Gas concentration measurement method for pillow packaging bags

Abstract

To provide a gas concentration measurement method for a pillow packaging bag, configured to ensure a sufficient irradiation time of laser light to a pillow packaging bag in an ambient air atmosphere to improve the measurement accuracy.SOLUTION: A pillow packaging machine includes a conveyance device that conveys a cylindrical packaging material 1, a side sealing device that seals the packaging material 1 in a width direction to continuously form a pillow packaging bag, and a laser-type gas concentration measurement device that measures gas concentrations of a specific gas remaining in the pillow packaging bag. The laser-type gas concentration measurement device includes a laser generation unit that emits a laser beam having a specific wavelength, and a laser receiving unit that receives the laser beam transmitted through the pillow packaging bag gas-replaced and sealed. A moving speed of the laser generation unit and the laser receiving unit is synchronized with a conveyance speed of the pillow packaging bag so that the laser generation unit and the laser receiving unit can be stopped relative to a measuring point provided in the pillow packaging bag.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gas concentration measurement method for measuring the gas concentration of a specific gas remaining in a packaging space of a pillow packaging bag having a packaging space partitioned by sealing a long cylindrical packaging material at a predetermined interval. [Background technology]

[0002] The shrink packaging device disclosed in Patent No. 3129463 processes and forms a continuously drawn strip of film into a cylindrical packaging material, stores the packaged item in the packaging material, and seals both ends of the packaged item with an end seal device. A packaging bag in which both ends of the packaged item stored in such a cylindrical packaging material are sealed is called a pillow packaging bag. In the above shrink packaging device, when sealing with the end seal device, gas replacement is performed by filling the inside of the packaging bag with nitrogen gas or the like. This makes it possible to maintain a high quality of the packaged item.

[0003] However, if a specific gas, such as oxygen gas, remains in a pillow packaging bag after gas replacement with nitrogen gas or the like at a specified concentration or higher, the specific gas will cause the quality of the packaged goods to be impaired. Therefore, the residual concentration of the specific gas remaining in the pillow packaging bag must be inspected, and if it is at or above the specified concentration, it must be removed from the packaging process on the packaging machine as a defective product. In the past, product inspections of this type were carried out by random sampling, in which a specified number of samples were selected from the multiple pillow packaging bags produced. However, while this type of random sampling could accurately test the residual gas concentration of one sample, the inspection accuracy was poor when viewed as an inspection of all the pillow packaging bags produced from a single strip of film, and the inspection only provided a statistical estimate of the occurrence rate of defective products.

[0004] In this regard, the gas concentration measurement method in a packaging machine disclosed in JP 2012-208126 A uses a laser type gas concentration measurement device consisting of a laser generating unit having a function of irradiating a specific gas with a laser light of a specific wavelength by a transmitter, and a laser receiving unit having a function of receiving the laser light emitted from the transmitter and passing through the specific gas by a receiver, measuring the intensity of the laser light absorbed by the gas, and outputting the concentration of the gas from the intensity, and a gas purge chamber of the laser type gas concentration measurement device in which the transmitter and receiver are arranged at a predetermined interval is provided in the product discharge path of the packaging machine that fills the pillow packaging bag with the packaged item, performs gas replacement, and then seals the opening, and measures the concentration of the specific gas in the pillow packaging bag that passes between the transmitter and the receiver while a purge gas is flowing in the gas purge chamber. This makes it possible to quickly measure the concentration of the specific gas in all pillow packaging bags by the laser type gas concentration measurement device provided in the packaging machine without damaging the packaging bags. In this way, in recent years, laser-type gas concentration measuring devices have been used to non-destructively inspect all pillow packaging bags formed by a packaging machine, thereby improving the inspection accuracy of the gas concentration of a specific gas remaining in the pillow packaging bags. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3129463 [Patent Document 2] JP 2012-208126 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the first problem with the above-mentioned gas concentration measurement method is that a gas purge chamber filled with an inert gas such as nitrogen gas is provided on the product discharge path of the packaging machine, and the pillow packaging bag passes through this gas purge chamber. In other words, new space is required to accommodate a gas purge chamber in the limited space near the packaging machine, and the newly installed gas purge chamber must be constantly filled with inert gas, which requires a large amount of inert gas in addition to the inert gas used to replace the gas inside the packaging bag, and a supply device must be provided to supply this large amount of inert gas to the gas purge chamber.

[0007] A second problem is how to improve the measurement accuracy of the laser type gas concentration measuring device. Here, the laser gas concentration measuring device is configured to measure the gas concentration based on the absorbance of the laser light by the specific gas remaining in the packaging bag when the laser light is transmitted through the packaging bag. The absorbance is based on the rate at which the molecules of the specific gas present on the optical path between the laser generating unit and the laser receiving unit absorb the specific spectrum of the laser light, so it is known that the measurement accuracy can be improved by making the molecules present on the optical path absorb more of the specific spectrum. A method for absorbing more of this specific spectrum is to increase the optical path length or to increase the irradiation time on the same optical path. However, in the above-mentioned gas concentration measurement method, it is difficult to ensure a long optical path length in the gas purge chamber located in a position on the packaging machine where space is limited, and since the laser generating unit and the laser receiving unit are fixed in predetermined positions within the gas purge chamber, the laser light is only momentarily irradiated onto the passing pillow packaging bag, and there is a problem that it is not possible to ensure a long irradiation time on the same optical path.

[0008] Therefore, the problem that the present invention aims to solve is to provide a method for measuring gas concentration inside a pillow packaging bag, which improves measurement accuracy by ensuring sufficient irradiation time of laser light onto the pillow packaging bag in the atmospheric environment. [Means for solving the problem]

[0009] The method for measuring a gas concentration in a pillow packaging bag according to claim 1 includes a vertical sealing device that rolls up a long film pulled out from a film roll in the width direction and continuously seals both overlapping ends to form a cylindrical packaging material; a conveying device including a conveying path for continuously conveying the packaging material along a longitudinal direction at a predetermined conveying speed; At least one horizontal sealing device including a sealer that seals the packaging material in a width direction and intermittently operates the sealer at a predetermined cycle; A filling device for filling the packaged items; and a gas replacement device for replacing the atmosphere of the filled package with a specified inert gas, a first sealing step in which the sealer seals the packaging material in the middle to form a first sealed portion and form a packaging space partitioned by the first sealed portion; A filling step in which the packaging space is filled with the packaged item from the filling device; A gas replacement step of replacing the atmosphere of the packaged item filled in the packaging space with the inert gas; A second sealing step in which the sealer seals the packaging space to form a second sealed portion. A pillow packaging machine that forms a pillow packaging bag by sealing the packaging space filled with the packaged item with the first sealing portion and the second sealing portion, A laser gas concentration measuring device is provided near the pillow packaging machine, the laser generating unit emitting a laser beam of a specific wavelength into the packaging space and a laser receiving unit receiving the laser beam, The gas concentration measuring method for a pillow packaging bag is configured such that the laser type gas concentration measuring device transmits the laser light through the gas-substituted and sealed packaging space, and measures the gas concentration of a specific gas remaining in the packaging space based on the absorption spectrum of the specific wavelength that changes before and after the laser light passes through the packaging space, The laser gas concentration measuring device is a measuring device arranging step of arranging the laser generating unit and the laser receiving unit at a predetermined first point opposite to a measuring point provided on the pillow packaging bag formed in the second sealing step; a gas concentration measurement step of measuring the gas concentration in the packaging space for a predetermined measurement time by emitting the laser light to the measurement point while moving the laser generating unit and the laser receiving unit in parallel along the conveying path at a predetermined moving speed from the first point to a predetermined second point; The laser generating unit and the laser receiving unit are moved from the second point to the first point. The return path is a generally U-shaped locus starting from the second point and ending at the first point on the opposite side to the conveying path. A return step of returning the light beam along a predetermined return path, During the gas concentration measurement process, the moving speed of the laser generating unit and the laser receiving unit is synchronized with the conveying speed of the pillow packaging bag so that the laser generating unit and the laser receiving unit are stopped relative to the measurement point, The present invention is characterized in that the laser type gas concentration measuring device measures the gas concentration within the packaging space in accordance with the pillow packaging bag being conveyed.

[0010] The gas concentration measuring method for a pillow packaging bag described in claim 2 is characterized in that, in the invention described in claim 1, the pillow packaging bags formed in series from the packaging material transported by the conveying device are arranged in a vertical direction.

[0011] The gas concentration measuring method for a pillow packaging bag described in claim 3 is characterized in that, in the invention described in claim 1, the pillow packaging bags formed continuously from the packaging material transported by the conveying device are arranged in a horizontal direction.

[0012] The method for measuring a gas concentration in a pillow packaging bag according to claim 4 is 2 or claims 3 In the invention described in the above, the measurement points are provided so that the laser light passes through along the width direction of the pillow packaging bag.

[0013] The method for measuring a gas concentration in a pillow packaging bag according to claim 5 is 2 or claims 3In the invention described in the above, the measurement points are provided so that the laser light passes through the pillow packaging bag in the thickness direction.

[0014] The method for measuring a gas concentration in a pillow packaging bag according to claim 6 is the same as the method for measuring a gas concentration in a pillow packaging bag according to claim 1, further comprising the steps of: providing a conveying path for conveying the pillow packaging bag formed by the pillow packaging machine in the vicinity of the pillow packaging machine; The present invention is characterized in that the laser type gas concentration measuring device is provided in the middle of the discharge path outside the pillow packaging machine. Effect of the Invention

[0015] According to the method for measuring the gas concentration in a pillow package bag of the present invention, the moving speed at which the laser generating unit and the laser receiving unit constituting the laser gas concentration measuring device move while measuring the gas concentration is synchronized with the conveying speed at which the conveying device conveys the pillow package bag, so that the laser generating unit and the laser receiving unit stop relative to the measurement point provided on the pillow package bag. During the gas concentration measurement, the distance between the laser generating unit and the laser receiving unit on either side of the measurement point is kept constant. In other words, the laser generating unit and the laser receiving unit, which have a constant optical path length, move together with the measurement point provided on the pillow package bag to measure the gas concentration. This allows the laser light to be irradiated along the same optical path for a long period of time, ensuring sufficient irradiation time of the laser light onto the pillow packaging bag in the atmospheric environment and improving measurement accuracy.

[0016] In addition, the return path of the laser generating unit and the laser receiving unit when they return from the second point to the first point after the measurement is completed is designed to trace an approximately U-shaped trajectory on the opposite side of the conveying path, starting from the second point and ending at the first point. This allows the laser generating unit and laser receiving unit to be separated from the pillow packaging bags during non-measurement times, making them less likely to interfere with other devices installed in the pillow packaging machine and preventing them from being caught in the flow of pillow packaging bags being conveyed out, thereby improving safety.

[0017] Furthermore, whether the pillow packaging bags are lined up vertically or horizontally, the movement speed of the laser generating unit and the laser receiving unit during gas concentration measurement is synchronized with the conveying speed of the pillow packaging bags, and the measurement points are configured so that the laser light passes through the pillow packaging bag in the width direction and also in the thickness direction. In either case, the optical path length between the laser generating unit and the laser receiving unit is kept constant and the optical path moves, making it possible to measure for long periods of time on the same optical path. This allows the laser gas concentration measuring device to be freely installed in accordance with the layout of the pillow packaging machine, improving design freedom and versatility. Also preferably, a laser type gas concentration measuring device is provided in the middle of the conveying path leading to the outside of the pillow packaging machine for carrying the formed pillow packaging bags, so that the gas concentration can be measured. This means that the laser type gas concentration measuring device can be installed near the pillow packaging machine, or can be installed along the discharge path outside the pillow packaging machine, allowing the laser type gas concentration measuring device to be freely installed in accordance with the layout of the pillow packaging machine, improving design freedom and versatility. [Brief description of the drawings]

[0018] [Figure 1] 1 is an explanatory diagram for explaining an outline of the configuration of a gas concentration measuring method for a pillow packaging bag according to a first embodiment; [Diagram 2] 1 is an explanatory diagram illustrating the outline of the configuration of a laser type gas concentration measurement device in a gas concentration measurement method for a pillow packaging bag according to a first embodiment. FIG. [Diagram 3]FIG. 11 is an explanatory diagram for explaining an outline of the configuration of a gas concentration measuring method for a pillow packaging bag according to a second embodiment. [Figure 4] FIG. 11 is an explanatory diagram for explaining an outline of the configuration of a gas concentration measuring method for a pillow packaging bag according to a third embodiment. [Diagram 5] FIG. 13 is an explanatory diagram for explaining the outline of the configuration of a gas concentration measuring method for a pillow packaging bag according to a fourth embodiment. Example 1

[0019] A first embodiment of the method for measuring gas concentration in a pillow packaging bag according to the present invention will be described below with reference to the attached drawings. Fig. 1 is an explanatory diagram for explaining the outline of the configuration of the method for measuring gas concentration in a pillow packaging bag according to this embodiment, and Fig. 2 is an explanatory diagram for explaining the outline of the configuration of the laser type gas concentration measurement device according to this embodiment.

[0020] The pillow packaging bag 10 is composed of a packaging material 1 formed into a cylindrical shape. The packaging material 1 is formed into a cylindrical shape by rolling or folding a long film pulled out from a film roll in the width direction and continuously sealing both overlapping widthwise edges with a vertical sealing device (not shown).

[0021] 1, the packaging material 1 is conveyed by a conveying device (not shown) along a conveying path 17 indicated by an arrow in the figure along the longitudinal direction. The horizontal sealing device 15 has sealers 16, 16 whose welding portions face each other. The sealers 16, 16 are configured to intermittently clamp and seal the conveyed packaging material 1 at a predetermined cycle across the width of the packaging material 1. This makes it possible to form a pillow packaging bag 10 along the conveying path 17 of the packaging material 1, which includes sealed portions 12, 13 at predetermined intervals and a packaging space 11 partitioned by the sealed portions and capable of being filled with the packaged item. Here, along conveying path 17 of packaging material 1, a lower part of the packaging space sealed earlier is defined as first sealed part 12, and an upper part of the packaging space sealed later is defined as second sealed part 13. As shown in Fig. 1, a pillow packaging machine that forms pillow packaging bags 10 by vertically connecting them is called a vertical pillow packaging machine. In this embodiment, as shown in Figure 1, two horizontal sealing devices 15 alternately seal the packaging material 1 periodically at predetermined intervals to form a first sealed portion 12 and a second sealed portion 13 connected between one packaging space 10 and the other packaging space 10, thereby continuously forming pillow packaging bags 10.

[0022] As shown in FIG. 1, a laser type gas concentration measuring device 20 is disposed below and in the vicinity of the horizontal sealing device 15. As shown in Figs. 1 and 2, the laser type gas concentration measuring device 20 has a laser generating unit 21 and a laser receiving unit 22 arranged to sandwich a pillow packaging bag.

[0023] As shown in FIG. 2, the laser generating unit 21 has a laser light source 23 and a control unit 24 that sets the wavelength of the laser light emitted from the light source 23 to a specific wavelength and adjusts it to a predetermined light intensity. The laser light source 23 includes a semiconductor laser element made of a diode with a variable wavelength, and is configured to be able to emit laser light in the near-infrared region. The semiconductor laser element according to this embodiment is a high-output semiconductor laser element called a DFB (Distributed Feed Back) laser. The control unit 24 is configured to adjust the wavelength of the laser light emitted from the semiconductor laser element to a specific wavelength specific to the specific gas to be measured, and to control amplification so that the laser light is emitted with a predetermined incident light intensity. The control unit 24 is also configured to output an incident light signal related to the intensity of the emitted incident light to the measurement unit 26. Here, the specific gas measured by the laser gas concentration measuring device 20 according to this embodiment is oxygen gas (O2). The absorption wavelength band specific to this oxygen gas is 760 nm band, and among a plurality of absorption spectra included in this absorption wavelength band, a specific wavelength related to one absorption spectrum is selected as the output wavelength of the laser light. In this embodiment, it is configured to detect oxygen gas that may deteriorate the packaged product due to oxidation, but it is not limited to this, and it is configured so that the absorption spectrum related to the absorption wavelength band that specifies the gas to be detected can be arbitrarily set.

[0024] As shown in FIG. 2, the laser receiving unit 22 has a light receiving sensor 25 that receives laser light that has passed through the pillow packaging bag 10 and is attenuated, and a measuring unit 26 that measures the gas concentration based on the light receiving signal from the light receiving sensor 25. Light receiving sensor 25 is composed of an element, such as a photodiode, that converts the transmitted light intensity of the laser light transmitted through pillow packaging bag 10 into an electrical transmitted light signal. This makes it possible to electrically process the transmitted light intensity of the laser light that has been attenuated by transmitting through packaging space 11 of pillow packaging bag 10. The measuring unit 26 is configured to calculate the transmittance based on a transmitted light signal related to the transmitted light intensity and an incident light signal related to the incident light intensity of the laser light output from the control unit 24 of the laser generating unit 21, to determine the absorbance of the laser light by a specific gas based on the transmittance, and to measure the gas concentration of the specific gas in the packaging space 11 based on the absorbance.

[0025] The path along which the laser light travels between the laser generating unit 21 and the laser receiving unit 22 is referred to as an optical path c, and its length is referred to as an optical path length. On the optical path c, there is the air atmosphere and packaging space 11 of the pillow packaging bag 10. Here, the specific gas exists in the atmosphere and remains in the packaging space 11. The specific gas absorbs a predetermined absorption spectrum related to a specific wavelength constituting the laser light on the optical path c. Therefore, the laser light is absorbed by the specific gas on the optical path c and attenuated. Then, the attenuated laser light on the optical path c is received by the light receiving sensor 25. The measuring unit 26 is configured to obtain the transmittance from the light intensity before attenuation and the transmitted light intensity attenuated by transmission, which are acquired from the control unit 24. The measuring unit 26 is configured to obtain the absorbance, which indicates how much of the absorption spectrum the specific gas has absorbed on the optical path c, from the obtained transmittance. The measuring unit 26 is configured to calculate the total concentration of the specific gas on the optical path c based on the obtained absorbance, and to measure the concentration of the specific gas remaining in the packaging space 11 from the total concentration, excluding the influence of the concentration of the specific gas that exists at a substantially constant concentration in the atmosphere. If the measured concentration of the residual specific gas is equal to or higher than a predetermined threshold value, it is determined that the specific gas, in this embodiment oxygen gas, remains in the packaging space 11 at a concentration above the allowable concentration, and the bag product manufactured by packaging the packaged item in the pillow packaging bag 10 is determined to be defective and is discharged outside the conveying route. The laser gas concentration measuring device 20 measures the gas concentration of a specific gas based on the degree of attenuation of the laser light that is absorbed and attenuated by the specific gas on the optical path c. Therefore, first, the measurement accuracy can be improved by ensuring a long optical path length and increasing the attenuation of the laser light. This can be achieved by ensuring a long measurement time when the optical path length is constant, and having the laser light emitted from the laser generating unit be reflected multiple times during the measurement time and received by the laser receiving unit. Secondly, the measurement accuracy can be improved by emitting the laser light multiple times and measuring multiple times. This is made possible by keeping the optical path length constant and ensuring a long measurement time, emitting the laser light multiple times from the laser generating unit during the measurement time, calculating the measurement error from the results of the multiple measurements, and feeding back the measurement error to the actual measurement value to calculate a measurement value with the error removed. In either case, in order to improve the measurement accuracy, it is important to ensure a long measurement time and to keep the optical path length long and constant during the measurement time.

[0026] A pillow packaging bag 10 corresponding to the above-mentioned laser type gas concentration measuring device 20 has measurement points P0, P0 through which laser light can pass, as shown in FIG. Here, the pillow packaging bag 10 is made of a predetermined film as described above. The film is preferably made of a synthetic resin such as vinyl chloride, polyethylene, or polypropylene, whose laser light transmittance is 0.00001% or more and less than 100%. That is, the laser type gas concentration measuring device 20 according to this embodiment is effective even if the pillow packaging bag 10 is colored, as long as the laser light can pass through it. Also, even if the film is colored, a window portion through which the laser light can pass may be provided at the position that corresponds to the measurement points P0, P0 when the pillow packaging bag 10 is formed from the packaging material 1. 1, the optical path in packaging space 11 at measurement points P0, P0 is formed in a space above pillow packaging bag 10 where the packaged items do not obstruct the laser light. This makes it possible to prevent the packaged items from absorbing and scattering the laser light, which would cause measurement errors.

[0027] In the vertical pillow packaging machine having the above-mentioned configuration, the pillow packaging bag 10 is filled with the packaged items through each process described below, and each package is inspected by a laser-type gas concentration measuring device 20. A conveying device (not shown) that conveys the packaging material 1 is configured to convey the packaging material 1 and a pillow package bag formed from the packaging material 1 along a conveying path 17 at a predetermined conveying speed. This enables the vertical pillow packaging machine to continuously produce and convey bag products in which pillow packaging bags formed from the packaging material 1 are filled with items to be packaged.

[0028] As shown in FIG. 1, the horizontal sealing device 15 is configured to perform two sealing steps together to form a continuous pillow packaging bag 10 from the packaging material 1. Of the sealing steps, the sealing step of sealing the middle of the packaging material 1 to form a first sealed portion 12 is referred to as the first sealing step, and the sealing step of forming a second sealed portion 13 that seals the packaging space 11 filled with the packaged item is referred to as the second sealing step. As shown in Fig. 1, in the second sealing step, when the sealers 16, 16 of the horizontal sealing device 15 seal and form the second sealed portion 12 of the packaging space 11 to seal the previous pillow packaging bag 10, the sealers 16, 16 are configured to seal and form the first sealed portion 12 of the subsequent pillow packaging bag 10 to form the packaging space 11. In this embodiment, as shown in FIG. 1, two horizontal sealing devices 15 alternately perform a sealing process in which a first sealing step and a second sealing step are simultaneously performed, repeating the process on a conveying path 17, thereby continuously forming pillow packaging bags 10 from a tubular packaging material 1. 1, the horizontal sealing device 15 is configured so that the sealers 16, 16 move a predetermined distance along the conveying path 17 while holding the packaging material 1. This ensures a predetermined sealing time for the sealers 16, 16 to weld the packaging material 1. After the predetermined sealing time has elapsed, sealers 16, 16 release pillow packaging bag 10 and return to the sealing start position in a so-called box motion, tracing a generally U-shaped trajectory starting from the position at which sealing ended and ending at the position at which sealing started, toward the opposite side of conveying path 17 along which pillow packaging bag 10 is conveyed. In this way, as shown in Figure 1, multiple horizontal sealing devices 15 each operate in a circular orbit on the same track, so that pillow packaging bags 10 can be formed continuously without stopping packaging material 1.

[0029] After the first sealing process, the pillow packaging bag 10 is subjected to a filling process in which the packaging space 11 is filled with the packaged items, a gas replacement process in which the atmosphere in the packaging space 11 is replaced with an inert gas, and preferably a degassing process in which the atmosphere in the packaging space 11 is evacuated, and a vibration process in which vibrations are applied to the packaged items in the packaging space 11. The filling step is a step of filling the packaging space 11 defined by the first sealed portion 12 in the middle of the tubular packaging material 1 with the packaged item. The gas replacement step is a step of replacing the air atmosphere of the packaged items filled in the packaging space 11 with an inert gas. The filling step may be performed simultaneously with the gas replacement step, or the filling step and the gas replacement step may be performed in that order. The inert gas used in the gas replacement step is, for example, nitrogen gas, carbon dioxide gas, etc., and the inert gas can be selected arbitrarily. Depending on the packaged items, the degassing step may be performed simultaneously with the filling step or between the filling step and the gas replacement step. Preferably, the vibration step is performed in parallel with the filling step and the gas replacement step. The vibration step can further degas the packaging space 11 and gather the packaged items downward. When the above-mentioned processes related to the filling step and the like are completed, a process of forming a second sealed portion that seals the packaging space 11 is performed by a second sealing step. In this way, a pillow packaging bag 10 is formed in which packaging space 11 filled with the packaged item is sealed by the first sealing portion and the second sealing portion, and the bag proceeds to an inspection process as shown in FIG. In this way, the vertical pillow packaging machine forms a tubular packaging material 1 from a long film, and forms a pillow packaging bag 10 filled with the packaged item through each process. Note that the vertical pillow packaging machine is a well-known packaging machine that is already widely known, including the shrink packaging device disclosed in Japanese Patent No. 3129463, which was cited as a prior art document, and therefore detailed explanations and illustrations of the configuration of each part will be omitted.

[0030] The inspection process performed by the laser type gas concentration measuring device 20 includes a measuring device placement process, a gas concentration measuring process, and a feedback process. The measurement device placement step is a step of placing laser generating unit 21 and laser receiving unit 22 at predetermined positions. As shown in Fig. 1, for any one of the multiple pillow packaging bags 10 connected below sealers 16, 16 of horizontal sealing device 15, laser generating unit 21 and laser receiving unit 22 are placed so as to face measurement points P0, P0 of pillow packaging bag 10 and to face each other across pillow packaging bag 10. Hereinafter, this position will be referred to as first point P1. Here, the direction in which sealers 16, 16 of horizontal sealing device 15 clamp and seal packaging material 1 is defined as the width direction of pillow packaging bag 10, and the direction perpendicular to the front and back of this width direction is defined as the thickness direction of pillow packaging bag 10. The positions of first point P1 and measurement points P0, P0 are located along the width direction of pillow packaging bag 10, as shown in Figure 1. After the laser generating unit 21 and the laser receiving unit 22 are placed at the first point P1, the process proceeds to the next gas concentration measurement step.

[0031] The gas concentration measurement process is a process in which laser light is emitted from laser generating unit 21 arranged at first point P1 to measurement points P0, P0, and the laser light attenuated in packaging space 11 is received by laser receiving unit 22 to measure the gas concentration of a specific gas remaining in packaging space 11. In the gas concentration measurement process, laser generating unit 21 and laser receiving unit 22 are configured to move at the same moving speed as that of packaging material 1 and pillow packaging bag 10, which is synchronized with the conveying speed at which packaging material 1 and pillow packaging bag 10 are conveyed on conveying path 17. As a result, laser generating unit 21 and laser receiving unit 22 are stopped relative to pillow packaging bag 10, and therefore laser generating unit 21 and laser receiving unit 22 can continue to emit laser light to measurement points P0, P0 even while pillow packaging bag 10 is being conveyed. The gas concentration measurement process ends when a predetermined measurement time has elapsed. At this time, the stopping position of laser generating unit 21 and laser receiving unit 22, which have moved together with pillow packaging bag 10 to be measured, is defined as second point P2. The measurement time is preferably the same length as the sealing time of horizontal sealing device 15. With this configuration, measurement can be started for pillow packaging bag 10 released from sealers 16, 16 after the release, and the next measurement can be started smoothly when the next pillow packaging bag 10 is released from sealers 16, 16. Note that when multiple sets of laser generating unit 21 and laser receiving unit 22 are provided, the measurement time is not limited to the sealing time but can be set arbitrarily. 1, the trajectory drawn by laser generating unit 21 and laser receiving unit 22 between first point P1 and second point P2 is along conveying path 17 for pillow packaging bag 10, and laser generating unit 21 and laser receiving unit 22 are configured to move parallel to each other with respect to the axis of conveying path 17 that hangs down from the center of sealers 16, 16 directly below horizontal sealing device 15. As a result, even if pillow packaging bag 10 is biased toward either laser generating unit 21 or laser receiving unit 22, the distance between laser generating unit 21 and laser receiving unit 22, i.e., the optical path length, can be kept constant, thereby suppressing measurement errors. According to the gas concentration measurement process configured as described above, laser generating unit 21 and laser receiving unit 22, which move together with pillow packaging bag 10, can continuously transmit laser light into packaging space 11 through measurement points P0, P0 which move during the conveying process, and the optical path length between laser generating unit 21 and laser receiving unit 22 can be kept constant during the conveying process. Therefore, whether the laser light is reflected multiple times or emitted multiple times, the optical path length can be kept constant and a long measurement time can be secured, thereby improving the measurement accuracy of the gas concentration by laser gas concentration measuring device 20. When the measurement time has elapsed, the laser generating unit 21 and the laser receiving unit 22 reach the second point P2, the gas concentration measurement process ends, and the process moves to the next feedback process.

[0032] The return process is a process of returning the laser generating unit 21 and the laser receiving unit 22 from the second point P2 to the first point P1. As shown in FIG. 1, the laser generating unit 21 and the laser receiving unit 22 are configured to move away from the second point P2 in a mutually opposite manner, and to return from the second point P2 to the first point P1 by drawing a substantially U-shaped trajectory starting from the second point P2 and ending at the first point P1 toward the side opposite the conveying path 17. That is, in the gas concentration measurement process and the return process, the laser generating unit 21 and the laser receiving unit 22 are configured to perform an operation of drawing a rectangular trajectory called a box motion. This makes it possible to prevent the laser generating unit 21 and the laser receiving unit 22 from being caught in the flow of the packaging material 1 and the pillow packaging bag 10, and to prevent interference with the sealers 16, 16 of the horizontal sealing device 15, which are also operating in a box motion. In addition, in this embodiment, a laser type gas concentration measuring device 20 having one set of a laser generating unit 21 and a laser receiving unit 22 is exemplified, but this is not limited to this, and a laser type gas concentration measuring device having multiple sets of a laser generating unit and a laser receiving unit may also be used. In this embodiment, as described above, the laser generating unit 21 and the laser receiving unit 22 are configured to operate in a box motion, so when multiple sets of the laser generating unit 21 and the laser receiving unit 22 are incorporated in the laser gas concentration measurement device, the next laser generating unit 21 and the laser receiving unit 22 can be kept waiting near the first point P1. This allows the pillow packaging bags 10 released one after another from the sealers 16, 16 of the horizontal sealing device 15 to be measured continuously without interruption. This makes it possible to increase the speed of the vertical pillow packaging machine, including the inspection process, and further improve the inspection efficiency and production efficiency of the pillow packaging bags 10. Similarly, in such a configuration, it is not necessary to make one sealing time correspond one-to-one with one measurement time as described above, and multiple sealing times may pass for one measurement time. This makes it possible to maintain a constant optical path length and ensure a long measurement time, thereby improving the measurement accuracy of the gas concentration by the laser gas concentration measuring device 20. In this embodiment, the laser generating unit 21 and the laser receiving unit 22 are configured to operate in a box motion, but this is not limited to this. They may be operated to trace a substantially semicircular trajectory starting from the second point P2 and ending at the first point P1, or a stop process may be provided between the transport processes, and during this stop process, the laser generating unit 21 and the laser receiving unit 22 may be operated to return along the path they took from the second point P2 to the first point P1 during the gas concentration measurement process. Example 2

[0033] Next, a second embodiment of the method for measuring gas concentration in a pillow packaging bag according to the present invention will be described with reference to the accompanying drawings. Fig. 3 is an explanatory diagram for explaining the outline of the configuration of the method for measuring gas concentration in a pillow packaging bag according to this embodiment.

[0034] The configurations of the pillow packaging machine and the laser type gas concentration measuring device 20 according to this embodiment are similar to those of the first embodiment, and therefore a description thereof will be omitted. On the other hand, the differences in the configuration between the first and second embodiments are the positions of measurement points P0A, P0A provided on the pillow packaging bag and the orientation of laser generating unit 21 and laser receiving unit 22 relative to pillow packaging bag 10.

[0035] If the direction in which sealers 16, 16 of horizontal sealing device 15 clamp and seal packaging material 1 is defined as the width direction of pillow packaging bag 10, and the direction perpendicular to the width direction in the front-to-back direction is defined as the thickness direction of pillow packaging bag 10, in the measuring device placement process of the first embodiment, the positions of measurement points P0, P0 and a first point P1 opposite measurement points P0, P0 are provided along the width direction of pillow packaging bag 10, as shown in Figure 1. In contrast, in the measurement device arrangement step according to this embodiment, the measurement points P0A, P0A and the first point P1A opposite to the measurement points P0A, P0A are positioned along the thickness direction of the pillow packaging bag 10, as shown in Fig. 3. Accordingly, the second point P2A and the return path are set. Example 3

[0036] Next, a third embodiment of the method for measuring gas concentration in a pillow packaging bag according to the present invention will be described with reference to the accompanying drawings. Fig. 4 is an explanatory diagram for explaining the outline of the configuration of the method for measuring gas concentration in a pillow packaging bag according to this embodiment. The configuration of the laser type gas concentration measurement device 20 according to this embodiment is similar to that of the first and second embodiments, and therefore a description thereof will be omitted. On the other hand, the configuration of the pillow packaging machine according to the third embodiment is different from the configurations of the above-mentioned first and second embodiments.

[0037] The pillow packaging machine according to the third embodiment is configured to form pillow packaging bags 10 in a horizontal direction as shown in FIG. 4, and is referred to as a horizontal pillow packaging machine. As shown in Fig. 4, the horizontal pillow packaging machine is conveyed along a conveying path 17A indicated by an arrow in the figure along the longitudinal direction by a conveying device equipped with a belt conveyor 18. The horizontal pillow packaging machine is configured such that a sealer 16 of a horizontal sealing device 15 intermittently seals the conveyed packaging material 1 at a predetermined cycle so as to cross the width direction of the packaging material 1, and then the formed pillow packaging bag 10 is placed on the belt conveyor 18 and conveyed out in the horizontal direction. Then, along the conveying path 17A of the packaging material 1, the front part of the packaging space 11 that has been sealed first is the first sealed part 12, and the rear part of the packaging space 11 that has been sealed later is the second sealed part 13. Then, as shown in Fig. 4, a pillow packaging machine that forms pillow packaging bags 10 in a row in the horizontal direction is called a horizontal pillow packaging machine. Here, the belt of the belt conveyor 18 is made of a material that is capable of transmitting laser light, for example, a belt made of a transparent synthetic resin. Also, preferably, a window portion through which the laser light can pass may be provided in the center of the belt. In this way, the laser type gas concentration measuring device 20 can transmit the laser light by arranging the laser generating unit 21 and the laser receiving unit 22 as shown in FIG. 4 for the pillow packaging bag 10 transported on the placement surface 18a of the belt conveyor 18. A horizontal pillow packaging machine can keep the height of the device lower than a vertical pillow packaging machine, and is therefore effective when sufficient height cannot be secured at the installation location of the packaging machine. In addition, since the formed pillow packaging bag 10 is conveyed horizontally, when the bag is filled with a packaged item that should not be tilted, the packaged item can be prevented from being biased in the packaging space 11. Alternatively, when performing some manual work on the pillow packaging bag 10, the work can be done on a table connected to the belt conveyor 18, and the burden on the worker can be reduced.

[0038] In this embodiment, an example has been given of a configuration in which a conveying device consisting of a belt conveyor 18 is incorporated into a horizontal pillow packaging machine, but this is not limited to this. For example, an unloading device consisting of a belt conveyor 18 and equipped with an unloading path for unloading manufactured pillow packaging bags in a horizontal direction can be provided immediately below the outside of the vertical pillow packaging machine illustrated in the first or second embodiment, and the above-mentioned laser type gas concentration measuring device can be provided midway along the unloading path, resulting in a configuration similar to that of the third embodiment. That is, in addition to the configuration in which laser type gas concentration measuring device 20 is incorporated into a horizontal pillow packaging machine as shown in the third embodiment, a vertical pillow packaging machine can be combined with an unloading device, or an unloading device can be connected to the conveying path 17A of the horizontal pillow packaging machine, so that laser type gas concentration measuring device 20 is installed in the middle of an unloading path provided outside the vertical pillow packaging machine or the horizontal pillow packaging machine. This allows laser generating unit 21 and laser receiving unit 22 to be arranged in the same way, so that laser type gas concentration measuring device 20 can be freely installed in accordance with the layout of the pillow packaging machine, thereby improving design freedom and versatility.

[0039] The inspection process of the laser gas concentration measuring device 20 associated with the horizontal pillow packaging machine configured as described above includes a measuring device placement process, a gas concentration measuring process, and a return process, similar to the first or second embodiment. The process of packaging the packaged object in the pillow packaging bag 10 is similar to the first embodiment, except for the processing process performed by the conveying device, and therefore a description thereof will be omitted. The conveying device is configured to alternately perform a conveying process in which the packaging material 1 and the pillow packaging bag 10 formed from the packaging material 1 are conveyed along a conveying path 17A of the packaging material 1 on a belt conveyor 18, and a stopping process in which the conveying is stopped. Moreover, unlike the first or second embodiment, the horizontal sealing device 15 according to this embodiment has one sealer 16 as shown in FIG. When the belt conveyor 18 is stopped during the stopping step, the sealer 16 descends toward the placement surface 18a of the belt conveyor 18 to press down and seal the packaging material 1. Therefore, the sealer 16 can periodically seal the packaging material 1 every time the belt conveyor 18 stops at a predetermined interval, and the first and second sealing steps described above in the first embodiment are performed. This makes it possible to form a pillow packaging bag 10 having a packaging space 11 partitioned by the first sealed portion 12 and the second sealed portion 13. Thereafter, sealer 16 rises to release pillow packaging bag 10, and the process moves to the conveying process again. Then, pillow packaging bag 10 moves to an inspection process consisting of a measuring device placement process, a gas concentration measurement process, and a return process.

[0040] The measurement device placement step is a step of placing laser generating unit 21 and laser receiving unit 22 at predetermined positions. As shown in Fig. 4, for any one pillow packaging bag 10 among the multiple pillow packaging bags 10 lined up to the side of sealer 16 of horizontal sealing device 15, laser generating unit 21 and laser receiving unit 22 are placed so as to face measurement points P0B, P0B of that pillow packaging bag 10 and to face each other across pillow packaging bag 10. Hereinafter, this position will be referred to as first point P1B. Here, the direction in which sealer 16 of horizontal sealing device 15 clamps and seals packaging material 1 is defined as the width direction of pillow packaging bag 10, and the direction perpendicular to the width direction is defined as the thickness direction of pillow packaging bag 10. The positions of first point P1B and measurement points P0B, P0B are provided along the thickness direction of pillow packaging bag 10, as shown in Figure 4. In the case of a horizontal pillow packaging machine, when the pillow packaging bag 10 placed on the belt conveyor 18 is filled with a packaged item consisting of a liquid or powder, the liquid or powder accumulates below the pillow packaging bag 10 due to the action of gravity. Therefore, as shown in FIG. 4, if the laser generating unit 21 and the laser receiving unit 22 are arranged to face each other in the vertical direction with the pillow packaging bag 10 in between, the packaged item may block the laser light in the packaging space 11. Therefore, the packaged item to be packaged in the pillow packaging bag 10 according to the third embodiment is preferably a liquid or powder contained in a tray, capsule, or the like. By wrapping and sealing the tray, capsule, or the like with the packaging material 1, it is possible to prevent the packaged item from being placed between the measurement points P0B, P0B in the packaging space 11, and therefore the optical path c of the laser light can be secured. After the laser generating unit 21 and the laser receiving unit 22 are placed at the first point P1B, the process proceeds to the next gas concentration measurement step.

[0041] The gas concentration measurement process is a process in which laser light is emitted from laser generating unit 21 arranged at first point P1B to measurement points P0B, P0B, and the laser light attenuated in packaging space 11 is received by laser receiving unit 22 to measure the gas concentration of a specific gas remaining in packaging space 11. In the gas concentration measurement process, laser generating unit 21 and laser receiving unit 22 are configured to move at the same moving speed as that of belt conveyor 18, which is synchronized with the conveying speed at which packaging material 1 and pillow packaging bag 10 are conveyed in the conveying process. As a result, laser generating unit 21 and laser receiving unit 22 are stopped relative to pillow packaging bag 10, so that laser generating unit 21 and laser receiving unit 22 can continue to emit laser light to measurement points P0B, P0B even while pillow packaging bag 10 is being conveyed. The gas concentration measurement process ends when the conveying process of belt conveyor 18 ends and transitions to a stopping process in which packaging material 1 and pillow packaging bags are stopped. At this time, the stopping position of laser generating unit 21 and laser receiving unit 22, which have moved together with pillow packaging bag 10 to be measured, is set to second point P2B. 4, the trajectories drawn by laser generating unit 21 and laser receiving unit 22 between first point P1B and second point P2B are configured so that laser generating unit 21 and laser receiving unit 22 are parallel to each other above and below the axis of placement surface 18a of belt conveyor 18 along conveying path 17A for pillow packaging bag 10. This allows laser generating unit 21 and laser receiving unit 22 to emit laser light to the pillow packaging bag even if pillow packaging bag 10 is biased to the left or right of placement surface 18a. According to the gas concentration measurement process configured as described above, laser generating unit 21 and laser receiving unit 22, which move together with pillow packaging bag 10, can continue to transmit laser light into packaging space 11 through measurement points P0B, P0B which move during the conveying process, and the optical path length between laser generating unit 21 and laser receiving unit 22 can be kept constant during the conveying process. Therefore, whether the laser light is reflected multiple times or emitted multiple times, the optical path length can be kept constant and a long measurement time can be secured, thereby improving the measurement accuracy of the gas concentration by laser gas concentration measuring device 20. When the laser generating unit 21 and the laser receiving unit 22 reach the second point P2B, the gas concentration measurement process ends and the process moves to the next feedback process.

[0042] The return process is a process of returning the laser generating unit 21 and the laser receiving unit 22 from the second point P2B to the first point P1B. As shown in Fig. 4, the laser generating unit 21 is configured to move upward from the second point P2B and return from the second point P2B to the first point P1B so as to trace a substantially U-shaped trajectory with the second point P2B as the starting point and the first point P1B as the ending point. That is, by combining the gas concentration measurement process and the return process, the laser receiving unit 22 is configured to perform an operation that traces a rectangular trajectory, so-called a box motion. Meanwhile, the laser receiving unit 22 is configured to perform an operation of returning from the second point P2B to the first point P1B along the path along which it moved in the gas concentration measurement process described above while the belt conveyor 18 is stopped. This makes it possible to prevent the laser generating unit 21 and the laser receiving unit 22 from being caught in the flow of the packaging material 1 and the pillow packaging bags. In this embodiment, the laser generating unit 21 is configured to operate in a box motion, but this is not limited to this. The laser generating unit 21 may be operated to trace a substantially semicircular trajectory starting from the second point P2B and ending at the first point P1B, and the laser receiving unit 22 may also be configured to return in a box motion similar to the laser generating unit 21. When both the laser generating unit 21 and the laser receiving unit 22 are configured to operate in a box motion, the present invention is not limited to the above-mentioned case in which the conveying process and the gas concentration measuring process correspond one-to-one, and a configuration can be adopted in which a laser gas concentration measuring device 20 including a plurality of sets of laser generating units 21 and laser receiving units 22 is provided, and the gas concentration measuring process is performed while the conveying process and the stopping process are repeated several times to extend the measurement time. When a plurality of sets of laser generating units 21 and laser receiving units 22 are incorporated in the laser gas concentration measuring device 20 in this way, the next laser generating unit 21 and laser receiving unit 22 can be kept waiting near the first point P1B. This allows the pillow packaging bags 10 that are conveyed out one after another from the horizontal sealing device 15 to be continuously measured regardless of the stopping time of the belt conveyor 18. This allows the pillow packaging machine to be operated at a high speed, and further allows the inspection efficiency and manufacturing efficiency of the pillow packaging bags 10 to be improved. Example 4

[0043] Next, a fourth embodiment of the method for measuring gas concentration in a pillow packaging bag according to the present invention will be described with reference to the accompanying drawings. Fig. 5 is an explanatory diagram for explaining the outline of the configuration of the method for measuring gas concentration in a pillow packaging bag according to this embodiment.

[0044] The configurations of the pillow packaging machine and the laser type gas concentration measuring device 20 according to this embodiment are similar to those of the third embodiment, and therefore a description thereof will be omitted. On the other hand, the differences in the configuration between the third and fourth embodiments are the positions of measurement points P0C, P0C provided on pillow packaging bag 10 and the orientation of laser generating unit 21 and laser receiving unit 22 relative to pillow packaging bag 10.

[0045] If the direction in which sealer 16 of horizontal sealing device 15 clamps and seals packaging material 1 is defined as the width direction of pillow packaging bag 10, and the direction perpendicular to the width direction is defined as the thickness direction of pillow packaging bag 10, then in the measuring device placement process of the third embodiment, the positions of measurement points P0B, P0B and a first point P1B opposite measurement points P0B, P0B are provided along the thickness direction of pillow packaging bag 10, as shown in Figure 4. In contrast, in the measurement device arrangement step according to this embodiment, the positions of the measurement points P0C, P0C and the first point P1C opposite to the measurement points P0C, P0C are provided along the width direction of the pillow packaging bag 10, as shown in Fig. 5. Accordingly, the second point P2C and the return path are set. With this configuration, even if liquid or powder accumulates in the lower part of packaging space 11 due to the effect of gravity acting on pillow packaging bag 10, packaging space 11 can be secured with no packaged items above it. Therefore, by providing measurement points P0C, P0C in packaging space 11, optical path c of the laser light can be secured. Therefore, as limited in pillow packaging bag 10 according to the third embodiment, packaged items consisting of liquid or powder can be easily measured without being placed in a tray, capsule, or the like.

[0046] According to the method for measuring the gas concentration of a pillow package bag according to this embodiment, laser generating unit 21 and laser receiving unit 22 of laser type gas concentration measuring device 20 are adapted to move at the same moving speed as and synchronized with the conveying speed of pillow package bag 10 conveyed by the conveying device of a vertical or horizontal pillow packaging machine or belt conveyor 18. As a result, laser generating unit 21 and laser receiving unit 22 are in a stationary state relative to pillow package bag 10. As a result, by emitting laser light to measurement points P0, P0 provided on pillow package bag 10, measurement can be performed over a long period of time during the conveying process, and the measurement accuracy of the specific gas concentration remaining in packaging space 11 of pillow package bag 10 can be improved. Furthermore, as shown in the above embodiment, the laser type gas concentration measuring device 20 can be freely set relative to the conveying path 17, 17A of the pillow packaging bag 10, and the laser generating unit 21 and the laser receiving unit 22 can be arranged in the optimal position according to the layout of the pillow packaging machine, thereby ensuring a sufficient optical path length for measurement. [Explanation of symbols]

[0047] 1...Packaging material, 10...pillow packaging bag, 11...packaging space, 12...first sealed portion, 13...second sealed portion. 15... horizontal sealing device, 16... sealer, 17, 17A... conveying path, 18... belt conveyor, 18a... placement surface, 20...Laser type gas concentration measuring device, 21... laser generating unit, 22... laser receiving unit, 23... light source, 24... control unit, 25... light receiving sensor, 26... measurement unit, P0, P0A, P0B, P0C...measurement points, P1, P1A, P1B, P1C...first points, P2, P2A, P2B, P2C...second points.

Claims

1. a vertical sealing device that rolls a long film pulled out from a film roll in the width direction and continuously seals both overlapping ends to form a cylindrical packaging material; a conveying device including a conveying path for continuously conveying the packaging material along a longitudinal direction at a predetermined conveying speed; At least one horizontal sealing device including a sealer that seals the packaging material in a width direction and intermittently operates the sealer at a predetermined cycle; A filling device for filling the packaged items; and a gas replacement device for replacing the atmosphere of the filled package with a specified inert gas, a first sealing step in which the sealer seals the packaging material in the middle to form a first sealed portion and form a packaging space partitioned by the first sealed portion; A filling step in which the packaging space is filled with the packaged item from the filling device; A gas replacement step of replacing the atmosphere of the packaged item filled in the packaging space with the inert gas; a second sealing step in which the sealer seals the packaging space to form a second sealed portion, A pillow packaging machine that forms a pillow packaging bag by sealing the packaging space filled with the packaged item with the first sealing portion and the second sealing portion, A laser gas concentration measuring device is provided near the pillow packaging machine, the laser generating unit emitting a laser beam of a specific wavelength into the packaging space and a laser receiving unit receiving the laser beam, The gas concentration measuring method for a pillow packaging bag is configured such that the laser type gas concentration measuring device transmits the laser light through the gas-substituted and sealed packaging space, and measures the gas concentration of a specific gas remaining in the packaging space based on the absorption spectrum of the specific wavelength that changes before and after the laser light passes through the packaging space, The laser gas concentration measuring device is a measuring device arranging step of arranging the laser generating unit and the laser receiving unit at a predetermined first point opposite to a measuring point provided on the pillow packaging bag formed in the second sealing step; a gas concentration measuring step of measuring the gas concentration in the packaging space for a predetermined measurement time by emitting the laser light to the measuring point while moving the laser generating unit and the laser receiving unit in parallel along the conveying path at a predetermined moving speed from the first point to a predetermined second point; a return process for returning the laser generating unit and the laser receiving unit from the second point to the first point along a predetermined return path that draws a substantially U-shaped locus on the opposite side to the conveying path, the return path having the second point as a start point and the first point as an end point, During the gas concentration measurement process, the moving speed of the laser generating unit and the laser receiving unit is synchronized with the conveying speed of the pillow packaging bag so that the laser generating unit and the laser receiving unit are stopped relative to the measurement point, A method for measuring gas concentration in a pillow packaging bag, characterized in that the laser gas concentration measuring device measures the gas concentration in the packaging space in accordance with the pillow packaging bag being transported.

2. 2. The method for measuring a gas concentration in a pillow packaging bag according to claim 1, wherein the pillow packaging bags formed in series from the packaging material conveyed by the conveying device are arranged in a vertical direction.

3. 2. The method for measuring a gas concentration in a pillow packaging bag according to claim 1, wherein the pillow packaging bags formed in series from the packaging material conveyed by the conveying device are arranged in a horizontal direction.

4. 4. The method for measuring a gas concentration in a pillow packaging bag according to claim 2 or 3, wherein the measurement points are provided so that the laser light passes through the pillow packaging bag in a width direction of the pillow packaging bag.

5. 4. A method for measuring a gas concentration in a pillow packaging bag according to claim 2 or 3, characterized in that the measurement points are provided so that the laser light passes through along the thickness direction of the pillow packaging bag.

6. a conveying path for conveying the pillow packaging bag formed by the pillow packaging machine to the vicinity of the pillow packaging machine; 2. The method for measuring a gas concentration in a pillow packaging bag according to claim 1, wherein the laser gas concentration measuring device is provided midway along the conveying path outside the pillow packaging machine.

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