U.S. patent application number 12/299118 was filed with the patent office on 2009-08-13 for vertical filling-packaging machine.
This patent application is currently assigned to ORIHIRO ENGINEERING CO., LTD.. Invention is credited to Katsumi Nagai, Orihiro Tsuruta.
Application Number | 20090199519 12/299118 |
Document ID | / |
Family ID | 38667524 |
Filed Date | 2009-08-13 |
United States Patent
Application |
20090199519 |
Kind Code |
A1 |
Tsuruta; Orihiro ; et
al. |
August 13, 2009 |
VERTICAL FILLING-PACKAGING MACHINE
Abstract
There is provided a vertical filling-packaging machine capable
of feeding fluidized content material into a tubular film with good
quantitative accuracy and in which air bubbles are mixed into the
content material. The packaging machine according to the present
invention performs an operation of feeding content material through
injection nozzle (15) into tubular film (1') that includes a bottom
portion. This packaging machine performs an operation of
transporting the tubular film downward, and an operation of tightly
sealing the tubular film by heat sealing using lateral sealing
mechanism (60). Lower end (15a) 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.
Inventors: |
Tsuruta; Orihiro; (Gunma,
JP) ; Nagai; Katsumi; (Gunma, JP) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET, FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Assignee: |
ORIHIRO ENGINEERING CO.,
LTD.
Takasaki-shi, Gunma
JP
|
Family ID: |
38667524 |
Appl. No.: |
12/299118 |
Filed: |
May 10, 2006 |
PCT Filed: |
May 10, 2006 |
PCT NO: |
PCT/JP2006/309370 |
371 Date: |
October 30, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2006/309370 |
May 10, 2006 |
|
|
|
12299118 |
|
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Current U.S.
Class: |
53/552 |
Current CPC
Class: |
B65B 9/213 20130101;
B65B 41/16 20130101; B65B 9/2028 20130101; B65B 9/2007 20130101;
B65B 51/303 20130101 |
Class at
Publication: |
53/552 |
International
Class: |
B65B 9/06 20060101
B65B009/06 |
Claims
1. A vertical filling-packaging machine comprising: an injection
nozzle for feeding content material that is fluidized into a
tubular film that includes a bottom portion; a transporter
configured to transport 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.
2. The vertical filling-packaging machine according to claim 1,
further comprising 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, wherein the operation of feeding the content
material is 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.
3. The vertical filling-packaging machine according to claim 2,
wherein the content material that has been accumulated in a
position higher than that of the squeezing rollers is 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 is configured to be higher than the injection
port of the injection nozzle.
4. The vertical filling-packaging machine according to claim 1,
further comprising 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.
5. The vertical filling-packaging machine according to claim 4,
further comprising: 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, wherein 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.
6. The vertical filling-packaging machine according to claim 5,
wherein the time to perform vertical sealing on the joint portion
is 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.
7. A method of manufacturing a packaged product, comprising a
series of packaging operations, said series comprising at least
following operations: feeding content material that is fluidized
through an injection nozzle into a tubular film that includes a
bottom portion; transporting the tubular film downward in a state
in which the content material is fed thereinto; and tightly sealing
the tubular film by heat sealing a portion of the tubular film in a
lateral direction, 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.
8. The method of claim 7, further comprising pinching the portion
of the tubular film in which the fed content material is present
with a pair of rotating squeezing rollers, thereby forming a flat
void-filled portion on the tubular film and transporting the
tubular film downward, wherein the operation of feeding the content
material is 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.
9. The method of claim 8, wherein the content material that has
been accumulated in a position higher than that of the squeezing
rollers is 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 is configured to be
higher than the injection port of the injection nozzle.
10. The method of claim 7, further comprising transferring the
content material from a reservoir tank wherein through a feed
passage to the injection nozzle.
11. The method of claim 10, wherein a pump drivers the transferring
of the content material from the reservoir tank to a side of the
injection nozzle.
12. The method of claim 11, further comprising returning the
content material from the side of the injection nozzle to the
reservoir tank via a return passage.
13. The method of claim 12, switching a valve between (a) feeding
the content material, which has been transferred through the feed
passage, into the tubular film through the injection nozzle and (b)
returning the content material, which has been transferred through
the feed passage, back to a side of the reservoir tank.
14. The method of claim 13, further comprising: joining an end
portion of a first film drawn from a first feed roll to an end
portion of a second film drawn from a second feed roll; feeding the
joined first and second films as a long film; and vertically
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.
15. The method of claim 14, wherein, in a state in which an
operation of transporting the long film is terminated, a joint
portion in which the first film and the second film are joined are
vertically sealed, and the valve 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.
16. The method of claim 15, wherein the time to perform vertical
sealing on the joint portion is 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.
17. A vertical filling-packaging machine comprising: 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.
Description
TECHNICAL FIELD
[0001] 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.
BACKGROUND ART
[0002] 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
FIG. 1.
[0003] FIG. 1A illustrates an initial state of the packaging
operation, in which lateral seal portion F2 formed in the previous
process is formed at the lower end portion of tubular film 1',
thereby allowing tubular film 1' to have a bottom portion. A pair
of squeezing rollers 45 is used to squeezingly divide the content
material injected into the tubular film. Lateral seal 60 is used to
tightly seal an upper opening portion of the tubular film.
[0004] Following the initial state of FIG. 1A, as shown in FIG. 1B,
first, the pair of squeezing rollers 45 is driven so as to pinch
tubular film 1 therebetween. Thus, the content material inside
tubular film 1' is divided into upper and lower portions. Since
squeezing rollers 45 squeezingly pinch the portion in which the
content material is present, in this way, the amount of air mixed
into the final packaging bag 91 can be minimized.
[0005] Then, as shown in FIG. 1C, when squeezing rollers 45 are
rotated, void-filled portion 2 in which no content material exists
is formed on tubular film 1', which is transported downward. When
void-filled portion 2 reaches a position where it is to be pinched
by lateral sealing mechanism 60, lateral sealing mechanism 60
pinches void-filled portion 2.
[0006] Then, as shown in FIG. 1D, lateral sealing mechanism 60 is
moved downward in a state in which the tubular film is pinched,
thereby forming lateral seal portion F2. During this process, the
content material continues to be fed from injection nozzle 15 and
the fed content material is accumulated in an upper area higher
than squeezing rollers 45.
[0007] Then, as shown in FIG. 1E, when lateral sealing mechanism 60
completes heat sealing and cutoff operations, one packaging bag 91
filled with content material is obtained. In the meantime, the pair
of squeezing rollers 45 is opened, whereby the content material
that has been accumulated in the area higher than squeezing rollers
45 are dropped downward. Subsequently, lateral sealing mechanism 60
is moved back to the original position to return to the initial
state of FIG. 1A.
[0008] 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.
[0009] However, such packaging operations as shown in FIGS. 1A to
1E have a problem in that when content material is fed from the
injection nozzle into a tubular film, a variation occurs in the
amount of fed content material or bubbles of air or the like are
mixed into the content material for the reasons described
below.
[0010] As shown in FIG. 2, the packaging operation of FIG. 1 is
configured such that when squeezing rollers 45 are opened, the
content material is dropped downward, and such that when the
content material is dropped, lower end 15a of the injection nozzle
is exposed. In the state as shown in FIG. 2A, injection nozzle 15
is filled with the content material. However, as shown in FIG. 2B,
when the lower end of the nozzle is exposed and open to air, the
content material remaining inside the nozzle is also dropped into
the tubular film.
[0011] 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.
[0012] In addition, as shown in FIG. 2B, when content material is
fed in a state in which lower end 15a of the nozzle is exposed,
lower end 15a is positioned higher than the liquid level, and thus
there is also a problem in that when content material is injected,
air bubbles tend to be mixed into the content material. Such an air
bubble mixture means that air remains in the final packaged
product. For example, if the content material is food, such an
existence of air therein contributes to the quality degradation of
the content material.
[0013] 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.
DISCLOSURE OF THE INVENTION
[0014] 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,
[0015] 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,
[0016] 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.
[0017] 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 FIG. 2, bubbles of air or the
like are difficult to be mixed into the content material.
[0018] 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 FIG. 2, the quantitative accuracy of the content material
to be fed is improved.
[0019] 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.
[0020] 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.
[0021] 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.
[0022] 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1A illustrates an example of a proposed packaging
operation;
[0024] FIG. 1B illustrates an example of a proposed packaging
operation;
[0025] FIG. 1C illustrates an example of a proposed packaging
operation;
[0026] FIG. 1D illustrates an example of a proposed packaging
operation;
[0027] FIG. 1E illustrates an example of a proposed packaging
operation;
[0028] FIG. 2A explains a problem that a proposed packaging
operation has;
[0029] FIG. 2B explains a problem that a proposed packaging
operation has;
[0030] FIG. 3 schematically illustrates an example of a vertical
filling-packaging machine of the present invention;
[0031] FIG. 4 is a perspective view explaining a joint portion
between films;
[0032] FIG. 5 illustrates a configuration of a content material
feeding mechanism, one of features of the present invention;
[0033] FIG. 6 illustrates a pillow type packaging bag capable of
being manufactured by the packaging machine of FIG. 3;
[0034] FIG. 7A is a process view explaining a packaging operation
of the packaging machine of FIG. 3;
[0035] FIG. 7B is a process view explaining a packaging operation
of the packaging machine of FIG. 3;
[0036] FIG. 7C is a process view explaining a packaging operation
of the packaging machine of FIG. 3;
[0037] FIG. 7D is a process view explaining a packaging operation
of the packaging machine of FIG. 3;
[0038] FIG. 7E is a process view explaining a packaging operation
of the packaging machine of FIG. 3;
[0039] FIG. 8 is a timing chart showing the timing of the operation
of an individual component of the packaging machine of FIG. 3;
[0040] FIG. 9 illustrates a packaging bag including a joint portion
of films;
[0041] FIG. 10A illustrates a configuration of an injection nozzle
of the packaging machine of FIG. 3; and
[0042] FIG. 10B illustrates another configuration of the injection
nozzle of the packaging machine of FIG. 3.
DESCRIPTION OF SYMBOLS
[0043] 1A, 1B Film [0044] 1' Tubular film [0045] 2 Void-filled
portion [0046] 5 Joint portion [0047] 10 Vertical filling-packaging
machine [0048] 10A Film feeding mechanism [0049] 14 Folding guide
[0050] 15 Injection nozzle [0051] 15a Lower end [0052] 17 Injection
port [0053] 20 Content material feeding mechanism [0054] 30
Vertical sealing mechanism [0055] 41 Transport roller [0056] 45
Squeezing roller [0057] 60 Lateral sealing mechanism [0058] 61
Heater bar [0059] 62 Heater bar receiver [0060] 71 Joint sealer
[0061] 83 Sensor [0062] 91, 92 Packaging bag [0063] F1 Vertical
sealed portion [0064] F2 Lateral sealed portion [0065] Ra, Rb Feed
roll
BEST MODE FOR CARRYING OUT THE INVENTION
[0066] As shown in FIG. 3, packaging machine 10 of the present
embodiment includes film feeding mechanism 10A that draws a film
from feed rolls Ra and Rb, and joins film 1A and film 1B as needed.
Further, packaging machine 10 includes packaging mechanism 10C that
forms the film unrolled from film feeding mechanism 10A into a
tubular shape, and that continuously manufactures a packaging bag
by forming a vertical sealed portion and a lateral sealed portion
thereon as needed.
[0067] 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
FIG. 3 uses two feed rolls Ra and Rb, and is configured such that,
for example, when film 1A of feed roll Ra has been used up, film 1B
of feed roll Rb is continuously unrolled. It should be noted that
FIG. 3 shows that film 1A is drawn into a side of the packaging
mechanism 10C as a film on the using side, and that film 1B is held
in the vicinity of joint sealer 71 as a film on the standby
side.
[0068] 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 FIG. 4, two films 1A and 1B are
partially overlapped and two films are joined together by forming
sealed portion 3. The region in which these two films are
overlapped and the region in which sealed portion 3 is formed is
called "joint portion 5".
[0069] 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.
[0070] Now going back to FIG. 3, packaging mechanism 10C will be
described. It should be noted that packaging mechanism 10C is the
same as the vertical filling-packaging machine disclosed in the
Applicant's Japanese Patent Laid-Open No. 2004-276930.
[0071] 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 FIG. 6)
and to form tubular film 1'; and a pair of transport rollers 41, a
pair of squeezing rollers 45 and lateral sealing mechanism 60, each
of which arranged on the downstream side in the film transport
direction from vertical sealing mechanism 30.
[0072] 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 A.sub.30 of FIG.
3.
[0073] 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 FIG. 3 in synchronism with
the film transport. The film to be heat-sealed receives heat from
heater bar 31, and both side edges of the film are joined together.
When heater bar 31 reaches a descending end position thereof,
heater bar 31 moves away from the film and returns to the original
height.
[0074] 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.
[0075] 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.
[0076] 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.
[0077] 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.
[0078] 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 FIG. 6) on the film.
[0079] 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 A.sub.60 of FIG.
3, heater bar 61 and heater bar receiver 62 with tubular film 1'
pinched therebetween move downward in synchronism with the film
transport. Heater bar 61 and heater bar move away from the film at
the descending end position, and go back to the original position
again.
[0080] 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.
[0081] Subsequently, the content material feeding mechanism, one of
features of the packaging machine of the present embodiment, will
be described with reference to FIG. 5. It should be noted that
vertical sealing mechanism 30 is not shown in FIG. 5, but this is
not an essential matter.
[0082] As shown in FIG. 5, content material feeding mechanism 20
includes reservoir tank 22 for reserving the content material; feed
passage 21a for transferring the accumulated content material to
injection nozzle 15; and pump 23 used as a driving source for
transferring the content material. Further, in the present
embodiment, there is return passage 21b for returning the content
material from a side of the injection nozzle 15 to a side of the
reservoir tank 22. Three-way-valve 25 is provided to switch between
the operation (referred to as "first mode") of feeding the content
material transferred to a side of the injection nozzle into the
tubular film and the operation (referred to as "second mode") of
returning the content material through return passage 21b back to
reservoir tank 22.
[0083] 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.
[0084] 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.
[0085] 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.
[0086] 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
FIG. 6. Packaging bag 91 is a so-called pillow type packaging bag
in which two lateral sealed portions F2a and F2b (hereinafter
collectively referred to as "F2") and vertical sealed portion F1
serving as a backlining are formed. The inside of packaging bag 91
is filled with fluidized content material (e.g., liquid). Vertical
sealed portion F1 is a heat-sealed portion formed by vertical
sealing mechanism 30, and lateral sealed portion F2 is a
heat-sealed portion formed by lateral sealing mechanism 60.
[0087] Next, an example of the packaging operation by packaging
machine 10 of the present embodiment configured as above will be
described with reference to FIGS. 7 and 8. FIG. 7 is a process view
explaining the packaging operation of packaging machine 10, and
FIG. 8 is a timing chart showing the timing of the operation of an
individual component thereof.
(Basic Packaging Operation)
[0088] First, the basic operation for manufacturing one packaging
bag 91 will be described.
[0089] FIG. 7A illustrates the initial state of a series of
packaging operations, which corresponds to the state of time
"t.sub.A" in FIG. 8. As shown in FIG. 7A, lateral seal portion F2
formed in the previous process is formed at the lower end portion
of tubular film 1', thereby allowing tubular film 1' to have a
bottom portion. A pair of squeezing rollers 45 and lateral sealing
mechanism 60 are both in a state of being open.
[0090] 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.
[0091] Then, as shown in FIG. 7B (see time "t.sub.B" of FIG. 8),
the pair of squeezing rollers 45 pinches a portion of tubular film
1', in which the content material is present, therebetween. Thus,
the content material in tubular film 1' is divided into upper and
lower portions. Such an operation of squeezing rollers 45 to pinch
a portion in which the content material is present assures that air
does not remain inside packaging bag 91. The operation of feeding
content material into the tubular film has already started since
the initial state as shown in FIG. 7A. Therefore, in the process of
FIG. 7B, the liquid level rises to a level of being slightly higher
than h1.
[0092] Then, as shown in FIG. 7C (see time "t.sub.C" of FIG. 8),
individual squeezing rollers 45 are rotated as shown by arrows in
the figure while the operation of feeding the content material is
continued, namely, without the feeding operation thereof being
terminated. Hence, flat void-filled portion 2 including no content
material therein is formed on tubular film 1', which is transferred
downward. It should be noted that although not shown in FIG. 7, the
feeding operation is configured such that transport rollers 41 (see
FIG. 3) are also rotatably driven in synchronism with the rotation
of squeezing rollers 45, thereby supporting the film transport.
[0093] 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.
[0094] Then, as shown in FIG. 7D (see time "t.sub.D" of FIG. 8), in
a state in which the tubular film is pinched by lateral sealing
mechanism 60, lateral sealing mechanism 60 is moved downward in
synchronism with the rotation of squeezing rollers 45. While being
pinched by lateral sealing mechanism 60, tubular film 1' is heated,
thereby forming lateral sealed portion F2. Although detailed
operation is not shown in the figure, after lateral sealing
mechanism 60 reaches the descending end position, a cutter
incorporated in the heater bar is protruded to cut and separate the
packaging bag. During this process, the operation of feeding the
content material continues, and the fed content material is
accumulated to a level higher than the position of squeezing
rollers 45. Liquid level height h2 in this process is the highest
of all in the series of packaging operations, corresponding to the
liquid level height "high" of FIG. 8.
[0095] Then, as shown in FIG. 7E (see time "t.sub.E" of FIG. 8),
both the operations of pinching the film by lateral sealing
mechanism 60 and the pair of squeezing rollers 45 are stopped.
Thereby, one packaging bag 91 filled with content material is
obtained, and at the same time, content material that has been
accumulated to a level higher than the position of squeezing
rollers 45 is dropped downward into tubular film 1'.
[0096] What matters in the process of FIG. 7E is that a feeding
operation is configured such that after the content material is
dropped downward, the liquid level of the content material is
higher than the position of lower end 15a of the nozzle
(specifically, the same liquid level height h1 as the initial
state). Such a configuration assures that lower end 15a of the
nozzle remains to be immersed in the content material continuously
during the series of packaging operations. Therefore, even after
the content material inside the nozzle is dropped downward, the
inside of the nozzle is not emptied. According to such a
configuration in which the inside of the nozzle is filled with the
content material and the operation of feeding the content material
starts in this state, the content material can be fed with a very
favorable quantitative accuracy. However, if the content material
is injected in a state in which the lower end of the nozzle is
exposed and where the inside of the nozzle is emptied, bubbles of
air or the like are mixed into the liquid while the content
material is being dropped downward. However, the above
configuration can prevent such a problem from occurring.
[0097] As shown in FIG. 7E, finally, lateral sealing mechanism 60
is moved back to the original position and the packaging machine
returns to the initial state of FIG. 7A. Packaging bag 91 can be
continuously manufactured by repeatedly performing the series of
packaging operation as described above.
[0098] With respect to the above described packaging operation,
more specifically, the time per cycle shown in FIG. 8 may be, for
example, 1.0 second. With respect to the operation of squeezing
rollers 45, the time when squeezing rollers 45 are opened may be
set to 0.4 seconds (corresponding to the individual process of
FIGS. 7A and 7E), and the time when squeezing rollers 45 are closed
may be set to 0.6 seconds (corresponding to the individual process
of FIGS. 7B to 7E).
(Packaging Operation with Respect to Film Joint Portion)
[0099] 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.
[0100] This will be described with reference to FIG. 9. As shown in
the figure, if joint portion 5 of the films is located on the
bellows of packaging bag 92, and, for example, if a sealing failure
occurs in vertical sealed portion F1' including joint portion 5,
the content material will leak from that place. In particular,
joint portion 5 is a portion where two films are overlapped, and
thus, insufficient heat sealing in the vertical sealing operation
may cause insufficient sealing strength. Accordingly, it is
preferable to sufficiently heat seal vertical sealed portion F1'
including the joint portion.
[0101] 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.
[0102] For example, there is no problem in a case in which
packaging bag 91 follows packaging bag 92 as shown in FIG. 9, but,
if packaging bag 91 has already been cut and separated, emptied
packaging bag 92 is in a state of hanging down at the bottom of the
tubular film. Since packaging bag 92 is emptied, the tensile force,
which is due to the weight of content material in packaging bag 92,
is not applied to the tubular film. Therefore, the emptied
packaging bag 92 may swingly move to be in contact with heater bar
61 (see FIG. 6). If packaging bag 92 is in contact with heater bar
61, the film may melt to adhere to the heater bar, which will
disturb the film transport. In order to prevent such problem, it is
preferable to feed the content material into packaging bag 92 in
the same way as for other packaging bags.
[0103] 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.
[0104] The film joint vertical sealing operation will be described
with reference to the timing chart of FIG. 8 again.
[0105] 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 FIG. 3) to vertical
sealing mechanism 30 and the length of a film transferred per
cycle; and after a predetermined number of ordinary vertical
sealing operations is performed, the film joint vertical sealing
operation may start.
[0106] The film joint vertical sealing operation starts when, as
shown by time "t.sub.H" of FIG. 8, the film transport is
terminated, squeezing rollers 45 are opened, and the liquid level
height is "high" (see FIG. 7D). According to the vertical sealing
operation, the time when vertical sealing mechanism 30 pinches the
film is set to, for example, 2.0 to 3.0 seconds. Since the pinching
time for the ordinary vertical sealing operation is 0.4 seconds,
the pinching time for the film joint vertical sealing operation is
about five times longer than the ordinary time.
[0107] Three-way-valve 25 (see FIG. 4) is switched at time t.sub.H
when the content material transferred from reservoir tank 22 is
returned to reservoir tank 22 through return passage 21b. Here,
pump 23 continues to be driven, so that the content material
circulates from feed passage 21a through the three-way-valve and
return passage 21b to reservoir tank 22.
[0108] 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.
[0109] 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.
[0110] After the above vertical sealing operation is performed for
a predetermined time, as shown by time t.sub.1 (see FIG. 8), an
ordinary packaging operation is resumed. More specifically,
squeezing rollers 45 are opened, the content material is dropped
downward (see FIG. 7D), three-way-valve 25 is switched, and the
operation of feeding the content material into tubular film is
resumed. Subsequently, the ordinary packaging operation is repeated
as described above so as to continuously manufacture packaging
bags.
[0111] 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 FIG. 6) thereof is not
limited to this, but a so-called butt-seam type or an envelope type
may be used.
[0112] Both vertical sealing mechanism 30 and lateral sealing
mechanism 60 of the packaging machine shown in FIG. 3 perform a
box-shaped motion, but the present invention is not limited to
this, and a general vertical sealing mechanism and lateral sealing
mechanism for performing heat sealing in situ without moving up and
down may be used. Packaging machine 10 of FIG. 3 is provided with
the pair of squeezing rollers 45, but the present invention is not
limited to this, and may be configured as a packaging machine
without a squeezing roller.
[0113] With respect to injection nozzle 15, as shown in FIG. 10A,
the injection port thereof may be formed at lower end 15a of the
nozzle or as shown in FIG. 10B, injection port 17 may be formed on
the outer periphery surface of the nozzle. For the configuration of
FIG. 10B, liquid level height h1 can be located higher than
injection port 17 after squeezing rollers 45 are opened as shown in
FIG. 7E. This assures that injection port 17 is not exposed to air,
and the content material inside the nozzle is not dropped into the
tubular film and remains in the nozzle. As a result, the same
advantage of the present invention as described above can be
obtained.
* * * * *