figure, but each of the bottles 2 is imaged with a lamp and a camera, processed by an image processing device, and shaped, scratched, foreign matter, It is determined whether there is an abnormality in discoloration or the like.

  The inspection device 28 is installed as necessary. The bottle body inspection means, the support ring inspection means, and the bottle neck top surface inspection means are selected as necessary.

  When the bottle 2 is inspected, the bottle 2 is removed from the conveyance path by a rejecting device (not shown), and only the acceptable product is conveyed from the wheel 26 through the wheel 21 to the wheel 27.

  The bottle after blow molding is sprayed with steam containing a sterilizing agent such as hydrogen peroxide, irradiated with an electron beam, etc. to add sterilization on the outer surface of the bottle, or to enhance the sterilizing effect on the inner surface of the bottle. Also good. For example, the wheel 21 or 27 may be provided with a sterilizing means such as a sterilizing agent-containing vapor spraying device or an electron beam irradiation device.

  The filling machine 17 has the 3rd conveyance path of the said conveyance means for bottles in the inside. This third transport path has a row of wheels 29, 30, 31, 32, 33, 34.

  In the filling machine 17, a filler 35 for filling the bottle 2 with the beverage a is provided, and a cap 4 for attaching and sealing the cap 4 (see FIG. 2G) to the bottle 2 filled with the beverage a. 36 is provided.

  In addition, since the filler 35 and the capper 36 may be the same as a well-known apparatus, description is abbreviate | omitted.

  The filling device is surrounded by a chamber 37, and the inside of the chamber 37 is partitioned into a sterilization zone and a gray zone. The preform feeder 15 and the blow molding machine 16 are arranged in the gray zone, and the filling machine 17 is arranged in the aseptic zone.

  Air sterilized with HEPA is constantly blown into the gray zone, whereby the bottle 2 sterilized at the time of molding is conveyed to the sterilization zone without being contaminated with microorganisms.

  Next, operation | movement of a filling apparatus is demonstrated with reference to FIG.

  First, the preform 1 is conveyed to the heating furnace 23a by the row of the preform conveyor 18 and the wheels 19, 20, 21, and 22.

  Before entering the heating furnace 23a, superheated steam S is blown from the nozzles 7 and 9 shown in FIG. 1 toward the inner and outer surfaces of the preform 1 (see FIG. 1A). Thereby, the entire surface of the preform 1 is sterilized.

  Subsequently, warm air H is blown into the preform 1 from the warm air nozzle 8, whereby the preform 1 is heated from the inside.

  Subsequently, the preform 1 reaches the inside of the heating furnace 23a and is uniformly heated to a temperature range suitable for molding while being conveyed by the conveyor 23 in the heating furnace 23a (FIG. 1 (C )reference).

  The preform 1 heated in the heating furnace 23 a is held by the mold 12 when passing through the outer periphery of the wheel 25, and is expanded to the finished product of the bottle 2 in the cavity C by blowing high-pressure air from the blow nozzle 13. (See FIG. 1D).

  The molded bottle 2 (see FIG. 2E) is taken out of the mold 12 by the gripper of the wheel 26 after the mold 12 is opened, and inspected by the inspection device 28 for molding defects or the like.

  Thereafter, the bottle 2 travels in the filling machine 17 while being transferred to a row of wheels 30, 31, 32, 33 and 34.

  In the filling machine 17, the bottle 2 is filled with the sterilized beverage a as shown in FIG. The bottle 2 filled with the beverage a is sealed by the cap 4 having the sterilized cap 4 put on the mouth 1a by the capper 36 (see FIG. 2G) and discharged from the outlet of the chamber 37.

  As described above, since the filler 35 and the capper 36 are well-known devices, the description of the method for filling the bottle 2 with the beverage and the method for sealing the bottle 2 will be omitted.

  The present invention can be implemented in various forms without being limited to the above-described embodiments. For example, the container to which the present invention is applied is not limited to a PET bottle, and can be applied to various resin containers. Molding of the container is not limited to injection blow, and can be molded by various blow molding such as direct blow. Moreover, the conveyance means which conveys a preform and a container is not limited to the wheel conveyance apparatus shown in FIG. Various transport devices that can be transported at a predetermined transport speed in the order in which the containers are formed, for example, a belt transport device, a bucket transport device, and an air transport device can also be used.

1 ... Preform 23a ... Heating furnace H ... Warm air S ... Superheated steam

Claims (3)

  At least the inner surface of the preform is sprayed with superheated steam of 200 ° C to 500 ° C made from water to sterilize the inner surface of the preform, and then hot air of 80 ° C to 120 ° C is blown into the preform. Preform sterilization characterized by heating from the inner surface and then introducing the preform into a heating furnace and sterilizing the preform by raising the temperature to the blow molding temperature while heating the preform from the outer surface. Method.   2. The preform sterilization method according to claim 1, wherein the warm air is blown into the preform for 0.5 second to 2 seconds.   2. The preform sterilization method according to claim 1, wherein the superheated steam is generated by induction heating of water.

Images