TECHNICAL FIELD
[0001] One or more embodiments relate to a cellulose acetate tow, a filter including the
               same, and an aerosol generating article including the filter.
 
            BACKGROUND ART
[0002] Recently, the demand for alternative methods to overcome the disadvantages of traditional
               cigarettes has increased. For example, there is growing demand for an aerosol generating
               device which generates aerosol by heating an aerosol generating material, rather than
               by combusting cigarettes. Accordingly, research into a smoking article or device operating
               in various ways has been actively conducted.
 
            DESCRIPTION OF EMBODIMENTS
TECHNICAL PROBLEM
[0003] A heated cigarette that generates aerosol as an aerosol generating material in the
               cigarette is heated provides a relatively less amount of smoke to a user than a previous
               traditional combustion cigarette, due to a relatively high absorption resistance and
               an aerosol removal capacity of a filter. Thus, research into increasing the amount
               of smoke provided to a user by the heated cigarette has been required.
 
            [0004] The objectives of one or more embodiments are to provide an aerosol generating article
               including a cellulose acetate tow for realizing a filter having a low absorption resistance;
               and a filter having a low absorption resistance.
 
            [0005] The problems to be solved by one or more embodiments are not limited to those described
               above, and other objectives that are not described may be clearly understood by one
               of ordinary skill in the art from the present specification and the accompanying drawings.
 
            SOLUTION TO PROBLEM
[0006] As a means for achieving the technical objectives described above, one or more embodiments
               provide an aerosol generating article including: a first portion including an aerosol
               generating material impregnated with an aerosol generating element; a second portion
               including a tobacco element; a third portion including a cooling element; and a fourth
               portion including a filter element, wherein the first portion, the second portion,
               the third portion, and the fourth portion are sequentially arranged in a longitudinal
               direction of the aerosol generating article, and the filter element includes a cellulose
               acetate tow having a denier per filament of about 17 to about 29 and a total denier
               of about 10,000 to about 40,000.
 
            [0007] One or more embodiments provide a filter including a cellulose acetate tow having
               a denier per filament of about 17 to about 29 and a total denier of about 10,000 to
               about 40,000.
 
            [0008] One or more embodiments provide a cellulose acetate tow having a denier per filament
               of about 17 to about 29 and a total denier of about 10,000 to about 40,000.
 
            [0009] The means for solving the problems is not limited thereto and may include all configurations
               which may be derived throughout the specification by one of ordinary skill in the
               art.
 
            ADVANTAGEOUS EFFECTS OF DISCLOSURE
[0010] An aerosol generating article according to one or more embodiments may include a
               cellulose acetate tow including relatively thick fibers, and thus, may have reduced
               absorption resistance and may provide improved smoking satisfaction to a user. Also,
               while a low absorption resistance is maintained, the amount of cellulose acetate tow
               may be increased, and thus, the rigidity of the filter may be increased, and the user
               convenience may be improved.
 
            [0011] Effects of the embodiments are not limited thereto and may include all effects which
               may be derived from the configurations described below.
 
            BRIEF DESCRIPTION OF DRAWINGS
[0012] FIGS. 1 through 3 are diagrams showing examples in which an aerosol generating article
               is inserted into an aerosol generating device.
 
            [0013] FIG. 4 is a view of an example of an aerosol generating device using induction heating.
 
            [0014] FIG. 5 is a schematic view of a structure of an aerosol generating article of an
               embodiment.
 
            BEST MODE
[0015] According to one or more embodiments, an aerosol generating article includes: a first
               portion including an aerosol generating material impregnated with an aerosol generating
               element; a second portion including a tobacco element; a third portion including a
               cooling element; and a fourth portion including a filter element, wherein the first
               portion, the second portion, the third portion, and the fourth portion are sequentially
               arranged in a longitudinal direction of the aerosol generating article, and the filter
               element includes a cellulose acetate tow having a denier per filament of about 17
               to about 29 and a total denier of about 10,000 to about 40,000.
 
            [0016] The cellulose acetate tow may have a denier per filament of about 18 to about 23
               and a total denier of about 15,000 to about 35,000.
 
            [0017] The fourth portion may include about 320 mg to about 510 mg of the cellulose acetate
               tow.
 
            [0018] A circumference of a cross-section of the fourth portion, the cross-section being
               perpendicular to the longitudinal direction of the aerosol generating article, may
               be about 14 mm to about 25 mm.
 
            [0019] An absorption resistance of the fourth portion may be about 0.5 mmH
2O to about 2.5 mmH
2O.
 
            [0020] The second portion may further include the aerosol generating element, and the second
               portion may include the aerosol generating element in about 10 weight percent (wt%)
               or less with respect to a dry weight of the aerosol generating material.
 
            [0021] The first portion may include the aerosol generating element in about 65 to about
               95 weight percent (wt%) with respect to a dry weight of the aerosol generating material.
 
            [0022] According to one or more embodiments, a filter included in an aerosol generating
               article includes: a cellulose acetate tow having a denier per filament of about 17
               to about 29 and a total denier of about 10,000 to about 40,000.
 
            [0023] The cellulose acetate tow may have a denier per filament of about 18 to about 23
               and a total denier of about 15,000 to about 35,000.
 
            [0024] The filter may include about 350 mg to about 510 mg of the cellulose acetate tow.
 
            [0025] A circumference of a cross-section of the filter, the cross-section being perpendicular
               to a longitudinal direction of the filter, may be about 14 mm to about 25 mm.
 
            [0026] An absorption resistance of the filter may be about 0.5 mmH
2O to about 2.5 mmH
2O.
 
            [0027] According to one or more embodiments, a cellulose acetate tow has a denier per filament
               of about 17 to about 29 and a total denier of about 10,000 to about 40,000.
 
            [0028] The cellulose acetate tow may have a denier per filament of about 18 to about 23
               and a total denier of about 15,000 to about 35,000.
 
            MODE OF DISCLOSURE
[0029] 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, and the like. 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.
 
            [0030] 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.
 
            [0031] Also, the terms used in this specification that include ordinal numbers such as "first,"
               "second," etc. may be used to describe various components, but the components shall
               not be limited by those terms. The terms may be used for distinguishing one component
               from another component.
 
            [0032] Throughout the specification, an "aerosol generating article" refers to an article
               used for smoking. As another example, the aerosol generating article may refer to
               a general combustion cigarette that is ignited and combusted or a heated cigarette
               heated by an aerosol generating device. As another example, the aerosol generating
               article may refer to an article including a cartridge containing a liquid that is
               heated.
 
            [0033] Throughout the specification, a "longitudinal direction of the aerosol generating
               article" denotes a direction in which a length of the aerosol generating article extends
               or a direction in which the aerosol generating article is inserted into an aerosol
               generating device.
 
            [0034] Throughout the specification, a "tobacco element" denotes an element including a
               tobacco material.
 
            [0035] Throughout the specification, a "tobacco material" denotes all types of materials
               including a component originated from a tobacco leaf.
 
            [0036] Throughout the specification, a "cooling element" denotes an element for cooling
               a material. For example, the cooling element may cool aerosol generated from an aerosol
               generating element or a tobacco element.
 
            [0037] Throughout the specification, a "filter element" denotes an element including a filtering
               material. For example, the filter element may include a plurality of fiber strands.
 
            [0038] Throughout the specification, a "denier per filament" denotes a denier of fibers,
               represented by a weight (g) of a strand of cellulose acetate fiber per 9000 m that
               is a unit length.
 
            [0039] Throughout the specification, the "total denier" denotes a denier of a tow, represented
               by a weight (g) of the tow per 9000 m that is a unit length.
 
            [0040] Hereinafter, embodiments of the disclosure are described in detail with reference
               to the accompanying drawings so that one of ordinary skill in the art may easily execute
               the embodiments of the disclosure. However, the disclosure may be embodied in many
               different forms and should not be construed as being limited to the embodiments set
               forth herein.
 
            [0041] Hereinafter, embodiments of the present disclosure will be described in detail with
               reference to the drawings.
 
            [0042] FIGS. 1 through 3 are diagrams showing examples in which an aerosol generating article
               is inserted into an aerosol generating device.
 
            [0043] Referring to FIG. 1, the aerosol generating device 100 may include a battery 110,
               a controller 120, and a heater 130.
 
            [0044] Referring to FIGS. 2 and 3, the aerosol generating device 100 may further include
               a vaporizer 140. Also, the aerosol generating article 200 may be inserted into an
               inner space of the aerosol generating device 100.
 
            [0045] FIGS. 1 through 3 illustrate components of the aerosol generating device 100, which
               are related to the present embodiment. Therefore, it will be understood by one of
               ordinary skill in the art related to the present embodiment that other general-purpose
               components may be further included in the aerosol generating device 100, in addition
               to the components illustrated in FIGS. 1 through 3.
 
            [0046] Also, FIGS. 2 and 3 illustrate that the aerosol generating device 100 includes the
               heater 130. However, as necessary, the heater 130 may be omitted.
 
            [0047] FIG. 1 illustrates that the battery 110, the controller 120, and the heater 130 are
               arranged in series. Also, FIG. 2 illustrates that the battery 110, the controller
               120, the vaporizer 140, and the heater 130 are arranged in series. Also, FIG. 3 illustrates
               that the vaporizer 140 and the heater 130 are arranged in parallel. However, the internal
               structure of the aerosol generating device 100 is not limited to the structures illustrated
               in FIGS. 1 through 3. In other words, according to the design of the aerosol generating
               device 100, the battery 110, the controller 120, the heater 130, and the vaporizer
               140 may be differently arranged.
 
            [0048] When the aerosol generating article 200 is inserted into the aerosol generating device
               100, the aerosol generating device 100 may operate the heater 130 and/or the vaporizer
               140 to generate aerosol from the aerosol generating article 200 and/or the vaporizer
               140. The aerosol generated by the heater 130 and/or the vaporizer 140 is delivered
               to a user by passing through the aerosol generating article 200.
 
            [0049] As necessary, even when the aerosol generating article 200 is not inserted into the
               aerosol generating device 100, the aerosol generating device 100 may heat the heater
               130.
 
            [0050] The battery 110 may supply power to be used for the aerosol generating device 100
               to operate. For example, the battery 110 may supply power to heat the heater 130 or
               the vaporizer 140, and may supply power for operating the controller 120. Also, the
               battery 110 may supply power for operations of a display, a sensor, a motor, etc.
               mounted in the aerosol generating device 100.
 
            [0051] The controller 120 may generally control operations of the aerosol generating device
               100. In detail, the controller 120 may control not only operations of the battery
               110, the heater 130, and the vaporizer 140, but also operations of other components
               included in the aerosol generating device 100. Also, the controller 120 may check
               a state of each of the components of the aerosol generating device 100 to determine
               whether or not the aerosol generating device 100 is able to operate.
 
            [0052] The controller 120 may include at least one processor. A processor can be implemented
               as an array of a plurality of logic gates or can be implemented as a combination of
               a general-purpose microprocessor and a memory in which a program executable in the
               microprocessor is stored. It will be understood by one of ordinary skill in the art
               that the processor can be implemented in other forms of hardware.
 
            [0053] The heater 130 may be heated by the power supplied from the battery 110. For example,
               when the aerosol generating article 200 is inserted into the aerosol generating device
               100, the heater 130 may be located outside the aerosol generating article 200. Thus,
               the heated heater 130 may increase a temperature of an aerosol generating material
               in the aerosol generating article 200.
 
            [0054] The heater 130 may include an electro-resistive heater. For example, the heater 130
               may include an electrically conductive track, and the heater 130 may be heated when
               currents flow through the electrically conductive track. However, the heater 130 is
               not limited to the example described above and may include all heaters which may be
               heated to a desired temperature. Here, the desired temperature may be pre-set in the
               aerosol generating device 100 or may be set by a user.
 
            [0055] As another example, the heater 130 may include an induction heater. In detail, the
               heater 130 may include an electrically conductive coil for heating an aerosol generating
               article in an induction heating method, and the aerosol generating article may include
               a susceptor which may be heated by the induction heater.
 
            [0056] For example, the heater 130 may include a tube-type heating element, a plate-type
               heating element, a needle-type heating element, or a rod-type heating element, and
               may heat the inside or the outside of the aerosol generating article 200, according
               to the shape of the heating element.
 
            [0057] Also, the aerosol generating device 100 may include a plurality of heaters 130. Here,
               the plurality of heaters 130 may be inserted into the aerosol generating article 200
               or may be arranged outside the aerosol generating article 200. Also, some of the plurality
               of heaters 130 may be inserted into the aerosol generating article 200 and the others
               may be arranged outside the aerosol generating article 200. In addition, the shape
               of the heater 130 is not limited to the shapes illustrated in FIGS. 1 through 3 and
               may include various shapes.
 
            [0058] The vaporizer 140 may generate aerosol by heating a liquid composition and the generated
               aerosol may pass through the aerosol generating article 200 to be delivered to a user.
               In other words, the aerosol generated via the vaporizer 140 may move along an air
               flow passage of the aerosol generating device 100 and the air flow passage may be
               configured such that the aerosol generated via the vaporizer 140 passes through the
               aerosol generating article 200 to be delivered to the user.
 
            [0059] For example, the vaporizer 140 may include a liquid storage, a liquid delivery element,
               and a heating element, but it is not limited thereto. For example, the liquid storage,
               the liquid delivery element, and the heating element may be included in the aerosol
               generating device 100 as independent modules.
 
            [0060] The liquid storage may store a liquid composition. For example, the liquid composition
               may be a liquid including a tobacco-containing material having a volatile tobacco
               flavor component, or a liquid including a non-tobacco material. The liquid storage
               may be formed to be detachable from the vaporizer 140 or may be formed integrally
               with the vaporizer 140.
 
            [0061] For example, the liquid composition may include water, a solvent, ethanol, plant
               extract, spices, flavorings, or a vitamin mixture. The spices may include menthol,
               peppermint, spearmint oil, and various fruit-flavored ingredients, but are not limited
               thereto. The flavorings may include ingredients capable of providing various flavors
               or tastes to a user. Vitamin mixtures may be a mixture of at least one of vitamin
               A, vitamin B, vitamin C, and vitamin E, but are not limited thereto. Also, the liquid
               composition may include an aerosol forming substance, such as glycerin and propylene
               glycol.
 
            [0062] The liquid delivery element may deliver the liquid composition of the liquid storage
               to the heating element. For example, the liquid delivery element may be a wick such
               as cotton fiber, ceramic fiber, glass fiber, or porous ceramic, but is not limited
               thereto.
 
            [0063] The heating element is an element for heating the liquid composition delivered by
               the liquid delivery element. For example, the heating element may be a metal heating
               wire, a metal hot plate, a ceramic heater, or the like, but is not limited thereto.
               In addition, the heating element may include a conductive filament such as nichrome
               wire and may be positioned as being wound around the liquid delivery element. The
               heating element may be heated by a current supply and may transfer heat to the liquid
               composition in contact with the heating element, thereby heating the liquid composition.
               As a result, aerosol may be generated.
 
            [0064] For example, the vaporizer 140 may be referred to as a cartomizer or an atomizer,
               but it is not limited thereto.
 
            [0065] The aerosol generating device 100 may further include general-purpose components
               in addition to the battery 110, the controller 120, the heater 130, and the vaporizer
               140. For example, the aerosol generating device 100 may include a display capable
               of outputting visual information and/or a motor for outputting haptic information.
               Also, the aerosol generating device 100 may include at least one sensor (a puff sensor,
               a temperature sensor, an aerosol generating article insertion detecting sensor, etc.).
               Also, the aerosol generating device 100 may be formed as a structure that, even when
               the aerosol generating article 200 is inserted into the aerosol generating device
               100, may introduce external air or discharge internal air.
 
            [0066] Although not illustrated in FIGS. 1 through 3, the aerosol generating device 100
               and an additional cradle may form together a system. For example, the cradle may be
               used to charge the battery 110 of the aerosol generating device 100. Alternatively,
               the heater 130 may be heated when the cradle and the aerosol generating device 100
               are coupled to each other.
 
            [0067] The aerosol generating article 200 may be similar to a general combustive cigarette.
               For example, the aerosol generating article 200 may be divided into a first portion
               including an aerosol generating material and a second portion including a filter,
               etc. Alternatively, the second portion of the aerosol generating article 200 may also
               include an aerosol generating material. For example, an aerosol generating material
               made in the form of granules or capsules may be inserted into the second portion.
 
            [0068] The entire first portion may be inserted into the aerosol generating device 100,
               and the second portion may be exposed to the outside. Alternatively, only a portion
               of the first portion may be inserted into the aerosol generating device 100, or the
               entire first portion and a portion of the second portion may be inserted into the
               aerosol generating device 100. The user may puff aerosol while holding the second
               portion by the mouth of the user. In this case, the aerosol is generated by the external
               air passing through the first portion, and the generated aerosol passes through the
               second portion and is delivered to the user's mouth.
 
            [0069] For example, the external air may flow into at least one air passage formed in the
               aerosol generating device 100. For example, opening and closing of the air passage
               and/or a size of the air passage formed in the aerosol generating device 100 may be
               adjusted by the user. Accordingly, the amount and the quality of smoking may be adjusted
               by the user. As another example, the external air may flow into the aerosol generating
               article 200 through at least one hole formed in a surface of the aerosol generating
               article 200.
 
            [0070] FIG. 4 is a view of an example of an aerosol generating device using induction heating.
 
            [0071] Referring to FIG. 4, the aerosol generating device 100 may include the battery 110,
               the controller 120, a coil C, and a susceptor S. Also, at least a portion of the aerosol
               generating article 200 may be accommodated in a cavity V of the aerosol generating
               device 100. The aerosol generating article 200, the battery 110, and the controller
               120 of FIG. 4 may correspond to the aerosol generating article 200, the battery 110,
               and the controller 120 of FIGS. 1 through 3. Also, the coil C and the susceptor S
               may be included in the heater 13000. Thus, the same descriptions are omitted.
 
            [0072] With respect to the aerosol generating device 100 illustrated in FIG. 4, components
               related to the present embodiment are illustrated. Therefore, it will be understood
               by one of ordinary skill in the art that other general-purpose components may further
               be included in the aerosol generating device 100, in addition to the components illustrated
               in FIG. 4.
 
            [0073] The coil C may be located around the cavity V. FIG. 4 illustrates that the coil C
               is arranged to surround the cavity V. However, it is not limited thereto.
 
            [0074] When the aerosol generating article 200 is accommodated in the cavity V of the aerosol
               generating device 100, the aerosol generating device 100 may supply power to the coil
               C for the coil C to generate a magnetic field. As the magnetic field generated by
               the coil C penetrates through the susceptor S, the susceptor S may be heated.
 
            [0075] The induction heating described above is a well-known phenomenon that is explained
               by the Faraday's law of induction. In detail, when magnetic induction in the susceptor
               S is changed, an electric field may be generated in the susceptor S so that an eddy
               current may flow in the susceptor S. The eddy current may generate heat that is proportional
               to a current density and an conductor resistance in the susceptor S.
 
            [0076] When the susceptor S is heated by the eddy current, and an aerosol generating material
               in the aerosol generating article 200 is heated by the heated susceptor S, aerosol
               may be generated. The aerosol generated from the aerosol generating material may be
               transferred to a user after passing through the aerosol generating article 200.
 
            [0077] The battery 110 may supply power for the coil C to generate a magnetic field. The
               controller 120 may be electrically connected to the coil C.
 
            [0078] The coil C may be an electrically conductive coil configured to generate a magnetic
               field from the power supplied from the battery 110. The coil C may be arranged to
               surround at least a portion of the cavity V. The magnetic field generated by the coil
               C may be applied to the susceptor S arranged at an inner end of the cavity V.
 
            [0079] The susceptor S may be heated as the magnetic field generated from the coil C passes
               therethrough and may include metal or carbon. For example, the susceptor S may include
               at least one of a ferrite, a ferromagnetic alloy, stainless steel, and Al.
 
            [0080] The susceptor S may include at least one of ceramics, such as graphite, Mo, silicon
               carbide, Nb, a nickel alloy, a metal film, zirconia, etc., a transition metal, such
               as Ni, Co, etc., and a metalloid, such as B, P. etc. However, the susceptor is not
               limited to the example described above and may include any material which may be heated
               to a desired temperature when a magnetic field is applied thereto. Here, the desired
               temperature may be predetermined in the aerosol generating device 100 or may be set
               as a desired temperature by a user.
 
            [0081] When the aerosol generating article 200 is inserted into the cavity V of the aerosol
               generating device 100, the susceptor S may be arranged to surround at least a portion
               of the aerosol generating article 200. Thus, the heated susceptor S may increase a
               temperature of the aerosol generating material in the aerosol generating article 200.
 
            [0082] FIG. 4 illustrates that the susceptor S is arranged to surround at least a portion
               of the aerosol generating article. However, the susceptor S is not limited thereto.
               For example, the susceptor S may include a tube-type heating element, a plate-type
               heating element, a needle-type heating element, or a rod-type heating element and
               may heat inside or outside the aerosol generating article 200 according to a shape
               of the heating element.
 
            [0083] Also, the susceptor S may be arranged in a multiple number in the aerosol generating
               device 100. Here, the plurality of susceptors S may be arranged outside the aerosol
               generating article 200 or may be inserted into the aerosol generating article 200.
               Also, some of the plurality of susceptors S may be inserted into the aerosol generating
               article 200, and the others may be arranged outside the aerosol generating article
               200. Also, a shape of the susceptor S is not limited to the shape illustrated in FIG.
               4, and the susceptor S may include various shapes.
 
            [0084] FIG. 5 is a schematic view of a structure of the aerosol generating article 200 according
               to an embodiment.
 
            [0085] Referring to FIG. 5, the aerosol generating article 200 may include a first portion
               210, a second portion 220, a third portion 230, and a fourth portion 240. In detail,
               the first portion 210, the second portion 220, the third portion 230, and the fourth
               portion 240 may include an aerosol generating element, a tobacco element, a cooling
               element, and a filter element, respectively. For example, the first portion 210 may
               include an aerosol generating material, the second portion 220 may include a tobacco
               material and a moisturizer, the third portion 230 may cool a current passing through
               the first portion 210 and the second portion 220, and the fourth portion 240 may include
               a filter material.
 
            [0086] Referring to FIG. 5, the first portion 210, the second portion 220, the third portion
               230, and the fourth portion 240 may be sequentially arranged in a longitudinal direction
               of the aerosol generating article 200. Here, the longitudinal direction of the aerosol
               generating article 200 may be a direction in which a length of the aerosol generating
               article 200 extends. For example, the longitudinal direction of the aerosol generating
               article 200 may be a direction from the first portion 210 toward the fourth portion
               240. Accordingly, aerosol generated from at least one of the first portion 210 and
               the second portion 220 may sequentially pass through the third portion 230 and the
               fourth portion 240 and may form a current, and thus, a smoker may absorb the aerosol
               from the fourth portion 240.
 
            [0087] The first portion 210 may include an aerosol generating element. Also, the first
               portion 210 may contain other additives, such as a flavor agent, a wetting agent,
               and/or an organic acid, or may contain a flavored liquid, such as menthol or a moisturizer.
               Here, the aerosol generating element may include, for example, at least one of glycerin,
               propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, triethylene
               glycol, tetraethylene glycol, and oleyl alcohol. However, the disclosure is not limited
               to the examples described above and may include all of various types of aerosol generating
               elements that are well-known in the art.
 
            [0088] The first portion 210 may include an aerosol generating material impregnated with
               the aerosol generating element. An example of the aerosol generating material may
               include a wound sheet, and the aerosol generating element may be included in the first
               portion 210 by being impregnated in the wound sheet. Also, other additives, such as
               a flavor agent, a wetting agent, and/or an organic acid, and a flavored liquid may
               be included in the first portion 210 by being absorbed by the wound sheet.
 
            [0089] The wound sheet may be a sheet including a polymer material. For example, the polymer
               material may include at least one of a paper, cellulose acetate, lyocell, and polylactic
               acid. For example, the wound sheet may be a paper sheet from which a smell is not
               generated due to heat even when the paper is heated to a high temperature. However,
               it is not limited thereto.
 
            [0090] The first portion 210 may extend from an end of the aerosol generating article 200
               by about 7 to about 20 mm, and the second portion 220 may extend from the last end
               of the first portion 210 by about 7 to about 20 mm. However, it is not necessarily
               limited to this numerical range. Each of the lengths in which the first potion 210
               and the second portion 220 extend may be appropriately adjusted within a range that
               may be easily changed by one of ordinary skill in the art.
 
            [0091] The second portion 220 may include a tobacco element. The tobacco element may be
               a predetermined type of tobacco material. For example, the tobacco element may be
               a type of pipe tobacco, a type of tobacco particle, a type of tobacco sheet, a type
               of tobacco beads, a type of tobacco granule, a type of tobacco powder, or a type of
               tobacco extract. Also, the tobacco material may include, for example, at least one
               from a tobacco leaf, lateral veins of tobacco leaves, a puff tobacco, a cut tobacco
               pipe, a tobacco sheet, and a reformulated tobacco.
 
            [0092] The third portion 230 may cool a current passing through the first portion 210 and
               the second portion 220. The third portion 230 may be formed of a polymer material
               or a biodegradable polymer material and may have a cooling function. For example,
               the third portion 230 may be formed of polylactic acid (PLA) fibers, but is not limited
               thereto. Alternatively, the third portion 230 may be formed of a cellulose acetate
               filter having a plurality of holes. However, the third portion 230 is not limited
               to the examples described above and may include any materials which may cool aerosol.
               For example, the third portion 230 may include a tube filter or a paper pipe including
               a cavity.
 
            [0093] The fourth portion 240 may include a filter element. For example, the fourth portion
               240 may be a cellulose acetate filter. A shape of the fourth portion 240 is not particularly
               limited. For example, the fourth portion 240 may be a cylindrical-type rod or a tubular-type
               rod including a hole. Also, the fourth portion 240 may be a recess-type rod. When
               the fourth portion 240 includes a plurality of segments, at least one of the plurality
               of segments may be formed to have a different shape from the other segments.
 
            [0094] The fourth portion 240 may be formed to generate spices. For example, a flavored
               liquid may be injected into the fourth portion 240, or an additional fiber coated
               with a flavored liquid may be inserted into the fourth portion 240.
 
            [0095] The aerosol generating article 200 may include a wrapper 250 surrounding at least
               one of the first through fourth portions 210 through 240. Also, the aerosol generating
               article 200 may include the wrapper 250 surrounding all of the first through fourth
               portions 210 through 240. The wrapper 250 may be located at an outermost end of the
               aerosol generating article 200, and the wrapper 250 may include a single wrapper or
               a combination of a plurality of wrappers.
 
            [0096] For example, the first portion 210 of the aerosol generating article 200 may include
               a wound wrinkled sheet containing an aerosol generating material, the second portion
               220 may include a tobacco sheet as a tobacco material and glycerin as a moisturizer,
               the third portion 230 may include a paper pipe, and the fourth portion 240 may include
               cellulose acetate (CA) fibers. However, the disclosure is not necessarily limited
               thereto.
 
            [0097] Hereinafter, the fourth portion 240 of the aerosol generating article 200 is described
               in more detail.
 
            [0098] As described above, the fourth portion 240 may include the filter element, and the
               filter element may include a CA tow having a denier per filament of 17 to 29 and a
               total denier of 10,000 to 40,000.
 
            [0099] The CA tow refers to an article formed by appropriately processing CA for forming
               a filter of the aerosol generating article. That is, the CA tow is CA made as thin
               fibers, and a thickness of the CA fibers affects physical factors such as the absorption
               resistance, a rigid circumference, etc. of the aerosol generating article. A CA tow
               used for a filter of a previous general combustion cigarette may have a denier per
               filament of 3.0 to 6.0, and a CA tow used for a filter of a common heated cigarette
               may have a denier per filament of 9.0 in general.
 
            [0100] The CA tow included in the filter element according to an embodiment may have a greater
               denier per filament and a greater total denier than the CA tow used in the previous
               general heated cigarette. Due to the increase of the denier per filament of fibers
               included in the CA tow, the fibers become thicker, and in the case of a tow having
               thicker fibers, more empty spaces are formed between the fibers than in the case of
               a tow having thinner fibers, and thus, the absorption resistance and an aerosol removal
               capacity of the filter may be reduced. Thus, when the filter including the CA tow
               according to an embodiment is used, the amount of smoke inhaled by a user may be increased.
 
            [0101] Desirably, the CA tow may have a denier per filament of 18 to 23 and a total denier
               of 15,000 to 35,000. Here, the absorption resistance and the aerosol removal capacity
               of the filter may be reduced, and at the same time, smoking satisfaction experienced
               by the user during smoking, with respect to a hitting sense, a harmonious flavor,
               stimulation, a sense of fulfillment, etc. may be increased.
 
            [0102] According to an embodiment, the fourth portion 240 may include the CA tow of 320
               to 510 mg. The fourth portion 240 of the aerosol generating article 200 according
               to an embodiment may include the CA tow having relatively thick fibers, and thus,
               even when a greater amount of tow than the previous CA tow having relatively thin
               fibers is injected, a low absorption resistance may be maintained. Because a relatively
               greater amount of CA tow may be included in the fourth portion 240 of the aerosol
               generating article 200, the roundness and the rigidity of the fourth portion 240 may
               be increased. For example, the fourth portion 240 of the aerosol generating article
               200 according to an embodiment may have a roundness that is greater than or equal
               to 93% and a rigidity that is greater than or equal to 95%.
 
            [0103] The roundness denotes a degree of roundness of a cross-section of the fourth portion
               240 and may be measured by a well-known art. For example, the roundness of the cross-section
               of the fourth portion 240 may be measured by using a comparator, etc. by rotating
               the fourth portion 240 after supporting the central portion of the fourth portion
               240, and an error of a radius may be obtained based on the movement of the measurer.
 
            [0104] The rigidity is a property related to elasticity and resilience of the fourth portion
               240 and denotes a degree of resistance to the pressure applied in a vertical direction
               of the longitudinal direction of the fourth portion 240. In order that a user may
               easily use an aerosol generating article, with the aerosol generating article maintaining
               its shape, a predetermined level of rigidity may have to be maintained.
 
            [0105] When the aerosol generating article 200 includes the CA tow that is less than 320
               mg, a recess phenomenon in which the CA tow located at the central portion of the
               cross-section of the fourth portion 240 is recessed in the longitudinal direction
               of the fourth portion 240 may occur. When the aerosol generating article 200 includes
               the CA tow that is greater than 510 mg, the amount of CA tow may become excessive,
               and thus, a wrapping state using the wrapper 250 is inferior or the wrapper 250 is
               damaged, and a standard deviation of results of repeated measurements of the absorption
               resistance is too high, and thus, it is difficult to provide the uniform performance.
 
            [0106] A circumference of the cross-section of the fourth portion 240, the cross-section
               being perpendicular to the longitudinal direction of the aerosol generating article
               200, may be 14 to 25 mm. As described above, the aerosol generating article 200 according
               to an embodiment may include the CA tow having relatively thick fibers, and thus,
               the rigidity of the aerosol generating article 200 may be improved. The circumferential
               range described above corresponds to a relatively smaller numerical value compared
               to a circumference of a cross-section of a general aerosol generating article 200.
               Even when a thickness, that is, a sectional circumference, of the fourth portion 240
               and the aerosol generating article 200 is decreased, the rigidity of the fourth portion
               240 and the aerosol generating article 200 may be improved to maintain the shape of
               the fourth portion 240 and the aerosol generating article 200, and thus, the usability
               may be secured.
 
            [0107] An absorption resistance of the fourth portion 240 may be 0.5 mmH
2O to 2.5 mmH
2O. The fourth portion 240 of the aerosol generating article 200 according to an embodiment
               may include the CA tow having relatively thick fibers, and thus, a low absorption
               resistance may be realized. The corresponding absorption resistance may provide satisfaction
               to the user by preventing an excessive force from being taken to absorb aerosol when
               the user uses the aerosol generating article 200. Also, the aerosol generating article
               200 according to an embodiment not only may have the low absorption resistance, but
               also may maintain the rigidity by including the tow including thick fibers, which
               allows the usability to be secured.
 
            [0108] A tensile strength of the CA tow may be less than about 3.5 kgf, and more desirably,
               may be equal to or less than about 3.0 kgf. Due to relatively thick fibers of the
               CA tow according to an embodiment, a yield rate of the CA tow according to an embodiment
               may be improved at a tensile strength that is less than about 3.5 kgf. When the tensile
               strength of the CA tow is equal to or greater than about 3.5 kgf, due to thick fibers,
               a folding property may become insufficient during a process of crimping the tow, and
               a mass production may become difficult.
 
            [0109] The second portion 220 may further include an aerosol generating element, wherein
               the second portion 220 may include the aerosol generating element in 10 weight percent
               (wt%) or less with respect to a dry weight of an aerosol generating material. Also,
               the first portion 210 may include the aerosol generating element in 65 to 95 wt% with
               respect to the dry weight of the aerosol generating material. The filter including
               the CA tow according to an embodiment may have a low aerosol removal capacity, and
               thus, even when a relatively small amount of aerosol generating element is included
               in the first portion 210 and the second portion 220, a sufficient amount of smoke
               and satisfaction may be provided to the user.
 
            [0110] Because it may be possible to improve the smoking satisfaction of the user during
               smoking, with respect to a hitting sense, a harmonious flavor, stimulation, fulfillment,
               etc., the second portion 220 may further include an aerosol generating element, wherein
               the second portion 220 may include the aerosol generating element in 3 wt% or less
               with respect to a dry weight of an aerosol generating material. Also, the first portion
               210 may include the aerosol generating element in 65 to 80 wt% with respect to the
               dry weight of the aerosol generating material.
 
            Embodiment 1. A CA tow
[0111] A CA tow having a denier per filament of 20.0 and a total denier of 25,000 is formed.
 
            Embodiment 2. Filters including the CA tow
[0112] Filters including the CA tow of Embodiment 1 are formed under conditions shown in
               Table 1 below. The formed filters are referred to by Embodiment 2-1, Embodiment 2-2,
               Embodiment 2-3, and Embodiment 2-4, respectively, according to weights (415 mg, 380
               mg, 350 mg, and 506 mg) of the AC tow included in the filters. As a wrapper for forming
               the filters, a general paper having a basis weight of 75 gsm is used, and as a plasticizer,
               triacetin is used.
               
               
Table 1
                  
                     
                        
                           
                           
                           
                           
                           
                           
                        
                        
                           
                              | Division | Tow weight (mg) | Filter weight (mg) | Circumference (mm) | Quality factor of a cross-section of a filter | Quality factor of an operation | 
                        
                        
                           
                              | Embodiment 2-1 | 415 | 645 | 21.95 | Good | Good | 
                           
                              | Embodiment 2-2 | 380 | 610 | 22.01 | Good | Good | 
                           
                              | Embodiment 2-3 | 350 | 520 | 21.90 | Occurrence of a recess phenomenon | - | 
                           
                              | Embodiment 2-4 | 506 | 676 | 21.92 | Bad | - | 
                        
                     
                   
                
            [0113] Also, a quality factor of a cross-section of the filter and a quality factor of an
               operation are evaluated in the process of forming the filter. Here, the quality factor
               of the cross-section of the filter is a value evaluated with respect to whether the
               cross-section of the filter is uniformly formed in a process of cutting the filter,
               and the quality factor of the operation is a value evaluated with respect to whether
               a wrapping operation using the wrapper in the process of forming the filter is processed
               well. As shown in Table 2, in the case of Embodiment 2-3 in which the tow weight is
               350 mg, a recess phenomenon in which the CA tow in the central portion of the cross-section
               of the filter is recessed in a longitudinal direction of the filter occurs, and because
               the amount of injected CA tow is excessively low, the wrapping state using the wrapper
               is bad. Also, in the case of Embodiment 2-4 in which the tow weight is 506 mg, the
               filter is not formed to have a uniform cross-section, and because the amount of injected
               CA tow is excessively high, the wrapping state using the wrapper is bad.
 
            Comparative Embodiment 1. A CA tow
[0114] A common CA tow used for a filter of a heated cigarette is used.
 
            Comparative Embodiment 2. A filter including the CA tow
[0115] A filter including the CA tow of Comparative Embodiment 1 is formed under a condition
               shown in Table 2 below. Also, like Embodiments 2-1 through 2-4, the quality factor
               of a cross-section of the filter and the quality factor of an operation in a process
               of forming the filter are evaluated and described in Table 2 below.
               
               
Table 2
                  
                     
                        
                           
                           
                           
                           
                           
                           
                        
                        
                           
                              | Division | Tow weight (mg) | Filter weight (mg) | Circum - ference (mm) | Quality factor of a cross-section of a filter | Quality factor of an operation | 
                        
                        
                           
                              | Comparative Embodiment 2 | 330 | 550 | 22.00 | Good | Good | 
                        
                     
                   
                
            Experimental Embodiment 1 Assessment of an absorption resistance and the physical
               performance of the filters including the CA tow
[0116] The absorption resistance, the roundness, and the rigidity of the filters of Embodiments
               2-1 through 2-4 and Comparative Embodiment 2 are assessed, and results thereof are
               indicated in Table 3 below.
               
               
Table 3
                  
                     
                        
                           
                           
                           
                           
                        
                        
                           
                              | Division | Absorption resistance (mmH2O) | Roundness (%) | Rigidity (%) | 
                        
                        
                           
                              | Embodiment 2-1 | 106.3 | 92.95 | 96.8 | 
                           
                              | Embodiment 2-2 | 88.1 | 94.92 | 95.6 | 
                           
                              | Embodiment 2-3 | 78.4 | 93.88 | - | 
                           
                              | Embodiment 2-4 | 151.7 | 93.53 | - | 
                           
                              | Comparative Embodiment 2 | 136.7 | 94.97 | 95.9 | 
                        
                     
                   
                
            [0117] As shown in Table 3, the absorption resistances of Embodiment 2-1 and Embodiment
               2-2 are 106.3 and 88.1 mmH
2O, respectively, which are lower than the absorption resistance of Comparative Embodiment
               2. However, the roundness and the rigidity of Embodiment 2-1 and Embodiment 2-2 maintain
               a similar level to those of Comparative Embodiment 2. Embodiment 2-3 and Embodiment
               2-4 have absorption resistances proportional to the weights of the injected tow. Also,
               as expected from the evaluation of the quality factor of the cross-section of the
               filter and the quality factor of the operation described above, the roundness is decreased,
               and the wrapping state using the wrapper is bad, and thus, it is impossible to measure
               the rigidity.
 
            Experimental Embodiment 2 An analysis of the amount of aerosol fulfillment
[0118] An aerosol generating article is formed by using the filters of Embodiment 2-1, Embodiment
               2-2, and Comparative Embodiment 2. The component amounts of nicotine, propylene glycol
               (PG), glycerin (Gly), and water, either included in aerosol fulfilled through the
               formed aerosol generating article or remaining in the filters after smoking, are measured,
               and results of the measurement are substituted in Equation 1 below to calculate removal
               capacities of the filters. 

 
            [0119] The aerosol generating article is formed as two types to include different configurations
               from each other, and the results of analysis with respect to the amount of aerosol
               fulfillment of the formed two types of aerosol generating articles are separately
               indicated in Table 4 and Table 5 below.
               
               
Table 4
                  
                     
                        
                           
                           
                           
                           
                           
                           
                           
                           
                           
                           
                           
                        
                        
                           
                              | Applied filter | The amount of aerosol fulfillment (mg) | The remaining amount in the filter after smoking (mg) | A removal capacity (%) | 
                           
                              | nicotine | PG | Gly | water | nicotine | PG | Gly | nicotine | PG | Gly | 
                        
                        
                           
                              | Embodi - ment 2-1 | 0.74 | 3.13 | 9.55 | 25.0 | 0.67 | 2.93 | 3.51 | 47.7 | 48.4 | 26.9 | 
                           
                              | Embodi - ment 2-2 | 0.79 | 3.84 | 12.32 | 26.8 | 0.62 | 2.87 | 3.44 | 44.0 | 42.8 | 21.8 | 
                           
                              | Comparative Embodiment 2 | 0.81 | 4.02 | 13.73 | 24.1 | 0.55 | 2.33 | 2.81 | 40.6 | 36.7 | 17.0 | 
                        
                     
                   
               [Table 5]
                  
                     
                        
                           
                           
                           
                           
                           
                           
                           
                           
                           
                           
                           
                        
                        
                           
                              | Applied filter | The amount of aerosol fulfillment (mg) | The remaining amount in the filter after smoking (mg) | A removal capacity (%) | 
                           
                              | nicotine | PG | Gly | water | nicotine | PG | Gly | nicotine | PG | Gly | 
                        
                        
                           
                              | Embodi - ment 2-1 | 0.62 | 2.46 | 8.60 | 20.1 | 0.52 | 3.57 | 5.49 | 45.7 | 59.2 | 38.9 | 
                           
                              | Embodi - ment 2-2 | 0.66 | 2.79 | 9.30 | 21.7 | 0.49 | 3.49 | 5.21 | 44.2 | 55.6 | 35.9 | 
                           
                              | Comparative Embodiment 2 | 0.74 | 2.90 | 9.67 | 22.5 | 0.46 | 3.31 | 4.83 | 38.1 | 53.3 | 33.3 | 
                        
                     
                   
                
            [0120] As shown in Table 4 and Table 5, compared to the aerosol generating article using
               the filter of Comparative Embodiment 2, the aerosol generating article using the filters
               of Embodiment 2-1 and Embodiment 2-2 generally has the improved amount of aerosol
               fulfillment.
 
            Experimental Embodiment 3. Sensory evaluation of the aerosol generating article
[0121] A sensory evaluation using the aerosol generating articles including the filters
               of Embodiment 2-1 and Comparative Embodiment 2-2 is performed on 20 adults. The aerosol
               generating article is formed as two types like the case of Experimental Embodiment
               2. The sensory evaluation is performed on the total 6 factors including a hitting
               sense, a force taken for absorbing smoke, a harmonious flavor, the amount of smoke,
               stimulation, and satisfaction, and a score for each item is recorded after a single
               use of an aerosol generating device into which the aerosol generating article is inserted.
               An average value of each item is indicated in Table 6 and Table 7 below according
               to the type of aerosol generating article.
               
               
Table 6
                  
                     
                        
                           
                           
                           
                        
                        
                           
                              | Evaluation item | Embodiment 2-1 | Comparative Embodiment 2 | 
                        
                        
                           
                              | Hitting sense | 4.6 | 4.8 | 
                           
                              | Force taken for absorbing smoke | 4.2 | 4.3 | 
                           
                              | Harmonious flavor | 4.625 | 4.675 | 
                           
                              | The amount of smoke | 5.625 | 5.3 | 
                           
                              | Stimulation | 4.075 | 4.525 | 
                           
                              | Satisfaction | 5.1 | 5.0 | 
                        
                     
                   
               [Table 7]
                  
                     
                        
                           
                           
                           
                        
                        
                           
                              | Evaluation item | Embodiment 2-1 | Comparative Embodiment 2 | 
                        
                        
                           
                              | Hitting sense | 4.275 | 4.275 | 
                           
                              | Force taken for absobring smoke | 3.225 | 3.75 | 
                           
                              | Harmonious flavor | 4.575 | 4.55 | 
                           
                              | The amount of smoke | 6.0 | 5.6 | 
                           
                              | Stimulation | 4.35 | 4.125 | 
                           
                              | Satisfaction | 4.975 | 5.15 | 
                        
                     
                   
                
            [0122] As shown in Table 6 and Table 7, the aerosol generating article including the filter
               of Embodiment 2-1 provides the greater amount of smoke than the aerosol generating
               article including the filter of Comparative Embodiment 2, and takes a less amount
               of force for absorbing smoke than the aerosol generating article including the filter
               of Comparative Embodiment 2.
 
            [0123] Those of ordinary skill in the art related to the present embodiments may understand
               that various changes in form and details can be made therein without departing from
               the scope of the characteristics described above. Therefore, the disclosed methods
               should be considered in a descriptive point of view, not a restrictive point of view.
               The scope of the present disclosure is defined by the appended claims rather than
               by the foregoing description, and all differences within the scope of equivalents
               thereof should be construed as being included in the present disclosure.