The present invention relates to a vertical filling-packaging machine which forms a long film drawn from a feed roll into a tubular film and feeding content material thereinto, thereby manufacturing a packaging bag (packaged product), and more particularly to a vertical filling-packaging machine which feeds the content material through an injection nozzle into the tubular film that includes a bottom portion.
There has been known a packaging machine which continuously manufactures a packaging bag filled with content material such as liquid (for example, see Japanese Patent Laid-Open No. 2005-112359). The packaging machine manufactures the packaging bag by folding a long sheet of film drawn from a feed roll to form a tubular shape and by injecting the content material into the tubular film or forming a predetermined seal portion. Hereinafter, a typical packaging operation will be described with reference to
Following the initial state of
Then, as shown in
Then, as shown in
Then, as shown in
As another technique related to the packaging machine of the present invention, there has been known a mechanism for, when one feed roll is used up, joining the end portion of a film of the feed roll to the start portion of a film of another feed roll to be used (see Japanese Patent Laid-Open No. H09-58616). The use of such a mechanism can eliminate the need of troublesome work such as setting a film again each time one feed roll has been used up.
However, such packaging operations as shown in
As shown in
This means that the injection nozzle is emptied. When content material is fed through such an emptied nozzle, the content material gradually flows downward inside the emptied nozzle, so that it is difficult to feed the content material with good quantitative accuracy.
In addition, as shown in
The present invention has been made with a view to solving the above-described problems, and an object of the present invention is to provide a vertical filling-packaging machine capable of feeding fluidized content material into a tubular film with good quantitative accuracy and with few air bubbles mixed into the content material.
In order to achieve the above object, a vertical filling-packaging machine comprises: an injection nozzle for feeding content material that is fluidized into a tubular film that includes a bottom portion; transport means for transporting the tubular film downward in a state in which the content material is fed thereinto; and a lateral sealing mechanism for tightly sealing the tubular film by heat sealing a portion of the tubular film,
wherein the vertical filling-packaging machine manufactures a packaged product by a series of packaging operations including at least following operations: an operation of feeding the content material through the injection nozzle; an operation of transporting the tubular film downward in a state in which the content material is fed thereinto; and an operation of heat sealing by the lateral sealing mechanism,
wherein an injection port of the injection nozzle is configured to be immersed in the content material throughout entirety of the series of packaging operations, and the operation of feeding the content material starts in a state in which the injection port of the injection nozzle is immersed in the content material.
According to the packaging machine of the above present invention, the operation of feeding the content material starts in a state in which the injection port of the injection nozzle is immersed in the content material. Therefore, compared to the proposed feeding method as shown in
In addition, the injection port of the injection nozzle is configured to be always immersed in the content material during the series of packaging operations (in other words, the injection port of the injection nozzle is configured not to be opened to air), so that the inside of the injection nozzle is configured not to be emptied. Therefore, compared to the proposed feeding method as shown in
The above vertical filling-packaging machine may further include a pair of squeezing rollers which pinches the portion of the tubular film in which the fed content material is present, and which rotates in a state in which the pair of squeezing rollers which pinches the portion of the tubular film in which the fed content material is present, thereby forming a flat void-filled portion on the tubular film and transporting the tubular film downward. The operation of feeding the content material may be to feed the content material into the tubular film that is located higher than the portion that is pinched by the pair of squeezing rollers. In this case, the content material that has been accumulated in a position higher than that of the squeezing rollers may be dropped downward into the tubular film located lower than the squeezing rollers at the same time when the pair of squeezing rollers is opened, and after the content material is dropped, liquid level of the content material may be configured to be higher than the injection port of the injection nozzle.
The above vertical filling-packaging machine may further include a content material feeding mechanism including: a reservoir tank for reserving the content material; a feed passage for transferring the content material from the reservoir tank to the injection nozzle; pump means used as a driving source for transferring the content material from the reservoir tank to a side of the injection nozzle; a return passage for returning the content material from the side of the injection nozzle to the reservoir tank; and valve means capable of switching between an operation of feeding the content material, which has been transferred through the feed passage, into the tubular film through the injection nozzle and an operation of returning the content material, which has been transferred through the feed passage, back to a side of the reservoir tank.
The above vertical filling-packaging machine may further include a film feeding device which holds two feed rolls, joins an end portion of a first film drawn from one of the feed rolls to an end portion of a second film drawn from the other of the feed rolls, and feeds the joined first and second films as a long film; and a vertical sealing mechanism which performs vertical sealing on side edge portions of the long film along a longitudinal direction of the long film so as to change the long film into the tubular film. The above vertical filling-packaging machine may be configured such that the vertical sealing mechanism performs vertical sealing on a joint portion in which the first film and the second film are joined in a state in which an operation of transporting the long film is terminated, and the valve means of the content material feeding mechanism is switched to a position on a side of returning the content material to the side of the reservoir tank while the vertical sealing operation is being performed on the joint portion. In this case, the time to perform vertical sealing on the joint portion may be configured to be longer than the time to perform an ordinary vertical sealing so as to prevent the content material from leaking from a vertical sealed portion formed by the vertical sealing.
As described above, according to the vertical filling-packaging machine of the present invention, the operation of feeding content material starts in a state in which the injection port of the injection nozzle is inside the content material, whereby the content material can be fed with good quantitative accuracy, and air bubbles mixed into the content material can be minimized.
As shown in
As film feeding mechanism 10A, a proposed film feeding mechanism, which includes a general configuration for such a packaging machine, can be used. Film feeding mechanism 10A shown in
A configuration is made such that, for example, sensor 83 can detect that film 1A on the using side runs short, and joint sealer 71 is driven on the basis of the detected result. Thus, the end portion of using side film 1A and the end portion of standby side film 1B are heat-sealed so as to join the two films together. More specifically, as shown in
According to packaging machine 10 of the present embodiment, the use of film feeding mechanism 10A as described above allows a film to be continuously fed into packaging mechanism 10C. Such a capability of continuously feeding a film is very advantageous in that there is no need to temporarily terminate manufacturing a packaging bag.
Now going back to
Packaging mechanism 10C includes folding guide 14 for folding a film into a tubular shape; vertical sealing mechanism 30 which performs vertical sealing on the side edges of films folded by folding guide 14 to form vertical sealed portion F1 (see
Vertical sealing mechanism 30 is provided with heater bar 31 incorporating heating means such as a heater. Heater bar 31 is configured to be able to advance and retreat (in the lateral direction in the figure) with respect to the film and also to move back and forth in the up/down direction in the figure, thereby providing a box-shaped motion as shown by arrow A30 of
Vertical sealing mechanism 30 performs sealing operation as follows. First, heater bar 31 moves in the direction of coming close to a film while in a state remaining at an ascending end position thereof, thereby allowing the film to be pinched between heater bar 31 and a main pipe (not shown). Then, in this pinched state, heater bar 31 moves downward in
The above vertical sealing operation is repeated to form a continuous vertical sealed portion on an overlapped portion of both side edges of the film. The vertical sealing mechanism performing such a box-shaped operation has an advantage of being capable of forming a vertical sealed portion without terminating the film transport.
It should be noted that tubular film 1′ is transferred in a state of including a substantially circular cross section, namely, in a state of including a space inside tubular film 1′ until tubular film 1′ passes through vertical sealing mechanism 30. When tubular film 1′ goes further downstream, tubular film 1′ is changed into a flat pressed shape by a guide plate (not shown) provided between vertical sealing mechanism 30 and transport rollers 41.
Transport rollers 41 are arranged so as to pinch both side edges in the width direction of tubular film 1′ pressed in this manner. Transport rollers 41 are one of film transport means in packaging mechanism 10C. When rotated, transport rollers 41 transport tubular film 1′ downward.
A pair of squeezing rollers 45 pinches the tubular film so as to divide filling material injected into the tubular film. When squeezing rollers 45 are rotated in this state, a void-filled portion including no filling material therein is formed on the tubular film, and the tubular film is transported downward. An advantage of forming such a flat void-filled portion is to enable the suppression of the occurrence of sealing failure during the lateral sealing operation described below.
Lateral sealing mechanism 60 includes heater bar 61 incorporating heating means such as a heater, and heater bar receiver 62 arranged facing heater bar 61. The pair of members is used to pinch tubular film 1′ and heat the film, thereby forming lateral sealed portion F2 (see
Heater bar 61 and heater bar receiver 62 are configured to perform a box-shaped motion in the same way as for vertical sealing mechanism 30. More specifically, as shown by arrow A60 of
It should be noted that heater bar 61 incorporates a cutter (not shown) for separating a packaging bag from tubular film 1′ by cutting lateral sealed portion F2. In addition, in response thereto, heater bar receiver 62 includes a relief groove formed so as to provide space between the protruded cutter and heater bar receiver 62.
Subsequently, the content material feeding mechanism, one of features of the packaging machine of the present embodiment, will be described with reference to
As shown in
When three-way-valve 25 is switched to “first mode” in a state in which pump 23 is being driven, the content material is fed into tubular film 1′ through injection nozzle 15. On the contrary, when three-way-valve 25 is switched to “second mode” in a state in which pump 23 is being driven, the operation of feeding the content material into the tubular film is terminated, and the content material is returned to a side of the reservoir tank 22 through return passage 21b.
Such a configuration is advantageous in that the operation of feeding the content material into the tubular film can be controlled simply by switching three-way-valve 25 while pump 23 is being driven. In general, it takes some time to stabilize the feed rate of pump 23. If intermittent feeding is performed by switching on/off pump 23, the amount of content material to be fed may vary.
In contrast, according to the configuration of the present embodiment, there is no need to terminate driving the pump and the pump feed rate is stable. Therefore, it is difficult for such a problem to occur. In addition, from another point of view, the fact that it is not necessary to terminate and to start driving the pump means that the burden applied to the pump is relieved, and thus pump failure can be minimized.
The type of the packaging bag manufactured by the vertical filling-packaging machine of the present invention is not limited to the type described above, but may be a packaging bag as shown in
Next, an example of the packaging operation by packaging machine 10 of the present embodiment configured as above will be described with reference to
First, the basic operation for manufacturing one packaging bag 91 will be described.
Content material has already been injected into tubular film 1′, and the liquid level thereof is located in a position (height h1) higher than lower end 15a of the injection nozzle. In other words, lower end 15a of the injection nozzle is in a state of being immersed into the content material. When lower end 15a is exposed to air, the content material inside the nozzle is dropped into the tubular film by its own weight, and thus the inside of the nozzle is in an empty state. In contrast, according to configuration of the present embodiment, since lower end 15a of the nozzle is immersed into the content material, the content material is not dropped, and the inside of the nozzle remains in a state of being filled with the content material.
Then, as shown in
Then, as shown in
After void-filled portion 2 is transferred to a position to be pinched by lateral sealing mechanism 60, lateral sealing mechanism 60 pinches void-filled portion 2 and the lateral sealing operation starts.
Then, as shown in
Then, as shown in
What matters in the process of
As shown in
With respect to the above described packaging operation, more specifically, the time per cycle shown in
(Packaging Operation with Respect to Film Joint Portion)
By the way, if the filled content material is liquid or the like, and a sealing failure occurs in sealed portion F1 or F2, or joint portion 5 of packaging bag 10, the content material may leak from that place. For this reason, the individual sealed portions of such a packaging bag need to be reliably heat-sealed.
This will be described with reference to
However, since packaging bag 92 includes joint portion 5, the bag may be a defective product in the first place. Therefore, it is considered that such a packaging bag does not have to be filled with the content material. However, if the content material is not fed into the packaging bag, the following problem may occur.
For example, there is no problem in a case in which packaging bag 91 follows packaging bag 92 as shown in
The vertical sealing operation is configured such that the time of the vertical sealing operation to be performed in a region including joint portion 5 is longer than the time of an ordinary vertical sealing operation. Here, the “ordinary vertical sealing operation” refers to vertical sealing that is to be performed on a region not including joint portion 5. For example, the time of the ordinary vertical sealing operation may be 1 second; and the time of the vertical sealing operation that is to be performed in a region including joint portion 5 (hereinafter referred to as “film joint vertical sealing operation”) may be 4 seconds.
The film joint vertical sealing operation will be described with reference to the timing chart of
This vertical sealing operation starts when joint portion 5 of the films reaches the position to be pinched by vertical sealing mechanism 30. For example, a sensor (not shown) for detecting joint portion 5 may be used to detect whether joint portion 5 reaches the position to be pinched by vertical sealing mechanism. Alternatively, back calculation may be made from the relation between the distance from joint sealer 71 (see
The film joint vertical sealing operation starts when, as shown by time “tH” of
Three-way-valve 25 (see
As described above, during the film joint vertical sealing operation, the content material is configured to circulate, thereby preventing more content material than is necessary from being fed into tubular film. The feeding of the content material can be controlled, for example, by temporarily terminating the driving of pump 23. However, as described above, controlling the feeding of the content material by turning on/off the pump tends to cause the amount of feeding content material to vary. In contrast, the present embodiment is configured to control the feeding of the content material just by switching three-way-valve 25 while pump 23 is being driven. Since the feeding rate of pump 23 is stable, it is difficult for a problem such as a reduction in quantitative accuracy to occur.
The use of three-way-valve 25 to switch the feeding of the content material has another advantage in which a change in the quality of the content material can be prevented. The vertical sealing operation of joint portion 5 of films needs to terminate the packaging operation only for several seconds, but for some reason, there may be a case in which terminating the packaging operations for a longer time may be required. In such a case, if the content material remains unmoved in a pipe while the feeding operation is being terminated, a change in temperature may cause the viscosity of the content material to be changed. The change in viscosity may cause the amount of feeding content material that is being fed into tubular film to vary. For this reason, as in the present embodiment, it is preferable to ensure that the content material is being circulated during the time when the feeding operation is being terminated, thereby assuring uniform temperature of the content material and suppressing the above problem from occurring.
After the above vertical sealing operation is performed for a predetermined time, as shown by time t1 (see
Hereinbefore, an embodiment of the present invention has been described, but the present invention is not limited to the above configuration and various modifications can be made. For example, the packaging bag is not limited to the pillow type, but a three-way seal type or a four-way seal type may be used. For the pillow type, vertical sealed portion F1 (see
Both vertical sealing mechanism 30 and lateral sealing mechanism 60 of the packaging machine shown in
With respect to injection nozzle 15, as shown in
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2006/309370 | 5/10/2006 | WO | 00 | 10/30/2008 |
Number | Date | Country | |
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Parent | PCT/JP2006/309370 | May 2006 | US |
Child | 12299118 | US |