RU2843714C1 - Aerosol-generating article with a low density substrate - Google Patents

Abstract

FIELD: aerosol-generating articles.

SUBSTANCE: presented group of inventions relates to an aerosol-generating article comprising an aerosol-generating substrate and configured to generate an inhalable aerosol when heated. Aerosol-generating article comprises an aerosol-generating substrate, a downstream section extending from the upstream end of the aerosol-generating substrate to the upstream end of the aerosol-generating article and an additional upstream section, which is located upstream of the aerosol-generating substrate. Aerosol-generating substrate has density of not more than 0.5 gram per cubic centimetre. Ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article is not more than 0.4. Upstream located section has resistance to tightening from 10 mm H₂O to 70 mm H₂O. Aerosol-generating system comprises said aerosol-generating article and aerosol-generating device having a distal end and a mouthpiece end. Aerosol-generating device comprises a body extending from a distal end to a mouthpiece end and forming a cavity of the device for detachably placing an aerosol-generating article on the mouthpiece end of the device and a heater for heating the aerosol-generating substrate when the aerosol-generating article is placed inside the cavity of the device.

EFFECT: improved and stable aerosol delivery for the whole session of using the aerosol-generating device.

15 cl, 7 dwg, 26 ex

Description

The present invention relates to an aerosol-generating article comprising an aerosol-generating substrate and configured to generate an inhalable aerosol upon heating. In particular, the present invention relates to an aerosol-generating article comprising an aerosol-generating substrate having a low density. The present invention also relates to an aerosol-generating system comprising such an aerosol-generating device and an aerosol-generating article.

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 heat transfer from a heat source to a physically separate aerosol-generating substrate or material, which may be located in contact with, within, around, 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 are entrained in air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol.

In a number of prior art documents, aerosol-generating devices for consuming aerosol-generating articles are disclosed. Such devices include, for example, electrically heated aerosol-generating devices, in which the aerosol is generated as a result of heat transfer from one or more electrical heating elements of the aerosol-generating device to an aerosol-generating substrate of the heated aerosol-generating article. For example, electrically heated aerosol-generating devices have been proposed that comprise an internal heating blade adapted to be inserted into an aerosol-generating substrate. Alternatively, inductively heated aerosol-generating articles have been proposed in WO 2015/176898, comprising an aerosol-generating substrate and a current collector located within the aerosol-generating substrate. Another alternative has been described in WO 2020/115151, which discloses an aerosol generating article used in combination with an external heating system comprising one or more heating elements located around the periphery of the aerosol generating article.

Aerosol-generating articles in which the tobacco-containing substrate is heated rather than burned pose a number of problems not present in conventional smoking articles. First, the tobacco-containing substrates are typically heated to significantly lower temperatures than those reached by the combustion front in a conventional cigarette. Because the tobacco-containing substrates are heated to significantly lower temperatures, these substrates often include one or more aerosol forming agents designed to facilitate the generation and delivery of the aerosol from the tobacco-containing substrates.

However, it has been found that existing aerosol-generating products containing an aerosol-generating substrate containing tobacco and an aerosol-forming substance may be unable to deliver a stable aerosol. In particular, it has been found that when using such products, the aerosol-forming substance is converted into an aerosol and delivered to the user after the nicotine aerosol from the tobacco. This may result in an undesirable user experience.

Accordingly, it would be desirable to create an aerosol-generating article that provides improved and stable aerosol delivery throughout the use session of the aerosol-generating article. There is also a need for an aerosol-generating article that is particularly suitable for use in combination with an external heating system.

The present disclosure relates to an aerosol-generating article. The aerosol-generating article may comprise an aerosol-generating substrate. The aerosol-generating article may comprise a downstream portion extending from a downstream end of the aerosol-generating substrate to a downstream end of the aerosol-generating article. The aerosol-generating substrate may have a density of no more than 0.5 grams per cubic centimeter. The ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article may be no more than 0.4.

According to the present invention, an aerosol-generating article is proposed. The aerosol-generating article comprises an aerosol-generating substrate and a downstream section extending from the downstream end of the aerosol-generating substrate to the downstream end of the aerosol-generating article. The aerosol-generating substrate has a density of no more than 0.5 grams per cubic centimeter. The ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article is no more than 0.4.

It has been found that providing an aerosol generating substrate having a density of no more than 0.5 grams per cubic centimeter provides an advantage in that it is possible to improve the generation and delivery of an aerosol during a use session. As described above, in the aerosol generating articles of the prior art, the aerosol forming substance was delivered to the user after the nicotine aerosol from tobacco. This may be due to the fact that nicotine is more volatile than the aerosol forming substance, and this means that the nicotine aerosol was generated at a lower temperature than the aerosol of the aerosol forming substance. In the present invention, providing an aerosol generating substrate having a relatively low density of no more than 0.5 grams per cubic centimeter can provide the ability to heat the aerosol generating substrate more quickly compared to a high density substrate. This may be due to the fact that the volumetric heat capacity of the high density substrate will be higher than the volumetric heat capacity of the low density substrate. Therefore, the low-density aerosol-generating substrate heats up relatively quickly, which means that the aerosol-generating substrate reaches the temperature at which the aerosol-forming substance is aerosolized more quickly. This results in a shorter time gap between the generation of nicotine aerosol and the aerosol generation of the aerosol-forming substance, which results in a more stable user experience.

In addition, providing an aerosol-generating substrate having a ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article of no more than 0.4 also provides a more stable delivery of the aerosol to the user. It has been found that if the aerosol-generating substrates are longer than the substrates of the present invention, wherein the ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article is greater than 0.4, it is possible that the aerosol-generating substrate is at a temperature sufficient to generate both a nicotine aerosol and an aerosol of the aerosol-forming substance at the upstream end of the aerosol-generating substrate. However, if the aerosol-generating substrate is relatively long, then a lower temperature is possible at the downstream end of the aerosol-generating substrate. Since it is possible for the aerosol forming agent to be aerosolized at a higher temperature than nicotine, it is possible for the aerosol forming agent to condense on a lower temperature downstream portion of the aerosol generating substrate, and at the same time, it is possible for the nicotine aerosol to pass through the downstream portion of the aerosol generating substrate. As a result, the aerosol delivered to the user may be unstable and may have a relatively low concentration of the aerosol forming agent.

Accordingly, the provision of a relatively short aerosol-generating substrate according to the present invention can provide an advantage because it is possible to obtain a uniform temperature along the entire length of the aerosol-generating substrate. This makes it possible to prevent condensation of the aerosol-forming substance in a downstream region, which as a result provides an advantage in that it is possible to more stably deliver the aerosol to the user.

Accordingly, the aerosol-generating article of the present invention provides an advantage of being able to provide improved aerosol generation. In particular, the aerosol-generating article of the present invention is capable of providing more stable generation of both nicotine aerosol and aerosol of a substance for forming an aerosol throughout the entire session of use.

In addition, the aerosol-generating article of the present invention provides an advantage in that it can provide improved aerosol delivery early in the use session. This can be particularly pronounced when the aerosol-generating article is used in a humid environment. It has been found that when aerosol-generating articles of the prior art are used in high humidity environments, the aerosol-generating substrates can take longer to reach a temperature sufficient to generate the desired aerosol. This can be due to the fact that adding moisture to the aerosol-generating substrate can increase the density and volumetric heat capacity of the substrate. Without wishing to be bound by theory, it should be noted that the shorter aerosol-generating substrates of the present invention are able to heat up faster, especially in humid conditions, since they have a smaller surface area compared to the substrates of the prior art, which provides an advantage in that the substrates of the present invention can absorb less moisture in humid conditions.

According to the present invention, an aerosol-generating article is proposed for generating an inhalable aerosol upon heating. The aerosol-generating article may comprise an element comprising an aerosol-generating substrate.

The term "aerosol-generating article" is used herein to refer to an article in which an aerosol-generating substrate is heated to create an inhalable aerosol and deliver it to a consumer. As used herein, the term "aerosol-generating substrate" refers to a substrate capable of releasing volatile compounds when heated to generate an aerosol.

A conventional cigarette is lit when the user applies a flame to one end of the cigarette and draws air through the other end. The localized heat provided by the flame and the oxygen in the air drawn through the cigarette causes the end of the cigarette to ignite, and the resulting combustion generates inhaled smoke. By comparison, in heated aerosol-generating articles, the aerosol is generated by heating a flavor-generating substrate, such as tobacco. Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles in which the aerosol is generated by transferring heat from a combustible heat-generating element or heat source to a physically separate aerosol-generating material. For example, the aerosol-generating articles according to the present invention find particular application in aerosol-generating systems comprising an electrically heated aerosol-generating device having an internal heating blade which is adapted to be inserted into a rod of an aerosol-generating substrate. Aerosol-generating articles of this type are described in the prior art, for example in EP 0 822 760.

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

The aerosol-generating substrate may be contained in an aerosol-generating element. The aerosol-generating element may be in the form of a rod containing or made of the aerosol-generating substrate. As used herein in connection with the present invention, the term "rod" is used to describe a substantially cylindrical element with a substantially circular, oval or elliptical cross-section.

As used herein, the term "longitudinal" refers to a direction corresponding to the major longitudinal axis of the aerosol-generating article that extends between the upstream and downstream ends of the aerosol-generating article. As used herein, the expressions "upstream" and "downstream" describe the relative positions of elements or portions of elements of the aerosol-generating article with respect to the direction in which the aerosol is transported through the aerosol-generating article during use. During use, air is drawn through the aerosol-generating article in the longitudinal direction.

As used herein, the term "length" refers to the longitudinal dimension of a component of an aerosol-generating article from the most upstream point of the component to the most downstream point of the component. For example, it may be used to refer to the longitudinal dimension of an aerosol-generating substrate or any elongated tubular elements.

As used herein, the term "density" with respect to an aerosol-generating substrate refers to the mass of the aerosol-generating substrate divided by the volume occupied by the aerosol-generating substrate when contained in an aerosol-generating article. The "mass" of the aerosol-generating substrate does not include the mass of any wrapping material surrounding the aerosol-generating substrate. The volume occupied by the aerosol-generating substrate does not include the volume of any wrapping material surrounding the aerosol-generating substrate.

The ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article is no more than 0.4. For example, the ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article may be no more than 0.3, no more than 0.2, or no more than 0.1.

The ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article may be at least 0.025. For example, the ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article may be at least 0.05, at least 0.1, at least 0.15, or at least 0.2.

The ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article may be from 0.025 to 0.4. For example, the ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article may be from 0.025 to 0.3, from 0.025 to 0.2, or from 0.025 to 0.1.

The ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article may be from 0.05 to 0.4. For example, the ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article may be from 0.05 to 0.3, from 0.05 to 0.2, or from 0.05 to 0.1.

The ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article may be from 0.1 to 0.4. For example, the ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article may be from 0.1 to 0.3 or from 0.1 to 0.2.

The ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article may be from 0.15 to 0.4. For example, the ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article may be from 0.15 to 0.3 or from 0.15 to 0.2.

The ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article may be from 0.2 to 0.4. For example, the ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article may be from 0.2 to 0.3.

The ratio of the length of the aerosol generating substrate to the length of the aerosol generating article may be approximately 0.26.

The aerosol-generating substrate may have a length of no more than 80 millimeters. For example, the aerosol-generating substrate may have a length of no more than 65 millimeters, no more than 60 millimeters, no more than 55 millimeters, no more than 50 millimeters, no more than 40 millimeters, no more than 35 millimeters, no more than 25 millimeters, no more than 20 millimeters, or no more than 15 millimeters.

The aerosol-generating substrate may have a length of at least 5 millimeters, at least 7 millimeters, at least 10 millimeters, or at least 12 millimeters.

The aerosol-generating substrate may have a length of 5 millimeters to 80 millimeters. For example, the aerosol-generating substrate may have a length of 5 millimeters to 65 millimeters, 5 millimeters to 60 millimeters, 5 millimeters to 55 millimeters, 5 millimeters to 50 millimeters, 5 millimeters to 40 millimeters, 5 millimeters to 35 millimeters, 5 millimeters to 25 millimeters, 5 millimeters to 20 millimeters, or 5 millimeters to 15 millimeters.

The aerosol-generating substrate may have a length of between 7 millimeters and 80 millimeters. For example, the aerosol-generating substrate may have a length of between 7 millimeters and 65 millimeters, between 7 millimeters and 60 millimeters, between 7 millimeters and 55 millimeters, between 7 millimeters and 50 millimeters, between 7 millimeters and 40 millimeters, between 7 millimeters and 35 millimeters, between 7 millimeters and 25 millimeters, between 7 millimeters and 20 millimeters, or between 7 millimeters and 15 millimeters.

The aerosol-generating substrate may have a length of 5 millimeters to 80 millimeters. For example, the aerosol-generating substrate may have a length of 10 millimeters to 65 millimeters, 10 millimeters to 60 millimeters, 10 millimeters to 55 millimeters, 10 millimeters to 50 millimeters, 10 millimeters to 40 millimeters, 10 millimeters to 35 millimeters, 10 millimeters to 25 millimeters, 10 millimeters to 20 millimeters, or 10 millimeters to 15 millimeters.

The aerosol-generating substrate may have a length of 5 millimeters to 80 millimeters. For example, the aerosol-generating substrate may have a length of 12 millimeters to 65 millimeters, 12 millimeters to 60 millimeters, 12 millimeters to 55 millimeters, 12 millimeters to 50 millimeters, 12 millimeters to 40 millimeters, 12 millimeters to 35 millimeters, 12 millimeters to 25 millimeters, 12 millimeters to 20 millimeters, or 12 millimeters to 15 millimeters.

Preferably, the aerosol generating substrate may have a length of from about 16 millimeters to about 11.5 millimeters or about 12 millimeters.

As described above, providing an aerosol-generating substrate that has a relatively short length makes it possible to reduce temperature changes along the length of the aerosol-generating substrate. In particular, providing an aerosol-generating substrate that has a length within the above-mentioned ranges makes it possible to prevent the upstream end of the aerosol-generating substrate from heating to a significantly higher temperature than the downstream end of the aerosol-generating substrate. This, in turn, makes it possible to prevent condensation of less volatile components, such as an aerosol-forming substance, on the downstream portion of the aerosol-generating substrate during use. This provides the advantage of being able to help deliver a stable aerosol to the user that contains the proper proportions of volatile components from the aerosol-generating substrate.

The aerosol-generating article may have a length of at least 25 millimeters. For example, the aerosol-generating article may have a length of at least 30 millimeters, at least 35 millimeters, at least 38 millimeters, at least 40 millimeters, or at least 42 millimeters.

An aerosol-generating article may have a length of no more than 100 millimeters. For example, an aerosol-generating article may have a length of no more than 80 millimeters, no more than 70 millimeters, no more than 60 millimeters, no more than 50 millimeters, or no more than 45 millimeters.

The aerosol-generating article may have a length of between 25 millimeters and 100 millimeters. For example, the aerosol-generating article may have a length of between 25 millimeters and 80 millimeters, between 25 millimeters and 70 millimeters, between 25 millimeters and 60 millimeters, between 25 millimeters and 50 millimeters, or between 25 millimeters and 45 millimeters.

The aerosol-generating article may have an overall length of between 30 millimeters and 100 millimeters. For example, the aerosol-generating article may have a length of between 30 millimeters and 80 millimeters, between 30 millimeters and 70 millimeters, between 30 millimeters and 60 millimeters, between 30 millimeters and 50 millimeters, or between 30 millimeters and 45 millimeters.

The aerosol-generating article may have a length of 35 millimeters to 100 millimeters. The aerosol-generating article may have a length of 35 millimeters to 80 millimeters, 35 millimeters to 70 millimeters, 35 millimeters to 60 millimeters, 35 millimeters to 50 millimeters, or 35 millimeters to 45 millimeters.

The aerosol-generating article may have a length of between 38 millimeters and 100 millimeters. For example, the aerosol-generating article may have a length of between 38 millimeters and 80 millimeters, between 38 millimeters and 70 millimeters, between 38 millimeters and 60 millimeters, between 38 millimeters and 50 millimeters, or between 38 millimeters and 45 millimeters.

The aerosol-generating article may have a length of between 40 millimeters and 100 millimeters. For example, the aerosol-generating article may have a length of between 40 millimeters and 80 millimeters, between 40 millimeters and 70 millimeters, between 40 millimeters and 60 millimeters, between 40 millimeters and 50 millimeters, or between 40 millimeters and 45 millimeters.

The aerosol-generating article may have a length of between 42 millimeters and 100 millimeters. For example, the aerosol-generating article may have a length of between 42 millimeters and 80 millimeters, between 42 millimeters and 70 millimeters, between 42 millimeters and 60 millimeters, between 42 millimeters and 50 millimeters, or between 42 millimeters and 45 millimeters.

The aerosol generating article may be approximately 45 millimetres in length.

The aerosol-generating article may be at least 20 millimeters longer than the aerosol-generating substrate. For example, the aerosol-generating article may be at least 25 millimeters longer than the aerosol-generating substrate, at least 30 millimeters longer than the aerosol-generating substrate, or at least 33 millimeters longer than the aerosol-generating substrate.

The aerosol-generating article may be no more than 100 millimeters longer than the aerosol-generating substrate. For example, the aerosol-generating article may be no more than 80 millimeters longer than the aerosol-generating substrate, no more than 60 millimeters longer than the aerosol-generating substrate, or no more than 40 millimeters longer than the aerosol-generating substrate.

The aerosol generating article may be approximately 33 millimeters longer than the aerosol generating substrate.

The aerosol-generating substrate may have a density of no more than 1 gram per cubic centimeter. For example, the aerosol-generating substrate may have a density of no more than 0.5 grams per cubic centimeter or 0.7 grams per cubic centimeter.

In preferred embodiments, the aerosol-generating substrate may have a density of no more than 0.45 grams per cubic centimeter, no more than 0.4 grams per cubic centimeter, no more than 0.34 grams per cubic centimeter, no more than 0.3 grams per cubic centimeter, or no more than 0.25 grams per cubic centimeter.

The aerosol-generating substrate may have a density of at least 0.1 grams per cubic centimeter. For example, the aerosol-generating substrate may have a density of at least 0.15 grams per cubic centimeter, at least 0.2 grams per cubic centimeter, or at least 0.24 grams per cubic centimeter.

The aerosol-generating substrate may have a density of between 0.1 grams per cubic centimeter and 0.45 grams per cubic centimeter. For example, the aerosol-generating substrate may have a density of between 0.1 grams per cubic centimeter and 0.4 grams per cubic centimeter, between 0.1 grams per cubic centimeter and 0.34 grams per cubic centimeter, between 0.1 grams per cubic centimeter and 0.3 grams per cubic centimeter, or between 0.1 grams per cubic centimeter and 0.34 grams per cubic centimeter.

The aerosol-generating substrate may have a density of 0.15 grams per cubic centimeter to 0.45 grams per cubic centimeter. For example, the aerosol-generating substrate may have a density of 0.15 grams per cubic centimeter to 0.4 grams per cubic centimeter, 0.15 grams per cubic centimeter to 0.34 grams per cubic centimeter, 0.15 grams per cubic centimeter to 0.3 grams per cubic centimeter, or 0.15 grams per cubic centimeter to 0.34 grams per cubic centimeter.

The aerosol-generating substrate may have a density of 0.2 grams per cubic centimeter to 0.45 grams per cubic centimeter. For example, the aerosol-generating substrate may have a density of 0.2 grams per cubic centimeter to 0.4 grams per cubic centimeter, 0.21 grams per cubic centimeter to 0.34 grams per cubic centimeter, 0.2 grams per cubic centimeter to 0.3 grams per cubic centimeter, or 0.2 grams per cubic centimeter to 0.34 grams per cubic centimeter.

The aerosol-generating substrate may have a density of 0.24 grams per cubic centimeter to 0.45 grams per cubic centimeter. For example, the aerosol-generating substrate may have a density of 0.24 grams per cubic centimeter to 0.4 grams per cubic centimeter, 0.24 grams per cubic centimeter to 0.34 grams per cubic centimeter, 0.24 grams per cubic centimeter to 0.3 grams per cubic centimeter, or 0.24 grams per cubic centimeter to 0.34 grams per cubic centimeter.

Preferably, the aerosol generating substrate may have a density of approximately 0.28 grams per cubic centimeter.

As noted above, providing an aerosol-generating substrate that has a relatively low density may allow for a relatively rapid increase in the temperature of the aerosol-generating substrate at the start of a use session. This may allow for the simultaneous aerosolization of all of the necessary volatile components within the aerosol-generating substrate to be promoted. This may provide the advantage of preventing less volatile components, such as the aerosol-forming agent, from being delivered to the user after more volatile components, such as nicotine. This may therefore result in a more consistent user experience.

The aerosol-generating substrate may be contained within an aerosol-generating element. For example, the aerosol-generating article may comprise a rod of aerosol-generating substrate surrounded by a wrapper.

The aerosol generating element may have a density of no more than 1 gram per cubic centimeter. For example, the aerosol generating element may have a density of no more than 0.5 grams per cubic centimeter or 0.7 grams per cubic centimeter.

As used herein, the term "density" with respect to an aerosol-generating element refers to the mass of the aerosol-generating element divided by the volume occupied by the aerosol-generating element when located in an aerosol-generating article. The mass of the aerosol-generating element includes the mass of the aerosol-generating substrate and any wrapping material surrounding the aerosol-generating substrate. The "volume" occupied by the aerosol-generating element includes the volume of the aerosol-generating substrate and the volume of any wrapping material surrounding the aerosol-generating substrate.

In preferred embodiments, the aerosol generating element may have a density of no more than 0.45 grams per cubic centimeter, no more than 0.4 grams per cubic centimeter, no more than 0.34 grams per cubic centimeter, no more than 0.3 grams per cubic centimeter, or no more than 0.25 grams per cubic centimeter.

The aerosol generating element may have a density of at least 0.1 grams per cubic centimeter. For example, the aerosol generating substrate may have a density of at least 0.15 grams per cubic centimeter, at least 0.2 grams per cubic centimeter, or at least 0.24 grams per cubic centimeter.

The aerosol generating element may have a density of 0.1 grams per cubic centimeter to 0.45 grams per cubic centimeter. For example, the aerosol generating element may have a density of 0.1 grams per cubic centimeter to 0.4 grams per cubic centimeter, 0.1 grams per cubic centimeter to 0.34 grams per cubic centimeter, 0.1 grams per cubic centimeter to 0.3 grams per cubic centimeter, or 0.1 grams per cubic centimeter to 0.34 grams per cubic centimeter.

The aerosol generating element may have a density of 0.15 grams per cubic centimeter to 0.45 grams per cubic centimeter. For example, the aerosol generating element may have a density of 0.15 grams per cubic centimeter to 0.4 grams per cubic centimeter, 0.15 grams per cubic centimeter to 0.34 grams per cubic centimeter, 0.15 grams per cubic centimeter to 0.3 grams per cubic centimeter, or 0.15 grams per cubic centimeter to 0.34 grams per cubic centimeter.

The aerosol generating element may have a density of 0.2 grams per cubic centimeter to 0.45 grams per cubic centimeter. For example, the aerosol generating element may have a density of 0.2 grams per cubic centimeter to 0.4 grams per cubic centimeter, 0.21 grams per cubic centimeter to 0.34 grams per cubic centimeter, 0.2 grams per cubic centimeter to 0.3 grams per cubic centimeter, or 0.2 grams per cubic centimeter to 0.34 grams per cubic centimeter.

The aerosol generating element may have a density of 0.24 grams per cubic centimeter to 0.45 grams per cubic centimeter. For example, the aerosol generating element may have a density of 0.24 grams per cubic centimeter to 0.4 grams per cubic centimeter, 0.24 grams per cubic centimeter to 0.34 grams per cubic centimeter, 0.24 grams per cubic centimeter to 0.3 grams per cubic centimeter, or 0.24 grams per cubic centimeter to 0.34 grams per cubic centimeter.

Preferably, the aerosol generating element may have a density of approximately 0.29 grams per cubic centimeter.

The aerosol-generating substrate may be a solid aerosol-generating substrate.

The aerosol-generating substrate may comprise homogenized plant material. The aerosol-generating substrate may comprise tobacco. The aerosol-generating substrate may comprise homogenized tobacco material.

As used herein, the term "homogenized plant material" encompasses any plant material obtained by agglomerating plant particles. For example, sheets or webs of homogenized tobacco material for aerosol-generating substrates according to the present invention can be obtained by agglomerating tobacco material particles obtained by grinding, milling or grinding the plant material and, optionally, one or more of the lamellae of tobacco leaf and the veins of tobacco leaf. The homogenized plant material can be obtained by casting processes, extrusion processes, papermaking or any other suitable methods known in the art.

The homogenized plant material may be provided in any suitable form.

The homogenized plant material may be in the form of one or more sheets. As used herein with reference to the present invention, the term "sheet" describes a flat element whose width and length are substantially greater than its thickness.

The homogenized plant material may be present in the form of a plurality of beads or granules.

The homogenized plant material may be present in the form of a plurality of strands, strips or pieces. As used herein, the term "strand" describes an elongated element of material whose length substantially exceeds its width and thickness. The term "strand" should be considered to include strips, pieces and any other homogenized plant material having a similar shape. The strands of homogenized plant material may be obtained from a sheet of homogenized plant material, for example, by cutting, grinding or other methods, such as an extrusion method.

In some embodiments, the filaments may be produced in situ within the aerosol-generating substrate by splitting or cracking a sheet of homogenized plant material during the production of the aerosol-generating substrate, such as by pleating. The filaments of homogenized plant material within the aerosol-generating substrate may be separated from each other. Alternatively, each filament of homogenized plant material within the aerosol-generating substrate may be at least partially connected to an adjacent filament or filaments along the length of the filaments. For example, adjacent filaments may be connected by one or more fibers. This may be the case, for example, if the filaments were produced by splitting a sheet of homogenized plant material during the production of the aerosol-generating substrate, as described above.

If the aerosol-generating substrate comprises homogenized plant material, this homogenized plant material can typically be provided in the form of one or more sheets. In particular, the sheets of homogenized plant material can be obtained by a casting process. Preferably, the sheets of homogenized plant material can be obtained by a papermaking process.

The aerosol-generating substrate may contain cut filler. The aerosol-generating substrate may contain cut tobacco filler.

As used herein, the term "cut filler" is used to describe a mixture of ground plant material, such as tobacco plant material, including, in particular, one or more of leaf blades, processed stems and veins, and homogenized plant material.

Cut filler may also contain other cut tobacco, filler tobacco or casing.

Preferably, the cut filler comprises at least 25 percent of the plant blades, more preferably at least 50 percent of the plant blades, even more preferably at least 75 percent of the plant blades, most preferably at least 90 percent of the plant blades. Preferably, the plant material is one of tobacco, mint, tea and cloves. However, as will be discussed in more detail below, the present invention is equally applicable to other plant material capable of releasing substances under the action of heat that can subsequently form an aerosol.

Preferably, the cut filler comprises tobacco plant material comprising lamellas of one or more of light tobacco, dark tobacco, aromatic tobacco and tobacco filler. As used herein, the term "tobacco" describes any plant of the genus Nicotiana.

Light tobaccos are tobaccos with generally large leaves of light color. Throughout this description, the term "light tobacco" is used for tobaccos that have been fire-cured. Examples of light tobaccos are Chinese flue-cured tobacco, Brazilian flue-cured tobacco, American flue-cured tobacco such as Virginia tobacco, Indian flue-cured tobacco, Tanzanian flue-cured tobacco or other African flue-cured tobaccos. Light tobacco is characterized by a high sugar to nitrogen ratio. From an organoleptic perception point of view, light tobacco is a type of tobacco that after curing is associated with a spicy and rich sensation. In the context of the present invention, light tobaccos are tobaccos with a reducing sugar content of from about 2.5 percent to about 20 percent based on the dry weight of the leaves and a total ammonia content of less than about 0.12 percent based on the dry weight of the leaves. Reducing sugars contain, for example, glucose or fructose. Total ammonia contains, for example, ammonia and ammonia salts.

Dark tobaccos are tobaccos with generally large leaves and a dark color. Throughout this description, the term "dark tobacco" is used for tobaccos that have been air-cured. In addition, dark tobaccos may be fermented. Tobaccos that are used primarily for chewing, snuff, cigars, and pipe blends are also included in this category. Typically, these dark tobaccos are air-cured and possibly fermented. From an organoleptic point of view, dark tobacco is a type of tobacco that, after curing, is associated with the smoke sensation characteristic of a dark type of cigar. Dark tobacco is characterized by a low sugar to nitrogen ratio. Examples of dark tobacco are Malawi Burley or other types of African Burley, dark cured Brazilian Galpao, and sun-cured or air-cured Indonesian Kasturi. According to the present invention, dark tobaccos are tobaccos with a reducing sugar content of less than about 5 percent based on the dry weight of the leaves and a total ammonia content of no more than about 0.5 percent based on the dry weight of the leaves.

Aromatic tobaccos are tobaccos that often have small, light-colored leaves. Throughout this description, the term "aromatic tobacco" is used in relation to other tobaccos that have a high content of aromatic substances, such as essential oils. From the point of view of organoleptic perception, aromatic tobacco is a tobacco of a type that, after curing, is associated with a spicy and aromatic sensation. Examples of aromatic tobaccos are Greek oriental, Turkish oriental, semi-oriental tobacco, but also fire-cured American Burley, such as Perique, shag, American Burley or Maryland. Filler tobacco is not a tobacco of a specific type and includes tobaccos of those types that are primarily used to complement other types of tobaccos used in a blend and which do not impart a specific characteristic aromatic property to the final product. Examples of filler tobacco are stems, midribs or petioles of other types of tobaccos. A specific example is the flue-cured stems from the lower petioles of flue-cured Brazilian tobacco.

The cut filler suitable for use in the present invention may be generally 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, more preferably the cut width of the cut filler is from 0.5 millimeters to 1.2 millimeters, and most preferably the cut width of the cut filler is from 0.6 millimeters to 0.9 millimeters. The cut width can affect the heat distribution inside the aerosol-generating element. Also, the cut width can affect the resistance to draw (RTD) of the article. In addition, the cut width can affect the overall density of the aerosol-generating substrate as a whole.

The length of the threads of the cut filler is to some extent a random value, since the length of the threads will depend on the overall size of the object from which the thread is cut. However, by conditioning the material before cutting, for example by adjusting the moisture content and the overall fineness of the material, it is possible to cut longer threads. Preferably, the threads have a length of from about 10 millimeters to about 40 millimeters before the threads are combined to form an aerosol generating element. Obviously, if the threads are located in the aerosol generating element in the longitudinal direction, wherein the longitudinal extent of the section is less than 40 millimeters, then the final aerosol generating element may contain threads that are on average shorter than the original thread length. Preferably, the length of the threads of the cut filler is such that from about 20 percent to 60 percent of the threads extend along the entire length of the aerosol generating element. This prevents the filaments from being easily displaced from the aerosol generating element.

The aerosol-generating substrate may contain any amount of cut filler. For example, the aerosol-generating substrate may contain at least 80 milligrams of cut filler, at least 100 milligrams of cut filler, at least 150 milligrams of cut filler, at least about 170 milligrams of cut filler.

The aerosol-generating substrate may contain no more than 400 milligrams of cut filler. For example, the aerosol-generating substrate may contain no more than 300 milligrams of cut filler, no more than 250 milligrams of cut filler, or no more than 220 milligrams of cut filler.

The aerosol-generating substrate may contain from 80 milligrams to 400 milligrams of cut filler. For example, the aerosol-generating substrate may contain from 100 milligrams to 300 milligrams of cut filler, from 150 milligrams to 250 milligrams of cut filler, or from 170 milligrams to 220 milligrams of cut filler.

Preferably, the aerosol generating substrate may contain approximately 200 milligrams of cut filler.

This amount of cut filler generally provides the ability to obtain a sufficient amount of material to form an aerosol. In addition, in light of the above-mentioned limitations on diameter and size, it provides the ability to obtain a density of the aerosol generating element that provides a balance between energy absorption, draw resistance and fluid passages within the aerosol generating element, wherein the aerosol generating substrate contains plant material.

The aerosol-generating substrate may contain an aerosol-generating substance.

If the aerosol-generating substrate comprises a cut filler, the cut filler may be impregnated with an aerosol-forming agent. The impregnation of the cut filler may be accomplished by spraying or other suitable application methods. The aerosol-forming agent may be added to the mixture during the preparation of the cut filler. For example, the aerosol-forming agent may be added to the mixture in a direct conditioning casing cylinder (DCCC). Conventional equipment may be used to apply the aerosol-forming agent to the cut filler. The aerosol-forming agent may be any suitable known compound or mixture of compounds that, when used, provide for the formation of a dense and stable aerosol. The aerosol-forming agent provides the ability to help the aerosol be substantially resistant to thermal deterioration at temperatures typically encountered during use of the aerosol-generating article. Suitable aerosol forming substances are, for example: polyhydric alcohols, such as, for example, triethylene glycol, 1,3-butanediol, propylene glycol and glycerol; esters of polyhydric alcohols, such as, for example, glycerol mono-, di- or triacetate; aliphatic esters of mono-, di- or polycarboxylic acids, such as, for example, dimethyl dodecanedioate and dimethyl tetradecanedioate; and combinations thereof.

Preferably, the aerosol forming agent comprises one or more of glycerin and propylene glycol. The aerosol forming agent may consist of glycerin or propylene glycol or a combination of glycerin and propylene glycol.

The aerosol-generating substrate may contain any amount of an aerosol-forming substance. For example, the aerosol-generating substrate may contain at least 5 weight percent of an aerosol-forming substance, at least 6 weight percent of an aerosol-forming substance, at least 8 weight percent of an aerosol-forming substance, or at least 10 weight percent of an aerosol-forming substance.

An aerosol-generating substrate may contain no more than 20 percent of an aerosol-forming substance. For example, an aerosol-generating substrate may contain no more than 18 percent of an aerosol-forming substance or no more than 15 percent of an aerosol-forming substance.

The aerosol-generating substrate may contain from 5 weight percent of the aerosol-forming agent to 20 weight percent of the aerosol-forming agent. For example, the aerosol-generating substrate may contain from 6 weight percent of the aerosol-forming agent to 18 weight percent of the aerosol-forming agent, from 8 weight percent of the aerosol-forming agent to 15 weight percent of the aerosol-forming agent, or from 10 weight percent of the aerosol-forming agent to 15 weight percent of the aerosol-forming agent.

Preferably, the aerosol-generating substrate comprises approximately 13 weight percent of the aerosol forming agent. The weight percentages of the aerosol forming agent are based on the dry weight of the cut filler.

The most optimal amount of aerosol former will also depend on the cut media, whether the cut media contains plant leaf blades or homogenized plant material. For example, among other factors, the type of cut media will determine the degree to which the aerosol former is able to facilitate the release of substances from the aerosol-generating substrate.

For these reasons, the aerosol generating element comprising the cut filler described above is capable of efficiently generating sufficient amounts of aerosol at relatively low temperatures. Temperatures of 150 degrees Celsius to 200 degrees Celsius in the heating chamber are sufficient for one such cut filler to generate sufficient amounts of aerosol, while aerosol generating devices using cast sheets of tobacco leaves typically use temperatures of approximately 250 degrees Celsius.

An additional benefit associated with operating at lower temperatures is that the need for aerosol cooling is reduced. Since generally low temperatures are used, a simpler cooling function may be sufficient. This, in turn, allows for a simpler and less complex design of the aerosol generating product.

As briefly described above, if the aerosol generating substrate comprises homogenized plant material, then the homogenized plant material may be provided in the form of one or more sheets.

Each of the one or more sheets described herein may have an individual thickness of 100 micrometers to 600 micrometers, preferably 150 micrometers to 300 micrometers, most preferably 200 micrometers to 250 micrometers. The individual thickness refers to the thickness of an individual sheet, while the aggregate thickness refers to the total thickness of all sheets that form the aerosol-generating substrate. For example, if the aerosol-generating substrate is formed from two individual sheets, then the aggregate thickness is the sum of the thicknesses of the two individual sheets or the measured thickness of the two sheets when these two sheets are stacked on each other in the aerosol-generating substrate.

Each of the one or more sheets described herein may have an individual grammage of from about 100 grams per square meter to about 600 grams per square meter.

Each of said one or more sheets, as described herein, may have an individual density of from about 0.3 grams per cubic centimeter to about 1.3 grams per cubic centimeter, preferably from about 0.7 grams per cubic centimeter to about 1.0 grams per cubic centimeter.

In those embodiments of the present invention in which the aerosol-generating substrate comprises one or more sheets of homogenized plant material, these sheets are preferably provided in the form of one or more assembled sheets. The term "assembled" as used herein is used to describe a sheet of homogenized plant material that is rolled, bent, or otherwise compressed or narrowed in a direction substantially transverse to the cylindrical axis of the plug or rod.

Said one or more sheets of homogenized plant material may be collected transversely relative to its longitudinal axis and surrounded by a wrapper to form a continuous rod or plug.

As an advantage, said one or more sheets of homogenized plant material may be corrugated or similarly treated. As used herein, the term "corrugated" means a sheet having a plurality of substantially parallel folds or corrugations. As an alternative or in addition to corrugation, said one or more sheets of homogenized plant material may be embossed, blind embossed, perforated or otherwise deformed to provide texture on one or both sides of the sheet.

Preferably, each sheet of homogenized plant material can be corrugated so that it has a plurality of folds or corrugations substantially parallel to the cylindrical axis of the plug. This treatment provides the advantage of being able to facilitate the collection of the corrugated sheet of homogenized plant material to form the plug. Preferably, said one or more sheets of homogenized plant material can be collected. It should be understood that the corrugated sheets of homogenized plant material can have a plurality of substantially parallel folds or corrugations located at an acute or obtuse angle to the cylindrical axis of the plug. The sheet can be corrugated to such an extent that the integrity of the sheet is broken at said plurality of parallel folds or corrugations, which causes separation of the material and leads to the formation of pieces, threads or strips of homogenized plant material.

Alternatively, said one or more sheets of homogenized plant material may be cut into threads, as mentioned above. In such embodiments, the aerosol-generating substrate comprises a plurality of threads of homogenized plant material. The threads may be used to form a plug. Typically, the width of such threads is about 5 millimeters, or about 4 millimeters, or about 3 millimeters, or about 2 millimeters or less. The length of the threads may be greater than about 5 millimeters, in particular from about 5 millimeters to about 15 millimeters, from about 8 millimeters to about 12 millimeters, or about 12 millimeters. Preferably, the threads have substantially the same length as each other.

The homogenized plant material may contain up to about 95 percent by weight of plant particles on a dry weight basis. Preferably, the homogenized plant material contains up to about 90 percent by weight of plant particles, more preferably up to about 80 percent by weight of plant particles, more preferably up to about 70 percent by weight of plant particles, more preferably up to about 60 percent by weight of plant particles, more preferably up to about 50 percent by weight of plant particles on a dry weight basis.

For example, the homogenized plant material may contain from about 2.5 percent to about 95 percent by weight of plant particles, or from about 5 percent to about 90 percent by weight of plant particles, or from about 10 percent to about 80 percent by weight of plant particles, or from about 15 percent to about 70 percent by weight of plant particles, or from about 20 percent to about 60 percent by weight of plant particles, or from about 30 percent to about 50 percent by weight of plant particles on a dry weight basis.

In some embodiments of the present invention, the homogenized plant material is a homogenized tobacco material comprising tobacco particles. Sheets of homogenized tobacco material for use in such embodiments of the present invention may have a tobacco content of at least about 40 percent by weight on a dry basis, more preferably at least about 50 percent by weight on a dry basis, more preferably at least about 70 percent by weight on a dry basis, and most preferably at least about 90 percent by weight on a dry basis.

As used herein, the term "tobacco particles" describes particles of any plant of the genus Nicotiana. The term "tobacco particles" includes ground or powdered tobacco leaf lamellae, ground or powdered tobacco leaf stems, tobacco dust, tobacco fines, and other particulate tobacco by-products generated during the processing, handling, and shipping of tobacco. In a preferred embodiment, substantially all of the tobacco particles are derived from tobacco leaf lamellae. In contrast, isolated nicotine and nicotine salts are compounds derived from tobacco but are not considered tobacco particles for the purposes of this invention and are not included in the percentage of particulate plant material.

The aerosol-generating substrate may further comprise one or more aerosol formers. Upon evaporation, the aerosol former may carry in the aerosol other vaporized compounds released from the aerosol-generating substrate upon heating, such as nicotine and flavoring agents. Aerosol formers suitable for inclusion in the homogenized plant material 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 such as glycerol mono-, di-, or triacetate; and aliphatic esters of mono-, di-, or polycarboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate.

The aerosol-generating substrate may have an aerosol forming agent content of about 5 percent to about 30 percent by weight on a dry weight basis, such as about 10 percent to about 25 percent by weight on a dry weight basis or about 15 percent to about 20 percent by weight on a dry weight basis. The aerosol-generating substrate may have an aerosol forming agent content of about 12 percent by weight on a dry weight basis.

The aerosol-generating substrate may have an aerosol-forming substance content of at least about 1 percent on a dry weight basis. For example, the aerosol-generating substrate may have an aerosol-forming substance content of at least about 5 percent, at least about 10 percent, at least about 15 percent, at least about 20 percent, at least about 25 percent, or at least about 30 percent on a dry weight basis.

For example, if the substrate is intended for use in an aerosol-generating article for an electric aerosol-generating system having a heating element, then it may preferably have an aerosol-forming substance content of from about 5 percent to about 30 percent by weight on a dry weight basis. If the substrate is intended for use in an aerosol-generating article for an electric aerosol-generating system having a heating element, then the aerosol-forming substance is preferably glycerin.

In other embodiments, the aerosol-generating substrate may have an aerosol forming agent content of from about 1 percent to about 5 percent by weight on a dry weight basis. For example, if the substrate is intended for use in an aerosol-generating article in which the aerosol forming agent is stored in a reservoir separate from the substrate, the substrate may have an aerosol forming agent content greater than 1 percent and less than about 5 percent. In such embodiments, the aerosol forming agent is vaporized upon heating, and a stream of the aerosol forming agent is contacted with the aerosol-generating substrate to entrain flavors from the aerosol-generating substrate into the aerosol.

In other embodiments, the aerosol-generating substrate may have an aerosol former content of from about 30 percent by weight to about 45 percent by weight. This relatively high level of aerosol former is particularly suitable for aerosol-generating substrates that are intended to be heated at a temperature of less than 275 degrees Celsius. In such embodiments, the aerosol-generating substrate preferably further comprises from about 2 percent by weight to about 10 percent by weight of a cellulose ether on a dry weight basis and from about 5 percent by weight to about 50 percent by weight of additional cellulose on a dry weight basis. It has been found that the use of a combination of a cellulose ether and additional cellulose provides particularly effective aerosol delivery when used in an aerosol-generating substrate having an aerosol former content of from 30 percent by weight to 45 percent by weight.

Suitable cellulose ethers include, but are not limited to, methylcellulose, hydroxypropylmethylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, ethylhydroxyethylcellulose, and carboxymethylcellulose (CMC). In particularly preferred embodiments, the cellulose ether is carboxymethylcellulose.

As used herein, the term "additional cellulose" encompasses any cellulosic material included in the aerosol-generating substrate and not derived from non-tobacco plant particles or tobacco particles provided in the aerosol-generating substrate. Accordingly, the additional cellulose is included in the aerosol-generating substrate in addition to the non-tobacco plant material or tobacco material as a source of cellulose separate and distinct from any cellulose originally provided in the non-tobacco plant particles or tobacco particles. The additional cellulose is typically derived from a plant other than that from which the non-tobacco plant particles or tobacco particles are derived. Preferably, the additional cellulose is present as an inert cellulose material that is inert to the senses and therefore does not significantly affect the organoleptic characteristics of the aerosol generated from the aerosol-generating substrate. For example, the additional cellulose is preferably a tasteless and odorless material.

Additional cellulose may contain cellulose powder, cellulose fibers, or a combination of both.

The aerosol forming agent can act as a humectant in the aerosol generating substrate.

The wrapper surrounding the rod of homogenized plant material may be a paper wrapper or a non-paper wrapper. Paper wrappers suitable for use in certain embodiments of the present invention are known in the art and include, but are not limited to: cigarette paper of various types and filter wicks. Non-paper wrappers suitable 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 materials. In certain preferred embodiments, the wrapper may be made of a laminate containing a plurality of layers. Preferably, the wrapper is made of a laminated sheet containing aluminum. The use of a laminated sheet containing aluminum provides the advantage of preventing combustion of the aerosol-generating substrate in the event that the aerosol-generating substrate is ignited rather than heated properly.

In some preferred embodiments of the present invention, the aerosol-generating substrate comprises a gel composition that includes an alkaloid compound and/or a cannabinoid compound. In particularly preferred embodiments, the aerosol-generating substrate comprises a gel composition that includes nicotine.

Preferably, the gel composition comprises an alkaloid compound and/or a cannabinoid compound; an aerosol forming agent; and at least one gelling agent. Preferably, said at least one gelling agent forms a solid medium, and glycerol is dispersed in said solid medium, and the alkaloid or cannabinoid is dispersed in glycerol. Preferably, the gel composition is a stable gel phase.

As an advantage, the stable gel composition containing nicotine provides a predictable shape of the composition during storage or transportation from the place of production to the consumer. The stable gel composition containing nicotine substantially retains its shape. The stable gel composition containing nicotine substantially does not release a liquid phase during storage or transportation from the place of production to the consumer. The stable gel composition containing nicotine is able to provide a simple design of the consumable part. This consumable part does not necessarily have to be designed to accommodate liquid, and thus it is possible to consider a wider range of materials and designs for the container.

The gel composition described herein may be combined with an aerosol generating device for delivering nicotine aerosol to the lungs at inhalation rates or airflow rates that do not exceed the inhalation rates or airflow rates of a typical smoking regimen. The aerosol generating device may continuously heat the gel composition. The consumer may inhale a plurality of inhalations or "puffs," with each "puff" delivering a certain amount of nicotine aerosol. The gel composition may be capable of delivering a high nicotine/low total particulate matter (TPM) aerosol to the consumer upon heating, preferably in a continuous manner.

The term "stable gel phase" or "stable gel" refers to a gel that substantially maintains its shape and mass under varying environmental conditions. A stable gel may substantially not release (moisture) or absorb water under standard temperature and pressure conditions with a relative humidity of about 10 percent to about 60 percent. For example, a stable gel may substantially maintain its shape and mass under standard temperature and pressure conditions with a relative humidity of about 10 percent to about 60 percent.

The gel composition includes an alkaloid compound and/or a cannabinoid compound. The gel composition may include one or more alkaloids. The gel composition may include one or more cannabinoids. The gel composition may include a combination of one or more alkaloids and one or more cannabinoids.

The term "alkaloid compound" refers to any of a class of naturally occurring organic compounds that contain one or more basic nitrogen atoms. Typically, an alkaloid contains at least one nitrogen atom in an amine-type structure. This or another nitrogen atom in the alkaloid compound molecule can be active as a base in acid-base reactions. Most alkaloid compounds have one or more nitrogen atoms as part of a cyclic system, such as a heterocyclic ring. In nature, alkaloid compounds are found primarily in plants, and they are especially common in certain families of flowering plants. However, some alkaloid compounds are found in certain species of animals and fungi. In the present disclosure, the term "alkaloid compound" refers to both naturally occurring alkaloid compounds and synthetically produced alkaloid compounds.

The gel composition may preferably include an alkaloid compound selected from the group consisting of nicotine, anatabine, and combinations thereof.

Preferably, the gel composition comprises nicotine.

The term "nicotine" refers to nicotine and nicotine derivatives such as pure nicotine, nicotine salts, and the like.

The term "cannabinoid compound" refers to any of a class of naturally occurring compounds found in parts of the cannabis plant, namely the species Cannabis sativa, Cannabis indica, and Cannabis ruderalis. Cannabinoid compounds are particularly concentrated in the female flower heads. Cannabinoid compounds naturally occurring in the cannabis plant include cannabidiol (CBD) and tetrahydrocannabinol (THC). In the present disclosure, the term "cannabinoid compounds" is used to describe both naturally occurring cannabinoid compounds and synthetically produced cannabinoid compounds.

Those embodiments of the present invention in which the aerosol-generating element comprises an aerosol-generating substrate comprising a gel composition as described above may advantageously comprise an upstream element that is positioned upstream of the aerosol-generating element. In this case, the upstream element provides the advantage of preventing physical contact with the gel composition. The upstream element also provides the advantage of being able to compensate for any potential decrease in drag resistance, such as due to evaporation of the gel composition when the aerosol-generating element is heated during use. Further details regarding the provision of one such upstream element will be described below.

The aerosol-generating substrate may have a length-to-diameter ratio of no greater than 6.0. For example, the aerosol-generating substrate may have a length-to-diameter ratio of no greater than 5.5, no greater than 5.0, no greater than 4.5, no greater than 4.0, no greater than 3.5, no greater than 3.0, no greater than 2.5, or no greater than 2.0. The aerosol-generating substrate may have a length-to-diameter ratio of no greater than 1.9.

The aerosol-generating substrate may have a length-to-diameter ratio of at least 0.25. For example, the aerosol-generating substrate may have a length-to-diameter ratio of at least 0.5, at least 0.75, at least 1.0, at least 1.25, at least 1.3, or at least 1.5.

The aerosol-generating substrate may have a length-to-diameter ratio of 0.25 to 6.0. For example, the aerosol-generating substrate may have a length-to-diameter ratio of 0.25 to 5.5, 0.25 to 5.0, 0.25 to 4.5, 0.25 to 4.0, 0.25 to 3.5, 0.25 to 3.0, 0.25 to 2.5, 0.25 to 2.0, or 0.25 to 1.9.

The aerosol-generating substrate may have a length-to-diameter ratio of 0.5 to 6.0. For example, the aerosol-generating substrate may have a length-to-diameter ratio of 0.5 to 5.5, 0.5 to 5.0, 0.5 to 4.5, 0.5 to 4.0, 0.5 to 3.5, 0.5 to 3.0, 0.5 to 2.5, 0.5 to 2.0, or 0.5 to 1.9.

The aerosol-generating substrate may have a length-to-diameter ratio of 0.75 to 6.0. For example, the aerosol-generating substrate may have a length-to-diameter ratio of 0.75 to 5.5, 0.75 to 5.0, 0.75 to 4.5, 0.75 to 4.0, 0.75 to 3.5, 0.75 to 3.0, 0.75 to 2.5, 0.75 to 2.0, or 0.75 to 1.9.

The aerosol-generating substrate may have a length-to-diameter ratio of 1.0 to 6.0. For example, the aerosol-generating substrate may have a length-to-diameter ratio of 1.0 to 5.5, 1.0 to 5.0, 1.0 to 4.5, 1.0 to 4.0, 1.0 to 3.5, 1.0 to 3.0, 1.0 to 2.5, 1.0 to 2.0, or 1.0 to 1.9.

The aerosol-generating substrate may have a length-to-diameter ratio of 1.25 to 6.0. For example, the aerosol-generating substrate may have a length-to-diameter ratio of 1.25 to 5.5, 1.25 to 5.0, 1.25 to 4.5, 1.25 to 4.0, 1.25 to 3.5, 1.25 to 3.0, 1.25 to 2.5, 1.25 to 2.0, or 1.25 to 1.9.

The aerosol-generating substrate may have a length-to-diameter ratio of 1.5 to 6.0. For example, the aerosol-generating substrate may have a length-to-diameter ratio of 1.5 to 5.5, 1.5 to 5.0, 1.5 to 4.5, 1.5 to 4.0, 1.5 to 3.5, 1.5 to 3.0, 1.5 to 2.5, 1.5 to 2.0, or 1.5 to 1.9.

In some particularly preferred embodiments, the aerosol-generating substrate may have a length-to-diameter ratio of about 1.6.

As briefly described above, the aerosol-generating article according to the present invention comprises an aerosol-generating substrate.

The aerosol-generating substrate may have a diameter of at least 3 millimeters. For example, the aerosol-generating substrate may have a diameter of at least 4 millimeters, at least 5 millimeters, or at least 6 millimeters.

The aerosol-generating substrate may have a diameter of no more than 12 millimeters. For example, the aerosol-generating substrate may have a diameter of no more than 10 millimeters, no more than 9 millimeters, or no more than 8 millimeters.

The aerosol-generating substrate may have a diameter of 3 millimeters to 12 millimeters. For example, the aerosol-generating substrate may have a diameter of 3 millimeters to 10 millimeters, 3 millimeters to 9 millimeters, or 3 millimeters to 8 millimeters.

The aerosol-generating substrate may have a diameter of 4 millimeters to 12 millimeters. For example, the aerosol-generating substrate may have a diameter of 4 millimeters to 10 millimeters, 4 millimeters to 9 millimeters, or 4 millimeters to 8 millimeters.

The aerosol-generating substrate may have a diameter of 5 millimeters to 12 millimeters. For example, the aerosol-generating substrate may have an outer diameter of 5 millimeters to 10 millimeters, 5 millimeters to 9 millimeters, or 5 millimeters to 8 millimeters.

The aerosol-generating substrate may have a diameter of 6 millimeters to 12 millimeters. The aerosol-generating substrate may have a diameter of 6 millimeters to 10 millimeters, 6 millimeters to 9 millimeters, or 6 millimeters to 8 millimeters.

The aerosol-generating substrate may have a diameter of 3.7 millimeters to 9 millimeters, 5.7 millimeters to 7.9 millimeters, or 6 millimeters to 7.5 millimeters.

In particularly preferred embodiments, the aerosol-generating substrate may have a diameter of less than about 7.5 millimeters. For example, the aerosol-generating substrate may have a diameter of about 7.2 millimeters.

In general, it has been noted that the smaller the diameter of the aerosol-generating substrate, the lower the temperature required to raise the temperature of the core of the aerosol-generating substrate so that sufficient quantities of evaporable particles are released from the aerosol-generating substrate to form the required amount of aerosol. At the same time, without resorting to theory, it is understood that a smaller diameter of the aerosol-generating substrate allows for faster penetration of heat applied to the aerosol-generating article into the entire volume of the aerosol-generating substrate. However, if the diameter of the aerosol-generating substrate is too small, then the ratio of the volume to the surface area of the aerosol-generating substrate becomes less favorable since the amount of available aerosol-generating substrate is reduced. In addition, if, for the reasons described above, the aerosol-generating substrate is relatively short, the diameter of the aerosol-generating substrate must remain large enough to ensure that there is a sufficient volume of aerosol-generating substrate in the aerosol-generating article to generate a sufficient amount of aerosol throughout the entire use session of the aerosol-generating article.

An aerosol-generating substrate diameter falling within the ranges described herein is particularly advantageous in terms of the balance between energy consumption and aerosol delivery. This advantage is particularly noticeable when an aerosol-generating article comprising an aerosol-generating substrate with a diameter described herein is used in combination with an external heater arranged around the periphery of the aerosol-generating article. Under such operating conditions, it has been found that less thermal energy is required to achieve a sufficiently high temperature in the core of the aerosol-generating substrate and, in general, in the core of the article. Thus, in the case of operation at lower temperatures, it is possible to achieve the desired target temperature in the core of the aerosol-generating substrate within a period of time that is shortened in a desired manner and with reduced energy consumption.

The aerosol-generating substrate may have a diameter that is approximately equal to the outer diameter of the aerosol-generating article.

As used herein, the term "diameter" refers to the maximum dimension of a component of the aerosol-generating article in the transverse direction. If a component does not have a circular cross-section, then the component may have a plurality of different dimensions in the transverse direction. In this case, the "diameter" refers to the largest or maximum dimension of the component in the transverse direction. The diameter of the aerosol-generating substrate refers to the maximum outer diameter of the aerosol-generating substrate and does not include the thickness of any wrapping material surrounding the aerosol-generating substrate, although in practice the thickness of any wrapping material may be immaterial. The term "transverse" refers to a direction that is perpendicular to the longitudinal axis. Any reference to a "section" of an aerosol-generating article or a component of an aerosol-generating article refers to a cross-section, unless otherwise specified.

The aerosol generating article may comprise a downstream section extending from a downstream end of the aerosol generating substrate to a downstream end of the aerosol generating article.

As will be apparent from the following description of various embodiments of the aerosol generating article of the present invention, the downstream section may comprise one or more downstream elements.

The downstream section may comprise a hollow section between the mouth end of the aerosol generating article and the aerosol generating element. The solid section may comprise a hollow tubular element.

As used herein, the term "hollow tubular element" is used to designate a generally elongated element that defines a lumen or passage for air flow along its longitudinal axis. In particular, the term "tubular" will be used hereinafter to refer to a tubular element that has a substantially cylindrical cross-section and defines at least one air flow channel that provides continuous fluid communication between an upstream end of the tubular element and a downstream end of the tubular element. However, it should be understood that alternative geometric configurations (e.g., alternative cross-sectional shapes) of the tubular element are possible.

Providing a hollow tubular element allows for the ability to prevent condensation of any less volatile components, such as the aerosol forming agent, and to filter them out of the inhaled aerosol in a downstream section. This provides the advantage of being able to produce a more stable aerosol.

The downstream section may have any length. The downstream section may have a length of at least about 10 millimeters. For example, the downstream section may have a length of at least about 15 millimeters, at least about 20 millimeters, at least about 25 millimeters, or at least about 30 millimeters.

Providing a downstream section that is longer than the above values provides the advantage of being able to provide space for the aerosol to cool and condense before it reaches the consumer. It also allows the user to be at a distance from the heating element when the aerosol generating article is used in combination with the aerosol generating device.

The downstream section may have a length of no more than about 60 millimeters. For example, the downstream section may have a length of no more than about 50 millimeters, no more than about 55 millimeters, no more than about 40 millimeters, or no more than about 35 millimeters.

The downstream section may have a length of about 10 millimeters to about 60 millimeters, about 15 millimeters to about 50 millimeters, about 20 millimeters to about 55 millimeters, about 25 millimeters to about 40 millimeters, or about 30 millimeters to about 35 millimeters. For example, the downstream section may have a length of about 33 millimeters.

The ratio between the length of the downstream section and the length of the aerosol generating substrate may be from about 1.0 to about 4.5.

Preferably, the ratio between the length of the downstream section and the length of the aerosol-generating substrate is at least about 1.5, more preferably at least about 2.0, even more preferably at least about 2.5. In preferred embodiments, the ratio between the length of the downstream section and the length of the aerosol-generating substrate is less than about 4.0, more preferably less than about 3.5, even more preferably less than about 3.0.

In some embodiments, the ratio between the length of the downstream section and the length of the aerosol generating substrate is from about 1.5 to about 4.0, preferably from about 2.0 to about 3.5, more preferably from about 2.5 to about 3.0.

In particularly preferred embodiments, the ratio between the length of the downstream section and the length of the aerosol generating substrate is approximately 2.75.

The ratio between the length of the downstream section and the overall length of the aerosol generating article may be from about 0.1 to about 1.5.

Preferably, the ratio between the length of the downstream section and the total length of the aerosol-generating article is at least about 0.25, more preferably at least about 0.50. The ratio between the length of the downstream section and the total length of the aerosol-generating article is preferably less than about 1.25, more preferably less than about 1.0.

In some embodiments, the ratio between the length of the downstream section and the overall length of the aerosol-generating article is preferably from about 0.25 to about 1.25, more

preferably from about 0.5 to about 1.0.

In a particularly preferred embodiment, the ratio between the length of the downstream section and the overall length of the aerosol generating article is approximately 0.73 or approximately 0.64.

The length of the downstream section may be equal to the sum of the lengths of the individual components that form the downstream section.

The draw resistance of the downstream section may be less than 100 millimeters _H2O . For example, the draw resistance of the downstream section may be less than 50 millimeters _H2O , less than 30 millimeters _H2O , less than 25 millimeters _H2O , less than 15 millimeters _H2O , less than 10 millimeters _H2O , less than 8 millimeters _H2O , less than 5 millimeters H2, less than 2 millimeters _H2O , or less than 1 millimeter _H2O .

The draw resistance of the downstream section may be greater than or equal to approximately 0 millimeters _H2O and less than approximately 10 millimeters _H2O . The draw resistance of the downstream section may be greater than 0 millimeters _H2O and less than approximately 1 millimeter _H2O .

The effect of providing a downstream section having such a low resistance to draw is that the aerosol generated in the aerosol generating substrate is able to pass to the downstream end of the downstream section relatively unimpeded. This provides the advantage of being able to maximise the delivery of the aerosol to the user. Prior art articles that have downstream sections with higher resistance to draw values typically have high density filter sections in the downstream section that remove flavour components from the aerosol. Providing a downstream section with a low resistance to draw provides the advantage of being able to prevent the above. Furthermore, in the context of the present invention in particular, providing a downstream section with a low resistance to draw makes it possible to prevent condensation and filtering of any less volatile components, such as the aerosol forming agent, from the inhaled aerosol in the downstream section. This provides the advantage of being able to produce a more stable aerosol.

Unless otherwise specified, the resistance to draw (RTD) of a component or aerosol-generating article is measured in accordance with ISO 6565-2015. Resistance to draw refers to the pressure required to force air through the entire length of the component. The terms "pressure drop" or "resistance to draw" of a component or article may also refer to "resistance to draw". Such terms generally refer to measurements in accordance with ISO 6565-2015, typically performed under test conditions in which the volumetric flow rate is approximately 17.5 millilitres per second at the outlet or downstream end of the component being measured, at a temperature of approximately 22 degrees Celsius, a pressure of approximately 101 kPa (approximately 760 Torr) and a relative humidity of approximately 60%.

The resistance to draw per unit length of a specific component (or element) of an aerosol-generating article, such as a downstream section, a first section or a first segment, can be calculated by dividing the measured resistance to draw of the component by the total axial length of the component. The resistance to draw per unit length refers to the pressure required to force air through a unit length of the component. Throughout this disclosure, a unit length refers to a length of 1 millimeter. Accordingly, to determine the resistance to draw per unit length of a specific component, a sample of the component of a certain length, such as 15 millimeters, can be used in the measurement. The resistance to draw of such a sample is measured in accordance with ISO 6565-2015. For example, if the measured resistance to draw is approximately 15 millimeters _H2O , then the resistance to draw per unit length of the component is approximately 1 millimeter _H2O per millimeter. The tightening resistance per unit length of a component depends, among other factors, on the design properties of the material used for the component and the cross-sectional geometry or profile of the component.

The relative draw resistance or draw resistance per unit length of the downstream section may be from about 0 millimeters _H2O per millimeter to about 3 millimeters _H2O per millimeter. The draw resistance per unit length of the downstream section may be from about 0 millimeters _H2O per millimeter to about 0.75 millimeters _H2O per millimeter.

As mentioned above, the relative draw resistance or draw resistance per unit length of the downstream section may be greater than about 0 millimeters _H2O per millimeter and less than about 3 millimeters _H2O per millimeter. The draw resistance per unit length of the downstream section may be greater than about 0 millimeters _H2O per millimeter and less than about 0.75 millimeters _H2O per millimeter.

The draw resistance per unit length of the downstream section may be greater than or equal to approximately 0 millimeters _H2O per millimeter. Thus, the draw resistance per unit length of the downstream section may be from approximately 0 millimeters _H2O per millimeter to approximately 3 millimeters _H2O per millimeter. The draw resistance per unit length of the downstream section may be from approximately 0 millimeters _H2O per millimeter to approximately 0.75 millimeters _H2O per millimeter.

The downstream section may comprise a clear path for air flow from the downstream end of the aerosol generating substrate to the downstream end of the downstream section.

The clear air flow path extending from the downstream end of the aerosol generating substrate to the downstream end of the downstream section has a minimum diameter of approximately 0.5 millimeters. For example, the clear air flow path may have a minimum diameter of 1 millimeter, 2 millimeters, 3 millimeters, or 5 millimeters.

The downstream section may comprise a hollow tubular segment.

Providing a hollow tubular element provides the advantage of being able to provide the required overall length of the aerosol generating article without unacceptably increasing the draw resistance.

The hollow tubular member may extend from the downstream end of the downstream section to the upstream end of the downstream section. In other words, the total length of the downstream section may be determined by the hollow tubular member. In this case, it should be understood that the lengths and length ratios specified above with respect to the downstream section apply equally to the length of the hollow tubular member.

The hollow tubular member may be adjacent to a downstream end of the aerosol generating article.

The hollow tubular element may be located at a distance from the downstream end of the aerosol-generating article. In this case, there may be a void space between the downstream end of the aerosol-generating substrate and the upstream end of the hollow tubular element.

The hollow tubular member may have an internal diameter. The hollow tubular member may have a constant internal diameter along the length of the hollow tubular member. The internal diameter of the hollow tubular member may vary along the length of the hollow tubular member.

The hollow tubular element may have an internal diameter of at least about 2 millimeters. For example, the hollow tubular element may have an internal diameter of at least about 4 millimeters, at least about 5 millimeters, or at least about 7 millimeters.

Providing a hollow tubular element having the above-mentioned internal diameter provides the advantage of being able to impart sufficient rigidity and strength to the hollow tubular element.

The hollow tubular member may have an internal diameter of no more than about 10 millimeters. For example, the hollow tubular member may have an internal diameter of no more than about 9 millimeters, no more than about 8 millimeters, or no more than about 7.5 millimeters.

Providing a hollow tubular element having the above-mentioned internal diameter provides the advantage of being able to reduce the tightening resistance of the hollow tubular element.

The hollow tubular member may have an internal diameter of from about 2 millimeters to about 10 millimeters, from about 4 millimeters to about 9 millimeters, from about 5 millimeters to about 8 millimeters, or from about 7 millimeters to about 7.5 millimeters.

The hollow tubular element may have an internal diameter of approximately 7.1 millimeters.

The ratio between the inner diameter of the hollow tubular element and the outer diameter of the hollow tubular element may be at least approximately 0.8. For example, the ratio between the inner diameter of the hollow tubular element and the outer diameter of the hollow tubular element may be at least approximately 0.85, at least approximately 0.9, or at least approximately 0.95.

The ratio between the inner diameter of the hollow tubular element and the outer diameter of the hollow tubular element may be no more than approximately 0.99. For example, the ratio between the inner diameter of the hollow tubular element and the outer diameter of the hollow tubular element may be no more than approximately 0.98.

The ratio between the inner diameter of the hollow tubular member and the outer diameter of the hollow tubular member may be approximately 0.97.

Providing a relatively large internal diameter provides the advantage of being able to reduce the tightening resistance of the hollow tubular element.

The lumen of the hollow tubular element may have any cross-sectional shape. The lumen of the hollow tubular element may have a circular cross-sectional shape.

The hollow tubular element may be made of any material. For example, the hollow tubular element may comprise cellulose acetate tow. If the hollow tubular element comprises cellulose acetate tow, the hollow tubular element may have a thickness of approximately 0.1 millimeter to approximately 1 millimeter. The hollow tubular element may have a thickness of approximately 0.5 millimeter.

If the hollow tubular element comprises cellulose acetate tow, the cellulose acetate tow may have a filament denier of about 2 to about 4 and a total denier of about 25 to about 40.

The hollow tubular support element may comprise paper. The hollow tubular element may comprise at least one layer of paper. The paper may be very rigid paper. The paper may be corrugated paper, such as corrugated heat-resistant paper or corrugated parchment paper. The paper may be cardboard. The hollow tubular segment may be a paper tube. The hollow tubular element may be a tube made of spirally wound paper. The hollow tubular segment may be made of a plurality of layers of paper. The paper may have a grammage of at least about 50 grams per square meter, at least about 60 grams per square meter, at least about 70 grams per square meter, or at least about 90 grams per square meter.

If the tubular element comprises paper, the thickness of the paper may be at least about 50 micrometers. For example, the paper may have a thickness of at least about 70 micrometers, at least about 90 micrometers, or at least about 100 micrometers.

The hollow tubular member may comprise a polymer. For example, the hollow tubular member may comprise a polymer film. The polymer film may comprise a cellulose film. The hollow tubular member may comprise low density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers.

The downstream section may comprise a modified tubular element. The modified tubular element may be provided instead of a hollow tubular element. The modified tubular element may be provided downstream of the aerosol-generating substrate immediately after it. The modified tubular element may be adjacent to the aerosol-generating substrate.

The modified tubular element may comprise a tubular body forming a cavity extending from the first, upstream end of the tubular body to the second, downstream end of the tubular body. The modified tubular element may also comprise a folded end portion forming a first end wall at the first, upstream end of the tubular body. The first end wall may form an opening allowing air flow to pass between said cavity and the area outside the modified tubular element. Preferably, said opening is designed to allow air flow to pass from the aerosol-generating substrate through said opening into said cavity.

The cavity of the tubular body may be substantially empty to ensure the possibility of substantially unimpeded passage of air flow along said cavity. The tightening resistance of the modified tubular element may be localized in a specific longitudinal location of the modified tubular element. In particular, the tightening resistance of the modified tubular element may be localized on the first end wall. Thus, it is possible to adjust the tightening resistance of the modified tubular element essentially by selecting the configuration of the first end wall and its corresponding opening. The tightening resistance of the modified tubular element (which essentially represents the tightening resistance of the first end wall) may be approximately 5 millimeters of H ₂ O.

The modified tubular element can be of any length.

The modified tubular element may have a length of about 10 millimeters to about 60 millimeters, about 15 millimeters to about 50 millimeters, about 20 millimeters to about 55 millimeters, about 25 millimeters to about 40 millimeters, or about 30 millimeters to about 35 millimeters. For example, the modified tubular element may have a length of about 33 millimeters.

The modified tubular element may have any outer diameter (D _E ). The modified tubular element may have an outer diameter (D _E ) of about 5 millimeters to about 12 millimeters, about 6 millimeters to about 12 millimeters, or about 7 millimeters to about 12 millimeters. The modified tubular element may have an outer diameter (D _E ) of about 7.3 millimeters.

The modified tubular element may have any internal diameter ( _DI ). The modified tubular element may have an internal diameter ( _DI ) of about 2 millimeters to about 10 millimeters, about 4 millimeters to about 9 millimeters, about 5 millimeters to about 8 millimeters, or about 7 millimeters to about 7.5 millimeters. The modified tubular element may have an internal diameter ( _DI ) of about 7.1 millimeters.

The modified tubular element may have a peripheral wall of any thickness. The peripheral wall of the modified tubular element may have a thickness of about 0.05 millimeters to about 0.5 millimeters. The peripheral wall of the modified tubular element may have a thickness of about 0.1 millimeters.

The aerosol generating article may comprise a first ventilation zone at a location along the downstream section. More specifically, the aerosol generating article may comprise a ventilation zone at a location along the hollow tubular element. In this way, fluid communication is provided between the flow channel formed inside the hollow tubular element and the external environment.

Ventilation may be provided to allow cooler air from outside the aerosol-generating article to enter the interior of the downstream section. Thus, providing a first ventilation zone allows for a temperature drop to be created by allowing cooler outside air from the cooler to enter the hollow tubular element. This allows for a beneficial effect on the nucleation and growth of aerosol particles, which in turn allows for improved delivery of the aerosol to the user. In addition, the ventilation allows for cooling of the inhaled aerosol without the need for highly efficient filter components in the downstream section. This allows for the prevention of condensation and filtering of less volatile components, such as the aerosol forming agent, from the inhaled aerosol in the downstream section. This provides the advantage of being able to produce a more stable aerosol.

The ventilation level of the aerosol generating article may typically be at least about 10 percent, preferably at least about 20 percent.

In preferred embodiments, the ventilation level of the aerosol-generating article is at least about 20 percent, or 25 percent, or 30 percent. More preferably, the ventilation level of the aerosol-generating article is at least about 35 percent.

The aerosol generating article preferably has a ventilation level of less than about 80 percent. More preferably, the aerosol generating article has a ventilation level of less than about 60 percent or less than about 50 percent.

An aerosol generating product may typically have a ventilation level from approximately 10 percent to approximately 80 percent.

In some embodiments, the aerosol-generating article has a ventilation level of about 20 percent to about 80 percent, preferably about 20 percent to about 60 percent, more preferably about 20 percent to about 50 percent. In other embodiments, the aerosol-generating article has a ventilation level of about 25 percent to about 80 percent, preferably about 25 percent to about 60 percent, more preferably about 25 percent to about 50 percent. In further embodiments, the aerosol-generating article has a ventilation level of about 30 percent to about 80 percent, preferably about 30 percent to about 60 percent, more preferably about 30 percent to about 50 percent.

In particularly preferred embodiments, the aerosol-generating article has a ventilation level of about 40 percent to about 50 percent. In some particularly preferred embodiments, the aerosol-generating article has a ventilation level of about 45 percent.

Without being bound by theory, the present inventors have found that a temperature drop caused by the introduction of cooler external air into the hollow tubular segment can have a beneficial effect on the nucleation and growth of aerosol particles.

The formation of an aerosol from a gaseous mixture containing various chemical compounds depends on the subtle interactions of nucleation, evaporation and condensation, and droplet coalescence, while taking into account changes in vapor concentration, temperature and velocity fields. The so-called classical nucleation theory is based on the assumption that the fraction of molecules in the gas phase is large enough to remain coherent for a long time with sufficient probability (e.g., with a probability of one half). These molecules represent a kind of critical threshold molecular clusters among short-lived

molecular aggregates, meaning that, in general, smaller molecular clusters in the gas phase are likely to disintegrate fairly quickly, while larger clusters are likely to grow in general. Such a critical cluster is identified as the key nucleation core from which droplet growth is expected due to condensation of molecules from the vapor.

It is assumed that the primary droplets that have just formed start with a certain initial diameter, and they can then grow by several orders of magnitude. This can be supported and enhanced by rapid cooling of the surrounding vapor, which causes condensation. In this regard, it should be kept in mind that evaporation and condensation are two sides of the same mechanism, namely gas-liquid mass transfer. While evaporation refers to a net mass transfer from the liquid droplets to the gas phase, condensation is a net mass transfer from the gas phase to the droplet phase. Evaporation (or condensation) will cause shrinkage (or growth) of the droplets, but will not change the number of droplets.

In this scenario, which may be further complicated by the phenomenon of droplet coalescence, temperature and cooling rate may play an important role in determining the response of the system. In general, different cooling rates may result in significantly different time behavior with respect to liquid phase (droplet) formation, since the nucleation process is typically nonlinear. Without resorting to theory, it is suggested that cooling may cause a rapid increase in droplet number concentration, followed by a strong short-term increase in droplet growth (nucleation burst). This nucleation burst may be more significant at lower temperatures. It may also be that higher cooling rates may favor an earlier onset of nucleation. Conversely, a decrease in the cooling rate may have a beneficial effect on the final size that the aerosol droplets eventually reach.

Therefore, the rapid cooling caused by the introduction of external air into the hollow tubular element can be used to advantage to promote the nucleation and growth of aerosol droplets. However, at the same time, the introduction of external air into the hollow tubular element has a significant drawback consisting in diluting the aerosol flow delivered to the consumer.

The inventors of the present invention have surprisingly found that the effect of dilution on the aerosol, which can be measured, in particular the effect on the delivery of the aerosol forming substance (such as glycerol contained in the aerosol-generating substrate), is successfully minimized if the ventilation level is within the above-mentioned ranges. In particular, it has been found that ventilation levels from 25 percent to 50 percent and, even more preferably, from 28 to 42 percent lead to particularly satisfactory values of the glycerol delivery. At the same time, the degree of nucleation and therefore the delivery of nicotine and the aerosol forming substance (for example glycerol) are improved.

The ventilation of the downstream section may be provided substantially along the entire length of the downstream section. In this case, the downstream section may comprise a porous material that allows air to enter the downstream section. For example, if the downstream section comprises a hollow tubular element, the hollow segment may be made of a porous material that allows air to enter the interior of the hollow tubular element. If the downstream section comprises a wrapper, the wrapper may be made of a porous material that allows air to enter the interior of the hollow tubular element.

The downstream section may comprise a first ventilation zone for providing ventilation of the downstream section. The first ventilation zone comprises a portion of the downstream section through which a greater volume of air can pass compared to the rest of the downstream section. For example, the first ventilation zone may be a portion of the downstream section having a higher porosity compared to the rest of the downstream section.

The first ventilation zone may comprise a porous portion of a downstream section having a ventilation level of at least 5 percent. For example, the first ventilation zone may comprise a porous portion of a downstream section having a ventilation level of at least 10 percent, at least 20 percent, at least 25 percent, at least 30 percent, or at least 35 percent.

The first ventilation zone may comprise a porous portion of a downstream section having a ventilation level of no more than 80 percent. For example, the first ventilation zone may comprise a porous portion of a downstream section having a ventilation level of no more than 60 percent or less than 50 percent.

The first ventilation zone may comprise a porous portion of the downstream section having a ventilation level of 10 percent to 80 percent, 20 percent to 80 percent, 20 percent to 60 percent, or 20 percent to 50 percent. In other embodiments, the first ventilation zone may comprise a porous portion of the downstream section having a ventilation level of 25 percent to 80 percent, 25 percent to 60 percent, or 25 percent to 50 percent. In further embodiments, the first ventilation zone may comprise a porous portion of the downstream section having a ventilation level of 30 percent to 80 percent, 30 percent to 60 percent, or 30 percent to 50 percent.

The first ventilation zone may comprise a porous portion of a downstream section having a ventilation level of 40 percent to 50 percent. In some particularly preferred embodiments, the first ventilation zone may comprise a porous portion of a downstream section having a ventilation level of 45 percent.

The first ventilation zone may comprise a first line of perforations surrounding a downstream section.

In some embodiments, the first ventilation zone may comprise two circumferential rows of perforations. For example, the perforations may be made on a production line during the manufacturing process of the aerosol-generating article. Each circumferential row of perforations may comprise from about 5 to about 40 perforations; for example, each circumferential row of perforations may comprise from about 8 to about 30 perforations.

If the aerosol-generating article comprises a unifying wick, the ventilation zone preferably comprises at least one corresponding circumferential row of perforations extending through a section of the unifying wick. They can also be produced on a production line during the manufacturing of the smoking article. Preferably, the circumferential row or rows of perforations extending through a section of the unifying wick are substantially aligned with the corresponding row or rows of perforations extending through a section located further downstream.

If the aerosol-generating article comprises a strip of tipping paper, wherein this strip of tipping paper extends over a circumferential row or rows of perforations in a downstream section, then the ventilation zone preferably comprises at least one corresponding circumferential row of perforations extending through said strip of tipping paper. They can also be produced on a production line during the manufacturing of the smoking article. Preferably, the circumferential row or rows of perforations extending through the strip of tipping paper are substantially aligned with the row or rows of perforations extending through the downstream section.

The first line of perforations may comprise at least one perforation having a width of at least about 50 micrometers. For example, the first line of perforations may comprise at least one perforation having a width of at least about 65 micrometers, at least about 80 micrometers, at least about 90 micrometers, or at least about 100 micrometers.

The first line of perforations may comprise at least one perforation having a width of no more than approximately 200 micrometers. For example, the first line of perforations may comprise at least one perforation having a width of no more than

approximately 175 micrometers, not greater than approximately 150 micrometers, not greater than approximately 125 micrometers, or not greater than approximately 120 micrometers.

The first line of perforations may comprise at least one perforation having a width of from about 50 micrometers to about 200 micrometers, from about 65 micrometers to about 175 micrometers, from about 90 micrometers to about 150 micrometers, or from about 100 micrometers to about 120 micrometers.

If the perforations are made using laser perforation technologies, the width of the perforations can be determined by the laser focusing diameter.

The first line of perforations may comprise at least one perforation having a length of at least about 400 micrometers. For example, the first line of perforations may comprise at least one perforation having a length of at least about 425 micrometers, at least about 450 micrometers, at least about 475 micrometers, or at least about 500 micrometers.

The first line of perforations may comprise at least one perforation having a length of no more than about 1 millimeter. For example, the first line of perforations may comprise at least one perforation having a length of no more than about 950 micrometers, no more than about 900 micrometers, no more than about 850 micrometers, or no more than about 800 micrometers.

The first line of perforations may comprise at least one perforation having a length of from about 400 micrometers to about 1 millimeter, from about 425 micrometers to about 950 micrometers, from about 450 micrometers to about 900 micrometers, from about 475 micrometers to about 850 micrometers, or from about 500 micrometers to about 800 micrometers.

The first line of perforations may comprise at least one perforation having an opening area of at least about 0.01 square millimeters. For example, the first line of perforations may comprise at least one perforation having an opening area of at least about 0.02 square millimeters, at least about 0.03 square millimeters, or at least about 0.05 square millimeters.

The first line of perforations may comprise at least one perforation having an opening area of no more than approximately 0.5 square millimeters.

For example, the first line of perforations may comprise at least one perforation having an opening area of no more than about 0.3 square millimeters, no more than about 0.25 square millimeters, or no more than about 0.1 square millimeters.

The first line of perforations may comprise at least one perforation having an opening area of about 0.01 square millimeters to about 0.5 square millimeters, about 0.02 square millimeters to about 0.3 square millimeters, about 0.03 square millimeters to about 0.25 square millimeters, or about 0.05 square millimeters to about 0.1 square millimeters. The first line of perforations may comprise at least one perforation having an opening area of about 0.05 square millimeters to about 0.096 square millimeters.

The first ventilation zone may comprise a second line of perforations that span a downstream section. The second line of perforations may have any of the properties described above with respect to the first line of perforations.

As noted above, the aerosol generating article may comprise a wrapper that encompasses at least a portion of the downstream section, wherein the first ventilation zone may comprise a porous portion of the wrapper.

The wrapper may be a paper wrapper and the first ventilation zone may comprise a section of porous paper.

As indicated above, the downstream section may comprise a hollow tubular element located at a distance from the downstream end of the aerosol-generating substrate. In this case, the hollow tubular element may be connected to the aerosol-generating substrate by means of a paper wrapper. The wrapper may be a porous paper wrapper. In this case, the first ventilation zone may comprise a portion of the porous paper wrapper lying over the gap between the downstream end of the aerosol-generating substrate and the upstream end of the hollow tubular element. In this case, the upstream end of the first ventilation zone adjoins the downstream end of the aerosol-generating substrate, and the downstream end of the first ventilation zone adjoins the upstream end of the hollow tubular element.

The porous portion of the wrapper that forms the first ventilation zone may have a lower grammage than the portion of the wrapper that does not form the portion of the first ventilation zone.

The porous portion of the wrapper that forms the first ventilation zone may have a thinner thickness than the portion of the wrapper that does not form the portion of the first ventilation zone.

The upstream end of the first ventilation zone may be less than 10 millimeters from the downstream end of the aerosol generating substrate.

For example, the upstream end of the first ventilation zone may be less than 8 millimeters, less than 5 millimeters, less than 3 millimeters, or less than 1 millimeter from the downstream end of the aerosol generating substrate.

The upstream end of the first ventilation zone may be aligned longitudinally with the comparatively downstream end of the aerosol generating substrate.

The upstream end of the first ventilation zone may be located at a distance of less than 25 percent of the length of the downstream element from the downstream end of the aerosol generating substrate. For example, the upstream end of the first ventilation zone may be located at a distance of less than 20 percent, less than 18 percent, less than 15 percent, less than 10 percent, less than 5 percent, or less than 1 percent of the length of the downstream element from the downstream end of the aerosol generating substrate.

The downstream end of the first ventilation zone may be located at a distance of less than 30 percent of the length of the downstream element from the downstream end of the aerosol generating substrate. For example, the downstream end of the first ventilation zone may be located at a distance of less than 25 percent, less than 20 percent, less than 18 percent, less than 15 percent, less than 10 percent, or less than 5 percent of the length of the downstream element from the downstream end of the aerosol generating substrate.

The downstream end of the first ventilation zone may be located at a distance of less than 10 millimeters from the downstream end of the aerosol-generating substrate. In other words, the first ventilation zone may be located entirely within 10 millimeters along the length of the aerosol-generating substrate.

For example, the downstream end of the first ventilation zone may be located at a distance of less than 8 millimeters, less than 5 millimeters, or less than 3 millimeters from the downstream end of the aerosol generating substrate.

The first ventilation zone may be located anywhere along the length of the downstream section. The downstream end of the first ventilation zone may be located no more than about 25 millimeters from the downstream end of the aerosol-generating article. For example, the first ventilation zone may be located no more than about 20 millimeters from the downstream end of the aerosol-generating article.

The arrangement of the first ventilation zone described above provides the advantage of being able to prevent blockage of the first ventilation zone when the aerosol-generating article is inserted into the aerosol-generating device.

The downstream end of the first ventilation zone may be located at a distance of at least approximately 8 from the downstream end of the aerosol-generating article. For example, the downstream end of the first ventilation zone may be located at a distance of at least approximately 10 millimeters, at least 12 millimeters, or at least approximately 15 millimeters from the downstream end of the aerosol-generating article.

The arrangement of the first ventilation zone described above provides the advantage of preventing the first ventilation zone from being blocked by the user's mouth or lips when using the aerosol generating product.

The downstream end of the first ventilation zone may be located at a distance of from about 8 millimeters to about 25 millimeters, from about 10 millimeters to about 25 millimeters, or from about 15 millimeters to about 20 millimeters from the downstream end of the aerosol-generating article. The downstream end of the first ventilation zone may be located at a distance of about 18 millimeters from the downstream end of the aerosol-generating article.

The upstream end of the first ventilation zone may be located at a distance of at least about 20 millimeters from the upstream end of the aerosol-generating article. For example, the upstream end of the first ventilation zone may be located at a distance of at least about 25 millimeters from the upstream end of the aerosol-generating article.

The arrangement of the first ventilation zone described above provides the advantage of being able to prevent blockage of the first ventilation zone when the aerosol-generating article is inserted into the aerosol-generating device.

The upstream end of the first ventilation zone may be located at a distance of no more than 37 millimeters from the upstream end of the aerosol-generating article. For example, the upstream end of the first ventilation zone may be located at a distance of no more than approximately 30 millimeters from the upstream end of the aerosol-generating article.

The arrangement of the first ventilation zone described above provides the advantage of preventing the first ventilation zone from being blocked by the user's mouth or lips when using the aerosol generating product.

The upstream end of the first ventilation zone may be located at a distance of from about 20 millimeters to about 37 millimeters, from about 25 millimeters to about 30 millimeters from the upstream end of the aerosol-generating article. The upstream end of the first ventilation zone may be located at a distance of about 27 millimeters from the downstream end of the aerosol-generating article.

The first ventilation zone may have any length. The first ventilation zone may have a length of at least 0.5 millimeters. In other words, the longitudinal distance between the downstream end of the first ventilation zone and the upstream end of the first ventilation zone is at least 0.5 millimeters. For example, the first ventilation zone may have a length of at least 1 millimeter, at least 2 millimeters, at least 5 millimeters, or at least 8 millimeters.

The first ventilation zone may be no longer than 10 millimeters. For example, the first ventilation zone may be no longer than 8 millimeters or no longer than 5 millimeters.

The first ventilation zone may have a length of 0.5 millimeters to 10 millimeters. For example, the first ventilation zone may have a length of 1 millimeter to 8 millimeters or 2 millimeters to 5 millimeters.

The aerosol-generating article may further comprise an upstream section. The upstream section may comprise an upstream element that is upstream of the aerosol-generating substrate. The upstream element may extend from the upstream end of the aerosol-generating substrate to the upstream end of the aerosol-generating article. The upstream element may be adjacent to the upstream end of the aerosol-generating article.

The aerosol-generating article may comprise an air inlet at the upstream end of the aerosol-generating article. If the aerosol-generating article comprises an upstream element, the air inlet may pass through the upstream element. Air passing through the air inlet may pass into the aerosol-generating substrate to generate an inhalable aerosol.

The upstream section may have high tightening resistance.

In embodiments of the present invention in which the downstream section has a relatively low resistance to draw, such as a resistance to draw of less than about 10 millimeters of H ₂ O, providing an upstream section having a relatively high resistance to draw provides an advantage in that an acceptable overall resistance to draw can be provided without the need for a high resistance to draw element, such as a filter, downstream of the aerosol-generating substrate. In use, air enters the aerosol-generating article through the upstream end of the upstream section, passes through the upstream section, and enters the aerosol-generating substrate. Air then enters the downstream section, passes through it, and exits from the downstream end of the downstream section.

The majority of the overall draw resistance of an aerosol generating product may be determined by the draw resistance of the upstream section.

The ratio of the tightening resistance of the upstream section to the tightening resistance of the downstream section may be greater than 1. For example, the ratio of the tightening resistance of the upstream section to the tightening resistance of the downstream section may be greater than about 2, greater than about 5, greater than about 8, greater than about 10, greater than about 15, greater than about 20, or greater than about 50.

The draw resistance of the upstream section may be at least about 5 millimeters _H2O . For example, the draw resistance of the upstream section may be at least about 10 millimeters _H2O , at least about 12 millimeters _H2O , at least about 15 millimeters _H2O , at least about 20 millimeters _H2O .

The tightening resistance of the upstream section may be no more than about 80 millimeters H ₂ O. For example, the tightening resistance of the upstream section may be no more than about 70 millimeters H ₂ O, no more than about 60 millimeters H ₂ O, no more than about 50 millimeters H ₂ O, or no more than about 40 millimeters H ₂ O.

The draw resistance of the upstream section may be from about 5 millimeters _H2O to about 80 millimeters _H2O . For example, the draw resistance of the upstream section may be from about 10 millimeters _H2O to about 70 millimeters _H2O , from about 12 millimeters _H2O to about 60 millimeters _H2O , from about 15 millimeters _H2O to about 50 _H2O , or from about 20 millimeters _H2O to about 40 millimeters _H2O .

The upstream section provides the advantage of being able to prevent direct physical contact with the upstream end of the aerosol-generating substrate. In particular, if the aerosol-generating substrate comprises a susceptor element, the upstream section provides the ability to prevent direct physical contact with the upstream end of the susceptor element. This helps prevent displacement or deformation of the susceptor element during handling or transport of the aerosol-generating article. This, in turn, helps maintain the shape and location of the susceptor element. In addition, the presence of the upstream section provides the ability to help prevent any loss of substrate, which can be useful, for example, if the substrate comprises particulate plant material.

The upstream section may also provide an improved appearance to the upstream end of the aerosol-generating article. Additionally, if desired, the upstream section may be used to provide information about the aerosol-generating article, such as information about the brand, flavor, content, or details about the aerosol-generating device with which the article is intended to be used.

If the upstream section comprises an upstream element, the upstream element may comprise a porous plug element. Preferably, the porous plug element has a porosity of at least about 50 percent in the longitudinal direction of the aerosol-generating article. More preferably, the porous plug element has a porosity of from about 50 percent to about 90 percent in the longitudinal direction. The porosity of the porous plug element in the longitudinal direction is determined by the ratio of the cross-sectional area of the material forming the porous plug element and the area of the internal cross-section of the aerosol-generating article at the location of the porous plug element.

The porous plug element may be made of a porous material or it may comprise a plurality of holes. This may be achieved, for example, by laser perforation. Preferably, said plurality of holes are distributed uniformly over the cross-section of the porous plug element.

Advantageously, the porosity or permeability of the upstream element may be varied to provide the desired overall draw resistance of the aerosol generating article.

In alternative embodiments, the upstream element may be made of an air-impermeable material. In such embodiments, the aerosol-generating article may be designed so that air flows into the rod of the aerosol-generating substrate through suitable ventilation means provided in the wrapper.

The upstream element may be made of any material suitable for use in an aerosol-generating article. For example, the upstream element may comprise a plug made of material. Suitable materials for making the upstream element include filter materials, ceramics, polymeric material, cellulose acetate, cardboard, zeolite, or an aerosol-generating substrate. Preferably, the upstream element comprises a plug comprising cellulose acetate.

If the upstream element comprises a plug of material, the downstream end of the plug of material may be adjacent to the upstream end of the aerosol-generating substrate. For example, the upstream element may comprise a plug comprising cellulose acetate and adjacent to the upstream end of the aerosol-generating substrate. This provides the advantage of helping to retain the aerosol-generating substrate in place.

If the upstream element comprises a plug of material, the downstream end of the plug of material may be spaced from the upstream end of the aerosol-generating substrate. The upstream element may comprise a plug comprising fibrous filter material.

Preferably, the upstream element is made of a heat-resistant material. For example, the upstream element is preferably made of a material that can withstand temperatures 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.

Preferably, the upstream section has a diameter that is approximately equal to the diameter of the aerosol generating article.

The upstream section may have a length of at least about 1 millimeter. For example, the upstream section may have a length of at least about 2 millimeters, at least about 4 millimeters, or at least about 6 millimeters.

The upstream section may have a length of no more than about 15 millimeters. For example, the upstream section may have a length of no more than about 12 millimeters, no more than about 10 millimeters, or no more than about 8 millimeters.

The upstream section may have a length of about 1 millimeter to about 15 millimeters. For example, the upstream section may have a length of about 2 millimeters to about 12 millimeters, or about 4 millimeters to about 10 millimeters, or about 6 millimeters to about 8 millimeters.

As an advantage, the length of the upstream section can be varied in order to provide the desired overall length of the aerosol-generating article. For example, if it is necessary to reduce the length of one of the other components of the aerosol-generating article, the length of the upstream section can be increased in order to maintain a constant overall length of the article.

The upstream section preferably has a substantially uniform structure. For example, the upstream section may have a substantially uniform texture and appearance. For example, the upstream section may have a continuous regular surface throughout its cross-section. For example, the upstream section may have no recognizable symmetries.

The upstream section may comprise a second tubular element. The second tubular element may be provided instead of the upstream element. The second tubular element may be provided upstream of the aerosol-generating substrate immediately before it. The second tubular element may be adjacent to the aerosol-generating substrate.

The second tubular element may comprise a tubular body forming a cavity extending from the first, upstream end of the tubular body to the second, downstream end of the tubular body. The second tubular element may also comprise a folded end portion forming a first end wall at the first, upstream end of the tubular body. The first end wall may form an opening which enables air flow between said cavity and the area outside the second tubular element. Preferably, air may flow out of said cavity through said opening into the aerosol-generating substrate.

The second tubular element may comprise a second end wall at the second end of its tubular body. This second end wall may be made by folding the end portion of the second tubular element at the second, further downstream, end of the tubular body. The second end wall may form an opening, which is also capable of providing the possibility of air flow between said cavity and the area outside the second tubular element. In the case of the second end wall, said opening may be made in such a way as to provide the possibility of air flow from the area outside the aerosol-generating article through said opening into said cavity. Thus, said opening is capable of providing a channel through which the possibility of air drawing into the aerosol-generating article and further through the aerosol-generating substrate is ensured.

The upstream element or the second tubular element is preferably surrounded by a wrapper. The wrapper surrounding the upstream element or the second tubular element is preferably a rigid filament, for example a filament having a grammage of at least about 80 grams per square meter (g/ ^m2 ) or at least about 100 g/ ^m2 or at least about 110 g/ ^m2 . This imparts structural rigidity to the upstream element.

The aerosol generating article, in addition to the hollow tubular element and the aerosol generating element, may further comprise an additional element or component, such as a filter segment or a mouthpiece segment. More preferably, the downstream section of the aerosol generating article, in addition to the hollow tubular element, may comprise an additional element or component, such as a filter segment or a mouthpiece segment.

Such an additional element may be located downstream of the hollow tubular element. Such an additional element may be located downstream of the hollow tubular element immediately after it. Such an additional element may be located between the aerosol generating element and the hollow tubular element. Such an additional element may extend from the downstream end of the hollow tubular element to the mouth end of the aerosol generating article or to the downstream end of the downstream section. Such an additional element is preferably a downstream element or segment. Such an additional element may be a filter element or segment or a mouth segment. Such an additional element may form a portion of the downstream section of the aerosol generating article according to the present disclosure. Such an additional element may be aligned along the axis with the remaining components of the aerosol generating article, such as the aerosol generating element and the hollow tubular element. In addition, the additional element may have a diameter equal to the outer diameter of the hollow tubular element, the diameter of the aerosol generating element, or the diameter of the aerosol generating article.

The aerosol-generating article of the present disclosure preferably comprises a wrapper surrounding the downstream section (or components of the downstream section). Such a wrapper may be an outer rim wrapper that surrounds the downstream section and a portion of the aerosol-generating element, such that the downstream section is attached to the aerosol-generating element.

The downstream section of the aerosol generating article of the present disclosure may define a cavity in the form of a recess.

The above-described "additional element" may also be referred to in the present disclosure as a "first section" or "first segment" of the "downstream section". The terms "first segment" or "additional element" may alternatively be referred to in the present disclosure as a "mouthpiece segment", "retaining segment", "downstream segment", "mouthpiece element", "retaining element", "filter element", "filter segment" or "downstream plug element". The term "mouthpiece" may refer to that element of the aerosol-generating article that is located downstream of the aerosol-generating element of the aerosol-generating article, preferably near the mouthpiece end of the article.

As mentioned above, from about 5 to about 35 percent of the length of the downstream section may be occupied by the first section defining the first empty region for air flow, and at least about 65 percent of the length of the downstream section may be occupied by the second section defining the second empty region for air flow, wherein the total cross-sectional area of the first empty region defined by the first section may be less than the total cross-sectional area of the second empty region defined by the second section. The inventors of the present invention have found that such a longitudinal distribution of the first and second empty regions in the downstream section ensures that a comparatively low drag resistance of the downstream section is achieved while simultaneously providing a downstream component (the first section) that does not significantly increase the drag resistance and forms a physical barrier that makes it possible to prevent any material separated from the aerosol-generating element during normal use from accidentally escaping from the mouth end of the aerosol-generating article.

The term "empty area" refers to an area or space through which air can flow. For example, a hollow tubular element can form a cavity that provides an empty area. An additional segment can contain a plurality of air flow channels passing through the segment, and this plurality of air flow channels can form an empty area inside the additional segment for air to flow through it. The filtering or retaining segment according to the present disclosure can also provide an empty area that is formed by a plurality of gaps for air to flow through them, provided inside the material forming the filtering or retaining segment.

The first section or portion of a downstream section refers to a section, portion, or component of a downstream section that forms a first void area or space. Similarly, the second section or portion of a downstream section refers to a section, portion, or component of a downstream section that forms a second void area or space.

The first downstream section may comprise one or more first segments according to the present disclosure. The first segment may comprise at least one segmental air flow channel extending along the longitudinal direction of the first segment. The first empty region may be formed by at least one (first) segmental air flow channel. The at least one segmental air flow channel may be formed within and by means of the first section of the downstream section. In other words, if the first section comprises the first segment, the at least one segmental air flow channel may be formed within and along the first segment of the downstream section. As discussed above, the first segment of the downstream section may comprise a mouthpiece segment. Preferably, the at least one segmental air flow channel extends along the entire length of the first segment, from the upstream end of the first segment to the downstream end of the first segment.

The second empty region may comprise at least one cavity. The at least one cavity may provide a free channel for the air flow, passing along the longitudinal direction of the aerosol-generating article. The second section of the downstream section may comprise a second segment. The second segment may be a hollow tubular element according to the present disclosure. The second section located downstream of the section may comprise at least one hollow tubular element. The second empty region may be formed by at least one hollow tubular element. Due to the fact that along most of the length of the downstream section the at least one hollow tubular element passes, a comparatively low drag resistance of the downstream section and the aerosol-generating article as a whole is achieved.

The downstream section may comprise a second portion comprising two hollow tubular elements and a first section comprising a first segment. The second empty region may be formed by two hollow tubular elements. The first section may be located between the two hollow tubular elements. The two hollow tubular elements may have different lengths or substantially the same lengths. In such an example, the two cavities formed by the two hollow tubular elements (together) form the second empty region. The second empty region may be divided into a plurality of empty regions.

Alternatively, the downstream section may comprise a second section comprising a hollow tubular element, and the first section comprises at least one first segment. The hollow tubular element may extend from the downstream end of the aerosol-generating element to the mouthpiece end of the aerosol-generating article. At least one first segment of the first section may be located inside and along the hollow tubular element. Therefore, said at least one first segment may divide the cavity formed by the hollow tubular element into two parts of the cavity, one of which is located upstream relative to said at least one first segment, and the other is located downstream relative to said at least one first segment. Said at least one first segment, forming the first section of the downstream section, may form the first empty region, and two parts of the cavity, formed on both sides of said at least one first segment, may form the second section of the downstream section, and they may define the second empty region. The outermost downstream part of the cavity may form a cavity in the form of a recess, extending from the downstream end of said at least one first segment to the mouth end of the aerosol-generating article, and the outermost upstream part of the cavity may form a cavity between the upstream end of said at least one first segment (or first section) and the downstream end of the aerosol-generating element (also considered as the upstream end of the downstream section).

The first segment may be located near the mouth end of the aerosol-generating article. The first segment may extend to the mouth end of the aerosol-generating article. The first segment may extend from the downstream end of the second section, which may comprise a hollow tubular element, to the mouth end of the aerosol-generating article. Alternatively, the first segment may be located upstream of the mouth end of the aerosol-generating article. Preferably, the first segment may be located downstream of any ventilation zones or ventilation lines provided in the downstream section. Preferably, the first segment is located in the downstream half of the downstream section. The downstream half of the downstream section refers to a portion of the downstream section extending from the middle or center of the downstream section to the mouth end or the downstream end of the downstream section. Thus, the length of the downstream half of the downstream section may be 50 percent of the length of the downstream section. Preferably, the first segment may be located at a location between the vent zone or line (or the outermost downstream vent zone or line) and the mouth end of the article.

By providing the first segment of the first section at or near the mouth end of the aerosol-generating article, structural rigidity and integrity are provided at a downstream portion of the downstream section, the majority of which may comprise at least one hollow tubular element that forms a cavity (or a second void), and at the same time, the possibility of some air flowing through it is also provided by providing the first void area to maintain a relatively low draw resistance of the aerosol-generating article and to form a physical barrier that prevents any separated fragments of the aerosol-generating element from escaping from the aerosol-generating article through the mouth end.

The upstream end of the first segment of the first section may be located downstream at a distance of approximately 18 millimeters or less from the downstream end of the downstream section. The upstream end of the first segment of the first section may be located downstream at a distance of approximately 15 millimeters or less from the downstream end of the downstream section. The upstream end of the first segment of the first section may be located downstream at a distance of approximately 12 millimeters or less from the downstream end of the downstream section. The upstream end of the first segment of the first section may be located downstream at a distance of approximately 0 millimeters from the outermost downstream zone or ventilation line. The upstream end of the first segment of the first section may be located downstream at a distance of approximately 1 millimeter from the outermost downstream zone or ventilation line. The upstream end of the first segment of the first section may be located downstream at a distance of approximately 2 millimeters from the outermost downstream zone or vent line.

Alternatively, the first segment may be located upstream of any ventilation zones or ventilation lines provided in the downstream section. The first segment may be located in the upstream half of the downstream section. The upstream half of the downstream section refers to the portion of the downstream section extending from the middle or center of the downstream section to the upstream end of the downstream section. Thus, the length of the upstream half of the downstream section may be 50 percent of the length of the downstream section. The first segment may be located at a location between the ventilation zone or line (or the outermost upstream zone or ventilation line) and the downstream end of the aerosol generating element.

The diameter of the first segment (or first section) may be substantially the same as the outer diameter of the hollow tubular element. As indicated in this disclosure, the outer diameter of the hollow tubular element may be approximately 7.3 millimeters.

The diameter of the first segment may be from about 5 millimeters to about 10 millimeters. The diameter of the first segment may be from about 6 millimeters to about 8 millimeters. The diameter of the first segment may be from about 7 millimeters to about 8 millimeters. The diameter of the first segment may be about 7.3 millimeters.

Alternatively, the diameter of the first segment (or first section) may be substantially the same as the inner diameter of said at least one hollow tubular element of the second section. In other words, the diameter of the first section may be the same as the inner diameter of the second section. As indicated in the present disclosure, the inner diameter of the hollow tubular element may be 7.1 millimeters. The diameter of the first segment may be approximately 7.1 millimeters. Instead, the first segment may be located inside the hollow tubular element of the second section of the downstream section. Therefore, the first segment may be surrounded by a wall of the hollow tubular element, preferably in an airtight manner, so as to make it impossible for air to flow between the inner surface of the hollow tubular element and the first segment and to allow it to flow only through the first segment.

Alternatively, from about 5 to about 30 percent of the length of the downstream section may be occupied by the first section defining the first empty region for air flow, and at least about 70 percent of the length of the downstream section may be occupied by the second section defining the second empty region for air flow. More preferably, from about 5 to about 25 percent of the length of the downstream section may be occupied by the first section defining the first empty region for air flow, and at least about 75 percent of the length of the downstream section may be occupied by the second section defining the second empty region for air flow. Even more preferably, from about 5 to about 20 percent of the length of the downstream section may be occupied by the first section defining the first empty region for air flow, and at least about 80 percent of the length of the downstream section may be occupied by the second section defining the second empty region for air flow.

Alternatively, from about 5 to about 15 percent of the length of the downstream section may be occupied by the first section forming the first empty region for air flow, and at least about 85 percent of the length of the downstream section may be occupied by the second section forming the second empty region for air flow. Preferably, from about 5 to about 10 percent of the length of the downstream section may be occupied by the first section forming the first empty region for air flow, and at least about 90 percent of the length of the downstream section may be occupied by the second section forming the second empty region for air flow.

The tightening resistance characteristics of the downstream section may be completely or substantially related to the tightening resistance characteristics of the first section of the downstream section. In other words, the tightening resistance of the first section of the downstream section may completely determine the tightening resistance of the downstream section.

The relative resistance to draw or the resistance to draw per unit length of the first section (or at least the first segment forming the first section) can be from about 0 millimeters _H2O per millimeter to about 3 millimeters _H2O per millimeter. The resistance to draw per unit length of the first section can be from about 0 millimeters _H2O per millimeter to about 0.75 millimeters _H2O per millimeter.

As mentioned above, the relative resistance to draw or the resistance to draw per unit length of the first section may be greater than about 0 millimeters _H2O per millimeter and less than about 3 millimeters _H2O per millimeter. The resistance to draw per unit length of the first section may be greater than about 0 millimeters _H2O per millimeter and less than about 0.75 millimeters _H2O per millimeter.

The resistance to draw per unit length of the first section may be greater than or equal to approximately 0 millimeters _H2O per millimeter. Thus, the resistance to draw per unit length of the first section may be from approximately 0 millimeters _H2O per millimeter to approximately 3 millimeters _H2O per millimeter. The resistance to draw per unit length of the first section may be from approximately 0 millimeters _H2O per millimeter to approximately 0.75 millimeters _H2O per millimeter.

The tightening resistance of the first section (or the first segment forming the first section) may be greater than or equal to approximately 0 millimeters _H2O and less than approximately 10 millimeters _H2O . The tightening resistance of the first section may be greater than 0 millimeters _H2O and less than approximately 1 millimeter _H2O .

The first segment may comprise at least one segmented air flow channel extending along the first segment. The segmented air flow channel may also be referred to as a segmented air flow channel throughout the present disclosure. Providing at least one segmented air flow channel in the first segment allows the downstream section to create a relatively low drag resistance by allowing air to flow through it, while at the same time allowing the first segment to form a physical barrier to prevent accidental release of the aerosol-generating element material from the mouth end of the aerosol-generating article. As mentioned in the present disclosure, the aerosol-generating element material may comprise cut plant filler, in particular cut tobacco filler.

The ratio of the total cross-sectional area of said at least one segmented channel to the total cross-sectional area of the first segment (or first section) of the downstream section may be at least about 5 percent. In other words, the open area or the first empty area formed by the first segment may have a total cross-sectional area that is at least about 5 percent of the total cross-sectional area of the first segment. The total cross-sectional area of the first segment, the first section, the second section, the downstream section, the aerosol-generating element or the aerosol-generating article may be the same as the cross-sectional area calculated based on the respective outer diameters of the first segment, the first section, the second section, the downstream section, the aerosol-generating element or the aerosol-generating article. The total cross-sectional area of a component in the present disclosure refers to the total area within the outer perimeter (cross-section) of such component. For example, the total cross-sectional area of the cylindrical component may be equal to the area of the circular cross-section calculated based on the outer diameter of the cylindrical component, that is, the amount of cross-sectional area that the component occupies. As another example, in the present disclosure, the total cross-sectional area of the hollow tubular element may be equal to the area of the circular cross-section calculated based on the outer diameter of the hollow tubular element. The total cross-sectional area of the first empty region may be the same as the sum of the cross-sectional areas of each of said at least one segmental channel formed by the first segment of the first section located downstream of the section.

The ratio of the total cross-sectional area of said at least one segmented channel (first segment) to the total cross-sectional area of the first segment (or section) may be at least approximately 10 percent. The ratio of the total cross-sectional area of said at least one segmented channel (first segment) to the total cross-sectional area of the first segment (or section) may be at least approximately 30 percent. The ratio of the total cross-sectional area of said at least one segmented channel (first segment) to the total cross-sectional area of the first segment (or section) may be at least approximately 40 percent. The ratio of the total cross-sectional area of said at least one segmented channel to the total cross-sectional area of the first segment may be at least approximately 65 percent. The ratio of the total cross-sectional area of said at least one segmented channel to the total cross-sectional area of the first segment may be at least approximately 70 percent. In addition, the first segment itself may be porous. Providing a large proportion of segment channels, open area, void space or void area ensures advantageously low draw resistance and draw resistance per unit length of the first segment and the downstream section while simultaneously ensuring that there is sufficient first segment material to prevent any fragments of the aerosol generating element from escaping from the article.

The ratio of the total cross-sectional area of said at least one segmented channel to the total cross-sectional area of the first segment may be a maximum of approximately 95 percent. The ratio of the total cross-sectional area of said at least one segmented channel to the total cross-sectional area of the first segment may be a maximum of approximately 85 percent. The ratio of the total cross-sectional area of said at least one segmented channel to the total cross-sectional area of the first segment may be a maximum of approximately 75 percent.

The ratio of the total cross-sectional area of the second empty region to the total cross-sectional area of the second section of the downstream section may be at least approximately 25 percent. In other words, the open area formed by the second empty region of the downstream section may be at least approximately 25 percent of the total cross-sectional area of the second section of the downstream section, which may have a constant cross-sectional area. Preferably, the total cross-sectional area of the first section of the downstream section is the same as the total cross-sectional area of the second section of the downstream section. Accordingly, the cross-sectional area of the downstream section may be substantially constant.

The ratio of the total cross-sectional area of the second empty region to the total cross-sectional area of the downstream section may be at least approximately 50 percent. The ratio of the total cross-sectional area of the second empty region to the total cross-sectional area of the downstream section may be at least approximately 75 percent. The ratio of the total cross-sectional area of the second empty region to the total cross-sectional area of the downstream section may be at least approximately 80 percent. Providing a large proportion of open area or empty region provides advantageously low resistance to draw and resistance to draw per unit length of the downstream section and the aerosol-generating article as a whole.

The ratio of the total cross-sectional area of the second empty region to the total cross-sectional area of the second section may be a maximum of approximately 99 percent. The ratio of the total cross-sectional area of the second empty region to the total cross-sectional area of the second section may be a maximum of approximately 95 percent. The ratio of the total cross-sectional area of the second empty region to the total cross-sectional area of the second section may be a maximum of approximately 90 percent.

The ratio of the total cross-sectional area of the second empty region to the total cross-sectional area of the first empty region, which can be formed by at least one segmental air flow channel, can be greater than about 1.1 (110 percent), preferably greater than about 1.3 (130 percent), more preferably about 1.5 (150 percent), and even more preferably about 2 (200 percent).

The internal diameter or width of at least one segmented air flow channel may be from about 1 millimeter to about 6 millimeters. The internal diameter or width of at least one segmented air flow channel may be from about 2 millimeters to about 5 millimeters. The internal diameter or width of at least one segmented air flow channel may be from about 3 millimeters to about 4 millimeters.

The internal diameter or width of at least one segmental air flow channel (which forms the first empty region) may be smaller than the internal diameter of the air flow channel formed by said at least one cavity of the second empty region. As discussed above, said at least one cavity may be formed by at least one hollow tubular element according to the present disclosure. Therefore, the hollow tubular element forming the second empty region may have the same characteristics and the same geometry as the hollow tubular element defined in the present disclosure.

The first segment can be made of a fibrous material. The first segment can be made of a porous material. The first segment can be made of a biodegradable material. The first segment can be made of a cellulose material, such as cellulose acetate. For example, the first segment can be made of a bundle of cellulose acetate fibers having a denier of approximately 10 to approximately 15. For example, the first segment is made of a relatively low-density cellulose acetate tow, such as a cellulose acetate tow containing fibers with a denier of approximately 12, which is capable of providing a draw resistance per unit length of approximately 0.8 to approximately 2.5 millimeters of H ₂ O per millimeter.

The first segment may be made of a polylactic acid-based material. The first segment may be made of a bioplastic material, preferably a starch-based bioplastic material. The first segment may be manufactured by injection molding or by extrusion. Bioplastic-based materials are preferred because they are capable of providing first segment designs that are simple and inexpensive to manufacture, have a specific complex cross-sectional profile, and may contain a plurality of relatively large air flow channels passing through the first segment material, which provides suitable draw-resistance characteristics.

The first segment may be made of a sheet of suitable material that has been corrugated, pleated, gathered, woven or folded into an element that forms a plurality of longitudinally extending channels. Such a sheet of suitable material may be made of paper, cardboard, a polymer such as polylactic acid or any other cellulose-based material, paper-based material or bioplastic-based material. The cross-sectional profile of such a first segment may have randomly oriented channels.

The first segment may be made by any other suitable method. For example, the first segment may be made from a bundle of longitudinally extending tubes. The longitudinally extending tubes may be made from polylactic acid. The first segment may be made by extrusion, casting, lamination, injection or milling of a suitable material. Thus, it is preferable that there is a low pressure drop (or low draw resistance) in the area from the upstream end of the first segment to the downstream end of the first segment.

The first segment may not consist of a hollow tubular element, which is defined in the present disclosure and forms a single free air flow channel between its upstream and downstream ends. Such a hollow tubular segment would effectively provide a draw resistance and a draw resistance per unit length of 0 millimeters H ₂ O.

The length of the first segment may be at least about 1 millimeter. The length of the first segment may be no more than about 15 millimeters. The length of the first segment may be from about 1 millimeter to about 15 millimeters. The length of the first segment may be from about 5 millimeters to about 15 millimeters. Preferably, the length of the first segment may be from about 1 millimeter to about 10 millimeters. The length of the first segment may be about 6 millimeters. Preferably, the length of the first section (or the first segment of the first section) is less than the length of the second downstream section, which may be formed by at least one hollow tubular element, so that the comparatively low characteristics of the resistance to draw of the downstream section will not be affected by the comparatively long first segment, which has a higher resistance to draw than the second section or portion of the downstream section.

The downstream section may further comprise a downstream plug of material. The downstream plug of material may be adjacent to the hollow tubular element. The downstream plug of material may comprise a filter material in the form of cellulose acetate tow. The filter material may have a denier of 8.4 and a total denier of 21,000. The plug of filter material may have a length of at least approximately 5 millimeters. The plug of filter material may have a length of no more than 15 millimeters. The plug of filter material may have a length of approximately 10 millimeters.

The aerosol-generating article may further comprise a hollow tubular element located downstream of the material plug. The hollow tubular element may comprise a tube made of a fibrous tow. Preferably, the hollow tubular element may have a length of at least 4 millimeters. The hollow tubular element may have a length of no more than 12 millimeters. The hollow tubular element may have a length of approximately 8 millimeters. The hollow tubular element may have a wall thickness of at least 0.5 millimeters. The hollow tubular element may have a wall thickness of no more than 1.5 millimeters. The hollow tubular element may have a wall thickness of approximately 1 millimeter.

The aerosol-generating article may further comprise a capsule embedded within the filter material of the material plug. The capsule may be a breakable capsule comprising a hard, fragile shell surrounding liquid contents. The liquid contents may comprise a flavouring substance or an aerosol-modifying substance. The capsule may have a diameter of at least 1 millimetre. The capsule may have a diameter of no more than 5 millimetres. The capsule may have a diameter of approximately 3 millimetres. The capsule may have a mass of at least approximately 15 milligrams. The capsule may have a mass of no more than 30 milligrams. The capsule may have a mass of approximately 20 milligrams.

The upstream end of the aerosol-generating article may be formed by a wrapper. Providing the wrapper at the upstream end of the aerosol-generating article provides the advantage of being able to retain the aerosol-generating substrate in the aerosol-generating article. This feature also provides the advantage of being able to prevent direct contact of the user with the aerosol-generating substrate.

The wrapper may be mechanically closed at the upstream end of the aerosol-generating article. This may be achieved by folding or twisting the wrapper. An adhesive may be used to close the upstream end of the aerosol-generating article.

The wrapper forming the upstream end of the aerosol generating article may be formed from the same piece of material as the wrapper surrounding at least a portion of the downstream section.

This provides the advantage of being able to simplify the manufacture of the aerosol-generating article, since only one piece of wrapping material may be required. In addition, the use of one piece of wrapping material provides the advantage of eliminating the need for a seam to join two pieces of wrapping material. This provides the advantage of being able to simplify the manufacture. The absence of a seam also provides the advantage of being able to prevent or reduce the leakage of any aerosol-generating substrate from the aerosol-generating article.

The aerosol-generating article may have an outer diameter of at least 5 millimeters. Preferably, the aerosol-generating article has an outer diameter of at least 6 millimeters. More preferably, the aerosol-generating article has an outer diameter of at least 7 millimeters.

Preferably, the aerosol-generating article has an outer diameter of less than or equal to about 12 millimeters. More preferably, the aerosol-generating article has an outer diameter of less than or equal to about 10 millimeters. Even more preferably, the aerosol-generating article has an outer diameter of less than or equal to about 8 millimeters.

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

The present disclosure also relates to an aerosol generating system. The aerosol generating system may comprise an aerosol generating article as described above. The aerosol generating system may comprise an aerosol generating device having a distal end and a mouthpiece end. The aerosol generating device may comprise a housing extending from the distal end to the mouthpiece end. The housing may form a cavity of the device for removably placing the aerosol generating article on the mouthpiece end of the device. The aerosol generating device may comprise a heater for heating an aerosol generating substrate when the aerosol generating article is placed inside the cavity of the device.

According to the present invention, an aerosol generating system is proposed, comprising an aerosol generating article described above, and an aerosol generating device having a distant (distal) end and a mouthpiece end. The aerosol generating device comprises: a housing extending from the distant end to the mouthpiece end, wherein the housing forms a cavity of the device for removable placement of the aerosol generating article on the mouthpiece end of the device; and a heater for heating an aerosol generating substrate, when the aerosol generating article is placed in the cavity of the device.

The aerosol generating device comprises a housing. The housing or casing of the aerosol generating device forms a cavity of the device for removable placement of the aerosol generating article on the mouthpiece end of the device. The aerosol generating device comprises a heating element or heater for heating the aerosol generating substrate when the aerosol generating article is placed inside the cavity of the device.

The cavity of the device may be referred to as the heating chamber of the aerosol-generating device. The cavity of the device may extend between the distal end and the mouthpiece or proximal end. The distal end of the cavity of the device may be a closed end, and the mouthpiece or proximal end of the cavity of the device may be an open end. The aerosol-generating article may be inserted into the cavity of the device or the heating chamber through the open end of the cavity of the device. The cavity of the device may have a cylindrical shape in order to match the same shape of the aerosol-generating article.

The expression "housed within" may refer to the fact that a component or element is wholly or partially housed within another component or element. For example, the phrase "an aerosol-generating article is housed within a cavity of a device" refers to an aerosol-generating article that is wholly or partially housed within a cavity of a device for an aerosol-generating article. When an aerosol-generating article is housed within a cavity of a device, the aerosol-generating article may be adjacent to a distal end of the cavity of the device. When an aerosol-generating article is housed within a cavity of a device, the aerosol-generating article may be in close proximity to a distal end of the cavity of the device. The distal end of the cavity of the device may be defined by an end wall.

The length of the cavity of the device may be from about 10 millimeters to about 50 millimeters. The length of the cavity of the device may be from about 20 millimeters to about 40 millimeters. The length of the cavity of the device may be from about 25 millimeters to about 30 millimeters. The length of the cavity of the device (or heating chamber) may be equal to or greater than the length of the rod of the aerosol-generating substrate.

The diameter of the cavity of the device may be from about 4 millimeters to about 50 millimeters. The diameter of the cavity of the device may be from about 4 millimeters to about 30 millimeters. The diameter of the cavity of the device may be from about 5 millimeters to about 15 millimeters. The diameter of the cavity of the device may be from about 6 millimeters to about 12 millimeters. The diameter of the cavity of the device may be from about 7 millimeters to about 10 millimeters. The diameter of the cavity of the device may be from about 7 millimeters to about 8 millimeters.

The diameter of the cavity of the device may be equal to or greater than the diameter of the aerosol-generating article. The diameter of the cavity of the device may be equal to the diameter of the aerosol-generating article for the purpose of forming an interference fit with the aerosol-generating article.

The cavity of the device may be designed to form a tight fit with an aerosol-generating article located inside the cavity of the device. The tight fit may be referred to as a tight fit. The aerosol-generating device may comprise a peripheral wall. Such a peripheral wall may form a cavity of the device or a heating chamber. The peripheral wall forming the cavity of the device may be designed to interact with the aerosol-generating article located in the cavity of the device by means of a tight fit, so that there is essentially no gap or empty space between the peripheral wall forming the cavity of the device and the aerosol-generating article when it is located in the device.

Such a press fit enables the formation of a hermetic fit or configuration between the cavity of the device and the aerosol-generating article placed therein.

With such a sealed configuration, there will be essentially no gap or empty space for air to pass through between the peripheral wall forming the cavity of the device and the aerosol generating article.

An interference fit with the aerosol generating article may be formed along the entire length of the cavity of the device or along a portion of the length of the cavity of the device.

The aerosol generating device may comprise an air flow channel extending between the channel inlet and the channel outlet. The air flow channel may be configured to establish fluid communication between the interior of the device cavity and the area outside the aerosol generating device. The air flow channel of the aerosol generating device may be formed inside the casing of the aerosol generating device to provide fluid communication between the interior of the device cavity and the area outside the aerosol generating device. The air flow channel may be configured to provide air flow into the article for the purpose of delivering the generated aerosol to the user who puffs through the mouthpiece end of the article when the aerosol generating article is placed inside the cavity of the device.

The air flow channel of the aerosol generating device may be formed inside or by the peripheral wall of the casing of the aerosol generating device. In other words, the air flow channel of the aerosol generating device may be formed 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 formed by the inner surface of the peripheral wall, and partially it may be formed within the thickness of the peripheral wall. The inner surface of the peripheral wall forms a peripheral boundary of the cavity of the device.

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

The aerosol generating device may comprise an elongated heater (or heating element) configured to be inserted into the aerosol generating article when the aerosol generating article is placed within the cavity of the device. The elongated heater may be located within the cavity of the device. The elongated heater may extend into the cavity of the device. Alternative heating structures will be discussed below.

The heater may be any suitable type of heater. Preferably, the heater is an external heater.

Preferably, the heater can externally heat the aerosol-generating article when it is placed inside the aerosol-generating device. Such an external heater can surround the aerosol-generating article when it is inserted into the aerosol-generating device or placed inside it.

The heater may be configured to surround the aerosol-generating article when the aerosol-generating article is placed within the cavity of the device.

In some embodiments, the heater is configured to heat the outer surface of the aerosol-generating substrate. In some embodiments, the heater is configured to be inserted into the aerosol-generating substrate when the aerosol-generating substrate is positioned within said cavity. The heater may be located within the cavity of the device or the heating chamber. Such a heater may be described as an external heater.

Providing a heater configured to surround the aerosol-generating article when the aerosol-generating article is placed within the cavity of the device allows for a faster increase in the temperature of the aerosol-generating substrate when using the heater. This provides the advantage of being able to help prevent less volatile components, such as an aerosol-forming substance, from being delivered to the user after more volatile components, such as nicotine.

The heater may comprise at least one heating element. The at least one heating element may be a heating element of any suitable type. In some embodiments, the device comprises only one heating element. In some embodiments, the device comprises a plurality of heating elements. The heater may comprise at least one resistive heating element. Preferably, the heater comprises a plurality of resistive heating elements. Preferably, the resistive heating elements are electrically connected in a parallel arrangement. Advantageously, providing a plurality of resistive heating elements electrically connected in a parallel arrangement makes it possible to facilitate the delivery of the required electrical power to the heater while reducing or minimizing the voltage required to provide the required electrical power. Advantageously, reducing or minimizing the voltage required to operate the heater makes it possible to facilitate the reduction or minimization of the physical size of the power source.

The at least one heating element may have any length. The term "length" as used herein with respect to a heating element refers to the distance between the most upstream point of the at least one heating element and the most downstream point of the at least one heating element. Some heating elements may extend along tortuous or serpentine paths. In this case, the "length" of the heating element is still considered to be the distance between the most upstream point of the at least one heating element and the most downstream point of the at least one heating element, regardless of the path between them.

Said at least one heating element may have a length of no more than 80 millimeters. For example, said at least one heating element may have a length of no more than 65 millimeters, no more than 60 millimeters, no more than 55 millimeters, no more than 50 millimeters, no more than 40 millimeters, no more than 35 millimeters, no more than 25 millimeters, no more than 20 millimeters, no more than 15 millimeters, or no more than 10 millimeters.

Providing a heater having a comparatively short said at least one heating element provides the advantage of being able to effectively heat, with its help, the entire length of a correspondingly short aerosol-generating substrate of an aerosol-generating article without heating those areas of the aerosol-generating article that do not contain an aerosol-generating substrate.

Suitable materials for producing said at least one resistive heating element include, but are not limited to: semiconductors such as doped ceramics, electrically "conductive" ceramics (such as molybdenum disilicide), carbon, graphite, metals, metal alloys, and composite materials made of a ceramic material and a metallic material. Such composite materials may comprise doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbides. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel-, cobalt-, chromium-, aluminum-, titanium-, zirconium-, hafnium-, niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese-, and iron-based alloys, as well as nickel-, iron-, cobalt-, stainless-steel-, timetal-, and iron-manganese-aluminum-based superalloys.

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

In some embodiments, said at least one heating element comprises an electrically insulating substrate, wherein said at least one resistive heating element is provided on said electrically insulating substrate.

The electrically insulating substrate may comprise any suitable material. For example, the electrically insulating substrate may comprise one or more of the following: paper, glass, ceramic, anodized metal, coated metal, and polyimide. The ceramic may comprise mica, aluminum oxide (Al ₂ O ₃ ), or zirconium dioxide (ZrO ₂ ). Preferably, the electrically insulating substrate has a thermal conductivity of less than about 40 watts per meter-kelvin or equal to about 40 watts per meter-kelvin, preferably less than about 20 watts per meter-kelvin or equal to about 20 watts per meter-kelvin, and ideally less than about 2 watts per meter-kelvin or equal to about 20 watts per meter-kelvin.

The heater may comprise a heating element comprising a rigid electrically insulating substrate with one or more conductive paths or a wire located on its surface. The size and shape of the electrically insulating substrate may provide the possibility of inserting it directly into the aerosol-generating substrate. If the electrically insulating substrate is not rigid enough, the heating element may comprise additional reinforcing means. Current may be passed through said one or more conductive paths to heat the heating element and the aerosol-generating substrate.

In some embodiments, the heater comprises an induction heating structure. The induction heating structure may comprise an induction coil and a power source configured to supply a high-frequency oscillating current to the induction coil. The term "high-frequency oscillating current" as used herein denotes an oscillating current with a frequency of from about 500 kHz to about 30 MHz. The heater may advantageously comprise a DC-AC converter for converting a DC current supplied by the DC power source into an AC current. The induction coil may be configured to generate a high-frequency oscillating electromagnetic field when receiving the high-frequency oscillating current from the power source. The induction coil may be configured to generate a high-frequency oscillating electromagnetic field in a cavity of the device. In some embodiments, the induction coil may substantially surround the cavity of the device. The induction coil may extend at least partially along the length of the cavity of the device.

The heater may comprise an induction heating element. The induction heating element may be a current collector. The term "current collector" as used herein refers to an element comprising a material that is capable of converting electromagnetic energy into heat. When the current collector is in an alternating electromagnetic field, the current collector heats up. The heating of the current collector may be the result of at least one of hysteresis losses and eddy currents induced in the current collector, depending on the electrical and magnetic properties of the current collector material.

The current-receiving element can be designed so that when the aerosol-generating article is located in the cavity of the aerosol-generating device, the oscillating electromagnetic field generated by the induction coil induces a current in the current-receiving element, which leads to heating of the current-receiving element. In these embodiments, the aerosol-generating device is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (H-field strength) from 1 to 5 kiloamperes per meter (kA/m), preferably from 2 to 3 kA/m, for example approximately 2.5 kA/m. The electric aerosol-generating device is preferably capable of generating a fluctuating electromagnetic field having a frequency from 1 to 30 MHz, for example from 1 to 10 MHz, for example from 5 to 7 MHz.

In some embodiments, the current-receiving element is located in the aerosol-generating article. In these embodiments, the current-receiving element is preferably located in contact with the aerosol-generating substrate. The current-receiving element can be located in the aerosol-generating substrate.

In some embodiments, the current-receiving element is located in the aerosol-generating device. In these embodiments, the current-receiving element may be located in said cavity. The aerosol-generating device may contain only one current-receiving element. The aerosol-generating device may contain a plurality of current-receiving elements.

In some embodiments, the current-receiving element is configured to heat the outer surface of the aerosol-generating substrate. In some embodiments, the current-receiving element is configured to be inserted into the aerosol-generating substrate when the aerosol-generating substrate is positioned within said cavity.

The current collecting element may comprise any suitable material. The current collecting element may be made of any material that is capable of being inductively heated to a temperature sufficient to release volatile compounds from the aerosol-generating substrate. Suitable materials for the elongated current collecting element include graphite, molybdenum, silicon carbide, stainless steels, niobium, aluminum, nickel, nickel compounds, titanium, and composites of metallic materials. Some current collecting elements comprise metal or carbon. As an advantage, the current collecting element may comprise a ferromagnetic material, such as ferritic iron, a ferromagnetic alloy, such as ferromagnetic steel or stainless steel, ferromagnetic particles, and ferrite, or consist of the above. A suitable current collecting element may consist of or contain aluminum. The current collecting element preferably comprises greater than about 5 percent, preferably greater than about 20 percent, more preferably greater than about 50 percent, or greater than about 90 percent of ferromagnetic or paramagnetic materials. Some elongated current collecting elements may be heated to a temperature greater than about 250 degrees Celsius.

The current-collecting element may comprise a non-metallic core with a metal layer located on the non-metallic core. For example, the current-collecting element may comprise metal tracks formed on the outer surface of a ceramic core or substrate.

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

During use, the heater may be controlled to operate within a certain operating temperature range below the maximum operating temperature. The operating temperature range is preferably from about 150 degrees Celsius to about 300 degrees Celsius in the heating chamber (or cavity of the device). The operating temperature range of the heater may be from about 150 degrees Celsius to about 250 degrees Celsius.

The operating temperature range of the heater may be from about 150 degrees Celsius to about 200 degrees Celsius. The operating temperature range of the heater may be from about 180 degrees Celsius to about 250 degrees Celsius.

The operating temperature range of the heater may be from about 180 degrees Celsius to about 200 degrees Celsius. In particular, it has been found that optimal and stable aerosol delivery can be achieved by using an aerosol generating device comprising an external heater that has an operating temperature range of about 180 degrees Celsius to about 200 degrees Celsius, with aerosol generating articles that have a relatively low draw resistance (e.g., with a downstream section that has a draw resistance of less than 10 millimeters of _H2O ), as described throughout this disclosure.

In those embodiments where the aerosol-generating article comprises a ventilation zone at a location along a downstream section or a hollow tubular element, the ventilation zone may be arranged so that it is open when the aerosol-generating article is placed in the cavity of the device. Thus, the length of the cavity of the device may be less than the distance from the upstream end of the aerosol-generating article to the ventilation zone located along the downstream section.

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, such as a lithium-cobalt, lithium-iron phosphate or lithium-polymer battery. However, in some embodiments, the power source may be a charge storage device of another type, such as a capacitor. The power source may require recharging and may have a capacity that allows storing a sufficient amount of energy for one or more user-performed operations, such as one or more aerosol generating sessions. For example, the power source may have a sufficient capacity to allow continuous heating of the aerosol generating substrate for a period of approximately six minutes, which corresponds to the typical time required to smoke a conventional cigarette or for a period that is a multiple of six minutes. In another example, the power source may have sufficient capacity to enable a specified number of puffs or individual heater activations.

The present invention is defined in the claims. However, a non-exhaustive list of non-limiting examples is provided below. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment or aspect described herein.

Example 1. An aerosol-generating article comprising: an aerosol-generating substrate; a downstream section extending from a downstream end of the aerosol-generating substrate to a downstream end of the aerosol-generating substrate, wherein the aerosol-generating substrate has a density of no more than 0.5 grams per cubic centimeter, and wherein the ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article is no more than 0.4.

Example 2. An aerosol-generating article according to example 1, wherein the ratio of the length of the aerosol-generating substrate to the total length of the aerosol-generating article is at least 0.1.

Example 3. An aerosol-generating article according to example 1 or example 2, wherein the ratio of the length of the aerosol-generating substrate to the total length of the aerosol-generating article is approximately 0.26.

Example 4. An aerosol-generating article according to any preceding example, wherein the aerosol-generating substrate has a length of at least 5 millimeters.

Example 5. An aerosol-generating article according to any preceding example, wherein the aerosol-generating substrate has a length of no more than 80 millimeters.

Example 6. An aerosol generating article according to any previous example, having a length of at least 35 millimetres.

Example 7. An aerosol-generating article according to any preceding example, having a length of no more than 100 millimetres.

Example 8. An aerosol-generating article according to any preceding example, having a length no more than 40 millimeters longer than the aerosol-generating substrate.

Example 9. An aerosol-generating article according to any preceding example, having a length at least 25 millimeters greater than the aerosol-generating substrate.

Example 10. An aerosol-generating article according to any preceding example, having a length approximately 33 millimeters greater than the aerosol-generating substrate.

Example 11. An aerosol-generating article according to any preceding example, wherein the aerosol-generating substrate has a density of no more than 0.34 grams per cubic centimeter.

Example 12. An aerosol-generating article according to any preceding example, wherein the aerosol-generating substrate has a density of at least 0.24 grams per cubic centimeter.

Example 13. An aerosol-generating article according to any preceding example, wherein the aerosol-generating substrate has a density of approximately 0.29 grams per cubic centimeter.

Example 14. An aerosol-generating article according to any preceding example, wherein the aerosol-generating substrate comprises tobacco.

Example 15. An aerosol-generating article according to example 14, wherein the aerosol-generating substrate comprises cut tobacco filler.

Example 16. An aerosol-generating article according to example 15, wherein the weight of the cut tobacco filler in the aerosol-generating substrate is at least about 100 milligrams.

Example 17. An aerosol-generating article according to any preceding example, wherein the aerosol-generating substrate comprises an aerosol-forming substance, wherein the aerosol-generating substrate has an aerosol-forming substance content of at least about 10 percent by weight.

Example 18. An aerosol generating article according to any preceding example, wherein the downstream section comprises a hollow tubular segment.

Example 19. An aerosol generating article according to any preceding example comprising a first ventilation zone at a location along a downstream section.

Example 20. An aerosol generating article according to example 19, having a ventilation level of at least about 10 percent.

Example 21. An aerosol generating article according to any preceding example, wherein the downstream section has a draw resistance of less than about 30 millimeters _H2O .

Example 22. An aerosol-generating article according to any preceding example, further comprising an upstream section located upstream of the aerosol-generating substrate, wherein the upstream section has a draw resistance of from about 10 millimeters _H2O to about 70 millimeters _H2O .

Example 23. An aerosol-generating system comprising: an aerosol-generating article according to any previous example and an aerosol-generating device having a distal end and a mouthpiece end, wherein the aerosol-generating device comprises: a housing extending from the distal end to the mouthpiece end and defining a cavity of the device for removably placing the aerosol-generating article on the mouthpiece end of the device; and a heater for heating an aerosol-generating substrate when the aerosol-generating article is placed in the cavity of the device.

Example 24. An aerosol generating system according to example 23, in which the heater of the aerosol generating device is designed to surround the aerosol generating article when the aerosol generating article is placed in the cavity of the device.

Example 25. An aerosol generating system according to example 23 or example 24, wherein the operating temperature of the heater is from about 180 to about 250 degrees Celsius.

Example 26. An aerosol generating system according to any of examples 23-25, wherein the heater has a length of no more than 40 millimeters.

The invention will now be further described with reference to the accompanying drawings, in which:

Fig. 1 is a schematic side sectional view of an aerosol generating article according to an embodiment of the present invention;

Fig. 2 shows a schematic side sectional view of another aerosol generating article according to another embodiment of the present invention.

Fig. 3 shows a schematic side view in section of the embodiment of the aerosol generating article according to Fig. 1;

Fig. 4 shows a schematic side view in section of a variant of the aerosol generating article according to Fig. 1;

Fig. 5 is a schematic side sectional view of an additional aerosol generating article according to an embodiment of the present invention;

Fig. 6 shows a schematic side sectional view of the embodiment of the aerosol generating article of Fig. 5; and

Fig. 7 is a schematic side sectional view of the mouthpiece end portion of an exemplary aerosol generating device and system, wherein the aerosol generating article shown in Fig. 1 is housed within the aerosol generating device.

The aerosol-generating article 10 shown in Fig. 1 comprises an aerosol-generating substrate 12 and a downstream section 14 at a location downstream of the aerosol-generating substrate 12. Thus, the aerosol-generating article 10 extends from an upstream or distal end 16, which substantially coincides with the upstream end of the aerosol-generating substrate 12, to a downstream or mouth end 18, which coincides with the downstream end of the downstream section 14.

The aerosol generating article 10 has an overall length of approximately 45 millimeters.

The aerosol-generating substrate 12 comprises cut tobacco filler impregnated with approximately 12 percent by weight of an aerosol-forming substance, such as glycerin. The cut tobacco filler comprises 90 percent by weight of tobacco leaf blades. The cut width of the cut tobacco filler is approximately 0.7 millimeters. The aerosol-generating substrate 12 comprises approximately 130 milligrams of cut tobacco filler.

The aerosol generating substrate 12 has a density of approximately 0.2 8 grams per cubic centimeter.

The aerosol-generating substrate 12 has a diameter of approximately 7.2 millimeters. The aerosol-generating substrate 12 has a length of approximately 11.5 millimeters. Therefore, the aerosol-generating substrate 12 has a length-to-diameter ratio of approximately 1.6.

The ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article is approximately 0.26.

The downstream section 14 comprises a hollow tubular element 20 located downstream of the aerosol-generating substrate 12 immediately thereafter, wherein the hollow tubular element 20 is aligned longitudinally with the aerosol-generating substrate 12. In the embodiment of Fig. 1, the upstream end of the hollow tubular element 20 is adjacent to the downstream end of the aerosol-generating substrate 12.

The hollow tubular element 20 forms a hollow section of the aerosol-generating article 10. The hollow tubular element does not substantially contribute to the overall draw resistance of the aerosol-generating article. More specifically, the draw resistance of the downstream section is approximately 0 millimeters H ₂ O.

The hollow tubular element 20 is provided in the form of a hollow cylindrical tube made of cellulose acetate or rigid paper, such as paper having a grammage (basis weight) of at least about 90 grams per square meter. The hollow tubular element 20 defines an internal cavity 22, which extends over the entire distance from the upstream end 24 of the hollow tubular segment to the downstream end 26 of the hollow tubular element 20. The internal cavity 22 is substantially empty, and thus allows for a substantially unimpeded flow of air along the internal cavity 22. The hollow tubular element 20 does not substantially contribute to the overall drag resistance of the aerosol-generating article 10.

The hollow tubular element 20 has a length of approximately 33 millimeters, an outer diameter (DE) of approximately 7.3 millimeters, and an inner diameter (Dx) of approximately 7.1 millimeters. Thus, the thickness of the peripheral wall of the hollow tubular element 20 is approximately 0.1 millimeters.

The aerosol-generating article 10 comprises a ventilation zone 30 provided at a location along the hollow tubular segment 20. More specifically, the ventilation zone 30 is provided at a distance of approximately 18 millimeters from the downstream end 26 of the hollow tubular element 20. Thus, in the embodiment of Fig. 1, the ventilation zone 30 is substantially provided at a distance of 18 millimeters from the mouthpiece end 18 of the aerosol-generating article 10. The ventilation level of the aerosol-generating article 10 is approximately 40 percent.

In the embodiment of Fig. 1, the aerosol generating article does not contain any additional component upstream of the aerosol generating substrate 12 or downstream of the hollow tubular segment 20.

The aerosol-generating article 100 shown in Fig. 2 differs from the aerosol-generating article 10 described above only by the presence of an upstream section at a location upstream of the aerosol-generating element. Accordingly, the aerosol-generating article 100 will be described only to the extent that it differs from the aerosol-generating article 10.

In addition to the aerosol-generating substrate 12 and the downstream section 14 at a location downstream of the aerosol-generating substrate 12, the aerosol-generating article 100 comprises an upstream section 40 at a location upstream of the aerosol-generating substrate 12. Thus, the aerosol-generating article 10 extends from a distal end 16, substantially coinciding with the upstream end of the upstream section 40, to a mouth end or downstream end 18, substantially coinciding with the downstream end of the downstream section 14.

The upstream section 40 comprises an upstream element 42, which is upstream of the aerosol-generating substrate 12 immediately upstream thereof, wherein the upstream element 42 is aligned longitudinally with the aerosol-generating substrate 12. In the embodiment of Fig. 2, the downstream end of the upstream element 42 is adjacent to the upstream end of the aerosol-generating substrate 12. The upstream element 42 is provided in the form of a cylindrical plug made of cellulose acetate, which is surrounded by a rigid wrapper.

The upstream element 42 has a length of approximately 5 millimeters. The tightening resistance of the upstream element 42 is approximately 30 millimeters H ₂ O.

Fig. 3 shows an aerosol-generating article 200, which is a variant of the aerosol-generating article 10 described above. The aerosol-generating article 200 is generally the same as the aerosol-generating article 10 according to the embodiment of Fig. 1, except that the aerosol-generating article 200 according to a sub-variant of the first embodiment does not comprise the cylindrical hollow tubular element 22 described above. Instead, the aerosol-generating article 200 according to a sub-variant of the first embodiment comprises a modified tubular element 220 located downstream of the aerosol-generating element 12 immediately after it.

The modified tubular element 220 comprises a tubular body 222 defining a cavity 224 extending from a first end of the tubular body 222 to a second end of the tubular body 222. The modified tubular element 220 also comprises a folded end portion defining a first end wall 226 at the first end of the tubular body 222. The first end wall 226 defines an opening 228 that allows air to flow between the cavity 224 and a region outside the modified tubular element 220. In particular, the embodiment of Fig. 3 is designed in such a way that aerosol can flow from the aerosol generating element 12 through the opening 228 into the cavity 224.

As in the case of the cavity 22 according to the first embodiment shown in Fig. 1, the cavity 224 of the tubular body 222 is substantially empty, so that a substantially unimpeded flow of air along the cavity 222 is ensured. Therefore, it is possible to localize the tightening resistance of the modified tubular element 220 in a specific longitudinal location of the modified tubular element 220, namely on the first end wall 226, and to adjust it by selecting the configuration of the first end wall 226 and its corresponding opening 228.

In the embodiment of Fig. 3, the modified tubular element 220 has a length of approximately 33 millimeters, an outer diameter (DE) of approximately 7.3 millimeters, and an inner diameter (DFTS) of approximately 7.1 millimeters. Thus, the thickness of the peripheral wall of the second hollow tubular body 222 is approximately 0.1 millimeters.

Fig. 4 shows an aerosol-generating article 300, which is a variant of the aerosol-generating article 100 described above. The aerosol-generating article 300 is generally the same as the aerosol-generating article 100 according to the embodiment of Fig. 2, except that the aerosol-generating article 300 according to a sub-variant of the second embodiment does not comprise an upstream element 42 provided in the form of a cylindrical plug made of cellulose acetate surrounded by a rigid wrapper. Instead, the aerosol-generating article 300 according to a sub-variant of the second embodiment comprises a second tubular element 44, located upstream of the aerosol-generating element 12 immediately upstream thereof. Therefore, in this sub-variant of the second embodiment, the hollow tubular element 20, located downstream of the aerosol-generating element 12 immediately upstream thereof, can be called the first tubular element 20.

The second tubular element 44 comprises a tubular body 46 defining a cavity 48 extending from the first end of the tubular body 46 to the second end of the tubular body 46. The second tubular element 44 also comprises a folded end portion defining a first end wall 50 at the first end of the tubular body 46. The first end wall 50 defines an opening 52 that enables air flow between the cavity 48 and the region outside the second tubular element 44. In particular, the embodiment according to Fig. 4 is designed in such a way that air can flow from the cavity 48 through the opening 52 into the aerosol generating element 12.

In addition, the second tubular element 44 comprises a second end wall 54 at the second end of its tubular body 46. This second end wall 54 is formed by folding the end portion of the second tubular element 44 at the second end of the tubular body 46. The second end wall 54 forms an opening 56, which also allows air to flow between the cavity 48 and the area outside the second tubular element 44. In the case of the second end wall 54, the opening 56 is formed in such a way that it is possible for air to flow from the area outside the aerosol-generating article 300 through the opening 56 into the cavity 48. Thus, the opening 56 provides a channel through which it is possible to draw air into the aerosol-generating article 300 and then through the aerosol-generating element 12.

In the sub-variant according to Fig. 4, the downstream second tubular element 44 adjoins the upstream end of the aerosol-generating substrate 12. The second tubular element 44 has a length of approximately 5 millimeters. The draw resistance of the second tubular element 44 is approximately 30 millimeters H ₂ O.

The aerosol generating article 400 shown in Fig. 5 differs from the aerosol generating article 10 described above by having a downstream plug of material 501. The plug of material 501 comprises a filter material in the form of cellulose acetate tow having an elementary fiber denier of 8.4 and a total denier of 21,000. The plug of filter material 501 has a length of approximately 10 millimeters.

The aerosol-generating article 400 further comprises a hollow tubular element 502 located downstream of the plug made of material 501. The hollow tubular element 502 comprises a tube made of a fibrous tow. The hollow tubular element 502 has a length of approximately 8 millimeters. The hollow tubular element 502 has a wall thickness of approximately 1 millimeter.

The aerosol generating article 400 has a diameter of approximately 6.7 millimeters. The aerosol generating substrate 12 has a length of approximately 35 millimeters.

The aerosol generating article 500 shown in Fig. 6 differs from the aerosol generating article 400 described above only by the presence of a capsule 601 embedded inside the filter material of the plug made of material 501. The capsule 601 is a breakable capsule containing a hard brittle shell surrounding a liquid content. The liquid content contains a flavoring substance or a substance for modifying the aerosol. The capsule 601 has a diameter of approximately 3 millimeters and a mass of approximately 20 milligrams.

Fig. 7 shows an aerosol generating system 1000 comprising an aerosol generating device 1 and an aerosol generating article 10 shown in Fig. 1. Fig. 7 shows a downstream mouthpiece end portion of the aerosol generating device 1, in which a cavity of the device is formed with the possibility of accommodating the aerosol generating article 10 therein. The aerosol generating device 1 comprises a casing (or body) 4 extending between the mouthpiece end 2 and the distal end (not shown). The casing 4 comprises a peripheral wall 6. The peripheral wall 6 forms a cavity of the device for accommodating the aerosol generating article 10. The cavity of the device is formed by a closed distal end and an open mouthpiece end. The mouthpiece end of the cavity of the device is located on the mouthpiece end of the aerosol-generating device 1. The aerosol-generating article 10 is designed with the possibility of its placement through the mouthpiece end of the cavity of the device and with the possibility of adjoining the closed end of the cavity of the device.

Inside the peripheral wall 6, a channel 5 for the air flow in the device is formed. The channel 5 for the air flow passes between the inlet opening 7, located at the mouthpiece end of the aerosol-generating device 1, and the closed end of the cavity of the device. It is possible to supply air to the aerosol-generating substrate 12 through an opening provided at the closed end of the cavity of the device, which ensures communication through a fluid medium between the channel 5 for the air flow and the aerosol-generating substrate 12.

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 for controlling such supply of power to the heater. The heater is configured to heat the aerosol-generating article 10 during use, when the aerosol-generating article 10 is placed inside the device 1. The heater is configured to externally heat the aerosol-generating substrate 12 for optimal aerosol generation. The ventilation zone 30 is arranged so that it is open when the aerosol-generating article 10 is placed inside the aerosol-generating device 1.

For the purposes of the present specification and the appended claims, except where otherwise indicated, all numbers expressing quantities, amounts, percentages, and so forth, are to be understood as modified in all instances by the adverb "about". Furthermore, all ranges include the disclosed maximum and minimum points and any intermediate ranges therebetween that may or may not be specifically recited herein. Therefore, in this context, the number A is to be understood as A ± 10 percent A. In this context, the number A may be considered to include numerical values that are within the normal standard error of measurement of the property that modifies the number A. The number A, in some instances, when used in the appended claims, may deviate by the percentages given above, provided that the amount by which A deviates does not materially affect the essential and novel characteristic(s) of the claimed invention. In addition, all ranges include disclosed high and low points and any intermediate ranges therebetween that may or may not be specifically listed herein.

Claims (24)

1. An aerosol-generating article comprising: aerosol generating substrate; a downstream section extending from a downstream end of the aerosol generating substrate to a downstream end of the aerosol generating article; the aerosol-generating substrate has a density of no more than 0.5 grams per cubic centimeter, wherein the ratio of the length of the aerosol-generating substrate to the length of the aerosol-generating article is no more than 0.4, and wherein the aerosol generating article further comprises an upstream section that is upstream of the aerosol generating substrate, wherein the upstream section has a draw resistance of from 10 millimeters of water column to 70 millimeters of water column. 2. The aerosol-generating article of claim 1, wherein the ratio of the length of the aerosol-generating substrate to the total length of the aerosol-generating article is at least 0.1. 3. An aerosol-generating article according to any of the preceding claims, wherein the aerosol-generating substrate has a length of at least 5 millimeters. 4. An aerosol-generating article according to any of the preceding claims, wherein the aerosol-generating substrate has a length of no more than 80 millimeters. 5. An aerosol generating article according to any of the preceding claims, having a length of at least 35 millimetres. 6. An aerosol-generating article according to any of the preceding paragraphs, having a length of no more than 100 millimetres. 7. An aerosol-generating article according to any one of the preceding claims, wherein the aerosol-generating substrate has a density of at least 0.24 grams per cubic centimeter. 8. An aerosol-generating article according to any of the preceding claims, wherein the aerosol-generating substrate comprises cut tobacco filler. 9. An aerosol-generating article according to any one of the preceding claims, wherein the aerosol-generating substrate comprises an aerosol-forming substance, and wherein the aerosol-generating substrate has an aerosol-forming substance content of at least 10 percent by weight. 10. An aerosol generating article according to any of the preceding claims, comprising a first ventilation zone at a location along a downstream section. 11. An aerosol generating article according to any of the preceding claims, wherein the downstream section has a draw resistance of less than 30 millimetres of water column. 12. An aerosol-generating article according to any one of the preceding claims, wherein the downstream section comprises a clear air flow path extending from the downstream end of the aerosol-generating substrate to the downstream end of the downstream section. 13. An aerosol generating system comprising: an aerosol-generating article according to any of the preceding claims; and an aerosol generating device having a distal end and a mouthpiece end, wherein the aerosol generating device comprises: a housing extending from the distal end to the mouthpiece end and defining a cavity of the device for removably receiving an aerosol generating article at the mouthpiece end of the device; and a heater for heating the aerosol-generating substrate when the aerosol-generating article is placed inside the cavity of the device. 14. An aerosol generating system according to claim 13, wherein the heater of the aerosol generating device is configured to surround the aerosol generating article when the aerosol generating article is placed within the cavity of the device. 15. An aerosol generating system according to claim 13 or 14, wherein the heater has a length of no more than 40 millimeters.