JP2000203539A - Method and apparatus for inspecting paper pack container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inspect leakage of a liq. without breaking a product and to shorten time for inspection by providing a process wherein a paper pack container filled with the liq. is arranged in an inspection container, which is then hermetically closed by closing the inspection container and after the inside of the inspection container is made vacuum to a specified pressure, the vent hole of the inspection container is closed and change in pressure in the inspection container is measured. SOLUTION: In the first process, a paper pack container 12 is arranged in an inspection container 13 and a direction control valve 23 is switched and a cylinder 24 is started and the lid 16 of the inspection container 13 is closed to make an hermetically closed condition. In the second process, a pressure sensor 14 is started to start measurement of pressure in the inspection container and a shut-off valve 18 is switched and air in the inspection container 13 is vented for a specified time by means of a vacuum pump 11 connected with the inspection container 13 to make the inside of the inspection container 10 vacuum. When the vacuum does not reach a specified pressure, inspection of the paper pack 12 is finished. In the third process, whether there exists furthermore a very small gap in the paper pack container 12 being brought to at most the specified pressure is measured by means of the pressure sensor 14 to judge leakage of the liq.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for inspecting a paper pack container, and more particularly to a method for inspecting a paper pack container containing liquor, drinking water, seasonings, and the like, and an inspection thereof. Related to the device.

[0002]

2. Description of the Related Art Paper pack containers are widely used as liquid packaging containers. Paper pack containers filled with drinking water containing water as a main component are often waterproofed with resin materials such as low waterproof plastic film.
In the case of liquor and the like, in order to reliably prevent evaporation of alcohol, those having a structure in which the inside is covered with highly waterproof aluminum foil have been used in many cases. For example, a paper pack container called a gable top type includes a type in which a thin film aluminum layer is sanded on the inner surface of the container and a type in which an aluminum vapor deposition layer is sanded. However, since a composite of aluminum and paper is difficult to recycle, paper pack containers used for alcohols have recently been shifting to those using a resin material instead of aluminum. The paper pack container 50 shown in FIG. 5 is made of one piece of paper with resin processed inside, and after assembly, the seal portions 51 to 53 (for example, the hatched portions in the drawing) are welded. , Increasing the waterproofness. In addition, spout 5
In the case where it has 5, a seal portion 54 is also provided around it.

[0003] In the process of filling a liquid into the paper pack container 50, poor sealing occurs due to the influence of the type and temperature of the liquid, and this may cause liquid leakage. A conventional method for inspecting a liquid leak is as follows. First, a paper pack container filled with liquid is withdrawn from the production line, and cut horizontally at a central portion of the paper pack container, for example, in the vicinity indicated by a two-dot chain line in FIG. Then, the contents are discarded from the cut paper pack container, and the penetrating liquid is filled in each cut container. After a lapse of 2 to 3 hours after filling with the penetrating liquid, it is visually confirmed whether there is any liquid leakage. Defective products were found by such a method.

[0004]

However, the conventional method for inspecting a paper pack container has the following problems. (1) The paper pack container used for the inspection was cut and could not be reused after the inspection. (2) Inspection takes 2 to 3 hours, so if a defective product is found, it may be necessary to discard all of the liquid-containing paper pack containers manufactured from the start of the inspection until the result is known. . (3) The use of a type using an aluminum foil with a high degree of sealing can reduce the number of defective products, but the problems (1) and (2) remain even if the number of defective products is reduced. Also, the problem of difficulty in recycling has not been solved.

[0005] In view of the above, there has been a demand for a simpler and faster inspection method. The present invention has been made in view of such circumstances, can be inspected without destroying the product,
Moreover, an object of the present invention is to provide a method for inspecting a paper pack container and an inspection apparatus for the same, which shorten the inspection time.

[0006]

According to the present invention, there is provided a method of inspecting a paper pack container according to the present invention, which comprises the steps of: Have. First step: The paper pack container is placed in an inspection container, and the inspection container is closed and sealed. Second step: After the pressure in the test container is reduced to a predetermined pressure A,
Close the exhaust port of the test container. Third step: The pressure change in the test container is measured. If the inside of the inspection container is left under a reduced pressure for a certain period of time, if there is a seal failure in the paper pack container, the liquid leaks from the defective portion of the paper pack container. Since the leaked liquid is vaporized in the depressurized container, the pressure in the container increases. By detecting this pressure change, liquid leakage is detected.

Here, in the second step, if the predetermined pressure A is not reached within the predetermined time T even by the deaeration processing from the exhaust port, the processing of the third step is not performed and the paper pack is not processed. Preferably, the inspection of the container is terminated. The predetermined time T refers to the time required to reduce the pressure in the test container to the predetermined pressure A when the paper pack container is a good product, and includes the volume of the paper pack container, the volume of the test container, and the vacuum pump. Determined by performance. In the second step, the air in the inspection container is evacuated only for a predetermined time T, so that when the gap of the seal failure portion of the paper pack container is large, the predetermined pressure A is applied.
It is possible to prevent a large amount of liquid inside the paper pack container from leaking without being decompressed.

It is preferable that the volume of the inspection container is 1.2 to 2.5 times the volume of the paper pack container. At this time, the volume of the inspection container is set to 1.2 times the volume of the paper pack container.
If it is smaller than 2 times, it is difficult to put the paper pack container in and out, and if it is larger than 2.5 times, the time for depressurizing the inside of the container becomes unnecessarily long, and the change in pressure inside the test container becomes small. The number of paper pack containers entering the inspection container is not limited to one, and a plurality of paper pack containers can be inspected simultaneously. The volume of the paper pack container at this time indicates the total volume of the plurality of paper pack containers that enter the inspection container at the same time. The predetermined pressure A is 260 to 660 m
mHg is preferred. When the vacuum is higher than 260 mmHg (a state close to 0 mmHg), the predetermined time T required for bleeding air becomes longer. This is because the time required for inspection becomes longer than necessary. The predetermined pressure A can be expressed as -500 to -100 mmHg on the basis of the atmospheric pressure (760 mmHg). An inspection apparatus for a paper pack container according to the present invention that meets the above object, an inspection container with a lid capable of storing a paper pack container filled with a liquid therein in a sealed state, an actuator for opening and closing the lid of the inspection container, It has a decompression pump connected to the exhaust port of the test container via a valve, a pressure sensor for measuring the pressure in the test container, and a control device for these. With this configuration, the pressure change in the paper pack container can be automatically measured, and the inspection can be performed quickly.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention.

First, the configuration of an inspection apparatus 10 used in an inspection method of a paper pack container according to an embodiment of the present invention will be described. Inspection apparatus 10 shown in FIGS. 1A and 1B
Has a built-in vacuum pump 11 as an example of a decompression pump at the lower part, and an inspection container 13 with an openable and closable lid 16 at the upper part capable of storing a paper pack container 12 filled with liquid therein in a sealed state. have. And the inspection device 10
A pressure sensor 14 for measuring and displaying the pressure in the inspection container 13 and a display panel 15 for displaying start-up confirmation and occurrence of trouble are provided on the right side of the upper part. The details will be described below. As shown in FIGS. 1 to 3, a suction pipe 17 is provided at an exhaust port 13 a at an upper portion of the inspection container 13, and is connected to the vacuum pump 11 via a closing valve 18 which is an example of a valve. Further, since the suction pipe 17 is also connected to the pressure sensor 14, the pressure inside the inspection container 13 can be measured with the closing valve 18 closed. The pressure sensor 14 may be connected to the inspection container 13 independently of the suction pipe 17. Further pressure sensor 1
Reference numeral 4 is connected to the display panel 15 and can display the operating status at the time of startup, the number of generated defects, and the like on a display.

As shown in FIG. 2, a sequencer 21 which is an example of a control device for controlling the devices in the inspection device 10 is installed inside the inspection device 10.
1, connected to the pressure sensor 14 and the shut-off valve. Thereby, the operations of the vacuum pump 11 and the pressure sensor 14 can be efficiently controlled. Also, sequencer 2
1 is provided with an area sensor (not shown) for detecting whether there is an obstacle around the lid 16 when the lid 16 is opened and closed 18 to improve safety. The direction control valve 23 inside the inspection device 10 supplies air from equipment outside the inspection device via an air pipe (not shown). Also, since the direction control valve 23 is connected to the sequencer 21 in a controllable state, an opening / closing mechanism (not shown) that opens and closes the lid 16 of the inspection container 13 via the cylinder 24 (actuator) (for example, a link mechanism using a cam) ) Can be activated. As shown in FIG. 3, the lower container 19 of the inspection container 13
Is provided with a space in which the paper pack container 12 can be stored, in which the paper pack container 12 can be installed.
A packing 20 made of rubber, for example, is provided around the space of the lower container 19. Thereby, when the lid 16 is covered, the inside of the inspection container 13 can be sealed. It is desirable that the volume of the inspection container 13 be adjusted to be about 1.2 to 2.5 times the volume of the paper pack container 12. By adjusting within this range,
The paper pack can be easily taken in and out, the time for bleeding the air can be shortened, and paper pack containers having different sizes can be inspected by the same inspection container 13. Also, since the suction pipe 17 is provided on the upper lid 16,
Even if a large amount of liquid leaks from the paper pack container, it is difficult to enter the suction pipe 17.

Next, a method of inspecting a paper pack container will be described. First, perform initial preparations before performing an inspection.
As shown in FIGS. 2 and 4, the breaker is turned on (S
1) Turn on the power of the inspection apparatus 10 and prepare for operation (S
2), the vacuum pump 11 is operated (S3). Inspection is started after confirming that this operation is stable. The operation from here on is automatically performed by the sequencer 21 except for the installation and removal of the paper pack container 12 filled with liquid.

In the first step, first, the paper pack container 12 is placed in the inspection container 13 (S4), and after confirming safety, the direction control valve 23 is switched to activate the cylinder 24 (S4).
5). At this time, the direction in which the paper pack container 12 is installed is as follows.
As shown in FIG. 3, it is preferable that the spout faces downward. This is because the sealing portion is brought into contact with the liquid inside the paper pack container 12 to promote liquid leakage. Inspection device 10
An obstacle is determined by the area sensor provided in (6). The area sensor is, for example, an optical sensor. When the vicinity of the inspection device 10 is shielded from light, it is determined that there is an obstacle, and an alarm device (for example, by sound or light).
Is activated to call attention and keep the device lid 16 from closing. If the area sensor is not shielded from light, the direction control valve 23 is switched to drive the cylinder 24 to close the lid 16 of the inspection container 13 to make it sealed (S7). In the second step, the pressure sensor 14 is activated,
After the pressure measurement in the inspection device 10 is started, the closing valve 18
Is switched, and air in the test container 13 is evacuated for a predetermined time T by the vacuum pump 11 connected to the test container 13,
The pressure inside the inspection device 10 is reduced (S8). Thereafter, after a predetermined time T, the exhaust port 13a is closed by the closing valve 18, and the pressure in the test container 13 is measured to check whether the pressure is equal to or lower than the predetermined pressure A. In the present embodiment, the predetermined pressure A is 260 to
660 mmHg. Note that if the equilibrium time of about 10 seconds is provided before the pressure is measured after the closing valve 18 is closed, the measurement can be performed stably. In this case, if the pressure A does not reach the predetermined pressure A within the predetermined time T even after the deaeration process through the exhaust port 13a, the inspection of the paper pack container is terminated without performing the process of the third step to be performed next (S9). ).

When the paper pack container 12 has a bad seal and a large gap is opened, the pressure inside the paper pack container 12 decreases with the pressure reduction around the paper pack container 12. The liquid inside the paper pack container 12 evaporates into a gas under the reduced atmospheric pressure, but when the liquid turns into a gas, the pressure increases because the volume increases. That is, if the vacuum pump 11 is set to be operated until the pressure in the test container 13 becomes equal to or lower than the predetermined pressure A, the depressurization in the test container 13 does not progress until the evaporation of all the liquids is completed. The evaporating liquid may be sucked by the vacuum pump 11 and the vacuum pump 11 may be damaged. In order to prevent this, the closing valve 18 is opened only for a minimum required time (predetermined time T), so that the evaporation of the liquid when there is a defective product having a large gap can be minimized. .

In the third step, a check is made to see if the paper pack container 12 which has fallen below the predetermined pressure A in the second step has no smaller gap. Specifically, after maintaining the test container 13 in a decompressed state for a certain period of time (for example, about 30 seconds to 60 seconds) (S10), the pressure in the test container 13 is measured, and the pressure in the test container 13 is not higher than a predetermined pressure A Is inspected to determine a liquid leak (S
11). The liquid leakage can also be determined by continuously or intermittently measuring the pressure change during this time. If there is a seal failure in the paper pack container 12 that is not found in the second step and a small gap or hole is open,
Even if the pressure around the paper pack container 12 is reduced, the paper
The pressure inside 2 does not change rapidly. However, as time passes, the liquid inside the paper pack container 12 gradually leaks from the gap to the outside, and evaporates into a gas in the depressurized test container 13, whereby the volume increases and the inside of the test container 13 increases. Is increased and exceeds a predetermined pressure A. Since this can be detected by the pressure sensor 14, it can be easily measured. Further, the result data can be stored in the microcomputer and used for the cause analysis of the defective product.

After the completion of the third step, the direction control valve 23 is switched, and the cylinder 24 is operated to operate the lid 1 of the inspection container 13.
6 is opened (S12), and the paper pack container 12 is taken out (S12).
13). If the paper pack container 12 is non-defective, it can be used as a product, so that there is no waste.

By performing the measurement by such a method, the measuring time, which conventionally took 3 to 4 hours since the leak was measured under the atmospheric pressure, is reduced by reducing the pressure and forcibly promoting the leak. The measurement can be performed in less than one minute, enabling a significant reduction in time. Since the inspection time is short, it is faster to detect a defective product and feed it back to the production line, thereby increasing production efficiency. As mentioned above, although one Embodiment of this invention was described, this invention is not limited to said Embodiment,
For example, the installation of the paper pack container 12 in the inspection apparatus 10 can be automated using, for example, a robot or the like, and the inspection apparatus 10 can be installed in a production line to perform 100% inspection. Furthermore, a plurality of test containers 13 can be connected and measured simultaneously. In this case, it is desirable to use the air tank 25 as shown by a two-dot chain line in FIG. By using the air tank 25, the use time of the vacuum pump 11 can be reduced, and the prescribed time required for bleeding air can be shortened. Further, the paper pack container 12 in the inspection container 13 may expand and deform due to the reduced pressure.
In this case, a spring, a baffle plate or the like (not shown) may be provided in a gap between the paper pack container 12 and the inspection container 13 so that the shape of the paper pack container 12 is suppressed so as not to be deformed. As a result, the difference between the internal pressure of the paper pack container 12 and the pressure within the inspection container 13 increases, and leakage of the liquid can be promoted, so that measurement can be performed in a shorter time.

[0018]

According to the method for inspecting a paper pack container according to the first to fourth aspects, the inside of the inspection container is depressurized by closing the inspection container and the pressure change in the inspection container is measured. It is possible to reduce the time required for the inspection by shortening the time until the liquid leaks. Further, since the pressure change is measured, even a seal failure that cannot be found visually can be easily detected, and the inspection can be performed without breaking the product. In particular, in the paper container inspection method according to the second aspect, in the second step, if the pressure A does not reach the predetermined pressure A within the predetermined time T, the inspection is terminated. When the size is large, it is possible to prevent a large amount of liquid inside the paper pack container from leaking.
Further, in the method for inspecting a paper pack container according to the third aspect, the volume of the inspection container is set to 1.2 to the volume of the paper pack container.
Since it is 2.5 times, the paper pack container can be easily taken in and out, and the time for depressurizing the inside of the container can be shortened. In the method for inspecting a paper pack container according to the fourth aspect, since the predetermined pressure A is set to 260 to 660 mmHg, the predetermined time T required for bleeding air can be shortened, and the liquid leaks from the inside of the paper pack container. , Thereby reducing the time required for the entire test. In the paper pack container inspection device according to the fifth aspect, since the pressure sensor for measuring the pressure in the inspection container is provided, the inspection can be performed quickly without breaking the product.

[Brief description of the drawings]

1A and 1B are a side view and a front view, respectively, of a paper pack container inspection device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an internal structure of the inspection device.

FIG. 3 is a perspective view of an inspection container provided in the inspection apparatus.

FIG. 4 is a flowchart of the inspection method.

FIG. 5 is a perspective view of a paper pack container according to a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Inspection apparatus 11 Vacuum pump (decompression pump) 12 Paper pack container 13 Inspection container 13a Exhaust port 14 Pressure sensor 15 Display panel 16 Cover 17 Suction pipe 18 Shut-off valve (valve) 19 Lower container 20 Packing 21 Sequencer (Control device) 23 Direction Control valve 24 Cylinder (actuator) 25 Air tank

Claims (5)

[Claims] 1. A method for inspecting a paper pack container filled with a liquid for leakage of paper, comprising the following steps. First step: The paper pack container is placed in an inspection container, and the inspection container is closed and sealed. Second step: After the pressure in the test container is reduced to a predetermined pressure A,
Close the exhaust port of the test container. Third step: The pressure change in the test container is measured. 2. The method for inspecting a paper pack container according to claim 1, wherein in the second step, when the predetermined pressure A does not reach the predetermined pressure A within a predetermined time T even after degassing from the exhaust port. The inspection of the paper pack container is completed without performing the three processes. 3. The paper container inspection method according to claim 1, wherein the volume of the inspection container is 1.2 to 2.5 times the volume of the paper container. Inspection method for pack containers. 4. The method for inspecting a paper pack container according to claim 1, wherein the predetermined pressure A is 26.
A method for inspecting a paper pack container, wherein the pressure is 0 to 660 mmHg. 5. An inspection container with a lid capable of storing a paper pack container filled with a liquid therein in a sealed state, an actuator for opening and closing the lid of the inspection container, and a valve at an exhaust port of the inspection container via a valve. An inspection apparatus for a paper pack container, comprising: a decompression pump connected thereto; a pressure sensor for measuring a pressure in the inspection container; and a control device for these.