Method for filling and sealing liquid content in spouted pouch and apparatus therefor

EXPLANATION OF REFERENCE NUMERALS

[0028] 1 pre-filling deoxidation step [0029] 1-1 pre-filling first degassing step [0030] 1-2 pre-filling inert gas blowing step [0031] 2 filling step [0032] 2-1 pre-filling second degassing step [0033] 2-2 content metered filling step [0034] 2-3 residual liquid discharge step [0035] 3 post-filling degassing step [0036] 4 spout washing and post-filling first gas replacement step [0037] 5 spout drying step [0038] 6 post-filling second gas replacement step [0039] 7 inner lid sealing step [0040] 7-1 inner lid pre-sealing degassing step [0041] 7-2 pre-sealing and punching step [0042] 7-3 first sealing step [0043] 7-4 second sealing step [0044] 8 outer lid attachment step [0045] 10, 13 evacuating and blowing head [0046] 11 chamber [0047] 12 degassing plate [0048] 15 pouch [0049] 16 spout [0050] 18 content [0051] 19 liquid level [0052] 20, 32 filling valve [0053] 21, 33 outer tube [0054] 22 outer rod [0055] 23 central rod [0056] 25 content supply port [0057] 26 fluid chamber [0058] 27 valve seat [0059] 28 filling nozzle [0060] 29 valve body [0061] 34 valve rod [0062] 35 discharge port [0063] 36 mesh screen [0064] 37 attachment jig [0065] 38 mesh nozzle [0066] 40 degassing device [0067] 41 washing and replacement nozzle [0068] 42 degassing plate [0069] 43 cylinder device [0070] 45 nozzle body [0071] 46 washing water spraying port [0072] 47 gas replacement nozzle [0073] 48 spring [0074] 49 holding plate [0075] 50 rod portion [0076] 51 flange [0077] 52 engagement protrusion

BEST MODE FOR CARRYING OUT THE INVENTION

[0078]An embodiment of the present invention will be described below in greater details with reference to the drawings.

[0079]In the apparatus for filling and sealing a liquid content in a spouted pouch of an embodiment of the present invention, clamps that are pouch conveying means for conveying a pouch by grasping a spout of the pouch are disposed with a predetermined pitch at the outer peripheral portion of a rotary table that rotates intermittently in the same manner as in the well-known device for filling and sealing spouted pouches of this kind, stations from pouch supply to pouch discharge after filling and sealing are provided along the rotary table, devices for conducting a step that is performed in the stations are disposed in corresponding stations, and by intermittently rotating the rotary table, various steps from the spout supply to the discharge of the filled and sealed spouted pouch products from the rotary table are conducted, the filling to sealing steps being performed therebetween. FIG. 1 is a block diagram illustrating principal steps of a method for filling and sealing a liquid content in a spouted pouch according to an embodiment of the present invention. Because methods similar to the conventional methods can be used for other processes, only the special steps will be described below.

[0080]In the embodiment of the present invention, first, a pre-filling deoxidation step 1 of flatly supplying a spouted pouch and removing the air (oxygen) from the pouch is performed in a pre-filling deoxidation station. In this state, the pouch has a flat shape in which the front wall and the rear wall thereof almost stick together and the amount of air inside the pouch is small. However, the tests conducted by the inventors to compare a case in which this step is implemented with a case in which the step is not implemented demonstrated a large effect produced by the step on deoxidation ratio after filling and sealing, and providing this step is especially effective in a case of the content that easily deteriorates. A pre-filling first degassing step 1-1 of degassing the pouch, a pre-filling inert gas blowing step 1-2 of blowing an inert gas into the pouch after the pre-filling first degassing step and performing gas replacement, and a gas-reduction vacuum step 1-3 of reducing the amount of inert gas inside the pouch for a predetermined amount from a state in which the pouch has been expanded by the inert gas blown thereinto are preferred as the pre-filling deoxidation method, but this method is not limited to the aforementioned processes and may include, for example, only the pre-filling first degassing step or only the pre-filling inert gas blow step.

[0081]A method of sandwiching a pouch body between a pair of degassing plates and squeezing out the gas inside the pouch, similarly to the below-described post-filling degassing step, or any method by which a vacuum suction nozzle is mated with the spout and the inside of the pouch is vacuum degassed may be used as the pre-filling first degassing step, but the preferred method includes, as shown in FIG. 2, evacuating and sucking out the air contained inside the pouch in a state in which an evacuating and blowing head 10 is brought into contact with a top end portion of a spout 16, because such a method ensures complete degassing of the inside of the pouch. The evacuating and blowing head 10 is connected to a pipe having a switchover valve that can be switchably connected to a vacuum pump and an inert gas supply source (in the present embodiment, a nitrogen gas cylinder), and the pre-filling first degassing step 1-1, pre-filling inert gas blowing step 1-2, and gas-reduction vacuum step 1-3, which constitute the pre-filling deoxidation step, can be continuously performed with the same head.

[0082]In the pre-filling inert gas blowing step 1-2 that is performed following the pre-filling first degassing step 1-1, the connection of the evacuating and blowing head 10 is automatically switched to the inert gas supply source, the inside of the pouch that has been degassed in the previous step is filled with a predetermined amount of inert gas, the inside of the pouch assumes a perfect inert gas state, and the combination of this step with degassing of the previous step makes it possible to obtain a state of complete deoxidation inside the spout prior to filling. As for the amount of the inert gas that is filled into the pouch in the pre-filling inert gas blowing step, it is preferred that the inert gas be blown to a full capacity of the pouch, thereby preventing the penetration of external air into the pouch during conveying to the filling step. Nitrogen gas is advantageous as the inert gas, but other inert gases may be also used. The medium to be used is not necessarily a gas, and liquid nitrogen that becomes inert gas upon gasification or fine grains of dry ice can be also used. Therefore, the concept of inert gas in the gas replacement step in accordance with the present invention includes these types of media.

[0083]The gas-reduction vacuum step 1-3 that is then performed in the pre-filling deoxidation station serves to reduce to a predetermined amount the amount of gas inside the pouch that has been expanded by the inert gas to a full capacity in the above-described inert gas blowing step. Thus, the amount of inert gas inside the pouch is reduced to the predetermined amount, as shown schematically in FIG. 2(c) by switching the connection of the evacuating and blowing head 10 again to the vacuum side and discharging a predetermined amount of inert gas from the pouch. The technological idea of this step is described below. As described hereinabove, in the deoxidation step performed prior to filling, from the standpoint of increasing the deoxidation ratio it is desirable that the pouch be conveyed to the next filling station in a state in which the inside of the pouch is filled with as large an amount of inert gas as possible, but in this case the degassing time of the pre-filling second degassing step performed in the filling station increases accordingly and the possibility of increasing the line speed is reduced. Furthermore, it is desirable, as will be described hereinbelow, that in the pre-filling second degassing step the pouch be sandwiched between the degassing plates and degassed at once, but if a large amount of inert gas is present at this time inside the pouch, the amount of gas that is discharged at once increases accordingly. The possible resultant problem is that the ejected inert gas will collide with the distal end of the filling nozzle and scatter in the environment the droplets of content that have adhered to the distal end of the filling nozzle. To prevent this from happening, in the present embodiment, the inert gas is once blown into the pouch to reduce the amount of oxygen inside the pouch to a minimum and then the amount of gas inside the pouch is reduced to an amount that prevents inconveniences such as the reduced possibility of increasing the line speed in the pre-filling deoxidation station and adverse effect on environment. In this case, the discharge of inert gas from the pouch is preferably performed by evacuation rather than with the pressurizing plates, and in the present embodiment, evacuation and gas discharge are performed with the evacuating and blowing head 10.

[0084]However, as shown in the below-described test example, it has been found that where the amount of inert gas inside the pouch is reduced, the corresponding amount of external air can easily penetrate into the pouch as the pouch is conveyed from the pre-filling deoxidation station to the filling station and the concentration of oxygen inside the pouch increases. In order to prevent this from occurring, the conveying path from the pre-filling deoxidation station to the filling station can be formed as a tunnel and filled with an inert gas atmosphere. Such an approach is, however, inconvenient because the equipment becomes complex and a large amount of inert gas is consumed. A comprehensive research has been conducted to resolve this problem. The results obtained demonstrated that the largest amount of the external gas penetrates into the container after amount reduction at the instant the evacuating and blowing head 10 is separated from the distal end of the spout after inert gas blowing. Therefore, where at least the atmosphere surrounding the spout at the instant the evacuating and blowing head 10 is separated from the spout is the inert gas atmosphere, the penetration of external air before the filling station is reached can be effective prevented and a high degree of deoxidation can be attained even if the conveying path from the pre-filling deoxidation station to the filling station is not under the inert gas atmosphere. Accordingly, in the present embodiment, as shown in FIG. 2(c), a chamber 11 that blows an appropriate inert gas is disposed so as to obtain an inert gas atmosphere in the vicinity of the contact portion of the spout 16 and the evacuating and blowing head 10 and this vicinity is at all times under the inert gas atmosphere.

[0085]The spouted pouch is conveyed to the filling station in a state in which the pouch is filled, as described hereinabove, with a predetermined amount of inert gas in the pre-filling deoxidation station, a pre-filling second degassing step 2-1 of degassing the inside of the pouch is implemented immediately prior to filling in the filling station and then a content metered amount filling step 2-2 of filling the pouch with the content and a residual liquid discharge step 2-3 of discharging the residual liquid contained inside the filling nozzle are implemented. The pre-filling second degassing step 2-1 is performed to reduce the generation of bubbles during filling and serves to obtain a substantially vacuum state inside the pouch by discharging the gas that has been filled in the pouch from the pouch that has been filled with the inert gas in the previous step. As shown schematically in FIG. 3, the gas is discharged by applying pressure to the pouch 15 with a pair of degassing plates 12. The gas can thus be instantaneously discharged and such a step is advantageous from the standpoint of increasing the line speed. However, the gas can be also discharged by evacuation, as in the previous step.

[0086]In the content metered filling step 2-2, a metered amount of the content is filled in a state in which the filling nozzle is brought into intimate contact with the spout opening in the pouch from which gas has been discharged. In this case, because the inside of the pouch is perfectly closed and in an almost vacuum state, no air flows into the pouch from the outside and no air penetrates into the content that is being filled. As a result, even an easily foamable content can be filled without causing foaming. However, where a perfectly negative pressure is created inside the pouch, the pouch is difficult to expand and filling is made difficult. For this reason, after the filling nozzle has been tightly attached to the pouch, the pouch is expanded by suction performed from the outside by a pair of suction tools with respect to the pouch body, thereby facilitating the filling, increasing the filling speed, and enabling a high-speed filling even with an easily foamable content. After the metered amount has been filled, a residual liquid discharge step 2-3 is performed in which the step is temporarily stopped in a state in which the filling nozzle is tightly attached to the pouch mouth and the residual liquid contained in the nozzle is discharge into the pouch.

[0087]Thus, the pouch that has been subjected to the deoxidation step in the previous step is additionally degassed before the pouch is filled with the content and then the filling is performed, thereby making it possible to perform the filling in a state with a lower amount of air inside the pouch and inhibit the occurrence of bubbles more effectively.

[0088]Furthermore, in the conventional method, compressed air is blown into the pouch after filling in order to prevent the residual liquid contained in the nozzle from sagging and lower the liquid level by expanding the pouch, but it has been found that in this case, in particular when the content is easily foamed, the residual liquid contained in the nozzle after filling is blown into the pouch by the compressed air, thereby generating bubbles inside the pouch. In accordance with the present invention, sagging of the residual liquid can be prevented, the occurrence of bubbles can be inhibited, and the deoxidation efficiency can be increased by providing the residual liquid discharge step 2-3 in which the step is temporarily stopped after the filling and the residual liquid remaining in the nozzle mouth is pushed out by a rod, without blowing compressed air after the filling. In a case where a nozzle equipped with a mesh screen is added to the filling nozzle, the liquid sagging can be prevented. Therefore, it is not necessary to discharge forcibly the residual liquid and the residual liquid discharge step 2-3 is not required to be performed after filling the liquid.

[0089]Then, in the present embodiment, a washing and post-filling deoxidation station is provided for performing a post-filling degassing step 3 of pushing out the bubbles that appeared in the head space in this station and discarding the air that penetrated into the head space as the pouch has been transferred from the filling station to the washing and post-filling deoxidation station and a spout washing and post-filling gas replacement step 4 of washing the outer peripheral surface of the spout and performing gas replacement by blowing an inert gas such as nitrogen gas into the pouch. A body of the pouch that has reached the washing and post-filling deoxidation station is compressed by a pair of degassing plates 42 in order to discharge the bubbles contained in the head space from the spout to the outside and perform the degassing inside the head space, and then a washing and replacement nozzle 41 is lowered, washing water is sprayed toward the top surface and outer peripheral portion of the spout, and the inert gas is blown into the pouch, as shown in FIG. 6. In this case, the washing and replacement nozzle 41 completely covers the spout mouth, only the inert gas is blown into the spout, and the washing water does not penetrate into the spout. As a result, the outer peripheral surface of the spout is washed, the adhesion of the content can be prevented, good heat sealing of the inner lid sealing material in the inner lid sealing step that is the last step is ensured, and the outer peripheral surface of the spout after sealing can be cleaned. Furthermore, because the inert gas is blown in the washing step, by contrast with a case where air or nitrogen gas is blown in the filling step, no foaming is caused by the residual liquid and, therefore, no bubbles are generated inside the pouch, the pouch can be expanded, the level of liquid inside the pouch is lowered, and spilling caused by conveying-induced impacts applied to the content liquid in the subsequent conveying step is prevented. In addition, because the pouch is expanded by the inert gas, rather than air, the deoxidation effect can be dramatically increased. Thus, because a step of expanding the pouch by air or inert gas in the filling step is not provided in the present embodiment, the generation of bubbles can be inhibited even in the case of easily foamable content. Furthermore, because the pouch body is expanded by suction from the outside during filling, the pouch can be expanded to a certain degree even when no compressed air is supplied into the pouch, and one-step conveying to the washing and post-filling deoxidation station, which is adjacent to the filling station, is performed although the decrease in the level of liquid after filling is small. Therefore, spilling of the content caused by impacts during conveying is small, and even if the spilling occurs, it causes no problems because it occurs before the pouch is washed.

[0090]The spout that has been fully expanded by blowing the inert gas thereinto and has a decreased liquid level is then conveyed to a spout drying station where the inert gas is blown onto the inner and outer surfaces of the spout, thereby drying the spout after washing with washing water. Because drying is performed with the inert gas, the inert gas produces an air purging action and prevents the air from flowing from the outside into the pouch. However, in the spout drying station, when the inert gas that is a drying medium is blown onto the spout, the blowing is performed in a state in which the spout opening is completely closed, thereby preventing the drying medium from penetrating into the pouch. Therefore, in this case, compressed air may be also used as the fitting medium. By scattering water that has adhered to the outer peripheral portion of the spout with compressed air, it is possible to perform drying within a short time.

[0091]However, in the present embodiment, the amount of oxygen inside the pouch can be dramatically reduced by performing deoxidation in the above-described pre-filling deoxidation step 1 and filling step 2 and the generation of bubbles is also small. Therefore, with the exception of a case where the content that can be foamed extremely easily is used, the spout washing and post-filling first gas replacement step 4 may be omitted and a transition may be directly made from the filling step 2 to a post-filling second gas replacement step 6, as shown by a broken line, in the step diagram shown in FIG. 1.

[0092]The step flow thus advances via the above-described steps to the sealing step, but in the present embodiment, the post-filling second gas replacement step 6 is implemented immediately prior to the inner lid sealing in order to increase further the deoxidation effect. In the post-filling second gas replacement step 6, gas replacement in the head space is performed by blowing the inert gas into the pouch in the post-filling second gas replacement station. Then, the pouch is conveyed to an inner lid preliminary sealing-punching-degassing station and an inner lid sealing step 7 is implemented. In the inner lid sealing step, the pouch body is pressurized by a pair of degassing plates in an inner lid sealing pre-degassing step 7-1 to a degree causing no spilling of the filled liquid, and an inner lid preliminary sealing-punching step 7-2 is implemented to preseal and punch the inner lid in this state. The inner lid preliminary sealing-punching step 7-2 is a step in which an inner lid material having heat fusion ability and gas barrier ability, such as a composite sealing material including an aluminum foil and a synthetic resin film, is pre-sealed to the spout and then punched, and a method similar to the conventional method can be used in this process. Then, the inner lid is covered on the entire top surface of spout opening by a first sealing step 7-3 and a second sealing step 7-4, and the pouch is completely sealed with the inner lid. An outer lid is then screwed in an outer lid attachment step 8.

[0093]The embodiment of the method for filling and sealing a liquid content in a spouted pouch in accordance with the present invention is described above, but the present invention is not limited to this embodiment and the sequence of steps can be changed or a step can be appropriately omitted or added within a scope in which the object of the invention can be reached.

[0094]FIG. 4 illustrates an embodiment of a filling valve as a filling means disposed in the filling station for performing the above-described function. The filling valve 20 is constituted by an outer tube 21, outer rod 22, and central rod 23. The outer tube 21 is formed in a hollow cylindrical shape and has a content supply port 25 that communicates with a content supply tank via a supply tube 24, a fluid chamber 26, a valve seat 27, and a filling nozzle 28. In the present embodiment, a pair of degassing plates (not shown in the figure) for performing the pre-filling second degassing step are disposed below the filling valve in the filling station. A pair of suction pads for performing suction and opening the pouch body after the step of filling the pouch with the content has been started are also disposed therein. However, in a case where the pre-filling second degassing step is performed by vacuum suction, without using the degassing plates, the supply tube 24 is switchably connected to the vacuum pump and the inside of the pouch is vacuum degassed before supplying the liquid. The outer rod 22 is provided inside the fluid chamber so that the outer rod can be driven and moved up and down by an appropriate actuator such as a cylinder. The outer rod functions as a valve body 29 that is seated on the valve seat 27, thereby opening and closing the filling nozzle 28. The valve body 29 has a through hollow section of approximately the same diameter as the filling nozzle 28 in the central thereof, and the central rod 23 is fitted in the hollow portion so that the central rod can be driven and moved up and down by an appropriate actuator such as a cylinder. The central rod 23 is formed as a solid rod and where the central rod is driven in a state in which the valve body 29 is seated on the valve seat, the distal end portion of the central rod advances inside the filling nozzle 28 and acts to push out the residual liquid remaining inside the filling nozzle into the pouch.

[0095]In the filling station that has disposed therein the filling valve 20 of the above-described configuration, where the pouch filled with the inert gas in the previous step reaches the filling station, the pre-filling second degassing step 2-1 is implemented by pressurizing the pouch body with a pair of degassing plates, then the filling valve is lowered, and the top portion of the spout 16 of the pouch mates with the filling nozzle 28, as shown in FIG. 4(a). In the content metered filling step 2-2, the valve body 29 rises integrally with the central rod 23, the filling nozzle 28 opens and communicates with the content filling tank via the supply tube, and the content is filled. After the content filling has started, suction of the body is performed with a pair of suction pads and the pouch is expanded as the content is filled. After metered filling, the outer rod 22 and central rod 23 are integrally lowered, as shown in FIG. 4(b), the valve body 29 is seated, the discharge of the content is stopped and then, the central rod 23 is lowered, as shown in FIG. 4(c), and the residual liquid contained in the filling nozzle 28 is pushed out. Therefore, with the present embodiment, the residual liquid contained in the filling nozzle can be discharged into the pouch, without using compressed air. Therefore, liquid sagging after filling is prevented and the generation of bubbles inside the pouch is reduced.

[0096]FIG. 5 shows a filling valve according to another embodiment that serves as a filling means. FIG. 5(a) shows a state in which the valve is open and the content is discharged thereof. FIG. 5(b) shows a state in which the valve is closed. With the filling valve 32 of this embodiment, by contrast with the above-described embodiment, the residual liquid after filling is not pushed out, but a mesh nozzle is provided below the discharge port to prevent the residual liquid from sagging. The filling valve 32 of the present embodiment is constituted by an outer tube 33 having a discharge port 35, a valve rod 34 that closes the discharge port by the lower end portion thereof that serves as a valve body and can seat on a valve seat, and a mesh nozzle 38 that is provided at the lower end of the discharge port 35 of the valve and has a mesh screen 36 in the intermediate section of a discharge path. The reference numeral 37 in the figure denotes an attachment jig for fixing the mesh screen 36 to the mesh nozzle 38. In the present embodiment the mesh screen 36 has three screens that are disposed with a spacing in the discharge path, as shown in the figure, wherein the mesh screen at the lowermost end is formed to have a dome-like shape that protrudes downward, but the number and shape of the screens are not limited to the present embodiment. Since the nozzle is provided with the mesh screen, generation of foaming is reduced by a flow regulation action produced on the content during content filling, and the residual liquid remaining inside the filling nozzle after the metered discharge has been performed remains till the next discharge, without sagging because of the surface tension between the meshes of the mesh screen. Therefore, in this case, the residual liquid is also not required to be discharged by compressed air and sagging and generation of bubbles can be prevented.

[0097]FIG. 6 is a cross-sectional view of a post-filling degassing device 40 and a washing and gas replacement means 41 disposed in the washing and post-filling deoxidation station. In the degassing device 40, a pair of degassing plates 42, 42 that pressurize the body 17 of the pouch 15 are provided so that the spacing between the degassing plates can be regulated by a cylinder device 43. The pouch 15 that has been filled with the content 18 in the filling station is in a somewhat expanded state due to the weight of the content, as shown in FIG. 6(a), a liquid level 19 is lowered, and a large head space is present above the liquid surface. When the pouch that is sandwiched and held between flanges provided at the outer peripheral portion of the spout 16 by a gripping device (not shown in the figure) reaches the washing and post-filling deoxidation station, the body 17 of the spout is positioned between a pair of degassing plates 42, the degassing plates 42 are displaced in this state by a predetermined stroke so as to come closer to each other, and the body 17 of the spout is pressurized to a predetermined degree, thereby raising the liquid level and discharging the bubbles and air contained inside the pouch from the pouch (see FIG. 6(b)). Then, the washing and gas replacement means is lowered, inert gas is sprayed, and the spout mouth is closed with the nozzle. At the same time, the degassing plates 42, 42 of the degassing device 40 return to the original state and the washing and post-filling first gas replacement step is started.

[0098]The washing and gas replacement means 41 is composed of a nozzle body 45 having a washing water spraying port 46, a gas replacement nozzle 47, and a holding plate 49 for holding a spring 48 that biases the gas replacement nozzle 47 downward, wherein the gas replacement nozzle 47 is fitted in the central portion in the axial direction of the nozzle body 45. The gas replacement nozzle 47 has formed therein, as shown in the figure, a flange 51 in the intermediate section of a rod portion 50 that is linked by the base end thereof to the inert gas supply source, and the discharge port at the lower end is formed so as to engage with the spout opening end. In the gas replacement nozzle 47, the flange 51 engages with an engagement protrusion 52 formed in the nozzle body 45, thereby regulating the lower limit position of the gas replacement nozzle and supporting the nozzle body, and the gas replacement nozzle is biased downward by the spring 48 that is fitted between the upper surface of the flange 51 and the holding plate 49. The nozzle body 45 is linked to the washing water supply source via a washing water supply port 53, a plurality of washing water spraying ports 46 that are formed in the direction toward the spout mouth end portion are formed with a predetermined pitch on a circumference of the lower end portion of the nozzle body, and the washing water spraying ports are also formed so that the washing water is sprayed over the entire outer peripheral portion of the spout and the opening end portion and outer peripheral portion of the spout are washed.

[0099]The washing and gas replacement means 41 has the above-described configuration, and when the aforementioned post-filling degassing step ends, the washing and gas replacement means moves down and when the gas replacement nozzle 47 engages with the opening end of the spout 16, the spring cushions the movement, the gas replacement nozzle 47 engages with the spout under a predetermined pressure, the spout mouth portion is sealed, penetration of the washing water into the spout can be reliably prevented, the vibrations or difference in displacement is absorbed, and damage can be prevented. In this state, the spout is washed by spraying the washing water from the washing water spraying ports formed in the nozzle body 45 onto the mouth end portion of the spout and the entire outer peripheral portion thereof. At the same time, the inert gas is sprayed from the gas replacement nozzle 47 and the inside of the pouch is filled with the inert gas. In this case, by contrast with the case in which the air is sprayed by using the filling nozzle, no bubbles are generated inside the pouch, the pouch can be effectively filled with the inert gas, the pouch is expanded to a predetermined degree, as shown in FIG. 6(c), and the liquid level can be lowered. Moreover, because in this case the inside of the head space is filled with the inert gas after degassing, the gas replacement ratio in the head space is high and oxidation of the content can be effectively prevented. Such a step is especially effective in the case where easily oxidizable content is used.

EXAMPLES

[0100]The following test was conducted to confirm the effect of deoxidation attained by providing the pre-filling deoxidation step.

[0101]As shown in Table 1, the test was divided into a test in which of the first degassing step, inert gas blowing step, and degassing step of the pre-filling deoxidation step, only the first degassing step and the inert gas blowing step were implemented, and the degassing step was not performed (No. 1 and No. 2), a test in which the degassing step was performed without a nitrogen atmosphere (No. 3), and a test in which the degassing step was performed under a nitrogen atmosphere (No. 4), the content of air, oxygen concentration, and amount of oxygen were measured after sealing, and the replacement ratio was found. The degassing was carried out for 0.5 sec for all the samples, and nitrogen was blown for 0.03 sec only in No. 1 and for 0.14 sec in other tests. The results are shown in Table 1. Data shown in Table 1 represent the measurement values obtained when the pouch was directly sealed, without filling the content, after the pre-filling deoxidation step.

TABLE 1 Time (sec) Content Oxygen Oxygen Nitrogen Nitrogen of air concentration amount Replacement No. Degassing blowing Degassing atmosphere (ml) (%) (ml) ratio (%) 1 0.5 0.03 — — 31 6.7 2.1 68 2 0.5 0.14 — — 65 1 0.7 95 3 0.5 0.14 0.61 — 23 5.1 1.2 75 4 0.5 0.14 0.61 Yes 27 2.7 0.7 87

[0102]As shown in Table 1, in No. 1 in which nitrogen blowing after degassing was very small and the pouch was sealed as is, the concentration of oxygen was high, the replacement ratio was low, and a sufficient replacement ratio was not obtained. Among other samples, in No. 2 that was directly sealed without degassing after nitrogen blowing, the gas replacement ratio was the highest, but the drawback occurring in this case was that the degassing amount was large and droplets located at the distal end of the filling nozzle were scattered in a case where the pre-filling degassing step involved pushing with the plates. Another drawback encountered when the pre-filling degassing step was implemented by evacuation was that the evacuation could not be performed within the predetermined time. Furthermore, in a case where the degassing was performed without the nitrogen atmosphere (No. 3), the concentration of oxygen increased due to the penetration of the external air in an amount corresponding to the degassing level, and the replacement ratio was lower than in the case of No. 2. However, when the degassing was performed with a nitrogen atmosphere (No. 4), the replacement ratio increased substantially over that of No. 3, and the effect of increasing the replacement ratio by performing the degassing step in the inert gas atmosphere was confirmed.

[0103]In order to confirm the deoxidation effect attained with the method in accordance with the present invention, as shown in Table 2, the content of air, oxygen concentration, and oxygen amount were measured, and the replacement ratio was found with respect to a case in which the steps including the during-filling degassing step, post-filling degassing step, and post-filling second gas replacement step were performed in a case where the pre-filling deoxidation step was carried out by the method shown in No. 4 in Table 1 (Example 2), and a case in which only the post-filling second gas replacement step of these steps was not performed (Example 1). Furthermore, the content of air, oxygen concentration, and oxygen amount were similarly measured, and the replacement ratio was found in comparative examples with respect to a case in which only the post-filling first gas replacement step was performed (Comparative Example 1), a case in which the post-filling degassing step and post-filling first gas replacement step were performed (Comparative Example 2), and a case in which the during-filling degassing step, post-filling degassing step, and post-filling first gas replacement step were performed (Comparative Example 3). The results are shown in Table 2.

TABLE 2 Post-filling Post-filling Pre-filling Pre-filling first second Content Oxygen Oxygen deoxidation second Post-filling nitrogen nitrogen of air conc. amount Replacement *3 deoxidation deoxidation replacement replacement (ml) (%) (ml) ratio (%) Comparative — — — Yes — 43 8.6 3.7 59 Example 1 Comparative — — Yes Yes — 42 7 3 67 Example 2 Comparative — Yes Yes Yes — 38 4.3 1.6 79 Example 3 Example 1 Yes Yes Yes Yes — 34 2.8 0.9 86 Example 2 Yes Yes Yes Yes Yes 32 2.6 0.8 88 *3 The pre-filling deoxidation method is No. 4 in Table 1

[0104]As shown in Table 2, in the examples, that is, when the pre-filling deoxidation was performed, the gas replacement ratio was confirmed to be greatly increased over that in comparative examples.

INDUSTRIAL APPLICABILITY

[0105]The method and apparatus for filling and sealing a liquid content in a spouted pouch in accordance with the present invention can inhibit the occurrence of bubbles and attain a high gas replacement ratio and are, therefore, especially advantageous in a case where a pouch is filled with a content in which bubbles can easily occur and a content that is easily deteriorated by oxidation and subjected to retort sterilization after filling and sealing. However, the method and apparatus are not limited to such cases and can be also used for typical normal-temperature filling, hot packing, and sterilization-free filling. In addition, the content is not limited to liquid foods, and the method and apparatus can be used for filling and sealing various liquid content such as detergents and oils in spouted pouches.