Patent Description:
Recently, the demand for alternative methods to overcome shortcomings of traditional cigarettes has increased. For example, there is growing demand for a method of generating an aerosol by heating an aerosol generating material in cigarettes, rather than by combusting cigarettes. Accordingly, research on a heating type cigarette and a heating type aerosol-generating device has been actively conducted.

In the case of an externally heated cigarette, in which heat generated from a heat source located outside the cigarette is transferred to the inside of the cigarette to form the aerosol, when the externally heated cigarette gets inserted into an aerosol-generating device, the cigarette is easily damaged and cut by external force because of its low strength.

Accordingly, there is a need for a cigarette having sufficient strength to maintain its shape without being damaged or wrinkled by stress and frictional force occurring while the cigarette is used by the user or inserted into the aerosol-generating device.

In addition, when heat generated from an external heat source is transferred to the inside of the cigarette, the heat is transferred to the inside of the cigarette through an outer wrapper, which absorbs the transferred heat. As a result, a rate of heat transfer to the inside of the cigarette may be reduced. As the heat transfer rate for the heat transferred to the inside of the cigarette decreases, the cigarette may not generating aerosol smoothly.

Accordingly, there is a need for a cigarette whose strength is increased to prevent the cigarette from being damaged or cut, and which allows heat generated from an external heat source to be smoothly transferred to the inside of the cigarette in order for the cigarette to effectively produce aerosol. <CIT> is prior art according to Art. <NUM>(<NUM>) EPC and relates to a device for generating an aerosol, the device including: a heater that generates the aerosol by heating an aerosol generating material; and a controller that variably increases an amount of power supplied to the heater to heat the aerosol generating material at a preheating temperature lower than a heating temperature for generating the aerosol. <CIT> is prior art according to Art. <NUM>(<NUM>) EPC and relates to an aerosol generating device which may include a first heater for heating a cigarette inserted into a first portion of the aerosol generating device; a second heater for heating a liquid composition stored in a cartridge detachably attached to a second portion of the aerosol generating device; and a controller for controlling power supplied to the first heater and the second heater, wherein the controller may control the power supplied to the second heater based on a heating pattern by which the first heater is heated. <CIT> relates to an aerosol generating apparatus and a cradle for receiving the same, the aerosol generating apparatus comprising: a cigarette insertion part into which a cigarette can be inserted; and a vaporizer which generates aerosol by heating a liquid composition and discharges the generated aerosol towards the inserted cigarette so that the generated aerosol passes through the cigarette that has been inserted into the cigarette insertion part. <CIT> relates to relates to cigarette filters. <CIT> relates to a smoking article comprising a tobacco rod and a mouthpiece. The mouthpiece comprises at least one segment and a wrapper circumscribing the at least one segment and defining a mouth end cavity. The mouthpiece is in axial alignment with the tobacco rod and has a rod end adjacent the tobacco rod and a mouth end opposite the rod end. One or more indicia are applied to the inner surface of the wrapper portion defining the mouth end cavity.

Embodiments provide a cigarette including an outer wrapper.

The technical problems to be solved by the present embodiments are not limited to the technical problems as described above, and other technical problems may be inferred from the following embodiments.

The problem is solved by the features of the independent claim.

A cigarette according to an embodiment includes a cigarette rod including an aerosol-generating material; a filter rod located at one end of the cigarette rod and including a first segment and a second segment; a front end plug located at the other end of the cigarette rod; and an outer wrapper wrapping the cigarette rod, the filter rod and the front end plug, wherein the outer wrapper has a basis weight of <NUM>/m<NUM> to <NUM>/m<NUM> and a thickness of <NUM> to <NUM> to increase strength of the cigarette, wherein the cigarette further comprises a second wrapper wrapping the cigarette rod.

The outer wrapper may have a tensile strength of <NUM> kgf/<NUM> to <NUM> kgf/<NUM>.

The cigarette may further include at least one of a first wrapper wrapping the front end plug, a third wrapper wrapping the first segment, and a fourth wrapper wrapping the second segment, wherein a basis weight of the second wrapper may be lower than a basis weight of the outer wrapper.

A porosity of the second wrapper is higher than a porosity of the outer wrapper.

The porosity of the second wrapper may be <NUM> cu to <NUM> cu.

A coating material is applied to at least one of an inner and an outer surface of the second wrapper such that a heat transfer rate for the heat transferred to the cigarette rod through the second wrapper is improved.

The coating material may include at least one of sodium-citrate (Na-citrate) and potassium-citrate (K-citrate).

An applied content of the coating material may be <NUM> % to <NUM> %.

A coating material may be applied to an outer surface facing an outer wrapper or an inner surface facing a cigarette rod, or both the inner surface and the outer surface, among surfaces of a second wrapper.

The coating material may include at least one of sodium-citrate and potassium-citrate. The above-described coating material may serve to increase heat transfer efficiency of heat transferred to a cigarette rod located inside the second wrapper.

A cigarette according to an embodiment may include a cigarette rod including an aerosol-generating material; a filter rod located at one end of the cigarette rod and including a first segment and a second segment; a front end plug located at the other end of the cigarette rod; and an outer wrapper wrapping the cigarette rod, the filter rod and the front end plug, wherein the outer wrapper has a basis weight of <NUM>/m2 to <NUM>/m2 and a thickness of <NUM> to <NUM> to increase strength of the cigarette.

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

<FIG> is a view showing a cigarette <NUM> according to the embodiment.

Referring to <FIG>, the cigarette <NUM> according to the embodiment includes a cigarette rod <NUM> including an aerosol-generating material, a filter rod <NUM> located at one end of the cigarette rod <NUM> and including a first segment <NUM> and a second segment <NUM>, a front end plug <NUM> located at the other end of the cigarette rod <NUM>, and an outer wrapper <NUM> wrapping the cigarette rod <NUM>, the filter rod <NUM>, and the front end plug <NUM>, wherein the outer wrapper <NUM> has a basis weight of <NUM>/m<NUM> to <NUM>/m<NUM> and a thickness of <NUM> to <NUM> in order to increase strength of the cigarette <NUM>.

A diameter of the cigarette <NUM> may be within a range of <NUM> to <NUM>, and a length of the cigarette <NUM> may be about <NUM>, but embodiments are not limited thereto. For example, the length of the cigarette rod <NUM> may be about <NUM>, the length of the first segment <NUM> of the filter rod <NUM> may be about <NUM>, the length of the second segment of the filter rod <NUM> may be about <NUM>, and the length of the third segment of the filter rod <NUM> may be about <NUM>, but embodiments are not limited thereto.

The cigarette rod <NUM> may include the aerosol-generating material. For example, the aerosol-generating material may include at least one of glycerin, propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and oleyl alcohol, but it is not limited thereto.

In addition, the cigarette rod <NUM> may contain other additives such as flavors, wetting agents and/or organic acids. In addition, a flavoring liquid such as menthol or moisturizer may be added to the cigarette rod <NUM> by spraying the flavoring liquid onto the cigarette rod <NUM>.

The cigarette rod <NUM> may be manufactured in various forms. For example, the cigarette rod <NUM> may be made of sheets or strands. In addition, the cigarette rod <NUM> may be made of shredded tobacco obtained by finely cutting a tobacco sheet. In addition, the cigarette rod <NUM> may be surrounded by a heat conducting material.

For example, the heat-conducting material surrounding the cigarette rod <NUM> may improve conductivity of heat applied to the cigarette rod <NUM> by evenly distributing heat transferred to the cigarette rod <NUM>, thereby improving a taste of cigarettes. In addition, the heat-conducting material surrounding the cigarette rod <NUM> may function as a susceptor that is heated by an induction heating type heater. Herein, although not shown in the drawing, the cigarette rod <NUM> may further include an additional susceptor in addition to the heat conducting material surrounding the outside thereof.

The filter rod <NUM> may be located at one end of the cigarette rod <NUM>, and the filter rod <NUM> may include one or more segments. Referring to <FIG>, the filter rod <NUM> includes the first segment <NUM> and the second segment <NUM>, but it is obvious to those skilled in the art that the number and shape of the filter rod <NUM> are not limited thereto, and may be changed as necessary.

For example, the filter rod <NUM> may include a segment that supports the cigarette rod <NUM>, a segment that cools aerosol, or a segment that filters certain components contained in the aerosol. Further, if necessary, the filter rod <NUM> may further include segments that perform other functions.

The first segment <NUM> may be made from cellulose acetate. For example, the first segment <NUM> may be a tube-shaped structure including a hollow inside thereof.

The second segment <NUM> may be made from cellulose acetate.

Also, at least one capsule <NUM> may be included in the second segment <NUM>. Here, the capsule <NUM> may generate flavor or the aerosol. For example, the capsule <NUM> may have a structure in which a liquid containing a flavor is wrapped with a film. The capsule <NUM> may have a spherical or cylindrical shape, but is not limited thereto.

The front end plug <NUM> may be located at the opposite end of the filter rod <NUM> positioned at one end of the cigarette rod <NUM> when the cigarette rod <NUM> is referenced. That is, when the filter rod <NUM> is located at one end of the cigarette rod <NUM>, the front end plug <NUM> may be located at the other end of the cigarette rod <NUM>. The front end plug <NUM> may prevent the cigarette rod <NUM> from escaping, and prevent liquefied aerosol from flowing from the cigarette rod <NUM> into the aerosol-generating device (<NUM> in <FIG> and <FIG>) during smoking.

The front end plug <NUM> may made of cellulose acetate.

In addition, if necessary, the front end plug <NUM> may include at least one channel, and the cross-sectional shape of the channel may vary.

The cigarette <NUM> may include an outer wrapper <NUM> wrapping the cigarette rod <NUM>, the filter rod <NUM>, and the front end plug <NUM>, and the outer wrapper <NUM> has a basis weight of <NUM>/m<NUM> to <NUM>/m<NUM> and a thickness of <NUM> to <NUM> in order to increase strength of the cigarette <NUM>. For example, the basis weight of the outer wrapper <NUM> may be <NUM>/m<NUM>, and the thickness of the outer wrapper <NUM> may be <NUM>.

The outer wrapper <NUM> may have a tensile strength of <NUM> kgf/<NUM> to <NUM> kgf/<NUM>. For example, the outer wrapper <NUM> may have the tensile strength of <NUM> kgf/<NUM>.

The outer wrapper <NUM> may be made of paper whose strength, water resistance, smoothness, etc., may have increased physical properties than ordinary paper. Accordingly, the cigarette <NUM> including the outer wrapper <NUM> may have the increased strength. Due to the high water resistance of the outer wrapper <NUM>, resistance to the external liquid that may contact the cigarette <NUM> may be increased. Due to the high smoothness of the outer wrapper <NUM>, printing on the outer wrapper <NUM> may be easy.

The outer wrapper <NUM> surrounds the cigarette <NUM> and forms the outermost surface of the cigarette <NUM>, and may provide strength to maintain the shape of the cigarette <NUM>. Herein, the strength of the cigarette <NUM> may be tensile strength to prevent damage and cutting by external force, and the strength of the cigarette <NUM> may be changed depending on the properties of the outer wrapper <NUM>.

As the strength of the cigarette <NUM> is increased, it is possible to prevent the cigarette <NUM> from being damaged or wrinkled by stress and frictional forces that may occur when the cigarette <NUM> is inserted into the aerosol-generating device, in addition to user's gripping of the cigarette <NUM>.

As the outer wrapper <NUM> forms an outermost surface of the cigarette <NUM>, the shape of the cigarette <NUM> may be changed depending on the shape of the outer wrapper <NUM>. Also, the outer wrapper <NUM> may easily print than an ordinary paper, because the outer wrapper <NUM> may have an increased smoothness than ordinary paper.

For example, letters, patterns, symbols, images, etc. may be printed on the outer wrapper <NUM>. The characters, patterns, symbols, images, etc. printed on the outer wrapper <NUM> may be changed, such that the cigarette <NUM> may provide various visual information.

The user may check the properties of the cigarette <NUM>, such as the flavor of the cigarette <NUM> or the ingredient ratio of the cigarette <NUM> by referring to letters, patterns, symbols, images, etc. printed on the outer wrapper <NUM>, and thus may distinguish and select the cigarette <NUM>. The outer wrapper <NUM> may include visual information such as printed characters, patterns, symbols, and images, and tactile information such as a thickness of the outer wrapper <NUM> and a diameter of the outer wrapper <NUM>, but the shape of the outer wrapper <NUM> is not limited thereto.

The outer wrapper <NUM> may prevent the cigarette <NUM> from being burned. For example, when the cigarette rod <NUM> is heated, there is a possibility that the cigarette <NUM> is burned. Specifically, when the temperature rises equal to or greater than an ignition point of any one of the substances included in the cigarette rod <NUM>, the cigarette <NUM> may be burned. However, since the outer wrapper <NUM> includes a non-combustible material, it is possible to prevent the cigarette <NUM> from being burned.

In addition, the outer wrapper <NUM> may prevent the outside of the cigarette <NUM> from being contaminated by substances generated in the cigarette <NUM>. Liquid substances may be generated in the cigarette <NUM> by the user's puff. For example, the aerosol generated in the cigarette <NUM> is cooled by external air, and thereby liquid substances (e.g., moisture, etc.) may be generated. As the outer wrapper <NUM> wraps the cigarette <NUM>, liquid substances generated in the cigarette <NUM> may be prevented from leaking out of the cigarette <NUM>.

<FIG> is a view showing a cigarette <NUM> according to another embodiment of the present disclosure.

The cigarette <NUM> according to this embodiment may further include at least one of a first wrapper <NUM> wrapping a front end plug <NUM>, a second wrapper <NUM> wrapping the cigarette rod <NUM>, a third wrapper <NUM> wrapping the first segment <NUM>, and a fourth wrapper <NUM> wrapping the second segment <NUM>. The basis weight of the second wrapper <NUM> may be lower than the basis weight of the outer wrapper <NUM>.

In addition, the porosity of the second wrapper <NUM> may be higher than that of the outer wrapper <NUM>, and the porosity of the second wrapper <NUM> may be <NUM> cu to <NUM> cu.

A coating material <NUM> may be applied to at least one surface of an inner surface and an outer surface of the second wrapper <NUM> to improve a heat transfer rate for the heat that is transferred into the cigarette rod <NUM> through the second wrapper <NUM>.

The coating material <NUM> to be applied to at least one of the inner surface and the outer surface of the second wrapper <NUM> may include at least one of sodium-citrate (Na-citrate) and potassium-citrate (K-citrate).

The cigarette <NUM> according to this embodiment may further include at least one of the first wrapper <NUM> to the fourth wrapper <NUM>. For example, the front end plug <NUM> may be wrapped by the first wrapper <NUM>, the cigarette rod <NUM> may be wrapped by the second wrapper <NUM>, the first segment <NUM> is wrapped by the third wrapper <NUM>, and the second segment <NUM> may be wrapped by the fourth wrapper <NUM>.

In addition, the entire cigarette <NUM> may be rewrapped by the outer wrapper <NUM>. As an example, a wrapper <NUM> may include the first wrapper <NUM>, the second wrapper <NUM>, the third wrapper <NUM>, the fourth wrapper <NUM>, and the outer wrapper <NUM>, but is not limited to the example.

A basis weight of the first wrapper <NUM> may be in the range of <NUM>/m<NUM> to <NUM>/m<NUM>, and preferably it may be <NUM>/m<NUM>.

The second wrapper <NUM> and the third wrapper <NUM> may be made of general filter wrapping paper. For example, the second wrapper <NUM> and the third wrapper <NUM> may be porous wrapping paper or non-porous wrapping paper.

For example, the porosity of the second wrapper <NUM> may be <NUM> cu, but is not limited thereto. In addition, a thickness of the second wrapper <NUM> may be in the range of <NUM> to <NUM>, and preferably it may be <NUM>. In addition, the basis weight of the second wrapper <NUM> may be in the range of <NUM>/m<NUM> to <NUM>/m<NUM>, and preferably it may be <NUM>/m<NUM>.

For example, a porosity of the third wrapper <NUM> may be <NUM> cu, but is not limited thereto. In addition, a thickness of the third wrapper <NUM> may be in the range of <NUM> to <NUM>, and preferably it may be <NUM>. In addition, a basis weight of the third wrapper <NUM> may be included within a range of <NUM>/m<NUM> to <NUM>/m<NUM>, and preferably it may be <NUM>/m<NUM>.

For example, a thickness of the fourth wrapper <NUM> may be in the range of <NUM> to <NUM>, and preferably it may be <NUM>. In addition, a basis weight of the fourth wrapper <NUM> may be included within a range of <NUM>/m<NUM> to <NUM>/m<NUM>, and preferably it may be <NUM>/m<NUM>.

As the cigarette <NUM> includes at least one of the first wrapper <NUM> to the fourth wrapper <NUM> and the outer wrapper <NUM>, the cigarette <NUM> may include a double wrapper. Accordingly, the strength provided by at least one wrapper of the first wrapper <NUM> to the fourth wrapper <NUM> and the strength provided by the outer wrapper <NUM> may be added to further increase the strength of the cigarette <NUM>.

The basis weight of the second wrapper <NUM> may be lower than the basis weight of the outer wrapper <NUM>, which means that the second wrapper <NUM> may be made of a thinner paper than the outer wrapper <NUM>. The thermal conductivity of the second wrapper <NUM> made of thin paper may be higher than that of the outer wrapper <NUM>. Accordingly, heat passing through the outer wrapper <NUM> may be smoothly transferred to the cigarette rod <NUM> under the second wrapper <NUM>.

The porosity of the second wrapper <NUM> may be higher than the porosity of the outer wrapper <NUM>. As the porosity of the second wrapper <NUM> is higher than that of the outer wrapper <NUM>, heat which is generated from an external heat source of the cigarette <NUM> and passed through the external wrapper <NUM> may be prevented from being absorbed by the second wrapper <NUM>. The heat transferred through the outer wrapper <NUM> may be easily passed through the second wrapper <NUM> and transferred into the cigarette rod <NUM> wrapped by the second wrapper <NUM>.

As heat is easily transferred into the cigarette rod <NUM> through the outer wrapper <NUM> and the second wrapper <NUM>, aerosol generated by heating the cigarette rod <NUM> may be generated more smoothly and abundantly. And then, the aerosol may be inhaled by the user through components inside the cigarette <NUM>.

On the other hand, it is obvious to those skilled in the art that heat may be transferred to the cigarette rod <NUM> in the cigarette <NUM> through various paths in addition to the path including the outer wrapper <NUM> and the second wrapper <NUM> having a higher porosity than the outer wrapper <NUM>.

The porosity of the second wrapper <NUM> may be <NUM> cu to <NUM> cu. For example, the porosity of the second wrapper <NUM> may be <NUM> cu, which may be higher than the porosity of the outer wrapper <NUM>. In addition, the second wrapper <NUM> may have the highest porosity among the wrappers. For example, the porosity of the second wrapper <NUM> may be higher than the porosity of the first wrapper <NUM>, the third wrapper <NUM>, and the fourth wrapper <NUM>.

Examining the cigarette <NUM> according to another embodiment in more detail with reference to <FIG>, the coating material <NUM> may be applied to the inner surface and/or the outer surface of the second wrapper <NUM> to improve the heat transfer rate for the heat transferred into the cigarette rod <NUM> through the second wrapper <NUM>. The coating material <NUM> to be applied to the inner surface and/or the outer surface of the second wrapper <NUM> may include at least one of sodium-citrate (Na-citrate) and potassium-citrate(K-citrate).

In order for the cigarette <NUM> to produce the aerosol properly, it is necessary that heat is smoothly transferred into the cigarette rod <NUM> with a heat transfer rate equal to or greater than a predetermined range. In the case where the cigarette <NUM> according to an embodiment further includes a second wrapper <NUM>, heat may be absorbed by the second wrapper <NUM> wrapping the cigarette rod <NUM>. In this regard, it is necessary to prevent heat transfer to the cigarette rod <NUM> from being blocked by the second wrapper <NUM>, thereby increasing the amount of heat transferred into the second wrapper <NUM>.

In order to increase the heat transfer rate for the heat generated from the external heat source of the cigarette <NUM> and transferred to the second wrapper <NUM> after passing through the outer wrapper <NUM>, the coating material <NUM> may be applied to the surface of the second wrapper <NUM>. The surface coating material, which is a material that allows heat to flow into the cigarette rod <NUM> in the second wrapper <NUM> without being absorbed by the second wrapper <NUM>, may be applied to at least one of the inner surface and the outer surface of the second wrapper <NUM>.

That is, the coating material <NUM> may be applied to the outer surface facing the outer wrapper <NUM> or the inner surface facing a cigarette rod <NUM>, or both the inner surface and the outer surface, among the surfaces of the second wrapper <NUM>. It is obvious to those skilled in the art that the coating material <NUM> may be applied only to a part of the inner surface or a part of the outer surface, and that the size/area of the surface and the amount of the coating material may be modified as necessary.

The coating material <NUM> may include at least one of sodium-citrate (Na-citrate) and potassium-citrate (K-citrate). The above-described coating material <NUM> may serve to increase the efficiency of heat transfer to the cigarette rod <NUM> located inside the second wrapper <NUM>.

Herein, the applied content of the coating material <NUM> may be <NUM> % to <NUM> %, but is not limited thereto, and the content value may be changed as necessary.

<FIG> are diagrams showing examples in which a cigarette <NUM> is inserted into an aerosol generating device.

Referring to <FIG> and <FIG>, the aerosol generating device <NUM> may further include a vaporizer <NUM>. Also, the cigarette <NUM> may be inserted into an inner space of the aerosol generating device <NUM>.

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 <NUM>.

Also, <FIG> and <FIG> illustrate that the aerosol generating device <NUM> includes the heater <NUM>. However, according to necessity, the heater <NUM> may be omitted.

<FIG> illustrates that the battery <NUM>, the controller <NUM>, the vaporizer <NUM>, and the heater <NUM> are arranged in series.

When the cigarette <NUM> is inserted into the aerosol generating device <NUM>, the aerosol generating device <NUM> may operate the heater <NUM> and/or the vaporizer <NUM> to generate an aerosol from the cigarette <NUM> and/or the vaporizer <NUM>. The aerosol generated by the heater <NUM> and/or the vaporizer <NUM> is delivered to a user by passing through the cigarette <NUM>.

According to necessity, even when the cigarette <NUM> is not inserted into the aerosol generating device <NUM>, the aerosol generating device <NUM> may heat the heater <NUM>.

The vaporizer <NUM> may generate an aerosol by heating a liquid composition and the generated aerosol may pass through the cigarette <NUM> to be delivered to a user. In other words, the aerosol generated via the vaporizer <NUM> may move along an air flow passage of the aerosol generating device <NUM> and the air flow passage may be configured such that the aerosol generated via the vaporizer <NUM> passes through the cigarette <NUM> to be delivered to the user.

The liquid storage may be formed to be attached/detached to/from the vaporizer <NUM> or may be formed integrally with the vaporizer <NUM>.

In addition, the heating element may include a conductive filament such as nichrome wire and may be positioned by being wound around the liquid delivery element. As a result, an aerosol may be generated.

The aerosol generating device <NUM> may further include general-purpose components in addition to the battery <NUM>, the controller <NUM>, the heater <NUM>, and the vaporizer <NUM>. For example, the aerosol generating device <NUM> may include a display capable of outputting visual information and/or a motor for outputting haptic information. Also, the aerosol generating device <NUM> may be formed as a structure where, even when the cigarette <NUM> is inserted into the aerosol generating device <NUM>, external air may be introduced or internal air may be discharged.

The cigarette <NUM> may be similar as a general combustive cigarette. For example, the cigarette <NUM> 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 cigarette <NUM> 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.

The user may puff the aerosol while holding the second portion in his or her mouth.

Claim 1:
A cigarette (<NUM>) comprising:
a cigarette rod (<NUM>) including an aerosol-generating material;
a filter rod (<NUM>) located at one end of the cigarette rod (<NUM>) and including a first segment (<NUM>) and a second segment (<NUM>);
a front end plug (<NUM>) located at another end of the cigarette rod (<NUM>); and
an outer wrapper (<NUM>) wrapping the cigarette rod (<NUM>), the filter rod (<NUM>) and the front end plug (<NUM>),
the cigarette being characterized in that
the outer wrapper (<NUM>) has a basis weight of <NUM>/m<NUM> to <NUM>/m<NUM> and a thickness of <NUM> to <NUM> to increase strength of the cigarette (<NUM>),
wherein the cigarette (<NUM>) further comprises a second wrapper (<NUM>) wrapping the cigarette rod (<NUM>), and
wherein porosity of the second wrapper (<NUM>) is higher than porosity of the outer wrapper (<NUM>).