WO2021124711A1 - Method for measuring gas concentration in packaging container - Google Patents

Abstract

[Problem] To provide a method for measuring the gas concentration in a packaging container, wherein a packaging container that is individually transported on a conveyor belt is measured with a laser gas concentration meter. [Solution] The present invention uses a gas concentration measurement device 10 having a laser gas concentration meter 12 which comprises a laser generation part 22 emitting laser light having a prescribed wavelength and a laser light reception part 30 receiving the laser light, and said gas concentration measurement device 10 transmits the laser light through a sealed packaging container P which has undergone gas substitution, and then measures the gas concentration of a specified gas remaining inside the packaging container on the basis of an absorption spectrum of a specified wavelength, which changes before and after passing through the packaging container. A pair of light transmission parts 44, 44, which oppose each other such that the laser light is transmissible therethrough, are respectively provided to side surface parts 43, 43 of the packaging container, and a groove 45 which cuts across a filling material 40 from one light transmission part to the other light transmission part is formed on said filling material, which fills the packaging container. The laser light emitted from the laser generation unit is transmitted from the one light transmission part along the groove to the other light transmission part and is incident to the laser light reception part.

Description

Gas concentration measurement method in the packaging container

The present invention relates to a method for measuring a gas concentration in a packaging container for measuring the gas concentration of a specific gas remaining in the package container that has been gas-replaced and sealed.

Conventionally, in the packaging process using a packaging bag, 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 to remove an inert gas such as nitrogen. Gas replacement packaging is performed in which gas is replaced with carbon dioxide or the like and then sealed. 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. 8, 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 use not only equipment for packaging bags but also predetermined packaging containers, and some package containers are transferred by a conveyor. As a type of the packaging container, for example, retort-packed white rice, jelly, jam, etc., which are filled up to the edge of the container using a predetermined container or bottle are known. For such food retort packs or bottled products, the container or bottle is sterilized by boiling, and after filling the filling, gas purging with an inert gas such as nitrogen gas is performed to prevent oxidation and spoilage. ing.
In the case of a pack container or bottle as described above, the packaging container is not individually gripped by a pair of grips as in the packaging machine described above, but is configured so that the packaging container is individually transferred on a conveyor. .. Therefore, in the packaging machine for the packaging container, it is difficult to position the packaging container to be inspected as in the gas concentration measuring device 1 described above.

Therefore, the problem to be solved by the present invention is to provide a method for measuring the gas concentration in the packaging container, which measures the packaging container individually transferred on the conveyor with a laser gas densitometer.

The method for measuring the gas concentration in a packaging container according to claim 1 includes a laser generating unit that emits laser light of a specific wavelength and a laser generating unit that emits laser light of a specific wavelength.
It has a laser type gas densitometer provided with a laser receiving unit that receives the laser light.
The laser beam is gas-substituted and transmitted through a sealed packaging container, and the gas concentration of the specific gas remaining inside the packaging container based on the absorption spectrum of a specific wavelength that changes before and after the transmission of the packaging container. It is a method of measuring the gas concentration in the packaging container to measure
The packaging container is provided with a translucent portion through which the laser beam can be transmitted.
A translucent space through which the laser beam transmitted through the translucent portion can be transmitted is formed in the object to be packaged stored in the packaging container.
The laser light emitted from the laser generating section is transmitted through the translucent section and the translucent space, and is received by the laser receiving section.

In the method for measuring the gas concentration in a packaging container according to claim 2, in the invention according to claim 1, a pair of light-transmitting portions facing each other are provided on opposite side surface portions of the packaging container.
The object to be packaged is a filling material filled in the packaging container.
The translucent space is formed on the filling along the groove formed from one of the transmissive portions to the other.
The laser light emitted from the laser generating portion passes through the translucent portion from one to the translucent portion along the translucent space in the packaging container, and is received by the laser receiving portion. It is characterized by doing so.

In the method for measuring the gas concentration in a packaging container according to claim 3, in the invention according to claim 1, an upper surface translucent portion through which the laser light can be transmitted is provided on the upper surface portion of the packaging container.
A bottom translucent portion through which the laser beam can be transmitted is provided on the bottom surface of the packaging container.
The object to be packaged is a filling material filled in the packaging container.
The translucent space is formed in the filling along the holes formed over the top translucent portion and the bottom translucent portion.
The laser light emitted from the laser generating portion passes through the upper surface translucent portion and the bottom translucent portion along the translucent space in the packaging container, and is received by the laser receiving portion. It is characterized by having done it.

In the method for measuring the gas concentration in a packaging container according to claim 4, in the invention according to claim 1, an upper surface translucent portion through which the laser light can be transmitted is provided on the upper surface portion of the packaging container.
A bottom reflecting portion capable of reflecting the laser beam is provided on the bottom surface of the packaging container.
The object to be packaged is a filling material filled in the packaging container.
The translucent space is formed in the filling along the holes formed over the top translucent portion and the bottom reflecting portion.
The laser light emitted from the laser generating portion passes through the upper surface transmissive portion along the transmissive space in the packaging container, is reflected by the bottom surface reflecting portion, and is transmitted through the upper surface transmissive portion again. Therefore, it is characterized in that the light is received by the laser light receiving unit.

The method for measuring the gas concentration in a packaging container according to claim 5 is that, in the invention according to claim 1, a plurality of the objects to be packaged contained in the packaging container are combined with one group of objects to be packaged and another. It is divided into a packaged object group, and the translucent space is formed between the packaged object groups.
One end of the translucent space is connected to one of the transmissive portions, and the other end of the transmissive space is connected to the other transmissive portion.

According to the method for measuring the gas concentration in a packaging container according to the present invention, the packaging container is provided with a translucent portion through which laser light can be transmitted, and the object to be packaged stored in the packaging container is provided with laser light transmitted through the translucent portion. Formed a translucent space through which the laser light can be transmitted, so that the laser light emitted from the laser generating portion passes through the translucent portion and the translucent space and is received by the laser receiving portion.
As a result, the laser beam having a specific wavelength can be absorbed by the specific gas in the translucent space inside the packaging container, so that the gas concentration of the specific gas remaining in the packaging container can be measured.

Further, preferably, in the case of a filling in which the object to be packaged is filled in the packaging container, a pair of translucent portions facing each other are provided on the facing side surfaces of the packaging container, and one translucent portion is provided on the filling. A light-transmitting space is formed along the groove formed over the other light-transmitting part. As a result, the optical path of the laser beam can be secured even when the object to be packaged is filled up to the edge of the packaging container. Therefore, since the laser beam having a specific wavelength can be absorbed by the specific gas, the gas concentration of the specific gas remaining in the packaging container can be measured.

Then, preferably, when the object to be packaged is a filling material as described above, a top surface translucent portion is formed on the upper surface portion of the packaging container, and a bottom surface translucent portion or a bottom surface reflecting portion is provided on the bottom surface portion. A translucent space is formed along the hole formed over the top translucent portion and the bottom translucent portion or the bottom reflecting portion. Then, the laser light is transmitted in the vertical direction, or the laser light incident from the upper surface side is reflected by the bottom surface portion and emitted to the upper surface side again. As a result, the optical path of the laser beam can be secured even when the object to be packaged is filled up to the edge of the packaging container. Therefore, since the laser beam having a specific wavelength can be absorbed by the specific gas, the gas concentration of the specific gas remaining in the packaging container can be measured.

Furthermore, when a plurality of objects to be packaged are stored in the packaging container, the objects to be packaged are divided into one group of objects to be packaged and another group of objects to be packaged in the packaging container, and between the groups of objects to be packaged. It is preferable that a translucent space is formed, one end of the transmissive space is connected to one transmissive portion, and the other end of the transmissive space is connected to the other transmissive portion. As a result, the optical path of the laser beam can be secured even if there are a plurality of objects to be packaged stored in the packaging container. Therefore, since the laser beam having a specific wavelength can be absorbed by the specific gas, the gas concentration of the specific gas remaining in the packaging container can be measured.

It is a top view which shows the outline of the structure of the apparatus about the gas concentration measuring method 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 apparatus which concerns on the gas concentration measurement method which concerns on 1st Example. It is explanatory drawing explaining the outline of the gas concentration measurement method which concerns on 1st Example. It is a side view which shows the outline of the structure of the packaging container with respect to the gas concentration measuring method which concerns on 1st Example. It is a top view which shows the outline of the structure of the apparatus about the gas concentration measuring method which concerns on 2nd Example. It is a side view along the width direction of the conveyor which shows the outline of the structure of the apparatus which concerns on the gas concentration measurement method which concerns on 2nd Example. It is a top view which shows the outline of the structure of the apparatus about the gas concentration measuring method which concerns on 3rd Example. It is a top view which shows the outline of the structure of the conventional gas concentration measuring apparatus.

An example of the gas concentration measuring method in the packaging container according to the present invention will be described with reference to the attached drawings. 1 and 2 are a plan view and a right side view showing an outline of the configuration of a gas concentration measuring device that performs the gas concentration measuring method in the packaging container according to the first embodiment. Before explaining the method for measuring the gas concentration in the packaging container according to this embodiment, the configuration of the gas concentration measuring device will be outlined below.

The gas concentration measuring device 10 includes a conveyor 11 for transferring the packaging container P and a laser gas concentration meter 12 capable of measuring the gas concentration in the packaging container P at a predetermined position on the conveyor 11.

As shown in FIG. 1, the conveyor 11 has a main rotor 15a on the start end side and a slave rotor 15b on the end side, and has a transfer belt 16 stretched between the master and slave rotors 15a and 15b with a predetermined tension. ing.
The main rotor 15a sends the transfer belt 16 in the forward direction from the start end side where the main rotor 15a is located to the end side where the slave rotor 15b is located by the stepping motor 17 which operates intermittently at a predetermined rotation speed. It is formed like this. The stepping motor 17 according to the present 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 slave rotor 15b is formed to follow the main rotor 15a via the transfer belt 16.
The packaging container P is placed on the transfer belt 16 in a predetermined orientation. The plurality of packaging containers P placed on the transfer belt 16 are supplied from outside the gas concentration measuring device 10 according to the present embodiment at predetermined intervals. As shown in FIGS. 1 and 2, a laser gas densitometer 12 is arranged in the vicinity of the center along the longitudinal direction of the transfer belt 16 with the transfer belt 16 interposed therebetween.
The conveyor 11 is formed so that the stepping motor 17 stops the transfer belt 16 when the packaging container P reaches a predetermined position sandwiched between the laser gas densitometer 12. By projecting the laser beam onto the packaging container P within the stop time, the laser gas concentration meter 12 can measure the gas concentration in the packaging container P.

As shown in FIGS. 1 and 2, the laser gas densitometer 12 has a main head 20 and a sub head 21 arranged so as to face each other with the conveyor 11 in between. The main head 20 is formed so as to be capable of emitting laser light having a specific wavelength. The sub-head 21 is configured such that the laser light emitted from the main head 20 passes through the packaging container P on the conveyor 11 and then receives light.
When the laser light of a specific wavelength is absorbed by the specific gas to be measured remaining in the packaging container P, it remains in the packaging container P based on the absorbance of the laser light received by the sub-head 21. The gas concentration of a specific gas can be measured.

As shown in FIGS. 1 and 2, the main head 20 has a laser generating unit 22 that emits laser light having a specific wavelength. The laser generation unit 22 includes a laser light source 23 and a control unit 24 that sets the wavelength of the laser light emitted from the laser light source to a specific wavelength and adjusts the wavelength to a predetermined light intensity.
The laser light source 23 includes a semiconductor laser element (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 24 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.
Further, as shown in FIG. 2, the main head 20 is formed so as to be movable along the width direction of the conveyor 11. Thereby, it can be formed so as to move from the widthwise end portion of the conveyor toward the center according to the size of the packaging container P.

The main head 20 has a lens barrel 25 connected to the laser light source 23, and a sapphire glass that easily allows light in the near infrared region to pass through is fitted into the laser emission port 25a facing the packaging container P of the lens barrel 25. ing.
The lens barrel 25 is provided with a gas valve (not shown). Thereby, the atmosphere in the lens barrel 25 can be evacuated or gas purged to a predetermined gas, the inside of the lens barrel 25 can be maintained in a vacuum, or the atmosphere in the lens barrel 25 can be nitrogen gas, carbon dioxide, or these. It is possible to replace the gas with an inert gas similar to the above. 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 25 before the laser light is emitted from the laser light source 23 through the laser emission port 25a. , The accuracy of gas concentration measurement can be improved.
Further, as shown in FIG. 2, since the main head 20 is formed so as to be movable along the width direction of the conveyor 11, the laser emission provided at the tip end portion of the lens barrel 25 with respect to the side surface portion of the packaging container P. The mouth 25a can be brought into contact with it. As a result, the influence of the atmosphere between the laser emission port 25a and the packaging container P can be extremely reduced, so that the measurement accuracy can be improved.

As shown in FIGS. 1 and 2, the sub-head 21 has a laser receiving unit 30 that receives laser light. The laser light receiving unit 30 has a light receiving sensor 31 that receives the laser light transmitted through the packaging container P, and a measuring unit 32 that measures the gas concentration based on the light receiving signal from the light receiving sensor 31.
The light receiving sensor 31 has an element that converts the transmitted light intensity of the laser light transmitted through the packaging container P 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 container P can be electrically processed.
The measuring unit 32 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 20, 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 container P is measured based on the absorbance.
Further, as shown in FIG. 2, the sub-head 21 is formed so as to be movable along the width direction of the conveyor 11. Thereby, it can be formed so as to move from the widthwise end portion of the conveyor toward the center according to the size of the packaging container P.

In the light receiving sensor 31 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 31a facing the packaging container P, like the lens barrel 25.
Similar to the lens barrel 25, the casing of the light receiving sensor 31 is also provided with a gas valve (not shown). As a result, the atmosphere inside the light receiving sensor 31 can be evacuated or gas purged to a predetermined gas, and the inside of the light receiving sensor 31 can be maintained in a vacuum, or the atmosphere inside the light receiving sensor 31 can be made of nitrogen gas, carbon dioxide, or these. It is possible to replace the gas with an inert gas similar to the above. 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 31 until the laser light is received by the photodiode from the laser light receiving port 31a. The accuracy of gas concentration measurement can be improved.
Further, as shown in FIG. 2, since the sub-head 21 is formed so as to be movable along the width direction of the conveyor 11, the laser receiver provided at the tip of the light receiving sensor 31 with respect to the side surface portion of the packaging container P. The mouth 31a can be brought into contact with the mouth 31a. As a result, the influence of the atmosphere between the laser light receiving port 31a and the packaging container P can be extremely reduced, so that the measurement accuracy can be improved.

As described above, as shown in FIG. 1 or 2, the laser gas densitometer 12 emits laser light from the main head 20 provided with the laser generating unit 21, and the laser light is directed to the packaging container P to be measured. The sub-head 21 provided with the laser light receiving unit 30 is configured to transmit the laser light and receive the laser light transmitted through the packaging container P.

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. 3, the wavelength variable semiconductor laser absorption spectroscopy (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, as shown in FIG. 1 or 2, the laser light output from the laser light source 23 provided in the laser generation unit 21 of the main head 20 is a nitrogen gas that may be mixed with oxygen gas. The filled packaging container P is transmitted, and the transmitted laser light absorbed by the oxygen gas is received by the light receiving sensor 31 provided in the laser light receiving unit 30 of the sub head 21, and the transmittance is obtained from the transmitted light intensity. , It is a method of measuring a gas concentration from the absorbance of a laser beam 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 the packaging container P. 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. 3, Lambert-Beer's law is that the incident light intensity is I ₀ , the transmitted light intensity transmitted through the packaging container P 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 25a of the main head 20 and the laser light receiving port 31a of the sub head 21 facing each other across the conveyor 11. 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 container P can be obtained, it remains in the packaging container P. The gas concentration C related to the oxygen gas can be obtained.
Here, since the oxygen gas is sealed in the packaging container P, 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 densitometer 12 according to the present embodiment shown in FIG. 1, the laser light receiving port 31a of the sub head 21 is arranged on the optical axis of the laser light emitted from the main head 20, but the present invention is limited to this. Instead, for example, a reflector is provided to reflect the laser beam between the main head 20 and the sub head 21 multiple times, or the laser beam is passed through the packaging container P so as to diagonally cross the packaging container P. 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.

As shown in FIG. 4, the packaging container P according to the present embodiment includes a container body 41 in which the object to be packaged 40 is stored and a lid portion 42 for sealing the container body 41. As shown in FIG. 1, the container body 41 is formed in a substantially rectangular shape when viewed in a plan view, and translucent portions 44, 44 through which laser light can be transmitted are formed on the opposite side surface portions 43, 43, respectively. There is. The translucent portion 44 is formed in a window made of a transparent material as shown by a dotted line in FIG. As a result, when the laser light is projected onto the translucent portion 44 provided on one side surface portion 43, the laser light can be transmitted to the translucent portion 44 provided on the other side surface portion 43.
The window is not limited to the window shown by the translucent portion 44 according to the present embodiment. For example, the entire side surface portion 43 or the entire container body 41 may be formed of a transparent material, and the side surface portion 43 or the container body may be formed. Even when 41 is colored, at least the translucent portion 44 may be a color capable of transmitting laser light in the near infrared region of the laser gas densitometer 12 or a translucent material.

The packaged object 40 housed in the container body 41 is a filling material filled in the container body 41 as shown in FIGS. 1 and 2, and FIG. A groove 45 is formed on the upper surface of the filling. The groove portion 45 is formed so as to traverse the object to be packaged 40 from one translucent portion 44 to the other transmissive portion 44. Then, a translucent space 45a is formed from one translucent portion 44 toward the other transmissive portion along the groove portion 45. As a result, the laser light incident on one translucent portion 44 can pass through the other transmissive portion 44 without being blocked or scattered by the object to be packaged 40.
The object to be packaged 40 to be stored in the container body 41 is preferably one having a small fluidity that can be filled in the container body 41. There are pastes such as jam, wasabi, mustard, and mayonnaise, and if the groove 45 can be formed, for example, a semi-solid such as jelly or a solid such as tofu may be used, and further. , Boiled beans, boiled soybeans, pickles, etc. may be fine. That is, when measuring the gas concentration at which the laser light must be transmitted from one translucent portion 44 to the other translucent portion 44, the shape of the groove portion 45 is maintained so that the laser light does not touch the packaged object 40. This is because it is sufficient if this can be done, and then, as time goes by, or when the packaging container P is being transported, the object to be packaged 40 may be leveled and the groove 45 may disappear. Therefore, the groove 45 may be formed in advance before the filling 40 is filled, and then the packaging container P may be filled, or the packaging container P may be filled with the packaged object 40 and then the rod body may be charged on the surface of the packaged object 40. It may be pressed against the surface to form the groove portion 45.
The packaging container P according to the present embodiment is a container body 41 made of a substantially rectangular flat synthetic resin filled with retort white rice, but the present invention is not limited to this, and the packaging container P is, for example, , A glass bottle, a plastic case, a tube, or the like, which may be a translucent container through which laser light can be transmitted.

Using the gas concentration measuring device 10 having the above configuration, the gas concentration measuring method in the packaging container P according to this embodiment is executed. The explanation will be given according to the attached drawings.

As shown in FIG. 4, the packaging container P to be measured is formed so that the packaged object 40 is housed in the container body 41. Here, the object to be packaged 40 is a filler to be filled in the packaging container P. A groove 45 is formed on the packaged object 40. The groove 45 is formed from one of the translucent portions 44 and 44 formed on the side surface portions 43 and 43 of the container body 41 of the packaging container P, respectively, from one transmissive portion 44 to the other transmissive portion 44. There is. As a result, a light-transmitting space 45a is formed in the packaging container P along the groove 45.
The container body 41 filled with the object to be packaged 40 having the groove portion 45 is sealed with a lid portion 42 after the inside of the container is replaced with an inert gas such as nitrogen gas. The sealed packaging container P is placed on the conveyor 11 of the gas concentration measuring device 10. The conveyor 11 sequentially transfers a plurality of packaging containers P from the start end side to the end end side in an intermittent operation.

In the laser gas densitometer 12, the main head 20 and the sub head 21 are arranged with the conveyor 11 interposed therebetween, and when the packaging container P is transferred between the main head 20 and the sub head 21, the conveyor 11 is moved. It is temporarily stopped by the stepping motor 17 that operates intermittently at a predetermined cycle. When the conveyor 11 is temporarily stopped, the light transmitting portions 44, 44 of the packaging container P are arranged at predetermined positions between the main head 20 and the sub head 21.
Then, within this stop time, the laser gas concentration meter 12 irradiates the packaging container P with laser light to measure the gas concentration of the oxygen gas remaining in the packaging container P.
The laser light emitted from the laser generating portion 22 provided on the main head 20 is incident on one translucent portion 44 provided on the side surface portion 43 of the packaging container P, and travels on the packaged object 40 along the groove 45. It transmits light, passes through the other translucent unit 44, and is received by the laser light receiving unit 30 provided on the sub head 21. The intensity of the transmitted light of the received laser light is compared with the intensity of the incident light to determine the absorbance, and the gas concentration in the packaging container P is measured based on the absorbance.
At this time, the main head 20 or the sub head 21 approaches each other toward the packaging container P, and the laser emitting port 25a provided at the tip of the lens barrel 25 included in the laser generating portion 22 of the main head 20 and the laser receiving light of the sub head 21. The laser light receiving port 31a provided at the tip of the light receiving sensor 31 included in the unit 30 may come into contact with the translucent parts 44, 44 of the packaging container P, respectively. As a result, the influence of the atmosphere between the laser emission port 25a or the laser light receiving port 31a and the packaging container P can be eliminated as much as possible, so that the measurement accuracy in the packaging container P can be improved.
The packaging container P irradiated with the laser beam is formed so as to flow to the downstream side of the conveyor 11 and move from the terminal side of the conveyor 11 to, for example, the shipping process. Here, as a result of measurement with the laser type gas concentration meter 12, the packaging container P whose gas concentration is higher than the predetermined concentration and fails the inspection is excluded without moving to the shipping process.

Next, a second embodiment of the gas concentration measuring method in the packaging container according to the present invention will be described with reference to the attached drawings. 5 or 6 is a plan view and a right side view showing an outline of the configuration of a gas concentration measuring device that performs the gas concentration measuring method in the packaging container according to the second embodiment. FIG. 5 omits the laser gas densitometer 12, and FIG. 6 shows an outline of the configuration according to the cross-sectional view taken along the line AA of FIG.

In the second embodiment, the configuration of the packaging container P2, the method of attaching the laser gas densitometer, and the measurement method are different from those of the first embodiment.
In the laser type gas densitometer 12A, the mounting angles of the main head 20A and the sub head 21A are different from those of the first embodiment. Since the configurations of the laser generating unit 22 and the laser receiving unit 30 are the same as those in the first embodiment, the description thereof will be omitted.
As shown in FIG. 6, the main head 20A and the sub head 21A are attached to each other at a predetermined angle with respect to the conveyor 11A. At the predetermined angle, the laser light emitted from the laser emission port 25a of the lens barrel 25 of the laser generation unit 22 is reflected on the surface of the transfer belt 16A of the conveyor 11A, and the laser light receiving port 31a of the light receiving sensor 31 of the laser receiving unit 30 is reflected. Is the angle at which light can be received. By making the laser beam reflective in this way, as shown in FIG. 6, even in a relatively narrow translucent space sandwiched between the objects to be packaged 50, an optical path length sufficient for measuring the gas concentration can be obtained. Can be secured.

Further, the transfer belt 16A of the conveyor 11A is made of a transparent and flexible synthetic resin material. A table (not shown) provided with a mirror body is arranged on the lower surface of the transfer belt between the main head 20A and the sub-head 21A of the conveyor 11A with the mirror surface (not shown) facing up. As a result, the laser light emitted from the laser generating unit 22 of the main head 20A can be reflected by the transfer belt 16A and received by the sub head 30.
If the laser beam is configured to be reflective, for example, a metal foil may be deposited on the transfer belt 16A itself.

As shown in FIGS. 5 and 6, the packaging container P2 according to the present embodiment includes a container body 51 in which the object to be packaged 50 is stored and a lid portion 52 for sealing the container body 51.
As shown in FIG. 5, the container body 51 is formed in a substantially rectangular shape when viewed in a plan view, and a bottom translucent portion 51a through which laser light can be transmitted is formed on the bottom surface of the container body 51 at a predetermined position. ing.
In the lid portion 52, the upper surface transmissive portion 52a is formed at a predetermined position facing the bottom translucent portion of the container body 51. As a result, as shown in FIG. 6, when the laser light is projected onto the top translucent portion 52a, the laser light passes through the bottom translucent portion 52a, is reflected by the transfer belt 16A, and is again again. The upper surface translucent portion 52a can be transmitted.

It should be noted that the laser beam can be reflected on the bottom surface of the container body 51 by depositing a metal foil on the inner surface of the bottom surface instead of the configuration of the top surface translucent portion 52a and the bottom surface translucent portion 51a as shown in this embodiment. The bottom surface reflecting portion (not shown) may be formed, and the laser light incident from the top surface transmissive portion 52 may be reflected by the bottom surface reflecting portion so as to be transmitted through the top surface transmissive portion 52a again. Even with this configuration, the residual gas concentration in the packaging container P2 can be measured with laser light in the same manner as described above.
Further, even when the container body 51 or the lid portion 52 is colored, at least the top surface transmissive portion 52a and the bottom surface translucent portion 51a transmit the laser light in the near infrared region of the laser gas densitometer 12. Any color that is possible or a translucent material may be used.

The packaged object 50 housed in the container body 51 is a filling material filled in the container body 51 as shown in FIGS. 5 and 6. The filling is a viscous object, and as shown in FIG. 5, a hole 55 penetrating in the vertical direction is formed in the central portion of the container body 51 for a predetermined time. In the packaged object 50 illustrated in FIG. 5, a viscous packaged object is arranged near the four corners of the container body 51, and a substantially diamond-shaped hole 55 is formed in the central portion. If the hole 55 can be formed, the storage is not limited to that as illustrated in FIG. 5, and for example, the hole 55 is formed in the object to be packaged 50 and then stored in the container body 51. You may.
Then, a translucent space 55a is formed from the top transmissive portion 52a toward the bottom translucent portion 51a along the hole portion 55. As a result, the laser light incident on the top surface transmissive portion 52a is transmitted through the bottom surface transmissive portion 51a without being blocked or scattered by the object to be packaged 50, reflected by the transfer belt 16A, and again the bottom surface transmissive portion. It can transmit through 51a, the translucent space 55a, and the upper surface translucent portion 52a.
The object to be packaged 50 stored in the container body 51 preferably has low fluidity and high viscosity that can be filled in the container body 51. For example, freshly made rice cake or miso, jam, wasabi, etc. There are paste-like ones such as mustard and mayonnaise, and if the holes 55 can be formed, for example, semi-solid ones such as jelly or solid ones such as tofu may be used. That is, when measuring the gas concentration at which the laser beam must be reflected and transmitted between the top surface transmissive portion 52a and the bottom surface transmissive portion 51a, the shape of the hole portion 55 is maintained so that the laser beam does not touch the packaged object 50. After that, the object to be packaged 50 may be leveled and the hole 55 may disappear over time or when the packaging container P2 is being transported. Therefore, the hole 55 may be formed in advance before filling the packaged object 50 and then filled in the packaging container P2, or the packaged object 50 may be filled in the packaging container P2 and then the rod body is packed in the packaged object. The hole 55 may be formed by pressing against the surface of the 50.
The packaging container P2 according to the present embodiment is a container body 51 made of a substantially rectangular flat synthetic resin filled with four rice cakes, but the present invention is not limited to this, and the packaging container P2 is not limited to this. For example, it may be a translucent container through which laser light can be transmitted, such as a glass bottle, a plastic case, and a tube.

Using the gas concentration measuring device 10A having the above configuration, the gas concentration measuring method in the packaging container P2 according to this embodiment is executed. The explanation will be given according to the attached drawings.

As shown in FIG. 4, the packaging container P2 to be measured is formed so that the packaged object 50 is housed in the container body 51. Here, the object to be packaged 50 is a filler to be filled in the packaging container. A substantially diamond-shaped hole 55 is formed in the central portion of the object to be packaged 50. The hole 55 is formed from the bottom translucent portion 51a formed on the bottom surface of the container body 51 of the packaging container P2 to the top translucent portion 52a formed on the lid portion 52. As a result, a light-transmitting space 55a is formed in the packaging container P2 along the hole 55. As shown in FIG. 5, the hole portion 55 may become smaller with time, and finally the packaged object 50 may be leveled and disappear.
The container body 51 filled with the object to be packaged 50 having the holes 55 is sealed with a lid 52 after the inside of the container is replaced with an inert gas such as nitrogen gas. The sealed packaging container P2 is placed on the conveyor 11 of the gas concentration measuring device 10A. The conveyor 11 sequentially transfers a plurality of packaging containers P2 from the start end side to the end end side in an intermittent operation.

In the laser gas densitometer 12A, the main head 20A and the sub head 21A are arranged with the conveyor 11 interposed therebetween, and when the packaging container P2 is transferred between the main head 20A and the sub head 21A, the conveyor 11A It is temporarily stopped by the stepping motor 17 that operates intermittently at a predetermined cycle. When the conveyor 11A is temporarily stopped, the top translucent portion 52a and the bottom translucent portion 51a of the packaging container P2 are arranged at predetermined positions between the main head 20A and the sub head 21A.
Then, within this stop time, the laser gas concentration meter 12A irradiates the packaging container P2 with laser light to measure the gas concentration of the oxygen gas remaining in the packaging container P2.
As shown in FIG. 6, the laser light emitted from the laser generating portion 22 provided on the main head 20A is incident from the upper surface transmissive portion 52a of the packaging container P2 and is filled along the translucent space 55a of the hole portion 55. It passes between objects 50, passes through the bottom surface transmissive part 51a, reflects on the transfer belt 16A, and again passes through the bottom surface transmissive part 51a, the translucent space 55a, and the top surface transmissive part 52a, and the sub head. The light is received by the laser light receiving unit 30 provided in 21A. The intensity of the transmitted light of the received laser light is compared with the intensity of the incident light to determine the absorbance, and the gas concentration in the packaging container P2 is measured based on the absorbance.
Even when the bottom surface reflecting portion is provided on the bottom surface portion of the container body 51, the laser beam can be reflected in the same manner as described above, and the gas concentration in the packaging container P2 can be measured in the same manner.
At this time, as in the first embodiment, the main head 20A or the sub head 21A approaches each other toward the packaging container P2, and the laser emission port 25a provided at the tip of the lens barrel 25 included in the laser generating portion 22 of the main head 20A. , And the laser light receiving port 31a provided at the tip of the light receiving sensor 31 included in the laser light receiving part 30 of the sub head 21A may come into contact with the upper surface transmissive part 52a of the packaging container P2, respectively. As a result, the influence of the atmosphere between the laser emission port 25a or the laser light receiving port 31a and the packaging container P2 can be eliminated as much as possible, so that the measurement accuracy in the packaging container P2 can be improved.
The packaging container P2 irradiated with the laser beam is formed so as to flow to the downstream side of the conveyor 11A and move from the terminal side of the conveyor 11A to, for example, the shipping process. Here, as a result of measurement with the laser type gas concentration meter 12A, the packaging container P whose gas concentration is higher than the predetermined concentration and fails the inspection is excluded without moving to the shipping process.

Next, a third embodiment of the gas concentration measuring method in the packaging container according to the present invention will be described with reference to the attached drawings. FIG. 7 is a plan view showing an outline of the configuration of a gas concentration measuring device that performs the gas concentration measuring method in the packaging container according to the third embodiment.

In the third embodiment, the configuration of the packaging container P3 is different from that in the first embodiment and the second embodiment, but the other configurations and measurement methods are the same as those in the first embodiment, and thus the description thereof will be omitted.

As shown in FIG. 7, the packaging container P3 according to the present embodiment includes a container body 61 in which a plurality of objects to be packaged 60 are stored, and a lid portion 62 for sealing the container body 61. The container body 61 is formed in a substantially rectangular shape when viewed in a plan view as shown in FIG. 7, and translucent portions 64 and 64 through which laser light can be transmitted are formed on the opposite side surface portions 63 and 63, respectively. There is. The translucent portion 64 is formed in a window made of a transparent material as shown by a dotted line in FIG. As a result, when the laser light is projected onto the translucent portion 64 provided on one side surface portion 63, the laser light can be transmitted to the translucent portion 64 provided on the other side surface portion 63.
The window is not limited to the window shown by the translucent portion 64 according to the present embodiment. For example, the entire side surface portion 63 or the entire container body 61 may be formed of a transparent material, and the side surface portion 63 or the container body may be formed. Even when 61 is colored, at least the translucent portion 64 may be a color capable of transmitting laser light in the near infrared region of the laser gas densitometer 12 or a translucent material.

As shown in FIG. 7, the packaged objects 60 in which a plurality of the objects to be packaged are stored in the container body 61 are arranged close to the side surface portions 63a and 63b of the container body 61 where the translucent portion 64 is not formed. The packaged object group 60a and the other packaged object group 60b are arranged and stored separately. A translucent space 65 is formed between the packaged objects 60a and 60b. The light-transmitting space 65 is formed so as to cross between the packaged objects 60a and 60b from one light-transmitting portion 64 to the other light-transmitting portion 64. As a result, the laser light incident on one translucent portion 64 can be transmitted through the other transmissive portion 64 without being blocked or scattered by the object to be packaged 60.
The packaged object 60 to be stored in the container body 61 is preferably a plurality of objects to be stored in the container body 61, for example, there are donuts, cakes, manjus, etc., and the packaged object 60 is packaged. For example, tofu or cake may be used as long as the translucent space 65 can be formed by storing the groups 60a and 60b separately. That is, when measuring the gas concentration at which the laser light must be transmitted from one translucent portion 64 to the other transmissive portion 64, the translucent space 65 is maintained between the packaged items 60a and 60b, and the laser beam is applied. It is sufficient to be able to avoid touching the package 60.
The packaging container P3 according to the present embodiment is a container body 61 made of a substantially rectangular flat synthetic resin in which a plurality of small donuts are stored, but the packaging container P3 is not limited to this. , For example, a glass bottle, a plastic case, a tube, or the like, which may be a translucent container through which laser light can be transmitted.

Using the gas concentration measuring device 10B having the above configuration, the gas concentration measuring method in the packaging container P3 according to this embodiment is executed, but the measuring method is the same as that in the first embodiment. Is omitted.

According to the gas concentration measuring method according to the present embodiment, the main heads 20 are arranged so as to face the packaging containers P, P2, and P3 that are individually transferred on the conveyors 11 and 11A with the conveyors 11 and 11A in between. The gas concentration in the packaging containers P, P2, and P3 can be measured by using the laser type gas densitometers 12 and 12A provided with the sub-head 21.
It should be noted that the present invention is not limited to the objects to be packaged 40, 50, 60 stored in the packaging containers P, P2, and P3 described in each of the above embodiments, and as mentioned in the above description, laser light can be transmitted. A method for measuring the gas concentration of a packaging container, if a translucent space as shown in each of the above examples can be secured between objects to be packaged in a glass bottle, a plastic case, a tube, or various other containers made of various materials. Can be applied.

10, 10A, 10B ... Gas concentration measuring device, P, P2, P3 ... Packaging container 11 ... Conveyor, 12, 12A ... Laser gas concentration meter,
15a ... main rotor, 15b ... slave rotor, 16, 16A ... transfer belt, 17 ... stepping motor,
20 ... main head, 21 ... sub head,
22 ... Laser generator, 23 ... Laser light source, 24 ... Control unit, 25 ... Lens barrel, 25a ... Laser outlet,
30 ... Laser light receiving unit, 31 ... Light receiving sensor, 31a ... Laser light receiving port, 32 ... Measuring unit,
40, 50, 60 ... Packaged object, 41, 51, 61 ... Container body, 42, 52, 62 ... Lid part, 43, 63 ... Side part, 44, 64 ... Translucent part, 45 ... Groove part,
51a ... bottom translucent part, 52a ... top translucent part, 55 ... hole part,
60a, 60b ... Packaged items,

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, B ... Packaging bag.

Claims (5)

1. A laser generator that emits laser light of a specific wavelength,
   It has a laser type gas densitometer provided with a laser receiving unit that receives the laser light.
   The laser beam is gas-substituted and transmitted through a sealed packaging container, and the gas concentration of the specific gas remaining inside the packaging container based on the absorption spectrum of a specific wavelength that changes before and after the transmission of the packaging container. It is a method of measuring the gas concentration in the packaging container to measure
   The packaging container is provided with a translucent portion through which the laser beam can be transmitted.
   A translucent space through which the laser beam transmitted through the translucent portion can be transmitted is formed in the object to be packaged stored in the packaging container.
   A method for measuring a gas concentration in a packaging container, characterized in that the laser light emitted from the laser generating portion is transmitted through the translucent portion and the translucent space and received by the laser receiving portion. ..
2. A pair of light-transmitting portions facing each other are provided on opposite side surface portions of the packaging container.
   The object to be packaged is a filling material filled in the packaging container.
   The translucent space is formed on the filling along the groove formed from one of the transmissive portions to the other.
   The laser light emitted from the laser generating portion is transmitted from one of the transmissive portions to the other transmissive portion along the transmissive space in the packaging container, and is received by the laser receiving portion. The method for measuring gas concentration in a packaging container according to claim 1, wherein the gas concentration is measured as described above.
3. An upper surface transmissive portion through which the laser beam can be transmitted is provided on the upper surface portion of the packaging container.
   A bottom translucent portion through which the laser beam can be transmitted is provided on the bottom surface of the packaging container.
   The object to be packaged is a filling material filled in the packaging container.
   The translucent space is formed in the filling along the holes formed over the top translucent portion and the bottom translucent portion.
   The laser light emitted from the laser generating portion passes through the upper surface translucent portion and the bottom translucent portion along the translucent space in the packaging container, and is received by the laser receiving portion. The method for measuring the gas concentration in a packaging container according to claim 1, wherein the method is characterized by the above.
4. An upper surface transmissive portion through which the laser beam can be transmitted is provided on the upper surface portion of the packaging container.
   A bottom reflecting portion capable of reflecting the laser beam is provided on the bottom surface of the packaging container.
   The object to be packaged is a filling material filled in the packaging container.
   The translucent space is formed in the filling along the holes formed over the top translucent portion and the bottom reflecting portion.
   The laser light emitted from the laser generating portion passes through the upper surface transmissive portion along the transmissive space in the packaging container, is reflected by the bottom surface reflecting portion, and is transmitted through the upper surface transmissive portion again. The method for measuring the gas concentration in a packaging container according to claim 1, wherein the laser receiving unit receives light.
5. The plurality of objects to be packaged stored in the packaging container are divided into one group of objects to be packaged and another group of objects to be packaged, and the translucent space is formed between the groups of objects to be packaged.
   The first aspect of the present invention, wherein one end of the translucent space is connected to one of the transmissive portions, and the other end of the transmissive space is connected to the other transmissive portion. A method for measuring the gas concentration in a packaging container.

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