U.S. patent application number 10/701522 was filed with the patent office on 2004-05-27 for packaging bag and method for manufacturing same.
This patent application is currently assigned to Hosokawa Yoko Co., Ltd.. Invention is credited to Ichikawa, Tooru.
Application Number | 20040101216 10/701522 |
Document ID | / |
Family ID | 32290448 |
Filed Date | 2004-05-27 |
United States Patent
Application |
20040101216 |
Kind Code |
A1 |
Ichikawa, Tooru |
May 27, 2004 |
Packaging bag and method for manufacturing same
Abstract
A packaging bag comprises a main bag body and a framework
member. The main bag body is made of plastic film material through
a main bag body formation process. The main bag body has an opening
and a plurality of heat sealed portions. The framework member is
disposed in the main bag body. The framework member is joined to
the main bag body prior to completion of the main bag body
formation process. The framework member is foldable/unfoldable
together with the main bag body, to enable the framework member and
the main bag body to be shifted between a generally flat collapsed
state and an expanded state.
Inventors: |
Ichikawa, Tooru;
(Chiyoda-ku, JP) |
Correspondence
Address: |
PARKHURST & WENDEL, L.L.P.
1421 PRINCE STREET
SUITE 210
ALEXANDRIA
VA
22314-2805
US
|
Assignee: |
Hosokawa Yoko Co., Ltd.
Chiyoda-ku
JP
|
Family ID: |
32290448 |
Appl. No.: |
10/701522 |
Filed: |
November 6, 2003 |
Current U.S.
Class: |
383/119 |
Current CPC
Class: |
B31B 70/008 20170801;
B31B 2170/20 20170801; B65B 29/028 20170801; Y02W 30/80 20150501;
B31B 2155/00 20170801; B31B 70/8123 20170801; B31B 2155/002
20170801; B31B 2160/10 20170801; B31B 2150/00 20170801; B65D 33/02
20130101 |
Class at
Publication: |
383/119 |
International
Class: |
B65D 033/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 27, 2002 |
JP |
2002-343845 |
Claims
What is claimed is:
1. A packaging bag comprising: a main bag body made of plastic film
material through a main bag body formation process, said main bag
body having an opening and a plurality of heat sealed portions; and
a framework member disposed in said main bag body, said framework
member being joined to said main bag body prior to completion of
said main bag body formation process, said framework member being
foldable/unfoldable together with said main bag body, to enable
said framework member and said main bag body to be shifted between
a generally flat collapsed state and an expanded state.
2. The bag as claimed in claim 1, further comprising: a linear
fastener provided on said opening of said main bag body.
3. The bag as claimed in claim 1 or 2, wherein: said main bag body
has a rectangular shape in a generally flat collapsed state, said
main bag body being provided on opposite side edges thereof with a
pair of heat-sealed portions.
4. The bag as claimed in claim 3, wherein: said framework member
comprises a pair of opposite reinforcing sections, each of said
reinforcing sections having a rectangular shape having first pair
of opposite side edges and second pair of opposite side edges, said
first pair of opposite side edges being embedded in said pair of
heat-sealed portions.
5. The bag as claimed in claim 4, wherein: said second pair of
opposite side edges is bonded to said main bag body at other
regions than said pair of heat-sealed portions.
6. The bag as claimed in claim 3, wherein: said framework member
comprises a pair of opposite reinforcing sections, each of said
reinforcing sections having a rectangular shape having first pair
of opposite side edges and second pair of opposite side edges, said
pair of opposite side edges and said second pair of opposite side
edges being thermally bonded to said main bag body at other regions
than said pair of heat-sealed portions.
7. The bag as claimed in claim 3, wherein: said framework member
comprises a sleeve.
8. A method for manufacturing a packaging bag, comprising the steps
of: (a) continuously feeding a single strip of plastic film
material for a main bag body in a longitudinal direction, said
single strip having opposite half portions between which a
longitudinal central line of said single strip exists; (b)
continuously feeding a pair of strips of thin sheet material for a
framework member to place said pair of strips for the framework
member on a surface of said single strip for the main bag body in
predetermined positions of the respective opposite half portions of
the single strip; (c) bonding said pair of strips for the framework
member to said single strip for the main bag body in respective
opposite half portions thereof; (d) folding said single strip for
the main bag body with said pair of strips for the framework member
in two along said longitudinal central line of said single strip
for the main bag body to bring one of said opposite half portions
of said single strip for the main bag body close to another of said
opposite half portions to prepare a folded composite strip so that
said pair of strips for the framework member are placed in an
inside of said folded composite strip; (e) thermally bonding said
folded composite strip in a perpendicular direction to a
longitudinal direction thereof by predetermined intervals to form
heat-sealed portions; and (f) cutting each of said heat-sealed
portions in two in said perpendicular direction to the longitudinal
direction of said folded composite strip, thereby continuously
manufacturing a plurality of packaging bags each of which comprises
the main bag body and the framework member, which is
foldable/unfoldable together with said main bag body, to enable
said framework member and said main bag body to be shifted between
a generally flat collapsed state and an expanded state.
9. The method as claimed in claim 8, further comprising the step
of: (g) prior to said step (b), forming bending facilitation
portions on each of said pair of strips for the framework member so
as to extend in a perpendicular direction to a feeding direction of
said pair of strips for the framework member.
10. The method as claimed in claim 8, wherein: said steps (a) to
(f) are carried out on a manufacturing line.
11. The method as claimed in claim 9, wherein: said steps (a) to
(g) are carried out on a manufacturing line.
12. A method for manufacturing a packaging bag, comprising the
steps of: (a) continuously feeding a pair of strips of plastic film
material for a main bag body in a longitudinal direction so as to
be apart from each other; (b) continuously feeding a pair of strips
of thin sheet material for a framework member to place said pair of
strips for the framework member on respective inner surfaces of
said pair of strips for the main bag body in predetermined
positions thereof; (c) bonding said pair of strips for the
framework member to said pair of strips for the main bag body,
respectively; (d) bringing one of said pair of strips for the main
bag body close to another of said pair of strips for the main bag
body so as to cause said pair of strips for the framework member
face each other, thus preparing a set of composite strips; (e)
thermally bonding said set of composite strips in a perpendicular
direction to a longitudinal direction thereof by predetermined
intervals to form side heat-sealed portions; (f) thermally bonding
said set of composite strips on one of longitudinal edges of said
set of composite strips to form a bottom heat-sealed portion; and
(g) cutting each of said side heat-sealed portions in two in said
perpendicular direction to the longitudinal direction of said set
of composite strips, thereby continuously manufacturing a plurality
of packaging bags each of which comprises the main bag body and the
framework member, which is foldable/unfoldable together with said
main bag body, to enable said framework member and said main bag
body to be shifted between a generally flat collapsed state and an
expanded state.
13. The method as claimed in claim 12, further comprising the step
of: (h) prior to said step (b), forming bending facilitation
portions on each of said pair of strips for the framework member so
as to extend in a perpendicular direction to a feeding direction of
said pair of strips for the framework member.
14. The method as claimed in claim 12, wherein: said steps (a) to
(g) are carried out on a manufacturing line.
15. The method as claimed in claim 13, wherein: said steps (a) to
(h) are carried out on a manufacturing line.
16. A method for manufacturing a packaging bag, comprising the
steps of: (a) preparing a single piece of plastic film material for
a main bag body, said single piece having opposite half portions
between which a central line of said single piece exists; (b)
placing a pair of pieces of thin sheet material for a framework
member on a surface of said single piece for the main bag body in
predetermined positions of respective opposite half portions of the
single piece; (c) bonding said pair of pieces for the framework
member to said single piece for the main bag body in respective
opposite half portions thereof; (d) folding said single piece for
the main bag body with said pair of pieces for the framework member
in two along said central line of said single piece for the main
bag body to bring one of said opposite half portions of said single
piece for the main bag body close to another of said opposite half
portions to prepare a folded composite piece so that said pair of
pieces for the framework member are placed in an inside of said
folded composite piece; and (e) thermally bonding said folded
composite piece on opposite sides thereof to form heat-sealed
portions, thereby manufacturing the packaging bag, which comprises
the main bag body and the framework member, which is
foldable/unfoldable together with said main bag body, to enable
said framework member and said main bag body to be shifted between
a generally flat collapsed state and an expanded state.
17. The method as claimed in claim 16, further comprising the step
of: (f) prior to said step (b), forming bending facilitation
portions on each of said pair of pieces for the framework
member.
18. A method for manufacturing a packaging bag, comprising the
steps of: (a) placing a pair of pieces of plastic film material for
a main bag body so as to be apart from each other; (b) placing a
pair of pieces of thin sheet material for a framework member on
respective inner surfaces of said pair of pieces for the main bag
body in predetermined positions thereof; (c) bonding said pair of
pieces for the framework member to said pair of pieces for the main
bag body, respectively; (d) bringing one of said pair of pieces for
the main bag body close to another of said pair of pieces for the
main bag body so as to cause said pair of pieces for the framework
face each other, thus preparing a set of composite pieces; and (e)
thermally bonding said set of composite pieces at opposite side
edges and a bottom edge thereof to form side heat-sealed portions
and a bottom heat-sealed portion; thereby manufacturing the
packaging bags, which comprises the main bag body and the framework
member, which is foldable/unfoldable together with said main bag
body, to enable said framework member and said main bag body to be
shifted between a generally flat collapsed state and an expanded
state.
19. The method as claimed in claim 18, further comprising the step
of: (f) prior to said step (b), forming bending facilitation
portions on each of said pair of pieces for the framework
member.
20. A method for manufacturing a packaging bag, comprising the
steps of: (a) placing a pair of pieces of plastic film material for
a main bag body so as to be apart from each other; (b) placing a
framework member, which is formed into a sleeve, on respective
inner surfaces of said pair of pieces for the main bag body in
predetermined positions thereof; (c) bonding said framework member
to said pair of pieces for the main bag body, respectively; (d)
bringing one of said pair of pieces for the main bag body close to
another of said pair of pieces for the main bag body so as to
receive said framework member between said pair of pieces for the
main bag body, thus preparing a set of composite pieces; and (e)
thermally bonding said set of composite pieces at opposite side
edges and a bottom edge thereof to form side heat-sealed portions
and a bottom heat-sealed portion; thereby manufacturing the
packaging bags, which comprises the main bag body and the framework
member, which is foldable/unfoldable together with said main bag
body, to enable said framework member and said main bag body to be
shifted between a generally flat collapsed state and an expanded
state.
21. The method as claimed in claim 20, further comprising the step
of: (f) prior to said step (b), forming bending facilitation
portions on said framework member.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a packaging bag in which a
main bag body can be kept in a prescribed shape by means of a
framework member, and to a method for manufacturing such a
packaging bag.
[0003] 2. Description of the Related Art
[0004] There have conventionally been various kinds of packaging
bags made of plastic film material. There has recently been a
strong demand to cause such a packaging bag to receive products
such as teabags having predetermined shapes, without collapsing
their shapes. The applicant has pursued the development of a
packaging bag in response to the above-mentioned demand. Such a
packaging bag is composed of a main bag body made of plastic film
material and a sleeve disposed therein. The sleeve is
foldable/unfoldable and is inserted into the main bag body from an
opening thereof. Accordingly, the sleeve received in the main bag
body is foldable/unfoldable together with the main bag body, to
enable the sleeve and the main bag body to be shifted between a
generally flat collapsed state and an expanded state. Japanese
Laid-Open Patent Application No. 2001-322187 discloses such a
packaging bag and technical effects provided by it.
[0005] In the above-mentioned packaging bag, it is essential to
place the sleeve having a suitable size to the main bag body in
proper position in the main bag body, in order to provide an
excellent external appearance of the packaging bag in the expanded
state.
[0006] However, it is not easy to insert the sleeve having the
suitable size into the main bag body from the opening thereof. More
specifically, when the length of the opening of the main bag body,
which is kept in the collapsed state, is identical to the width of
the sleeve, which is also kept in the collapsed state, the total
thickness of the collapsed sleeve makes it difficult to insert the
sleeve into the main bag body, because of no existence of gusset.
In case where the main bag body is provided in its opening with a
linear fastener, the liner fastener makes the insertion operation
of the sleeve more difficult. Such difficulty in insertion
operation of the sleeve deteriorates a manufacturing efficiency of
the packaging bag, thus leading to an increased manufacturing cost
thereof.
[0007] It is conceivable to reduce the size of the sleeve in order
to facilitate the inserting operation of the sleeve into the main
bag body. In this case, the sleeve kept in the expanded state is
loosely fitted into the main body kept in the same expanded state
to cause a large gap between the sleeve and the main body, thus
deteriorating an external appearance of the packaging bag.
SUMMARY OF THE INVENTION
[0008] An object of the present invention, which was made to solve
the above-described problems, is to provide a packaging bag, which
permits to facilitate manufacture thereof, thus reducing the
manufacturing cost, and provide an excellent external appearance in
an expanded state, as well as a method for manufacturing such a
packaging bag.
[0009] In order to solve the above-mentioned object, a packaging
bag according to the first aspect of the present invention
comprises:
[0010] a main bag body made of plastic film material through a main
bag body formation process, said main bag body having an opening
and a plurality of heat sealed portions; and
[0011] a framework member disposed in said main bag body, said
framework member being joined to said main bag body prior to
completion of said main bag body formation process, said framework
member being foldable/unfoldable together with said main bag body,
to enable said framework member and said main bag body to be
shifted between a generally flat collapsed state and an expanded
state.
[0012] The above-mentioned packaging bag may further comprise a
linear fastener provided on said opening of said main bag body.
[0013] In the above-mentioned packaging bag, said main bag body may
have a rectangular shape in a generally flat collapsed state, said
main bag body being provided on opposite side edges thereof with a
pair of heat-sealed portions.
[0014] In the above-mentioned packaging bag, said framework member
may comprise a pair of opposite reinforcing sections, each of said
reinforcing sections having a rectangular shape having first pair
of opposite side edges and second pair of opposite side edges, said
first pair of opposite side edges being embedded in said pair of
heat-sealed portions.
[0015] In the above-mentioned packaging bag, said second pair of
opposite side edges may be bonded to said main bag body at other
regions than said pair of heat-sealed portions.
[0016] In the above-mentioned packaging bag, said framework member
may comprise a pair of opposite reinforcing sections, each of said
reinforcing sections having a rectangular shape having first pair
of opposite side edges and second pair of opposite side edges, said
pair of opposite side edges and said second pair of opposite side
edges being thermally bonded to said main bag body at other regions
than said pair of heat-sealed portions.
[0017] In order to solve the above-mentioned object, a method
according to the second aspect of the present invention for
manufacturing a packaging bag, comprises the steps of:
[0018] (a) continuously feeding a single strip of plastic film
material for a main bag body in a longitudinal direction, said
single strip having opposite half portions between which a
longitudinal central line of said single strip exists;
[0019] (b) continuously feeding a pair of strips of thin sheet
material for a framework member to place said pair of strips for
the framework member on a surface of said single strip for the main
bag body in predetermined positions of the respective opposite half
portions of the single strip;
[0020] (c) bonding said pair of strips for the framework member to
said single strip for the main bag body in respective opposite half
portions thereof;
[0021] (d) folding said single strip for the main bag body with
said pair of strips for the framework member in two along said
longitudinal central line of said single strip for the main bag
body to bring one of said opposite half portions of said single
strip for the main bag body close to another of said opposite half
portions to prepare a folded composite strip so that said pair of
strips for the framework member are placed in an inside of said
folded composite strip;
[0022] (e) thermally bonding said folded composite strip in a
perpendicular direction to a longitudinal direction thereof by
predetermined intervals to form heat-sealed portions; and
[0023] (f) cutting each of said heat-sealed portions in two in said
perpendicular direction to the longitudinal direction of said
folded composite strip,
[0024] thereby continuously manufacturing a plurality of packaging
bags each of which comprises the main bag body and the framework
member, which is foldable/unfoldable together with said main bag
body, to enable said framework member and said main bag body to be
shifted between a generally flat collapsed state and an expanded
state.
[0025] In the above-mentioned method, said steps (a) to (f) may be
carried out on a manufacturing line.
[0026] The above-mentioned method may further comprise the step
of:
[0027] (g) prior to said step (b), forming bending facilitation
portions on each of said pair of strips for the framework member so
as to extend in a perpendicular direction to a feeding direction of
said pair of strips for the framework member.
[0028] In the above-mentioned method, said steps (a) to (g) may be
carried out on a manufacturing line.
[0029] In order to solve the above-mentioned object, a method
according to the third aspect of the present invention for
manufacturing a packaging bag, comprises the steps of:
[0030] (a) continuously feeding a pair of strips of plastic film
material for a main bag body in a longitudinal direction so as to
be apart from each other;
[0031] (b) continuously feeding a pair of strips of thin sheet
material for a framework member to place said pair of strips for
the framework member on respective inner surfaces of said pair of
strips for the main bag body in predetermined positions
thereof;
[0032] (c) bonding said pair of strips for the framework member to
said pair of strips for the main bag body, respectively;
[0033] (d) bringing one of said pair of strips for the main bag
body close to another of said pair of strips for the main bag body
so as to cause said pair of strips for the framework member face
each other, thus preparing a set of composite strips;
[0034] (e) thermally bonding said set of composite strips in a
perpendicular direction to a longitudinal direction thereof by
predetermined intervals to form side heat-sealed portions;
[0035] (f) thermally bonding said set of composite strips on one of
longitudinal edges of said set of composite strips to form a bottom
heat-sealed portion; and
[0036] (g) cutting each of said side heat-sealed portions in two in
said perpendicular direction to the longitudinal direction of said
set of composite strips,
[0037] thereby continuously manufacturing a plurality of packaging
bags each of which comprises the main bag body and the framework
member, which is foldable/unfoldable together with said main bag
body, to enable said framework member and said main bag body to be
shifted between a generally flat collapsed state and an expanded
state.
[0038] In the above-mentioned method, said steps (a) to (g) may be
carried out on a manufacturing line.
[0039] The above-mentioned method may further comprise the step
of:
[0040] (h) prior to said step (b), forming bending facilitation
portions on each of said pair of strips for the framework member so
as to extend in a perpendicular direction to a feeding direction of
said pair of strips for the framework member.
[0041] In the above-mentioned method, said steps (a) to (h) may be
carried out on a manufacturing line.
[0042] In order to solve the above-mentioned object, a method
according to the fourth aspect of the present invention for
manufacturing a packaging bag, comprises the steps of:
[0043] (a) preparing a single piece of plastic film material for a
main bag body, said single piece having opposite half portions
between which a central line of said single piece exists;
[0044] (b) placing a pair of pieces of thin sheet material for a
framework member on a surface of said single piece for the main bag
body in predetermined positions of the respective opposite half
portions of the single piece;
[0045] (c) bonding said pair of pieces for the framework member to
said single piece for the main bag body in respective opposite half
portions thereof;
[0046] (d) folding said single piece for the main bag body with
said pair of pieces for the framework member in two along said
central line of said single piece for the main bag body to bring
one of said opposite half portions of said single piece for the
main bag body close to another of said opposite half portions to
prepare a folded composite piece so that said pair of pieces for
the framework member are placed in an inside of said folded
composite piece; and
[0047] (e) thermally bonding said folded composite piece on
opposite sides thereof to form heat-sealed portions,
[0048] thereby manufacturing the packaging bag, which comprises the
main bag body and the framework member, which is
foldable/unfoldable together with said main bag body, to enable
said framework member and said main bag body to be shifted between
a generally flat collapsed state and an expanded state.
[0049] The above-mentioned method may further comprise the step
of:
[0050] (f) prior to said step (b), forming bending facilitation
portions on each of said pair of pieces for the framework
member.
[0051] In order to solve the above-mentioned object, a method
according to the fifth aspect of the present invention for
manufacturing a packaging bag, comprises the steps of:
[0052] (a) placing a pair of pieces of plastic film material for a
main bag body so as to be apart from each other;
[0053] (b) placing a pair of pieces of thin sheet material for a
framework member on respective inner surfaces of said pair of
pieces for the main bag body in predetermined positions
thereof;
[0054] (c) bonding said pair of pieces for the framework member to
said pair of pieces for the main bag body, respectively;
[0055] (d) bringing one of said pair of pieces for the main bag
body close to another of said pair of pieces for the main bag body
so as to cause said pair of pieces for the framework face each
other, thus preparing a set of composite pieces; and
[0056] (e) thermally bonding said set of composite pieces at
opposite side edges and a bottom edge thereof to form side
heat-sealed portions and a bottom heat-sealed portion;
[0057] thereby manufacturing the packaging bags, which comprises
the main bag body and the framework member, which is
foldable/unfoldable together with said main bag body, to enable
said framework member and said main bag body to be shifted between
a generally flat collapsed state and an expanded state.
[0058] The above-mentioned method may further comprise the step
of:
[0059] (f) prior to said step (b), forming bending facilitation
portions on each of said pair of strips for the framework
member.
[0060] In order to solve the above-mentioned object, a method
according to the sixth aspect of the present invention for
manufacturing a packaging bag, comprises the steps of:
[0061] (a) placing a pair of pieces of plastic film material for a
main bag body so as to be apart from each other;
[0062] (b) placing a framework member, which is formed into a
sleeve, on respective inner surfaces of said pair of pieces for the
main bag body in predetermined positions thereof;
[0063] (c) bonding said framework member to said pair of pieces for
the main bag body, respectively;
[0064] (d) bringing one of said pair of pieces for the main bag
body close to another of said pair of pieces for the main bag body
so as to receive said framework member between said pair of pieces
for the main bag body, thus preparing a set of composite pieces;
and
[0065] (e) thermally bonding said set of composite pieces at
opposite side edges and a bottom edge thereof to form side
heat-sealed portions and a bottom heat-sealed portion;
[0066] thereby manufacturing the packaging bags, which comprises
the main bag body and the framework member, which is
foldable/unfoldable together with said main bag body, to enable
said framework member and said main bag body to be shifted between
a generally flat collapsed state and an expanded state.
[0067] The above-mentioned method may further comprise the step
of:
[0068] (f) prior to said step (b), forming bending facilitation
portions on said framework member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0069] FIG. 1 is a front view of a packaging bag according to an
embodiment of the present invention;
[0070] FIG. 2 is a perspective view illustrating the packaging bag
in which a framework member is kept in an expanded state and a main
bag body is deformed accordingly;
[0071] FIG. 3 is a partial perspective view illustrating the
packaging bag in which the lower portion of the main bag body,
projecting downward from the lower end of the framework member is
folded to form a bottom;
[0072] FIG. 4 is a perspective view illustrating the packaging bag
provided with the bottom as shown in FIG. 3;
[0073] FIG. 5 is a perspective view illustrating the packaging bag
in which the upper portion of the main bag body, projecting upward
from the upper edge of the framework member is folded into a flat
state, after the packaging bag is filled with contents;
[0074] FIG. 6 is a perspective view illustrating the packaging bag
in which the opposite edges of the upper portion of the main bag
body, projecting horizontally from the upper edge of the framework
member as shown in FIG. 5, are further folded so as to come into
contact with the opposite sides of the packaging bag, respectively,
thus providing a rectangular parallelepiped;
[0075] FIG. 7 is a perspective view illustrating a strip of plastic
film for forming the main bag body, on which a set of male members
and a set of female members for forming a linear fastener are
provided while unrolling the strip of plastic film;
[0076] FIG. 8 is a schematic perspective view illustrating a pair
of strips of plastic film material for forming the framework
member, which are subjected to a bending facilitation portion
forming step to form bending facilitation portions thereon and then
traveled so as to face each other;
[0077] FIG. 9 is a partial cross-sectional view illustrating a
roller having a projection, which is used to carry out the bending
facilitation portion forming step and a resultant bending
facilitation portion formed on the strip of plastic film by means
of the projection;
[0078] FIG. 10 is a schematic perspective view illustrating a step
for folding the single strip for the main bag body with the pair of
strips for the framework member in two along the longitudinal
central line of the single strip for the main bag body;
[0079] FIG. 11 is a schematic descriptive view illustrating a step
for thermally bonding a folded composite strip of the single strip
for the main bag body and the pair of strips for the framework
member in a perpendicular direction to a longitudinal direction
thereof by predetermined intervals to form heat-sealed
portions;
[0080] FIG. 12 is a schematic descriptive view illustrating a step
for cutting each of the heat-sealed portions in two in the
perpendicular direction to the longitudinal direction of the folded
composite strip;
[0081] FIG. 13 is a perspective view illustrating the packaging bag
manufactured by the method according to the other embodiment of the
present invention;
[0082] FIG. 14 is a perspective view illustrating the packaging bag
as shown in FIG. 13, which is turned upside down;
[0083] FIG. 15 is a schematic perspective view illustrating a step
for continuously feeding a pair of strips of plastic film material
for the main bag body, while continuously feeding a pair of strips
of thin sheet material for the framework member to place the pair
of strips for the framework member on the respective inner surfaces
of the pair of strips for the main bag body;
[0084] FIG. 16 is a schematic descriptive view illustrating a step
for thermally bonding a set of composite strips of the pair of
strips for the main bag body and the pair of strips for the
framework member in a perpendicular direction to a longitudinal
direction thereof by predetermined intervals to form side
heat-sealed portions, a step for thermally bonding the set of
composite strips on one of longitudinal edges of the set of
composite strips to form a bottom heat-sealed portion, and a step
for cutting each of the heat-sealed portions in two in the
perpendicular direction to the longitudinal direction of the set of
composite strips;
[0085] FIG. 17 is a plan view illustrating the packaging bag kept
in a flat collapsed state, which is manufactured through completion
of the steps as shown in FIG. 16;
[0086] FIG. 18 is a schematic sectional view illustrating the
modification of the method of the present invention, in which a set
of three packaging bags can be provided in a region of the set of
composite strips, which extends in the perpendicular direction to
the feeding direction of the set of composite strips;
[0087] FIG. 19 is a schematic descriptive view illustrating a
series of steps of the modification as shown in FIG. 18;
[0088] FIG. 20 is a schematic descriptive view illustrating the
method according to the other embodiment of the present invention,
which utilizes a single piece of plastic film for the main bag body
and a pair of pieces of thin sheet material for the framework
member in order to manufacture the single packaging bag;
[0089] FIG. 21 is a schematic descriptive view illustrating the
method according to the other embodiment of the present invention,
which utilizes a pair of pieces of plastic film for the main bag
body and a pair of pieces of thin sheet material for the framework
member in order to manufacture the single packaging bag; and
[0090] FIG. 22 is a schematic descriptive view illustrating the
method according to the other embodiment of the present invention,
which utilizes a pair of pieces of plastic film for the main bag
body and a sleeve serving as the framework member in order to
manufacture the single packaging bag.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0091] Embodiments of the present invention will be described below
with reference to the drawings.
[0092] FIG. 1 is a front view of a packaging bag 1 according to an
embodiment of the present invention. The packaging bag 1 is
composed of a main bag body 2 and a framework member 10, which is
joined to the main bag body 2 prior to completion of a formation
process thereof and is foldable/unfoldable together with the main
bag body 2, to enable the framework member 10 and the main bag body
2 to be shifted between a generally flat collapsed state and an
expanded state.
[0093] More specifically, the main bag body 2 is made of plastic
film material through a main bag body formation process in a
rectangular shape in a generally flat collapsed state. The main bag
body 2 is formed by folding a single rectangular piece of plastic
film material for the main bag body in two along the central line
to form a pair of opposite panel members 3, 3 and thermally bonding
the opposite sides of the thus folded piece to form side
heat-sealed portions 4, 4. The main bag body 2 has an opening at an
opposite side to the central line along which the above-mentioned
piece is folded in two. The main bag body 2 is provided at the
opening with a linear fastener 5. The linear fastener 5 is composed
of a male member 5a formed on the inner surface of one of the panel
members 3, 3 at the above-mentioned opening and a female member 5b
formed on the inner surface of the other of the panel members 3, 3
at the opening. The male member 5a can engage with or disengage
from the female member 5b so as to close or open the upper end of
the main bag body 2.
[0094] The framework member 10 is made of thin sheet material such
as plastic material or plastic/paper composite material. The
framework member 10 is composed of a pair of opposite reinforcing
sections, which are thermally bonded to the inner surfaces of the
panel members 3, 3. Each of the reinforcing sections has a
rectangular shape. The positional determination of the reinforcing
section relative to the panel member 3 is made so as to keep a
distance "L1" between the lower edge 13 of the reinforcing section
and the lower edge of the panel member 3 and a distance "L2"
between the upper edge 12 of the reinforcing section and the upper
edge of the panel member 3, as shown in FIG. 1. Each of the
reinforcing sections has the first pair of opposite side edges
(i.e., the right and left hand side edges in FIG. 1) and the second
pair of opposite side edges (i.e., the upper and lower side edges
in FIG. 1). The length of each of the upper and lower side edges of
the reinforcing section is substantially identical to the width of
the main bag body 2 so that the right and left hand side edges of
the reinforcing section are embedded in the side heat-sealed
portions 4, 4. Each of the upper and lower side edges of each of
the reinforcing sections is thermally bonded to the inner surface
of each of the panel members 3, 3 at the other regions than the
side heat-sealed portions 4, 4.
[0095] Each of the reinforcing sections of the framework member 10
is provided at positions shifted inward from the right and left
hand side edges of the main bag body 2 with a pair of bending
facilitation portions 11, 11 extending in parallel with the side
heat-sealed portions 4, 4. The bending facilitation portion 11
enables the reinforcing section to be easily bent along it, thus
ensuring a folding/unfolding operation of the framework member
10.
[0096] The male member 5a of the linear fastener 5 is composed of
three sections, i.e., a set of a central main section and opposite
side sections, which are placed in line so as to be apart from each
other, as shown in FIG. 7. Gaps between the central main section
and the opposite side sections are placed so as to correspond to
the above-mentioned bending facilitation portions. The female
member 5b of the linear fastener 5 is also composed of three
sections in the similar manner as the male member 5a. The gaps of
each of the male member 5a and the female member 5b enable the main
bag body 2 to be easily folded in accordance with the shift of the
framework member 10 between the collapsed state and the expanded
state.
[0097] The main bag body 2 and the framework member 10 are designed
so that the height of the framework member 10 is substantially
identical to the height of the packaging bag 1, which is shifted to
an expanded state and subjected to a bending finishing step to
provide a finished product in the form of a rectangular
parallelepiped. The framework member 10 is bent at right angles at
the bending facilitation portions 11, 11, thus forming the four
side corner edges of the rectangular parallelepiped.
[0098] Now, description will be given below of the plastic film
material for the main bag body 2 and the thin sheet material for
the framework member 10.
[0099] A plastic laminate film having a plurality of layers is used
to form the main bag body 2. There may be used, for example, a
laminate film having a layer structure of an oriented polypropylene
(OPP) layer having a thickness of 25 .mu.m and a polyethylene (PE)
layer having a thickness of 50 .mu.m, which are thermally bonded to
each other. In this case, the main bag body 2 is designed so that
the oriented polypropylene layer is placed on the inner side of the
main bag body 2. It is preferable to add an aluminum layer to the
laminate film in order to improve barrier property. In this case,
there may be used a laminate film having a layer structure of an
oriented polypropylene (OPP) layer having a thickness of 25 .mu.m,
an aluminum layer having a thickness of 5 .mu.m, and a polyethylene
(PE) layer having a thickness of 50 .mu.m, which are thermally
bonded to each other.
[0100] A plastic film having a predetermined strength that enables
the predetermined shape into which the main bag body 2 is shifted
together with the framework member 10 in an expanded state, to be
appropriately maintained is used to form the framework member 10. A
polyethylene (PE) film having a thickness of 100 .mu.m is for
example used for the framework member 10.
[0101] The packaging bag 1 having the above-described structure is
shifted from the generally flat collapsed state as shown in FIG. 1
to the expanded finished state as shown in FIG. 6 through the
intermediate states as shown in FIGS. 2 to 5.
[0102] First, the opposite sides of the packaging bag 1, which is
kept in the generally flat collapsed state, are pushed inwardly in
directions as shown by arrows in FIG. 2, with the result that the
pair of opposite reinforcing sections of the framework member 10
are folded at right angles along the bending facilitation portions
11, 11, thus shifting the framework member 10 together with the
main bag body 2 from the generally flat collapsed state to the
expanded state in the form of sleeve. Such a pushing operation
provides opposite front and rear panel portions 8a, 8b, and
opposite side panel portions 6, 6. The above-mentioned pushing
operation also provides an upper portion 3a, which upwardly
projects from the upper edge 12 of the framework member 10, and a
lower portion 3b, which downwardly projects from the lower edge 13
of the framework member 10. In such a pushing operation, the side
heat-sealed portions 4, 4 are bent rearward.
[0103] Then, the lower portion 3b downwardly projecting from the
lower edge 13 of the framework member 10 is folded along the lower
edge 13 of the framework member 10 into a flat state so as to
provide a pair of triangular portions 7a, 7a extending outwardly
and generally horizontally as shown in dotted lines in FIG. 2. The
triangular portions 7a, 7a are bent inwardly along the lower edge
of the framework member 10 and thermally bonded to the counterpart,
as shown in solid lines in FIG. 3, to form a bottom panel portion 7
of the packaging bag 1. Any other suitable bonding may be
applicable to the bonding of the triangular portions 7a, 7a, and
these portions 7a, 7a may be bonded to the counterpart by a
suitable adhesive agent. The folding process of the lower portion
3b of the packaging bag 1 to form the bottom panel portion 7 is
completed in this manner. At this stage, the packaging bag 1 is
provided on its lower side with the lower portion, which is folded
into a box with a flat bottom having a rectangular shape, on its
upper side with the upper portion 3a, which upwardly projects from
the upper edge of the framework member 10 and is kept in a
semi-folded state in which the width of the upper portion 3a of the
packaging bag 1 in its plan view gradually increases with its
height, as shown in FIG. 4.
[0104] Then, the upper portion 3a, which upwardly projects from the
upper edge of the framework member 10, is also folded along the
upper edge 12 of the framework member 10 into a flat state so as to
provide a pair of trapezoidal portions 9a, 9a projecting outwardly
and generally horizontally as shown in FIG. 5. In such a folding
operation, the opening of the packaging bag 1, which is closed by
the linear fastener 5, is brought close to the rear panel portion
8b.
[0105] The above-mentioned pair of trapezoidal portions 9a, 9a is
bent downwardly along the upper edge of the framework member 10 and
thermally bonded to the opposite side panel portions 6, 6,
respectively, thus providing a finished product, as shown in FIG.
6. The folding process of the upper portion 3a of the packaging bag
1 to form the top panel portion 9 is completed in this manner. Any
other suitable bonding may be applicable to the bonding of the
trapezoidal portions 9a, 9a, and these portions 9a, 9a may be
bonded to the opposite side panel portions 6, 6 by a suitable
adhesive agent. Of course, the above-mentioned folding process is
carried out after the packaging bag 1 is filled with contents.
[0106] The packaging bag 1, which is shifted from the generally
flat collapsed state to the expanded state, this providing an
external appearance of the box, has the opposite front and rear
panel portions 8a, 8b, which face in parallel with each other, the
side panel portions 6, 6, which also face in parallel with each
other on the opposite sides of the front and rear panel portions
8a, 8b, the bottom panel portion 7 that has been formed by folding
the bottom portion 3b of the packaging bag 1 in the flat state, and
the top panel portion 9 that has been formed by folding the upper
portion 3a of the packaging bag 1 in the flat state. The height of
each of the front and rear panel portions 8a, 8b and the side panel
portions 6, 6 is substantially identical to the height of the
framework member 10, which is provided in the packaging bag 1. More
specifically, the lower edge 13 of the framework member 10 forms
the corners 1a, 1a, 1a, 1a between the front, rear and side panel
portions 8a, 8b, 6, 6 and the bottom panel portion 7, on the one
hand, and the upper edge 12 of the framework member 10 forms the
corners 1c, 1c, 1c, 1c between the front, rear and side panel
portions 8a, 8b, 6, 6 and the top panel portion 9, on the one hand.
In addition, the bent portions of the framework member 10, which
are provided by bending the framework member 10 along the bending
facilitation portions 11, form the corners 1b, 1b, 1b, 1b between
the front and rear panel portions 8a, 8b and the side panel
portions 6, 6.
[0107] The packaging bag 1 can be shifted from the generally flat
collapsed state to the expanded state and then subjected to the
folding processes to convert into a box shape, which corresponds to
the framework member 10 kept in the expanded state. Accordingly, it
is possible to receive products such as teabags having the
predetermined shape in the packaging bag 1 kept in the expanded
state, without collapsing their shapes. The linear fastener 5,
which is provided at the opening of the packaging bag 1, makes the
packaging bag 1 reclosable even after opening the packaging bag
1.
[0108] In the above-described packaging bag 1 of the embodiment of
the present invention, each of the upper and lower side edges of
each of the reinforcing sections of the framework member 10 is
thermally bonded to the inner surface of each of the panel members,
3, 3 at the other regions than the side heat-sealed portions 4, 4.
However, the upper and lower side edges of each of the reinforcing
sections of the framework member 10 is may not necessarily bonded
to the inner surface of each of the panel members 3, 3 at the other
regions than the side heat-sealed portions 4, 4, in case where a
proper contact state of the reinforcing sections with the inner
surface of the panel members 3, 3 can be ensured, or an existence
of a possible gap between the reinforcing sections and the panel
members 3, 3 cause no problem in a filling operation of the
packaging bag 1 with contents.
[0109] The above-described packaging bag 1 of the embodiment of the
present invention is provided with the linear fastener 5. Such a
linear fastener may be omitted, as an occasion demands.
[0110] Now, a method of the first embodiment of the present
invention for manufacturing the above-described packaging bag 1
will be described below with reference to FIGS. 7 to 12.
[0111] In the first embodiment of the method of the present
invention, the single strip 20 for the main bag body 2 and the pair
of strips 30, 30 for the framework member 10 are used to
manufacture the plurality of packaging bags 1.
[0112] More specifically, the method for manufacturing the
packaging bag 1 includes the essential steps of:
[0113] (1-a) continuously feeding a single strip 20 of plastic film
material for the main bag body 2 in a longitudinal direction, the
single strip 20 having opposite half portions between which a
longitudinal central line of the single strip 20 exists;
[0114] (1-b) continuously feeding a pair of strips 30, 30 of thin
sheet material for the framework member 10 to place the pair of
strips 30, 30 for the framework member 10 on a surface of the
single strip 20 for the main bag body 2 in predetermined positions
of the respective opposite half portions of the single strip
20;
[0115] (1-c) bonding the pair of strips 30, 30 for the framework
member 10 to the single strip 20 for the main bag body 2 in
respective opposite half portions thereof;
[0116] (1-d) folding the single strip 30 for the main bag body 3
with the pair of strips 30, 30 for the framework member 10 in two
along the longitudinal central line of the single strip 20 for the
main bag body 2 to bring one of the opposite half portions of the
single strip 20 for the main bag body 2 close to another of the
opposite half portions to prepare a folded composite strip so that
the pair of strips 30, 30 for the framework member 10 are placed in
an inside of the folded composite strip;
[0117] (1-e) thermally bonding the folded composite strip in a
perpendicular direction to a longitudinal direction thereof by
predetermined intervals to form heat-sealed portions 4 . . . 4;
and
[0118] (1-f) cutting each of the heat-sealed portions 4 . . . 4 in
two in the perpendicular direction to the longitudinal direction of
the folded composite strip,
[0119] and further includes optional steps of:
[0120] (1-g) prior to the step (1-b), forming bending facilitation
portions 11 . . . 11 on each of the pair of strips 30, 30 for the
framework member so as to extend in the perpendicular direction to
the feeding direction of the pair of strips 30, 30 for the
framework member 10; and
[0121] (1-h) during the step (1-a), providing a set of male members
5a and a set of female members 5b in each of the respective
consecutive regions for the packaging bags on the single strip for
the main bag body 2.
[0122] First, the step (1-a) is carried out to unroll the single
strip 20 of plastic film material for the main bag body 2 to
continuously feed it in the longitudinal direction. The single
strip 20 has the opposite half portions between which the
longitudinal central line of the single strip 20 exists. The layer
structure of the single strip 20 of plastic film material for the
main bag body 2 is the same as that of the main bag body 2 of the
packaging bag 1 of the present invention as described above and
description of the layer structure is therefore omitted.
[0123] The step (1-h) is carried out to continuously provide a
plurality of sets of male members 5a and a plurality of
corresponding sets of female members 5b on the longitudinal
opposite side edge portions of the upper surface of the single
strip 20 for the main bag body 2, so as to form these members 5a,
5b integrally with the single strip 20 through an insert injection.
A gap 15 exists between the adjacent sets of male members 5a and
another gap 15 also exists between the adjacent sets of female
members 5b corresponding to the above-mentioned gap 15. The
corresponding gaps 15, 15 are placed on the same two-dot chain
straight line as shown in FIG. 7, which is perpendicular to the
feeding direction of the single strip 20 for the main bag body 2.
The single strip 20 will be cut along the above-mentioned straight
line into pieces for the respective main bodies 2. Each set of male
members 5a is composed of a central main section and opposite side
sections, which are placed in line so as to be apart from each
other, as shown in FIG. 7. Gaps 16 . . . 16 between the central
main section and the opposite side sections are placed so as to
correspond to the bending facilitation portions 11 . . . 11 as
described later. Each set of female members 5b is also composed of
three sections in the similar manner as the set of male members 5a.
The set of male members 5a can be engaged with or removed from the
set of female members 5b.
[0124] The step (1-b) is carried out to unroll the pair of strips
30, 30 for the framework member 10 from a pair of rolls, which is
disposed on the left-hand side of FIG. 8, but not shown therein, to
continuously feed them in their longitudinal directions to place
them on the surface of the single strip 20 for the main bag body 2
in the predetermined positions of the respective half portions.
[0125] More specifically, the strips 30, 30 for the framework
member 10 are unrolled at the different positions from each other
and fed together in a prescribed zone, thus traveling in parallel
with each other in their longitudinal directions. Before the pair
of strips 30, 30 for the framework member 10 reaches the
above-mentioned prescribed zone, the step (1-g) is carried out to
form the bending facilitation portions 11 . . . 11 on the opposite
inner surfaces of the pair of strips 30, 30 for the framework
member 10 so as to extend in the perpendicular direction to the
feeding direction of the pair of strips 30, 30 for the framework
member 10. The bending facilitation portions 11 . . . 11 are
classified into a plurality of pairs of bending facilitation
portions 11, 11, which are placed so as to be apart from each other
by a predetermined distance in the feeding direction of the pair of
strips 30, 30 for the framework member 10. The adjacent pairs of
bending facilitation portions 11, 11, 11, 11 are placed so as to be
apart from each other by a smaller distance than the
above-mentioned predetermined distance. The pair of strips 30, 30
is cut, as mentioned later, along the respective central lines
between the adjacent pairs of bending facilitation portions into
pieces of a plurality of sets of reinforcing sections. Each of the
reinforcing sections is composed of (i) a central portion defined
by the pair of bending facilitation portions 11, 11 and (ii)
opposite side portions extending from the respective bending
facilitation portions 11, 11.
[0126] The pair of reinforcing sections is used for the single
packaging bag 1 so that the central portions of the pair of
reinforcing sections define the opposite front and rear panel
portions 8a, 8b of the packaging bag 1 as shown in FIG. 6,
respectively, and the combinations of the corresponding side
portions of the pair of reinforcing sections define the side panel
portions 6, 6 of the packaging bag 1, respectively.
[0127] FIG. 9 shows a typical device for carrying out the
above-mentioned step (1-g) to form the bending facilitation
portions 11 . . . 11 on each of the pair of strips 30, 30 for the
framework member 10. The device is composed of a roller 40 provided
with a projection 41 formed on the periphery thereof. The
projection 41 extends over the roller 40 in its longitudinal
direction. The central axis of the roller 40 is perpendicular to
the feeding direction of the strip 30 for the framework member 10.
A base plate (not shown) is disposed so as to face the roller 40
and extend along it in its longitudinal direction. The distance
between the base plate and the outer peripheral surface of the
roller 40 is substantially identical or smaller than the thickness
of the strip 30 for the framework member 10. The above-mentioned
base plate may be substituted by another roller having no
projection.
[0128] The strip 30 passes through between the base plate and the
roller 40 to dig the projection 41 into the strip 30, thus forming
a groove serving as the bending facilitation portion 11, which
extends in the perpendicular direction to the feeding direction of
the strip 30. A set of rollers, i.e., the above-mentioned roller 40
and the other roller having the same structure, which are disposed
so as to be away from each other by a predetermined distance, are
utilized to form the above-described plurality of pairs of bending
facilitation portions 11 . . . 11 on one of the pair of strips 30,
30 for the framework member 10. The other set of rollers having the
same structure are utilized to form the plurality of pairs of
bending facilitation portions 11 . . . 11 on the other of the pair
of strips 30, 30 for the framework member 10. According to these
sets of rollers, it is possible to continuously form the plurality
of pairs of bending facilitation portions 11 . . . 11 on the pair
of strips 30, 30 for the framework member 10, without halting the
feeding of the strips 30, 30.
[0129] The device for carrying out the step (1-g) is not limited
only to the above-mentioned roller type. For example, an elongated
pushing block having a longitudinal edge may be used to form the
bending facilitation portions 11 . . . 11 on the strip 30 for the
framework member 10. In this case, the feeding of the strip 30 is
intermittently halted and the pushing block is pressed against the
strip 30 to form the bending facilitation portion 11 during the
halting period of time.
[0130] The pair of strips 30, 30 for the framework member 10, on
which the bending facilitation portions 11 . . . 11 have been
formed by carrying out the step (1-g), is continuously fed, during
the step (1-b), to place them on the inner surface of the single
strip 20 for the main bag body 2 in the respective opposite half
portions thereof.
[0131] The step (1-c) is carried out to thermally bond the pair of
strips 30, 30 at the respective opposite longitudinal edges thereof
to the single strip 20 for the main bag body 2 in respective
opposite half portions thereof.
[0132] Then, the step (1-d) is carried out to fold the single strip
30 for the main bag body 3 with the pair of strips 30, 30 for the
framework member 10 in two along the longitudinal central line of
the single strip 20 for the main bag body 2 to bring one of the
opposite half portions of the single strip 20 for the main bag body
2. close to another of the opposite half portions to prepare a
folded composite strip so that the pair of strips 30, 30 for the
framework member 10 are placed in an inside of the folded composite
strip, as shown in FIG. 10. In the step (1-d), the set of male
members 5a is engaged with the set of the female members 5b. Of
course, the step (1-d) may be carried out, while conducting the
steps (1-a), (1-b) and (1-c).
[0133] As is clear from FIG. 10, the positional determination of
each of the strips 30, 30 relative to the folded composite strip is
made so as to keep a distance "L1" between the lower edge 13 of the
folded composite strip and the lower edge of each of the strips 30,
30 and a distance "L2" between the upper edge 12 of the each of the
strips 30. 30 and the upper edge of the folded composite strip. The
lower portion of the folded composite strip, which corresponds to
the distance "L1", is used to form the bottom panel portions 7 of
the packaging bags 1, as shown in FIG. 3. The upper portion of the
folded composite strip, which corresponds to the distance "L2", is
used to form the top panel portions 9 of the packaging bags 1, as
shown in FIG. 6.
[0134] The step (1-e) is carried out to thermally bond the folded
composite strip in a perpendicular direction to the longitudinal
direction thereof by predetermined intervals to form heat-sealed
portions 4 . . . 4, as shown in FIG. 11. Such a thermal bonding
process is conducted with the use of a heat-sealing plate, which is
brought into contact with the outer surface of the folded composite
strip. The portions of the folded composite strip, to which the
thermal bonding process is to be applied, correspond to the
respective central lines between the adjacent pairs of bending
facilitation portions 11, 11, 11, 11 as described above.
[0135] Then, the step (1-f) is carried out to cut each of the
heat-sealed portions 4 . . . 4 in two in the perpendicular
direction to the longitudinal direction of the folded composite
strip, thereby continuously manufacturing the plurality of
packaging bags 1. In each of the packaging bags 1, the opposite
side edges of the reinforcing section, which are in parallel with
the bending facilitation portions 11, 11 are embedded in the heat
sealed portions 4, 4.
[0136] In the above-described method of the present invention, the
steps (1-a) to (1-h) are carried out on the manufacturing line. The
steps (1-a) to (1-h) may however be carried out independently each
other on the different manufacturing lines.
[0137] In the above-described method of the present invention, each
of the bending facilitation portions 11 . . . 11 provided by the
step (1-g) is formed into a groove. The bending facilitation
portion 11 may have any other structure that enables the
reinforcing section, which is obtained by cutting the strip 30, to
be easily bent along the bending facilitation portion 11. The
bending facilitation portion 11 may for example be provided in the
different form for example of perforations.
[0138] In the above-described method of the present invention, the
insert injection is applied to carry out the step (1-h). The male
members 5a and the female members 5b, which have been previously
formed through extrusion, may however be bonded to the single strip
20 for the main bag body 2.
[0139] The above-described method of the present invention includes
the step (1-h) to provide the sets of male members 5a and the sets
of female members 5b on the single strip 20 for the main bag body
2. The step (1-h) may however be omitted, as an occasion
demands.
[0140] Now, the method of the second embodiment of the present
invention for manufacturing the above-described packaging bag 1
will be described below with reference to FIGS. 13 to 17.
[0141] FIGS. 13 and 14 illustrate the packaging bag 50 manufactured
by the method of the second embodiment of the present invention.
The packaging bag 50 is different from the packaging bag 1 as shown
in FIGS. 1 to 6 in that the former has a heat-sealed portion on the
bottom panel portion. The packaging bag 50 is composed of a main
bag body 60 formed of plastic film material and a framework member
70, which is joined to the main bag body 60 prior to completion of
the formation process thereof. A framework member 70 is folded
along bending facilitation portions 73 . . . 73 formed thereon into
a rectangular parallelepiped, with the result that the main bag
body 60 is also folded into the similar shape. After the packaging
bag 50 is filed with contents, the upper portion of the main bag
body 60 is folded along the upper edge 71 of the framework member
70 into a flat state to form an overlapped portion 61a. The
overlapped portion 61a is then bent toward the rear panel portion
52 to provide a pair of trapezoidal portions 62a, 62a projecting
outwardly. The pair of trapezoidal portions 62a, 62a is bent
downwardly along the upper edge of the framework member 70 and
thermally bonded to the opposite side panel portions 54, 54,
respectively, thus providing a finished product, as shown in FIG.
13. The folding process of the upper portion of the packaging bag
50 to form the top panel portion 62 is completed in this manner.
Any other suitable bonding may be applicable to the bonding of the
trapezoidal portions 62a, 62a, and these portions 62a, 62a may be
bonded to the opposite side panel portions 54, 54 by a suitable
adhesive agent. Of course, the above-mentioned folding process is
carried out after the packaging bag 50 is filled with contents.
[0142] FIG. 14 is a perspective view of the packaging bag 50, which
is folded and then subjected to the additional folding process to
provide the finished product, illustrating the bottom of the
packaging bag 50. When the packaging bag 50 is shifted from a
generally flat collapsed state to the expanded state, the lower
portion of the packaging bag 50 downwardly projects from the lower
edge 72 of the framework member 70. The above-mentioned lower
portion, which has a bottom heat-sealed portion 57 formed on the
lowermost edge thereof so as to extend in the width direction of
the packaging bag 50, is folded along the lower edge 72 of the
framework member 70 into a flat state so as to provide a pair of
triangular portions 63a, 63a extending outwardly. The triangular
portions 63a, 63a, which include the opposite side portions of the
above-mentioned bottom heat-sealed portion 57, respectively, are
bent inwardly along the lower edge 72 of the framework member 70
and thermally bonded to the counterpart, as shown in solid lines in
FIG. 14, to form a bottom panel portion 63 of the packaging bag 50.
Any other suitable bonding may be applicable to the bonding of the
triangular portions 7a, 7a, and these portions 7a, 7a may be bonded
to the counterpart by a suitable adhesive agent. The folding
process of the lower portion of the packaging bag 50 to form the
bottom panel portion 63 is completed in this manner.
[0143] Now, a method of the second embodiment of the present
invention for manufacturing the above-described packaging bag 50
will be described below with reference to FIGS. 15 to 17.
[0144] In the second embodiment of the method of the present
invention, the pair of strips 80, 80 for the main bag body 60 and
the pair of strips 30, 30 for the framework member 10 are used to
manufacture the plurality of packaging bags 50.
[0145] More specifically, the method for manufacturing the
packaging bag 50 includes the essential steps of:
[0146] (2-a) continuously feeding a pair of strips 80, 80 of
plastic film material for the main bag body 60 in a longitudinal
direction so as to be apart from each other;
[0147] (2-b) continuously feeding a pair of strips 90, 90 of thin
sheet material for the framework member 70 to place the pair of
strips 90, 90 for the framework member 70 on respective inner
surfaces of the pair of strips 80, 80 for the main bag body 60 in
predetermined positions thereof;
[0148] (2-c) bonding the pair of strips 90, 90 for the framework
member 70 to the pair of strips 80, 80 for the main bag body 60,
respectively;
[0149] (2-d) bringing one of the pair of strips 80, 80 for the main
bag body 60 close to another of the pair of strips 80, 80 for the
main bag body 60 so as to cause the pair of strips 80, 80 for the
framework member face 70 each other, thus preparing a set of
composite strips;
[0150] (2-e) thermally bonding the set of composite strips in a
perpendicular direction to a longitudinal direction thereof by
predetermined intervals to form side heat-sealed portions 56 . . .
56;
[0151] (2-f) thermally bonding the set of composite strips on the
lower longitudinal edges of the set of composite strips to form a
bottom heat-sealed portion 57; and
[0152] (2-g) cutting each of the side heat-sealed portions 56 . . .
56 in two in the perpendicular direction to the longitudinal
direction of the set of composite strips,
[0153] and further includes optional steps of:
[0154] (2-i) prior to said step (2-b), forming bending facilitation
portions 73 . . . 73 on each of the pair of strips 90, 90 for the
framework member 70 so as to extend in a perpendicular direction to
a feeding direction of the pair of strips 90, 90 for the framework
member 70; and
[0155] (2-j) during the step (2-a), providing a set of male members
(not shown) and a set of female members (not shown) in each of the
respective consecutive regions for the packaging bags on the pair
of strips 80, 80 for the main bag body 60.
[0156] First, the step (2-a) is carried out to unroll the pair of
strips 80, 80 for the main bag body 60 from the rolled strips 81,
8a to continuously feed them in the longitudinal direction so as to
be apart from each other. The strips 80, 80 pass through between a
pair of pressing rollers 101, 101 so as to come into contact with
each other, as shown in FIG. 15. The layer structure of each of the
strips 80, 80 for the main bag body 60 is the same as that of the
main bag body 2 of the packaging bag 1 of the present invention as
described above and description of the layer structure is therefore
omitted.
[0157] The step (2-j) is carried out to continuously provide a set
of male members (not shown) and a set of female members (not shown)
in each of the respective consecutive regions for the packaging
bags on the pair of strips 80, 80 for the main bag body 60. The
step (2-j) is carried out on the upstream side of the
above-mentioned pressing rollers 101, 101 relative to the feeding
direction of the strips 80, 80 for the main bag body 60. The step
(2-j) is identical to the step (1-h) described above of the first
embodiment of the method of the present invention and the detailed
description of the step (2-j) is therefore omitted.
[0158] The step (2-b) is carried out to unroll the pair of strips
90, 90 for the framework member 70 from the rolled strips 91, 91 to
place them between the pair of strips 80, 80 for the main bag body
60 so that the pair of strips 90, 90 for the framework member 70 is
located on respective inner surfaces of the pair of strips 80, 80
for the main bag body 60 in predetermined positions thereof. As a
result, the pair of strips 90, 90 for the framework member 70
passes through between the above-mentioned pressing rollers 101,
101 together with the pair of strips 80, 80 for the main bag body
60 to carry out the step (2-d) to bring one of the pair of strips
80, 80 for the main bag body 60 close to another of the pair of
strips 80, 80 for the main bag body 60 so as to cause the pair of
strips 80, 80 for the framework member face 70 each other, thus
preparing a set of composite strips. The pair of strips 90, 90 for
the framework member 70 is guided by means of a pair of guide
rollers 100, 100, as shown in FIG. 15. The layer structure of each
of the strips 90, 90 for the framework member 70 is the same as
that of the framework member 10 of the packaging bag 1 of the
present invention as described above and description of the layer
structure is therefore omitted.
[0159] As is clear from FIG. 16, the positional determination of
each of the strips 90, 90 for the main bag body 60 is made so as to
keep a distance "L4" between the lower edge of the strips 80, 80
for the main bag body 60 and the lower edge of each of the strips
90, 90 and a distance "L3" between the upper edge of the each of
the strips 90. 90 and the upper edge of the strips 80, 80 for the
main bag body 60. The lower portion of the strips 80, 80 for the
main bag body 60, which corresponds to the distance "L4", is used
to form the bottom panel portions 55 of the packaging bags 50, as
shown in FIG. 14. The upper portion of the strips 80, 80 for the
main bag body 60, which corresponds to the distance "L3", is used
to form the top panel portions 53 of the packaging bags 50, as
shown in FIG. 13.
[0160] Before the pair of strips 90, 90 for the framework member 70
reaches the above-mentioned guide rollers 100, 100, the step (2-i)
is carried out to form the bending facilitation portions 73 . . .
73 on the opposite inner surfaces of the pair of strips 90, 90 for
the framework member 70 so as to extend in the perpendicular
direction to the feeding direction of the pair of strips 90, 90 for
the framework member 70. The step (2-i) is identical to the step
(1-g) described above of the first embodiment of the method of the
present invention and the detailed description of the step (2-i) is
therefore omitted.
[0161] The step (2-c) is carried out to thermally bond the pair of
strips 90, 90 for the framework member 70 on the opposite
longitudinal edge portions thereof to the pair of strips 80, 80 for
the main bag body 60, respectively. The step (2-c) is conducted on
the downstream side of the pressing rollers 101, 101 relative to
the feeding direction of the strips 80, 80 for the main bag body
60.
[0162] In addition, the step (2-e) is carried out to thermally bond
the combination of the pair of strips 80, 80 for the main bag body
60 with the pair of strips 90, 90 for the framework member 70,
i.e., the set of composite strips in a perpendicular direction to
the longitudinal direction thereof by predetermined intervals to
form side heat-sealed portions 56 . . . 56.
[0163] The step (2-f) is also carried out to thermally bond the set
of composite strips on the lower longitudinal edges of the set of
composite strips to form a bottom heat-sealed portion 57.
[0164] Then, the step (2-g) is carried out to cut each of the side
heat-sealed portions 56 . . . 56 in two in the perpendicular
direction to the longitudinal direction of the set of composite
strips, thereby continuously manufacturing the plurality of
packaging bags 50. In each of the packaging bags 50, the opposite
side edges of the reinforcing section of the framework member 70,
which are in parallel with the bending facilitation portions 73, 73
are embedded in the side heat sealed portions 56, 56, as shown in
FIG. 17.
[0165] In the above-described method of the present invention, the
steps (2-a) to (2-j) are carried out on the manufacturing line. The
steps (2-a) to (2-j) may however be carried out independently each
other on the different manufacturing lines.
[0166] In the above-described second embodiment of the method of
the present invention, the step (2-i) may be modified in the same
manner as the step (1-g) of the method of the first embodiment of
the present invention.
[0167] In the above-described second embodiment of the method of
the present invention, the step (2-j) may be modified in the same
manner as the step (1-h) of the method of the first embodiment of
the present invention.
[0168] The above-described second embodiment of the method of the
present invention includes the step (2-j) to provide the sets of
male members 5a and the sets of female members 5b on the pair of
strips 80, 80 for the main bag body 60. The step (2-j) may however
be omitted, as an occasion demands.
[0169] In the above-described second embodiment of the method of
the present invention, the width of the pair of strips 80, 80 for
the main bag body 60 is substantially identical to the height of
the packaging bag 50. Accordingly, each of the consecutive steps
(2-g), i.e., the single cutting operation provides the single
packaging bag 50. However, there may be adopted a modification in
which the width of each of the pair of strips 80, 80 for the main
bag body 60 is increased so that a plurality of main bag bodies 60
can be allocated in a region of the strip 80, which extends over
the entire width thereof, on the one hand, and a plurality of pairs
of strips 90, 90 for the framework member 70 is fed, on the other
hand.
[0170] Now, description will be given of an example of such
modification in which three main bag bodies are allotted in a
region of the strip 80, which extends over the entire width
thereof, with reference to FIGS. 18 and 19.
[0171] FIG. 18 is a schematic sectional view illustrating the
modification of the method of the present invention, in which a set
of three packaging bags can be provided in a region of the set of
composite strips, which extends in the perpendicular direction to
the feeding direction of the set of composite strips. The
horizontal direction in FIG. 18 corresponds to the width direction,
i.e., the perpendicular direction to the feeding direction of the
pair of strips 110, 110 for the main bag body.
[0172] Each of the pair of strips 110, 110 for the main bag body
has a width three times as much as the width of the packaging bag
50 to be manufactured. These strips 110, 110 are fed in their
longitudinal directions so as to be apart from each other in the
similar manner to the step (2-a) of the above-described second
embodiment of the method of the present invention.
[0173] Three pairs of strips 120, 120 for the framework member are
also fed in their longitudinal directions so as to be placed
between the above-mentioned pair of strips 110, 110 for the main
bag body in the similar manner to the step (2-b) of the
above-described second embodiment of the method of the present
invention. The three pairs of strips 120, 120 are spaced apart from
each other in the width direction of the strips 110, 110 for the
main bag body by a predetermined distance.
[0174] The opposite longitudinal edge portions 121, 122 of the
respective strips 120 are thermally bonded to the corresponding
strip 110 for the main bag body, and then one of the pair of strips
110, 110 for the main bag body is brought close to another thereof
so as to cause one of each pair of strips 120, 120 for the
framework member face another thereof to prepare a set of composite
strips in the similar manner to the steps (2-c) and (2-d) of the
above-described second embodiment of the method of the present
invention, as shown in the first region between the two-dot chain
straight lines "A1" and "A2" in FIG. 19.
[0175] Then, the set of composite strips are thermally bonded in
the longitudinal direction at three positions, i.e., the lowermost
position of the set of composite strips as shown in FIG. 19 and the
additional two positions, which divide the set of composite strips
in the width direction (i.e., the vertical direction in FIG. 19)
into three equal parts, to form three bottom heat-sealed portions
111, 111, 111 in the similar manner to the step (2-f) of the
above-described second embodiment of the method of the present
invention, as shown in the second region between the two-dot chain
straight lines "A2" and "A3" in FIG. 19.
[0176] In addition, the set of composite strips are thermally
bonded in a perpendicular direction to the longitudinal direction
thereof by predetermined intervals to form side heat-sealed
portions 112 . . . 112 in the similar manner to the step (2-e) of
the above-described second embodiment of the method of the present
invention, as shown in the third region between the two-dot chain
straight lines "A3" and "A4" in FIG. 19. Each of the thus formed
side heat-sealed portions 112 . . . 112 extends over the set of
composite strips in the width direction thereof. Areas defined by
the bottom heat-sealed portions 111, 111, 111 and the side
heat-sealed portions 112 . . . 112 are to form the respective
packaging bags.
[0177] Then, the set of composite strips thus heat-sealed are cut
in the longitudinal direction at two positions into three
semi-finished strips for the packaging bags, as shown in the fourth
region between the two-dot chain straight lines "A4" and "A5" in
FIG. 19. These two positions are located directly below the
above-mentioned additional two positions for the thermal bonding,
which divide the set of composite strips in the width direction
into three equal parts, as shown in FIG. 19. As a result, the
resultant three semi-finished strips for the packaging bags have
substantially the same width. Each of the thus prepared
semi-finished strips for the packaging bags is formed into a chain
of packaging bags. The above-described second embodiment of the
method of the present invention does not include such a cutting
step.
[0178] Then, each of the semi-finished strips for the packaging
bags is subjected to a further cutting step to cut each of the side
heat-sealed portions 112 . . . 112 in two in the perpendicular
direction to the longitudinal direction of the semi-finished strip,
thereby manufacturing a plurality of independent packaging
bags.
[0179] The above-described modification of the method of the
present invention makes it possible to improve remarkably the
manufacturing efficiency.
[0180] The above-described embodiments of the method of the present
invention and the modification thereof provide the continuous
manufacture of the plurality of packaging bags. The method of the
present invention may be worked in the form of batch manufacturing
system in a manner as described below.
[0181] Now, the method of the third embodiment of the present
invention for manufacturing the above-described packaging bag will
be described below with reference to FIG. 20.
[0182] In the third embodiment of the method of the present
invention, the single piece for the main bag body and the pair of
pieces 140, 140 for the framework member are used to manufacture
the single packaging bags.
[0183] More specifically, the method for manufacturing the
packaging bag includes the essential steps of:
[0184] (3-a) preparing a single piece of plastic film material for
a main bag body, the single piece having opposite half portions
131, 131 between which a central line 130b of the single piece
exists;
[0185] (3-b) placing a pair of pieces 140, 140 of thin sheet
material for a framework member on a surface of the single piece
for the main bag body in predetermined positions of the respective
opposite half portions 131, 131 of the single piece;
[0186] (3-c) bonding the pair of pieces 140, 140 for the framework
member to the single piece for the main bag body in respective
opposite half portions 131, 131 thereof;
[0187] (3-d) folding the single piece for the main bag body with
the pair of pieces for the framework member in two along the
central line 130b of the single piece for the main bag body to
bring one of the opposite half portions 131, 131 of the single
piece for the main bag body close to another of the opposite half
portions 131, 131 to prepare a folded composite piece so that the
pair of pieces 140, 140 for the framework member are placed in an
inside of the folded composite piece; and
[0188] (3-e) thermally bonding the folded composite piece on
opposite sides thereof to form heat-sealed portions,
[0189] and further includes optional steps of:
[0190] (3-f) prior to the step (b), forming bending facilitation
portions on each of the pair of pieces for the framework member;
and
[0191] (3-g) providing a set of male members (not shown) and a set
of female members (not shown) in each of the opposite longitudinal
sides of the single piece for the main bag body so as to extend in
the width direction thereof.
[0192] First, the step (3-a) is carried out to prepare the single
piece of plastic film material for the main bag body. Such a piece
for the main bag body is formed into a rectangular shape provided
with a long side having a length of "M" and a short side having a
length of "N". FIG. 20 illustrates the piece for the main bag body,
which is semi-folded in two, with the result that FIG. 20 includes
the indication of "M/2". The piece for the main bag body has the
opposite half portions 131, 131 between which the central line 130b
of the single piece exists. The layer structure of the piece for
the main bag body 60 is the same as that of the main bag body 2 of
the packaging bag 1 of the present invention as described above and
description of the layer structure is therefore omitted.
[0193] The step (3-g) is carried out to provide a set of male
members (not shown) and a set of female members (not shown) on the
respective half portions of the piece for the main bag body so as
to extend in the width direction on the opposite portions of the
long side of the piece for the main bag body. The step (3-g) is
similar to the step (1-h) described above of the first embodiment
of the method of the present invention and the detailed description
of the step (3-g) is therefore omitted.
[0194] The pair of pieces 140, 140 for the framework member is
prepared. Each of the pieces 140, 140 has a smaller width than the
width of the piece for the main bag body, i.e., the short side
having the length of "N", by a length twice as much as the width
"N1" of a portion 132 to be thermally bonded of the piece for the
main bag body, as shown in FIG. 20. The layer structure of each of
the pieces 140, 140 for the framework member is the same as that of
the framework member 10 of the packaging bag 1 of the present
invention as described above and description of the layer structure
is therefore omitted.
[0195] The thus prepared pieces 140, 140 for the framework member
is subjected, prior to the step (3-b) described later, to the step
(3-f) to form a pair of bending facilitation portions 141 on each
of the pair of pieces 140, 140 for the framework member in the
similar manner as the step (1-g) described above of the first
embodiment of the method of the present invention. Each of the
pieces 140, 140 has the first pair of opposite side edges (i.e.,
the right-hand and left-hand side edges) and the second pair of
opposite side edges (i.e., the upper and lower side edges) 142,
143. The bending facilitation portion 141 extends in parallel to
the right-hand and left-hand side edges of the piece 140 for the
framework member, as shown in FIG. 20.
[0196] Then, the step (3-b) is carried out to place the pair of
pieces 140, 140 of thin sheet material for the framework member on
the surface of the single piece for the main bag body in the
predetermined positions of the respective opposite half portions
131, 131. The piece 140 is placed on the half portion 131 in the
predetermined position so as to keep a distance "M1" between the
upper edge 142 of the piece 140 and one of the opposite short side
edges of the single piece for the main bag body and a distance "M2"
between the lower edge of the piece 140 and the central line 130b
of the single piece. The same positional determination of the piece
140 relative to the half portion 131 of the single piece for the
main bag body is also made on the other half portion 131
thereof.
[0197] Then, the step (3-c) is carried out to thermally bond the
pair of pieces 140, 140 for the framework member to the single
piece for the main bag body in the respective opposite half
portions 131, 131 thereof. The pieces 140, 140 are thermally bonded
at their periphery as hatched in FIG. 20 to the respective half
portions 131, 131 of the single piece for he main bag body.
[0198] Then, the step (3-d) is carried out to fold the single piece
for the main bag body with the pair of pieces 140, 140 for the
framework member in two along the central line 130b of the single
piece for the main bag body to bring one of the opposite half
portions 131, 131 of the single piece for the main bag body close
to another of the opposite half portions 131, 131 to prepare a
folded composite piece so that the pair of pieces 140, 140 for the
framework member are placed in an inside of the folded composite
piece.
[0199] Then, the step (3-e) is carried out to thermally bond the
folded composite piece on opposite sides thereof, i.e., at the
portions 132, 132 to form heat-sealed portions having the width of
"N1", thereby manufacturing the packaging bag. The thus
manufactured packaging bag is composed of the main bag body formed
of the single piece and the pair of reinforcing sections formed of
the pair of pieces 140, 140. The right-hand and left-hand side
edges (i.e., the first pair of opposite side edges) of the
reinforcing section 140 and the upper and lower side edges (i.e.,
the second pair of opposite side edges) thereof are thermally
bonded to the main bag body at other regions than the pair of side
heat-sealed portions.
[0200] The packaging bag is shifted to an expanded state and
subjected to a bending finishing step to provide a finished product
in the form of a rectangular parallelepiped in the same manner as
the packaging bag as described above and illustrated in FIGS. 1 to
6.
[0201] Now, the method of the fourth embodiment of the present
invention for manufacturing the packaging bag will be described
below with reference to FIG. 21.
[0202] In the fourth embodiment of the method of the present
invention, the pair of pieces 150, 150 for the main bag body and
the pair of pieces 140, 140 for the framework member are used to
manufacture the single packaging bags.
[0203] More specifically, the method for manufacturing the
packaging bag includes the essential steps of:
[0204] (4-a) placing a pair of pieces 150, 150 of plastic film
material for the main bag body so as to be apart from each
other;
[0205] (4-b) placing a pair of pieces 160, 160 of thin sheet
material for the framework member on respective inner surfaces of
the pair of pieces 150, 150 for the main bag body in predetermined
positions thereof;
[0206] (4-c) bonding the pair of pieces 160, 160 for the framework
member to the pair of pieces 150, 150 for the main bag body,
respectively;
[0207] (4-d) bringing one of the pair of pieces 150, 150 for the
main bag body close to another of the pair of pieces 150, 150 for
the main bag body so as to cause the pair of pieces 160, 160 for
the framework face each other, thus preparing a set of composite
pieces; and
[0208] (4-e) thermally bonding the set of composite pieces at
opposite side edges and a bottom edge thereof to form side
heat-sealed portions and a bottom heat-sealed portion;
[0209] and further includes optional steps of:
[0210] (4-f prior to the step (b), forming bending facilitation
portions on each of the pair of pieces for the framework member;
and
[0211] (4-g) providing a set of male members (not shown) and a set
of female members (not shown) in each of the pair of pieces 150,
150 for the main bag body so as to extend in the width direction
thereof.
[0212] First, the step (4-a) is carried out to place the pair of
pieces 150, 150 of plastic film material for the main bag body so
as to be apart from each other. Each of the pieces 150, 150 for the
main bag body has the same rectangular shape. The layer structure
of the pieces 150, 150 for the main bag body is the same as that of
the main bag body 2 of the packaging bag 1 of the present invention
as described above and description of the layer structure is
therefore omitted.
[0213] The step (4-g) is carried out to provide a set of male
members (not shown) and a set of female members (not shown) in each
of the pair of pieces 150, 150 for the main bag body so as to
extend in the width direction thereof. The step (4-g) is similar to
the step (1-h) described above of the first embodiment of the
method of the present invention and the detailed description of the
step (4-g) is therefore omitted.
[0214] The pair of pieces 160, 160 for the framework member is
prepared. Each of the pieces 160, 160 has a smaller width than the
width of each of the pieces 150, 150 for the main bag body by a
length twice as much as the width "R" of a portion 151 to be
thermally bonded of the piece for the main bag body, as shown in
FIG. 21. The layer structure of each of the pieces 160, 160 for the
framework member is the same as that of the framework member 10 of
the packaging bag 1 of the present invention as described above and
description of the layer structure is therefore omitted.
[0215] The thus prepared pieces 160, 160 for the framework member
is subjected, prior to the step (4-b) described later, to the step
(4-f) to form a pair of bending facilitation portions 161, 161 on
each of the pair of pieces 160, 160 for the framework member in the
similar manner as the step (1-g) described above of the first
embodiment of the method of the present invention. Each of the
pieces 160, 160 has the first pair of opposite side edges (i.e.,
the right-hand and left-hand side edges) and the second pair of
opposite side edges (i.e., the upper and lower side edges) 162,
163. The bending facilitation portion 161 extends in parallel to
the right-hand and left-hand side edges of the piece 160 for the
framework member, as shown in FIG. 21.
[0216] Then, the step (4-b) is carried out to place the pair of
pieces 160, 160 for the framework member on respective inner
surfaces of the pair of pieces 150, 150 for the main bag body in
predetermined positions thereof. The piece 160 is placed on the
piece 150 in the predetermined position so as to keep a distance
"P1" between the upper edge 162 of the piece 160 and one of the
opposite short side edges of the piece 150 for the main bag body
and a distance "P2" between the lower edge of the piece 160 and the
other the opposite short side edges of the piece 150 for the main
bag body. The same positional determination of the piece 160
relative to the other piece for the main bag body is also made.
[0217] Then, the step (4-c) is carried out to thermally bond the
pair of pieces 160, 160 for the framework member to the pair of
pieces 150, 150 for the main bag body, respectively. The pieces
160, 160 are thermally bonded at their periphery as hatched in FIG.
21 to the respective pieces 150, 150 for he main bag body.
[0218] Then, the step (4-d) is carried out to bring one of the pair
of pieces 150, 150 for the main bag body close to another of the
pair of pieces 150, 150 for the main bag body so as to cause the
pair of pieces 160, 160 for the framework face each other, thus
preparing a set of composite pieces.
[0219] Then, the step (4-e) is carried out to thermally bond the
set of composite pieces at opposite side edges 151, 151 and a
bottom edge 151 thereof to form side heat-sealed portions and a
bottom heat-sealed portion, thereby manufacturing the packaging
bag. The thus manufactured packaging bag is composed of the main
bag body formed of the pair of pieces 150, 150 and the pair of
reinforcing sections formed of the pair of pieces 160, 160. The
right-hand and left-hand side edges (i.e., the first pair of
opposite side edges) of the reinforcing section 160 and the upper
and lower side edges (i.e., the second pair of opposite side edges)
thereof are thermally bonded to the main bag body at other regions
than the pair of side heat-sealed portions.
[0220] The packaging bag is shifted to an expanded state and
subjected to a bending finishing step to provide a finished product
in the form of a rectangular parallelepiped in the same manner as
the packaging bag as described above and illustrated in FIGS. 1 to
6.
[0221] Now, the method of the fifth embodiment of the present
invention for manufacturing the packaging bag will be described
below with reference to FIG. 22.
[0222] In the fifth embodiment of the method of the present
invention, the pair of pieces 180, 180 for the main bag body and a
framework member 170, which is formed into a sleeve, are used to
manufacture the single packaging bags.
[0223] More specifically, the method for manufacturing the
packaging bag includes the essential steps of:
[0224] (5-a) placing a pair of pieces 180, 180 of plastic film
material for a main bag body so as to be apart from each other;
[0225] (5-b) placing a framework member 170, which is formed into a
sleeve, on respective inner surfaces of the pair of pieces 180, 180
for the main bag body in predetermined positions thereof;
[0226] (5-c) bonding the framework member 170 to the pair of pieces
180, 180 for the main bag body, respectively;
[0227] (5-d) bringing one of the pair of pieces 180, 180 for the
main bag body close to another of the pair of pieces 180, 180 for
the main bag body so as to receive the framework 170 between the
pair of pieces 180, 180 for the main bag body, thus preparing a set
of composite pieces; and
[0228] (5-e) thermally bonding the set of composite pieces at
opposite side edges and a bottom edge thereof to form side
heat-sealed portions and a bottom heat-sealed portion;
[0229] and further includes optional steps of:
[0230] (5-f) prior to the step (b), forming bending facilitation
portions on the framework member; and
[0231] (5-g) providing a set of male members (not shown) and a set
of female members (not shown) in each of the pair of pieces 150,
150 for the main bag body so as to extend in the width direction
thereof.
[0232] First, the step (5-a) is carried out to place the pair of
pieces 180, 180 of plastic film material for the main bag body so
as to be apart from each other. Each of the pieces 180, 180 for the
main bag body has the same rectangular shape. The layer structure
of the pieces 180, 180 for the main bag body is the same as that of
the main bag body 2 of the packaging bag 1 of the present invention
as described above and description of the layer structure is
therefore omitted.
[0233] The step (5-g) is carried out to provide a set of male
members (not shown) and a set of female members (not shown) in each
of the pair of pieces 180, 180 for the main bag body so as to
extend in the width direction thereof. The step (5-g) is similar to
the step (1-h) described above of the first embodiment of the
method of the present invention and the detailed description of the
step (5-g) is therefore omitted.
[0234] The framework member 170 is prepared in the form of sleeve,
which has openings on the upper and lower sides thereof. The
framework member 170, which is formed of a piece of plastic
material, is composed of the pair of opposite reinforcing sections
each having the same rectangular shape. The opposite reinforcing
sections are combined to each other by means of a pair of bending
facilitation portions 172, 172, which extend in the opening
direction of the sleeve, i.e., the framework member 170. In
addition, each of the opposite reinforcing sections has the other
pair of bending facilitation portions 171, 171, which extend in
parallel with the above-mentioned pair of bending facilitation
portions 172, 172 in positions shifted inwardly therefrom by the
predetermined distance. The six pending facilitation portions,
i.e., the above-described pair of bending facilitation portions
172, 172, the first pair of bending facilitation portions 171, 171
provided in one of the opposite reinforcing sections and the second
pair of bending facilitation portions 171, 171 provided in the
other thereof enables the framework member 170 to be shifted
between a generally flat collapsed state and an expanded state. The
width of the framework member 170, which is kept in the generally
flat collapsed state, is smaller than the width of each of the
pieces 180, 180 for the main bag body by a length twice as much as
the width of a side edge portion 181 to be thermally bonded of the
piece 180 for the main bag body, as shown in FIG. 22. The layer
structure of the plastic material for the framework member is the
same as that of the framework member 10 of the packaging bag 1 of
the present invention as described above and description of the
layer structure is therefore omitted.
[0235] The above-described framework member 10 is obtained by
carrying out the step (5-f) to form the bending facilitation
portions 171, 171, 171, 171, 172, 172 on the elongated piece of
plastic material for the framework member 170 and then the further
additional step for bringing one edge of the above-mentioned piece
for the framework member 170 close to the other edge thereof and
combining these edges to each other. The step (5-f) is carried out
in the similar manner as the step (1-g) described above of the
first embodiment of the method of the present invention. The
connection portion in which the opposite edges of the piece for the
framework member 170 is connected to each other, may be designed to
serve as one of the bending facilitation portions 171, 171, 171,
171, 172, 172.
[0236] Then, the step (5-b) is carried out to place the framework
member 170, which is kept in the generally flat collapsed state, on
respective inner surfaces of the pair of pieces 180, 180 for the
main bag body in predetermined positions thereof. The framework
member 170 is placed on the piece 180 in the predetermined position
so as to keep a distance "S1" between the upper edge 173 of the
framework member 170 and one of the opposite short side edges of
the piece 150 for the main bag body and a distance "S2" between the
lower edge of the framework member 170 and the other the opposite
short side edges of the piece 180 for the main bag body. The same
positional determination of the framework member 170 relative to
the other piece 180 for the main bag body is also made.
[0237] Then, the step (5-c) is carried out to thermally bond the
framework member 170 to the pair of pieces 180, 180 for the main
bag body, respectively. The framework member 170 is thermally
bonded at its opposite peripheries as hatched in FIG. 22 to the
respective pieces 180, 180 for the main bag body.
[0238] Then, the step (5-d) is carried out to bring one of the pair
of pieces 180, 180 for the main bag body close to another of the
pair of pieces 180, 180 for the main bag body so as to receive the
framework 170 between the pair of pieces 180, 180 for the main bag
body, thus preparing a set of composite pieces.
[0239] Then, the step (5-e) is carried out to thermally bond the
set of composite pieces at opposite side edges 181, 181 and a
bottom edge 181 thereof to form side heat-sealed portions and a
bottom heat-sealed portion, thereby manufacturing the packaging
bag. The thus manufactured packaging bag is composed of the main
bag body formed of the pair of pieces 180, 180 and the framework
member 170, i.e., the sleeve. The portions 181, 181 of the pieces
180, 180 are thermally bonded to form the opposite side heat-sealed
portions to which the pair of bending facilitation portions 172,
172 of the framework member 170 are placed to be adjacent.
[0240] The packaging bag is shifted to an expanded state and
subjected to a bending finishing step to provide a finished product
in the form of a rectangular parallelepiped in the same manner as
the packaging bag as described above and illustrated in FIGS. 1 to
6.
[0241] According to the present invention described above, the
packaging bag comprises the main bag body and the framework member,
which is joined to the main bag body prior to completion of the
main bag body formation process, it is possible to avoid problems
when inserting the sleeve into the main bag body in accordance with
the prior art so as to facilitate manufacture of the packaging bag,
thus reducing the manufacturing cost. It is also possible to
provide an excellent external appearance in the expanded state.
[0242] According to the method of the present invention, it is
possible to manufacture the above-mentioned packaging bag in an
effective manner.
[0243] The entire disclosure of Japanese Patent Application No.
2002-343845 filed on Nov. 27, 2002 including the specification,
claims, drawings and summary is incorporated herein by reference in
its entirety.
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