JP2021096133A - Gas concentration measuring device for packaging bags - Google Patents

Abstract

To provide a gas concentration measuring device for packaging bags, with which it is possible to measure packaging bags with a laser type gas densitometer that are individually transported on a conveyor, especially it is possible to measure gas concentration in a pillow packaging bag.SOLUTION: A gas concentration measuring device 10 is constituted so as to emit a laser beam of a specific wavelength from a main head 25 so as to pass through a pillow packaging bag B, receive the laser beam with a sub-head 26 and measure gas concentration of a specific gas remaining inside of the packaging bag, on the basis of an absorption spectrum of the specific wavelength that changes before and after passage through the packaging bag. A pair of guides 13a, 13b is arranged, across a conveyor 11 that intermittently transports packaging bas that are placed thereupon, on both sides in a width direction of the conveyor so as to face each other. When a packaging bag placed on the conveyor is transported to between the main head and the sub-head, the packaging bag is held between the two guides, with an upper part of the packaging bag thereby inflated, so that the laser beam passes through a measurement space formed inside of the inflated packaging bag.SELECTED DRAWING: Figure 1

Description

The present invention relates to a packaging bag gas concentration measuring device for measuring the gas concentration of a specific gas remaining in a gas-replaced and sealed packaging bag, and particularly for packaging bag gas concentration measurement in which the packaging bag is made by pillow packaging. It is about the device.

Conventionally, in the packaging process, the air in the packaging bag containing a specific oxidation-causing gas that may shorten the storage period or the taste period of the packaged object is removed, and the gas is converted into an inert gas such as nitrogen or carbon dioxide. Gas replacement packaging is performed after replacement and sealing. As a result, the oxidation-causing gas inside the packaging bag is removed, and the packaged object, particularly the food, can secure a long storage period and a shelf life.
Then, in the inspection step after gas replacement packaging, inspection is performed to see if the concentration of the oxidation-causing gas, particularly oxygen, is equal to or less than the predetermined value.
However, the current mainstream method for measuring oxygen concentration is a sampling test in which an injection needle is inserted into a packaging bag arbitrarily selected as a sample and the composition of a small amount of gas sucked from the packaging bag is inspected. In the sampling inspection, the packaging bag on which the injection mark is formed must be discarded. Further, if the number of samples is increased in order to improve the inspection accuracy, the inspection time becomes long, and there is a disadvantage that the economic and time loss increases due to the increased amount of waste.

On the other hand, the applicant of the present application has developed a gas concentration measuring device capable of measuring the concentration of a specific gas inside without damaging the packaging bag.
As shown in FIG. 9, the packaging bag gas concentration measuring device 1 disclosed in Japanese Patent Application Laid-Open No. 2010-107197 is connected to a laser generating unit 2 having a transmitter and the laser generating unit 2, and a laser beam is emitted. It is composed of a main head 3 to be generated, a laser light receiving unit 4 having a receiver, and a sub head 5 which is connected to the laser light receiving unit 4 and receives laser light. The main head 3 and the sub head 5 provided so as to be relatively close to each other and separated from each other sandwich the packaging bag B to be inspected held by the pair of grips 6 and 6, and the sub head 5 is relative to the main head 3. Are arranged so that they face each other. As a result, the laser beam can pass through the packaging bag from the main head 3 to the sub head 5 at the shortest distance, and when measuring the concentration of a specific gas such as oxygen remaining in the packaging bag, the packaging bag All of them can be measured quickly without damaging the packaging bag at all.

JP-A-2010-107197

However, in the gas concentration measuring device 1, the preformed packaging bag B is supplied to the packaging machine, and both ends of the packaging bag B near the bag mouth are gripped by grip pairs 6 and 6, and the packaging is filled with the filling. It corresponds to the machine. In the case of the packaging machine, since each packaging bag is gripped by a pair of grips, it can be easily fixed when transferred between the main head and the sub head of the laser gas densitometer, and has high accuracy. Measurements can be made.
On the other hand, some packaging machines transfer packaging bags by a conveyor instead of a pair of grips. A pillow packaging machine is known as a type of packaging machine in which a packaging bag after packaging is transferred on a conveyor.
The pillow wrapping machine rolls a strip-shaped film, seals the overlapping both ends on the back side to form a cylinder, places a filling inside the cylinder, and then replaces the inside of the cylinder with gas. This is a wrapping machine that seals and seals both front and rear ends of a cylinder, and sequentially transfers pillow packaging bags with the sealed portions separated at both front and rear ends on a conveyor.
In the case of the pillow packaging machine, the packaging bags are not individually gripped by the grip pair, and after the filling is packaged, the packaging bags are individually transferred on the conveyor. Therefore, the pillow packaging bag is measured for the above gas concentration. It is difficult to position the device 1 between the main head and the sub head.

Therefore, the problem to be solved by the present invention is that the packaging bags individually transferred on the conveyor can be measured with a laser gas densitometer, and in particular, the packaging capable of measuring the gas concentration in the pillow packaging bag. It is to provide a gas concentration measuring device for a bag.

The gas concentration measuring device for a packaging bag according to claim 1 emits laser light of a specific wavelength from the main head so as to pass through the packaging bag, receives the laser light with the sub-head, and transmits the laser light to the packaging bag. A packaging bag gas concentration measuring device that measures the gas concentration of a specific gas remaining inside the packaging bag based on an absorption spectrum of a specific wavelength that changes before and after.
A pair of guides are arranged so as to face each other on both sides in the width direction of the conveyor, sandwiching the conveyor on which the packaging bag is placed and intermittently transferred.
When the packaging bag placed on the conveyor is transferred between the main head and the sub-head, the packaging bag is sandwiched between both guides and the upper part of the packaging bag swells, so that the inside of the packaging bag is measured. Form a space,
It is characterized in that the laser light is transmitted through the space to be measured.

In the invention of claim 1, the packaging bag gas concentration measuring device according to claim 2 rolls a light-transmissive film and seals both overlapping ends on the back side as the packaging bag. After forming a cylinder and placing a filling in the cylinder, a pillow packaging bag is used in which the inside of the cylinder is gas-replaced and both front and rear ends of the cylinder are sealed and sealed.
The pillow packaging bags are arranged one by one with the back side facing down and intermittently transferred by the conveyor.

The gas concentration measuring device for a packaging bag according to claim 3 comprises a guide plate in which the guides are formed so as to be in contact with each other in the invention according to claim 1 or 2.
When the guide plate approaches and is pressed so as to sandwich the pillow packaging bag,
The pillow packaging bag is characterized in that the space to be measured is formed.

In the invention according to claim 1 or 2, the guide for the gas concentration measuring device for a packaging bag according to claim 4 is larger on the upstream side than the pillow packaging bag along the longitudinal direction of the conveyor. It consists of a guide plate that is widened and gradually narrowed so that the width between the guides is gradually narrowed so as to sandwich and hold the pillow packaging bag toward the downstream direction.
When the pillow packaging bag moving on the conveyor is sandwiched and pressed by the guide plate,
The pillow packaging bag is characterized in that the space to be measured is formed.

In the invention according to claim 3 or 4, the packaging bag gas concentration measuring device according to claim 5 is provided with a window portion capable of transmitting the laser beam at a predetermined position on each of the guide plates.
When the guide plate sandwiches and presses the pillow packaging bag to form the space to be measured.
The film of the pillow packaging bag adheres to the window portion, and the film is brought into close contact with the window portion.
The laser beam emitted from the main head passes through the window portion and the space to be measured, and is incident on the sub head.

In the invention according to claim 1 or 2, in the packaging bag gas concentration measuring device according to claim 6, the guides are formed so as to be in contact with each other, and the pillow packaging bag is sandwiched and fixed by suction. Consists of a sucker device
When the suction cup device sandwiches and fixes the pillow packaging bag and pushes the pillow packaging bag close to each other.
The pillow packaging bag is characterized in that the space to be measured is formed.

According to the packaging bag gas concentration measuring device according to the present invention, when the packaging bag placed on the conveyor is transferred between the main head and the sub head, the packaging bag is sandwiched between both guides and the upper part of the packaging bag. By swelling, the laser beam is allowed to pass through the space to be measured formed inside the packaging bag.
As a result, the laser beam can be transmitted from the main head to the sub head without being blocked by the filling material, and the gas concentration in the packaging bag transferred on the conveyor can be measured by the laser gas densitometer. ..
Further, the packaging bag is preferably a pillow packaging bag in which the films are rolled and the overlapping side ends are sealed on the back side, the filling is filled, and then the front and rear ends are sealed and separated.
As a result, the inside of the pillow packaging bag in which the filling material is individually packaged and individually transferred on the conveyor can be measured with a laser gas densitometer.
Then, it is preferable that both guides that sandwich the pillow packaging bag are composed of guide plates that can be brought into contact with each other. By pressing the guide plate so as to sandwich the pillow packaging bag, the upper portion of the packaging bag can be inflated, and a space to be measured can be formed inside the packaging bag.
In addition, the guide plates that sandwich the pillow packaging bag are widened on the upstream side along the longitudinal direction of the conveyor, and the width between the guides gradually narrows toward the downstream direction so as to sandwich and hold the pillow packaging bag. It is preferable to configure from. By pressing the guide plate so as to sandwich the pillow packaging bag, the upper portion of the packaging bag can be inflated, and a space to be measured can be formed inside the packaging bag.
Here, a window portion through which laser light can be transmitted is provided at a predetermined position on any of the guide plates that are pressed close to each other and the guide plates that are fixed and narrow in width. Then, when the guide plate sandwiches and presses the pillow packaging bag, the film of the pillow packaging bag is brought into close contact with the window portion. As a result, when measuring the gas concentration in the pillow packaging bag, the influence of the atmospheric atmosphere can be eliminated as much as possible, and the gas concentration can be measured more accurately.
Further, it is preferable that both guides for sandwiching the pillow packaging bag are detachable from each other and consist of a suction cup device for sucking and fixing the pillow packaging bag. When the sucker device sandwiches and fixes the pillow packaging bag and pushes the pillow packaging bag from both sides close to each other, the upper part of the packaging bag can be inflated to form a space to be measured inside the packaging bag. Can be done.

It is a top view which shows the outline of the structure of the gas concentration measuring apparatus for a packaging bag which concerns on 1st Example. It is a side view along the longitudinal direction of the conveyor which shows the outline of the structure of the gas concentration measuring apparatus for a packaging bag which concerns on 1st Example. It is a side view along the width direction of the conveyor which shows the outline of the structure of the gas concentration measuring apparatus for a packaging bag which concerns on 1st Example. It is explanatory drawing explaining the outline of the structure of the laser type gas densitometer of the gas concentration measuring apparatus for a packaging bag which concerns on 1st Example. It is a side view along the width direction of the conveyor which shows the outline of the structure of another guide about the gas concentration measuring apparatus for a packaging bag which concerns on 1st Example. It is explanatory drawing which shows the outline of the structure of the pillow packaging bag used for the gas concentration measuring apparatus for a packaging bag which concerns on 1st Example. It is a top view which shows the outline of the structure of the gas concentration measuring apparatus for a packaging bag which concerns on 2nd Example. It is a top view which shows the outline of the structure of the gas concentration measuring apparatus for a packaging bag which concerns on 3rd Example. It is a side view which shows the outline of the structure of the conventional gas concentration measuring apparatus for a packaging bag.

An example of the gas concentration measuring device for a packaging bag according to the present invention will be described with reference to the attached drawings. FIG. 1 is a plan view showing an outline of the configuration of a gas concentration measuring device for a packaging bag according to this embodiment. 2 and 3 are side views showing an outline of the configuration of the gas concentration measuring device for a packaging bag according to the present embodiment.

The packaging bag gas concentration measuring device 10 includes a conveyor 11, two laser gas concentration meters 12A and 12B, and a pair of guides 13.
The conveyor 11 is sandwiched between the laser gas densitometers 12A and 12B and the guide pairs 13 and 13, and transfers the packaging bag B to the laser gas densitometers 12A and 12B. It is composed of a supply conveyor 11b that supplies B one by one.
The measuring conveyor 11a has a slave rotor 14a on the start end side and a main rotor 14b on the end side, and has a measurement feed belt 15 stretched between the master and slave rotors 14a and 14b with a predetermined tension.
A plurality of stoppers 16 are vertically arranged on the measurement feed belt 15 at predetermined intervals. The stopper 16 may lie down with respect to the measurement feed belt 15 after the packaging bag B has been transferred. The stoppers 16 according to this embodiment are arranged on the measurement feed belt 15 at intervals of 100 mm.
The main rotor 14b is formed so as to rotate intermittently in the forward direction by a stepping motor 14c that operates intermittently. As a result, the measurement feed belt 15 can intermittently feed the packaging bag B in the forward direction from the start end to the end of the measurement conveyor 11a. The stepping motor 14c according to this embodiment is formed so as to intermittently operate in a cycle of a rotation time of 0.8 seconds and a stop time of 0.7 seconds and to rotate in the forward direction at a rotation speed of 40 rpm.

The supply conveyor 11b has a main rotor (not shown) on the start end side and a slave rotor 20 on the end side, and has a supply feed belt 21 stretched between the master and slave rotors with a predetermined tension. The end side of the supply conveyor 11b is connected to the start end of the measurement conveyor 11a. As a result, the packaging bag B can be sent from the supply conveyor 11b to the measurement conveyor 11a.
The main rotor of the supply conveyor 11b is formed so as to continuously rotate in the forward direction by a continuously operating motor (not shown). As a result, the supply feed belt 21 can continuously feed the packaging bag B in the forward direction from the start end to the end of the supply conveyor 11b. The motor according to this embodiment is formed so as to rotate in the forward direction at a rotation speed of 80 rpm.
The conveyor 11 according to the present embodiment is configured such that the supply conveyor 11b arranges the packaging bag B on the supply feed belt 21 at a pitch of 100 mm and supplies the packaging bag B to the measuring conveyor 11a according to the motor rotation speed of 80 rpm. Has been done. On the other hand, in the measuring conveyor 11a according to the present embodiment, the stoppers 16 are erected at intervals of 100 mm and are configured to operate intermittently according to the stepping motor rotation speed of 40 rpm, so that the measuring conveyor 11a is arranged at a pitch of 100 mm from the supply conveyor 11b. Two packaging bags B are fed, that is, 100 mm × 2 at a 200 mm pitch, and the measurement feed belt 15 feeds two packaging bags B from the start end side of the measurement conveyor 11a toward the end end at the 200 mm pitch. It is formed so as to be intermittently fed.
The feed pitch of the packaging bag B according to this embodiment is not limited to the above example, and can be arbitrarily set according to the size of the packaging bag B and the like.

As described above, the measuring conveyor 11a according to the present embodiment is formed so as to intermittently feed the packaging bags B at a pitch of two each. Therefore, two laser gas densitometers 12A and 12B according to the present embodiment are arranged side by side along the measuring conveyor 11a in order to measure two packaging bags B at a time. As a result, two packaging bags B can be measured for each intermittent pitch, so that the measurement efficiency can be improved. That is, according to the gas concentration measuring device 10 according to the present embodiment, it is configured to measure two packaging bags at a time, but the present invention is not limited to this, and the intermittent pitch is used to improve the measurement efficiency. It can also be configured to measure three or more at a time.

As described above, since the two laser gas densitometers 12A and 12B are the same, they will be described below as the laser gas densitometer 12.
As shown in the figure, the laser gas densitometer 12 has a main head 25 and a sub head 26 arranged so as to face each other with the measuring conveyor 11a in between. The main head 25 is formed so as to be capable of emitting laser light having a specific wavelength. The sub-head 26 is configured such that the laser light emitted from the main head 25 passes through the packaging bag B on the measuring conveyor 11a and then receives the light.
When the laser light of a specific wavelength is absorbed by the specific gas to be measured remaining in the packaging bag B, it remains in the packaging body B based on the absorbance of the laser light received by the sub-head 26. The gas concentration of a specific gas can be measured.

As shown in FIGS. 1 and 3, the main head 25 includes a laser light source 27 and a control unit 28 that sets the wavelength of the laser light emitted from the light source to a specific wavelength and adjusts the wavelength to a predetermined light intensity. doing.
The laser light source 27 includes a semiconductor laser device (not shown) made of a diode having a variable wavelength, and is formed so as to be capable of outputting laser light in the near infrared region.
The control unit 28 adjusts the wavelength of the laser light output from the semiconductor laser element to a specific wavelength peculiar to the specific gas to be measured, and controls to amplify the laser light so that it is emitted at a predetermined incident light intensity. It is formed like this.
Here, the specific gas measured by the laser type gas densitometer 12 according to this embodiment is oxygen gas (O ₂ ). The absorption wavelength band peculiar to the oxygen gas is the 760 nm band, and among the plurality of absorption lines included in the absorption wavelength band, a specific wavelength related to one absorption line is selected as the output wavelength of the laser light.

The main head 25 has a lens barrel 29 that is connected to the laser light source 27, and a sapphire glass that easily allows light in the near infrared region to pass through is fitted into the laser emission port 29a that faces the packaging bag B of the lens barrel 29. ing.
The lens barrel 29 is provided with a gas valve (not shown). Thereby, the atmosphere in the lens barrel 29 can be evacuated or gas purged to a predetermined gas, and the inside of the lens barrel can be maintained in a vacuum or filled with nitrogen gas, carbon dioxide or an inert gas similar thereto. be able to. Therefore, it is possible to prevent the laser light from being absorbed by the specific gas, in this embodiment, the oxygen gas in the lens barrel 29 before the laser light is emitted from the laser light source 27 through the laser emission port 29a. , The accuracy of gas concentration measurement can be improved.

As shown in FIGS. 1 and 3, the sub-head 26 has a light receiving sensor 30 that receives the laser light transmitted through the packaging bag B, and a measuring unit 31 that measures the gas concentration based on the light receiving signal from the light receiving sensor. And have.
The light receiving sensor 30 has an element that converts the transmitted light intensity of the laser light transmitted through the packaging bag B into an electrically transmitted light signal, for example, a photodiode (not shown). Thereby, the transmitted light intensity of the laser light transmitted through the packaging bag B can be electrically processed.
The measuring unit 31 calculates the transmittance based on the transmitted light signal related to the transmitted light intensity and the incident light signal related to the incident light intensity of the laser light output from the main head 25, and the laser light is based on the transmittance. The absorbance of the specific gas is determined, and the concentration of the specific gas in the packaging bag B is measured based on the absorbance.

In the light receiving sensor 30 having a built-in photodiode, sapphire glass that easily allows light in the near infrared region to pass through is fitted in the laser light receiving port 30a facing the packaging bag B, like the lens barrel 29.
Similar to the lens barrel 29, the casing of the light receiving sensor 30 is also provided with a gas valve (not shown). Thereby, the atmosphere in the light receiving sensor 30 can be evacuated or gas purged to a predetermined gas, and the inside of the light receiving sensor 30 can be maintained in a vacuum, or nitrogen gas, carbon dioxide or an inert gas similar thereto can be used. Can be met. Therefore, it is possible to prevent the laser light from being absorbed by the specific gas, in this embodiment, the oxygen gas in the light receiving sensor 30 until the laser light is received by the photodiode from the laser light receiving port 30a. The accuracy of gas concentration measurement can be improved.

As described above, as shown in FIG. 1 or 3, the laser gas densitometer 12 emits laser light from the main head 25 and transmits the laser light through the packaging bag B to be measured, so that the sub head 26 Is configured to receive the laser light transmitted through the packaging bag B.

Here, the laser type gas concentration meter 12 is an instrument that analyzes the gas concentration of a specific gas sealed in a predetermined cell by tunable semiconductor laser absorption spectroscopy.
As shown in FIG. 4, the wavelength variable semiconductor laser absorption spectrometry (TDLAS) is a predetermined incident light intensity related to the laser light output from the semiconductor laser element of the laser light source, and the measurement target. The transmittance is obtained from the transmitted light intensity of the transmitted laser light absorbed by the specific gas after passing through the cell containing the gas containing the specific gas, and from the absorbance of the laser light based on the transmittance. This is a method for measuring the gas concentration.
According to this embodiment, the laser light output from the main head 25 is transmitted through the packaging bag B filled with nitrogen gas which may be mixed with oxygen gas, and the transmitted laser is absorbed by the oxygen gas. This is a method in which light is received by the sub-head 26, the transmittance is obtained from the transmitted light intensity, and the gas concentration is measured from the absorbance of the laser light based on the transmittance.

It is known that gases such as oxygen gas and nitrogen gas each have a unique absorption wavelength band, and the absorption wavelength band includes a plurality of absorption lines related to wavelengths that absorb light more strongly. .. TDLAS modulates and amplifies the wavelength of the output laser light in the near-infrared region so as to match the specific wavelength of one absorption line among the plurality of absorption lines of the specific gas to be measured. It is configured as follows. Then, the gas concentration is measured by obtaining the absorbance of the laser beam based on the absorption spectrum of a specific wavelength that changes before and after the transmission of the cell. In this embodiment, the gas to be measured is oxygen gas, and the cell that seals the gas to be measured is a packaging bag. Further, the absorption wavelength band peculiar to oxygen gas is the 760 nm band, and among a plurality of absorption lines included in the absorption wavelength band, a specific wavelength related to one absorption line is selected as the output wavelength of the laser light.

Tunable semiconductor laser absorption spectroscopy (TDLAS) measures gas concentration based on Lambert-Beer's law. As shown in FIG. 4, Lambert-Beer's law is that the incident light intensity is I ₀ , the transmitted light intensity transmitted through the packaging bag B is It, the transmittance of the transmitted light with respect to the incident light is T, and the optical path length is L. Assuming that the gas concentration is C, the relationship is such that Equation 1 holds with the absorbance A of the laser light emitted in the absorption spectrum of a specific wavelength. Here, ε is a unique absorption coefficient at which a predetermined gas to be measured absorbs laser light.

The optical path length L can be easily obtained from the distance between the laser emission port 29a of the main head 25 and the laser light receiving port 30a of the sub head 26 facing each other with the measurement conveyor 11a in between. Therefore, if the transmittance T of the transmitted light with respect to the incident light or the absorbance A of the absorption spectrum related to the specific wavelength of the laser light absorbed by the oxygen gas in the packaging bag B can be obtained, it remains in the packaging bag B. The gas concentration C related to the oxygen gas can be obtained.
Here, since the oxygen gas is sealed in the packaging bag B, when the gas concentration C is quantitatively measured, the transmittance T of the transmitted light with respect to the incident light or the absorbance A of the absorption spectrum changes significantly, that is, the absorbance. By increasing the optical path length L proportional to A, the detection sensitivity of the gas concentration can be improved.
That is, in the laser gas densitometers 12A and 12B according to the present embodiment shown in FIG. 1, the laser light receiving port 30a of the sub head 26 is arranged on the optical axis of the laser light emitted from the main head 25. For example, a reflecting mirror is provided to reflect the laser beam a plurality of times between the main head 25 and the sub head 26, or the laser beam is passed through the packaging bag so as to diagonally cross the packaging bag. , The optical path length L may be secured for a long time.
By improving the detection sensitivity in this way, for example, when the detectable range is expanded so that gas concentration of several ppm level can be detected, measurement of gas concentration of several% level can be easily performed, and the measurement accuracy thereof. Can be greatly improved.

The guides 13 are composed of a pair of guide plates 13a and 13b which are arranged to face each other on both sides of the measuring conveyor 11a in the width direction and are formed so as to be in contact with each other. One guide plate 13a is arranged in the vicinity of the main head 25 of the laser gas densitometers 12A and 12B, and the other guide plate 13b is arranged in the vicinity of the sub head 26. As shown in FIG. 3, both guide plates 13a and 13b are arranged so that their upper ends are inclined toward the measuring conveyor 11a. As a result, when both guide plates 13a and 13b come into close contact with the packaging bag B, as shown in FIG. 3, both guide plates 13a and 13b sandwich the packaging bag B to be guided in a C shape. It is configured as follows. At this time, since the packaging bag B is pressed by both guide plates 13a and 13b toward the measurement feed belt 15 side of the measuring conveyor 11a, the guide plates 13a and 13b can inflate the upper portion of the packaging bag B.
By inflating the upper part of the packaging bag B in this way, it is possible to form a space in the packaging bag B in which the filling does not interfere. By transmitting laser light through the space, the gas concentration of oxygen gas in the packaging bag B can be measured. Therefore, the space formed by inflating the upper part of the packaging bag B is referred to as a space to be measured. As shown in FIG. 2 or 3, the space to be measured is formed so as to be exposed from the upper end edges of the guide plates 13a and 13b. By projecting the laser beam onto the space to be measured exposed from the upper end edges of the guide plates 13a and 13b in this way, the gas concentration can be measured.

Further, as shown in FIG. 5, the guide plates 13a and 13b are formed large upward, and a window portion 35a through which the laser light emitted from the main head 25 can be transmitted is provided at a predetermined position of one guide plate 13a. The other guide plate 13b is provided with a window portion 35b capable of transmitting laser light at a position facing the window portion 35a provided on one guide plate 13a, and the laser light transmitted through the window portion 35 is subordinated. The head 26 may be configured to receive light.
At this time, the laser ejection port 29a at the tip of the lens barrel 29 is overlapped and brought into contact with the window 35a on the one guide plate 13a side, and the tip of the light receiving sensor 30 is brought into contact with the window 35b on the other guide plate 13b side. It is preferable that the laser light receiving ports 30a are overlapped and brought into contact with each other.
As a result, when the guide plates 13a and 13b press the packaging bag B and inflate the upper portion, the packaging bag B can be brought into close contact with the window portions 35a and 35b of both the guide plates 13a and 13b. Further, since the windows 35a and 35b are overlapped with the leather ejection port 29a of the lens barrel 29 and the laser receiving port 30a of the light receiving sensor 30, respectively, they are in contact with each other. The effect can be eliminated as much as possible. Therefore, the measurement accuracy when measuring the gas concentration of oxygen gas can be improved.

Further, as shown in FIG. 3, the sub-head 26 may be configured to approach the main head 25 of the laser gas densitometers 12A and 12B at the timing when the guide plates 13a and 13b approach each other. good. By reducing the gap between the main head 25 and the sub-head 26 and the outer film of the packaging bag B in this way, the optical path length other than the measurement space can be shortened with respect to the optical path length of the measurement space. .. With this configuration, the influence of the atmosphere can be eliminated as much as possible before and after the space to be measured through which the laser beam is transmitted, so that the measurement accuracy when measuring the gas concentration of oxygen gas can be improved.

Here, the packaging bag B according to the present embodiment is preferably what is called a pillow packaging bag, as shown in FIG. The pillow packaging bag B is formed of a strip-shaped film. It is preferable that the film can transmit light, particularly laser light in the near infrared region according to this embodiment. The strip-shaped film is rolled from both ends in the width direction of the supply conveyor 11b shown in FIG. 1, and the overlapping both ends are sealed on the back side to form a cylinder having the back seal portion 40. Then, the inside of the cylinder is filled with fillings at predetermined intervals and arranged along the longitudinal direction of the supply conveyor 11b shown in FIG. After that, the inside of the cylinder is replaced with an inert gas such as nitrogen gas (gas purge), and the cylinder is sealed between the front and back of the filling along the longitudinal direction of the supply conveyor 11b shown in FIG. .. The front seal portion 41 and the rear seal portion 42 formed before and after the filling are separated from each other, and the back sealing portion 40 is provided on the back side as shown in FIG. A pillow packaging bag B having a portion 41 and a rear seal portion 42 is formed.
As shown in FIG. 1, the pillow packaging bag B filled with the filling is placed on the supply conveyor 11b with the back seal portion 40 on the back side facing down, and even when the pillow packaging bag B is moved from the supply conveyor 11b to the measurement conveyor 11a. Further, it is moved with the back side facing down, and is transferred on the measurement feed belt of the measuring conveyor 11a with the back side facing down.
As a result, it is possible to prevent the laser light from being scattered or diffusely reflected by the back surface sealing portion 40 on which the films overlap, so that the measurement accuracy can be improved. In addition, the reason why the back seal portion 40 on which the films are overlapped is directed downward is that the pillow packaging bag B is sandwiched between the guide plates 13a and 13b when the back seal portion 40 is facing upward. At this time, since the rigidity of the back seal portion 40 is higher than that of the other film portions, it is difficult to bend, and there is a possibility that the upper portion of the pillow packaging bag B cannot be inflated well.

The gas concentration measuring device 10 having the above configuration operates as follows.
The pillow packaging bag B filled with the filling is aligned on the supply feed belt 21 sent by the main rotor rotating at 80 rpm at a pitch of 100 mm and transferred toward the end of the supply conveyor 11b.
Then, the pillow packaging bag B is partitioned by stoppers 16 erected at intervals of 100 mm, and the measurement feed belt 15 is fed by the main rotor 14b rotating at 40 rpm from the end of the supply conveyor 11b to the measurement conveyor 11a. Two are sent to the start end at a timing of 100 mm pitch x 2. As a result, one pillow packaging bag B can be arranged for each area formed by the stopper 16.

As shown in FIG. 1, the pillow packaging bag B placed on the measurement conveyor 11a is arranged in a row with the measurement feed belt 15 sandwiched between the main head 25 and the sub of the laser gas densitometers 12A and 12B. It is transferred between the heads 26.
Of the two pillow packaging bags B that are intermittently transferred, one pillow packaging bag B is transferred between the main head 25 and the sub head 26 of the laser gas concentration meter 12A, and the other pillow packaging bag B is transferred. When transferred between the main head 25 and the sub head 26 of the laser gas densitometer 12B, both guide plates 13a and 13b approach each other, sandwich both pillow packaging bags B, and the upper part of both pillow packaging bags B It is inflated to form a space to be measured.

As shown in FIG. 3, the sub-head 26 is configured to approach the main head 25 of the laser gas densitometers 12A and 12B at the timing when the guide plates 13a and 13b approach each other. As shown in FIG. 3, when the guide plates 13a and 13b are close to each other, the main head 25 and the sub head 26 face each other with the measurement space in between. Then, while the measuring conveyor 11a that is intermittently transferred is stopped, the laser beam is emitted from the main head 25, passes through the space to be measured, and is received by the sub head 26. After that, the gas concentration of the residual oxygen gas inside the pillow packaging bag B is measured, and the pillow packaging bag B having the gas concentration exceeding the reference value is regarded as rejected and provided with the gas concentration measuring device 10 according to the present embodiment. It is discharged from the inspection process of the pillow packaging bag B.

Next, an example of a gas concentration measuring device having a configuration different from that of the first embodiment will be described with reference to the attached drawings. FIG. 7 is a plan view showing an outline of the configuration of the gas concentration measuring device according to the second embodiment.
Here, the difference between the gas concentration measuring device 10 according to the first embodiment and the gas concentration measuring device 10A according to the second embodiment is related to the configuration of the guide. Since the configurations of the conveyor 11 and the laser gas densitometers 12A and 12B are the same as those in the first embodiment, the description thereof will be omitted.

The guide included in the gas concentration measuring device 10A according to the second embodiment is composed of a pair of guide plates 13c and 13d. As shown in FIG. 7, the guide plates 13c and 13d are formed so as to be twisted while the upper end edge is greatly warped in a bow shape.
Therefore, when one guide plate 13c is fixed to the side of the measuring conveyor 11a on the main head 25 side and the other guide plate 13d is fixed to the side of the measuring conveyor 11a on the sub head 26 side, both guide plates 13c and 13d are fixed. Along the longitudinal direction of the measuring conveyor 11a, the distance between the upper end edges is configured so that the upstream side expands more than the pillow packaging bag B and gradually narrows toward the downstream direction, and the laser gas densitometer 12A , The upper end edges of the guide plates 13c and 13d facing each other are configured to fall toward the measuring conveyor 11a so as to sandwich and hold the pillow packaging bag B as it approaches between the main head 25 and the sub head 26 of 12B. There is.
Therefore, both guide plates 13c and 13d fold and sandwich the front and rear sealing portions 41 and 42 as the pillow packaging bag B transferred between the guide plates 13c and 13d advances in the downstream direction, and the upper portion of the pillow packaging bag B is sandwiched. Since it can be inflated, when the pillow packaging bag B is transferred between the main head 25 and the sub head 26, a space to be measured can be formed inside the pillow packaging bag B.

The guide plates 13c and 13d according to the present embodiment also have the laser beam emitted from the main head 25 at a predetermined position of one guide plate 13c as in the variation of the guide plates 13a and 13b of the first embodiment. A transparent window portion is provided, and the other guide plate 13d is provided with a window portion capable of transmitting laser light at a position facing the window portion provided on one guide plate 13c, and a laser transmitted through the window portion is provided. The sub-head 26 may be configured to receive light.
Further, the laser emission port 29a of the lens barrel 29 is overlapped and brought into contact with the window portion on the one guide plate 13c side, and the laser light receiving port 30a of the light receiving sensor 30 is overlapped on the window portion on the other guide plate 13d side. It is preferable that they are configured to come into contact with each other.
As a result, when both the guide plates 13c and 13d press the pillow packaging bag B and inflate the upper portion, the film of the pillow packaging bag B can be brought into close contact with the window portion provided on both the guide plates 13c and 13d. Further, since the window portion is in contact with the leather injection port 29a of the lens barrel 29 and the laser light receiving port 30a of the light receiving sensor 30, the influence of the atmosphere should be eliminated as much as possible before and after the space to be measured through which the laser light is transmitted. Can be done. Therefore, the measurement accuracy when measuring the gas concentration of oxygen gas can be improved.

In the operation of the gas concentration measuring device 10A having the above configuration, the pillow packaging bag B transferred on the measuring conveyor 11a is transferred between the main head 25 and the sub head 26 of the laser type gas concentration meters 12A and 12B. At that time, with respect to a series of flows for measuring the residual oxygen gas concentration in the pillow packaging bag B by transmitting laser light through the space to be measured formed on the upper portion of the pillow packaging bag B, the gas according to the first embodiment. This is the same as the concentration measuring device 10.
However, in the gas concentration measuring device 10A according to the second embodiment, as the pillow packaging bag B is transferred on the measuring conveyor 11a, the guides are arranged so as to face each other with the measuring conveyor 11a in between and fixed to the side of the measuring conveyor 11a. When the pillow packaging bag is gradually sandwiched between the plates 13c and 13d and transferred between the main head 25 and the sub head 26 of the laser gas densitometers 12A and 12B, the space to be measured is created above the pillow packaging bag B. It was configured to be formed.
As described above, the gas concentration measuring device 10A according to the second embodiment can reduce the number of parts of the device as compared with the guide plates 13a and 13b according to the first embodiment formed so as to be in contact with each other. it can. That is, when the size of the pillow packaging bag B does not change for a long period of time depending on the product to be filled, by using the fixed guide plates 13c and 13d as in this embodiment, the number of parts can be reduced and maintenance-free. Because it can be done, the cost can be suppressed.

Next, an example of a gas concentration measuring device having a configuration different from that of the first embodiment or the second embodiment will be described with reference to the attached drawings. FIG. 8 is a side view showing an outline of the configuration of the gas concentration measuring device according to the third embodiment.
Here, the difference between the gas concentration measuring devices 10 and 10A according to the first embodiment and the second embodiment and the gas concentration measuring device 10B according to the third embodiment is related to the configuration of the guide 13. Since the configurations of the conveyor 11 and the laser gas densitometers 12A and 12B are the same as those in the first embodiment, the description thereof will be omitted.

The guide 13 included in the gas concentration measuring device according to the third embodiment includes a pair of suction cup devices 13e and 13f. One suction cup device 13e is arranged near the main head 25 of the laser gas densitometers 12A and 12B shown in FIG. 1, and the other suction cup device 12f is arranged near the sub head 26 of the laser gas densitometers 12A and 12B. To. The suction cup devices 13e and 13f have at least one, preferably a plurality of suction cups 45 formed so as to be able to move forward and backward. The suction cup 45 is configured so that the pillow packaging bag B to be adsorbed can be detachably attached. As a result, the suction cup devices 13e and 13f can freely attach / detach the pillow packaging bag B at a predetermined position. That is, when the pillow packaging bag B is transferred between the main head 25 and the sub head 26, the suction cup 45 sucks a predetermined portion of the pillow packaging bag B, so that the suction cup devices 13e and 13f mainly use the pillow packaging bag B. It can be fixed between the head 25 and the sub head 26.
The suction cups 13e and 13f facing each other attract and fix the pillow packaging bag, and the suction cups 45 formed so as to advance and retreat push the pillow packaging bag B from both sides toward the center from both ends in the width direction of the measuring conveyor 11a. The upper part of the pillow packaging bag B can be inflated, and a space to be measured can be formed inside the pillow packaging bag B.

In the operation of the gas concentration measuring device 10B having the above configuration, the pillow packaging bag B transferred on the measuring conveyor 11a is transferred between the main head 25 and the sub head 26 of the laser type gas concentration meters 12A and 12B. At that time, with respect to a series of flows for measuring the residual oxygen gas concentration in the pillow packaging bag B by transmitting laser light through the space to be measured formed on the upper portion of the pillow packaging bag B, the gas according to the first embodiment. This is the same as the concentration measuring device 10.
However, in the gas concentration measuring device 10B according to the third embodiment, when the pillow packaging bag B is transferred between the suction cup devices 13e and 13f arranged so as to sandwich the measuring conveyor 11a, the pillow packaging bag B is used. The suction cup 45 is suction-fixed and pressed from both ends of the measuring conveyor 11a in the width direction so that a space to be measured is formed in the upper part of the pillow packaging bag B.
As described above, in the gas concentration measuring device 10B according to the third embodiment, the pillow packaging bag B is sandwiched between the guide plates 13a and 13b according to the first embodiment, and between the guide plates 13c and 13d according to the second embodiment. In comparison with the configuration in which the pillow packaging bag B is slid and sandwiched between the two, the orientation of the pillow packaging bag B mounted on the measuring conveyor 11a is not limited to the front and back or the front, back, left and right directions. Even so, if it is possible to suck and fix the pillow packaging bag B to the sucker 45, when the pillow packaging bags B are transferred one by one by the stopper 16 as shown in FIG. 2, the pillow packaging is concerned. Each bag B can be sucked and fixed to form a space to be measured. That is, when a wide variety of pillow packaging bags B are transferred on the conveyor 11, they can be easily dealt with by suction-fixing them with suction cup devices 13e and 13f as in this embodiment.

In each of the above embodiments, the packaging bag to be used is a pillow packaging bag, but the present invention is not limited to this, and any packaging bag having a shape that can be transferred on a conveyor and sandwiched between guides is used. It can be applied to the gas concentration measuring device according to the example.

B ... Packaging bag, pillow packaging bag,
10, 10A, 10B ... Gas concentration measuring device, 11 ... Conveyor, 11a ... Measuring conveyor, 11b ... Supply conveyor, 12, 12A, 12B ... Laser gas concentration meter, 13 ... Guide,
13a, 13b ... Guide plate according to the first embodiment, 13c, 13d ... Guide plate according to the second embodiment, 13e, 13f ... Sucker device,
14a ... Sub-rotor of measurement conveyor, 14b ... Main rotor of measurement conveyor, 14c ... Stepping motor of measurement conveyor,
15 ... Measurement feed belt, 16 ... Stopper,
20 ... Sub-rotor of supply conveyor, 21 ... Supply feed belt,
25 ... main head, 26 ... sub head,
27 ... laser light source, 28 ... control unit, 29 ... lens barrel, 29a ... laser ejection port,
30 ... light receiving sensor, 30a ... laser light receiving port, 31 ... measuring unit,
40 ... back seal part, 41 ... front seal part, 42 ... rear seal part,
45 ... Sucker.

1 ... Conventional gas concentration measuring device, 2 ... Conventional laser generator, 3 ... Conventional main head, 4 ... Conventional laser light receiving unit, 5 ... Conventional sub head, 6 ... Grip.

Claims (6)

A laser beam of a specific wavelength is emitted from the main head so as to pass through the packaging bag, the laser beam is received by the sub head, and the packaging bag is based on an absorption spectrum of a specific wavelength that changes before and after transmission of the packaging bag. It is a gas concentration measuring device for packaging bags that measures the gas concentration of a specific gas remaining inside the bag.
A pair of guides are arranged so as to face each other on both sides in the width direction of the conveyor, sandwiching the conveyor on which the packaging bag is placed and intermittently transferred.
When the packaging bag placed on the conveyor is transferred between the main head and the sub-head, the packaging bag is sandwiched between both guides and the upper part of the packaging bag swells, so that the inside of the packaging bag is measured. Form a space,
A gas concentration measuring device for a packaging bag, characterized in that the laser beam is transmitted through the space to be measured. As the packaging bag, a film that allows light to pass through is rolled up and both overlapping ends are sealed on the back side to form a cylinder, and a filling material is placed inside the cylinder, and then the inside of the cylinder is replaced with gas. At the same time, use a pillow packaging bag that seals and seals both front and rear ends of the cylinder.
The gas concentration measuring device for a packaging bag according to claim 1, wherein the pillow packaging bags are arranged one by one with the back side facing down and intermittently transferred by the conveyor. The guides consist of guide plates formed so as to be in contact with each other.
When the guide plate approaches and is pressed so as to sandwich the pillow packaging bag,
The gas concentration measuring device for a packaging bag according to claim 1 or 2, wherein the space to be measured is formed in the pillow packaging bag. Along the longitudinal direction of the conveyor, the guides expand wider on the upstream side than the pillow packaging bag, and the width between the guides gradually narrows toward the downstream side so as to sandwich and hold the pillow packaging bag. Consists of installed guide plates
When the pillow packaging bag moving on the conveyor is sandwiched and pressed by the guide plate,
The gas concentration measuring device for a packaging bag according to claim 1 or 2, wherein the space to be measured is formed in the pillow packaging bag. Each of the guide plates is provided with a window portion through which the laser beam can be transmitted at a predetermined position.
When the guide plate sandwiches and presses the pillow packaging bag to form the space to be measured.
The film of the pillow packaging bag adheres to the window portion, and the film is brought into close contact with the window portion.
The packaging bag according to claim 3 or 4, wherein the laser beam emitted from the main head passes through the window portion and the space to be measured and is incident on the sub head. Gas concentration measuring device. The guides are formed so as to be detachable from each other, and consist of a suction cup device that sandwiches and fixes the pillow packaging bag.
When the suction cup device sandwiches and fixes the pillow packaging bag and pushes the pillow packaging bag close to each other.
The gas concentration measuring device for a packaging bag according to claim 1 or 2, wherein the space to be measured is formed in the pillow packaging bag.

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