JPH085514B2 - Aseptic filling method and apparatus for PET bottles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and apparatus for aseptically filling food products, particularly beverages, into polyethylene terephthalate bottles, commonly called PET bottles (PET bottles).

(Prior Art) PET bottles, that is, bottles made of polyethylene terephthalate resin, are used for food, especially juice, oolong tea,
It is extremely suitable for filling beverages such as tea, coffee, beverages with milk, etc., but if it is not completely sterilized, it cannot be put on the store floor at room temperature due to spoilage.

For canned foods, retort pouched foods, and cupped foods, heat sterilization is performed after filling.On the other hand, aseptically filled foods for canned foods, paper boxes, and plastic cups are sterilized by heating steam at around 300 ° C in canned foods. In the case of paper boxes and plastic cups, the containers are sterilized by UV irradiation, immersion in hydrogen peroxide solution, spraying and drying, and then aseptically filled with food that has been sterilized by a post heat exchanger, etc. We offer products that do not lose, but in the case of PET bottles, there is a risk that PET will shrink when heat sterilized, and even if ultraviolet rays are irradiated from outside the bottle, the benzene ring present in the PET resin absorbs ultraviolet rays. Therefore, the sterilizing effect is not exerted, and when the method of dipping and spraying hydrogen peroxide solution is performed, the sterilizing effect of the hydrogen peroxide solution is at the time of drying the hydrogen peroxide solution. water When the container is sterilized by using, it is essential to dry after treating with hydrogen peroxide.

In addition, since PET bottles are stretch-molded, they have residual stress.
The fatal drawback of shrinking PET bottles occurs.

(Problems to be solved by the invention) Foods, especially beverages that are extremely perishable, such as beverages containing milk, are subjected to heat sterilization after filling, or superheated steam, ultraviolet irradiation sterilization in aseptic filling, and hydrogen peroxide solution. It is an object of the present invention to provide a method and apparatus for aseptically filling a PET bottle without using a method of sterilizing by heating and drying after dipping or spraying.

(Means for solving the problem) In order to solve the above problems, the present inventors have conducted extensive studies and found that a method of filling a sterilized filling liquid after sterilizing a PET bottle is effective. And completed the present invention.

The present invention is: 1. In a sterilized space, a PET bottle is pre-washed with a sterilizing solution, then the PET bottle is filled with the sterilizing solution, placed on a reciprocating conveyor, and the conveyor is run in one direction. After that, the running direction is reversed, and the running direction is reversed several times to reverse the direction of the acceleration applied to the sterilizing solution filled in the PET bottle, thereby creating a turbulent flow in the sterilizing solution and causing the sterilizing solution to flow into the PET bottle. After sterilizing by fluid contact with the bottle, invert the bottle to remove the sterilizing liquid, then wash the outside and inside of the bottle with sterile water to wash away the sterilizing liquid and continue without going through the drying process. An aseptic filling method for PET bottles, which comprises filling a sterilized cap with a filling liquid filled in the step.

2. A pre-cleaning device 1 for pre-cleaning a PET bottle and filling it with a sterilizing solution, and a conveyor group 2 formed by a plurality of conveyors connected to this device and traveling in mutually opposite directions,
A sterilizing agent-removing outer side cleaning device 3 which is connected to the conveyor to remove the sterilizing liquid by inverting the PET bottle and then cleans the outside of the PET bottle, and which is arranged next to the cleaning device.
It is composed of a sterile water cleaning device 4 for cleaning the inside of a PET bottle with aseptic water, a filling device 5 connected to this cleaning device, and a capping device 6 for capping the cap, and each device is connected by a conveyor. An aseptic filling device for PET bottles, which comprises a tunnel 7 to which each device and a conveyor are supplied and which is supplied with sterilized gas.

3. In the sterile water washing device 4, a stop ring 1 for fixing the rotary packing 101 of the rotary joint 100 that rotates while sending sterile water into the PET bottle.
02, the space 106 between the stop ring 105 for fixing the ball bearing 103 by sandwiching the spacer 104, by forming a barrier to prevent the invasion of bacteria by filling the sterilizing solution or sterile water,
The filling device according to claim 2, wherein the void 106 is kept aseptic. Regarding

(Operation) The first feature of the present invention is to sterilize a PET bottle using an aqueous solution of a disinfectant (sterilizing solution), sterilize using a sterilizing solution, wash the bottle with a sterile liquid, and then wash away the sterilizing solution. It is to fill the liquid to be filled as it is.

Since the sterilizing solution has been washed away, there is no need to use a drying process, the process can be shortened, and the deformation of the PET bottle can be prevented.

A second feature of the present invention is that a PET bottle filled with a sterilizing solution is placed on a reciprocating conveyor and brought into fluid contact for a required time. If the sterilizing solution is filled and left standing, the fluidizing contact effect of the sterilizing solution is not exerted, so the osmotic diffusion effect is small and the sterilizing effect is small.

When the bottle filled with the sterilizing liquid is placed on the conveyor and conveyed, the sterilizing liquid flows in the PET bottle because acceleration due to the progress of the conveyor and force due to the vibration of the conveyor are applied to the sterilizing liquid.

However, if the traveling direction of the conveyor is one direction, the flow of the sterilizing solution becomes a constant direction and the flow is rectified, so that the fluid contact effect is small.

Sterilization with a sterilizing solution requires a longer time than sterilization with heating, irradiation with ultraviolet rays, hydrogen peroxide, etc., and therefore there are many practical problems when left alone or transported in one direction.

The present inventor considered that the sterilizing solution is made to be in a turbulent state in the bottle to enhance the sterilizing effect. There are methods to place a baffle on the bottle and blow air to make it into a turbulent state,
This is not preferable because the device becomes complicated and there is a risk of contamination with bacteria.

The PET bottle filled with the sterilizing liquid, which is a feature of the present invention, is placed on a conveyor that reciprocates and transported, and the apparatus does not become complicated when the sterilization is performed by reciprocating the conveyor by reversing the traveling direction a required number of times. There is no mixing of such as. The sterilizing liquid in the bottle reverses its flow direction every time the traveling direction of the conveyor changes.
Because of the turbulent flow state, the fluid contact effect becomes large, the concentration of the sterilizing solution becomes uniform, the sterilization time can be shortened remarkably, and the sterilization becomes complete. The easiest way to reverse the direction of travel of the conveyor is to make a meandering run. In fluid contact using a reciprocating conveyor, since the conveyor conveys an article placed at a desired location while reversing the traveling direction, it is easy to incorporate in the entire process of filling beverages, This is because it can be arranged as a transport device without complicating the device.

A third feature of the present invention is that each device and a conveyor for connecting each device are housed in a tunnel to which sterilized gas is supplied, and contamination of bacteria is prevented. This is the second book
It is an invention.

The fourth feature of the present invention is to arrange a rotating rotary joint at a joint portion of an injection nozzle for sending aseptic water in a step of injecting aseptic water into a PET bottle from which a sterilizing liquid has been discharged and cleaning the same, thereby providing a cleaning effect. This is because the rotary joint has a space between the rotary packing and the lower stop ring, and sterile water or sterilizing liquid is injected into the space to prevent bacteria from entering from the rotary joint.

Although it is extremely rare, in the step 4 of injecting sterile water into the PET bottle that has discharged the sterilizing solution and washing it, there is a risk that various bacteria will be mixed in from the rotary joint section that sends the sterile water. By forming a liquid barrier, this problem was solved and the third invention was completed.

That is, in the third aspect of the present invention, the sterile water cleaning device 4
The rotary joint 100 that rotates while sending sterile water into the PET bottle, the stop ring 102 that fixes the rotary packing 101, and the gap 106 between the stop ring 105 that fixes the ball bearing 103 by holding the spacer 104, sterilize Forming a barrier to prevent the invasion of bacteria by filling the liquid or sterile water, the void 106 was kept sterile.
It is the filling device according to claim 2.

(Example) An example of the present invention will be described with reference to FIGS. 1 and 2.

Embodiment 1 FIG. 1 is a plan view of a specific example of the aseptic filling device of the present invention.

In FIG. 1, PET bottles whose bottoms are from A are sequentially loaded and introduced into the preliminary cleaning apparatus 1. Then, drug P3
-HTW (sterilizing solution) was poured into the PET bottle so as to overflow, and then introduced into the reciprocating conveyor 2 by the conveyor in the tunnel 7 to which the sterilized gas was supplied.

The PET bottle filled with the chemicals makes a fluid contact while being reciprocated on the reciprocating conveyor 2, and is reciprocated several times by the conveyor, and the sterilization process inside the bottle proceeds. At this time, the sterilizing liquid may be spilled due to the reciprocating movement, so add additional doses as necessary. Fluid contact is carried out for a time sufficient for sterilization.

The PET bottle that has passed through the reciprocating conveyor 2 is introduced into the germicide-removing outside cleaning device 3 through the tunnel 7.

In the disinfectant-removal outer side cleaning device 3, the PET bottle is turned upside down to discharge the disinfectant solution inside, and the outer side is cleaned. At this time, it is usually washed with sterile water, but a sterilizing solution can be used if necessary.

Then, it was introduced into the sterile water washing device 4 through the tunnel 7 and washed with sterile water to remove the remaining sterilizing liquid.

Then, with the mouth of the PET bottle turned upside down and introduced into the filling device 5, the sterilized oolong tea was filled and introduced into the crowning device 6 to crown the sterilized gap.
The product of oolong tea in PET bottle was loaded.

The obtained product did not deteriorate even if left at room temperature for one year.

Comparative Test 1 Instead of the oolong tea filled in Example 1, 1.5 liters of completely sterilized water was filled with a liquid suitable for growth of microorganisms containing 7.5 g of meat extract, 15 g of peptone and 7.5 g of sodium chloride. The allowable limit for defective products is 1 or less per 1,000,000, but there is a clear difference at 20,000.

Comparative Example 1 Without using the reciprocating conveyor 2 in Example 1,
The same was done except that it was allowed to stand for the same time.

Comparative Example 2 Example 1 except using a conveyor that moves in only one direction
Same as.

 The presence or absence of deterioration was observed after 1 month of standing at room temperature.

 The results are shown in Table 1.

From the viewpoint of safety of foods and drinks, in the case of canned and bottled products, the tolerance of defective products is 1 or less per 1,000,000 bottles, so it is understood that the comparative example is very unsatisfactory.

Embodiment 2 FIG. 2 is a sectional view of a rotary joint used in the third invention.

This rotary joint introduces sterile water from C,
It is used for cleaning the inside of the PET bottle by ejecting from D. It slides on the rotary packing 101 and the lower stop ring 102, and rotates around the vertical center line. ing.

In the present invention, a void 106 is provided between the lower stop ring 102 and the upper stop ring 105, and sterile water or a sterilizing solution is injected from A into this void to form a barrier layer, and B
It is designed to be discharged from.

Therefore, when sterile water flows from C to D,
Even if the rotary packing 101 is decompressed, it does not suck in bacteria.

In the aseptic water washing process of Example 2, the beverage containing milk was filled using the aseptic water washing device 4 equipped with the rotary joint provided with the barrier layer on the rotating part.

The content of the obtained product was not deteriorated even if left at room temperature for one year.

Comparative test 2 Instead of the milk-filled beverage filled in Example 2, the same liquid as that used in Comparative test 1 was filled.

Comparative Example 3 In the same manner as in Example 2 except that washing was performed with an aseptic water washing device (rinser) equipped with a rotary joint having no barrier layer, the presence or absence of deterioration of both was observed after 1 month of standing at room temperature.

The results are shown in Table 2. Defective product tolerance limit is 1,
There were less than, 000,000, but there was a clear difference with 100,000.

In complete sterilization filling, one defective product in 100,000 indicates that this filling method is insufficient.

(Effect of the Invention) The present invention remarkably improves the sterilization effect because a reciprocating conveyor causes the flow direction of the sterilizing solution in the bottle to be reversed due to reversal of the traveling direction of the conveyor, resulting in a turbulent flow and a large fluid contact effect. To do. Moreover, since the reciprocating conveyor also carries the material, it is possible to prevent the apparatus from becoming complicated.

[Brief description of drawings]

FIG. 1 shows an embodiment of an aseptic filling device, and FIG. 2 shows an embodiment of a rotary joint. 1 ... Preliminary cleaning device, 2 ... Reciprocating vibration conveyor, 3 ...
Reciprocating agent removal outer washing device, 4 ... Aseptic water washing device, 5 ...
… Filling device, 6… Crowned device, 7… Tunnel, 100…
… Rotary joint, 101 …… Rotary packing, 102 …… Stop ring, 103 …… Ball bearing, 104 …… Spacer, 105 …… Stop ring, 10
6 ... void.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References Japanese Patent Publication No. 39-4446 (JP, B2) Patent 126132 (JP, C2)

Claims (3)

[Claims] 1. A plastic bottle is pre-washed with a sterilizing solution in a sterilized space, and then the PET bottle is filled with the sterilizing solution and placed on a reciprocating conveyor to run the conveyor in one direction. By reversing the rearward traveling direction and reversing this traveling direction multiple times to reverse the direction of the acceleration applied to the sterilizing solution filled in the PET bottle, a turbulent flow is generated in the sterilizing solution and the sterilizing solution is used as the PET bottle. After performing sterilization by fluidizing contact, the bottle is tumbled to remove the sterilizing liquid, then the outside and inside of the bottle are washed with sterile water to wash away the sterilizing liquid and then the continuous process without passing through the drying process. A method for aseptically filling a PET bottle, which comprises filling a filling liquid with a cap and a cap sterilized. 2. A pre-cleaning device 1 for pre-cleaning a PET bottle and filling it with a sterilizing solution, a conveyor group 2 formed of a plurality of conveyors connected to the device and running in mutually opposite directions, and the conveyor. The sterilizing agent-removing outer side cleaning device 3 for inclining the connected PET bottle to remove the sterilizing liquid and then cleaning the outside of the PET bottle, and the inside of the PET bottle with sterile water disposed next to the cleaning device. Aseptic water washing device 4 for washing and filling device 5 connected to this washing device
And a capping device 6 that caps the cap, each device is connected by a conveyor, and a tunnel 7 for supplying a sterilized gas containing each device and the conveyor is provided.
Aseptic filling equipment for PET bottles. 3. A rotary joint for rotating the sterile water cleaning device 4 while sending sterile water into a plastic bottle.
Stop ring 102 for fixing rotary packing 101 and ball bearing 103 for spacer 104
In the gap 106 between the stop rings 105 that holds and fixes
The filling device according to claim 2, wherein the sterilization liquid or sterile water is filled to form a barrier for preventing invasion of bacteria, and the void 106 is maintained in a sterile state.