U.S. patent application number 10/680232 was filed with the patent office on 2005-04-14 for evacuable bag.
Invention is credited to Tanaka, Kazuya.
Application Number | 20050079308 10/680232 |
Document ID | / |
Family ID | 34422182 |
Filed Date | 2005-04-14 |
United States Patent
Application |
20050079308 |
Kind Code |
A1 |
Tanaka, Kazuya |
April 14, 2005 |
Evacuable bag
Abstract
An evacuable bag is provided which can prevent any possible
contact between laminated sheets so as to achieve a complete
deaeration, and can be produced at low cost. Said evacuable bag 10
has a bag main body 1 composed of flexible non-breathable laminated
sheets 11, and provided with an air-outlet 2 which allows the bag
main body 1 to communicate with the outside, and a closable opening
3, the air-outlet 2 permits deaeration of the air in the bag main
body 1, the laminated sheet 11 consists of at least two layers, the
outer layer is composed of non-breathable synthetic resin films 12,
13, and the inner layer is a nonwoven layer formed with a mass of
synthetic fibers and unevenness on the surface thereof, at least
one part of the synthetic fibers constituting said nonwoven layer
has thermoweldability.
Inventors: |
Tanaka, Kazuya;
(Sakurai-shi, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
34422182 |
Appl. No.: |
10/680232 |
Filed: |
October 8, 2003 |
Current U.S.
Class: |
428/36.1 |
Current CPC
Class: |
B65D 81/2023 20130101;
B65D 77/225 20130101; B65D 31/02 20130101; B65D 33/01 20130101;
B65D 2205/00 20130101; Y10T 428/1362 20150115 |
Class at
Publication: |
428/036.1 |
International
Class: |
B65D 001/00 |
Claims
What is claimed is:
1. An evacuable bag having a bag main body constituted by flexible
non-breathable laminated sheets, the bag main body comprising an
air-outlet which permits the bag main body to communicate with the
outside, and a closable opening, so that air subsisting within the
bag main body may be evacuated through said air-outlet, wherein the
laminated sheets consists of at least two layers, of which the
outer layer is a combination of non-breathable synthetic resin
films, the inner layer is a nonwoven layer made of a mass of
synthetic fibers, and said nonwoven layer has
thermoweldability.
2. The evacuable bag as defined in claim 1, wherein said nonwoven
layer has a ground texture and islet textures which lie scattered
on the ground texture and arranged in a manner to rise from the
ground texture, the surface of the nonwoven layer is rendered
uneven by the ground texture and islet textures, and at least one
cluster of unevenness is formed on the unwoven layer in a portion
for air flow located near the air-outlet in the bag main body.
3. The evacuable bag as defined in claim 2, wherein, referring to
the unevenness as formed by the ground texture and islet textures,
the average of the size difference H between the minimum size of
the nonwoven layer in the ground texture in the direction of
thickness of the nonwoven layer and the maximum size of the
nonwoven layer in the area of the islet textures preferably ranges
from 50 microns to 300 microns.
4. The evacuable bag as defined in claim 2, wherein the synthetic
fibers constituting the nonwoven layer is polyolefin synthetic
fibers.
5. The evacuable bag as defined in claim 4, wherein that the outer
layer of the laminated sheet consists of nylon film and
polyethylene film piled up in this order as viewed from the outside
of the evacuable bag, in the nonwoven layer, the inner layer of the
laminated sheet, said ground texture consists of polyethylene
synthetic pulps and polyethylene-polypropylenes conjugate fibers,
and said islet texture consists of polyethylene-polypropylene
conjugate fibers and the two opposed nonwoven layers lying in the
inner side are adhered to each other by heat-seal into a bag main
body.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates to an evacuable bag which is
to be deaerated after it contains an article.
[0003] 2. Background Art
[0004] As disclosed in Japanese publication No. H01-294027, there
existed in the past evacuable bags which have an air outlet formed
on the bag main body made of flexible synthetic resin for
compacting an article such as clothing and beddings in the bag.
[0005] To be brief, the way of use comprises putting beddings etc.
through an opening into the evacuable bag, then closing the opening
by means of a sliding fastener, attaching the nozzle of a vacuum to
the air outlet to suck up the air inside the bag, so that the air
can be expelled from the outlet. And then, the evacuable bag can be
retained vacuumed by shutting the air outlet against incoming air.
When the bag containing an article such as clothing and beddings is
deaerated, the air within the contents may also be sucked out
simultaneously. So the size of the package may become small as much
as the volume has reduced.
[0006] In addition to the above purpose, if food such as meats and
vegetable as packed under negative pressure in the evacuable bag is
preserved in the refrigerator, it can be protected from spoilage
caused by the air in the bag.
[0007] Said prior art evacuable bags are made of laminated sheets
of synthetic resin film, such as nylon or polyethylene, and
partially heat-sealed.
[0008] The surface of each laminated sheet is smooth, and when the
bag is evacuated, the opposite inner sides of the evacuable bag are
brought into close contact with each other. However, in deaeration
by a vacuum, laminated sheets corresponding to the air outlet in
position may partly stick to each other during the process, thus
resulting in incomplete deaeration.
[0009] In this connection, the above Japanese publication No.
H01-294027 has proposed "TUBULAR CONTAINER", in which the surface
of the synthetic resin films constituting laminated sheets is made
uneven by embossing process, thereby preventing the laminated
sheets from sticking to each other at the inner side of the
evacuable bag. With this prior art container, the laminated sheet
has an embossed surface in a checked pattern, which may avoid
contact between the surface of the laminated sheets to achieve
complete deaeration.
[0010] However, such a way of making a raised pattern on the
surface of the laminated sheet may cause a high cost of
production.
[0011] Meanwhile, for the sake of better appearance, there have
been laminated sheets consisting of an embossed sheet with a random
pattern called in Japanese "Unryu", which literally means clouds
and dragons, as conventionally used on Japanese paper, and a sheet
of synthetic resin film. The inventor of the present invention has
figured out a way of using the uneven surface of said sheet of a
Japanese-paper style so as to avoid any possible contact between
the laminated sheets.
[0012] However, it was found that the Japanese-paper-style sheets
were composed of natural fibers, or rayon fibers used in a
paper-making process and not desirable concerning heat-sealing.
[0013] Thus, with the uneven surface of the Japanese-paper-style
sheets laid down inside the evacuable bag, the laminated sheets did
not be heat-sealed in a bag-making process. In order for the
Japanese-paper-style sheets to make hot-sealable, it was necessary
to have the sheet backed with a synthetic resin film like a
polyethylene film. But, this additional process will result in
covering the entire surface of the Japanese-paper-style sheet with
the backing film, whereby the uneven surface will not appear on the
back face of the sheet, only to fail an achievement the inventor
intends.
[0014] In view of this, the object of the present invention is to
provide an evacuable bag in which complete deaeration can be
carried out with no accompaniment by any possible contact between
the laminated sheets, and the production process can be performed
at a low cost.
SUMMARY OF THE INVENTION
[0015] For the purpose of overcoming said problems, a first aspect
of the present invention provides an evacuable bag having a bag
body 1 constituted by flexible non-breathable laminated sheets 11,
the body 1 comprising an air-outlet 2 which permits the body 1 to
communicate with the outside, and a closable opening 3, so that air
in the body 1 may be evacuated through said air-outlet 2, wherein
the laminated sheets 11 consists of at least two layers, of which
the outer layer being a combination of non-breathable synthetic
resin films 12, 13, the inner layer a nonwoven layer 14 made of a
mass of synthetic fibers, and said nonwoven layer 14 has
thermoweldability.
[0016] A second aspect of the present invention provides the
evacuable bag as defined in the first aspect of the present
invention, wherein said nonwoven layer 14 has a ground texture 14a
and islet textures 14b which lie scattered on the ground texture
14a and arranged in a manner to rise from the ground texture 14a,
the surface of the nonwoven layer 14 is rendered uneven by the
ground texture 14a and islet textures 14b, and at least one cluster
of unevenness is formed on the nonwoven layer 14 in a portion 2a
for air flow located near the air-outlet 2 and in the bags main
body 1.
[0017] A third aspect of the present invention as defined in the
second aspect of the present invention, wherein referring to the
unevenness as defined by the ground texture 14a and islet textures
14b, the average of the size difference H between the minimum size
of the nonwoven layer 14 in the ground texture 14a in the direction
of thickness of the nonwoven layer 14 and the maximum size of the
nonwoven layer 14 in the area of the islet textures 14b preferably
ranges from 50 microns to 300 microns.
[0018] A fourth aspect of the present invention as defined in the
second aspect of the present invention, wherein the synthetic
fibers constituting the nonwoven layer 14 is polyolefin synthetic
fibers.
[0019] A fifth aspect of the present invention as defined in the
fourth aspect of the present invention, wherein the outer layer of
the laminated sheet 11 consists of nylon film 12 and polyethylene
film 13 piled up in this order as viewed from the outside of the
evacuable bag 10, in the nonwoven layer 14, which is the inner
layer of the laminated sheet 11, said ground texture 14a consists
of polyethylene synthetic pulps and polyethylene-polypropylene
conjugate fibers, and the two opposed nonwoven layers 14 lying in
the inner sides are adhered to each other by heat seal into a bag
main body 1.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a plan view showing the evacuable bag in
accordance with one embodiment of the present invention.
[0021] FIG. 2(A) is a cross sectional diagram showing a laminated
sheet of said evacuable bag. FIG. 2(B) is a perspective diagram
showing a nonwoven layer of said evacuable bag. FIG. 2(C) is a
partially enlarged and cross sectional diagram of FIG. 2(B) taken
along a line I-I.
[0022] FIG. 3 is a diagram showing a specific production process
for stock sheet 14s of the nonwoven layer 14 in accordance with the
present invention.
DETAILED DESCRIPTION OF THE PREFERABLE EMBODIMENT
[0023] The present invention will be described with reference to an
embodiment.
[0024] An evacuable bag 10 of the present embodiment has a bag main
body 1 made of two plane laminated sheets 11 of a flexible and
non-breathable nature, the laminated sheets laid one upon another
and being heat-sealed at predetermined section such as the edges,
said main body 1 having a tight-sealable space to contain an
article.
[0025] The bag main body 1 includes a closable opening 3, where a
fastener 31 is disposed for hermetic closure of the opening 3.
[0026] The bag main body 1 also includes an air-outlet 2 which
admits to the outside thereof. In the present embodiment, the
air-outlet 2 is formed with a check valve 21. In brief on its
structure, the check valve 21 is made of plane synthetic resin
sheets laid one upon another, serving to allow air flow from inside
to outside the bag main body 1, while checking the air flow in the
reverse direction. After an article is put in the bag main body 1
and the opening 3 is closed, the air inside the main body 1 can be
manually compressed, or smoothly deaerated from the edge of the
bag, which contains the article of a large-sized configuration such
as beddings, by using a vacuum to attach the nozzle thereof to the
air-outlet 2. And the check valve 21 may check air flow from
outside the bag to ensure that the bag main body 1 will maintain
the deaerated state.
[0027] As shown in FIG. 1, an air passage 22 is formed by
heat-sealing the laminated sheets 11 outside the check valve 21, so
the check valve 21 will not move outside the evacuable bag 10.
However, said air passage 22 is not essential to the present
invention. It may be omitted accordingly.
[0028] The evacuable bag 10 in accordance with the present
invention may not be restricted to the above-mentioned
configuration. For example, the bag main body 1 may be formed by
folding a piece of laminated sheet 11. The volume of the bag main
body 1 may be made larger by providing a gusset at the lateral
sides and/or the bottom side. Instead of provision of the check
valve 21 in the air-outlet 2, closing means such as a cover, tap or
fastener may be employed to prevent incoming air from outside the
bag main body 1. Deaeration without the air-outlet 2 may be carried
out through the opening 3. Or the opening 3 and air-outlet 2 may
not be limited to be positioned at the edge of the bag main body 1,
may be disposed on the surface of the main body 1. Thus, the
evacuable bag 10 of the present invention can be designed in
different structures.
[0029] As shown in FIG. 2(A), the laminated sheets 11 in the
evacuable bag 10 in accordance with the present invention are
formed integrally by laminating a plurality of resin films, each of
which has appropriate compositions for specific applications. In
the present embodiment, the laminated sheets 11 are composed of
three layers.
[0030] The laminated sheets 11 of the embodiment are formed by
laminating a nylon film 12, a polyethylene film 13, and a nonwoven
layer 14 in this order. The nonwoven layer 14 is disposed as an
inner surface of the bag main body 1 in forming the bag main body
1.
[0031] Although on both inner surfaces of the evacuable bag 10 in
this embodiment are disposed the nonwoven layer 14, the present
invention is not limited to this. It may be arranged only on either
inner surface.
[0032] The nonwoven layer 14 consists of synthetic fibers. In this
embodiment, the synthetic fibers used here are polyethylene
synthetic pulps and polyethylene-polypropylene conjugate fibers.
The synthetic fibers should not be restricted to the abovementioned
articles, and choice may be made of a variety of compositions.
However, at least one of the synthetics must be thermoweldable. For
example, polyolefin synthetic fibers may be applicable.
Incidentally, polyolefin is chain hydrocarbon having a double bond,
and means polymer as formed by addition of polymerization of
olefins, which is shown in its general formula CnH2n, such as
ethylene (C2H4), propylene (C3H6), and buthylene (C4H8). In this
embodiment, the respective different fibers are bonded by
thermofusing of part of polyethylene among said synthetic
fibers.
[0033] Forming process of the nonwoven layer 14 is to join said
synthetic fibers together into a sheet-like web, and fuse some of
the synthetic fibers with thermoweldability, polyethylene in this
case, by heating said web into an integrated sheet.
[0034] In this embodiment, the nonwoven layer 14 has a ground
texture 14a and islet textures 14b. The islet textures are arranged
to lie scattered on the ground texture 14a, or the arrangement may
be so-called "island-in-the-sea" arrangement. The ground texture
14a is relatively of a fine texture, consisting of polyethylene
synthetic pulps and polyethylene-polypropylene conjugate fibers,
while the islet texture 14b is relatively of a coarse texture,
consisting of polyethylene-polypropyle- ne conjugate fibers. This
is because the islet texture 14b is composed of synthetic fibers
gathered into a single solid of high density.
[0035] Having thus arranged, the nonwoven layer 14 presents a
random pattern resembling an old Japanese design called "Unryu",
which literally means "clouds and dragons" in appearance. By
varying the islet textures 14b into different shapes, the diversity
of patterns other than the above Unryu pattern can be obtained.
[0036] The use of the synthetic fibers tinged with pigment may
create colorful nonwoven layer 14. In the present embodiment,
titanium oxide has been applied to the polyethylene-polypropylene
conjugate fibers, thereby taking white color. Furthermore,
ornaments such as metallic foil or tinged resin pieces may lie
scattered together with islet textures 14b on the ground texture
14a in such a manner that they will not be the least inconvenience
at the time when the unwoven fabric is heated.
[0037] Now, a production method for stock sheet 14s of the nonwoven
layer 14 in accordance with the present invention will be explained
specifically with reference with FIG. 3 by way of example.
[0038] The polyethylene-polypropylene conjugate fibers comprising
the ground texture 14a (hereinafter called "fiber A") has a
structure composed of a sheath portion made of polyethylene and a
core portion of polypropylene, a single fiber being 3.3 decitex
(dtex) in thickness and 15 millimeter (mm) in length.
[0039] The polyethylene-polypropylene conjugate fibers consisting
of the islet textures 14b (hereinafter called "fiber B") has a
structure composed of a sheath portion made of polyethylene and a
core portion of polypropylene and a single fiber being 3.3 dtex in
thickness and 25 mm in length.
[0040] Referring to the components constituting the nonwoven layer
14 of the present embodiment, the weight ratio of polyethylene
pulps (hereafter referred to as "pulp"), fiber A, and fiber B is
respectively 40%, 50%, and 10%.
[0041] The size of single fibers for fibers A, B is not restricted
to the abovementioned. The thickness may be 1 to 7 dtex, preferably
2 to 4 dtex, and the length 10 mm to 20 mm for fiber A, and 20 mm
to 30 mm for fiber B.
[0042] A web 14W, a layer-like aggregate of the pulps and the
fibers, is produced by a process using a round net.
[0043] In this process, pulps and fiber A are at first agitated in
the water within a first agitating tank 21. The pulps are subjected
to beating before introduced into the first agitating tank 21 so as
to facilitate subsequent intertwining of pulp fibers.
[0044] On the other hand, fiber B and a sticking agent are agitated
in a second agitating tank 22 into an aggregate of fibers which is
to become islet textures 14b. For production of conventional type
of unwoven fabric using rayon fibers, said aggregate could easily
be formed merely by agitating rayon fibers and a sticking agent.
However, since it is difficult for olefin fibers like fiber B of
this embodiment to aggregate themselves in the level of fiber unit,
it is impossible to make an aggregate of fibers by the production
method applicable for rayon fiber aggregate. In this connection,
prior to mixing with a sticking agent, fiber B is soaked in an
anchoring agent so as to facilitate its coherence, and then,
agitated together with the sticking agent until the fiber aggregate
has been formed.
[0045] Then, the pulps and fiber A as agitated in the first
agitating tank 21 and the aggregate of fiber B as agitated in the
second agitating tank 22 are mixed together, and introduced into a
tank 23. The pulps, fiber A, and fiber B are taken with the round
net 14 now in rotary motion as disposed within the tank 23, and
then, transferred to felt 25 sliding as it keeps in contact with
the round net 24, thereby forming a web 14W. The round net 24 is a
cylindrical object defined by a metallic net with very small
meshes.
[0046] The resultant web 14W is conveyed to a dryer 26. The dryer
26 here used is a so-called Yankee Dryer, which serves to dry the
web 14W moving on a heated roller.
[0047] The dried web 14W is then transferred to a heat suction unit
27. In this production process, heated air 27, which is lower than
the melting point of polypropylene in the core portion of the
fibers A, B, and higher than that of polyethylene in the sheath
portion of the pulps and the fibers A, B, specifically 100.degree.
C. to 150.degree. C. at the temperature, is transmitted through the
web 14W, whereby some portion of polyethylene in the pulps and the
fibers A, B of the web 14W will melt. This may cause the pulps and
fibers A, B to join together into a stock sheet 14s.
[0048] As the entire stock sheet 14s thus produced is composed of
olefin synthetic fibers, it is heat-sealable unlike the
conventional Japanese-paper-style sheet using natural fibers or
rayon fibers. Therefore, the nonwoven layer 14 can be attached on
the inner surface of the evacuable bag 10. Additionally, it is not
necessary to have said stock sheet 14s backed by synthetic resin
like polyethylene, as has been practiced in the past. This may help
cost-reduction on the production.
[0049] In addition to the abovementioned, referring to a matter of
severance, fusion cutting was not applicable to the conventional
Japanese-paper-style sheet, and the only cutting way ended up in a
cutter. However, the stock sheet 14s of polyolefin constituting the
nonwoven layer 14 of the present invention can be fusion-cut.
Therefore can be selected the optimum severance for each of
specific production processes, which may help reduce production
cost.
[0050] Furthermore, as a secondary effect due to the provision of
the nonwoven layer 14 with an appearance of the Unryu pattern of a
Japanese-paper-style, the evacuable bag 10 having an excellent
appearance is provided.
[0051] As illustrated in FIG. 1(B), the islet textures 14b of the
nonwoven layer 14 lie scattered on the ground texture 14a, and in
FIG. 2(C) which is a cross sectional view, at least some of the
islet textures 14b are arranged as if they float in the ground
texture 14a. The islet textures 14b rise from the surface of the
ground texture 14a, which renders the surface of the nonwoven layer
14 uneven. This unevenness depends upon the state of the synthetic
fibers constituting the islet textures 14b, and the degree of
"protrusion" of the islet textures 14b from the surface of the
ground texture 14a, so that though it is not uniform as a whole,
the average value of the size difference H between the minimum size
of the nonwoven layer 14 on the ground texture 14a in the direction
of thickness of he nonwoven layer 14 and the maximum size of the
nonwoven layer 14 in the area of the islet textures 14b preferably
ranges from 50 microns to 300 microns.
[0052] And the nonwoven layer 14 is stuck on the synthetic resin
films 12, 13 in a fashion to lie on top until a laminated sheet has
been formed, then, a bag main body 1 is formed by the nonwoven
layer 14 arranged as an inner layer in the inner surface
thereof.
[0053] In case of the conventional evacuable bags as made of
laminated sheets with smooth surface, the areas of the laminated
sheets in the position corresponding to the air-outlet were
inclined to closely contact with each other in deaeration, thereby
leading to incompletion. However, with the evacuable bag 10 in
accordance with the present invention, both inner surfaces of the
body 1 of the evacuable bag 10 are composed of nonwoven layers 14
with the surfaces rendered uneven by the ground texture 14a and
islet textures 14b, so that the inner surfaces may be immune from
undesirable contact to ensure the suitable maintenance of
interspaces which permit air flow in any event. In deaeration the
air in the bag main body 1 can be easily led to the air-outlet 2
and ensure complete deaeration.
[0054] It will be noted that at least one cluster of unevenness is
formed on the nonwoven layer 14 in a portion 2a for air flow
located near the air-outlet 2 in the bag main body 1. This region
2a may be wide enough to prevent any subsequent contact between the
laminated sheets 11 and to secure an air passage to the air-outlet
2, specifically, the range of the region 2a shall be within 50 mm
from the air-outlet 2 (in the present embodiment, the internal open
end 21a of the check valve 21).
[0055] It will also be noted that the formation of the islet
textures 14b is not essential in the present invention. Even if the
nonwoven layer 14 has been formed only by the ground texture 14a,
as the ground texture 14a itself is made of synthetic fibers
twisted together, it has an uneven surface, which may afford an
effect similar to the above-mentioned.
[0056] In the case of the production of the nonwoven layer 14 can
be used the known production process for general nonwovens just as
it is, such as a paper-making process, carding process, air-lay
process, spanbond process, or melt-blow process. The foregoing
process using the round net is a kind of the paper-making process.
Therefore, as compared with the prior art method of rendering
uneven the surfaces of the synthetic resin film constituting the
laminated sheet as disclosed by the aforementioned patent
publication, the production can be conducted at much lower
cost.
[0057] This particular evacuable bag 10 is most suitable for use in
bulky objects as impregnated with air, such as beddings, articles
of clothing, and foods which may spoil by air contact, as meat,
vegetables. It is well adabtable to other different objects without
limitation to the above-mentioned.
[0058] When in use, the evacuable bag 10 always can retain an
interspace for admitting air flow which may arise from the fact
that the laminated sheets 11 will never stick to each other because
both inner sides of the body 1 of the evacuable bag 10 are
constituted by nonwoven layers 14 with uneven surface. Thus, during
evacuation, air within the bog body 1 is smoothly led to the
air-outlet 2 to ensure complete deaeration.
[0059] Additionally, for the production of the nonwoven layer 14
can be used the known production process for the general nonwovens,
such as a paper-making process, carding process, air-lay process,
spanbond process, or melt-blow process just as it is. Therefore, as
compared with the conventional method of rendering uneven the
surfaces of the synthetic resin films consisting the laminated
sheets, production can be performed at much lower cost.
[0060] Unlike the conventional Japanese-paper-style sheets
containing natural fibers or rayon fibers, the sheets of the
present invention can be heat-sealed into a bag main body, and
moreover, the backing process for synthetic resin, as polyethylene,
for rendering the sheets heat-sealable is not necessary, which may
help cut production cost accordingly.
[0061] Additionally, because the nonwoven layer 14 looks like
Japanese paper in appearance, the evacuable bag has an excellent
appearance.
* * * * *