JPS5831533B2 - You can read the full story here. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for inspecting flexible containers (including semi-rigid containers).

Conventionally, various methods have been used to detect pinholes, test the strength of the seal, and perform destructive tests on containers of this type. However, if there is a part where the seal is incomplete, an airtight leak will occur in that part, so this method is not practical.

Drop tests have also been conducted, but there are problems in quantifying strength, and it cannot be said to be a method suitable for rational quality control.

On the other hand, when a can tester used to test hard containers such as canned goods is applied to a flexible container, it is necessary to maintain airtightness between the pipe and the insertion port of the pipe for introducing pressure medium into the container. Moreover, since the material of the container is flexible and weak, the vicinity of the insertion opening is destroyed, making accurate inspection impossible.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks and to provide an inspection method that allows flexible containers to be inspected extremely easily and accurately, and that also allows the strength of the containers to be quantified.

Examples of the present invention will be described below.

The method of the present invention uses an inspection apparatus as shown in the accompanying drawings.

In FIG. 1, reference numeral 1 denotes an inspection box for storing a container 2 to be inspected, and a pressure plate 4 deflected downward by a coil spring 3 is provided inside this box.

This pressure plate 4 is provided with a pressure medium supply hollow needle 5 that passes through the center thereof and has a tip projecting downward.

The needle 5 may be fixed to the pressure plate 4 or may be slidable up and down, so that an airtight state can be maintained in either case.

Reference numeral 6 denotes a sealing member such as an O ring fixed to the lower surface of the pressure plate 4, which presses against the container 2 to be inspected surrounding the needle 5, so that the pressure medium supplied from the needle 5 is not exposed to the outside. This is to prevent leakage.

Further, 8 is a support plate for the spring 3, 9 is a flexible hose, 1
0 is a pressure gauge, 11 is an adjustment valve, and 12 is an on-off valve.

The sealing member may be constructed integrally with the pressure plate 4 as shown in FIG.

Alternatively, the support plate 8 may be placed on the top surface of the box 1 and fixed with the clamp 13.

One end of the spring for deflecting the pressure plate 4 downward may be fixed to the bottom surface of the box 1 as shown in FIG. 3, or may be fixed to the side wall as shown in FIG. 4.

In short, any structure may be used as long as the pressure plate 4 can apply downward pressure.

Furthermore, in addition to coil springs, various elastic means such as sponge, rubber, and air cylinders can be used.

The inspection apparatus used in the method of the present invention has the above-mentioned configuration, and the inspection procedure will be explained next.

First, as shown in the figure, the inspection box 1 was filled with enough water to completely submerge the sealed container 2 to be inspected, then the container to be inspected was placed in the box 1, and the pressure medium supply needle 5 was inserted into the container to be inspected. After adjusting the flow rate adjustment valve 11 and opening the valve 12, a pressure medium such as air is introduced into the container to be inspected to apply internal pressure.

At this time, if there is a defect in the seal of the container to be inspected, bubbles will appear in the water.

If there is no defect in the seal, further pressurization will gradually deform the container to be inspected, leading to destruction of the seal.

The pressure at this time is read with the pressure gauge 10.

Further, if the strength of the seal portion is greater than the material strength of the container to be inspected, material destruction will occur, and the pressure at that time is similarly read by the pressure gauge 10.

Even if the container is deformed by the pressure medium during the above inspection, since the pressure plate 4 is deflected by the spring, the sealing member 6 remains in close contact with the container, and the pressure medium does not leak outside.

Therefore, breaking strength etc. can be measured extremely accurately, and pinholes etc. can be detected more frequently.

Note that depending on the testing method, there may be cases where the box 1 does not need to be filled with water.

Alternatively, the container 2 may be brought into pressure contact with the pressure plate 4 by elastic means.

FIG. 5 is a graph showing test results using a conventional can tester and the method of the present invention.

For the test, an aluminum foil container with an internal volume of 125 cubic meters was filled with 80 liters of water, and the water was heated to 260°C x 20 KP/ryn.
Using sealed containers whose lids were completely sealed at 3×1 sec, a destructive test was conducted on 5 seals of 100 containers each.

As shown in A in the figure, when testing is performed using a conventional can tester, the bursting pressure varies widely due to damage to the container and leakage of airtightness near the insertion point of the pressure medium supply needle.
In contrast, as shown by B in the figure, the method of the present invention has a normal distribution, indicating that it is a reasonable testing method that guarantees the significance of the measured values.

As described above, according to the method of the present invention, flexible containers can be inspected extremely easily and accurately, and accurate numerical ratios of test results can be obtained, making it extremely effective when applied to quality control, etc. be.

[Brief explanation of drawings]

1 to 4 are cross-sectional views of the inspection apparatus used in the method of the present invention, and FIG. 5 is a graph comparing the inspection results of the conventional method and the method of the present invention. In the figure, 1 is an inspection box, 2 is a container to be inspected, 3 is a coil spring, 4 is a pressure plate, 5 is a pressure medium supply needle, and 6 is a sealing member.

Claims (1)

[Claims] 1 Press the flexible sealed container against the pressure plate,
A hollow needle for pressure medium supply that passes through the pressure plate in an airtight manner is pierced into the container, and while a sealing member provided on the pressure plate surrounding the hollow needle is hermetically pressed against the container, the hollow needle is A method for inspecting a flexible container, comprising supplying a pressure medium into said container via a pressure medium.