JPH0562287B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for detecting seal leakage in a bag packaging body for detecting seal leakage in a bag packaging body filled with easily damaged solid foods.

[Technical background of the invention and its problems]

For example, bagged packaging in which perishable solid foods such as potato chips are filled and sealed in packaging bags is used to prevent chemical changes or moisture in the food during the distribution route, or to prevent the generation of bacteria that may adhere to the food. Gas is sealed together with the food, and the opening is hermetically sealed. Increasing the amount of gas sealed together with the food in the packaged bag keeps the packaging bag inflated, and the sealed gas acts as a buffer for the food contained, preventing breakage such as potato chips. It has the effect of buffering the impact of external forces applied to solid foods and preventing them from being damaged.

However, since the food package contains a large amount of gas and is in a swollen state,
When storing in a cardboard box for transportation,
Since the number of bagged packages stored in a cardboard box decreases due to expansion, it is desirable that the amount of gas sealed together with the food is as small as possible;
The amount is limited to an appropriate amount that does not damage solid foods that are easily damaged by external impacts.

The conventional method for detecting seal leakage at the sealed part of a bag package filled with solid food and gas is as follows:
Place the bag package in an airtight test pressure container, fill the airtight test pressure container with gas or liquid, increase the pressure inside the airtight test pressure container, and temporarily control the increased pressure. The presence or absence of seal leakage in the bagged package is detected by detecting the drop in pressure inside the airtight test pressure vessel. It takes a considerable amount of time to inspect
Furthermore, since the inspection process cannot be configured as a continuous process, it is not suitable for inspection on a production line in a factory.

In addition, there is a known technical method that detects seal leakage by applying a special chemical to the seal part of the package and reading changes in the applied chemical layer. This method requires a considerable amount of time to inspect, and is not suitable for 100% inspection on a production line.

Furthermore, a method has been proposed in which seal leakage in bagged packaging is detected using an electrical load sensor, but this testing method does not damage the contents of bagged packaging containing gas. It is difficult to pressurize the bag without causing any damage, and the bag itself deforms after pressurization, making it difficult to distinguish between the pressure drop that occurs and the pressure drop due to gas leakage.
There are problems such as it takes time for the bag itself to stabilize its deformation.

That is, in the above seal leakage inspection method, the fourth
As shown in the figure, the load reduction phenomenon 1 due to bag deformation is likely to occur, even when the bag is in a state where there is no leakage.
The measured load P is not constant, and it is difficult to distinguish between the decrease due to bag leakage and the decrease phenomenon 1 described above. In an attempt to suppress this drop phenomenon 1, when the measurement load P is lowered, minute gas leaks from the bag cannot be detected.
When the measured load P is increased, the above-mentioned decrease phenomenon 1 occurs, and the time required for the pressure decrease P ₁ to reach the decrease phenomenon 1, that is, the deformation of the bag subsides and the load becomes stable, is T.
becomes long, making rapid detection impossible.
According to experiments, the time T required for the pressure drop P ₁ to stop deforming the bag and stabilize the load is 1
In some cases, the bag continued to deform, making measurements impossible.

[Purpose of the invention]

The present invention has been made in view of the above points, and
An object of the present invention is to provide a seal leakage detection method for a bagged package, which accurately and quickly detects minute leaks in a sealed part by pressurizing the bagged package in two stages.

[Summary of the invention]

The method for detecting seal leakage of a bagged package according to the present invention is as follows:
A pressurizing body and a fixing body of a detection device equipped with a pressurizing body and a fixing body of a size corresponding to the dimensions of the bag packaging body filled with a perishable solid food and an appropriate amount of gas. The pressurizing body presses one side of the bagged package with a pressure higher than the set measuring pressure, and then the pressurizing force of the pressurizing body is reduced to a measuring pressure smaller than this pressurizing force. , a load sensor attached to the pressurizing body detects the load of the pressurizing body after depressurization for a certain period of time, and after a certain period of time, the detection signal of the load sensor is compared with the standard setting value, and the seal of the bagged package is calculated. configured to detect leaks.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a system diagram of a method for detecting seal leakage in a bagged package according to the present invention, in which a suitable amount of a perishable solid food 10 such as potato chips is placed in the bagged package to be inspected for seal leakage. It is a bagged package that is filled with gas and sealed in a packaging bag that is heat-sealed on all four sides. The packaging bag for the above bagged package is, for example, PT20μ/PE15μ/Al foil 9μ/PE50μ
Made of laminated film.

The bagged package 11 is placed on a detection table 13 of a detection device 12, and seal leakage is detected by a pressurizing body 14 that is arranged opposite to this detection table 13 and moves up and down. This pressurizing body 14 has a size corresponding to the dimensions of the bagged package, and uniformly presses the entire surface of the bagged package. An electrical load sensor 15 such as a strain gauge is attached to the pressurizing body 14, and the bagged package 11 placed on the detection table 13 is pressurized by a linear drive device 16 such as a servo motor. The linear drive device 16 is controlled by a load control circuit 17.

That is, the linear drive device 16 is connected to the load control circuit 1
After pressurizing the pressurizing body 14 to a preload setting load 19 of a load setting circuit 18 incorporated in the load setting circuit 7, for example, 1000 g, the pressure is reduced to a measurement setting load 20 of, for example, 400 g. The preload setting load value P ₂ is set to a pressure value greater than the measurement setting load value P ₃ .

On the other hand, a load decrease determination circuit 21 is connected to the electrical load sensor 15, and is designed to detect a decrease in load from the detection signal of the electrical load sensor 15, that is, the measured set load value _P3 , as a seal leakage from the bag. I have to.

Therefore, in order to detect seal leakage of a bagged package in which a perishable solid food is filled and sealed together with an appropriate amount of gas, the bagged package 10 is moved to a detection device 12.
The measurement pressure P ₃ is set by the pressure body 14, which is placed between the pressure body 14 and the fixed body 13, and has one side of the bagged package 10 sized corresponding to the size of the bagged package.
Pressure is applied with a pressure P ₂ higher than , and then the pressure P ₂ of the pressure body 14 is set to a measurement pressure smaller than this pressure.
By reducing the pressure to P ₃ , detecting the load g of the pressurizing body at the time of depressurization with the load sensor 15 attached to the pressurizing body, and comparing and calculating the detection signal of this load sensor with the standard setting value, the bagging and packaging process is performed. Detects body seal leakage.

FIG. 2 is a diagram showing changes in measured values when there is no seal leakage in the bag in the method for detecting seal leakage in a bagged package according to the present invention, and FIG. It is a figure which shows the change of the measured value when there is a seal leak in the bag in a detection method.

In the method for detecting seal leakage in a bagged package according to the present invention, if there is no seal leakage in the bag, the second
As shown in the figure, from the preload set value _P2 to the measured load value
The load reduction judgment circuit 21 detects the load after a certain period of time T ₁ (0.5 seconds to 2.0 seconds) has elapsed from the time it stopped at P ₃ .
In this case, the load g is the measured load value.
Not lower than P ₃ .

In the method for detecting seal leakage of a bagged package according to the present invention, if there is a seal leakage in the bag, the third
As shown in the figure, from the preload set value _P2 to the measured load value
The load reduction judgment circuit 21 detects the load after a certain period of time T ₁ (0.5 seconds to 2.0 seconds) has elapsed from the time it stopped at P ₃ .
In this case, the load g is the measured load value.
It is lower than P ₃ . Therefore, this load decrease value P ₄ is produced by the load decrease determination circuit 21.

Note that the numerical values of the preload load and the measurement load are obtained through preliminary experiments based on the material of the bag, the thickness of the material, dimensions, shape, etc. It goes without saying that the bags to be inspected can be similarly detected even if they are placed between an upright detection stand and a pressurizing body.

If the bag is a pillow packaging bag that has a sealing part in the middle part of the rear surface, grooves extending in the vertical and horizontal directions on the pressurizing surface of the pressurizing body are used to accurately detect leakage of gas or liquid from the sealing part. or use the pressure body itself as a lattice-shaped backing plate.

〔Effect of the invention〕

As described above, according to the present invention, a preload higher than the measurement pressure is applied to the bagged package to be measured, and then the pressure is lowered to the measurement pressure. Conformity and deformation due to pressure are promoted, and a constant measurement load can be obtained instantly, making it possible to accurately measure the presence or absence of bag seal leakage. It is possible to quickly measure minute leaks of gas or liquid, and moreover, there is an effect that the solid food, which is easily damaged in the packaged bag, is not damaged during the measurement.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of the method for detecting seal leakage in bags and packaging according to the present invention, FIGS. 2 and 3 are diagrams showing changes in measured values by the method for detecting seal leakage according to the present invention, and FIG. 4 is a diagram showing the conventional method for detecting seal leakage. It is a figure which shows the change of the measured value by the seal leakage detection method of a packed package. 11... Bagged package, 13... Detection stand, 14...
... Pressure body, 15 ... Load sensor, 16 ... Linear drive device, 17 ... Load control circuit, 18 ... Load setting circuit, 19 ... Preload setting load, 20 ... Measurement setting load.

Claims (1)

[Claims] 1. Fixing a bagged package in which a perishable solid food is filled and sealed with an appropriate amount of gas to a pressurizing body of a detection device equipped with a pressurizing body and a fixing body of a size corresponding to the dimensions of the bagged package. The pressurizing body presses one side of the bagged package with a pressure higher than the set measuring pressure, and then the pressurizing force of the pressurizing body is reduced to a measuring pressure smaller than this pressurizing force. Then, a load sensor attached to the pressurizing body detects the load of the pressurizing body after depressurization for a certain period of time, and after a certain period of time, the detection signal of the load sensor is compared with the standard setting value and calculated. A method for detecting seal leakage in a packed package, characterized by detecting seal leakage.