U.S. patent application number 10/635785 was filed with the patent office on 2004-02-12 for bag vacuum packaging method using ultrasonic sealing device and vacuum packaging machine equipped with ultrasonic sealing device.
This patent application is currently assigned to Toyo Jidoki Co., Ltd.. Invention is credited to Hiramoto, Shinichi.
Application Number | 20040025474 10/635785 |
Document ID | / |
Family ID | 30437750 |
Filed Date | 2004-02-12 |
United States Patent
Application |
20040025474 |
Kind Code |
A1 |
Hiramoto, Shinichi |
February 12, 2004 |
Bag vacuum packaging method using ultrasonic sealing device and
vacuum packaging machine equipped with ultrasonic sealing
device
Abstract
An ultrasonic sealing device and method, in which an ultrasonic
sealing device is disposed near a bag take-out position of a rotary
type vacuum processing device that has a plurality of vacuum
chambers disposed at equal intervals on the circumference of an
intermittently rotating table, a degassed bag is taken out of the
interior of a vacuum chamber stopped at the bag take-out position
and is transported to and positioned in the sealing position of the
ultrasonic sealing device, a horn element and an anvil are caused
to advance and press-hold a predetermined position on the bag mouth
and perform ultrasonic sealing to the bag. The temporary sealing to
the bag mouth is preferably performed in the rotary type vacuum
processing device so that the degassed state inside the bag is
maintained when the vacuum chamber is placed in an atmospheric
pressure state.
Inventors: |
Hiramoto, Shinichi;
(Iwakuni-shi, JP) |
Correspondence
Address: |
KODA & ANDROLIA
2029 CENTURY PARK EAST
SUITE 1430
LOS ANGELES
CA
90067-3024
US
|
Assignee: |
Toyo Jidoki Co., Ltd.
|
Family ID: |
30437750 |
Appl. No.: |
10/635785 |
Filed: |
August 5, 2003 |
Current U.S.
Class: |
53/434 ;
53/512 |
Current CPC
Class: |
B29C 65/76 20130101;
B29C 66/81463 20130101; B29C 66/81427 20130101; B29C 66/8322
20130101; B29K 2705/02 20130101; B65B 51/22 20130101; B29C 65/086
20130101; B29C 66/232 20130101; B29C 66/83221 20130101; B29C 65/18
20130101; B29C 66/8242 20130101; B29L 2031/7128 20130101; B29C
66/72321 20130101; B65B 31/024 20130101; B29C 66/1122 20130101;
B29C 66/723 20130101; B29C 66/3452 20130101; B29C 66/8221 20130101;
B29C 66/81413 20130101; B29C 65/08 20130101; B29C 66/43121
20130101; B29C 65/7882 20130101; B29C 66/81419 20130101; B29C
66/8226 20130101; B65B 31/022 20130101; B29C 66/83511 20130101;
B29C 66/849 20130101 |
Class at
Publication: |
53/434 ;
53/512 |
International
Class: |
B65B 031/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 7, 2002 |
JP |
2002-229701 |
Claims
1. A vacuum packaging method that uses a rotary type vacuum
processing device, said rotary type vacuum processing device being
comprised of: a rotary table, and a plurality of vacuum chambers
disposed at equal intervals on a circumference of said rotary
table, wherein each one of said vacuum chambers comprises: a main
body that is fastened to said rotary table, and a cover that is
caused to open and close with respect to said main body; each
vacuum chamber is caused to be placed in a vacuum state or in an
atmospheric pressure state with a predetermined timing; and
grippers that suspend filled bags in a state in which bag mouths of
said filled bags face upward are disposed on said main body,
wherein said vacuum packaging method comprises the steps of, during
rotation of said rotary table, accommodating filled bags inside
said vacuum chambers, performing a degassing treatment by placing
interiors of said vacuum chambers in a vacuum state so that a
vacuum is caused to act on said filled bags, placing said vacuum
chambers back to an atmospheric pressure state, and opening said
cover; and the further steps of: taking out said filled bags, which
have been subjected to said degassing treatment, from said vacuum
chambers, and conveying said filled bags to an ultrasonic sealing
device disposed near said rotary type vacuum processing device,
where bag mouths of said filled bags are ultrasonically sealed by
means of said ultrasonic sealing device.
2. The vacuum packaging method according to claim 1, wherein said
bag mouths are placed under tension by being pulled from both edges
thereof prior to performing ultrasonic sealing.
3. A vacuum packaging method that uses a rotary type vacuum
processing device, said rotary type vacuum processing device being
comprised of: an intermittently rotating table, and a plurality of
vacuum chambers disposed at equal intervals on a circumference of
said intermittently rotating table, wherein each one of said vacuum
chambers comprises: a main body that is fastened to said
intermittently rotating table, and a cover that is caused to open
and close with respect to said main body, each vacuum chamber is
caused to be placed in a vacuum state or in an atmospheric pressure
state with a predetermined timing, grippers that suspend filled
bags in a state in which bag mouths of said filled bags face upward
are disposed on said main body, and an anvil which forms a part of
an ultrasonic sealing device is disposed above said grippers
disposed on said main body, wherein said vacuum packaging method
comprises the steps of, during repeated rotation and stopping of
said rotary table: accommodating filled bags inside said vacuum
chambers, performing a degassing treatment by placing interiors of
said vacuum chambers in a vacuum state so that a vacuum is caused
to act on said filled bags, placing said vacuum chambers back to an
atmospheric pressure state, opening said cover, and causing a horn
element of an ultrasonic sealing device disposed near said rotary
type vacuum processing device so as to hold the bag mouth of the
filled bag between the horn element and the anvil and to perform
ultrasonic sealing; and the further step of: releasing said
grippers so that sealed filled bags are taken out of said vacuum
chambers.
4. The vacuum packaging method according to any one of claims 1
through 3, wherein said bag mouths are temporarily sealed following
said degassing treatment so that a degassed state inside said
filled bags is maintained when said vacuum chambers are placed back
to said atmospheric pressure state.
5. The vacuum packaging method according to claim 4, wherein a
sealing position of said ultrasonic sealing is located below said
sealing position of temporary sealing.
6. A vacuum packaging machine equipped with an ultrasonic sealing
device, said vacuum packaging machine comprising: (1) a rotary type
vacuum processing device that is comprised of: an intermittently
rotating table, and a plurality of vacuum chambers disposed at
equal intervals on a circumference of said intermittently rotating
table, wherein each one of said vacuum chambers comprises: a main
body that is fastened to said intermittently rotating table, and a
cover that is caused to open and close with respect to said main
body; each vacuum chamber is caused to be placed in a vacuum state
or in an atmospheric pressure state with a predetermined timing;
and grippers that suspend filled bags in a state in which bag
mouths of said filled bags face upward are disposed on said main
body, wherein said rotary type vacuum processing device, during
repeated rotation and stopping of said intermittently rotating
table, accommodates filled bags inside said vacuum chambers, and
performs a degassing treatment by placing interiors of said vacuum
chambers in a vacuum state so that a vacuum is caused to act on
said filled bags; (2) an ultrasonic sealing device which is
disposed near said rotary type vacuum processing device; and (3) a
bag transporting device which takes out said filled bags that have
been subjected to said degassing treatment from said vacuum
chambers stopped at a take-out position and then transports said
filled bags to a sealing position of said ultrasonic sealing
device.
7. The vacuum packaging machine equipped with an ultrasonic sealing
device according to claim 6, wherein said bag transporting device
comprises: a first transporting device that takes out said filled
bags, which have been subjected to said degassing treatment, from
said vacuum chambers stopped at said take-out position and
transports said filled bags to a predetermined position, and a
second transporting device that receives said filled bags from said
first transporting device at said predetermined position and
transports said filled bags to said sealing position.
8. The vacuum packaging machine equipped with an ultrasonic sealing
device according to claim 7, wherein said second transporting
device is equipped with a pair of grippers that grip both side
edges of said filled bags, a spacing between said grippers being
caused to be widened and narrowed.
9. The vacuum packaging machine equipped with an ultrasonic sealing
device according to any one of claims 6 through 8, wherein a
temporary sealing device that holds and temporarily seals said bag
mouths is disposed inside each one of said vacuum chambers.
10. A vacuum packaging machine equipped with an ultrasonic sealing
device, said vacuum packaging machine comprising: (1) a rotary type
vacuum processing device that is comprised of: an intermittently
rotating table, and a plurality of vacuum chambers disposed at
equal intervals on a circumference of said intermittently rotating
table, wherein each one of said vacuum chambers comprises: a main
body that is fastened to said intermittently rotating table, and a
cover that is caused to open and close with respect to said main
body; each vacuum chamber is caused to be placed in a vacuum state
or in an atmospheric pressure state with a predetermined timing;
and grippers that suspend filled bags in a state in which bag
mouths of said filled bags face upward are disposed on said main
body, wherein said rotary type vacuum processing device, during
repeated rotation and stopping of said intermittently rotating
table, accommodates filled bags inside said vacuum chambers, and
performs a degassing treatment by placing interiors of said vacuum
chambers in a vacuum state so that a vacuum is caused to act on
said filled bags; and (2) an ultrasonic sealing device which is
disposed near a cover opening position of said rotary type vacuum
processing device, said ultrasonic sealing device having an anvil
which is provided above said grippers of said main body of each one
of said vacuum chambers, wherein a horn element of said ultrasonic
sealing device is caused to advance toward and withdraw from said
anvil provided in each one of said vacuum chambers stopped at said
cover opening position, and said horn element performs ultrasonic
sealing by press-holding said bag mouths against said anvil.
11. The vacuum packaging machine equipped with an ultrasonic
sealing device according to claim 10, wherein a temporary sealing
device which holds and temporarily seals said bag mouths is
disposed inside each one of said vacuum chambers.
12. The vacuum packaging machine equipped with an ultrasonic
sealing device according to claim 11, wherein said anvil is
provided below said temporary sealing devices.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a vacuum packaging method
that performs a degassing treatment to filled bags and then
ultrasonically seals the bag mouths and also to a vacuum packaging
machine that performs this method.
[0003] 2. Prior Art
[0004] Japanese Patent Application Laid-Open (Kokai) No. H9-48409
discloses a vacuum packing machine.
[0005] In this vacuum packing machine, a plurality of vacuum
chambers are disposed at equal intervals on the circumference of an
intermittently rotating table, and each vacuum chamber comprises a
main body that is fastened to the table and a cover that can be
opened and closed with respect to the main body. The vacuum chamber
can be placed in a vacuum state or in an atmospheric pressure state
with a predetermined timing, and grippers that suspend filled bags
in a state in which the bag mouths face upward are disposed on the
main body of the vacuum chamber. Furthermore, an impulse sealing
device is disposed above the grippers; and typically a moving
element (a heater stand) is disposed on the main body of the vacuum
chamber, and a receiving stand is disposed on the cover of the
vacuum chamber.
[0006] In this vacuum packaging machine, filled bags are
accommodated inside the vacuum chambers while the table makes
repeated rotation and stopping movements, and a degassing treatment
is performed by placing the interiors of the vacuum chambers in a
vacuum state so that a vacuum is caused to act on the filled bags.
Then, after the bag mouths are sealed by the impulse sealing
devices, the interiors of the vacuum chambers are placed back in
the atmospheric pressure state, the covers are opened, and then the
sealed filled bags are taken out of the chambers.
[0007] Japanese Patent Application Publication (Kokoku) No.
H5-58988 (that corresponds to the Laid-Open (Kokai) No. H1-99924)
discloses a vacuum packaging machine in which the table rotates
continuously.
[0008] However, the vacuum packaging machines described above have
problems. There is a considerable chance that portions of the
contents with which the bags are filled will adhere to the sealing
portions as a result of vibration that occurs when the filled bags
are received from the filling machine via the transfer device or as
a result of boiling of liquid contents during the degassing
process, etc. If impulse sealing is performed to such sealing
portions, a so-called "bite-in" seal (in which a portion of the
contents with which the bags are filled will bite into the sealed
portion) tends to occur, resulting in incomplete sealing of the bag
mouths. Furthermore, since impulse sealing always requires cooling
after the sealing, the total time required for sealing increases;
as a result, the productivity cannot be increased. If the number of
vacuum chambers is increased in order to raise the productivity,
then the size of the apparatus increases.
[0009] Japanese Patent No. 3079185 (that correspond to the
Laid-Open (Kokai) No. H3-212327) discloses different sealing
method. In the ultrasonic sealing method of this Japanese patent,
even if a portion of the contents with which the bag is filled
adheres to the sealing portions, these contents are expelled in the
upward and downward directions by ultrasonic waves; as a result,
the problem of a "bite-in" seal does not occur, and sealing of the
bag mouths is assuredly accomplished. Furthermore, such sealing is
completed in a shorter time compared to heat sealing or impulse
sealing.
[0010] Accordingly, if an impulse sealing device is provided in
vacuum chambers instead of a conventional impulse sealing device,
it is considered that the above-described "bite-in" seal that tends
to occur in vacuum packaging machines is prevented and that the
sealing time can be shortened at the same time, thus improving the
productivity.
[0011] However, compared to impulse sealing devices, ultrasonic
sealing devices are large and expensive. In addition, when such
devices are disposed in the respective vacuum chambers in the same
configuration as impulse sealing devices, the vacuum packaging
apparatus as a whole increases in size and cost. Furthermore, the
covers of the vacuum chambers tend to open during the sealing
process by the action of a holding force that is higher than that
of an impulse sealing device; and if measures are taken to prevent
this, then the size of the vacuum packaging apparatus increases,
and its structure becomes more complicated.
[0012] It can be, however, conceivable to provide an ultrasonic
sealing device near a vacuum packaging machine as disclosed in
Japanese Patent Application Laid-Open (Kokai) No. S61-33915.
[0013] In this prior art, a sealing device is not installed inside
the vacuum chambers. Instead, a sealing device is installed near a
vacuum packaging machine, the bag mouths of vacuum-treated bags are
gripped by a sealing bar of this sealing device and a receiving
member, the sealing device is rotated so that the bags are taken
out of the vacuum chambers and rotationally transported to a
predetermined position, so that the bag mouths are sealed in the
process of this movement. In other words, in this prior art, an
ultrasonic sealing device acts as both a sealing device and a bag
removing device (with its horn element and anvil respectively
corresponding to the sealing bar and receiving member of the
above-described sealing device).
[0014] However, the ultrasonic sealing device in this case is large
and heavy and cannot be simply rotated as a whole as in the case of
the impulse sealing device described in the above-described
Japanese Patent Application Laid-Open (Kokai) No. H9-48409.
Further, if sealing is performed while this device is rotating,
there is an increased possibility of a deviation in the sealing
position. Moreover, when such a technique is used, it is necessary
to complete the sealing action while the sealing device is rotating
and the bags are rotationally transported to a predetermined
position, and the time required for return to the original position
is not allotted to the time required for sealing. Consequently,
only half of the time required for one process (i.e., the time
required for one stop and one rotation) is allotted to the sealing
time. Accordingly, it is difficult to shorten the time of one
process and to increase the productivity.
SUMMARY OF THE INVENTION
[0015] The present invention is to solve the above-described
problems that occur when an ultrasonic sealing device is applied to
a vacuum packaging machine; and it is an object of the present
invention to provide a vacuum packaging method and vacuum packaging
machine that can avoid any sealing position deviation and increase
the productivity without increasing the size or cost of the
apparatus.
[0016] The above object is accomplished by unique steps of the
present invention for a vacuum packaging method that uses a rotary
type vacuum processing device, wherein
[0017] the rotary type vacuum processing device is comprised
of:
[0018] an intermittently rotating or continuously rotating table,
and
[0019] a plurality of vacuum chambers disposed at equal intervals
on the circumference of the intermittently rotating or continuously
rotating table, in which each one of the vacuum chambers comprises
a main body that is fastened to the table and a cover that can be
opened and closed with respect to the main body;
[0020] each vacuum chamber can be placed in a vacuum state or in an
atmospheric pressure state with a predetermined timing; and
[0021] grippers that suspend filled bags in a state in which bag
mouths of the filled bags face upward are disposed on the main
body; and
[0022] the method includes, during the intermittent rotation or
continuous rotation of the table, the steps of:
[0023] accommodating a filled bag inside each vacuum chamber,
[0024] performing a degassing treatment by placing the interior of
the vacuum chamber in a vacuum state so that a vacuum is caused to
act on the filled bag,
[0025] placing the vacuum chambers back to an atmospheric pressure
state, and opening the cover; and
[0026] the further steps of:
[0027] taking out the filled bag, which has been subjected to the
degassing treatment, from the vacuum chamber, and
[0028] conveying the filled bag to an ultrasonic sealing device
disposed near the rotary type vacuum processing device, where the
bag mouth of the filled bag is ultrasonically sealed by means of
the ultrasonic sealing device.
[0029] In this method, the bag mouths are preferably placed under
tension by way of pulling both edges of the bag mouths prior to the
ultrasonic sealing. As a result, a formation of wrinkles in the
location where the ultrasonic sealing is performed is prevented.
Furthermore, it is preferable that the bag mouths be temporarily
sealed following the degassing treatment. This is done so that the
degassed state inside the bags is securely maintained when the
vacuum chambers are placed back in the atmospheric pressure state.
When this temporary sealing is performed, it is preferable that the
sealing position of the ultrasonic sealing be lower than the
position of the temporary sealing.
[0030] In the above-described method of the present invention,
there is no need to dispose ultrasonic sealing devices in the
respective vacuum chambers. Accordingly, an increase in the cost
and size of the vacuum packaging machine is prevented. Furthermore,
since the ultrasonic sealing device is not rotated, deviations in
the sealing position is prevented. Moreover, the ultrasonic sealing
device performs ultrasonic sealing while using in full the time
that passes until the next bag is transported by the transporting
device. Moreover, since the ultrasonic sealing completes the
sealing in a short time as described above, the time required for
one process is shortened, and the productivity improves. Moreover,
the characteristics of the ultrasonic sealing device is
sufficiently utilized; and thus bite-in sealing, for instance, can
be prevented.
[0031] The above object is accomplished also by a unique structure
of the present invention for a vacuum packaging machine equipped
with an ultrasonic sealing device, and the vacuum packaging machine
comprises a rotary type vacuum processing device, an ultrasonic
sealing device and a bag transporting device; and
[0032] (1) the rotary type vacuum processing device is comprised
of:
[0033] an intermittently rotating table, and
[0034] a plurality of vacuum chambers disposed at equal intervals
on the circumference of the intermittently rotating table,
wherein
[0035] each one of the vacuum chambers comprises a main body that
is fastened to the table and a cover that can be opened and closed
with respect to the main body;
[0036] each vacuum chamber can be placed in a vacuum state or in an
atmospheric pressure state with a predetermined timing; and
[0037] grippers that suspend filled bags in a state in which bag
mouths of the filled bags face upward are disposed on the main body
of the vacuum chamber; and
[0038] the rotary type vacuum processing device, during the
repeated rotation and stopping of the table,
[0039] accommodates filled bags inside the vacuum chambers, and
[0040] performs a degassing treatment by placing interiors of the
vacuum chambers in a vacuum state so that a vacuum is caused to act
on the filled bags;
[0041] (2) the ultrasonic sealing device is disposed near the
rotary type vacuum processing device; and
[0042] (3) the bag transporting device takes out the filled bags
that have been subjected to the degassing treatment from the vacuum
chambers stopped at a take-out position of the rotary type vacuum
processing device and then transports the filled bags to a sealing
position of the ultrasonic sealing device.
[0043] In this vacuum packaging machine, the bag transporting
device preferably comprises:
[0044] a first transporting device that takes out the filled bags,
which have been subjected to the degassing treatment, from the
vacuum chambers stopped at the take-out position and transports the
filled bags to a predetermined position, and
[0045] a second transporting device that receives the filled bags
from the first transporting device at the predetermined position
and transports the filled bags to a sealing position.
[0046] The second transporting device can be equipped with a pair
of grippers that grip both side edges of the filled bags, and the
spacing between the grippers can be widened and narrowed.
[0047] By way of widening the spacing of the grippers so that the
bag mouths are pulled in the opposite directions from both edges
and thus placed under tension, a formation of wrinkles in the area
that is ultrasonically sealed can be prevented. Furthermore, in the
above structure of the vacuum packaging machine, a temporary
sealing device that holds and temporarily seals the bag mouths is
disposed inside the respective vacuum chambers. This temporary
sealing device is comprised of a receiving stand and a moving
element (hot plate, for instance) that is pressed against the
receiving stand.
[0048] The above object is further accomplished by another set of
unique steps of the present invention for a vacuum packaging method
that uses a rotary type vacuum processing device, wherein
[0049] the rotary type vacuum processing device is comprised
of:
[0050] an intermittently rotating table, and
[0051] a plurality of vacuum chambers disposed at equal intervals
on the circumference of the intermittently rotating table, in which
each one of the vacuum chambers comprises a main body that is
fastened to the table and a cover that can be opened and closed
with respect to the main body,
[0052] each vacuum chamber can be placed in a vacuum state or in an
atmospheric pressure state with a predetermined timing,
[0053] grippers that suspend filled bags in a state in which bag
mouths of the filled bags face upward are disposed on the main body
of the vacuum chamber, and
[0054] an anvil which forms a part of an ultrasonic sealing device
is provided above the grippers disposed on the main body; and
[0055] the method includes, during the repeated rotation and
stopping of the table, the steps of:
[0056] accommodating a filled bag inside the vacuum chambers,
[0057] performing a degassing treatment by placing interiors of the
vacuum chambers in a vacuum state so that a vacuum is caused to act
on the filled bag,
[0058] placing the vacuum chambers back to an atmospheric pressure
state,
[0059] opening the cover, and
[0060] causing a horn element of an ultrasonic sealing device
disposed near the rotary type vacuum processing device to advance
so as to press-hold the bag mouth of the filled bag between the
horn element and the anvil and to perform ultrasonic sealing,
and
[0061] the further steps of:
[0062] releasing the grippers so that sealed filled bag is taken
out of the vacuum chambers.
[0063] In this method, it is preferable that the bag mouths be
temporarily sealed following the degassing operation. When this
temporary sealing is performed, it is preferable that the sealing
position of the ultrasonic sealing be located below the sealing
position of the temporary sealing.
[0064] In the method, anvils that form a part of the ultrasonic
sealing device are disposed in the main bodies of the respective
vacuum chambers. If only anvils are thus disposed, the size and
weight involved are not very great, and the press-holding force
that accompanies ultrasonic sealing can be received by the main
bodies of the vacuum chambers. Accordingly, it is possible to avoid
a size increase, complexity and cost of the vacuum packaging
machine. Furthermore, there is no need to transport the bags to a
separate sealing position from the interiors of the vacuum
chambers, and there is likewise no rotation of the ultrasonic
sealing device; accordingly, deviations in the sealing position can
be prevented. Moreover, though ultrasonic sealing is performed
while the vacuum chambers are stopped, since ultrasonic sealing can
complete sealing in a short period of time as described above, the
stopping time is shortened and the productivity improves.
Furthermore, the characteristics of the ultrasonic sealing device
can be sufficiently utilized, and thus bite-in sealing, for
instance, can be prevented.
[0065] The above object is accomplished by another unique structure
of the present invention for a vacuum packaging machine equipped
with an ultrasonic sealing device, and the vacuum packaging machine
comprises a rotary type vacuum processing device and an ultrasonic
sealing device; and
[0066] (1) the rotary type vacuum processing device is comprised
of:
[0067] an intermittently rotating table, and
[0068] a plurality of vacuum chambers disposed at equal intervals
on the circumference of the intermittently rotating table,
wherein
[0069] each one of the vacuum chambers comprises a main body that
is fastened to the table and a cover that can be opened and closed
with respect to the main body;
[0070] each vacuum chamber can be placed in a vacuum state or in an
atmospheric pressure state with a predetermined timing; and
[0071] grippers that suspend filled bags in a state in which bag
mouths of the filled bags face upward are disposed on the main body
of the vacuum chamber; and
[0072] the rotary type vacuum processing device, during the process
of repeated rotation and stopping of the table,
[0073] accommodates filled bags inside the vacuum chambers, and
[0074] performs a degassing treatment by placing interiors of the
vacuum chambers in a vacuum state so that a vacuum is caused to act
on the filled bags; and
[0075] (2) the ultrasonic sealing device is disposed near a cover
opening position of the rotary type vacuum processing device, the
ultrasonic sealing device having an anvil which is provided above
the grippers of the main body of each one of the vacuum chambers,
wherein a horn element of the ultrasonic sealing device can advance
toward and withdraw from the anvil provided in each one of the
vacuum chambers stopped at the cover opening position, and the horn
element performs ultrasonic sealing by press-holding the bag mouths
against the anvil.
[0076] In this structure, a temporary sealing device that holds and
temporarily seals the bag mouth is disposed inside each one of the
vacuum chambers. It is preferable that the anvil be provided below
the temporary sealing device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0077] FIG. 1 is a top view of the vacuum packaging machine
according to the present invention;
[0078] FIG. 2(a) is a front view of one step of the transporting
and ultrasonic sealing process of a degassed bag in the vacuum
packaging machine, and FIG. 2(b) is a side view thereof;
[0079] FIG. 3(a), a front view, and FIG. 3(b), a side view, of the
next step thereof;
[0080] FIG. 4(a), a front view, and FIG. 4(b), a side view, of the
next step thereof;
[0081] FIG. 5(a), a front view, and FIG. 5(b), a side view, of the
next step thereof;
[0082] FIG. 6 is a top view of another vacuum packaging machine
according to the present invention; and
[0083] FIG. 7 is an enlarged sectional side view of one of the
vacuum chambers of the vacuum packaging machine.
DETAILED DESCRIPTION OF THE INVENTION
[0084] The present invention will be concretely described below
with reference to FIGS. 1 through 7.
[0085] First, as seen from FIG. 1, the vacuum packaging machine 1
of the present invention comprises a rotary type vacuum processing
device 2, an ultrasonic sealing device 3 and a bag transporting
device (which is comprised of a first transporting device and a
second transporting device). As to the first and second
transporting devices, only the gripping elements 5 and 6 of are
illustrated in the drawings. The vacuum packaging machine 1 is
substantially the same as those described in, for example, Japanese
Patent Application Laid-Open (Kokai) Nos. H9-254931 and 2001-122219
and is installed near a filling machine 7.
[0086] The filling machine 7 is more or less the same as those
described in the above-described laid-open patent applications. The
filling machine 7 grips empty bags W, which are supplied from a bag
supplying device 8, by means of grippers 11 (only one pair of
grippers are shown) that are disposed at equal intervals on the
circumference of an intermittently rotating rotor 9 and
successively performs processes such as printing on the bags W,
opening of the mouths of the bags (called "bag mouths"), filling
the bags with solid contents, filling the bags with liquid contents
and partial sealing (sealing that leaves an unsealed portion in
order to allow a degassing treatment) as the rotor 9 rotates
intermittently. Afterward, in the discharge process (that occurs at
the stopping position 7), the bags W filled with solid contents
and/or liquid contents (called "filled bags") are gripped by a
transfer device (only its gripping portion 12 is shown in the
drawings) and transferred to the rotary type vacuum processing
device 2.
[0087] In the rotary type vacuum processing device 2, a plurality
of vacuum chambers 14 are disposed at equal intervals on the
circumference of an intermittently rotating table (or a rotary
table) 13. Each vacuum chamber 14 comprises a main body 15, which
is fastened to the table 13, and a cover 16, which opens and closes
with respect to the main body 15. Grippers (see the grippers 39 in
FIG. 7), which grip the bag W, and a moving element (sealing stand)
(see the moving element 42 in FIG. 7) of a temporary sealing device
are disposed on the main body 15, and a receiving stand (see the
receiving stand 44 in FIG. 7) of the temporary sealing device is
disposed on the cover 16.
[0088] In this rotary type vacuum processing device 2, filled bags
(merely called "bags" below) W are received from the (gripping
portion 12 of the) above-described transfer device and are held by
the grippers (39) disposed in the main bodies 15 of the vacuum
chambers 14. During the repeated rotation and stopping of the table
13, the cover 16 of each vacuum chamber 14 is closed and then the
interior of the vacuum chamber 14 is placed in a vacuum state so
that a vacuum is caused to act on the bag inside the chamber 14,
thus accomplishing a degassing treatment on the bags and
temporarily sealing the bag mouth (so as to be sealed to such an
extent that the degassed state inside the bag is maintained when
the vacuum chamber 14 is placed back in an atmospheric pressure
state); and then, the interior of the vacuum chamber 14 is placed
back in the atmospheric pressure state, and the cover 16 is
opened.
[0089] The rotary type vacuum processing device 2 itself is
basically the same as that of vacuum packaging machines described
in the above-described Japanese Patent Application Laid-Open
(Kokai) Nos. H9-254931 and 2001-122219, except that the main
sealing operation is not performed in the shown vacuum processing
device 2.
[0090] Then, at a take-out position (which is the stopping position
9) of the rotary type vacuum processing device 2, the degassed bag
W inside the vacuum chamber 14 that is stopped with its cover 16
opened is taken out by the first transporting device and
transported to a predetermined position of the ultrasonic sealing
device 3. Then, the bag W is received by the second transporting
device and is transported to and positioned in a specified sealing
position of the ultrasonic sealing device 3.
[0091] The ultrasonic sealing device 3 has a horn element 17 and an
anvil 18 (both will be described below) that can advance and
retract. The horn element 17 and the anvil 18 are caused to advance
toward the bag W that has been gripped by the gripping element 6 of
the second transporting device and positioned in the
above-described specified sealing position. Predetermined positions
on the bag mouth are held, and ultrasonic sealing is performed to
the bag.
[0092] The above-described transporting process of the bags W
performed by the first and second transporting devices and the
ultrasonic sealing process of the ultrasonic sealing device 3 can
be described as follows with reference to FIGS. 2(a) through
5(b).
[0093] (1) The first transporting device grips the upper edges of
the bag W inside the vacuum chamber 14 (that is stopped at the
take-out position 9 of the rotary type vacuum processing device 2)
by means of its gripping elements 5 (next, the grippers of the
vacuum chamber 14 are opened) and rotationally transports this bag
in the horizontal plane. Then, the first transporting device stops,
so that the bag W is positioned in a predetermined position. As
shown in FIGS. 1 and 2(a) and 2(b), this predetermined position is
directly beneath the above-described specified sealing position,
and the pair of gripping elements 6 of the second transporting
device wait in an open state in a position that is slightly below
the gripping elements 5. A device similar to the moving means
described in the above-described Japanese Patent Application
Laid-Open (Kokai) No. H9-254931 can be used as the first
transporting device. In FIGS. 2(a) and 2(b), the reference numerals
19 refer to the side sealed portions of the bag W, 21 indicates the
bottom sealed portion, and 24 indicates a product conveying
conveyor.
[0094] (2) Next, as shown in FIG. 3(b), the gripping elements 6
close so as to grip both edges of the bag W, and the gripping
elements 5 are opened. The lateral spacing of the gripping elements
6 is widened as shown by arrows in FIG. 3(a) so that the bag mouths
are pulled and placed under tension (placed in a tautly stretched
state); meanwhile, the gripping elements 5 return so as to grip and
transport next bag W. In FIGS. 3(a) and 3(b), the reference numeral
22 indicates the temporarily sealed portion of the bag W, the
temporarily sealed portion being formed by thermal welding made by
the above-described moving element (hot plate, for instance) and
receiving stand.
[0095] (3) Next, as shown in FIGS. 4(a) and 4(b), the gripping
elements 6 are raised so that the bag W is moved upward, and the
bag W is positioned in the sealing position. In this sealing
position, the horn element 17 and anvil 18 (both having a lateral
size sufficiently larger that the lateral size of the mouth portion
of a bag) of the ultrasonic sealing device 3 are caused to advance
toward each other (see FIG. 4(b)) so as to ultrasonically seal a
predetermined position on the bag mouth.
[0096] (4) Next, as shown in FIGS. 5(a) and 5(b), the horn element
17 and anvil 18 of the ultrasonic sealing device 3 are retracted
(see Figures and 5(b)), the gripping elements 6 are opened, and the
bag W is dropped. The bag W drops onto the product conveying
conveyor 24 via a guide chute 23 and is discharged from the bottom
of the ultrasonic sealing device 3.
[0097] In FIGS. 5(a) and 5(b), the reference numeral 25 indicates
the ultrasonically sealed portion, which is formed below the
temporarily sealed portion 22. As a result of the ultrasonically
sealed portion 25 being below the temporarily sealed portion 22,
the bag mouth is completely sealed even if there is some bite-in
sealing in the temporarily sealed portion 22. If such bite-in
sealing exists, the fused layer of a laminated film that forms the
bag (which consists, for instance, of a three-layer laminated body
of a plastic film/aluminum foil/plastic film, with the plastic film
of the inner layer acting as the fused layer) is easily ruptured,
and the inside liquid substances leak from this area, leading to
the possibility of leakage to the outside via the glue layers
between the film layers. For this reason, and since the sealing
reliability in the temporarily sealed portion 22 is low, it is
preferable that the ultrasonically sealed portion 25 be positioned
below the temporarily sealed portion 22 as in the shown
embodiment.
[0098] In the above, the first transporting device and the second
transporting device are installed as bag transporting devices.
However, bags can be positioned by way of using a single
transporting device.
[0099] Furthermore, in the above-described structure, the rotary
type vacuum processing device 2 rotates intermittently; however,
the present invention is applicable to a rotary type vacuum
processing device that rotates continuously (which is of the type
described in, for instance, the above-described Japanese Patent
Application Publication (Kokoku) No. H5-58988). In such a
continually rotating device, for example, the gripping elements of
the bag transporting device are moved in synchronization with the
movement of the vacuum chambers over a specified distance, these
gripping elements grip the degassed bags inside the vacuum
chambers, and the gripping elements then take out the bags from the
vacuum chambers and transport the bags to a predetermined position
(Though the above-described Japanese Patent Application Publication
(Kokoku) No. H5-58988 discloses a transfer of bags to a rotary type
vacuum processing device that rotates continuously, it describes
bag press-holding claws that make a movement similar to that of the
above-described gripping elements).
[0100] Another vacuum packaging machine 31 of the present invention
will be described with reference to FIGS. 6 and 7. The vacuum
packaging machine 31 comprises a rotary type vacuum processing
device 32 and an ultrasonic sealing device 33. Like the vacuum
packaging machine 1 described above, the vacuum packaging machine
31 is disposed near a filling machine 7.
[0101] The vacuum packaging machine 31 differs from the vacuum
packaging machine 1 in that no bag transporting device is installed
and in that an anvil 45 that forms a part of the ultrasonic sealing
device 33 is disposed on the main body 35 of each one of the vacuum
chambers 34 provided in the rotary type vacuum processing device
32.
[0102] As seen from FIG. 7, each of the vacuum chambers 34 of the
rotary type vacuum processing device 32 is comprised of a main body
35, which is fastened to a rotary table 37, and a cover 36. The
cover 36 is the same as that described in the above-described
Japanese Patent Application Laid-Open (Kokai) No. H9-48409; and it
opens when an opening-and-closing lever 38 is rotated to the left
(in FIG. 7) by the action of a cam mechanism (not shown) and closes
under its own weight when the cam mechanism does not act on the
opening-and-closing lever 38. FIG. 7 shows the opened cover 36.
[0103] Grippers 39 that grip the bag W and the moving element (hot
plate) 42 of a temporary sealing device 41 are disposed on the main
body 35 of each one of the vacuum chambers 34. This moving element
42 is actuated by an air cylinder 43. A receiving stand 44 of the
temporary sealing device 41 is disposed on the cover 36.
Furthermore, the anvil 45 of the ultrasonic sealing device 33 is
provided on the main body 35 of each vacuum chamber 34 so that it
is positioned beneath the temporary sealing device 41.
[0104] The rotary type vacuum processing device 32 differs from the
rotary type vacuum processing device 2 (shown in FIG. 1) only in
that the anvil 45 is provided on the main body 35; otherwise, there
are no differences in structure or operation.
[0105] The ultrasonic sealing device 33 (except for the anvil 45)
is disposed near the rotary type vacuum processing device 32. The
horn element 46 of this ultrasonic sealing device 33 is disposed so
as to face the anvil 45 provided inside the vacuum chamber 34 that
is stopped at a cover-opening position (or at the stopping position
9) of the rotary type vacuum processing device 32, so that this
horn element 46 can advance toward and withdraw from this anvil
45.
[0106] When each vacuum chamber 34 stops with the cover 36 opened
at the cover-opening position, the horn element 46 advances so as
to hold a predetermined position on the bag mouth of a degassed bag
W between the horn element 46 and the anvil 45, thus performing
ultrasonic sealing to the bag. Following the completion of sealing,
the horn element 46 withdraws, and then the grippers 39 open and
release the bag W in the next process (stopping position 10). This
bag W drops onto a product conveying conveyor 47 via a guide chute
(not shown) and is discharged from the rotary type vacuum
processing device 32.
[0107] As seen from the above, according to the present invention,
deviations in the sealing position are prevented without increasing
the size or cost of the overall apparatus in cases where an
ultrasonic sealing device is used in a vacuum packaging machine.
Furthermore, the productivity of the vacuum packaging machine
improves by way of using the characteristics of the ultrasonic
sealing device, which makes it possible to perform the sealing in a
short time.
* * * * *