JP4024412B2 - Liquid leak inspection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
[Means for Solving the Problems]
The present invention relates to how you check in sealed containers, leakage due to incomplete sealing portion.
[0002]
[Prior art]
Various materials are used for the sealed container, particularly in a container that seals the entire surface or a part of the container by heat treatment, such as a liquid container that heats and seals a heat seal part such as paper or film after filling the contents. Has taken a method of leaking the content liquid from the incompletely sealed portion to the outside of the sealed container by holding the filled container in a reduced pressure to a certain value for a predetermined time.
[0003]
However, the conventional technique has the following problems. There is a limit to the reduced pressure value for leaking out the content liquid, and there are time restrictions in terms of inspection processing capacity as well as the reduced pressure holding time. Therefore, there is a limit to the promotion of leakage to incompletely sealed parts. In addition, the liquid leaked from the incompletely sealed portion is sucked into the decompression device side, but the problem is that if the cleaning is not performed, the sucked liquid will contaminate the sealed portion of the liquid container that is the object of inspection at the next inspection. In particular, in a certain number of decompression inspections, a large vacuum that discharges a large amount of liquid by decompression, which can be judged as a leaking container even before inspection, for example, due to a poor seal position in the container to be treated in a certain number. If there is a container that causes a pressure drop, there is a problem that a vacuum pressure drop or an inspection failure occurs due to the apparatus being stopped.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and its object is to provide a container that seals the entire surface or a part of the container by heat treatment, for example, a heat seal part such as paper or film after filling the contents. Liquid that can accurately detect liquid leakage from an incompletely sealed part of a liquid container that heats and seals it, and can prevent contamination due to leaked liquid to other containers, with the impact of intermittent decompression and pressurization. It is an object of the present invention to provide a leakage detection method and a liquid leakage inspection system capable of preventing in advance inspection failures due to vacuum pressure drop or the like.
[0005]
[Means for Solving the Problems]
The present invention has been made to solve the above-mentioned problems , and a decompression means having a check valve for decompressing a sealing surface of a liquid container at a decompression port, and a check valve for pressurizing the sealing surface of a liquid container as a pressurization port. A liquid leak inspection apparatus comprising: a pressurizing means having a head; a head formed with a space between the pressure reducing means and the sealed portion of the liquid container; a means for bringing the liquid container and the head surface into close contact; A liquid leak inspection method,
The pressure reducing means and the pressurizing means are operated alternately, the container sealed portion is alternately depressurized and pressurized, and an impact due to the pressure difference is applied, the breakage of the incompletely sealed portion is promoted to leak the liquid, and the leaked liquid This is a liquid leakage inspection method characterized by detecting the liquid leakage by means of a liquid leakage determination means.
[0006]
Further, in the above method, there is provided a liquid leakage inspection method using a liquid leakage inspection device provided with means for discharging a defective determination product.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Due to the pressure difference between the pressure reducing means and the pressurizing means described above, the pressure reduction and pressurization are freely and intermittently combined multiple times in the sealing portion in accordance with the function of reducing the pressure of the sealing portion. It gives an impact, promotes the breakage of the imperfectly sealed part, and allows it to leak out.
[0008]
The liquid leaking from the imperfectly sealed part is sucked into the decompression side, but there is a check valve at the decompression port, so that the sucked liquid does not contaminate the sealed part of the liquid container to be inspected again and is added. Since the pressure port also has a check valve, it is possible to prevent the leaked liquid from entering.
[0009]
Furthermore, in the above description, even in a processing mode in which a plurality of simultaneous inspections are performed, the leaked liquid that has entered the pressure reducing line is not a separate pipe for each inspection target but a continuous connection pipe. It is possible to prevent contamination from other inspection objects through the pressurizing port during decompression without contaminating other inspection objects, and to easily connect the decompression and pressurization piping lines.
[0010]
In particular, in a multi-process depressurization inspection, a container that generates a large vacuum pressure drop due to a defective seal position or the like is preliminarily removed from an inspection object to be processed by a predetermined number by an inspection and exclusion means by an image processing apparatus. As a result, it is possible to prevent a leak detection failure due to a vacuum pressure drop or an apparatus stop.
[0011]
【Example】
Embodiments of the liquid leakage detection device and the liquid leakage inspection system according to the present embodiment will be described below with reference to the drawings. The object to be inspected here is a cylindrical liquid container 1, and the sealed portion is in the drinking hole on the top surface, so that the top surface is the inspection surface.
[0012]
As shown in FIG. 2, the liquid containers 1A, 1B, and 1C that have finished forming the container and filling the contents pass through an imaging position under the CCD camera 2 under the light source 3 such as an LED in the order of conveyance. The detected image is sent to the computer 4 capable of image determination.
[0013]
Here, as shown in the top view of the container in FIG. 3, the inside of the drinking mouth, which is an incompletely sealed portion, appears as a shadow in the detection image of the liquid container 1B where the drinking mouth is visible due to the positional deviation of the sealed portion. Therefore, it is recognized as a defective product by the determination of the computer 4 by the binarization process, a command is transmitted to the discharge means 5, and the liquid container 1B is excluded during the conveyance to the leak detection device. That is, a leak is determined by detecting a shadow on the inspection surface of the object to be inspected due to the inside of the container being not sealed or due to a displacement of the sealing portion, or due to a defective sealing member.
[0014]
As a means for discharging the defective product in the liquid container, a normal removing means that pushes away in the direction perpendicular to the transport direction is used.
[0015]
Next, as shown in FIG. 1, the liquid containers conveyed to the leak detection device are collected by a certain number and then pressed against the surface of the head 10 having the pressure reducing ports 6 and the pressure ports 7 by the pressing means 11. Adhere the sealed part.
[0016]
In the state where the container is pressed against the head surface by the pressing means 11, the electromagnetic valve 12, 13 is alternately opened and closed several times, thereby changing the container sealed part environment to depressurization and pressurization, and giving an impact due to the pressure difference, Leaks from imperfectly sealed parts. At this time, the vacuum pressure is −65 cmHg or more during decompression, and the atmospheric pressure or more during pressurization. The decompression and pressurization time depends on the environment and the volume of the piping line. In this case, intermittent pulling with a period of 1 second or less is effective.
[0017]
In the above item, when the container sealing portion is arranged or operated in the direction of gravity, the content liquid directly contacts the sealing portion in the container, which is more effective in occurrence of leakage.
[0018]
When liquid leakage occurs from an incompletely sealed part, the check valve 8 prevents pressure from entering other inspected objects at the time of decompression, and the check line 9 reduces pressure at the pressure line. Also prevents leakage liquid from entering other inspected objects.
[0019]
After the liquid leakage is detected, the liquid container is discharged after the pressing means 11 is released, and as shown in FIG. 4, a liquid leakage inspection 14 is performed to detect the presence or absence of leakage liquid in the sealed portion of the liquid container. The inspection itself is a known technique, for example, using a method such as liquid detection by image processing, liquid detection by a contact sensor, detection using ultrasonic waves or infrared rays, etc., and the defective product is recognized by the determination and discharged. The command is transmitted to 15, and the defective sealed liquid container is excluded by the same method as the discharging means 5.
[0020]
In the above example, because the liquid container itself has a shape having a space between the sealing portion of the top surface and the head of the apparatus, the contact surface of the head was a flat surface. When the surface including the portion has a planar shape, it is possible to deal with any sealed container by providing a space with the container sealing portion on the contact surface of the head.
[0021]
【The invention's effect】
According to the present invention, in particular, leakage from an incompletely sealed portion of a liquid container is accurately detected by simultaneous processing of a single unit or a fixed number, and another inspection object due to leaked liquid sucked into a piping line at the time of occurrence of leakage Contamination can also be prevented.
[0022]
After inspecting the sealed part of the inspected object after filling and removing the defective product, leak detection is performed to prevent inspection failures such as vacuum pressure drop and machine stoppage. A liquid leak inspection system that discharges non-defective products can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a liquid leak detection device of the present invention during pressure increase / decrease.
FIG. 2 is a schematic cross-sectional view during image detection before pressurization / decompression of the liquid leakage detection apparatus of the present invention.
FIG. 3 is a top view of the container of FIG.
FIG. 4 is a schematic cross-sectional view during image detection after pressurization / decompression of the liquid leakage detection apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Liquid container 2 ... CCD camera 3 ... Light source, such as LED 4 ... Computer 5 ... Discharge means 6 ... Pressure-reduction port 7 ... Pressurization port 8 ... Check valve 9 ... Check valve 10 ... Head 11 ... Pushing means 12 ... Solenoid valve 13 ... Solenoid valve 14 ... Liquid leak inspection device 15 ... Discharge means

Claims (2)

Depressurization means having a check valve for depressurizing the sealing surface of the liquid container at the decompression port, pressurization means having a check valve for pressurizing the sealing surface of the liquid container at the pressurization port, the depressurization means and the pressurization means, A liquid leakage inspection method using a liquid leakage inspection device including a head in which a space is formed between sealed portions of a liquid container, a means for bringing the liquid container and a head surface into close contact, and a liquid leakage determination means,
The pressure reducing means and the pressurizing means are operated alternately, the container sealed portion is alternately depressurized and pressurized, and an impact due to the pressure difference is applied, the breakage of the incompletely sealed portion is promoted to leak the liquid, and the leaked liquid Is detected by a liquid leak determination means.   The liquid leakage inspection method according to claim 1, wherein a liquid leakage inspection apparatus including means for discharging a defective determination product is used.

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