JP2008272674A - Container washing machine and container washing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a container washing machine capable of reducing the using amount of a detergent by the improvement of a washing effect, improving environmental fitness and successively and continuously washing containers by using microbubbles, and to solve the problem of container service life decline due to an alkaline detergent by using the microbubbles and using a neutral or acidic detergent. <P>SOLUTION: The container washing machine comprises a preliminary rinsing tub 2, a washing tub 3, a finish rinsing tub 4, a container carrying means 7 for making non-washed containers 1a successively and continuously pass through the preliminary rinsing tub, the washing tub and the finish rinsing tub, a washing liquid circulating means 24 for making washing liquid 10 stored in the washing tub flow, and a microbubble generator 31 installed in the washing liquid in the washing tub. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a container cleaning machine and a container cleaning method for repeatedly using a returnable or refillable container such as a glass bottle or a plastic bottle.

  When passing through a device equipped with a plurality of tanks called a washing machine, the glass container is immersed in water, hot water or cleaning liquid in each tank and cleaned to a refillable level (for example, (See Patent Document 1). Usually, an alkaline detergent such as sodium hydroxide is used for the washing liquid.

  On the other hand, there is a technique for generating fine bubbles called microbubbles (hereinafter also referred to as “microbubbles”) in a cleaning liquid in order to increase the efficiency of cleaning (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 5-50051 JP 2004-121962 A

  The alkaline detergent used in the washing machine described in Patent Document 1 has a strong detergency, but has a property of corroding glass, and affects the number of times the glass bottle can be used repeatedly. In the case of a bottle made of polyethylene terephthalate (PET) resin whose surface is coated with a thin film for beer use, hydrolysis of the PET resin is promoted. Therefore, in the long term, there arises a problem that the gas barrier performance of the thin film is gradually lowered.

  In order to solve various problems in the alkaline cleaning agent, it is conceivable to use an acidic cleaning agent. However, acidic detergents generally lack protein and other detergency and have not been put to practical use.

  The cleaning technique using microbubbles represented by the disclosure of Patent Document 2 is known to have an effect of reducing or reducing the amount of cleaning agent used such as an organic solvent. While attention has been focused mainly on environmentally friendly technologies in Japan, the principle has not been elucidated so far, and there have been no known examples of use in beverage container washing machines.

  Accordingly, an object of the present invention is to provide a container washer that uses microbubbles to reduce the amount of cleaning agent used by improving the cleaning effect, improve environmental suitability, and sequentially and continuously clean containers. is there. Another object of the present invention is to use microbubbles to solve the problem of container life reduction due to alkaline cleaning agents using neutral or acidic cleaning agents, and to increase the amount of cleaning agents used by improving the cleaning effect. It is intended to provide a container cleaning method capable of reducing and improving environmental suitability and sequentially and continuously cleaning containers.

  In the container washing machine having a plurality of tanks, the present inventors generate a fine bubble in the washing tank and efficiently bring the fine bubble into contact with the container, thereby allowing the beverage container to be washed with a neutral or acidic cleaning liquid. The present invention has been completed by finding that it can be washed sequentially and continuously to the extent that returnable use is possible. That is, the container washing machine according to the present invention is a container that allows a preliminary rinsing tank, a cleaning tank, a finishing rinsing tank, and an unwashed container to sequentially pass through the preliminary rinsing tank, the cleaning tank, and the finishing rinsing tank. It has a conveyance means, a cleaning liquid circulation means for generating a flow in the cleaning liquid stored in the cleaning tank, and a fine bubble generator installed in the cleaning liquid of the cleaning tank.

  In the container washer according to the present invention, it is preferable that the fine bubble generator generates fine bubbles having a number average diameter or a median diameter of 50 μm or less. The cleaning effect can be enhanced by using fine bubbles having a number average diameter or median diameter of 50 μm or less as the generated bubbles.

  In the container washer according to the present invention, the cleaning liquid circulation means is preferably a pipe with a circulation pump that sucks and discharges the cleaning liquid stored in the cleaning tank at a position lower than the liquid level. It is possible to increase the flow of the cleaning liquid in the cleaning tank, and it is possible to quickly move the fine bubbles to the container and to suppress the foaming of the cleaning liquid at that time.

  In the container washer according to the present invention, the cleaning liquid circulation means may be a pipe with a circulation pump that pumps the cleaning liquid stored in the cleaning tank from a low position to the liquid level of the cleaning liquid. The cleaning liquid in the cleaning tank can be circulated evenly from the top to the bottom, and fine bubbles can be distributed throughout the cleaning tank.

  In the container washer according to the present invention, it is preferable that the flow direction of the cleaning liquid is orthogonal or substantially orthogonal to the container conveyance direction of the container conveyance means. It is possible to efficiently bring the fine bubbles into contact with the container being transported in the cleaning tank.

  In the container washer according to the present invention, it is preferable that the fine bubble generator generates fine bubbles at a location where a flow of the cleaning liquid stored in the cleaning tank is present. Fine bubbles can be quickly distributed throughout the cleaning tank.

  In the container washer according to the present invention, it is preferable that the fine bubble generator is arranged on the upstream side of the flow of the cleaning liquid with respect to the container being cleaned. Since the fine bubbles may not be able to diffuse against the flow of the cleaning liquid, such an arrangement allows the fine bubbles to contact the container being cleaned effectively and uniformly.

  In the container washer according to the present invention, it is preferable that the container transport means transports the container so that the opening of the container being cleaned is opposed to the fine bubble generator. In the washing tank, the container can be transported while freely changing the top and bottom of the container, but the fine bubbles can be improved in quality by making the container opening (nozzle or spout) face the fine bubble generator. In particular, it is possible to easily reach the inside of an important container, and the cleaning efficiency can be increased.

  The container cleaning method according to the present invention is used in the cleaning tank in a container cleaning method in which unwashed containers are successively passed through a preliminary rinsing tank, a cleaning tank, and a final rinsing tank in order to obtain a cleaned container. The cleaning liquid is a neutral cleaning liquid, a weak acidic cleaning liquid or an acidic cleaning liquid, and the cleaning liquid is circulated to generate fine bubbles in the flow of the generated cleaning liquid.

  The container cleaning method according to the present invention includes a form in which the container is a glass container, a plastic container, a coated glass container, or a coated plastic container. Here, the form in which the thin film or the coating film is coated on the container is included, and further, the form in which the thin film is a thin film having gas barrier properties is included.

  In the container cleaning method according to the present invention, the fine bubbles are preferably bubbles having a number average diameter or a median diameter of 50 μm or less. The cleaning effect can be enhanced by using fine bubbles having a number average diameter or median diameter of 50 μm or less as the generated bubbles. If the bubbles are bubbles of such a fine diameter, it is suppressed from rapidly rising to the liquid surface due to the buoyancy acting on the bubbles while moving in the cleaning liquid, and the fine bubbles are diffused into the uniform cleaning liquid and not washed. Uniform contact with the container is possible. Therefore, from the viewpoint of buoyancy, it is more preferably 10 μm or less, and more preferably 1 μm or less.

  The container washer of the present invention can use microbubbles to reduce the amount of cleaning agent used by improving the cleaning effect, improve the environmental suitability, and sequentially and continuously clean the container. In addition, the container cleaning method of the present invention can solve the problem of a decrease in container life due to an alkaline cleaning agent using a neutral or acidic cleaning agent using microbubbles. Moreover, the amount of cleaning agent used can be reduced by improving the cleaning effect, environmental suitability can be improved, and the container can be cleaned sequentially and continuously.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiment described below is an example of the configuration of the present invention, and the present invention is not limited to the following embodiment, and can be appropriately changed within the scope of the effects of the present invention.

  A container washer according to this embodiment will be described with reference to FIGS. FIG. 1 is a schematic view for explaining the overall configuration of the container washer according to the present embodiment. FIG. 2 is a schematic view for explaining the configuration of the cleaning tank. As shown in FIG. 1, the container washer 100 according to this embodiment includes a preliminary rinsing tank 2, a cleaning tank 3, a finish rinsing tank 4, and an unwashed container 1 a successively and sequentially. In the cleaning liquid in the cleaning tank 3, the container transport means 7 that passes through the cleaning tank 3 and the finishing rinsing tank 4, the cleaning liquid circulation means (reference numeral 24 in FIG. 2) that causes the cleaning liquid 10 stored in the cleaning tank 3 to flow. And an installed fine bubble generator (reference numeral 31 in FIG. 2). The container washer 100 according to this embodiment further includes a preliminary rinsing tank 2, a cleaning tank 3, a finishing rinsing tank 4, a preliminary tank 5 of the preliminary rinsing tank 2, and a preliminary tank 6 of the finishing rinsing tank 4. Have. With reference to FIG. 1 and FIG. 2, the container washing machine which concerns on this embodiment, and its operating condition are demonstrated.

  The container washer according to the present embodiment shown in FIG. 1 includes two preliminary rinsing tanks 2a and 2b. Here, one or three or more preliminary rinsing tanks may be used. The unwashed container 1a is not put on the preliminary rinsing tank 2 immediately after being placed on the container conveying means 7, and before that, the water is washed with water or hot water by the jet water jetting machine 13 to be physically washed. The water or hot water sprayed by the jet water jetting machine 13 hits the unwashed container 1 a and is then stored in the spare tank 5 of the spare rinsing tank 2. The container 1b that is being washed with a stream of water or hot water is attached to the preliminary rinsing tanks 2a and 2b by the container transport means 7. In the preliminary rinsing tank 2, water or hot water is stored and circulated with the water or hot water in the preliminary tank 5.

  The container transport means 7 may be in any form as long as it can transport the containers to the preliminary rinsing tank 2, the washing tank 3 and the finishing rinse tank 4 sequentially and continuously. Are arranged and fixed in the direction of the conveyor. An example of the container holder is a holder having a container structure, a gripping structure, a knob structure, or a pinching structure.

  The container 1a to be cleaned is a glass container (glass bottle), a plastic container, a coated glass container, or a coated plastic container. These containers may be used one-way, but may be returnable and used repeatedly. Here, as a coating thing, there exists a thin film or a coating film, for example. Examples of the thin film include various thin films having gas barrier properties such as a diamond-like carbon (DLC) thin film, a SiOx thin film, an alumina thin film, and a nitride thin film. In addition, examples of the coating film include a ceramic or resin coating film for preventing breakage or a coating film for the purpose of label printing.

  The container washer according to this embodiment shown in FIG. 1 includes three washing tanks 3a, 3b, and 3c. Here, it may be composed of two or less or four or more cleaning tanks. The container 1b that is being cleaned is attached to the cleaning tanks 3a, 3b, and 3c by the container conveying means 7 following the preliminary rinsing tank 2. The cleaning liquid 10 is stored in the cleaning tank 3, and the cleaning liquids 10a, 10b, and 10c stored in the cleaning tanks 3a, 3b, and 3c are circulated with each other. Further, the cleaning liquid is jetted into the cleaning tank 3 by the jet water jetting machine 14, and the cleaning liquid is bathed in the cleaning container 1b to perform physical cleaning. The cleaning liquid sprayed by the jet water jetting machine 14 is stored in the cleaning tank 3 after hitting the container 1b being cleaned.

  As the cleaning liquid 10, a neutral cleaning liquid (pH is approximately 7), a weak acidic cleaning liquid (pH is 4 or more and less than 7) or an acidic cleaning liquid (pH is less than 4) is preferable from the viewpoint of preventing a decrease in the life of the container. However, in the container washer according to the present embodiment, it is also possible to use an alkaline detergent containing an alkaline agent such as sodium hydroxide or sodium gluconate conventionally used as the washing liquid 10.

  As shown in FIG. 2, the cleaning liquid circulation means 24 has two or more openings 23 provided in the cleaning tank 3 at a position lower than the water surface of the cleaning liquid 10, and the openings 23 a and 23 b are arranged outside the cleaning tank 3. And a circulation pump 21 for supplying a flow to the cleaning liquid in the piping 22. That is, the cleaning liquid circulation means 24 is a pipe with a circulation pump that pumps the cleaning liquid 10 stored in the cleaning tank 3 from a low position to the liquid level of the cleaning liquid 10. By the cleaning liquid circulating means 24, the cleaning liquid 10 stored in the cleaning tank 3 is sucked through the opening 23a at a position lower than the liquid surface and discharged from the opening 23b. In addition to being able to keep the dirt in the cleaning liquid and the cleaning liquid concentration constant, it is possible to increase the flow 25 of the cleaning liquid 10 in the cleaning tank 3, and the fine bubbles can be quickly moved to the container. 10 foaming can be suppressed. In FIG. 2, * 1 means that the pipe 22 is connected.

  FIG. 3 is a schematic view for explaining another embodiment of the cleaning liquid circulation means. As shown in FIG. 3, the cleaning liquid circulating means 24 includes an opening 23 provided in the cleaning tank 3 at a position lower than the water surface of the cleaning liquid 10, one end connected to the opening 23 b, and the other end to the water surface of the cleaning liquid 10. And a circulating pump 21 that gives a flow to the cleaning liquid in the piping 22. That is, the cleaning liquid circulation means 24 may be a pipe with a circulation pump that pumps the cleaning liquid 10 stored in the cleaning tank 3 from a low position to the liquid level of the cleaning liquid 10. Here, the other end of the pipe 22 is positioned above the water surface of the cleaning liquid 10, but may be positioned slightly lower than the water surface of the cleaning liquid 10. The cleaning liquid 10 stored in the cleaning tank 3 is sucked by the cleaning liquid circulating means 24 through the opening 23 positioned lower than the liquid surface and discharged from the other end of the pipe 22. In addition to keeping the dirt and cleaning solution concentration in the cleaning liquid constant, the cleaning liquid 10 in the cleaning tank 3 can be circulated uniformly from top to bottom, and fine bubbles can be distributed throughout the cleaning tank 3 accordingly. It becomes. Further, when the other end of the pipe 22 is located at a position slightly lower than the water surface of the cleaning liquid 10, foaming of the cleaning liquid is suppressed.

  The method of the fine bubble generator may be any method as long as it can generate fine bubbles called microbubbles. For example, there is an ultra-high speed swirling / shearing method, a pressurized gas-liquid mixing method, or an ultrasonic method. The fine bubble generator 31 shown in FIG. 2 is in the form of an ultra-high speed swirl / shear method. At this time, the fine bubble generating means 33 includes a circulation pipe 30 passing through a position lower than the water surface of the cleaning liquid 10 in the cleaning tank 3, a circulation pump 32 for supplying a flow to the cleaning liquid in the circulation pipe 30, and the cleaning tank 3. A fine bubble generator 31 connected to the circulation pipe 30 and an air intake port 29 for taking air into the circulation pipe 30. The fine bubble generator 31 shown in FIG. 2 is installed in the cleaning liquid 10 of the cleaning tank 3. In the circulation pipe 30, the air taken in from the air intake port 29 and the cleaning liquid form a gas-liquid mixed fluid and circulate at high speed. The air may be taken in from the atmosphere or may be taken in after being pressurized. Air pressure can affect bubble formation. Then, the gas-liquid mixed fluid is branched from the circulation pipe and supplied to the fine bubble generator 31. In the fine bubble generator 31, the gas-liquid mixed fluid is given a high-speed rotational flow, and fine bubbles are generated.

  In the container washer according to the present embodiment, it is preferable that the fine bubble generator 31 generates fine bubbles having a number average diameter or a median diameter of 50 μm or less. The fine bubble generator 31 may generate coarse bubbles having a diameter of the order of mm, but the cleaning effect can be enhanced by mainly generating fine bubbles having a number average diameter or median diameter of 50 μm or less. . The fine bubbles referred to in the present embodiment include nano-order ultrafine bubbles. In addition, even if the fine bubble generator 31 generates bubbles exceeding 50 μm in diameter due to its mechanism, as long as fine bubbles having a number average diameter or a median diameter of 50 μm or less are generated, the container washer of the present embodiment It can be used as a fine bubble generator.

  In the container washer according to the present embodiment, as shown in FIG. 2, the direction of the cleaning liquid flow 25 is preferably orthogonal or almost orthogonal to the container conveying direction of the container conveying means 7. If the flow 25 of the cleaning liquid is applied to the container 1b that is being transported in the cleaning tank, fine bubbles can also be brought into contact with the container 1b that is being cleaned efficiently.

  In the container washer according to the present embodiment, as shown in FIG. 2, it is preferable that the fine bubble generator 31 generates fine bubbles at a location where the flow 25 of the cleaning liquid 10 stored in the cleaning tank 3 is present. Fine bubbles can be quickly distributed throughout the cleaning tank. Further, when a plurality of fine bubble generators 31 are installed, it is preferable to arrange them along the direction of the cleaning liquid flow 25. The density | concentration of the fine bubble which contacts the container 1b during washing | cleaning can be raised.

  In the container washer according to the present embodiment, the fine bubble generator 31 is preferably arranged on the upstream side of the flow of the cleaning liquid with respect to the container being cleaned. In FIG. 2, the fine bubble generator 31 a is installed on the upstream side of the flow 25 of the cleaning liquid with respect to the container transport means 7. Since the fine bubbles may not be able to diffuse against the flow of the cleaning liquid, such an arrangement allows the fine bubbles to contact the container being cleaned effectively and uniformly.

  In the container washer according to this embodiment, it is preferable that the container transport means 7 transports the container so that the opening of the container being cleaned is opposed to the fine bubble generator. In the washing tank 3, the container can be transported while freely changing the top and bottom of the container. However, the fine bubbles can be produced by making the opening (drinking or spout) of the container and the fine bubble generator face each other. It is easy to get inside the container, which is particularly important, and can increase the cleaning efficiency. Further, even if the position of the fine bubble generator 31 and the flow 25 of the cleaning liquid are adjusted so that the fine bubbles are present at a position where the cleaning container is attached to the cleaning liquid and the cleaning liquid enters from the opening of the container. Good.

  The container washer according to this embodiment shown in FIG. 1 includes one finishing rinse tank 4. Here, it may be composed of two or more finishing rinse tanks. The container 1b being cleaned is attached to the finishing rinsing tank 4 by the container conveying means 7 following the cleaning tank 3. The finishing rinsing tank 4 stores water or hot water 11 and circulates between the water or hot water 12a, 12b, and 12c stored in the auxiliary tank 6 in the downstream. In addition, water or hot water is jetted into the finishing rinsing tank 4 by the jet water jetting machine 15, and water or hot water is bathed in the container 1b being cleaned to perform physical cleaning, and mainly the cleaning liquid is dropped. The water or hot water sprayed by the jet water jetting machine 15 hits the container 1b being cleaned, and is then stored in the reserve tank 6.

  As described above, the container that has passed through the container cleaning machine 100 is finished as the cleaned container 1c.

  In FIG. 1, the preliminary rinsing tank 2, the cleaning tank 3, and the finish rinsing tank 4 have been described as being arranged in order, but the container washer according to the present embodiment is not limited to this form. For example, a preliminary rinsing tank, a washing tank and a finishing rinsing tank may be arranged in an annular shape in this order to form a rotary type container washing machine.

  Next, the container cleaning method according to the present embodiment will be described using the container cleaning machine 100 as an example. The container cleaning method according to the present embodiment is a container cleaning method in which the uncleaned container 1a is sequentially passed through the preliminary rinsing tank 2, the cleaning tank 3 and the finishing rinsing tank 4 to obtain the cleaned container 1c. The cleaning liquid 10 used in the cleaning tank 3 is a neutral cleaning liquid (pH is approximately 7), weak acidic cleaning liquid (pH is 4 or more and less than 7) or acidic cleaning liquid (pH is less than 4), and is generated by circulating the cleaning liquid 10 Microbubbles are generated in the cleaning liquid flow 25. By generating fine bubbles, the cleaning power is enhanced regardless of the type of cleaning agent, so that the amount of cleaning agent used can be reduced and the cost can be reduced. As in the container cleaning method according to the present embodiment, even when a neutral cleaning liquid, a weak acidic cleaning liquid, or an acidic cleaning liquid is used as the cleaning liquid, the container can be cleaned to the same level as the alkaline cleaning agent.

  When the container 1a to be cleaned is a glass container (glass jar), if it is an alkaline cleaning agent, the glass is easy to dissolve, so the scratches generated on the glass surface are enlarged. If a weakly acidic cleaning solution or an acidic cleaning solution is used, the glass hardly dissolves, so that the scratch does not spread and the life of the container is extended. In the case of plastic containers, such as PET bottles, the use of an alkaline cleaner causes the hydrolysis of the resin, so that scratches generated on the surface are magnified in the same manner as glass bottles. Alternatively, if an acidic cleaning solution is used, the resin is hardly hydrolyzed, so that the scratches are not spread and the life of the container is extended. Furthermore, when a thin film or coating film is formed on the surface of a glass container or plastic container, glass dissolution or plastic hydrolysis tends to occur at the interface between the thin film or coating film and the surface of the glass container or plastic container. The thin film or coating film is easy to peel off. If a neutral cleaning liquid, a weak acidic cleaning liquid or an acidic cleaning liquid is used as the cleaning liquid, glass dissolution or plastic hydrolysis is unlikely to occur, so that the thin film or coating film is difficult to peel off and the life of the container is extended. When a weakly acidic cleaning solution is used as the cleaning agent, the cleaning rate is high as demonstrated in the examples described later, and the cleaning can be performed well beyond the case of the alkaline cleaning agent.

  Using cleaning agents having different pHs, the cleaning effect due to the generation of fine bubbles was confirmed.

（３）１０リットルの模擬洗浄槽内で、できるだけ水流を発生させないように、各サンプルを液面下に設置した。このとき、各洗浄剤及びマイクロバブルを水道水に所定の状態となるように加えた。５５℃１０分間放置し、その後の光沢度を測定した。図４に各条件（Ｎ＝３）でのサンプルの光沢度の平均値のグラフを示した。表２に図４のデータを整理した。なお、水流を発生させないようにしたのは、水流による誤差を含ませないためである。
（４）ここで、洗浄率（％）は、数１によって求めた。洗浄率（％）が８０％以上で合格品に相当する。

(Procedure until washing)
(1) A mixture paste of diatomaceous earth, calcium oxalate, beer and milk was applied to a sample plate having an area of 76 mm × 25 mm and dried at 60 ° C. for 16 hours to fix beer model stains.
(2) Before and after fixing the model dirt, the glossiness of each sample plate was measured with a handy glossiness meter (IG-320 manufactured by Horiba). The glossiness of each sample was as shown in Table 1. The film thickness of the DLC film was 20 nm. As a method for forming the DLC film, for example, the method disclosed in Patent Document 3 was used.
Japanese Patent No. 2788412

(3) Each sample was placed below the liquid level so as not to generate a water flow as much as possible in a 10-liter simulated washing tank. At this time, each cleaning agent and microbubbles were added to tap water in a predetermined state. It was left to stand at 55 ° C. for 10 minutes, and then the glossiness was measured. FIG. 4 shows a graph of the average gloss value of the sample under each condition (N = 3). Table 2 summarizes the data of FIG. The reason why the water flow is not generated is that an error due to the water flow is not included.
(4) Here, the cleaning rate (%) was obtained by Equation 1. The cleaning rate (%) is 80% or more and corresponds to an acceptable product.

(Type of cleaning agent)
(1) Strong alkaline detergent: 1 w / w (%) NaOH water with a commercially available surfactant Room temperature pH 13
(2) Weak alkaline detergent: 5 w / w (%) sodium silicate with a commercially available surfactant pH 11 at room temperature.
(3) Weakly acidic detergent: 1.2 w / w (%) A trial detergent obtained by adding a surfactant and a weak acid to glycolic acid, and has a room temperature pH of 4.
(4) Neutral detergent: NaOH was added to a commercially available weakly acidic detergent to adjust the pH to room temperature. Room temperature pH 7.

(Cleaning conditions)
The temperature was 55 ° C. for 10 minutes. The following apparatus was used for the fine bubble generator.
Horus Power Mist ECP J-150S.

  As shown in FIG. 4, the following was found. That is, it was possible to clean both the glass plate and the PET plate with microbubbles. In particular, even a weakly acidic cleaning agent was able to wash better than a strong alkaline cleaning agent.

(Verification of retention rate of gas barrier properties before and after cleaning)
Using a 500 ml PET bottle coated with a DLC film on the inner surface as a sample, without applying model dirt, fine bubbles were generated using each of the cleaning liquids described above, and the conditions were set at 55 ° C. for 10 minutes. 10 times. The oxygen transmission rate was compared before and after 10 washes. For measuring the oxygen transmission rate, Oxtran 2/21 manufactured by Mocon was used. At this time, the measurement temperature was 23 ° C. and the humidity was 90%. The average value was obtained with the number of samples N = 2. The results are shown in Table 3.

なお、洗浄前の酸素透過率は、０．００２５ｃｃ／日／本であった。 The gas barrier property retention ratio (%) was obtained from Equation 2.

The oxygen transmission rate before washing was 0.0025 cc / day / book.

  It was found that when a weakly acidic detergent was used, a high gas barrier property retention rate was obtained. From this result, it can be predicted that the returnable number of PET bottles coated with a DLC film is larger than when a strong alkaline detergent or a weak alkaline detergent is used.

It is the schematic for demonstrating the structure of the whole container washing machine which concerns on this embodiment. It is the schematic for demonstrating the structure of a washing tank. It is the schematic for demonstrating the other form of a washing | cleaning-liquid circulation means. It is a graph which shows the average value of the glossiness of the sample on each condition (N = 3) in an Example.

Explanation of symbols

1a Unwashed container 1b Washed container 1c Washed container 2, 2a, 2b Pre-rinse tank 3, 3a, 3b, 3c Wash tank 4 Finish rinse tank 5 Pre-rinse tank spare tank 6 Finish rinse tank spare tank 7 Container Conveying means 10, 10a, 10b, 10c Cleaning liquid 11, 12, 12a, 12b, 12c Water or hot water 24 Cleaning liquid circulation means 31 Fine bubble generator 13, 14, 15 Jet water flow injector 21 Circulation pump 22 Piping 23, 23a, 23b Opening 25 Flow of cleaning liquid 29 Air intake port 30 Circulation piping 31, 31a, 31b, 31c Fine bubble generator 32 Circulation pump 100 Container washer

Claims (11)

  Preliminary rinsing tank, washing tank, finishing rinsing tank, container transport means for passing unwashed containers sequentially through the preliminary rinsing tank, the washing tank and the finishing rinsing tank, and stored in the washing tank A container cleaning machine comprising: a cleaning liquid circulating means for causing a flow in the cleaning liquid; and a fine bubble generator installed in the cleaning liquid of the cleaning tank.   The container washer according to claim 1, wherein the fine bubble generator generates fine bubbles having a number average diameter or a median diameter of 50 µm or less.   The container cleaning machine according to claim 1 or 2, wherein the cleaning liquid circulation means is a pipe with a circulation pump that sucks and discharges the cleaning liquid stored in the cleaning tank at a position lower than the liquid level. .   The container cleaning machine according to claim 1 or 2, wherein the cleaning liquid circulation means is a pipe with a circulation pump that pumps the cleaning liquid stored in the cleaning tank from a low position to the liquid level of the cleaning liquid.   5. The container washer according to claim 1, wherein the flow direction of the cleaning liquid is orthogonal or substantially orthogonal to the container conveyance direction of the container conveyance means.   6. The container washer according to claim 1, 2, 3, 4, or 5, wherein the fine bubble generator generates fine bubbles at a location where a flow of cleaning liquid stored in the cleaning tank is present.   The container cleaning machine according to claim 1, 2, 3, 4, 5 or 6, wherein the fine bubble generator is arranged on the upstream side of the flow of the cleaning liquid with respect to the container being cleaned.   The said container conveyance means conveys this container so that the opening part of the container in washing | cleaning may oppose the said fine bubble generator, The 1, 2, 3, 4, 5, 6 or 7 characterized by the above-mentioned. The container washer described.   In the method of cleaning a container which is made to pass through an unwashed container sequentially and continuously through a preliminary rinsing tank, a washing tank and a finishing rinsing tank, the washing liquid used in the washing tank is a neutral washing liquid or a weakly acidic washing liquid. Alternatively, the container cleaning method is characterized in that an acidic cleaning liquid is used and the cleaning liquid is circulated to generate fine bubbles in the generated flow of the cleaning liquid.   The container cleaning method according to claim 9, wherein the container is a glass container, a plastic container, a coated glass container, or a coated plastic container.   11. The container cleaning method according to claim 9, wherein the fine bubbles are bubbles having a number average diameter or a median diameter of 50 μm or less.

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