The present invention relates to an extraction bag for obtaining extraction liquid by immersing an extraction material filled in a bag main body made of a water permeable filter sheet in hot water.
For the purpose of brewing beverages such as green tea, black tea, and oolong tea in an easy and simple manner, tea bags in which such tea leaves are filled in water permeable bag main bodies having hanging strings have been widely used conventionally. Also for coffee, a tea bag type coffee extraction bag according to which a bag main body filled with ground coffee is immersed in hot water has been used in addition to a drip type extraction bag according to which hot water is poured into ground coffee. When it is attempted to immerse such a tea bag type coffee extraction bag into hot water, however, the bag main body filled with ground coffee is apt to float in the hot water due to carbon dioxide contained in the ground coffee, thus making it difficult to extract coffee sufficiently. In view of this, an extraction bag in which a hooking piece formed by a thin plate-like member is attached to one surface of a bag main body to be filled with ground coffee so that the hooking piece can be hooked onto an edge of a cup in order to prevent the bag main body filled with ground coffee from floating in hot water has been proposed (Patent Literature 1).
It has been also proposed that a handle portion configured to expand and contract like a pantograph by folding a thin plate-like member is attached to a bag main body filled with ground coffee and the extraction of the coffee is facilitated by moving the handle portion up and down in hot water in which the bag main body is immersed (Patent Literature 2).
In such a conventional coffee extraction bag according to which the bag main body filled with ground coffee is immersed in hot water, however, even when it is attempted to sink the floating bag main body forcibly into the hot water by gripping the hooking piece or the handle portion formed by the thin plate-like member, the thin plate-like member undergoes bending or deflection, thus making it difficult to sink the bag main body into the hot water. Even when the hooking piece or the handle portion is moved up and down in order to facilitate the extraction of the coffee, the bag main body cannot move up and down in the hot water in the same manner as the handle portion. Even if the bag main body temporarily sinks into the hot water, only a surface layer of the entire ground coffee filled in the bag main body swells by hot water, and the hot water is less likely to penetrate into the inside of the entire ground coffee. Thus, it is difficult for such a tea bag type extraction bag according to which the bag main body is immersed in hot water to obtain coffee liquid having a concentration about equal to that of a drip type extraction bag in an amount of time about equal to or less than that of the drip type extraction bag.
In view of this, it is an object of the present invention to provide a tea bag type extraction bag configured to obtain extraction liquid by immersing a bag main body filled with an extraction material such as ground coffee in hot water, capable of allowing the bag main body to be easily sunk into the hot water or moved up and down and capable of allowing the hot water to be distributed through the entire extraction material in the bag main body so as to obtain extraction liquid having a sufficient concentration easily.
The present inventor has achieved the present invention by conceiving the following: in a tea bag type extraction bag in which a thin plate-like member is attached to a bag main body filled with an extraction material, the thin plate-like member can be formed into a rigid stick shape extending from a central portion of the bag main body by configuring the thin plate-like member so as to have a particular shape. By gripping the stick-shaped portion, the bag main body can be easily sunk into hot water or moved up and down; moreover, the area of an upper surface of a portion occupied by the extraction material in the bag main body as well as its headspace can be increased; consequently, when the bag main body is moved up and down in the hot water, the hot water flows downwardly with respect to the upper surface of the extraction material in the bag main body, thus facilitating the penetration of the hot water into the inside of the extraction material.
Specifically, the present invention provides an extraction bag including: a bag main body formed of a water permeable filter sheet; a thin plate-like member provided on an outer surface of the bag main body; and an extraction material filled in the bag main body, wherein
the bag main body has a first surface and a second surface opposed to each other, and an upper side corresponding to edges of the first and second surfaces;
when the bag main body is developed so that the first surface is located under the upper side and the second surface is located above the upper side,
the thin plate-like member includes a first member on the first surface of the bag main body, and a second member on the second surface of the bag main body, and the first member and the second member are continuous with each other via a first horizontal folding line extending along the upper side; and
the thin plate-like member includes
The present invention also provides a hand-filled extraction bag in which the bag main body in the above-described extraction bag is unfilled with the extraction material and an opening for filling an extraction material is provided in the bag main body.
According to the present invention, by folding the pair of elongated regions of the thin plate-like member provided on the outer surface of the bag main body filled with the extraction material so as to be opposed to each other, the pair of elongated regions suppress deflection with respect to each other and have a rigid stick shape extending from the one surface of the bag main body. Thus, the bag main body can be easily sunk into hot water or moved up and down by gripping such a stick-shaped portion. Consequently, the hot water can easily run through the bag main body.
Moreover, since the pair of elongated regions are provided across the two surfaces of the bag main body opposed to each other, the stick-shaped portion obtained by forming such elongated regions into a stick shape has a longer length as compared to a stick shape formed by a pair of elongated regions provided only on one surface of the bag main body. Thus, the hand gripping the stick-shaped portion can be prevented from getting hot by steam when the bag main body in the hot water is sunk or moved up and down by gripping the stick-shaped portion.
Furthermore, according to the present invention, the shape of the portion occupied by the extraction material in the bag main body can be changed so as to increase the area of its upper surface, and its headspace can be also increased by gripping the stick-shaped portion in such a manner as to be inclined. Consequently, hot water flowed into the bag main body is more likely to flow downwardly from the upper surface of the extraction material. Thus, extraction not only from the surface of the portion occupied by the extraction material in the bag main body but also from the entire extraction material can be facilitated. In particular, in an aspect in which the second surface of the bag main body is pulled up by a central pull-up portion of the thin plate-like member, flattening of the bag main body as a result of the bag main body being pulled in a downward direction due to the weight of the extraction material can be prevented also by the pulling up of the bag main body by the central pull-up portion, thus increasing the headspace. According to an aspect in which a reinforced portion extending in a width direction of the bag main body is further provided below the stick-shaped portion, contraction of the bag main body in the width direction thereof can be prevented from occurring, thus expanding the whole space in the bag main body.
Therefore, the present invention can increase the extraction rate, and thus enables extraction liquid having a concentration about equal to or higher than that of a drip type extraction method to be obtained easily in a short amount of time.
The present invention will be specifically described below with reference to the drawings. Note that the same reference signs in the drawings denote the identical or equivalent components.
General Configuration
The extraction bag 1A includes: the bag main body 3 constituted of a flat bag formed by a water permeable filter sheet; the thin plate-like member 10 provided on an outer surface of the bag main body 3; and an extraction material filled in the bag main body 3. The bag main body 3 has a first surface 3A and a second surface 3B opposed to each other, and an upper side 4a corresponding to edges of these surfaces. The upper side 4a in the present embodiment corresponds to a mountain fold between the first surface 3A and the second surface 3B.
The first member 10A and the second member 10B are continuous with each other via a first horizontal folding line Lh1. The first horizontal folding line Lh1 overlaps with the upper side 4a of the bag main body, and extends along the upper side 4a.
A central bonded portion 11 bonded to the first surface 3A of the bag main body is formed in a central portion of the first member 10A. The bonded region of the central bonded portion 11 preferably includes at least a region near the first horizontal folding line Lh1. In the present embodiment, an approximately entire surface of the central bonded portion 11 is bonded to the bag main body 3.
The thin plate-like member 10 includes a pair of elongated regions 12 (regions surrounded by long dashed double-short dashed lines in
The thin plate-like member 10 is provided with vertical folding lines along which the pair of elongated regions 12 can be pulled out from sides closer to lateral sides 4b of the bag main body so as to be opposed to each other as shown in
Note that the horizontal folding line Lh1 and the vertical folding lines Lv1, Lv2, and Lv3 of the thin plate-like member 10 can be formed, for example, by perforation, half cutting, or creasing.
Configuring the pair of elongated regions 12 extending across the first member 10A and the second member 10B to be capable of being pulled out from the bag main body 3 along the vertical folding lines so as to be opposed to each other is a characteristic configuration of the present invention. The pair of elongated regions 12 pulled out from the bag main body 3 can serve as a long rigid stick-shaped handle when the extraction material in the bag main body 3 is sunk into hot water.
In the present embodiment, the first member 10A includes a reinforced portion 13 bonded to the bag main body 3 in a region closer to the lower side 4c of the bag main body than lower end portions of the elongated regions 12 (
The second member 10B in the present embodiment, on the other hand, includes a central upper end portion 14 extending from the first horizontal folding line Lh1 between the pair of elongated regions 12. The central upper end portion 14 is continuous with the elongated regions 12 via the second vertical folding lines Lv2, and floated without being bonded to the bag main body 3. The second member 10B also includes a central pull-up portion 15 continuous with the central upper end portion 14 via a second horizontal folding line Lh2. The central pull-up portion 15 is separated from the elongated regions 12. Moreover, the central pull-up portion 15 includes a bonded region 15A bonded with the bag main body at a portion distant from the central upper end portion 14. Thus, when the pair of elongated regions 12 are pulled out from the bag main body 3 so as to be opposed to each other, a central portion of the second surface 3B of the bag main body is pulled up in the direction of the upper side 4a of the bag main body as shown in
Extraction Material
Examples of the extraction material filled in the bag main body 3 may include ground coffee, tea leaves such as black tea or green tea, and Chinese herbs. When ground coffee is filled in the bag main body 3 and it is attempted to immerse such a bag main body into hot water, the bag main body is generally apt to float due to carbon dioxide contained in the ground coffee, thus making extraction difficult. According to the present invention, however, the bag main body 3 can be forcibly sunk into hot water in a cup or moved up and down in the hot water in an easy manner by pulling out the elongated regions 12 so as to have a rigid stick shape and using the stick-shaped portion as a handle extending from the central portion of the bag main body 3. This allows the hot water to penetrate into not only a surface layer of the entire ground coffee in the bag main body but also the inside of the entire ground coffee, thus making it possible to obtain extraction liquid efficiently from the entire ground coffee. With regard to an extraction material other than ground coffee, hot water can be similarly allowed to permeate the extraction material, so that extraction liquid can be obtained efficiently from the entire extraction material.
Since the extraction bag of the present invention is used with the extraction material being sealed in the bag main body 3, no extraction material is spread into the outside of the bag main body during the use of the extraction bag.
Bag Main Body
The bag main body 3 in the present embodiment has a shape of a flat bag having the upper side corresponding to the mountain fold of the water permeable filter sheet and three sealed sides. The shape of the bag main body 3 in the present invention is not limited to such a flat bag. For example, a gusset bag having a gusset at its bottom or side may be used. Moreover, the upper side 4a of the bag main body 3 is not limited to a mountain fold, but may be a sealed side. In consideration of the producing method of the extraction bag, however, it is preferable that the upper side be a mountain fold.
Net planar dimensions of the bag main body 3 can be set appropriately in accordance with the size of a cup or a container used when obtaining extraction liquid using the extraction bag. For example, the bag main body 3 may have a size suitable for a commercially-available coffee cup.
Water Permeable Filter Sheet
A variety of sheets having water permeability and filterability so as to be used for extracting an extraction material can be employed as a water permeable filter sheet for forming the bag main body. A constituent material of the water permeable filter sheet can also be selected appropriately in accordance with a type of the extraction material. For example, synthetic fibers such as polyester, nylon, polyethylene, polypropylene, and vinylon; semisynthetic fibers such as rayon; woven fabrics or non-woven fabrics made of natural fibers, such as Broussonetia papyrifera and Edgeworthia papyrifera, used alone or as composite fibers; mixed paper, or the like, made of Manila hemp, wood pulp, a polypropylene fiber, or the like; and paper materials such as a tea bag base sheet have been generally known as water permeable filter sheets for extracting beverages. These water permeable filter sheets can be used also in the present invention. In terms of the disposability of a used extraction bag, the water permeable filter sheet preferably contains biodegradable fiber. Examples of such biodegradable fiber may include polylactic acid, polybutylene succinate, and polyethylene succinate. In terms of imparting transparency to the water permeable filter sheet so that the state of the extraction material in the bag main body can be seen, it is preferable that a content of an inorganic pigment be reduced or no inorganic pigment be contained.
Whereas hot water is directly poured into an extraction material in a drip type extraction bag, hot water is always supplied to the extraction material through the water permeable filter sheet according to the extraction bag of the present invention. Thus, as far as no powder leakage of the extraction material occurs, it is preferable to employ a water permeable filter sheet having meshes larger than those of the water permeable filter sheet used in the drip type extraction bag. When the extraction material is ground coffee, for example, the air permeability of the water permeable filter sheet can be set to 130 to 600 cm3/cm2/sec (Method A of JIS LH1096 for air permeability (the method using a Frazier air permeability tester)).
Thin Plate-Like Member
The thin plate-like member preferably has water repellency. The thin plate-like member can be formed by punching a thin plate-like material such as a paper board having a surface on which a resin is laminated, or a plastic sheet. In terms of the disposability of the used extraction bag 1A, it is preferable that the thin plate-like member be formed of a biodegradable material such as polylactic acid, polybutylene succinate, and polyethylene succinate.
Method of Use
As a packaging and distribution form of the extraction bag 1A, it is preferable that the entire thin plate-like member 10 be provided on the surfaces of the bag main body 3 and the bag main body be flattened as shown in
Thereafter, the thin plate-like member is folded along the first vertical folding lines Lv1, the second vertical folding lines Lv2, and the third vertical folding line Lv3 so that the pair of elongated regions 12 are opposed to each other as shown in
The bag main body after the extraction can be taken out from the container by gripping the stick-shaped portion.
According to such an extraction bag 1A, extraction liquid having a desired concentration can thus be obtained easily and speedily.
Producing Method
As a method of producing the extraction bag 1A, a sheet 20 for producing extraction bags is prepared as shown in
The extraction bags 1A can be produced successively by using such a sheet 20 for producing extraction bags in a packaging and filling machine. In this case, the sheet 20 for producing extraction bags is first folded in half so that lateral sides thereof in the long-side direction of the sheet 20 for producing extraction bags are overlapped with each other as shown in
Modifications
Various changes can be made to the extraction bag of the present invention. For example, an extraction bag 1B having a developed view shown in
An extraction bag 1C having a developed view shown in
According to this extraction bag 1C, the first member 10A includes a reinforced portion 13a bonded to the bag main body 3 in an outer peripheral portion of the elongated regions 12. The reinforced portion 13a is extended to an upper portion of the second member 10B beyond the upper side 4a of the bag main body so as to form a reinforced portion 13b bonded to the bag main body also in the upper portion of the second member 10B. Consequently, when the elongated regions 12 are pulled out, the upper portion of the second surface 3B of the bag main body is held down by the reinforced portion 13b, and the second surface 3B of the bag main body is partially pulled up by the central pull-up portion 15 as shown in
An extraction bag 1D having a developed view shown in
An extraction bag 1E having a developed view shown in
Unlike the above-described extraction bags, an extraction bag 1F having a developed view shown in
Also in this extraction bag 1F, a rigid stick-shaped portion extending from the first surface 3A of the bag main body can be formed by the elongated regions 12 as shown in
Moreover, an upper bonded portion 18 bonded to the bag main body is formed in a portion interposed between the pair of elongated regions 12 in the second member 10B. Consequently, when the elongated regions 12 are pulled out so as to be opposed to each other, a middle portion of the bag main body expands as shown in
An extraction bag 1x having a developed view shown in
Lengths of the first member and the second member in the long-side direction may be identical with, or different from, each other in the present invention. For example, in an extraction bag 1G having a developed view shown in
Hand-Filled Extraction Bag
A hand-filled extraction bag may be produced by leaving the bag main body 3 as an empty bag without filling the extraction material in the bag main body 3 in each of the above-described extraction bags 1A, 1B, 1C, 1D, 1E, 1F, and 1G and providing an opening used for filling an extraction material in the bag main body 3. With such a hand-filled extraction bag, an individual user of the extraction bag can fill the empty bag with an extraction material according to his or her taste, and its extraction liquid can be obtained.
It is preferable that the opening of the hand-filled extraction bag be provided with a means to close the opening after an extraction material is filled. For example, as an empty hand-filled bag corresponding to the above-described extraction bag 1A, a fold-back portion 5 obtained by folding back the water permeable filter sheet that forms the first surface 3A toward the front surface side may be provided at a lower part of the first surface 3A of the bag main body 3, and an opening 6 may be provided without sealing the lower end of the bag main body 3 as in a hand-filled extraction bag 30 shown in
The means to close the opening 6 of the empty bag is not limited to the provision of the fold-back portion 5 at the lower part of the bag main body 3. For example, a zipper described in Japanese Patent No. 4289363 may be provided in the opening 6, or a double-faced tape for food packaging may be used.
Although various aspects of the present invention have been described above, the changes in the various aspects may be combined as appropriate in the present invention.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2020/010487 | 3/11/2020 | WO |
Publishing Document | Publishing Date | Country | Kind |
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WO2021/181555 | 9/16/2021 | WO | A |
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