TOBACCO MATERIAL COMPRISING FLAVOR MATERIAL AND METHOD OF PREPARING THE SAME

Abstract

The disclosure relates to a tobacco material including a flavor material and a method of preparing the tobacco material. The tobacco material may have a core-shell structure in which a core includes a first tobacco mixture and a flavor material and is surrounded by a shell including a second tobacco mixture, such that the aerosol generating article including the tobacco material generates a characteristic flavor.

Description

TECHNICAL FIELD

The disclosure relates to a tobacco material including a flavor material and a method of preparing the same.

BACKGROUND ART

Recently, the demand for alternatives to a traditional cigarette has increased. For example, there is growing demand for an aerosol generating device which generates an aerosol by heating an aerosol generating material (e.g., tobacco material) in the aerosol generating article (e.g., cigarette) without combustion.

DISCLOSURE

Technical Problem

There a need for a tobacco material including a flavor material and a method of preparing the same.

The technical objectives to be achieved by the disclosure are not limited to the above-described objectives, and other technical objectives may be inferred from the following embodiments.

Technical Solution

According to an embodiment of the disclosure, a tobacco material includes a core including a first tobacco mixture; and a shell formed around the core and including a second tobacco mixture, wherein the first tobacco mixture includes first tobacco particles and a first flavor material, and the second tobacco mixture includes second tobacco particles.

According to an embodiment of the disclosure, a method of preparing a tobacco material includes a first operation of forming a core by growing a first composition; and a second operation of forming a shell surrounding the core.

Advantageous Effects

The tobacco material according to an embodiment of the present disclosure may effectively retain a flavor, and may continuously provide a flavor to a user until the end of smoking.

In addition, according to the preparing method according to an embodiment, the tobacco material may be prepared through a relatively simple process, and a production yield may be improved.

The effects of the present disclosure are not limited to the above description, and may include all effects inferable from the configuration to be described below.

DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a tobacco material according to an embodiment.

FIG. 2A is a diagram illustrating a tobacco material according to an embodiment.

FIG. 2B is a diagram illustrating a tobacco material according to an embodiment.

FIG. 3A is a diagram illustrating a smoking article according to an embodiment.

FIG. 3B is a diagram illustrating a smoking article according to an embodiment.

FIG. 3C is a diagram illustrating a smoking article according to an embodiment.

FIG. 3D is a diagram illustrating a smoking article according to an embodiment.

FIG. 4 is a flowchart of a method of preparing a tobacco material according to an embodiment.

FIG. 5A is a diagram illustrating a first operation of a method of preparing a tobacco material according to an embodiment.

FIG. 5B is a diagram illustrating a second operation of a method of preparing a tobacco material according to an embodiment.

BEST MODE

According to one aspect of the disclosure, provided is a tobacco material including a core including a first tobacco mixture; and a shell formed around the core and including a second tobacco mixture, wherein the first tobacco mixture includes first tobacco particles and a first flavor material, and the second tobacco mixture includes second tobacco particles.

The tobacco material may include 5.0 to 8.0 parts by weight of moisture with respect to 100 parts by weight of the total tobacco material.

The second tobacco mixture may further include a second flavor material.

The first tobacco mixture may include the first flavor material in an amount less than or equal to 20 parts by weight with respect to 100 parts by weight of the first tobacco mixture.

The core may have a diameter of 0.1 mm to 0.5 mm, and the shell has a diameter of 0.4 mm to 1.2 mm.

The tobacco material may have a viscosity of 5 cps to 200 cps.

The tobacco material may have a surface roughness of 0.1 to 10.0.

According to another aspect of the disclosure, provided is a smoking article including a tobacco rod including a tobacco material described above; and a filter segment.

According to another aspect of the disclosure, provided is a method of preparing a tobacco material including a first operation of forming a core by growing a first composition; and a second operation of forming a shell surrounding the core.

The first operation may include introducing the first composition into a chamber; and growing the first composition in the chamber under conditions of a temperature in the range of about 30° C. to about 60° C., and an air pressure less than or equal to about 1.5 bar.

The second operation may include placing the core in a chamber; introducing a second composition into the chamber; and growing the second composition around the core at a temperature in a range of about 50° C. to about 90° C., and under an air pressure less than or equal to about 1.5 bar.

The first composition may include 0.1% to 20% by volume of the first flavor material.

MODE FOR INVENTION

With respect to the terms used to describe in the various embodiments, the general terms which are currently and widely used are selected in consideration of functions of structural elements in the various embodiments of the present disclosure. However, meanings of the terms can be changed according to intention, a judicial precedence, the appearance of a new technology, etc. In addition, in certain cases, a term which is not commonly used can be selected. In such a case, the meaning of the term will be described in detail at the corresponding portion in the description of the present disclosure. Therefore, the terms used in the various embodiments of the present disclosure should be defined based on the meanings of the terms and the descriptions provided herein.

In addition, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. In addition, the terms “-er”, “-or”, and “module” described in the specification mean units for processing at least one function and operation and can be implemented by hardware components or software components and combinations thereof.

Throughout the specification, a “core-shell structure” means a structure in which a core is located inside and a shell is located outside of the core. For example, the core-shell structure may mean a capsule structure in which a core is surrounded by a film.

Throughout the specification, a “tobacco material” means all forms of a material including an ingredient derived from a tobacco plant.

Throughout the specification, “tobacco particles” means a particle form of an ingredient derived from a tobacco plant. For example, the tobacco particles may be tobacco grains or tobacco powder.

Throughout the specification, a “smoking article” means an article used by a user to smoke. The smoking article may be, for example, a combustible cigarette, or may be an aerosol generating article that is heated without being combusted by an aerosol-generating device.

Throughout the specification, “surface roughness” means a degree of roughness of a surface of an object. For example, the surface roughness may be expressed as a centerline average roughness Ra according to the KS B 0161 standard.

Throughout the specification, the term “parts by weight” refers to a value calculated with respect to 100 parts by weight of the tobacco material, unless stated otherwise.

Furthermore, in the following embodiments, while such terms as “first,” “second,” etc., may be used to describe various components, such components must not be limited to the above terms. The above terms are used only to distinguish one component from another.

Hereinafter, the present disclosure will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the present disclosure are shown such that one of ordinary skill in the art may easily work the present disclosure. The disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

FIG. 1 is a diagram illustrating a tobacco material 100 according to an embodiment.

The tobacco material 100 may have a core-shell structure, and may include a core 110 including a first tobacco mixture, and a shell 120 including a second tobacco mixture. Specifically, the first tobacco mixture may be located in the center of the tobacco material 100, and the second tobacco mixture may be located outside the tobacco material 100. The first tobacco mixture may be partially or completely surrounded by the second tobacco mixture.

The core 110 may include the first tobacco mixture. The first tobacco mixture may include first tobacco particles and a first flavor material.

The first tobacco particles may be, for example, tobacco powder having a size of about 0.1 mm to about 0.3 mm, but are not limited thereto.

The first tobacco particles may include various types of tobacco powder. The first tobacco particles may include, for example, at least one of flue-cured tobacco powder, burley tobacco powder, and native tobacco powder (e.g., fire-cured tobacco powder, sun-cured tobacco powder, and air-cured tobacco powder).

The first flavor material may be a material emitting a specific flavor. For example, the first flavor material may include a plant flavor such as cinnamon, sage, herbs, chamomile, reeds, chamomile, lavender, bergamot, lemon, orange, jasmine, ginger, vanilla, spearmint, peppermint, acacia, coffee, celery, sandalwood, cocoa, etc.

As another example, the first flavor material may include an animal flavor such as musk, ambergris, civet, castrium, etc.

As another example, the first flavor material may be an alcohol compound such as menthol, geraniol, linalol, anethol, eugenol, etc. In addition, the first flavor material may be an aldehyde compound such as vanillin, benzaldehyde, anisaldehyde, etc. In addition, the first flavor material may be an ester compound such as isoamyl acetate, linaryl acetate, isoamyl propionate, linaryl butyrate, etc. The first flavor material may preferably be menthol.

An amount of the first flavor material may be equal to or less than about 20 parts by weight with respect to 100 parts by weight of the first tobacco mixture. However, the present disclosure is not particularly limited thereto, and various weights of the first flavor material may be included.

The first tobacco mixture may be, for example, a tobacco paste including the first tobacco particles and the first flavor material. The first tobacco mixture may have a suitable viscosity by being formed using a solvent such as water or ethanol. Even after the solvent is removed, the first tobacco mixture may retain moisture. A process of preparing the first tobacco mixture will be described in detail below.

The shell 120 may include the second tobacco mixture. The second tobacco mixture may include second tobacco particles. The description of the first tobacco particles given above may be applied to the second tobacco particles in the same or similar way.

The second tobacco mixture may be, for example, a tobacco paste including the second tobacco particles. The second tobacco mixture may have a suitable viscosity by being formed using a solvent such as water or ethanol. Even after the solvent is removed, the second tobacco mixture may retain moisture. A process of preparing the second tobacco mixture will be described in detail below.

In an embodiment, the second tobacco mixture may further include a second flavor material. The description of the first flavor material given above may be applied to the second flavor material in the same or similar way.

When the second tobacco mixture further includes the second flavor material, the tobacco material 100 may also generate a flavor on a surface of the shell 120. Accordingly, the tobacco material 100 may generate a flavor even before smoking starts and in the early stage of smoking.

The core 110 may have a diameter d1. The diameter d1 may be, for example, about 0.1 mm to about 0.5 mm, but is not necessarily limited thereto. The shell 120 may have a diameter d2. Also, d2 may be, for example, about 0.4 mm to about 1.2 mm, but is not necessarily limited thereto.

The tobacco material 100 may contain moisture of about 5.0 to about 8.0 parts by weight. In a case where the tobacco material 100 contains moisture of the above-described numerical range, at least one characteristic of hardness, flavor retention, and flavor expression of the tobacco material 100 may be improved. When the tobacco material 100 contains moisture less than about 5.0 parts by weight, the flavor expression of the tobacco material 100 may be reduced. When the tobacco material 100 contains moisture exceeding about 8.0 parts by weight, the tobacco material 100 may have a low hardness.

Meanwhile, the core 110 may contain moisture of about 8.0 to about 15.0 parts by weight. In a case where the core 110 contains moisture of the above-described numerical range, at least one characteristic of flavor retention and flavor expression of the core 110 may be improved. In addition, a moisture content of the core 110 is greater than a moisture content of the shell 120, and thus the tobacco material 100 may have excellent hardness, flavor retention, and flavor expression.

The tobacco material 100 may not include a binder. In general, in order to prepare the robust tobacco mixture, the tobacco material 100 may include a binder such as hydroxypropylmethylcellulose (HPMC) or carboxymethylcellulose (CMC). However, according to the present disclosure, the tobacco material 100 may have excellent characteristics such as durability, hardness, viscosity, etc. without including the above-described binder.

The tobacco material 100 may have a viscosity of about 5 cps to about 200 cps. In a case where the tobacco material 100 has a viscosity of the above-described numerical range, at least one characteristic of hardness, flavor retention, and flavor expression of the tobacco material 100 may be improved. The viscosity of the tobacco material 100 may be adjusted according to an amount of moisture.

The tobacco material 100 may have a hardness equal to or greater than about 90%. Specifically, the tobacco material 100 may have a hardness of about 95% to about 99.9%. A “hardness of a tobacco material” is a physical property related to elasticity and recovery, and means a degree of resistance to pressure applied to the tobacco material 100. The “hardness of a tobacco material” is measured using a hardness meter, and is calculated through an equation below.

Hardness (%)=[D−a]*100/D

(D: diameter of the tobacco material, and a: distance (mm) that the tobacco material is pressed by a weight of 300 g)

The tobacco material 100 may have a density of about 0.60 to about 0.90 g/cc. Preferably, the tobacco material 100 may have a density of about 0.62 to about 0.75 g/cc.

Tobacco material 100 may have the surface roughness Ra of about 0.1 to about 10.0. The surface roughness of the tobacco material 100 will be described in detail below with reference to FIGS. 2A and 2B.

Tobacco material 100 may generate a flavor during combustion or heating by including the flavor material in the core 110. As an example, when the flavor material is not included in the shell 120, the tobacco material 100 may not generate a flavor in the early stage of smoking.

As another example, when the first flavor material is included in the core 110 and the second flavor material is included in the shell 120, the tobacco material 100 may generate a flavor by the second flavor material in the early stage of smoking and may generate a flavor by the first flavor material thereafter. Accordingly, a smoker may receive a flavor that varies over time while smoking.

FIG. 2A is a diagram illustrating a tobacco material 200 according to an embodiment.

Referring to FIG. 2A, the tobacco material 200 includes a core 210 and a shell 220. The core 210 may include a first tobacco mixture, and the shell 220 may include a second tobacco mixture. The descriptions given above with reference to FIG. 1 may be applied to the core 210 and the shell 220 in the same or similar way.

The tobacco material 200 may have a shape of a sphere as a whole. The core 210 has the shape of the sphere, and thus the shell 220 formed around the core 210 may also have a shape of a sphere. A surface of the shell 220 may have, for example, the surface roughness Ra of about 0.1 to about 10.0. In a case where the surface of the shell 220 has the surface roughness Ra of the numerical range described above, a flavor expression of the tobacco material 200 may be improved, and a rather smooth surface may be formed. Accordingly, the number of the tobacco materials 200 filled in a smoking article (not shown) may be increased.

In addition, the flavor expression of the tobacco material 200 may be adjusted, by adjusting a porosity of the surface of the shell 220.

FIG. 2B is a diagram illustrating a tobacco material 300 according to an embodiment.

Referring to FIG. 2B, the tobacco material 300 includes a core 310 and a shell 320. The core 310 may include a first tobacco mixture, and the shell 320 may include a second tobacco mixture. The descriptions given above with reference to FIG. 1 may be applied to the core 310 and the shell 320 in the same or similar way.

The tobacco material 300 may have an atypical shape as a whole. When a shape of the core 310 is not completely spherical, a shape of the shell 320 that grows around the core 310 during a process of preparing the tobacco material 300 may also not be completely spherical. Accordingly, as shown in FIG. 2B, the tobacco material 300 may have an uneven shape. In this case, a surface of the shell 320 may have the surface roughness Ra of about 5.0 to about 10.0. As the surface roughness Ra of the surface of the shell 320 increases, a flavor expression may be improved. In addition, when a plurality of tobacco materials 300 are filled in a smoking article (not shown), the plurality of tobacco materials 300 may be stably retained in the smoking article by a frictional force. Also, a surface area of the tobacco material 300 is increased, and thus an amount of nicotine transferred during heating may be increased.

FIG. 3A is a diagram illustrating a smoking article 400 according to an embodiment. The smoking article 400 may be, for example, a combustive cigarette.

Referring to FIG. 3A, the smoking article 400 may include a first portion 410 and a second portion 420. The first portion 410 may be a tobacco rod, and the second portion 420 may be a filter segment.

The first portion 410 may include a plurality of tobacco materials 411. The tobacco material 411 may have the core-shell structure described above. The first portion 410 may be ignited and combusted by a user.

The second portion 420 may be the filter segment. The second portion 420 may include a filter material. For example, the second portion 420 may be a cellulose acetate filter. The second portion 420 may be a cylindrical filter or a hollow filter, but a shape of the second portion 420 is not particularly limited. The user may smoke while holding the second portion 420 in his/her mouth.

When the first portion 410 is combusted, a flavor may be generated from the plurality of tobacco materials 411. For example, when the tobacco material 411 includes menthol in a core, a menthol flavor may not be generated in the early stage of smoking, but the menthol flavor may be generated as smoking progresses.

As another example, when the tobacco material 411 contains menthol in the core and also in a surface of a shell, the menthol flavor may be generated even before smoking begins and in the early stage of smoking, and the menthol flavor may be continuously generated through the rest of smoking.

FIG. 3B is a diagram illustrating a smoking article 500 according to an embodiment. The smoking article 500 may be, for example, an article that generates an aerosol without combustion when heated.

The smoking article 500 may include a first portion 510, a second portion 520, a third portion 530, and a fourth portion 540. The first portion 510, the second portion 520, the third portion 530, and the fourth portion 540 may be sequentially arranged in a longitudinal direction of the smoking article 500.

The first portion 510 may include a tobacco material 511. The tobacco material 511 may be a tobacco material having the core-shell structure described above. The first portion 510 may further include an aerosol generating material. The aerosol generating material may be applied, for example, to a surface of the tobacco material 511. The aerosol generating material may be, for example, at least one of glycerin, propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and oleyl alcohol. The first portion 510 may be heated by an aerosol generating device (not shown).

The second portion 520 may serve as a support for supporting the smoking article 500. As a specific example, the second portion 520 may be a hollow filter. The second portion 520 may serve to connect and support the first portion 510 and the third portion 530.

The third portion 530 may be a cooling portion that cools an airflow (i.e., aerosol). As a specific example, the third portion 530 may be a hollow tube or a paper tube. The hollow tube or the paper tube may include a venting area (not shown) that introduces external air into the smoking article 500. The third portion 530 may serve to cool an aerosol generated from the first portion 510.

The fourth portion 540 may be a filter segment. The fourth portion 540 may include a filter material. For example, the fourth portion 540 may be a cellulose acetate filter. The fourth portion 540 may be a cylindrical filter or a hollow filter, but a shape of the fourth portion 540 is not particularly limited. A user may smoke while holding the fourth portion 540 in his/her mouth.

FIG. 3C is a diagram illustrating a smoking article 600 according to an embodiment. The smoking article 600 may generate an aerosol without combustion when heated.

Referring to FIG. 3C, the smoking article 600 may include a first portion 610, a second portion 620, a third portion 630, and a fourth portion 640. The first portion 610, the second portion 620, the third portion 630, and the fourth portion 640 may be sequentially arranged in a longitudinal direction of the smoking article 600.

The first portion 610 may be a filter segment. For example, the first portion 610 may be a cellulose acetate filter including a hollow of a specific shape. As a specific example, the first portion 610 may be a cellulose acetate filter including a -shaped hollow. However, the present disclosure is not necessarily limited thereto.

The second portion 620 may include a tobacco material 621. The tobacco material 621 may have the core-shell structure described above. The second portion 620 may further include an aerosol generating material. The aerosol-generating material may be applied, for example, to a surface of the tobacco material 621. The aerosol generating material may be, for example, at least one of glycerin, propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and oleyl alcohol. The second portion 620 may be heated by an aerosol generating device (not shown).

The third portion 630 may be a cooling portion that cools an airflow. As a specific example, the third portion 630 may be a hollow tube or a paper tube. The hollow tube or the paper tube may include a venting area (not shown) that introduces external air into the smoking article 600. The third portion 630 may serve to cool an aerosol.

The fourth portion 640 may be a filter segment. The fourth portion 640 may include a filter material. For example, the fourth portion 640 may be a cellulose acetate filter. The fourth portion 640 may be a cylindrical filter or a hollow filter, but a shape of the fourth portion 640 is not particularly limited. A user may smoke while holding the fourth portion 640 in his/her mouth.

FIG. 3D is a diagram illustrating a smoking article 700 according to an embodiment. The smoking article 700 may generate an aerosol without combustion when heated.

Referring to FIG. 3D, the smoking article 700 may include a first portion 710, a second portion 720, a third portion 730, and a fourth portion 740. The first portion 710, the second portion 720, the third portion 730, and the fourth portion 740 may be sequentially arranged in a longitudinal direction of the smoking article 700.

The first portion 710 may be an aerosol generating portion. The aerosol generating portion may include, for example, a paper sheet in which an aerosol generating material is impregnated. The aerosol generating material may be, for example, at least one of glycerin, propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and oleyl alcohol. The first portion 710 may be heated by an aerosol generating device (not shown).

The second portion 720 may be a nicotine generating portion. The second portion 720 may include a tobacco material 721. The tobacco material 721 may have the core-shell structure described above. In addition, the second portion 720 may include, for example, a paper sheet in which the tobacco material 721 and the aerosol generating material are impregnated. The second portion 720 may be heated by an aerosol generating device (not shown).

The third portion 730 may be a cooling portion that cools an airflow. As a specific example, the third portion 730 may be a hollow tube or a paper tube. The hollow tube or a paper tube may include a venting area (not shown) that introduces external air into the smoking article 700. The third portion 730 may serve to cool an aerosol.

The fourth portion 740 may be a filter segment. The fourth portion 740 may include a filter material. For example, the fourth portion 740 may be a cellulose acetate filter. The fourth portion 740 may be a cylindrical filter or a hollow filter, but a shape of the fourth portion 740 is not particularly limited. A user may smoke while holding the fourth portion 740 in his/her mouth.

FIG. 4 is a flowchart of a method S100 of preparing a tobacco material according to an embodiment. Referring to FIG. 4, the method S100 of preparing the tobacco material may include first operation S110 and second operation S120.

First operation S110 may be an operation of forming a core of the tobacco material by growing a first composition. The first composition may include tobacco powder, water, and a flavor material. Specifically, the first composition may include the flavor material of about 0.1% to about 20% by volume. For example, the first composition may be a tobacco paste containing the flavor material.

Specifically, in first operation S110, the first composition may be floating in a chamber, and may be dried by hot air for about 6 hours while receiving water at a temperature equal to or less than about 60° C.

Second operation S120 may be an operation of forming a shell around the core of the tobacco material. The shell may be formed using a second composition. The second composition may include tobacco powder and water. Specifically, the second composition may include tobacco powder of about 40% to about 70% by volume, and water of about 30% to about 60% by volume. For example, the second composition may be a tobacco paste.

The tobacco material prepared through first operation S110 and second operation S120 may have a core-shell structure.

The core prepared in first operation S110 may have a moisture content of about 8% to about 15% with respect to the total weight of the tobacco material. In addition, the core may have a hardness of about 85% to about 95%.

When compared with the core, the shell prepared in second operation S120 has a relatively low moisture content and a high hardness. The tobacco material prepared through second operation S120 may have a moisture content of about 5% to about 8% with respect to the total weight. In addition, the shell may have a hardness of about 95% to about 99.9%. Accordingly, the tobacco material may have a hardness of about 95% to about 99.9%.

First operation S110 and second operation S120 will be described in more detail below with reference to FIGS. 5A and 5B.

FIG. 5A is a diagram illustrating first operation S110 of a method of preparing a tobacco material according to an embodiment.

Referring to FIG. 5A, a device for preparing the tobacco material may include a storage 1100, a supplier 1200, and a chamber 1300. The storage 1100 may store a first composition A1. The supplier 1200 may supply the first composition A1 from the storage 1100 to the chamber 1300. The chamber 1300 may be a place where the first composition A1 is formed into a core S of the tobacco material. The chamber 1300 may include an inlet 1310 into which air flows from the outside.

First operation S110 may include moving the first composition A1 from the storage 1100 to the supplier 1200. Accordingly, the first composition A1 may be introduced into the chamber 1300 from the supplier 1200.

The first composition A1 may be grown in the chamber 1300 at a temperature in the range of about 30° C. to about 60° C., and an air pressure equal to or lower than about 1.5 bar. External air may flow from outside of the chamber 1300 to inside through the inlet 1310. Accordingly, the first composition A1 may be grown by agglomeration, thereby forming the core S of the tobacco material.

FIG. 5B is a diagram illustrating second operation S120 of a method of preparing a tobacco material according to an embodiment. The descriptions given above with reference to FIG. 5A may be applied to a device for preparing the tobacco material in the same or similar way.

Referring to FIG. 5B, in second operation S120, the core S formed in first operation S110 may be located in the chamber 1300, and a second composition A2 may be input into the chamber 1300 from the supply unit 1200.

The second composition A2 may be grown around the core S in the chamber 1300 where a temperature is in the range of about 50° C. to about 90° C., and an air pressure is equal to or lower than about 1.5 bar. External air may be introduced from outside of the chamber 1300 to inside through the inlet 1310. Accordingly, the second composition A2 may be agglomerated around the core S to grow into a shell. Through first operation S120 and second operation S120, the tobacco material of the core-shell structure may be obtained.

Unlike the first composition A1, the second composition A2 may include ethanol. As such, a drying time of the shell may be reduced, and hardness and roughness of the shell may be appropriately adjusted. In addition, the shell may be sterilized and an off-flavor may be removed.

In an embodiment, the first composition A1 in first operation S110 may be grown at a lower temperature than the second composition A2 in second operation S120. The first composition A1 contains a first flavor material, and thus growing at a lower temperature than the second composition A2 may be advantageous in improving flavor retention and flavor expression of the tobacco material.

Although not shown in FIG. 5B, the method of preparing the tobacco material may further include a third operation. The third operation may be an operation of adding a second flavor material to a surface of the tobacco material having a core-shell structure formed in second operation S120. The second flavor material may be, for example, a material usable as the first flavor material, and the second flavor material may be sprayed onto a surface of the shell of the tobacco material.

In an embodiment, when the tobacco material of the core-shell structure prepared through first to third operations is heated or combusted, the tobacco material may emit a flavor by the second flavor material before and in the early stage of smoking, and emit a flavor by the first flavor material through the rest of smoking.

It will be understood by one of ordinary skill in the art related to the present embodiment that the present embodiment may be implemented in a modified form within a range that does not depart from the essential characteristics of the above description. Therefore, the disclosed embodiments are to be considered to be illustrative but not restrictive. The scope of the present disclosure is presented in the claims rather than by the foregoing description, and all differences within the scope of equivalents thereto should be construed as being included in the present disclosure.

Claims

1. A tobacco material comprising:

a core comprising a first tobacco mixture; and

a shell formed around the core and comprising a second tobacco mixture,

wherein the first tobacco mixture comprises first tobacco particles and a first flavor material, and

the second tobacco mixture comprises second tobacco particles.

2. The tobacco material of claim 1, wherein the tobacco material comprises 5.0 to 8.0 parts by weight of moisture with respect to 100 parts by weight of the tobacco material.

3. The tobacco material of claim 1, wherein the second tobacco mixture further comprises a second flavor material.

4. The tobacco material of claim 1, wherein the first tobacco mixture comprises the first flavor material in an amount less than or equal to 20 parts by weight with respect to 100 parts by weight of the first tobacco mixture.

5. The tobacco material of claim 1, wherein the core has a diameter of 0.1 mm to 0.5 mm, and the shell has a diameter of 0.4 mm to 1.2 mm.

6. The tobacco material of claim 1, wherein the tobacco material has a viscosity of 5 cps to 200 cps.

7. The tobacco material of claim 1, wherein the tobacco material has a surface roughness of 0.1 to 10.0.

8. A smoking article comprising:

a tobacco rod comprising the tobacco material according to claim 1; and

a filter segment.

9. A method of preparing a tobacco material, the method comprising:

a first operation of forming a core by growing a first composition; and

a second operation of forming a shell surrounding the core.

10. The method of claim 9, wherein the first operation comprises:

introducing the first composition into a chamber; and

growing the first composition at a temperature in a range of about 30° C. to about 60° C., and under an air pressure less than or equal to about 1.5 bar.

11. The method of claim 9, wherein the second operation comprises:

placing the core in a chamber;

introducing a second composition into the chamber; and

growing the second composition around the core in the chamber under conditions of a temperature in a range of about 50° C. to about 90° C., and an air pressure less than or equal to about 1.5 bar.

12. The method of claim 9, wherein the first composition comprises a first flavor material in an amount of 0.1% to 20% by volume.

13. The method of claim 9, further comprising a third operation of adding a second flavor material to a surface of the formed shell.