Aerosol generating article with low-resistance airflow path

Abstract

To provide a heated aerosol-generating article for use with an aerosol-generating device that is designed to be difficult to light in the manner of traditional cigarettes.SOLUTION: A heated aerosol-generating article (10) comprises a plurality of components, including an aerosol-forming substrate (20), assembled within a wrapper (60) to form a rod having a mouth end (70) and a distal end (80) upstream from the mouth end. The heated aerosol-generating article defines a first air-flow path in which air drawn into the aerosol-generating article through the mouth end passes through the aerosol-forming substrate, and a second air-flow path in which air drawn into the aerosol-generating article through the mouth end does not pass through the aerosol-forming substrate. The resistance to draw (RTD) of the second air-flow path is lower than the RTD of the first air-flow path when the heated aerosol-generating article is not coupled to an aerosol-generating device.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This specification relates to aerosol-generating articles comprising an aerosol-forming substrate for generating inhalable aerosols when heated using an aerosol generator. When not engaged by an aerosol generator, the aerosol-generating articles define low-resistance airflow paths that do not pass through the aerosol-forming substrate. This specification also relates to methods of using such aerosol-generating articles. [Background technology]

[0002] Aerosol-generating articles in which an aerosol-forming substrate, such as a tobacco-containing substrate, is heated rather than burned are well known in this industry. One purpose of such heated aerosol-generating articles is to reduce the well-known harmful smoke components produced by the combustion and thermal decomposition of tobacco in conventional cigarettes.

[0003] Conventional cigarettes are ignited when the user places a flame on one end of the cigarette and draws air through the other end. The localized heat provided by the flame and the oxygen in the air drawn through the cigarette ignites the end of the cigarette, and the resulting combustion produces inhalable smoke. In contrast, in heated aerosol generating articles, typically, the inhalable aerosol is generated by heat transfer to an aerosol-forming substrate or material that is physically away from the heat source, which may be located in, around, or downstream of the heat source. During consumption, volatile compounds are released from the aerosol-forming substrate by heat transfer from the heat source and carried together into the air drawn through the aerosol generating article. As the released compounds cool, they condense to form an aerosol, which is inhaled by the consumer.

[0004] Heated aerosol generating articles, including tobacco that generates aerosols by heating rather than combustion, are well known in the industry. For example, WO2013 / 102614 discloses an aerosol generating system comprising a heated aerosol generating article and an aerosol generating device having a heater for heating the heated aerosol generating article to generate aerosols.

[0005] Tobacco used as part of the aerosol-forming substrate in heated aerosol generating articles is designed to generate aerosols when heated, not when burned. Therefore, such tobacco generally contains high levels of aerosol-forming agents, such as glycerin or propylene glycol. If a user lights a heated aerosol generating article and smokes it as if it were a conventional cigarette, they will not experience the intended user experience. It would be desirable to manufacture heated aerosol generating articles that have little to no tendency to ignite with a flame. Such heated aerosol generating articles should preferably be difficult to ignite when attempted with a lighter (flame, etc.) in the same way as a traditional cigarette. [Overview of the Initiative]

[0006] A heated aerosol generating article may be provided for use with an aerosol generator. The heated aerosol generating article may comprise several components, including an aerosol forming substrate assembled inside a wrapper to form a rod having a mouth end and a distal end upstream of the mouth end. The heated aerosol generating article defines a first potential airflow path through which air drawn into the aerosol generating article through the mouth end passes through the aerosol forming substrate, and a second potential airflow path through which air drawn into the aerosol generating article through the mouth end does not pass through the aerosol forming substrate. When the heated aerosol generating article is not coupled to an aerosol generator, the draw resistance (RTD) of the second airflow path is smaller than the RTD of the first airflow path. The second airflow path has lower resistance compared to the first airflow path.

[0007] When a heated aerosol generating article is not coupled to an aerosol generator, the preferred airflow path for air drawn into the heated aerosol generating article through the mouth end is the second airflow path. Therefore, if a user inhales from the mouth end of a heated aerosol generating article without engaging it with an aerosol generator, virtually no air is drawn through the aerosol-forming substrate. If a user attempts to ignite a heated aerosol generating article in the same way as a conventional cigarette, that is, by bringing the flame close to the distal end of the rod and inhaling from the mouth end, virtually no air flows through the aerosol-forming substrate. This lack of airflow makes ignition of the aerosol-forming substrate difficult.

[0008] A heated aerosol-generating article may have a low effective draw-to-discharge (RTD) when not connected to an aerosol generator. For example, the effective RTD may be close to zero. This may prevent the user from drawing enough air through the aerosol-forming substrate to ignite it. The second airflow path may be any airflow path that prevents sufficient airflow through the aerosol-forming substrate to prevent the substrate from burning independently when attempting to ignite the article.

[0009] The interaction between the heated aerosol generating article and the aerosol generator is preferably such that the RTD along the second airflow path is increased so that the airflow along the first airflow path is preferred. The engagement between the heated aerosol generating article and the aerosol generator may partially or completely block the second airflow path so that the second airflow path has higher resistance than the first airflow path. Thus, the air drawn through the heated aerosol generating article can preferentially flow through the aerosol forming substrate along the first airflow path.

[0010] The aerosol-forming substrate of a heated aerosol-generating article may be located at or toward the distal end of the rod. One or more holes or perforations defined through the wrapper downstream of the aerosol-forming substrate may define a portion of a second airflow path. Thus, when the heated aerosol-generating article is not engaged with an aerosol generator, the airflow path with the least resistance is the one entering the article through the holes or perforations in the wrapper downstream of the aerosol-forming substrate. The air flowing into the article through this path is then drawn out through the mouth end of the rod and does not flow over or through the aerosol-forming substrate.

[0011] The wrapper is preferably a highly perforated wrapper that allows air to be drawn out through the wrapper downstream of the aerosol-forming substrate to the heated aerosol-generating article. A perforated wrapper can reduce the RTD of the heated aerosol-generating article to near zero.

[0012] Support elements, such as hollow acetate tubes, may be positioned downstream of the aerosol-forming substrate. Radially extending holes may be defined through the radial walls of the support elements, which form part of a second airflow path. These holes are preferably large enough to reduce the RTD of the heated aerosol-generating article to near zero. A wrapper may define holes that overlap with the radially extending holes. Alternatively, the wrapper may be a highly perforating wrapper.

[0013] In a preferred embodiment, the aerosol-forming substrate is in the form of an aerosol-generating rod comprising an assembly of at least one material sheet. The assembly of material sheets may be a homogenized tobacco sheet. The aerosol-forming substrate may also be a tobacco assembly rod as described in WO 2012 / 164009.

[0014] A heated aerosol generating system may comprise a heated aerosol generating article according to any one of the embodiments described above, and an aerosol generating device including means for heating an aerosol-forming substrate. The aerosol generating device is positioned to engage with the heated aerosol generating article such that when a user inhales through the mouth end of the rod, a second airflow path is interrupted and air is drawn through the aerosol-forming substrate.

[0015] It is preferable that the resistance along the second airflow path increases due to the engagement of the aerosol generating article with the heated aerosol generator. Therefore, the preferred airflow path is the first airflow path through the aerosol forming substrate.

[0016] The aerosol generator may define a chamber for receiving an aerosol generating article. The chamber may seal at least a portion of the outer surface of the aerosol generating article to the extent that it increases resistance to or completely obstructs airflow along a second airflow path. The device allows air to pass through the aerosol-forming substrate when the heated aerosol generating article is engaged with the aerosol generator. The aerosol generator may interact with the aerosol generating article to seal one or more airflow holes or perforations defined within the aerosol generating article.

[0017] The aerosol generator includes means for heating the aerosol-forming substrate of the aerosol-generating article. Such means may include, for example, a heating element that can be inserted into the aerosol-generating article or a heating element that can be positioned adjacent to the aerosol-generating article. The heating means may include an inductor for interacting with the susceptor, for example, an induction coil.

[0018] A method for smoking or consuming an aerosol-generating article as described herein may include the steps of engaging a heated aerosol-generating article with an aerosol generator such that a second airflow path is interrupted, operating the aerosol generator to heat an aerosol-forming substrate, and drawing in the article at the mouth end of a rod so that it flows along the first airflow path, wherein as the article passes through the aerosol-forming substrate, the aerosol generated by the heating of the aerosol-forming substrate is mixed into the air.

[0019] As used herein, the term “aerosol-forming substrate” is used to describe a substrate capable of releasing volatile compounds that can form aerosols in response to heating. The aerosols produced from the aerosol-forming substrates of the aerosol-generating articles described herein may be visible or invisible and may include vapors (e.g., fine particles of a substance that is normally liquid or solid at room temperature in a gaseous state) as well as liquid droplets of the gas and condensed vapors.

[0020] As used herein, the terms “upstream” and “downstream” are used to describe the relative position of an element or part of an aerosol generating article with respect to the direction in which the user inhales with the aerosol generating article during its use.

[0021] A heated aerosol generating article includes two ends: a proximal end through which the aerosol exits the article, and a distal end delivered to the user. In use, the user may draw out the proximal end to inhale the aerosol generated by the aerosol generating article.

[0022] Furthermore, the proximal end may also be called the oral end or downstream end, and is located downstream of the distal end. Conversely, the distal end may also be called the upstream end, and is located upstream of the proximal end.

[0023] As used herein, the term "aerosol cooling element" is used to describe an element having a large surface area and low draw resistance. In use, the aerosol formed by volatile compounds released from the aerosol-forming substrate passes through and is cooled by the aerosol cooling element before being inhaled by a user. In contrast to high draw resistance filters and other mouthpieces, the aerosol cooling element has low draw resistance. Furthermore, chambers and cavities within an aerosol-generating article are not considered to be aerosol cooling elements.

[0024] The heated aerosol-generating article is preferably a smoking article that generates an aerosol directly inhalable into a user's lungs through the user's mouth. Furthermore, the heated aerosol-generating article is preferably a smoking article that generates a nicotine-containing aerosol directly inhalable into a user's lungs through the user's mouth.

[0025] As used herein, the term "aerosol-generating device" is used to describe a device that interacts with the aerosol-forming substrate of an aerosol-generating article to generate an aerosol. The aerosol-generating device is preferably a smoking device that interacts with the aerosol-forming substrate of a heated aerosol-generating article to generate an aerosol directly inhalable into a user's lungs through the user's mouth. Preferably, the aerosol-generating device interacts with the aerosol-generating article to cause air to flow through the aerosol-forming substrate.

[0026] For the avoidance of doubt, in the following description, the term "heating element" is used to mean one or more heating elements.

[0027] In a preferred embodiment, the aerosol-forming substrate is located at the upstream end of the aerosol-generating article.

[0028] As used herein, the term “diameter” is used to describe the maximum lateral dimension of an aerosol-generating article. As used herein, the term “length” is used to describe the maximum length of an aerosol-generating article along its long axis.

[0029] The aerosol-forming substrate is preferably a solid aerosol-forming substrate. The aerosol-forming substrate may contain solid and liquid components.

[0030] Preferably, the aerosol-forming substrate contains nicotine. More preferably, the aerosol-forming substrate contains tobacco.

[0031] Alternatively, or additionally, the aerosol-forming substrate may include a non-tobacco material containing an aerosol-forming material.

[0032] If the aerosol-forming substrate is a solid aerosol-forming substrate, it may include one or more of the following: herb leaves, tobacco leaves, tobacco stems, puffed tobacco, and homogenized tobacco, for example, one or more of the following: powder, granules, pellets, fragments, strands, slivers, or sheets.

[0033] Optionally, the solid aerosol-forming substrate may contain tobacco or non-tobacco volatile flavor compounds, which are released in response to heating of the solid aerosol-forming substrate. Alternatively, the solid aerosol-forming substrate may contain, for example, one or more capsules containing further tobacco volatile flavor compounds or non-tobacco volatile flavor compounds, such capsules may dissolve during heating of the solid aerosol-forming substrate.

[0034] Optionally, the solid aerosol-forming substrate may be provided on or embedded within a thermally stable carrier. The carrier may be in the form of a powder, granules, pellets, fragments, strands, strips, or sheets. The solid aerosol-forming substrate may be deposited on the surface of the carrier, for example, in the form of a sheet, foam, gel, or slurry. The solid aerosol-forming substrate may be deposited on the entire surface of the carrier, or alternatively, in a certain pattern to provide non-uniform flavor delivery during use.

[0035] In a preferred embodiment, the aerosol-forming substrate comprises homogenized tobacco material.

[0036] As used herein, the term “homogenized tobacco material” refers to a material formed by aggregating particulate tobacco.

[0037] The aerosol-forming substrate preferably includes an aggregate of homogenized tobacco material sheets.

[0038] As used herein, the term "sheet" means a thin, layered element having a width and length substantially greater than its thickness.

[0039] As used herein, the term “collected” is used to describe a sheet that has been wrapped, folded, or compressed or shrunk substantially transversely to the longitudinal axis of a separate aerosol-generating article.

[0040] The use of aerosol-forming substrates containing sheets of homogenized tobacco material has the advantage of significantly reducing the risk of "end loosening" compared to aerosol-forming substrates containing fragments of tobacco material (i.e., loss of tobacco material fragments from the ends of the rod). End loosening, however, can lead to the need for more frequent cleaning of aerosol generators and manufacturing equipment used in conjunction with aerosol-generating articles.

[0041] In a preferred embodiment, the aerosol-forming substrate comprises an aggregate of textured sheets of homogenized tobacco material.

[0042] As used herein, the term “textured sheet” means a sheet that has been crumpled, embossed, debossed, perforated, or otherwise deformed. The aerosol-forming substrate may include an aggregate of textured sheets of homogenized tobacco material containing multiple spaced indentations, protrusions, perforations, or combinations thereof.

[0043] In a particularly preferred embodiment, the aerosol-forming substrate comprises an aggregate of crimped sheets of homogenized tobacco material.

[0044] The use of textured sheets of homogenized tobacco material may conveniently facilitate the aggregation of these sheets to form an aerosol-forming substrate.

[0045] As used herein, the term “crimped sheet” means a sheet having a plurality of substantially parallel ridges or wrinkles. When the aerosol-generating article is assembled, it is preferable that the substantially parallel ridges or wrinkles extend along or parallel to the longitudinal axis of the aerosol-generating article. This conveniently facilitates the assembly of crimped sheets of homogenized tobacco material to form an aerosol-forming substrate. However, it is recognized that crimped sheets of homogenized tobacco material to be included in the aerosol-generating article may, in addition to or otherwise, have a plurality of substantially parallel ridges or wrinkles that are arranged at acute or obtuse angles to the longitudinal axis of the aerosol-generating article when the aerosol-generating article is assembled.

[0046] In certain embodiments, the aerosol-forming substrate may comprise an aggregate of homogenized tobacco material sheets that are substantially uniformly textured across their entire surface. For example, the aerosol-forming substrate may comprise an aggregate of crumpled sheets of homogenized tobacco material having a plurality of substantially parallel ridges or wrinkles substantially uniformly spaced across the width of the sheet.

[0047] The aerosol-forming substrate may be in the form of a plug containing an aerosol-forming material surrounded by paper or other wrappers. When the aerosol-forming substrate is in the form of a plug, the entire plug, including any wrappers, is considered to be the aerosol-forming substrate.

[0048] In one preferred embodiment, the aerosol generating substrate includes a plug comprising an aggregate of textured sheets of homogenized tobacco material surrounded by a wrapper. In a particularly preferred embodiment, the aerosol generating substrate includes a plug comprising an aggregate of crimped sheets of homogenized tobacco material surrounded by a wrapper.

[0049] In certain embodiments, a sheet of homogenized tobacco material for use in an aerosol generating substrate may have a tobacco content of approximately 70% or more by weight on a dry mass basis.

[0050] A homogenized tobacco material sheet for use in an aerosol-generating substrate comprises one or more intrinsic binders, which are endogenous tobacco binders, and one or more exogenous tobacco binders, which are exogenous tobacco binders, or a combination thereof, to assist in agglomerating particulate tobacco. Alternatively, or in addition, a homogenized tobacco material sheet for use in an aerosol-generating substrate may also comprise, but are not limited to, tobacco and non-tobacco fibers, aerosol-forming agents, wetting agents, plasticizers, flavoring agents, fillers, aqueous and non-aqueous solvents, and combinations thereof.

[0051] Suitable exogenous binders for inclusions in homogenized tobacco material sheets for use in aerosol generating substrates are well known in the art and include, but are not limited to, rubbers such as guar gum, xanthan gum, acacia gum, and locust bean gum; cellulose binders such as hydroxypropylcellulose, carboxymethylcellulose, hydroxyethylcellulose, methylcellulose, and ethylcellulose; polysaccharides such as starch, organic acids such as alginic acid, sodium alginate, agar, and conjugated base salts of organic acids such as pectin; and combinations thereof.

[0052] Suitable non-tobacco fibers for inclusion in a sheet of homogenized tobacco material for use in an aerosol generating substrate are well known in the art and include, but are not limited to, cellulose fibers; soft wood fibers; hard wood fibers; jute fibers and combinations thereof. Before inclusion in a sheet of homogenized tobacco material for use in an aerosol generating substrate, the non-tobacco fibers may be treated by suitable processes well known in the art, including, but are not limited to, mechanical pulping; purification; chemical pulping; decolorization; sulfate pulping; and combinations thereof.

[0053] A sheet of homogenized tobacco material for use in an aerosol generating substrate must have sufficiently high tensile strength to withstand the aggregation required to form the aerosol generating substrate. In certain embodiments, non-tobacco fibers may be included in the sheet of homogenized tobacco material for use in an aerosol generating substrate to achieve adequate tensile strength.

[0054] For example, a homogenized tobacco material sheet for use in an aerosol generating substrate may contain non-tobacco fibers at a dry mass basis of approximately 1% to 5% by weight.

[0055] The aerosol-forming substrate preferably contains an aerosol-forming agent.

[0056] As used herein, the term “aerosol-forming agent” is used to describe any suitable well-known compound or mixture of compounds that facilitates aerosol formation in use and is substantially resistant to thermal decomposition at the operating temperature of the aerosol-generating article.

[0057] Suitable aerosol-forming agents are well known in the industry and include, but are not limited to, polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3-butanediol, and glycerin), esters of polyhydric alcohols (such as glycerol mono-, di-, or triacetate), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanediate and dimethyl tetradecanediate).

[0058] Preferred aerosol-forming agents are polyhydric alcohols or mixtures thereof (e.g., propylene glycol, triethylene glycol, 1,3-butanediol, and most preferably glycerin).

[0059] The aerosol-forming substrate may contain a single aerosol-forming agent. Alternatively, the aerosol-forming substrate may contain a combination of two or more aerosol-forming agents.

[0060] The aerosol-forming substrate preferably contains more than 5% of the aerosol-forming agent on a dry mass basis.

[0061] The aerosol-forming substrate may contain an aerosol-forming agent in an amount between approximately 5% and approximately 30% on a dry mass basis.

[0062] In a preferred embodiment, the aerosol-forming substrate has an aerosol-forming agent content of approximately 20% on a dry mass basis.

[0063] Aerosol-forming substrates, including aggregates of homogenized tobacco sheets for use in aerosol-generating articles, can be manufactured by methods well known in the art, for example, those disclosed in WO 2012 / 164009 A2.

[0064] In a preferred embodiment, a homogenized tobacco material sheet for use in an aerosol-generating article is formed by a casting process from a slurry containing particulate tobacco, guar gum, cellulose fibers, and glycerin.

[0065] The aerosol-forming element preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol-generating article.

[0066] The outer diameter of the aerosol-forming substrate is preferably at least 5 millimeters. The aerosol-forming substrate may have an outer diameter between approximately 5 millimeters and approximately 12 millimeters, for example, between approximately 5 millimeters and approximately 10 millimeters, or between approximately 6 millimeters and approximately 8 millimeters. In a preferred embodiment, the aerosol-forming substrate has an outer diameter of 7.2 millimeters ± 10%.

[0067] The aerosol-forming substrate may have a length between approximately 7 mm and approximately 15 mm. In one embodiment, the aerosol-forming substrate may have a length of approximately 10 mm. In a preferred embodiment, the aerosol-forming substrate has a length of approximately 12 mm.

[0068] The aerosol-forming substrate is preferably substantially cylindrical.

[0069] For example, support elements such as hollow support elements may be located immediately downstream of the aerosol-forming substrate.

[0070] The support element may be formed from any suitable material or combination of materials. For example, the support element may be formed from one or more materials selected from the group consisting of cellulose acetate; cardboard; crimped paper such as crimped heat-resistant paper or crimped sulfuric acid paper; and polymer materials such as low-density polyethylene (LDPE). In a preferred embodiment, the support element is formed from cellulose acetate.

[0071] The support element may include a hollow tubular element. In a preferred embodiment, the support element includes a hollow cellulose acetate tube.

[0072] The support element preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol-generating article.

[0073] The support element may have an outer diameter between approximately 5 mm and approximately 12 mm, for example between approximately 5 mm and approximately 10 mm or between approximately 6 mm and approximately 8 mm. In a preferred embodiment, the support element has an outer diameter of 7.2 mm ± 10%.

[0074] The support element may have a length between approximately 5 mm and approximately 15 mm. In a preferred embodiment, the support element has a length of approximately 8 mm.

[0075] The aerosol cooling element may be located downstream of the aerosol-forming substrate. For example, in some embodiments, the aerosol cooling element may be located immediately downstream of a support element located downstream of the aerosol-forming substrate.

[0076] The aerosol cooling element may be located between the support element and the mouthpiece, which is positioned at the downstream end of the aerosol generating article.

[0077] The aerosol cooling element may have a total surface area of ​​approximately 300 to 1000 square millimeters per millimeter length. In a preferred embodiment, the aerosol cooling element has a total surface area of ​​approximately 500 square millimeters per millimeter length.

[0078] Aerosol cooling elements can also be referred to as heat exchangers.

[0079] The aerosol cooling element preferably has low draw resistance. That is, the aerosol cooling element preferably provides low resistance to the passage of air through the aerosol generating article. It is preferable that the aerosol cooling element does not substantially affect the draw resistance of the aerosol generating article.

[0080] Preferably, the aerosol cooling element has a porosity between 50% and 90% in the longitudinal direction. The porosity of the aerosol cooling element in the longitudinal direction is defined by the ratio of the cross-sectional area of ​​the material forming the internal cross-sectional area of ​​the aerosol cooling element to the cross-sectional area of ​​the aerosol generating article at the location of the aerosol cooling element.

[0081] The aerosol cooling element may include multiple paths extending in the longitudinal direction. These multiple paths may be defined by sheet material that undergoes one or more processes, such as crimping, pleating, bundling, or folding, to form the paths. Alternatively, the multiple paths may be defined by a single sheet that undergoes one or more processes, such as crimping, pleating, bundling, or folding, to form the multiple paths.

[0082] In some embodiments, the aerosol cooling element may include an assembly of material sheets selected from the group consisting of metal foil, polymer materials, and substantially non-porous paper or cardboard. In some embodiments, the aerosol cooling element may include an assembly of material sheets selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), and aluminum foil.

[0083] The aerosol cooling element may have an outer diameter between approximately 5 mm and approximately 10 mm, for example between approximately 6 mm and approximately 8 mm. In a preferred embodiment, the aerosol cooling element has an outer diameter of 7.2 mm ± 10%.

[0084] The aerosol cooling element may have a length between approximately 5 mm and approximately 25 mm. In a preferred embodiment, the aerosol cooling element has a length of approximately 18 mm.

[0085] In some embodiments, the aerosol cooling element may include an assembly of material sheets selected from the group consisting of metal foil, polymer materials, and substantially non-porous paper or cardboard. In some embodiments, the aerosol cooling element may include an assembly of material sheets selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), and aluminum foil.

[0086] In a preferred embodiment, the aerosol cooling element comprises an assembly of sheets of biodegradable polymer material, such as polylactic acid or grades of Mater-Bi® (a commercially available family of starch-based copolyesters).

[0087] In a particularly preferred embodiment, the aerosol cooling element includes an assembly of polylactic acid sheets.

[0088] The aerosol generating article may include a mouthpiece located at the downstream end of the aerosol generating article.

[0089] The mouthpiece may be located directly downstream of the aerosol cooling element or adjacent to it.

[0090] The mouthpiece may include a filter. The filter may be formed from one or more suitable filtration materials. Many such filtration materials are well known in the art. In one embodiment, the mouthpiece may include a filter formed from cellulose acetate tow.

[0091] The mouthpiece preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol generating article.

[0092] The mouthpiece may have an outer diameter between approximately 5 mm and approximately 10 mm, for example between approximately 6 mm and approximately 8 mm. In a preferred embodiment, the mouthpiece has an outer diameter of 7.2 mm ± 10%.

[0093] The mouthpiece may have a length between approximately 5 millimeters and approximately 20 millimeters. In a preferred embodiment, the mouthpiece has a length of approximately 14 millimeters.

[0094] The mouthpiece may have a length between approximately 5 millimeters and approximately 14 millimeters. In a preferred embodiment, the mouthpiece has a length of approximately 7 millimeters.

[0095] The aerosol-forming substrate and any other components of the heated aerosol-generating article are assembled within a surrounding wrapper. The wrapper may be formed from any suitable material or combination of materials. The outer wrapper is preferably cigarette paper.

[0096] The downstream end of the wrapper may be surrounded by a strip of chipping paper.

[0097] The appearance of the heated aerosol generating article may mimic the appearance of a conventional cigarette with an ignition end.

[0098] The aerosol-generating article may have an outer diameter between approximately 5 mm and approximately 12 mm, for example between approximately 6 mm and approximately 8 mm. In a preferred embodiment, the aerosol-generating article has an outer diameter of 7.2 mm ± 10%.

[0099] The aerosol-generating article may have a total length between approximately 30 mm and approximately 100 mm. In a preferred embodiment, the aerosol-generating article has a total length of approximately 45 mm.

[0100] The aerosol generator may include: a housing; a heating element; a power source connected to the heating element; and a control element configured to control the supply of power from the power source to the heating element.

[0101] The housing may define a recess surrounding a heating element, which is configured to receive a heated aerosol generating article and interact with the aerosol generating article to interrupt or close a second airflow path, thereby drawing air through the aerosol forming substrate.

[0102] The aerosol generator is preferably a portable or handheld aerosol generator that is easy for the user to hold between the fingers of one hand.

[0103] The aerosol generator may be substantially cylindrical in shape.

[0104] The aerosol generator may have a length between approximately 70 millimeters and approximately 120 millimeters.

[0105] The power source may be any suitable power source, such as a DC voltage source such as a battery. In one embodiment, the power source is a lithium-ion battery. Alternatively, the power source may be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery, such as a lithium-cobalt, lithium iron phosphate, lithium titanate, or lithium polymer battery.

[0106] The control element may be a simple switch. Alternatively, the control element may be an electrical circuit and may include one or more microprocessors or microcontrollers.

[0107] The heating element of the aerosol generator may be any suitable heating element that can be inserted into the aerosol-forming substrate of the aerosol-generating article. For example, the heating element may be in the form of a pin or a blade.

[0108] The heating element may have a tapered, pointed, or sharpened end to facilitate insertion of the heating element into the aerosol-forming substrate of the aerosol-generating article.

[0109] The draw resistance (RTD) of the aerosol generating article before engagement with the aerosol generating article is preferably close to zero (e.g., less than 10 mmWG). The RTD after engagement with the aerosol generating device can be approximately 80 mmWG to approximately 140 mmWG, and is preferably 110 to 115 mmWG.

[0110] When used herein, the draw resistance is expressed in units of pressure "mmWG" or "mm of the water level gauge" and is measured in accordance with ISO 6565:2002.

[0111] In another embodiment, a heated aerosol generating article is provided for use in conjunction with an aerosol generating device, the heated aerosol generating article comprising a plurality of components including an aerosol forming substrate assembled inside a wrapper to form a rod having a mouth end and a distal end upstream of the mouth end, the heated aerosol generating article defines a first airflow path through which air drawn into the aerosol generating article through the mouth end passes through the aerosol forming substrate, and a second airflow path through which air drawn into the aerosol generating article through the mouth end is drawn into the rod through the wrapper, the second airflow path merging with the first airflow path downstream of the aerosol forming substrate, and the draw resistance (RTD) of the second airflow path through the wrapper is smaller than the RTD of the first airflow path through the aerosol forming substrate.

[0112] The RTD of the second airflow path is preferably not more than 0.9 times that of the RTD of the first airflow path, more preferably 0.2 to 0.7 times that of the RTD of the first airflow path, and even more preferably 0.3 to 0.5 times that of the RTD of the first airflow path.

[0113] In a further embodiment, a heated aerosol generating article is provided for use in conjunction with an aerosol generating device, the heated aerosol generating article comprising a plurality of components including an aerosol forming substrate assembled inside a wrapper to form a rod having a mouth end and a distal end upstream of the mouth end, the heated aerosol generating article defines a first airflow path through which air drawn into the aerosol generating article through the mouth end passes through the aerosol forming substrate, and a second airflow path through which air drawn into the aerosol generating article through the mouth end is drawn into the rod via the wrapper, where the second airflow path merges with the first airflow path downstream of the aerosol forming substrate, and the aerosol generating article is configured such that when suction is made to the mouth end of the rod, neither the first nor the second airflow path is blocked, and a larger volume of air is drawn through the second airflow path than is drawn through the first airflow path.

[0114] Preferably, the volume of air drawn through the second airflow path is at least twice the volume of air drawn through the first airflow path.

[0115] Furthermore, features described in relation to one aspect or embodiment may be applicable to other aspects and embodiments. For example, features described in relation to the aerosol generating article and aerosol generating system described above may also be used in conjunction with methods of using the aerosol generating article and aerosol generating system described above.

[0116] A specific embodiment will be explained here with reference to the diagram. [Brief explanation of the drawing]

[0117] [Figure 1] Figure 1 is a schematic cross-sectional view of an embodiment of a heated aerosol generating article for use in conjunction with an aerosol generating device. [Figure 2] Figure 2 is a schematic cross-sectional view of an embodiment of a further heated aerosol generating article for use in conjunction with an aerosol generator. [Figure 3] Figure 3 is a schematic cross-sectional view of an embodiment of an aerosol generation system including an electrically heated aerosol generator containing a heating element and an aerosol generating article according to the embodiment shown in Figure 1. [Figure 4] Figure 4 is a schematic cross-sectional view of the aerosol generator shown in Figure 3. [Modes for carrying out the invention]

[0118] Figure 1 illustrates a heated aerosol generating article 10 according to a preferred embodiment. The aerosol generating article 10 includes four elements arranged coaxially: an aerosol forming substrate 20, a support element 30, an aerosol cooling element 40, and a mouthpiece 50. These four elements are arranged in sequence and surrounded by an outer wrapper 60 to form the heated aerosol generating article 10. The aerosol generating article 10 has a proximal or oral end 70 which the user inserts into the user's mouth during use, and a distal end 80 located at the opposite end of the aerosol generating article 10 from the oral end 70. The outer wrapper 60 is a highly perforated paper that offers little to no resistance to airflow through the paper. Non-perforated chipping paper 65 surrounds the mouthpiece end of the article 10.

[0119] Furthermore, the distal end 80 of the aerosol generating article may be described as the upstream end of the aerosol generating article 10, and the mouth end 70 of the aerosol generating article 10 may also be described as the downstream end of the aerosol generating article 10. An element of the aerosol generating article 10 located between the mouth end 70 and the distal end 80 may be described as being upstream of the mouth end 70, or alternatively, downstream of the distal end 80.

[0120] The aerosol-forming substrate 20 is located at the distal or upstream end of the aerosol-generating article 10. In the embodiment shown in Figure 1, the aerosol-forming substrate 20 comprises an assembly of crumpled and homogenized tobacco material sheets surrounded by a wrapper. The crumpled sheets of homogenized tobacco material contain glycerin as an aerosol-forming agent.

[0121] The support element 30 is located directly downstream of the aerosol-forming substrate 20 and adjacent to the aerosol-forming substrate 20. In the embodiment shown in Figure 1, the support element is a hollow cellulose acetate tube. The support element 30 positions the aerosol-forming substrate 20 at the distal end 80 of the aerosol-generating article 10 so that it can be penetrated by the heating element of the aerosol generator. The support element 30 also acts to prevent the aerosol-forming substrate 20 from being pushed downstream into the aerosol-generating article 10 toward the aerosol cooling element 40 when the heating element of the aerosol generator is inserted into the aerosol-forming substrate 20. The support element 30 also acts as a spacer, creating a gap between the aerosol-forming substrate 20 and the aerosol cooling element 40 of the aerosol-generating article 10.

[0122] The aerosol cooling element 40 is located directly downstream of the support element 30 and adjacent to the support element 30. In use, volatile substances released from the aerosol-forming substrate 20 pass along the aerosol cooling element 40 toward the mouth end 70 of the aerosol-generating article 10. The volatile substances may cool within the aerosol cooling element 40 to form an aerosol that is inhaled by the user. In the embodiment shown in Figure 1, the aerosol cooling element includes an assembly of crimped sheets of polylactic acid surrounded by a wrapper 90. The assembly of crimped sheets of polylactic acid defines multiple longitudinal paths extending along the length of the aerosol cooling element 40.

[0123] The mouthpiece 50 is located directly downstream of the aerosol cooling element 40 and adjacent to the aerosol cooling element 40. In the embodiment shown in Figure 1, the mouthpiece 50 includes a conventional cellulose acetate tow filter with low filtration efficiency.

[0124] To assemble the aerosol-generating article 10, the four elements described above are aligned and tightly wrapped within a perforated outer wrapper 60. In the embodiment shown in Figure 1, the distal end portion of the outer wrapper 60 of the aerosol-generating article 10 is surrounded by a strip of non-perforated chipping paper 65.

[0125] When a user draws air through the mouthpiece of the device without engaging the heated aerosol generating article with the aerosol generating device, the draw resistance is minimal. As indicated by the arrows in Figure 1, air enters the article 10 through the perforated outer wrapper 60. Since air can flow more easily through the wrapper than it can flow through the aerosol forming substrate, virtually no air flows through the aerosol forming substrate. Therefore, if a user attempts to ignite the heated aerosol generating article by applying a flame to the distal end 80 and sucking on the mouth end 70, the airflow through the aerosol forming substrate is insufficient, easily suppressing combustion and minimizing the risk of ignition.

[0126] Figure 2 illustrates a second embodiment of the heated aerosol generating article. All elements are as described in Figure 1, with the exception of the hollow tube, where a support element 30 defines a radially extending hole 37 between the inner surface of tube 31 and the outer surface of tube 32. The hole provides an additional airflow path that allows access between the inner portion of the aerosol generating article and the perforated wrapper 60. Thus, the RTD of the article illustrated in Figure 2 may be even smaller than that illustrated in Figure 1.

[0127] The relative volume of the airflow through the aerosol-forming substrate and the airflow through the perforated wrapper depends on numerous parameters.

[0128] Using Darcy's law regarding flow through a porous body, the airflow through an aerosol-forming substrate can be estimated. The airflow rate Q through the aerosol-forming substrate is... p It can be calculated as follows:

number

[0129] The air flow rate through a single perforation in the wrapper can be approximated using the Hagen-Poiseuille equation for laminar fluid flow. [Formula] In the formula, (ΔP) v is the pressure drop across the perforation, μ is the kinematic viscosity of air, t v is the thickness of the wrapper, Q v,i is the air flow rate through a single perforation, d v is the diameter of the perforation.

[0130] When there are n perforations, the total flow rate through all perforations is as follows. [Formula]

[0131] Accordingly, the distribution of air flow through the first air flow path and the second air flow path is as follows. [Formula]

[0132] (ΔP) p is estimated to be equal to (ΔP) v ,the formula can be simplified as follows. [Formula]

[0133] Therefore, it can be seen that both the size and number of perforations, as well as the size and shape of the aerosol-forming substrate and wrapper, are important. The permeability of the plug is also an important factor, depending on the porosity of the aerosol-forming substrate and the thickness of the crimped tobacco sheet used.

[0134] By varying these parameters, a desirable ratio of airflow through the wrapper to airflow through the plug can be obtained. For example, increasing the size or number of perforations in the wrapper reduces the RTD through the wrapper. Increasing the length of the aerosol-forming substrate increases the RTD through the aerosol-forming substrate.

[0135] The aerosol generating article 10, as shown in Figure 1 or Figure 2, is designed to engage with an aerosol generating device containing a heating element for inhalation or consumption by the user. In use, the heating element of the aerosol generating device heats the aerosol-forming substrate 20 of the aerosol generating article 10 to a temperature sufficient to form an aerosol, which is drawn downstream through the aerosol generating article 10 and inhaled by the user.

[0136] Figure 3 illustrates a portion of the aerosol generating system 100, including the aerosol generating device 110 and the aerosol generating article 10, according to the embodiment described above and illustrated in Figure 1.

[0137] The aerosol generator includes a heating element 120. As shown in Figure 3, the heating element 120 is mounted inside the aerosol generating article receiving chamber of the aerosol generator 110. In use, the user inserts the aerosol generating article 10 into the aerosol generating article receiving chamber of the aerosol generator 110 so that the heating element 120 is directly inserted into the aerosol forming substrate 20 of the aerosol generating article 10 as shown in Figure 3. In the embodiment shown in Figure 3, the heating element 120 of the aerosol generator 110 is a heater blade. The aerosol generator 110 includes a power supply and electronic equipment that can operate the heating element 120. Such operation may be manual or may occur automatically in response to the user pulling out the aerosol generating article 10 inserted into the aerosol generating article receiving chamber of the aerosol generator 110.

[0138] When the heated aerosol generating article 10 is properly engaged with the aerosol generator, the lip of the receiving chamber engages with the outer surface of the article 10. The circumferential engagement between the article and the lip substantially obstructs the airflow into the receiving chamber, and thus substantially restricts the airflow into the receiving chamber. Multiple openings are provided to the aerosol generator, allowing air to flow to the distal end of the aerosol generating article 10. Therefore, when a user inhales from the mouth end of the article, the airflow path with the least resistance is through the distal end of the article and through the aerosol generating substrate, and the direction of this airflow is indicated by the arrows in Figure 3.

[0139] The support element 30 of the aerosol generating article 10 resists the penetrating force experienced by the aerosol generating article 10 during the insertion of the heating element 120 of the aerosol generating device 110 into the aerosol forming substrate 20. As a result, the support element 30 of the aerosol generating article 10 resists the downstream movement of the aerosol forming substrate within the aerosol generating article 10 during the insertion of the heating element of the aerosol generating device into the aerosol forming substrate.

[0140] When the internal heating element 120 is inserted into the aerosol-forming substrate 10 of the aerosol-generating article 10 and activated, the aerosol-forming substrate 20 of the aerosol-generating article 10 is heated to a temperature of approximately 375 degrees Celsius by the heating element 120 of the aerosol generator 110. At this temperature, volatile compounds are released from the aerosol-forming substrate 20 of the aerosol-generating article 10. As the user inhales through the mouth-side end 70 of the aerosol-generating article 10, the volatile compounds released from the aerosol-forming substrate 20 are drawn downstream through the aerosol-generating article 10 and condense to form an aerosol drawn into the user's mouth through the mouthpiece 50 of the aerosol-generating article 10.

[0141] As the aerosol passes downstream through the aerosol cooling element 40, the temperature of the aerosol decreases due to the transfer of thermal energy from the aerosol to the aerosol cooling element 40. When the aerosol enters the aerosol cooling element 40, its temperature is approximately 60 degrees Celsius. Due to cooling within the aerosol cooling element 40, when the aerosol exits the aerosol cooling element, its temperature is approximately 40 degrees Celsius.

[0142] The support elements of the aerosol-generating articles according to the embodiments described above and illustrated in Figure 1 are formed from cellulose acetate, but this is not essential, and it will be recognized that aerosol-generating articles according to other embodiments may include support elements formed from other suitable materials or combinations of materials.

[0143] Similarly, while the aerosol generating article illustrated in Figure 1 according to the above-described embodiment includes an aerosol cooling element comprising an aggregate of crimped polylactic acid sheets, this is not essential, and it will be recognized that aerosol generating articles according to other embodiments may also include other aerosol cooling elements.

[0144] Furthermore, while the aerosol-generating article illustrated in Figure 1 according to the above-described embodiment has four elements surrounded by an outer wrapper, this is not essential, and it will be recognized that aerosol-generating articles according to other embodiments may include more or fewer elements.

[0145] It will be further recognized that the dimensions provided for the elements of the aerosol generating article shown in Figure 1 according to the above-described embodiment, and for the parts of the aerosol generating device shown in Figure 3 according to the above-described embodiment, are merely illustrative, and appropriate alternative dimensions may be selected.

[0146] In Figure 4, the components of the aerosol generator 110 are shown in a simplified form. In particular, the components of the aerosol generator 110 are not depicted to the scale shown in Figure 4. Components not relevant to understanding the embodiment have been omitted, and Figure 4 has been simplified.

[0147] As shown in Figure 4, the aerosol generator 110 includes a housing 6130. The heating element 6120 is mounted in the aerosol generating article receiving chamber within the housing 6130. The aerosol generating article 10 (shown by a dashed line in Figure 4) is inserted into the aerosol generating article receiving chamber within the housing 6130 of the aerosol generator 110 so that the heating element 6120 is directly inserted into the aerosol forming substrate 20 of the aerosol generating article 10.

[0148] Inside the housing 6130 is an electrical energy supply 6140, such as a rechargeable lithium-ion battery. The controller 6150 is connected to the heating element 6120, the electrical energy supply 6140, and the user interface 6160, such as buttons or a display. The controller 6150 controls the power supplied to the heating element 6120 to regulate its temperature.

[0149] The exemplary embodiments described above are not limiting. Other embodiments consistent with the exemplary embodiments described above will be apparent to those skilled in the art.

[0150] 1. A heated aerosol generating article for use with an aerosol generator, wherein the heated aerosol generating article comprises a plurality of components, including an aerosol forming substrate assembled inside a wrapper to form a rod having a mouth end and a distal end upstream of the mouth end, the heated aerosol generating article defines a first airflow path through which air drawn into the aerosol generating article through the mouth end passes through the aerosol forming substrate, and a second airflow path through which air drawn into the aerosol generating article through the mouth end does not pass through the aerosol forming substrate, and the heated aerosol generating article wherein, when the heated aerosol generating article is not coupled to an aerosol generator, the drawout resistance (RTD) of the second airflow path is smaller than the RTD of the first airflow path. 2. The heated aerosol generating article according to claim 1, wherein the RTD of the second airflow path is less than 10 mmWG when the heated aerosol generating article is not coupled to an aerosol generating device. 3. The heated aerosol generating article according to claim 1 or 2, wherein the RTD of the second airflow path does not exceed 0.9 times that of the first airflow path, preferably 0.2 to 0.7 times that of the first airflow path, and more preferably 0.3 to 0.5 times that of the first airflow path. 4. The heated aerosol generating article according to 1, 2, or 3, wherein the interaction between the heated aerosol generating article and the aerosol generating device increases the RTD along the second airflow path, so as to be preferred along the first airflow path. 5. The heated aerosol generating article according to any one of 1 to 4, wherein the aerosol-forming substrate is located at or toward the distal end of the rod, and one or more perforations penetrating the wrapper downstream of the aerosol-forming substrate form part of the second airflow path. 6. A heated aerosol generating article according to any one of 1 to 5, wherein the wrapper is a highly perforating wrapper, allowing air to be drawn out to the heated aerosol generating article through the wrapper located downstream of the aerosol forming substrate. 7. A heated aerosol generating article according to any one of 1 to 6, wherein a support element is located downstream of the aerosol forming substrate, and a hole defined through the radial wall of the support element forms part of the second airflow path. 8. A heated aerosol generating article according to any one of 1 to 7, wherein the aerosol forming substrate comprises an aggregate of homogenized tobacco sheets. 9. A heated aerosol generating article comprising a plurality of components, including an aerosol forming substrate assembled inside a wrapper to form a rod having a mouth end and a distal end upstream of the mouth end, wherein the heated aerosol generating article defines a first airflow path through which air drawn into the aerosol generating article through the mouth end passes through the aerosol forming substrate, and a second airflow path through which air drawn into the aerosol generating article through the mouth end does not pass through the aerosol forming substrate, and the draw resistance (RTD) of the second airflow path is smaller than the RTD of the first airflow path when the heated aerosol generating article is not coupled to an aerosol generator. A heated aerosol generating system comprising an aerosol generating device equipped with means for heating the aerosol forming substrate, wherein the aerosol generating device is arranged to engage with the heated aerosol generating article such that when a user inhales through the mouth end of the rod, the second airflow path is interrupted and air is drawn out through the aerosol forming substrate. 10. The heated aerosol generating system according to 8, wherein the heated aerosol generating article is the aerosol generating article described in any of 1 to 8. 11. A heated aerosol generating system according to either 9 or 10, wherein when the heated aerosol generating article is engaged with the aerosol generating device, the RTD of the second airflow path is greater than the RTD of the first airflow path. 12. The heating type aerosol generator according to any one of 9 to 11, wherein the means for heating the aerosol-forming substrate includes one or more heating elements that can be inserted into the aerosol-forming substrate. 13. The heating aerosol generator according to any one of 9 to 12, wherein the means for heating the aerosol-forming substrate includes one or more heating elements that are radially spaced from the aerosol-generating article when the aerosol-generating article is engaged with the aerosol generator. 14. A heated aerosol generator according to any one of 9 to 13, wherein the means for heating the aerosol-forming substrate includes an inductor for heating a susceptor. 15. A method for smoking a heated aerosol generating article comprising a plurality of components, including an aerosol-forming substrate assembled inside a wrapper to form a rod having a mouth end and a distal end upstream of the mouth end, wherein the heated aerosol generating article defines a first airflow path through which air drawn into the aerosol generating article through the mouth end passes through the aerosol-forming substrate, and a second airflow path through which air drawn into the aerosol generating article through the mouth end does not pass through the aerosol-forming substrate, and the draw resistance (RTD) of the second airflow path is smaller than the RTD of the first airflow path when the heated aerosol generating article is not coupled to an aerosol generator, and the method a) A step of engaging the heated aerosol generating article with the aerosol generating device such that the second airflow path is interrupted, b) A step of operating the aerosol generating device to heat the aerosol forming substrate, c) A method comprising the step of drawing air in with the mouth end of the rod so that air flows along the first airflow path, wherein an aerosol generated by heating the aerosol forming substrate is mixed with the air as it passes through the aerosol forming substrate. 16. The method according to 15, wherein the heated aerosol generating article is an aerosol generating article defined in any of 1 to 9. 17. A heated aerosol generating article for use in conjunction with an aerosol generating device, wherein the heated aerosol generating article comprises a plurality of components including an aerosol forming substrate assembled inside a wrapper to form a rod having a mouth end and a distal end upstream of the mouth end, the heated aerosol generating article defines a first airflow path through which air drawn into the aerosol generating article through the mouth end passes through the aerosol forming substrate, and a second airflow path through which air drawn into the aerosol generating article through the mouth end passes through the wrapper to the rod, the second airflow path merging with the first airflow path downstream of the aerosol forming substrate, and the drawout resistance (RTD) of the second airflow path through the wrapper is smaller than the RTD of the first airflow path through the aerosol forming substrate. 18. The heated aerosol generating article according to 17, wherein the RTD of the second airflow path does not exceed 0.9 times the RTD of the first airflow path. 19. A heated aerosol generating article for use with an aerosol generating device, the heated aerosol generating article comprising a plurality of components including an aerosol forming base assembled inside a wrapper to form a rod having a mouth end and a distal end upstream of the mouth end, wherein the heated aerosol generating article defines a first airflow path through which air drawn into the aerosol generating article through the mouth end passes through the aerosol forming base, and a second airflow path through which air drawn into the aerosol generating article through the mouth end passes through the wrapper to the rod, the second airflow path merging with the first airflow path downstream of the aerosol forming base, and the aerosol generating article is configured such that when suction is made to the mouth end of the rod and neither the first nor the second airflow path is blocked, a larger volume of air is drawn through the second airflow path than is drawn through the first airflow path. 20. The heated aerosol generating article according to 19, wherein the volume of air drawn through the second airflow path is at least twice the volume of air drawn through the first airflow path.

Claims

1. A heated aerosol generating article comprising an aerosol-forming substrate for generating an inhalable aerosol when heated using an aerosol generator, wherein the aerosol generating article comprises a plurality of components, including the aerosol-forming substrate, which is assembled inside a wrapper to form a rod having a mouth end and a distal end upstream of the mouth end, wherein the aerosol generating article defines a first airflow path through which air drawn into the aerosol generating article through the mouth end passes through the aerosol-forming substrate, and a second airflow path through which air drawn into the aerosol generating article through the mouth end does not pass through the aerosol-forming substrate, wherein the draw resistance of the second airflow path is lower than the draw resistance of the first airflow path, and the aerosol generating article has a low tendency to ignite with flame.

2. The aerosol generating article according to claim 1, wherein the second airflow path is configured to obstruct sufficient airflow through the aerosol-forming substrate in order to prevent the aerosol-forming substrate from burning independently while an attempt is being made to ignite the aerosol generating article.

3. The aerosol generating article according to claim 1 or claim 2, wherein the aerosol-forming substrate comprises an aerosol-forming agent.

4. The aerosol generating article according to claim 3, wherein the content of the aerosol-forming agent in the aerosol-forming substrate is between 5% and 30% on a dry mass basis.

5. The aerosol generating article according to claim 3 or claim 4, wherein the aerosol-forming substrate contains an aerosol-forming agent selected from propylene glycol, triethylene glycol, 1,3-butanediol, glycerin, glycerol mono, di, or triacetate, dimethyl dodecanedioate, and dimethyl tetradecanediate in an amount between 5% and 30% on a dry mass basis.

6. The aerosol generating article according to any one of claims 1 to 5, wherein the plurality of components further comprises a hollow tubular element and a mouthpiece, and the hollow tubular element is located upstream of the mouthpiece and immediately downstream of the aerosol forming substrate.

7. The aerosol generating article according to claim 6, wherein a hole forming part of the second airflow path is defined through the radial wall of the hollow tubular element.

8. The aerosol generating article according to claim 7, wherein the wrapper is a highly perforating wrapper, allowing air to be drawn into the aerosol generating article through the wrapper located downstream of the aerosol forming substrate.

9. The aerosol generating article according to any one of claims 6 to 8, wherein the hollow tubular element is made of cardboard.

10. The aerosol generating article according to any one of claims 6 to 9, wherein the hollow tubular element has a length of at least 5 millimeters.

11. The aerosol generating article according to any one of claims 6 to 10, wherein the mouthpiece includes a filter formed from cellulose acetate tow.

12. The aerosol generating article according to any one of claims 6 to 11, wherein the mouthpiece has a length of 5 mm to 20 mm.

13. The aerosol generating article according to any one of claims 1 to 12, wherein the draw resistance of the second airflow path is 0.9 times or less the draw resistance of the first airflow path.

14. The aerosol generating article according to any one of claims 1 to 13, wherein the aerosol-forming substrate is located at or toward the distal end of the rod, and one or more perforations passing through the wrapper downstream of the aerosol-forming substrate form part of the second airflow path.

15. an aerosol generating article according to any one of claims 1 to 14, and an aerosol generating apparatus including means for heating the aerosol-forming substrate, An aerosol generation system equipped with the following features.

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