U.S. patent application number 11/988281 was filed with the patent office on 2009-05-14 for sealing structure of container and lid for such structure.
This patent application is currently assigned to TOYO SEIKAN KAISHA, LTD.. Invention is credited to Naoto Matsuda, Akihito Miyazaki, Toshiki Sakaguchi, Yasuyuki Takeuchi, Kenji Yoshihiro.
Application Number | 20090120935 11/988281 |
Document ID | / |
Family ID | 37727287 |
Filed Date | 2009-05-14 |
United States Patent
Application |
20090120935 |
Kind Code |
A1 |
Miyazaki; Akihito ; et
al. |
May 14, 2009 |
Sealing Structure of Container and Lid for Such Structure
Abstract
A sealing member 13 is heat-sealed to the upper end surface of
the mouth portion 12 of a container, and a lid 15 which is provided
with a top panel 15a that covers the mouth portion 12 of the
container, and which has an inner peripheral projection 15e that is
positioned in the vicinity of a place inner than the inner
periphery of the mouth portion 12 of the container on the inside
surface of the top panel 15a is fitted to the mouth portion 12 to
make it easy to peel (open and peel) the sealing member 13 while
high sealing property is ensured, and to prevent the seal member 13
from peeling at the inner periphery of the mouth portion 15 of the
container which peeling is caused by a rise in the internal
pressure in the container.
Inventors: |
Miyazaki; Akihito;
(Kanagawa, JP) ; Takeuchi; Yasuyuki; (Kanagawa,
JP) ; Yoshihiro; Kenji; (Kanagawa, JP) ;
Sakaguchi; Toshiki; (Kanagawa, JP) ; Matsuda;
Naoto; (Kanagawa, JP) |
Correspondence
Address: |
KANESAKA BERNER AND PARTNERS LLP
1700 DIAGONAL RD, SUITE 310
ALEXANDRIA
VA
22314-2848
US
|
Assignee: |
TOYO SEIKAN KAISHA, LTD.,
TOKYO
JP
|
Family ID: |
37727287 |
Appl. No.: |
11/988281 |
Filed: |
August 2, 2006 |
PCT Filed: |
August 2, 2006 |
PCT NO: |
PCT/JP2006/315326 |
371 Date: |
January 4, 2008 |
Current U.S.
Class: |
220/254.1 ;
220/288 |
Current CPC
Class: |
B65D 51/20 20130101;
B65D 2251/0093 20130101; B65D 2251/0015 20130101; B65D 75/5883
20130101 |
Class at
Publication: |
220/254.1 ;
220/288 |
International
Class: |
B65D 51/18 20060101
B65D051/18; B65D 41/04 20060101 B65D041/04 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 9, 2005 |
JP |
2005-230687 |
Claims
1. A sealing structure of a container, the sealing structure
comprising heat-sealing a seal member to the upper end surface of
the mouth portion of a container and fitting a lid to said mouth
portion to thereby seal the inside of the container, wherein an
inner peripheral projection that is positioned in the vicinity of a
place inner than the inner periphery of said mouth portion and is
in direct contact with said seal member is formed on the inside
surface of the top panel of said lid.
2. A sealing structure of a container according to claim 1, wherein
said lid is provided with a cyclic projection that is in contact
with the upper end surface of said mouth portion through said seal
member on the inside surface of the top panel thereof.
3. A sealing structure of a container according to claims 1,
wherein said lid is fitted to said mouth portion so as to form a
clearance between said lid and said seal member.
4. A sealing structure of a container according to claim 1, wherein
said lid is fitted to said mouth portion in a resealable
manner.
5. A lid fitted to the mouth portion of a container sealed with a
seal member, the lid comprising: a top panel covering said mouth
portion; and an inner peripheral projection that is positioned in
the vicinity of a place inner than the inner periphery of said
mouth portion and is in direct contact with said seal member on the
inside surface of the top panel when it is fitted to the mouth
portion.
6. A lid according to claim 5, the lid having a cyclic projection
that is in contact with the upper end surface of said mouth portion
through said seal member on the inside surface of said top panel.
Description
TECHNICAL FIELD
[0001] The present invention relates to a sealing structure of a
container which makes it easy to open and peel the seal member
though it ensures high sealing property by sealing the mouth
portion of a container with a seal member and by providing the
container with a lid, and to a lid used for above container.
BACKGROUND ART
[0002] For instance, Patent Document 1 discloses retort plastic
container in which the opening of the body of the container is
sealed with an inner lid made of a plastic sheet by bonding the
sheet with a bonding strength under which the sheet is more
peelable from the container body, and an outer lid is covered on
the inner lid and screw-fitted to the container body. According to
the retort plastic container disclosed in Patent Document 1, it is
reported that the inner lid with which the container is sealed is
not peeled during retort sterilization treatment but can be peeled
easily when the lid is opened.
[0003] Also, Patent Document 2 discloses a pouch spout produced by
thermally welding a seal member on the top panel of an pouring
cylinder and by screw-fitting a cap, provided with a contact ring
on its inside surface that is in direct contact with the top panel
of the pouring cylinder. The pouch spout disclosed in Patent
Document 2 ensures that because the seal member is pressed by the
contact ring and the sealing property of the seal member can be
therefore improved, it is unnecessary to increase the adhesive
strength of the seal member to a required level or more and the
seal member can be easily opened and peeled when the content is
poured from the pouch spout.
[0004] Also, Patent Document 3 discloses a package bag with a mouth
in which the outer periphery of a seal material is fused with the
outside surface of the opening end of the mouth portion and the
seal material that seals the opening end of the mouth portion is
pressed by a dome-like projection disposed on the backside of a
cap. According to the package bag with a mouth portion which is
disclosed in Patent Document 3, the dome-like projection does not
break the seal material but is in close contact with the seal
material, making it possible to prevent water from penetrating into
the upper surface of the seal material that seals the mouth portion
at the time of heat treatment.
[0005] Patent Document 1: Japanese Patent Application Laid-Open No.
6-219464
[0006] Patent Document 2: Japanese Patent Application Laid-Open No.
No. 2002-104453
[0007] Patent Document 3: Japanese Patent Application Laid-Open No.
2004-224355
DISCLOSURE OF THE INVENTION
Problem to be Solved by the Invention
[0008] However, the container of Patent Document No. 1 has the
problem that though the inner lid made of a plastic sheet is
pressed against the upper surface of the opening of the container
by a packing made of silicone rubber that is disposed on the inside
surface of the outer lid, the inner lid is peeled from the upper
surface of the opening on the inner peripheral side of the upper
surface of the opening when the pressure in the container is raised
when the container is sterilized at high temperatures or when a
impact of falling is applied and the inner lid is raised towards
the inside of the outer lid against the elastic force of the
packing of the packing. When even a part of the inner peripheral
side of the inner lid is peeled off, this is undesirable because
the content in the container enters into that part and there is a
fear of giving a feeling of discomfort to purchasers when the
container is opened.
[0009] Particularly, in the case of containers, such as a spout
pouch and squeeze bottle, which are made of flexible materials, the
containers are largely deformed and the degree of a rise in
internal pressure is increased when a impact of falling during the
distribution process is applied or persons in charge strongly grasp
them. Along with the increase in the internal pressure, the impact
applied to the inner lid is increased when the internal pressure is
raised. There is therefore a tendency that the above problem
becomes significant and such a problem is pointed out likewise in
the case of the pouch spout described in Patent Document 2.
[0010] Also, the package bag with a mouth portion of Patent
Document 3 is reduced in the fear of the above problem because the
dome-like projection disposed on the backside of the cap is in
direct contact with the inner peripheral side of the opening.
[0011] However, in the structure disclosed in Patent Document 3, it
is necessary to bind the outside periphery of the seal material
with the outer plane of the opening end by fusion to prevent the
seal material from peeling off when the dome-like projection is
pressed against the seal material. There is therefore the problem
that even if a tab portion for peeling is left, it is difficult to
peel the seal material completely from the mouth portion when the
seal material is opened and peeled. Moreover, because the seal
material is in close contact with the dome-like projection, there
is the problem that there is no place for escape of the pressure
when the pressure in the container is raised in high-temperature
sterilization or when an impact of falling is applied and a rise in
inner pressure cannot be absorbed.
[0012] The present invention has been made in view of the above
situation, and it is an object of the present invention to provide
a sealing structure of a container which makes it easy to peel
(opened peeling) a seal material when the container is opened while
ensuring high sealing property by sealing the mouth portion of the
container with the seal material and by providing the container
with a lid, the structure enabling the container to prevent the
seal material from peeling even if a impact of falling is applied
or the pressure in the container is raised, and also to provide a
lid used in this structure.
Means for Solving the Problem
[0013] A sealing structure of a container according to the present
invention includes heat-sealing a seal member to the upper end of
the mouth portion of a container and fitting a lid to said mouth
portion to thereby seal the inside of the container, wherein an
inner peripheral projection that is positioned in the vicinity of a
place inner than the inner periphery of said mouth portion and is
in direct contact with said seal member is formed on the top panel
of said lid.
[0014] Such a structure ensures high sealing property and also,
makes it easy to open and peel the seal member. Further, it
prevents the peeling of the sealing material on the inner periphery
of the mouth portion of which peeling is caused by an impact of
falling or a rise in the pressure in the container, with the result
that a phenomenon that the content of the container enters into the
space between the upper end surface of the mouth portion and the
seal member can be effectively avoided.
[0015] The sealing structure of a container according to the
present invention may take a structure in which said lid is
provided with a cyclic projection that is in contact with the upper
end surface of said mouth portion through said seal member on the
inside surface of the top panel thereof.
[0016] Such a structure can prevent the seal member from being
peeled caused by a rise in the pressure in the container more
reliably and also can prevent sterilizing water used in
high-temperature sterilization from penetrating between the lid and
the seal member.
[0017] The sealing structure of a container according to the
present invention may take a structure in which said lid is fitted
to said mouth portion so as to form a clearance between said lid
and said seal member.
[0018] Such a structure allows the seal member to be curved upward
in the lid to absorb an increase in pressure when the internal
pressure in the container is increased.
[0019] Also, the sealing structure of a container according to the
present invention may be one in which said lid is fitted to said
mouth portion in a resealable manner.
[0020] Such a structure makes it possible to reseal the container
with the lid also after the container is opened.
[0021] Also, the lid according to the present invention is one
which is used in the aforementioned sealing structure of a
container and fitted to the mouth portion of the container sealed
with the seal material, is provided with a top panel covering said
mouth portion and is provided with an inner peripheral projection
that is positioned in the vicinity of a place inner than the inner
periphery of said mouth portion and is in direct contact with said
seal member on the inside surface of the top panel when it is
fitted to the mouth portion. Also, the lid according to the present
invention may have a structure provided with a cyclic projection
that is in contact with the upper end surface of said mouth portion
through said seal member on the inside surface of said top
panel.
Effect of the Invention
[0022] According to the present invention, the mouth portion of a
container is sealed with a seal member and a lid is fitted, thereby
ensuring high sealing property and also making easy to open and
peel the seal member, and further, it prevents the peeling of the
sealing material on the inner periphery of the mouth portion by the
inner peripheral projection formed on the inside surface of the top
panel of the lid, with the result that a phenomenon that the
content of the container enters into the space between the upper
end surface of the mouth portion and the seal member can be
effectively avoided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a partially broken sectional view showing the
outline of an embodiment in which the sealing structure of a
container according to the present invention is applied to a pouch
spout.
[0024] FIG. 2 is an enlarged sectional view of an essential part of
an embodiment shown in FIG. 1.
[0025] FIG. 3 is a plan view showing the condition that a seal
member is heat-sealed to the upper end surface of an opening of a
pouring cylinder.
[0026] FIG. 4 is a front view showing one example of a pouch with a
spout.
DESCRIPTION OF THE REFERENCE NUMERALS
[0027] 1 Spout [0028] 10 Spout body [0029] 12 Pouring cylinder
(mouth portion of a container) [0030] 13 Seal member [0031] 15 Cap
(lid) [0032] 15a Top panel [0033] 15d Cyclic projection [0034] 15e
Inner peripheral projection [0035] 2 Clearance
BEST MODE FOR CARRYING OUT THE INVENTION
[0036] Preferred embodiments according to the present invention
will be explained with reference to the drawings.
[0037] Here, FIG. 1 is a partially broken sectional view of a spout
showing an embodiment in which the sealing structure of a container
according to the present invention is applied to the pouch spout.
FIG. 2 is an enlarged sectional view of an essential part enclosed
by the chain line in FIG. 1.
[0038] A spout 1 shown in FIG. 1 has a spout body 10 provided with
a boat-form portion 11 and an pouring cylinder 12 having a
cylindrical form and extended upwards from the boat-form cylinder
12 and the upper end of an opening of the pouring cylinder 12 is
heat-sealed with a seal member 13. Also, screw threads 14 for
screw-fitting a cap 15 is formed on outside peripheral surface of
the pouring cylinder 12 and provided with plural drain slits 14a in
a peripheral direction.
[0039] Then, as shown in drawings, the opening of the pouring
cylinder 12 is sealed with the seal member 13 and the cap 15 is
screw-fitted to the pouring cylinder 12 so as to cover the seal
member 13. If the cap 15 is fitted to the pouring cylinder 12 by
screw fitting in the above manner, this is preferable because the
spout can be resealed by the cap 15 after opening. However, the
fitting means of the cap 15 is not limited to the above means.
[0040] Also, in the example illustrated, the boat-form portion 11
contained in the spout body 10 is provided with a cylinder portion
11a connected to the pouring cylinder 12, three welded substrate
11b that project horizontally in a triangle form from this cylinder
portion 11a so as to be almost symmetrical in the figure and a
flange portion 11c positioned at the boundary between the pouring
cylinder 12 and the cylinder portion 11a.
[0041] This welded substrates 11b are arranged at predetermined
intervals along the direction of the center axis of the cylinder
portion 11a and are connected in a vertical direction through a
column portion 11d positioned at front end side. Also, a spout seal
portion 35 of a pouch body 3 is heat-sealed with the entire
periphery of the side surface of the welded substrate 11b as
described later. At this time, the flange portion 11c is so devised
that it is in direct contact with the side of the spout seal
portion 35 and is aligned with a soft wrapping material forming the
pouch body 3 (see FIG. 4).
[0042] In this embodiment, the spout body 10 and the cap 15 may be
produced using a thermoplastic resin typified by a polyolefin resin
such as polypropylene and polyethylene by a molding means such as
injection molding.
[0043] Here, in this embodiment the spout 1 is given as the
example. However, the present invention may be applied to various
containers such as bottle type containers other than this spout
1.
[0044] When the present invention is applied to a bottle type
container, the mouth portion of a bottle type container
corresponding to the spout body 10 used in the above embodiment can
be integrated with the container body by molding and besides the
above polyolefin resins, various thermoplastic resins including
polyethylene terephthalate and polyethylene naphthalate may be
used. Though the bottle type containers may be produced by direct
blow molding or stretch blow molding, the mouth portion of the
container may be allowed to take a desired shape when a preform is
molded by injection molding prior to the blow molding in the case
of stretch blow molding.
[0045] In any of these embodiments, the cap and the mouth portion
of the container may be produced using the same resins or by
blending other thermoplastic resins or properly produced in known
structures, for example, a multilayer structure using functional
resins such as an oxygen barrier resin.
[0046] Also, the seal member 13 heat-sealed to the upper end
surface of the opening of the pouring cylinder 12 is, as shown in
FIG. 3, made of an almost circular film material and two
projections 13a are formed and projected in radius directions
opposite to each other. These projections 13a are formed as thumb
arms making easy to peel the seal member 13 when the seal member 13
is opened and peeled. These projections are preferably formed in
such a manner that when the cap 15 is fitted to the pouring
cylinder 12, the projections 13a are bent along the inside surface
shape of the cap 15 whereas when the cap 15 is taken off from the
pouring cylinder 12, they recover its shape by their
elasticity.
[0047] It is to be noted that FIG. 3 is a plan view showing the
condition that the upper end surface of the opening of the pouring
cylinder 12 is heat-sealed with the seal member 13.
[0048] Examples of the film material used for the seal member 13
may include film materials having a multilayer structure in which a
base material layer, an intermediate layer (barrier layer) and a
sealant layer are laminated in this order through an adhesive
layer. The specific structure of the film material may be properly
selected in consideration of the required tensile strength,
resistance to an impact of falling, pinhole resistance, resistance
to the content, gas barrier property and also, heat resistance when
high temperature sterilization such as hot water sterilization and
retort sterilization is required.
[0049] In the case of using the film material of the above
multilayer structure as the film material for the seal member 13,
base material films superior in mechanical property such as tensile
strength, resistance to the impact and pinhole resistance are
preferably used for the base layer. Specifically, materials
obtained by laminating biaxial oriented films made of, for example,
polyester type resins such as polyethylene terephthalate, polyamide
type resins such as nylon or polyolefin type resins such as
polypropylene singly or plurally.
[0050] Such a base material film itself may be provided with
barrier property according to the need by vapor-depositing, for
example, a metal such as aluminum or an inorganic oxide such as
alumina (aluminum oxide) and silica (silicon oxide), by coating
this base material film with a barrier organic material such as
polyvinylidene chloride and polyacrylic acid, or by blending an
oxygen absorbing resin containing an oxidizing polymer or an oxygen
absorber made of, for example, a reducing metal compound.
[0051] Also, as the intermediate layer, synthetic resin films
provided with barrier property that stands to various gases and
steam may be used.
[0052] Examples of such a synthetic resin film include an
ethylene/vinyl alcohol copolymer film; vinylidene chloride
copolymer film; crystalline polyamide film (Nylon MXD6) obtained by
a polymerization condensation reaction between methaxylenediamine
(MXDA) and adipic acid; acrylonitrile copolymer film; polyglycolic
acid and its copolymer film; polyglycolic acid film; clay type
nanocomposite synthetic resin film; inorganic film deposited film;
films coated with a barrier organic material such as polyvinylidene
chloride and polyacrylic acid; and films coated with, as a base, a
clay type nanocomposite material such as a phenol resin, epoxy
resin and polyimide resin. These films may be blended with an
oxygen absorbing resin containing an oxidizing polymer and an
oxygen absorber made of, for example, a reducing metal compound.
Also, when no transparency is required, a metal foil (including an
alloy film) such as aluminum foil or steal foil may be used as
other materials imparting barrier property.
[0053] Also, it is demanded of the sealant layer to have
heat-sealing property (which means that a subject material can be
melted, diffused and resolidified at temperatures lower than the
melting point of the material constituting at least the base
material layer), heat-sealing strength, heat resistance
(heat-sealing strength at high temperatures), resistance to
contents and sanitary property.
[0054] Examples of the synthetic resin material having heat-sealing
property adaptable to the sealant layer include polyolefin type
resins such as low-density polyethylene, linear low-density
polyethylene (Ziegler type (multisite catalyst) and metallocene
type (single-site catalyst)), ethylene/.alpha.-olefin copolymer,
olefin copolymer graft-modified by ethylene type unsaturated
carboxylic acid or its anhydride, middle-density polyethylene,
high-density polyethylene, polypropylene, propylene/ethylene
copolymer, polybutene-1, polymethylpentene, ethylene/vinyl acetate
vinyl copolymer, ethylene/acrylic acid copolymer,
ethylene/methacrylic acid copolymer, ion-crosslinked olefin
copolymer (ionomer) obtained by introducing a metal ion into a part
of a ethylene/methacrylic acid copolymer or the like and
ethylene/tetracyclododecene copolymer (cyclic olefin copolymer);
aromatic vinyl copolymers such as polystyrene and styrene/butadiene
copolymer; vinyl halide resin such as polyvinyl chloride and
polyvinylidene chloride; acrylonitrile copolymer such as an
acrylonitrile/styrene copolymer and acrylonitrile/butadiene/styrene
copolymer; polylactic acid type resin (including polymesolactide
compound type); and polyester type resins having a relatively low
melting point such as polybutylene terephthalate when the spout 1
is constituted of a polyolefin type resin. These resins may be used
either singly or in combinations of two or more according to the
need.
[0055] When the spout 1 is constituted of a polyester type resin,
copolymer polyesters obtained by modifying polyethylene
terephthalate or polybutylene terephthalate with a polyvalent
carboxylic acid component such as isophthalic acid and adipic acid
or a polyhydric alcohol component such as 1,4-butanediol and
1,4-cyclohexanedimethanol are preferably used as the synthetic
resin material used in the sealant layer. Easily peeling ability
can be imparted to the sealant layer by blending an incompatible
synthetic resin material such as polyethylene and polypropylene in
such a copolymer polyester.
[0056] Also, examples of materials used to form an adhesive layer
that binds the above layers among them include polyurethane type
resins such as a polyether type polyurethane resin and polyester
type polyurethane resin, polyester type resins, epoxy type resins,
acryl type resins and olefin type resins into which a polar group
is introduced.
[0057] When a film material having such a multilayer structure is
used as the seal member 13, synthetic films constituting each layer
may be obtained by a usual method such as a casting method, T-die
method, calendering method or inflation method. Then, the film
material having a multilayer structure may be obtained by a usual
method such as dry lamination method using a film molded in advance
and a sandwich lamination method, lamination coating method or melt
co-extrusion method using a molten resin. At this time, in order to
improve the adhesiveness of each of the base material layer,
intermediate layer and sealant layer, the surface of each layer,
which surface is in contact with the adhesive layer may be
subjected to surface reforming treatment using corona discharge
treatment, flame treatment, ultraviolet treatment, ozone treatment,
primer coating treatment (coated with alkyl titanate,
polyethyleneimine, a silane coupling agent, isocyanate type
compound or a polyurethane type compound).
[0058] Also, in the example illustrated, the cap 15 is provided
with a top panel 15a that covers the opening of the pouring
cylinder 12 and a thread groove 15b corresponding to a screw thread
14 of the pouring cylinder 12 is formed on the inside peripheral
surface of a cylinder wall 15c descending from the peripheral end
of the top panel 15a. Moreover, a cyclic projection 15d that is in
contact with the upper end surface of the opening of the pouring
cylinder 12 through the seal member 13 is formed on the inside
surface of the top panel 15a. The cyclic projection 15d is formed
along the upper end surface of the opening of the pouring cylinder
12, such that the seal member 13 is pressed against the upper end
surface of the opening of the pouring cylinder 12 by the cyclic
projection 15d.
[0059] Such a structure ensures that even if the seal member 13 is
raised upward along with a rise in the internal pressure, for
example, in high-temperature sterilization or when an impact of
falling is applied, it is possible to efficiently prevent the
occurrence of a phenomenon that the seal member 13 is peeled from
the upper end surface of the opening of the pouring cylinder 12 and
the sealing property of the container (pouch) can be retained.
[0060] Therefore, in this embodiment in which the seal member 13 is
prevented from peeling by the cap 15 fitted to the pouring cylinder
12, the seal strength of the seal member 13 is determined without
the necessity for considering high-temperature sterilization after
the content is filled and sealed and peeling during the
distribution process and may be properly set, for example, to a
range from 5 to 25 N/15 mm and particularly 15 N/15 mm or less by
giving priority to easy peeling ability.
[0061] In the case of carrying out retort sterilization as the
high-temperature sterilization, the seal strength is fixed to 23
N/15 mm or more according to the related law. However seal strength
for the seal member 13 can be selected in the above range.
[0062] Moreover, if sterilizing water used in the high-temperature
sterilization penetrates between the cap 15 and the seal member 13
and is left unremoved in the product, and the product is put in a
distribution process, there is a fear that the product is
misunderstood as a defective as if the content leaked. Because, in
this embodiment, the cyclic projection 15d is designed to be in
contact with the upper end surface of the opening of the pouring
cylinder 12 through the seal member 13 and it is therefore possible
to prevent sterilizing water from penetrating into the upper
surface of the seal member 13.
[0063] Also, in the example illustrated, a cyclic inner peripheral
projection 15e located on the inner peripheral side of the cyclic
projection 15d is formed concentrically together with the cyclic
projection 15d on the inside surface of the top panel 15a of the
cap 15. This inner peripheral projection 15e is formed such that
the tip side of the inner peripheral projection 15e is in contact
with the seal member 13 when the cap 15 is fitted to the pouring
cylinder 12. Also, this inner peripheral projection 15e is formed
such that it has such a projected length allowing the tip thereof
to be positioned below the horizontal plane including the upper end
surface of the opening of the pouring cylinder 12 when the cap 15
is fitted to the pouring cylinder 12 (see FIG. 2).
[0064] Although in the example illustrated, the tip of the inner
peripheral projection 15e is designed to be positioned below the
horizontal plane including the upper end surface of the opening of
the pouring cylinder 12, it is only required that the tip of the
inner peripheral projection 15e is positioned on the horizontal
plane including at least the upper end surface of the opening of
the pouring cylinder 12 and is in contact with the seal member
13.
[0065] According to this embodiment, the inner peripheral
projection 15e like this is formed. Therefore, when force that
likely lifts the seal member 13 upwards arises along with a rise in
the internal pressure, the inner peripheral projection 15e is
pressed against the seal member 13 positioned in the vicinity of
the inner periphery of the opening of the pouring cylinder 12 to
thereby prevent the seal member 13 from peeling from the upper end
surface of the opening at the inner periphery of the opening of the
pouring cylinder 12.
[0066] Specifically, in this embodiment, the above cyclic
projection 15d and inner peripheral projection 15e are formed for
the following main purposes. Specifically, the above cyclic
projection 15d prevents the whole peeling of the seal member 13
from the upper end surface of the opening whereas the inner
peripheral projection 15e prevents the partial peeling of the seal
member 13 at the inner periphery of the opening.
[0067] Here, if the position where the inner peripheral projection
15e is formed far distant from the inner periphery of the opening,
the inner peripheral projection 15e cannot prevent the occurrence
of the phenomenon that the seal member 13 positioned in the
vicinity of the inner periphery of the opening of the pouring
cylinder 12 is lifted upwards when the internal pressure is
increased, with the result that the function of preventing the
peeling of the seal member 13 at the inner periphery of the opening
of the pouring cylinder 12 is damaged. For this, the inner
peripheral projection 15e must be formed between the inner
periphery of the opening and a position distant about half the
diameter of the opening of the pouring cylinder 12: specifically,
at a position in the vicinity of a place inner than the inner
periphery of the opening of the pouring cylinder 12 so as not to be
too far from the inner periphery of the opening.
[0068] If even a part of the seal member 13 is peeled or a part
which does not seal with the seal member 13 is present at the inner
periphery of the opening of the pouring cylinder 12, the content in
the container enters into that part and there is a fear of giving a
feeling of discomfort to purchasers when the seal member 13 is
opened and peeled. According to this embodiment, the inner
peripheral projection 15e that is in contact with the seal member
13 is formed on the inside surface of the top panel 15a of the cap
15 to thereby prevent the seal member 13 positioned on the outer
peripheral side than the inner peripheral projection 15e from being
lifted over the upper end surface of the opening of the pouring
cylinder 12. This makes it possible to maintain the situation where
the seal member 13 is in close contact with the upper end surface
of the opening of the pouring cylinder 12 and it is therefore
possible to effectively prevent the content of the container from
entering between the upper end surface of the opening of the
pouring cylinder 12 and the seal member 13.
[0069] In this embodiment, the inner peripheral projection 15e is
not limited to the above type having a cyclic form and may be one
formed by arranging plural small projections cyclically insofar as
the aforementioned function is obtained. Its specific structure may
be modified properly to the extent that the aforementioned function
is not damaged.
[0070] Also, the example illustrated is so designed that a
predetermined clearance 2 is formed between the cap 15 and the seal
member 13 when the cap 15 is fitted to the pouring cylinder 12.
Such a structure allows the seal member 13 to be curved upward in
the cap 15 to absorb an increase in pressure when the internal
pressure in the container is increased in high-temperature
sterilization or when an impact of falling is applied, so that an
impact applied to the seal member 13 when the internal pressure is
increased is eased.
[0071] The spout 1 as mentioned above is fitted to a pouch body 3
as shown in FIG. 4 and used as a mouth that pours the content.
[0072] In the example illustrated, the pouch body 3 is constituted
of a body portion 31 and a bottom portion 32 formed of a soft
wrapping material such as a resin film. The side periphery of the
body portions 31 is sealed with a side seal 33 in the condition
that the bottom portion 32 is folded at a fold line 32a and also,
the body portion 31 and the bottom portion 32 are sealed with a
bottom seal 34. Also, a slant portion 4 that is cut diagonally is
formed at a corner portion on the upper left side in the figure. In
a spout seal portion 35 of this slant portion 4, the entire
periphery of the side surface of the welded substrate 11b of the
spout 1 is heat-sealed with the soft wrapping material forming the
pouch body 3.
[0073] Such a pouch with a spout is generally conveyed to a
content-filling step in the condition that its top portion is
opened and the top portion is sealed with a top seal 36 after the
content is filled. At this time, the spout 1 fitted as the pouring
mouth has s structure in which the opening of the pouring cylinder
12 is sealed with the seal member 13 and the cap 15 is fitted to
the pouring cylinder 12 so as to cover the seal member 13. For
this, the seal strength of the seal member 13 is designed to be at
such a level that the seal member 13 is easily peeled, the content
can be filled and sealed highly tightly. When the content is
poured, the seal member 13 is opened and peeled after the cap 15 is
dismounted. At this time, the seal member 13 can be heat-sealed at
such a strength level that it is easily peelable. The seal member
13 can be therefore peeled and opened easily.
[0074] Although the invention has been described in its preferred
embodiment, the present invention is not limited to the above
embodiment. It is needless to say that various modifications and
variations are possible within the scope of the present
invention.
[0075] For example, in the aforementioned embodiment, the inner
peripheral projection 15e is formed, together with the cyclic
projection 15d that is in contact with the upper end surface of the
opening of the pouring cylinder 12 through the seal member 13, on
the side inner than the cyclic projection 15d on the inside surface
of the top panel 15a of the cap 15. However, if the seal member 13
is prevented from peeling from the upper end surface of the opening
only by the inner peripheral projection 15e and sufficient sealing
property can be secured, the above cyclic projection 15d may be
omitted according to the need.
[0076] Also, the example in which the present invention is applied
to a pouch spout is given in the above embodiment. However, the
container to which the present invention may be applied is not
limited to a pouch as those mentioned above. The present invention
may be applied to, for example, a squeeze bottle to be filled with
a content such as mayonnaise or a wide-mouth container to be filled
with a content such as jam. However, the present invention is
preferably used for containers, such as a pouch and squeeze bottle,
made of flexible materials which are largely deformed and allow a
large increase in internal pressure when an impact of falling is
applied and a person in charge grasps these containers strongly
during the distribution process.
INDUSTRIALLY APPLICABILITY
[0077] As explained above, the present invention provides a sealing
structure of a container which makes it easy to open and peel a
seal member while securing high sealing property by sealing the
mouth portion of the container with the seal member and by
providing the container with a lid, whereby the present invention
may be utilized in various containers.
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