JP4925188B2 - Inspection method for defective sealing of bag-like containers - Google Patents

Description

  The present invention is to inspect a sealing failure at a seal portion formed on a peripheral edge of a container by adhering stacked sheet members to a so-called pouch that is filled and sealed with contents. In particular, the present invention relates to a sealing failure inspection method for bag-like containers that can be inspected in a non-contact manner for a large number of containers that are continuously conveyed.

  As one type of bag-like containers called pouches, using sheets with inner surfaces that can be bonded by heat sealing or the like, the sheets that are overlapped so that the inner surfaces are in contact with each other at the periphery of the container Filling port left unbonded after part of the container (for example, the central part of one of the four sides) is left unattached as a filling port and the peripheral edge of the container is bonded by heat sealing or the like to form a bag It is conventional to fill and seal the contents inside the bag-like container by filling the contents into the bag-like container and then finally bonding the unbonded filling port by heat sealing or the like. It is done from.

  However, in the case of a bag-like container in which a seal portion is formed on the peripheral edge of the container by adhering such superposed sheets, when the unadhered filling port is finally adhered after filling the contents There is a possibility that a defective seal may occur at the portion due to the contents or the like adhering to the filling port. Therefore, it is necessary to inspect the sealability (presence or absence of leakage) at the seal portion for all products in the bag-like container after filling and sealing.

Regarding inspection of such a bag-like container, the following Patent Document 1 discloses a flexible pouch leakage inspection machine by a high frequency high voltage application method, and as an inspection method using such an inspection machine, “An insulating flexible pouch filled with and sealed with conductive contents is interposed between the electrodes, and the voltage applied between the electrodes is set in advance to a value that does not destroy the insulating flexible pouch. If there is a pinhole, in the inspection method using a high frequency high voltage application method that detects a pinhole by a discharge current that flows through the circuit by flashing, pressurizing the pouch for a predetermined time before the pinhole inspection "A flexible pouch inspection method characterized by the above" is disclosed.
JP 2000-35373 A

  By the way, according to a conventionally known inspection method as described above, a bag-like container in which a seal part is formed on the peripheral part of the container by bonding the overlapped sheets is used in the sealed part of the filled and sealed container. In the conventional well-known inspection method as described above, each container needs to be pressed in advance by a pressurizing device, and is installed between both electrodes. Since it is necessary, there is a problem that it takes a lot of time to inspect all the many containers continuously conveyed by a conveyor or the like.

  In addition, when the filled and sealed product is sterilized by heating and then cooled with cooling water, it is necessary to dry the surface of the container completely after cooling. May occur, and even a product having no problem may be treated as a defective product.

  An object of the present invention is to solve the above-described problems. Specifically, for a bag-like container in which a seal part formed by adhesion between sheets is formed at the peripheral part of the container, a large number of containers are transported. It is an object of the present invention to make it possible to inspect 100% of the defects of the seals in the respective containers without fail while they are being conveyed.

  In order to solve the above-mentioned problems, the present invention is a method for inspecting a defect in a seal part of a bag-like container in which a seal part is formed on the peripheral part of the container by bonding the stacked sheets to each other. A wireless tag having a resonance circuit comprising an antenna coil and a capacitor having a predetermined electric circuit constant and capable of obtaining a predetermined resonance frequency is provided in a seal portion between the stacked sheets, and the wireless tag If the return electromagnetic wave cannot be detected by detecting the return electromagnetic wave having a predetermined resonance frequency transmitted from the wireless tag in response to the transmitted electromagnetic wave, the seal portion is defective. It is characterized in that it is determined that there is.

  According to the sealing failure inspection method of the bag-like container of the present invention as described above, when there is no problem in the seal part where the sheets are bonded to each other, an electromagnetic wave having a predetermined resonance frequency is transmitted to the wireless tag. The antenna coil generates an amount of electric charge corresponding to the resonance frequency, the capacitor stores the electric charge, and returns an electromagnetic wave having a predetermined resonance frequency received by the antenna coil with the energy.

  On the other hand, when there is a problem with the seal part where the sheets are bonded together, the foreign matter such as contents contacts the antenna coil, the inductance of the antenna coil changes, and the impedance that is a predetermined electric circuit constant changes. As a result, the wireless tag cannot resonate with an electromagnetic wave having a predetermined resonance frequency, and therefore, a return electromagnetic wave having a predetermined resonance frequency is not transmitted.

  Therefore, an electromagnetic wave having a predetermined resonance frequency is transmitted to each of the radio tags of a large number of bag-like containers being conveyed by a conveyor or the like, and a return electromagnetic wave having a predetermined resonance frequency is returned from the radio tag in response to the transmitted electromagnetic wave. By detecting, when the return magnetic wave cannot be detected, it can be determined that the seal portion where the sheets are bonded is defective. As a result, while a large number of bag-like containers are being conveyed by a conveyor or the like, it is possible to easily inspect all of the defective seals in each container without contact.

  Of the sealing part of the bag-like container, the part of the filling port to be bonded lastly after filling the contents in the container is the part most likely to cause a seal failure due to adhesion of the contents etc. However, by forming only the antenna coil portion of the wireless tag in this portion, it is possible to reliably detect a defective seal portion at that portion. In addition, the antenna coil and the capacitor constituting the wireless tag are thinly formed by printing, so that the seal property at the seal portion is not affected and a good seal portion can be maintained.

  Furthermore, when there is a problem with the seal part and a return electromagnetic wave with a predetermined resonance frequency cannot be detected, there are various types of resonance circuits for wireless tags whose impedance has changed due to contact with foreign matter such as liquid contents. By transmitting an electromagnetic wave having a frequency to cause the wireless tag to resonate, the degree of failure at the seal portion can be determined by the magnitude of the frequency of the transmitted electromagnetic wave from which the resonance is obtained.

  About the bag-like container in which the seal part by the adhesion of sheets is formed in the peripheral part of the container, while transporting a large number of containers on a conveyor, etc., it is ensured that the seal part in each container is defective without contact. The objective of enabling 100% inspection, as specifically shown in the following embodiment as the best mode, is a resonant circuit comprising an antenna coil and a capacitor having a predetermined electric circuit constant to obtain a predetermined resonance frequency. The wireless tag formed with is provided in a seal portion between the stacked sheets, and an electromagnetic wave having a predetermined resonance frequency is transmitted to the wireless tag, and a predetermined resonance is returned from the wireless tag according to the transmitted electromagnetic wave. By detecting a return electromagnetic wave having a frequency, the seal part is determined to be defective when the return electromagnetic wave cannot be detected.

The bag-like container to which the sealing failure inspection method of the present invention is applied is a so-called pouch in which contents are filled and sealed, and the sheet for forming such a bag-like container The layer structure is not particularly limited as long as it does not use a metal foil such as an aluminum foil or the like, and the surface on the inner surface side of the container can be adhered by heat sealing or the like. May have a single-layer structure or a multilayer structure in which an EVOH resin or a polyamide resin excellent in gas barrier properties is sandwiched. In addition, about the thickness of a sheet | seat, about 100-120 micrometers is suitable for a total thickness.
An embodiment of the seal failure inspection method of the present invention applied to a bag-like container called a pouch made of such a sheet will be described below.

  With respect to the bag-like container to which the sealing failure inspection method of the present invention is applied, in this embodiment, two long rectangular sheets having the same shape are used as shown in FIG. The side walls 2 and 3 on the front side and the back side are overlapped so that the heat-sealable surfaces face each other, and the connecting portions of the side walls 2 and 3 are folded inward so After the folded bottom wall portion 4 is sandwiched between the side wall portions 2 and 3 at the lower end portion of the container, as shown in FIG. 3 (B), a portion along the peripheral edge portion of the side wall portions 2 and 3 ( The outer part of the sheet is heat-sealed and the parts 2, 3 and 4 of the sheet are heat-bonded to each other on the inner surface of the container, so that the seal part 1a is formed at the peripheral part of the container. A single bag-like container 1 is formed.

  In the formation of such a bag-like container 1, when heat-sealing the part along the peripheral edge of the container, the center part of the upper end of each side wall part 2, 3 is a filling port for filling the contents. No. 5 is left unbonded without being heat-sealed. After filling the bag-like container with the contents from the unbonded filling port 5, the unbonded portion of the filling port 5 is heat-sealed. By heat bonding and sealing, the product in a container in which the contents are filled and sealed inside the bag-like container is obtained.

  In addition, about the seal | sticker part 1a along the peripheral part of a container, although each side wall part 2 and 3 and the bottom wall part 4 will be heat-sealed in the lower end part of a container, in this Example, the side wall part 2 , 3 and the bottom wall portion 4 are heat-sealed so that the upper end shape of the seal portion (the shape indicated by the two-dot chain line in the bottom wall portion 4) is a boat shape when viewed from the front side.

  The bottom wall 4 has a semi-circular removed portion 4a (that is, the bottom wall 4 of a single sheet) on both sides of the bottom wall 4 when viewed from the front side in a state of being folded in two. In this state, a total of four removed portions 4a) are formed on the left and right sides of the two folded portions, and the side wall portions 2 and 3 are directly heat-sealed in the removed portion 4a. Yes. As a result, when the bottom is widened to stand up the bag-like container 1, the bottom of the bag-like container 1 does not spread in a planar shape but spreads in a boat shape in plan view.

  Moreover, in the upper end part of the container whose central part is the filling port 5 of the unbonded part, as a spout for taking out the filled and sealed contents in one corner part (left corner part), An unbonded portion that extends toward the outer edge of the corner portion and does not reach the outer edge of the corner portion is formed as a pouring hook portion 6, and a cutout for cutting off the corner portion is formed on both sides of the corner portion. The notches 7 and 7 are formed, and the container is opened at the portion of the pouring bar 6 by cutting off the corners across the notches 7 and 7.

  By the way, in the bag-like container 1 in which the respective parts 2, 3 and 4 of the sheet are thermally bonded by heat sealing at the peripheral part of the container as described above, in the present embodiment, on the inner surface of one side wall part 2 of the sheet, the other As shown in FIG. 1, a conductive antenna coil is formed along the entire periphery of the container peripheral portion with respect to the portions (the seal portion 1a and the filling port 5) to be bonded to the side wall portion 3 and the bottom wall portion 4 of the container. In order to make this antenna coil 10 a resonant circuit, a conductive plate portion 8 and an insulating chip are formed in a part of the peripheral portion of the container and in the vicinity of the line end portion of the coil wire of the antenna coil 10. 9 and the antenna coil 10 form a capacitor 11.

  In this embodiment, the antenna coil 10 is printed with resin conductive ink mixed with metal powder that is harmless to the human body such as iron powder, silver powder, and gold powder. Specifically, the antenna coil 10 is a quadruple coil. It is printed, the coil wire width is about 0.4 mm, the interval between each coil wire is about 0.8 mm, the length of the short side at the outer edge of the antenna coil 10 is about 74 mm, the length of the long side , About 116 mm, and its inductance exhibits a value of 8.86 μH.

  Further, the capacitor 11 is also formed by printing. As shown in FIG. 2, a part of the peripheral edge of the container (the seal portion between the side wall portion 2 and the bottom wall portion 4) is formed outside the antenna coil 10. One coil wire end portion on the edge side is connected to the conductive plate portion 8, and the entire coil width of the antenna coil 10 excluding this coil wire end portion is opposed to the conductive plate portion 8 in a state of being blocked by the insulating chip 9. Thus, this portion is formed in the capacitor 11, and the role of the storage battery, which is an energy source for resonating the electromagnetic wave received by the resonance circuit composed of the antenna coil 10 and returning the electromagnetic wave of the resonance frequency, is achieved. It is done.

  Specifically, in this embodiment, the conductive plate portion 8 is first printed with conductive ink on the inner surface of one side wall portion 2, and a part of the conductive plate portion 8 is left on the conductive plate portion 8. The insulating chip 9 is printed with resin ink so as to cover the portion 8, and the antenna coil 10 is formed of four coil wires with conductive ink along the entire periphery of the peripheral portion of the side wall portion 2 from above. Is printed, and three of the four coil wires except one of the end portions on the outer edge side are passed over the insulating chip 9, and one of the end portions of the coil wire on the outer edge side is passed through the conductive plate. By passing over the exposed portion of the portion 8 (the portion not overlapping the insulating chip 9), only one end portion of the coil wire on the outer edge side of the antenna coil 10 is connected to the conductive plate portion 8. In such a wireless tag, the capacitance of the capacitor 11 has a value of 5.3 pf, and the resonance frequency is 33.9 MHz.

  In this way, the resonance circuit composed of the antenna coil 10 and the capacitor 11 is formed in advance on the side wall portion 2 of the sheet by printing in advance, whereby the respective portions 2, 3, and 4 of the sheet are heat sealed to form the bag-like container 1. Then, after filling the contents into the container from the filling port 5 which is the non-bonded portion, when the non-bonded portion of the filling port 5 is heat-sealed and sealed, An antenna coil 10 and a capacitor 11 (conductive plate portion 8, insulating chip 9, antenna coil 10) are provided on the seal portion (between the side wall portions 2 and 3 and between the side wall portion 2 and the bottom wall portion 4). A wireless tag having a resonance circuit consisting of the above is provided. In addition, only the antenna coil 10 by the quadruple coil wire is formed in the non-bonded portion (heat-sealed after filling the contents) which becomes the filling port 5 of the bag-like container 1 without forming the capacitor 11. ing.

  In the sealing failure inspection method of the present embodiment using the bag-like container provided with the wireless tag as described above, a predetermined amount is applied to the bag-like container that is continuously conveyed in a state where the contents are filled and sealed. When an electromagnetic wave having a resonance frequency is transmitted, a return electromagnetic wave having a predetermined resonance frequency returned from the wireless tag according to the transmitted electromagnetic wave is detected, and when the returned magnetic wave is detected, there is no problem with the seal portion. It is judged that there is not.

  Specifically, in this embodiment, an electromagnetic wave having a resonance frequency of about 33.9 MHz is transmitted to the wireless tag by a dip meter, and an amount of electric charge corresponding to the resonance frequency is generated in the antenna coil 10, and the capacitor 11 transfers the electric charge. When the electromagnetic wave having a resonance frequency of about 33.9 MHz received by the antenna coil 10 is returned with the energy stored therein, and the returned electromagnetic wave is received by the dip meter, it is determined that there is no problem in the seal portion. is doing.

  On the other hand, if there is a problem with the seal portion and foreign matter such as contents are in contact with the antenna coil 10, the inductance of the antenna coil 10 of the wireless tag changes and the impedance changes accordingly. Since the resonance circuit of the tag does not respond to the electromagnetic wave of the resonance frequency and the electromagnetic wave of the predetermined resonance frequency is not detected even if the electromagnetic wave of the predetermined resonance frequency is transmitted, the seal part is defective in that case. Judging that there is.

  According to the sealing failure inspection method for the bag-like container of the present embodiment as described above, first, the antenna coil 10 and the capacitor 11 (the conductive plate portion 8 and the insulating chip 9) constituting the wireless tag provided in the bag-like container. Since both are formed thin by printing, even if they are provided in the seal portion between the stacked sheets, the seal at the seal portion is hardly affected, with little effect on the sealing performance at the seal portion. The property can be maintained well.

  And, for each of a large number of bag-like containers transported by a conveyor or the like, an electromagnetic wave of a predetermined resonance frequency is transmitted to the wireless tag of each container, and the return electromagnetic wave is detected, thereby the seal portion of each container Inspecting for defects at the seal part of each container easily and non-contactly while a large number of bag-like containers are being transported continuously by a conveyor, etc. Can do.

  If there is a problem with the seal part and a return electromagnetic wave with a predetermined resonance frequency cannot be detected, and you want to separate the level of defects (defects) at the seal part, a bag-like container rejected as a seal defect by inspection Resonance is obtained by transmitting electromagnetic waves of various frequencies to cause resonance in the wireless tag to the resonance circuit of the wireless tag whose impedance has changed due to contact with foreign matter such as contents. The degree of failure at the seal portion can be easily determined according to the frequency of the transmitted electromagnetic wave.

  That is, when the number of shorts due to the contact of foreign matter such as contents among a plurality of coil wires (four in the embodiment) in the width direction of the antenna coil 10 increases, the frequency of electromagnetic waves that resonate and return increases. Because of the nature, it can be determined that the higher the frequency of the electromagnetic wave that is resonated and returned, the greater the degree of defects (seal failure) at the seal portion due to contact with foreign matter such as contents. Specifically, when the resonance frequency is slightly higher than the predetermined resonance frequency, it can be determined that the degree of failure at the seal portion is light, while it is about 1.7 times higher than the predetermined resonance frequency. In the case of a high resonance frequency, about three of the four antenna coils 10 in the width direction are short-circuited, so that it can be determined that there is a serious defect that the contents are likely to leak from the seal portion. .

  As mentioned above, although one Example of the sealing defect inspection method of the bag-shaped container of this invention was described, this invention is not limited only to the above Examples, For example, it implements about a bag-shaped container. It is not limited to one in which each wall (two side walls and one bottom wall) is formed by folding a long sheet as shown in the example. It may be a bag-like container having an appropriate structure such as one having a bottom part or a so-called pillow-type one having no bottom wall part in which the peripheral parts of two side wall parts are heat-sealed. The wireless tag including a resonance circuit composed of a coil and a capacitor is not limited to the one shown in the embodiment, and the number of coil wires in the width direction of the antenna coil (how many coils are used) is appropriately determined. Is selectable Needless to say, the printing order of the conductive plate portion of the wireless tag, the insulating chip, and the antenna coil on the sheet surface may be changed as appropriate, such as printing in the reverse order of the embodiment. Absent.

Front explanatory drawing which shows the state in which the radio | wireless tag is formed in one side wall part in an example of the bag-shaped container to which the test | inspection method of this invention is applied. Sectional drawing of the part along the AA line of FIG. 1 which shows the part of the capacitor | condenser provided in the seal | sticker part between the side wall part and bottom wall part of a container about the radio | wireless tag shown in FIG. 1, (A) a side view showing a state of a sheet before being formed into a bag-like container by heat sealing, and (B) a filling port by heat-sealing the peripheral portion of the container. The front view which shows the state shape | molded in the open bag-like container.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bag-shaped container 1a Seal part 2 Side wall part 3 Side wall part 4 Bottom wall part 4a (Bottom wall part) removal part 5 Filling port 6 Outlet part 7 Cutting part 8 Conductive plate part 9 Insulating chip 10 Antenna coil 11 Capacitor

Claims (4)

  In a method for inspecting a defect in a seal part of a bag-like container in which a seal part is formed on the peripheral part of the container by bonding the overlapped sheets, an antenna coil and a capacitor having a predetermined electric circuit constant And a radio tag having a resonance circuit capable of obtaining a predetermined resonance frequency is provided in a seal portion between the stacked sheets, and an electromagnetic wave having a predetermined resonance frequency is transmitted to the radio tag. In response, by detecting a return electromagnetic wave having a predetermined resonance frequency returned from the wireless tag, when the return electromagnetic wave cannot be detected, it is determined that the seal portion is defective. Seal defect inspection method.   2. The part of the seal portion of the bag-like container, which is bonded last after filling the contents in the container, is formed with only the antenna coil portion of the wireless tag. The sealing defect inspection method for the bag-shaped container as described.   When an electromagnetic wave having a predetermined resonance frequency is transmitted to the wireless tag and a response electromagnetic wave having a predetermined resonance frequency returned from the wireless tag according to the transmitted electromagnetic wave is detected, The resonance circuit is searched for a transmission electromagnetic wave from which resonance is obtained, and the degree of failure in the seal portion is determined by the magnitude of the frequency of the transmission electromagnetic wave from which resonance is obtained. The sealing defect inspection method for a bag-like container according to claim 1 or 2.   In order to form a wireless tag, an antenna coil is formed along the entire circumference of the peripheral portion of the sheet surface with respect to the sheet surface which is the inner surface side of one side wall portion of the bag-like container, and the peripheral portion of the sheet surface The coil wire end portion of the antenna coil is connected to the conductive plate portion at a part of the antenna coil, and the entire coil coil width excluding the coil wire end portion is opposed to the conductive plate portion while being cut off by the insulating chip. 2. A conductive plate portion made of conductive ink, an insulating chip made of resin ink, and an antenna coil made of conductive ink are formed by printing so as to form a capacitor, respectively. 4. A method for inspecting a sealing failure of a bag-like container according to any one of 3 to 3.

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