JP5919913B2 - Preform sterilization method and apparatus - Google Patents

Description

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

  Conventionally, in order to sterilize a PET (polyethylene terephthalate) bottle with hydrogen peroxide solution, the bottle is introduced into the chamber, the hydrogen peroxide solution is sprayed into the chamber, and an air flow is introduced into the chamber. ing. Thereby, even if it is a bottle which has a complicated shape, the mist of hydrogen peroxide solution adheres to the bottle surface uniformly, and the bottle surface is sterilized uniformly (for example, refer patent document 1). ).

  Attempts have also been made to sterilize at the preform stage prior to bottle molding. That is, the mouth of the preform is directly opposed to a nozzle opened vertically downward, and a chemical such as hydrogen peroxide is injected from the nozzle, and then the preform is introduced into a heating furnace, and the preform is brought to a blow molding temperature. While being heated, the sterilizing effect is enhanced, and thereafter, it is sandwiched with a molding die and blow-molded into a bottle (see, for example, Patent Document 2).

  Also, when sterilizing at the preform stage, a large number of preforms each dropped with an aqueous hydrogen peroxide solution are sealed in a container, and the hydrogen peroxide vaporized in the container is transported and stored when the container is transported and stored. Attempts have been made to sterilize the inner and outer surfaces of the preform with steam. The preform taken out from the container at the container delivery destination is molded into a sterile bottle by the destination molding machine (see, for example, Patent Document 3).

Japanese Patent Laid-Open No. 5-65148 Special table 2001-510104 gazette JP 2000-326935 A

  The conventional method of sterilizing bottles using hydrogen peroxide solution mist requires the use of an expensive mist generator because the mist of hydrogen peroxide solution needs to be refined. There is a problem of inviting up.

  Further, in the method of injecting a chemical such as hydrogen peroxide onto the preform, the preform needs to be aligned and run in an upright state, and it is necessary to guide the preform into the heating furnace immediately after the chemical is adhered. For this reason, there exists a problem that a sterilization system becomes complicated, enlarges, and causes a cost increase.

  Moreover, the method of dropping and sterilizing an aqueous hydrogen peroxide solution on a preform requires the preforms to be aligned and transported, and it is difficult to process a large amount of preforms at a high speed. Furthermore, since the aqueous hydrogen peroxide solution is dropped in a predetermined amount on each preform, there is a disadvantage that an expensive apparatus for discharging the aqueous hydrogen peroxide solution while measuring it is required.

  An object of the present invention is to eliminate such problems.

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

  That is, in the invention according to claim 1, a large number of preforms (1) formed in a bottomed cylindrical shape are put on the conveyor (4) to be in an uneven recumbent state, and these preforms (1) (4) Each is passed through the chamber (5), and in the chamber (5), the hydrogen peroxide solution is sprayed in the direction crossing the conveyor (4) from both sides of the conveyor (4). A preform sterilization method for adhering to the inner and outer surfaces of the preform (1) on the conveyor (4) is adopted.

  As described in claim 2, in the preform sterilization method according to claim 1, the hydrogen peroxide solution can be misted by a two-fluid spray using pressurized air.

  As described in claim 3, in the preform sterilization method according to claim 1 or 2, the concentration of the hydrogen peroxide solution may be 20% to 35%.

  As described in claim 4, in the preform sterilization method according to claim 2 or claim 3, air heated to 40 ° C. to 150 ° C. may be mixed with hydrogen peroxide mist. .

  According to a fifth aspect of the present invention, in the preform sterilization method according to any one of the first to fourth aspects, the chamber (5) is preliminarily passed before the sterilization of the preform (1) is started. It may be sterilized by spraying with hydrogen oxide water.

  Moreover, the invention which concerns on Claim 6 was installed in the horizontal running part of this conveyor (4) and the conveyor (4) which carries the preform (1) formed in the bottomed cylindrical shape in a lying state, and conveys it. A hydrogen peroxide solution is sprayed in a direction across the conveyor (4) from both sides of the chamber (5) in the chamber (5), and the hydrogen peroxide solution is preformed on the conveyor (4). A sterilizer equipped with a spray nozzle (10) attached to the inner and outer surfaces of (1) is employed.

  According to the present invention, a large number of preforms (1) formed in the shape of a bottomed cylinder are put on a conveyor (4) to be in an uneven recumbent state, and these preforms (1) are put together with the conveyor (4). The chamber (5) is passed through, and in the chamber (5), the hydrogen peroxide solution is sprayed in the direction crossing the conveyor (4) from both sides of the conveyor (4), and the sprayed hydrogen peroxide solution is transferred to the conveyor (4). Since the preform sterilization method is attached to the inner and outer surfaces of the upper preform (1), the preform (1) discharged from the preform molding machine is received by the conveyor (4) and is lying on the conveyor (4). It is sufficient to introduce the conveyer (4) into the chamber (5) while keeping it. In the chamber (5), the hydrogen peroxide solution is sprayed in the direction crossing the conveyor (4) from both sides of the conveyor (4), so that the mist of the hydrogen peroxide solution is transformed into the preform (1) on the conveyor (4). Adhere to the outer surface of At that time, since the preform (1) can roll over on the conveyor (4) by vibration or the like, the hydrogen peroxide solution uniformly adheres to the outer surface of the preform (1). At the same time, the mist of hydrogen peroxide solution also flows into the preform (1) from the mouth portion of the preform (1) which is turned sideways, and uniformly adheres to the inner surface of the preform (1). Thereby, the entire surface of the preform (1) is properly sterilized with hydrogen peroxide. In addition, as a result of adopting the method of the present invention, a large amount of preforms can be sterilized reliably and inexpensively without the need for a preform aligning apparatus and an expensive hydrogen peroxide solution dispensing apparatus as in the prior art. it can.

An example of the preform which can be sterilized by the sterilization method concerning this invention is shown, (A) is a top view, (B) is a front view. It is a partial notch top view which shows the outline of the apparatus for enforcing the preform sterilization method which concerns on this invention. It is a vertical sectional view which shows the outline of the said apparatus.

  The form for implementing this invention is demonstrated below.

  A preform to be sterilized by the present invention is formed as a bottomed tubular body having a test tube shape by injection molding of PET. The preform is later formed into a bottle (not shown) having a desired shape. As shown in FIGS. 1A and 1B, the preform 1 has a mouth portion similar to that in the bottle after molding. 1a is given at the beginning of the molding. A male screw 2 is formed on the outer peripheral surface of the mouth portion 1 a simultaneously with the molding of the preform 1. The male screw 2 can be screwed with a female screw of a cap (not shown) that covers the mouth 1a of the bottle. Below the male screw 2 is formed a support ring 3 that is used when a beverage or the like is filled into the bottle later.

  An apparatus for sterilizing the preform 1 is configured as shown in FIGS.

  2 and 3, reference numeral 4 denotes an endless belt type conveyor. A preform molding machine (not shown) is arranged on the upstream side of the running direction indicated by the arrow of the conveyor 4. The molded preform 1 discharged from the preform molding machine is received at the upstream portion of the conveyor 4 by using a hopper or the like (not shown). As shown in FIG. 2, the molded preform 1 is placed on the conveyor 4 in a lying state in an uneven direction.

  The intermediate portion of the conveyor 4 can run horizontally, and the chamber 5 is covered in a hood shape on the intermediate portion.

  The chamber 5 shields the both side walls 6 disposed so as to sandwich the conveyor 4 from both sides, the front and rear walls 7 and 8 disposed at the front and rear ends of the both side walls 6, and the upper sides of the both side walls 6 and the front and rear walls 7 and 8. And the top wall 9 to be used.

  Spray nozzles 10 for spraying the hydrogen peroxide solution in the direction crossing the conveyor 4 from the side edge side of the conveyor 4 are respectively attached to the side walls 6. The spray nozzles 10 can be attached to the side walls 6 one by one. Preferably, a plurality of spray nozzles 10 are arranged on the side walls 6 in the running direction of the conveyor 4.

  Further, a two-fluid spray nozzle is desirably employed as the spray nozzle 10, and hydrogen peroxide solution is supplied from one flow path of each nozzle 10, and pressurized air is supplied from the other flow path. ing.

  When the pressurized air flows through the two-fluid spray nozzle 10 at a high speed, the hydrogen peroxide solution is taken into the pressurized air and discharged as mist from the tip of each nozzle 10 into the chamber 5. Mist produced by spraying the hydrogen peroxide solution adheres to the surface of the preform 1 on the conveyor 4.

  The mist may be mixed with warm air of 40 ° C. to 150 ° C. and sprayed onto the preform 1.

  2 and 3, reference numeral 12 denotes a nozzle that injects the heated air. The heated air jetted from this nozzle is mixed with the hydrogen peroxide solution misted by the two-fluid spray nozzle 10 and flows toward the preform while heating the mist. The bactericidal effect is enhanced by heating the mist.

  Further, the mist of hydrogen peroxide solution is discharged from the both sides of the conveyor 4 in the chamber 5 in a direction crossing the conveyor 4, and the preform 1 can roll over on the conveyor 4 due to vibration or the like. It adheres evenly to the outer surface. At the same time, the mist of hydrogen peroxide solution also flows into the preform 1 from the mouth portion 1 a of the preform 1 which is turned sideways, and adheres uniformly to the inner surface of the preform 1. Furthermore, since the mist of hydrogen peroxide water discharged from the two-fluid spray nozzle 10 fills and circulates in the chamber 5, the mist riding on this flow also uniformly adheres to the surface of the preform 1. Thereby, the whole surface of the preform 1 is appropriately sterilized with hydrogen peroxide.

  The concentration of hydrogen peroxide used for sterilization of the preform 1 is preferably 20% to 35%. If the concentration is less than 20%, sterilization defects such as survival of spore bacteria are likely to occur, and if it is more than 35%, a large amount of hydrogen peroxide tends to remain in the preform.

  Further, it is desirable to mix warm air of 40 ° C. to 150 ° C. with the mist. If the temperature of the mist is lower than 40 ° C., sterilization defects are likely to occur, and if it is higher than 150 ° C., there is a problem that deformation of the preform is likely to occur.

  Openings 7 a and 8 a are formed in the front and rear walls 7 and 8 of the chamber 5 so that the conveyor 4 and the preform 1 riding on the conveyor 4 can pass therethrough. An exhaust duct 11 is connected to the top wall 9. The mist of the hydrogen peroxide solution discharged into the chamber 5 is sucked into the exhaust duct 11 by driving a blower (not shown) and flows to the recovery device. Thereby, the mist of the hydrogen peroxide solution is prevented from flowing out of the chamber 5 through the openings 7a and 8a of the front and rear walls 7 and 8.

  The downstream side of the conveyor 4 from the chamber 5 extends toward a large container such as a container (not shown). The preform 1 to which the mist of hydrogen peroxide water adheres in the chamber 5 is conveyed to a large container by the conveyor 4 and is put into the large container. The large container is sealed after a predetermined amount of the preform 1 is placed, stored, and transported to a factory for forming into a bottle. The preform 1 is sterilized by hydrogen peroxide confined in the large container together with the preform 1 during storage and transportation.

  In addition, when the downstream side of the conveyor 4 from the chamber 5 is connected to a blow molding machine, the sterilized preform 1 is immediately subjected to blow molding and molded into a container such as a bottle. Furthermore, when the blow molding machine is connected to a content filling machine such as a beverage, a container such as a bottle is filled with the content such as a beverage, sealed, and discharged as an aseptic filling package.

  Next, the operation of the preform sterilizer will be described together with the preform sterilization method.

  Before the sterilization treatment of the preform 1 is started, hydrogen peroxide solution is sprayed into the chamber 5 from the spray nozzle 10 in advance, and the inside of the chamber 5 is sterilized.

  By the operation of the preform molding machine, the molded preform 1 is loaded on the upstream side of the conveyor 4 on which the preform 1 runs. The preform 1 discharged from the preform molding machine is received at the upstream portion of the conveyor 4 and is in an uneven lying state on the conveyor 4 as shown in FIG.

  The preform 1 on the conveyor 4 enters the chamber 5 together with the conveyor 4 and is sprayed with hydrogen peroxide solution by the spray nozzle 10.

  The sprayed hydrogen peroxide solution mist is mixed with warm air sprayed from the nozzle 12 as necessary.

  The mist of the hydrogen peroxide solution is discharged from both sides of the conveyor 4 in the chamber 5 in the direction crossing the conveyor 4, and the preform 1 can roll over on the conveyor 4 due to vibration or the like. It adheres evenly to the outer surface.

  The mist of the hydrogen peroxide solution also flows into the preform 1 from the mouth portion 1a of the preform 1 which is turned sideways and adheres uniformly to the inner surface of the preform 1.

  Since the mist of the hydrogen peroxide solution discharged from the spray nozzle 10 fills the inside of the chamber 5 and circulates, the mist also adheres uniformly to the surface of the preform 1 while flowing. Thereby, the entire surface of the preform 1 is uniformly sterilized with hydrogen peroxide.

  The preform 1 passes through the chamber 5 together with the conveyor 4 while being sprayed with a mist of hydrogen peroxide, and is put into a large container such as a container. Or it is conveyed to a blow molding machine and a filling machine without being packed in a container or the like, and discharged as an aseptic package.

  The present invention can be implemented in various forms without being limited to the above-described embodiments.

  Hydrogen peroxide solution of 35% concentration and pressurized air are supplied to the two-fluid spray to generate a mist of hydrogen peroxide solution. The generated mist is mixed with 60 ° C. warm air, and the nozzle is put into the chamber. A mist of hydrogen peroxide was sprayed. The chamber was a bottomless box type having a width of 1,000 mm, a length of 1,500 mm, and a height of 200 mm, and was installed at a fixed position on a conveyor having a width of 600 mm. The preform for a 500 mL bottle was supplied to the conveyor at 860 lines / minute, and the conveyor was operated at a speed of 0.2 m / second. At this time, the adhesion amount of hydrogen peroxide water per preform was about 50 mg.

When the bactericidal activity was evaluated using Bacillus.subtilis as an indicator fungus, the inner surface of the preform was 4.2D and the outer surface was 5.3D.

  The preform was molded into a bottle, filled with water, and the residual amount of hydrogen peroxide was measured. As a result, it was 0.012 ppm.

DESCRIPTION OF SYMBOLS 1 ... Preform 4 ... Conveyor 5 ... Chamber 10 ... Spray nozzle

Claims (6)

  A large number of preforms formed in the shape of a bottomed cylinder are put on the conveyor to make an uneven lie down, and these preforms are passed through the chamber together with the conveyor, and in the chamber in a direction crossing the conveyor from both sides of the conveyor. A preform sterilization method, characterized by spraying hydrogen peroxide solution and adhering the sprayed hydrogen peroxide solution to the inner and outer surfaces of the preform on a conveyor.   2. The preform sterilization method according to claim 1, wherein the hydrogen peroxide solution is misted by a two-fluid spray using pressurized air.   The preform sterilization method according to claim 1 or 2, wherein the concentration of the hydrogen peroxide solution is 20% to 35%.   The preform sterilization method according to claim 2 or 3, wherein warm air of 40 ° C to 150 ° C is mixed with the hydrogen peroxide mist.   The preform sterilization method according to any one of claims 1 to 4, wherein the chamber is preliminarily sterilized by spraying hydrogen peroxide water into the chamber before starting the sterilization of the preform. A preform sterilization method characterized by the above.   A conveyor that transports a preform formed in a bottomed cylindrical shape while lying on its side, a chamber installed in the horizontal running section of this conveyor, and a peroxide in the direction across the conveyor from both sides of the conveyor in this chamber A sterilizing apparatus comprising a spray nozzle for spraying hydrogen water and allowing hydrogen peroxide water to adhere to the inner and outer surfaces of the preform on the conveyor.

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