Aerosol-generating article having two or more substrate segments

Abstract

An aerosol-generating article (10) (110) (210) comprising: an aerosol-generating strip (12) (112) (212) for generating an inhalable aerosol upon heating, the aerosol-generating strip (12) (112) (212) comprising: a first aerosol-generating segment (24) (124) (224) comprising a first aerosol-generating substrate, and a second aerosol-generating segment (26) (126) (226) at a location upstream of the first aerosol-generating segment (24) (124) (224) and comprising a second aerosol-generating substrate. The second aerosol-generating substrate has a higher aerosol former content than the first aerosol-generating substrate. The second aerosol-generating substrate has a higher density than the first aerosol-generating substrate.

Description

[0001] The present invention relates to an aerosol-generating article comprising an aerosol-generating substrate and adapted to generate an inhalable aerosol upon heating.

[0002] Aerosol generating articles in which an aerosol generating substrate such as a tobacco-containing substrate is heated rather than burned are known in the art. Typically, in such heated smoking articles, aerosol is generated by transferring heat from a heat source to a physically separated aerosol generating substrate or material, which can be positioned to contact the heat source, inside, around or downstream of the heat source. During the use of the aerosol generating article, volatile compounds are released from the aerosol generating substrate by heat transfer from the heat source and are entrained in the air drawn by the aerosol generating article. When the released compound cools, the compound condenses to form an aerosol.

[0003] Many prior art documents disclose aerosol generating devices for consuming aerosol generating articles. Such devices include, for example, electrically heated aerosol generating devices, in which an aerosol is generated by transferring heat from one or more electric heater elements of the aerosol generating device to an aerosol generating substrate of a heated aerosol generating article. For example, electrically heated aerosol generating devices including internal heater blades have been proposed, and the internal heater blades are suitable for being inserted into the aerosol generating substrate. It is also known to use aerosol generating articles in combination with external heating systems. For example, WO2020 / 115151 describes the provision of one or more heating elements arranged around the periphery of the aerosol generating article when the aerosol generating article is received in the cavity of the aerosol generating device. As an alternative, an inductively heatable aerosol generating article is proposed by WO2015 / 176898, which includes an aerosol generating substrate and a receptor arranged in the aerosol generating substrate.

[0004] Aerosol-generating articles in which a tobacco-containing substrate is heated rather than combusted present a number of challenges not encountered with conventional smoking articles.

[0005] First, compared with the temperature reached by the combustion front in conventional cigarettes, the tobacco-containing substrate is usually heated to a significantly lower temperature. This may affect the nicotine release of the tobacco-containing substrate and deliver nicotine to the consumer. Meanwhile, if the heating temperature increases in an attempt to enhance nicotine delivery, the generated aerosol usually needs to be cooled to a greater extent and more quickly before it reaches the consumer.

[0006] Secondly, it takes a certain amount of time to heat the aerosol-generating substrate to the temperature required for aerosol formation, and therefore there may be a delay in the delivery of the aerosol to the consumer after heating has begun. This phenomenon whereby the aerosol reaching the user when the user initially draws on the article may be relatively low in flavor or nicotine content, or both, is commonly referred to as the "cold draw" effect or the "empty draw" effect.

[0007] It is desirable to provide a novel aerosol-generating article having an arrangement that provides improved consistency of aerosol delivery during heating. It is also desirable to provide an aerosol-generating article that provides greater control over the puff profile and, in particular, is capable of providing satisfactory aerosol delivery to a consumer within a relatively short period of time after heating has commenced. It would be further desirable if such an aerosol-generating article could be produced using existing manufacturing equipment and methods without significant modification.

[0008] The present disclosure relates to an aerosol generating article. The aerosol generating article may include an aerosol generating strip for generating an inhalable aerosol when heated. The aerosol generating strip may include a first aerosol generating segment, the first aerosol generating segment including a first aerosol generating substrate. The aerosol generating strip may include a second aerosol generating segment, the second aerosol generating segment including a second aerosol generating substrate. The second aerosol generating substrate may be located upstream of the first aerosol generating substrate. The second aerosol generating substrate may have a higher aerosol forming agent content than the first aerosol generating substrate. The second aerosol generating substrate may have a higher density than the first aerosol generating substrate. The first aerosol generating substrate may include at least one aerosol forming agent, wherein the aerosol forming agent content of the first aerosol generating substrate is less than 30% by weight on a dry weight basis. The second aerosol generating substrate may include at least one aerosol forming agent, wherein the aerosol forming agent content of the second aerosol generating substrate is at least 40% by weight on a dry weight basis.

[0009] According to the present invention, there is provided an aerosol-generating article comprising: a first aerosol-generating segment comprising a first aerosol-generating substrate; and a second aerosol-generating segment comprising a second aerosol-generating substrate.

[0010] In a preferred embodiment, an aerosol generating article is provided, comprising: a first aerosol generating segment, the first aerosol generating segment comprising a first aerosol generating substrate; a second aerosol generating segment, the second aerosol generating segment being located upstream of the first aerosol generating segment and comprising a second aerosol generating substrate, wherein the second aerosol generating substrate has a higher aerosol former content than the first aerosol generating substrate, and wherein the second aerosol generating substrate has a higher density than the first aerosol generating substrate.

[0011] In a preferred embodiment, an aerosol generating article is provided, comprising an aerosol generating strip for generating an inhalable aerosol when heated, the aerosol generating strip comprising: a first aerosol generating segment, the first aerosol generating segment comprising a first aerosol generating substrate, wherein the first aerosol generating substrate comprises at least one aerosol former, and wherein the aerosol former content of the first aerosol generating substrate is less than 30 weight% on a dry weight basis; and a second aerosol generating segment, the second aerosol generating segment being located upstream of the first aerosol generating segment and comprising a second aerosol generating substrate, wherein the second aerosol generating substrate comprises at least one aerosol former, and wherein the aerosol former content of the second aerosol generating substrate is at least 40 weight% on a dry weight basis.

[0012] In a preferred embodiment, an aerosol generating article is provided, comprising an aerosol generating strip for generating an inhalable aerosol when heated, the aerosol generating strip comprising: a first aerosol generating segment, the first aerosol generating segment comprising a first aerosol generating substrate, wherein the first aerosol generating substrate comprises at least one aerosol former, and wherein the aerosol former content of the first aerosol generating substrate is less than 30 weight%; and a second aerosol generating segment, the second aerosol generating segment is located upstream of the first aerosol generating segment and comprises a second aerosol generating substrate, wherein the second aerosol generating substrate comprises at least one aerosol former, wherein the aerosol former content of the second aerosol generating substrate is at least 40 weight% on a dry weight basis, and wherein the density of the second aerosol generating substrate is at least 1.2 times the density of the first aerosol generating substrate.

[0013] In a preferred embodiment, an aerosol generating article is provided, comprising an aerosol generating strip for generating an inhalable aerosol when heated, the aerosol generating strip comprising: a first aerosol generating segment, the first aerosol generating segment comprising a first aerosol generating substrate, wherein the first aerosol generating substrate comprises at least one aerosol former, wherein the aerosol former content of the first aerosol generating substrate is less than 30 weight %, and wherein the first aerosol generating substrate has a density of less than 400 mg / cubic centimeter; and a second aerosol generating segment, the second aerosol generating segment being located upstream of the first aerosol generating segment and comprising a second aerosol generating substrate, wherein the second aerosol generating substrate comprises at least one aerosol former, wherein the aerosol former content of the second aerosol generating substrate is at least 40 weight % on a dry weight basis, and wherein the density of the second aerosol generating substrate is greater than 500 mg / cubic centimeter.

[0014] In a preferred embodiment, an aerosol generating article is provided, comprising an aerosol generating strip for generating an inhalable aerosol when heated, the aerosol generating strip comprising: a first aerosol generating segment, the first aerosol generating segment comprising a first aerosol generating substrate, wherein the first aerosol generating substrate comprises at least one aerosol former, and wherein the aerosol former content of the first aerosol generating substrate is less than 30 weight %; and a second aerosol generating segment, the second aerosol generating segment is located upstream of the first aerosol generating segment and comprises a second aerosol generating substrate, wherein the second aerosol generating substrate comprises at least one aerosol former, wherein the aerosol former content of the second aerosol generating substrate is at least 40 weight % on a dry weight basis, and wherein the ratio of the length of the first aerosol generating segment to the length of the second aerosol generating segment does not exceed 0.5.

[0015] The term "aerosol-generating article" as used herein refers to an article comprising an aerosol-generating substrate that is heated to generate and deliver an inhalable aerosol to a consumer. As used herein, the term "aerosol-generating substrate" means a substrate that is capable of releasing volatile compounds upon heating to generate an aerosol.

[0016] As used herein, the term "aerosol-generating device" refers to a device comprising a heater element that interacts with an aerosol-generating substrate of an aerosol-generating article to generate an aerosol.

[0017] As used herein with reference to the present invention, the term "rod" is intended to denote a generally elongated element, preferably a cylindrical element, of substantially circular, oval or elliptical cross-section. In the article of the present invention, the aerosol-generating rod is formed of two or more aerosol-generating segments, which are different elements formed of aerosol-generating substrates having different compositions from each other. The aerosol-generating segments are coaxially combined so as to form the aerosol-generating rod.

[0018] As used herein, the term "longitudinal" refers to a direction corresponding to the main longitudinal axis of the aerosol-generating article, which direction extends between the upstream end and the downstream end of the aerosol-generating article. As used herein, the terms "upstream" and "downstream" describe the relative position of an element or part of an element of an aerosol-generating article relative to the direction in which an aerosol is transported through the aerosol-generating article during use.

[0019] During use, air is drawn through the aerosol-generating article in the longitudinal direction. The term "transverse" refers to a direction perpendicular to the longitudinal axis. Unless otherwise stated, any reference to a "section" of an aerosol-generating article or component of an aerosol-generating article refers to a cross-section.

[0020] The term "length" refers to the dimension of a component of an aerosol-generating article in the longitudinal direction. For example, it may be used to refer to the dimension of a strip or an elongated tubular element in the longitudinal direction.

[0021] Unless otherwise specified, the aerosol-forming agent content of the first aerosol-generating substrate is expressed as a weight percentage on a dry weight basis.The aerosol-forming agent content of the first aerosol-generating substrate is based on the weight of the first aerosol-generating substrate.

[0022] Unless otherwise specified, the aerosol-forming agent content of the second aerosol-generating substrate is expressed as a weight percentage on a dry weight basis.The aerosol-forming agent content of the second aerosol-generating substrate is based on the weight of the second aerosol-generating substrate.

[0023] The present invention relates to an aerosol generating article having an aerosol generating strip, the aerosol generating strip having two different sections of an aerosol generating substrate, the sections having different aerosol forming agent contents from each other. In particular, the first aerosol generating substrate and the second aerosol generating substrate are adapted so that the second aerosol generating substrate arranged in the second upstream aerosol generating section has a higher aerosol forming agent content than the first aerosol generating substrate arranged in the first downstream aerosol generating section. The first aerosol generating substrate and the second aerosol generating substrate may be adapted so that the second aerosol generating substrate arranged in the second upstream aerosol generating section has a significantly higher aerosol forming agent content than the first aerosol generating substrate arranged in the first downstream aerosol generating section.

[0024] Providing, for example, an upstream segment of an aerosol-generating substrate having a relatively high aerosol-forming agent content (greater than 40% by weight) and a downstream segment of an aerosol-generating substrate having a relatively low aerosol-forming agent content (less than 30% by weight) such an arrangement provides improved aerosol delivery when heating an aerosol-generating strip. The first aerosol-generating substrate with a lower level of aerosol-forming agent will heat faster due to lower thermal inertia, and will begin to produce a measurable amount of aerosol in a relatively short period of time. Therefore, the time for the first puff can be minimized, and the aerosol can be delivered to the consumer relatively quickly after heating begins. The first aerosol-generating substrate will release a higher level of aerosol than the second aerosol-generating substrate during an earlier puff in the puff curve, but will be exhausted relatively quickly due to the lower level of aerosol-forming agent.

[0025] The second aerosol generating substrate with a significantly higher level of aerosol forming agent takes longer to begin releasing a measurable amount of aerosol after heating begins, but continues to release aerosol after the aerosol release of the first aerosol generating substrate is completed. Therefore, the second aerosol generating substrate will release a higher level of aerosol than the first aerosol generating substrate during subsequent puffs in the puff curve. Combined, the first aerosol generating segment and the second aerosol generating segment are therefore able to provide highly consistent and more continuous aerosol delivery over time. The total duration of delivering aerosols can also be increased to provide consumers with an overall longer experience.

[0026] Once an aerosol has been generated from the first aerosol-generating substrate, the remaining exhausted first aerosol-generating segment will typically have a relatively low weight and density. This advantageously means that the first aerosol-generating segment provides a minimum level of filtration of the aerosol generated from the second upstream aerosol-generating segment during subsequent puffs. This enables aerosol delivery to the consumer to be maintained throughout the experience.

[0027] The use of two different aerosol generating segments within an aerosol generating strip can also be used to more precisely control the delivery of active compounds such as nicotine and flavorings to the consumer during the experience, as the composition of the two aerosol generating substrates can be adapted to make them different from each other. The combination of two different aerosol generating substrates can also enable the generation of more complex aerosols with potentially novel combinations of active compounds.

[0028] The benefits provided by using two distinct aerosol-generating segments may be achieved while still using a single heater element to heat both segments, so that no adaptation of the apparatus suitable for heating the aerosol-generating article is required.

[0029] The use of dual aerosol-generating segments within an aerosol-generating rod does not necessarily affect the overall construction of the aerosol-generating article.Thus, an aerosol-generating rod comprising dual segments may advantageously be incorporated into existing high-speed production lines without requiring major modifications to the technical equipment.

[0030] As defined above, the aerosol generating article according to the present invention comprises an aerosol generating strip. In addition, the aerosol generating article according to the present invention typically comprises one or more elements arranged downstream of the aerosol generating strip. Where present, the one or more elements downstream of the aerosol generating strip form a downstream section of the aerosol generating article. The aerosol generating article according to the present invention may also comprise one or more elements arranged upstream of the aerosol generating substrate. Where present, the one or more elements upstream of the aerosol generating strip form an upstream section of the aerosol generating article.

[0031] The aerosol generating strip comprises a first aerosol generating segment and a second aerosol generating segment. As described below, it may further comprise one or more additional aerosol generating segments. The second aerosol generating segment is arranged upstream of the first aerosol generating segment. Preferably, the second aerosol generating segment is adjacent to the first aerosol generating segment. Preferably, the downstream end of the second aerosol generating segment is adjacent to the upstream end of the first aerosol generating segment. Preferably, substantially the entire surface of the downstream end of the second aerosol generating segment is adjacent to the upstream end of the first aerosol generating segment. The second aerosol generating segment may extend to the upstream end of the aerosol generating article. Alternatively, as described in more detail below, one or more additional elements may be arranged upstream of the second aerosol generating segment.

[0032] The first aerosol generating substrate and the second aerosol generating substrate that form the first aerosol generating segment and the second aerosol generating segment, respectively, have different compositions from each other. In particular, according to the present invention, the second aerosol generating substrate has a significantly higher level of aerosol forming agent than the first aerosol generating substrate. The level of the aerosol forming agent is important because it controls the amount of aerosol that can be generated from the aerosol generating substrate and the speed at which the aerosol will be generated when heated. When volatilized, the aerosol forming agent transmits other volatile compounds (such as nicotine and flavoring agents) released from the aerosol generating substrate when heated into the aerosol.

[0033] Suitable aerosol formers included in the first aerosol-generating substrate and the second aerosol-generating substrate are known in the art and include, but are not limited to: polyols, such as triethylene glycol, propylene glycol, 1,3-butylene glycol and glycerol; esters of polyols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate.

[0034] The first aerosol-generating substrate and the second aerosol-generating substrate may comprise the same aerosol-forming agent (or agents) as each other, or different aerosol-forming agents may be used.

[0035] The first aerosol-generating substrate preferably has an aerosol-forming agent content of no more than 30 wt.-% on a dry weight basis. More preferably, the first aerosol-generating substrate has an aerosol-forming agent content of no more than 25 wt.-% on a dry weight basis. More preferably, the first aerosol-generating substrate has an aerosol-forming agent content of no more than 20 wt.-% on a dry weight basis.

[0036] Preferably, the first aerosol-generating substrate has an aerosol-forming agent content of at least 5 wt.-% on a dry weight basis. More preferably, the first aerosol-generating substrate has an aerosol-forming agent content of at least 10 wt.-% on a dry weight basis. More preferably, the first aerosol-generating substrate has an aerosol-forming agent content of at least 15 wt.-% on a dry weight basis.

[0037] For example, the aerosol-forming agent content of the first aerosol-generating substrate may be between 5 wt % and 30 wt %, or between 10 wt % and 25 wt %, or between about 15 wt % and about 20 wt % on a dry weight basis. Thus, the aerosol-forming agent content of the first aerosol-generating substrate is relatively low.

[0038] Preferably, the first aerosol-generating substrate comprises glycerol as an aerosol-forming agent. For example, the first aerosol-generating substrate may comprise 5 to 30 wt% glycerol, or 10 to 25 wt% glycerol, or 15 to 20 wt% glycerol on a dry weight basis.

[0039] The second aerosol-generating substrate preferably has a higher aerosol-forming agent content than the first aerosol-generating substrate. Preferably, the second aerosol-generating substrate has an aerosol-forming agent content of at least 40 wt.-% on a dry weight basis. More preferably, the second aerosol-generating substrate has an aerosol-forming agent content of at least 45 wt.-% on a dry weight basis. More preferably, the second aerosol-generating substrate has an aerosol-forming agent content of at least 50 wt.-% on a dry weight basis.

[0040] Preferably, the second aerosol-generating substrate has an aerosol-forming agent content of no more than 80 wt % on a dry weight basis. More preferably, the second aerosol-generating substrate has an aerosol-forming agent content of no more than 75 wt % on a dry weight basis. More preferably, the second aerosol-generating substrate has an aerosol-forming agent content of no more than 70 wt % on a dry weight basis.

[0041] For example, the second aerosol-generating substrate may have an aerosol-former content of between 40% and 80%, or between 45% and 75%, or between 50% and 70% by dry weight.Thus, the aerosol-former content of the second aerosol-generating substrate is relatively high.

[0042] Preferably, the second aerosol-generating substrate comprises glycerol as an aerosol-forming agent. For example, the second aerosol-generating substrate may comprise 40% to 80% glycerol, or 45% to 75% glycerol, or 50% to 70% glycerol, or 15% to 20% glycerol by weight on a dry weight basis.

[0043] Preferably, the aerosol-forming agent content of the second aerosol-generating substrate is at least 15% higher by weight than the aerosol-forming agent content of the first aerosol-generating substrate on a dry weight basis. For example, if the first aerosol-generating substrate has an aerosol-forming agent content of 15% by weight, the second aerosol-generating substrate preferably has an aerosol-forming agent content of at least 30% by weight. More preferably, the aerosol-forming agent content of the second aerosol-generating substrate is at least 20% higher by weight than the aerosol-forming agent content of the first aerosol-generating substrate on a dry weight basis. More preferably, the aerosol-forming agent content of the second aerosol-generating substrate is at least 25% higher by weight than the aerosol-forming agent content of the first aerosol-generating substrate on a dry weight basis. The aerosol-forming agent content of the second aerosol-generating substrate may be up to 60% higher by weight than the aerosol-forming agent content of the first aerosol-generating substrate.

[0044] Preferably, the aerosol-forming agent content of the second aerosol-generating substrate is at least 1.2 times the aerosol-forming agent content of the first aerosol-generating substrate, based on dry weight. More preferably, the aerosol-forming agent content of the second aerosol-generating substrate is at least 1.5 times the aerosol-forming agent content of the first aerosol-generating substrate, based on dry weight. More preferably, the aerosol-forming agent content of the second aerosol-generating substrate is at least twice the aerosol-forming agent content of the first aerosol-generating substrate, based on dry weight. The aerosol-forming agent content of the second aerosol-generating substrate may be at most 4 times the aerosol-forming agent content of the first aerosol-generating substrate.

[0045] Preferably, the glycerol content of the second aerosol generating substrate is at least 5% higher by weight than the glycerol content of the first aerosol generating substrate, or at least 10% higher by weight than the glycerol content of the first aerosol generating substrate, or at least 15% higher by weight than the glycerol content of the first aerosol generating substrate, based on dry weight. More preferably, the glycerol content of the second aerosol generating substrate is at least 20% higher by weight than the glycerol content of the first aerosol generating substrate, based on dry weight. More preferably, the glycerol content of the second aerosol generating substrate is at least 25% higher by weight than the glycerol content of the first aerosol generating substrate, based on dry weight. The glycerol content of the second aerosol generating substrate may be up to 60% higher by weight than the glycerol content of the first aerosol generating substrate.

[0046] Preferably, the glycerol content of the second aerosol-generating substrate is at least 1.2 times the glycerol content of the first aerosol-generating substrate, based on dry weight. More preferably, the glycerol content of the second aerosol-generating substrate is at least 1.5 times the glycerol content of the first aerosol-generating substrate, based on dry weight. More preferably, the glycerol content of the second aerosol-generating substrate is at least twice the aerosol-forming agent content of the first aerosol-generating substrate, based on dry weight. The glycerol content of the second aerosol-generating substrate may be up to 3 or 4 times the glycerol content of the first aerosol-generating substrate.

[0047] Typically, the first and second aerosol-generating substrates will also differ from each other in composition, form or other aspects of physical properties.For example, the second aerosol-generating substrate preferably has a higher density than the first aerosol-generating substrate.

[0048] The term "density" as used herein in relation to an aerosol-generating substrate refers to the bulk density of the aerosol-generating substrate. This can be calculated by measuring the total weight of the aerosol-generating substrate and dividing it by the volume of the segment of aerosol-generating substrate (excluding any packaging).

[0049] As described above, providing different densities between the first and second aerosol-generating substrates may further optimize the speed and consistency of aerosol generation, thereby enhancing the benefits provided by the different aerosol former contents.

[0050] Preferably, the density of the second aerosol generating substrate is at least 25 mg / cm3 higher than the density of the first aerosol generating substrate, or at least 50 mg / cm3 higher than the density of the first aerosol generating substrate, or at least 75 mg / cm3 higher than the density of the first aerosol generating substrate, or at least 100 mg / cm3 higher than the density of the first aerosol generating substrate. More preferably, the density of the second aerosol generating substrate is at least 150 mg / cm3 higher than the density of the first aerosol generating substrate. More preferably, the density of the second aerosol generating substrate is at least 200 mg / cm3 higher than the density of the first aerosol generating substrate. The density of the second aerosol generating substrate may be up to 500 mg / cm3 higher than the density of the first aerosol generating substrate.

[0051] Preferably, the density of the second aerosol generating substrate is at least 1.05 times the density of the first aerosol generating substrate, or at least 1.1 times the density of the first aerosol generating substrate, or at least 1.2 times the density of the first aerosol generating substrate. More preferably, the density of the second aerosol generating substrate is at least 1.3 times the density of the first aerosol generating substrate, or at least 1.4 times the density of the first aerosol generating substrate, or at least 1.5 times the density of the first aerosol generating substrate. More preferably, the density of the second aerosol generating substrate is at least twice the density of the first aerosol generating substrate. The density of the second aerosol generating substrate may be at most 4 times the density of the first aerosol generating substrate.

[0052] In a preferred embodiment of the invention, the density of the second aerosol-generating substrate is at least 1.2 times the density of the first aerosol-generating substrate and the aerosol-forming agent content of the second aerosol-generating substrate is at least twice the aerosol-forming agent content of the first aerosol-generating substrate.

[0053] Preferably, the first aerosol-generating substrate has a density of at least 100 mg / cm3. More preferably, the density of the first aerosol-generating substrate is at least 125 mg / cm3. More preferably, the density of the first aerosol-generating substrate is at least 150 mg / cm3. Even more preferably, the density of the first aerosol-generating substrate is at least 200 mg / cm3.

[0054] Preferably, the first aerosol-generating substrate has a density of less than 400 mg / cm3. More preferably, the density of the first aerosol-generating substrate is less than 375 mg / cm3. More preferably, the density of the first aerosol-generating substrate is less than 350 mg / cm3. More preferably, the density of the first aerosol-generating substrate is less than 300 mg / cm3.

[0055] For example, the density of the first aerosol-generating substrate may be between 100 mg / cm3 and 400 mg / cm3, or between 125 mg / cm3 and 375 mg / cm3, or between 150 mg / cm3 and 350 mg / cm3, or between 200 mg / cm3 and 300 mg / cm3.

[0056] Therefore, the first aerosol generating substrate preferably has a relatively low density. Combined with a relatively low aerosol former content, this further reduces the thermal inertia of the first aerosol generating substrate, so that the first aerosol generating substrate can quickly reach the temperature required for aerosol generation. The low density of the first aerosol generating substrate further minimizes the filtering effect of the first aerosol generating substrate on the aerosol generated by one or more upstream aerosol generating substrate segments.

[0057] Preferably, the second aerosol-generating substrate has a density of at least 500 mg / cm3. More preferably, the density of the second aerosol-generating substrate is at least 525 mg / cm3. More preferably, the density of the second aerosol-generating substrate is at least 550 mg / cm3. Even more preferably, the density of the second aerosol-generating substrate is at least 600 mg / cm3.

[0058] Preferably, the second aerosol-generating substrate has a density of less than 1000 mg / cm3. More preferably, the density of the second aerosol-generating substrate is less than 900 mg / cm3. More preferably, the density of the second aerosol-generating substrate is less than 800 mg / cm3. More preferably, the density of the second aerosol-generating substrate is less than 750 mg / cm3.

[0059] For example, the density of the second aerosol-generating substrate may be between 500 mg / cm3 and 1000 mg / cm3, or between 525 mg / cm3 and 900 mg / cm3, or between 550 mg / cm3 and 880 mg / cm3, or between 600 mg / cm3 and 750 mg / cm3.

[0060] Therefore, the second aerosol-generating substrate preferably has a relatively high density. Combined with a relatively high aerosol-forming agent content, this further increases the thermal inertia of the second aerosol-generating substrate, so that the second aerosol-generating substrate requires significantly longer time to reach the temperature required for aerosol generation, and thus can deliver aerosol during subsequent puffs. The high density also enables a relatively large amount of aerosol-forming agent and active compound to be provided per volume of aerosol-generating substrate, so that aerosol delivery can be increased in both concentration and duration.

[0061] The first aerosol-generating substrate and the second aerosol-generating substrate may be formed from the same type of substrate as each other. Suitable types of materials for use in the aerosol-generating articles of the present invention are described below and include, for example, tobacco cut filler, homogenized tobacco material, such as cast leaf, aerosol-generating films, and gel compositions. Preferably, the first aerosol-generating substrate and the second aerosol-generating substrate are different types of materials from each other.

[0062] Preferably, the first aerosol generating substrate comprises tobacco material. In certain preferred embodiments, the first aerosol generating substrate comprises shredded tobacco material. For example, as described in more detail below, shredded tobacco material can be in the form of shredded filler. Alternatively, shredded tobacco material can be in the form of shredded material of homogenized tobacco material. Suitable homogenized tobacco material for the present invention is described below.

[0063] In the context of this specification, the term "cut filler" is used to describe a blend of chopped plant material, such as tobacco plant material, including in particular one or more of leaves, processed stems and ribs, homogenised plant material.

[0064] Cut filler may also include other post-cut filler tobaccos or addenda.

[0065] Preferably, the shredded filler comprises at least 25% plant leaves, more preferably at least 50% plant leaves, still more preferably at least 75% plant leaves, and most preferably at least 90% plant leaves. Preferably, the plant material is one of tobacco, mint, tea and cloves. Most preferably, the plant material is tobacco. However, the present invention is equally applicable to other plant materials having the ability to release a substance upon application of heat and subsequently form an aerosol.

[0066] Preferably, the cut filler comprises tobacco plant material including thin layers of one or more of flue-cured tobacco, sun-cured tobacco, oriental tobacco and filler tobacco.With reference to the present invention, the term "tobacco" describes any plant member of the genus Nicotiana.

[0067] Cut filler suitable for use with the present invention may be generally similar to cut filler used in conventional smoking articles. The cut filler preferably has a cut width of between 0.3 mm and 2.0 mm, or between 0.5 mm and 1.2 mm, or between 0.6 mm and 0.9 mm.

[0068] Preferably, the strand has a length of between about 10 millimetres and about 40 millimetres prior to being collated to form the aerosol-generating rod.

[0069] In a preferred embodiment, the weight of the cut filler is between 25 mg and 150 mg, preferably between 30 mg and 125 mg, more preferably between 40 mg and 100 mg. This amount of cut filler generally allows sufficient material to form an aerosol during early puffs.

[0070] Preferably, the shredded filler is soaked with an aerosol forming agent. Soaking the shredded filler can be accomplished by spraying or by other suitable application methods. The aerosol forming agent can be applied to the blend during the preparation of the shredded filler. For example, the aerosol forming agent can be applied to the blend in a direct conditioning casing cylinder (DCCC). Conventional machines can be used to apply the aerosol forming agent to the shredded filler. Suitable aerosol forming agents are described above.

[0071] Preferably, the aerosol forming agent in the shredded filler comprises one or more of glycerol and propylene glycol. The aerosol forming agent may consist of glycerol or propylene glycol or a combination of glycerol and propylene glycol.

[0072] In other preferred embodiments, the first aerosol-generating substrate comprises homogenised plant material, preferably homogenised tobacco material.

[0073] As used herein, the term "homogenized plant material" includes any plant material formed by the agglomeration of plant particles. For example, sheets or webs of homogenized tobacco material used for aerosol-generating substrates of the present invention can be formed by agglomerating particles of tobacco material, which are obtained by pulverizing, grinding or grinding plant material and one or more of optional tobacco leaves and tobacco stems. Homogenized plant material can be produced by casting, extruding, papermaking technology or other any suitable process known in the art.

[0074] The homogenised plant material may be provided in any suitable form.

[0075] In some embodiments, the homogenised plant material may be in the form of one or more sheets.As used herein with reference to the present invention, the term "sheet" describes a laminar element having a width and length substantially greater than its thickness.

[0076] The homogenized plant material may be in the form of a plurality of pellets or granules.

[0077] Homogenized plant material can be in the form of multiple stocks, strips or fragments. As used herein, the term "stock" describes an elongated element material whose length is significantly greater than its width and thickness. The term "stock" should be considered to include strips, fragments and any other homogenized plant material with similar forms. The stock of homogenized plant material can be formed by the sheet of homogenized plant material, such as by cutting or chopping, or by other methods, such as by extrusion methods.

[0078] As mentioned above, when the homogenised plant material is in the form of one or more sheets, the sheets may be produced by a casting process. Alternatively, the sheets of homogenised plant material may be produced by a papermaking process.

[0079] One or more sheets as described herein may each individually have a thickness between 100 and 600 microns, preferably between 150 and 300 microns, and most preferably between 200 and 250 microns. Individual thickness refers to the thickness of an individual sheet, while combined thickness refers to the total thickness of all sheets constituting the aerosol generating substrate.

[0080] One or more sheets as described herein may each individually have a grammage between 100 g / m2 and 600 g / m2.

[0081] One or more sheets as described herein may each individually have a density of 0.3 g / cm3 to 1.3 g / cm3, and preferably 0.7 g / cm3 to 1.0 g / cm3.

[0082] One or more sheets as described herein may be one or more of curled, folded, gathered, and pleated.

[0083] One or more sheets of homogenized plant material can be cut into stocks as described above. In such embodiments, the aerosol generating matrix comprises a plurality of homogenized plant material stocks. Stock can be used to form a rod. Usually, the width of these stocks is about 5 millimeters, or about 4 millimeters, or about 3 millimeters, or about 2 millimeters or less. The length of stock can be greater than about 5 millimeters, between about 5 millimeters and about 15 millimeters, about 8 millimeters to about 12 millimeters, or about 12 millimeters. Preferably, stock has substantially the same length as each other.

[0084] The homogenized plant material may comprise between 2.5 wt% and 95 wt% plant particles, or between 5 wt% and 90 wt% plant particles, or between 10 wt% and 80 wt% plant particles, or between 15 wt% and 70 wt% plant particles, or between 20 wt% and 60 wt% plant particles, or between 30 wt% and 50 wt% plant particles on a dry weight basis.

[0085] In certain embodiments of the present invention, the homogenized plant material is a homogenized tobacco material comprising tobacco particles. The sheet material of the homogenized tobacco material of this type of embodiment of the present invention can have at least about 40% by weight on a dry weight basis, more preferably at least about 50% by weight on a dry weight basis, more preferably at least about 70% by weight on a dry weight basis, and most preferably at least about 90% by weight tobacco content on a dry weight basis.

[0086] With reference to the present invention, term " tobacco particles " describes the particle of any plant member of Nicotiana.Term " tobacco particles " comprises ground or pulverized tobacco leaf blade, ground or pulverized tobacco leaf stem, tobacco dust, tobacco fines and other particle tobacco byproducts formed in the processing, operation and transportation process of tobacco.In a preferred embodiment, tobacco particles are all derived from tobacco leaf blade basically.By contrast, isolated nicotine and nicotine salt are compounds derived from tobacco, but are not considered to tobacco particles for purposes of the present invention, and are not included in the percentage of granular plant material.

[0087] The second aerosol-generating substrate may include nicotine. As used herein with respect to the present invention, the term "nicotine" is used to describe nicotine, nicotine base, or nicotine salt. In embodiments where the second aerosol-generating substrate includes nicotine base or nicotine salt, the amount of nicotine described herein is the amount of free base nicotine or the amount of protonated nicotine, respectively.

[0088] Preferably, the second aerosol generating substrate comprises at least 0.5% by weight of nicotine on a dry weight basis. More preferably, the second aerosol generating substrate comprises at least 1% by weight of nicotine on a dry weight basis. Even more preferably, the second aerosol generating substrate comprises at least 2% by weight of nicotine on a dry weight basis. Additionally, or as an alternative, the second aerosol generating substrate preferably comprises less than 10% by weight of nicotine on a dry weight basis. More preferably, the second aerosol generating substrate comprises less than 8% by weight of nicotine on a dry weight basis. More preferably, the second aerosol generating substrate comprises less than 6% by weight of nicotine on a dry weight basis.

[0089] For example, the second aerosol-generating substrate may comprise between 0.5 wt% and 10 wt%, or between 1 wt% and 8 wt%, or between 2 wt% and 6 wt% nicotine on a dry weight basis.

[0090] The second aerosol-generating substrate may be substantially free of tobacco.

[0091] As described above, the second aerosol-generating substrate may be in the form of cut filler or homogenised tobacco material.

[0092] Preferably, the second aerosol-generating substrate is in the form of an aerosol-generating film comprising a cellulose-based film-forming agent, nicotine and an aerosol-forming agent. The aerosol-generating film may further comprise a cellulose-based reinforcing agent. The aerosol-generating film may further comprise water, preferably 30 wt% or less of water.

[0093] As used herein, the term "film" is used to describe a solid laminar element whose thickness is less than its width or length. The film can be self-supporting. In other words, the film can have cohesive and mechanical properties so that the film can be separated from the supporting surface even if it is obtained by casting a film formulation on a supporting surface. Alternatively, the film can be arranged on a support or sandwiched between other materials. This can enhance the mechanical stability of the film.

[0094] The aerosol-forming agent content of the aerosol-generating film is within the range defined above for the second aerosol-generating substrate.

[0095] In the context of the present invention, the term "cellulose-based film former" is used to describe a cellulosic polymer that is capable of forming a continuous film, either alone or in the presence of an auxiliary thickener.

[0096] Preferably, the cellulose-based film former is selected from hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), hydroxyethyl methylcellulose (HEMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC) and combinations thereof.

[0097] More preferably, the cellulose-based film former is selected from hydroxypropylmethylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC) and combinations thereof.

[0098] In a particularly preferred embodiment, the cellulose-based film former is HPMC.

[0099] The aerosol-generating film has a cellulose-based film-forming agent content of between 10 wt% and 40 wt%, alternatively between 15 wt% and 35 wt%, alternatively between 20 wt% and 30 wt%, based on dry weight.

[0100] Preferably, the aerosol-generating film further comprises a cellulose-based reinforcing agent.Preferably, the cellulose-based reinforcing agent is selected from the group consisting of cellulose fibers, microcrystalline cellulose (MCC), cellulose powder and combinations thereof.

[0101] The aerosol-generating film may have a cellulose-based strengthening agent content of between 0.5 wt% and 40 wt% on a dry basis, or between 5 wt% and 30 wt% on a dry basis, or between 10 wt% and 25 wt% on a dry basis.

[0102] The aerosol-forming film may further comprise carboxymethylcellulose, preferably sodium carboxymethylcellulose.

[0103] The aerosol-generating film may have a carboxymethylcellulose content of between 1 wt% and 15 wt%, alternatively between 2 wt% and 12 wt%, alternatively between 4 wt% and 10 wt%, based on dry weight.

[0104] The aerosol-generating film preferably comprises nicotine.

[0105] In embodiments where the aerosol-generating film comprises nicotine base or nicotine salt, the amounts of nicotine recited herein are the amounts of freebase nicotine or the amounts of protonated nicotine, respectively.

[0106] The aerosol-generating film may comprise natural nicotine or synthetic nicotine.

[0107] The aerosol-generating film may comprise one or more monobasic nicotine salts.

[0108] As used herein with respect to the present invention, the term "monobasic nicotine salt" is used to describe the nicotine salt of the monobasic acid.

[0109] Preferably, the aerosol-generating film comprises at least 0.5% by weight of nicotine on a dry weight basis. More preferably, the aerosol-generating film comprises at least 1% by weight of nicotine on a dry weight basis. Even more preferably, the aerosol-generating film comprises at least 2% by weight of nicotine on a dry weight basis. Additionally, or as an alternative, the aerosol-generating film preferably comprises less than 10% by weight of nicotine on a dry weight basis. More preferably, the aerosol-generating film comprises less than 8% by weight of nicotine on a dry weight basis. More preferably, the aerosol-generating film comprises less than 6% by weight of nicotine on a dry weight basis.

[0110] For example, the aerosol-generating film may comprise between 0.5 wt% and 10 wt% nicotine, or between 1 wt% and 8 wt% nicotine, or between 2 wt% and 6 wt% nicotine on a dry weight basis.

[0111] The aerosol-generating film may be a substantially tobacco-free aerosol-generating film.

[0112] In a preferred embodiment, the aerosol-forming film comprises an acid. More preferably, the aerosol-forming film comprises one or more organic acids. Even more preferably, the aerosol-forming film comprises one or more carboxylic acids. In a particularly preferred embodiment, the acid is lactic acid, benzoic acid, fumaric acid or levulinic acid.

[0113] Preferably, the aerosol-forming film comprises between 0.25 wt% and 3.5 wt% acid, or between 0.5 wt% and 3 wt% acid, or between 1 wt% and 2.5 wt% acid on a dry weight basis.

[0114] The aerosol-forming film may have a thickness of about 0.1 mm to about 1 mm, more preferably about 0.1 mm to about 0.75 mm, even more preferably about 0.1 mm to about 0.5 mm. In a particularly preferred embodiment, a layer of the film-forming composition having a thickness of about 50 microns to 400 microns, more preferably about 100 microns to 200 microns, is formed.

[0115] Alternatively, the aerosol-generating film may be provided on a suitable carrier element within the second aerosol-generating segment.

[0116] In an alternative embodiment of the invention, the second aerosol-generating substrate may comprise a gel composition comprising nicotine, at least one gelling agent and an aerosol former. The gel composition is preferably substantially free of tobacco.

[0117] Preferred weight ranges for nicotine in the gel composition are the same as those defined above for the aerosol-forming film.

[0118] The gel composition preferably comprises at least 50 wt% aerosol former, more preferably at least 60 wt% aerosol former, more preferably at least 70 wt% aerosol former, based on dry weight. The gel composition may comprise up to 80 wt% aerosol former. The aerosol former in the gel composition is preferably glycerol.

[0119] The gel composition preferably includes at least one gelling agent. Preferably, the gel composition includes a total amount of gelling agent in the range of about 0.4 wt % to about 10 wt %, or about 0.5 wt % to about 8 wt %, or about 1 wt % to about 6 wt %, or about 2 wt % to about 4 wt %, or about 2 wt % to about 3 wt %.

[0120] The term "gelling agent" refers to a compound that, when added to a mixture of 50 wt % water / 50 wt % glycerol in an amount of about 0.3 wt %, homogeneously forms a solid medium or support matrix that results in a gel. Gelling agents include, but are not limited to, hydrogen bond cross-linking gelling agents and ion cross-linking gelling agents.

[0121] The term "hydrogen-bonding cross-linking gelling agent" refers to a gelling agent that forms non-covalent cross-links or physical cross-links via hydrogen bonds.

[0122] The hydrogen-bond cross-linking gelling agent may include one or more of galactomannan, gelatin, agarose or konjac gum or agar. The hydrogen-bond cross-linking gelling agent may preferably include agar.

[0123] The term "ionic cross-linking gelling agent" refers to a gelling agent that forms non-covalent cross-links or physical cross-links through ionic bonds.

[0124] The ionically cross-linked gelling agent may include low acyl gellan gum, pectin, kappa carrageenan, iota carrageenan or alginate. The ionically cross-linked gelling agent may preferably include low acyl gellan gum.

[0125] The gelling agent may include one or more biopolymers. The biopolymer may be formed from a polysaccharide.

[0126] Biopolymers include, for example, gellan gum (natural, low acyl gellan gum, high acyl gellan gum, preferably low acyl gellan gum), xanthan gum, alginates (alginic acid), agar, guar gum, etc. The composition may preferably include xanthan gum. The composition may include two biopolymers. The composition may include three biopolymers. The composition may include two biopolymers of substantially equal weight. The composition may include three biopolymers of substantially equal weight.

[0127] The gel composition may also include a viscosity increasing agent. The viscosity increasing agent in combination with the hydrogen bonding cross-linking gelling agent and the ionic cross-linking gelling agent appears to unexpectedly support the solid medium and maintain the gel composition even when the gel composition includes high levels of glycerol.

[0128] The term "viscosity increasing agent" refers to a compound which, when homogeneously added in an amount of 0.3 wt. % to a mixture of 50 wt. % water / 50 wt. % glycerol at 25°C, increases viscosity without causing gel formation, the mixture remaining or remaining fluid.

[0129] The gel composition preferably includes a viscosity increasing agent in the range of about 0.2 wt % to about 5 wt %, or about 0.5 wt % to about 3 wt %, or about 0.5 wt % to about 2 wt %, or about 1 wt % to about 2 wt %.

[0130] The thickener may include one or more of xanthan gum, carboxymethyl cellulose, microcrystalline cellulose, methyl cellulose, gum arabic, guar gum, lambda-carrageenan or starch. The thickener may preferably include xanthan gum.

[0131] The gel composition may also include divalent cations. Preferably, the divalent cations include calcium ions, such as calcium lactate in solution. For example, divalent cations (such as calcium ions) can help form a gel of a composition including a gelling agent such as an ionically cross-linked gelling agent. Ionic effects can help gel formation. The divalent cations can be present in the gel composition in a range of about 0.1% to about 1% by weight or about 0.5% by weight.

[0132] The gel composition may also include an acid. The acid may include a carboxylic acid. The carboxylic acid may include a keto group. Preferably, the carboxylic acid may include a keto group having less than about 10 carbon atoms, or less than about 6 carbon atoms, or less than about 4 carbon atoms, such as levulinic acid or lactic acid. Preferably, the carboxylic acid has three carbon atoms (such as lactic acid).

[0133] The gel composition preferably includes some water. When the gel composition includes some water, the gel composition is more stable.

[0134] Preferably, the gel composition comprises water in an amount of from about 8 wt % to about 32 wt %, or from about 15 wt % to about 25 wt %, or from about 18 wt % to about 22 wt %, or about 20 wt %.

[0135] Preferably, when a gel composition is used, the second aerosol-generating substrate comprises a porous medium loaded with the gel composition. An advantage of a porous medium loaded with the gel composition is that the gel composition is retained within the porous medium, and this may aid in the manufacture, storage or transport of the gel composition. It may help maintain the desired shape of the gel composition, particularly during manufacture, transport or use.

[0136] The term "porous" is used herein to refer to a material that provides a plurality of pores or openings that allow air to pass through the material.

[0137] The porous medium can be any suitable porous material capable of containing or retaining the gel composition. Ideally, the porous medium allows the gel composition to move therein. In particular embodiments, the porous medium comprises a natural material, a synthetic or semi-synthetic material, or a combination thereof. In particular embodiments, the porous medium comprises a sheet material, a foam or a fiber, such as a loose fiber; or a combination thereof. In particular embodiments, the porous medium comprises a woven, non-woven or extruded material, or a combination thereof. Preferably, the porous medium comprises cotton, paper, viscose, PLA or cellulose acetate, or a combination thereof. Preferably, the porous medium comprises a sheet material, such as cotton or cellulose acetate. In a particularly preferred embodiment, the porous medium comprises a sheet made of cotton fibers.

[0138] The porous media used in the present invention may be curled or shredded.

[0139] The porous media may be in the form of sheets, wires or tubular elements.

[0140] The first aerosol generating segment and the second aerosol generating segment may have substantially the same length as each other. More preferably, the length of the first aerosol generating segment is less than the length of the second aerosol generating segment. This may help to maximize the amount of aerosol that can be generated from the aerosol generating strip and the duration of aerosol release.

[0141] The ratio of the length of the first aerosol generating segment to the length of the second aerosol generating segment preferably does not exceed 1. For example, the ratio of the length of the first aerosol generating segment to the length of the second aerosol generating segment may not exceed 0.8, not exceed 0.6, or not exceed 0.5.

[0142] The ratio of the length of the first aerosol generating segment to the length of the second aerosol generating segment is preferably at least 0.1. For example, the ratio of the length of the first aerosol generating segment to the length of the second aerosol generating segment may be at least 0.2, at least 0.3 or at least 0.4.

[0143] The ratio of the length of the first aerosol generating segment to the length of the second aerosol generating segment may be between 0.1 and 1, between 0.2 and 0.8, between 0.3 and 0.6, or between 0.4 and 0.5. The ratio of the length of the first aerosol generating segment to the length of the second aerosol generating segment may be about 0.4 or about 0.42.

[0144] In a preferred embodiment of the present invention, the density of the second aerosol generating substrate is at least 1.2 times the density of the first aerosol generating substrate, the aerosol former content of the second aerosol generating substrate is at least twice the aerosol former content of the first aerosol generating substrate on a dry weight basis, and the length ratio of the first aerosol generating segment to the second aerosol generating segment does not exceed 0.5.

[0145] The length of the second aerosol generating segment is preferably at least 2 mm greater than the length of the first aerosol generating segment. For example, the length of the second aerosol generating segment may be at least 4 mm greater than the length of the first aerosol generating segment, or at least 6 mm greater than the length of the first aerosol generating article.

[0146] The length of the second aerosol generating segment may be no more than 15 mm greater than the length of the first aerosol generating segment. For example, the length of the second aerosol generating segment may be no more than 12 mm greater than the length of the first aerosol generating segment, or no more than 10 mm greater than the length of the first aerosol generating segment.

[0147] The length of the second aerosol generating segment may be between 2 mm and 15 mm greater than the length of the first aerosol generating segment, or between 4 mm and 12 mm greater than the length of the first aerosol generating segment, or between 6 mm and 10 mm greater than the length of the first aerosol generating segment. The length of the second aerosol generating segment may be approximately 7 mm greater than the length of the first aerosol generating segment.

[0148] In certain preferred embodiments, the first aerosol generating segment may have a length of at least 2 mm, or at least 3 mm, or at least 4 mm. In these embodiments, the first aerosol generating segment may have a length of no more than 8 mm, or no more than 7 mm, or no more than 6 mm. For example, the first aerosol generating segment may have a length between 2 mm and 8 mm, between 3 mm and 7 mm, or between 4 mm and 6 mm. The first aerosol generating segment may have a length of about 5 mm.

[0149] In certain preferred embodiments, the second aerosol generating segment may have a length of at least 8 mm, or at least 9 mm, or at least 10 mm. In these embodiments, the second aerosol generating segment may have a length of no more than 16 mm, or no more than 15 mm, or no more than 14 mm. For example, the second aerosol generating segment may have a length between 8 mm and 16 mm, between 9 mm and 15 mm, or between 10 mm and 14 mm. The second aerosol generating segment may have a length of about 12 mm.

[0150] The combined length of the first aerosol generating segment and the second aerosol generating segment may be at least 10 mm. For example, the combined length of the first aerosol generating segment and the second aerosol generating segment may be at least 12 mm, at least 14 mm, or at least 16 mm.

[0151] The combined length of the first aerosol generating segment and the second aerosol generating segment may not exceed 24 mm. For example, the combined length of the first aerosol generating segment and the second aerosol generating segment may not exceed 22 mm, not exceed 20 mm, or not exceed 18 mm.

[0152] The combined length of the first aerosol generating segment and the second aerosol generating segment may be between 10 mm and 24 mm. For example, the combined length of the first aerosol generating segment and the second aerosol generating segment may be between 12 mm and 22 mm, between 14 mm and 20 mm, or between 16 mm and 18 mm.

[0153] The combined length of the first aerosol generating segment and the second aerosol generating segment may be approximately 17 mm.

[0154] In other preferred embodiments, the first aerosol generating segment may have a length of at least 10 mm, or at least 15 mm, or at least 18 mm. In these embodiments, the first aerosol generating segment may have a length of no more than 30 mm, or no more than 25 mm, or no more than 20 mm. For example, the first aerosol generating segment may have a length between 10 mm and 30 mm, between 15 mm and 25 mm, or between 18 mm and 20 mm. The first aerosol generating segment may have a length of about 18.5 mm. The first aerosol generating segment may have a length of about 17 mm.

[0155] In other preferred embodiments, the second aerosol generating segment may have a length of at least 10 mm, or at least 15 mm, or at least 18 mm. In these embodiments, the second aerosol generating segment may have a length of no more than 30 mm, or no more than 25 mm, or no more than 20 mm. For example, the second aerosol generating segment may have a length between 10 mm and 30 mm, between 15 mm and 25 mm, or between 18 mm and 20 mm. The second aerosol generating segment may have a length of about 18.5 mm. The second aerosol generating segment may have a length of about 17 mm.

[0156] The combined length of the first aerosol generating segment and the second aerosol generating segment may be at least 20 mm. For example, the combined length of the first aerosol generating segment and the second aerosol generating segment may be at least 25 mm, at least 30 mm, or at least 35 mm.

[0157] The combined length of the first aerosol generating segment and the second aerosol generating segment may not exceed 55 mm. For example, the combined length of the first aerosol generating segment and the second aerosol generating segment may not exceed 50 mm, not exceed 45 mm, or not exceed 40 mm.

[0158] The combined length of the first aerosol generating segment and the second aerosol generating segment may be between 20 mm and 55 mm. For example, the combined length of the first aerosol generating segment and the second aerosol generating segment may be between 25 mm and 50 mm, between 30 mm and 45 mm, or between 35 mm and 40 mm.

[0159] The combined length of the first aerosol generating segment and the second aerosol generating segment may be about 37 mm. The combined length of the first aerosol generating segment and the second aerosol generating segment may be about 34 mm.

[0160] The aerosol generating strip may further include a third aerosol generating segment, which is upstream of the second aerosol generating segment and includes a third aerosol generating substrate. For example, the aerosol generating strip may include a third aerosol generating segment adjacent to the upstream end of the second aerosol generating segment. Including a third aerosol generating segment at the upstream end of the aerosol generating strip may further enhance aerosol delivery from the aerosol generating article according to the present invention.

[0161] In some cases, when the aerosol generating article is completely received within the heating chamber of the aerosol generating device, the third aerosol generating segment may be only partially disposed within the heating zone, or the entire length of the third aerosol generating segment may be disposed outside the heating zone. In such cases, at least a portion of the third aerosol generating segment will not be directly heated by the heating element. However, the third aerosol generating segment may be indirectly heated by conduction and still generate a useful amount of aerosol. In this case, the third aerosol generating substrate will typically heat relatively slowly compared to the first aerosol generating substrate and the second aerosol generating substrate, thereby providing additional aerosol in subsequent puffs and possibly extending the duration over which the aerosol can be delivered.

[0162] Since the third aerosol-generating substrate can be heated by indirect conduction, it is preferably provided with a relatively low aerosol-forming agent content or a relatively low density or both. For example, the third aerosol-generating substrate preferably has an aerosol-forming agent content and a density within the ranges defined above for the first aerosol-generating substrate. The teachings provided above with respect to the first aerosol-generating substrate also apply to the third aerosol-generating substrate.

[0163] The third aerosol generating segment may have any length. The third aerosol generating segment may have a length of at least 2 mm, or at least 3 mm, or at least 4 mm. The third aerosol generating segment may have a length of no more than 8 mm, or no more than 7 mm, or no more than 6 mm.

[0164] For example, the third aerosol generating segment may have a length between 2 mm and 8 mm, between 3 mm and 7 mm, or between 4 mm and 6 mm. The third aerosol generating segment may have a length between 1 mm and 6 mm, between 2 mm and 5 mm, or between 3 mm and 4 mm. The third aerosol generating segment may have a length of about 5 mm. The third aerosol generating segment may have a length of about 3.5 mm.

[0165] The combined length of the first, second and third aerosol generating segments may be at least 10 mm, or at least 12 mm, or at least 14 mm, or at least 16 mm.

[0166] The combined length of the first aerosol generating segment, the second aerosol generating segment and the third aerosol generating segment may be no more than 24 mm, or no more than 22 mm, or no more than 20 mm, or no more than 18 mm.

[0167] For example, the combined length of the first aerosol generating segment, the second aerosol generating segment and the third aerosol generating segment can be between 10 mm and 24 mm, or between 12 mm and 22 mm, or between 14 mm and 20 mm, or between 16 mm and 18 mm. The combined length of the first aerosol generating segment, the second aerosol generating segment and the third aerosol generating segment can be about 17 mm.

[0168] The combined length of the aerosol-generating segments preferably corresponds to the length of the aerosol-generating rod.

[0169] The aerosol-generating rod preferably has an outer diameter that is substantially equal to the outer diameter of the aerosol-generating article.

[0170] Preferably, the outer diameter of the aerosol generating rod is between 5 mm and 12 mm, more preferably between 6 mm and 10 mm, more preferably between 7 mm and 8 mm. In some embodiments, the outer diameter of the aerosol generating rod may be less than 7 mm, for example between 5 mm and 7 mm, or between 6 mm and 7 mm.

[0171] The first aerosol-generating segment preferably has an outer diameter that is substantially equal to the outer diameter of the aerosol-generating article.Preferably, the outer diameter of the first aerosol-generating segment is substantially constant along the length of the first aerosol-generating segment.

[0172] Preferably, the outer diameter of the first aerosol generating segment is between 5 mm and 12 mm, more preferably between 6 mm and 10 mm, and more preferably between 7 mm and 8 mm. In some embodiments, the outer diameter of the first aerosol generating segment may be less than 7 mm, for example, between 5 mm and 7 mm, or between 6 mm and 7 mm.

[0173] The second aerosol-generating segment preferably has an outer diameter that is substantially equal to the outer diameter of the aerosol-generating article.Preferably, the outer diameter of the second aerosol-generating segment is substantially constant along the length of the first aerosol-generating segment.

[0174] Preferably, the outer diameter of the second aerosol generating segment is between 5 mm and 12 mm, more preferably between 6 mm and 10 mm, more preferably between 7 mm and 8 mm. In some embodiments, the outer diameter of the second aerosol generating segment may be less than 7 mm, for example, between 5 mm and 7 mm, or between 6 mm and 7 mm.

[0175] The third aerosol-generating segment preferably has an outer diameter that is substantially equal to the outer diameter of the aerosol-generating article.Preferably, the outer diameter of the third aerosol-generating segment is substantially constant along the length of the third aerosol-generating segment.

[0176] Preferably, the outer diameter of the third aerosol generating segment is between 5 mm and 12 mm, more preferably between 6 mm and 10 mm, more preferably between 7 mm and 8 mm. In some embodiments, the outer diameter of the third aerosol generating segment can be less than 7 mm, for example, between 5 mm and 7 mm, or between 6 mm and 7 mm.

[0177] Preferably, the first aerosol-generating segment, the second aerosol-generating segment and the third aerosol-generating segment (where present) have substantially the same outer diameter as each other.

[0178] The average cross-sectional area of ​​the first aerosol-generating segment is preferably at least 50% of the average cross-sectional area of ​​the aerosol-generating article, more preferably at least 80% of the average cross-sectional area of ​​the aerosol-generating article, more preferably at least 90% of the average cross-sectional area of ​​the aerosol-generating article.

[0179] The cross-sectional area of ​​the first aerosol generating segment at its upstream end is preferably at least 50% of the average cross-sectional area of ​​the aerosol generating article, more preferably at least 80% of the average cross-sectional area of ​​the aerosol generating article, more preferably at least 90% of the average cross-sectional area of ​​the aerosol generating article.

[0180] The second aerosol generating segment preferably has an average cross-sectional area of ​​at least 50% of the average cross-sectional area of ​​the aerosol generating article, more preferably at least 80% of the average cross-sectional area of ​​the aerosol generating article, more preferably at least 90% of the average cross-sectional area of ​​the aerosol generating article.

[0181] The cross-sectional area of ​​the second aerosol generating segment at its downstream end is preferably at least 50% of the average cross-sectional area of ​​the aerosol generating article, more preferably at least 80% of the average cross-sectional area of ​​the aerosol generating article, more preferably at least 90% of the average cross-sectional area of ​​the aerosol generating article.

[0182] The cross-sectional area of ​​the first aerosol generating segment at its upstream end is substantially the same as the cross-sectional area of ​​the second aerosol generating segment at its downstream end.

[0183] In certain embodiments of the present invention, the aerosol-generating article further comprises one or more elongated susceptor elements within the aerosol-generating strip. For example, the one or more elongated susceptor elements may be arranged substantially longitudinally within the aerosol-generating strip and in thermal contact with the aerosol-generating substrate. Where the aerosol-generating strip comprises one or more elongated susceptor elements, one or more aerosol-generating segments may comprise susceptor elements extending longitudinally within the element. With this arrangement, separate susceptor elements may be disposed in the first aerosol-generating segment and the second aerosol-generating segment.

[0184] As used herein with reference to the present invention, the term "susceptor element" refers to a material that is capable of converting electromagnetic energy into heat. When located within a fluctuating electromagnetic field, eddy currents induced in the susceptor element result in heating of the susceptor element. As the susceptor element is positioned in thermal contact with the aerosol-generating substrate, the aerosol-generating substrate is heated by the susceptor element.

[0185] The term "elongated" when used to describe a susceptor element means that the length dimension of the susceptor element is greater than its width dimension or its thickness dimension, such as greater than twice its width dimension or its thickness dimension.

[0186] The susceptor element is arranged substantially longitudinally within the strip or segment. This means that the length dimension of the elongated susceptor element is arranged substantially parallel to the longitudinal direction of the strip, for example within plus or minus 10 degrees of parallel to the longitudinal direction of the strip. In a preferred embodiment, the elongated susceptor element may be positioned at a radially central position within the strip or segment and extend along the longitudinal axis of the strip or segment.

[0187] The susceptor element is preferably in the form of a pin, a bar, a strip or a blade.

[0188] The susceptor element preferably has a width of 1 mm to 5 mm.

[0189] The thickness of the susceptor element is typically 0.01 mm to 2 mm, such as 0.5 mm to 2 mm. In some embodiments, the susceptor element preferably has a thickness of 10 microns to 500 microns, more preferably 10 microns to 100 microns.

[0190] Preferably, the length of the elongate susceptor element is equal to or shorter than the length of the aerosol generating segment in which the elongate susceptor element is contained.Preferably, the elongate susceptor element has the same length as the aerosol generating segment in which the elongate susceptor element is contained.

[0191] The susceptor element may be formed from any material that is capable of being inductively heated to a temperature sufficient to generate an aerosol from the aerosol-generating substrate.Preferably the susceptor element comprises metal or carbon.

[0192] Preferred susceptor elements may comprise or consist of a ferromagnetic material, such as a ferromagnetic alloy, ferritic iron, or a ferromagnetic steel or stainless steel. Suitable susceptor elements may be or comprise aluminium.

[0193] Suitable susceptor elements may include a non-metallic core having a metal layer disposed on the non-metallic core, such as metal tracks formed on the surface of a ceramic core. The susceptor element may have an outer protective layer, such as a ceramic protective layer or a glass protective layer encapsulating the susceptor element. The susceptor element may include a protective coating formed of glass, ceramic or an inert metal formed on the core of the susceptor element material.

[0194] The susceptor element is arranged in thermal contact with an aerosol-generating substrate comprising an aerosol-generating segment of the susceptor element. Thus, when the susceptor element heats up, the aerosol-generating substrate heats up and forms an aerosol. Preferably, the susceptor element is arranged in direct physical contact with the aerosol-generating substrate, for example within the aerosol-generating substrate.

[0195] Preferably, the first aerosol-generating substrate is defined by a first wrapper, and wherein the second aerosol-generating substrate is defined by a second wrapper separate from the first wrapper. Thus, each of the aerosol-generating segments has its own distinct stick wrapper surrounding the respective aerosol-generating substrate.

[0196] An aerosol-generating rod comprising the first aerosol-generating segment and the second aerosol-generating segment may be defined by a further wrapper which may combine the aerosol-generating segments and hold them in position relative to each other.

[0197] The wrapper defining the aerosol-generating strip may be a paper wrapper or a non-paper wrapper. Suitable paper wrappers for use in particular embodiments of the invention are known in the art and include, but are not limited to: cigarette papers; and filter segment wrappers. Suitable non-paper wrappers for use in particular embodiments of the invention are known in the art and include, but are not limited to, sheets of homogenized tobacco material.

[0198] The paper wrapper may have a grammage of 15 to 35 gsm, preferably 20 to 30 gsm.

[0199] The paper wrapper may have a thickness of 25 to 55 microns, preferably 30 to 50 microns, more preferably 35 to 45 microns.

[0200] In certain preferred embodiments, the wrapper may be formed from a laminate material comprising a plurality of layers. Preferably, the wrapper is formed from an aluminium co-laminated sheet.

[0201] The paper layer of the co-laminated sheet may have a grammage of 35 gsm to 55 gsm, preferably 40 gsm to 50 gsm.

[0202] The paper layer of the co-laminated sheet may have a thickness of 50 to 80 microns, preferably 55 to 75 microns, more preferably 60 to 70 microns.

[0203] The metal layer of the co-laminated sheet may have a grammage of 12 gsm to 25 gsm, preferably 15 gsm to 20 gsm.

[0204] The metal layer of the co-laminated sheet may have a thickness of 2 to 15 microns, preferably 3 to 12 microns, more preferably 5 to 10 microns.

[0205] The packaging material defining the aerosol-generating strip may be a paper packaging material comprising PVOH (polyvinyl alcohol) or silicone (or polysiloxane) (or polysiloxane). Adding PVOH (polyvinyl alcohol) or silicone (or polysiloxane) may improve the grease barrier properties of the packaging material.

[0206] The paper packaging material comprising PVOH or silicone (or polysiloxane) may have a grammage of 20 gsm to 50 gsm, preferably 25 gsm to 45 gsm, more preferably 30 gsm to 40 gsm.

[0207] The paper packaging material comprising PVOH or silicone (or polysiloxane) may have a thickness of 25 to 50 microns, preferably 30 to 45 microns, more preferably 35 to 40 microns.

[0208] The wrapper defining the aerosol-generating strip may include a flame retardant composition comprising one or more flame retardant compounds. The term "flame retardant compound" is used herein to describe compounds that, when added to or otherwise incorporated into a carrier substrate (e.g., paper or plastic compound), provide varying degrees of flammability protection to the carrier substrate.

[0209] Many suitable flame retardant compounds are known to the skilled person. In particular, several flame retardant compounds and formulations suitable for treating cellulosic materials are known and have been disclosed and can be used in the manufacture of packaging for aerosol-generating articles according to the present invention.

[0210] The package including the flame retardant composition may have a grammage of 20 gsm to 45 gsm, preferably 25 gsm to 40 gsm, more preferably 30 gsm to 35 gsm.

[0211] The packaging material including the flame retardant composition may have a thickness of at least 25 microns, preferably at least 30 microns, and even more preferably at least 35 microns. The packaging material including the flame retardant composition may have a thickness of less than or equal to 50 microns, preferably less than or equal to 45 microns, and even more preferably less than or equal to 40 microns.

[0212] The aerosol-generating article according to the present disclosure may further comprise an upstream section located upstream of the aerosol-generating strip. The upstream section is preferably located immediately upstream of the aerosol-generating strip. The upstream section preferably extends between the upstream end of the aerosol-generating article and the aerosol-generating strip. The upstream section may comprise one or more upstream elements located upstream of the aerosol-generating strip.

[0213] The aerosol-generating article of the present invention preferably comprises an upstream element located upstream and adjacent to the aerosol-generating strip. The upstream element advantageously prevents direct physical contact with the upstream end of the aerosol-generating strip. In addition, the presence of the upstream element helps prevent any loss of the substrate, which may be advantageous, for example, if the substrate contains particulate plant material.

[0214] In the case where the upstream segment of the aerosol-generating rod comprises shredded tobacco (e.g., tobacco cut filler), the upstream segment or its elements may additionally help prevent loose tobacco particles from being lost from the upstream end of the article. For example, this may be particularly important when the shredded tobacco has a relatively low density.

[0215] The upstream element may be a porous rod element. Preferably, the upstream element has a porosity of at least 50% in the longitudinal direction of the aerosol-generating article. More preferably, the upstream element has a porosity of between 50% and 90% in the longitudinal direction. The porosity of the upstream element in the longitudinal direction is defined by the ratio of the cross-sectional area of ​​the material forming the upstream element to the internal cross-sectional area of ​​the aerosol-generating article at the location of the upstream element.

[0216] The upstream element may be made of a porous material or may include a plurality of openings. For example, this may be achieved by laser perforation. Preferably, the plurality of openings are evenly distributed over the cross section of the upstream element.

[0217] The porosity or permeability of the upstream element may advantageously be designed to provide the aerosol-generating article with a particular overall resistance to draw (RTD) without substantially affecting the filtration provided by other parts of the article.

[0218] The upstream element may be formed from a material that is impermeable to air.In such embodiments, the aerosol-generating article may be configured such that air flows into the aerosol-generating rod via suitable ventilation means provided in the packaging.

[0219] In certain preferred embodiments of the present invention, it may be desirable to minimize the RTD of the upstream element. For example, as described herein, this may be the case for an article that is intended to be inserted into the cavity of an aerosol generating device such that the aerosol generating substrate is externally heated. For such articles, it is desirable to provide the article with as low an RTD as possible so that the majority of the consumer's RTD experience is provided by the aerosol generating device rather than the article.

[0220] The RTD of the upstream element may be less than 30 mm H2O, or less than 20 mm H2O, or less than 10 mm H2O, or less than 5 mm H2O, or less than 2 mm H2O.

[0221] The RTD of the upstream element may be at least 0.1 mm H2O, or at least 0.25 mm H2O, or at least 0.5 mm H2O.

[0222] Preferably, the RTD of the upstream element is less than 2 mm H2O / mm length, more preferably less than 1.5 mm H2O / mm length, more preferably less than 1 mm H2O / mm length, more preferably less than 0.5 mm H2O / mm length, more preferably less than 0.3 mm H2O / mm length, more preferably less than 0.2 mm H2O / mm length.

[0223] Preferably, the combined RTD of the upstream section or upstream element thereof and the aerosol-generating strip is less than 15 mm H2O, more preferably less than 12 mm H2O, more preferably less than 10 mm H2O.

[0224] In certain preferred embodiments, the upstream element is formed by a solid cylindrical rod element having a filled cross section. Such rod elements may be referred to as "plain" elements. As described above, solid rod elements may be porous, but do not have a tubular form and therefore do not provide longitudinal flow channels. Solid rod elements preferably have a substantially uniform cross section.

[0225] In other preferred embodiments, the upstream element is formed by a hollow tubular segment defining a longitudinal cavity that provides an unrestricted flow channel. In such embodiments, as described above, the upstream element can provide protection for the aerosol-generating substrate while having minimal impact on the overall resistance to draw (RTD) and filtration properties of the article.

[0226] Preferably, the diameter of the longitudinal lumen of the hollow tubular segment forming the upstream element is at least 3 mm, more preferably at least 3.5 mm, more preferably at least 4 mm, and more preferably at least 4.5 mm. Preferably, the diameter of the longitudinal lumen is maximized in order to minimize the RTD of the upstream segment or its upstream element.

[0227] Preferably, the wall thickness of the hollow tubular segment is less than 2 mm, more preferably less than 1.5 mm, and more preferably less than 1 mm.

[0228] The upstream element of the upstream section may be made of any material suitable for use in an aerosol generating article. The upstream element may, for example, be made of the same material as one of the other components of the aerosol generating article, such as a downstream filter segment or a hollow tubular cooling element. Suitable materials for forming the upstream element include filter materials, ceramics, polymeric materials, cellulose acetate, paperboard, zeolites, or an aerosol generating matrix. The upstream element may include a rod of cellulose acetate. The upstream element may include a hollow acetate tube or a paperboard tube.

[0229] Preferably, the upstream element is formed from a heat resistant material. For example, preferably, the upstream element is formed from a material that resists temperatures up to 350 degrees Celsius. This ensures that the upstream element is not adversely affected by the heating means used to heat the aerosol generating substrate.

[0230] Preferably, the upstream segment or its upstream element has an outer diameter substantially equal to the outer diameter of the aerosol-generating article. Preferably, the outer diameter of the upstream segment or its upstream element is between 5 mm and 12 mm, more preferably between 6 mm and 10 mm, more preferably between 7 mm and 8 mm. In some embodiments, the outer diameter of the upstream segment may be less than 7 mm, for example, between 5 mm and 7 mm, or between 6 mm and 7 mm.

[0231] Preferably, the upstream section or upstream element has a length between 2 mm and 10 mm, more preferably between 3 mm and 8 mm, more preferably between 2 mm and 6 mm. In a particularly preferred embodiment, the upstream section or upstream element has a length of 5 mm.

[0232] The upstream section is preferably defined by a wrapper such as a stick wrapper. The wrapper defining the upstream section is preferably a rigid stick wrapper, for example a stick wrapper having a basis weight of at least 80 grams per square meter (gsm), or at least 100 gsm, or at least 110 gsm. This provides structural rigidity to the upstream section.

[0233] The upstream section is preferably connected to the aerosol-generating rod and optionally at least a part of the downstream section by means of an outer wrapper as described herein.

[0234] The aerosol generating article according to the present invention preferably also includes a downstream section located downstream of the aerosol generating strip. The downstream section is preferably located immediately downstream of the aerosol generating strip. The downstream section of the aerosol generating article preferably extends between the aerosol generating strip and the downstream end of the aerosol generating article. The downstream section may include one or more elements, each of which will be described in more detail within the present disclosure.

[0235] The length of the downstream section may be at least 20 mm, or at least 25 mm, or at least 30 mm.

[0236] The length of the downstream section may be less than 70 mm, or less than 60 mm, or less than 50 mm.

[0237] For example, the length of the downstream section may be between 20 mm and 70 mm, or between 25 mm and 60 mm, or between 30 mm and 50 mm.

[0238] Preferably, the downstream section of an aerosol-generating article according to the invention comprises a hollow tubular cooling element disposed downstream of the aerosol-generating rod.The hollow tubular cooling element may advantageously provide an aerosol-cooling element for the aerosol-generating article.

[0239] The hollow tubular cooling element may be arranged immediately downstream of the aerosol generating strip. In other words, the hollow tubular cooling element may be adjacent to the downstream end of the aerosol generating strip. The hollow tubular cooling element may define the upstream end of the downstream section of the aerosol generating article. The downstream end of the aerosol generating article may coincide with the downstream end of the downstream section. In some embodiments, the downstream section of the aerosol generating article comprises a single hollow tubular element. In other words, the downstream section of the aerosol generating article may include only one hollow tubular element. In other embodiments, as described below, the downstream section comprises two or more hollow tubular elements.

[0240] As used throughout this disclosure, the term "hollow tubular element" refers to a generally elongated element that defines a lumen or airflow passage along its longitudinal axis. In particular, the term "tubular" will be used hereinafter to refer to a tubular element having a substantially cylindrical cross-section and defining at least one airflow conduit that establishes uninterrupted fluid communication between an upstream end of the tubular element and a downstream end of the tubular element. However, it should be understood that alternative geometries of the tubular element (e.g., alternative cross-sectional shapes) may be possible. The hollow tubular cooling element may be a single discrete element of the aerosol-generating article having a defined length and thickness.

[0241] In the context of the present invention, the hollow tubular cooling element provides an unrestricted flow channel. This means that the hollow tubular cooling element provides a negligible resistance to suction (RTD) level. The term "negligible RTD level" is used to describe a hollow tubular cooling element having an RTD of less than 1 mm H2O / 10 mm length, preferably less than 0.4 mm H2O / 10 mm length of the hollow tubular cooling element, and more preferably less than 0.1 mm H2O / 10 mm length of the hollow tubular cooling element.

[0242] The RTD of the hollow tubular cooling element is preferably less than or equal to 10 mm H2O, or less than or equal to 5 mm H2O, or less than or equal to 2.5 mm H2O, or less than or equal to 2 mm H2O, or less than or equal to 1 mm H2O.

[0243] The RTD of the hollow tubular cooling element may be at least 0 mm H2O, or at least 0.25 mm H2O, or at least 0.5 mm H2O, or at least 1 mm H2O.

[0244] In an aerosol-generating article according to the invention, the overall RTD of the article depends substantially on the RTD of the strip and optionally on the RTD of downstream and / or upstream elements. This is because the hollow tubular cooling element is substantially empty and thus substantially only minimally affects the overall RTD of the aerosol-generating article.

[0245] Therefore, the flow channel should be free of any components that would hinder the flow of air in the longitudinal direction.Preferably, the flow channel is substantially empty, and particularly preferably the flow channel is empty.

[0246] As will be described in more detail within the present disclosure, the aerosol-generating article may include a ventilation zone at a location along the downstream segment. In some embodiments, the aerosol-generating article may include a ventilation zone at a location along the hollow tubular cooling element. This ventilation zone or any ventilation zone may extend through the peripheral wall of the hollow tubular cooling element. Thus, fluid communication is established between the flow channel defined by the interior of the hollow tubular cooling element and the external environment. Ventilation zones are further described within the present disclosure.

[0247] The length of the hollow tubular cooling element may be at least 15 mm, or at least 20 mm, or at least 25 mm, or at least 30 mm.

[0248] The length of the hollow tubular cooling element may be less than 50 mm, or less than 45 mm, or less than 40 mm.

[0249] For example, the length of the hollow tubular cooling element may be between 15 mm and 50 mm, or between 20 mm and 45 mm, or between 20 mm and 40 mm, or between 20 mm and 30 mm, or between 25 mm and 40 mm, or between 30 mm and 40 mm.

[0250] The relatively long hollow tubular cooling element provides and defines a relatively long internal cavity within the aerosol generating article and downstream of the aerosol generating strip. As discussed in the present disclosure, providing a cavity downstream (preferably, immediately downstream) of the aerosol generating substrate enhances the nucleation of aerosol particles generated by the substrate. Providing a relatively long cavity maximizes such nucleation benefits, thereby improving aerosol formation and cooling.

[0251] The wall thickness of the hollow tubular cooling element may be between 100 microns and 2 millimeters, or between 150 microns and 1.5 millimeters, or between 200 microns and 1.25 millimeters.

[0252] The hollow tubular cooling element preferably has an outer diameter that is substantially equal to the outer diameter of the aerosol-generating rod and the outer diameter of the aerosol-generating article.

[0253] Preferably, the outer diameter of the hollow tubular cooling element is between 5 mm and 12 mm, more preferably between 6 mm and 10 mm, and more preferably between 7 mm and 8 mm. In some embodiments, the outer diameter of the hollow tubular cooling element can be less than 7 mm, for example, between 5 mm and 7 mm, or between 6 mm and 7 mm.

[0254] The hollow tubular cooling element may have an inner diameter. Preferably, the hollow tubular cooling element may have a constant inner diameter along the length of the hollow tubular cooling element. However, the inner diameter of the hollow tubular cooling element may vary along the length of the hollow tubular cooling element.

[0255] The hollow tubular cooling element may have an inner diameter of at least 2 mm. For example, the hollow tubular cooling element may have an inner diameter of at least 3 mm, at least 4 mm, or at least 5 mm.

[0256] Providing a hollow tubular cooling element having an inner diameter as described above may advantageously provide the hollow tubular cooling element with sufficient rigidity and strength.

[0257] The hollow tubular cooling element may have an inner diameter of no more than 10 mm. For example, the hollow tubular cooling element may have an inner diameter of no more than 9 mm, no more than 8 mm, or no more than 7 mm.

[0258] Providing a hollow tubular cooling element having an inner diameter as described above may advantageously reduce the pumping resistance of the hollow tubular cooling element.

[0259] The hollow tubular cooling element may have an inner diameter of between 2 mm and 10 mm, between 3 mm and 9 mm, between 4 mm and 8 mm, or between 5 mm and 7 mm.

[0260] The lumen or cavity of the hollow tubular cooling element may have any cross-sectional shape. The lumen of the hollow tubular cooling element may have a circular cross-sectional shape.

[0261] The hollow tubular cooling element may comprise a paper based material. The hollow tubular cooling element may comprise at least one paper layer. The paper may be a very stiff paper. The paper may be a curled paper, such as a curled heat resistant paper or a curled parchment paper.

[0262] Preferably, the hollow tubular cooling element may comprise paperboard. The hollow tubular cooling element may be a paperboard tube. The hollow tubular cooling element may be formed from paperboard. Advantageously, paperboard is a cost-effective material that provides a balance between being deformable to provide ease of insertion of the article into the aerosol generating device and being sufficiently rigid to provide appropriate engagement of the article with the interior of the device. Thus, the paperboard tube may provide suitable resistance to deformation or compression during use.

[0263] The hollow tubular cooling element may be a paper tube. The hollow tubular cooling element may be a tube formed from spirally wound paper. The hollow tubular cooling element may be formed from a plurality of paper layers. The paper may have a basis weight of at least 50 g / m2, at least 60 g / m2, at least 70 g / m2 or at least 90 g / m2.

[0264] The hollow tubular cooling element may include a polymer material. For example, the hollow tubular cooling element may include a polymer film. The polymer film may include a cellulose film. The hollow tubular cooling element may include low density polyethylene (HDPE) or polyhydroxyalkanoate (PHA) fibers. The hollow tube may include cellulose acetate tow.

[0265] Where the hollow tubular cooling element comprises cellulose acetate tow, the cellulose acetate tow may have a denier per filament between 2 and 4 and a total denier between 25 and 40.

[0266] In some embodiments, aerosol-generating articles according to the invention may comprise a ventilation zone at a position along the downstream segment. In more detail, in those embodiments in which the downstream segment comprises a hollow tubular cooling element, the ventilation zone may be provided at a position along the hollow tubular cooling element. Alternatively, in those embodiments in which the downstream segment comprises a downstream hollow tubular element, as described below, the ventilation zone may be provided at a position along the downstream hollow tubular element.

[0267] Thus, the ventilation cavity is arranged downstream of the aerosol generating strip. This provides several potential technical benefits. Firstly, the inventors have found that one such ventilated hollow tubular cooling element provides particularly effective aerosol cooling. Thus, satisfactory aerosol cooling can be achieved even with relatively short downstream sections. Secondly, the inventors have surprisingly found that such rapid cooling of the volatile substances released when heating the aerosol generating substrate promotes enhanced nucleation of aerosol particles.

[0268] The ventilation zone may typically comprise a plurality of perforations through the peripheral wall of the hollow tubular cooling element. Preferably, the ventilation zone comprises at least one row of circumferential perforations. In some embodiments, the ventilation zone may comprise two rows of circumferential perforations. For example, the perforations may be formed on a production line during manufacture of the aerosol-generating article. Preferably, each row of circumferential perforations comprises 8 to 30 perforations.

[0269] Aerosol-generating articles according to the invention may have a ventilation level of at least 25%.

[0270] Throughout this specification, the term "ventilation level" is used to denote the volume ratio between the airflow entering the aerosol-generating article via the ventilation zone (ventilation airflow) and the sum of the aerosol airflow and the ventilation airflow. The greater the ventilation level, the higher the dilution of the aerosol flow delivered to the consumer. The aerosol-generating article preferably has a ventilation level of at least 25%, more preferably at least 30%, even more preferably at least 40%, even more preferably at least 50%.

[0271] Aerosol-generating articles according to the invention may have a ventilation level of up to 90%. Preferably, aerosol-generating articles according to the invention have a ventilation level of less than or equal to 80%, more preferably less than or equal to 70%, even more preferably less than or equal to 60%.

[0272] Thus, aerosol-generating articles according to the invention may have a ventilation level of from 25% to 90%, preferably from 30% to 80%, more preferably from 40% to 70%, even more preferably from 50% to 60%.

[0273] As discussed in the present disclosure, the downstream segment may include a downstream filter segment. The downstream filter segment may extend to a downstream end of the downstream segment. The downstream filter segment may be located at the downstream end of the aerosol-generating article. The downstream end of the downstream filter segment may define the downstream end of the aerosol-generating article.

[0274] The downstream filter segment may be located downstream of the hollow tubular cooling element as described above.The downstream filter segment may extend between the hollow tubular cooling element and the downstream end of the aerosol-generating article.

[0275] The downstream filter segment is preferably a solid rod, which may also be described as a "plain" rod and is non-tubular. Thus, the filter segment preferably has a substantially uniform cross-section.

[0276] The downstream filter segment is preferably formed of a fibrous filter material. The fibrous filter material can be used to filter the aerosol generated by the aerosol generating substrate. Suitable fibrous filter materials will be known to the skilled person. Particularly preferably, at least one downstream filter segment comprises a cellulose acetate filter segment formed of cellulose acetate tow.

[0277] In certain preferred embodiments, the downstream section comprises a single downstream filter segment.In alternative embodiments, the downstream section comprises two or more downstream filter segments axially aligned in end-to-end abutting relationship with each other.

[0278] The downstream filter segment may optionally include a flavoring agent, which may be provided in any suitable form. For example, the downstream filter segment may include one or more capsules, beads or particles of a flavoring agent, or one or more threads or wires loaded with a flavoring agent.

[0279] Preferably, the downstream filter segment has a low particle filtration efficiency.

[0280] Preferably, the downstream filter segment is defined by the stick wrap.Preferably, the downstream filter segment is not ventilated, such that air does not enter the aerosol-generating article along the downstream filter segment.

[0281] The downstream filter segment is preferably connected to one or more of the adjacent upstream components of the aerosol-generating article by means of a tipping wrapper.

[0282] The downstream filter segment preferably has an outer diameter substantially equal to the outer diameter of the aerosol-generating article.The outer diameter of the downstream filter segment may be substantially the same as the outer diameter of the hollow tubular cooling element.

[0283] Preferably, the outer diameter of the downstream filter segment is between 5 mm and 12 mm, more preferably between 6 mm and 10 mm, more preferably between 7 mm and 8 mm. In some embodiments, the outer diameter of the downstream filter segment may be less than 7 mm, such as between 5 mm and 7 mm, or between 6 mm and 7 mm.

[0284] Unless otherwise stated, the draw resistance (RTD) of a component or aerosol generating article is measured according to ISO6565-2015. RTD refers to the pressure required to force air through the full length of the component. The term "pressure drop" or "draw resistance" of a component or article may also refer to "resistance to draw". Such terms generally refer to measurements according to ISO 6565-2015. Generally, in the test, at a temperature of 22 degrees Celsius, a pressure of 101 kPa (about 760 torr) and a relative humidity of 60%, a volume flow rate of 17.5 ml / sec is carried out at the output or downstream end of the measuring component. The conditions and smoking machine specifications for smoking are set forth in ISO standard 3308 (ISO 3308:2000). The atmosphere for adjustment and testing is set forth in ISO standard 3402 (ISO 3402:1999).

[0285] The resistance to draw (RTD) of the downstream section may be at least 0 mm H2O. The RTD of the downstream section may be at least 3 mm H2O. The RTD of the downstream section may be at least 6 mm H2O.

[0286] The RTD of the downstream section may be no greater than 12 mm H2O. The RTD of the downstream section may be no greater than 11 mm H2O. The RTD of the downstream section may be no greater than 10 mm H2O.

[0287] The resistance to draw (RTD) characteristics of the downstream segment may be entirely or primarily attributable to the RTD characteristics of the downstream filter segment of the downstream segment. In other words, the RTD of the downstream filter segment of the downstream segment may entirely define the RTD of the downstream segment.

[0288] The resistance to draw (RTD) of the downstream filter segment may be at least 0 mm H2O, or at least 3 mm H2O, or at least 6 mm H2O.

[0289] The RTD of the downstream filter segment may be no greater than 12 mm H2O, or no greater than 11 mm H2O, or no greater than 10 mm H2O.

[0290] As described above, the downstream filter segment can be formed of a fiber filter material. The downstream filter segment can be formed of a porous material. The downstream filter segment can be formed of a biodegradable material. The downstream filter segment can be formed of a cellulose material such as cellulose acetate. For example, the downstream filter segment can be formed of bundled cellulose acetate fibers having a single filament denier between 10 and 15. For example, the downstream filter segment is formed of a relatively low-density cellulose acetate tow (such as a cellulose acetate tow comprising fibers having a single filament denier of 12).

[0291] The downstream filter segment can be formed by a material based on polylactic acid. The downstream filter segment can be formed by a bioplastic material (preferably a bioplastic material based on starch). The downstream filter segment can be made by injection molding or by extrusion. Bioplastic-based materials are advantageous because they can provide a downstream filter segment structure that is simple and inexpensive to manufacture, has a specific and complex cross-sectional profile, which can include a plurality of relatively large airflow channels extending through the downstream filter segment material, which provides suitable RTD characteristics.

[0292] The length of the downstream filter segment can be at least 5 mm, or at least 10 mm. The length of the downstream filter segment can be less than 25 mm, or less than 20 mm. For example, the length of the downstream filter segment can be between 5 mm and 25 mm, or between 10 mm and 25 mm, or between 5 mm and 20 mm, or between 10 mm and 20 mm.

[0293] The downstream section may also include one or more additional hollow tubular elements.

[0294] In certain embodiments, the downstream section may comprise a hollow tubular support element upstream of the hollow tubular cooling element described above. Preferably, the hollow tubular support element is adjacent to the downstream end of the aerosol generating strip. Preferably, the hollow tubular support element is adjacent to the upstream end of the hollow tubular cooling element. Preferably, the hollow tubular support element and the hollow tubular cooling element are adjacent to each other and together provide a hollow tubular section within the downstream section.

[0295] The hollow tubular support element may be formed of any suitable material or combination of materials. For example, the support element may be formed of one or more materials selected from the group consisting of: cellulose acetate; paperboard; curled paper, such as curled heat-resistant paper or curled parchment; and polymeric materials, such as low-density polyethylene (LDPE). In a preferred embodiment, the support element is formed of cellulose acetate. Other suitable materials include polyhydroxyalkanoate (PHA) fibers. In a preferred embodiment, the hollow tubular support element comprises a hollow acetate tube.

[0296] The hollow tubular support element preferably has an outer diameter that is substantially equal to the outer diameter of the aerosol-generating rod and the outer diameter of the aerosol-generating article.

[0297] Preferably, the outer diameter of the hollow tubular support element is between 5 mm and 12 mm, more preferably between 6 mm and 10 mm, and more preferably between 7 mm and 8 mm. In some embodiments, the outer diameter of the hollow tubular support element can be less than 7 mm, for example, between 5 mm and 7 mm, or between 6 mm and 7 mm.

[0298] The hollow tubular support element may have a wall thickness of at least 1 mm, preferably at least 1.5 mm, more preferably at least 2 mm.

[0299] The hollow tubular support element may have a length of at least 5 mm. Preferably, the support element has a length of at least 6 mm, more preferably at least 7 mm.

[0300] The hollow tubular support element may have a length of less than 15 mm. Preferably, the hollow tubular support element has a length of less than 12 mm, more preferably less than 10 mm.

[0301] In some embodiments, the support element has a length of 5 mm to 15 mm, preferably 6 mm to 15 mm, more preferably 7 mm to 15 mm. In other embodiments, the support element has a length of 5 mm to 12 mm, preferably 6 mm to 12 mm, more preferably 7 mm to 12 mm. In other embodiments, the support element has a length of 5 mm to 10 mm, preferably 6 mm to 10 mm, more preferably 7 mm to 10 mm.

[0302] Alternatively or in addition to the hollow tubular support element, the downstream section may also include a downstream hollow tubular element downstream of the hollow tubular cooling element. The downstream hollow tubular element may be arranged in close proximity to the hollow tubular cooling element. Alternatively or preferably, the downstream hollow tubular element is separated from the hollow tubular cooling element by at least one other component. For example, the downstream section may include a downstream filter segment between the hollow tubular cooling element and the downstream hollow tubular element.

[0303] Preferably, the downstream hollow tubular element extends to the downstream end of the downstream section. Thus, the downstream hollow tubular element preferably extends to the downstream end of the aerosol generating article. In certain embodiments, additional downstream hollow tubular elements may be provided so that the downstream section comprises two adjacent downstream hollow tubular elements downstream of the downstream filter segment.

[0304] The RTD of the downstream hollow tubular element may be less than or equal to 10 mm H2O, or less than or equal to 5 mm H2O, or less than or equal to 2.5 mm H2O, or less than or equal to 2 mm H2O. Preferably, the RTD of the downstream hollow tubular element is less than or equal to 1 mm H2O.

[0305] The RTD of the downstream hollow tubular element may be at least 0 mm H2O, or at least 0.25 mm H2O, or at least 0.5 mm H2O, or at least 1 mm H2O.

[0306] Therefore, the flow channel of the downstream hollow tubular element should be free of any components that would hinder the flow of air in the longitudinal direction.Preferably, the flow channel is substantially empty, and particularly preferably the flow channel is empty.

[0307] Preferably, the length of the downstream hollow tubular element is at least 3 mm, more preferably at least 4 mm, more preferably at least 5 mm, more preferably at least 6 mm.

[0308] The length of the downstream hollow tubular element is preferably less than 20 mm, more preferably less than 15 mm, more preferably less than 12 mm, more preferably less than 10 mm.

[0309] The lumen or cavity of the downstream hollow tubular element may have any cross-sectional shape.The lumen of the downstream hollow tubular element may have a circular cross-sectional shape.

[0310] The downstream hollow tubular element may comprise a paper-based material. The downstream hollow tubular element may comprise at least one paper layer. The paper may be a very hard paper. The paper may be a curled paper, such as a curled heat-resistant paper or a curled parchment paper.

[0311] The downstream hollow tubular element may comprise cardboard.The downstream hollow tubular element may be a cardboard tube.

[0312] The downstream hollow tubular element may be a paper tube. The downstream hollow tubular element may be a tube formed by spirally winding paper. The downstream hollow tubular element may be formed from multiple paper layers. The paper may have a basis weight of at least 50 g / m2, at least 60 g / m2, at least 70 g / m2, or at least 90 g / m2.

[0313] The downstream hollow tubular element may include a polymer material. For example, the downstream hollow tubular element may include a polymer film. The polymer film may include a cellulose film. The downstream hollow tubular element may include low density polyethylene (HDPE) or polyhydroxyalkanoate (PHA) fibers. Preferably, the downstream hollow tubular element includes cellulose acetate tow. For example, in a preferred embodiment, the downstream hollow tubular element includes a hollow acetate tube.

[0314] Where the downstream hollow tubular element comprises cellulose acetate tow, the cellulose acetate tow may have a denier per filament of between 2 and 4 and a total denier of between 25 and 40.

[0315] In case the downstream section further comprises an additional downstream hollow tubular element, as described above, the additional downstream hollow tubular element may be formed of the same material as the downstream hollow tubular element or of a different material.

[0316] In certain preferred embodiments, the downstream section may include a ventilation zone at a location on the downstream hollow tubular element. In one example, this ventilation zone at a location on the downstream hollow tubular element may be provided instead of a ventilation zone at a location on the hollow tubular cooling element. In another example, a ventilation zone at a location on the downstream hollow tubular element may be provided in addition to the ventilation zone provided at a location on the hollow tubular cooling element.

[0317] The ventilation zone at a location along the downstream hollow tubular element may include a plurality of perforations through the peripheral wall of the downstream hollow tubular element. Preferably, the ventilation zone at a location along the downstream hollow tubular element includes at least one row of circumferential perforations. In some embodiments, the ventilation zone may include two rows of circumferential perforations. For example, the perforations may be formed on a production line during manufacture of the aerosol-generating article. Preferably, each row of circumferential perforations includes 8 to 30 perforations.

[0318] The overall RTD of the aerosol-generating article may be at least 10 mm H 2 O. For example, the overall RTD of the aerosol-generating article may be at least 20 mm H 2 O, at least 30 mm H 2 O, at least 35 mm H 2 O, or at least 40 mm H 2 O.

[0319] The overall RTD of the aerosol-generating article may be no more than 70 mm H 2 O. For example, the overall RTD of the aerosol-generating article may be no more than 60 mm H 2 O, no more than 55 mm H 2 O, no more than 50 mm H 2 O, or no more than 45 mm H 2 O.

[0320] The overall RTD of the aerosol generating article may be between 10 mm H2O and 70 mm H2O. For example, the overall RTD of the aerosol generating article may be between 20 mm H2O and 60 mm H2O, between 30 mm H2O and 55 mm H2O, between 35 mm H2O and 50 mm H2O, or between 40 mm H2O and 45 mm H2O.

[0321] The overall RTD of the aerosol-generating article may be between 40 mm H2O and 60 mm H2O, between 35 mm H2O and 40 mm H2O, between 45 mm H2O and 50 mm H2O, or between 55 mm H2O and 65 mm H2O.

[0322] The overall RTD of the aerosol-generating article may be about 38 mm H2O, about 48 mm H2O, or about 60 mm H2O.

[0323] Aerosol-generating articles according to the invention may have an overall length of at least 40 mm, or at least 50 mm, or at least 60 mm.

[0324] Aerosol-generating articles according to the invention may have an overall length of less than or equal to 90 mm, or less than or equal to 85 mm, or less than or equal to 80 mm.

[0325] In some embodiments, the overall length of the aerosol-generating article is preferably 40 mm to 70 mm, more preferably 45 mm to 70 mm. In other embodiments, the overall length of the aerosol-generating article is preferably 40 mm to 60 mm, more preferably about 45 mm to about 60 mm. In further embodiments, the overall length of the aerosol-generating article is preferably 40 mm to 50 mm, more preferably 45 mm to 50 mm. In an exemplary embodiment, the overall length of the aerosol-generating article is about 45 mm.

[0326] In alternative embodiments, the overall length of the aerosol-generating article is preferably 50 mm to 90 mm, more preferably 60 mm to 90 mm, and even more preferably 70 mm to 90 mm. In other embodiments, the overall length of the aerosol-generating article is preferably 50 mm to 85 mm, more preferably 60 mm to 85 mm, and even more preferably 70 mm to 85 mm. In further embodiments, the overall length of the aerosol-generating article is preferably 50 mm to 80 mm, more preferably 60 mm to 80 mm, and even more preferably 70 mm to 80 mm. In an exemplary embodiment, the overall length of the aerosol-generating article is 75 mm.

[0327] The outer diameter of the aerosol-generating article may be at least 5 mm, or at least 6 mm, or at least 7 mm.

[0328] The aerosol-generating article may have an outer diameter of less than or equal to about 12 mm, or less than or equal to about 10 mm, or less than or equal to about 8 mm.

[0329] In some embodiments, the aerosol-generating article has an outer diameter of about 5 mm to about 12 mm, preferably about 6 mm to about 12 mm, and more preferably about 7 mm to about 12 mm. In other embodiments, the aerosol-generating article has an outer diameter of about 5 mm to about 10 mm, preferably about 6 mm to about 10 mm, and more preferably about 7 mm to about 10 mm. In further embodiments, the aerosol-generating article has an outer diameter from about 5 mm to about 8 mm, preferably from about 6 mm to about 8 mm, and more preferably from about 7 mm to about 8 mm. In other embodiments, the aerosol-generating article has an outer diameter of less than 7 mm.

[0330] The outer diameter of the aerosol-generating article may be substantially constant over the entire length of the article. Alternatively, different parts of the aerosol-generating article may have different outer diameters.

[0331] In particularly preferred embodiments, one or more of the components of the aerosol-generating article is individually defined by its own wrapper.

[0332] Preferably, at least one component of the aerosol-generating article is packaged in a hydrophobic wrapper.

[0333] The term "hydrophobic" refers to a surface that exhibits water repellent properties. A useful method for determining this is to measure the water contact angle. The "water contact angle" is the angle conventionally measured across a liquid when a liquid / vapor interface encounters a solid surface. It quantifies the wettability of a solid surface by a liquid via Young's equation. Hydrophobicity or water contact angle can be determined by utilizing the TAPPI T558 test method, and the results are presented as the interfacial contact angle and are reported in "degrees," and can range from near zero to near 180 degrees.

[0334] In a preferred embodiment, the hydrophobic wrapper is a wrapper comprising a paper layer having a water contact angle of about 30 degrees or greater, and preferably about 35 degrees or greater, or about 40 degrees or greater, or about 45 degrees or greater.

[0335] For example, the paper layer may include PVOH (polyvinyl alcohol) or silicon. PVOH may be applied to the paper layer as a surface coating, or the paper layer may include a surface treatment including PVOH or silicon.

[0336] The present disclosure also relates to an aerosol generating system comprising an aerosol generating device having a distal end and a mouth end. The aerosol generating device may include a body. The body or housing of the aerosol generating device may define a device cavity for removably receiving an aerosol generating article at the mouth end of the device. The aerosol generating device may include a heating element or heater for heating an aerosol generating substrate when the aerosol generating article is received in the device cavity.

[0337] The device cavity may be referred to as a heating chamber of the aerosol-generating device. The device cavity may extend between a distal end and an oral end or a proximal end. The distal end of the device cavity may be a closed end, and the oral end or the proximal end of the device cavity may be an open end. The aerosol-generating article may be inserted into the device cavity or the heating chamber via the open end of the device cavity. The device cavity may be cylindrical so as to conform to the same shape of the aerosol-generating article.

[0338] The expression "received within" may refer to the fact that a component or element is fully or partially received within another component or element. For example, the expression "the aerosol-generating article is received within the device cavity" means that the aerosol-generating article is fully or partially received within the device cavity of the aerosol-generating article. When the aerosol-generating article is received within the device cavity, the aerosol-generating article may be adjacent to the distal end of the device cavity. When the aerosol-generating article is received within the device cavity, the aerosol-generating article may be substantially proximal to the distal end of the device cavity. The distal end of the device cavity may be defined by an end wall.

[0339] The length of the device lumen may be between 15 mm and 80 mm, or between 20 mm and 70 mm, or between 25 mm and 60 mm, or between 25 mm and 50 mm.

[0340] The length of the device lumen may be between 25 mm and 29 mm, or between 26 mm and 29 mm, or between 27 mm or 28 mm.

[0341] The length of the device cavity (or heating chamber) may be equal to or greater than the length of the aerosol generating strip. The length of the device cavity may be equal to or greater than the combined length of the upstream section or element and the aerosol generating strip. Preferably, the length of the device cavity is such that when the aerosol generating article is received in the aerosol generating device, at least 75% of the length of the aerosol generating strip is inserted or received in the device cavity. More preferably, the length of the device cavity is such that when the aerosol generating article is received in the aerosol generating device, at least 80% of the length of the aerosol generating strip is inserted or received in the device cavity. More preferably, the length of the device cavity is such that when the aerosol generating article is received in the aerosol generating device, at least 90% of the length of the aerosol generating strip is inserted or received in the device cavity. This maximizes the length of the aerosol generating strip along which the aerosol generating substrate can be heated during use, thereby optimizing the generation of aerosol from the aerosol generating substrate and reducing tobacco waste.

[0342] The length of the device cavity may be such that the downstream segment or a portion thereof is configured to protrude from the device cavity when the aerosol-generating article is received in the device cavity. The length of the device cavity may be such that a portion of the downstream segment (such as a hollow tubular cooling element or a downstream filter segment) is configured to protrude from the device cavity when the aerosol-generating article is received in the device cavity. The length of the device cavity may be such that a portion of the downstream segment (such as a hollow tubular cooling element or a downstream filter segment) is configured to be received in the device cavity when the aerosol-generating article is received in the device cavity.

[0343] When the aerosol-generating article is received in the device, at least 25% of the length of the downstream segment may be inserted or received in the device cavity.When the aerosol-generating article is received in the device, at least 30% of the length of the downstream segment may be inserted or received in the device cavity.

[0344] The diameter of the device lumen may be between 4 mm and 10 mm. The diameter of the device lumen may be between 5 mm and 9 mm. The diameter of the device lumen may be between 6 mm and 8 mm. The diameter of the device lumen may be between 6 mm and 7 mm.

[0345] The diameter of the device cavity may be substantially equal to or greater than the diameter of the aerosol-generating article.The diameter of the device cavity may be the same as the diameter of the aerosol-generating article so as to establish a close fit with the aerosol-generating article.

[0346] The device cavity may be configured to establish a tight fit with an aerosol generating article received in the device cavity. Tight fit may refer to a snug fit. The aerosol generating device may include a peripheral wall. The peripheral wall may define the device cavity or the heating chamber. The peripheral wall defining the device cavity may be configured to engage with the aerosol generating article received in the device cavity in a tight fit, such that when the aerosol generating article is received in the device, there is substantially no gap or empty space between the peripheral wall defining the device cavity and the aerosol generating article.

[0347] Such a tight fit may establish an air-tight fit or configuration between the device cavity and the aerosol-generating article received therein.

[0348] With such an airtight configuration, there will be substantially no gaps or empty spaces between the peripheral wall defining the device cavity and the aerosol-generating article for air to flow through.

[0349] The close fit with the aerosol-generating article may be established along the entire length of the device cavity or along a portion of the length of the device cavity.

[0350] The aerosol generating device may include an airflow channel extending between a channel inlet and a channel outlet. The airflow channel may be configured to establish fluid communication between the interior of the device cavity and the exterior of the aerosol generating device. The airflow channel of the aerosol generating device may be defined within a housing of the aerosol generating device to enable fluid communication between the interior of the device cavity and the exterior of the aerosol generating device. When the aerosol generating article is received in the device cavity, the airflow channel may be configured to provide airflow into the article so as to deliver the generated aerosol to a user who draws from the mouth end of the article.

[0351] The airflow passage of the aerosol generating device may be defined within or by the peripheral wall of the housing of the aerosol generating device. In other words, the airflow passage of the aerosol generating device may be defined within the thickness of the peripheral wall or by the inner surface of the peripheral wall, or a combination of both. The airflow passage may be partially defined by the inner surface of the peripheral wall and may be partially defined within the thickness of the peripheral wall. The inner surface of the peripheral wall defines the peripheral boundary of the device cavity.

[0352] The airflow channel of the aerosol generating device may extend from an inlet at the mouth or proximal end of the aerosol generating device to an outlet distal to the mouth end of the device.The airflow channel may extend in a direction parallel to the longitudinal axis of the aerosol generating device.

[0353] The heater may be any suitable type of heater. Preferably, in the present invention, the heater is an external heater.

[0354] Preferably, the heater may externally heat the aerosol-generating article when the aerosol-generating article is received in the aerosol-generating device.Such an external heater may confine the aerosol-generating article when the aerosol-generating article is inserted into or received in the aerosol-generating device.

[0355] In some embodiments, the heater is arranged to heat an outer surface of the aerosol-generating substrate. In some embodiments, the heater is arranged to be inserted into the aerosol-generating substrate when the aerosol-generating substrate is received in the cavity. The heater may be positioned within the device cavity or a heating chamber.

[0356] The heater may include at least one heating element. The at least one heating element may be any suitable type of heating element. In some embodiments, the device includes only one heating element. In some embodiments, the device includes multiple heating elements.

[0357] Suitable materials for forming at least one resistive heating element include, but are not limited to, semiconductors such as doped ceramics, electrically "conductive" ceramics (e.g., molybdenum disilicide), carbon, graphite, metals, metal alloys, and composite materials made from ceramic materials and metallic materials. Such composite materials may include doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel-containing alloys, cobalt-containing alloys, chromium-containing alloys, aluminum-containing alloys, titanium-containing alloys, zirconium-containing alloys, hafnium-containing alloys, niobium-containing alloys, molybdenum-containing alloys, tantalum-containing alloys, tungsten-containing alloys, tin-containing alloys, gallium-containing alloys, manganese-containing alloys, and iron-containing alloys, and superalloys based on nickel, iron, and cobalt, stainless steel, and iron-manganese-aluminum based alloys.

[0358] In some embodiments, at least one resistive heating element comprises one or more stamped portions of a resistive material such as stainless steel. Alternatively, at least one resistive heating element may comprise a heating wire or filament, such as Ni-Cr (nickel-chromium), platinum, tungsten or alloy wire.

[0359] In some embodiments, the at least one heating element comprises an electrically insulating substrate, wherein the at least one resistive heating element is disposed on the electrically insulating substrate.

[0360] The electrically insulating substrate may include any suitable material. For example, the electrically insulating substrate may include one or more of paper, glass, ceramic, anodized metal, coated metal, and polyimide. The ceramic may include mica, aluminum oxide (Al2O3), or zirconium oxide (ZrO2). Preferably, the electrically insulating substrate has a thermal conductivity of less than or equal to about 40 W / m·Kelvin, preferably less than or equal to about 20 W / m·Kelvin, and ideally less than or equal to about 2 W / m·Kelvin.

[0361] The heater may comprise a heating element comprising a rigid electrically insulating substrate having one or more conductive tracks or wires disposed on its surface. The size and shape of the electrically insulating substrate may allow it to be inserted directly into the aerosol generating substrate. If the electrically insulating substrate is not rigid enough, the heating element may comprise additional reinforcement means. An electric current may be passed through the one or more conductive tracks to heat the heating element and the aerosol generating substrate.

[0362] In some embodiments, the heater comprises an induction heating device. The induction heating device may include an inductor coil and a power supply configured to provide a high-frequency oscillating current to the inductor coil. As used herein, a high-frequency oscillating current means an oscillating current having a frequency between about 500kHz and about 30MHz. Advantageously, the heater may include a DC / AC inverter for converting a DC current supplied by a DC power supply into an alternating current. The inductor coil may be arranged to generate a high-frequency oscillating electromagnetic field when receiving a high-frequency oscillating current from a power supply. The inductor coil may be arranged to generate a high-frequency oscillating electromagnetic field in a device cavity. In some embodiments, the inductor coil may substantially define the device cavity. The inductor coil may extend at least partially along the length of the device cavity.

[0363] The heater may comprise an inductive heating element. The inductive heating element may be a susceptor element. The susceptor element may be arranged such that when the aerosol generating article is received in the cavity of the aerosol generating device, the oscillating electromagnetic field generated by the inductor coil induces a current in the susceptor element, thereby causing the susceptor element to heat up. In these embodiments, the aerosol generating device is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (H field strength) of between 1 kiloamperes per meter and 5 kiloamperes per meter (kA m), preferably between 2 kA / m and 3 kA / m, for example about 2.5 kA / m. Preferably, the electrically operated aerosol generating device is capable of generating a fluctuating electromagnetic field having a frequency of between 1 MHz and 30 MHz, for example between 1 MHz and 10 MHz, for example between 5 MHz and 7 MHz.

[0364] In these embodiments, the susceptor element is preferably positioned to contact the aerosol generating substrate. In some embodiments, the susceptor element is located in the aerosol generating device. In these embodiments, the susceptor element may be located in a cavity. The aerosol generating device may include only one susceptor element. The aerosol generating device may include a plurality of susceptor elements. In some embodiments, the susceptor element is preferably arranged to heat the outer surface of the aerosol generating substrate.

[0365] As described above with respect to susceptor elements incorporated into aerosol-generating strips, the susceptor element may comprise any suitable material.

[0366] In some embodiments, the aerosol generating device may comprise at least one resistive heating element and at least one inductive heating element. In some embodiments, the aerosol generating device may comprise a combination of resistive heating elements and inductive heating elements.

[0367] During use, the heater can be controlled to operate within a limited operating temperature range below the maximum operating temperature. An operating temperature range between about 150 degrees Celsius and about 300 degrees Celsius in the heating chamber (or device cavity) is preferred. The operating temperature range of the heater may be between about 150 degrees Celsius and about 250 degrees Celsius.

[0368] The aerosol generating device may include a power source. The power source may be a DC power source. In some embodiments, the power source is a battery. The power source may be a nickel metal hydride battery, a nickel cadmium battery, or a lithium-based battery, such as a lithium cobalt battery, a lithium iron phosphate battery, or a lithium polymer battery. However, in some embodiments, the power source may be another form of charge storage device, such as a capacitor. The power source may need to be recharged and may have a capacity that allows storage of enough energy for one or more user operations (e.g., one or more aerosol generating experiences).

[0369] A non-exhaustive list of non-limiting examples is provided below.Any one or more features of these examples may be combined with any one or more features of another example, embodiment or aspect described herein.

[0370] EX1. An aerosol generating article, comprising: an aerosol generating strip for generating an inhalable aerosol when heated, the aerosol generating strip comprising: a first aerosol generating segment, the first aerosol generating segment comprising a first aerosol generating matrix, and a second aerosol generating segment, the second aerosol generating segment being located upstream of the first aerosol generating segment and comprising a second aerosol generating matrix.

[0371] EX2. An aerosol-generating article according to example EX1, wherein the first aerosol-generating substrate comprises an aerosol former, and wherein the aerosol former content of the first aerosol-generating substrate does not exceed 30 wt% on a dry weight basis.

[0372] EX3. An aerosol-generating article according to example EX1 or EX2, wherein the second aerosol-generating substrate comprises an aerosol former, and wherein the aerosol former content of the second aerosol-generating substrate is at least 40 wt% on a dry weight basis.

[0373] EX4. An aerosol-generating article according to example EX3, wherein the second aerosol-generating substrate comprises at least 50 wt.% glycerol.

[0374] EX5. An aerosol-generating article according to any one of examples EX2 to EX4, wherein the aerosol-forming agent content of the second aerosol-generating substrate is at least 15% higher than the aerosol-forming agent content of the first aerosol-generating substrate.

[0375] EX6. An aerosol-generating article according to any one of examples EX2 to EX5, wherein the aerosol-forming agent content of the second aerosol-generating substrate is at least 1.2 times the aerosol-forming agent content of the first aerosol-generating substrate.

[0376] EX7. An aerosol-generating article according to any one of examples EX2 to EX6, wherein the aerosol-forming agent content of the first aerosol-generating substrate is between 5 wt% and 30 wt% on a dry weight basis.

[0377] EX8. An aerosol-generating article according to any one of examples EX2 to EX7, wherein the aerosol-forming agent content of the second aerosol-generating substrate is between 40 wt% and 80 wt% on a dry weight basis.

[0378] EX9. An aerosol-generating article according to any preceding example, wherein the second aerosol-generating substrate has a higher aerosol-forming agent content than the first aerosol-generating substrate.

[0379] EX10. An aerosol-generating article according to any preceding example, wherein the second aerosol-generating substrate has a higher density than the first aerosol-generating substrate.

[0380] EX11. An aerosol-generating article according to example EX10, wherein the density of the second aerosol-generating substrate is at least 100 mg / cm3 higher than the density of the first aerosol-generating substrate.

[0381] EX12. An aerosol-generating article according to any one of examples EX9 to EX11, wherein the first aerosol-generating substrate has a density of less than 400 mg / cm3.

[0382] EX13. An aerosol-generating article according to example EX12, wherein the first aerosol-generating substrate has a density between 100 mg / cm3 and 400 mg / cm3.

[0383] EX14. An aerosol-generating article according to any one of examples EX9 to EX13, wherein the second aerosol-generating substrate has a density of at least 500 mg / cm3.

[0384] EX15. An aerosol-generating article according to example EX14, wherein the second aerosol-generating substrate has a density between 500 mg / cm3 and 1000 mg / cm3.

[0385] EX16. An aerosol-generating article according to any one of examples EX9 to EX15, wherein the density of the second aerosol-generating substrate is at least 1.2 times the density of the first aerosol-generating substrate.

[0386] EX17. An aerosol-generating article according to any preceding example, wherein the first aerosol-generating substrate comprises shredded tobacco material.

[0387] EX18. An aerosol-generating article according to example EX17, wherein the first aerosol-generating substrate comprises tobacco cut filler.

[0388] EX19. An aerosol-generating article according to example EX17, wherein the first aerosol-generating substrate comprises a sheet of shredded homogenised tobacco material.

[0389] EX20. An aerosol-generating article according to example EX19, wherein the second aerosol-generating substrate comprises an aerosol-generating film.

[0390] EX21. An aerosol-generating article according to example EX20, wherein the aerosol-generating film comprises a cellulose film-forming agent, nicotine, and an aerosol-forming agent.

[0391] EX22. An aerosol-generating article according to example EX21, wherein the aerosol-generating film further comprises a cellulose-based reinforcing agent.

[0392] EX23. An aerosol-generating article according to example EX21 or EX22, wherein the aerosol-generating film further comprises carboxymethyl cellulose.

[0393] EX24. An aerosol-generating article according to any one of examples EX20 to EX23, wherein the aerosol-generating film further comprises an acid.

[0394] EX25. An aerosol-generating article according to any one of examples EX20 to EX24, wherein the aerosol-generating film is substantially free of tobacco.

[0395] EX26. An aerosol-generating article according to any one of examples EX1 to EX19, wherein the second aerosol-generating substrate comprises a gel composition comprising nicotine, at least one gelling agent and the aerosol-forming agent.

[0396] EX27. An aerosol generating segment according to any of the preceding examples, wherein a ratio of a length of the first aerosol generating segment to a length of the second aerosol generating segment is between 0.3 and 0.6.

[0397] EX28. An aerosol-generating article according to any of the preceding examples, wherein the length of the second aerosol-generating segment is at least 4 mm greater than the length of the first aerosol-generating article.

[0398] EX29. An aerosol-generating article according to any preceding example, wherein the first aerosol-generating substrate is defined by a first packaging, and wherein the second aerosol-generating substrate is defined by a second packaging separate from the first packaging.

[0399] EX30. An aerosol-generating article according to any preceding example, wherein the aerosol-generating strip further comprises a third aerosol-generating segment, the third aerosol-generating segment being disposed upstream of the second aerosol-generating segment and comprising a third aerosol-generating substrate.

[0400] EX31. An aerosol-generating article according to example EX30, wherein the third aerosol-generating substrate comprises shredded tobacco material.

[0401] EX32. An aerosol-generating article according to example EX30 or EX31, wherein the third aerosol-generating substrate comprises at least one aerosol former, and wherein the aerosol former content of the third aerosol-generating substrate is no more than 30 wt % on a dry weight basis.

[0402] EX33. An aerosol-generating article according to any preceding example, further comprising a downstream section disposed downstream of the aerosol-generating strip.

[0403] EX34. An aerosol-generating article according to example EX33, wherein the downstream section extends to a downstream end of the aerosol-generating article.

[0404] EX35. An aerosol-generating article according to example EX33 or EX34, wherein the downstream section comprises a hollow tubular cooling element.

[0405] EX36. An aerosol-generating article according to example EX35, wherein the hollow tubular cooling element has a length of at least 20 mm.

[0406] EX37. An aerosol-generating article according to example EX35 or EX36, wherein the downstream section comprises a ventilation zone located at a position along the hollow tubular cooling element.

[0407] EX38. An aerosol-generating article according to any one of Examples EX33 to EX37, wherein the downstream section comprises a downstream filter segment.

[0408] EX39. An aerosol-generating article according to example EX38, wherein the downstream filter segment is a solid rod.

[0409] EX40. An aerosol-generating article according to example EX38 or EX39, wherein the downstream filter segment has a length of at least 5 mm.

[0410] EX41. An aerosol-generating article according to any one of examples EX35 to EX40, wherein the downstream section further comprises a hollow tubular support element located upstream of the hollow tubular cooling element.

[0411] EX42. An aerosol-generating article according to any one of examples EX35 to EX41, wherein the downstream section further comprises a downstream hollow tubular element located downstream of the hollow tubular cooling element.

[0412] EX43. An aerosol-generating article according to any preceding example, further comprising an upstream element located upstream of the aerosol-generating strip.

[0413] EX44. An aerosol-generating article according to any preceding example, wherein the aerosol-generating article has a ventilation level of at least 40%.

[0414] EX45. An aerosol-generating article according to any preceding example, wherein the length of the aerosol-generating article is between 40 mm and 50 mm.

[0415] EX46. An aerosol-generating article according to any one of examples EX1 to EX44, wherein the length of the aerosol-generating article is between 70 mm and 80 mm.

[0416] EX47: The aerosol-generating article according to any preceding example, wherein the second aerosol-generating substrate has a higher aerosol-forming agent content than the first aerosol-generating substrate, and wherein the second aerosol-generating substrate has a higher density than the first aerosol-generating substrate.

[0417] EX48: An aerosol-generating article according to any preceding example, wherein the second aerosol-generating substrate has a higher aerosol-forming agent content than the first aerosol-generating substrate, and wherein the first aerosol-generating substrate has a density of less than 400 mg / cm3.

[0418] EX49: An aerosol-generating article according to any of the preceding examples, wherein the first aerosol-generating substrate comprises at least one aerosol former, and wherein the aerosol former content of the first aerosol-generating substrate is no more than 30 wt %, and wherein the aerosol former content of the second aerosol-generating substrate is at least 40 wt % on a dry weight basis.

[0419] EX50: An aerosol generating system, comprising an aerosol generating article and an aerosol generating device according to any of the preceding examples, the aerosol generating device comprising a heating chamber for receiving the aerosol generating article and at least a heating element arranged at or around the periphery of the heating chamber.

[0420] A non-exhaustive list of non-limiting clauses is provided below.Any one or more features of these clauses may be combined with any one or more features of another example, embodiment or aspect described herein.

[0421] Item 1: An aerosol generating article, comprising: an aerosol generating strip, the aerosol generating strip being used to generate an inhalable aerosol when heated, the aerosol generating strip comprising: a first aerosol generating segment, the first aerosol generating segment comprising a first aerosol generating substrate, wherein the first aerosol generating substrate comprises at least one aerosol former, and wherein the aerosol former content of the first aerosol generating substrate is not more than 30 weight% on a dry weight basis; and a second aerosol generating segment, the second aerosol generating segment being located upstream of the first aerosol generating segment and comprising a second aerosol generating substrate, wherein the second aerosol generating substrate comprises at least one aerosol former, and wherein the aerosol former content of the second aerosol generating substrate is at least 40 weight% on a dry weight basis.

[0422] Clause 2: An aerosol-generating article according to clause 1, wherein the second aerosol-generating substrate comprises an aerosol-generating film comprising a cellulose-based film-forming agent, nicotine and glycerine, wherein the aerosol-generating film has a glycerine content of at least 40% by weight.

[0423] Clause 3. An aerosol-generating article according to Clause 2, wherein the aerosol-generating film is substantially free of tobacco.

[0424] Clause 4: An aerosol-generating article according to any preceding clause, wherein the first aerosol-generating substrate comprises tobacco cut filler.

[0425] Clause 5: An aerosol-generating article according to any preceding clause, wherein the second aerosol-generating segment is adjacent to an upstream end of the first aerosol-generating segment.

[0426] Clause 6: An aerosol-generating article according to any preceding clause, wherein the second aerosol-generating substrate comprises at least 50 wt% glycerol on a dry weight basis.

[0427] Clause 7: An aerosol-generating article according to any preceding clause, wherein the first aerosol-generating substrate is defined by a first wrapper, and wherein the second aerosol-generating substrate is defined by a second wrapper separate from the first wrapper.

[0428] Clause 8: An aerosol-generating article according to any preceding clause, wherein the aerosol-forming agent content of the second aerosol-generating substrate is at least 25% higher than the aerosol-forming agent content of the first aerosol-generating substrate, on a dry weight basis.

[0429] Clause 9: An aerosol-generating article according to any preceding clause, wherein the aerosol-forming agent content of the second aerosol-generating substrate is at least 1.5 times the aerosol-forming agent content of the first aerosol-generating substrate on a dry weight basis.

[0430] Clause 10: An aerosol-generating article according to any preceding clause, wherein the ratio of the length of the first aerosol-generating segment to the length of the second aerosol-generating segment does not exceed 0.6.

[0431] Clause 11: An aerosol-generating article according to any preceding clause, wherein the bulk density of the first aerosol-generating substrate is less than 400 mg / cm3 and the bulk density of the second aerosol-generating substrate is greater than 500 mg / cm3.

[0432] Clause 12: An aerosol-generating article according to any preceding clause, further comprising an upstream element disposed upstream of the aerosol-generating strip and adjacent an upstream end of the second aerosol-generating segment.

[0433] Clause 13: An aerosol-generating article according to any preceding clause, further comprising a downstream section disposed downstream of the aerosol-generating strip and extending to a downstream end of the aerosol-generating article, wherein the downstream section comprises a hollow tubular cooling element.

[0434] Clause 14: An aerosol-generating article according to any preceding clause, wherein the aerosol-generating article has a ventilation level of at least 40%.

[0435] Clause 15: An aerosol generating system, comprising an aerosol generating article according to any one of clauses 1 to 14 and an aerosol generating device, the aerosol generating device comprising a heating chamber for receiving the aerosol generating article and at least a heating element arranged at or around the periphery of the heating chamber.

[0436] In the following, the present invention will be further described with reference to the figures of the accompanying drawings, in which:

[0437] Figure 1 shows a schematic side perspective view of an aerosol-generating article according to a first embodiment of the invention;

[0438] Figure 2 Shows Figure 1 A schematic side cross-sectional view of an aerosol-generating article;

[0439] Figure 3 Shown include Figure 1 and Figure 2 a schematic side cross-sectional view of an aerosol-generating article and an aerosol-generating system of an aerosol-generating device as shown;

[0440] Figure 4 shows a schematic side cross-sectional view of an aerosol-generating article according to a second embodiment of the invention; and

[0441] Figure 5 A schematic side cross-sectional view of an aerosol-generating article according to a third embodiment of the invention is shown.

[0442] Figure 1 The aerosol-generating article 10 shown in FIG. 1 comprises an aerosol-generating strip 12 and a downstream section 14 at a location downstream of the strip 12. Thus, the aerosol-generating article 10 extends from an upstream end or distal end 16 substantially coinciding with the upstream end of the strip 12 to a downstream end or mouth end 18 coinciding with the downstream end of the downstream section 14. The downstream section 14 comprises a hollow tubular cooling element 20 and a downstream filter segment 50.

[0443] The aerosol-generating article 10 has an overall length of approximately 45 mm and an outer diameter of approximately 7.2 mm.

[0444] The aerosol-generating strip 12 comprises a first aerosol-generating segment 24 and a second aerosol-generating segment 26 coaxially aligned with each other. The second aerosol-generating article 26 is disposed upstream of the first aerosol-generating segment 24 adjacent its upstream end.

[0445] The first aerosol generating segment 24 has a length of 5 mm and comprises a first aerosol generating substrate formed of about 50 mg of shredded tobacco material, the first aerosol generating substrate comprising between 15% and 20% by weight of glycerol. The density of the first aerosol generating substrate is about 300 mg / cm3. The first aerosol generating segment 24 is individually wrapped by a stick wrapper (not shown).

[0446] The second aerosol-generating segment 26 has a length of 12 mm and comprises a second aerosol-generating substrate formed from fragments of an aerosol-generating film. Exemplary ingredients of the aerosol-generating film are shown in Table 1 below:

[0447] Table 1: Aerosol-generating film compositions

[0448]

[0449] As indicated above, the second aerosol-generating substrate has a glycerol content of about 50 wt. %, thus being more than 10 % higher than the glycerol content of the first aerosol-generating substrate. The density of the aerosol-generating substrate is above 600 mg / cm3. The first aerosol-generating segment 24 is individually wrapped by a stick wrapper (not shown).

[0450] The hollow tubular cooling element 20 of the downstream section 14 is located immediately downstream of the aerosol generating strip 12, the hollow tubular cooling element 20 being longitudinally aligned with the strip 12. The upstream end of the hollow tubular cooling element 20 abuts the downstream end of the strip 12.

[0451] The hollow tubular cooling element 20 defines a hollow section of the aerosol-generating article 10. The hollow tubular cooling element 20 does not substantially affect the overall RTD of the aerosol-generating article. In more detail, the RTD of the hollow tubular cooling element 20 is about 0 mmH2O.

[0452] like Figure 2 As shown in FIG, the hollow tubular cooling element 20 is provided in the form of a hollow cylindrical tube made of paperboard. The hollow tubular cooling element 20 defines an inner cavity 22 extending from the upstream end of the hollow tubular cooling element 20 to the downstream end of the hollow tubular cooling element 20. The inner cavity 22 is substantially empty, and thus substantially unrestricted airflow is achieved along the inner cavity 22.

[0453] The hollow tubular cooling element 20 has a length of about 21 mm, an outer diameter of about 7.2 mm, and an inner diameter of about 6.7 mm. Therefore, the peripheral wall thickness of the hollow tubular cooling element 20 is about 0.25 mm.

[0454] The aerosol-generating article 10 includes ventilation zones 30 disposed at locations along the hollow tubular cooling element 20. The ventilation zones 30 include a row of circumferential openings or perforations that define the hollow tubular cooling element 20. The perforations of the ventilation zones 30 extend through the wall of the hollow tubular cooling element 20 so as to allow fluid to enter the interior cavity 22 from the exterior of the article 10. The ventilation level of the aerosol-generating article 10 is about 40%.

[0455] The downstream filter segment 50 extends from the downstream end of the hollow tubular cooling element 20 to the downstream or mouth end of the aerosol generating article 10. The downstream filter segment 50 has a length of about 7 mm. The outer diameter of the downstream filter segment 50 is about 7.2 mm. The downstream filter segment 50 includes a low density cellulose acetate filter segment. The RTD of the downstream filter segment 50 is about 8 mmH2O. The downstream filter segment 50 can be wrapped separately by a stick wrapper (not shown).

[0456] like Figure 1 and Figure 2 As shown, the article 10 includes an upstream wrapper 44 that defines the aerosol-generating strip 12 and the hollow tubular cooling element 20. The ventilation zone 30 may also include a row of circumferential perforations disposed on the upstream wrapper 44. The perforations of the upstream wrapper 44 overlap the perforations disposed on the hollow tubular cooling element 20. Thus, the upstream wrapper 44 overlies the perforations of the ventilation zone 30 disposed on the hollow tubular cooling element 20.

[0457] The article 10 further includes a tipping wrapper 52 defining the hollow tubular cooling element 20 and the mouthpiece element 50. The tipping wrapper 52 overlies the portion of the upstream wrapper 44 overlying the hollow tubular cooling element 20. In this way, the tipping wrapper 52 effectively joins the mouthpiece element 50 to the remaining components of the article 10. The tipping wrapper 52 has a width of about 26 millimeters. Additionally, the ventilation zone 30 may include a row of circumferential perforations disposed on the tipping wrapper 52. The perforations of the tipping wrapper 52 overlap the perforations disposed on the hollow tubular cooling element 20 and the upstream wrapper 44. Thus, the tipping wrapper 52 overlies the perforations of the ventilation zone 30 disposed on the hollow tubular cooling element 20 and the upstream wrapper 44.

[0458] Figure 3 An aerosol generating system 100 is shown, which includes an exemplary aerosol generating device 1 and a Figure 1 and 2 A comparable aerosol-generating article 10 is shown in . Figure 3A downstream mouth end portion of an aerosol generating device 1 is shown, in which a device cavity is defined and in which an aerosol generating article 10 can be received. The aerosol generating device 1 includes a housing (or body) 4 extending between a mouth end 2 and a distal end (not shown). The housing 4 includes a peripheral wall 6. The peripheral wall 6 defines a device cavity for receiving an aerosol generating article 10. The device cavity is defined by a closed distal end and an open mouth end. The mouth end of the device cavity is located at the mouth end of the aerosol generating device 1. The aerosol generating article 10 is configured to be received by the mouth end of the device cavity and is configured to be adjacent to the closed end of the device cavity.

[0459] The device airflow channel 5 is defined within the peripheral wall 6. The airflow channel 5 extends between an inlet 7 located at the mouth end of the aerosol generating device 1 and a closed end of the device cavity. Air can enter the aerosol generating substrate 12 via an orifice (not shown) provided at the closed end of the device cavity to ensure fluid communication between the airflow channel 5 and the aerosol generating substrate 12.

[0460] The aerosol generating device 1 further comprises a heater (not shown) and a power source (not shown) for supplying power to the heater. A controller (not shown) is also provided to control such power supply to the heater. The heater is configured to controllably heat the aerosol generating article 10 during use when the aerosol generating article 1 is received in the device 1. The heater is preferably arranged to externally heat the aerosol generating substrate 12 to achieve optimal aerosol generation. The ventilation zone 30 is arranged to be exposed when the aerosol generating article 10 is received in the aerosol generating device 1.

[0461] exist Figure 3 In the embodiment shown in , the length of the device cavity defined by the peripheral wall 6 is 28 mm. When the article 10 is received in the device cavity, the aerosol generating strip 12 and the upstream portion of the hollow tubular cooling element 20 are received in the device cavity. The length of this upstream portion of the hollow tubular cooling element 20 is 11 mm. Therefore, about 28 mm of the article 10 is received in the device 1, and about 17 mm of the article 10 is located outside the device 1. In other words, when the article 10 is received in the device, the article 10 protrudes from the device 1 by about 17 mm. This length of the article 10 protruding from the device 1 is about 11 mm. Figure 3 Shown in.

[0462] Figure 4 An alternative embodiment of the present invention is shown. Figure 4 The aerosol generating article 110 shown has Figure 1 The aerosol-generating articles 10 shown are of similar construction and differ only in the following respects.

[0463] The aerosol-generating strip 112 includes a first aerosol-generating segment 124, a second aerosol-generating segment 126, and a third aerosol-generating segment 128 that are coaxially aligned with each other. The second aerosol-generating segment 126 is disposed upstream of the first aerosol-generating segment 124, adjacent to the upstream end of the first aerosol-generating segment 124. The third aerosol-generating segment 128 is disposed upstream of the second aerosol-generating segment 126, adjacent to the upstream end of the second aerosol-generating segment 126. The third aerosol-generating segment 128 extends to the upstream end of the aerosol-generating article 110.

[0464] The first aerosol generating section 124 is similar to the above description of Figure 1 The third aerosol-generating segment 128 is substantially the same as the first aerosol-generating segment 24 described with reference to the aerosol-generating article 10 of claim 11 . The third aerosol-generating segment 128 is substantially the same as the first aerosol-generating segment 124 , having the same length and composition.

[0465] The second aerosol generating section 126 is similar to the above description of Figure 1 The second aerosol generating segment 26 described for the aerosol generating article 10 of FIG. 1 is substantially the same as the second aerosol generating segment 26 described for the aerosol generating article 10 of FIG. Figure 1 The aerosol-generating article 10 of WO 2014 / 036888 differs only in that a third aerosol-generating segment 128 is included at the upstream end of the aerosol-generating strip 112 .

[0466] Figure 5 Another alternative embodiment of the present invention is shown. Figure 5 The illustrated aerosol-generating article 210 comprises an aerosol-generating rod 212 and a downstream section 214 located at a position downstream from the aerosol-generating rod 212 .

[0467] The aerosol-generating article 210 has an overall length of approximately 80 mm and an outer diameter of approximately 6.5 mm.

[0468] The aerosol-generating strip 212 comprises a first aerosol-generating segment 224 and a second aerosol-generating segment 226 coaxially aligned with each other. The second aerosol-generating article 226 is disposed upstream of the first aerosol-generating segment 224 adjacent to an upstream end thereof.

[0469] The first aerosol generating segment 224 has a length of about 15 mm and includes a first aerosol generating substrate formed of shredded tobacco material, the first aerosol generating substrate comprising about 15% by weight glycerol. The bulk density of the first aerosol generating substrate is about 250 mg / cm3. The first aerosol generating segment 224 is individually wrapped by a stick wrapper (not shown).

[0470] The second aerosol generating segment 226 has a length of about 25 mm and includes a second aerosol generating substrate formed of homogenized tobacco material, the second aerosol generating substrate comprising tobacco particles and more than 40% by weight of glycerol on a dry weight basis. The bulk density of the second aerosol generating substrate is about 600 mg / cm3. The second aerosol generating segment 226 is individually wrapped by a stick wrapper (not shown).

[0471] The downstream section 214 includes a hollow tubular cooling element 220 , a downstream filter segment 250 , and a downstream hollow tubular element 260 .

[0472] The hollow tubular cooling element 220 is located immediately downstream of the aerosol-generating strip 212, with the hollow tubular cooling element 220 longitudinally aligned with the strip 212. The upstream end of the hollow tubular cooling element 220 abuts the downstream end of the strip 212 of aerosol-generating substrate.

[0473] The hollow tubular element 220 has the same Figure 1 The hollow tubular cooling element 20 is depicted to be of similar form but having a longer length of approximately 25 mm.

[0474] As mentioned above about Figure 1 As described, the aerosol-generating article 210 includes a ventilation zone 230 disposed at a location along the hollow tubular cooling element 220. The ventilation zone 230 includes a row of circumferential openings or perforations that define the hollow tubular cooling element 220. The perforations of the ventilation zone 230 extend through the wall of the hollow tubular element 220 so as to allow fluid to enter the inner cavity from the outside of the article 210. The ventilation level of the aerosol-generating article 210 is about 70%.

[0475] The downstream filter segment 250 comprises a cylindrical rod of cellulose acetate tow. The length of the downstream filter segment 250 is approximately 10 mm.

[0476] The downstream hollow tubular element 260 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The downstream hollow tubular element 260 defines an inner cavity extending from the upstream end of the downstream hollow tubular cooling element 220 to the downstream end of the downstream hollow tubular element 260. The inner cavity is substantially empty and thus substantially unrestricted airflow is achieved along the inner cavity. The downstream hollow tubular element 260 does not substantially affect the overall RTD of the aerosol generating article 10. The length of the downstream hollow tubular element 260 is approximately 6 mm. The wall thickness of the downstream hollow tubular element 260 is approximately 1 mm.

[0477] For the purpose of this specification and the appended claims, unless otherwise stated, all numbers representing amounts, quantities, percentages, etc. should be understood to be modified by the term "about" in all cases. Moreover, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein that may be specifically listed or may not be listed herein. Therefore, in this article, the number A is understood to be ± 10% of A. In this article, the number A may be considered to be included in the numerical value within the general standard error of the measurement of the property modified by the number A. In some cases used in the appended claims, the number A may deviate from the percentages listed above, provided that the amount of A deviation will not substantially affect the basic features and novel features of the invention claimed for protection. Moreover, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein that may be specifically listed or may not be listed herein.

Claims

1. An aerosol-generating article, comprising: An aerosol-generating rod for generating an inhalable aerosol upon heating, the aerosol-generating rod comprising: a first aerosol-generating segment comprising a first aerosol-generating substrate; and a second aerosol-generating segment at a location upstream of the first aerosol-generating segment and comprising a second aerosol-generating substrate, wherein the second aerosol-generating substrate has a higher aerosol-forming agent content than the first aerosol-generating substrate, and Wherein the second aerosol-generating substrate has a higher density than the first aerosol-generating substrate.

2. An aerosol-generating article according to claim 1, wherein the second aerosol-generating substrate comprises an aerosol-generating film, the aerosol-generating film comprising a cellulose-based film-forming agent, nicotine and glycerin, wherein the aerosol-generating film has a glycerin content of at least 40% by weight.

3. An aerosol-generating article according to claim 2, wherein the aerosol-generating film is substantially free of tobacco.

4. An aerosol-generating article according to any preceding claim, wherein the first aerosol-generating substrate comprises tobacco cut filler.

5. An aerosol-generating article according to any preceding claim, wherein the second aerosol-generating segment is adjacent to an upstream end of the first aerosol-generating segment.

6. An aerosol-generating article according to any preceding claim, wherein the second aerosol-generating substrate comprises at least 50 wt% glycerol on a dry weight basis.

7. An aerosol-generating article according to any preceding claim, wherein the first aerosol-generating substrate is defined by a first wrapper, and wherein the second aerosol-generating substrate is defined by a second wrapper separate from the first wrapper.

8. An aerosol-generating article according to any preceding claim, wherein the second aerosol-generating substrate has an aerosol-former content that is at least 25% higher than the aerosol-former content of the first aerosol-generating substrate on a dry weight basis.

9. An aerosol-generating article according to any preceding claim, wherein the aerosol-forming agent content of the second aerosol-generating substrate is at least 1.5 times the aerosol-forming agent content of the first aerosol-generating substrate on a dry weight basis.

10. An aerosol-generating article according to any preceding claim, wherein the ratio of the length of the first aerosol-generating segment to the length of the second aerosol-generating segment does not exceed 0.

6.

11. An aerosol-generating article according to any preceding claim, wherein the bulk density of the first aerosol-generating substrate is less than 400 mg / cm3 and the bulk density of the second aerosol-generating substrate is greater than 500 mg / cm3.

12. An aerosol-generating article according to any preceding claim, further comprising an upstream element disposed upstream of the aerosol-generating strip and adjacent an upstream end of the second aerosol-generating segment.

13. An aerosol-generating article according to any preceding claim, further comprising a downstream section disposed downstream of the aerosol-generating strip and extending to a downstream end of the aerosol-generating article, wherein the downstream section comprises a hollow tubular cooling element.

14. An aerosol-generating article according to any preceding claim, wherein the aerosol-generating article has a ventilation level of at least 40%.

15. An aerosol generating system, comprising: An aerosol-generating article according to any one of claims 1 to 14; as well as An aerosol-generating device comprises a heating chamber for receiving the aerosol-generating article and at least a heating element arranged at or around a periphery of the heating chamber.

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