JP7803527B2 - Inspection device and packaging machine equipped with said inspection device - Google Patents

Description

The present invention relates to an inspection device that inspects for residual gas when gas is replaced inside a packaging bag, and a packaging machine equipped with this inspection device.

In the conventional packaging process, in which the mouth of a packaging bag is opened, the contents to be packaged are filled into the bag, and the mouth is sealed to form a bag product, a method known as gas purging is known in which the air inside the packaging bag is replaced with an inert gas, such as nitrogen gas or carbon dioxide gas, to prevent oxidation and deterioration of the contents. If oxygen gas remains in the packaging bag at a concentration above a certain level after gas purging, there is a very high risk of the contents being oxidized, so it is important to measure the residual gas concentration inside the package.

Conventionally, a zirconia-type oxygen analyzer has been widely used to measure the residual gas concentration in a packaging bag. The zirconia-type oxygen analyzer has an oxygen concentration cell that generates an electromotive force corresponding to the partial pressure difference when there is oxygen partial pressure on both sides of a zirconia partition wall heated to a high temperature, and an oxygen sensor that can detect the oxygen concentration by utilizing a principle/phenomenon called an oxygen pump, in which oxygen molecules pass in the direction opposite to the current when a current is passed through the high-temperature zirconia partition wall.
In addition to the zirconia type, galvanic or polaro type oxygen sensors are also known. However, because galvanic or polaro type oxygen sensors require a container filled with an electrolyte and a gas-permeable diaphragm covering the container, they have a short lifespan due to factors such as damage or fouling of the diaphragm, evaporation of the electrolyte, and consumption of the electrolyte. Furthermore, because the detection current flows after the electrolyte reacts with the diaphragm, the response speed tends to be slow. For this reason, zirconia type oxygen sensors, which have a longer lifespan and a faster response speed than galvanic or polaro type oxygen sensors, are more commonly used.

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However, when a flammable gas such as alcohol is mixed in with the inert gas and residual oxygen gas, the zirconia oxygen sensor may cause a combustion reaction between the sensor and the high-temperature zirconia partition wall, resulting in an error in the measurement value. Such an error in the measurement value is likely to occur when the packaged item to be placed in the packaging bag is prone to generate a flammable gas such as alcohol.
Furthermore, when the high-temperature zirconia partition wall reacts with water or water vapor, hydrogen is generated. The generated hydrogen reacts with the zirconia, embrittling it. In addition to hydrogen, corrosive gases such as hydrogen may be mixed into the inert gas, reacting with the high-temperature zirconia and embrittling and corroding it. Furthermore, since the oxygen concentration cell or oxygen pump phenomenon is a type of catalytic reaction, if a toxic substance that inhibits the catalytic reaction is contained in the packaged item or is mixed into the inert gas, the sensor's function may be inhibited and deteriorated. Thus, if the oxygen sensor deteriorates depending on the type of packaged item stored in the packaging bag or the water vapor or corrosive gas mixed into the inert gas, it may need to be replaced frequently.
Furthermore, due to the structure of the sensor, the zirconia partition must be heated to a high temperature, so the oxygen analyzer must be warmed up after being turned on.If the oxygen analyzer is connected to a packaging machine, there is a risk of errors occurring until the oxygen analyzer stabilizes.

The problem that this invention aims to solve is to provide an inspection device that minimizes the measurement error of oxygen sensors, extends the product life of the oxygen sensors, and makes them maintenance-free, as well as a packaging machine equipped with this inspection device.

The inspection device according to claim 1 includes an inspection unit that inspects a gas to be inspected, the gas being inspected comprising a predetermined inert gas that is used to gas-substitute a packaging space partitioned by the seals and air remaining in the packaging space after gas substitution, after rolling a long film into a cylindrical shape and sealing it at predetermined intervals;
a gas flow passage having a suction nozzle that suctions at least the inspection target gas from the packaging space and introduces the inspection target gas into the inspection unit ,
the inspection unit includes a cylindrical gas cell having a predetermined length and a measuring device for measuring the concentration of a predetermined residual gas mixed in the inspection target gas in the gas cell;
the measuring device comprises a laser light source that generates laser light of a predetermined wavelength, an emission unit that is connected to one end of the gas cell and that emits the laser light into the gas cell, a light receiving unit that is connected to the other end of the gas cell and that receives the laser light that has passed through the gas cell, and a gas concentration meter that measures the concentration of the residual gas in the gas cell,
the gas concentration meter compares the wavelength of the laser light emitted from the emission unit with the wavelength of the laser light absorbed by the residual gas in the gas cell, and measures the concentration of the residual gas based on the absorbance of an absorption spectrum related to the absorbed wavelength;
The present invention is characterized in that the concentration of the residual gas contained in the gas to be inspected in the packaging space is inspected based on the measurement results relating to the concentration of the residual gas in the gas cell.

The inspection device according to claim 2 is the invention according to claim 1, wherein the gas flow path includes a pump that continuously sucks the inspection target gas from at least the packaging space;
a gas flow meter for measuring the flow rate of the test gas being sucked;
The gas flowmeter is characterized by including a pipeline connecting the suction nozzle, the pump, and the gas flow meter.

The packaging machine according to claim 3 includes a conveying device that rolls a long film into a cylindrical shape and seals it at predetermined intervals, and conveys a pillow-type packaging bag having a packaging space partitioned by the seals along a predetermined conveying path;
A filling device that performs a filling step of filling the packaging space with the packaged item;
a gas replacement device that performs a gas replacement step of filling the packaging space with a predetermined inert gas and replacing the packaging space with the inert gas;
A packaging machine that fills the packaging space of the pillow-type packaging bag with the packaged material on the conveying path and replaces the gas in the packaging space with the inert gas to produce a predetermined packaged product,
The packaging machine includes an inspection unit that inspects the inspection target gas, which is the inert gas that replaces the gas in the packaging space and the air that remains in the packaging space after the gas replacement;
and a gas flow path equipped with a suction nozzle that suctions at least the inspection target gas from the packaging space and introduces the inspection target gas into the inspection unit ,
the inspection unit includes a cylindrical gas cell having a predetermined length and a measuring device for measuring the concentration of a predetermined residual gas mixed in the inspection target gas in the gas cell;
the measuring device comprises a laser light source that generates laser light of a predetermined wavelength, an emission unit that is connected to one end of the gas cell and that emits the laser light into the gas cell, a light receiving unit that is connected to the other end of the gas cell and that receives the laser light that has passed through the gas cell, and a gas concentration meter that measures the concentration of the residual gas in the gas cell,
the gas concentration meter compares the wavelength of the laser light emitted from the emission unit with the wavelength of the laser light absorbed by the residual gas in the gas cell, and measures the concentration of the residual gas based on the absorbance of an absorption spectrum related to the absorbed wavelength;
The present invention is characterized in that the concentration of the residual gas contained in the gas to be inspected in the packaging space is inspected based on the measurement results relating to the concentration of the residual gas in the gas cell.

A packaging machine according to a fourth aspect of the present invention is the packaging machine according to the third aspect, further comprising: a pump configured to continuously suck the inspection target gas from at least the packaging space;
a gas flow meter for measuring the flow rate of the test gas being sucked;
The gas flowmeter is characterized by including a pipeline connecting the suction nozzle, the pump, and the gas flow meter.

According to the inspection device of the present invention, a long film is rolled into a cylindrical shape and sealed at predetermined intervals, and an inspection unit is provided to inspect the gas to be inspected, which consists of an inert gas that gas-substitutes the gas in the packaging space partitioned by the seals , and air that remains in the packaging space after the gas substitution.The inspection unit has a cylindrical gas cell of a predetermined length and a measuring device that measures the concentration of a predetermined residual gas mixed in the gas to be inspected in the gas cell.
The measuring device is a laser-type gas concentration measuring device comprising a laser light source that generates laser light of a predetermined wavelength, an emission unit that is connected to one end of the gas cell and emits the laser light into the gas cell, a light receiving unit that is connected to the other end of the gas cell and receives the laser light that has passed through the gas cell, and a gas concentration meter that measures the concentration of the residual gas in the gas cell.
Because this laser gas concentration measurement device is configured to transmit laser light through the test gas isolated in the gas cell, the sensor unit does not deteriorate like a zirconia oxygen sensor, which allows for a longer product life. Furthermore, because the test gas is isolated in the gas cell, measurement errors can be minimized even when the test gas contains flammable gases such as alcohol.

Furthermore, according to the packaging machine of the present invention, the inspection device combined with the packaging machine is connected by a gas flow passage , and the gas flow passage is configured to roll the long film into a cylindrical shape and seal it at predetermined intervals, and to send to the inspection section a gas to be inspected, which gas is an inert gas that replaces the gas in the packaging space partitioned by the seals , and air that remains in the packaging space after the gas replacement.
This makes it possible to configure various packaging machines equipped with a gas replacement process , particularly pillow-type packaging machines that roll long film into a cylindrical shape and seal it at predetermined intervals, and that have a packaging space partitioned by the seals , by connecting the above-mentioned inspection device to the packaging machine equipped with an inspection device that measures the residual gas concentration within the packaging space.

1 is an explanatory diagram showing an outline of the configuration of an inspection device and a packaging machine according to a first embodiment; FIG. 1 is a left side view showing an outline of the configuration of an inspection device according to a first embodiment. 1 is a front view showing an outline of the configuration of an inspection device according to a first embodiment; FIG. 10 is a left side view showing the outline of the configuration of another inspection device according to the first embodiment. FIG. 10 is a rear view showing the outline of the configuration of another inspection device according to the first embodiment. FIG. 2 is an explanatory diagram showing an outline of the configuration of a measurement device included in the inspection device according to the first embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an inspection device according to the present invention and a packaging machine equipped with the inspection device will be described with reference to the accompanying drawings.
FIG. 1 is an explanatory diagram showing the outline of the configuration of an inspection device and a packaging machine according to this embodiment.

The packaging machine according to this embodiment is a vertical pillow type packaging machine, which has a packaging machine main body 11 that rolls a long film F into a cylindrical shape and seals it at predetermined intervals to continuously form pillow type packaging bags in which the packaging space defined by the seals is filled with the packaged item, as shown in Fig. 1, and an inspection device 100 that is installed near the packaging machine main body 11 and inspects at least the gas in the packaging space of the pillow type packaging bags.
In this way, in explaining the inspection device 100 according to this embodiment, the vertical pillow type packaging machine 10 having the packaging machine main body 11 with which the inspection device 100 can be easily combined is adopted because it is the most suitable.
Therefore, the inspection device 100 according to this embodiment is not limited to the vertical pillow type packaging machine 10 exemplified in this embodiment, but can be combined with a horizontal pillow type packaging machine that produces pillow type packaging bags lined up horizontally, or a packaging machine that fills packaging containers such as boxes and trays with packaged items, or a packaging machine that fills packaging spaces provided in specified packaging bags or packaging containers or similar packaging bodies with packaged items, and that is equipped with a gas replacement process that fills the packaging space with a specified inert gas to replace the gas.

As shown in FIG. 1, the packaging machine main body 11 has a film supply device 12, a cylinder making device 13, a bag making device 14, and a discharge device 15, as well as a conveying device, a filling device, and a gas replacement device, which are not shown.
The film supply device 12 has a film roll 12a around which the long film F is wound, and a tension roller 12b equipped with multiple rollers that apply a predetermined tension to the long film F to smooth out wrinkles. Thus, the film supply device 12 is configured to pull out the long film F from the film roll 12a, and supply the long film F, whose wrinkles have been smoothed out by the tension roller 12b, to the cylinder making device 13.
The conveying device (not shown) has guide rollers (not shown) that convey the long film F at a predetermined conveying speed along a predetermined conveying path (arrow T). As shown in FIG. 1 , the conveying path T is formed from above near the end of the tension roller 12b of the film supplying device 12 of the packaging machine main body 10 toward the cutter below. The long film F supplied from the film supplying device 12 is sent along the conveying path T by the guide rollers, and is formed into a bag shape through the tube making device 13 and the bag making device 14, and is formed into a bag product through the filling device, and is then conveyed out of the packaging machine main body 10 by the conveying device 15.

1, the cylinder making device 13 includes a film guide 13a and a center sealer 13b. The film guide 13a is configured to roll the long film F in the width direction so that both widthwise ends of the long film F overlap each other by a predetermined width. The center sealer 13b is configured to heat or ultrasonically weld and seal both widthwise ends of the long film F overlapped by the film guide 13a, thereby forming a center seal portion Cs.
This allows the cylinder making device 13 to form a cylindrical packaging material R from the long film F.

As shown in Figure 1, the bag making device 14 is equipped with an end sealer. The end sealer is a heat sealer consisting of a pair of opposing rod-shaped heaters 14a, 14a arranged side by side. The pair of heaters 14a, 14a is configured to be able to open and close at a predetermined cycle. When the pair of heaters 14a, 14a are open, the packaging material R is fed along the conveying path T by guide rollers, and when the pair of heaters 14a, 14a are closed, the packaging material R is sealed to form end seal sections Es. The end seal sections Es divide the packaging material R at predetermined intervals, forming packaging spaces B between the end seal sections Es that can be filled with packaged items.
The end sealer is not limited to a heat sealer equipped with a pair of heaters 14a, 14a, and an ultrasonic welding device equipped with a horn and anvil may also be used.
Further, when the heater pair 14a, 14a is closed, as shown in FIG. 1, the heater pair 14a, 14a may be configured to move along the conveying path T to ensure the sealing time.

The filling device has a funnel inserted into the tubular packaging material R near the top open end of the packaging material R above the conveying path T, and a stocker installed above the funnel and containing the packaged items. The stocker has a discharge port equipped with a shutter that opens and closes at a predetermined interval. When the shutter is open, a predetermined amount of packaged items is poured into the funnel from the discharge port, and the packaged items that fall from the funnel into the packaging material R are filled and stored in the packaging space B.

The gas replacement device has a gas nozzle inserted into the cylindrical packaging material R from near the upper open end of the packaging material R above the conveying path T. The gas nozzle is configured to be able to continuously supply an inert gas stored in a tank or cylinder, such as nitrogen gas (N ₂ ), carbon dioxide gas (CO ₂ ), or argon gas (Ar), into the packaging material R and the packaging space B for a predetermined period of time.
The gas replacement device is particularly configured to continuously supply an inert gas into the packaging space B, thereby degassing the air in the packaging space B with the gas pressure of the inert gas and replacing the gas in the packaging space B. As a result, the degassed air is discharged to the outside air from the upper open end of the packaging material R above the packaging space B.
In this way, the gas replacement device operates to replace the air in packaging space B with inert gas, but depending on the state of the airflow emitted from the gas nozzle when the inert gas is fed, the air in packaging space B may be mixed with the inert gas, and oxygen contained in the air may remain in packaging space B. In order to inspect the concentration of this residual oxygen gas, vertical pillow type packaging machine 10 according to this embodiment has inspection device 100 installed in juxtaposition to packaging machine main body 11. Inspection device 100 is configured to inspect inspection target gas G, which consists of at least the inert gas continuously blown into packaging space B and the air remaining in packaging space B. Inspection device 100 will be described later.

As shown in FIG. 1, the discharge device 15 includes a cutter 15a located below the pair of heaters 14a, 14a of the bag making device 14, and a conveyor 15b that discharges the bag products. The cutter 15a has one or more blades. The cutter 15a has a straight blade that cuts along the width of the end seal portion Es formed by the end sealer sealing the packaging space, separating the pillow-type packaging bags one by one. Preferably, the blade also includes a perforation blade that forms perforations along the width of the end seal portion Es between adjacent connected pillow-type packaging bags when forming a chain of packaging bags made up of two or more connected pillow-type packaging bags. This allows the discharge device 15 to discharge a chain of packaging bags made up of one or more connected pillow-type packaging bags from the packaging machine main body 11 via the conveyor 15b.

1, the inspection device 100 is composed of a gas cell 101 into which the inspection target gas is introduced from the packaging machine main body 11, and a measuring device 102 that measures the inspection target gas G filled in the gas cell 101. The inspection device 100 is installed near the packaging machine main body 11, and is connected to the gas cell 101 by a gas flow path 103, as shown in FIG.
The inspection device 100 according to this embodiment will be described below using as examples a stationary inspection device 100A configured to be installed near the packaging machine main body 11 as shown in Figures 2 and 3, and a portable inspection device 100B configured to be portable between one packaging machine main body 11 and another packaging machine main body 11 as shown in Figures 4 and 5.
The gas G to be inspected is composed of at least the inert gas supplied by the gas replacement device and the air remaining inside the packaging space and the packaging material connected to the packaging space.Furthermore, depending on the type of packaged item and the state in which the packaged item is filled into the packaging space, it may contain flammable gases such as evaporated alcohol and hydrogen gas, water vapor or mist-like moisture, and may also contain small amounts of corrosive gases generated from hydrogen sulfide, sulfurous acid, nitrous acid, chlorine, ammonia, etc. contained in food additives.

The gas flow passage 103 is composed of a suction nozzle 104, a pump 105, a gas flow meter 106, and a pipeline.
The suction nozzle 104 is inserted into the tubular packaging material R from above the conveying path T, near the upper opening end of the packaging material R, and is preferably configured with the nozzle tip positioned near the packaging space B to suction the gas G to be inspected within the packaging space B.
The pump 105 is configured to send the test target gas G sucked from the packaging space B to the gas flow meter 106 side. By balancing a predetermined pressure when the gas replacement device sends the inert gas into the packaging space B with the pressure when the pump 105 sucks out the test target gas G from the packaging space B, the pressure inside the packaging material R and the packaging space B can be maintained at a constant level and gas replacement can be performed.
The gas flow meter 106 is configured to measure the flow rate of the test target gas G being sucked in by the pump 105. This allows the flow rate of the test target gas G being continuously sucked in from the packaging space B to be at least visually confirmed.
The pipeline is composed of multiple pipes connected together, and is preferably a tube or pipe made of synthetic resin, rubber, or metal, which is less susceptible to the influence of the test target gas G. The first pipe 107 is configured to connect the suction nozzle 104 to a gas connector 108 provided on the testing device 100. As shown in FIG. 2 or 6 , the pipeline is composed of a second pipe 109 connecting the gas connector 108 to the pump 105, a third pipe 110 connecting the pump 105 to the gas flow meter 106, and a fourth pipe 111 connecting the gas flow meter 106 to the gas cell 101. This allows the test target gas G to be sent from the packaging space B and the packaging material R connected to the packaging space to the gas cell 101 through the pipeline. Note that the pipeline is not shown in FIGS. 3 to 5 .

2 and 3, the stationary inspection device 100A has a control panel 120 mounted on a rectangular frame 115. Within the frame 115, the gas cell 101, laser generating unit 125, light receiving unit 130, pump 105, and gas flow meter 106 are arranged at predetermined positions.
A gas concentration meter 120a is provided in the control panel 120. The gas concentration meter 120a, the laser generating unit 125, and the light receiving unit 130 constitute a measuring device 102 that measures the concentration of residual oxygen gas contained in the gas G to be inspected.
The pump 105 is an electromagnetic air pump with a pumping force of 10.6 kPa and a rated output of 4 L/min. A second pipe 109 connected to a gas connector 108 is fitted to the intake port, and a third pipe 110 connected to a gas flow meter 106 is connected to the exhaust port. The electromagnetic air pump is composed of a rod made of a permanent magnet, an electromagnet that surrounds and holds the rod, a diaphragm fixed to the tip of the rod, and a cylindrical air chamber (all not shown) with one end sealed by the diaphragm and the other end equipped with an intake valve communicating with the intake port and an exhaust valve communicating with the exhaust port. The rod vibrates due to the electromagnet, deforming the diaphragm, changing the volume of the air chamber. This change in volume compresses and exhausts the air drawn into the air chamber.
The gas flow meter 106 is a float-type flow meter with a float sealed in a cylindrical body, and is connected to the pump 105 by a third pipe 110 and to the gas cell 101 by a fourth pipe 111. The float-type gas flow meter allows visual measurement of the gas flow rate by having a pointer on the float point to a scale engraved on the cylindrical body.
The power input terminal 140 is configured to be connectable to a predetermined external power source, thereby supplying power to the control panel 120 and the measuring device 102, and power can be supplied from the control panel 120 to the laser generating unit 125, the light receiving unit 130, and the pump 105.
The packaging machine interlocking terminal 141 is configured to be connectable to the packaging machine main body 11. This allows a synchronization signal to be sent and received between the packaging machine main body and the inspection device, and the synchronization signal can be used to interlock with each device in the packaging machine main body, particularly the bag making device, filling device, and gas replacement device.

As shown in Figures 4 and 5, the portable inspection device 100B has a control panel 120, gas cell 101, laser generating unit 125, light receiving unit 130, pump 105, and gas flow meter 106 arranged at predetermined positions within a frame 105 that is assembled in an approximately cubic shape.
A gas concentration meter 120a is provided in the control panel 120. The gas concentration meter 120a, the laser generating unit 125, and the light receiving unit 130 constitute a measuring device 102 that measures the concentration of residual oxygen gas contained in the gas G to be inspected.
The gas cell 101 is not arranged along the vertical frame 105, but is arranged diagonally along a diagonal between the vertical frame 105 and the control panel 120, as shown in Fig. 4. This ensures a longer optical path length than in a vertical arrangement, and also allows the inspection device 100B to be configured more compactly.
The pump 105 is an electromagnetic air pump configured in the same manner as the stationary inspection device 100A.
The gas flow meter 106 includes a flow sensor capable of continuously detecting the gas flow rate in the gas flow passage 103 and a monitor capable of digitally displaying the gas flow rate. The gas flow rate detected by the flow sensor is electrically converted into a numerical value and encoded into a gas flow signal. The gas flow signal is collected in a predetermined storage device within the control panel 120 to form gas flow data. If a predetermined threshold value is set for the gas flow rate, for example, when the gas flow signal indicates that the gas flow rate has fallen below the threshold, an alarm can be issued, such as by flashing a lamp or sounding an alarm or melody. The inspection device 100B is connected to the packaging machine main body 11 via the packaging machine interlocking terminal 141. Therefore, a decrease in gas flow rate, i.e., a decrease in gas pressure, can be fed back to the packaging machine main body 11 to stop the packaging process described below, thereby preventing the occurrence of defective products.
Furthermore, the flow rate of the inert gas can be adjusted and understood based on the gas flow data, and the timing for replacing a supply source of the inert gas, such as a cylinder, can be predicted, for example.
Although not shown, the pipeline consisting of pipes connecting the gas connector 108 to the pump 105, the gas flow meter 106, and the gas cell 101 is configured in the same manner as in the stationary testing device 100A.
The power input terminal 140 and packaging machine interlocking terminal 141 are also configured in the same manner as the stationary inspection device 100A.
The portable inspection device 100B is configured to be more compact than the stationary inspection device 100A by revising the size and arrangement of the gas cell 101, gas flow meter 106, etc. to save space. This allows for greater freedom in installation location than the stationary inspection device 100A, for example, when adding the device to an existing vertical pillow type packaging machine 10 later.
Furthermore, the portable inspection device 100B is easier to carry than the stationary inspection device 100A, and after inspection on one vertical pillow type packaging machine 10, it can be easily moved to another vertical pillow type packaging machine 10 and inspected thereafter.
Therefore, when it is desired to constantly test the entire amount of residual oxygen gas concentration in bag products manufactured by the vertical pillow type packaging machine 10, a stationary inspection device 100A can be combined; when testing between multiple vertical pillow type packaging machines 10, for example when replacing an inert gas cylinder in one vertical pillow type packaging machine 10, an inspection can be performed from the time the inert gas being blown into the packaging material R starts to blow out until it stabilizes, or when extracting the gas G to be tested during production and performing a sampling inspection, a portable inspection device 100B can be combined; and the inspection device 100 can be selected according to the intended use.

Here, an explanatory diagram showing an outline of the configuration of the stationary inspection device 100A or the portable inspection device 100B is shown in FIG. 6, and each part constituting the gas cell 101 and the measuring device 102 will be described.
The gas cell 101 is made of a cylindrical body and has a gas inlet 101a formed at one end of the gas cell 101 and an exhaust port 101b formed at the other end, as shown in FIG. 6 . The gas inlet 101a is connected to a gas flow meter 106 by a third pipe 111, as shown in FIG. 6 . The open end of the cylindrical body constituting the gas cell 101 is covered by a measuring device 102. The gas cell 101 is configured so that the test gas G is injected into the gas cell 101 through the gas inlet 101a, fills the gas cell 101, and then is exhausted through the exhaust port 101b. Since the gas cell 101 is irradiated with laser light inside the cylinder and the absorbance of the laser light is measured as described below, it is preferable that the gas cell 101 be a cylindrical body with light-shielding properties that can eliminate the influence of light from outside the gas cell.

As shown in Figure 6, the measuring device 102 comprises a laser generating unit 125 arranged to cover one end of the gas cell 101, a light receiving unit 130 arranged to cover the other end of the gas cell 101, and a gas concentration meter 120a housed in the control panel 120, and is configured to measure the concentration of residual oxygen gas contained in the test gas G.

As shown in FIGS. 3, 5 and 6, the laser generating section 125 has a laser light source 126 and an emission section 127 that emits the laser light generated by the laser light source 126.
The laser light source 126 includes a semiconductor laser element made of a diode with a tunable wavelength, and is configured to be able to emit laser light in the near-infrared region. The semiconductor laser element according to this embodiment is, for example, a high-output semiconductor laser element called a DFB (Distributed Feedback) laser.
3 and 5, the emission unit 127 is configured to emit laser light generated by the laser light source 126 from one end to the other end of the gas cell 101 inside the cylinder of the gas cell 101. In addition, at this time, the emission unit 127 is configured to electrically convert the emission light intensity of the emitted laser light, and output an emission light signal amplified by a predetermined magnification to the gas concentration meter 120a.

As shown in FIGS. 3, 5 and 6, the light receiving section 130 includes a light receiving sensor 131 that receives laser light, and a light receiving amplifier 132.
The light receiving sensor 131 includes a photoelectric element, such as a photodiode, that converts the transmitted light intensity of the laser light that has passed through the gas cell 101 and been attenuated by the test target gas G into an electrical light receiving signal.
The light receiving amplifier 132 is configured to amplify the light receiving signal formed by the light receiving sensor 131 by a predetermined magnification and output a light receiving signal based on the transmitted light intensity to the gas concentration meter 120a.
This allows the gas concentration meter 120 a to measure the residual oxygen gas concentration in the gas cell 101 based on the emitted light signal input from the emitter 127 and the received light signal input from the light receiver 130 .

As shown in FIG. 6, the gas concentration meter 120a has a control unit 150 that controls the wavelength and intensity of the emitted laser light, and a measurement unit 151 that measures the residual gas concentration by comparing the emitted light signal with the received light signal.
The control unit 150 is configured to perform adjustment control and amplification control of the laser light in the laser generating unit 125. The adjustment control is control for adjusting the wavelength of the laser light emitted from the semiconductor laser element of the laser light source 126 to a specific wavelength specific to the residual gas contained in the gas to be measured. The amplification control is control for amplifying the laser light from the laser light source 126 so that it is emitted from the emission unit 127 at a predetermined emission light intensity. This allows the laser generating unit 125 to emit laser light having a specific wavelength specific to the residual oxygen gas from the emission unit 127 at a predetermined emission light intensity.
Here, the residual gas measured by the measuring device 102 according to this embodiment is oxygen gas ( _O2 ) as described above. The absorption wavelength band specific to this oxygen gas is the 760 nm band, and a specific wavelength related to one of the multiple absorption spectra included in this absorption wavelength band is selected as the output wavelength of the laser light. In this embodiment, the device is configured to detect oxygen gas that may deteriorate the packaged goods due to oxidation, but this is not limited to this, and the adjustment function of the control unit 150 is configured to be able to arbitrarily adjust and set the absorption spectrum related to the absorption wavelength band that specifies the gas to be detected.

The measurement unit 151 is configured to periodically measure the residual gas concentration at intervals of 0.1 to 2.0 seconds using a predetermined measurement method based on the emitted light signal and the received light signal. Since the laser light passing through the gas cell 101 is absorbed and attenuated by the residual oxygen gas in the test target gas G, the residual oxygen gas concentration in the test target gas G can be determined by calculating this attenuation rate. In other words, the measurement method in this embodiment compares the emitted light intensity of the emitted light signal with the transmitted light intensity of the received light signal to calculate the attenuation rate of the laser light over a predetermined optical path length, in other words, the transmittance of the laser light. Based on this transmittance, the absorbance of the laser light absorbed by the residual oxygen gas in the gas cell 101 is determined, and the gas concentration of the residual oxygen gas in the gas cell is measured based on this absorbance.

Here, the method for measuring the gas concentration will be explained in more detail. The method is based on wavelength tunable semiconductor laser absorption spectroscopy.
Tunable diode laser absorption spectroscopy (TDLAS) is a method for measuring a gas concentration C from the absorbance A of the laser light based on the transmittance T, which is obtained in a gas cell having a predetermined optical path length L and in which a test target gas G is sealed, by determining a predetermined emission light intensity I ₀ of a laser light emitted from an emission unit 127 and a transmitted light intensity I _t when the laser light is absorbed by residual oxygen gas contained in the test target gas and received by a light receiving unit.

It is known that gases such as oxygen gas and nitrogen gas each have their own unique absorption wavelength band, and that this absorption wavelength band contains multiple absorption lines corresponding to wavelengths at which light is more strongly absorbed. TDLAS is a method configured to modulate and amplify the wavelength of the emitted laser light in the near-infrared region to match a specific wavelength corresponding to an arbitrarily selected absorption line from among these absorption lines, thereby causing the laser light to be more significantly absorbed by the gas being measured. The gas concentration is measured by determining the absorbance of the laser light based on the absorption spectrum of the specific wavelength, which changes before and after passing through the gas cell 101.
In this embodiment, the measurement target gas included in the test target gas is oxygen gas ( _O2 ) having an absorption wavelength band of 760 nm. The control unit 150 is configured to select a specific wavelength associated with one of a plurality of absorption lines included in the absorption wavelength band as the wavelength of the emitted laser light.

Tunable-wavelength semiconductor laser absorption spectroscopy (TDLAS) measures gas concentrations based on the Beer-Lambert law. As shown in Figure 6, the Beer-Lambert law states that, when the emitted light intensity is I ₀ , the transmitted light intensity through the test gas in the gas cell is I _t , the transmittance of the transmitted light relative to the emitted light is T, the optical path length is L, and the gas concentration is C, the following mathematical expression 1 holds between I 0 and the absorbance A of laser light emitted at a specific wavelength of the absorption spectrum: where ε is the specific absorption coefficient of the specific gas being measured.

The light emitting unit 127 and the light receiving unit 130 are fixed to both ends of the cylindrical gas cell 101, so that the optical path length L is constant. That is, the gas concentration C of oxygen gas in the gas cell can be obtained by obtaining the transmittance T of the transmitted light obtained from the intensity of the emitted light and the intensity of the transmitted light, or by obtaining the absorbance A of the absorption spectrum of a specific wavelength of laser light absorbed by oxygen gas contained in the test gas in the gas cell.
Here, since the relationship between absorbance A and optical path length L is proportional, ensuring a sufficient length of the gas cell can improve the detection sensitivity of gas concentration C. Therefore, the measuring device 102 is not limited to the configuration in which the laser light is transmitted in a straight line between the emission unit 127 and the light receiving unit 130 as shown in Fig. 6, but may be configured, for example, to provide opposing reflecting mirrors at both ends of the gas cell 101 so that the laser light is reflected multiple times between the emission unit 127 and the light receiving unit 130, thereby extending the optical path length L of the laser light transmitted through the test target gas G.
By improving the detection sensitivity in this way, if the detectable range is expanded so that gas concentrations down to the level of several ppm can be detected, gas concentrations at the level of several percent can be easily measured, and the measurement accuracy can be greatly improved.

The gas concentration meter 120a according to this embodiment can provide a wide measurable detection range for the residual oxygen gas concentration, and therefore can set a wide threshold range for the allowable range of the residual oxygen gas to match the detection range. If the detected residual oxygen gas concentration is equal to or greater than a predetermined threshold, an alarm signal can be issued using, for example, a lamp or buzzer provided on the control panel 120, or a display can be displayed on a monitor screen.
Furthermore, according to the gas concentration meter 120a of this embodiment, the inspection device 100 equipped with the gas concentration meter 120a is connected to the packaging machine main body 11 via the packaging machine interlocking terminal 141 so as to be interlocked with the packaging machine main body 11, and therefore, when the gas concentration in the gas cell 101 becomes higher than a predetermined threshold, the packaging machine main body 11 can be brought to an emergency stop, thereby preventing the occurrence of defective products.
Furthermore, according to the gas concentration meter 120a of this embodiment, since the gas cell 101, which continuously supplies the gas G to be inspected, is configured to continuously irradiate laser light into the gas cell 101, it is possible to manage the measurement history of the gas G to be inspected and compare the measurement history with the manufacturing history of the bag products continuously manufactured by the vertical pillow-type packaging machine 10 connected via the packaging machine interlocking terminal 141, and it is also possible to track the residual oxygen gas concentration in the packaging space B of the pillow-type packaging bag.

The vertical pillow-type packaging machine 10 configured as described above has a packaging process in which the contents to be packaged are filled into pillow-type packaging bags to form bag products, and an inspection process in which the residual gas concentration within the packaging space of the pillow-type packaging bag is inspected.

The packaging process consists of a film supply process, a tube-making process, a bag-making process, a filling process, a gas exchange process, and a conveying process. As explained below, in this packaging process, a long film F drawn from a film roll 12a is supplied onto a conveying path T and conveyed at a predetermined conveying speed to form packaging material R. The bottom of a pillow-type packaging bag is formed from the packaging material R, and a packaging space B is also formed. The packaging space B is filled with the packaged item, the gas is exchanged within the packaging space B, and the bag opening is sealed, producing a bag product for the pillow-type packaging bag. In this way, the vertical pillow-type packaging machine 10 can continuously produce and convey bag products from a continuously supplied long film F.

The film supply process is a process in which the film supply device 12 supplies the long film pulled out from the film roll 12a to the transport path T.

The tube making process is a process in which the tube making device 13 rolls the long film F so that both widthwise ends overlap, forming a cylindrical packaging material R. In this tube making process, the film guide 13a overlaps both widthwise ends of the long film F and rolls the long film F into a cylindrical shape, and the center sealer 13b continuously seals both widthwise ends of the overlapped long film F to form a center seal portion Cs. In this way, a cylindrical packaging material R can be formed from the long film F on the conveying path T.

The bag making process is a process for continuously forming interconnected pillow-type packaging bags from the packaging material R. The bag making process includes a first sealing process and a second sealing process in which the cylindrical packaging material R is sealed across the width direction with an end sealer equipped with a pair of heaters 14 a, 14 a to form an end seal portion Es.
The first sealing step is a step of forming an end seal portion Es on the bag bottom side of the pillow-type packaging bag, thereby forming the packaging space B. After the first sealing step is performed, the conveying device conveys the packaging material R along the conveying path T, and the second sealing step is performed above the packaging space B. Between the first and second sealing steps, a filling step and a gas replacement step are performed.
The second sealing step is a step of sealing the opening of the pillow-type packaging bag in which the packaging space B is filled with the packaged item, to form an end seal portion Es on the opening side of the bag.
In the second sealing step, when the opening of the first pillow-type packaging bag is sealed, the packaging space B of the subsequent pillow-type packaging bag can be formed at the same time in the first sealing step. In this way, a continuous series of pillow-type packaging bags is formed in which the packaging spaces B partitioned by the end seal portions Es are continuous.

After the first sealing step, a filling step, a gas replacement step and a degassing step are carried out.
The filling process is a process in which the filling device fills a predetermined amount of packaged material stored in a stocker into the packaging space B partitioned by the end seal portion Es formed in the first sealing process through a funnel.
The gas replacement process and degassing process are processes in which an inert gas is blown using a gas nozzle into the cylindrical packaging material R and the packaging space B formed adjacent to the packaging material R. As a result, the inert gas pushes out the air in the packaging material R and the packaging space B, degassing the space, and filling the space with the inert gas.
The filling step may be performed simultaneously with the gas replacement step, or the filling step and the gas replacement step may be performed in that order. The inert gas used in the gas replacement step according to this embodiment is nitrogen gas, but is not limited to this and any inert gas may be used.
Preferably, a vibration process may be performed in parallel with the filling process, gas replacement process, and degassing process. The vibration process is a process in which, depending on the type of packaged item, vibration is applied to at least the packaging space B to eliminate gaps between the packaged items and expel excess air. This makes it possible to further evacuate the packaging space B and replace the gas, and by gathering the packaged items downward, it is possible to save space, for example, when stacking and storing them.
When the above-mentioned filling process and other processes are completed, a second sealing process is carried out to seal the opening of the pillow-type packaging bag and seal the packaging space B, thereby forming the pillow-type packaging bag, and a first sealing process is carried out to form the packaging space B for the next pillow-type packaging bag.
In this way, pillow-type packaging bags are continuously formed, with the packaging space B filled with the packaged item and partitioned by the end seal portion Es.
In this way, the vertical pillow type packaging machine 10 forms a tubular packaging material R from a long film F, and after going through each process, forms a chain of pillow type packaging bags filled with the packaged item, which are lined up vertically as shown in Figure 1.

The discharge process involves discharging the string of packaging bags formed through the above processes from the vertical pillow type packaging machine 10 using the discharge device 15. The discharge device 15 has a cutter 15a equipped with a straight blade capable of cutting the packaging bags or a perforation blade capable of forming perforations, and a conveyor 15b capable of conveying the bag products out of the vertical pillow type packaging machine 10. The cutter 15a is configured to cut or perforate the end seal portion Es of the string of packaging bags along the width direction, separating the string of packaging bags one by one or in a predetermined number of bags. This allows the bag products, in which pillow type packaging bags have been separated one by one or in a predetermined number of bags, from the string of pillow type packaging bags formed in a series through the above processes, to be conveyed out of the vertical pillow type packaging machine 10 using the conveyor 15b.

The inspection process carried out in parallel with the packaging process is a process for inspecting the concentration of residual oxygen gas mixed in the inert gas filled in at least the packaging space B with the bag mouth open, and preferably in the space within the cylindrical packaging material R connected to the upper part of the packaging space B. Therefore, the packaging processes carried out in parallel with the inspection process are the filling process, the gas replacement process, and the deaeration process before the second sealing process in which the bag mouth is sealed.
The inspection process includes a gas extraction process and a gas concentration measurement process.

The gas extraction process is a process of extracting the inspection target gas G from the packaging space B and the packaging material R through the gas flow path 103.
A suction nozzle 104 is inserted into the packaging space B and the packaging material R connected to the packaging space B. The test target gas G is sucked from the suction nozzle 104 by a pump 105 and introduced into the gas cell 101 via a gas flow meter 106. A gas concentration measurement process is performed by irradiating the test target gas G filled in the gas cell 101 with a laser beam.
In this way, by configuring the inspection system to suck in and inspect the gas G to be inspected within the packaging space B and the packaging material R, the inspection process can be carried out faster than inspecting each pillow-type packaging bag one by one. Furthermore, the residual oxygen gas concentration remaining in the inert gas filling the packaging material R can be measured continuously as long as the packaging material R is being formed, in accordance with the packaging material R being formed until the long film F of the film roll 12a is used up. This makes it easy to understand the change over time in the residual oxygen gas concentration within the packaging space B or the packaging material R.

The gas concentration measurement process is a process in which a laser beam is emitted into the gas cell 101, the laser beam attenuated in the gas cell 101 is received by the light receiving unit 130, and the gas concentration of the residual oxygen gas contained in the test gas G filled in the gas cell 101 is measured by the laser gas concentration meter 120a. The test gas G is a gas in which an inert gas is mixed with residual air, and is a gas composed of gases generated from the packaged items, etc., although in small amounts, and the residual gas to be measured is mainly oxygen gas ( _O2 ) contained in the air.
The gas concentration measurement process is configured to use a gas cell 101 having a sufficient optical path length L, and to measure the test target gas G continuously supplied to the gas cell 101 over a long period of time using a gas concentration meter 120a. The method for measuring the test target gas G using the gas concentration meter 120a has been described above, so a description thereof will be omitted.
According to the gas concentration measurement process using the measurement device 102 of this embodiment, the optical path length L can be kept constant between the laser generating unit 125 and the light receiving unit 130, which are arranged on both ends of the gas cell 101. Furthermore, since the optical path length L can be kept constant and measurements can be performed continuously over a long period of time, the measurement device 102 can improve the measurement accuracy of the residual oxygen gas concentration.

According to the vertical pillow type packaging machine 10 of this embodiment, an inert gas is blown into the space surrounded by the packaging material R and into the packaging space B to degas and replace the gas, thereby making it possible to continuously test the concentration of residual oxygen gas in the space.
This makes it possible to easily inspect all pillow packaging bags manufactured by the vertical pillow packaging machine 10 to determine whether the residual oxygen gas concentration in the packaging space B is kept below a specified level.
Furthermore, since the inert gas being blown in is sucked out by the suction nozzle 104 for inspection, if, for example, the supply of inert gas decreases and the residual oxygen gas concentration increases, when the residual oxygen gas concentration exceeds a predetermined threshold value, an alarm can be issued by flashing a light or sounding a buzzer or melody in conjunction with an alarm device installed on the control panel 120.

Furthermore, as described above, the inspection device 100 according to this embodiment may be combined with, in addition to the vertical pillow type packaging machine 10 exemplified in this embodiment, a horizontal pillow type packaging machine that produces pillow type packaging bags lined up horizontally, a packaging machine that fills packaging containers such as boxes or trays with packaged items, or a packaging machine that fills packaging spaces provided in specified packaging bags or packaging containers or similar packaging bodies with packaged items, and that is equipped with a gas replacement process that fills the packaging space with a specified inert gas to replace the gas.
Furthermore, the inspection device 100 according to this embodiment is not limited to inspecting all gas-substituted packaged products in combination with these various packaging machines, but may also be adapted to perform sample inspections in which a predetermined number of samples are extracted and inspected for each predetermined production lot consisting of multiple packaged products.

10...Vertical pillow type packaging machine,
11... packaging machine main body, 12... film supply device, 13... cylinder making device, 14... bag making device, 15... carrying-out device
T... conveying path, F... long film, R... packaging material, B... packaging space, Cs... center seal, Es... end seal,
100...inspection device,
101...gas cell, 102...measuring device, 103...gas flow path,
104...suction nozzle, 105...pump, 106...gas flow meter,
107...first pipe, 108...gas connector, 109...second pipe, 110...third pipe, 111...fourth pipe,
120...control panel, 120a...gas concentration meter,
125...laser generating unit, 126...laser light source, 127...emitting unit,
130...light receiving unit, 131...light receiving sensor, 132...light receiving amplifier,
140...power supply input terminal, 141...packaging machine interlocking terminal,
150...control unit, 151...measurement unit,
G: inspection target gas; C: gas concentration; L: optical path length; I ₀ : emitted light intensity; I _t : transmitted light intensity; T: transmittance; A: absorbance; ε: absorption coefficient.

Claims (4)

an inspection unit that rolls a long film into a cylindrical shape and seals it at predetermined intervals, and inspects the inspection target gas, which is made up of a predetermined inert gas that is used to gas-substitute the gas in the packaging space partitioned by the seals, and air that remains in the packaging space after the gas substitution;
a gas flow passage having a suction nozzle that suctions at least the inspection target gas from the packaging space and introduces the inspection target gas into the inspection unit ,
the inspection unit includes a cylindrical gas cell having a predetermined length and a measuring device for measuring the concentration of a predetermined residual gas mixed in the inspection target gas in the gas cell;
the measuring device comprises a laser light source that generates laser light of a predetermined wavelength, an emission unit that is connected to one end of the gas cell and that emits the laser light into the gas cell, a light receiving unit that is connected to the other end of the gas cell and that receives the laser light that has passed through the gas cell, and a gas concentration meter that measures the concentration of the residual gas in the gas cell,
the gas concentration meter compares the wavelength of the laser light emitted from the emission unit with the wavelength of the laser light absorbed by the residual gas in the gas cell, and measures the concentration of the residual gas based on the absorbance of an absorption spectrum related to the absorbed wavelength;
An inspection device characterized in that the concentration of the residual gas contained in the inspection target gas in the packaging space is inspected based on the measurement results related to the concentration of the residual gas in the gas cell. a pump through which the gas flow passage continuously draws the test target gas from at least the packaging space;
a gas flow meter for measuring the flow rate of the test gas being sucked;
2. The inspection device according to claim 1, further comprising a pipeline connecting the suction nozzle, the pump, and the gas flow meter. a conveying device that rolls a long film into a cylindrical shape and seals it at predetermined intervals, and conveys a pillow-type packaging bag having a packaging space partitioned by the seals along a predetermined conveying path;
A filling device that performs a filling step of filling the packaging space with the packaged item;
a gas replacement device that performs a gas replacement step of filling the packaging space with a predetermined inert gas and replacing the packaging space with the inert gas;
A packaging machine that fills the packaging space of the pillow-type packaging bag with the packaged material on the conveying path and replaces the gas in the packaging space with the inert gas to produce a predetermined packaged product,
The packaging machine includes an inspection unit that inspects the inspection target gas, which is the inert gas that replaces the gas in the packaging space and the air that remains in the packaging space after the gas replacement;
and a gas flow path equipped with a suction nozzle that suctions at least the inspection target gas from the packaging space and introduces the inspection target gas into the inspection unit ,
the inspection unit includes a cylindrical gas cell having a predetermined length and a measuring device for measuring the concentration of a predetermined residual gas mixed in the inspection target gas in the gas cell;
the measuring device comprises a laser light source that generates laser light of a predetermined wavelength, an emission unit that is connected to one end of the gas cell and that emits the laser light into the gas cell, a light receiving unit that is connected to the other end of the gas cell and that receives the laser light that has passed through the gas cell, and a gas concentration meter that measures the concentration of the residual gas in the gas cell,
the gas concentration meter compares the wavelength of the laser light emitted from the emission unit with the wavelength of the laser light absorbed by the residual gas in the gas cell, and measures the concentration of the residual gas based on the absorbance of an absorption spectrum related to the absorbed wavelength;
A packaging machine characterized in that the concentration of the residual gas contained in the gas to be inspected in the packaging space is inspected based on the measurement results related to the concentration of the residual gas in the gas cell. a pump through which the gas flow passage continuously draws the test target gas from at least the packaging space;
a gas flow meter for measuring the flow rate of the test gas being sucked;
4. The packaging machine according to claim 3, further comprising a pipeline connecting the suction nozzle, the pump, and the gas flow meter.