TEA BAG

TECHNICAL FIELD

The present invention relates to a tea bag, and more particularly, to a tea bag from which tea can be extracted only for a predetermined period of time so that a user can enjoy optimum taste and aroma.

BACKGROUND ART

In general, a conventional tea bag includes a packaging tea bag containing a predetermined amount of raw tea material such as Ground coffee in powder form or various tea leaves or extracts such as green tea, round tea, black tea, etc., a string connected to the tea bag so that the tea bag can be put in and removed from a container containing water, and a tag connected to the tea bag string to function as a grip to pull the tea bag string.

When such a tea bag is placed in a container containing hot water, raw tea material is brewed in the hot water, and then a user drinks a solution in the material is brewed. In this case, the taste and aroma of tea depend on whether the contents of the tea bag are brewed in hot water for an appropriate period of time. Accordingly, there is a problem in that when the contents are brewed for a critical period of time or longer, tea tastes bitter and aroma disappears, so that the best taste and aroma of the tea contained in the tea bag cannot be enjoyed.

In order to solve this problem, the present applicant, in Korean Patent Application No. 10-2020-0126855, proposes a tea bag including a tea pocket containing raw tea material therein so that tea can be easily enjoyed, wherein the tea pocket is provided with water-expandable material that expands such that the raw tea material contained therein can be sealed such that it is not released to the outside after a predetermined period of time has elapsed in water.

This application is a more specific improvement of the preceding application of the present applicant.

As a related patent document, International Publication No. WO 2017/137399 discloses a technology in which a tea bag folded in a disk or circle shape is expanded when it absorbs water. However, this patent does not disclose a structure and function that prevents water from being absorbed after a predetermined period of time. Korean Patent Application Publication No. 10-2019-0127978 discloses a non-woven cellulose fiber fabric that is expanded by water. The differences in pore size are already determined during fabrication. A structure and function for initially absorbing water and blocking the inflow of water after a predetermined period of time are not disclosed. Japanese Patent Application Publication No. 2009-114569 discloses a mesh having a mesh that expands upon absorbing water. However, this patent does not disclose a technology in which the size of the mesh decreases when water is absorbed.

DISCLOSURE
Technical Problem

Therefore, an object of the present invention is to provide a tea bag that is made of water-expandable material and blocks the flow of water thereto when a predetermined amount of time for sufficient taste has elapsed after tea is submerged in water and exposed to water, so that the original flavor and taste of the tea can be maintained and preserved.

Technical Solution

In order to accomplish the above object, the present invention provides a tea bag containing tea therein, wherein the tea bag is made of water-expandable material that has an expansion coefficient in a first direction larger than an expansion coefficient in a second direction perpendicular to the first direction upon contact with water, and the water-expandable material has the expansion coefficients such that a part in the first direction expands more than a part in the second direction after a predetermined time has elapsed and obstructs a flow of water.

The water-expandable material may be fiber, the first direction may be a thickness (transverse) direction, and the second direction may be a longitudinal (lateral) direction.

Furthermore, the present invention provides a tea bag containing tea therein, wherein the tea bag is made of water-expandable material that has a contraction coefficient in a second direction larger than a contraction coefficient in a first direction perpendicular to the second direction upon contact with water, and the water-expandable material has the contraction coefficients such that a part in the second direction contracts more than a part in the first direction after a predetermined time has elapsed and obstructs a flow of water.

The water-expandable material may be fiber, the first direction may be a thickness (transverse) direction, and the second direction may be a longitudinal (lateral) direction.

Furthermore, the present invention provides a tea bag containing tea therein, wherein the tea bag has a composite structure including a single or plurality of grid-shaped compartments and water-expandable material arranged in a space formed by each of the compartments; wherein the compartments are formed by lateral rows extending in parallel while forming respective lines in a lateral direction and formed at predetermined intervals in a vertical direction, and vertical rows extending in parallel while forming respective lines in the vertical direction and formed at predetermined intervals in the lateral direction; and wherein the compartments are made of material that does not expand or contract upon contact with water and has a shape and structure that do not change upon contact with water.

The water-expandable material may include cellulose that expands upon contact with water.

The water-expandable material may be formed by stitching material that has an expansion coefficient in a first direction larger than an expansion coefficient in a second direction perpendicular to the first direction upon contact with water or by stitching material that has a contraction coefficient in the second direction larger than a contraction coefficient in the first direction perpendicular to the second direction upon contact with water.

Furthermore, the present invention provides a tea bag containing tea therein, wherein the tea bag includes water-expandable material that is provided in a deformed state by plastic processing and allows the flow of water and that returns to its original shape and blocks a flow of water when it is in contact with water for a predetermined period of time.

Furthermore, the present invention provides a tea bag containing tea therein, wherein the tea bag includes water-expandable material; and wherein the water-expandable material has a multilayer structure in which a core portion is formed of material having a small expansion coefficient for water and at least one periphery portion having a large expansion coefficient is formed in a periphery surrounding the core portion.

Furthermore, the present invention provides a tea bag containing tea therein, wherein: the tea bag has a composite structure in which water-expandable material is added or applied to all or part of fabric material through which water flows freely; and the water-expandable material has a structure in which an expansion coefficient in a first direction is larger than an expansion coefficient in a second direction perpendicular to the first direction upon contact with water or a structure in which a contraction coefficient in the second direction is larger than a contraction coefficient in the first direction perpendicular to the second direction upon contact with water.

Furthermore, the present invention provides a tea bag containing tea therein, wherein: the tea bag has a composite structure in which water-expandable material is added or applied to all or part of fabric material through which water flows freely; and the water-expandable material has a structure in which an expansion coefficient in a first direction set as the thickness direction is larger than an expansion coefficient in a second direction perpendicular to the first direction and set as the longitudinal direction upon contact with water or a structure in which a contraction coefficient in the second direction is larger than a contraction coefficient in the first direction perpendicular to the second direction upon contact with water.

Furthermore, the present invention provides a tea bag containing tea therein, wherein the tea bag includes water-expandable material, and wherein the water-expandable material has a multilayer structure in which a second portion expands more than a first portion to obstruct the flow of water when a predetermined time has elapsed after contact with water, the first portion forms the core portion of the water-expandable material, and the second portion forms a periphery portion surrounding the core portion.

Furthermore, the present invention provides a tea bag containing tea therein, wherein the tea bag includes water-expandable material, and wherein the water-expandable material has a multilayer structure in which a first portion contracts more than a second portion when a predetermined time has elapsed after contact with water, so that the cross-sectional area of each path through which water passes is reduced to obstruct the flow of water, the first portion forms the core portion of the water-expandable material, and the second portion forms a periphery portion surrounding the core portion.

The water-expandable material may include a fibrous material.

The periphery portion formed by the second portion may have a two-or more-layer structure.

Advantageous Effects

The present invention provides the effect of satisfying various tastes of consumers and enhancing marketability by allowing tea to be extracted only for a predetermined period of time so that users can enjoy optimal taste and aroma.

DESCRIPTION OF DRAWINGS

FIGS. 1A-1B are diagrams illustrating the structure and principle of water-expandable material constituting a feature of the tea bag of the present invention in terms of expansion coefficients;

FIGS. 2A-2E are diagrams showing an expansion process when a fabric woven with warp and weft yarns is exposed to water based on the principle of FIGS. 1A-1B;

FIGS. 3A-3B are diagrams illustrating the structure and principle of water-expandable material constituting a feature of the tea bag of the present invention in terms of contraction coefficients;

FIGS. 4A-4E are diagrams showing a contraction process when a fabric woven with warp and weft yarns is exposed to water based on the principle of FIGS. 3A-3B;

FIG. 5 is a view showing an embodiment of a tea bag containing the water-expandable material of the present invention;

FIG. 6 is a view showing another embodiment of a tea bag containing the water-expandable material of the present invention;

FIG. 7 is a view showing still another embodiment of a tea bag containing the water-expandable material of the present invention;

FIGS. 8A-8B are views showing another embodiment of a tea bag containing the water-expandable material of the present invention using the principle of FIG. 7; and

FIGS. 9A-9B are views showing still another embodiment of a tea bag containing the water-expandable material of the present invention.

BEST MODE

The structure and principle of the water-expandable material 10 constituting the features of the tea bag 1 of the present invention will be described. It should be noted that fiber will be described as an example of the water-expandable material 10 but the material is not necessarily limited to fibers.

Mode for Invention

The objects and effects of the present invention, and the technical configurations for achieving them will become clearly understood by referring to embodiments described later in conjunction with the accompanying drawings. In the description of the present invention, when it is determined that a specific description of a known function or configuration may unnecessarily make the gist of the present invention obscure, the detailed description will be omitted.

Throughout the present specification, when a part is described as “including” a component, this means that it may further include another component, not excluding another component unless specifically stated to the contrary. Meanwhile, in the embodiments of the present invention, each component, function block or means may be configured to include one or more sub-components. First, the structure and principle of a water-expandable material 10 constituting the feature of the tea bag 1 of the present invention will be described. Although a fiber will be described as a representative example of the water-expandable material 10, it should be noted that the water-expandable material 10 is not necessarily limited to the fiber.

FIG. 1A shows a portion of a fiber having an initial length L₀and an initial thickness D₀.

When the longitudinal expansion coefficient of the fiber is set to α, the length L of the fiber after the elapse of a specific time t is as follows:

$L = L_{O} (1 + αΔ t) (α > 0)$

Although temperature as well as time acts as an important variable for the length of the fiber, it is excluded here because the fact that it is a fair factor that affects both variations in length and thickness is taken into consideration.

Next, when the thickness expansion coefficient of the fiber is set to β, the thickness D of the fiber after the elapse of a specific time t is as follows:

$D = D_{O} (1 + βΔ t) (β > 0)$

In this case, when the longitudinal expansion coefficient α and the thickness expansion coefficient β are the same, a variation ratio in length and a variation ratio in thickness are the same. In contrast, when the thickness expansion coefficient β is larger than the longitudinal expansion coefficient α, the fiber expands a lot in the thickness direction and expands little or has a considerably small expanded length in the longitudinal direction, as shown in FIG. 1B.

FIGS. 2A-2E illustrate the principle of FIGS. 1A-1B in the cases of α=β and β>α through an expansion process when a fabric woven with warp and weft yarns is exposed to water.

As shown in the drawing, in an initial state without water, the fabric is in the state of FIG. 2A.

In the case where α=β, when the fabric is exposed to water, the length and thickness of fibers expand at the same rate (FIG. 2B), so that the area of each cavity between the fibers (the cross-sectional area of a grid) increases, with the result that the inflow and outflow of water are maintained naturally (FIG. 2C).

In contrast, in the case where β>α, when the fabric is exposed to water, the thickness of the fibers expands more than the length thereof (FIG. 2D), so that the area of each cavity (the cross-sectional area of a grid) formed by four fibers is narrowed by the thicknesses expanded from all sides, with the result that the flow of water is slowed down or blocked (FIG. 2E).

Therefore, the first condition of the water-expandable material 10 of the present invention is that the water-expandable material 10 is a material (fiber) that has a thickness expansion coefficient larger than a longitudinal expansion coefficient after the elapse of a specific period of time.

Next, the principle that is the same as described above will be described in terms of the contraction coefficient.

FIG. 3A shows a portion of a fiber having an initial length L₀and an initial thickness D₀.

In FIG. 3A, when the longitudinal contraction coefficient of the fiber is set to |α′|, the length L of the fiber after the elapse of a specific time t is as follows:

$L = L_{O} (1 + α^{'} Δ t) (α^{'} < 0)$

Next, when the thickness expansion coefficient of the fiber is set to |β′|, the thickness D of the fiber after the elapse of a specific time t is as follows:

$D = D_{O} (1 + β^{'} Δ t) (β^{'} < 0)$

In this case, when the longitudinal contraction coefficient |α′| and the thickness contraction coefficient |β′| are the same, a variation ratio in length and a variation ratio in thickness are the same. In contrast, when the longitudinal contraction coefficient |α′| is larger than the thickness contraction coefficient |β′|, the fiber contracts a lot in the longitudinal direction and contracts little or has a considerably small contracted length in the thickness direction, as shown in FIG. 3B.

FIGS. 4A-4E illustrate the principle of FIGS. 3A-3B in the cases of |α′|=|β′| and |α′|>|β′ through a contraction process when a fabric woven with warp and weft yarns is exposed to water.

As shown in the drawing, in a state without water, the fabric is in the state of FIG. 4A.

In the case where |α′|=|β′|, when the fabric is exposed to water, the length and thickness of fibers contract at the same rate (FIG. 4B), so that there is no change in the ratio of the area of each cavity between fibers to the overall area, with the result that the inflow and outflow of water are maintained naturally (FIG. 4C).

In contrast, in the case where |α′|>|β′|, when the fabric is exposed to water, the length of the fibers contracts more than the thickness thereof (FIG. 4D), so that the area of each cavity formed by four fibers is narrowed by the length contracted from all sides, with the result that the flow of water is slowed down or blocked (FIG. 4E).

Therefore, another alternative condition of the water-expandable material 10 of the present invention is that the water-expandable material 10 is a material (fiber) that has a longitudinal contraction coefficient larger than a thickness contraction coefficient after the elapse of a specific period of time.

In summary, it can be seen that the water-expandable material 10 constituting the tea bag 1 of the present invention needs to satisfy the condition that the expansion coefficient “a” in a first direction is larger than an expansion coefficient “b” in a second direction perpendicular to the first direction or that a contraction coefficient |α′| in the second direction is larger than a contraction coefficient |β′| in the first direction perpendicular to the second direction.

Based on the above description, an embodiment of a tea bag 1 containing the water-expandable material 10 of the present invention will be described with reference to FIG. 5.

In this embodiment, the water-expandable material 10 of the tea bag 1 is shown as being woven or knitted horizontally and vertically to form the tea bag 1 directly. When an expansion coefficient in the thickness direction is larger than an expansion coefficient in the longitudinal direction, the flow of water is slowed down or blocked as shown in FIGS. 2A-2B. Accordingly, unwanted tea ingredients are not dissolved or dispersed in water, so that the original taste of tea can be maintained. The expansion of the water-expandable material 10 should not occur rapidly at the moment of contact with water, and first, sufficient time for the tee material to dissolve in water should be secured. That is, a tea bag needs to be fabricated such that each grid space formed by lateral and vertical fibers gradually narrows over time, and when it reaches a critical area or less, the flow of water molecules is blocked, suppressed, or slowed down. In consideration of this point, the expansion coefficients in the longitudinal and thickness directions, the difference between the two expansion coefficients, and the predetermined time, i.e., the contact time for which water-expandable material is in contact with water, are appropriately determined.

Even when the contraction coefficient in the longitudinal direction is larger than the contraction coefficient in the thickness direction, the effects that are the same as described above are obtained. Since this is obvious to those skilled in the art, a detailed description thereof will be omitted.

Next, as another embodiment of the present invention, another structure of a tea bag 1 containing water-expandable material 10 will be described with reference to FIG. 6.

In FIG. 6, the tea bag 1 has a composite structure including a plurality of grid-shaped compartments 20 and water-expandable material 10 formed by being woven in a sheet shape in each of the compartments 20.

The compartments 20 are formed by lateral rows 22 extending in parallel while forming respective lines in the lateral direction and formed at predetermined intervals in the vertical direction, and vertical rows 24 extending in parallel while forming respective lines in the vertical direction and formed at predetermined intervals in the lateral direction. The plurality of compartments 20 are formed throughout the tea bag 1, and each of the compartments 20 provides, e.g., a square grid element-shaped space A. The compartments 20 of the present invention are made of a material having considerably small expansion and contraction coefficients. Accordingly, despite contact with water, the shape and structure of each compartment 20 rarely change, the volume of each compartment 20 does not increase, and the size of space A is constant. The compartment 20 may be made of a fiber material or a clean plastic material harmless to the human body.

The water-expandable material 10 of the present invention may be stitched in the form of a sheet in the space A provided by each compartment 20. Alternatively, a pocket through which water passes may be formed for each compartment 20, and then the water-expandable material 10 may be filled in the pocket.

As shown in the enlarged view, the water-expandable material 10 includes a plurality of celluloses 10A that expand upon contact with water. When the celluloses 10A come in contact with water, their volumes increase and thus their sizes increase. When the celluloses 10A come into contact with water, they, i.e., the water-expandable material 10, expand, but do not expand up to adjacent compartments 20 because the framework and shape of the compartment 20 do not change. Accordingly, the celluloses 10A expand within the predetermined compartment 20, the gaps between the fibers are narrowed, and the flow of water is obstructed.

The celluloses 10A function like, for example, agar that becomes bulky when in contact with water, and the expansion direction thereof may be arbitrary. However, as described with reference to FIGS. 1A to 5, it is obvious that the same effect may be expected even when materials having different expansion or contraction coefficients are woven laterally and vertically in the space of each compartment 20.

FIG. 7 is a diagram illustrating the principle in which a film or sheet made of an artificial or natural material is plastically deformed by an external force by punching or other methods and in this case, it is restored to its original state in the case of being wet or at a temperature higher than a specific temperature in a state in which the physical or chemical deformation of a deformed portion is maintained, as another embodiment of the present invention. This is similar to a kind of shape memory effect.

Paper or natural fiber material is subject to an expansion and contraction phenomenon, and has the property of restoring a state, permanently deformed by an external force, to a state before plastic deformation in water. The sheet includes a collection of yarns or celluloses, and may be implemented in fabric or paper. Plastic deformation includes plastic deformation of fibers or celluloses, which are components of a fabric, other than tearing and separation from a sheet.

As shown in FIG. 7, the water-expandable material 10 has a multilayer structure of a first layer A1, a second layer B1, and a third layer C1, the plastic strain is in the order of the first layer>the second layer>the third layer, and the water-expandable material 10 is in a state deformed by an external force. When the water-expandable material 10 is exposed to water and reaches a temperature higher than a predetermined level, it is restored to its original position, and thus water paths are closed and the passage of water is suppressed. In addition, in FIG. 7, the first layer A1, the second layer B1, and the third layer C1 may be made of actually different materials, or may be made of a single material, which has physical properties that are changed during a plastic deformation process.

When a fiber having a specific length in a fabric is plastically deformed by an external force, the distal end of the fiber may protrude as shown in FIG. 7. In this case, in the case of being exposed to water or at a specific temperature, the fiber is restored to a state before plastic deformation and suppresses the movement of water.

FIGS. 8A-8B shows another embodiment using the principles of FIG. 7.

If the water-expandable material 10 is made of a plastically deformed material as shown in FIG. 8A before the tea bag 1 comes into contact with water, the flow of water is natural before the predetermined time elapses after the tea bag of contact with water. After the predetermined time has elapsed, the water-expandable material 10 returns to its original state and the paths of water are blocked, thereby suppressing the movement of water, as shown in FIG. 8B. In FIGS. 8A-8B, the water-expandable material 10 may be composed multiple layers or a single layer, as shown in FIG. 7.

FIGS. 9A-8B show the cross section of a fiber that is made of water-expandable material 10 in which a core portion 10b is made of a material having a small expansion coefficient for water and an periphery portion 10c having a large expansion coefficient is formed in a periphery surrounding the core portion 10b, as shown in FIG. 9A, as another embodiment of the present invention.

FIG. 9B shows water-expandable material 10 having higher thermal expansion coefficients in the direction toward the periphery thereof. In a single cellulose, fibers having different expansion coefficients during spinning and weaving may be implemented in several stages in the radial direction from the center of the fiber.

In the case of the embodiment of FIGS. 9A-8B, the periphery of the fiber may be produced to have a larger thermal expansion coefficient than the core of the fiber naturally or artificially by physicochemical treatment in a spinning and weaving the process, and thus water-expandable material 10 is easy to manufacture. The reason for this is that when the water-expandable material 10 constitutes a tea bag 1, it is highly affected by the temperature of the water that dissolves tea, so that the periphery of the fiber warms up faster and holds more water.

Unlike in the above case, a first portion may be configured to contract more than a second portion. The reason for this is that, when the absolute value of the thermal contraction coefficient of a core material, which is the first portion, attributable to the temperature of the water is made to be larger than that of the thermal contraction coefficient of the second portion, the cross-sectional area of each hole through which water passes can be reduced according to the same principle as described with reference to FIGS. 4A-4E.

In the case of FIGS. 9A-9B, even in the case of the same material, the physical properties of the core portion of a fiber may be configured to be different from those of the periphery portion thereof during the process of manufacturing the fiber or upon being exposed to water and high temperature, the core and periphery portions may be made of the same material or different materials.

Although several embodiments of the present invention have been described above, various modifications may be made to the present invention. For example, it is also possible to manufacture the tea bag 1 with a conventional fabric material that allows water to flow freely, and to fabricate a composite structure in which the water-expandable material of the present invention is padded or applied to all or part of the fabric.

It is obvious that the scope of the present invention extends to the scopes that are the same as or equivalent to the scope of the claims to be described below.

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