RU2846332C1 - Aerosol-generating system with low resistance to inhalation and improved aroma delivery - Google Patents

Abstract

FIELD: smoking accessories.

SUBSTANCE: invention relates to an aerosol-generating system. Aerosol-generating system (1000) comprises aerosol-generating article (10) for generating an inhalable aerosol when heated, and aerosol-generating device (1) having a distal end and mouthpiece end (2). Aerosol-generating article (10) extends from mouthpiece end (18) to distal end (16). Aerosol-generating article (10) comprises aerosol-generating element (12). Aerosol-generating article (10) comprises downstream section (14) which is located further downstream of aerosol-generating element (12). Downstream section (14) extends from the downstream end of aerosol-generating element (12) to mouthpiece end (18) of aerosol-generating article (10). Downstream section (14) comprises hollow tubular element (20). Drawing resistance of downstream section (14) is less than 10 mm of water column. Aerosol generating device (1) comprises housing (4). Body (4) of aerosol-generating device (1) forms a cavity of the device for detachably placing aerosol-generating article (10) on mouthpiece end (2) of device (1). Aerosol-generating device (1) comprises a heater for heating aerosol-generating element (12) when aerosol-generating article (1) is placed inside the cavity of the device. Providing a downstream section with such low resistance to drawing ensures that all resistance to drawing of the aerosol-generating article is provided by the aerosol-generating element itself.

EFFECT: optimized delivery of aerosol to consumer, especially when using product in combination with external heating system.

15 cl, 5 dwg

Description

The present invention relates to an aerosol generating system comprising an aerosol generating device and an aerosol generating article. The present disclosure also relates to an aerosol generating article comprising an aerosol generating element and configured to generate an inhalable aerosol upon heating.

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 that may be placed 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. A further alternative embodiment 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 that have not been encountered in traditional smoking articles. First, tobacco-containing substrates are typically heated to significantly lower temperatures than those reached by the combustion front in a conventional cigarette. This can impact the release of nicotine from the tobacco-containing substrate and the delivery of nicotine to the consumer. At the same time, if the heating temperature is increased in an attempt to increase nicotine delivery, the generated aerosol typically must be cooled to a greater extent and more quickly before it reaches the consumer. However, technical solutions that have been widely used to cool the inhaled smoke in traditional smoking articles, such as the provision of a highly efficient filter segment at the mouth end of a cigarette, may create undesirable effects in an aerosol-generating article in which the tobacco-containing substrate is heated rather than burned, as they may reduce nicotine delivery.

In order to solve one or more problems specifically related to heating, rather than burning, an aerosol-generating aerosol-generating substrate, a number of aerosol-generating articles have been proposed in which several elements are combined, for example, with longitudinal alignment, with an aerosol-generating element enclosing an aerosol-generating substrate. For example, the aerosol-generating element has been combined with a support element to impart improved structural strength to the article, an aerosol cooling element configured to reduce the temperature of the aerosol, a mouthpiece element with low filtration efficiency, etc.

In general, there is a need for aerosol-generating articles that are easy to use, have increased practicality and are more environmentally friendly. In addition, it would be desirable to create aerosol-generating articles that are easier to manufacture and are able to make the entire production chain more balanced and economical. There is also a need for an aerosol-generating article that is particularly suitable for use in combination with an external heating system, and in particular for such an aerosol-generating article that would be characterized by improved aerosol generation and delivery of the aerosol-forming substance.

It would thus be desirable to provide a new and improved aerosol-generating article capable of satisfying at least one of the needs described above. It would also be desirable to provide such an aerosol-generating article that allows for its efficient and high-speed manufacture, preferably with acceptably low variability in draw resistance from one article to another.

As described above, the present disclosure relates to an aerosol generating system. The aerosol generating system may comprise an aerosol generating article according to the present disclosure. The aerosol generating article may be suitable for creating an inhalable aerosol upon heating. The aerosol generating system may further comprise an aerosol generating device having a distal end and a mouthpiece end. The aerosol generating article may extend from the mouthpiece end to the distal end. The aerosol generating article may comprise an aerosol generating element. The aerosol generating article may comprise a downstream section that is located downstream of the aerosol generating element. The downstream section may extend from the downstream end of the aerosol generating element to the mouthpiece end of the aerosol generating article. The downstream section may comprise a hollow tubular element. The draw resistance of the downstream section may be less than approximately 10 mm _H2O (millimeters of water column). The aerosol generating device may comprise a housing. The aerosol generating device or the housing of the aerosol generating device may form a cavity of the device for removably placing the aerosol generating article on the mouth end of the device. The aerosol generating device may comprise a heater for heating the aerosol generating element when the aerosol generating article is placed inside the cavity of the device. The aerosol generating system may comprise an aerosol generating substrate.

According to the present invention, an aerosol generating system is proposed, comprising an aerosol generating article for creating an inhalable aerosol upon heating and an aerosol generating device having a distal end and a mouthpiece end. The aerosol generating article extends from the mouthpiece end to the distal end. The aerosol generating article comprises an aerosol generating element. The aerosol generating article comprises a downstream section, which is located downstream relative to the aerosol generating element. The downstream section extends from the downstream end of the aerosol generating element to the mouthpiece end of the aerosol generating article. The downstream section comprises a hollow tubular element. The draw resistance of the downstream section is less than 10 mm H ₂ O (millimeters of water column). The aerosol generating device comprises a housing. The body 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 contains a heater for heating the aerosol generating element when placing the aerosol generating article inside the cavity of the device.

Thus, the aerosol generating system according to the present invention provides a new arrangement comprising an aerosol generating article having a section which is located downstream of the aerosol generating element and has a draw resistance of less than 10 mm H ₂ O (millimeters of water column).

Providing a downstream section with such a low draw resistance has the effect that substantially all of the draw resistance of the aerosol-generating article is provided by the aerosol-generating element itself and, if present, by a section located upstream of the aerosol-generating element. The inventors of the present invention have found that if the aerosol-generating article has such a draw resistance distribution along the length of the article, then an advantage is provided in that the delivery of the aerosol to the consumer can be optimized, especially if the article is used in combination with an aerosol-generating device of the present system.

This is desirable because it simplifies the design and operation of both the aerosol generating article and the heating device. It has also been found to allow the substrate to be heated to lower temperatures without compromising the quality and quantity of aerosol delivered to the consumer.

In addition, since providing such a low draw resistance downstream of the aerosol generating rod can be achieved by providing a hollow tubular element downstream of the aerosol generating rod, a substantially empty volume is provided within the article that facilitates the nucleation and growth of aerosol particles, while the draw resistance is substantially eliminated. This can further contribute to improving the generation and delivery of aerosol compared to existing aerosol generating articles and systems, and thus improving the overall user experience.

Providing a downstream section with such a low draw resistance creates the effect that substantially all of the draw resistance of the aerosol-generating article is provided by the aerosol-generating element itself (e.g., a rod-shaped aerosol-generating element), and, if necessary, by elements located upstream of the aerosol-generating element. The inventors of the present invention have found that if the aerosol-generating article has such a draw resistance distribution along the length of the article, then an advantage is provided in that the delivery of the aerosol to the consumer can be optimized, especially if the article is used in combination with an external heating system or heater. The delivery of the aerosol can be affected to some extent by the draw resistance of the aerosol-generating element itself. This is due to the fact that the aerosol generated in the upstream section of the aerosol-generating element must first pass through the remaining downstream section of the aerosol-generating element. Thus, controlling the geometric characteristics of the aerosol generating element also provides the ability to more effectively control the aerosol delivery, and overall the aerosol delivery becomes more stable from one aerosol generating article to another, especially when used in combination with an external heating system or heater.

According to the present invention, an aerosol-generating article is proposed for generating an inhalable aerosol upon heating. The aerosol-generating article comprises an element containing 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 and deliver an inhalable aerosol to a user. 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 oxygen in the air drawn through the cigarette causes the end of the cigarette to ignite, and the resulting combustion generates inhalable smoke. In contrast, 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 element may be in the form of a rod made of or containing an aerosol generating substrate. As used herein in connection with the present disclosure, the term "rod" is used to describe a generally 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 terms "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. The term "transverse" refers to the 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 the cross-section unless otherwise specified.

The term "length" refers to the longitudinal dimension of a component of an aerosol-generating article. For example, it can be used to refer to the longitudinal dimension of a rod or elongated tubular elements.

The aerosol-generating article further comprises a downstream section at a location downstream of the rod of the aerosol-generating substrate. As will be apparent from the following description of various embodiments of the aerosol-generating article according to the present invention, the downstream section may comprise one or more downstream elements.

In some embodiments, the downstream section may comprise a hollow section between the mouth end of the aerosol-generating article and the aerosol-generating element. The hollow 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 in relation to a tubular element that has a substantially cylindrical cross-section and defines at least one passage for air flow 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 shapes (e.g., alternative cross-sectional shapes) of the tubular element are possible.

In the context of the present disclosure, the hollow tubular element or segment provides a free flow channel. This means that the hollow tubular segment provides an insignificant level of resistance to draw (RTD). The term "insignificant level of resistance to draw" is used to describe a resistance to draw of less than 1 mm _H2O (millimeters of water column) per 10 millimeters of the length of the hollow tubular element, preferably less than 0.4 mm _H2O (millimeters of water column) per 10 millimeters of the length of the hollow tubular element, more preferably less than 0.1 mm _H2O (millimeters of water column) per 10 millimeters of the length of the hollow tubular element.

Therefore, the flow channel must be free of any components that would interfere with the longitudinal flow of air. Preferably, the flow channel is substantially empty.

In some embodiments, the aerosol-generating article may comprise a 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 internally by the hollow tubular element and the external environment.

The aerosol-generating article may further comprise an upstream section at a location upstream of the aerosol-generating substrate rod. The upstream section may comprise one or more upstream elements. In some embodiments, the upstream section may comprise an upstream element that is upstream of the aerosol-generating element in close proximity to it.

As briefly described above, the aerosol generating article according to the present disclosure comprises an aerosol generating element comprising an aerosol generating substrate.

In some embodiments, the aerosol generating element may be provided in the form of a rod containing an aerosol generating substrate. For example, the aerosol generating element may comprise a rod of aerosol generating substrate surrounded by a wrapper.

The rod containing the aerosol-generating substrate may have a length of at least about 5 millimeters. Preferably, the rod containing the aerosol-generating substrate has a length of at least about 7 millimeters. More preferably, the rod containing the aerosol-generating substrate has a length of at least about 10 millimeters. In particularly preferred embodiments, the rod containing the aerosol-generating substrate has a length of at least about 12 millimeters.

The rod containing the aerosol-generating substrate may have a length of up to about 80 millimeters. Preferably, the rod containing the aerosol-generating substrate has a length of less than about 65 millimeters or equal to about 65 millimeters. More preferably, the rod containing the aerosol-generating substrate has a length of less than about 60 millimeters or equal to about 60 millimeters. Even more preferably, the rod containing the aerosol-generating substrate has a length of less than about 55 millimeters or equal to about 55 millimeters.

In particularly preferred embodiments, the rod containing the aerosol-generating substrate has a length of less than about 50 millimeters or equal to about 50 millimeters, more preferably less than about 35 millimeters or equal to about 35 millimeters, even more preferably less than about 25 millimeters or equal to about 25 millimeters. In particularly preferred embodiments, the rod containing the aerosol-generating substrate has a length of less than about 20 millimeters or equal to about 20 millimeters, or even less than about 15 millimeters or equal to about 15 millimeters.

In some embodiments, the rod containing the aerosol-generating substrate has a length of about 5 millimeters to about 60 millimeters, preferably about 6 millimeters to about 60 millimeters, more preferably about 7 millimeters to about 60 millimeters, even more preferably about 10 millimeters to about 60 millimeters, most preferably about 12 millimeters to about 60 millimeters. In other embodiments, the rod containing the aerosol-generating substrate has a length of about 5 millimeters to about 55 millimeters, preferably about 6 millimeters to about 55 millimeters, more preferably about 7 millimeters to about 55 millimeters, even more preferably about 10 millimeters to about 55 millimeters, most preferably about 12 millimeters to about 55 millimeters. In further embodiments, the rod containing the aerosol-generating substrate has a length of from about 5 millimeters to about 50 millimeters, preferably from about 6 millimeters to about 50 millimeters, more preferably from about 7 millimeters to about 50 millimeters, even more preferably from about 10 millimeters to about 50 millimeters, most preferably from about 12 millimeters to about 50 millimeters.

In some particularly preferred embodiments, the rod containing the aerosol-generating substrate has a length of about 5 millimeters to about 30 millimeters, preferably about 6 millimeters to about 30 millimeters, more preferably about 7 millimeters to about 30 millimeters, even more preferably about 10 millimeters to about 30 millimeters. In other particularly preferred embodiments, the rod containing the aerosol-generating substrate has a length of about 5 millimeters to about 20 millimeters, preferably about 6 millimeters to about 20 millimeters, more preferably about 7 millimeters to about 20 millimeters, even more preferably about 10 millimeters to about 20 millimeters. In further particularly preferred embodiments, the rod containing the aerosol-generating substrate has a length of from about 5 millimeters to about 15 millimeters, preferably from about 7 millimeters to about 20 millimeters, more preferably from about 9 millimeters to about 16 millimeters, even more preferably from about 10 millimeters to about 15 millimeters.

The rod containing the aerosol-generating substrate preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article.

Preferably, the rod containing the aerosol-generating substrate has an outer diameter of at least about 5 millimeters. More preferably, the rod containing the aerosol-generating substrate has an outer diameter of at least about 6 millimeters. Even more preferably, the rod containing the aerosol-generating substrate has an outer diameter of at least about 7 millimeters.

The rod containing the aerosol-generating substrate preferably has an outer diameter less than about millimeters or equal to about 12 millimeters. More preferably, the rod containing the aerosol-generating substrate has an outer diameter less than about 10 millimeters or equal to about 10 millimeters. Even more preferably, the rod containing the aerosol-generating substrate has an outer diameter less than about 8 millimeters or equal to about 8 millimeters.

In general, it has been observed that the smaller the diameter of the rod containing the aerosol-generating substrate, the lower the temperature required to raise the temperature of the core of the aerosol-generating element so that sufficient amounts of evaporable substances 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 rod containing the aerosol-generating substrate allows for a faster penetration of heat supplied to the aerosol-generating article into the entire volume of the aerosol-generating substrate. However, if the diameter of the rod containing the aerosol-generating substrate is too small, 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 decreases.

The diameter of the rod containing the aerosol-generating substrate falling within the ranges described herein provides a particular advantage in terms of the balance between energy consumption and aerosol delivery. This advantage is particularly noticeable in particular when the aerosol-generating article in which the rod containing the aerosol-generating substrate has the diameter described herein is used in combination with an external heater located at the periphery of the aerosol-generating article. It has been observed that under such operating conditions, less thermal energy is required to achieve a sufficiently high temperature in the core of the rod containing the aerosol-generating substrate and, in general, in the core of the article. Thus, during operation at lower temperatures, it is possible to achieve the desired target temperature in the core of the aerosol-generating substrate within a requiredly reduced period of time and with lower energy consumption.

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

In particularly preferred embodiments, the rod containing the aerosol-generating substrate has an outer diameter of less than about 7.5 millimeters. For example, the rod containing the aerosol-generating substrate may have an outer diameter of about 7.2 millimeters.

The length to diameter ratio of the aerosol generating element may be at least about 0.5. Preferably, the length to diameter ratio of the aerosol generating element is at least about 0.75. More preferably, the length to diameter ratio of the aerosol generating element is at least about 1.0. Even more preferably, the length to diameter ratio of the aerosol generating element is at least about 1.25.

The length to diameter ratio of the aerosol generating element may be less than or equal to approximately 3.0. Preferably, the length to diameter ratio of the aerosol generating element is less than or equal to approximately 2.75. More preferably, the length to diameter ratio of the aerosol generating element is less than or equal to approximately 2.5. Even more preferably, the length to diameter ratio of the aerosol generating element is less than or equal to approximately 2.25.

In some embodiments, the length to diameter ratio of the aerosol generating element may be from about 0.5 to about 3.0. Preferably, the length to diameter ratio of the aerosol generating element is from about 0.75 to about 3.0. More preferably, the length to diameter ratio of the aerosol generating element is from about 1.0 to about 3.0. Even more preferably, the length to diameter ratio of the aerosol generating element is from about 1.25 to about 3.0.

In other embodiments, the length to diameter ratio of the aerosol generating element may be from about 0.5 to about 2.75. Preferably, the length to diameter ratio of the aerosol generating element is from about 0.75 to about 2.75. More preferably, the length to diameter ratio of the aerosol generating element is from about 1.0 to about 2.75. Even more preferably, the length to diameter ratio of the aerosol generating element is from about 1.25 to about 2.75.

In further embodiments, the length to diameter ratio of the aerosol generating element may be from about 0.5 to about 2.5. Preferably, the length to diameter ratio of the aerosol generating element is from about 0.75 to about 2.5. More preferably, the length to diameter ratio of the aerosol generating element is from about 1.0 to about 2.5. Even more preferably, the length to diameter ratio of the aerosol generating element is from about 1.25 to about 2.5.

In other additional embodiments, the length to diameter ratio of the aerosol generating element may be from about 0.5 to about 2.25. Preferably, the length to diameter ratio of the aerosol generating element is from about 0.75 to about 2.25. More preferably, the length to diameter ratio of the aerosol generating element is from about 1.0 to about 2.25. Even more preferably, the length to diameter ratio of the aerosol generating element is from about 1.25 to about 2.25.

In particularly preferred embodiments, the length to diameter ratio of the aerosol generating element may be at least about 1.3, more preferably about 1.4, even more preferably about 1.5.

In particularly preferred embodiments, the length to diameter ratio of the aerosol generating element may be less than or equal to about 2.0, more preferably less than or equal to about 1.9, even more preferably less than or equal to about 1.8.

In some embodiments, the length to diameter ratio of the aerosol generating element is preferably from about 1.3 to about 2.0, more preferably from about 1.4 to about 2.0, even more preferably from about 1.5 to about 2.0. In other embodiments, the length to diameter ratio of the aerosol generating element is preferably from about 1.3 to about 1.9, more preferably from about 1.4 to about 1.9, even more preferably from about 1.5 to about 1.9. In further embodiments, the length to diameter ratio of the aerosol generating element is preferably from about 1.3 to about 1.8, more preferably from about 1.4 to about 1.8, even more preferably from about 1.5 to about 1.8.

The ratio between the length of the aerosol generating element and the total length of the aerosol generating article may be at least about 0.10. Preferably, the ratio between the length of the aerosol generating element and the total length of the aerosol generating article is at least about 0.15. More preferably, the ratio between the length of the aerosol generating element and the total length of the aerosol generating article is at least about 0.20. Even more preferably, the ratio between the length of the aerosol generating element and the total length of the aerosol generating article is at least about 0.25.

In general, the ratio between the length of the aerosol generating element and the overall length of the aerosol generating article may be less than or equal to about 0.60. Preferably, the ratio between the length of the aerosol generating element and the overall length of the aerosol generating article is less than or equal to about 0.50. More preferably, the ratio between the length of the aerosol generating element and the overall length of the aerosol generating article is less than or equal to about 0.45. Even more preferably, the ratio between the length of the aerosol generating element and the overall length of the aerosol generating article is less than or equal to about 0.40. In particularly preferred embodiments, the ratio between the length of the aerosol generating element and the overall length of the aerosol generating article is less than or equal to about 0.35, most preferably less than or equal to about 0.30.

In some embodiments, the ratio between the length of the aerosol-generating element and the overall length of the aerosol-generating article is from about 0.10 to about 0.45, preferably from about 0.15 to about 0.45, more preferably from about 0.20 to about 0.45, even more preferably from about 0.25 to about 0.45. In other embodiments, the ratio between the length of the aerosol-generating element and the overall length of the aerosol-generating article is from about 0.10 to about 0.40, preferably from about 0.15 to about 0.40, more preferably from about 0.20 to about 0.40, even more preferably from about 0.25 to about 0.40. In further embodiments, the ratio between the length of the aerosol-generating element and the overall length of the aerosol-generating article is from about 0.10 to about 0.35, preferably from about 0.15 to about 0.35, more preferably from about 0.20 to about 0.35, even more preferably from about 0.25 to about 0.35. In still further embodiments, the ratio between the length of the aerosol-generating element and the overall length of the aerosol-generating article is from about 0.10 to about 0.30, preferably from about 0.15 to about 0.30, more preferably from about 0.20 to about 0.30, even more preferably from about 0.25 to about 0.30.

Preferably, the aerosol generating element comprises a rod of aerosol generating substrate having a substantially constant cross-section along the length of the rod. Particularly preferably, the rod of aerosol generating substrate has a substantially circular cross-section.

As will be described more specifically below, the aerosol-generating article according to the present disclosure comprises a downstream section that may comprise a hollow tubular element. In the aerosol-generating article according to the present disclosure, the ratio between the length of the aerosol-generating element and the length of the hollow tubular element may be less than or equal to about 0.66. Preferably, the ratio between the length of the aerosol-generating element and the length of the hollow tubular element may be less than or equal to about 0.60. More preferably, the ratio between the length of the aerosol-generating element and the length of the hollow tubular element may be less than or equal to about 0.50. Even more preferably, the ratio between the length of the aerosol-generating element and the length of the hollow tubular element may be less than or equal to about 0.40.

In the aerosol-generating article according to the present disclosure, the ratio between the length of the aerosol-generating element and the length of the hollow tubular element may be at least about 0.10. Preferably, the ratio between the length of the aerosol-generating element and the length of the hollow tubular element may be at least about 0.15. More preferably, the ratio between the length of the aerosol-generating element and the length of the hollow tubular element may be at least about 0.20. Even more preferably, the ratio between the length of the aerosol-generating element and the length of the hollow tubular element may be at least about 0.25. In particularly preferred embodiments, the ratio between the length of the aerosol-generating element and the length of the hollow tubular element may be at least about 0.30.

In some embodiments, the ratio between the length of the aerosol generating element and the length of the hollow tubular element is from about 0.15 to about 0.60, preferably from about 0.20 to about 0.60, more preferably from about 0.25 to about 0.60, even more preferably from about 0.30 to about 0.60. In other embodiments, the ratio between the length of the aerosol generating element and the length of the hollow tubular element is from about 0.15 to about 0.50, preferably from about 0.20 to about 0.50, more preferably from about 0.25 to about 0.50, even more preferably from about 0.30 to about 0.50. In further embodiments, the ratio between the length of the aerosol generating element and the length of the hollow tubular element is from about 0.15 to about 0.40, preferably from about 0.20 to about 0.40, more preferably from about 0.25 to about 0.40, even more preferably from about 0.30 to about 0.40. For example, the ratio between the length of the aerosol generating element and the length of the hollow tubular element can be about 0.35.

The density of the aerosol-generating substrate may be at least about 100 micrograms/cubic centimeter. Preferably, the density of the aerosol-generating substrate is at least about 115 micrograms/cubic centimeter. More preferably, the density of the aerosol-generating substrate is at least about 130 micrograms/cubic centimeter. Even more preferably, the density of the aerosol-generating substrate is at least about 140 micrograms/cubic centimeter.

The density of the aerosol-generating substrate may be less than about 200 micrograms/cubic centimeter or equal to about 200 micrograms/cubic centimeter. Preferably, the density of the aerosol-generating substrate is less than about 185 micrograms/cubic centimeter or equal to about 185 micrograms/cubic centimeter. More preferably, the density of the aerosol-generating substrate is less than about 170 micrograms/cubic centimeter or equal to about 170 micrograms/cubic centimeter. Even more preferably, the density of the aerosol-generating substrate is less than about 160 micrograms/cubic centimeter or equal to about 160 micrograms/cubic centimeter.

In some embodiments, the density of the aerosol-generating substrate is from 100 micrograms/cubic centimeter to 200 micrograms/cubic centimeter, preferably from 100 micrograms/cubic centimeter to 185 micrograms/cubic centimeter, more preferably from 100 micrograms/cubic centimeter to 170 micrograms/cubic centimeter, even more preferably from 100 micrograms/cubic centimeter to 160 micrograms/cubic centimeter. In other embodiments, the density of the aerosol-generating substrate is from 115 micrograms/cubic centimeter to 200 micrograms/cubic centimeter, preferably from 115 micrograms/cubic centimeter to 185 micrograms/cubic centimeter, more preferably from 115 micrograms/cubic centimeter to 170 micrograms/cubic centimeter, even more preferably from 115 micrograms/cubic centimeter to 160 micrograms/cubic centimeter. In further embodiments, the density of the aerosol-generating substrate is from 130 micrograms/cubic centimeter to 200 micrograms/cubic centimeter, preferably from 130 micrograms/cubic centimeter to 185 micrograms/cubic centimeter, more preferably from 130 micrograms/cubic centimeter to 170 micrograms/cubic centimeter, even more preferably from 130 micrograms/cubic centimeter to 160 micrograms/cubic centimeter. In yet other embodiments, the density of the aerosol-generating substrate is from 140 micrograms/cubic centimeter to 200 micrograms/cubic centimeter, preferably from 140 micrograms/cubic centimeter to 185 micrograms/cubic centimeter, more preferably from 140 micrograms/cubic centimeter to 170 micrograms/cubic centimeter, even more preferably from 140 micrograms/cubic centimeter to 160 micrograms/cubic centimeter. In some particularly preferred embodiments, the density of the aerosol generating substrate is approximately 150 micrograms/cubic centimeter.

The density of the aerosol-generating substrate may be at least about 100 milligrams/cubic centimeter. Preferably, the density of the aerosol-generating substrate is at least about 115 milligrams/cubic centimeter. More preferably, the density of the aerosol-generating substrate is at least about 130 milligrams/cubic centimeter. Even more preferably, the density of the aerosol-generating substrate is at least about 140 milligrams/cubic centimeter.

The density of the aerosol-generating substrate may be less than about 200 milligrams/cubic centimeter or equal to about 200 milligrams/cubic centimeter. Preferably, the density of the aerosol-generating substrate is less than about 185 milligrams/cubic centimeter or equal to about 185 milligrams/cubic centimeter. More preferably, the density of the aerosol-generating substrate is less than about 170 milligrams/cubic centimeter or equal to about 170 milligrams/cubic centimeter. Even more preferably, the density of the aerosol-generating substrate is less than about 160 milligrams/cubic centimeter or equal to about 160 milligrams/cubic centimeter.

In some embodiments, the density of the aerosol-generating substrate is from 100 milligrams/cubic centimeter to 200 milligrams/cubic centimeter, preferably from 100 milligrams/cubic centimeter to 185 milligrams/cubic centimeter, more preferably from 100 milligrams/cubic centimeter to 170 milligrams/cubic centimeter, even more preferably from 100 milligrams/cubic centimeter to 160 milligrams/cubic centimeter. In other embodiments, the density of the aerosol-generating substrate is from 115 milligrams/cubic centimeter to 200 milligrams/cubic centimeter, preferably from 115 milligrams/cubic centimeter to 185 milligrams/cubic centimeter, more preferably from 115 milligrams/cubic centimeter to 170 milligrams/cubic centimeter, even more preferably from 115 milligrams/cubic centimeter to 160 milligrams/cubic centimeter. In further embodiments, the density of the aerosol-generating substrate is from 130 milligrams/cubic centimeter to 200 milligrams/cubic centimeter, preferably from 130 milligrams/cubic centimeter to 185 milligrams/cubic centimeter, more preferably from 130 milligrams/cubic centimeter to 170 milligrams/cubic centimeter, even more preferably from 130 milligrams/cubic centimeter to 160 milligrams/cubic centimeter. In yet other embodiments, the density of the aerosol-generating substrate is from 140 milligrams/cubic centimeter to 200 milligrams/cubic centimeter, preferably from 140 milligrams/cubic centimeter to 185 milligrams/cubic centimeter, more preferably from 140 milligrams/cubic centimeter to 170 milligrams/cubic centimeter, even more preferably from 140 milligrams/cubic centimeter to 160 milligrams/cubic centimeter. In some particularly preferred embodiments, the density of the aerosol-generating substrate is approximately 150 milligrams/cubic centimeter.

For example, the aerosol generating element may comprise from about 100 milligrams to about 250 milligrams of an aerosol generating substrate. In some embodiments, the aerosol generating element comprises from about 210 milligrams to about 230 milligrams of an aerosol generating substrate, preferably from 215 milligrams to about 220 milligrams of an aerosol generating substrate. In other embodiments, the aerosol generating element comprises from about 150 milligrams to about 180 milligrams of an aerosol generating substrate, preferably from 160 milligrams to about 165 milligrams of an aerosol generating substrate.

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

In some preferred embodiments, the aerosol generating substrate comprises homogenized plant material, preferably 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 of the present disclosure may be obtained by agglomerating tobacco material particles obtained by grinding, milling, or crushing plant material and, optionally, one or more of tobacco leaf lamellas and tobacco leaf veins. The homogenized plant material may be obtained by casting, extrusion, papermaking, or any other suitable processes known in the art.

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

In some embodiments, the homogenized plant material may be present in the form of one or more sheets. As used herein in connection with the present invention, the term "sheet" describes a flat element whose width and length significantly exceed its thickness.

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

Alternatively or additionally, 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 or grinding, or by other methods, for example, by extrusion.

In some embodiments, the filaments may be produced in situ within the aerosol-generating substrate by dividing or splitting 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 dividing 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.

In some preferred embodiments, the aerosol-generating substrate comprises a chopped filler. In the context of the present description, the term "chopped 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 petioles and veins, homogenized plant material.

Shredded filler may also contain other trimmings, tobacco filler, or sauce.

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, and 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 described more specifically below, the present invention is equally applicable to other plant material capable of releasing substances upon application of heat that can subsequently form an aerosol.

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

Light tobaccos are tobaccos with generally large leaves that are light in color. Throughout the present description, the term "light tobacco" is used for tobaccos that have been flue-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 standpoint, light tobacco is a type of tobacco that, after curing, is associated with a spicy and rich sensation. In the context of the present disclosure, 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 include, for example, glucose or fructose. Total ammonia includes, for example, ammonia and ammonia salts.

Dark tobaccos are tobaccos with generally large leaves that are dark in color. Throughout this description, the term "dark tobacco" is used for tobaccos that have been air-cured. Additionally, dark tobaccos may be fermented. Tobaccos that are used primarily for chewing, snuff, cigars, and pipe blends are also included in this category. These dark tobaccos are usually air-cured and may be fermented. From an organoleptic point of view, dark tobacco is a type of tobacco that, after curing, is associated with a smoky sensation of a dark cigar type. Dark tobacco is characterized by a low sugar to nitrogen ratio. Examples of dark tobacco are Malawi Burley or other African Burleys, air-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 up to 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 an organoleptic point of view, aromatic tobacco is a tobacco of a type that, after curing, is associated with a spicy and aromatic sensation. Examples of varieties of aromatic tobacco are Greek Oriental, Turkish Oriental, semi-Oriental tobacco, but also fire-cured tobacco, American Burley such as Perique, Country tobacco or Maryland. Filler tobacco is not a tobacco of a specific type, but includes tobaccos of those types that are used primarily to complement the tobaccos of other types used in the blend and which do not impart a specific characteristic aromatic note to the final product. Examples of filler tobacco are stems, midribs or petioles of tobaccos of other types. 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 disclosure may be generally similar to the cut filler used in traditional 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 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 the aerosol generating element. It is obvious that 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 threads from being easily displaced from the aerosol generating element.

In preferred embodiments, the weight of the cut filler is from 80 milligrams to 400 milligrams, preferably from 150 milligrams to 250 milligrams, more preferably from 170 milligrams to 220 milligrams. This amount of cut filler usually allows for obtaining a sufficient amount of material for forming an aerosol. In addition, in light of the above-mentioned limitations on diameter and size, this allows for achieving a density of the aerosol-generating element that provides a balance between energy absorption, resistance to draw and fluid passages in the aerosol-generating element, wherein the aerosol-generating substrate comprises plant material.

Preferably, the cut filler is impregnated with an aerosol forming agent. Impregnation of the cut filler can be carried out by spraying or other suitable application methods. The aerosol forming agent can be added to the mixture when preparing the cut filler. For example, the aerosol forming agent can be added to the mixture in a direct conditioning casing cylinder (DCCC). Conventional equipment can be used to apply the aerosol forming agent to the cut filler. The aerosol forming agent can 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 possibility of helping the aerosol to 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.

Preferably, the amount of the aerosol forming agent is from 6 percent to 20 percent by weight based on the dry weight of the cut filler, more preferably, the amount of the aerosol forming agent is from 8 percent to 18 percent by weight based on the dry weight of the cut filler, most preferably, the amount of the aerosol forming agent is from 10 percent to 15 percent by weight based on the dry weight of the cut filler. By adding the aerosol forming agent to the cut filler in the amounts described above, the cut filler can become relatively sticky. This provides the advantage of helping to retain the cut filler in a given location within the article, since the particles of the cut filler show a tendency to adhere to the surrounding particles of the cut filler, as well as to the surrounding surfaces (for example, the inner surface of the wrapper surrounding the cut filler).

In some embodiments, the amount of aerosol forming agent has a target value of approximately 13 percent by weight based on the dry weight of the cut filler. The most effective amount of aerosol forming agent will also depend on the cut filler, regardless of whether the cut filler contains plant leaf blades or homogenized plant material. For example, among other factors, the type of cut filler will determine the extent to which the aerosol forming agent is able to facilitate the release of substances from the cut filler.

For these reasons, an aerosol generating element comprising a cut filler as 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 employ temperatures of approximately 250 degrees Celsius.

An additional benefit associated with operating at lower temperatures is the reduced need for aerosol cooling. Since the temperatures involved are generally low, a simpler cooling function may be sufficient. This, in turn, allows for a simpler, 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 about 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, 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 said one or more sheets as 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 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 collected sheets. The term "collected" 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 ridges 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 may be corrugated so as to have a plurality of folds or corrugations substantially parallel to the cylindrical axis of the plug. This treatment provides the advantage of facilitating the collection of the corrugated sheet of homogenized plant material to form a plug. Preferably, one or more sheets of homogenized plant material may be collected. It should be noted that the corrugated sheets of homogenized plant material, alternatively or additionally, may have a plurality of substantially parallel ridges or corrugations located at an acute or obtuse angle to the cylindrical axis of the plug. The sheet may be corrugated to such an extent that the integrity of the sheet is broken at the plurality of parallel ridges 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, 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, 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 belonging to the genus Nicotiana. The term "tobacco particles" includes ground or powdered tobacco leaf blades, ground or powdered tobacco leaf petioles, 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 blades. In contrast, isolated nicotine and nicotine salts are compounds derived from tobacco but are not considered tobacco particles for the purposes of the present invention and are not included in the percentage of particulate plant material.

Alternatively or additionally, the aerosol-generating substrate may further comprise one or more aerosol formers. Upon evaporation, the aerosol former is capable of carrying other vaporized compounds released from the aerosol-generating substrate upon heating, such as nicotine and flavoring agents, into the aerosol. 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 substance content of from about 5 percent to about 30 percent by weight on a dry weight basis, such as from about 10 percent to about 25 percent by weight on a dry weight basis or from about 15 percent to about 20 percent by weight 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 retained 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 by heating, and a stream of the aerosol forming agent is contacted with the aerosol-generating substrate to entrain flavor substances from the aerosol-generating substrate into the aerosol.

In other embodiments, the homogenized plant material 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 homogenized plant material 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 that is included in the homogenized plant material and is not derived from tobacco plant particles or tobacco particles provided in the homogenized plant material. Therefore, the additional cellulose is included in the homogenized plant material, in addition to the non-tobacco plant material or tobacco material, as a source of cellulose separate and distinct from any cellulose originally provided within the non-tobacco plant particles or tobacco particles. The additional cellulose is typically derived from a plant other than that from which said non-tobacco plant particles or tobacco particles are derived. Preferably, the additional cellulose is present as an inert cellulose material that is organoleptically inert 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 particular 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 particular embodiments of the present invention are known in the art and include, but are not limited to, sheets of homogenized tobacco materials. In some 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 alternative embodiments of the present disclosure, 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 contain 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 contain one or more alkaloids. The gel composition may contain one or more cannabinoids. The gel composition may contain 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 contains 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 indiea, 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 downstream section of the aerosol-generating article 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 provides the ability to ensure that the user is kept away 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 rod 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 rod 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 rod 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 rod 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.

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 tightening resistance of the downstream section may be no more than about 100 mm _H2O (millimeters of water column). For example, the tightening resistance of the downstream section may be no more than about 50 mm _H2O (millimeters of water column), no more than about 25 mm _H2O (millimeters of water column), no more than about 15 mm _H2O (millimeters of water column), no more than about 10 mm _H2O (millimeters of water column), no more than about 8 mm _H2O (millimeters of water column), no more than about 5 mm _H2 , or no more than about 1 mm _H2O (millimeters of water column).

The downstream section may comprise a clear air flow path extending 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. The hollow tubular segment may be referred to as a hollow tube, a hollow tubular element, or 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 tube 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 defined by the hollow tubular segment. In this case, it should be noted that the lengths and length ratios specified above for the downstream section apply equally to the length of the hollow tubular segment.

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

The hollow tubular segment 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 segment.

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

The hollow tubular segment may have an internal diameter of at least about 2 millimeters. For example, the hollow tubular segment 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 segment having the above-mentioned internal diameter provides the advantage of being able to impart sufficient rigidity and strength to the hollow tubular segment.

The hollow tubular segment may have an internal diameter of no more than about 10 millimeters. For example, the hollow tubular segment 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 segment having the above-mentioned internal diameter provides the advantage of being able to reduce the tightening resistance of the hollow tubular segment.

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

The ratio between the inner diameter of the hollow tubular segment and the outer diameter of the hollow tubular segment may be at least approximately 0.8. For example, the ratio between the inner diameter of the hollow tubular segment and the outer diameter of the hollow tubular segment 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 segment and the outer diameter of the hollow tubular segment may be no greater than approximately 0.99. For example, the ratio between the inner diameter of the hollow tubular segment and the outer diameter of the hollow tubular segment may be no greater than approximately 0.98.

The ratio between the inner diameter of the hollow tubular segment and the outer diameter of the hollow tubular segment 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 segment.

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

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

If the hollow tubular segment 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 segment may comprise paper. The hollow tubular segment 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 segment may be made in the form of a tube of spirally wound paper. The hollow tubular segment may be made of several 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 segment comprises paper, the paper may have a thickness of 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 segment may comprise a polymer. For example, the hollow tubular segment may comprise a polymer film. The polymer film may comprise a cellulose film. The hollow tubular segment 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 upstream of the aerosol-generating substrate in close proximity thereto. 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 bent end portion forming a first end wall at the first, upstream end of the tubular body. The first end wall may form the boundaries of an opening which enables an air flow to flow between said cavity and the area outside the modified tubular element. Preferably, said opening is made in such a way that it enables an air flow to flow from the aerosol-generating substrate through said opening into said cavity.

The cavity of the tubular body may be substantially empty to provide the possibility of substantially unimpeded 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. In this way, it is possible to substantially regulate the tightening resistance of the modified tubular element by selecting the configuration of the first end wall and its corresponding opening. The tightening resistance of the modified tubular element (which is substantially equivalent to the tightening resistance of the first end wall) has the same order of magnitude as the tightening resistance of the hollow tubular segment described in the present disclosure.

The modified tubular element may have 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 outside diameter (D _E ). The modified tubular element may have an outside 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 outside diameter (D _E ) of about 7.3 millimeters.

The modified tubular element may have any inner diameter ( _DI ). The modified tubular element may have an inner 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 inner 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 downstream section may be ventilated. The ventilated section may be provided to allow cooler air from outside the aerosol generating article to enter the interior of the downstream section.

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

In preferred embodiments, the aerosol-generating article has a ventilation level of at least about 20 percent, or 25 percent, or 30 percent. More preferably, the aerosol-generating article has a ventilation level of 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 discovered that a temperature drop caused by introducing cooler external air into the hollow tubular segment can favorably influence 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, as well as droplet coalescence, while taking into account changes in concentration, temperature and vapor 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 a sufficient probability (e.g., one-half probability). These molecules represent a kind of critical threshold molecular clusters among short-lived molecular aggregates, which means that, in general, smaller molecular clusters in the gas phase are likely to disintegrate fairly quickly, while larger clusters are generally likely to grow. 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 appear 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, causing 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 the droplets to shrink (or grow), 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 (such as 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 segment, the hollow tubular segment may be made of a porous material that allows air to enter the interior of the hollow tubular segment. 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 segment.

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 perforated openings surrounding the downstream section.

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

If the aerosol-generating article comprises a unifying wick, the ventilation zone preferably comprises at least one corresponding circumferential row of perforated holes passing through a section of the unifying wick. They can also be made on the production line during the manufacture of the smoking article. Preferably, the circumferential row or rows of perforated holes passing through a section of the unifying wick are substantially aligned with the corresponding row or rows of perforated holes passing 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 perforated holes in a downstream section, then the ventilation zone preferably comprises at least one corresponding circumferential row of perforated holes extending through said strip of tipping paper. They can also be made on the production line during the manufacture of the smoking article. Preferably, the circumferential row or rows of perforated holes extending through the strip of tipping paper are substantially aligned with the row or rows of perforated holes extending through the downstream section.

The first line of perforated holes may comprise at least one perforated hole having a width of at least approximately 50 micrometers. For example, the first line of perforated holes may comprise at least one perforated hole having a width of at least approximately 65 micrometers, at least approximately 80 micrometers, at least approximately 90 micrometers, or at least approximately 100 micrometers.

The first line of perforated holes may comprise at least one perforated hole having a width of no more than about 200 micrometers. For example, the first line of perforated holes may comprise at least one perforated hole having a width of no more than about 175 micrometers, no more than about 150 micrometers, no more than about 125 micrometers, or no more than about 120 micrometers.

The first line of perforated holes may comprise at least one perforated hole 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 perforated holes are made using laser perforation technologies, the width of the perforated holes can be determined by the laser focusing diameter.

The first line of perforated holes may comprise at least one perforated hole having a length of at least approximately 400 micrometers. For example, the first line of perforated holes may comprise at least one perforated hole having a length of at least approximately 425 micrometers, at least approximately 450 micrometers, at least approximately 475 micrometers, or at least approximately 500 micrometers.

The first line of perforated holes may comprise at least one perforated hole having a length of no more than about 1 millimeter. For example, the first line of perforated holes may comprise at least one perforated hole 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 perforated holes may comprise at least one perforated hole 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 perforated holes may comprise at least one perforated hole having an opening area of at least approximately 0.01 square millimeters. For example, the first line of perforated holes may comprise at least one perforated hole having an opening area of at least approximately 0.02 square millimeters, at least approximately 0.03 square millimeters, or at least approximately 0.05 square millimeters.

The first line of perforated holes may comprise at least one perforated hole having an opening area of no more than about 0.5 square millimeters. For example, the first line of perforated holes may comprise at least one perforated hole 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 perforated holes may comprise at least one perforated hole having an opening area from about 0.01 square millimeter to about 0.5 square millimeter, from about 0.02 square millimeter to about 0.3 square millimeter, from about 0.03 square millimeter to about 0.25 square millimeter, or from about 0.05 square millimeter to about 0.1 square millimeter. The first line of perforated holes may comprise at least one perforated hole having an opening area from about 0.05 square millimeter to about 0.096 square millimeter.

As noted above, the aerosol generating article may comprise a wrapper surrounding 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 longitudinally aligned with the 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 no more than 8 millimeters, no more than 5 millimeters, or no more than 3 millimeters from the downstream end of the aerosol-generating substrate. The first ventilation zone may be located at any point along the length of the downstream section. The downstream end of the first ventilation zone may be located at a distance of no more than approximately 25 millimeters from the downstream end of the aerosol-generating article. For example, the first ventilation zone may be located at a distance of no more than approximately 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 about 8 millimeters 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 about 10 millimeters, at least 12 millimeters, or at least about 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, 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. 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 in close proximity to 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 axially aligned 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.

Unless otherwise specified, the resistance to draw (RTD) of a component or aerosol-generating article shall be 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 mm. 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 mm, 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 mm _H2O (millimeters of water column), then the resistance to draw per unit length of the component is approximately 1 mm _H2O (millimeters of water column) per mm. 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 mm _H2O (millimeters of water column) per mm to about 3 mm _H2O (millimeters of water column) per mm. Alternatively, the draw resistance per unit length of the downstream section may be from about 0 mm _H2O (millimeters of water column) per mm to about 2.5 mm _H2O (millimeters of water column) per mm. Alternatively, the draw resistance per unit length of the downstream section may be from about 0 mm _H2O (millimeters of water column) per mm to about 2 mm _H2O (millimeters of water column) per mm. The draw resistance per unit length of the downstream section may be from about 0 mm _H2O (millimeters of water column) per mm to about 1 mm _H2O (millimeters of water column) per mm. The draw resistance per unit length of the downstream section may be from about 0 mm _H2O (millimeters of water column) per mm to about 0.75 mm _H2O (millimeters of water column) per mm.

As mentioned above, the relative resistance to draw, or the resistance to draw per unit length, of the downstream section may be greater than about 0 mm _H2O (millimeters of water column) per mm and less than about 3 mm _H2O (millimeters of water column) per mm. Alternatively, the resistance to draw per unit length of the downstream section may be greater than about 0 mm _H2O (millimeters of water column) per mm and less than about 2.5 mm _H2O (millimeters of water column) per mm. Alternatively, the resistance to draw per unit length of the downstream section may be greater than about 0 mm _H2O (millimeters of water column) per mm and less than about 2 mm _H2O (millimeters of water column) per mm. The draw resistance per unit length of the downstream section may be greater than approximately 0 mm _H2O (millimeters of water column) per mm and less than approximately 1 mm _H2O (millimeters of water column) per mm. The draw resistance per unit length of the downstream section may be greater than approximately 0 mm _H2O (millimeters of water column) per mm and less than approximately 0.75 mm _H2O (millimeters of water column) per mm.

The draw resistance per unit length of the downstream section may be greater than or equal to approximately 0 mm _H2O (millimeters of water column) per mm. Thus, the draw resistance per unit length of the downstream section may be from approximately 0 mm _H2O (millimeters of water column) per mm to approximately 3 mm _H2O (millimeters of water column) per mm. Alternatively, the draw resistance per unit length of the downstream section may be from approximately 0 mm _H2O (millimeters of water column) per mm to approximately 2.5 mm _H2O (millimeters of water column) per mm. Alternatively, the draw resistance per unit length of the downstream section may be from about 0 mm _H2O (millimeters of water column) per mm to about 2 mm _H2O (millimeters of water column) per mm. The draw resistance per unit length of the downstream section may be from about 0 mm _H2O (millimeters of water column) per mm to about 1 mm _H2O (millimeters of water column) per mm. The draw resistance per unit length of the downstream section may be from about 0 mm _H2O (millimeters of water column) per mm to about 0.75 mm _H2O (millimeters of water column) per mm.

The resistance to draw (RTD) of the downstream section may be greater than or equal to approximately 0 _mmH2O (millimeters of water column) and less than approximately 10 _mmH2O (millimeters of water column). The resistance to draw of the downstream section may be greater than or equal to 0 _mmH2O (millimeters of water column) and less than approximately 5 _mmH2O (millimeters of water column). The resistance to draw of the downstream section may be greater than or equal to 0 _mmH2O (millimeters of water column) and less than approximately 2 _mmH2O (millimeters of water column). The resistance to draw of the downstream section may be greater than or equal to 0 _mmH2O (millimeters of water column) and less than approximately 1 _mmH2O (millimeters of water column).

In other words, the tightening resistance of the downstream section may be less than 10 mm _H2O (millimeters of water column). The tightening resistance of the downstream section may be less than 5 mm _H2O (millimeters of water column). The tightening resistance of the downstream section may be less than 2 mm _H2O (millimeters of water column). The tightening resistance of the downstream section may be less than 1 mm _H2O (millimeters of water column). The tightening resistance of the downstream section may be 0 mm _H2O (millimeters of water column) or more.

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 a single piece of wrapping material provides the ability to eliminate 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 of the present disclosure may further 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 upstream element may be referred to as an upstream section.

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 entering 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 mm H ₂ O (millimeters of water column), providing an upstream element having a relatively high resistance to draw provides an advantage in that an acceptable overall resistance to draw can be achieved 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 tightening resistance of the upstream section may be at least about 5 mm _H2O (millimeters of water column). For example, the tightening resistance of the upstream section may be at least about 10 mm _H2O (millimeters of water column), at least about 12 mm _H2O (millimeters of water column), at least about 15 mm _H2O (millimeters of water column), at least about 20 mm _H2O (millimeters of water column).

The tightening resistance of the upstream section may be no more than about 80 mm _H2O (millimeters of water column). For example, the tightening resistance of the upstream section may be no more than about 70 mm _H2O (millimeters of water column), no more than about 60 mm _H2O (millimeters of water column), no more than about 50 mm _H2O (millimeters of water column), or no more than about 40 mm _H2O (millimeters of water column).

The tightening resistance of the upstream section can range from approximately 5 mm _H2O (millimeters of water column) to approximately 80 mm _H2O (millimeters of water column). For example, the tightening resistance of the upstream section may be from about 10 mm _H2O (millimeters of water column) to about 70 mm _H2O (millimeters of water column), from about 12 mm _H2O (millimeters of water column) to about 60 mm _H2O (millimeters of water column), from about 15 mm _H2O (millimeters of water column) to about 50 mm _H2O (millimeters of water column), or from about 20 mm _H2O (millimeters of water column) to about 40 mm _H2O (millimeters of water column).

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 transportation 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, fragrance, contents, or details about the aerosol-generating device with which the article is intended to be used.

The upstream section may comprise a porous plug element. The porous plug element may have 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 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 internal cross-sectional area of the aerosol-generating article, at the location where the porous plug element is located.

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.

As an advantage, the porosity or permeability of the upstream section may be varied to provide the desired overall draw resistance of the aerosol generating article.

In alternative embodiments, the upstream section 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 section 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 section include filter materials, ceramics, polymeric material, cellulose acetate, cardboard, zeolite, or an aerosol-generating substrate. Preferably, the upstream section comprises a plug comprising cellulose acetate.

If the upstream section 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 section 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 section 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 section is made of a heat-resistant material. For example, the upstream section is preferably made of a material that can withstand temperatures of up to 350 degrees Celsius. This ensures that the upstream section is not adversely affected by the heating means for heating the aerosol-generating substrate.

Preferably, the upstream section has a diameter 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, 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 to provide the desired overall length of the aerosol-generating article. For example, if the length of one of the other components of the aerosol-generating article needs to be reduced, the length of the upstream section can be increased to maintain the same overall length of the article.

The upstream section preferably has a substantially uniform structure. For example, the upstream section may be substantially uniform in texture and appearance. For example, the upstream section may have a continuous, regular surface across its entire 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 in close proximity thereto. 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 bent end portion forming a first end wall at the first upstream end of the tubular body. The first end wall may form the boundaries of an opening which enables air flow between said cavity and the area outside the second tubular element. Preferably, air flow from said cavity through said opening into the aerosol-generating substrate is enabled.

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 the boundaries of 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 air can be drawn into the aerosol-generating article and then through the aerosol-generating substrate.

The upstream section is preferably surrounded by a wrapper. The wrapper surrounding the upstream element or the second tubular element is preferably a rigid filament, such as 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.

As stated above, the present invention relates to an aerosol generating system comprising an aerosol generating device having a distal end and a mouth end. The aerosol generating device comprises a housing. The housing or casing of the aerosol generating device may form a cavity of the device for detachably placing an aerosol generating article on the mouth end of the device. The aerosol generating device may comprise a heating element or a heater for heating an aerosol generating substrate when placing the aerosol generating substrate inside the cavity of the device.

The cavity of the device may be called the heating chamber of the aerosol-generating device. The cavity of the device may extend between the distal end and the mouthpiece or near end. The distal end of the cavity of the device may be a closed end, and the mouthpiece or near 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 formed by an end wall.

The length of the cavity of the device may be from about 10 mm to about 50 mm. The length of the cavity of the device may be from about 20 mm to about 40 mm. The length of the cavity of the device may be from about 25 mm to about 30 mm. 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 mm to about 50 mm. The diameter of the cavity of the device may be from about 4 mm to about 30 mm. The diameter of the cavity of the device may be from about 5 mm to about 15 mm. The diameter of the cavity of the device may be from about 6 mm to about 12 mm. The diameter of the cavity of the device may be from about 7 mm to about 10 mm. The diameter of the cavity of the device may be from about 7 mm to about 8 mm.

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 so as to form an interference fit with the aerosol-generating article.

The cavity of the device may be designed to form a tight fit with the aerosol-generating article placed in the cavity of the device. The tight fit may be called a tight fit. The aerosol-generating device may comprise a peripheral wall. Such a peripheral wall may form the 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 placed 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 placed inside the device.

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

With such an airtight configuration, there will be essentially no gap or void through which air can flow 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 provide 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 a combination of both. The air flow channel may be partially formed by the inner surface of the peripheral wall, and partially 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. Preferably, the heater can be designed to externally heat the aerosol-generating article when it is placed inside the aerosol-generating device. Such an external heater can be designed to surround the aerosol-generating article when it is inserted into the aerosol-generating device or placed inside it.

In some embodiments, the heater is configured to heat the outer surface of the aerosol-forming substrate. In some embodiments, the heater is configured to be inserted into the aerosol-forming substrate when the aerosol-forming substrate is placed inside said cavity. The heater may be located inside the cavity of the device or the heating chamber.

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. As an advantage, 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. As an advantage, 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.

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 portions 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 2 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 about 500 kHz to about 30 MHz. As an advantage, the heater may 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 is heated. Heating of the current collector may occur due to 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 inductance coil induces a current in the current-receiving element, causing the current-receiving element to heat up. In these embodiments, the aerosol-generating device is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of 1 to 5 kiloamperes per meter (kA/m), preferably 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 of 1 to 30 MHz, for example 1 to 10 MHz, for example 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 may 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 induction heating 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 be made of or comprise 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.

Preferably, the operating temperature range of the heater may be from about 150 degrees Celsius to about 200 degrees Celsius. More preferably, 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 from 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 H ₂ O), as described throughout this disclosure.

In those embodiments in which the aerosol-generating article comprises a ventilation zone at a location along a downstream section or a hollow tubular element, this 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 it 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 aerosol generating article may have a length of from approximately 35 millimeters to approximately 100 millimeters.

Preferably, the total length of the aerosol-generating article according to the present invention is at least about 38 millimeters. More preferably, the total length of the aerosol-generating article according to the present invention is at least about 40 millimeters. Even more preferably, the total length of the aerosol-generating article according to the present invention is at least about 42 millimeters.

The total length of the aerosol-generating article according to the present invention is preferably less than 70 millimeters or equal to 70 millimeters. More preferably, the total length of the aerosol-generating article according to the present invention is preferably less than 60 millimeters or equal to 60 millimeters. Even more preferably, the total length of the aerosol-generating article according to the present invention is preferably less than 50 millimeters or equal to 50 millimeters.

In some embodiments, the overall length of the aerosol-generating article is preferably from about 38 millimeters to about 70 millimeters, more preferably from about 40 millimeters to about 70 millimeters, even more preferably from about 42 millimeters to about 70 millimeters. In other embodiments, the overall length of the aerosol-generating article is preferably from about 38 millimeters to about 60 millimeters, more preferably from about 40 millimeters to about 60 millimeters, even more preferably from about 42 millimeters to about 60 millimeters. In further embodiments, the overall length of the aerosol-generating article is preferably from about 38 millimeters to about 50 millimeters, more preferably from about 40 millimeters to about 50 millimeters, even more preferably from about 42 millimeters to about 50 millimeters. In the exemplary embodiment, the overall length of the aerosol generating article is approximately 45 millimeters.

The aerosol-generating article has 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.

One or more components of the aerosol-generating article may be individually surrounded by a wrapper. In preferred embodiments, all components of the aerosol-generating article are individually surrounded by their own wrapper. Preferably, at least one of the components of the aerosol-generating article is wrapped in a hydrophobic wrapper.

The term "hydrophobic" refers to a surface that exhibits water-repellent properties. One useful way to determine this is by measuring the water contact angle. The "water contact angle" is the angle, usually measured through a liquid where the liquid/vapor interface meets a solid surface. It quantifies the wettability of the solid surface by the liquid using Young's equation. Hydrophobicity or water contact angle can be determined using TAPPI Test Method T558 and the result can be reported as the contact angle at the interface, which is expressed in "degrees" and can range from approximately zero to approximately 180 degrees.

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

For example, the paper layer may contain PVOH (polyvinyl alcohol) or silicone. Polyvinyl alcohol may be applied to the paper layer as a surface coating, or the paper layer may be surface treated with polyvinyl alcohol or silicone.

In a particularly preferred embodiment, the aerosol generating article according to the present invention comprises, in a linear sequential arrangement, an aerosol generating element comprising a rod of aerosol generating substrate and a hollow tubular element located downstream of the aerosol generating element in close proximity thereto.

More specifically, the hollow tubular element may be adjacent to the aerosol generating element.

The aerosol generating article has a substantially cylindrical shape and has an outer diameter of approximately 7.3 millimeters.

The hollow tubular element has the form of a hollow cellulose acetate tube, and its internal diameter is approximately 7.1 millimeters. Thus, the thickness of the peripheral wall of the hollow tubular element is approximately 0.1 millimeters. A ventilation zone is provided at a location along the hollow tubular element.

The aerosol generating element has the form of a rod of aerosol generating substrate surrounded by a paper wrapper and contains an aerosol generating substrate of at least one of the types described above, such as cut plant filler, in particular cut tobacco filler, homogenized tobacco, a gel composition or homogenized plant material containing particles of a plant other than tobacco.

An outer rim wrapper surrounds the hollow tubular member and a portion of the aerosol generating member such that the hollow tubular member is attached to the aerosol generating member.

The aerosol-generating substrate rod is approximately 12 millimeters long and the hollow tubular element is approximately 33 millimeters long. Thus, the total length of the aerosol-generating article is approximately 45 millimeters.

In another preferred embodiment, the aerosol-generating article according to the present disclosure comprises, in a linear sequential arrangement, an upstream element; an aerosol-generating element located downstream of the upstream element in close proximity thereto; an aerosol-generating element comprising a rod comprising an aerosol-generating substrate; and a hollow tubular element located downstream of the aerosol-generating element in close proximity thereto.

More specifically, the rod of the aerosol-generating substrate may be adjacent to the upstream element. In addition, the hollow tubular element may be adjacent to the aerosol-generating element.

The aerosol generating article has a substantially cylindrical shape and has an outer diameter of approximately 7.3 millimeters.

The hollow tubular element has the form of a hollow cellulose acetate tube, and its internal diameter is approximately 7.1 millimeters. Thus, the thickness of the peripheral wall of the hollow tubular element is approximately 0.1 millimeters. A ventilation zone is provided at a location along the hollow tubular element.

The aerosol generating element has the form of a rod of aerosol generating substrate surrounded by a paper wrapper and comprises an aerosol generating substrate of at least one of the types described above, such as cut plant filler and, in particular, cut tobacco filler, homogenized tobacco, gel composition or homogenized plant material containing particles of a plant other than tobacco.

An outer rim wrapper surrounds the hollow tubular member and a portion of the aerosol generating member such that the hollow tubular member is attached to the aerosol generating member.

The upstream element has a length of 5 millimeters, the rod of the aerosol-generating substrate has a length of approximately 12 millimeters, and the hollow tubular element has a length of approximately 28 millimeters. Thus, the total length of the aerosol-generating article is approximately 45 millimeters.

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 system comprising:

an aerosol generating article for creating an inhalable aerosol upon heating, the aerosol generating article extending from a mouthpiece end to a distal end and comprising:

an aerosol generating element; and

a downstream section that is located downstream of the aerosol generating element, wherein the downstream section extends from the downstream end of the aerosol generating element to the mouthpiece end of the aerosol generating article;

wherein the downstream section comprises a hollow tubular member, and the draw resistance of the downstream section is less than approximately 10 mm _H2O (millimeters of water column);

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, wherein the housing defines a cavity of the device for detachably receiving an aerosol generating article at the mouthpiece end of the device; and

a heater for heating the aerosol generating element when the aerosol generating article is placed inside the cavity of the device.

Example 2. An aerosol generating system according to example 1, wherein the hollow tubular element of the aerosol generating article extends from a downstream end of the aerosol generating element to a mouthpiece end of the aerosol generating article.

Example 3. An aerosol generating system according to example 1 or 2, in which the heater of the aerosol generating device is designed to surround the aerosol generating article when the aerosol generating article is placed inside the cavity of the device.

Example 4. An aerosol generating system according to any of the previous examples, wherein the operating temperature of the heater is from about 180 to about 200 degrees Celsius.

Example 5. An aerosol generating system according to any of the previous examples, wherein the downstream section comprises a ventilation zone at a location along the hollow tubular member.

Example 6. An aerosol generating system according to example 5, wherein the distance between the ventilation zone and the mouth end of the aerosol generating article is less than approximately 25 millimetres.

Example 7. An aerosol generating system according to example 5 or 6, wherein the distance between the ventilation zone and the mouth end of the aerosol generating article is less than approximately 10 millimetres.

Example 8. An aerosol generating system according to one of examples 5, 6 and 7, wherein the ventilation zone is arranged so that it is open when the aerosol generating article is placed inside the cavity of the device.

Example 9. An aerosol generating system according to any of the previous examples, wherein the aerosol generating article has a ventilation level of at least about 10 percent.

Example 10. An aerosol generating system according to any of the previous examples, wherein the aerosol generating element has a length of from about 10 millimeters to about 20 millimeters.

Example 11. An aerosol generating system according to any of the previous examples, wherein the aerosol generating element comprises cut tobacco filler.

Example 12. An aerosol generating system according to any of the previous examples, wherein the content of the aerosol forming substance in the aerosol generating element is at least about 10 percent by weight.

Example 13. An aerosol generating system according to any of the previous examples, wherein the hollow tubular element has a length of at least about 25 millimeters, and the cross-section of the hollow tubular element is substantially constant.

Example 14. An aerosol generating system according to any of the previous examples, wherein the thickness of the peripheral wall of the hollow tubular element is less than about 1.5 millimeters.

Example 15. An aerosol generating system according to any of the previous examples, wherein the hollow tubular member defines a clear path for air flow extending from a downstream end of the aerosol generating member to a downstream end of the downstream section.

The present 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 is a schematic side sectional view of another aerosol generating article according to another embodiment of the present invention;

Fig. 3 shows a schematic side sectional view of a modification of the aerosol generating article of Fig. 1;

Fig. 4 shows a schematic side sectional view of a modification of the aerosol generating article of Fig. 2; and

Fig. 5 shows a schematic side sectional view of the mouthpiece end portion of the exemplary aerosol generating device and system, wherein the aerosol generating article shown in Fig. 1 is located inside the aerosol generating device.

The aerosol-generating article 10 shown in Fig. 1 comprises a rod 12 of an aerosol-generating substrate and a downstream section 14 at a location downstream of the rod 12 of the aerosol-generating substrate. Thus, the aerosol-generating article 10 extends from an upstream or distal end 16, which substantially coincides with the upstream end of the rod 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 4.5 millimeters.

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

The downstream section 14 comprises a hollow tubular element 20 located downstream of the rod 12 of the aerosol generating substrate in close proximity thereto, wherein the hollow tubular element 20 is in longitudinal alignment with the rod 12. In the embodiment of Fig. 1, the upstream end of the hollow tubular element 20 is adjacent to the downstream end of the rod 12 of the aerosol generating substrate.

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

The hollow tubular element 20 is provided in the form of a hollow cylindrical tube made of cellulose acetate or of rigid paper, such as paper having a grammage (basic weight) of at least approximately 90 grams per square meter. The hollow tubular element 20 forms 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 therefore it is possible to substantially freely flow air along the internal cavity 22. The hollow tubular element 20 does not substantially affect 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 (D _E ) of approximately 7.3 millimeters, and an inner diameter (D _I ) 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 element 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 actually provided at a distance of 18 millimeters from the mouth 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 rod 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 having an upstream section at a location upstream of the aerosol-generating element. Accordingly, the aerosol-generating article 100 will be described below only in the part in which it differs from the aerosol-generating article 10.

On top of the rod 12 of the aerosol-generating substrate and the downstream section 14 at a location downstream of the rod 12, the aerosol-generating article 100 comprises an upstream section 40 at a location upstream of the rod 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 rod 12 in close proximity thereto, wherein the upstream element 42 is in longitudinal alignment with the rod 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 rod 12. The upstream element 42 is provided in the form of a cylindrical plug made of cellulose acetate surrounded by a rigid wrapper. The upstream element 4 2 has a length of approximately 5 millimetres. The draw resistance of the upstream element 42 is approximately 30 millimetres H ₂ O.

Fig. 3 shows an aerosol-generating article 200, which is a modification 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 the modification of the first embodiment does not include the cylindrical hollow tubular element 22 described above. Instead, the aerosol-generating article 200 according to the modification of the first embodiment includes a modified tubular element 220 located downstream of the aerosol-generating element 12 in close proximity thereto.

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 bent end portion defining a first end wall 226 at the first end of the tubular body 222. The first end wall 226 defines the boundaries of an opening 228 that allows air 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, and thus the possibility of a substantially unimpeded flow of air along the cavity 222 is ensured. Therefore, the possibility of localizing the resistance to tightening 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 the possibility of adjusting it (the resistance) by selecting the configuration of the first end wall 226 and its corresponding opening 228 is ensured.

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

Fig. 4 shows an aerosol-generating article 300, which is a modification 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 the modification of the second embodiment does not include 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 the modification of the second embodiment includes a modified tubular element 44, located upstream of the aerosol-generating element 12 in close proximity to it. Therefore, in this modification of the second embodiment, the hollow tubular element 20, located downstream of the aerosol-generating element 12 in close proximity to it, 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 bent end portion defining a first end wall 50 at the first end of the tubular body 46. The first end wall 50 defines the boundaries of 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 flow is enabled from the cavity 4 8 through the opening 52 into the aerosol generating element 12.

Additionally, 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 bending the end portion of the second tubular element 44 at the second end of the tubular body 46. The second end wall 54 forms the boundaries of 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. Consequently, the opening 56 provides a passage through which air can be drawn into the aerosol-generating article 300 and then through the aerosol-generating element 12.

In the embodiment of Fig. 4, the downstream end of the second tubular element 44 is adjacent to the upstream end of the rod 12 of the aerosol-generating substrate. 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.

Fig. 5 shows an aerosol generating system 1000 comprising an aerosol generating device 1 and an aerosol generating article 10 shown in Fig. 1. Fig. 5 shows a downstream mouthpiece section of the aerosol generating device 1, where a cavity of the device is formed and where the aerosol generating article 10 can be accommodated. The aerosol generating device 1 comprises a casing (or body) 4 extending between a mouthpiece end 2 and a 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. Air can enter the aerosol generating substrate 12 through an opening provided at the closed end of the cavity of the device and providing 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 1 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 indicated in numerical form herein. Accordingly, in this context, the number A is to be understood as A ± 10% of 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 the number A modifies. In some instances, the number A, when used in the appended claims, may vary by the percentages listed above, provided that the amount by which A varies does not materially affect the essential and novel characteristic(s) of the claimed invention. In addition, all ranges include disclosed maximum and minimum points and any intermediate ranges therebetween, which may or may not be specifically stated in numerical form herein.

Claims (15)

1. An aerosol generating system comprising: an aerosol generating article for creating an inhalable aerosol upon heating, wherein the aerosol generating article extends from a mouthpiece end to a distal end and comprises: an aerosol generating element; and a downstream section that is located downstream of said aerosol generating element, wherein said downstream section extends from a downstream end of the aerosol generating element to said mouthpiece end of the aerosol generating article; wherein the downstream section comprises a hollow tubular element, and the draw resistance of the downstream section is less than 10 mm H2O; 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, wherein said housing forms a cavity of the device for removable placement of an aerosol-generating article on the mouthpiece end of said device; and a heater for heating the aerosol-generating element when placing the aerosol-generating article in the cavity of said device, wherein said heater is configured to externally heat said aerosol-generating article when it is placed in the cavity of said aerosol-generating device. 2. The aerosol generating system of claim 1, wherein the hollow tubular member of the aerosol generating article extends from a downstream end of the aerosol generating element to a mouthpiece end of the aerosol generating article. 3. An aerosol generating system according to claim 1 or 2, wherein the heater of the aerosol generating device is configured to surround the aerosol generating article when the aerosol generating article is placed in the said cavity of the device. 4. An aerosol generating system according to any of the preceding claims, wherein the operating temperature of the heater is from 180 to 200 degrees Celsius. 5. An aerosol generating system according to any one of the preceding claims, wherein the downstream section comprises a ventilation zone at a location along the hollow tubular member. 6. An aerosol generating system according to claim 5, wherein the distance between said ventilation zone and the mouthpiece end of the aerosol generating article is less than 25 millimeters. 7. An aerosol generating system according to claim 5 or 6, wherein the distance between the ventilation zone and the mouth end of the aerosol generating article is at least 10 millimetres. 8. An aerosol generating system according to one of paragraphs 5, 6 and 7, in which the ventilation zone is located with the possibility of being open when the aerosol generating article is placed in the specified cavity of the device. 9. An aerosol generating system according to any one of the preceding claims, wherein the aerosol generating article has a ventilation level of at least 10 percent. 10. An aerosol generating system according to any of the preceding claims, wherein the aerosol generating element has a length of from 10 to 20 millimeters. 11. An aerosol generating system according to any one of the preceding claims, wherein the aerosol generating element comprises cut tobacco filler. 12. An aerosol generating system according to any one of the preceding claims, wherein the content of the aerosol forming substance in the aerosol generating element is at least 10 percent by weight. 13. An aerosol generating system according to any one of the preceding claims, wherein the hollow tubular member has a length of at least 25 millimetres and the cross-section of the hollow tubular member is substantially constant. 14. An aerosol generating system according to any of the preceding claims, wherein the thickness of the peripheral wall of the hollow tubular element is less than 1.5 millimeters. 15. An aerosol generating system according to any one of the preceding claims, wherein the hollow tubular member defines a clear path for air flow from a downstream end of the aerosol generating member to a downstream end of the downstream section.