JPH11342919A - Process and device for sterilization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a chemical consumption amount to a low level and provide effective sterilization performance. SOLUTION: An acetic peracid sterilization solution in a sterilization liquid circulating tank 16 is kept at 250-1,500 ppm acetic peracid concentration and at 50-60 deg.C temperature by an acetic peracid concentration sensor 25, an automatic control valve 26, a heat exchanger 20 and a heater 21, and the acetic peracid sterilization solution kept at the 250-1,500 ppm concentration and the 50-60 deg.C temperature is jetted out of nozzles 12 and 13 and brought into contact with a container 11 to carry out the sterilization of the container 11, and the chemical consumption amount is controlled to the low level to provide the effective sterilization performance and reduce residual H2 O2 in the container 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and apparatus for sterilizing food containers and caps.

[0002]

2. Description of the Related Art A conventional method for sterilizing food containers is disclosed in Japanese Patent Application No. 7-291236.
This method comprises a hot water sterilization step of bringing hot water of 63 ° C. or higher into contact with at least the inner surface of the food container, and sterilization of hydrogen peroxide, peracetic acid, a mixture of the peracetic acid and hydrogen peroxide, sodium hypochlorite, and the like. This is a sterilization method combining a drug sterilization step of bringing a drug into contact with the inner and outer surfaces of a food container. In this disinfecting method, the working temperature of the peracetic acid disinfectant is 40 ° C.
Food containers that can use this sterilization method include PET bottles, plastic bottles such as those made of polyolefin, and glass containers. An apparatus for performing this sterilization method has a configuration as a conceptual diagram shown in FIG.

[0003] In FIG. 20, reference numeral 01 denotes a container conveying device;
Reference numeral 2 denotes a container hot water sterilization area, 03 denotes a bottle medicine sterilization area in which a sealed oxonia supply nozzle is disposed, 04 denotes a rinse area in which a nozzle for ejecting sterile water is disposed, and 05 denotes a filling sealing area. This conventional example is intended to sterilize all microorganisms to be sterilized without using a large amount of a sterilizing agent, and to provide an economical method for sterilizing containers having excellent sterilizing power.

As a conventional method for sterilizing food containers, a method disclosed in Japanese Patent Application Laid-Open No. 8-58744 is known. According to the method for sterilizing a food container, (1) a peracetic acid-based germicide mixed with hydrogen peroxide is heated to 60 ° C. or higher.
(2) Heat the peracetic acid concentration to above 55 ° C at 1500ppm or more and 2000ppm or less.
(4) Peracetic acid concentration is 3000pp
Heat to 45 ° C or more at m or more.
The container is sterilized by contacting the inner surface of the container for a second.

FIG. 21 is a layout diagram showing the steps of this container sterilization method. In FIG. 21, reference numeral 001 denotes a container transporter, 002 denotes a sterilizing section of the container, and a heating means (not shown) for heating the peracetic acid-based germicide to a desired temperature, which is maintained at a sterile level of class 10,000 in the sterilizer 002, is provided. Have
A disinfecting nozzle (not shown) for spraying the heated disinfectant into the container is provided. Reference numeral 003 denotes a sterile air transfer unit that blows sterile air to convey the container while drying the container. 004 denotes a filling and sealing unit, which includes a washing machine 005 for washing the container, and a filling machine 00 for filling the container with a beverage liquid.
6 and a capper 00 for sealing the container opening with a cap after filling.
7 is provided. 008 is a cap sterilizer for sterilizing the cap.

[0006]

When sterilizing food packaging materials such as food containers and caps using hot water and a peracetic acid-based disinfectant as shown in FIG. 20, 40 peracetic acid-based disinfectant is used. ℃, sterilization time is long (3
Min), the equipment in the sterilization area becomes large, and the equipment and operating costs are large.

In addition, the conventional treatment at a high temperature of 60 ° C. or higher using only the peracetic acid-based disinfectant or the treatment at a high concentration of peracetic acid of 1500 ppm or more shown in FIG. 21 requires a relatively short processing time. However, the drug is quickly decomposed, consumes a large amount of the drug to make up for the shortage caused by the decomposition, and uses a large amount of clean water for rinsing the container because a large amount of the drug remains in the container due to the use of a high concentration of the drug. Required, operating costs are high and uneconomical. In addition, to reduce drug consumption, 6
The use of a peracetic acid-based fungicide with a lower peracetic acid concentration (1500 ppm or less) at a temperature around 0 ° C has a weak effect on one part of drug-resistant bacteria (mold), and is limited to food packaging even after sterilization. There are problems such as the possibility of survival.

[0008] An object of the present invention is to provide an economical sterilizing method and an economical sterilizing apparatus by determining the use conditions of a low-concentration sterilizing agent.

[0009]

According to the present invention, there is provided a sterilization treatment method according to the present invention, wherein the peracetic acid concentration is from 250 ppm to 1500 pp.
m, sterilizing food containers using a peracetic acid-based disinfectant solution at a temperature of 50 ° C to 60 ° C. Then, the peracetic acid-based disinfectant solution is circulated and used, and the peracetic acid-based disinfectant solution is cooled in a circulation path to a temperature lower than the temperature at the time of the sterilization treatment. In the circulation path,
Heat exchange is performed between the low-temperature peracetic acid-based disinfectant solution supplied to the sterilization treatment before being heated to the sterilization treatment temperature and the high-temperature peracetic acid-based disinfectant solution after the sterilization treatment before being cooled. The method is characterized in that the acetic acid-based disinfectant solution is heated. Also,
It is characterized by the combined use of sterilization treatment with hot water.

[0010] In order to achieve the above object, the sterilization apparatus of the present invention comprises the steps of:
pm to 1500 ppm, control means for maintaining the temperature at 50 ° C to 60 ° C, and supply means for bringing the peracetic acid-based disinfectant solution maintained at a peracetic acid concentration of 250 ppm to 1500 ppm and the temperature at 50 ° C to 60 ° C into contact with the food container. It is characterized by having. And a circulation path for circulating the peracetic acid-based disinfectant solution, and cooling means for cooling the peracetic acid-based disinfectant solution to a temperature lower than the temperature at the time of the sterilization treatment in the circulation path. I do. Further, in the circulation system, a low-temperature peracetic acid-based disinfectant solution supplied to the disinfection treatment before being heated to the disinfection treatment temperature, and a high-temperature peracetic acid-based disinfectant solution after the disinfection treatment before being cooled. And a heat exchanging means for exchanging heat and heating the low-temperature peracetic acid-based germicide solution. In addition, a hot water supply means for bringing hot water into contact with the food container is provided in order to use sterilization treatment with hot water in combination.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sterilization method and a sterilization apparatus in which the sterilization method of the present invention is applied to bottle sterilization will be described. FIG. 1 shows a layout state of a bottling line including a sterilization apparatus for performing a sterilization method according to a first embodiment of the present invention, and FIG. 2 shows a system description of the sterilization apparatus.

In FIG. 1, 1 is a container conveying device, 2 is a sterilization room for a bottle (container) 11, 3 is a conveyor for carrying the container 11 in an aseptic state, 4 is a washing room, and 5 is a sterile room for the container 11. Conveyor to convey, 6 is a dryer for container 11, 7 is container 11
Is a conveyer for aseptically transporting the container, 8 is a filling and capping machine, and 9 is a conveyor for sending out the filled container 11 to the next step.

Referring to FIG. 2, the sterilizing chamber 2 and its surroundings will be described first. Reference numeral 2a denotes a sterilizing chamber main body, 12 denotes a sterilizing solution nozzle for spraying a sterilizing solution inside the container 11, 1
Reference numeral 3 denotes a sterilizing solution nozzle for spraying a sterilizing solution on the outside of the container 11. Reference numeral 17 denotes a filter provided at the liquid discharge portion of the sterilizing chamber main body 2a, 16 denotes a sterilizing solution circulation tank, 18 denotes a pump for pumping the sterilizing solution from the circulation tank 16 to the sterilizing solution nozzles 12 and 13, and 19 denotes a sterilizing solution. A pump for returning to the circulation tank 16, 20 is a heat exchanger for utilizing the heat of the high-temperature sterilant solution on the return side to heat the low-temperature sterilant solution for sending to the sterilizing solution nozzles 12 and 13, and 21 is heat The heater 22 further heats the sterilant solution passing through the exchanger 20 to a specified value (50 to 65 ° C.), and further cools the sterilant solution on the side returned to the circulation tank 16 cooled by the heat exchanger 20. 3
The cooler is cooled to 0 ° C. to 45 ° C. and exchanges heat with low-temperature washing water described later.

The disinfectant solution sent from the circulation tank 16 to the disinfectant nozzles 12 and 13 receives heat from the disinfectant solution on the side returning to the circulation tank 16 in the heat exchanger 20 to heat the disinfectant solution. The thermal efficiency of the cooling system has been improved. Reference numeral 25 denotes a peracetic acid (CH ₃ COOOH) concentration sensor for the disinfectant solution in the circulation tank 16. Reference numeral 26 denotes a disinfectant containing peracetic acid (for example, a solution of P3-oxonia aktiv) controlled by a signal generated by the concentration sensor 25. This is an automatic control valve that opens and closes the supply passage 28 and charges the germicide into the circulation tank 16.

The temperature of 30 ° C. stored in the circulation tank 16
The 45 ° C. disinfectant solution is supplied to the solution piping 27a and the pump 1
8, through pipe 27b, 40 ° C to 55 ° C in heat exchanger 20
Is heated to a specified value (50-65 ° C.) at the time of sterilization by the heater 21 via the pipe 27c, and is sent to the sterilizing liquid nozzle 13 via the pipe 27d and to the sterilizing liquid nozzle 12 via the pipe 27e. Then, the inside and outside of the container 11 are sprayed for a specified time (for example, 15 seconds). After spray disinfection, the disinfectant solution collected at the bottom of the disinfection chamber main body 2a is filtered.
7 to remove solid matter, pipe 29c through pipe 29a through operation valve 23, pipe 29d from pump 19, heat exchanger 20
Then, the disinfectant solution is further cooled to 30 ° C. to 45 ° C. by the cooler 22 through the pipe 29 e and returned to the circulation tank 16. The disinfectant solution branches off in the pipe 29b, and a part of the disinfectant solution is discharged from the operation valve 24 as needed.

Next, the cleaning chamber 4 shown in FIG. 2 and its surroundings will be described. Reference numeral 4a denotes a cleaning chamber main body, 14 denotes a cleaning water nozzle for spraying the cleaning liquid into the container 11 to wash out the sterilizing liquid attached thereto, and 15 denotes a sterilizing liquid spraying the cleaning liquid to the outside of the container 11 to adhere thereto. The washing water nozzle to wash away. 31 is a cleaning liquid circulation tank, 32 is a pump for pumping the cleaning liquid from the circulation tank 31 to the cleaning water nozzles 14 and 15, and 33 is a pump for returning the cleaning liquid discharged from the cleaning chamber main body 4a to the circulation tank 31. Numeral 34 denotes a neutralizing device for neutralizing a germicide mixed in the washing water, and numeral 35 denotes a cooler for the washing water.

The washing water stored in the circulation tank 31 passes through a washing water pipe 41a, a pump 32, and a pipe 41b.
In the cooler 22 (the disinfectant solution returning to the circulation tank 16 is
℃-45 ℃, warmed to 45 ℃, pipe 41c,
While being sent to the washing water nozzle 15 via the pipe 41d,
The water is sent to the washing water nozzle 14 via the pipe 41e,
The inside and outside are spray-cleaned for a specified time (for example, 15 seconds).
After the cleaning, the cleaning water mixed with the germicide collected at the bottom of the cleaning chamber main body 4a is supplied from the pipe 43a to the operation valve 38 and the pipe 43.
c, from the pump 33, through the pipe 43d, and after neutralizing the peracetic acid in the neutralization device 34, through the pipe 43e,
It is cooled to about 35 ° C. by the cooler 35 and returned to the circulation tank 31 via the pipe 43f. The discharged washing water is supplied to the pipe 43
The branch is made at b, and a part is discharged to the outside from the operation valve 39 as necessary. The circulation tank 31 is provided with a level sensor 37 for detecting the level of the cleaning water, and the detection signal from the level sensor 37 opens and closes an automatic operation valve 36 provided in a pipe 42 for supplying the cleaning water, and Level can be kept in the normal range.

[0018]

EXAMPLE 1 In order to confirm the effectiveness of the container sterilization method of the present invention, 50 PET bottle samples each having a capacity of 500 ml were sterilized under the following test conditions, and the number of viable bacteria after the sterilization process was determined. investigated. The test conditions are as follows: After injecting the designated bacteria into a PET bottle that has been sufficiently sterilized and washed with water, and drying the PET bottle, the PET bottle is treated with a solution of P3-oxonia aktiv of six types of CH ₃ COOOH (peracetic acid) at six temperatures. In the same manner as in the actual bottle line working process, the disinfectant solution is treated by spraying into the bottle by a nozzle for 15 seconds, and after the treatment, the inside of the PET bottle is washed with sterile water and the treated water is filtered. Through
The bacteria remaining on the filter are cultured for 7 days and the number of visible colonies is counted to evaluate the sterilization performance. The sterilization performance was quantified by equation (1). Sterilization performance = log (initial bacterial count of PET bottle (8.0 × 10 ⁶ / bottle) / average number of colonies after sterilization treatment of 50 samples + 2 × standard deviation) (1)

The bacteria used in this experiment float in the air.
Are generally difficult to kill with heat and drugs.
Bacillus subtilis spores were used. (Sterilization performance is 5 or less
The top shows that proper sterilization was performed. ) The test result
The results are as shown in the table of FIG.
Was sprayed into the bottle for 15 seconds. CH at 40 ° C_ThreeCOO
OH concentration 1000ppm ~ 1500ppm, 500ppm ~ 1500pp at 45 ℃
m, at 50 ° C and 55 ° C, 250 ppm to 1500 ppm, 60 ° C
At 65 ° C and 150ppm to 1500ppm, sterilization performance 5
The above was obtained. When sterilization performance of 6 or more is required
Is CH at 50 ° C _ThreeCOOOH concentration 500ppm ~ 1500ppm, 55
℃, 60 ℃, 65 ℃ reach 250ppm-1500ppm each range
It was confirmed that it could be achieved.

Example 2 In place of the bacterium Bacillus subtilis, Ch, which is a micro-species floating in the air, is considered to be difficult to be sterilized by a peracetic acid bactericide.
The procedure was performed under the same conditions as in Example 1 except that spores of aetomium globosum were used. The results of the experiment are as shown in the table of FIG. 5, and a bactericide under the following conditions was sprayed into the bottle for 15 seconds. CH ₃ COOOH concentration at 50 ° C to 65 ° C
A sterilization performance of 5 or more was obtained in the range of 250 ppm to 1500 ppm.
It was also confirmed that when a sterilization performance of 6 or more was required, the range of 500 ppm to 1500 ppm could be achieved at 60 ° C. to 65 ° C.

The results of Example 1 and Example 2 are summarized in the table of FIG. From these results, the conditions under which both bacteria and microbes can be sterilized at the same time with a sterilization performance of 5 or more are 50 ° C to 6 ° C.
The CH ₃ COOOH concentration at 5 ° C. is 250 ppm to 1500 ppm. The conditions that can be sterilized at a sterilization performance level of 6 or more are 60 ° C to 65 ° C.
And the CH ₃ COOOH concentration is 500 ppm to 1500 ppm.

FIG. 3 is a graph showing the relationship between the holding temperature of the germicide and the decrease in the concentration of CH ₃ COOOH in the germicide solution over time. In FIG. 3, the vertical axis represents the initial concentration of CH ₃ COOOH in the disinfectant solution as 1.0, and represents the concentration ratio to this initial value, and the horizontal axis represents the elapsed time. In the figure, the solid line shows the disinfectant solution at 40 ° C., and the broken line shows the disinfectant solution at 6 ° C.
The case of 0 ° C. is shown. Thus the CH in the disinfectant solution
₃ The decrease in the concentration of COOOH is greatly affected by temperature.In disinfection of containers, it is necessary to keep the disinfectant solution at a low temperature and reduce consumption of disinfectant as much as possible except when the disinfectant solution comes into contact with the container. desirable.

By setting the concentration of peracetic acid as low as 250 ppm to 1500 ppm and the liquid temperature at 50 ° C. to 65 ° C., it is possible to suppress the consumption of chemicals and obtain an effective sterilization performance of 5 or more. Due to the low concentration described above, there is little residual H ₂ O ₃ in the container (lower limit of detection). By circulating the sterilizing agent and cooling the liquid from 50 ° C to 65 ° C to 30 ° C to 45 ° C before returning to the circulation tank, decomposition of the agent can be suppressed and consumption can be reduced. The disinfectant solution sent from the circulation tank to the disinfectant spray nozzle receives heat from the disinfectant solution on the side returning to the circulation tank in the heat exchanger, thereby improving the thermal efficiency of the disinfectant heating / cooling system. Peracetic acid (CH ₃ C) of the disinfectant solution installed in the circulation tank
OOOH) A signal from the concentration sensor causes the automatic control valve to cause a disinfectant containing peracetic acid (eg, a solution of P3-oxonia aktiv)
The supply passage is opened and closed and the disinfectant is charged into the circulation tank 16, so that a stable peracetic acid concentration can be maintained.

An embodiment of a sterilization method and a sterilization apparatus in which the sterilization method of the present invention is applied to the sterilization of food packaging materials will be described. FIG. 7 shows a layout state of a bottle filling line including a cap sterilizing apparatus for performing the sterilizing method according to the second embodiment of the present invention, FIG. 8 illustrates a system of the sterilizing apparatus, and FIG. 3 shows the enlargement status of part A of FIG.

In FIG. 7, reference numeral 101 denotes a container conveying device;
Is a cleaning and sterilizing section of the container, 103 is a conveyor for transporting and drying the container aseptically, 104 is a filling and capping section, and 10 is
Reference numeral 5 denotes a conveyor for sending the full containers to the next process, and 106 denotes a capping machine. 107 is a cap alignment machine, 11
0 is the cap supply conveyor, 120 is the hot water washing section of the cap, 130 is the cap conveyor, 140 is the sterilization section of the cap, 150 is the conveyor that transports the cap aseptically, 160
Is a washing section for washing the cap with sterile clean water, and 170 is a cap conveyor for feeding the cap to the capping machine 106 in an aseptic state.

Referring to FIG. 8, first, the hot water cleaning section 120 of the cap and its periphery will be described. Reference numeral 120a denotes a hot water cleaning chamber main body, and reference numeral 124 denotes a hot water nozzle (having the same shape as the sterilizing liquid nozzle 145 as shown in FIG. 9) for spraying hot water into and out of the cap 108. Reference numeral 125 denotes a filter provided on a discharge pipe 132a of the hot water cleaning chamber main body 120a, and reference numeral 128 denotes a hot water pump from the hot water manifold 131a to a hot water nozzle 124 via a heater 123 through a circulation pipe 132f. It is a pump. The heater 123 has a temperature sensor and a flow control valve for the heat medium of the heater 123 in order to maintain the hot water jetted from the hot water nozzle 124 at a predetermined temperature between 70 to 80 ° C. I do.

A cap carrier chain 109 with an endless attachment is driven at a constant speed inside the cleaning chamber main body 120a of the hot water cleaning section 120 so that the caps 108 transferred from the cap supply conveyor 110 are aligned. The wafer is continuously circulated while being sprayed with hot water from the hot water nozzle 124. Collected at the bottom of the hot water washing room main body 120a,
The hot water sent through the pipe 132a, the filter 125, the pipe 132b, and the operation valve 126 or the hot water that joins in the pipe 165b of the washing unit 160 is determined at 70 to 80 ° C. by the heater 23 through the pipe 132f by the pump 128. Pipe 13
It is pressure-fed to the hot water manifold 131a via 1 g, and is continuously ejected from the hot water nozzle 124 toward the cap 108. When the cap 108 placed on the cap carrier chain 109 passes between the hot water nozzles 124, the hot water spray is applied for a specified time (for example, 10 seconds). The cap 108 after the hot water spray is transferred from the cap carrier chain 109 to the cap conveyor 130.

The sterilizing section 140 of the cap and its surroundings will be described. 140a is a sterilization room main body, and 145 is a cap 8
A sterilizing solution nozzle that sprays a sterilizing solution inside and outside the
Denotes a jet port of the sterilizing solution nozzle 145. 141 is a disinfectant circulation tank, 142 is a pump for pumping disinfectant solution from the circulation tank 141 to the disinfectant nozzle 145, 148 is a pump for returning disinfectant solution to the circulation tank 141, and 143 is a high temperature disinfectant on the return side. A heat exchanger 144 is used to heat the low temperature sterilant solution on the side that sends the heat of the solution to the sterilizing solution nozzle 145. The heat exchanger 144 further converts the sterilant solution passed through the heat exchanger 143 to a specified value (50 to 6).
5 ° C.). The heater 144 is provided with a temperature sensor and a flow control valve for the heating medium of the heater 123 in order to maintain the sterilant solution ejected from the sterilant nozzle 145 at a predetermined temperature between 50 and 85 ° C. And 155 is a circulation tank cooled by heat exchanger 143
A cooler that cools the sterilant solution on the side returning to 141 and lowers the temperature to 30 to 45 ° C. is configured to exchange heat with low-temperature washing water described later.

The disinfectant solution sent from the circulation tank 141 to the disinfectant nozzle 145 receives heat from the disinfectant solution on the side returning to the circulation tank 141 in the heat exchanger 143, thereby forming a disinfectant heating / cooling system. The thermal efficiency has been improved. 156 is a peracetic acid (CH ₃ COOOH) concentration sensor of the disinfectant solution in the circulation tank 141, and 149 is a disinfectant containing peracetic acid (for example, a solution of P3-oxonia aktiv) controlled by a signal generated by the peracetic acid temperature sensor 156. ) Is an automatic control valve that opens and closes the supply passage and feeds the germicide into the circulation tank 141.

Inside the sterilization chamber main body 140a, the same endless cap carrier chain 109 with an attachment as that in the hot water cleaning chamber main body 120a is circulated at a constant speed and delivered from the cap conveyor 130. Sterilizing solution nozzle with cap 108 aligned and jetting continuously
Circulate and transport while bathing 145 sprays. After the disinfectant solution spray is completed, the cap 108 is transferred from the cap carrier chain 109 to a cap conveyor 150 which carries the cap 108 aseptically.

30 to 4 stored in the circulation tank 141
The 5 ° C. disinfectant solution passes through the solution piping 151a and the pump 142.
And heated to about 50 ° C in the heat exchanger 143.
After passing through 151b, the specified value at the time of sterilization by heater 144 (50-65)
(° C.), sent to the sterilizing solution nozzle 145 through the sterilizing solution manifold 151c, and continuously sprays the sterilizing solution toward the cap 108. The cap 108 placed on the cap carrier chain 109 passes between the sterilizing solution nozzles 145,
The duration of the germicide solution spray is, for example, 20 seconds.

After spray sterilization, the sterilant solution collected at the bottom of the sterilization chamber main body 140a passes through the operation valve 146 and the pipe 152c from the pipe 152a, and passes through the heat exchanger 143 from the pump 148 to the pipe 152d.
, Where it is cooled to about 50 ° C., and the disinfectant solution is further cooled to 30-45 ° C. by a cooler 155 via a pipe 152e, and returns to a circulation tank 141 via a pipe 152f. The germicide solution is branched in the pipe 152a, and a part of the germicide solution is discharged to the outside through the pipe 152b by opening the operation valve 147 as necessary.

Next, the cleaning section 160 shown in FIG. 8 and its periphery will be described. 160a is the cleaning room main body, 161 is the cap 10
Spray a clean, sterile cleaning solution inside and outside
A washing water nozzle for washing out the disinfectant solution attached to 108. Reference numeral 166 denotes a pump for feeding aseptic cleaning water to the cleaning water nozzle 161. The above-mentioned cooler 155 uses the aseptic cleaning water as a coolant to return the sterilant solution returning to the circulation tank 141 for 30 to 30 minutes.
After cooling to 45 ° C., the aseptic washing water is warmed to about 45 ° C. in a cooler 155, and is passed through a manifold 164b to a washing water nozzle 161.
Then, the inside and outside of the cap 108 are spray-cleaned with hot water. The warmed cap 108 has a shorter drying time.

Inside the cleaning chamber main body 160a, the same endless attachment cap carrier chain 109 as the inside of the above-described hot water cleaning chamber main body 120a and sterilization chamber main body 140a is provided.
Is circulated at a constant speed, and the cap conveyor 150
Of the washing water nozzle 161 is circulated and conveyed continuously while aligning the direction of the cap 108 delivered from the washing machine.

Cap 10 after spraying sterile cleaning water
8 is transferred from the cap carrier chain 109 to the cap conveyor 170, dried with aseptic hot air in the cap conveyor 170, and conveyed aseptically to the capping machine 106 (see FIG. 7). The cleaning water stored at the bottom of the cleaning chamber main body 160a is discharged through a pipe 165a, an operation valve 163, and a pipe 165c. If necessary, the operation valve 162 is opened, and a part of the washing water drainage is sent from the pipe 165b to the pipe 132e and added to the circulating hot water.

The pipe of sterile cleaning water shown in FIG. 8 is configured to circulate. However, in order to collect and circulate the cleaning water, a circulation tank for the cleaning water is provided. May be connected to a circulation tank to form a circulation pipe. However, in this case, a neutralizing device for neutralizing the germicide mixed in the washing water is required in the middle of the washing water pipe for returning the collected washing water to the circulation tank.

[0037]

EXAMPLES In order to confirm the effectiveness of the food packaging material sterilization method of the present invention, 50 cap samples for food containers were sterilized under the following test conditions to check for the presence of microorganisms. The sterilization performance was quantified according to the above (1). That is, sterilization performance = log (the initial number of bacteria attached to the cap sample / the average value of the number of colonies after treatment + 2 x standard deviation) (1) If the sterilization performance is 5 or more, appropriate sterilization is required. Indicates that it was done.

The test conditions are such that a designated bacterium is put into a sufficiently sterilized and washed cap, dried, and then sprayed from a nozzle into and out of the cap from a nozzle in accordance with the actual sterilization operation of the cap supply line. 60 ℃ on the cap,
After contacting each hot water of 70 ° C and 80 ° C for 10 seconds,
C, 45 ° C, 50 ° C, 55 ° C, 60 ° C, 65 ° C and CH ₃ COOOH (peracetic acid) concentration 150ppm, 250ppm, 500ppm,
750ppm, 1000ppm, 1500ppm P3-oxonia a
After treatment, the cap is washed with sterile water, the treated water is passed through a filter, and the remaining filter is cultured for 7 days, and the number of visible colonies is counted and sterilized. The performance was evaluated.

The microorganisms used in this test are generally heat-resistant Baci as representatives of bacteria floating in the air.
llus subtilis spores, Chaetomium glo
bosum. The test results are as shown in the tables of FIG. 10 and FIG. 11, and the hot water temperature is 70 ° C. to 80 ° C. as the processing conditions that can achieve the sterilization performance of 5 or more for the above two types of microorganisms that are difficult to sterilize. , Peracetic acid is 750p at 45 ℃
pm to 1500ppm, 250ppm to 1500ppm at 50 ° C to 55 ° C,
At 60 ° C to 65 ° C, the range is 150 ppm to 1500 ppm.

Comparative Example 1 The test conditions were as follows: the designated bacteria were put into a cap that had been sufficiently sterilized and washed with water, dried, and sprayed from a nozzle into and out of the cap from a nozzle in accordance with the actual sterilization operation of the cap supply line. 60 ° C, 70 ° C, 80 ° C on the cap by the method
Hot water at the three stages of temperature is contacted for 10 seconds, 20 seconds, and 30 seconds for treatment. After the treatment, the cap is washed with sterile water, the treated water is passed through a filter, and the residue remaining on the filter is cultured for 7 days. The number of colonies that can be visually observed was counted to evaluate the sterilization performance.

The microorganisms used in this test generally have heat resistance as representative of bacteria floating in the air (1)
Bacillus subtilis spores, representatives of microbes (2) Neosar
terya sp, (3) Arthsinium sp, (4) Chaetomium globo
Sum spores. The test results are as shown in the tables of FIGS. 12 to 15, and Neosarterya sp and Arthsinium sp
Showed a sterilization performance of 5 or more under all conditions.
For aetomium globosum, the disinfection performance was as low as 3 to 4 at the hot water temperature of 60 ° C. For Bacillus subtilis, the disinfection performance was less than 3 under all conditions, and sufficient disinfection performance was obtained only with hot water. Did not.

Comparative Example 2 The test conditions are as follows: the designated bacteria are put into a cap that has been sufficiently sterilized and washed, dried, and sprayed from the nozzle into and out of the cap from a nozzle according to the actual sterilization operation process of the cap supply line. Method, the temperature is 40 ° C, 45 ° C, 50 ° C,
6 steps of 5 ° C, 60 ° C, 65 ° C and CH ₃ COOOH (peracetic acid)
Concentration 150ppm, 250ppm, 500ppm, 750ppm, 1000ppm, 1500
A solution of P3-oxonia activ in 6 stages of ppm was treated by contacting for 30 seconds. After the treatment, the cap was washed with sterile water, and the treated water was passed through a filter.
The bactericidal performance was evaluated by counting the number of visible colonies after culturing for one day. The microorganisms used in this test are the same as in Comparative Example 1.

The test results are shown in the tables of FIG. 16 to FIG. 19, and for Neosarterya sp, 750p at 40 ° C.
pm or more, at 45 ° C. 500 ppm or more, at 50 ° C. 250 ppm or more, at 55 ° C. 150 ppm or more can obtain sterilization performance 5 or more,
For Arthsinium sp.
It was confirmed that a sterilization performance of 5 or more was obtained at 250 ° C. or more at 150 ° C. and 150 ppm or more at 50 ° C. to 65 ° C., and that it was possible to easily sterilize even at low temperature and low concentration. Bacillus subtilis, which had extremely low bactericidal performance with hot water alone, was 10
At least 50 ppm at 50 ° C. to 60 ° C.
At 150C, sterilization performance of 5 or more was obtained at 150 ppm or more. However, it was confirmed that the bactericidal performance of Chaetomium globosum was significantly lower than that of the other three cells. Compared to Comparative Examples 1 and 2, the hot water or peracetic acid bactericide alone tends to deviate in bactericidal performance depending on the bacterial species.

As described above, the decrease in the concentration of CH ₃ COOOH in the disinfectant solution is greatly affected by the temperature. In disinfecting the container, the disinfectant solution is kept at a low temperature as much as possible except when the disinfectant solution comes into contact with the container. It is desirable to keep the disinfectant consumption low.

The peracetic acid concentration is set to a low concentration of 250 to 1500 ppm, the liquid temperature is set to 50 to 65 ° C., and the sterilizing action by spraying hot water at 70 to 80 ° C. for a short time is combined with 1500 ppm or less. A sufficient bactericidal effect can be obtained against bacteria (mold) having a strong resistance to the concentration of peracetic acid, the amount of drug consumption can be suppressed, and an effective bactericidal performance can be obtained. By circulating the sterilizing agent and cooling the liquid from 50 ° C to 65 ° C to 30 ° C to 45 ° C before returning to the circulation tank, the decomposition of the agent can be suppressed and the consumption can be further reduced.

Because of the low concentration described above, the amount of residual peracetic acid (CH ₃ COOOH) and hydrogen peroxide (H ₂ O ₃ ) in the container is small (lower limit of detection), and the use of clean water for rinsing the container is required. The amount is small. The disinfectant solution sent from the disinfectant spray nozzle from the circulation tank receives heat from the disinfectant solution on the side returning to the circulation tank in the heat exchanger,
The heat efficiency of the sterilizing liquid heating / cooling system can be improved.

As described above, since the sterilization treatment can be performed in a short time, the equipment can be reduced in size, the consumption of chemicals can be kept low, the amount of clean water used for rinsing the container can be reduced, and the thermal efficiency of the heating and cooling system for the sterilization liquid can be improved. Therefore, it is possible to achieve the object of providing an economical method and apparatus for sterilizing food packaging materials.

[0048]

The sterilization method of the present invention has a peracetic acid concentration of 25%.
Since the food container is sterilized using a peracetic acid-based disinfectant solution at 0 ppm to 1500 ppm and a temperature of 50 ° C. to 60 ° C., it is possible to suppress the consumption of the drug low and obtain an effective sterilization performance. The residual H ₂ O ₂ in the food container can be reduced.

Further, the peracetic acid-based disinfectant solution is circulated and used, and the peracetic acid-based disinfectant solution is cooled in the circulation path to a temperature lower than the temperature at the time of the sterilization treatment. The suppression consumption can be reduced. Further, in the circulation path, a low-temperature peracetic acid-based disinfectant solution supplied to the disinfection treatment before being heated to the disinfection treatment temperature, and a high-temperature peracetic acid-based disinfectant solution after the disinfection treatment before cooling. And heats the low-temperature peracetic acid-based germicide solution, so that the thermal efficiency of the germicidal solution heating / cooling system can be improved. Furthermore, because the sterilization treatment with hot water was used together,
A sufficient bactericidal effect can be obtained against bacteria that are resistant to peracetic acid at a concentration of 1500 ppm or less.

The sterilizing apparatus according to the present invention comprises a control means for maintaining the peracetic acid-based disinfectant solution at a peracetic acid concentration of 250 ppm to 1500 ppm and a temperature of 50 ° C. to 60 ° C., and a peracetic acid concentration of 250 ppm to 1500 ppm and a temperature of 50 ppm.
Supply means for contacting the peracetic acid-based disinfectant solution held at 60 ° C to 60 ° C with a food container, and a peracetic acid concentration of 250 ppm to 1500
Food containers are sterilized using a peracetic acid-based disinfectant solution with a ppm and a temperature of 50 ° C to 60 ° C, so that the consumption of chemicals can be kept low and effective sterilization performance can be obtained. H ₂ O ₂ can be reduced.

[0051] Further, there is provided a circulation path for circulating the peracetic acid-based disinfectant solution, and cooling means for cooling the peracetic acid-based disinfectant solution to a temperature lower than the temperature at the time of the sterilization treatment in the circulation path. The acetic acid-based disinfectant solution is circulated, and the peracetic acid-based disinfectant solution is cooled to a temperature lower than the temperature at the time of the sterilization treatment in the circulation path, so that decomposition of the drug is suppressed and consumption is reduced. Can be. Further, in the circulation system,
The low-temperature peracetic acid-based disinfectant solution supplied to the sterilization treatment before being heated to the sterilization treatment temperature and the high-temperature peracetic acid-based disinfectant solution after the sterilization treatment before being cooled are heat-exchanged, and the low-temperature peracetic acid Since a heat exchange means for heating the system-based germicide solution is provided, heat exchange is performed between the low-temperature peracetic acid-based germicide solution and the high-temperature peracetic-acid-based germicide solution, and the low-temperature peracetic acid-based germicide solution is heated. The heat efficiency of the sterilizing liquid heating / cooling system can be improved. Furthermore, a hot water supply means for bringing hot water into contact with the food container is provided for the simultaneous use of the hot water sterilization treatment, and the hot water sterilization treatment is also used. A sufficient bactericidal effect is obtained.

[Brief description of the drawings]

FIG. 1 is a layout diagram of a bottling line including a sterilization apparatus for performing a sterilization method according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a system of a sterilization apparatus.

FIG. 3 is a graph showing the change over time in the concentration of peracetic acid.

FIG. 4 is a table showing the results of a sterilization experiment.

FIG. 5 is a table showing the results of a sterilization experiment.

FIG. 6 is a table showing the results of a sterilization experiment.

FIG. 7 is a layout diagram of a bottle filling line including a cap sterilizing apparatus for performing a sterilizing method according to the second embodiment of the present invention.

FIG. 8 is a system explanatory diagram of a sterilization treatment apparatus.

9 is an enlarged view of a portion A in FIG.

FIG. 10 is a table showing the results of a sterilization experiment.

FIG. 11 is a table showing the results of a sterilization experiment.

FIG. 12 is a table showing the results of a sterilization experiment.

FIG. 13 is a table showing the results of a sterilization experiment.

FIG. 14 is a table showing the results of a sterilization experiment.

FIG. 15 is a table showing the results of a sterilization experiment.

FIG. 16 is a table showing the results of a sterilization experiment.

FIG. 17 is a table showing the results of a sterilization experiment.

FIG. 18 is a table showing the results of a sterilization experiment.

FIG. 19 is a table showing the results of a sterilization experiment.

FIG. 20 is a schematic configuration diagram of a conventional sterilization apparatus.

FIG. 21 is a schematic configuration diagram of a conventional sterilization apparatus.

[Explanation of symbols]

 2 sterilizing chamber 4 washing chamber 11 container 12,13 sterilizing liquid nozzle 14,15 washing water nozzle 16 sterilizing liquid circulation tank 20 heat exchanger 21 heater 22 heat exchanger 25 sterilizing liquid concentration sensor 26 automatic control valve 31 cleaning water circulation tank 35 cooler 108 Cap 109 Cap transfer chain 120 Hot water washing unit 120a Hot water washing unit main body 123 Heater 124 Hot water nozzle 126 Hot water pump 140 Sterilizing unit 140a Sterilizing unit main body 141 Sterilizing water circulation tank 142 Pump 143 Heat exchanger 144 Heater 145 Sterilizing solution nozzle 148 Sterilizing water pump 155 Heat exchanger 160 Clean water cleaning section 160a Clean water cleaning section main body 161 Cleaning water nozzle 166 Pump

Claims (8)

[Claims] 1. A peracetic acid concentration of 250 ppm to 1500 ppm and a temperature of 50 ° C.
A sterilization method comprising sterilizing a food container using a peracetic acid-based germicide solution at 60 ° C. 2. The method according to claim 1, wherein the peracetic acid-based disinfectant solution is circulated, and the peracetic acid-based disinfectant solution is cooled to a temperature lower than a temperature at the time of the sterilization treatment in a circulation path. Sterilization treatment method. 3. The method according to claim 2, wherein:
Heat exchange is performed between the low-temperature peracetic acid-based disinfectant solution supplied to the sterilization treatment before being heated to the sterilization treatment temperature and the high-temperature peracetic acid-based disinfectant solution after the sterilization treatment before being cooled. A sterilization method comprising heating an acetic acid-based germicide solution. 4. A sterilization method according to claim 1, wherein a sterilization process using hot water is used in combination. 5. A peracetic acid-based disinfectant solution containing a peracetic acid concentration of 250 ppm.
~ 1500 ppm, control means for maintaining the temperature at 50 ° C to 60 ° C, and supply means for bringing the peracetic acid-based disinfectant solution maintained at a peracetic acid concentration of 250 ppm to 1500 ppm, the temperature at 50 ° C to 60 ° C into contact with the food container. A sterilization treatment apparatus characterized in that: 6. The circulating route for circulating the peracetic acid-based germicide solution according to claim 5, and cooling means for cooling the peracetic acid-based germicide solution to a temperature lower than the temperature at the time of sterilization in the circulation route. And a sterilization treatment apparatus comprising: 7. The method according to claim 6, wherein:
The low-temperature peracetic acid-based disinfectant solution supplied to the sterilization treatment before being heated to the sterilization treatment temperature and the high-temperature peracetic acid-based disinfectant solution after the sterilization treatment before being cooled are heat-exchanged, and the low-temperature peracetic acid A sterilization apparatus comprising a heat exchanging means for heating a system germicide solution. 8. The method according to claim 5, further comprising hot water supply means for bringing hot water into contact with the food container in order to use the sterilizing treatment with hot water. Sterilization processing equipment.