FIELD OF THE INVENTION
[0001] The present invention relates to the improvement for the handling of a container
for liquid which is generally called as a bag-in-box, comprising an inner bag prepared
by heat sealing synthetic resin films and an outer box made of cardboard, which is
used for the purpose of filling up, preserving and transferring of liquid. More in
detail, the present invention relates to the improvement of self-standing ability
and mechanical strength of an inner bag for bag-in-box when it is filled up with liquid
and handled without an outer box, further the present invention aims to reduce the
remaining amount of liquid in a container after whole contents are discharged, and
further to improve the easiness for handling of the inner bag filled up with liquid.
BACKGROUND OF THE INVENTION
[0002] In general, a container for liquid composed of an inner bag produced by heat sealing
of synthetic resin films and an outer box made of cardboard which is prepared for
the purpose of filling up, preserving and transferring of fluid such as liquid or
powder is commonly called as a bag-in-box, and ones whose capacity are from 5 to 20
liter are broadly used as a container for foods or medicines. These containers are
mainly applied for the business use, and actually used as a container for materials
of foods or medicines, or as a large size container for subdivisional use. Recently,
for the purpose of severe sanitary controlling of production environment of foods
or medicines, the requirements to pick out an inner bag from an outer box and carrying
it in alone into production environment so as to protect the producing environment
from the contamination by dusts generated from the outer box is becoming more serious.
[0003] However, an inner bag made of an ordinary synthetic resin film is a flat square bag
whose four sides are sealed, and when the inner bag is filled up and handled without
an outer box, the following problems are arisen. That is, the self-standing ability
of the bag is very poor, and since there is no handling part, the handling of the
inner bag is very bad. Further, in a case when the inner bag of flat square shape
is set in the outer box and entire contents in the inner bag is discharged, there
is also a problem that the small portion of the contents is easily remaining between
the films at the corners of the inner bag. Concerning the above mentioned problems,
there is a strong demand from the consumers of the bag-in-box to develop a new inner
bag for bag-in-box having self-standing ability, with easiness in handling and the
amount of remaining liquid is small.
[0004] Regarding to the improvement of the self-standing ability, uses of molded type containers
having good shape maintaining stability fabricated by a blow molding method or by
a vacuum forming method can be considered. However, from the view point that the reduction
of the amount of garbage is currently strongly required and from the view point of
the manufacturing costs, an inner bag for bag-in-box made of film, which is recognized
to have a good disposable adaptability and to be lower price, is requested. The gazette
type inner bag disclosed in Japanese Utility Model Laid-open Publication JP64-9174
has adequate self-standing ability as a container when taken out from an outer box
and handled. Further, as disclosed in Japanese Patent Laid-open Publication JP2-8736,
in a case of said gazette type inner bag, an upper folding part can be used as a handling
part, and can be said as the more desirable shape than a flat shape bag (refer to
Fig.11 and Fig.12).
[0005] However, even if the said gazette shape bag, when it is filled up, the shape of the
bag becomes to have peculiarity that the frame part of it is more swollen than the
bottom part and the center of gravity of it exists at the higher position, therefore,
the self-standing ability of it is not sufficient. Further, concerning the case to
discharged the contents in an inner bag without an outer box, it is necessary to hold
the container by one hand for the easiness of work, therefore, when the gazette shape
inner bag is handled by using an upper folded in part as the handle part, the easiness
for holdling is not sufficient.
DISCLOSURE OF THE INVENTION
[0006] The present invention is carried out to dissolve the above mentioned problems and
the object of this invention can be illustrated as follows. That is, the object of
the present invention is to provide good self-standing ability and substantial mechanical
strength to a filled up inner bag for bag-in-box when it is handled without an inner
bag. Further, the object of the present invention is to obtain an inner bag for bag-in-box
characterized that the remaining amount of the liquid at the discharging operation
is small, the easiness for holding of the container is improved and easiness in handling
and convenience are improved and having strong mechanical strength.
[0007] The inner bag for bag-in-box of the present invention is comprising, a front film
with a spout, a rear film and a self-standing bag prepared by adhering a bottom film
to be folded in between said front film and said rear by heat sealing with said front
and rear films, wherein said inner bag for bag-in-box possesses at the upper position
a corner part divided from a containing part by a heat sealed part.
BRIEF ILLUSTRATION OF THE DRAWINGS
[0008]
Fig.1 is the plane view of the folded state of one example of the inner bag for bag-in-box
of the present invention.
Fig.2 is the plane view of the folded state of the other example of the inner bag
for bag-in-box of the present invention.
Fig.3 is the plane view of the folded state of the other example of the inner bag
for bag-in-box of the present invention.
Fig.4 is the cross sectional view by A-A' line of the inner bag of Fig.3.
Fig.5 is the perspective illustration of the inner bag for bag-in-box of Fig.1 in
which liquid is filled up without an outer box.
Fig.6 is the perspective view illustrating the discharging operation of the contents
from the inner bag for bag-in-box of Fig.1 filled up with liquid after taken out from
the outer box.
Fig.7 is the other example of the present invention.
Fig.8 is the other example of the present invention.
Fig.9 is the other example of the present invention.
Fig. 10 is the perspective diagram illustrating the discharging operation of the contents
setting the inner bag to the outer box.
Fig.11 is the plane view of the folded state of a conventional gazette type inner
bag for bag-in-box.
Fig.12 is the perspective illustration of a conventional type inner bag for bag-in-box
in which liquid is filled up.
THE BEST EMBODYMENT TO CARRY OUT THE INVENTION
[0009] As mentioned above, the shape of the inner bag of the present invention is so called
standing pouch, characterized by being prepared by inserting a bottom film which is
folded in into inner side between a front film and a rear film and the side periphery
part of these films are adhered by heat sealing. When the inner bag of this shape
is empty and folded in, it is flat and not bulky, however, when the bag is filled
up with liquid, the bottom film is opened and becomes an excellent inner bag with
good self-standing ability.
[0010] Further, it is possible to prepare a corner part by dividing a containing part with
a oblique heat sealed part formed from the side periphery part toward the upper periphery
part. By preparing said corner part, in a case to discharge the contained liquid in
the inner bag by turning the bag upside down, it can be possible to reduce the remaining
amount of liquid in the upper part of the inner bag. Furthermore, it is desirable
to make a hole in the corner part, because the hole can act as a handle part and make
the easiness of handling better in cases when the inner bag is transferred without
an outer box or when the contents in the inner bag is discharged. The outer periphery
surrounding the hole can be sealed by heat or not be sealed by heat, however, it is
preferable not to prepare a heat sealed part surrounding the hole, because the mechanical
strength is improved and the function as the handle part becomes more reliable and
the load burdened to fingers becomes smaller.
[0011] It is also preferable to prepare a handle part at the upper position of the upper
sealing part instead of making a hole in a corner part.
[0012] The preferable shape of a bottom film of the inner bag of the present invention is
rectangular or square. And as the type of the inner bag, the DOY PACK (registered
trademark) type having radius in bottom seal or a so-called square bottom type having
a bottom straight line seal and a oblique heat sealed part can be mentioned. And it
is desirable to use the inner bag with square bottom, because said inner bag becomes
stable when it is filled up with contents and placed in an outer box. Further, at
the lower part of the inner bag of the present invention a bottom film is folded in
into inner side between a front film and a rear film and the outer periphery side
of these films are adhered by heat sealing. In this case, it is desirable to prepare
a oblique belt shape heat sealed part which traverses from the crossing point of crease
of folding part of the bottom film and the front film or the rear film or near the
crossing point to the voluntary point of the heat sealed part of the lower side of
the inner bag.
[0013] And, a case that a film on the outermost surface of which a resin layer not easily
sealed by heat is arranged, such as a co-extruded multi layered film of polyamide
and polyethylene or a laminate film prepared by laminating a polyolefin resin layer
with a biaxial orientated film is used as the bottom film of the inner bag of the
present invention will be illustrated as follows. Namely, a structure that a front
film and a rear film are adhered by heat sealing can be obtained at the position where
the side periphery heat sealed part is sealed by heat by making a cutting off part
e.g. a punch hole in the bottom film at the corresponding position to the side periphery
heat sealed part locating lower than the crossing point of above mentioned oblique
belt shape heat sealed part and the side periphery heat sealed part. By said structural
feature, the bottom film expands when contents is filled up into the inner bag, and
the sole part of the bag forms a solid body and provides excellent self-standing ability
to the filled up inner bag. And by preparing above mentioned oblique heat sealed part,
it becomes possible to reduce the remaining amount of liquid between films at the
corner of the bottom part when contained liquid is discharged from the inner bag.
[0014] Further, by above mentioned structural feature, even if a laminate film based on
not-stretchable film e.g. a biaxial orientated film is used as the bottom film, since
a front film and a rear film locating at the lower position from the crossing point
of above mentioned oblique belt shape heat sealed part and the side periphery heat
sealed part are adhered each other by heat sealing, it is possible to prevent the
opening of the bottom film when inner pressure is loaded to the inner bag. Therefore,
the stress burdened to the crossing point of the folding line of the bottom film and
the side periphery heat sealed part can be reduced, and the substantial mechanical
strength against the abnormal impact caused by careless falling down of the inner
bag can be improved.
[0015] Furthermore, it is possible to make at least one similar cut off part at further
lower position than above mentioned cut off part or preferably at a corner part, and
to adhere a front film and a rear film each other by heat sealing at said cut off
part. By above mentioned structural feature, it becomes possible to improve the self-standing
ability by providing a shape maintaining ability to the inner bag, and the effect
to prevent the opening of the bottom film when inner pressure is loaded to the inner
bag can be increased, therefore the substantial mechanical strength against the abnormal
impact caused by careless falling down of the inner bag can be improved.
[0016] Still further, it is possible to make the bottom film of the inner bag open easily
so that the operation for filling up the inner bag becomes easy by cutting off lower
corner parts locating at the outer periphery of above mentioned oblique heat sealed
part along with the oblique seal part. However, when this part is cut off, the self-standing
ability of the inner bag and the mechanical strength against the falling down of the
inner bag are deteriorated, it is necessary to select the materials and constitution
of the inner bag voluntarily according to the required function level for the inner
bag. And, when a laminate prepared so as a resin layer not easily sealed by heat is
arranged on the outermost surface is used as the bottom film of the inner bag, it
is desirable to cut off a lower angled corner part locating closely below the crossing
point of a oblique sealing part and a side periphery heat sealed part.
[0017] The present invention will be illustrated more in detail.
[0018] As the materials of the inner bag used in the present invention, a polyolefin film
e.g. polyethylene or polypropylene film can be used by alone, further, a laminated
film can be also used. As the laminate, a laminated film prepared by following constitution
can be used. Namely, a resin layer having good adhesive ability by heat sealing e.g.
polyolefin type resin such as polyethylene or polypropylene (CPP) is arranged in the
inmost layer, and a film having relatively high mechanical strength such as biaxial
orientated polyamide, biaxial orientated polyester or biaxial orientated polypropylene
is used as a base material. For the purpose to add a further necessary function, other
kind of film can be further laminated. For example, according to the required function,
a laminated film which laminates an adequate functional film can be voluntarily selected.
For example, when the moisture-proof ability is necessary, a silica evaporated film
or copolymer of ethylene-vinylalcohol can be added to the laminate, and when a light
shielding ability is necessary, an aluminum foil or an aluminum metalized film can
be added to the laminate. For example, a laminate film composed of polyester, aluminum
foil and polyethylene, a co-extruded multi layered film of EVOH and polyethylene or
a co-extruded multi layered film of polyamide, EVOH and polyethylene can be mentioned.
Further, these films can be used alone or can be used by overlapping with polyethylene
single film without adhering, however, not intending to be limited to them.
[0019] Examples of the present invention are illustrated in accordance with the drawings.
[0020] Fig.1 to Fig.4 are the examples of an inner bag for bag-in-box of the present invention
showing the folded state. And Fig.4 is the A-A' line cross sectional view of the inner
bag of Fig.3.
[0021] In Fig.1 to Fig.4, 1 is an inner bag, 2 is an upper heat sealed part, 3 is a lower
heat sealed part, 4 is a bottom film in folded in state, 5, 5' are through holes maked
in the bottom film before sealing process, 6 is a front film of the inner bag, 7 is
a rear film of the inner bag, 8 is a side periphery heat sealed part, 9 is a oblique
heat sealed part at the bottom and 10 is an upper oblique heat sealed part. 14 is
a spout for pouring the contents out.
[0022] To the folded in bottom film 4 a through holes 5 and 5' are previously made closely
under the crossing point 12 of side periphery heat sealed part 8 and lower oblique
heat sealed part, then by adhering the side periphery by heat using the front film
and rear film are sealed by heat at this hole.
[0023] Further, a handle hole 15 is prepared at the outer side of the upper oblique heat
sealed part 10.
[0024] Fig.5 shows the filled up state of the inner bag for bag-in-box of Fig.3 with liquid
without an outer box. The bottom film is extended and forms a sole of the container.
Since the inner bag is characterized to have full-cheeked shape, center of gravity
of the bag locates at the lower position, the excellent self-standing ability can
be obtained.
[0025] And, since the front film and the rear film of the bag are forming one body by through
hole heat sealed parts 5 and 5', the film at the crossing point 12 does not extend
and the substantial mechanical strength can be improved.
[0026] Fig.6 is showing the discharging process of the contents from the filled up inner
bag for bag-in-box of Fig.3 by taking out the bag from the outer box. The upper part
of the bag is double folded and two upper handle parts are grasped by one hand by
piling up them each other and one corner part of the bottom part is grasped by another
hand. Thus, the handling of the inner bag is very easy.
[0027] Fig.7 is the other example of the present invention, and shows that a bottom angled
corner is cut off remaining the heat sealed part of the front film and the rear film
of the bottom part.
[0028] Fig.8 and Fig.9 are also the other examples of the present invention and showing
that a handle part 16 is formed at the upper position of the upper heat sealed part
2.
[0029] And, Fig.10 is the perspective diagram of the inner bag illustrating the state that
the content in the inner bag is discharged while the inner bag is set to the outer
box.
[0030] In the meanwhile, Fig.11 is the perspective illustration of an example of an inner
bag for bag-in-box of the conventional gazette shape type bag-in-box and Fig.12 is
an example of an inner bag for bag-in-box of the conventional gazette shape type bag-in-box.
POSSIBILITY FOR THE INDUSTRIAL USE
[0031] As mentioned above, the inner bag for bag-in-box of the present invention is characterized
to have structural features described below. That is, a bottom film is folded in to
the inner side and put between lower part of a front film and a rear film, then the
outer periphery side of these films is adhered by heat sealing. A oblique belt shape
heat sealed part which traverses from the crossing point of crease of folding part
of the bottom film and a front film or a rear film or near the crossing point to the
voluntary point of the heat sealed part of the lower side of the inner bag is prepared.
And a front film and a rear film are adhered by heat sealing at the position where
the side periphery is sealed by making a cutting off part e.g. a punch hole in the
bottom film at the corresponding position to the side periphery heat sealed part locating
lower than the crossing point of above mentioned oblique belt shape heat sealed part
and the side periphery heat sealed part. By performing above mentioned structural
feature, it becomes possible to provide an excellent self-standing ability to the
inner bag and to reduce the remaining amount of liquid between films at the corner
of the bottom part when contained liquid is discharged from the inner bag. Further,
in a case when the abnormal inner pressure is loaded to the inner bag, the stress
burdened to the crossing point of the folding line of the bottom film and the side
periphery heat sealed part can be reduced, and the substantial mechanical strength
against the abnormal impact caused by careless falling down of the inner bag can be
improved.
[0032] Further, by preparing a oblique heat sealed part which connect an upper heat sealed
part and side periphery heat sealed part on both corners of the upper part of the
bag, in a case to discharge the contained liquid in the inner bag by turning the bag
upside down, it can be possible to reduce the amount of remaining liquid in the upper
corner part of the inner bag.
[0033] Furthermore, it is possible to seal the side periphery by making a hole in the bottom
film closely lower the crossing point of above mentioned lower oblique heat sealed
point and side periphery heat sealed part, and to cut off the outer part of said oblique
heat sealed part along with the oblique seal part remaining the heat sealed part of
the front film and the rear film. Thus, it becomes possible to make the bottom film
of the inner bag open easily so that the operation for filling up the inner bag becomes
easy.
[0034] Still further, by making a hole for handling at the outer side of the oblique heat
sealed part connecting an upper heat sealed part and side periphery heat sealed part
on both corners of the upper part of the bag, easiness of handling of the filled up
inner bag without outer box can be accomplished.