U.S. patent application number 10/514407 was filed with the patent office on 2005-10-06 for multi-bag and method of producing the same, and multi-bag for bag-making and filling.
Invention is credited to Kato, Yoshitake, Matsunaga, Shinji, Tsukanome, Kazuhiko.
Application Number | 20050220376 10/514407 |
Document ID | / |
Family ID | 35054339 |
Filed Date | 2005-10-06 |
United States Patent
Application |
20050220376 |
Kind Code |
A1 |
Tsukanome, Kazuhiko ; et
al. |
October 6, 2005 |
Multi-bag and method of producing the same, and multi-bag for
bag-making and filling
Abstract
A multi-bag comprises a multi-film made by superposing at least
an inner film and an outer film and sealing the cylindrically
curved superposed region to form a back seal. The multi-film
constituting the multi-bag is a double film formed by flattening a
tube-like film into a two-layer form, with the opposite end edges,
which are parallel with the direction of extrusion, continuing to
each other. The multi-bag is formed in a sealed state by a back
seal, a planar seal at one end, and a planar seal at the other end.
The supply system for the multi-film may be such that one system is
prepared for each double so as to simplify the device. Further, in
the film supply process, it is possible to obtain a multi-bag of
high quality without applying a shift-preventive means to between
the multi-films.
Inventors: |
Tsukanome, Kazuhiko;
(Kanagawa, JP) ; Kato, Yoshitake; (Saitama,
JP) ; Matsunaga, Shinji; (Fukuoka, JP) |
Correspondence
Address: |
MAINE & ASMUS
100 MAIN STREET
P O BOX 3445
NASHUA
NH
03061-3445
US
|
Family ID: |
35054339 |
Appl. No.: |
10/514407 |
Filed: |
June 9, 2005 |
PCT Filed: |
May 15, 2003 |
PCT NO: |
PCT/JP03/06044 |
Current U.S.
Class: |
383/109 ;
383/66 |
Current CPC
Class: |
B65D 75/26 20130101;
B65D 75/5883 20130101; B65D 2575/583 20130101; B65D 75/5877
20130101; B65D 75/48 20130101 |
Class at
Publication: |
383/109 ;
383/066 |
International
Class: |
B65D 030/08 |
Foreign Application Data
Date |
Code |
Application Number |
May 15, 2002 |
JP |
2002-140776 |
Claims
1. A multiple bag structured by sealing a portion in which a
multiple film formed by overlapping at least an inner film and an
outer film is bent in a tubular shape and is overlapped, wherein
each of the films of the multiple film structuring said multiple
bag is connected with each other in both side end edges
thereof.
2. A multiple bag as claimed in claim 1, wherein the multiple film
structuring the multiple bag is constituted by a multiple film
obtained by forming a tubular film in a flat shape so as to form a
two-ply film and connecting both side end edges thereof to each
other.
3. A multiple bag as claimed in claim 1, wherein two opposing films
of the tubular film are set as an inner film and an outer film, a
back lining seal portion is structured by welding a portion near
both sides of the connected end edges of said film and the outer
film, and a lateral seal portion is structured by welding a portion
near both sides of the end edge in which said inner film and the
outer film are not connected.
4. A multiple bag as claimed in claim 1, wherein the end edges of
the tubular bent multiple film are overlapped with each other in a
flat shape, and the overlapped portion is back sealed.
5. A multiple bag as claimed in claim 1, wherein a plug body
mounting hole is formed in a step of bending the multiple film in
the tubular shape, and a plug body is provided in the plug body
mounting hole in accordance with a welding process.
6. A multiple bag as claimed in claim 1, wherein the portion formed
by bending the multiple film in the tubular shape and overlapping
the multiple film is formed in one side end edge of the multiple
bag, and a plug body is held in an inner side of the overlapped
portion.
7. A multiple bag structured by overlapping a multiple film formed
by overlapping at least an inner film and an outer film in a
two-fold shape and sealing both end portions, wherein the multiple
film structuring said multiple bag is overlapped in a two-fold
shape such that both side end edges in which the respective films
are connected to each other are in the same side, and both end edge
sides in which the respective films of the multiple film are
connected to each other form an open side of the bag.
8. A multiple bag as claimed in claim 7, wherein the multiple film
is constituted by a multiple film obtained by forming a tubular
film in a flat shape so as to form a two-ply film and connecting
both side end edges thereof to each other.
9. A method of producing a multiple bag structured by sealing a
portion in which a multiple film formed by overlapping at least an
inner film and an outer film is bent in a tubular shape and is
overlapped, wherein the multiple film is formed in accordance with
an inflation method or a T-die extruding method so as to be
sequentially overlapped by extruding, and bonding both side end
edges parallel to the extruding direction of each of the overlapped
films in accordance with a welding means, a bonding means or the
like so as to form a multiple film connected to each other, and the
multiple bag is structured by sealing the portion in which the
multiple film is bent in the tubular shape and overlapped.
10. A method of producing a multiple bag structured by sealing a
portion in which a multiple film formed by overlapping at least an
inner film and an outer film is bent in a tubular shape and is
overlapped, wherein the multiple film is structured by forming a
tubular film in accordance with an inflation method so as to be
sequentially extrude, forming the extruded tubular film in a flat
shape so as to form a two-ply film, forming a multiple film in
which both side end edges parallel to the extruding direction are
connected to each other, and sealing the portion in which the
multiple film is bent in the tubular shape and overlapped.
11. A multiple bag for filling and closing a bag-making, in which a
tubular is structured in a flat shape such that two opposing films
form an inner film and an outer film, a back lining seal portion is
structured by welding a portion near both sides of the end edges in
which said inner film and the outer film are connected, and a
lateral seal portion is structured by welding a portion near both
sides of the end edges in which said inner film and the outer film
are not connected, wherein said tubular film is constituted by a
tubular co-extrusion inflation film having a polyolefin layer in
both sides of a core layer.
12. A multiple bag for filling and closing a bag-making, in which a
tubular is structured in a flat shape such that two opposing films
form an inner film and an outer film, a back lining seal portion is
structured by welding a portion near both sides of the end edges in
which said inner film and the outer film are connected, and a
lateral seal portion is structured by welding a portion near both
sides of the end edges in which said inner film and the outer film
are not connected, wherein said tubular film is constituted by a
tubular co-extrusion inflation film having a polyolefin layer in
both sides of a un-oriented polyamide layer.
13. A multiple bag as claimed in claim 2, wherein two opposing
films of the tubular film are set as an inner film and an outer
film, a back lining seal portion is structured by welding a portion
near both sides of the connected end edges of said film and the
outer film, and a lateral seal portion is structured by welding a
portion near both sides of the end edge in which said inner film
and the outer film are not connected.
14. A multiple bag as claimed in claim 2, wherein the end edges of
the tubular bent multiple film are overlapped with each other in a
flat shape, and the overlapped portion is back sealed.
15. A multiple bag as claimed in claim 2, wherein a plug body
mounting hole is formed in a step of bending the multiple film in
the tubular shape, and a plug body is provided in the plug body
mounting hole in accordance with a welding process.
16. A multiple bag as claimed in claim 3, wherein a plug body
mounting hole is formed in a step of bending the multiple film in
the tubular shape, and a plug body is provided in the plug body
mounting hole in accordance with a welding process.
17. A multiple bag as claimed in claim 4, wherein a plug body
mounting hole is formed in a step of bending the multiple film in
the tubular shape, and a plug body is provided in the plug body
mounting hole in accordance with a welding process.
18. A multiple bag as claimed in claim 13, wherein a plug body
mounting hole is formed in a step of bending the multiple film in
the tubular shape, and a plug body is provided in the plug body
mounting hole in accordance with a welding process.
19. A multiple bag as claimed in claim 14, wherein a plug body
mounting hole is formed in a step of bending the multiple film in
the tubular shape, and a plug body is provided in the plug body
mounting hole in accordance with a welding process.
20. A multiple bag as claimed in claim 2, wherein the portion
formed by bending the multiple film in the tubular shape and
overlapping the multiple film is formed in one side end edge of the
multiple bag, and a plug body is held in an inner side of the
overlapped portion.
Description
TECHNICAL FIELD
[0001] The present invention relates to a multiple bag, a
manufacturing method of the same and a multiple bag for filling and
closing a bag-making, and more particularly to a multiple bag
structured by sealing a portion in which a multiple film formed by
overlapping at least an inner film and an outer film is bent in a
tubular shape and is overlapped, and a manufacturing method of the
same and a multiple bag for filling and closing a bag-making.
BACKGROUND ART
[0002] The multiple bag structured by sealing the portion in which
the multiple film formed by overlapping the inner film and the
outer film is bent in a tubular shape and is overlapped is shown in
Japanese Patent Application Laid-open No. 2000-185743 or Japanese
Patent Application Laid-open No. 8-301296.
[0003] The multiple bag mentioned above is formed in a bag shape by
discharging each of the inner film and the outer film by a carrying
roll so as to overlap each other and bending them in the tubular
shape. In the bag making step of the multiple bag as mentioned
above, at least two systems are required as a supply system of the
film. Accordingly, not only a film supply apparatus comes to a
large scale, but also there is a problem that in order to prevent
the multiple films from being displaced from each other in the film
discharging step, there is required a complex step such as applying
a partial seal between the multiple films in the film supplying
step, applying a slip proofing process between the multiple films
and the like.
[0004] Further, as a countermeasure for improving a pinhole
resistance of the bag-making filling and closing bag having an
oriented polyamide (PA) as a base material, Japanese Patent
Application Laid-open No. 8-323937 proposes arranging a protective
layer made of a polyolefin resin such as a linear low density
polyethylene, a high density polyethylene and the like in which a
coefficient of static friction at 110.degree. C. is equal to or
less than 0.1 in an outer side of the oriented PA.
[0005] In other words, this technique intends to apply a resistance
against a repeated bending, apply a resistance force against a
friction to a cardboard, and prevent an acute angle portion in a
folded portion and a corner portion from sticking the adjacent bag
so as to be ruptured due to a buffering effect of the protective
layer, on the basis of the protective layer made of the polyolefin
resin. Further, since the oriented PA is excellent in a slip
performance and a thickness uniformity, the oriented PA is
frequently employed as the base material of the bag-making filling
and closing bag.
[0006] However, the problem of the pinhole is taken a close-up in
an intended use of a heavy material and a low temperature
distribution, and the problem can be improved to some degree by
arranging the polyolefin protective layer in the outer side as
mentioned above, however, the pinhole resistance of the base
material itself can not be improved, and a practical problem can
not be solved as was before.
[0007] The present invention can solve the conventional problem
mentioned above. In other words, and an object of the present
invention is to provide a multiple bag in which it is possible to
set every two supply systems of a multiple film to one system so as
to simplify an apparatus by supplying a multiple film in which both
side end edges parallel to an extruding direction of each of the
films are connected with each other, such as a two-ply film
obtained by forming a tubular film in a flat shape, to a producing
step of a multiple bag, and a high quality can be obtained without
applying a displacement preventing means between the multiple films
in the film supplying step, a producing method of the same and a
multiple bag for filling and closing a bag-making.
[0008] In this case, a packing body formed by sealing peripheral
end portions of an upper film and a lower film is disclosed in
Japanese Patent Application Laid-open No. 2000-185743. Further, a
packing body constituted by an inner layer, an intermediate layer
and an outer layer and using a tubular film for the inner layer and
a sheet-like film for the intermediate layer and the outer layer
respectively is disclosed in Japanese Patent Application Laid-open
No. 8-301296. Further, a rolled film for multiple packing is
disclosed in Japanese Patent Application Laid-open No. 9-254301.
Further, a packing body in which a film forming a packing body is
constituted by a two-ply film is disclosed in Japanese Patent
Application Laid-open No. 9-294530. Further, a filling and closing
multiple bag producing apparatus is disclosed in Japanese Patent
Application Laid-open No. 10-35602. Further, a packing body formed
by a two-ply film obtained by overlapping an inner film and an
outer film in two sheets, and a producing method of the same are
disclosed in Japanese Patent Application Laid-open No.
2003-26234.
[0009] However, the known publications neither discloses anything
about the technique in accordance with the present invention, nor
pay attention thereto.
DISCLOSURE OF THE INVENTION
[0010] In order to achieve the technical object mentioned above, in
accordance with a first aspect of the present invention, there is
provided a multiple bag structured by sealing a portion in which a
multiple film formed by overlapping at least an inner film and an
outer film is bent in a tubular shape and is overlapped, wherein
each of the films of the multiple film structuring the multiple bag
is connected with each other in both side end edges thereof.
[0011] In accordance with the structure mentioned above, since the
multiple film in which both side end edges parallel to the
extruding direction of each of the films are connected with each
other is supplied in a producing step of the multiple bag, it is
possible to set every two supply systems of the multiple film to
one system so as to simplify the apparatus. Further, it is possible
to obtain the multiple bag having a high quality without applying
the displacement preventing means between the multiple films in the
film supplying step.
[0012] Further, in accordance with a second aspect of the present
invention, there is provided a multiple bag as recited in the first
aspect, wherein the multiple film structuring the multiple bag is
constituted by a multiple film obtained by forming a tubular film
in a flat shape so as to form a two-ply film and connecting both
side end edges thereof to each other.
[0013] In accordance with the structure mentioned above, since the
multiple film in which the tubular film is formed in the flat shape
so as to form the two-ply film and both side end edges parallel to
the extruding direction of each of the films are connected with
each other is supplied in a producing step of the multiple bag, it
is possible to set every two supply systems of the multiple film to
one system so as to simplify the apparatus.
[0014] Further, in accordance with a third aspect of the present
invention, there is provided a multiple bag as recited in the first
or second aspect, wherein two opposing films of the tubular film
are set as an inner film and an outer film, a back lining seal
portion is structured by welding a portion near both sides of the
connected end edges of the film and the outer film, and a lateral
seal portion is structured by welding a portion near both sides of
the end edge in which the inner film and the outer film are not
connected.
[0015] In accordance with the structure mentioned above, there is
provided the aspect in which both side end edges of the inner film
and the outer film of the multiple bag are connected to each other,
and all of the end surface sides in the back seal portion are
closed. Accordingly, no film peeling is generated in the back seal
portion.
[0016] Further, in accordance with a fourth aspect of the present
invention, there is provided a multiple bag as recited in the first
or second aspect, wherein the end edges of the tubular bent
multiple film are overlapped with each other in a flat shape, and
the overlapped portion is back sealed.
[0017] In accordance with the structure mentioned above, there is
provided the aspect in which the end surface side of the back seal
portion gets in the multiple bag in one end side and gets out of
the multiple bag in the other end side, however, all of the end
surface sides of the back seal portion are closed in the bag shape.
Accordingly, no film peeling is generated in the back seal
portion.
[0018] Further, in accordance with a fifth aspect of the present
invention, there is provided a multiple bag as recited in the
first, second, third or fourth aspect, wherein a plug body mounting
hole is formed in a step of bending the multiple film in the
tubular shape, and a plug body is provided in the plug body
mounting hole in accordance with a welding process.
[0019] In accordance with the structure mentioned above, the
multiple bag integrally provided with the plug body is
obtained.
[0020] Further, in accordance with a sixth aspect of the present
invention, there is provided a multiple bag as recited in the first
or second aspect, wherein the portion formed by bending the
multiple film in the tubular shape and overlapping the multiple
film is formed in one side end edge of the multiple bag, and a plug
body is held in an inner side of the overlapped portion.
[0021] In accordance with the structure mentioned above, the
multiple bag integrally provided with the plug body is
obtained.
[0022] Further, in accordance with a seventh aspect of the present
invention, there is provided a multiple bag structured by
overlapping a multiple film formed by overlapping at least an inner
film and an outer film in a two-fold shape and sealing both end
portions, wherein the multiple film structuring the multiple bag is
overlapped in a two-fold shape such that both side end edges in
which the respective films are connected to each other are in the
same side, and both end edge sides in which the respective films of
the multiple film are connected to each other form an open side of
the bag.
[0023] In accordance with the structure mentioned above, since the
multiple film in which both side end edges parallel to the
extruding direction of each of the films are connected with each
other is supplied in a producing step of the multiple bag, it is
possible to set every two supply systems of the multiple film to
one system so as to simplify the apparatus. Further, it is possible
to obtain the multiple bag having a high quality without applying
the displacement preventing means between the multiple films in the
film supplying step.
[0024] Further, in accordance with an eighth aspect of the present
invention, there is provided a multiple bag as recited in the
seventh aspect, wherein the multiple film structuring the multiple
bag is constituted by a multiple film obtained by forming a tubular
film in a flat shape so as to form a two-ply film and connecting
both side end edges thereof to each other.
[0025] In accordance with the structure mentioned above, since the
multiple film in which the tubular film is formed in the flat shape
so as to form the two-ply film and both side end edges parallel to
the extruding direction of each of the films are connected with
each other is supplied in a producing step of the multiple bag, it
is possible to set every two supply systems of the multiple film to
one system so as to simplify the apparatus.
[0026] Further, in accordance with a ninth aspect of the present
invention, there is provided a method of producing a multiple bag
structured by sealing a portion in which a multiple film formed by
overlapping at least an inner film and an outer film is bent in a
tubular shape and is overlapped, wherein the multiple film is
formed in accordance with an inflation method or a T-die extruding
method so as to be sequentially overlapped by extruding, and
bonding both side end edges parallel to the extruding direction of
each of the overlapped films in accordance with a welding means, a
bonding means or the like so as to form a multiple film connected
to each other, and the multiple bag is structured by sealing the
portion in which the multiple film is bent in the tubular shape and
overlapped.
[0027] In accordance with the structure mentioned above, since it
is possible to supply the multiple film in which both side end
edges parallel to the extruding direction of each of the films are
connected with each other, such as the structure in which the
tubular film is formed in the flat shape so as to form the two-ply
film, in the producing step of the multiple bag, it is possible to
set every two supply systems of the multiple film to one system so
as to simplify the apparatus. Further, the multiple bag having a
high quality can be obtained without applying the displacement
preventing means between the multiple films in the film supplying
step.
[0028] Further, in accordance with a tenth aspect of the present
invention, there is provided a method of producing a multiple bag
structured by sealing a portion in which a multiple film formed by
overlapping at least an inner film and an outer film is bent in a
tubular shape and is overlapped, wherein the multiple film is
structured by forming a tubular film in accordance with an
inflation method so as to be sequentially extrude, forming the
extruded tubular film in a flat shape so as to form a two-ply film,
forming a multiple film in which both side end edges parallel to
the extruding direction are connected to each other, and sealing
the portion in which the multiple film is bent in the tubular shape
and overlapped.
[0029] In accordance with the structure mentioned above, since it
is possible to supply the multiple film in which both side end
edges parallel to the extruding direction of each of the films are
connected with each other, such as the structure in which the
tubular film is formed in the flat shape so as to form the two-ply
film, in the producing step of the multiple bag, it is possible to
set every two supply systems of the multiple film to one system so
as to simplify the apparatus. Further, the multiple bag having a
high quality can be obtained without applying the displacement
preventing means between the multiple films in the film supplying
step.
[0030] Further, in accordance with an eleventh aspect of the
present invention, there is provided a multiple bag for filling and
closing a bag-making, in which a tubular is structured in a flat
shape such that two opposing films form an inner film and an outer
film, a back lining seal portion is structured by welding a portion
near both sides of the end edges in which the inner film and the
outer film are connected, and a lateral seal portion is structured
by welding a portion near both sides of the end edges in which the
inner film and the outer film are not connected, wherein the
tubular film is constituted by a tubular co-extrusion inflation
film having a polyolefin layer in both sides of a core layer.
[0031] In accordance with the structure mentioned above, the seal
portion is not extremely collapsed so as to be formed extremely
thin. Accordingly, the edge is not generated in a boundary portion
between the seal portion and the adjacent film portion. Further, it
is possible to maintain a film rigidity at a time of filling and
closing the bag-making, and it is possible to widely improve a seal
performance in comparison with the conventional structure.
[0032] Further, in accordance with a twelfth aspect of the present
invention, there is provided a multiple bag for filling and closing
a bag-making, in which a tubular is structured in a flat shape such
that two opposing films form an inner film and an outer film, a
back lining seal portion is structured by welding a portion near
both sides of the end edges in which the inner film and the outer
film are connected, and a lateral seal portion is structured by
welding a portion near both sides of the end edges in which the
inner film and the outer film are not connected, wherein the
tubular film is constituted by a tubular co-extrusion inflation
film having a polyolefin layer in both sides of a un-oriented
polyamide layer.
[0033] In accordance with the structure mentioned above, an
excellent pinhole resistance is obtained in comparison with the
conventional structure in which the oriented polyamide film is the
base material. Further, it is possible to satisfy a bag-making
filling and closing property, it is possible to maintain a slip
performance and a rigidity of the bag surface and it is possible to
improve a seal performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIGS. 1A to 1F show a producing step of a multiple bag in
accordance with an embodiment of the present invention, in which
FIG. 1A is a perspective view of a supply aspect of a multiple film
to the producing step of the multiple bag, FIG. 1B is a perspective
view of details of the multiple film shown in FIG. 1A, FIG. 1C is a
perspective view of an aspect of bending the multiple film in a
tubular shape in the producing step of the multiple bag, FIG. 1D is
a perspective view of an aspect of back sealing a portion which is
overlapped in the step in FIG. 1C, FIG. 1E is a perspective view of
an aspect of sealing an end surface of one end side from the step
in FIG. 1D, and thereafter receiving a received material so as to
apply an end surface seal in the other end side, and FIG. 1F is a
cross sectional view of details in a direction of an arrow A-A in
FIG. 1E;
[0035] FIGS. 2A to 2F show a producing step of a multiple bag in
accordance with the other embodiment of the present invention, in
which FIG. 2A is a perspective view of a supply aspect of a
multiple film to the producing step of the multiple bag, FIG. 2B is
a perspective view of details of the multiple film shown in FIG.
2A, FIG. 2C is a perspective view of an aspect of bending the
multiple film in a tubular shape in the producing step of the
multiple bag, FIG. 2D is a perspective view of an aspect of back
sealing a portion which is overlapped in the step in FIG. 2C, FIG.
2E is a perspective view of an aspect of sealing an end surface of
one end side from the step in FIG. 2D, and thereafter receiving a
received material so as to apply an end surface seal in the other
end side, and FIG. 2F is a cross sectional view of details in a
direction of an arrow B-B in FIG. 2E;
[0036] FIGS. 3A to 3E show a producing step of a multiple bag in
accordance with further the other embodiment of the present
invention, in which FIG. 3A is a perspective view of a supply
aspect of a multiple film to the producing step of the multiple
bag, FIG. 3B is a perspective view of details of the multiple film
shown in FIG. 3A, FIG. 3C is a perspective view of an aspect of
bending the multiple film in a tubular shape in the producing step
of the multiple bag, FIG. 3D is a perspective view of an aspect of
back sealing a portion which is overlapped in the step in FIG. 3C,
and FIG. 3E is a perspective view of an aspect of sealing an end
surface of one end side from the step in FIG. 3D, and thereafter
receiving a received material so as to apply an end surface seal in
the other end side;
[0037] FIGS. 4A to 4D show a producing step of a multiple bag in
accordance with further the other embodiment of the present
invention, in which FIG. 4A is a perspective view of a supply
aspect of a multiple film to the producing step of the multiple
bag, FIG. 4B is a perspective view of details of the multiple film
shown in FIG. 4A, FIG. 4C is a perspective view showing an aspect
of bending the multiple film in a tubular shape so as to form an
overlapping portion in one side end edge of the multiple bag in the
producing step of the multiple bag, and holding a plug body 15 in
an inner side of the overlapping portion, and FIG. 4D is a
perspective view of an aspect of surface sealing three surfaces
comprising a portion which is overlapped in the step in FIG. 4C,
one end side and the other end side so as to structure the multiple
bag;
[0038] FIGS. 5A to 5C show the other embodiment of a multiple bag
in accordance with the present invention, in which FIG. 5A is a
perspective view showing an aspect of the multiple film, FIG. 5B is
a perspective view of one example of the produced multiple bag, and
FIG. 5C is a perspective view of the other example in the same
manner; and
[0039] FIG. 6 is an explanatory view exemplifying an inflation
method of obtaining the multiple film used in the multiple bag in
accordance with the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0040] In order to explain the present invention in more detail, a
description will be given of the present invention with reference
to the accompanying drawings.
[0041] FIG. 1 shows a producing step of a multiple bag in
accordance with an embodiment of the present invention, in which
FIG. 1A is a perspective view of a supply aspect of a multiple film
to the producing step of the multiple bag, FIG. 1B is a perspective
view of details of the multiple film shown in FIG. 1A, FIG. 1C is a
perspective view of an aspect of bending the multiple film in a
tubular shape in the producing step of the multiple bag, FIG. 1D is
a perspective view of an aspect of back sealing a portion which is
overlapped in the step in FIG. 1C, FIG. 1E is a perspective view of
an aspect of sealing an end surface of one end side from the step
in FIG. 1D, and thereafter receiving a received material so as to
apply an end surface seal in the other end side, and FIG. 1F is a
cross sectional view of details in a direction of an arrow A-A in
FIG. 1E.
[0042] A multiple bag 1 in accordance with the present embodiment
shown in FIG. 1 is structured by a multiple film 4 in which an
inner film 2 and an outer film 3 are formed in a two-ply state. As
shown in FIG. 1A, the multiple film 4 is supplied to a multiple bag
producing step from a roll-like film 5 around which a tubular film
is wound in a flat shape, in such a manner that the inner film 2
and the outer film 3 are overlapped in a two-ply state.
Accordingly, the multiple film 4 supplied to the multiple bag
producing step is structured such that both side end edges 6 and 6
of the inner film 2 and the outer film 3 parallel to an extruding
direction thereof are connected with each other.
[0043] In the multiple bag producing step, the multiple film 4
supplied in the manner mentioned above is bent in a tubular shape
such as a cylindrical shape or the like, and portions 7 and 8
overlapped in a rising manner by bending are back sealed in
accordance with a welding process. Reference numeral 9 denotes a
back seal portion. The back seal portion 9 gets out of the multiple
bag 1 and is formed so as to be in contact with an outer surface of
the outer film 3. In this case, since both side end edges 6 and 6
of the inner film 2 and the outer film 3 of the multiple film 4 are
connected with each other, all of end surface sides 10 and 10 of
the back seal portion 9 are formed in a bag-like closed aspect, as
is apparent in FIG. 1F.
[0044] Next, the multiple film 4 back sealed in the manner
mentioned above structures the multiple bag 1 in which one end side
orthogonal to the extruding direction is sealed by an end surface
and one end is open. FIG. 1E exemplifies a sealed packing body 11
in which a received material is received in the multiple bag and
the other end side orthogonal to the extruding direction of the
multiple film 4 is sealed by the end surface. In FIG. 1E, reference
numeral 12 denotes an end surface seal portion in one end side, and
reference numeral 13 denotes an end surface seal portion in the
other end side.
[0045] FIG. 2 shows a producing step of a multiple bag in
accordance with the other embodiment of the present invention, in
which FIG. 2A is a perspective view of a supply aspect of a
multiple film to the producing step of the multiple bag, FIG. 2B is
a perspective view of details of the multiple film shown in FIG.
2A, FIG. 2C is a perspective view of an aspect of bending the
multiple film in a tubular shape in the producing step of the
multiple bag, FIG. 2D is a perspective view of an aspect of back
sealing a portion which is overlapped in the step in FIG. 2C, FIG.
2E is a perspective view of an aspect of sealing an end surface of
one end side from the step in FIG. 2D, and thereafter receiving a
received material so as to apply an end surface seal in the other
end side, and FIG. 2F is a cross sectional view of details in a
direction of an arrow B-B in FIG. 2E.
[0046] In the embodiment shown in FIG. 2, the multiple bag is
structured by overlapping the end edges of the tubular bent
multiple film 4 with each other in a flat shape and back sealing
the overlapped portion. Accordingly, as is apparent in FIG. 2F,
there is provided an aspect in which one end side of the end
surface side of the back seal portion 9 gets in the multiple bag 1
and the other end thereof gets out of the multiple bag 1, however,
all of the end surface sides 10 and 10 of the back seal portion 9
are closed in a bag shape. In this case, since the other structures
are the same as those of the embodiment shown in FIG. 1, the same
reference numerals are attached to the same structure portions, and
a description thereof will be omitted.
[0047] FIG. 3 shows a producing step of a multiple bag in
accordance with further the other embodiment of the present
invention, in which FIG. 3A is a perspective view of a supply
aspect of a multiple film to the producing step of the multiple
bag, FIG. 3B is a perspective view of details of the multiple film
shown in FIG. 3A, FIG. 3C is a perspective view of an aspect of
bending the multiple film in a tubular shape in the producing step
of the multiple bag, FIG. 3D is a perspective view of an aspect of
back sealing a portion which is overlapped in the step in FIG. 3C,
and FIG. 3E is a perspective view of an aspect of sealing an end
surface of one end side from the step in FIG. 3D, and thereafter
receiving a received material so as to apply an end surface seal in
the other end side.
[0048] The embodiment shown in FIG. 3 is structured such that a
plug body mounting hole 14 is formed in an opposite surface to a
side of the back seal portion 9 and a plug body 15 is provided, in
the multiple bag 1 in accordance with the aspect shown in FIG. 2.
In other words, the plug body mounting hole 14 is formed in a step
of bending the multiple film 4 in a tubular shape as shown in FIG.
3C, and the plug body 15 is provided in the plug body mounting hole
14 by welding as shown in FIG. 3D. The plug body 15 has a flange 16
for securely welding to the multiple film 4. In this case, since
the other structures are the same as those of the embodiment shown
in FIG. 1, the same reference numerals are attached to the same
structure portions, and a description thereof will be omitted.
[0049] FIG. 4 shows a producing step of a multiple bag in
accordance with further the other embodiment of the present
invention, in which FIG. 4A is a perspective view of a supply
aspect of a multiple film to the producing step of the multiple
bag, FIG. 4B is a perspective view of details of the multiple film
shown in FIG. 4A, FIG. 4C is a perspective view showing an aspect
of bending the multiple film in a tubular shape so as to form an
overlapping portion in one side end edge of the multiple bag in the
producing step of the multiple bag, and holding a plug body 15 in
an inner side of the overlapping portion, and FIG. 4D is a
perspective view of an aspect of surface sealing three surfaces
comprising a portion which is overlapped in the step in FIG. 4C,
one end side and the other end side so as to structure the multiple
bag.
[0050] In the embodiment shown in FIG. 4, the plug body 15 is
welded to one side end edge of the multiple bag 1, however, as
shown in FIG. 4C, the plug body 15 is temporarily fastened to an
inner side of the overlapped portion by an adhesive tape 17 in a
step of bending the multiple film 4 in the tubular shape, and is
welded in the surface sealing step shown in FIG. 4D. In this case,
since the other structures are the same as those of the embodiment
shown in FIG. 1, the same reference numerals are attached to the
same structure portions, and a description thereof will be
omitted.
[0051] The multiple bag in accordance with the present invention
can be structured as shown in FIG. 5. In other words, the multiple
film 4 is overlapped in a two-ply shape as shown in FIG. 5A, and
one end side and the other end side of the multiple film 4
overlapped in the two-ply shape are respectively sealed by end
surface as shown in FIG. 5B, whereby the respective films of the
multiple film 4 make both the side end edges 6 and 6 connected with
each other open. Reference numerals 18 and 18 denote an end surface
seal portion. Further, as shown in FIG. 5C, the structure is made
such as to further seal by end surface an open side and an opposite
side end edge of the multiple film 4 overlapped in the two-ply
shape. Reference numeral 19 denotes the end surface seal
portion.
[0052] The multiple bag in accordance with the present invention is
used as an inner bag of a bag in box in addition to being used as a
simple substance. Further, the term "multiple" includes triple and
fourfold in addition to double. As an example in which the multiple
bag is used as a simple substance, there is a large-size bag
receiving a content at 2 to 20 kg packing a liquid-state food such
as sauce, ketchup, juice and the like. The multiple bag in
accordance with the present invention is particularly preferable as
a business oriented large-size packing bag stored and circulated in
a frozen state or a cold state because the multiple bag is
excellent in a pinhole resistance. The bag in box is structured in
a container aspect by employing an inner bag which is formed by
overlapping two or more films for receiving the liquid in an
interior side and sealing by heat in a bag shape, employing a
plastic container or a cardboard box provided with a rigidity
sufficient for maintaining the shape in the transport and the
storage in an exterior side, and combining the inner bag and the
exterior side. The bag in box is widely used in a liquid-state food
field such as juice, mineral water, soft drink, coffee, condiment,
vegetable oil, sauce, ketchup, juice and the like particularly.
[0053] The multiple film used in the multiple bag in accordance
with the present invention is obtained in accordance with an
inflation method or a T-die extruding method. A film having a
single layer or a multiple layer is obtained in accordance with the
inflation method or the T-die extruding method. However, a
co-extrusion is executed for obtaining the multiple layer film. In
this case, the films can be combined and laminated in accordance
with a dry laminate or an extrusion laminate.
[0054] It is preferable that the multiple film used in the multiple
bag in accordance with the present invention is obtained in
accordance with an inflation film method. In other words, because
the inflation film is previously formed in the tubular shape, and
can be used in an aspect as it is produced, it is not necessary to
form the film in the tubular shape in accordance with the later
step and no joint line is generated. In comparison with the
inflation film method, it is necessary to cut both sides orthogonal
to the extruding direction in the T-die extruding method. Further,
while the inflation film can easily produce a thick film of about
60 .mu.m to 150 .mu.m, it is hard to produce the thick film in
accordance with the T-die extruding method.
[0055] FIG. 6 is an explanatory view exemplifying the inflation
method for obtaining the multiple film used in the multiple bag in
accordance with the present invention. In FIG. 5, reference numeral
20 denotes an extruding machine, and reference numeral 21 denotes a
die for inflation. A molten resin extruded in a tubular shape from
the extruding machine 20 via the die 21 is inflated by an air
supplied from an air supply pipe 22 in a process of being pulled up
in a vertical direction, and is made flat while being cooled by air
so as to be taken up by a take-up apparatus 23, whereby a roll-like
film 5 in which the tubular film is wound in a flat shape is
obtained. In FIG. 5, reference numeral 24 denotes an air ring for
air cooling, reference numerals 25, 25, 26 and 26 denote a guide
roller, and reference numerals 27 and 27 denote a pinch roll.
[0056] The present invention is characterized by structuring the
multiple bag from the tubular film, however, it is most preferable
that the tubular film is constituted by the inflation film as
mentioned above. However, it is possible to the other films as far
as the film is the tubular film. For example, the tubular shape can
be obtained by welding both ends of two band-like films.
[0057] The structure of the preferable inflation film of the
multiple bag in accordance with the present invention is as
follows.
[0058] <Single Layer Case>
[0059] LDPE simple substance
[0060] HDPE simple substance
[0061] PP simple substance
[0062] <Multiple Layer Case (Layer Structure Appears from Outer
Side Toward Inner Side)>
[0063] LDPE/LDPE
[0064] HDPE/LDPE
[0065] MDPE/LDPE
[0066] PP/LDPE
[0067] LDPE/HDPE/LDPE
[0068] LDPE/PA/LDPE
[0069] LDPE/MDPE/LDPE
[0070] LDPE/LDPE/LDPE
[0071] LDPE/EVOH/LDPE
[0072] In this case,
[0073] LDPE: low density polyethylene
[0074] (including linear low density polyethylene, straight chain
low density polyethylene, very low density polyethylene)
[0075] HDPE: high density polyethylene
[0076] MDPE: middle density polyethylene
[0077] PA: polyamide
[0078] PP: polypropylene
[0079] EVOH: ethylene-vinyl acetate copolymer saponified
material
[0080] <Resin Structuring Innermost Layer>
[0081] The resin structuring the innermost layer of the multiple
bag employs the LDPE which is excellent in the heat seal
performance, preferably a tough and strong LLDPE (straight chain
low density polyethylene), and more preferably VLDPE (straight
chain very low density polyethylene) produced by a single site
(metallocene) catalyst which is controlled in a poly smell and is
excellent in an elution resistance. In other words, since the LLDPE
produced by a multi site catalyst such as Mg compound or Ti group
has a wide molecular weight distribution while being excellent in a
film workability, the LLDPE includes a lot of components in a low
molecular weight region, which causes the poly smell and affects
taste and odor of the content which is in contact with the film,
and there is a hygienic problem due to transition (elusion) of the
low molecular weight material. On the contrary, since the VLDPE
produced by the single site catalyst has a narrow molecular weight
distribution and a small amount of component in the low molecular
weight region, it is possible to control the transition of the poly
smell.
[0082] It is preferable that the multiple bag in accordance with
the present invention is structured by the un-oriented film
produced by the inflation method. In other words, in general, in
the case of the three sided seal packaging bag having the back seal
portion, four films are overlapped in a portion at which the back
seal portion and the end surface seal portion cross, a pressure
welding is not sufficiently executed in a boundary portion with the
portion at which two adjacent films are overlapped, and a narrow
tunnel-like unsealed portion tends to be generated. In particular,
in the case of using the laminated film including the film having
the rigidity such as a biaxial oriented nylon or the like and
producing double film, the welding is avoided by the oriented film
having the rigidity, and eight films are overlapped in the portion
at which the back seal portion and the end surface seal portion
cross, whereby a further narrow tunnel-like unsealed portion tends
to be generated.
[0083] Accordingly, in the present invention, since the welding can
be well executed to be comparatively soft by structuring by the
un-oriented film of 60 .mu.m to 140 .mu.m produced by the inflation
method of the polyethylene (including LD, LLDPE, VLDPE, HDPE and
MDPE, and including the single layer and the multiple layer), it is
possible to inhibit the pinhole from being generated in the
unsealed portion, and it is possible to inhibit the pinhole from
being generated at a time of conveying and circulating.
[0084] (1) Demand Characteristics of Bag-Making Filling and Closing
Bag
[0085] (1-1) <Improvement of Pinhole Resistance>
[0086] In the case of the bag-making filling and closing bag, a
solution of the pinhole resistance generates a great object. A
detailed phenomenon is mentioned below. In the case of the
bag-making filling and closing bag, the content of the liquid or
the viscous body is filled in an upper side of the bag in the seal
portion. When the seal bar is opened under this state, the center
portion of the bag is going to expand due to its own weight of the
content if the rigidity of the bag itself is deteriorated. Further,
there is a problem that the film itself is extended and a seal
failure is generated. As a result of various experiments executed
by the inventors of the present invention, the following matters
are known with regard to an origination condition of the pinhole
and the seal performance and the like.
[0087] (1-2) <Seal and Pinhole>
[0088] A seal condition of the film is generally determined by
setting a seal temperature, a pressurizing pressure and a seal
time. Further, in the case of the bag-making filling and closing
bag, it is necessary to set such a condition that the weld state is
maintained even just after being sealed after filling the content.
The set condition comes to a more severe condition in the case of
the heavy bag and the high temperature filling. If it is intended
to achieve a sufficient seal condition in correspondence thereto,
the seal portion is extremely collapsed, that is, becomes thin, and
the edge is generated in the boundary portion between the thin seal
portion and the film portion which is adjacent to the seal portion.
It is known that the edge causes the pinhole.
[0089] (1-3) <Pinhole Prevention by Laminated Film>
[0090] A preferable aspect in accordance with the present invention
will be shown below. In other words, it is possible to prevent the
seal portion from becoming extremely thin, it is possible to
maintain the film rigidity at a time of filling and closing the
bag-making, and it is possible to widely improve the seal
performance, by using the tubular inflation film having the low
density polyethylene layer (preferably, the linear low density
polyethylene layer) having the thickness of 10 to 70 .mu.m in both
sides of the core layer (the resin layer selected from the
un-oriented PA, EVOH, LDPE and HDPE) having the thickness of 7 to
30 .mu.m. In particular, in the case that the core layer is
constituted by the un-oriented PA, it is possible to obtain an
excellent pinhole resistance in comparison with the oriented PA, it
is possible to make a melting point higher than the polyolefin
layer arranged in both sides, and it is possible to prevent the
film from being extended at a time of sealing, whereby it is
possible to obtain an improving effect of the seal performance and
the pinhole resistance. In other words, the preferable aspect of
the present invention is as follows.
[0091] (1-4) <Structure of Multiple Bag for Filling and Closing
Bag-Making>
[0092] A multiple bag for filling and closing a bag-making, in
which a tubular is structured in a flat shape such that two
opposing films form an inner film and an outer film, a back lining
seal portion is structured by welding a portion near both sides of
the end edges in which the inner film and the outer film are
connected, and a lateral seal portion is structured by welding a
portion near both sides of the end edges in which the inner film
and the outer film are not connected, wherein the tubular film is
constituted by a tubular co-extrusion inflation film having a
polyolefin layer in both sides of a core layer.
[0093] (1-5) <Effect of Multiple Bag for Filling and Closing
Bag-Making>
[0094] In accordance with the structure mentioned above, the seal
portion is not extremely collapsed so as to be formed extremely
thin. Accordingly, the edge is not generated in a boundary portion
between the seal portion and the adjacent film portion. Further, it
is possible to maintain a film rigidity at a time of filling and
closing the bag-making, and it is possible to widely improve a seal
performance in comparison with the conventional structure.
[0095] (1-6) <Further Preferable Example of Multiple Bag for
Filling and Closing Bag-Making>
[0096] First, it is preferable in view of the pinhole resistance,
the seal strength, the seal stability and the impact resisting bag
rupture performance that the tubular film used in the multiple bag
for filling and closing the bag-making is constituted by the
tubular co-extrusion inflation film having the polyolefin layer
having the thickness of 10 to 70 .mu.m in both sides of the core
layer having the thickness of 7 to 30 .mu.m.
[0097] Secondly, in the case that the core layer is constituted by
the resin layer selected from the un-oriented PA, EVOH and HDPE, it
is possible to obtain the excellent pinhole resistance, it is
possible to make the melting point higher than the polyolefin layer
(preferably, the linear low density polyethylene layer) arranged in
both sides, and it is possible to prevent the film from being
extended at a time of sealing, whereby it is possible to obtain the
improving effect of the seal performance and the pinhole
resistance.
[0098] Thirdly, it is possible to improve the packing machine
property and it is possible to prevent the blocking property
between the inner surfaces of the bag-making filling and closing
bag, by adding an anti-blocking material and/or a slip material to
the inner and outer layers of the tubular film structuring the
inner and outer surfaces of the inner film and the inner and outer
surfaces of the outer film.
[0099] (2-1) <Bag Having PA as Base Material>
[0100] In this case, there has been known an aspect that the film
for bag having the oriented PA as the base material employs the
film obtained by laminating the thermal welding film having a
comparatively low melting point such as the linear low density
polyethylene or the like on the inner layer, the end portion of the
film is thermally welded, and the bag-making is filled and closed
while repeating the cutting process and the welding process.
Further, in order to extend a retention cycle of the content, the
PA obtained by further laminating a gas barrier film is sometimes
employed as the base material.
[0101] (2-2) <Relation between Pinhole and Lamination
Layer>
[0102] However, the bag-making filling and closing bag having the
oriented PA as the base material has the problem that the pinhole
tends to be generated due to the impact and the friction with the
cardboard box in the circulating process, or the bending of the
film or the like. Further, there is a tendency that the pinhole
phenomenon is propagated to the other film even if the other film
is laminated adjacently, whereby there is a problem that the leak
of the content, the contamination of the content, and the bag
rupture are generated. In other words, in the film obtained by
laminating the gas barrier film such as the EVOH or the like on the
oriented PA of the base material, the improvement of the rigidity
of the lamination film causes the increase of the pinhole, and
there is a case that the friction with the cardboard box for
circulation, the projection portion in the corner of the bag, and
the corner portion generated by the bending of the film stick to
the bag so as to generate the bag rupture.
[0103] (2-3) <Other Induction Reason of Pinhole>
[0104] Further, with regard to the pinhole phenomenon mentioned
above, in the case of the intended use in which it is requested to
keep the low temperature in the process of the circulation and the
storage, there is a problem that the rigidity of the laminated film
is increased at a time of low temperature, whereby the pinhole
phenomenon is increased, and in the case of the intended use in
which the bag specification is provided for filling and closing the
bag-making and the capacity is heavy such as 1 to 20 Kg, the
problem tends to be particularly significantly generated, and it is
requested that the bag-making filling and closing bag is
improved.
[0105] (2-4) <Countermeasure for Improving Pinhole>
[0106] As a countermeasure for improving the pinhole resistance of
the bag-making filling and closing bag having the oriented PA as
the base material, there is proposed arranging the protective layer
made of the polyolefin resin such as the linear low density
polyethylene, the high density polyethylene and the like in which
the coefficient of static friction at 110.degree. C. is equal to or
less than 0.1 in the outer side of the oriented PA (Japanese Patent
Application Laid-open No. 8-323937).
[0107] This technique intends to apply the resistance against the
repeated bending, apply the resistance force against the friction
to the cardboard, and prevent the acute angle portion in the folded
portion and the corner portion from sticking the adjacent bag so as
to be ruptured due to the buffering effect of the protective layer,
on the basis of the protective layer made of the polyolefin
resin.
[0108] (2-5) <Problem of Technique Mentioned Above>
[0109] Since the oriented PA is excellent in the slip performance
and the thickness uniformity, the oriented PA is frequently
employed as the base material of the bag-making filling and closing
bag. However, the problem of the pinhole is taken a close-up in the
intended use of the heavy material and the low temperature
distribution, and the problem can be improved to some degree by
arranging the polyolefin protective layer in the outer side as
mentioned above, however, the pinhole resistance of the base
material itself cannot be improved, and the practical problem can
not be solved as was before.
[0110] (2-6) <Attempt at Employing Un-Oriented PA>
[0111] As mentioned above, the un-oriented PA is considered to be
improper as the base material of the bag-making filling and closing
bag in view of the general film selecting reason while the oriented
PA is frequently employed as the base material of the bag-making
filling and closing bag. In other words, since the un-oriented PA
is inferior to the oriented PA in the slip performance, and a
biased thickness tends to be generated, it is considered that there
is a problem that the smooth supply of the film is prevented, that
is, a problem that the machine property is inferior in the
bag-making filling and packing machine.
[0112] (2-7) <Relation between Filling and Seal>
[0113] The other reason why the un-oriented PA is considered to be
improper as the base material of the bag-making filling and closing
bag is a problem at a time of sealing. In other words, in the case
of the bag-making filling and closing bag, when the content such as
the liquid and the viscous body is filled in the upper side of the
bag in the seal portion just after the lateral seal portion forming
the bottom portion of the bag is welded by the seal bar, and the
seal bar is opened under this state, there is a problem that the
center portion of the bag is going to expend on the basis of its
own weight of the content due to the lack of rigidity of the bag
itself, the film itself is extended, and the seal failure is
generated due to the biased thickness of the film itself. The
problem mentioned above caused by using the un-oriented PA as the
base material of the bag-making filling and closing bag is
significantly generated particularly in the case of the heavy bag
having the lateral seal width of the bag equal to or more than 300
mm, and the case of the high temperature filling equal to or more
than 70.degree. C. This matter is confirmed by the experiments of
the inventors.
[0114] (2-8) <Application of Un-Oriented PA in Present
Invention>
[0115] Surprisingly, it has been known that the un-oriented PA
which has been considered to be improper can be employed as the
base material of the bag-making filling and closing bag, by using a
specific means. It is possible to satisfy the bag-making filling
and closing property, it is possible to maintain the slip
performance of the bag surface and the rigidity thereof and it is
possible to improve the seal performance, by using the tubular
inflation film having the polyolefin layer (preferably, the linear
low density polyethylene layer) having the thickness of 10 to 70
.mu.m in both sides of the un-oriented PA layer having the
thickness of 7 to 30 .mu.m.
[0116] (2-9) <Back Seal and Un-Oriented PA Film>
[0117] Further, in order to apply the un-oriented PA film, it is
preferable to select the seal means. In the conventional bag-making
filling and closing bag, there is generally employed a bag-making
simultaneously filling and closing apparatus in which the back seal
portion is structured by a so-called "butt seaming" of using the
laminated film of the double layer structure in which the
polyolefin seal layer is laminated in the inner side of the base
material made of the oriented PA film, and welding the inner
surfaces of the opposing films to each other as shown in FIG. 1.
Because the polyolefin is not welded to the PA and the seal
performance is not provided in a so-called "envelope seaming" of
welding the inner surface of the other film on the outer surface of
one film as shown in FIG. 2. It is intended to weld the back seal
portion in accordance with the butt seaming which is conventionally
used frequently, by using the un-oriented PA film, however, the
problem is generated. In other words, in the case that it is
intended to continuously seal in accordance with the butt seaming
at a time when the film is applied to the bag-making filling and
closing machine and the film passes through the former, a force
pulling the film in the longitudinal direction is applied, and
there is generated a problem that the film is extended in the
longitudinal direction by the continuous seal and the pulling
stress. However, it is known that that the back seal can be stably
executed even by the un-oriented PA film, by arranging the
polyolefin layer in both sides of the film and intermittently
sealing in accordance with the envelop seaming.
[0118] (2-10) <Other Structure of Multiple Bag for Bag-Making
Filling and Closing>
[0119] A multiple bag for filling and closing a bag-making, in
which a tubular is structured in a flat shape such that two
opposing films form an inner film and an outer film, a back lining
seal portion is structured by welding a portion near both sides of
the end edges in which the inner film and the outer film are
connected, and a lateral seal portion is structured by welding a
portion near both sides of the end edges in which the inner film
and the outer film are not connected, wherein the tubular film is
constituted by a tubular co-extrusion inflation film having a
polyolefin layer in both sides of an un-oriented polyamide
layer.
[0120] (2-11) <Effect of Other Multiple Bag for Filling and
Closing Bag-Making>
[0121] An excellent pinhole resistance is obtained in comparison
with the conventional structure in which the oriented polyamide
film is the base material. Further, it is possible to satisfy the
bag-making filling and closing property, it is possible to maintain
the slip performance and the rigidity of the bag surface and it is
possible to improve the seal performance. In particular, in the
case that the bag is the heavy bag and the lateral seal width of
the bag is equal to or more than 300 mm, or in the case of filling
at a high temperature equal to or more than 70.degree. C., the
effect can be preferably achieved.
[0122] (2-12) <Further Preferable Example of other Multiple Bag
for Filling and Closing Bag-Making>
[0123] First, in addition to the structure mentioned above, it is
possible to improve the seal strength of the film by structuring
the back seal portion in accordance with the envelop seaming, the
film is not extended at a time of sealing the bag-making, and it is
possible to apply a stable machine property.
[0124] Secondly, it is preferable in view of the pinhole
resistance, the seal strength, the seal stability and the impact
resisting bag rupture performance that the tubular film used in the
multiple bag for filling and closing the bag-making is made of the
tubular co-extrusion inflation film having the polyolefin layer
having the thickness of 10 to 70 .mu.m in both sides of the core
layer having the thickness of 7 to 30 .mu.m.
[0125] Thirdly, it is possible to improve the sealing performance
and the pinhole resistance in correspondence to the heavy bag and
the high temperature filling by constituting the polyolefin layer
arranged in both sides by the linear low density polyethylene.
[0126] Fourthly, it is possible to improve the packing machine
property and it is possible to prevent the blocking property
between the inner surfaces of the bag-making filling and closing
bag, by adding the anti-blocking material and/or the slip material
to the inner and outer layers of the tubular film structuring the
inner and outer surfaces of the inner film and the inner and outer
surfaces of the outer film.
[0127] (3) Experiment Example
[0128] (3-1) <Used Film>
[0129] Membrane: inflation formed tubular film (F1 to F7)
[0130] Fold width of tubular film (F1 to F7): 1230 mm
[0131] Lateral width of band-like film (F8): 1230 mm
[0132] Length of whole cloth winding roll (F1 to F8): 1500 m
[0133] (3-2) <Evaluation Result of Film and Bag-Making Filling
and Closing Bag Used in Experiment>
1 Film Layer structure (A) (B) (C) F1 LL
(20)/AD(3)/C-Ny(10)/AD(3)/LL (20) .circleincircle. .circleincircle.
.circleincircle. F2 LL (20)/AD(3)/EVOH(7)/AD(3)/LL (20)
.circleincircle. .circleincircle. .DELTA. F3 LL
(15)/AD(3)/C-Ny(10)/EVOH(10)/AD(3)/ .circleincircle.
.circleincircle. .largecircle. LL (15) F4 LL (20)/HDPE (20)/LL (20)
.largecircle. .DELTA. .largecircle. F5 LL (20)/C4(30)/LL (20)
.largecircle. .DELTA. .largecircle. F6 LL (20)/LD(20)/LL (20)
.largecircle. .DELTA. .largecircle. F7 LL (60) [Single layer]
.DELTA. .DELTA. .DELTA. F8 Dry laminate .largecircle.
.circleincircle. x (A):Seal strength (B):Seal stability (C):Impact
resisting bag rupture performance
[0134] (3-3) <About Evaluation Method>
[0135] The seal strength in Table shows a result obtained by
cutting the portion of the back seal portion in the produced bag
and executing a tension test, a case that the seal strength is
equal to or more than 70 N/15 mm is expressed by .circle-w/dot., a
case that the strength is equal to or more than 50 N/15 mm is
expressed by .largecircle., a case that the seal strength less than
50 N/15 mm is rarely generated during a running test is expressed
by .DELTA., and a case that the seal strength of most of the
products is less than 50 N/15 mm during the running test is
expressed by x.
[0136] The seal stability in Table evaluates whether or not the
improved seal performance can be maintained even if a certain
degree of dispersion (within 3.degree. C. with respect to the set
temperature) is generated in the seal temperature of the back seal
portion and the lateral seal portion during the running test, and a
case that no change is generated with respect to the dispersion is
expressed by .circle-w/dot., a case that any change is not
substantially generated is expressed by .largecircle., a case that
the seal strength is partly generated is expressed by .DELTA., and
a case that the seal strength is extremely lowered is expressed by
x. The impact resisting bag rupture performance in Table is a means
for evaluating the pinhole resistance. In other words, it is
evaluated by totally determining a drop test and a vibration test.
The drop test is executed by falling down from the height of 1.2 m
above the concrete floor. The drop state is constituted by
alternately executing a drop in a vertical direction (in a
direction in which the lateral seal portion comes to a lower side)
and a drop in a lateral direction (in a direction in which the back
surface of the bag having no back seal comes to a lower side), and
the generation of the pinhole and the leak state are checked.
[0137] The vibration is executed by using a vibration tester which
is reciprocated at 170 times per minute with a lateral amplitude of
40 mm, and receiving four bag-making filling and closing bags
produced by the specific film in the cardboard box, and vibrating
the tester in the longitudinal direction of the cardboard box, and
the generation of the pinhole and the leak state are checked in the
same manner as the drop test. As a result of totally determining
the drop test and the vibration test, a case that any problems are
not generated at all is expressed by .circle-w/dot., a case that
any problems are not generated in the substantial circulation and
use is expressed by .largecircle., a case that the pinhole and the
leak phenomenon are partly generated is expressed by .DELTA., and a
case that any improvement is practically required in the film
structure and the bag-making filling and closing specification is
expressed by x.
[0138] (3-4) <Description of Used Film>
[0139] Numerical values in parenthesis in the layer structure in
Table 1 indicates the thickness [.mu.m].
[0140] Reference symbol LL denotes a resin obtained by adding a
micronized silica having an average grain diameter of 3.5 .mu.m at
0.0015 wt % as the anti-blocking agent and an erucic acid amide at
0.03 wt % as the slip agent to the linear low density polyethylene
having a density of 0.922 and MI of 1.2. Reference symbol C-Ny
denotes an un-oriented polyamide. Reference symbol C4 denotes an
ethylene-.alpha. olefin (C4) copolymer having a density of 0.924
and MI of 1.0. Reference symbol EVOH denotes an ethylene-vinyl
acetate copolymer saponified material having a methylene content of
32 mol % and a saponification degree of 98%. Reference numeral AD
denotes an adhesive polyolefin obtained by denaturing a maleic
anhydride.
[0141] Reference symbol F8 denotes a comparative example. The
comparative example is constituted by a laminated film obtained by
dry laminating the LL (40) on one side (the inner layer forming the
seal layer) of the film (15) formed by biaxial orienting the
un-oriented polyamide film formed by the T-die in accordance with
the after process. In this case, the back seal portion of the
pillow (the three sided seal) is formed as the normal continuous
butt seaming as shown in FIG. 1. On the contrary, the films F1 to
F7 produce the pillow type bag structured as the envelop seaming as
shown in FIG. 2.
[0142] (3-5) <Condition of Bag-Making>
[0143] Bag size: transversal 600 mm.times.longitudinal 500 mm
(outer shape size at a time of compressing empty bag)
[0144] Seal width: 20 mm (the back seaming seal portion is
structured, as shown in FIG. 2, such that the lower surface of the
inner film of the other end portion is lapped over the upper side
of the outer film of one end portion, and is welded at a width of
20 mm along a center of the overlapped portion of the width 30 mm.
Further, the lateral seal portion is welded at 20 mm of the film
end portion.)
[0145] Filling and packing machine used in experiment: bag-making
simultaneous filling and packing machine "ONPACK-2000" manufactured
by ORIHIRO
[0146] Filler: fruit juice
[0147] Filling weight: 7500 g
INDUSTRIAL APPLICABILITY
[0148] In the multiple bag, the manufacturing method and the
multiple bag for filling and closing the bag-making in accordance
with the present invention, since it is possible to supply the
multiple film in which both side end edges parallel to the
extruding direction of the respective films are connected with each
other, such as the structure in which the tubular film is formed in
the flat shape and in the two-ply film in the producing step of the
multiple bag, it is possible intend to simplify the apparatus by
setting every two supply systems of the multiple film to one
system, thereby being useful. Further, it is possible to obtain the
multiple bag having a high quality without applying the
displacement preventing means between the-multiple films in the
film supplying step and it is possible to provide the producing
method thereof, thereby being useful.
* * * * *