U.S. patent application number 10/508026 was filed with the patent office on 2005-06-30 for self-standing bag and method of manufacturing the bag.
Invention is credited to Ikeda, Kazuhiro, Shimizu, Takashi.
Application Number | 20050141788 10/508026 |
Document ID | / |
Family ID | 28035474 |
Filed Date | 2005-06-30 |
United States Patent
Application |
20050141788 |
Kind Code |
A1 |
Ikeda, Kazuhiro ; et
al. |
June 30, 2005 |
Self-standing bag and method of manufacturing the bag
Abstract
A self-standing bag (1) comprising a bag body (2), a spout (3),
and a reverse-recessed frame (4), wherein the spout (3) is provided
at the upper portion of the bag body (2) composed of body films
(2c, 2c) and a bottom film (2d) folded down on the bottom portion
in a reverse V-shape, and integrally formed with the
reverse-recessed frame (4) starting at the upper edge (2b) toward
both side edges (2a, 2a) of the bag body (2), the bag body has
fusion bonding parts at the lower edges and a part of each side
edge of the bag body (2) which are fusion bonded to each other so
that at least the bottom film (2d) can be fixed to the body films
(2c, 2c).
Inventors: |
Ikeda, Kazuhiro; (Tokyo,
JP) ; Shimizu, Takashi; (Tokyo, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
28035474 |
Appl. No.: |
10/508026 |
Filed: |
September 16, 2004 |
PCT Filed: |
March 18, 2003 |
PCT NO: |
PCT/JP03/03225 |
Current U.S.
Class: |
383/104 ;
383/119; 383/906 |
Current CPC
Class: |
B65D 75/008
20130101 |
Class at
Publication: |
383/104 ;
383/906; 383/119 |
International
Class: |
B65D 030/16 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 19, 2002 |
JP |
2002-76890 |
Claims
1. A self-standing bag comprising a bag body composed of two body
films and a bottom film folded down in a reverse V-shape at the
bottom portion, and a spout at an upper portion of the bag body,
said bag body having fusion bonding parts at the lower edges and at
least a part of each side edge to which the bottom film is present
so that at least the bottom film is fixed with both of the body
films and a frame of a reverse-recessed shape integrally molded
with the spout being attached from the upper edge to each side edge
of the bag body.
2. The self-standing bag of claim 1 wherein the frame is provided
at each side edge to which the fusion bonding part is present so
that a part or the whole of the fusion bonding part is left.
3. The self-standing bag of claim 1 or 2 wherein the frame is
provided so that the outer surface of each edge is covered with the
frame.
4. A method of manufacturing the self-standing bag of claim 1,
comprising the steps of joining by fusion bonding the lower edges
and at least a part of each side edge to which the bottom film is
present so that at least the bottom film is fixed with the two body
films, and then attaching the frame to the bag body so that the
spout is integral with the frame, thereby preparing the
self-standing bag having the spout.
Description
TECHNICAL FIELD
[0001] The present invention relates to a self-standing bag having
a spout, and more particularly to a self-standing bag that is
flexible and has good self-standing performance and high fixing
strength of the spout, and also to a method of manufacturing the
self standing bag.
BACKGROUND ART
[0002] Conventionally, self-standing bags for fluids in which a
liquid is filled have been used mainly for refilling use, and
little attention has been paid to the self-standing performance.
Therefore, when the amount of the content has been decreased, the
conventional self-standing bag loses its self-standing function
because of bending at the upper portion of the bag. Particularly, a
self-standing bag for a fluid may have a spout for pouring the
content. In such a case, the upper portion of the bag becomes heavy
and the self-standing performance may be considerably injured. In
addition, the conventional self-standing bag having a spout has
been formed by a method in which peripheral edges of a bag body are
sealed by fusion bonding, the spout is separately molded, and the
molded spout is manually inserted between sheets constituting the
bag body to fusion bond to the inner surfaces of the sheets,
thereby attaching the spout to the bag. Such a manual operation not
only affects the mass-productivity, but also renders the fusion
bonding between the spout and the sheets unsatisfactory, resulting
in an insufficient strength of the bag body. On the other hand,
molded vessels naturally have a sufficient self-standing
performance, but they cannot be reduced in size by folding at the
time of disposal.
DISCLOSURE OF INVENTION
[0003] It is an object of the present invention to provide a
self-standing bag which maintains the self-standing performance
until the content is used up, can be reduced in volume by folding
in case of disposing of the bag, and has a high fixing strength of
a spout, and a method of manufacturing such a self-standing
bag.
[0004] According to the present invention, there is provided a
self-standing bag comprising a bag body composed of two body films
and a bottom film folded down in a reverse V-shape at the bottom
portion, and a spout at an upper portion of the bag body, said bag
body having fusion bonding parts at the lower edges and at least a
part of each side edge to which the bottom film is present so that
at least the bottom film is fixed with each body film, and a frame
of a reverse-recessed shape integrally molded with the spout being
attached from the upper edge to each side edge of the bag body. It
is preferred that the frame is provided at each side edge to which
the fusion bonding part is present so that a part or the whole of
the fusion bonding part at each side edge is left, or provided so
that the outer surface of each edge is covered with the frame.
[0005] The present invention also provides a method of
manufacturing the above self-standing bag comprising the steps of
joining by fusion bonding the lower edges and at least a part of
each side edge to which the bottom film is present so that at least
the bottom film is fixed with two body films, and then attaching
the frame to the bag body so that the spout is integral with the
frame, thereby preparing the self-standing bag having the
spout.
[0006] The inventive self-standing bag comprises a bag body
composed of two body films and a bottom film folded down in a
reverse V-shape at the bottom portion, and a spout at an upper
portion of the bag body, said bag body having fusion bonding parts
at the lower edges and at least a part of each side edge to which
the bottom film is present so that at least the bottom film is
fixed with both the body films, and a frame of a reverse-recessed
shape integrally molded with the spout being attached from the
upper edge to each side edge of the bag body. Accordingly, the
parts of the frame present at each side edge of the bag body
constitute so-called ribs to the bag body and function as supports
of the bag body, thereby improving the self-standing property of
the bag body. Although the spout is provided at the upper portion
of the bag body, the self-standing performance can be sufficiently
maintained until the content is completely used up. In addition,
since the spout is integrally molded with the frame, the bag is
excellent in the attachment strength of the spout. Moreover, a
variety of spouts can be easily attached securely.
[0007] The spout can be integrally molded simultaneously upon
molding the frame. The spout may be preliminarily molded and the
thus molded spout may be integrated with the frame by in-mold
molding upon molding the frame. The fusion bonding parts can be
formed at parts of the side edges to which the bottom film is not
present, the lower edges, the lower corners (i.e., lower
semi-arcuate fusion bonding parts, etc.) or the like in addition to
parts of the side edges to which the bottom film is present.
[0008] The frame in the present invention may be attached to the
bag body so as to extend over the entire length of the range from
the upper edge to both side edges of the bag body, as will be
described later. However, when the frame is attached to the bag
body at a part of each side edge to which the fusion bonding parts
is present so that a part or the whole of each fusion bonding is
left, the self-standing performance can be assured by spreading the
bottom film, and the amount of the resin used for molding the frame
can be reduced, thereby leading to a lighter weight. In addition,
the parts the bag body free of the frame become easier to fold, and
the bag becomes easier to scrap. Therefore, such a configuration is
preferable.
[0009] When the frame is attached so that the outer surface of each
edge of the bag body is covered with the frame, the joint strength
of the upper edge and both side edges of the bag body can be
reinforced. This configuration is also preferable.
[0010] In the method of manufacturing the self-standing bag, the
films constituting the bag body are formed as a self-standing
shape. And the lower edges and at least a part of each side edge to
which the bottom film is present are joined by fusion bonding so
that at least the bottom film is fixed with the two body films, and
thereafter the frame is attached to the bag body so that the spout
is integral with the frame, thereby preparing a self-standing bag
having the spout. Accordingly, even when the lower edges and only
the lower parts of the side edges are fusion bonded so that only
the bottom film is fixed to the body films of the bag body in the
manufacture of the self-standing bag according to the present
invention, the upper edge which is an unjoined edge and the
unjoined parts of the side edges can be joined with the frame upon
the attachment of the frame to the bag body, thereby obtaining a
self-standing bag having the spout. Even when the bag body is
formed in such a weak joining strength as that the parts except the
lower parts of the side edges barely keep the bag shape, the
attachment of the frame can reinforce the joining strength, thereby
easily and surely joining the edges of the bag body. More
specifically, the bag body may be formed completely or incompletely
into a bag shape so long as the bottom film is fusion bonded. It is
preferred as the method of manufacturing the self-standing bag
according to the present invention to use the bag body completely
formed into a bag shape, whereby the resulting self-standing bag
becomes excellent in strength. The attachment of the spout and the
frame is conducted more easily and surely.
[0011] The formation of the frame and the attachment and joining of
the frame is preferably conducted by injection molding a resin. In
this case, it is desirable to integrally mold the spout
simultaneously with the frame or to integrally attach the
previously molded spout with the frame.
[0012] The self-standing bag according to the present invention is
flexible and has good self-standing performance, so that the bag
functions as a self-standing packing bag and fulfills the
self-standing performance until the contents are completely
consumed upon use in spite that the spout is attached, and the bag
can be disposed by rolling up the bag with a reduction in volume
after the completion of use. Further, the self-standing bag is high
in fixing strength of the spout to the bag. It is also possible to
reinforce the joining strength. Therefore, the self-standing bag
according to the present invention is easy to use, is excellent in
strength as a packing bag, and is easy to reduce in volume in case
of disposing the bag after the completion of use, which is suited
to environmental protection. According to the method of
manufacturing the self-standing bag of the present invention, the
self-standing bag having the above-mentioned characteristics and
particularly having an excellent seal strength of the bag body can
be manufactured easily and securely.
BRIEF DESCRIPTION OF DRAWINGS
[0013] FIG. 1 is a schematic perspective view of a self-standing
bag for illustrating an embodiment of configuration of the
self-standing bag according to the present invention.
[0014] FIG. 2 is a schematic front view of the bag body obtained by
the first step illustrating an embodiment of the method of
manufacturing the self-standing bag according to the present
invention.
[0015] FIG. 3 is a schematic front view of the self-standing bag
obtained by the second step of the above manufacturing method.
BEST MODE FOR CARRYING OUT THE INVENTION
[0016] The present invention will be described more in detail
below, referring to the drawings. FIG. 1 illustrates one embodiment
of configuration of the self-standing bag according to the present
invention, and is a schematic perspective view showing the
condition where the self-standing bag 1 is expanded. The
self-standing bag 1 has a spout 3 at an upper edge of a bag body 2.
A frame 4 having a reverse-recessed shape which is integrally
molded with the spout is attached ranging from one side edge 2a
through the upper edge 2b to the other side edge 2a so as to clamp
the edges 2a, 2b, 2a from the outer sides.
[0017] The bag body 2 is formed by folding an elongate film in four
at the lower portion so as to provide two body films 2c, 2c and a
bottom film 2d folded down at the bottom portion in a reverse
V-shape, then, as will be described later, joining by fusion
bonding the side edges 2a, 2a of the body films 2c, 2c, and fusion
bonding the folded portion parts in semi-arcuate shapes to form
lower semi-arcuate fusion bonding parts 2e, 2e, thereby forming a
bottom portion. The bag body 2 is reinforced in strength of the
bottom portion and in self-standing property by the lower
semi-arcuate fusion bonding parts.
[0018] The film (the body films 2c, 2c and the bottom film 2d) for
forming the bag body 2 can be a monolayer or multilayer film. The
film may be the conventional film, but may not necessarily have a
fusion-bondability. It is preferable, however, that the film
surface which is to become an outer surface of a bag has a good
adhesion with a resin to be injected for forming the frame. The
multilayer film is a co-extruded film, a laminate film, or the
like. An oriented or unoriented polyolefin, nylon, polyester film,
or a film for imparting required functions to the resin layer
including a co-extrusion type film with a gas barrier layer (EVOH,
saran, ceramic vapor deposition, etc.) or a laminate type film
thereof is suitably used.
[0019] The thickness of the film is 20 to 900 .mu.m. From the
viewpoint of self-standing property, a thick film is suitable. From
the viewpoint of flexibility and light-weightness, a thin film is
preferably used. Even a thin film can secure the self-standing
property by attaching the frame 4. In view of moldability and
handleability, the film thickness is preferably 60 to 200 .mu.m.
The film is not limited to those made of synthetic resin, and may
be a monolayer or laminate film of paper or metal foil.
[0020] The spout 3 is not particularly limited as to shape and size
thereof. The spout 3 can have arbitrary shape and size according to
the purpose of use of the packing bag. Generally, the self-standing
bag with the spout is manufactured by inserting the spout into the
upper edge of the self-standing bag by a separate operation using
hands or an automatic inserting machine, followed by fusion
bonding. Therefore, when the thickness of the spout is large, it is
difficult to bond tightly the spout to a spout inserting gate at
the upper edge of the self-standing bag body, and the fusion
operation involves difficulties in many cases. On the other hand,
in the present invention, such difficulties are obviated because
the spout 3 is integrally molded with the frame 4, as will be
described later.
[0021] The frame 4 is integrally molded simultaneously with the
spout 3 by, for example, injection molding, or is integrally molded
with a previously molded spout 3 in a mold. The resin for forming
the spout is not particularly limited, so long as the resin can be
injection molded and can be joined to the edges of the bag body 2.
Examples of the resin which can be utilized include not only
general-purpose resins such as polyethylene and polypropylene
resins but also injectable plastics, e.g., nylon, polyester, etc.,
a variety of engineering resins, and blends and copolymer resins of
these resins with elastomers or the like.
[0022] The frame 4 is shaped along the portion ranging from one
side edge 2a through the upper edge 2b to the other side edge 2a of
the bag body 2 composed of a resin film preliminarily molded in a
predetermined self-standing bag shape. The frame in the
self-standing bag according to the present invention may be a frame
4' shown in FIG. 3, in which the frame part along each side edge
has such a length as to extend over the whole length of each side
edge. Alternatively, the frame may be a frame 4 shown in FIG. 1, in
which the frame part along each side edge has such a length as to
leave the lower portion of each side edge. In this case, the
self-standing property and the strength as a bag, which are aimed
at in the present invention, can be obtained because the bottom
strength and the self-standing property are reinforced by the lower
semi-arcuate fusion bonding parts 2e, 2e where the folded portion
parts of the film of the bag body 2 are fusion bonded in
semi-arcuate shapes, and also by the fusion bonding portions of the
side edges.
[0023] When the length of the frame parts corresponding to the side
edges 2a, 2a is so set as to leave the lower portions of the side
edges 2a, 2a, the length of each corresponding part of the frame 4
is desirably not less than 60%, particularly not less than 80%,
based on the whole length of each side edge. If the corresponding
parts of the frame 4 are too short, the effects of the present
invention may be insufficient. It should be noted that when only
the lower portions of the side edges 2a, 2a are fusion bonded so
that the undersurface 2f is formed as will be described later, it
is favorable that the frame has such a length that the tip ends of
the frame reach at least the upper portions of the fusion bonding
parts and the lower portions thereof are left.
[0024] The frame 4 is not particularly limited in width or
thickness. For example, when the frame is so shaped that the parts
corresponding to the side edges 2a, 2a are tapered on the tip ends
(on the lower portions in the figure) as in the case of the frame 4
shown in FIG. 1, the frame 4 is preferably so shaped that, at the
parts having a uniform width, the width is 1 to 20 mm, particularly
5 to 10 mm, and the thickness is 1 to 10 mm, particularly 2 to 5
mm. When the frame is generally uniform over the entire part
thereof as in the case of the frame 4' shown in FIG. 3, it is
preferable that its average width and average thickness are in the
above-mentioned ranges, respectively. When the width is too small
or the thickness is too small, it may be difficult to obtain a
sufficient strength of the attachment of the frame to the bag body
2. When the thickness is too large, the amount of the resin to be
used is increased, which is unfavorable from the viewpoint of
scrapping property. When the width is too large, it may be
difficult for the self-standing bag to have a sufficient inside
volume.
[0025] Next, one embodiment of the method of manufacturing the
self-standing bag according to the present invention will be
described referring to FIGS. 2 and 3. FIG. 2 is a front view of a
self-standing bag formed by a first step, before the attachment of
the frame, and FIG. 3 is a front view of another configuration of
the self-standing bag according to the present invention obtained
by a second step.
[0026] In the first step, by the use of an ordinary self-standing
bag manufacturing machine, an elongate film for constituting a bag
body 2 is folded to have a four-folded part on the lower side into
the shape of a self-standing bag having body films 2c, 2c and a
bottom film 2d folded down to the bottom portion in a reverse
V-shape, then the lower edge, one side edge 2a and the other side
edge 2a are joined by fusion bonding such as heat sealing or
ultrasonic sealing, and the folded portion parts 2e, 2e of the film
are joined by a means such as fusion bonding in semi-arcuate
shapes, whereby body films 2c, 2c and the bottom film 2d are fixed
to manufacture a top-open bag body 2 as shown in FIG. 2. In this
step, a part of the upper edge 2b of the bag body 2 may be fusion
bonded, as long as the attachability of the spout is not spoiled,
as will be described later.
[0027] In the joining of one side edge 2a and the other side edge
2a, only the lower edges and on the lower-end portions of one side
edge 2a and the other side edge 2a may be fusion bonded as long as
the body films 2c, 2c and the bottom film 2d can be fixed and an
undersurface 2f can be formed. It is preferable that, as shown in
FIG. 2, the fusion bonding parts include the intersections of one
side edge 2a and the other side edge 2a with the line indicating
the undersurface 2f (the joint parts of the bottom film), in view
of an excellent strength obtained upon completion of the
self-standing bag according to the present invention. In this case,
only the parts ranging from about 2/5 times the whole length of
each side edge on the upper portion to the lower end of each of the
side edges 2a, 2a (arrows 2g, 2g in FIG. 2) may be fusion bonded.
Particularly, when the frame is not attached over the whole length
of both side edges, as in the case of the self-standing bag shown
in FIG. 1, the parts of both side edges where the frame is not to
be attached must be fusion bonded in advance. It is desirable that
the lower semi-arcuate fusion bonding parts 2e, 2e formed for
enhancing the self-standing property are also fusion bonded in
advance, taking workability into account.
[0028] In addition, even when one side edge 2a and the other side
edge 2a are preliminarily joined over the entire length thereof, a
joint strength comparable to that in the conventional self-standing
bag is not specially required; for example, such a joint strength
as to maintain a bag shape for the time being may suffice. In this
case, however, since the presence of only the frame may not provide
a sufficient bond strength of the bottom portion (in the
self-standing bag, stress is exerted most heavily on the joint
parts of the bottom film); it is preferable that at least the part
for forming the bottom face 2f is fusion bonded in advance with a
sufficient joint strength. When the frame does not extend over the
whole length of both side edges as above-mentioned, it is
preferable that the parts of both side edges where the frame is not
attached are fusion bonded in advance with a sufficient joint
strength.
[0029] In case of the present invention, at least parts of the side
edges and the lower edges of the film folded so as to form at least
the undersurface as mentioned above are fusion bonded, so that the
alignment of the back and face films is facilitated, and the spout
and the frame can be integrally molded at accurate positions. In
addition, even when a separately-molded spout is used, the spout
can be integrally molded with the frame at an accurate position by
such a technique as insert molding.
[0030] In the second step, the film constituting the bag body 2
obtained in the first step is set in an ordinary injection molding
machine, the spout 3 is injection molded at a position to be a
predetermined upper portion of the film constituting the bag body
2, simultaneously when the frame 4' is injection molded from a
thermoplastic resin extending from the spout so as to cover the
outer surfaces (back and face surfaces) of the upper edge 2b and
both side edges 2a, 2a of the film constituting the bag body 2, and
the frame 4 is joined to the upper edge 2b and both side edges 2a,
2a of the bag body 2, to thereby manufacture the self-standing bag
1' shown in FIG. 3.
[0031] The self-standing bag is filled with contents (not shown)
via the spout, whereby it is set into a self-standing shape with
the undersurface spread, then the spout is stoppered, and the
self-standing bag with the contents therein is stored or
transported. Upon use, the contents can be discharged through the
spout. The kind of the contents is not particularly limited, and,
by appropriately selecting the kinds of materials of the film
constituting the bag body and of the spout, it is possible to cope
with a wide range of products as the contents. Among the various
contents, those having fluidity are preferred. Examples of the
fluid contents include liquids, consistency materials, powders,
small-diameter solids, etc. The self-standing bag can maintain the
self-standing performance until the contents therein are completely
used up, because the frame parts along both side edges function as
ribs, and can be reduced in volume by folding or crumpling at the
time of scrapping. Therefore, according to the self-standing bag of
the present invention, there is obtained a flexible container which
is compatible with a bottle, a can or the like and which can be
fitted into or over a variety of spout.
[0032] The present invention is not limited to the above-described
embodiments. For example, instead of providing the lower
semi-arcuate fusion bonding parts, a simple rectilinear lower end
fusion bonding parts may be provided. In place of the lower
semi-arcuate fusion bonding parts, skew 45.degree. rectilinear
fusion bonding parts extending from the joint parts of the bottom
film may be provided in addition to the rectilinear lower end
fusion bonding parts. Further, a bottom film different from the
body films may be used. Thus, various modifications are possible
within the scope of the gist of the present invention.
[0033] As for the spout, a variety of selections can be made. For
example, a cap of a screw sealing type or a cap capable of being
opened and closed at a hinge may be added, and a spout having a
nozzle for taking out the contents by suction may be used.
[0034] Furthermore, as to the shape of the bag body, variously
designed irregularly shaped bags may be adopted, as long as the
self-standing function through spreading of the bottom is not
spoiled.
* * * * *