Aerosol generating article having two or more substrate segments

Abstract

The aerosol-generating articles (10)(110)(210) comprise aerosol-generating rods (12)(112)(212) for generating an inhalable aerosol upon heating, and the aerosol-generating rods (12)(112)(212) comprise first aerosol-generating segments (24)(124)(224) including a first aerosol-generating substrate, and second aerosol-generating segments (26)(126)(226) which are located upstream of the first aerosol-generating segments (24)(124)(224) and include 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

Technical Field

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

Background Art

[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, an aerosol is generated by transferring heat from a heat source to a physically separated aerosol-generating substrate or material, which may be in contact with the heat source, within the heat source, around the heat source, or downstream of the heat source. During use of the aerosol-generating article, volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source and entrained in the air drawn through the aerosol-generating article. The released compounds condense as they are cooled to form an aerosol.

[0003] Numerous 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 heat transfer from one or more electrical heater elements of the aerosol-generating device to the aerosol-generating substrate of the heated aerosol-generating article. For example, an electrically heated aerosol-generating device has been proposed that comprises an internal heater blade adapted to be inserted into the aerosol-generating substrate. The use of aerosol-generating articles in combination with external heating systems is also known. For example, WO 2020 / 115151 describes the provision of one or more heating elements arranged around the perimeter of an aerosol-generating article when the aerosol-generating article is received within a cavity of the aerosol-generating device. Alternatively, an inductively heatable aerosol-generating article comprising an aerosol-generating substrate and a susceptor disposed within the aerosol-generating substrate has been proposed by WO 2015 / 176898.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Aerosol generating articles in which the tobacco-containing substrate is heated rather than burned present numerous problems not seen in conventional smoking articles.

[0005] First, the tobacco-containing substrate is typically heated to a significantly lower temperature compared to the temperature reached by the burning front of conventional tobacco. This can affect nicotine release from the tobacco-containing substrate and nicotine delivery to the consumer. At the same time, if the heating temperature increases in an attempt to enhance nicotine delivery, the aerosol produced typically needs to be cooled more extensively and rapidly before reaching the consumer.

[0006] Second, heating the aerosol-generating substrate to the temperature required for aerosol formation takes a certain amount of time, so aerosol delivery to the consumer may be delayed after heating is initiated. When the user first inhales on the article, the aerosol reaching the user may have a relatively low flavor or nicotine content, or both, often referred to as the "cold puff" effect or the "empty puff" effect.

[0007] It would be desirable to provide a novel aerosol generating article having an arrangement that provides improved consistency in aerosol delivery during heating. It would be even more desirable to provide an aerosol generating article that offers greater control over the smoking profile and, in particular, has the ability to provide a satisfactory aerosol delivery to the consumer within a relatively short time after the start of heating. Further, it would be desirable to provide such aerosol generating articles that can be manufactured at high speed using existing devices and methods without significant modification.

Brief Description of the Drawings

[0008]

Figure 1

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Mode for Carrying Out the Invention

[0009] The present disclosure relates to an aerosol generating article. The aerosol generating article may include an aerosol generating rod for generating an inhalable aerosol upon heating. The aerosol generating rod may include a first aerosol generating segment including a first aerosol generating substrate. The aerosol generating rod may include a 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 former 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 contain at least one aerosol former, and the aerosol former content of the first aerosol generating substrate is less than 30 weight percent on a dry weight basis. The second aerosol generating substrate may contain at least one aerosol former, and the aerosol former content of the second aerosol generating substrate is at least about 40 weight percent on a dry weight basis.

[0010] According to the present invention, there is provided an aerosol generating article comprising a first aerosol generating segment including a first aerosol generating substrate and a second aerosol generating segment including a second aerosol generating substrate.

[0011] In a preferred embodiment, there is provided an aerosol generating article comprising a first aerosol generating segment including a first aerosol generating substrate and a second aerosol generating segment including a second aerosol generating substrate and located upstream of the first aerosol generating segment, the second aerosol generating substrate having a higher aerosol former content than the first aerosol generating substrate and the second aerosol generating substrate having a higher density than the first aerosol generating substrate.

[0012] According to a preferred embodiment, there is provided 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 including a first aerosol generating substrate, the first aerosol generating substrate including at least one aerosol former and the aerosol former content of the first aerosol generating substrate being less than 30 weight percent on a dry weight basis, and a second aerosol generating segment including a second aerosol generating substrate and located upstream of the first aerosol generating segment, the second aerosol generating substrate including at least one aerosol former and the aerosol former content of the second aerosol generating substrate being at least 40 weight percent on a dry weight basis.

[0013] According to a preferred embodiment, there is provided 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 including a first aerosol generating substrate, the first aerosol generating substrate including at least one aerosol former, the aerosol former content of the first aerosol generating substrate being less than 30 weight percent on a dry weight basis, a first aerosol generating segment, and a second aerosol generating segment located upstream of the first aerosol generating segment and including a second aerosol generating substrate, the second aerosol generating substrate including at least one aerosol former, the aerosol former content of the second aerosol generating substrate being at least 40 weight percent on a dry weight basis, and the density of the second aerosol generating substrate being at least 1.2 times that of the first aerosol generating substrate.

[0014] According to a preferred embodiment, there is provided 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 including a first aerosol generating substrate, the first aerosol generating substrate including at least one aerosol former, the aerosol former content of the first aerosol generating substrate being less than 30 weight percent, the first aerosol generating substrate having a density of less than 400 mg per cubic centimeter, a first aerosol generating segment, and a second aerosol generating segment located upstream of the first aerosol generating segment and including a second aerosol generating substrate, the second aerosol generating substrate including at least one aerosol former, the aerosol former content of the second aerosol generating substrate being at least 40 weight percent on a dry weight basis, and the density of the second aerosol generating substrate being greater than 500 mg per cubic centimeter.

[0015] According to a preferred embodiment, there is provided 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 including a first aerosol generating substrate, the first aerosol generating substrate including at least one aerosol former, the aerosol former content of the first aerosol generating substrate being less than 30% by weight, a second aerosol generating segment located upstream of the first aerosol generating segment and including a second aerosol generating substrate, the second aerosol generating substrate including at least one aerosol former, the aerosol former content of the second aerosol generating substrate being at least 40% by weight on a dry weight basis, and the ratio of the length of the first aerosol generating segment to the length of the second aerosol generating segment being 0.5 or less.

[0016] As used herein, the term "aerosol generating article" refers to an article that heats an aerosol generating substrate to generate an inhalable aerosol and delivers it to a consumer. As used herein, the term "aerosol generating substrate" means a substrate having the ability to release a volatile compound upon heating to generate an aerosol.

[0017] As used herein, the term "aerosol generating device" refers to a device comprising a heating element that interacts with the aerosol generating substrate of an aerosol generating article to generate an aerosol.

[0018] As used herein in connection with the present invention, the term "rod" is generally used to denote an elongated element, preferably a cylindrical element having a substantially circular, oval or elliptical cross-section. In the articles of the present invention, the aerosol generating rod is formed of two or more aerosol generating segments, which are discrete elements formed from aerosol generating substrates having different compositions. The aerosol generating segments are coaxially combined to form the aerosol generating rod.

[0019] As used herein, the term "longitudinal direction" refers to the direction corresponding to the major longitudinal axis of the aerosol-generating article, which 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 a portion of an element) of the aerosol-generating article with respect to the direction in which the aerosol is conveyed through the aerosol-generating article during use.

[0020] During use, air is drawn longitudinally through the aerosol-generating article. The term "transverse direction" refers to the direction perpendicular to the longitudinal axis. Any reference to a "cross-section" of the aerosol-generating article or a component of the aerosol-generating article refers to a transverse cross-section, unless otherwise specified.

[0021] The term "length" means the dimension of a component of the aerosol-generating article in the longitudinal direction. For example, it may be used to mean the dimension of a rod or an elongated tubular element in the longitudinal direction.

[0022] Unless otherwise specified, the aerosol-forming agent content in the first aerosol-generating substrate is in weight percent units 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.

[0023] Unless otherwise specified, the aerosol-forming agent content in the second aerosol-generating substrate is in weight percent units 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.

[0024] The present invention relates to an aerosol generating article having an aerosol generating rod with two separate segments of an aerosol generating substrate having mutually different aerosol former contents. In particular, the first and second aerosol generating substrates are adapted such that the second aerosol generating substrate provided in the second upstream aerosol generating segment has a higher aerosol former content than the first aerosol generating substrate provided in the first downstream aerosol generating segment. The first and second aerosol generating substrates may be adapted such that the second aerosol generating substrate provided in the second upstream aerosol generating segment has a significantly higher aerosol former content than the first aerosol generating substrate provided in the first downstream aerosol generating segment.

[0025] For example, provision of such an arrangement having an upstream segment of an aerosol generating substrate having a relatively high aerosol former content (above 40 weight percent) and a downstream segment of an aerosol generating substrate having a relatively low aerosol former content (below 30 weight percent) provides an improvement in the delivery of aerosol with heating of the aerosol generating rod. The first aerosol generating substrate having a lower level of aerosol former is heated more quickly due to its lower thermal inertia and begins to generate a measurable amount of aerosol within a relatively short time. Thus, the time to first puff can be minimized and the aerosol can be delivered to the consumer relatively quickly after the start of heating. The first aerosol generating substrate releases a higher level of aerosol than the second aerosol generating substrate during the preceding puff of the puff profile but will deplete relatively quickly due to the lower level of aerosol former.

[0026] The second aerosol generating substrate having a significantly high level of aerosol former takes a longer time after the start of heating to begin releasing a measurable amount of aerosol, but continues to release aerosol after the release of aerosol from the first aerosol generating substrate has ended. Thus, the second aerosol generating substrate releases a higher level of aerosol than the first aerosol generating substrate during smoking after the smoking profile. Thus, in combination, the first aerosol generating segment and the second aerosol generating segment can provide a highly consistent and more sustained aerosol delivery over time. It is also possible to extend the total time period during which the aerosol is delivered to provide the consumer with a longer overall experience.

[0027] When aerosol is generated from the first aerosol generating substrate, the remaining depleted first aerosol generating segment typically has a relatively low weight and density. This advantageously means that the first aerosol generating segment provides a minimal level of filtration of the aerosol generated from the second upstream aerosol generating segment during later smoking. This enables the delivery of aerosol to the consumer to be maintained throughout the experience.

[0028] The use of two separate aerosol generating segments within the aerosol generating rod can also be used to more precisely control the delivery of active compounds such as nicotine and flavor to the consumer over the course of the experience, since the compositions of the two aerosol generating substrates can be adapted to be different from each other. The combination of two different aerosol generating substrates can also enable the generation of a more complex aerosol having a potentially novel combination of active compounds.

[0029] The beneficial effects provided by the use of two separate aerosol generating segments can be achieved while still using a single heater element to heat both segments, such that the device for heating the aerosol generating article need not be adapted.

[0030] The use of the dual aerosol generating segments within the aerosol generating rod does not necessarily affect the overall structure of the aerosol generating article. Thus, an aerosol generating rod with a dual plug of homogenized tobacco material can advantageously be incorporated into existing high-speed production lines without the need for significant modification of the apparatus or technology.

[0031] As defined above, an aerosol generating article according to the present invention comprises an aerosol generating rod. Further, an aerosol generating article according to the present invention typically comprises one or more elements provided downstream of the aerosol generating rod. When present, the one or more elements downstream of the aerosol generating rod form a downstream section of the aerosol generating article. An aerosol generating article according to the present invention may comprise one or more elements provided upstream of the aerosol generating substrate. When present, the one or more elements upstream of the aerosol generating rod form an upstream section of the aerosol generating article.

[0032] The aerosol generating rod comprises a first aerosol generating segment and a second aerosol generating segment. As will be described below, this may additionally include one or more further aerosol generating segments. The second aerosol generating segment is provided at a position upstream of the first aerosol generating segment. The second aerosol generating segment is preferably adjacent to the first aerosol generating segment. The downstream end of the second aerosol generating segment preferably abuts the upstream end of the first aerosol generating segment. Preferably, substantially the entire surface of the downstream end of the second aerosol generating segment abuts 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 will be described in more detail below, one or more additional elements may be provided upstream of the second aerosol generating segment.

[0033] The first and second aerosol generating substrates forming the first and second aerosol generating segments 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 former than the first aerosol generating substrate. The level of aerosol former is important for controlling the amount of aerosol that can be generated from the aerosol generating substrate and the rate at which the aerosol is generated upon heating. Upon volatilization, the aerosol former transports other vaporized compounds such as nicotine and flavorants in the aerosol that are released from the aerosol generating substrate upon heating.

[0034] Aerosol formers suitable for inclusion in the first and second aerosol generating substrates are known in the art and include, but are not limited to, polyhydric alcohols (such as triethylene glycol, propylene glycol, 1,3 - butanediol and glycerol), esters of polyhydric alcohols (glycerol mono-, di- or triacetate), and aliphatic esters of mono-, di- or polycarboxylic acids (such as dimethyl dodecanedioate and dimethyl tetradecanedioate).

[0035] The first and second aerosol generating substrates may contain the same aerosol former (or aerosol formers) as each other, or different aerosol formers may be used.

[0036] The first aerosol generating substrate preferably has an aerosol former content of about 30 weight percent or less on a dry weight basis. More preferably, the first aerosol generating substrate has an aerosol former content of 25 weight percent or less on a dry weight basis. Even more preferably, the first aerosol generating substrate has an aerosol former content of 20 weight percent or less on a dry weight basis.

[0037] Preferably, the first aerosol generating substrate has an aerosol forming agent content of at least 5% by weight on a dry weight basis. More preferably, the first aerosol generating substrate has an aerosol forming agent content of at least 10% by weight on a dry weight basis. Even more preferably, the first aerosol generating substrate has an aerosol forming agent content of at least 15% by weight on a dry weight basis.

[0038] For example, the aerosol forming agent content of the first aerosol generating substrate may be from 5% to 30% by weight, or from 10% to 25% by weight, or from about 15% to about 20% by weight on a dry weight basis. Thus, the content of the aerosol forming agent in the first aerosol generating substrate is relatively low.

[0039] The first aerosol generating substrate preferably contains glycerol as the aerosol forming agent. For example, the first aerosol generating substrate may contain from 5% to 30% by weight of glycerol, or from 10% to 25% by weight of glycerol, or from 15% to 20% by weight of glycerol on a dry weight basis.

[0040] The second aerosol generating substrate preferably has a higher content of the aerosol forming agent than the first aerosol generating substrate. Preferably, the second aerosol generating substrate has an aerosol forming agent content of at least 40% by weight on a dry weight basis. More preferably, the second aerosol generating substrate has an aerosol forming agent content of at least 45% by weight on a dry weight basis. Even more preferably, the second aerosol generating substrate has an aerosol forming agent content of at least 50% by weight on a dry weight basis.

[0041] Preferably, the aerosol former in the second aerosol generating substrate has a content of 80% by weight or less on a dry weight basis. More preferably, the aerosol former in the second aerosol generating substrate has a content of 75% by weight or less on a dry weight basis. Even more preferably, the aerosol former in the second aerosol generating substrate has a content of 70% by weight or less on a dry weight basis.

[0042] For example, the content of the aerosol former in the second aerosol generating substrate may be 40% to 80% by weight, or 45% to 75% by weight, or 50% to 70% by weight on a dry weight basis. Therefore, the content of the aerosol former in the second aerosol generating substrate is relatively high.

[0043] The second aerosol generating substrate preferably contains glycerol as the aerosol former. For example, the second aerosol generating substrate may contain 40% to 80% by weight, or 45% to 75% by weight, or 50% to 70% by weight, or 15% to 20% by weight of glycerol on a dry weight basis.

[0044] The content of the aerosol former in the second aerosol generating substrate is preferably at least 15 weight percent higher than the content of the aerosol former in the first aerosol generating substrate on a dry weight basis. For example, the first aerosol generating substrate preferably has a content of 15 weight percent of the aerosol former, and the second aerosol generating substrate preferably has a content of at least 30 weight percent of the aerosol former. More preferably, the content of the aerosol former in the second aerosol generating substrate is at least 20 weight percent higher than the content of the aerosol former in the first aerosol generating substrate on a dry weight basis. Even more preferably, the content of the aerosol former in the second aerosol generating substrate is at least 25 weight percent higher than the content of the aerosol former in the first aerosol generating substrate on a dry weight basis. The content of the aerosol former in the second aerosol generating substrate may be up to 60 weight percent higher than the content of the aerosol former in the first aerosol generating substrate.

[0045] The content of the aerosol former in the second aerosol generating substrate is preferably at least 1.2 times higher than the content of the aerosol former in the first aerosol generating substrate on a dry weight basis. More preferably, the content of the aerosol former in the second aerosol generating substrate is at least 1.5 times higher than the content of the aerosol former in the first aerosol generating substrate on a dry weight basis. Even more preferably, the content of the aerosol former in the second aerosol generating substrate is at least 2 times higher than the content of the aerosol former in the first aerosol generating substrate on a dry weight basis. The content of the aerosol former in the second aerosol generating substrate may be up to 4 times higher than the content of the aerosol former in the first aerosol generating substrate.

[0046] The glycerol content of the second aerosol - generating substrate is preferably at least 5 weight percent higher, or at least 10 weight percent higher, or at least 15 weight percent higher than the glycerol content of the first aerosol - generating substrate on a dry - weight basis. More preferably, the glycerol content of the second aerosol - generating substrate is at least 20 weight percent higher than the glycerol content of the first aerosol - generating substrate on a dry - weight basis. Even more preferably, the glycerol content of the second aerosol - generating substrate is at least 25 weight percent higher than the glycerol content of the first aerosol - generating substrate on a dry - weight basis. The glycerol content of the second aerosol - generating substrate may be up to 60 weight percent higher than the glycerol content of the first aerosol - generating substrate.

[0047] Preferably, the glycerol content of the second aerosol - generating substrate is at least 1.2 times higher than the glycerol content of the first aerosol - generating substrate on a dry - weight basis. More preferably, the glycerol content of the second aerosol - generating substrate is at least 1.5 times higher than the glycerol content of the first aerosol - generating substrate on a dry - weight basis. Even more preferably, the glycerol content of the second aerosol - generating substrate is at least 2 times higher than the glycerol content of the aerosol - forming body of the first aerosol - generating substrate on a dry - weight basis. The glycerol content of the second aerosol - generating substrate may be up to 3 times or 4 times higher than the glycerol content of the first aerosol - generating substrate.

[0048] Typically, the first and second aerosol - generating substrates also differ from each other in other aspects of composition, morphology, or physical properties. For example, the second aerosol - generating substrate preferably has a higher density than the first aerosol - generating substrate.

[0049] As used herein in connection with an aerosol generating substrate, the term "density" 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 this by the volume of the segments of the aerosol generating substrate (excluding the wrapper).

[0050] Providing a different density between a first aerosol generating substrate and a second aerosol generating substrate can further optimize the rate and consistency of aerosol generation and enhance the beneficial effects provided by different aerosol former contents, as described above.

[0051] Preferably, the density of the second aerosol generating substrate is at least 25 mg / cubic centimeter higher than the density of the first aerosol generating substrate, or at least 50 mg / cubic centimeter higher than the density of the first aerosol generating substrate, or at least 75 mg / cubic centimeter higher than the density of the first aerosol generating substrate, or at least 100 mg / cubic centimeter 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 / cubic centimeter higher than the density of the first aerosol generating substrate. Even more preferably, the density of the second aerosol generating substrate is at least 200 mg / cubic centimeter higher than the density of the first aerosol generating substrate. The density of the second aerosol generating substrate may be up to 500 mg / cubic centimeter higher than the density of the first aerosol generating substrate.

[0052] The density of the second aerosol generation substrate is preferably at least 1.05 times, or at least 1.1 times, or at least 1.2 times the density of the first aerosol generation substrate. The density of the second aerosol generation substrate is more preferably at least 1.3 times, or at least 1.4 times, or at least 1.5 times the density of the first aerosol generation substrate. The density of the second aerosol generation substrate is even more preferably at least 2 times the density of the first aerosol generation substrate. The density of the second aerosol generation substrate may be at most 4 times the density of the first aerosol generation substrate.

[0053] In a preferred embodiment of the present invention, the density of the second aerosol generation substrate is at least 1.2 times the density of the first aerosol generation substrate, and the content of the aerosol former in the second aerosol generation substrate is at least 2 times the content of the aerosol former in the first aerosol generation substrate.

[0054] Preferably, the first aerosol generation substrate has a density of at least 100 mg / cubic centimeter. More preferably, the first aerosol generation substrate has a density of at least 125 mg / cubic centimeter. More preferably, the first aerosol generation substrate has a density of at least 150 mg / cubic centimeter. Even more preferably, the first aerosol generation substrate has a density of at least 200 mg / cubic centimeter.

[0055] More preferably, the first aerosol generation substrate has a density of less than 400 mg / cubic centimeter. More preferably, the first aerosol generation substrate has a density of less than 375 mg / cubic centimeter. More preferably, the first aerosol generation substrate has a density of less than 350 mg / cubic centimeter. More preferably, the first aerosol generation substrate has a density of less than 300 mg / cubic centimeter.

[0056] For example, the first aerosol generation substrate may have a density of 100 milligrams per cubic centimeter to 400 milligrams per cubic centimeter, or 125 milligrams per cubic centimeter to 375 milligrams per cubic centimeter, or 150 milligrams per cubic centimeter to 350 milligrams per cubic centimeter, or 200 milligrams per cubic centimeter to 300 milligrams per cubic centimeter.

[0057] Therefore, the first aerosol generation substrate preferably has a relatively low density. This, in combination with a relatively low aerosol former content, further reduces the thermal inertia of the first aerosol generation substrate, and as a result, the first aerosol generation substrate can be rapidly heated to the temperature required for aerosol generation. The low density of the first aerosol generation substrate further minimizes the filtering effect of the first aerosol generation substrate on the aerosol generated from the upstream aerosol generation substrate segment.

[0058] Preferably, the density of the second aerosol generation substrate is at least 500 mg per cubic centimeter. More preferably, the density of the second aerosol generation substrate is at least 525 mg per cubic centimeter. More preferably, the density of the second aerosol generation substrate is at least 550 mg per cubic centimeter. Even more preferably, the density of the second aerosol generation substrate is at least 600 mg per cubic centimeter.

[0059] Preferably, the density of the second aerosol generation substrate is less than 1000 mg per cubic centimeter. More preferably, the density of the second aerosol generation substrate is less than 900 mg per cubic centimeter. More preferably, the density of the second aerosol generation substrate is less than 800 mg per cubic centimeter. Even more preferably, the density of the second aerosol generation substrate is less than 750 mg per cubic centimeter.

[0060] For example, the second aerosol generation substrate may have a density of 500 milligrams per cubic centimeter to 1000 milligrams per cubic centimeter, or 525 milligrams per cubic centimeter to 900 milligrams per cubic centimeter, or 550 milligrams per cubic centimeter to 880 milligrams per cubic centimeter, or 600 milligrams per cubic centimeter to 750 milligrams per cubic centimeter.

[0061] Therefore, it is preferable that the second aerosol generation substrate has a relatively high density. In combination with a relatively high aerosol former content, this further increases the thermal inertia of the second aerosol generation substrate, so that the second aerosol generation substrate takes significantly longer to reach the temperature required for aerosol generation, and thus can deliver aerosol during subsequent smoking. The high density also makes it possible to provide a relatively large amount of aerosol former and active compounds per volume of the aerosol generation substrate so that aerosol delivery can be increased in both concentration and duration.

[0062] The first aerosol generation substrate and the second aerosol generation substrate may be formed of 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, homogenized tobacco materials such as tobacco cut filler, cast leaf, aerosol generating films, and gel compositions. The first aerosol generation substrate and the second aerosol generation substrate are preferably of different types of materials from each other.

[0063] The first aerosol generation substrate preferably contains a tobacco material. In a particularly preferred embodiment, the first aerosol generation substrate contains shredded tobacco material. For example, the shredded tobacco material may be in the form of cut filler, as will be described in more detail below. Alternatively, the shredded tobacco material may be in the form of a cut sheet of homogenized tobacco material. Suitable homogenized tobacco materials for use in the present invention are described below.

[0064] In the context of this specification, the term "cut filler" is used to describe a blend of finely cut plant material, such as tobacco plant material, which specifically includes one or more of the leaf blade, processed stems and veins, and homogenized plant material.

[0065] Cut filler may also include other cut materials, filler tobacco, or a wrapper.

[0066] Preferably, the cut filler comprises at least 25 percent plant leaf lamina, more preferably at least 50 percent plant leaf lamina, even more preferably at least 75 percent plant leaf lamina, and most preferably at least 90 percent plant leaf lamina. Preferably, the plant material is one of tobacco, mint, tea, and clove. Most preferably, the plant material is tobacco. However, it is preferred that the present invention is equally applicable to other plant materials that have the ability to release substances that can form an aerosol upon heating.

[0067] The cut filler preferably comprises tobacco plant material, including the leaf blade of one or more of bright tobacco, dark tobacco, aromatic tobacco, and filler tobacco. For the purposes of the present invention, the term "tobacco" describes any plant of the Nicotiana genus.

[0068] The cut filler suitable for use in the present invention may generally be similar to the cut filler used in conventional smoking articles. The cut width of the cut filler is preferably from 0.3 millimeters to 2.0 millimeters, or from 0.5 millimeters to 1.2 millimeters, or from 0.6 millimeters to 0.9 millimeters.

[0069] Preferably, the strands have a length of from about 10 millimeters to about 40 millimeters, and the strands are then arranged to form an aerosol generating rod.

[0070] In a preferred embodiment, the weight of the cut filler is from 25 milligrams to 150 milligrams, preferably from 30 milligrams to 125 milligrams, more preferably from 40 milligrams to 100 milligrams. This amount of cut filler can typically be sufficient material for aerosol formation during early smoking.

[0071] The cut filler is preferably immersed in the aerosol former. The immersion of the cut filler can be carried out by spraying or other suitable application methods. The aerosol former can be added to the blend during the preparation of the cut filler. For example, the aerosol former may be applied directly to the blend in a direct conditioning casing cylinder (DCCC). Conventional machinery can be used to add the aerosol former to the cut filler. Suitable aerosol formers are presented above.

[0072] The aerosol former within the cut filler preferably comprises one or more of glycerol and propylene glycol. The aerosol former may consist of glycerol, or propylene glycol, or a combination of glycerol and propylene glycol.

[0073] In another preferred embodiment, the first aerosol generating substrate comprises homogenized plant material, preferably homogenized tobacco material.

[0074] As used herein, the term "homogenized plant material" encompasses any plant material formed by the aggregation of plant particles. For example, a sheet or web of homogenized tobacco material for the aerosol generating substrate of the present invention can be formed by aggregating tobacco material particles obtained by grinding, pulverizing, or subdividing plant material and optionally one or more of tobacco leaf lamina and tobacco leaf stem. The homogenized plant material may be produced by casting, extrusion, a papermaking process, or any other suitable process known in the art.

[0075] The homogenized plant material can be provided in any suitable form.

[0076] In some embodiments, the homogenized plant material may be in the form of one or more sheets. As used herein in the context of the present invention, the term "sheet" describes a thin, layer-like element having a width and length that are considerably larger than its thickness.

[0077] The homogenized plant material may be in the form of a plurality of pellets or granules.

[0078] The homogenized plant material may be in the form of a plurality of strands, flakes, or pieces. As used herein, the term "strand" describes an elongated element of material having a length that is substantially larger than its width and thickness. The term "strand" should be considered to encompass any other homogenized plant material having the form of flakes, pieces, and the like. Strands of the homogenized plant material may be formed from a sheet of the homogenized plant material, for example, by cutting or shredding, or by other means, such as an extrusion process.

[0079] As described above, when the homogenized plant material is in the form of one or more sheets, the sheets may be manufactured by a casting process. Alternatively, the sheets of the homogenized plant material may be manufactured by a papermaking process.

[0080] Each of one or more sheets as described herein may individually have a thickness of from 100 micrometers to 600 micrometers, preferably from 150 micrometers to 300 micrometers, and most preferably from 200 micrometers to 250 micrometers. The individual thickness refers to the thickness of an individual sheet, and the combined thickness refers to the total thickness of all the sheets that make up the aerosol-generating substrate.

[0081] One or more sheets described herein may each individually have a basis weight of from 100 grams per square meter to 600 grams per square meter.

[0082] One or more sheets as described herein may each individually have a density of from 0.3 grams per cubic centimeter to 1.3 grams per cubic centimeter, preferably from 0.7 grams per cubic centimeter to 1.0 grams per cubic centimeter.

[0083] One or more sheets described herein may be subjected to one or more of curling, folding, gathering, and pleating.

[0084] One or more sheets of homogenized plant material may be cut into strands as mentioned above. In such embodiments, the aerosol-generating substrate comprises a plurality of strands of homogenized plant material. The strands may be used to form plugs. Typically, the width of such strands is about 5 millimeters, or about 4 millimeters, or about 3 millimeters, or about 2 millimeters, or less. The length of the strands may be longer than about 5 millimeters, may be from about 5 millimeters to about 15 millimeters, may be from about 8 millimeters to about 12 millimeters, or may be about 12 millimeters. The strands preferably have substantially the same length as each other.

[0085] Homogenized plant material may contain, on a dry weight basis, from 2.5 weight percent to 95 weight percent plant particles, or from 5 weight percent to 90 weight percent plant particles, or from 10 weight percent to 80 weight percent plant particles, or from 15 weight percent to 70 weight percent plant particles, or from 20 weight percent to 60 weight percent plant particles, or from 30 weight percent to 50 weight percent plant particles.

[0086] In certain embodiments of the present invention, the homogenized plant material is a homogenized tobacco material containing tobacco particles. The sheet of homogenized tobacco material used in such embodiments of the present invention may have a tobacco content of at least about 40 weight percent, more preferably at least about 50 weight percent, more preferably at least about 70 weight percent, and most preferably at least about 90 weight percent on a dry weight basis.

[0087] For the purposes of the present invention, the term "tobacco particle" refers to particles of any plant member of the Nicotiana species. The term "tobacco particle" includes ground or powdered tobacco leaf lamina, ground or powdered tobacco leaf stems, tobacco dust, tobacco fines, and other particulate tobacco by-products formed during the processing, handling, and shipping of tobacco. In preferred embodiments, the tobacco particles are substantially all derived from tobacco leaf lamina. In contrast, isolated nicotine and nicotine salts, while being compounds derived from tobacco, are not considered tobacco particles for the purposes of the present invention and are not included in the proportion of particulate plant material.

[0088] The second aerosol-generating substrate may contain nicotine. As used herein in connection with the present invention, the term "nicotine" is used to describe nicotine, nicotine base, or nicotine salts. In embodiments where the second aerosol-generating substrate contains nicotine base or nicotine salts, the amounts of nicotine recited herein are the amounts of free-base nicotine or protonated nicotine, respectively.

[0089] The second aerosol generating substrate preferably contains at least 0.5 weight percent nicotine on a dry weight basis. The second aerosol generating substrate more preferably contains at least 1 weight percent nicotine on a dry weight basis. The second aerosol generating substrate even more preferably contains at least 2 weight percent nicotine on a dry weight basis. Additionally, or alternatively, the second aerosol generating substrate preferably contains less than 10 weight percent nicotine on a dry weight basis. The second aerosol generating substrate more preferably contains less than 8 weight percent nicotine on a dry weight basis. The second aerosol generating substrate more preferably contains less than 6 weight percent nicotine on a dry weight basis.

[0090] For example, the second aerosol generating substrate may contain from 0.5 weight percent to 10 weight percent nicotine, or from 1 weight percent to 8 weight percent nicotine, or from 2 weight percent to 6 weight percent nicotine on a dry weight basis.

[0091] The second aerosol generating substrate may not substantially contain tobacco.

[0092] As described above, the second aerosol generating substrate may be in the form of a cut filler or a homogenized tobacco material.

[0093] The second aerosol generating substrate is preferably in the form of an aerosol generating film containing a cellulose-based film former, nicotine, and an aerosol former. The aerosol generating film may further contain a cellulose-based strengthening agent. The aerosol generating film preferably contains 30 weight percent or less water.

[0094] As used herein, the term "film" is used to describe a solid, layered element having a thickness that is less than its width or length. The film may be self-supporting. In other words, the film may have cohesive and mechanical properties such that it can be separated from the support surface even if it is obtained by casting a film-forming formulation on the support surface. Alternatively, the film may be disposed on a support or sandwiched between other materials. This can enhance the mechanical stability of the film.

[0095] The content of the aerosol former in the aerosol-generating film is within the range defined above for the second aerosol-generating substrate.

[0096] In the context of the present invention, the term "cellulosic film-forming agent" is used to describe a cellulose polymer that has the ability to form a continuous film, either by itself or in the presence of an auxiliary thickener.

[0097] The cellulosic film-forming agent is preferably selected from the group consisting of hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), hydroxyethyl methylcellulose (HEMC), hydroxyethylcellulose (HEC), hydroxypropylcellulose (HPC), and combinations thereof.

[0098] More preferably, the cellulosic film-forming agent is selected from the group consisting of hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), and combinations thereof.

[0099] In a particularly preferred embodiment, the cellulosic film-forming agent is HPMC.

[0100] The aerosol generating film may have a cellulose-based film-forming agent content of 10% to 40% by dry weight, or 15% to 35% by dry weight, or 20% to 30% by dry weight.

[0101] The aerosol generating film preferably further contains a cellulose-based strengthening agent. The cellulose-based strengthening agent is preferably selected from the group consisting of cellulose fibers, microcrystalline cellulose (MCC), and cellulose powder, and combinations thereof.

[0102] The aerosol generating film may have a cellulose-based strengthening agent content of 0.5% to 40% by dry weight, or 5% to 30% by dry weight, or 10% to 25% by dry weight.

[0103] The aerosol generating film may further contain carboxymethyl cellulose, preferably sodium carboxymethyl cellulose.

[0104] The aerosol generating film may have a carboxymethyl cellulose content of 1% to 15% by dry weight, or 2% to 12% by dry weight, or 4% to 10% by dry weight.

[0105] The aerosol generating film preferably contains nicotine.

[0106] In embodiments where the aerosol generating film contains nicotine base or nicotine salt, the amounts of nicotine listed herein are the amounts of free base nicotine or protonated nicotine, respectively.

[0107] The aerosol generating film may contain natural nicotine or synthetic nicotine.

[0108] The aerosol generating film may contain one or more monobasic nicotine salts.

[0109] As used herein in connection with the present invention, the term "monobasic nicotine salt" is used to describe a nicotine salt of a monobasic acid.

[0110] Preferably, the aerosol generating film contains at least 0.5 weight percent nicotine on a dry weight basis. More preferably, the aerosol generating film contains at least 1 weight percent nicotine on a dry weight basis. Even more preferably, the aerosol generating film contains at least 2 weight percent nicotine on a dry weight basis. Additionally, or alternatively, preferably the aerosol generating film contains less than 10 weight percent nicotine on a dry weight basis. More preferably, the aerosol generating film contains less than 8 weight percent nicotine on a dry weight basis. Even more preferably, the aerosol generating film contains less than 6 weight percent nicotine on a dry weight basis.

[0111] For example, the aerosol generating film may contain 0.5 weight percent to 10 weight percent nicotine, or 1 weight percent to about 8 weight percent nicotine, or about 2 weight percent to about 6 weight percent nicotine on a dry weight basis.

[0112] The aerosol generating film may be an aerosol generating film that is substantially tobacco-free.

[0113] In a preferred embodiment, the aerosol generating film contains an acid. More preferably, the aerosol generating film contains one or more organic acids. Even more preferably, the aerosol generating film contains one or more carboxylic acids. In a particularly preferred embodiment, the acid is lactic acid, benzoic acid, fumaric acid, or levulinic acid.

[0114] The aerosol generating film preferably contains 0.25 to 3.5 weight percent of an acid, or 0.5 to 3 weight percent of an acid, or about 1 to 2.5 weight percent of an acid on a dry weight basis.

[0115] In a preferred embodiment, the aerosol generating film has a thickness of about 0.1 millimeter to about 1 millimeter, more preferably about 0.1 millimeter to about 0.75 millimeter, still more preferably about 0.1 millimeter to about 0.5 millimeter. In a particularly preferred embodiment, a layer of the film-forming composition having a thickness of about 50 micrometers to 400 micrometers, more preferably about 100 micrometers to 200 micrometers is formed.

[0116] The aerosol generating film may optionally be provided within a second aerosol generating segment on a suitable carrier element.

[0117] In an alternative embodiment of the present invention, the second aerosol generating substrate may comprise a gel composition containing nicotine, at least one gelling agent and an aerosol former. The gel composition preferably does not substantially contain tobacco.

[0118] The preferred weight range of nicotine in the gel composition is the same as that defined above in relation to the aerosol generating film.

[0119] The gel composition preferably contains at least 50 weight percent of an aerosol former, more preferably at least 60 weight percent, still more preferably at least 70 weight percent of an aerosol former on a dry weight basis. The gel composition may contain up to 80 weight percent of an aerosol former. The aerosol former in the gel composition preferably contains glycerol.

[0120] The gel composition preferably contains at least one gelling agent. Preferably, the gel composition contains the total amount of the gelling agent in the range of from about 0.4 weight percent to about 10 weight percent, or from about 0.5 weight percent to about 8 weight percent, or from about 1 weight percent to about 6 weight percent, or from about 2 weight percent to about 4 weight percent, or from about 2 weight percent to about 3 weight percent.

[0121] The term "gelling agent" refers to a compound that, when added in an amount of about 0.3 weight percent to a homogeneous mixture of 50 weight percent water / 50 weight percent glycerol, forms a solid medium or support matrix leading to a gel. Examples of gelling agents include, but are not limited to, hydrogen bond cross-linked gelling agents and ion cross-linked gelling agents.

[0122] The term "hydrogen bond cross-linked gelling agent" refers to a gelling agent that forms non-covalent cross-links or physical cross-links via hydrogen bonds.

[0123] The hydrogen bond cross-linked gelling agent may include one or more of galactomannan, gelatin, agarose, konjac gum, or agar. In some cases, it is preferable for the hydrogen bond cross-linked gelling agent to include agar.

[0124] The term "ion cross-linked gelling agent" refers to a gelling agent that forms non-covalent cross-links or physical cross-links via ionic bonds.

[0125] The ion cross-linked gelling agent may include low acyl gellan, pectin, kappa carrageenan, iota carrageenan, or alginate. It is preferably for the ion cross-linked gelling agent to include low acyl gellan.

[0126] The gelling agent may include one or more biopolymers. The biopolymer may be formed of a polysaccharide.

[0127] Examples of biopolymers include, for example, gellan gum (natural gellan gum, low acyl gellan gum, high acyl gellan gum, low acyl gellan gum is preferred), xanthan gum, alginate (algic acid), agar, guar gum, and the like. The composition may preferably contain xanthan gum. The composition may contain two biopolymers. The composition may contain three biopolymers. The composition may contain two biopolymers in substantially equal weights. The composition may contain three biopolymers in substantially equal weights.

[0128] The gel composition may further contain a thickening agent. The thickening agent combined with a hydrogen bond cross-linking gelling agent and an ionic cross-linking gelling agent surprisingly supports the solid medium and maintains the gel composition even when the gel composition contains a high level of glycerol.

[0129] The term "thickening agent" refers to a compound that increases the viscosity without causing gel formation and keeps the mixture in a fluid state when uniformly added in an amount of 0.3 weight percent in a mixture of 50 weight percent water / 50 weight percent glycerol at 25°C.

[0130] The gel composition preferably contains a thickening agent in the range of about 0.2 weight percent to about 5 weight percent, or about 0.5 weight percent to about 3 weight percent, or about 0.5 weight percent to about 2 weight percent, or about 1 weight percent to about 2 weight percent.

[0131] The thickening agent may include one or more of xanthan gum, carboxymethyl cellulose, microcrystalline cellulose, methyl cellulose, gum arabic, guar gum, lambda carrageenan, or starch. The thickening agent preferably may contain xanthan gum.

[0132] The gel composition may further contain a divalent cation. Preferably, the divalent cation includes calcium ions such as calcium lactate in the solution. Divalent cations (such as calcium ions) can assist in the gel formation of a composition containing a gelling agent such as an ionic cross-linking gelling agent. The ionic effect may assist in gel formation. The divalent cation may be present in the gel composition in the range of about 0.1 to about 1 weight percent, or about 0.5 weight percent.

[0133] The gel composition may further contain an acid. The acid may include a carboxylic acid. The carboxylic acid may contain a ketone group. Preferably, the carboxylic acid may contain a ketone 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, this carboxylic acid has three carbon atoms (such as lactic acid).

[0134] The gel composition preferably contains some water. When the composition contains some water, the gel composition is more stable.

[0135] The gel composition preferably contains from about 8 weight percent to about 32 weight percent water, or from about 15 weight percent to about 25 weight percent water, or from about 18 weight percent to about 22 weight percent water, or about 20 weight percent water.

[0136] Preferably, when the gel composition is used, the second aerosol generating substrate includes a porous medium filled with the gel composition. The advantage of the porous medium filled with the gel composition is that the gel composition is retained within the porous medium, which can assist in the manufacture, storage, or transportation of the gel composition. This can be useful in maintaining the desired shape of the gel composition, especially during manufacture, transportation, or use.

[0137] 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.

[0138] The porous medium may be any suitable porous material capable of holding or retaining the gel composition. Ideally, the porous medium should be able to allow the gel composition to move therein. In certain embodiments, the porous medium includes natural materials, synthetic, or semi-synthetic, or combinations thereof. In certain embodiments, the porous medium includes sheet materials, foams, or fibers, such as cotton fibers, or combinations thereof. In certain embodiments, the porous medium includes woven fabrics, non-woven fabrics, or extruded materials, or combinations thereof. The porous medium preferably includes cotton, paper, viscose, PLA, or cellulose acetate, or combinations thereof. The porous medium preferably includes a sheet material, such as cotton or cellulose acetate. In a particularly preferred embodiment, the porous medium includes a sheet made from cotton fibers.

[0139] The porous medium used in the present invention may be crimped or shredded.

[0140] The porous medium may be in the form of a sheet, thread, or tubular element.

[0141] 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 shorter than the length of the second aerosol generating segment. This can help to maximize the amount of aerosol that can be generated from the aerosol generating rod and the duration of aerosol release.

[0142] The ratio of the length of the first aerosol generating segment to the length of the second aerosol generating segment is preferably 1 or less. For example, the ratio of the length of the second aerosol generating segment to the length of the first aerosol generating segment may be 0.8 or less, 0.6 or less, or 0.5 or less.

[0143] The ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment is preferably at least 0.1. For example, the ratio of the length of the second aerosol generation segment to the length of the first aerosol generation segment may be at least 0.2, at least 0.3, or at least 0.4.

[0144] The ratio of the length of the second aerosol generation segment to the length of the first aerosol generation segment may be 0.1 to 1, 0.2 to 0.8, 0.3 to 0.6, or 0.4 to 0.5. The ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be about 0.4, or about 0.42.

[0145] In a preferred embodiment of the present invention, the density of the second aerosol generation substrate is at least 1.2 times the density of the first aerosol generation substrate, the aerosol former content of the second aerosol generation substrate is at least 2 times the aerosol former content of the first aerosol generation substrate on a dry weight basis, and the ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment is 0.5 or less.

[0146] The length of the second aerosol generation segment is preferably at least 2 millimeters greater than the length of the first aerosol generation segment. For example, the length of the second aerosol generation segment may be at least 4 millimeters greater than the length of the first aerosol generation segment, or at least 6 millimeters greater than the length of the first aerosol generation article.

[0147] The length of the second aerosol generation segment may be 15 millimeters or less than the length of the first aerosol generation segment. For example, the length of the second aerosol generation segment may be 12 millimeters or less than the length of the first aerosol generation segment, or 10 millimeters greater than the length of the first aerosol generation segment.

[0148] The length of the second aerosol generation segment may be 2 millimeters to 15 millimeters greater than the length of the first aerosol generation segment, or may be 4 millimeters to 12 millimeters greater than the length of the first aerosol generation segment, or may be 6 millimeters to 10 millimeters greater than the length of the first aerosol generation segment. The length of the second aerosol generation segment may be about 7 millimeters greater than the length of the first aerosol generation segment.

[0149] In certain preferred embodiments, the first aerosol generation segment may have a length of at least 2 millimeters, or at least 3 millimeters, or at least 4 millimeters. In those embodiments, the first aerosol generation segment may have a length of 8 millimeters or less, or 7 millimeters or less, or 6 millimeters or less. For example, the first aerosol generation segment may have a length of 2 millimeters to 8 millimeters, 3 millimeters to 7 millimeters, or 4 millimeters to 6 millimeters. The first aerosol generation segment may have a length of about 5 millimeters.

[0150] In certain preferred embodiments, the second aerosol generation segment may have a length of at least 8 millimeters, or at least 9 millimeters, or at least 10 millimeters. In those embodiments, the second aerosol generation segment may have a length of 16 millimeters or less, or 15 millimeters or less, or 14 millimeters or less. For example, the second aerosol generation segment may have a length of 8 millimeters to 16 millimeters, 9 millimeters to 15 millimeters, or 10 millimeters to 14 millimeters. The second aerosol generation segment may have a length of about 12 millimeters.

[0151] The combined length of the first aerosol generation segment and the second aerosol generation segment may be at least 10 millimeters. For example, the combined length of the first aerosol generation segment and the second aerosol generation segment may be at least 12 millimeters, at least 14 millimeters, or at least 16 millimeters.

[0152] The combined length of the first aerosol generation segment and the second aerosol generation segment may be 24 millimeters or less. For example, the combined length of the first aerosol generation segment and the second aerosol generation segment may be 22 millimeters or less, 20 millimeters or less, or 18 millimeters or less.

[0153] The combined length of the first aerosol generation segment and the second aerosol generation segment may be from 10 millimeters to 24 millimeters. For example, the combined length of the first aerosol generation segment and the second aerosol generation segment may be from 12 millimeters to 22 millimeters, from 14 millimeters to 20 millimeters, or from 16 millimeters to 18 millimeters.

[0154] The combined length of the first aerosol generation segment and the second aerosol generation segment may be about 17 millimeters.

[0155] In other preferred embodiments, the first aerosol generation segment may have a length of at least 10 millimeters, at least 15 millimeters, or at least 18 millimeters. In these embodiments, the first aerosol generation segment may have a length of 30 millimeters or less, or 25 millimeters or less, or 20 millimeters or less. For example, the first aerosol generation segment may have a length of from 10 millimeters to 30 millimeters, from 15 millimeters to 25 millimeters, or from 18 millimeters to 20 millimeters. The first aerosol generation segment may have a length of about 18.5 millimeters. The first aerosol generation segment may have a length of about 17 millimeters.

[0156] In other preferred embodiments, the second aerosol generation segment may have a length of at least 10 millimeters, at least 15 millimeters, or at least 18 millimeters. In these embodiments, the second aerosol generation segment may have a length of 30 millimeters or less, or 25 millimeters or less, or 20 millimeters or less. For example, the second aerosol generation segment may have a length of from 10 millimeters to 30 millimeters, from 15 millimeters to 25 millimeters, or from 18 millimeters to 20 millimeters. The second aerosol generation segment may have a length of about 18.5 millimeters. The second aerosol generation segment may have a length of about 17 millimeters.

[0157] The combined length of the first aerosol generation segment and the second aerosol generation segment may be at least 20 millimeters. For example, the combined length of the first aerosol generation segment and the second aerosol generation segment may be at least 25 millimeters, at least 30 millimeters, or at least 35 millimeters.

[0158] The combined length of the first aerosol generating segment and the second aerosol generating segment may be 55 millimeters or less. For example, the combined length of the first aerosol generating segment and the second aerosol generating segment may be 50 millimeters or less, 45 millimeters or less, or 40 millimeters or less.

[0159] The combined length of the first aerosol generating segment and the second aerosol generating segment may be from 20 millimeters to 55 millimeters. For example, the combined length of the first aerosol generating segment and the second aerosol generating segment may be from 25 millimeters to 50 millimeters, from 30 millimeters to 45 millimeters, or from 35 millimeters to 40 millimeters.

[0160] The combined length of the first aerosol generating segment and the second aerosol generating segment may be about 37 millimeters. The combined length of the first aerosol generating segment and the second aerosol generating segment may be about 34 millimeters.

[0161] The aerosol generating rod may be upstream of the second aerosol generating segment and further include a third aerosol generating segment including a third aerosol generating substrate. For example, the aerosol generating rod may include a third aerosol generating segment that abuts the upstream end of the second aerosol generating segment. Incorporating the third aerosol generating segment at the upstream end of the aerosol generating rod can further enhance the aerosol delivery from the aerosol generating article according to the present invention.

[0162] In some cases, when the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, the third aerosol-generating segment may be disposed only partially 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 is not directly heated by the heating element. However, the third aerosol-generating segment may be indirectly heated by conduction and can still generate a useful amount of aerosol. In this case, the third aerosol-generating substrate is typically heated relatively slowly compared to the first aerosol-generating substrate and the second aerosol-generating substrate, thereby providing additional aerosol for later smoking and potentially extending the duration over which aerosol can be delivered.

[0163] Since the third aerosol-generating substrate can be heated by indirect conduction, it is preferred that a relatively low content of aerosol former, or a relatively low density, or both are provided. For example, the third aerosol-generating substrate preferably has a content and density of aerosol former within the ranges defined above for the first aerosol-generating substrate. The teachings described above in connection with the first aerosol-generating substrate also apply in connection with the third aerosol-generating substrate.

[0164] The third aerosol-generating segment can have any length. The third aerosol-generating segment may have a length of at least 2 millimeters, at least 3 millimeters, or at least 4 millimeters. The third aerosol-generating segment can have a length of 8 millimeters or less, 7 millimeters or less, or 6 millimeters or less.

[0165] For example, the third aerosol generation segment may have a length of 2 millimeters to 8 millimeters, 3 millimeters to 7 millimeters, or 4 millimeters to 6 millimeters. The third aerosol generation segment may have a length of 1 millimeter to 6 millimeters, 2 millimeters to 5 millimeters, or 3 millimeters to 4 millimeters. The third aerosol generation segment may have a length of about 5 millimeters. The third aerosol generation segment may have a length of about 3.5 millimeters.

[0166] The combined length of the first aerosol generation segment, the second aerosol generation segment, and the third aerosol generation segment may be at least 10 millimeters, or at least 12 millimeters, or at least 14 millimeters, or at least 16 millimeters.

[0167] The combined length of the first aerosol generation segment, the second aerosol generation segment, and the third aerosol generation segment may be 24 millimeters or less, or 22 millimeters or less, or 20 millimeters or less, or 18 millimeters or less.

[0168] For example, the combined length of the first aerosol generation segment, the second aerosol generation segment, and the third aerosol generation segment may be 10 millimeters to 24 millimeters, or 12 millimeters to 22 millimeters, or 14 millimeters to 20 millimeters, or 16 millimeters to 18 millimeters. The combined length of the first aerosol generation segment, the second aerosol generation segment, and the third aerosol generation segment may be about 17 millimeters.

[0169] The combined length of the aerosol generation segments preferably corresponds to the length of the aerosol generation rod.

[0170] The aerosol generating rod preferably has an outer diameter substantially equal to the outer diameter of the aerosol generating article.

[0171] The outer diameter of the aerosol generating rod is preferably from about 5 millimeters to about 12 millimeters, more preferably from about 6 millimeters to about 10 millimeters, and even more preferably from about 7 millimeters to about 8 millimeters. In some embodiments, the outer diameter of the aerosol generating rod may be less than 7 millimeters, for example, from 5 millimeters to 7 millimeters, or from 6 millimeters to 7 millimeters.

[0172] The first aerosol generating segment preferably has an outer diameter substantially equal to the outer diameter of the aerosol generating article. The outer diameter of the first aerosol generating segment is preferably substantially constant along the length of the first aerosol generating segment.

[0173] The outer diameter of the first aerosol generating segment is from 5 millimeters to 12 millimeters, preferably from 6 millimeters to 10 millimeters, and more preferably from 7 millimeters to 8 millimeters. In some embodiments, the outer diameter of the first aerosol generating segment may be less than 7 millimeters, for example, from 5 millimeters to 7 millimeters, or from 6 millimeters to 7 millimeters.

[0174] The second aerosol generating segment preferably has an outer diameter substantially equal to the outer diameter of the aerosol generating article. The outer diameter of the second aerosol generating segment is preferably substantially constant along the length of the first aerosol generating segment.

[0175] Preferably, the outer diameter of the second aerosol generating segment is from 5 millimeters to 12 millimeters, more preferably from 6 millimeters to 10 millimeters, and even more preferably from 7 millimeters to 8 millimeters. In some embodiments, the outer diameter of the second aerosol generating segment may be less than 7 millimeters, for example, from 5 millimeters to 7 millimeters, or from 6 millimeters to 7 millimeters.

[0176] The third aerosol generation segment preferably has an outer diameter substantially equal to the outer diameter of the aerosol generating article. The outer diameter of the third aerosol generation segment is preferably substantially constant along the length of the third aerosol generation segment.

[0177] Preferably, the outer diameter of the third aerosol generation segment is from 5 millimeters to 12 millimeters, more preferably from 6 millimeters to 10 millimeters, and even more preferably from 7 millimeters to 8 millimeters. In some embodiments, the outer diameter of the third aerosol generation segment may be less than 7 millimeters, for example, from 5 millimeters to 7 millimeters, or from 6 millimeters to 7 millimeters.

[0178] The first aerosol generation segment, the second aerosol generation segment, and the third aerosol generation segment (if present) preferably have substantially the same outer diameter as each other.

[0179] The average cross-sectional area of the first aerosol generation segment is preferably at least 50 percent of the average cross-sectional area of the aerosol generating article, more preferably at least 80 percent of the average cross-sectional area of the aerosol generating article, and even more preferably at least 90 percent of the average cross-sectional area of the aerosol generating article.

[0180] The cross-sectional area of the first aerosol generation segment at its upstream end is preferably at least 50 percent of the average cross-sectional area of the aerosol generating article, more preferably at least 80 percent of the average cross-sectional area of the aerosol generating article, and even more preferably at least 90 percent of the average cross-sectional area of the aerosol generating article.

[0181] The average cross-sectional area of the second aerosol generation segment is preferably at least 50 percent of the average cross-sectional area of the aerosol generating article, more preferably at least 80 percent of the average cross-sectional area of the aerosol generating article, and even more preferably at least 90 percent of the average cross-sectional area of the aerosol generating article.

[0182] The cross-sectional area of the second aerosol generation segment at its downstream end is preferably at least 50 percent of the average cross-sectional area of the aerosol generating article, more preferably at least 80 percent of the average cross-sectional area of the aerosol generating article, and even more preferably at least 90 percent of the average cross-sectional area of the aerosol generating article.

[0183] The cross-sectional area of the first aerosol generation segment at its upstream end is substantially the same as the cross-sectional area of the second aerosol generation segment at its downstream end.

[0184] In certain embodiments of the present invention, the aerosol generating article further comprises one or more elongate susceptor elements within the aerosol generating rod. For example, the one or more elongate susceptor elements may be disposed substantially axially within the aerosol generating rod and be in thermal contact with the aerosol generating substrate. When the aerosol generating rod comprises one or more elongate susceptor elements, one or more of the aerosol generation segments may include a susceptor element extending axially within that element. In such an arrangement, separate susceptor elements may be provided for the first and second aerosol generation segments.

[0185] As used herein with respect to the present invention, the term "susceptor element" refers to a material capable of converting electromagnetic energy into heat. When located within a varying electromagnetic field, induced eddy currents in the susceptor element cause heating of the susceptor element. Since the susceptor element is positioned in thermal contact with the aerosol generating substrate, the aerosol generating substrate is heated by the susceptor element.

[0186] When used to describe a susceptor element, the term "elongated" means that the susceptor element has a length dimension that is greater than its width dimension or its thickness dimension, e.g., greater than twice its width dimension or its thickness dimension.

[0187] The susceptor element is disposed substantially along the longitudinal axis within a rod or segment. This means that the length dimension of the elongated susceptor element is disposed substantially parallel to the longitudinal axis of the rod, e.g., within ±10 degrees parallel to the longitudinal axis of the rod. In a preferred embodiment, the elongated susceptor element may be positioned radially centered within the rod or segment and extend along the longitudinal axis of the rod or segment.

[0188] The susceptor element is preferably in the form of a pin, rod, strip, or blade.

[0189] The susceptor element preferably has a width of from 1 millimeter to 5 millimeters.

[0190] The susceptor element may generally have a thickness of from 0.01 millimeter to 2 millimeters, e.g., from 0.5 millimeter to 2 millimeters. In some embodiments, the susceptor element preferably has a thickness of from 10 micrometers to 500 micrometers, more preferably from 10 micrometers to 100 micrometers.

[0191] The elongated susceptor element preferably has a length that is the same as or shorter than the length of the aerosol generating segment in which it is incorporated. The elongated susceptor element preferably has the same length as the aerosol generating segment in which it is incorporated.

[0192] The susceptor element can be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol generating substrate. Preferred susceptor elements include metal or carbon.

[0193] Preferred susceptor elements may include, or may consist of, ferromagnetic materials such as, for example, ferromagnetic alloys, ferrite iron, or ferromagnetic steel, or stainless steel. Suitable susceptor elements may be aluminum or may include aluminum.

[0194] Suitable susceptor elements may comprise a non-metallic core with a metal layer, such as a metal strip disposed on the surface of a ceramic core. The susceptor element may have a protective outer layer encapsulating the susceptor element, such as a protective ceramic layer or a protective glass layer. The susceptor element may comprise a protective coating formed of glass, ceramic, or an inert metal, formed over the core of the susceptor element material.

[0195] The susceptor element is arranged to be in thermal contact with the aerosol-generating substrate of the aerosol-generating segment in which the susceptor element is incorporated. Thus, when the temperature of the susceptor element increases, the aerosol-generating substrate is heated and an aerosol is formed. The susceptor element is preferably disposed, for example, within the aerosol-generating substrate in physical and direct contact with the aerosol-generating substrate.

[0196] The first aerosol-generating substrate is preferably surrounded by a first wrapper, and the second aerosol-generating substrate is preferably surrounded by a second wrapper separate from the first wrapper. Thus, each of the aerosol-generating segments has its own separate plug wrapper around the respective aerosol-generating substrate.

[0197] An aerosol-generating rod including a first aerosol-generating segment and a second aerosol-generating segment may be surrounded by a further wrapper, which may combine the aerosol-generating segments and hold them in a predetermined position relative to each other.

[0198] The wrapper surrounding the aerosol generating rod can be a paper wrapper or a non-paper wrapper. Suitable paper wrappers for use in certain embodiments of the present invention are known in the art and include, but are not limited to, cigarette papers and filter plug wrappers. Suitable non-paper wrappers for use in certain embodiments of the present invention are known in the art and include, but are not limited to, sheets of homogenized tobacco material.

[0199] The paper wrapper may have a basis weight of 15 gsm to 35 gsm, preferably 20 gsm to 30 gsm.

[0200] The paper wrapper may have a thickness of 25 micrometers to 55 micrometers, preferably 30 micrometers to 50 micrometers, more preferably 35 micrometers to 45 micrometers.

[0201] In certain preferred embodiments, the wrapper may be formed from a laminated material comprising a plurality of layers. The wrapper is preferably formed from an aluminum co-laminated sheet.

[0202] The paper layer of the co-laminated sheet may have a basis weight of 35 gsm to 55 gsm, preferably 40 gsm to 50 gsm.

[0203] The paper layer of the co-laminated sheet may have a thickness of about 50 micrometers to about 80 micrometers, preferably about 55 micrometers to about 75 micrometers, more preferably about 60 micrometers to about 70 micrometers.

[0204] The metal layer of the co-laminated sheet may have a basis weight of 12 gsm to 25 gsm, preferably 15 gsm to 20 gsm.

[0205] The metal layer of the co-laminated sheet may have a thickness of about 2 micrometers to about 15 micrometers, preferably about 3 micrometers to about 12 micrometers, more preferably about 5 micrometers to about 10 micrometers.

[0206] The wrapper surrounding the aerosol generating rod can be a paper wrapper containing PVOH (polyvinyl alcohol) or silicon (or polysiloxane) (or polysiloxane). The addition of PVOH (polyvinyl alcohol) or silicon (or polysiloxane) may improve the grease barrier properties of the wrapper.

[0207] The paper wrapper containing PVOH or silicon (or polysiloxane) may have a basis weight of 20 gsm to 50 gsm, preferably 25 gsm to 45 gsm, more preferably 30 gsm to 40 gsm.

[0208] The paper wrapper containing PVOH or silicon (or polysiloxane) may have a thickness of 25 micrometers to 50 micrometers, preferably 30 micrometers to 45 micrometers, more preferably 35 micrometers to 40 micrometers.

[0209] The wrapper surrounding the aerosol generating rod can contain a flame retardant composition containing one or more flame retardant compounds. The term "flame retardant compound" is used herein to describe a compound that provides varying degrees of flammability protection to a carrier substrate when added to or otherwise incorporated into a carrier substrate such as a paper or plastic compound.

[0210] Numerous suitable flame retardant compounds are known to those skilled in the art. Specifically, several flame retardant compounds and formulations suitable for the treatment of cellulosic materials are known and disclosed and may be found to be useful in the manufacture of wrappers for aerosol generating articles according to the present invention.

[0211] The wrapper containing the flame retardant composition may have a basis weight of 20 gsm to 45 gsm, preferably 25 gsm to 40 gsm, more preferably 30 gsm to 35 gsm.

[0212] The wrapper containing the flame-retardant composition may have a thickness of at least 25 micrometers, preferably at least 30 micrometers, and even more preferably 35 micrometers. The wrapper containing the flame-retardant composition may have a thickness of 50 micrometers or less, preferably 45 micrometers or less, and even more preferably 40 micrometers or less.

[0213] The aerosol-generating article according to the present disclosure may further include an upstream section located upstream of the aerosol-generating rod. The upstream section is preferably located immediately upstream of the aerosol-generating rod. The upstream section preferably extends between the upstream end of the aerosol-generating article and the aerosol-generating rod. The upstream section may include one or more upstream elements located upstream of the aerosol-generating rod.

[0214] The aerosol-generating article of the present invention preferably includes an upstream element located upstream of and adjacent to the aerosol-generating rod. Advantageously, the upstream element prevents direct physical contact with the upstream end of the aerosol-generating rod. Furthermore, the presence of the upstream element helps prevent any loss of the substrate, which may be advantageous, for example, when the substrate contains particulate plant material.

[0215] When the upstream segment of the aerosol-generating rod includes shredded tobacco such as tobacco cut filler, the upstream section or its elements may additionally help prevent loss of loose tobacco particles from the upstream end of the article. This can be particularly important, for example, when the density of the shredded tobacco is relatively low.

[0216] The upstream element may be a porous plug element. The upstream element preferably has a porosity of at least 50 percent in the longitudinal direction of the aerosol-generating article. More preferably, the upstream element has a porosity of 50 percent to 90 percent 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 position of the upstream element.

[0217] The upstream element may be made of a porous material or may comprise a plurality of openings. This can be achieved, for example, by laser drilling. The plurality of openings are preferably uniformly distributed across the cross-section of the upstream element.

[0218] Advantageously, the porosity or permeability of the upstream element is designed to provide an aerosol-generating article having a specific overall draw resistance (RTD) that does not substantially affect the filtration provided by other parts of the article.

[0219] 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 through suitable ventilation means provided within the wrapper.

[0220] In certain preferred embodiments of the present invention, it may be desirable to minimize the RTD of the upstream element. For example, this may apply to articles intended to be inserted into the cavity of an aerosol-generating device such that the aerosol-generating substrate is externally heated, as described herein. In the case of such articles, it is desirable to provide the article with as low an RTD as possible such that most of the RTD experience by the consumer is provided by the aerosol-generating device rather than the article.

[0221] The RTD of the upstream element may be 30 millimeters H2O or less, 20 millimeters H2O or less, 10 millimeters H2O or less, 5 millimeters H2O or less, or 2 millimeters H2O or less.

[0222] The RTD of the upstream element may be at least 0.1 millimeter H2O, or at least 0.25 millimeter H2O, or at least 0.5 millimeter H2O.

[0223] The upstream element preferably has an RTD of less than 2 millimeters of H2O per millimeter of length, more preferably less than 1.5 millimeters of H2O per millimeter of length, more preferably less than 1 millimeter of H2O per millimeter of length, more preferably less than 0.5 millimeter of H2O per millimeter of length, more preferably less than 0.3 millimeter of H2O per millimeter of length, and more preferably less than 0.2 millimeter of H2O per millimeter of length.

[0224] Preferably, the combined RTD of the upstream section or its upstream element and the aerosol generating rod is less than 15 millimeters of H2O, more preferably less than 12 millimeters of H2O, and more preferably less than 10 millimeters of H2O.

[0225] In certain preferred embodiments, the upstream element is formed of a solid cylindrical plug element having a filled cross-section. Such a plug element may be referred to as a "plane" element. The solid plug element may be porous as described above, but does not have a tubular form and thus does not provide a longitudinal flow channel. The solid plug element preferably has a substantially uniform cross-section.

[0226] In other preferred embodiments, the upstream element is formed from a hollow tubular segment that defines a longitudinal cavity providing an unrestricted flow channel. In such embodiments, the upstream element can provide protection to the aerosol generating substrate as described above, while having a minimal effect on the overall draw resistance (RTD) and filtration characteristics of the article.

[0227] Preferably, the diameter of the longitudinal cavity of the hollow tubular segment forming the upstream element is at least 3 millimeters, more preferably at least 3.5 millimeters, more preferably at least 4 millimeters, and more preferably at least 4.5 millimeters. Preferably, the diameter of the longitudinal cavity is maximized to minimize the RTD of the upstream section or its upstream element.

[0228] Preferably, the wall thickness of the hollow tubular segment is less than 2 millimeters, more preferably less than 1.5 millimeters, and even more preferably less than 1 millimeter.

[0229] 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 be made of the same material as one of the other components of the aerosol generating article, such as, for example, 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, cardboard, zeolites, or the aerosol generating substrate. The upstream element may include a plug of cellulose acetate. The upstream element may comprise a hollow acetate tube or a cardboard tube.

[0230] The upstream element is preferably formed from a heat-resistant material. For example, the upstream element is preferably formed from a material that can withstand a temperature of up to 350 degrees Celsius. This ensures that the upstream element is not adversely affected by the heating means for heating the aerosol generating substrate.

[0231] The upstream section or its upstream element preferably has an outer diameter that is substantially equal to the outer diameter of the aerosol generating article. Preferably, the outer diameter of the upstream section or its upstream element is 5 millimeters to 12 millimeters, more preferably 6 millimeters to 10 millimeters, and even more preferably 7 millimeters to 8 millimeters. In some embodiments, the outer diameter of the upstream section is less than 7 millimeters, for example, 5 millimeters to 7 millimeters, or 6 millimeters to 7 millimeters.

[0232] Preferably, the upstream section or the upstream element has a length of 2 millimeters to 10 millimeters, more preferably 3 millimeters to 8 millimeters, and even more preferably 2 millimeters to 6 millimeters. In a particularly preferred embodiment, the upstream section or the upstream element has a length of 5 millimeters.

[0233] The upstream section is preferably surrounded by a wrapper such as a plug wrap. The wrapper surrounding the upstream section is preferably a hard plug wrap, for example, a plug wrap having a basis weight of at least 80 grams per square meter (gsm), or at least 100 gsm, or at least 110 gsm. Thereby, structural rigidity is provided to the upstream section.

[0234] The upstream section is preferably connected by the outer wrapper described herein to the aerosol generating rod and optionally at least a portion of the downstream section.

[0235] The aerosol generating article according to the present invention preferably further comprises a downstream section located downstream of the aerosol generating rod. The downstream section is preferably located immediately downstream of the aerosol generating rod. The downstream section of the aerosol generating article preferably extends between the aerosol generating rod and the downstream end of the aerosol generating article. The downstream section may comprise one or more elements, each of which is described in more detail within the present disclosure.

[0236] The length of the downstream section may be at least 20 millimeters, at least 25 millimeters, or at least 30 millimeters.

[0237] The length of the downstream section may be less than 70 millimeters, or less than 60 millimeters, or less than 50 millimeters.

[0238] For example, the length of the downstream section may be from 20 millimeters to 70 millimeters, or from 25 millimeters to 60 millimeters, or from 30 millimeters to 50 millimeters.

[0239] The downstream section of the aerosol-generating article according to the present invention preferably comprises a hollow tubular cooling element provided downstream of the aerosol-generating rod. The hollow tubular cooling element may advantageously provide an aerosol cooling element for the aerosol-generating article.

[0240] The hollow tubular cooling element may be provided immediately downstream of the aerosol-generating rod. In other words, the hollow tubular cooling element may abut against the downstream end of the aerosol-generating rod. 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 comprise only one hollow tubular element. In other embodiments, the downstream section comprises two or more hollow tubular elements, as described below.

[0241] As used throughout this disclosure, the term "hollow tubular element" generally means an elongated element that defines a lumen or air flow path along its longitudinal axis. In particular, the term "tubular" is used hereinafter with respect to a tubular element that has a substantially cylindrical cross-section and defines at least one air flow conduit that establishes unbroken fluid communication between the upstream end of the tubular element and the downstream end of the tubular element. However, of course, alternative shapes of the tubular element (e.g., alternative cross-sectional shapes) may be possible. The hollow tubular cooling element may be a separate individual element of the aerosol-generating article having a defined length and thickness.

[0242] 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 level of draw resistance (RTD). The term "negligible level of RTD" is used to describe an RTD of less than 1 millimeter H2O per 10 millimeters of the length of the hollow tubular cooling element, preferably less than 0.4 millimeter H2O per 10 millimeters of the length of the hollow tubular cooling element, more preferably less than 0.1 millimeter H2O per 10 millimeters of the length of the hollow tubular cooling element.

[0243] The RTD of the hollow tubular cooling element may preferably be 10 millimeters H2O or less, 5 millimeters H2O or less, 2.5 millimeters H2O or less, 2 millimeters H2O or less, or 1 millimeter H2O or less.

[0244] The RTD of the hollow tubular cooling element can be at least 0 millimeters H2O, or at least 0.25 millimeters H2O, or at least 0.5 millimeters H2O, or at least 1 millimeter H2O.

[0245] In the aerosol generating article according to the present invention, the overall RTD of the article essentially depends on the RTD of the rod and optionally the RTD of downstream and / or upstream elements. This is because the hollow tubular cooling element is substantially empty and thus contributes only negligibly to the overall RTD of the aerosol generating article.

[0246] Therefore, the flow channel should not include any components that would impede the axial air flow. The flow channel is preferably substantially empty, and particularly preferably empty.

[0247] As described in more detail within the present disclosure, the aerosol-generating article may comprise a ventilation zone at a location along the downstream section. In some embodiments, the aerosol-generating article may comprise a ventilation zone at a location along a hollow tubular cooling element. Such, or any, ventilation zone may extend through the peripheral wall of the hollow tubular cooling element. In this way, fluid communication is established between the flow channel internally defined by the hollow tubular cooling element and the external environment. The ventilation zone is further described within the present disclosure.

[0248] The length of the hollow tubular cooling element may be at least 15 millimeters, or at least 20 millimeters, or at least 25 millimeters, or at least 30 millimeters.

[0249] The length of the hollow tubular cooling element may be less than 50 millimeters, or less than 45 millimeters, or less than 40 millimeters.

[0250] For example, the length of the hollow tubular cooling element may be from 15 millimeters to 50 millimeters, or from 20 millimeters to 45 millimeters, or from 20 millimeters to 40 millimeters, or from 20 millimeters to 30 millimeters, or from 25 millimeters to 40 millimeters, or from 30 millimeters to 40 millimeters.

[0251] 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 rod. As contemplated within the present disclosure, providing an empty 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 the advantages of such nucleation, thereby improving aerosol formation and cooling.

[0252] The wall thickness of the hollow tubular cooling element may be from 100 micrometers to 2 millimeters, or from 150 micrometers to 1.5 millimeters, or from 200 micrometers to 1.25 millimeters.

[0253] The hollow tubular cooling element preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol generating rod and the outer diameter of the aerosol generating article.

[0254] Preferably, the outer diameter of the hollow tubular cooling element is from 5 millimeters to 12 millimeters, more preferably from 6 millimeters to 10 millimeters, and even more preferably from 7 millimeters to 8 millimeters. In some embodiments, the outer diameter of the hollow tubular cooling element is less than 7 millimeters, for example, from 5 millimeters to 7 millimeters, or from 6 millimeters to 7 millimeters.

[0255] 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.

[0256] The hollow tubular cooling element may have an inner diameter of at least 2 millimeters. For example, the hollow tubular cooling element may have an inner diameter of at least 3 millimeters, at least 4 millimeters, or at least 5 millimeters.

[0257] By providing a hollow tubular cooling element having an inner diameter as presented above, advantageously, sufficient rigidity and strength can be provided to the hollow tubular cooling element.

[0258] The hollow tubular cooling element may have an inner diameter of 10 millimeters or less. For example, the hollow tubular cooling element may have an inner diameter of 9 millimeters or less, 8 millimeters or less, or 7 millimeters or less.

[0259] The provision of a hollow tubular cooling element having an inner diameter as presented above is advantageously such that the withdrawal resistance of the hollow tubular cooling element may be reduced.

[0260] The hollow tubular cooling element may have an inner diameter of 2 millimeters to 10 millimeters, 3 millimeters to 9 millimeters, 4 millimeters to 8 millimeters, or 5 millimeters to 7 millimeters.

[0261] 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.

[0262] The hollow tubular cooling element may contain a paper-based material. The hollow tubular cooling element may comprise at least one layer of paper. The paper may be very stiff paper. The paper may be curled paper such as heat-resistant curled paper or curled sulfuric acid paper.

[0263] Preferably, the hollow tubular cooling element may contain cardboard. The hollow tubular cooling element may be a cardboard tube. The hollow tubular cooling element may be formed from cardboard. Advantageously, cardboard provides a balance between being deformable to facilitate the insertion of articles into the aerosol generating device and being sufficiently rigid to provide proper engagement of the articles with the interior of the device, and is a cost-effective material. Thus, the cardboard tube may provide adequate resistance to deformation or compression during use.

[0264] 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 multiple layers of paper. The paper may have a basis weight of at least 50 grams per square meter, at least 60 grams per square meter, at least 70 grams per square meter, or at least 90 grams per square meter.

[0265] The hollow tubular cooling element may contain a polymer material. For example, the hollow tubular cooling element may comprise a polymer film. The polymer film may comprise a cellulose film. The hollow tubular cooling element may contain low density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. The hollow tube may contain cellulose acetate tow.

[0266] When the hollow tubular cooling element comprises cellulose acetate tow, the cellulose acetate tow can have from 2 to 4 denier per filament and a total denier of from 25 to 40.

[0267] In some embodiments, the aerosol generating article according to the present invention may include a ventilation zone at a location along the downstream section. More particularly, in those embodiments where the downstream section comprises a hollow tubular cooling element, the ventilation zone may be provided at a location along the hollow tubular cooling element. Alternatively, in those embodiments where the downstream section comprises a downstream hollow tubular element, the ventilation zone may be provided at a location along the downstream hollow tubular element.

[0268] Thus, a vented cavity is provided downstream of the aerosol generating rod. This provides several potential technical advantages. First, the inventors have found that one such vented hollow tubular cooling element provides particularly efficient cooling of the aerosol. Therefore, satisfactory cooling of the aerosol can be achieved even by a relatively short downstream section. Second, the inventors have surprisingly found that such rapid cooling of the volatile species released upon heating of the aerosol generating substrate promotes and enhances the nucleation of aerosol particles.

[0269] The ventilation zone may typically include a plurality of perforations through the circumferential wall of the hollow tubular cooling element. The ventilation zone preferably includes at least one circumferential row of perforations. In some embodiments, the ventilation zone may include two circumferential rows of perforations. For example, the perforations may be formed online during the manufacture of the aerosol generating article. Preferably, each circumferential row of perforations includes from 8 to 30 perforations.

[0270] The aerosol generating article according to the present invention may have a ventilation level of at least 25 percent.

[0271] The term "ventilation level" is used throughout this specification to mean the volume ratio between the airflow entering the aerosol-generating article through 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 stream delivered to the consumer. The aerosol-generating article preferably has a ventilation level of at least 25 percent, more preferably at least 30 percent, still more preferably at least 40 percent, and still more preferably at least 50 percent.

[0272] The aerosol-generating article according to the present invention may have a ventilation level of up to 90 percent. Preferably, the aerosol-generating article according to the present invention has a ventilation level of 80 percent or less, more preferably 70 percent or less, and still more preferably 60 percent or less.

[0273] Therefore, the aerosol-generating article according to the present invention may have a ventilation level of 25 percent to 90 percent, preferably 30 percent to 80 percent, more preferably 40 percent to 70 percent, and still more preferably 50 percent to 60 percent.

[0274] As discussed in this disclosure, the downstream section may comprise a downstream filter segment. The downstream filter segment may extend to the downstream end of the downstream section. 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.

[0275] 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.

[0276] The downstream filter segment is preferably a solid plug, which may also be described as a "plane" plug and is non-tubular. Thus, the filter segment preferably has a substantially uniform cross-section.

[0277] The downstream filter segment is preferably formed of a fibrous filter material. The fibrous filter material can be for filtering the aerosol generated from the aerosol generating substrate. Suitable fibrous filter materials will be known to those skilled in the art. Particularly preferably, at least one downstream filter segment comprises a cellulose acetate filter segment formed from cellulose acetate tow.

[0278] In a particular preferred embodiment, the downstream section comprises a single downstream filter segment. In an alternative embodiment, the downstream section comprises two or more downstream filter segments axially aligned in an end-to-end abutting relationship with each other.

[0279] The downstream filter segment may optionally contain a flavorant provided in any suitable form. For example, the downstream filter segment may comprise one or more capsules, beads, or granules of flavorant, or a thread or filament filled with one or more flavors.

[0280] The downstream filter segment preferably has a low particle filtration efficiency.

[0281] The downstream filter segment is preferably surrounded by a plug wrap. The downstream filter segment is preferably non-vented so that air does not enter the aerosol generating article along the downstream filter segment.

[0282] The downstream filter segment is preferably connected by a tipping wrapper to one or more of the adjacent upstream components of the aerosol generating article.

[0283] 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.

[0284] Preferably, the outer diameter of the downstream filter segment is from 5 millimeters to 12 millimeters, more preferably from 6 millimeters to 10 millimeters, and even more preferably from 7 millimeters to 8 millimeters. In some embodiments, the outer diameter of the downstream filter segment may be less than 7 millimeters, for example, from 5 millimeters to 7 millimeters, or from 6 millimeters to 7 millimeters.

[0285] Unless otherwise specified, the draw resistance (RTD) of a component or an aerosol-generating article is measured in accordance with ISO6565-2015. RTD refers to the pressure required to force air through the entire length of the component. The terms "pressure drop" or "draw resistance" of a component or article may also refer to "resistance to draw". Such terms generally refer to measurements in accordance with ISO 6565-2015 being carried out normally under test conditions of a temperature of 22 degrees Celsius, a pressure of 101 kPa (about 760 Torr), a relative humidity of 60%, and a volume flow rate of 17.5 milliliters per second at the output or downstream end of the measured component. The conditions for smoking and the specifications of the smoking machine are presented in ISO standard 3308 (ISO3308:2000). The atmosphere for conditioning and testing is presented in ISO standard 3402 (ISO3402:1999).

[0286] The draw resistance (RTD) of the downstream section may be at least 0 millimeter H2O. The RTD of the downstream section may be at least 3 millimeters H2O. The RTD of the downstream section may be at least 6 millimeters H2O.

[0287] The RTD of the downstream section may be 12 millimeters H2O or less. The RTD of the downstream section may be 11 millimeters H2O or less. The RTD of the downstream section may be 10 millimeters H2O or less.

[0288] The pull - out resistance (RTD) characteristics of the downstream section may be entirely or mostly due to the RTD characteristics of the downstream filter segment of the downstream section. In other words, the RTD of the downstream filter segment of the downstream section may fully define the RTD of the downstream section.

[0289] The pull - out resistance (RTD) of the downstream filter segment may be at least 0 millimeters H2O, at least 3 millimeters H2O, or at least 6 millimeters H2O.

[0290] The RTD of the downstream filter segment may be 12 millimeters H2O or less, or 11 millimeters H2O or less, or 10 millimeters H2O or less.

[0291] As described above, the downstream filter segment may be formed of a fibrous material. The downstream filter segment may be formed of a porous material. The downstream filter segment may be formed of a biodegradable material. The downstream filter segment may be formed of a cellulose material such as cellulose acetate. For example, the downstream filter segment may be formed from a bundle of cellulose acetate fibers having 10 - 15 denier per filament. For example, the downstream filter segment may be formed from a relatively low - density cellulose acetate tow containing fibers of 12 denier per filament.

[0292] The downstream filter segment can be formed of a polylactic acid-based material. The downstream filter segment can be formed of a bioplastic material, preferably a starch-based bioplastic material. The downstream filter segment can be produced by injection molding or extrusion molding. The bioplastic-based material is advantageous because it can provide a specific complex cross-sectional profile with a plurality of relatively large air flow channels extending through the downstream filter segment material that provides suitable RTD characteristics, enabling the production of a downstream filter segment structure that is simple and inexpensive to manufacture.

[0293] The length of the downstream filter segment may be at least 5 millimeters, or at least 10 millimeters. The length of the downstream filter segment may be less than 25 millimeters, or less than 20 millimeters. For example, the length of the downstream filter segment may be 5 millimeters to 25 millimeters, or 10 millimeters to 25 millimeters, or 5 millimeters to 20 millimeters, or 10 millimeters to 20 millimeters.

[0294] The downstream section may further comprise one or more additional hollow tubular elements.

[0295] 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 rod. Preferably, the hollow tubular support element abuts the upstream end of the hollow tubular cooling element. The hollow tubular support element and the hollow tubular cooling element are preferably adjacent to each other and together provide a hollow tubular section within the downstream section.

[0296] The hollow tubular support element may be formed from any suitable material or combination of materials. For example, the support element may be formed from one or more materials selected from the group consisting of cellulose acetate, cardboard, crimped paper (such as crimped heat-resistant paper or crimped sulfuric acid paper), and polymeric materials (such as low-density polyethylene (LDPE)). In a preferred embodiment, the support element is formed from cellulose acetate. Other suitable materials include polyhydroxyalkanoate (PHA) fibers. In a preferred embodiment, the hollow tubular support element includes a hollow acetate tube.

[0297] The hollow tubular support element preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol generating rod and the outer diameter of the aerosol generating article.

[0298] Preferably, the outer diameter of the hollow tubular support element is from 5 millimeters to 12 millimeters, more preferably from 6 millimeters to 10 millimeters, and even more preferably from 7 millimeters to 8 millimeters. In some embodiments, the outer diameter of the hollow tubular support element is less than 7 millimeters, for example, having an outer diameter from 5 millimeters to 7 millimeters, or from 6 millimeters to 7 millimeters.

[0299] The hollow tubular support element may have a wall thickness of at least 1 millimeter, preferably at least 1.5 millimeters, and more preferably at least 2 millimeters.

[0300] The hollow tubular support element may have a length of at least 5 millimeters. The support element preferably has a length of at least 6 millimeters, more preferably at least about 7 millimeters.

[0301] The hollow tubular support element may have a length of less than 15 millimeters. Preferably, the hollow tubular support element has a length of less than 12 millimeters, more preferably less than 10 millimeters.

[0302] In some embodiments, the support element has a length of from 5 millimeters to 15 millimeters, preferably from 6 millimeters to 15 millimeters, more preferably from 7 millimeters to 15 millimeters. In other embodiments, the support element has a length of from 5 millimeters to 12 millimeters, preferably from 6 millimeters to 12 millimeters, more preferably from 7 millimeters to 12 millimeters. In further embodiments, the support element has a length of from 5 millimeters to 10 millimeters, preferably from 6 millimeters to 10 millimeters, more preferably from 7 millimeters to 10 millimeters.

[0303] As an alternative to, or in addition to, the hollow tubular support element, the downstream section may further comprise a downstream hollow tubular element downstream of the hollow tubular cooling element. The downstream hollow tubular element may be provided immediately adjacent to the hollow tubular cooling element. 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 comprise a downstream filter segment between the hollow tubular cooling element and the downstream hollow tubular element.

[0304] The downstream hollow tubular element preferably 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, an additional downstream hollow tubular element may be provided such that the downstream section comprises two adjacent downstream hollow tubular elements downstream of the downstream filter segment.

[0305] The RTD of the downstream hollow tubular element may be 10 millimeters H2O or less, 5 millimeters H2O or less, 2.5 millimeters H2O or less, or 2 millimeters H2O or less. Preferably, the RTD of the downstream hollow tubular element is 1 millimeter H2O or less.

[0306] The RTD of the downstream hollow tubular element may be at least 0 millimeters H2O, or at least 0.25 millimeters H2O, or at least 0.5 millimeters H2O, or at least 1 millimeter H2O.

[0307] Therefore, the air flow channel of the downstream hollow tubular element should not include any components that would impede the flow of air in the longitudinal axis direction. Preferably, the flow channel is substantially empty, and particularly preferably, the flow channel is empty.

[0308] The downstream hollow tubular element preferably has a length of at least 3 millimeters, more preferably at least 4 millimeters, more preferably at least 5 millimeters, more preferably at least 6 millimeters.

[0309] The length of the downstream hollow tubular element is preferably less than 20 millimeters, more preferably less than 15 millimeters, more preferably less than 12 millimeters, more preferably less than 10 millimeters.

[0310] 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.

[0311] The downstream hollow tubular element may include a paper-based material. The downstream hollow tubular element may include at least one layer of paper. The paper can be very stiff paper. The paper can be curled paper such as heat-resistant curled paper or curled sulfuric acid paper.

[0312] The downstream hollow tubular element may include cardboard. The downstream hollow tubular element can be a cardboard tube.

[0313] The downstream hollow tubular element can be a paper tube. The downstream hollow tubular element can be a tube formed from spirally wound paper. The downstream hollow tubular element can be formed from a plurality of layers of paper. The paper can have a basis weight of at least 50 grams per square meter, at least 60 grams per square meter, at least 70 grams per square meter, or at least 90 grams per square meter.

[0314] The downstream hollow tubular element may include a polymer material. For example, the downstream hollow tubular element can include a polymer film. The polymer film can include a cellulose film. The downstream hollow tubular element can include low density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. The downstream hollow tubular element preferably comprises cellulose acetate tow. For example, in a preferred embodiment, the downstream hollow tubular element includes a hollow acetate tube.

[0315] When the downstream hollow tubular element includes cellulose acetate tow, the cellulose acetate tow can have 2 to 4 denier per filament and a total denier of 25 to 40.

[0316] When 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 or a different material as the downstream hollow tubular element.

[0317] 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 can be provided in place of the ventilation zone at a location on the hollow tubular cooling element. In another example, the ventilation zone at a location on the downstream hollow tubular element can be provided in addition to the ventilation zone provided at a location on the hollow tubular cooling element.

[0318] The ventilation zone at a position along the downstream hollow tubular element may include a plurality of perforations through the peripheral wall of the downstream hollow tubular element. The ventilation zone at a position along the downstream hollow tubular element preferably includes at least one circumferential row of perforations. In some embodiments, the ventilation zone may include two circumferential rows of perforations. For example, the perforations may be formed online during the manufacture of the aerosol generating article. Preferably, each circumferential row of perforations includes 8 to 30 perforations.

[0319] The overall RTD of the aerosol generating article may be at least 10 millimeters of H2O. For example, the overall RTD of the aerosol generating article may be at least 20 millimeters of H2O, at least 30 millimeters of H2O, at least 35 millimeters of H2O, or at least 40 millimeters of H2O.

[0320] The overall RTD of the aerosol generating article may be 70 millimeters of H2O or less. For example, the overall RTD of the aerosol generating article may be 60 millimeters of H2O or less, 55 millimeters of H2O or less, 50 millimeters of H2O or less, or 45 millimeters of H2O or less.

[0321] The overall RTD of the aerosol generating article may be from 10 millimeters of H2O to 70 millimeters of H2O. For example, the overall RTD of the aerosol generating article may be from 20 millimeters of H2O to 60 millimeters of H2O, from 30 millimeters of H2O to 55 millimeters of H2O, from 35 millimeters of H2O to 50 millimeters of H2O, or from 40 millimeters of H2O to 45 millimeters of H2O.

[0322] The overall RTD of the aerosol generating article may be from 40 millimeters of H2O to 60 millimeters of H2O, from 35 millimeters of H2O to 40 millimeters of H2O, from 45 millimeters of H2O to 50 millimeters of H2O, or from 55 millimeters of H2O to 65 millimeters of H2O.

[0323] The overall RTD of the aerosol-generating article may be about 38 millimeters H2O, about 48 millimeters H2O, or about 60 millimeters H2O.

[0324] The aerosol-generating article of the present invention may have an overall length of at least 40 millimeters, at least 50 millimeters, or at least 60 millimeters.

[0325] The aerosol-generating article of the present invention may have an overall length of 90 millimeters or less, 85 millimeters or less, or 80 millimeters or less.

[0326] In some embodiments, the overall length of the aerosol-generating article is preferably from 40 millimeters to 70 millimeters, more preferably from 45 millimeters to 70 millimeters. In other embodiments, the overall length of the aerosol-generating article is preferably from 40 millimeters to 60 millimeters, more preferably from about 45 millimeters to about 60 millimeters. In further embodiments, the overall length of the aerosol-generating article is preferably from 40 millimeters to 50 millimeters, more preferably from 45 millimeters to 50 millimeters. In an exemplary embodiment, the overall length of the aerosol-generating article is about 45 millimeters.

[0327] In other embodiments, the overall length of the aerosol-generating article is preferably from 50 millimeters to 90 millimeters, more preferably from 60 millimeters to 90 millimeters, still more preferably from 70 millimeters to 90 millimeters. In other embodiments, the overall length of the aerosol-generating article is preferably from 50 millimeters to 85 millimeters, more preferably from 60 millimeters to 85 millimeters, still more preferably from 70 millimeters to 85 millimeters. In further embodiments, the overall length of the aerosol-generating article is preferably from 50 millimeters to 80 millimeters, more preferably from 60 millimeters to 80 millimeters, still more preferably from 70 millimeters to 80 millimeters. In an exemplary embodiment, the overall length of the aerosol-generating article is 75 millimeters.

[0328] The aerosol-generating article may have an outer diameter of at least 5 millimeters, at least 6 millimeters, or at least 7 millimeters.

[0329] The aerosol-generating article may have an outer diameter of about 12 millimeters or less, about 10 millimeters or less, or about 8 millimeters or less.

[0330] In some embodiments, the aerosol-generating article has an outer diameter of from about 5 millimeters to about 12 millimeters, preferably from about 6 millimeters to about 12 millimeters, more preferably from about 7 millimeters to about 12 millimeters. In other embodiments, the aerosol-generating article has an outer diameter of from about 5 millimeters to about 10 millimeters, preferably from about 6 millimeters to about 10 millimeters, more preferably from about 7 millimeters to about 10 millimeters. In further embodiments, the aerosol-generating article has an outer diameter of from about 5 millimeters to about 8 millimeters, preferably from about 6 millimeters to about 8 millimeters, more preferably from about 7 millimeters to about 8 millimeters. In other embodiments, the aerosol-generating article has an outer diameter of less than 7 millimeters.

[0331] The outer diameter of the aerosol-generating article may be substantially constant over the entire length of the article. Alternatively, different portions of the aerosol-generating article may have different outer diameters.

[0332] In a particularly preferred embodiment, one or more of the components of the aerosol-generating article are individually surrounded by their own wrapper.

[0333] Preferably, at least one of the components of the aerosol-generating article is wrapped in a hydrophobic wrapper.

[0334] The term "hydrophobic" refers to a surface that exhibits water-repellent properties. One useful way to determine this is by measuring the water contact angle. The "water contact angle" is the angle conventionally measured through a liquid, where the liquid / vapor interface meets the solid surface. This quantifies the wetting of the solid surface by the liquid via Young's equation. The hydrophobicity or water contact angle may be determined by utilizing the TAPPI T558 test method, and the results are expressed as the interfacial contact angle and reported in "degrees", which can range from approximately zero to approximately 180 degrees.

[0335] In a preferred embodiment, the hydrophobic wrapper includes a paper layer having a water contact angle of about 30 degrees or more, preferably about 35 degrees or more, or about 40 degrees or more, or about 45 degrees or more.

[0336] As an 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.

[0337] The present disclosure also relates to an aerosol generation system comprising an aerosol generating device having a distal end and a mouth-side end. The aerosol generating device may comprise 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-side end of the device. The aerosol generating device may comprise a heating element or heater for heating an aerosol generating substrate when the aerosol generating article is received within the device cavity.

[0338] The device cavity may be referred to as the heating chamber of the aerosol generating device. The device cavity may extend between the distal end and the mouth-side (or proximal) end. The distal end of the device cavity may be a closed end, and the mouth-side (or proximal) end of the device cavity may be an open end. The aerosol generating article may be inserted into the device cavity or heating chamber through 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.

[0339] The expression "received therein" may refer to the fact that a component or element is received, either fully or partially, within another component or element. For example, the expression "the aerosol-generating article is received within the device cavity" refers to the fact that the aerosol-generating article is received, either fully or partially, 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 abut against 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 proximate to the distal end of the device cavity. The distal end of the device cavity may be defined by an end wall.

[0340] The length of the cavity of the device may be 15 millimeters to 80 millimeters, or 20 millimeters to 70 millimeters, or 25 millimeters to 60 millimeters, or 25 millimeters to 50 millimeters.

[0341] The length of the cavity of the device may be 25 millimeters to 29 millimeters, or 26 millimeters to 29 millimeters, or 27 millimeters to 28 millimeters.

[0342] The length of the device cavity (or heating chamber) may be the same as or longer than the length of the aerosol generating rod. The length of the device cavity may be the same as or longer than the combined length of the upstream section or element and the aerosol generating rod. The length of the device cavity is preferably such that when the aerosol generating article is received with the aerosol generating device, at least 75 percent of the length of the aerosol generating rod is inserted or received within the device cavity. More preferably, the length of the device cavity is such that when the aerosol generating article is received with the aerosol generating device, at least 80 percent of the length of the aerosol generating rod is inserted or received within the device cavity. Even more preferably, the length of the device cavity is such that when the aerosol generating article is received with the aerosol generating device, at least 90 percent of the length of the aerosol generating rod is inserted or received within the device cavity. This maximizes the length of the aerosol generating rod that can heat the aerosol generating substrate during use, thereby optimizing the generation of aerosol from the aerosol generating substrate and reducing tobacco waste.

[0343] The length of the device cavity may be configured such that when the aerosol generating article is received within the device cavity, a downstream section or a portion thereof protrudes from the device cavity. The length of the device cavity may be such that when the aerosol generating article is received within the device cavity, a portion of the downstream section (such as a hollow tubular cooling element or a downstream filter segment) protrudes from the device cavity. The length of the device cavity may be such that when the aerosol generating article is received within the device cavity, a portion of the downstream section (such as a hollow tubular cooling element or a downstream filter segment) is configured to be received within the device cavity.

[0344] At least 25 percent of the length of the downstream section may be inserted or received within the device cavity when the aerosol-generating article is received within the device. At least 30 percent of the length of the downstream section may be inserted or received within the device cavity when the aerosol-generating article is received within the device.

[0345] The diameter of the device cavity may be from 4 millimeters to 10 millimeters. The diameter of the device cavity may be from 5 millimeters to 9 millimeters. The diameter of the device cavity may be from 6 millimeters to 8 millimeters. The diameter of the device cavity may be from 6 millimeters to 7 millimeters.

[0346] The diameter of the device cavity may be substantially the same as or larger 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 to establish a tight fit therewith.

[0347] The device cavity may be configured to establish a tight fit with the aerosol-generating article received within the device cavity. A tight fit may refer to a slip fit. The aerosol-generating device may comprise a peripheral wall. Such a peripheral wall may define the device cavity or the heating chamber. The peripheral wall defining the device cavity may be configured to engage in a tight fit with the aerosol-generating article received within the device cavity such that there is substantially no gap or empty space between the peripheral wall defining the device cavity and the aerosol-generating article when received within the device.

[0348] Such an airtight fit may establish an airtight fit or configuration between the device cavity and the aerosol-generating article received therein.

[0349] In such an airtight configuration, there will be substantially no gap or empty space between the peripheral wall defining the device cavity and the aerosol-generating article through which air passes and flows.

[0350] A tight 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.

[0351] The aerosol-generating device may comprise an air flow channeling extending between a channel inlet and a channel outlet. The air flow channel may be configured to establish a fluid communication between the interior of the device cavity and the exterior of the aerosol-generating device. The air flow channel of the aerosol-generating device may be defined within the housing of the aerosol-generating device to enable a fluid communication between the interior of the device cavity and the exterior of the aerosol-generating device. When the aerosol-generating article is received within the device cavity, the air flow channel may be configured to provide air flowing into the article to deliver the generated aerosol to a user who aspirates from the mouth-side end of the article.

[0352] The air flow channel 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 air flow channel 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 by a combination of both. The air flow channel 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 periphery of the device cavity.

[0353] The air flow channel of the aerosol-generating device may extend from an inlet located at the mouth-side end or proximal end of the aerosol-generating device to an outlet located away from the mouth-side end of the device. The air flow channel may extend along a direction parallel to the longitudinal axis of the aerosol-generating device.

[0354] The heater may be of any suitable type. In the present invention, the heater is preferably an external heater.

[0355] Preferably, the heater may externally heat the aerosol-generating article when received within the aerosol-generating device. Such an external heater may surround the aerosol-generating article when inserted or received within the aerosol-generating device.

[0356] In some embodiments, the heater is disposed to heat the outer surface of the aerosol generating substrate. In some embodiments, the heater is disposed for insertion into the aerosol generating substrate when the aerosol generating substrate is received within the cavity. The heater may be positioned within the device cavity or the heating chamber.

[0357] The heater may comprise at least one heating element. The at least one heating element can be any suitable type of heating element. In some embodiments, the device comprises only one heating element. In some embodiments, the device comprises a plurality of heating elements.

[0358] Suitable materials for forming at least one resistive heating element include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (such as molybdenum disilicide), carbon, graphite, metals, metal alloys, and composite materials made of ceramic materials and metal materials. Such composite materials may include doped ceramics 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, cobalt-containing, chromium-containing, aluminum-containing, titanium-containing, zirconium-containing, hafnium-containing, niobium-containing, molybdenum-containing, tantalum-containing, tungsten-containing, tin-containing, gallium-containing, manganese-containing, and iron-containing alloys, as well as nickel, iron, cobalt, stainless steel-based superalloys, Timetal®, and iron-manganese-aluminum-based alloys.

[0359] In some embodiments, at least one resistive heater includes one or more stamped portions of an electrically resistive material (such as stainless steel). Alternatively, at least one resistive heater may include a heating wire or filament (e.g., a wire of Ni—Cr (nickel-chromium), platinum, tungsten, or an alloy).

[0360] In some embodiments, at least one heating element includes an electrically insulated substrate, and at least one resistive heater is provided on the electrically insulated substrate.

[0361] The electrically insulated substrate may include any suitable material. For example, the electrically insulated substrate may include one or more of paper, glass, ceramic, anodized metal, coated metal, and polyimide. The ceramic may include mica, alumina (Al2O3), or zirconia (ZrO2). The electrically insulated substrate preferably has a thermal conductivity of about 40 watts per meter kelvin or less, preferably about 20 watts per meter kelvin or less, and ideally about 2 watts per meter kelvin or less.

[0362] The heater may comprise a heating element including a rigid electrically insulated substrate having one or more conductive tracks or wires disposed on its surface. The size and shape of the electrically insulated substrate may allow the heater to be inserted directly into the aerosol generating substrate. If the electrically insulated substrate is not sufficiently rigid, the heating element may include additional reinforcement means. Current may pass through one or more conductive tracks to heat the heating element and the aerosol generating substrate.

[0363] In some embodiments, the heater comprises an induction heating arrangement. The induction heating device may comprise an inductor coil and a power supply configured to provide a high-frequency oscillating current to the inductor coil. As used herein, the high-frequency oscillating current means an oscillating current having a frequency of about 500 kHz to about 30 MHz. Advantageously, the heater may comprise 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 the power supply. The inductor coil may be arranged to generate a high-frequency oscillating electromagnetic field within the device cavity. In some embodiments, the inductor coil can substantially surround the device cavity. The inductor coil may at least partially extend along the length of the device cavity.

[0364] The heater may include an induction heating element. The induction heating element may be a susceptor element. The susceptor element may be arranged such that when the aerosol generating article is received within the cavity of the aerosol generating device, the oscillating electromagnetic field generated by the inductor coil induces a current within the susceptor element and heats the susceptor element. In these embodiments, it is preferred that the aerosol generating device is capable of generating a varying electromagnetic field having a magnetic field strength (strength of the H field) of 1 to 5 kiloamperes per meter (kA / m), preferably 2 to 3 kA / m, for example about 2.5 kA / m. An electrically operating aerosol generating device preferably has the ability to generate a varying electromagnetic field having a frequency of 1 to 30 MHz, for example 1 to 10 MHz, for example 5 to 7 MHz.

[0365] In these embodiments, the susceptor element is preferably positioned in contact with the aerosol generating substrate. In some embodiments, the susceptor element is located within the aerosol generating device. In these embodiments, the susceptor element may be located within the cavity. The aerosol generating device may include only one susceptor element. The aerosol generating device may comprise a plurality of susceptor elements. In some embodiments, the susceptor element is preferably arranged to heat the outer surface of the aerosol generating substrate.

[0366] The susceptor element may include any suitable material described above in connection with the susceptor element incorporated within the aerosol generating rod.

[0367] 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 a resistive heating element and an inductive heating element.

[0368] In use, the heater can be controlled to operate within a defined operating temperature range below the maximum operating temperature. The operating temperature range within the heating chamber (or device cavity) is preferably from about 150 degrees Celsius to about 300 degrees Celsius. The operating temperature range of the heater may be from about 150 degrees Celsius to about 250 degrees Celsius.

[0369] The aerosol generating device may comprise 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 (e.g., a lithium cobalt, lithium iron phosphate, or 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 be rechargeable and may have a capacity that allows for sufficient energy storage for one or more user operations such as one or more experiences of aerosol generation.

[0370] The following provides a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more of the features of another example, embodiment, or aspect described herein.

[0371] [Example 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 including a first aerosol generating substrate and a second aerosol generating segment located upstream of the first aerosol generating segment and including a second aerosol generating substrate.

[0372] [Example 2] The aerosol generating article according to Example 1, wherein the first aerosol generating substrate contains an aerosol former and the content of the aerosol former in the first aerosol generating substrate is 30% by weight or less on a dry weight basis.

[0373] [Example 3] The aerosol generating article according to any one of Example 1 or 2, wherein the second aerosol generating substrate contains an aerosol former and the content of the aerosol former in the second aerosol generating substrate is at least 40% by weight on a dry weight basis.

[0374] [Example 4] The aerosol generating article according to Example 3, wherein the second aerosol generating substrate contains at least 50% by weight of glycerol.

[0375] [Example 5] The aerosol generating article according to any one of Example 2 to 4, wherein the content of the aerosol former in the second aerosol generating substrate is at least 15% higher than the content of the aerosol former in the first aerosol generating substrate.

[0376] [Example 6] The aerosol generating article according to any one of Example 2 to 5, wherein the content of the aerosol former in the second aerosol generating substrate is at least 1.2 times the content of the aerosol former in the first aerosol generating substrate.

[0377] [Example 7] The aerosol generating article according to any one of Examples 2 to 6, wherein the aerosol former content of the first aerosol generating substrate is 5% to 30% by dry weight.

[0378] [Example 8] The aerosol generating article according to any one of Examples 2 to 7, wherein the aerosol former content of the second aerosol generating substrate is 40% to 80% by dry weight.

[0379] [Example 9] The aerosol generating article according to any one of Examples 1 to 8, wherein the second aerosol generating substrate has a higher aerosol former content than the first aerosol generating substrate.

[0380] [Example 10] The aerosol generating article according to any one of Examples 1 to 9, wherein the second aerosol generating substrate has a higher density than the first aerosol generating substrate.

[0381] [Example 11] The aerosol generating article according to Example 10, 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.

[0382] [Example 12] The aerosol generating article according to any one of Examples 9 to 11, wherein the first aerosol generating substrate has a density of less than 400 mg / cm³.

[0383] [Example 13] The aerosol generating article according to Example 12, wherein the first aerosol generating substrate has a density of 100 mg / cm³ to 400 mg / cm³.

[0384] [Example 14] The aerosol generating article according to any one of Examples 9 to 13, wherein the second aerosol generating substrate has a density of at least 500 mg / cm³.

[0385] [Example 15] The second aerosol generation substrate is the aerosol generating article according to Example 14, having a density of 500 mg / cubic centimeter to 1000 mg / cubic centimeter.

[0386] [Example 16] The aerosol generating article according to any one of Examples 9 to 15, wherein the density of the second aerosol generation substrate is at least 1.2 times the density of the first aerosol generation substrate.

[0387] [Example 17] The aerosol generating article according to any one of Examples 1 to 16, wherein the first aerosol generation substrate contains cut tobacco material.

[0388] [Example 18] The aerosol generating article according to Example 17, wherein the first aerosol generation substrate contains tobacco cut filler.

[0389] [Example 19] The aerosol generating article according to Example 17, wherein the first aerosol generation substrate contains a sheet of homogenized and cut tobacco material.

[0390] [Example 20] The aerosol generating article according to Example 19, wherein the second aerosol generation substrate further comprises an aerosol generating film.

[0391] [Example 21] The aerosol generating article according to Example 20, wherein the aerosol generating film contains a cellulose-based film former, nicotine, and an aerosol former.

[0392] [Example 22] The aerosol generating article according to Example 21, wherein the aerosol generating film further contains a cellulose-based strengthening agent.

[0393] [Example 23] The aerosol generating article according to Example 21 or Example 22, wherein the aerosol generating film further contains carboxymethyl cellulose.

[0394] [Example 24] The aerosol generating article according to any one of Examples 20 to 23, wherein the aerosol generating film further contains an acid.

[0395] [Example 25] The aerosol generating article according to any one of Examples 20 to 24, wherein the aerosol generating film substantially does not contain tobacco.

[0396] [Example 26] The aerosol generating article according to any one of Examples 1 to 19, wherein the second aerosol generating substrate contains a gel composition containing nicotine, at least one gelling agent and an aerosol former.

[0397] [Example 27] The aerosol generating segment according to any one of Examples 1 to 26, wherein the ratio of the length of the first aerosol generating segment to the length of the second aerosol generating segment is 0.3 to 0.6.

[0398] [Example 28] The aerosol generating article according to any one of Examples 1 to 12, wherein the length of the second aerosol generating segment is at least 4 millimeters greater than the length of the first aerosol generating article.

[0399] [Example 29] The aerosol generating article according to any one of Examples 1 to 11, wherein the first aerosol generating substrate is surrounded by a first wrapper and the second aerosol generating substrate is surrounded by a second wrapper separate from the first wrapper.

[0400] [Example 30] The aerosol generating rod is provided upstream of the second aerosol generating segment and further includes a third aerosol generating segment including a third aerosol generating substrate, the aerosol generating article according to any one of Examples 1 to 11.

[0401] [Example 31] The aerosol generating article according to Example 30, wherein the third aerosol generating substrate includes cut tobacco material.

[0402] [Example 32] The aerosol generating article according to Example 30 or 31, wherein the third aerosol generating substrate includes at least one aerosol former, and the content of the aerosol former in the third aerosol generating substrate is 30% by weight or less on a dry weight basis.

[0403] [Example 33] The aerosol generating article according to any one of Examples 1 to 32, further comprising a downstream section provided downstream of the aerosol generating rod.

[0404] [Example 34] The aerosol generating article according to Example 33, wherein the downstream section extends to the downstream end of the aerosol generating article.

[0405] [Example 35] The aerosol generating article according to Example 33 or 34, wherein the downstream section includes a hollow tubular cooling element.

[0406] [Example 36] The aerosol generating article according to Example 35, wherein the hollow tubular cooling element has a length of at least 20 millimeters.

[0407] [Example 37] The aerosol generating article according to Example 35 or 36, wherein the downstream section includes a ventilation zone at a position along the hollow tubular cooling element.

[0408] [Example 38] The aerosol generating article according to any one of Examples 33 to 37, wherein the downstream section includes a downstream filter segment.

[0409] [Example 39] The aerosol generating article according to Example 38, wherein the downstream filter segment is a solid plug.

[0410] [Example 40] The aerosol generating article according to Example 38 or 39, wherein the downstream filter segment has a length of at least 5 millimeters.

[0411] [Example 41] The aerosol generating article according to any one of Examples 35 to 40, wherein the downstream section further includes a hollow tubular support element upstream of the hollow tubular cooling element.

[0412] [Example 42] The aerosol generating article according to any one of Examples 35 to 41, wherein the downstream section further includes a downstream hollow tubular element provided downstream of the hollow tubular cooling element.

[0413] [Example 43] The aerosol generating article according to any one of Examples 1 to 42, further including an upstream element upstream of the aerosol generating rod.

[0414] [Example 44] The aerosol generating article according to any one of Examples 1 to 43, wherein the aerosol generating article has a ventilation level of at least about 40 percent.

[0415] [Example 45] The aerosol generating article according to any one of Examples 1 to 44, wherein the length of the aerosol generating article is 40 millimeters to 50 millimeters.

[0416] [Example 46] The aerosol generating article has a length of 70 millimeters to 80 millimeters, and is the aerosol generating article according to any one of Examples 1 to 44.

[0417] [Example 47] The aerosol generating article according to any one of Examples 1 to 46, wherein the second aerosol generating substrate has a higher aerosol former content than the first aerosol generating substrate, and the second aerosol generating substrate has a higher density than the first aerosol generating substrate.

[0418] [Example 48] The aerosol generating article according to any one of Examples 1 to 47, wherein the second aerosol generating substrate has a higher aerosol former content than the first aerosol generating substrate, and the first aerosol generating substrate has a density of less than 400 mg / cubic centimeter.

[0419] [Example 49] The aerosol generating article according to any one of Examples 1 to 48, wherein the first aerosol generating substrate contains at least one aerosol former, the aerosol former content of the first aerosol generating substrate is 30 weight percent or less on a dry weight basis, and the aerosol former content of the second aerosol generating substrate is at least 40 weight percent.

[0420] [Example 50] An aerosol generating system comprising the aerosol generating article according to any one of Examples 1 to 49, a heating chamber for receiving the aerosol generating article, and an aerosol generating device provided with at least a heating element provided around or around the heating chamber.

[0421] The following provides a non-exhaustive section of non-limiting examples. Any one or more of the features of these sections may be combined with any one or more of the features of another example, embodiment, or aspect described herein.

[0422] Section 1. An aerosol-generating article, which is an aerosol-generating rod for generating an inhalable aerosol upon heating, wherein the aerosol-generating rod comprises a first aerosol-generating segment including a first aerosol-generating substrate, the first aerosol-generating substrate includes at least one aerosol-forming agent, and the aerosol-forming agent content of the first aerosol-generating substrate is 30 wt% or less on a dry weight basis; and a second aerosol-generating segment located upstream of the first aerosol-generating segment and comprising a second aerosol-generating substrate, the second aerosol-generating substrate includes at least one aerosol-forming agent, and the aerosol-forming agent content of the second aerosol-generating substrate is at least 40 wt% on a dry weight basis.

[0423] Section 2. The aerosol-generating article according to Section 1, wherein the second aerosol-generating substrate includes an aerosol-generating film, the aerosol-generating film includes a cellulose-based film-forming agent, nicotine, and glycerol, and the aerosol-generating film has a glycerol content of at least 40 wt%.

[0424] Section 3. The aerosol-generating article according to Section 2, wherein the aerosol-generating film substantially does not contain tobacco.

[0425] Section 4. The aerosol-generating article according to any one of Sections 1 to 3, wherein the first aerosol-generating substrate includes tobacco cut filler.

[0426] Section 5. The aerosol-generating article according to any one of Items 1 to 3, wherein the second aerosol-generating segment abuts against the upstream end of the first aerosol-generating segment.

[0427] Section 6. The aerosol-generating article according to any one of Sections 1 to 5, wherein the second aerosol-generating substrate includes at least 50 wt% glycerol on a dry weight basis.

[0428] Section 7 The aerosol generating article according to any one of items 1 to 6, wherein the first aerosol generating substrate is surrounded by a first wrapper, and the second aerosol generating substrate is surrounded by a second wrapper separate from the first wrapper.

[0429] Section 8 The aerosol generating article according to any one of sections 1 to 7, wherein the aerosol former content of the second aerosol generating substrate is at least 25 percent higher on a dry weight basis than the aerosol former content of the first aerosol generating substrate.

[0430] Section 9 The aerosol generating article according to any one of sections 1 to 8, wherein the aerosol former content of the second aerosol generating substrate is at least 1.5 times that of the first aerosol generating substrate on a dry weight basis.

[0431] Section 10 The aerosol generating article according to any one of sections 1 to 9, wherein the ratio of the length of the first aerosol generating segment to the length of the second aerosol generating segment is 0.6 or less.

[0432] Section 11 The aerosol generating article according to any one of sections 1 to 10, wherein the bulk density of the first aerosol generating substrate is less than 400 mg / cubic centimeter and the bulk density of the second aerosol generating substrate is more than 500 mg / cubic centimeter.

[0433] Section 12 The aerosol generating article according to any one of sections 1 to 11, further comprising an upstream element provided upstream of the aerosol generating rod and abutting against the upstream end of the second aerosol generating segment.

[0434] Section 13 The aerosol generating article according to any one of sections 1 to 12, further comprising a downstream section provided downstream of the aerosol generating rod and extending to the downstream end of the aerosol generating article, the downstream section comprising a hollow tubular cooling element.

[0435] Section 14: An aerosol-generating article as described in any one of Sections 1 to 13, having a ventilation level of at least 40 percent.

[0436] Section 15: An aerosol generation system comprising an aerosol-generating article as described in any one of Sections 1 to 14, and an aerosol generation device including a heating chamber for receiving the aerosol-generating article and at least a heating element installed around or adjacent to the heating chamber.

[0437] Hereinafter, the present invention will be further described with reference to the drawings of the accompanying drawings.

[0438] The aerosol-generating article 10 shown in FIG. 1 includes an aerosol generation rod 12 and a downstream section 14 located downstream of the rod 12. Therefore, the aerosol-generating article 10 extends from an upstream or distal end 16 that substantially coincides with the upstream end of the rod 12 to a downstream or mouth-side end 18 that coincides with the downstream end of the downstream section 14. The downstream section 14 includes a hollow tubular cooling element 20 and a downstream filter segment 50.

[0439] The aerosol-generating article 10 has an overall length of about 45 millimeters and an outer diameter of about 7.2 mm.

[0440] The aerosol generation rod 12 includes a first aerosol generation segment 24 and a second aerosol generation segment 26 that are coaxially aligned with each other. The second aerosol generation article 26 is provided upstream of the first aerosol generation segment 24 and abuts against the upstream end of the first aerosol generation segment 24.

[0441] The first aerosol generation segment 24 includes a first aerosol generation substrate formed of a cut tobacco material of about 50 mg containing 15 wt% to 20 wt% glycerol and having a length of 5 millimeters. The density of the first aerosol generation substrate is about 300 mg / cubic centimeter. The first aerosol generation segment 24 is individually wound by a plug wrap (not shown).

[0442] The second aerosol generation segment 26 has a length of 12 millimeters and includes a second aerosol generation substrate formed from a fragment of the aerosol generation film. An exemplary composition of the aerosol generation film is shown in Table 1 below.

[0443] Table 1. Aerosol Generation Film Composition (w / w) JPEG2025523469000002.jpg58152

[0444] The second aerosol generation substrate has, as described above, a glycerol content of about 50 weight percent and thus is 10 weight percent higher than the glycerol content of the first aerosol generation substrate. The density of the second aerosol generation substrate exceeds about 600 mg / cubic centimeter. The first aerosol generation segment 24 is individually wound by a plug wrap (not shown).

[0445] The hollow tubular cooling element 20 of the downstream section 14 is located immediately downstream of the aerosol generation rod 12, and the hollow tubular cooling element 20 is aligned with the rod 12 in the longitudinal axis direction. The upstream end of the hollow tubular cooling element 20 abuts against the downstream end of the rod 12.

[0446] The hollow tubular cooling element 20 defines a hollow section of the aerosol generation article 10. The hollow tubular cooling element 20 may not substantially contribute to the overall RTD of the aerosol generation article. More specifically, the RTD of the hollow tubular cooling element 20 is about 0 mmH2O.

[0447] As shown in FIG. 2, the hollow tubular cooling element 20 is provided in the form of a hollow cylindrical tube made of cardboard. The hollow tubular cooling element 20 defines an internal cavity 22 that extends entirely from the upstream end of the hollow tubular cooling element 20 to the downstream end of the hollow tubular cooling element 20. The internal cavity 22 is substantially empty, and thus a substantially unrestricted airflow is possible along the internal cavity 22.

[0448] The hollow tubular cooling element 20 has a length of about 21 millimeters, an outer diameter of about 7.2 millimeters, and an inner diameter of about 6.7 millimeters. Accordingly, the thickness of the peripheral wall of the hollow tubular cooling element 20 is about 0.25 millimeters.

[0449] The aerosol generating article 10 comprises a ventilation zone 30 provided at a position along the hollow tubular cooling element 20. The ventilation zone 30 comprises a circumferential row of openings or perforations surrounding the hollow tubular cooling element 20. The perforations of the ventilation zone 30 extend through the wall of the hollow tubular cooling element 20 to allow the entry of fluid from the outside of the article 10 into the internal cavity 22. The ventilation level of the aerosol generating article 10 is about 40 percent.

[0450] The downstream filter segment 50 extends from the downstream end of the hollow tubular cooling element 20 to the downstream end or the mouth side end of the aerosol generating article 10. The downstream filter segment 50 has a length of about 7 millimeters. The outer diameter of the downstream filter segment 50 is about 7.2 millimeters. The downstream filter segment 50 comprises a filter segment of low density cellulose acetate. The RTD of the downstream filter segment 50 is about 8 mmH2O. The downstream filter segment 50 may be individually wound by a plug wrap (not shown).

[0451] As shown in FIGS. 1 and 2, the article 10 comprises an upstream bellows 44 surrounding the aerosol generating rod 12 and the hollow tubular cooling element 20. The ventilation zone 30 may also comprise a circumferential row of perforations provided on the upstream bellows 44. The perforations of the upstream bellows 44 overlap the perforations provided on the hollow tubular cooling element 20. As a result, the upstream bellows 44 is above the perforations of the ventilation zone 30 provided on the hollow tubular cooling element 20.

[0452] The article 10 also includes a tipping wrapper 52 that surrounds the hollow tubular cooling element 20 and the mouthpiece element 50. The tipping wrapper 52 is located on a portion of the upstream wrapper 44 that is on top of the hollow tubular cooling element 20. In this way, the tipping wrapper 52 effectively couples the mouthpiece element 50 to the remaining components of the article 10. The width of the tipping wrapper 52 is approximately 26 millimeters. Additionally, the ventilation zone 30 may include a circumferential row of perforations provided on the tipping wrapper 52. The perforations of the tipping wrapper 52 overlap the perforations provided on the hollow tubular cooling element 20 and the upstream wrapper 44. As a result, the tipping wrapper 52 is located on top of the perforations of the ventilation zone 30 provided on the hollow tubular cooling element 20 and the upstream wrapper 44.

[0453] Figure 3 illustrates an aerosol generating system 100 that includes an exemplary aerosol generating device 1 and an aerosol generating article 10 equivalent to those shown in FIGS. 1 and 2. Figure 3 illustrates a downstream mouth-side end portion of the aerosol generating device 1 in which a device cavity is defined and in which the aerosol generating article 10 can be received. The aerosol generating device 1 includes a housing (or body) 4 that extends between a mouth-side 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 the aerosol generating article 10. The device cavity is defined by a closed distal end and an open mouth-side end. The mouth-side end of the device cavity is located at the mouth-side end of the aerosol generating device 1. The aerosol generating article 10 is configured to be received through the mouth-side end of the device cavity and to abut against the closed end of the device cavity.

[0454] An airflow channel 5 of the device is defined within the peripheral wall 6. The airflow channel 5 extends between an inlet 7 located at the mouth-side end of the aerosol generating device 1 and the closed end of the device cavity. Air may enter the aerosol generating substrate 12 through an opening (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.

[0455] 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 the supply of such power 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 within the device 1. The heater is preferably arranged to externally heat the aerosol generating substrate 12 for optimal aerosol generation. The ventilation zone 30 is arranged to be exposed when the aerosol generating article 10 is received within the aerosol generating device 1.

[0456] In the embodiment shown in FIG. 3, the device cavity defined by the peripheral wall 6 has a length of 28 millimeters. When the article 10 is received within the device cavity, the aerosol generating rod 12 and the upstream portion of the hollow tubular cooling element 20 are received within the device cavity. Such an upstream portion of the hollow tubular cooling element 20 has a length of 11 millimeters. As a result, approximately 28 millimeters of the article 10 is received within the device 1 and approximately 17 millimeters of the article 10 is located outside of the device 1. In other words, approximately 17 millimeters of the article 10 protrudes from the device 1 when the article 10 is received therein. Such a length of the article 10 protruding from the device 1 is shown in FIG. 3.

[0457] FIG. 4 shows another embodiment of the present invention. The aerosol generating article 110 shown in FIG. 4 is similar to the aerosol generating article 10 shown in FIG. 1 and differs only in the following aspects.

[0458] The aerosol generating rod 112 comprises 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 provided upstream of the first aerosol generating segment 124 and abuts against the upstream end of the first aerosol generating segment 124. The third aerosol generating segment 128 is provided upstream of the second aerosol generating segment 126 and abuts against the upstream end of the second aerosol generating segment 126. The third aerosol generating segment 128 extends from the upstream end of the aerosol generating article 110.

[0459] The first aerosol generating segment 124 is substantially identical to the first aerosol generating segment 24 described above with respect to the aerosol generating article 10 of FIG. 1. The third aerosol generating segment 128 is substantially the same as the first aerosol generating segment 124 and has the same length and composition.

[0460] The second aerosol generating segment 126 is substantially identical to the second aerosol generating segment 26 described above with respect to the aerosol generating article 10 of FIG. 1. Thus, the aerosol generating article 110 differs from the aerosol generating article 10 of FIG. 1 only in that it includes the third aerosol generating segment 128 at the upstream end of the aerosol generating rod 112.

[0461] FIG. 5 is a diagram showing a further alternative embodiment of the present invention. The aerosol generating article 210 shown in FIG. 5 comprises an aerosol generating rod 212 and a downstream section 214 located downstream of the aerosol generating rod 212.

[0462] The aerosol generating article 210 has an overall length of about 80 millimeters and an outer diameter of about 6.5 millimeters.

[0463] The aerosol generating rod 212 comprises a first aerosol generating segment 224 and a second aerosol generating segment 226 that are coaxially aligned with each other. The second aerosol generating article 226 is provided upstream of the first aerosol generating segment 224 and abuts against the upstream end of the first aerosol generating segment 224.

[0464] The first aerosol generating segment 224 includes a first aerosol generating substrate having a length of about 15 millimeters and formed of a flake tobacco material containing about 15 weight percent glycerol. The bulk density of the first aerosol generating substrate is about 250 mg / cubic centimeter. The first aerosol generating segment 224 is individually wound by a plug wrap (not shown).

[0465] The second aerosol generating segment 226 includes a second aerosol generating substrate having a length of about 25 millimeters and formed of a homogenized tobacco material containing tobacco particles and more than 40 weight percent glycerol on a dry weight basis. The bulk density of the second aerosol generating substrate is about 600 mg / cubic centimeter. The second aerosol generating segment 226 is individually wound by a plug wrap (not shown).

[0466] For example, the downstream section 214 includes a downstream filter segment 250 between a hollow tubular cooling element 220 and a downstream hollow tubular element 260.

[0467] The hollow tubular cooling element 220 is located immediately downstream of the aerosol generating rod 212, and the hollow tubular cooling element 220 is axially aligned with the rod 212. The upstream end of the hollow tubular cooling element 220 is adjacent to the downstream end of the rod 212 of the aerosol generating substrate.

[0468] The hollow tubular element 220 has a similar configuration to the hollow tubular cooling element 20 described above in connection with FIG. 1, but has a longer length of about 25 millimeters.

[0469] As described above in connection with FIG. 1, the aerosol generating article 210 comprises a ventilation zone 230 provided at a location along the hollow tubular cooling element 220. The ventilation zone 230 comprises a circumferential array of openings or perforations surrounding the hollow tubular cooling element 220. The perforations of the ventilation zone 230 extend through the wall of the hollow tubular element 220 to allow the entry of fluid from the exterior of the article 210 into the internal cavity. The ventilation level of the aerosol generating article 210 is about 70 percent.

[0470] The downstream filter segment 250 comprises a cylindrical plug of cellulose acetate tow. The length of the downstream filter segment 250 is about 10 millimeters.

[0471] 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 internal cavity that extends throughout from the upstream end of the downstream hollow tubular cooling element 220 to the downstream end of the downstream hollow tubular element 260. The internal cavity is substantially empty and thus allows for substantially unrestricted airflow along the internal cavity. The downstream hollow tubular element 260 does not substantially contribute to the overall RTD of the aerosol generating article 10. The length of the downstream hollow tubular element 260 is about 6 millimeters. The wall thickness of the downstream hollow tubular element 260 is about 1 millimeter.

[0472] For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, etc. are to be understood as being modified in all instances by the term "about". Also, all ranges include the disclosed maximum and minimum points, and any intermediate ranges therebetween, whether or not specifically enumerated herein. Thus, in this context, the number A is to be understood as A ± 10%. Within this context, the number A may be considered to include numerical values within the general standard error of the measurement of the property being modified by the number A. The number A may deviate by the percentages recited above, in some instances used in the appended claims, provided that the amount by which A deviates does not substantially affect the basic and novel characteristics of the claimed invention. Also, all ranges include the disclosed maximum and minimum points, and any intermediate ranges therebetween, whether or not specifically enumerated herein.

Claims

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

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

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

4. The aerosol-generating article according to any one of claims 1 to 3, wherein said first aerosol-generating substrate comprises tobacco cut filler.

5. The aerosol-generating article according to any one of claims 1 to 4, wherein said second aerosol-generating segment abuts an upstream end of said first aerosol-generating segment.

6. The aerosol-generating article according to any one of claims 1 to 5, wherein said second aerosol-generating substrate comprises at least 50% by weight of glycerol on a dry weight basis.

7. The aerosol-generating article according to any one of claims 1 to 6, wherein said first aerosol-generating substrate is surrounded by a first wrapper and said second aerosol-generating substrate is surrounded by a second wrapper separate from said first wrapper.

8. The aerosol-generating article according to any one of claims 1 to 7, wherein the aerosol-forming agent content of said second aerosol-generating substrate is at least 25% higher than the aerosol-forming agent content of said first aerosol-generating substrate on a dry weight basis.

9. The aerosol-forming agent content of the second aerosol-generating substrate is at least 1.5 times that of the first aerosol-generating substrate on a dry weight basis. The aerosol-generating article according to any one of claims 1 to 8.

10. The ratio of the length of the first aerosol-generating segment to the length of the second aerosol-generating segment is 0.6 or less. The aerosol-generating article according to any one of claims 1 to 9.

11. The bulk density of the first aerosol-generating substrate is less than 400 mg / cubic centimeter, and the bulk density of the second aerosol-generating substrate is more than 500 mg / cubic centimeter. The aerosol-generating article according to any one of claims 1 to 10.

12. An upstream element provided upstream of the aerosol-generating rod and adjacent to the upstream end of the second aerosol-generating segment. The aerosol-generating article according to any one of claims 1 to 11.

13. A downstream section provided downstream of the aerosol-generating rod and extending to the downstream end of the aerosol-generating article, the downstream section comprising a hollow tubular cooling element. The aerosol-generating article according to any one of claims 1 to 12.

14. The aerosol-generating article has a ventilation level of at least 40 percent. The aerosol-generating article according to any one of claims 1 to 13.

15. An aerosol-generating system, The aerosol-generating article according to any one of claims 1 to 14, An aerosol-generating device comprising a heating chamber for receiving the aerosol-generating article and at least a heating element provided around or in the vicinity of the heating chamber. An aerosol-generating system comprising the same.

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