Aerosol-generating article comprising a tubular element having two end walls

Abstract

An aerosol-generating article (1) is provided that includes a plurality of elements assembled in the form of a rod. The plurality of elements includes an aerosol-forming substrate (20) and a tubular element (30). The tubular element (30) is positioned downstream of the aerosol-forming substrate (20). The tubular element (20) includes an upstream end wall (31) that defines an upstream opening (32) for allowing fluid communication between the interior of the tubular element (30) and the exterior of the tubular element (30). The tubular element (30) includes a downstream end wall (33) that defines a downstream opening (34) for allowing fluid communication between the interior of the tubular element (30) and the exterior of the tubular element (30).

Description

[Technical Field]

[0001] The present disclosure relates to an aerosol-generating article comprising an aerosol-forming substrate adapted to generate an inhalable aerosol. [Background technology]

[0002] Aerosol-generating articles in which an aerosol-forming substrate, such as a tobacco-containing substrate, is heated rather than combusted are known in the art. Typically, in such heated aerosol-generating articles, an aerosol is generated by transferring heat from a heat source to a physically separated aerosol-forming substrate or material, which may be located in contact with, within, around, or downstream of the heat source. During use of the aerosol-generating article, volatile compounds are released from the aerosol-forming substrate by heat transfer from the heat source. The volatile compounds are then entrained in air and drawn through the aerosol-generating article. As the volatile compounds cool, they condense to form an aerosol.

[0003] It is known to provide aerosol-generating articles having one or more elements downstream of an aerosol-forming substrate configured to perform a specific function. For example, WO 2013 / 120565 discloses an aerosol-generating article including an aerosol-cooling element for cooling an aerosol formed from the substrate. In one embodiment disclosed in WO 2013 / 120565, a hollow cellulose acetate tube is located immediately downstream of the aerosol-forming substrate, and an aerosol-cooling element made from a sheet of polylactic acid is located downstream of the hollow cellulose acetate tube. The function of the hollow cellulose acetate tube is described as preventing the aerosol-forming substrate from being pushed downstream when a heating element is inserted into the aerosol-forming substrate. Summary of the Invention [Problem to be solved by the invention]

[0004] Providing an aerosol-generating article with such elements downstream of the aerosol-forming substrate can increase the cost and complexity of manufacturing the aerosol-generating article. Furthermore, these elements downstream of the aerosol-forming substrate can have an undesirable effect on the resistance to draw (RTD) of the aerosol-generating article. For example, an aerosol-generating article with an RTD that is too low or too high can lead to an unsatisfactory consumer experience.

[0005] It would be desirable to provide an aerosol-generating article having an element downstream of the aerosol-forming substrate that is capable of performing one or more of the above-mentioned functions while being relatively simple and inexpensive to manufacture. It would also be desirable for such an element to provide improved functionality over known prior art downstream elements. It would further be desirable to be able to control the RTD of the element to provide a satisfactory RTD. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 shows a schematic cross-sectional view of an aerosol-generating article according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 shows a schematic cross-sectional view of an aerosol-generating article according to a second embodiment of the present disclosure. [Figure 3] FIG. 3 shows a schematic cross-sectional view of an aerosol-generating article according to a third embodiment of the present disclosure. [Figure 4] FIG. 4 shows a schematic cross-sectional view of an aerosol-generating article according to a fourth embodiment of the present disclosure. [Figure 5] FIG. 5 shows a schematic cross-sectional view of an aerosol-generating article according to a fifth embodiment of the present disclosure. [Figure 6] FIG. 6 shows a schematic cross-sectional view of an aerosol-generating article according to a sixth embodiment of the present disclosure. [Figure 7] FIG. 7 shows a perspective view of a tubular element according to the present disclosure. [Figure 8A] FIG. 8A illustrates a method of forming a tubular element according to the present disclosure. [Figure 8B]FIG. 8B illustrates a method of forming a tubular element according to the present disclosure. [Figure 8C] FIG. 8C illustrates a method of forming a tubular element according to the present disclosure. [Figure 8D] FIG. 8D illustrates a method of forming a tubular element according to the present disclosure. [Figure 9] FIG. 9 illustrates an alternative method of forming a tubular element according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0007] The present disclosure relates to an aerosol-generating article. The aerosol-generating article may comprise a plurality of elements assembled in the form of a rod. The plurality of elements may include an aerosol-forming substrate. The plurality of elements may comprise a tubular element. The tubular element may be positioned downstream of the aerosol-forming substrate. The tubular element may comprise an upstream end wall. The upstream end wall may define an upstream opening for allowing fluid communication between an interior of the tubular element and an exterior of the tubular element. The tubular element may comprise a downstream end wall. The downstream end wall may define a downstream opening for allowing fluid communication between an interior of the tubular element and an exterior of the tubular element.

[0008] According to the present disclosure, there is provided an aerosol-generating article. The aerosol-generating article comprises a plurality of elements assembled in the form of a rod. The plurality of elements comprises an aerosol-forming substrate and a tubular element. The tubular element is positioned downstream of the aerosol-forming substrate. The tubular element has an upstream end wall defining an upstream opening for allowing fluid communication between the interior of the tubular element and the exterior of the tubular element. The tubular element has a downstream end wall defining a downstream opening for allowing fluid communication between the interior of the tubular element and the exterior of the tubular element.

[0009] When the aerosol-forming substrate is heated, volatile compounds are released from the aerosol-forming substrate, and when a consumer inhales the downstream end of the aerosol-generating article, the volatile compounds are entrained in the air and drawn downstream. By positioning the tubular element downstream of the aerosol-forming substrate, the volatile compounds entrained in the air are drawn through the tubular element before being inhaled by the consumer. As the volatile compounds and air pass through the internal passage of the tubular element, heat is dissipated to the tubular wall of the tubular element, allowing the volatile compounds to cool and condense to form an aerosol. Advantageously, this allows the tubular element to function as a cooling element.

[0010] As the volatile compounds and air pass through the upstream opening defined by the upstream end wall, they may be accelerated by the constriction created by the upstream opening, which may lead to a reduction in the pressure of the fluid flow and, consequently, a reduction in the temperature of the fluid flow. This may result in faster aerosol formation due to rapid condensation of the volatile compounds. Furthermore, the upstream opening may promote turbulence downstream of the upstream opening, which may lead to increased heat dissipation. Advantageously, this may allow the tubular element configured to function as a cooling element to have a shorter length than a tubular element without an upstream opening defined by an upstream end wall.

[0011] When the aerosol-forming substrate is heated, it dries and shrinks, which can lead to portions of the aerosol-forming substrate, or in extreme cases, the entire aerosol-forming substrate, migrating downstream toward the downstream end of the aerosol-generating article. By providing an upstream end wall on the tubular element, portions of the aerosol-forming substrate can be prevented from migrating downstream toward the downstream end of the aerosol-generating article. Similarly, by providing a downstream end wall on the tubular element, portions of the aerosol-forming substrate that can pass through the upstream opening can prevent portions of the aerosol-forming substrate from migrating downstream toward the downstream end of the aerosol-generating article. That is, having both an upstream end wall and a downstream end wall allows the tubular element two opportunities: to prevent downstream portions of the aerosol-forming substrate from migrating while still allowing fluid to flow through the tubular element. This can prevent portions of the aerosol-forming substrate from being inhaled by the consumer. Advantageously, this means that the tubular element can also function as a filter element.

[0012] As used herein, the term "aerosol-generating article" refers to an article that is capable of generating and delivering an inhalable aerosol to a consumer.

[0013] As used herein, the term "aerosol-forming substrate" refers to a substrate capable of forming an inhalable aerosol. The aerosol-forming substrate may be capable of releasing a volatile compound to form an inhalable aerosol. Such a volatile compound may be released by heating the aerosol-forming substrate.

[0014] As used herein, the term "rod" refers to an elongated element. A rod may have a substantially polygonal transverse cross-sectional shape. A circular, elliptical, or oval transverse cross-sectional shape is preferred.

[0015] As used herein, the term "elongated" refers to an element having a length dimension that is greater than its width or its diameter dimension, for example, more than twice its width or its diameter dimension.

[0016] As used herein, "transverse" refers to a direction perpendicular to the longitudinal axis. References to a "cross section" of an aerosol-generating article or a component of an aerosol-generating article refer to a transverse cross section, unless otherwise specified.

[0017] As used herein, the term "longitudinal" refers to a direction corresponding to the major longitudinal axis of the aerosol-generating article, extending between the upstream and downstream ends of the aerosol-generating article. During use, air is drawn longitudinally through the aerosol-generating article.

[0018] As used herein, the terms "upstream" and "downstream" refer to the relative position of an element, or part of an element, of an aerosol-generating article with respect to the direction in which air is transported through the aerosol-generating article during use.

[0019] As used herein, the term "length" refers to the dimension of an aerosol-generating article or a component of an aerosol-generating article in the longitudinal direction. For example, it may be used to refer to the dimension of an aerosol-forming substrate or a tubular element in the longitudinal direction.

[0020] As used herein, the term "equivalent diameter" refers to the diameter of a circular opening having the same cross-sectional area as the opening.

[0021] As used herein, the term "tubular element" refers to an elongate element that defines a lumen or airflow passage in its longitudinal axis. Specifically, the term "tubular" is used to describe a tubular element that has a substantially cylindrical transverse cross-sectional shape and defines at least one airflow passage that establishes uninterrupted fluid communication between the upstream end of the tubular element and the downstream end of the tubular element. However, it will be appreciated that alternative shapes (e.g., alternative transverse cross-sectional shapes) of the tubular element may be possible. For example, the tubular element may have a circular, elliptical, or oval transverse cross-sectional shape.

[0022] As used herein, the term "upstream end wall" refers to the wall at the most upstream end of a tubular element. The material forming the upstream end wall is substantially impermeable.

[0023] As used herein, the term "downstream end wall" refers to the wall at the most downstream end of a tubular element. The material forming the downstream end wall is substantially impermeable.

[0024] As used herein, the term "filter" refers to a section of an aerosol-generating article that is configured to at least partially remove gas-phase or particulate-phase components, or both gas-phase and particulate-phase components, from the mainstream aerosol drawn through the filter.

[0025] As used herein, the term "aerosol-generating device" refers to a device that interacts with an aerosol-forming substrate to generate an aerosol from the aerosol-forming substrate. The aerosol-generating device may be a heated aerosol-generating device. The aerosol-generating device may be an electrically heated aerosol-generating device. For example, the aerosol-generating device may include one or more components that are used to supply energy from a power source to the aerosol-forming substrate to generate an aerosol. The aerosol-generating device may be a smoking device that interacts with the aerosol-forming substrate to generate an aerosol that can be inhaled directly through the user's mouth into the user's lungs.

[0026] In a conventional cigarette, a user lights the end of the cigarette, and the localized heat provided by the flame and oxygen in the air ignites the end of the cigarette, resulting in inhalable smoke being produced by combustion. In contrast, in a heated aerosol-generating article, the aerosol is generated by heating rather than burning an aerosol-forming substrate. Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles in which the aerosol is generated by the transfer of heat from a combustible fuel element or heat source to a physically separated aerosol-forming substrate.

[0027] The aerosol-generating article according to the present disclosure may be a heated aerosol-generating article. The aerosol-generating article may be an electrically heated aerosol-generating article. A heated aerosol-generating article may produce fewer components that need to be filtered before inhalation by the consumer, compared to an aerosol-generating article configured so that the aerosol-forming substrate is combusted. Advantageously, this may mean that the aerosol-generating article may have fewer components downstream of the aerosol-forming substrate, leading to a cheaper aerosol-generating article to manufacture. Furthermore, for the same size aerosol-generating article, it may mean that the aerosol-generating article may be provided with a larger aerosol-forming substrate, which may provide the consumer with a longer usage session.

[0028] In many known aerosol-generating articles, a filter element is located at the downstream end of the aerosol-generating article. Typically, the filter element is configured to provide the RTD of the aerosol flowing through the filter element. This means that the RTD through the filter element must be taken into account when determining the overall RTD of the aerosol-generating article. This can be a challenge when there are several components within the aerosol-generating article and it is desirable to obtain consistent RTD between the aerosol-generating articles produced. In some known aerosol-generating articles, the filter element is made of cellulose acetate, which can provide the RTD.

[0029] In the aerosol-generating article of the present disclosure, a filter element made of cellulose acetate may not be positioned downstream of the tubular element. In fact, there may be no filter element downstream of the tubular element. Additionally or alternatively, any element positioned downstream of the tubular element may have a smaller resistance to withdrawal than the tubular element. For example, any element positioned downstream of the tubular element may have a resistance of less than about 30 mmH2O, preferably less than about 20 mmH2O, more preferably less than about 10 mmH2O, or most preferably about 0 mmH2O. Advantageously, this means that it is easier to provide a consistent RTD among the aerosol-generating articles manufactured. The term "any element positioned downstream of the tubular element" includes the absence of an element positioned downstream of the tubular element.

[0030] The element positioned downstream of the tubular element may be hollow.The element positioned downstream of the tubular element may be tubular.

[0031] The tubular element may be the most downstream element of the aerosol-generating article. Thus, there may be no elements positioned between the downstream end wall of the tubular element and the most downstream end of the aerosol-generating article. Advantageously, this may mean that the aerosol-generating article is easier to manufacture, as fewer components need to be assembled into the aerosol-generating article. Furthermore, this may allow the downstream opening of the tubular element to contract and accelerate the flow of aerosol into the consumer's mouth without obstructing the aerosol accelerated by elements downstream of the tubular element. This may provide a comfortable sensation to the consumer.

[0032] The downstream end wall of the tubular element may be spaced apart from the downstream end of the aerosol-generating article. By spacing the downstream end wall apart from the downstream end of the aerosol-generating article, the aerosol stream exiting the downstream end of the tubular element has a region in which to expand before entering the consumer's mouth. Advantageously, this may provide a greater volume and feel of the aerosol stream into the consumer's mouth, increasing consumer satisfaction.

[0033] The downstream end wall of the tubular element may be positioned about 3 millimeters to about 20 millimeters from the downstream end of the aerosol-generating article. The downstream end wall of the tubular element may be positioned about 3 millimeters to about 15 millimeters from the downstream end of the aerosol-generating article. The downstream end wall of the tubular element may be positioned about 3 millimeters to about 10 millimeters from the downstream end of the aerosol-generating article. The downstream end wall of the tubular element may be positioned about 3 millimeters to about 8 millimeters from the downstream end of the aerosol-generating article. These ranges provide a compromise between providing an area for the aerosol to expand before entering the consumer's mouth and not significantly increasing the overall length, and therefore the cost, of the aerosol-generating article. Advantageously, the range of about 3 millimeters to about 8 millimeters has been found to provide the best trade-off between the area for aerosol expansion and the length of the aerosol-generating article.

[0034] The downstream end wall of the tubular element may be positioned less than 20 millimeters from the downstream end of the aerosol-generating article. The downstream end wall of the tubular element may be positioned less than 15 millimeters from the downstream end of the aerosol-generating article. The downstream end wall of the tubular element may be positioned less than 10 millimeters from the downstream end of the aerosol-generating article. The downstream end wall of the tubular element may be positioned less than 5 millimeters from the downstream end of the aerosol-generating article. The downstream end wall of the tubular element may be positioned less than 3 millimeters from the downstream end of the aerosol-generating article.

[0035] The tubular element may be located at the most downstream end of the aerosol-generating article, and may therefore act as a mouthpiece element to support the lips surrounding the aerosol-generating article when the consumer inhales the aerosol-generating article.

[0036] The upstream end wall may be positioned adjacent to the substrate portion. The upstream end wall may be positioned adjacent to the aerosol-forming substrate. This may limit the extent to which undesirable components, such as aerosol-forming substrate particles, can pass downstream before being blocked by the upstream end wall. This may also allow the aerosol to be cooled by the tubular element before interacting with any further elements downstream of the aerosol-forming substrate. Advantageously, this may reduce the need for elements downstream of the aerosol-forming substrate to be made from heat-resistant materials.

[0037] As used herein, the term "adjacent" refers to the upstream end wall of the tubular element that is positioned longitudinally next to the aerosol-forming substrate. In particular, this term indicates that no other elements of the aerosol-generating article are positioned longitudinally between the aerosol-forming substrate and the tubular element.

[0038] The upstream end wall may be positioned adjacent to the aerosol-forming substrate, or may not be in physical contact with the aerosol-forming substrate. A gap of empty space may separate the upstream end wall and the aerosol-forming substrate in the longitudinal direction of the aerosol-generating article. The gap may be 5 millimeters or less. The gap may be 4 millimeters or less. The gap may be 3 millimeters or less. The gap may be 2 millimeters or less. The gap may be 1 millimeter or less. Advantageously, such a gap may provide space for loose particles or fragments to agglomerate from the aerosol-forming substrate during use of the aerosol-generating article.

[0039] The upstream end wall may be in physical contact with the downstream end of the aerosol-forming substrate. The upstream end wall may be positioned adjacent to and in physical contact with the downstream end of the aerosol-forming substrate. Advantageously, physical contact between the upstream end wall and the aerosol-forming substrate may prevent the aerosol-forming substrate from migrating downstream, for example, as the aerosol-forming substrate dries and shrinks, or when a heating element is inserted into the aerosol-forming substrate from the upstream end of the aerosol-generating article.

[0040] The tubular element may extend from the downstream end of the aerosol-forming substrate to the downstream end of the aerosol-generating article. That is, the upstream end wall may be positioned in physical contact with the aerosol-forming substrate, and the downstream end wall may be positioned at the most downstream end of the aerosol-generating article. Advantageously, this may optimally cool the volatile compounds and air to form an aerosol. Furthermore, this means that there is one continuous element positioned between the aerosol-forming substrate and the downstream end of the aerosol-generating article. Advantageously, this may make the aerosol-generating article more resistant to bending or deformation.

[0041] The tubular element may have a length of at least about 10 percent of the length of the aerosol-generating article. The tubular element may have a length of at least about 20 percent of the length of the aerosol-generating article. The tubular element may have a length of at least about 30 percent of the length of the aerosol-generating article. The tubular element may have a length of at least about 40 percent of the length of the aerosol-generating article. The tubular element may have a length of at least about 50 percent of the length of the aerosol-generating article. The tubular element may have a length of at least about 60 percent of the length of the aerosol-generating article. The tubular element may have a length of at least about 70 percent of the length of the aerosol-generating article.

[0042] The tubular elements may have a length of about 10 millimeters to about 40 millimeters. The tubular elements may have a length of about 15 millimeters to about 35 millimeters. The tubular elements may have a length of about 20 millimeters to about 35 millimeters. The tubular elements may have a length of about 25 millimeters to about 30 millimeters. The tubular elements may have a length of about 28 millimeters to about 29 millimeters.

[0043] The upstream end wall may be formed by the first folded end portion, and the downstream end wall may be formed by the second folded end portion.

[0044] By providing upstream and downstream end walls formed from the folded ends of the tubular element, the tubular element can be configured to have a desired RTD by configuring the size and shape of the end walls and openings. In particular, the tubular element and its end walls can be manufactured efficiently and quickly, and have a satisfactory RTD and low RTD variability between products. Furthermore, the configuration of the tubular element and its end walls means that the RTD can be localized to a specific longitudinal location of the tubular element, rather than being continuously distributed along the length of the tubular element. Advantageously, this means that the tubular element can be configured to have more consistent properties while maintaining a cost-effective manufacturing process.

[0045] The tubular element may include a tubular element body extending from the upstream end wall of the tubular element to the downstream end wall of the tubular element. The tubular element body may be formed from a sheet of material rolled into a tube. Opposing longitudinal edges of the sheet of material may be bonded together, for example, with an adhesive. Opposing longitudinal edges of the sheet of material may overlap. Advantageously, the overlap region may prevent aerosols, volatile compounds, or air from escaping through the longitudinally extending wall of the tubular element. Advantageously, the overlap region may provide a suitable surface area for bonding the opposing longitudinal edges together. The opposing longitudinal edges may overlap by about 2 millimeters to about 5 millimeters. Advantageously, this range has been found to be an appropriately sized area for bonding the opposing longitudinal edges to provide good strength to prevent the longitudinal edges from separating.

[0046] The folded ends forming the upstream end wall and the tubular element body may be formed from the same material. The folded ends forming the upstream end wall and the tubular element body may be formed from a continuous sheet of material. The folded ends forming the downstream end wall and the tubular element body may be formed from the same material. The folded ends forming the downstream end wall and the tubular element body may be formed from a continuous sheet of material. The folded ends forming the upstream end wall, the folded ends forming the downstream end wall, and the tubular element body may be formed from the same material. The folded ends forming the upstream end wall, the folded ends forming the downstream end wall, and the tubular element body may be formed from a continuous sheet of material. Advantageously, this may make the tubular element cheaper and simpler to manufacture.

[0047] The tubular element may include a cavity extending from the upstream end wall to the downstream end wall. The cavity may be defined by the tubular element body. As referred to herein, the "interior of the tubular element" may refer to the cavity.

[0048] The cavity may be empty. Advantageously, this may provide an uninterrupted passage for fluid flow through the cavity of the tubular element.

[0049] The cavity diameter may be at least about 50 percent of the diameter of the tubular element. The cavity diameter may be at least about 60 percent of the diameter of the tubular element. The cavity diameter may be at least about 70 percent of the diameter of the tubular element. The cavity diameter may be at least about 80 percent of the diameter of the tubular element. The cavity diameter is at least about 90 percent of the diameter of the tubular element. Preferably, the cavity diameter is at least about 95 percent of the diameter of the tubular element. The volatile compounds and air flowing through the tubular element at least partially dissipate heat to the inner wall of the cavity. Generally, the larger the cavity diameter, the greater the surface area of ​​the inner wall of the cavity. It has been found advantageously to have a cavity diameter that is at least about 50 percent of the diameter of the tubular element, providing good heat dissipation and a wall thickness of the tubular element with good structural rigidity. It has been found that excellent heat dissipation can be achieved when the cavity diameter is at least about 95 percent of the diameter of the tubular element.

[0050] The diameter of the cavity may increase between the upstream and downstream end walls. The diameter of the cavity may increase from the upstream end wall to the downstream end wall. Advantageously, the increase in diameter may act to slow down the flow within the tubular element.

[0051] The diameter of the cavity may decrease between the upstream and downstream end walls. The diameter of the cavity may decrease from the upstream end wall to the downstream end wall. Advantageously, the decrease in diameter may act to accelerate flow within the tubular element.

[0052] The diameter of the cavity may be substantially constant between the upstream end wall and the downstream end wall. The diameter of the cavity may be substantially constant from the upstream end wall to the downstream end wall. A substantially constant diameter may help maintain a constant flow rate throughout the cavity, which may allow the flow to have equal contact time with all portions of the interior wall of the cavity. Advantageously, this may allow the flow to efficiently dissipate heat to the interior wall of the cavity.

[0053] The upstream opening may have an equivalent diameter of about 10 percent or more of the diameter of the upstream end wall. The upstream opening may have an equivalent diameter of about 20 percent or more of the diameter of the upstream end wall. The upstream opening may have an equivalent diameter of about 30 percent or more of the diameter of the upstream end wall. The upstream opening may have an equivalent diameter of about 40 percent or more of the diameter of the upstream end wall. The upstream opening may have an equivalent diameter of about 50 percent or more of the diameter of the upstream end wall.

[0054] The upstream opening may have an equivalent diameter of about 1 millimeter to about 12 millimeters. The upstream opening may have an equivalent diameter of about 1 millimeter to about 9 millimeters. The upstream opening may have an equivalent diameter of about 1 millimeter to about 6 millimeters. Preferably, the upstream opening may have an equivalent diameter of about 1 millimeter to about 3 millimeters. Advantageously, an upstream opening having an equivalent diameter of about 1 millimeter to about 3 millimeters has been found to provide a good compromise between providing an acceptable RTD for the tubular element and the ability to prevent undesirable components of the aerosol-forming substrate from migrating downstream. In a particularly preferred embodiment, the upstream opening has an equivalent diameter of about 2.5 millimeters.

[0055] The downstream opening may have an equivalent diameter of about 10 percent or more of the diameter of the downstream end wall. The downstream opening may have an equivalent diameter of about 20 percent or more of the diameter of the downstream end wall. The downstream opening may have an equivalent diameter of about 30 percent or more of the diameter of the downstream end wall. The downstream opening may have an equivalent diameter of about 40 percent or more of the diameter of the downstream end wall. The downstream opening may have an equivalent diameter of about 50 percent or more of the diameter of the downstream end wall.

[0056] The downstream opening may have an equivalent diameter of about 1 millimeter to about 12 millimeters. The downstream opening may have an equivalent diameter of about 1 millimeter to about 9 millimeters. The downstream opening may have an equivalent diameter of about 1 millimeter to about 6 millimeters. Preferably, the downstream opening may have an equivalent diameter of about 1 millimeter to about 3 millimeters. Advantageously, having a downstream opening with an equivalent diameter of about 1 millimeter to about 3 millimeters provides a good compromise between providing an acceptable RTD for the tubular element and filtering undesirable volatile compounds before the aerosol exits the downstream end of the aerosol-generating article. In a particularly preferred embodiment, the downstream opening has an equivalent diameter of about 2.5 millimeters.

[0057] The upstream opening may have an equivalent diameter larger than that of the downstream opening. For example, the upstream opening may have an equivalent diameter of about 4 millimeters, and the downstream opening may have an equivalent diameter of about 2 millimeters. The larger upstream opening may allow the volatile compounds and air to move quickly away from the aerosol-forming substrate and into the tubular element, while the smaller downstream opening may act to slow the passage of the volatile compounds and air within the tubular element. Advantageously, this may prevent the volatile compounds and air from being heated to excessively high temperatures near the aerosol-forming substrate, while increasing the length of time the volatile compounds and air cool within the tubular element, resulting in an aerosol with desired properties.

[0058] The upstream opening may have an equivalent diameter that is smaller than the equivalent diameter of the downstream opening, for example, the upstream opening may have an equivalent diameter of about 2 millimeters and the downstream opening may have an equivalent diameter of about 4 millimeters.

[0059] The upstream opening may have an equivalent diameter substantially equal to the equivalent diameter of the downstream opening, for example, both the upstream opening and the downstream opening may have an equivalent diameter of about 2.5 millimeters.

[0060] The upstream opening may have an equivalent diameter that is 500 percent or more of the equivalent diameter of the downstream opening. The upstream opening may have an equivalent diameter that is 400 percent or more of the equivalent diameter of the downstream opening. The upstream opening may have an equivalent diameter that is 300 percent or more of the equivalent diameter of the downstream opening. The upstream opening may have an equivalent diameter that is 200 percent or more of the equivalent diameter of the downstream opening. The upstream opening may have an equivalent diameter that is 150 percent or more of the equivalent diameter of the downstream opening. The upstream opening may have an equivalent diameter that is 140 percent or more of the equivalent diameter of the downstream opening. The upstream opening may have an equivalent diameter that is 130 percent or more of the equivalent diameter of the downstream opening. The upstream opening may have an equivalent diameter that is 120 percent or more of the equivalent diameter of the downstream opening. The upstream opening may have an equivalent diameter that is 110 percent or more of the equivalent diameter of the downstream opening.

[0061] The downstream opening may have an equivalent diameter that is 500 percent or more of the equivalent diameter of the upstream opening. The downstream opening may have an equivalent diameter that is 400 percent or more of the equivalent diameter of the upstream opening. The downstream opening may have an equivalent diameter that is 300 percent or more of the equivalent diameter of the upstream opening. The downstream opening may have an equivalent diameter that is 200 percent or more of the equivalent diameter of the upstream opening. The downstream opening may have an equivalent diameter that is 150 percent or more of the equivalent diameter of the upstream opening. The downstream opening may have an equivalent diameter that is 140 percent or more of the equivalent diameter of the upstream opening. The downstream opening may have an equivalent diameter that is 130 percent or more of the equivalent diameter of the upstream opening. The downstream opening may have an equivalent diameter that is 120 percent or more of the equivalent diameter of the upstream opening. The downstream opening may have an equivalent diameter that is 110 percent or more of the equivalent diameter of the upstream opening.

[0062] The upstream opening may be radially aligned with the downstream opening. Alternatively, the upstream opening may be radially offset from the downstream opening. Advantageously, radially offset openings may promote turbulent flow within the tubular element.

[0063] The upstream opening may be radially offset from the radially central axis of the tubular element. When the upstream opening is radially offset from the radially central axis, aerosol generated within the aerosol-forming substrate, such as aerosol generated near the radially central axis, may be moved radially outward as the aerosol is drawn through the aerosol-forming substrate. This is particularly advantageous in embodiments in which a heat source is positioned at a radially central position within the aerosol-forming substrate, such as a susceptor element or heating element of a device that is inserted into the substrate during use. Typically, in such embodiments, the peripheral portion of the substrate is cooler than the radially central portion of the substrate. Thus, the aerosol may be cooled as it moves radially outward within the aerosol-forming substrate. This may be particularly beneficial during a user's first puff on an article, when most of the aerosol may be formed near the heat source. Such an offset upstream opening may also prevent a heat source located radially central within the aerosol-forming substrate from moving downstream. This is particularly evident when the upstream end wall of the tubular element is in physical contact with the downstream end of the aerosol-forming substrate.

[0064] The upstream opening may be radially centered. For example, the upstream opening may be located at the radial center of the upstream end wall. The downstream opening may be radially centered. For example, the downstream opening may be located at the radial center of the downstream end wall.

[0065] The upstream end wall may define a plurality of openings for allowing fluid communication between the interior of the tubular element and the exterior of the tubular element. The downstream end wall may define a plurality of openings for allowing fluid communication between the interior of the tubular element and the exterior of the tubular element. Advantageously, providing multiple openings rather than a single opening allows each of the multiple openings to have a smaller equivalent diameter while still providing an acceptable RTD.

[0066] The number of openings defined in the upstream end wall may be greater than the number of openings defined in the downstream end wall. The number of openings defined in the upstream end wall may be less than the number of openings defined in the downstream end wall.

[0067] The aerosol-generating article may include a front plug located upstream of the aerosol-forming substrate. Advantageously, such a front plug may prevent the aerosol-forming substrate from exiting the upstream end of the aerosol-generating article. The front plug may also assist in positioning the aerosol-forming substrate a predetermined distance from the upstream end of the aerosol-generating article for optimal engagement with a heat source, such as a heating element. The front plug may also reduce the likelihood that a consumer will accidentally use the aerosol-generating article like a conventional cigarette and ignite the end of the aerosol-generating article.

[0068] The front plug may be the most upstream element of the aerosol-generating article. The front plug may be in physical contact with the upstream end of the aerosol-forming substrate.

[0069] The front plug may be penetrable by the heating element so that it can contact or penetrate the aerosol-forming substrate. In such embodiments, the aerosol-forming substrate may shrink during the aerosol generation stage to contact the heating element. The aerosol-forming substrate may also shrink to reduce contact with the outer wrapper of the aerosol-generating article. Without the front plug, withdrawing the heating element from the rod would weaken the bond between the aerosol-forming substrate and the cigarette paper due to increased adhesion between the aerosol-forming substrate and the heating element, and the aerosol-forming substrate may also be withdrawn. However, the front plug may facilitate removal or extraction of the heating element from the rod by limiting the movement of the aerosol-forming substrate toward the distal end of the rod. The front plug may block the passage of the aerosol-forming substrate, thus preventing it from being withdrawn from the aerosol-generating article.

[0070] The front plug may be made of a filter material that allows air to be drawn through the front plug. This may allow the consumer to draw air through the aerosol-generating article through the front plug. The front plug may conveniently be formed from the same material as a conventional mouthpiece filter. For example, the front plug may be formed from a length of cellulose acetate tow. The permeability of the front plug may be varied to help control the resistance to drawing air through the aerosol-generating article. Alternatively, the front plug may be formed from an air-impermeable material. In such an embodiment, the aerosol-generating article may be configured to allow air to flow through a sidewall of the aerosol-generating article upstream of the aerosol-forming substrate and into the aerosol-forming substrate.

[0071] The front plug may comprise one or more materials selected from the group including ceramic, polymer, biopolymer, metal, zeolite, paper, cardboard, inert material, and inorganic material. The front plug has a diameter approximately equal to the diameter of the aerosol-generating article. The front plug preferably has a diameter of about 5 to 10 millimeters. The front plug may have a front plug length of about 1 to 10 millimeters, about 2 to 8 millimeters, or about 4 to 8 millimeters. The front plug may be cylindrical and may have a length of at least 2 millimeters, preferably at least 3 millimeters, or at least 4 millimeters to facilitate assembly of the aerosol-generating article. The front plug may have a length of about 5 millimeters. Advantageously, a longer plug may also improve cleaning by increasing the amount of front plug material available to wipe the heating element as it is withdrawn from the plug.

[0072] The tubular element may be provided with a hydrophobic coating. At least a portion of the tubular element may be provided with a hydrophobic coating. The entire tubular element may be provided with a hydrophobic coating. The volatile compounds and air are cooled as they pass through the tubular element. The volatile compounds may condense on the tubular element. Advantageously, the hydrophobic coating may prevent degradation of the structural integrity of the tubular element by condensed materials.

[0073] The upstream end wall may be provided with a hydrophobic coating. The downstream end wall may be provided with a hydrophobic coating. The cavity of the tubular element may be provided with a hydrophobic coating.

[0074] As used herein, the term "hydrophobic" refers to a surface that exhibits the property of repelling water. One useful way to determine this is to measure the water contact angle. The "water contact angle" is the angle, traditionally measured through a liquid, where the liquid / vapor interface meets the solid surface. It quantifies the wettability of a solid surface by a liquid via Young's equation.

[0075] The hydrophobic coating is approximately 40 g / m 2 Less than 35g / m 2 Less than 30g / m 2 Less than or about 25 g / m 2 The composition may have a Cobb water absorption (ISO 535:1991) value (at 60 seconds) of less than 100%.

[0076] The hydrophobic coating may have a water contact angle of at least about 90 degrees, at least about 95 degrees, at least about 100 degrees, at least about 110 degrees, at least about 120 degrees, at least about 130 degrees, at least about 140 degrees, at least about 150 degrees, at least about 160 degrees, or at least about 170 degrees. Hydrophobicity is determined using the TAPPI T558 om-97 test, with results presented as interfacial contact angles, reported in degrees, which can range from approximately 0 degrees to approximately 180 degrees. If no contact angle is specified with the term hydrophobic, the water contact angle is at least 90 degrees.

[0077] The tubular element may be formed from a paper material, such as paper, paperboard, or cardboard. The tubular element may be formed from multiple overlapping paper layers, such as multiple parallel wound paper layers or multiple spirally wound paper layers. Forming the tubular element from multiple overlapping paper layers may help improve the tubular element's resistance to collapse or deformation.

[0078] When the tubular element is formed from a paper material, the paper material may have a basis weight of at least about 90 grams per square meter. The paper material may have a basis weight of less than about 300 grams per square meter. The paper material may have a basis weight of about 100 to 200 grams per square meter. Advantageously, providing the tubular element with such a wall basis weight can help improve the tubular element's resistance to collapse or deformation.

[0079] The tubular elements may have a wall thickness of at least about 0.1 millimeter, more preferably at least about 0.2 millimeter. The tubular elements may have a wall thickness of less than about 1.5 millimeters, preferably less than about 1.25 millimeters. In one preferred embodiment, the tubular elements have a wall thickness of less than about 1 millimeter. The tubular elements therefore preferably have a wall thickness of about 0.1 millimeter to about 1.5 millimeters, or about 0.2 millimeter to about 1.25 millimeters, or about 0.5 millimeter to about 1 millimeter. Advantageously, providing the tubular elements with such wall thicknesses can help improve the resistance of the tubular elements to collapse or deformation.

[0080] The tubing element may be adapted to generate an RTD from approximately 0 millimeters HO to approximately 80 millimeters HO, more preferably from approximately 20 millimeters HO to approximately 70 millimeters HO, and even more preferably from approximately 30 millimeters HO to approximately 70 millimeters HO. For example, the tubing element may be adapted to generate an RTD from approximately 35 millimeters HO to approximately 70 millimeters HO.

[0081] The tubular element may be adapted to generate an RTD from approximately 0 millimeters H2O to approximately 20 millimeters H2O, more preferably from approximately 0 millimeters H2O to approximately 10 millimeters H2O.

[0082] The aerosol-generating article may include an outer wrapper surrounding at least the tubular element. The outer wrapper may define the outer surface of the aerosol-generating article. The outer wrapper may surround at least the aerosol-forming substrate and the aerosol-forming substrate. The outer wrapper may surround all of the multiple elements of the aerosol-generating article that are assembled in the form of a rod. The outer wrapper may extend from the upstream end of the aerosol-forming substrate to the downstream end of the tubular element.

[0083] The outer wrapper may be tipping paper. The outer wrapper surrounding the tubular element may be a paper wrapper or a non-paper wrapper. Suitable paper wrappers include, but are not limited to, cigarette paper and filter plug wrap. Suitable non-paper wrappers for use in certain embodiments of the present invention are known in the art and include, but are not limited to, sheets of homogenized tobacco material. In certain preferred embodiments, the outer wrapper may be formed from a laminate material comprising multiple layers. Preferably, the wrapper is formed from an aluminum co-laminate sheet. The use of an aluminum-containing co-laminate sheet advantageously prevents combustion of the outer wrapper if the aerosol-forming substrate is to be ignited rather than heated in the intended manner.

[0084] The aerosol-generating article includes a ventilation zone, which can advantageously increase cooling of the air and volatile compounds within the interior of the tubular element by drawing in cooler ambient air, and can also increase turbulence within the tubular element, particularly if the ventilation zone draws air into the tubular element in a direction transverse to the longitudinal axis of the tubular element.

[0085] The ventilation zone may be located downstream of the aerosol-forming substrate. The ventilation zone may be located at a position along the tubular element. For example, the ventilation zone may be located longitudinally between the upstream and downstream end walls of the tubular element. The characteristics of the ventilation zone are described below with respect to the aerosol-generating article. However, it will be understood that they may also be applied directly to the tubular element itself.

[0086] The ventilation zone can be located from about 5 millimeters to about 15 millimeters from the upstream end wall of the tubular element or the downstream end wall of the tubular element. The ventilation zone may be located at least 2 millimeters from the upstream end wall of the tubular element or the downstream end wall of the tubular element, more preferably at least 3 millimeters from the upstream end wall of the tubular element or the downstream end wall of the tubular element, and even more preferably at least 5 millimeters from the upstream end wall of the tubular element or the downstream end wall of the tubular element.

[0087] The ventilation zone may be located less than 20 millimeters from the upstream end wall of the tubular element or the downstream end wall of the tubular element, more preferably less than 15 millimeters from the upstream end wall of the tubular element or the downstream end wall of the tubular element, and even more preferably less than 10 millimeters from the upstream end wall of the tubular element or the downstream end wall of the tubular element.

[0088] The ventilation zone may be located in the downstream section of the tubular element. Preferably, the ventilation zone is located between about 1 millimeter and about 10 millimeters from the downstream end wall of the tubular element, more preferably between about 2 millimeters and about 8 millimeters from the downstream end wall of the tubular element, and even more preferably between about 3 millimeters and about 6 millimeters from the downstream end wall of the first tubular element.

[0089] The ventilation zone may be located at least 1 millimeter from the downstream end wall of the tubular element, more preferably the ventilation zone is located at least 2 millimeters from the downstream end wall of the tubular element, and even more preferably the ventilation zone is located at least 3 millimeters from the downstream end of the tubular element.

[0090] The ventilation zone may be located less than 10 millimeters from the downstream end wall of the tubular element, more preferably the ventilation zone may be located less than 8 millimeters from the downstream end wall of the tubular element, and even more preferably the ventilation zone may be located less than 6 millimeters from the downstream end wall of the tubular element.

[0091] The ventilation zone may comprise a plurality of perforations through the peripheral wall of the aerosol-generating article, the tubular element, or both the aerosol-generating article and the tubular element. Preferably, the ventilation zone comprises at least one circumferential row of perforations. The ventilation zone may also comprise two circumferential rows of perforations. For example, the perforations may be formed during manufacture of the aerosol-generating article. Preferably, each circumferential row of perforations comprises between 8 and 30 perforations.

[0092] Aerosol-generating articles according to the present invention may have a breathability level of at least about 5 percent.

[0093] The term "ventilation level" is used throughout this specification to mean the volume ratio of the airflow entering the aerosol-generating article via the ventilation zone (ventilation airflow) to the sum of the aerosol airflow and the ventilation airflow. The greater the ventilation level, the greater the dilution of the aerosol stream delivered to the consumer.

[0094] Aerosol-generating articles may typically have a breathability level of at least about 10 percent, preferably at least about 15 percent, and more preferably at least about 20 percent.

[0095] In preferred embodiments, the aerosol-generating article has a breathability level of at least about 25 percent. Preferably, the aerosol-generating article has a breathability level of less than about 60 percent. The aerosol-generating article may have a breathability level of about 45 percent or less. More preferably, the aerosol-generating article may have a breathability level of about 40 percent or less, and even more preferably, about 35 percent or less.

[0096] In particularly preferred embodiments, the aerosol-generating article has a ventilation level of about 30 percent. The aerosol-generating article may have a ventilation level of about 20% to about 60%, preferably about 20% to about 45%, and more preferably about 20% to about 40%. The aerosol-generating article may have a ventilation level of about 25% to about 60%, preferably about 25% to about 45%, and more preferably about 25% to about 40%. In further embodiments, the aerosol-generating article has a ventilation level of about 30% to about 60%, preferably about 30% to about 45%, and more preferably about 30% to about 40%. The aerosol-generating article may have a ventilation level of about 30% to about 60%. The aerosol-generating article may have a ventilation level of about 40% to about 50%.

[0097] In some preferred embodiments, the aerosol-generating article has a breathability level of about 28 percent to about 42 percent. In some particularly preferred embodiments, the aerosol-generating article has a breathability level of about 30 percent.

[0098] Embodiments in which ventilation zones are provided at locations along the tubular elements may provide a number of advantages. For example, without wishing to be bound by theory, the inventors have found that the temperature reduction caused by admitting cooler ambient air into the tubular elements via the ventilation zone may have a beneficial effect on aerosol particle nucleation and growth.

[0099] The aerosol-generating article may comprise a susceptor element positioned within and in thermal contact with the aerosol-forming substrate. The susceptor element may be positioned within the aerosol-forming substrate. The susceptor element may be positioned within the aerosol-forming substrate. The susceptor element may be an elongated susceptor element. The susceptor element may be an elongated susceptor element. The susceptor element extends longitudinally within the aerosol-forming substrate. The susceptor element may extend along a radial central axis of the aerosol-forming substrate.

[0100] As used herein, the term "susceptor element" refers to a material capable of converting electromagnetic energy into heat. When positioned within a varying electromagnetic field, induced eddy currents in the susceptor element cause the susceptor element to heat. When the elongated susceptor element is positioned in thermal contact with the aerosol-forming substrate, the aerosol-forming substrate is heated by the susceptor element.

[0101] The term "elongated" when used to describe a susceptor element means that the susceptor element has a length dimension that is greater than its width dimension or its thickness dimension, for example, more than twice its width dimension or its thickness dimension.

[0102] The susceptor elements may be disposed substantially longitudinally within the aerosol-forming substrate. This means that the length dimension of the elongated susceptor elements is disposed approximately parallel to the longitudinal axis of the aerosol-forming substrate, for example, within ±10 degrees of parallel to the longitudinal axis of the aerosol-forming substrate. In a preferred embodiment, the elongated susceptor elements may be positioned at a radially central position within the aerosol-forming substrate and extend along the longitudinal axis of the aerosol-forming substrate.

[0103] The susceptor element may extend from the upstream end of the aerosol-forming substrate to the downstream end of the aerosol-forming substrate. Preferably, the susceptor element extends all the way to the downstream end of the aerosol-forming substrate. The susceptor element may extend all the way to the upstream end of the aerosol-forming substrate. In a particularly preferred embodiment, the susceptor element has substantially the same length as the aerosol-forming substrate and extends from the upstream end of the aerosol-forming substrate to the downstream end of the aerosol-forming substrate.

[0104] The susceptor elements are preferably in the form of pins, rods, strips or blades.

[0105] The susceptor element preferably has a length of about 5 millimeters to about 15 millimeters, such as, for example, about 6 millimeters to about 12 millimeters, or about 8 millimeters to about 10 millimeters.

[0106] The ratio of the length of the susceptor element to the overall length of the aerosol-generating article may be from about 0.2 to about 0.35.

[0107] Preferably, the ratio of the length of the susceptor element to the total length of the aerosol-generating article is at least about 0.22, more preferably at least about 0.24, and even more preferably at least about 0.26. The ratio of the length of the susceptor element to the total length of the aerosol-generating article is preferably less than about 0.34, more preferably less than about 0.32, and even more preferably less than about 0.3.

[0108] The ratio of the length of the susceptor element to the total length of the aerosol-generating article may be about 0.22 to about 0.34, more preferably about 0.24 to about 0.34, and even more preferably about 0.26 to about 0.34. The ratio of the length of the susceptor element to the total length of the aerosol-generating article may be about 0.22 to about 0.32, more preferably about 0.24 to about 0.32, and even more preferably about 0.26 to about 0.32. In a further embodiment, the ratio of the length of the susceptor element to the total length of the aerosol-generating article is preferably about 0.22 to about 0.3, more preferably about 0.24 to about 0.3, and even more preferably about 0.26 to about 0.3.

[0109] In a particularly preferred embodiment, the ratio of the length of the susceptor element to the overall length of the aerosol-generating article is about 0.27.

[0110] The susceptor element preferably has a width of about 1 millimeter to about 5 millimeters.

[0111] The susceptor element may generally have a thickness of about 0.01 millimeters to about 2 millimeters, for example, about 0.5 millimeters to about 2 millimeters. The susceptor element may have a thickness of about 10 micrometers to about 500 micrometers, and more preferably about 10 micrometers to about 100 micrometers.

[0112] When the susceptor element has a constant cross-section, for example a circular cross-section, it has a preferred width or diameter of about 1 millimeter to about 5 millimeters.

[0113] When the susceptor elements have the form of strips or blades, the strips or blades preferably have a rectangular shape, preferably having a width of about 2 millimeters to about 8 millimeters, more preferably about 3 millimeters to about 5 millimeters. As an example, a susceptor element in the form of a blade strip may have a width of about 4 millimeters.

[0114] When the susceptor elements are in the form of strips or blades, the strips or blades preferably have a rectangular shape and a thickness of about 0.03 millimeters to about 0.15 millimeters, more preferably about 0.05 millimeters to about 0.09 millimeters. As an example, a susceptor element in the form of a blade strip may have a thickness of about 0.07 millimeters.

[0115] In a preferred embodiment, the elongated susceptor elements are in the form of strips or blades, preferably having a rectangular shape and a thickness of about 55 micrometers to about 65 micrometers.

[0116] More preferably, the elongated susceptor elements have a thickness of about 57 micrometers to about 63 micrometers. Even more preferably, the elongated susceptor elements have a thickness of about 58 micrometers to about 62 micrometers. In a particularly preferred embodiment, the elongated susceptor elements have a thickness of about 60 micrometers.

[0117] The elongated susceptor elements preferably have a length that is the same as or shorter than the length of the aerosol-forming substrate. Preferably, the elongated susceptor elements have the same length as the aerosol-forming substrate.

[0118] The susceptor element may be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol-forming substrate. Preferred susceptor elements comprise metal or carbon.

[0119] Preferred susceptor elements may include or consist of a ferromagnetic material, such as a ferromagnetic alloy, ferritic iron, or ferromagnetic steel or stainless steel. Suitable susceptor elements may be or include aluminum. Preferred susceptor elements may be formed from 400 series stainless steel, such as grade 410, grade 420, or grade 430 stainless steel. Different materials dissipate different amounts of energy when placed in electromagnetic fields of similar frequency and field strength.

[0120] Thus, any of the susceptor element parameters, such as type of material, length, width, and thickness, can be varied to provide a desired power distribution within a known electromagnetic field. Preferred susceptor elements may be heated to temperatures in excess of 250 degrees Celsius.

[0121] Suitable susceptor elements may include a non-metallic core having a metal layer, such as a metal band formed on the surface of the ceramic core. The susceptor element may have a protective outer layer, such as a protective ceramic or glass layer, encapsulating the susceptor element. The susceptor element may include a protective coating formed of glass, ceramic, or an inert metal formed over a core of susceptor element material.

[0122] The susceptor element may be a multi-material susceptor element and may comprise a first susceptor element material and a second susceptor element material. The first susceptor element material is disposed in close physical contact with the second susceptor element material. The second susceptor element material preferably has a Curie temperature below 500 degrees Celsius. The first susceptor element material is preferably primarily used to heat the susceptor element when the susceptor element is placed in a fluctuating electromagnetic field. Any suitable material may be used. For example, the first susceptor element material may be aluminum or an iron-based material such as stainless steel. The second susceptor element material is preferably primarily used to indicate when the susceptor element reaches a specific temperature, which is the Curie temperature of the second susceptor element material. The Curie temperature of the second susceptor element material can be used to regulate the temperature of the entire susceptor element during operation. Therefore, the Curie temperature of the second susceptor element should be below the ignition point of the aerosol-forming substrate.Suitable materials for the second susceptor element material may include nickel and certain nickel alloys.

[0123] The heating of the aerosol-forming substrate and the temperature control of the heating can be separated by providing a susceptor element having at least first and second susceptor element materials with a second susceptor element material having a Curie temperature and a first susceptor element material having no Curie temperature, or by providing first and second susceptor element materials having different first and second Curie temperatures. The first susceptor element material is preferably a magnetic material having a Curie temperature greater than 500°C. From the standpoint of heating efficiency, it is desirable that the Curie temperature of the first susceptor element material exceed any maximum temperature to which the susceptor element can be heated. The second Curie temperature may be selected to be preferably lower than 400°C, preferably lower than 380°C, or even lower than 360°C. The second susceptor element material is preferably a magnetic material selected to have a second Curie temperature substantially equal to the desired maximum heating temperature. That is, the second Curie temperature is preferably approximately the same as the temperature to which the susceptor element must be heated to generate an aerosol from the aerosol-forming substrate. The second Curie temperature may be, for example, within the range of 200° C. to 400° C., or within the range of 250° C. to 360° C. The second Curie temperature of the second susceptor element material may be selected such that the overall average temperature of the aerosol-forming substrate does not exceed 240° C. when heated by a susceptor element having a temperature equal to the second Curie temperature.

[0124] The aerosol-forming substrate may have a length of from about 10 millimeters to about 15 millimeters. The aerosol-forming substrate may be from about 11 millimeters to about 12 millimeters in length.

[0125] The aerosol-forming substrate may comprise tobacco cut filler.

[0126] The aerosol-forming substrate may comprise a tobacco cast leaf.

[0127] The aerosol-forming substrate may be an assemblage of sheets of homogenized tobacco material, which may extend across substantially the entire transverse cross-sectional area of ​​the rod.

[0128] The homogenized tobacco material sheet assembly is 100 g / m 2 ~about 300g / m 2 The sheet may have a basis weight of

[0129] The aggregate sheet of homogenized tobacco material may have a thickness of from 50 μm to about 300 μm.

[0130] The collected sheet of homogenized tobacco material may be a collected crimped sheet of homogenized tobacco material. The collected crimped sheet of homogenized tobacco material may have a plurality of ridges or corrugations substantially parallel to the longitudinal axis of the rod.

[0131] In certain preferred embodiments, the aerosol-forming substrate comprises homogenized plant material, preferably homogenized tobacco material.

[0132] As used herein, the term "homogenized plant material" encompasses any plant material formed by agglomeration of plant particles. For example, a sheet or web of homogenized tobacco material for the aerosol-forming substrate of the present invention may be formed by agglomerating particles of tobacco material obtained by grinding, crushing, or comminuting plant material and, optionally, one or more of tobacco lamina and tobacco stems. Homogenized plant material may be produced by casting, extrusion, a papermaking process, or any other suitable process known in the art.

[0133] The homogenized plant material may be provided in any suitable form. For example, the homogenized plant material may be in the form of one or more sheets. As used herein, the term "sheet" describes a thin layer of material having a width and length substantially greater than its thickness. The homogenized plant material may be in the form of a plurality of pellets or granules. The homogenized plant material may also be in the form of a plurality of strands, pieces, or fragments. As used herein, the term "strand" describes an elongated element of material having a length substantially greater than its width and thickness. The term "strand" should be considered to encompass pieces, fragments, and any other homogenized plant material having a similar form. The strands of homogenized plant material may be formed from a sheet of homogenized plant material, for example, by cutting or chopping, or by other methods, such as extrusion.

[0134] The strands may be formed in situ within the aerosol-forming substrate as a result of splitting or cracking of the sheet of homogenized plant material during the formation of the aerosol-forming substrate, for example, as a result of crimping. The strands of homogenized plant material within the aerosol-forming substrate may be separated from one another. At least some strands of homogenized plant material within the aerosol-forming substrate may be at least partially connected to adjacent strands or strands along their length. For example, adjacent strands may be connected by one or more fibers. This may occur, for example, when strands are formed due to splitting of the sheet of homogenized plant material during the manufacture of the aerosol-forming substrate, as described above.

[0135] The aerosol-forming substrate is preferably in the form of one or more sheets of homogenized plant material. The one or more sheets of homogenized plant material may be produced by a casting process. The one or more sheets of homogenized plant material may be produced by a paper-making process. The one or more sheets described herein may each individually have a thickness of 100 micrometers to 600 micrometers, preferably 150 micrometers to 300 micrometers, and most preferably 200 micrometers to 250 micrometers. Individual thickness refers to the thickness of an individual sheet, while combined thickness refers to the total thickness of all sheets comprising the aerosol-forming substrate. For example, if the aerosol-forming substrate is formed from two individual sheets, the combined thickness is the thickness of the two individual sheets or the sum of the measured thicknesses of the two sheets when the two sheets are stacked within the aerosol-forming substrate.

[0136] One or more of the sheets described herein may each individually have a weight of about 100 g / m 2 ~about 300g / m 2 The sheet may have a basis weight of

[0137] One or more of the sheets described herein may each individually have a density of about 0.3 g / cm 3 ~Approx. 1.3g / cm 3 and may have a density of about 0.7 g / cm 3 ~Approx. 1.0g / cm 3 It is preferred that the density of the granular material is 0.05 to 0.15.

[0138] In embodiments in which the aerosol-forming substrate comprises one or more sheets of homogenized plant material, the sheets are preferably in the form of an assembly of one or more sheets. As used herein, the term "assembly" means that the sheets of homogenized plant material are coiled, folded, or otherwise compressed or contracted in a direction substantially transverse to the cylindrical axis of the plug or rod.

[0139] One or more sheets of homogenized plant material may be gathered transversely to their longitudinal axes and surrounded by a wrapper to form a continuous rod or plug.

[0140] One or more sheets of homogenized plant material may advantageously be crimped or similarly treated. As used herein, the term "crimped" means a sheet having a plurality of substantially parallel ridges or corrugations. Alternatively or additionally to being crimped, one or more sheets of homogenized plant material may be embossed, debossed, perforated, or otherwise deformed to provide texture to one or both sides of the sheet.

[0141] Preferably, each sheet of homogenized plant material may be crimped to have a plurality of ridges or corrugations substantially parallel to the longitudinal axis of the rod. This advantageously facilitates assembling the crimped sheets of homogenized plant material to form the aerosol-forming substrate. Preferably, one or more sheets of homogenized plant material may be assembled. Of course, the crimped sheets of homogenized plant material may alternatively or additionally have a plurality of substantially parallel ridges or corrugations that form acute or obtuse angles with respect to the longitudinal axis of the rod. The sheet may be crimped to an extent that the integrity of the sheet is interrupted at the plurality of parallel ridges or corrugations, causing separation of the material and resulting in the formation of fragments, strands, or pieces of homogenized plant material.

[0142] One or more sheets of homogenized plant material may be cut into strands, as mentioned above. The aerosol-forming substrate may contain multiple strands of homogenized plant material. The strands may be used to form plugs. Typically, the width of such strands is about 5 millimeters, about 4 millimeters, about 3 millimeters, or about 2 millimeters or less. The length of the strands may be greater than about 5 millimeters, about 5 millimeters to about 15 millimeters, about 8 millimeters to about 12 millimeters, or about 12 millimeters. Preferably, the strands have substantially the same length as each other. The length of the strands may be determined by the manufacturing process by which the rod is cut into shorter plugs, and the length of the strands corresponds to the length of the plugs. Strands are fragile and may break, especially during transport. In such cases, the length of some of the strands may be shorter than the length of the plugs.

[0143] The strands preferably extend substantially longitudinally along the length of the aerosol-forming substrate, aligned with the longitudinal axis, and are therefore preferably aligned substantially parallel to one another.

[0144] The homogenized plant material may contain up to about 95 weight percent plant particles on a dry weight basis, preferably up to about 90 weight percent plant particles, more preferably up to about 80 weight percent plant particles, more preferably up to about 70 weight percent plant particles, more preferably up to about 60 weight percent plant particles, and even more preferably up to about 50 weight percent plant particles on a dry weight basis.

[0145] For example, the homogenized plant material can contain, on a dry weight basis, from about 2.5 weight percent to about 95 weight percent plant particles, or from about 5 weight percent to about 90 weight percent plant particles, or from about 10 weight percent to about 80 weight percent plant particles, or from about 15 weight percent to about 70 weight percent plant particles, or from about 20 weight percent to about 60 weight percent plant particles, or from about 30 weight percent to about 50 weight percent plant particles.

[0146] The homogenized plant material may be a homogenized tobacco material comprising tobacco particles. The sheets of homogenized tobacco material used in such embodiments may have a tobacco content of at least about 40 weight percent on a dry weight basis, more preferably at least about 50 weight percent on a dry weight basis, even more preferably at least about 70 weight percent on a dry weight basis, and most preferably at least about 90 weight percent on a dry weight basis.

[0147] The term "tobacco particles" refers to particles of any plant member of the genus Nicotiana. The term "tobacco particles" encompasses ground or powdered tobacco lamina, ground or powdered tobacco stems, tobacco dust, tobacco fines, and other particulate tobacco by-products formed during tobacco processing, handling, and shipping. In preferred embodiments, the tobacco particles are derived substantially entirely from tobacco lamina. In contrast, isolated nicotine and nicotine salts, although tobacco-derived compounds, are not considered tobacco particles for purposes of the present invention and are not included in the proportion of particulate plant material.

[0148] The tobacco particles may be prepared from one or more tobacco plant varieties. Any type of tobacco may be used in the blend. Examples of tobacco types that may be used include, but are not limited to, sun-cured tobacco, flue-cured tobacco, burley tobacco, Maryland tobacco, Orient tobacco, Virginia tobacco, and other specialty tobaccos.

[0149] Flame-curing is a tobacco curing method used specifically with Virginia tobacco. During the flue-curing process, heated air is circulated through tightly packed tobacco. During the first stage, the tobacco leaves yellow and wither. During the second stage, the leaf lamina dries completely. During the third stage, the leaf stem dries completely.

[0150] Burley tobacco plays an important role in many tobacco blends. It has a unique flavor and aroma and the ability to absorb large amounts of casing.

[0151] Orient is a type of tobacco with small leaves and high aromatic qualities. However, Orient tobacco has a milder flavor than, for example, Burley. Therefore, Orient tobacco is generally used in relatively small proportions in tobacco blends.

[0152] Kasturi, Madura, and Jatim are subtypes of sun-cured tobacco that can be used. Preferably, Kasturi and flue-cured tobaccos are blended to produce tobacco particles. Thus, the tobacco particles in the particulate plant material can comprise a blend of Kasturi and flue-cured tobaccos.

[0153] The tobacco particles may have a nicotine content of at least about 2.5 weight percent on a dry weight basis. More preferably, the tobacco particles may have a nicotine content of at least about 3 weight percent on a dry weight basis, even more preferably at least about 3.2 weight percent, even more preferably at least about 3.5 weight percent, and most preferably at least about 4 weight percent.

[0154] The homogenized plant material may include tobacco particles combined with non-tobacco plant flavor particles. Preferably, the non-tobacco plant flavor particles are selected from one or more of ginger, rosemary, eucalyptus, clove, and star anise particles. Preferably, in such embodiments, the homogenized plant material comprises, on a dry weight basis, at least about 2.5 weight percent of non-tobacco plant flavor particles, with the remaining plant particles being tobacco particles. Preferably, the homogenized plant material comprises, on a dry weight basis, at least about 4 weight percent of non-tobacco plant flavor particles, more preferably at least about 6 weight percent of non-tobacco plant flavor particles, more preferably at least about 8 weight percent of non-tobacco plant flavor particles, and more preferably at least about 10 weight percent of non-tobacco plant flavor particles. Preferably, the homogenized plant material comprises, on a dry weight basis, at most about 20 weight percent of non-tobacco plant flavor particles, more preferably at most about 18 weight percent of non-tobacco plant flavor particles, and more preferably at most about 16 weight percent of non-tobacco plant flavor particles.

[0155] The weight ratio of non-tobacco plant flavor particles and tobacco particles in the particulate plant material forming the homogenized plant material can vary depending on the desired flavor characteristics and composition of the aerosol generated from the aerosol-forming substrate during use. Preferably, the homogenized plant material comprises, on a dry weight basis, a weight ratio of non-tobacco plant flavor particles to tobacco particles of at least 1:30, more preferably a weight ratio of non-tobacco plant flavor particles to tobacco particles of at least 1:20, more preferably a weight ratio of non-tobacco plant flavor particles to tobacco particles of at least 1:10, and most preferably a weight ratio of non-tobacco plant flavor particles to tobacco particles of at least 1:5.

[0156] The homogenized plant material may include cannabis particles. The term "cannabis particles" refers to particles of the cannabis plant, such as Cannabis sativa, Cannabis indica, and Cannabis ruderalis.

[0157] The homogenized plant material preferably comprises no more than 95 weight percent particulate plant material on a dry weight basis. Accordingly, the particulate plant material is typically combined with one or more other ingredients to form the homogenized plant material.

[0158] The homogenized plant material may further comprise a binder for modifying the mechanical properties of the particulate plant material, wherein the binder is included in the homogenized plant material during production as described herein. Suitable exogenous binders known to those skilled in the art are known in the art and include, but are not limited to, gums such as guar gum, xanthan gum, gum arabic, and locust bean gum; cellulose binders such as hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, and ethyl cellulose; polysaccharides such as starch, organic acids such as alginic acid, sodium alginate, agar, and conjugate base salts of organic acids such as pectin, and combinations thereof. Preferably, the binder comprises guar gum.

[0159] The binder may be present in an amount of about 1 weight percent to about 10 weight percent based on the dry weight of the homogenized plant material, preferably in an amount of about 2 weight percent to about 5 weight percent based on the dry weight of the homogenized plant material.

[0160] The homogenized plant material may further include one or more lipids to enhance the diffusion rate of the volatile components (e.g., aerosol formers, gingerol, and nicotine), where the lipids are included in the homogenized plant material during the processes described herein. Suitable lipids for inclusion in the homogenized plant material include, but are not limited to, medium chain triglycerides, cocoa butter, palm oil, palm kernel oil, mango oil, shea butter, soybean oil, cottonseed oil, coconut oil, hydrogenated coconut oil, candelilla wax, carnauba wax, shellac, sunflower wax, sunflower oil, rice bran, and Revel A, and combinations thereof.

[0161] The homogenized plant material may further include a pH modifier.

[0162] The homogenized plant material may further include fibers to alter the mechanical properties of the homogenized plant material, where the fibers are included in the homogenized plant material during the manufacturing process described herein. Suitable exogenous fibers for inclusion in the homogenized plant material are known in the art and include fibers formed from non-tobacco and non-ginger materials, including, but not limited to, cellulose fibers, soft wood fibers, hard wood fibers, jute fibers, and combinations thereof. Exogenous fibers derived from tobacco and / or ginger may also be added. Any fibers added to the homogenized plant material are not considered to form part of the "particulate plant material" defined above. Before being included in the homogenized plant material, the fibers may be processed by a suitable process known in the art, including, but not limited to, mechanical pulping, refining, chemical pulping, bleaching, sulfate pulping, and combinations thereof. Typically, the fibers have a length greater than their width.

[0163] Suitable fibers are typically greater than 400 micrometers and have a length of 4 millimeters or less, with lengths in the range of 0.7 millimeters to 4 millimeters being preferred. The fibers are preferably present in an amount of about 2 weight percent to about 15 weight percent, most preferably about 4 weight percent, based on the dry weight of the substrate.

[0164] The aerosol-forming substrate, particularly the homogenized plant material, may further comprise one or more aerosol formers. Upon volatilization, the aerosol formers may carry other vaporized compounds, such as nicotine and flavorings in the aerosol, that are released from the aerosol-forming substrate upon heating. Suitable aerosol formers 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 tetradecanedioate).

[0165] The aerosol-forming substrate, particularly homogenized plant material, may have an aerosol former content of from about 5 weight percent to about 30 weight percent on a dry weight basis (such as from about 10 weight percent to about 25 weight percent on a dry weight basis, or from about 15 weight percent to about 20 weight percent on a dry weight basis).

[0166] For example, when the substrate is intended for use in an aerosol-generating article for an electrically-operated aerosol-generating system having a heating element, the aerosol former content may preferably be about 5 weight percent to about 30 weight percent on a dry weight basis.When the substrate is intended for use in an aerosol-generating article for an electrically-operated aerosol-generating system having a heating element, the aerosol former is preferably glycerol.

[0167] The aerosol-forming substrate, particularly the homogenized plant material, may have an aerosol former content of 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 former is held in a reservoir separate from the substrate, the substrate may have an aerosol former content greater than 1 percent and less than about 5 percent. In such embodiments, the aerosol former volatilizes upon heating, and the aerosol former stream contacts the aerosol-forming substrate in a manner that incorporates flavors from the aerosol-forming substrate into the aerosol.

[0168] The aerosol-forming substrate, particularly the homogenized plant material, may have an aerosol-former content of about 30 weight percent to about 45 weight percent. This relatively high level of aerosol former is particularly suitable for aerosol-forming substrates intended to be heated at temperatures below 275 degrees Celsius. In such embodiments, the homogenized plant material preferably further comprises, on a dry weight basis, about 2 weight percent to about 10 weight percent of a cellulose ether and about 5 weight percent to about 50 weight percent of additional cellulose. The use of a combination of a cellulose ether and additional cellulose has been found to provide particularly effective aerosol delivery when used in an aerosol-forming substrate having an aerosol-former content of 30 weight percent to 45 weight percent.

[0169] Suitable cellulose ethers include, but are not limited to, methyl cellulose, hydroxypropyl methyl cellulose, ethyl cellulose, hydroxyl ethyl cellulose, hydroxyl propyl cellulose, ethyl hydroxyl ethyl cellulose and carboxymethyl cellulose (CMC). In a particularly preferred embodiment, the cellulose ether is carboxymethyl cellulose.

[0170] As used herein, the term "additional cellulose" encompasses any cellulose material incorporated into the homogenized plant material that is not derived from the non-tobacco plant particles or tobacco particles provided in the homogenized plant material. Thus, the additional cellulose is incorporated into the homogenized plant material as a separate and distinct cellulose source in addition to the non-tobacco plant material or tobacco material, relative to any cellulose inherently provided within the non-tobacco plant particles or tobacco particles. The additional cellulose is typically derived from a plant different from the non-tobacco plant particles or tobacco particles. Preferably, the additional cellulose is in the form of an inert cellulose material that is sensorily inert and therefore does not substantially affect the sensory properties of the aerosol generated from the aerosol-forming substrate. For example, the additional cellulose is preferably a tasteless and odorless material.

[0171] The additional cellulose may include cellulose powder, cellulose fiber, or a combination thereof.

[0172] The aerosol former may act as a wetting agent in the aerosol-forming substrate.

[0173] The wrapper surrounding the rod of homogenized plant material can be a paper wrapper or a non-paper wrapper. Suitable paper wrappers for use in certain embodiments of the present invention are known in the art and include, but are not limited to, cigarette paper and filter plug wrap. Suitable non-paper wrappers for use in certain embodiments of the present invention are known in the art and include, but are not limited to, sheets of homogenized tobacco material. In certain preferred embodiments, the wrapper may be formed from a laminate material comprising multiple layers. Preferably, the wrapper is formed from an aluminum co-laminate sheet. The use of an aluminum-containing co-laminate sheet advantageously prevents combustion of the aerosol-forming substrate if the aerosol-forming substrate is to be ignited rather than heated in the intended manner.

[0174] In some preferred embodiments, the aerosol-forming substrate comprises a gel composition comprising an alkaloid compound, or a cannabinoid compound, or both an alkaloid compound and a cannabinoid compound, hi particularly preferred embodiments, the aerosol-forming substrate comprises a gel composition comprising nicotine.

[0175] Preferably, the gel composition comprises an alkaloid compound, or a cannabinoid compound, or both an alkaloid compound and a cannabinoid compound, an aerosol former, and at least one gelling agent. Preferably, the at least one gelling agent forms a solid medium, the glycerol is dispersed in the solid medium, and the alkaloid or cannabinoid is dispersed in the glycerol. Preferably, the gel composition is in a stable gel phase.

[0176] Advantageously, the stable gel composition comprising nicotine provides a predictable composition shape upon storage or during transition from manufacture to consumer. The stable gel composition comprising nicotine substantially maintains its shape. The stable gel composition comprising nicotine does not substantially release a liquid phase upon storage or during transition from manufacture to consumer. The stable gel composition comprising nicotine may provide a simple consumable design. The consumable may not need to be designed to contain a liquid, and therefore a wider range of materials and container configurations may be contemplated.

[0177] The gel compositions described herein may be combined with an aerosol generating device to provide nicotine aerosol to the lungs at inhalation or airflow rates within those of traditional smoking. The aerosol generating device may continuously heat the gel composition. The consumer may take multiple inhalations or "puffs," with each "puff" delivering a quantity of nicotine aerosol. Upon heating, the gel composition may deliver a high-nicotine / low total particulate matter (TPM) aerosol to the consumer, preferably in a continuous manner.

[0178] The phrase "stable gel phase" or "stable gel" refers to a gel that substantially maintains its shape and mass when exposed to various environmental conditions. A stable gel cannot substantially release or absorb water (sweat) when exposed to standard temperatures and pressures while varying relative humidity from about 10 percent to about 60 percent. For example, a stable gel can substantially maintain its shape and mass when exposed to standard temperatures and pressures while varying relative humidity from about 10 percent to about 60 percent.

[0179] The gel composition may contain an alkaloid compound, or a cannabinoid compound, or both an alkaloid compound and 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.

[0180] The term "alkaloid compound" refers to any class of naturally occurring organic compounds containing one or more basic nitrogen atoms. Generally, alkaloids contain at least one nitrogen atom in an amine-type structure. This or another nitrogen atom within the molecule of an alkaloid compound can be active as a base in an acid-base reaction. Most alkaloid compounds have one or more of their nitrogen atoms as part of a ring system, such as a heterocycle. In nature, alkaloid compounds are found primarily in plants and are particularly common in certain families of flowering plants. However, some alkaloid compounds are found in animal species and fungi. In this disclosure, the term "alkaloid compound" refers to both naturally occurring and synthetically produced alkaloid compounds.

[0181] The gel composition preferably comprises an alkaloid compound selected from the group consisting of nicotine, anatabine, and combinations thereof.

[0182] Preferably, the gel composition comprises nicotine.

[0183] The term "nicotine" refers to nicotine and nicotine derivatives (eg, free base nicotine, nicotine salts, and the like).

[0184] The term "cannabinoid compounds" refers to any one of a class of naturally occurring compounds found in parts of the cannabis plant, including Cannabis sativa, Cannabis indica, and Cannabis ruderalis. Cannabinoid compounds are particularly concentrated in the female flower heads. Cannabinoid compounds that occur naturally in cannabis plants include cannabidiol (CBD) and tetrahydrocannabinol (THC). In this disclosure, the term "cannabinoid compounds" is used to describe both naturally occurring and synthetically produced cannabinoid compounds.

[0185] The gel may comprise a cannabinoid compound selected from the group consisting of cannabidiol (CBD), tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), cannabichromene (CBC), cannabicyclol (CBL), cannabivarin (CBV), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabigerol monomethyl ether (CBGM), cannabielsoin (CBE), cannabicitran (CBT), and combinations thereof.

[0186] The gel composition may preferably comprise a cannabinoid compound selected from the group consisting of cannabidiol (CBD), THC (tetrahydrocannabinol) and combinations thereof.

[0187] The gel may preferably contain cannabidiol (CBD).

[0188] The gel composition may include nicotine and cannabidiol (CBD).

[0189] The gel composition may include nicotine, cannabidiol (CBD), and THC (tetrahydrocannabinol).

[0190] The gel composition preferably contains about 0.5 to about 10 weight percent alkaloid compounds, or about 0.5 to about 10 weight percent cannabinoid compounds, or a total of about 0.5 to about 10 weight percent alkaloid and cannabinoid compounds. The gel composition may contain about 0.5 to about 5 weight percent alkaloid compounds, or about 0.5 to about 5 weight percent cannabinoid compounds, or a total of about 0.5 to about 5 weight percent alkaloid and cannabinoid compounds. The gel composition preferably contains about 1 to about 3 weight percent alkaloid compounds, or about 1 to about 3 weight percent cannabinoid compounds, or a total of about 1 to about 3 weight percent alkaloid and cannabinoid compounds. The gel composition may preferably contain about 1.5 weight percent to about 2.5 weight percent alkaloid compounds, or about 1.5 weight percent to about 2.5 weight percent cannabinoid compounds, or a total amount of about 1.5 weight percent to about 2.5 weight percent alkaloid compounds and cannabinoid compounds. The gel composition may preferably contain about 2 weight percent alkaloid compounds, or about 2 weight percent cannabinoid compounds, or a total amount of about 2 weight percent alkaloid compounds and cannabinoid compounds. The alkaloid compound component of the gel formulation may be the most volatile component of the gel formulation. In some embodiments, water may be the most volatile component of the gel formulation, and the alkaloid compound component of the gel formulation may be the second most volatile component of the gel formulation. The cannabinoid compound component of the gel formulation may be the most volatile component of the gel formulation. In some embodiments, water may be the most volatile component of the gel formulation, and the alkaloid compound component of the gel formulation may be the second most volatile component of the gel formulation.

[0191] Preferably, nicotine is included in the gel composition. Nicotine can be added to the composition in free base or salt form. The gel composition contains about 0.5 weight percent to about 10 weight percent nicotine, or about 0.5 weight percent to about 5 weight percent nicotine. Preferably, the gel composition contains about 1 weight percent to about 3 weight percent nicotine, or about 1.5 weight percent to about 2.5 weight percent nicotine, or about 2 weight percent nicotine. The nicotine component of the gel formulation can be the most volatile component of the gel formulation. In some embodiments, water can be the most volatile component of the gel formulation, and the nicotine component of the gel formulation can be the second most volatile component of the gel formulation.

[0192] The gel composition preferably includes an aerosol former. Ideally, the aerosol former is substantially resistant to thermal degradation at the operating temperature of the associated aerosol-generating device. Suitable aerosol formers include, but are not limited to, polyhydric alcohols (such as triethylene glycol, 1,3-butanediol, and glycerin), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate), and aliphatic esters of monocarboxylic, dicarboxylic, or polycarboxylic acids (such as dimethyl dodecanedioate and dimethyl tetradecanedioate). The polyhydric alcohol or mixture thereof may be one or more of triethylene glycol, 1,3-butanediol, and glycerin (glycerol or propane-1,2,3-triol) or polyethylene glycol. The aerosol former is preferably glycerol.

[0193] The gel composition comprises a majority of the aerosol former. The gel composition may comprise a mixture of water and aerosol former, with the aerosol former forming a majority (by weight) of the gel composition. The aerosol former may form at least about 50 weight percent of the gel composition. The aerosol former may form at least about 60 weight percent, or at least about 65 weight percent, or at least about 70 weight percent of the gel composition. The aerosol former may form about 70 weight percent to about 80 weight percent of the gel composition. The aerosol former may form about 70 weight percent to about 75 weight percent of the gel composition.

[0194] The gel composition may comprise a majority of glycerol. The gel composition may comprise a mixture of water and glycerol, with glycerol forming the majority (by weight) of the gel composition. Glycerol may form at least about 50 weight percent of the gel composition. Glycerol may form at least about 60 weight percent, or at least about 65 weight percent, or at least about 70 weight percent of the gel composition. Glycerol may form about 70 weight percent to about 80 weight percent of the gel composition. Glycerol may form about 70 weight percent to about 75 weight percent of the gel composition.

[0195] The gel composition preferably includes at least one gelling agent. The gel composition preferably includes a total amount of gelling agents ranging from about 0.4 weight percent to about 10 weight percent. More preferably, the composition includes gelling agents in a range of about 0.5 weight percent to about 8 weight percent. More preferably, the composition includes gelling agents in a range of about 1 weight percent to about 6 weight percent. More preferably, the composition includes gelling agents in a range of about 2 weight percent to about 4 weight percent. More preferably, the composition includes gelling agents in a range of about 2 weight percent to about 3 weight percent.

[0196] The term "gelling agent" refers to a compound that, when homogeneously added in an amount of about 0.3 weight percent to a 50 weight percent water / 50 weight percent glycerol mixture, forms a solid medium or support matrix leading to a gel. Gelling agents include, but are not limited to, hydrogen-bond cross-linking gelling agents and ionic cross-linking gelling agents.

[0197] The gelling agent may comprise one or more biopolymers, which may be formed from polysaccharides.

[0198] Examples of biopolymers include gellan gum (natural gellan gum, low acyl gellan gum, high acyl gellan gum, and low acyl gellan gum are preferred), xanthan gum, alginate (alginic acid), agar, and guar gum. It may be preferable for the composition to include xanthan gum. The composition may include two biopolymers. The composition may include three biopolymers. The composition may include two biopolymers in substantially equal amounts by weight. The composition may include three biopolymers in substantially equal amounts by weight.

[0199] Preferably, the gel composition contains at least about 0.2 weight percent of a hydrogen-bond cross-linked gelling agent. The gel composition preferably contains at least about 0.2 weight percent of an ionic cross-linked gelling agent. Most preferably, the gel composition contains at least about 0.2 weight percent of a hydrogen-bond cross-linked gelling agent and at least about 0.2 weight percent of an ionic cross-linked gelling agent. The gel composition may contain from about 0.5 weight percent to about 3 weight percent of a hydrogen-bond cross-linked gelling agent and from about 0.5 weight percent to about 3 weight percent of an ionic cross-linked gelling agent, or from about 1 weight percent to about 2 weight percent of a hydrogen-bond cross-linked gelling agent and from about 1 weight percent to about 2 weight percent of an ionic cross-linked gelling agent. The hydrogen-bond cross-linked gelling agent and the ionic cross-linked gelling agent may be present in substantially equal amounts in the gel composition.

[0200] The term "hydrogen-bond cross-linking gelator" refers to a gelator that forms non-covalent or physical cross-links via hydrogen bonds. Hydrogen bonds are not covalent bonds to hydrogen atoms, but rather a type of electrostatic dipole-dipole attraction between molecules. They result from the attraction between a hydrogen atom covalently bonded to another extremely electronegative atom, such as an N, O, or F atom, and another extremely electronegative atom.

[0201] The hydrogen-bond cross-linking gelling agent may comprise one or more of galactomannan, gelatin, agarose, or konjac gum, or agar. Preferably, the hydrogen-bond cross-linking gelling agent comprises agar.

[0202] The gel composition preferably contains from about 0.3 weight percent to about 5 weight percent of the hydrogen-bond cross-linking gelling agent. Preferably, the composition contains from about 0.5 weight percent to about 3 weight percent of the hydrogen-bond cross-linking gelling agent. Preferably, the composition contains from about 1 weight percent to about 2 weight percent of the hydrogen-bond cross-linking gelling agent.

[0203] The gel composition may contain galactomannan in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the galactomannan may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the galactomannan may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the galactomannan may be in the range of about 1 weight percent to about 2 weight percent.

[0204] The gel composition may contain gelatin in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the gelatin may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the gelatin may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the gelatin may be in the range of about 1 weight percent to about 2 weight percent.

[0205] The gel composition may contain agarose in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the agarose may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the agarose may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the agarose may be in the range of about 1 weight percent to about 2 weight percent.

[0206] The gel composition may contain konjac gum in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the konjac gum may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the konjac gum may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the konjac gum may be in the range of about 1 weight percent to about 2 weight percent.

[0207] The gel composition may contain agar in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the agar may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the agar may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the agar may be in the range of about 1 weight percent to about 2 weight percent.

[0208] The term "ionically cross-linking gelator" refers to a gelator that forms non-covalent or physical cross-links through ionic bonds. Ionic cross-linking involves the association of polymer chains through non-covalent interactions. A cross-linked network is formed when multivalent molecules with opposite charges are electrostatically attracted to each other, resulting in a cross-linked polymer network.

[0209] The ionic cross-linking gelling agent may include low acyl gellan, pectin, kappa carrageenan, iota carrageenan or alginate. Preferably, the ionic cross-linking gelling agent may include low acyl gellan.

[0210] The gel composition may comprise an ionically cross-linked gelling agent in the range of about 0.3 weight percent to about 5 weight percent. Preferably, the composition comprises an ionically cross-linked gelling agent in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the composition comprises an ionically cross-linked gelling agent in the range of about 1 weight percent to about 2 weight percent.

[0211] The gel composition may contain low acyl gellan in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the low acyl gellan may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the low acyl gellan may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the low acyl gellan may be in the range of about 1 weight percent to about 2 weight percent.

[0212] The gel composition may comprise pectin in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the pectin may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the pectin may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the pectin may be in the range of about 1 weight percent to about 2 weight percent.

[0213] The gel composition may comprise kappa carrageenan in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the kappa carrageenan may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the kappa carrageenan may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the kappa carrageenan may be in the range of about 1 weight percent to about 2 weight percent.

[0214] The gel composition may comprise iota carrageenan in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the iota carrageenan may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the iota carrageenan may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the iota carrageenan may be in the range of about 1 weight percent to about 2 weight percent.

[0215] The gel composition may comprise alginate in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the alginate may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the alginate may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the alginate may be in the range of about 1 weight percent to about 2 weight percent.

[0216] The gel composition may contain a hydrogen-bond cross-linking gelator and an ionic cross-linking gelator in a ratio of about 3:1 to about 1:3. Preferably, the gel composition may contain a hydrogen-bond cross-linking gelator and an ionic cross-linking gelator in a ratio of about 2:1 to about 1:2. Preferably, the gel composition may contain a hydrogen-bond cross-linking gelator and an ionic cross-linking gelator in a ratio of about 1:1.

[0217] The gel composition may further comprise a thickening agent. The thickening agent in combination with the hydrogen-bond cross-linking gelling agent and the ionic cross-linking gelling agent surprisingly appears to support a solid medium and maintain the gel composition even when the gel composition contains high levels of glycerol.

[0218] The term "thickener" refers to a compound that, when uniformly added in an amount of 0.3 weight percent to a 50 weight percent water / 50 weight percent glycerol mixture at 25 degrees Celsius, increases the viscosity without resulting in the formation of a gel, and causes the mixture to remain fluid. Preferably, a thickener refers to a compound that, when uniformly added in an amount of 0.3 weight percent to a 50 weight percent water / 50 weight percent glycerol mixture at 25 degrees Celsius, increases the viscosity to at least 50 cPs, preferably at least 200 cPs, preferably at least 500 cPs, preferably at least 1000 cPs, at a shear rate of 0.1 s-1, without resulting in the formation of a gel, and causes the mixture to remain fluid. Preferably, a thickener refers to a compound that, when homogeneously added in an amount of 0.3 weight percent to a 50 weight percent water / 50 weight percent glycerol mixture at 25 degrees Celsius, increases the viscosity at a shear rate of 0.1 s-1 by at least 2 times, at least 5 times, at least 10 times, or at least 100 times greater than before addition without resulting in the formation of a gel, and the mixture becomes or remains fluid.

[0219] The viscosity values ​​provided herein may be measured using a Brookfield RVT viscometer with a disc type RV#2 spindle rotating at 25 degrees Celsius at a speed of 6 revolutions per minute (rpm).

[0220] The gel composition preferably comprises a thickening agent in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the composition comprises a thickening agent in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the composition comprises a thickening agent in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the composition comprises a thickening agent in the range of about 1 weight percent to about 2 weight percent.

[0221] The thickening agent may comprise one or more of xanthan gum, carboxymethylcellulose, microcrystalline cellulose, methylcellulose, gum arabic, guar gum, lambda carrageenan, or starch. Preferably, the thickening agent may comprise xanthan gum.

[0222] The gel composition may contain xanthan gum in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the xanthan gum may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the xanthan gum may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the xanthan gum may be in the range of about 1 weight percent to about 2 weight percent.

[0223] The gel composition may contain carboxymethylcellulose in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the carboxymethylcellulose may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the carboxymethylcellulose may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the carboxymethylcellulose may be in the range of about 1 weight percent to about 2 weight percent.

[0224] The gel composition may contain microcrystalline cellulose in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the microcrystalline cellulose may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the microcrystalline cellulose may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the microcrystalline cellulose may be in the range of about 1 weight percent to about 2 weight percent.

[0225] The gel composition may contain methylcellulose in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the methylcellulose may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the methylcellulose may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the methylcellulose may be in the range of about 1 weight percent to about 2 weight percent.

[0226] The gel composition may include gum arabic in the range of about 0.2 weight percent to about 5 weight percent. Preferably, gum arabic may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, gum arabic may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, gum arabic may be in the range of about 1 weight percent to about 2 weight percent.

[0227] The gel composition may contain guar gum in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the guar gum may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the guar gum may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the guar gum may be in the range of about 1 weight percent to about 2 weight percent.

[0228] The gel composition may comprise lambda carrageenan in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the lambda carrageenan may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the lambda carrageenan may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the lambda carrageenan may be in the range of about 1 weight percent to about 2 weight percent.

[0229] The gel composition may comprise starch in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the starch may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the starch may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the starch may be in the range of about 1 weight percent to about 2 weight percent.

[0230] The gel composition may further comprise a divalent cation. Preferably, the divalent cation comprises calcium ions, such as calcium lactate in solution. The divalent cation (e.g., calcium ions) may aid in gel formation in compositions that include a gelling agent, such as an ionically crosslinking gelling agent. Ionic effects may aid gel formation. The divalent cation may be present in the gel composition in a range of about 0.1 to about 1 weight percent, or about 0.5 weight percent.

[0231] The gel composition may further comprise an acid. The acid may comprise a carboxylic acid. The carboxylic acid may comprise a ketone group. Preferably, the carboxylic acid may comprise a ketone group having less than about 10 carbon atoms, such as levulinic acid or lactic acid, or less than about 6 carbon atoms, or less than about 4 carbon atoms. Preferably, the carboxylic acid has three carbon atoms (such as lactic acid). Lactic acid surprisingly improves the stability of the gel composition over similar carboxylic acids. The carboxylic acid may aid in gel formation. The carboxylic acid may reduce changes in the alkaloid compound concentration, or cannabinoid compound concentration, or both the alkaloid compound concentration and the cannabinoid compound concentration in the gel composition during storage. The carboxylic acid may reduce changes in the nicotine concentration in the gel composition during storage.

[0232] The gel composition may include a carboxylic acid in the range of about 0.1 weight percent to about 5 weight percent. Preferably, the carboxylic acid may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the carboxylic acid may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the carboxylic acid may be in the range of about 1 weight percent to about 2 weight percent.

[0233] The gel composition may contain lactic acid in the range of about 0.1 weight percent to about 5 weight percent. Preferably, the lactic acid may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the lactic acid may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the lactic acid may be in the range of about 1 weight percent to about 2 weight percent.

[0234] The gel composition may include levulinic acid in the range of about 0.1 weight percent to about 5 weight percent. Preferably, the levulinic acid may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the levulinic acid may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the levulinic acid may be in the range of about 1 weight percent to about 2 weight percent.

[0235] The gel composition preferably contains some water. When the composition contains some water, the gel composition is more stable. The gel composition preferably contains at least about 1 weight percent, or at least about 2 weight percent, or at least about 5 weight percent water. The gel composition preferably contains at least about 10 weight percent or at least about 15 weight percent water.

[0236] The gel composition preferably contains about 8 weight percent to about 32 weight percent water. The gel composition preferably contains about 15 weight percent to about 25 weight percent water. The gel composition preferably contains about 18 weight percent to about 22 weight percent water. The gel composition preferably contains about 20 weight percent water.

[0237] Preferably, the aerosol-forming substrate contains from about 150 mg to about 350 mg of the gel composition.

[0238] Preferably, in embodiments comprising a gel composition, the aerosol-forming substrate comprises a porous medium loaded with the gel composition. An advantage of a porous medium loaded with a gel composition is that the gel composition is retained within the porous medium, which may aid in the manufacture, storage, or transport of the gel composition. This may help maintain the desired shape of the gel composition, particularly during manufacture, transport, or use.

[0239] The term "porous" is used herein to refer to a material that provides a plurality of pores or openings that allow the passage of air through the material.

[0240] The porous medium may be any suitable porous material capable of holding or retaining the gel composition. Ideally, the porous medium allows the gel composition to move within. In certain embodiments, the porous medium comprises natural, synthetic, or semi-synthetic materials, or a combination thereof. In certain embodiments, the porous medium comprises a sheet material, a foam, or a fiber, e.g., loose fiber, or a combination thereof. In certain embodiments, the porous medium comprises a woven fabric, a nonwoven fabric, or an extruded material, or a combination thereof. Preferably, the porous medium comprises cotton, paper, viscose, PLA, or cellulose acetate, or a combination thereof. Preferably, the porous medium comprises a sheet material, e.g., cotton or cellulose acetate. In a particularly preferred embodiment, the porous medium comprises a sheet made from cotton fibers.

[0241] The porous medium may be crimped or chopped. In a preferred embodiment, the porous medium is crimped. In an alternative embodiment, the porous medium comprises chopped porous medium. The crimping or chopping process can be before or after loading with the gel composition.

[0242] Crimping the sheet material has the advantage of improving the structure and allowing passageways through the structure. The passageways through the crimped sheet material aid in gel loading, gel retention, and fluid passage through the crimped sheet material. Therefore, there are advantages to using crimped sheet materials as porous media.

[0243] The shredding provides the medium with a high surface area to volume ratio so that it can readily absorb the gel.

[0244] In certain embodiments, the sheet material is a composite material. Preferably, the sheet material is porous. The sheet material may aid in the manufacture of the tubular element containing the gel. The sheet material may aid in the introduction of an active agent into the tubular element containing the gel. The sheet material may help stabilize the structure of the tubular element containing the gel. The sheet material may aid in the transportation or storage of the gel. The use of the sheet material allows or aids in adding structure to the porous medium, for example, by crimping the sheet material.

[0245] The porous medium can be a thread. The thread can include, for example, cotton, paper, or acetate tow. The thread can also be loaded with a gel, like any other porous medium. An advantage of using thread as the porous medium is that it can aid in ease of manufacturing.

[0246] The thread may be loaded with gel by any known means. The thread may simply be coated with gel, or the thread may be impregnated with gel. In manufacturing, the thread may be impregnated with gel and stored ready to use for inclusion in the assembly of tubular elements.

[0247] Preferably, in embodiments in which the first component comprises a gel composition, as described above, the tubular component has a length of less than 10 millimeters. The use of such a relatively short tubular component in combination with the gel composition can optimize delivery of the aerosol to the consumer.

[0248] The aerosol-generating article may comprise a capsule. The aerosol-forming substrate may be disposed within the capsule. The aerosol-generating article may comprise a substrate portion. The substrate portion may comprise the aerosol-forming substrate. The substrate portion may comprise a capsule.

[0249] During use, a consumer may burst the capsule and inhale the aerosol-generating article, which causes the capsule to move within the aerosol-generating article and release the aerosol-forming substrate to form an aerosol that can be inhaled and delivered to the consumer's lungs. As used herein, the term "rupturing" refers to providing at least one opening within the capsule to allow the aerosol-forming substrate within the capsule to exit the capsule. For example, a consumer may insert a bursting element through the distal end of the aerosol-generating article to burst the capsule. As another example, the capsule may be burst by the consumer applying force to the capsule, such as with their finger.

[0250] The capsule may include a capsule shell for enclosing the aerosol-forming substrate. The capsule may be any suitable pharmaceutical capsule, such as a hard-shell capsule. The capsule shell may be made from a gelling agent such as gelatin and / or a polysaccharide. The capsule shell may be formed from hydroxypropyl methylcellulose (HPMC). The capsule shell may include a plasticizer such as glycerin or sorbitol.

[0251] As used herein, the term "pharmaceutically active ingredient" refers to an ingredient that alters one or more chemical or physiological functions of a cell, tissue, organ, or organism.

[0252] The aerosol-forming substrate disposed within the capsule may be a dry powder. The dry powder may include a pharmaceutically active ingredient. The pharmaceutically active ingredient may be nicotine.

[0253] According to one aspect of the present invention, there is provided an electrically heated aerosol generating system comprising an aerosol-generating article as described herein and an aerosol generating device comprising an electrical element for heating an aerosol-forming substrate.

[0254] The aerosol generating device may include a power source. The power source may be configured to provide power to the electrical elements. The power source may be any suitable power source, for example, a DC voltage source such as a battery. In one embodiment, the power source is a lithium-ion battery. Alternatively, the power source may be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery (e.g., a lithium-cobalt battery, a lithium iron phosphate battery, a lithium titanate battery, or a lithium polymer battery).

[0255] The electrical element may be a heating element. The heating element may be disposed within or around the heating chamber to heat an aerosol-generating article insertable into the heating chamber. The heating chamber may be hollow. The electrical element may be an inductor, such as an induction coil.

[0256] The aerosol-generating device may comprise an internal heating element, for example a pin or blade that is inserted at least partially into the aerosol-forming substrate for use. The internal heating element may be configured to be inserted into a radially central position of the aerosol-forming substrate.

[0257] The aerosol generating device may include an external heating element positioned around the periphery of the heating chamber. The external heating element may take any suitable form. For example, the external heating element may take the form of one or more flexible heating foils on a dielectric substrate such as polyimide. The flexible heating foils may be shaped to fit the periphery of the heating chamber. Alternatively, the external heating element may take the form of metal grid(s), flexible printed circuit boards, molded circuit components (MIDs), ceramic heating elements, flexible carbon fiber heating elements, or may be formed using coating techniques such as plasma deposition on a suitably shaped substrate.

[0258] It will be appreciated that any feature described with respect to one aspect of the invention or disclosure is equally applicable to any other aspect of the invention or disclosure.

[0259] [Example] The present invention is defined in the claims. However, below is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features described above, for example, with any one or more features of other examples, embodiments, or aspects described herein.

[0260] Example 1 1. An aerosol-generating article comprising a plurality of elements assembled in the form of a rod, the plurality of elements comprising: an aerosol-forming substrate; a tubular element positioned downstream of the aerosol-forming substrate, an upstream end wall defining an upstream opening for allowing fluid communication between the interior of the tubular element and the exterior of the tubular element; a downstream end wall defining a downstream opening for allowing fluid communication between the interior of the tubular element and the exterior of the tubular element. Example 2. 10. The aerosol-generating article of claim 1, wherein any element positioned downstream of the tubular element has a withdrawal resistance of about 0 mmH2O. Example 3 An aerosol-generating article as described in Example 1 or 2, wherein no filter element made of cellulose acetate is positioned downstream of the tubular element. Example 4. An aerosol-generating article according to any one of Examples 1 to 3, wherein no filter element is positioned downstream of the tubular element. Example 5. An aerosol-generating article according to any one of Examples 1 to 4, wherein the tubular element is the most downstream element of the aerosol-generating article. Example 6 An aerosol-generating article according to any one of Examples 1 to 5, wherein the tubular element is located at the most downstream end of the aerosol-generating article. Example 7 An aerosol-generating article according to any one of Examples 1 to 5, wherein the downstream end wall is positioned less than 15 millimeters from the downstream end of the aerosol-generating article. Example 8 An aerosol-generating article according to any one of Examples 1 to 5, wherein the downstream end wall is positioned less than 10 millimeters from the downstream end of the aerosol-generating article. Example 9. An aerosol-generating article according to any one of Examples 1 to 5, wherein the downstream end wall is positioned less than 5 millimeters from the downstream end of the aerosol-generating article. Example 10. An aerosol-generating article according to any one of Examples 1 to 9, wherein the upstream end wall is positioned adjacent to the aerosol-forming substrate. Example 11 11. An aerosol-generating article according to any one of Examples 1 to 10, wherein the upstream end wall is in physical contact with the downstream end of the aerosol-forming substrate. Example 12 An aerosol-generating article according to any one of Examples 1 to 11, wherein the tubular element extends from the downstream end of the aerosol-forming substrate to the downstream end of the aerosol-generating article. Example 13 An aerosol-generating article according to any one of Examples 1 to 12, wherein the tubular element has a length of at least about 10 percent of the length of the aerosol-generating article. Example 14. An aerosol-generating article according to any one of Examples 1 to 13, wherein the tubular element has a length that is at least about 20 percent of the length of the aerosol-generating article. Example 15. An aerosol-generating article according to any one of Examples 1 to 14, wherein the tubular element has a length that is at least about 30 percent of the length of the aerosol-generating article. Example 16. An aerosol-generating article according to any one of Examples 1 to 15, wherein the tubular element has a length that is at least about 40 percent of the length of the aerosol-generating article. Example 17. An aerosol-generating article according to any one of Examples 1 to 16, wherein the tubular element has a length that is at least about 50 percent of the length of the aerosol-generating article. Example 18. An aerosol-generating article according to any one of Examples 1 to 17, wherein the tubular element has a length of from about 10 millimeters to about 40 millimeters. Example 19. An aerosol-generating article according to any one of Examples 1 to 18, wherein the tubular element has a length of from about 15 millimeters to about 35 millimeters. Example 20. 20. An aerosol-generating article according to any one of Examples 1 to 19, wherein the tubular element has a length of from about 20 millimeters to about 35 millimeters. Example 21. 21. An aerosol-generating article according to any one of Examples 1 to 20, wherein the tubular element has a length of from about 25 millimeters to about 30 millimeters. Example 22. 22. An aerosol-generating article according to any one of Examples 1 to 21, wherein the tubular element has a length of about 28 millimeters to about 29 millimeters. Example 23. 23. An aerosol-generating article according to any one of Examples 1 to 22, wherein the tubular element comprises a cavity extending from the upstream end wall to the downstream end wall. Example 24. An aerosol-generating article as described in Example 23, wherein the cavity is empty. Example 25. 25. The aerosol-generating article of example 23 or 24, wherein the diameter of the cavity is at least about 50 percent of the diameter of the tubular element. Example 26. 26. An aerosol-generating article according to any one of Examples 23 to 25, wherein the diameter of the cavity is at least about 60 percent of the diameter of the tubular element. Example 27. 27. An aerosol-generating article according to any one of Examples 23 to 26, wherein the diameter of the cavity is at least about 70 percent of the diameter of the tubular element. Example 28. An aerosol-generating article according to any one of Examples 23 to 27, wherein the diameter of the cavity is at least about 80 percent of the diameter of the tubular element. Example 29. An aerosol-generating article according to any one of Examples 23 to 28, wherein the diameter of the cavity is at least about 90 percent of the diameter of the tubular element. Example 30. 30. An aerosol-generating article according to any one of Examples 23 to 29, wherein the diameter of the cavity is at least about 95 percent of the diameter of the tubular element. Example 31. 31. The aerosol-generating article of any one of Examples 23 to 30, wherein the diameter of the cavity increases between the upstream end wall and the downstream end wall. Example 32. 32. The aerosol-generating article of any one of Examples 23 to 31, wherein the diameter of the cavity increases from the upstream end wall to the downstream end wall. Example 33. 31. The aerosol-generating article of any one of Examples 23 to 30, wherein the diameter of the cavity decreases between the upstream end wall and the downstream end wall. Example 34. 31. The aerosol-generating article of any one of Examples 23 to 30, wherein the diameter of the cavity decreases from the upstream end wall to the downstream end wall. Example 35. An aerosol-generating article according to any one of Examples 23 to 30, wherein the diameter of the cavity is substantially constant between the upstream end wall and the downstream end wall. Example 36. 36. The aerosol-generating article of Example 35, wherein the diameter of the cavity is substantially constant from the upstream end wall to the downstream end wall. Example 37. 37. An aerosol-generating article according to any one of Examples 1 to 36, wherein the upstream opening has an equivalent diameter of about 10 percent or more of the diameter of the upstream end wall. Example 38. An aerosol-generating article according to any one of Examples 1 to 37, wherein the upstream opening has an equivalent diameter of at least about 20 percent of the diameter of the upstream end wall. Example 39. An aerosol-generating article according to any one of Examples 1 to 38, wherein the upstream opening has an equivalent diameter of at least about 30 percent of the diameter of the upstream end wall. Example 40. 40. An aerosol-generating article according to any one of Examples 1 to 39, wherein the upstream opening has an equivalent diameter of at least about 40 percent of the diameter of the upstream end wall. Example 41. 41. An aerosol-generating article according to any one of Examples 1 to 40, wherein the upstream opening has an equivalent diameter that is greater than or equal to about 50 percent of the diameter of the upstream end wall. Example 42. 42. An aerosol-generating article according to any one of Examples 1 to 41, wherein the upstream opening has an equivalent diameter of from about 1 millimeter to about 3 millimeters. Example 43. An aerosol-generating article according to any one of Examples 1 to 42, wherein the downstream opening has an equivalent diameter of at least about 10 percent of the diameter of the downstream end wall. Example 44. An aerosol-generating article according to any one of Examples 1 to 43, wherein the downstream opening has an equivalent diameter of about 20 percent or more of the diameter of the downstream end wall. Example 45. An aerosol-generating article according to any one of Examples 1 to 44, wherein the downstream opening has an equivalent diameter of at least about 30 percent of the diameter of the downstream end wall. Example 46. An aerosol-generating article according to any one of Examples 1 to 45, wherein the downstream opening has an equivalent diameter of at least about 40 percent of the diameter of the downstream end wall. Example 47. An aerosol-generating article according to any one of Examples 1 to 46, wherein the downstream opening has an equivalent diameter that is greater than or equal to about 50 percent of the diameter of the downstream end wall. Example 48. An aerosol-generating article according to any one of Examples 1 to 47, wherein the downstream opening has an equivalent diameter of from about 1 millimeter to about 3 millimeters. Example 49. An aerosol-generating article according to any one of Examples 1 to 48, wherein the upstream opening has an equivalent diameter greater than the equivalent diameter of the downstream opening. Example 50. An aerosol-generating article according to any one of Examples 1 to 48, wherein the upstream opening has an equivalent diameter smaller than the equivalent diameter of the downstream opening. Example 51. An aerosol-generating article according to any one of Examples 1 to 48, wherein the upstream opening has an equivalent diameter substantially equal to the equivalent diameter of the downstream opening. Example 52. 52. The aerosol-generating article of any one of Examples 1 to 51, wherein the upstream opening is radially aligned with the downstream opening. Example 53. 52. The aerosol-generating article of any one of Examples 1 to 51, wherein the upstream opening is radially offset from the downstream opening. Example 54. An aerosol-generating article according to any one of Examples 1 to 53, wherein the upstream opening is radially central. Example 55. An aerosol-generating article according to any one of Examples 1 to 54, wherein the downstream opening is radially central. Example 56. An aerosol-generating article described in any one of Examples 1 to 55, wherein the upstream end wall defines a plurality of openings to allow fluid communication between the interior of the tubular element and the exterior of the tubular element. Example 57. An aerosol-generating article described in any one of Examples 1 to 56, wherein the downstream end wall defines a plurality of openings to allow fluid communication between the interior of the tubular element and the exterior of the tubular element. Example 58. 58. An aerosol-generating article according to any one of Examples 1 to 57, wherein the number of openings defined in the upstream end wall is greater than the number of openings defined in the downstream end wall. Example 59. An aerosol-generating article according to any one of Examples 1 to 58, further comprising a front plug located upstream of the aerosol-forming substrate. Example 60. 60. The aerosol-generating article of Example 59, wherein the front plug is the most upstream element of the aerosol-generating article. Example 61. 61. The aerosol-generating article of example 59 or 60, wherein the front plug is in physical contact with the upstream end of the aerosol-forming substrate. Example 62. 62. The aerosol-generating article of any one of Examples 59 to 61, wherein the front plug is a hollow element, for example, the front plug is in the form of a tube. Example 63. 63. The aerosol-generating article of any one of Examples 59 to 62, wherein the front plug is made from cellulose acetate, for example, the front plug is a hollow cellulose acetate tube. Example 64. An aerosol-generating article according to any one of Examples 59 to 63, wherein the front plug has a length of from about 2 millimeters to about 8 millimeters. Example 65. The aerosol generation of any one of Examples 59-64, wherein the front plug has a length of about 5 millimeters. Example 66. 66. An aerosol-generating article according to any one of Examples 1 to 65, wherein the tubular element comprises a hydrophobic coating. Example 67. 67. The aerosol-generating article of any one of Examples 1 to 66, wherein the upstream end wall comprises a hydrophobic coating. Example 68. 68. The aerosol-generating article of any one of Examples 1 to 67, wherein the downstream end wall comprises a hydrophobic coating. Example 69. An aerosol-generating article according to any one of Examples 1 to 68, wherein the cavity of the tubular element is provided with a hydrophobic coating. Example 70. 69. The aerosol-generating article of any one of Examples 1 to 69, wherein the tubular element is formed from a paper material. Example 71. 71. The aerosol-generating article of any one of Examples 1 to 70, wherein the tubular element is formed from cardboard. Example 72. An aerosol-generating article according to any one of Examples 1 to 71, comprising at least an aerosol-forming substrate and an outer wrapper surrounding the aerosol-forming substrate. Example 73. 73. The aerosol-generating article of example 72, wherein the outer wrapper extends from the upstream end of the aerosol-forming substrate to the downstream end of the tubular element. Example 74. 74. An aerosol-generating article according to any one of Examples 72 to 73, wherein the outer wrapper surrounds all of the multiple elements of the aerosol-generating article that are assembled in the form of a rod. Example 75. 75. The aerosol-generating article of any one of Examples 72-74, wherein the outer wrapper is a paper wrapper or a non-paper wrapper. Example 76. An aerosol-generating article according to any one of Examples 1 to 75, further comprising a ventilation zone located between the upstream end of the aerosol-generating article and the downstream end of the aerosol-generating article. Example 77. 77. The aerosol-generating article of example 76, wherein the ventilation zone is located downstream of the aerosol-forming substrate. Example 78. 78. The aerosol-generating article of example 76 or 77, wherein the ventilation zone is located at a position along the tubular element. Example 79. 79. The aerosol-generating article of any one of Examples 76 to 78, wherein the ventilation zone comprises a plurality of perforations surrounding the aerosol-generating article. Example 80. 80. The aerosol-generating article of Example 79, wherein the ventilation zone comprises at least one circumferential row of perforations. Example 81. 81. The aerosol-generating article of example 79 or 80, wherein the ventilation zone comprises two circumferential rows of perforations. Example 82. 82. The aerosol-generating article of any one of Examples 76-81, wherein the aerosol-generating article has a breathability level of about 30 percent to about 60 percent. Example 83. 83. The aerosol-generating article of any one of Examples 76 to 82, wherein the aerosol-generating article has a breathability level of about 40 percent to about 50 percent. Example 84. The aerosol-generating article of any one of Examples 1-83, further comprising a susceptor element positioned in thermal contact with the aerosol-forming substrate. Example 85. 85. The aerosol-generating article of example 84, wherein the susceptor element is positioned within the aerosol-forming substrate. Example 86. 86. The aerosol-generating article of example 84 or 85, wherein the susceptor element is an elongated susceptor element longitudinally disposed within the aerosol-forming substrate. Example 87. 87. The aerosol-generating article of any one of Examples 84 to 86, wherein the susceptor element extends along a radial central axis of the aerosol-forming substrate. Example 88. 88. The aerosol-generating article of any one of Examples 84 to 87, wherein the susceptor element extends from the upstream end of the aerosol-forming substrate to the downstream end of the aerosol-forming substrate. Example 89. The aerosol-generating article of any one of Examples 84 to 88, wherein the susceptor element is in the form of a pin, rod, or blade. Example 90. The aerosol-generating article of any one of Examples 1 to 89, wherein the aerosol-forming substrate comprises tobacco cut filler. Example 91. 89. The aerosol-generating article of any one of Examples 1 to 89, wherein the aerosol-forming substrate comprises a tobacco cast leaf. Example 92. 90. An aerosol-generating article according to any one of Examples 1 to 89, wherein the aerosol-forming substrate is an assembly of sheets of homogenized tobacco material. Example 93. An aerosol-generating article as described in Example 92, wherein the aggregate of sheets of homogenized tobacco material extends substantially across the entire transverse cross-sectional area of ​​the rod. Example 94. The homogenized tobacco material sheet aggregate is 100 g / m 2 and approximately 300 g / m 2 94. The aerosol-generating article of Example 92 or 93, having a basis weight of Example 95. 95. The aerosol-generating article of any one of Examples 92 to 94, wherein the assembly of sheets of homogenized tobacco material has a thickness of from 50 μm to about 300 μm. Example 96. 96. The aerosol-generating article of any one of Examples 92 to 95, wherein the collection of sheets of homogenized tobacco material is a collection of crimped sheets of homogenized tobacco material. Example 97. An aerosol-generating article as described in Example 96, wherein the assembly of crimped sheets of homogenized tobacco material has a plurality of ridges or corrugations substantially parallel to the longitudinal axis of the rod. Example 98. 98. The aerosol-generating article of any one of Examples 1 to 97, wherein the aerosol-forming substrate comprises one or more aerosol-forming bodies. Example 99. 99. The aerosol-generating article of example 98, wherein the aerosol-forming substrate has an aerosol former content of about 10 weight percent to about 50 weight percent on a dry weight basis. Example 100. 99. The aerosol-generating article of any one of Examples 1 to 99, wherein the aerosol-forming substrate has a length of from about 10 millimeters to about 15 millimeters. Example 101. 101. The aerosol-generating article of any one of Examples 1 to 100, wherein the aerosol-forming substrate has a length of from about 11 millimeters to about 12 millimeters.

[0261] The embodiments will now be further described with reference to the figures.

[0262] 1 shows an aerosol-generating article 1 according to a first embodiment, comprising a plurality of elements assembled in the form of a rod. The plurality of elements includes an aerosol-forming substrate 20 and a tubular element 30 positioned downstream of the aerosol-forming substrate 20. The aerosol-generating article 1 has an overall length of about 45 millimeters, extending from a distal end 2 (or upstream end) to a mouth end 3 (or downstream end). The aerosol-generating article 1 has a diameter of about 7 millimeters.

[0263] The aerosol-generating article 1 includes an outer wrapper 40 that surrounds all of the multiple elements assembled in the form of a rod. The outer wrapper 40 is made from tipping paper and extends from the upstream end 2 of the aerosol-generating article 1 to the downstream end 3 of the aerosol-generating article 1. The outer wrapper 40 has a thickness of approximately 500 micrometers.

[0264] The aerosol-forming substrate 20 comprises an assemblage of a crimped sheet of homogenized tobacco material having a plurality of ridges or corrugations extending substantially parallel to the longitudinal axis of the rod. The assemblage of crimped sheets of homogenized tobacco material extends across substantially the entire transverse cross-sectional area of ​​the aerosol-generating article 1. The aerosol-forming substrate 20 comprises an aerosol former, i.e., glycerol, and has an aerosol former content of about 10 percent on a dry weight basis. The aerosol-forming substrate 20 has a length of about 12 millimeters. The aerosol-forming substrate 20 is substantially cylindrical and has a diameter of about 6 millimeters.

[0265] The tubular element 30 comprises an upstream end wall 31 defining an upstream opening 32 for allowing fluid communication between the interior of the tubular element 30 and the exterior of the tubular element 30. The upstream end wall 31 is formed by a first folded end portion, as will be described in more detail in connection with Figures 8A-8D. The tubular element 30 comprises a downstream end wall 33 defining a downstream opening 34 for allowing fluid communication between the interior of the tubular element 30 and the exterior of the tubular element 30. The downstream end wall 33 is formed by a second folded end portion.

[0266] The upstream opening 32 is radially centered on the upstream end wall 31 and has an equivalent diameter of approximately 3 millimeters. That is, the upstream opening 32 has an equivalent diameter that is approximately 50 percent of the diameter of the upstream end wall 31. Similarly, the downstream opening 34 is radially centered on the downstream end wall 33 and has an equivalent diameter of approximately 3 millimeters. That is, the downstream opening 34 has an equivalent diameter that is approximately 50 percent of the diameter of the downstream end wall 33. In this embodiment, the upstream opening 32 and the downstream opening 34 are radially aligned.

[0267] The upstream end wall 31 is positioned adjacent to and in physical contact with the downstream end of the aerosol-forming substrate 20. The tubular element 30 has a length of approximately 28 millimeters and extends from the downstream end of the aerosol-forming substrate 20 toward the downstream end 3 of the aerosol-generating article 1. Although the tubular element 30 is the most downstream element of the aerosol-generating article 1, the tubular element 30 does not extend all the way to the downstream end 3 of the aerosol-generating article 1. Instead, the downstream end wall 33 of the tubular element 30 is spaced approximately 5 millimeters from the downstream end 3 of the aerosol-generating article 1.

[0268] The tubular element 30 is cylindrical and has a diameter of approximately 6 millimeters. The tubular element 30 is made from cardboard having a basis weight of approximately 100 grams per square meter and a thickness of approximately 1 millimeter. The tubular element 30 has an RTD of approximately 40 millimeters of HO.

[0269] In use, a heating element from an electrically operated aerosol-generating device is inserted into or positioned around the aerosol-forming substrate 20, heating the aerosol-forming substrate 30 and releasing volatile compounds. The consumer inhales on the downstream end 3 of the aerosol-generating article 1, drawing air through the upstream end 2 of the aerosol-generating article 1. The air is then drawn through the aerosol-forming substrate 20, and the volatile compounds released from the heated aerosol-forming substrate 20 are entrained in the air drawn through the aerosol-generating article 1. The volatile compounds and air then pass through the upstream opening 32 of the tubular element 30. The volatile compounds and air cool and condense within the tubular element 30, in part by releasing heat to the tubular wall of the tubular element 30. The cooled and condensed volatile compounds and air form an aerosol, which is drawn through the downstream opening 34 of the tubular element 30 and inhaled by the consumer.

[0270] FIG. 2 shows an aerosol-generating article 1 according to a second embodiment, comprising multiple elements assembled in the form of a rod. The aerosol-generating article 1 of FIG. 2 is similar to the aerosol-generating article 1 of FIG. 1 and also comprises an aerosol-forming substrate 20, a tubular element 30, and an outer wrapper 40. However, the tubular element 30 is positioned adjacent to the aerosol-forming substrate 20 but is not in physical contact with the downstream end of the aerosol-forming substrate 20. Instead, there is a gap 50 positioned between the downstream end of the aerosol-forming substrate 20 and the upstream end wall 31 of the tubular element 30. The gap 50 has a length of approximately 5 millimeters. Furthermore, the tubular element 30 extends from the downstream end 3 of the aerosol-generating article 1 toward the downstream end of the aerosol-forming substrate 20. More specifically, the tubular element 30 is positioned at the most downstream end of the aerosol-generating article 1. That is, the downstream end wall 33 is positioned at the downstream end 3 of the aerosol-generating article 1.

[0271] Figure 3 shows an aerosol-generating article 1 according to a third embodiment, comprising multiple elements assembled in the form of a rod. The aerosol-generating article 1 of Figure 3 is similar to the aerosol-generating article 1 of Figure 1 and also comprises an aerosol-forming substrate 20, a tubular element 30, and an outer wrapper 40. The aerosol-generating article 1 of Figure 3 further comprises an elongated susceptor element 60.

[0272] An elongated susceptor element 60 is positioned within the aerosol-forming substrate 20. More specifically, the susceptor element 60 is disposed substantially longitudinally within the aerosol-forming substrate 20, such as approximately parallel to the longitudinal axis of the rod. Furthermore, the susceptor element 60 is positioned at a radially central position within the rod and effectively extends along the longitudinal axis of the rod. The susceptor element 60 extends all the way from the upstream end to the downstream end of the aerosol-forming substrate 20. In effect, the susceptor element 60 has substantially the same length as the aerosol-forming substrate 20.

[0273] The susceptor element 60 is provided in the form of a strip, having a length of about 12 millimeters, a thickness of about 60 micrometers, and a width of about 4 millimeters.

[0274] The upstream end wall 31 of the tubular element 30 is positioned adjacent to and in physical contact with the downstream end of the aerosol-forming substrate 20. Furthermore, the width of the susceptor element 60 is greater than the width of the upstream opening 32 of the tubular element 30. This prevents the susceptor element 60 from moving downstream. The tubular element 30 extends from the downstream end of the aerosol-forming substrate 20 to the downstream end 3 of the aerosol-generating article 1.

[0275] Figure 4 shows an aerosol-generating article 1 according to a fourth embodiment, comprising multiple elements assembled in the form of a rod. The aerosol-generating article 1 of Figure 4 is similar to the aerosol-generating article 1 of Figure 3 and also comprises an aerosol-forming substrate 20, a tubular element 30, an outer wrapper 40, and a susceptor element 60. The aerosol-generating article 1 of Figure 4 further comprises a front plug 70 and a ventilation zone 80.

[0276] The front plug 70 is located immediately upstream of the aerosol-forming substrate 20. The downstream end of the front plug abuts the upstream end of the aerosol-forming substrate 20. This advantageously prevents the susceptor element 60 from becoming dislodged. Furthermore, this ensures that consumers cannot accidentally come into contact with the heated susceptor element 60 after use.

[0277] The front plug 70 is provided in the form of a cylindrical plug of cellulose acetate surrounded by a hard wrapper. The front plug 70 is about 5 millimeters long and has an RTD of about 30 millimeters H2O.

[0278] The aerosol-generating article 1 includes a ventilation zone 80 provided at a location along the tubular element 30. More specifically, the ventilation zone 80 is provided approximately 4 millimeters from the upstream end of the tubular element and includes a plurality of perforations through the outer wrapper 40 and the tubular element 30. The ventilation level of the aerosol-generating article is approximately 40 percent.

[0279] Figure 5 shows an aerosol-generating article 1 according to a fifth embodiment, comprising multiple elements assembled in the form of a rod. The aerosol-generating article 1 of Figure 5 is similar to the aerosol-generating article 1 of Figure 3 and also comprises an aerosol-forming substrate 20, a tubular element 30, an outer wrapper 40, and a susceptor element 60. Like the aerosol-generating article 1 of Figure 4, the aerosol-generating article 1 of Figure 5 comprises a ventilation zone 80 provided approximately 4 millimeters from the downstream end of the tubular element 30. The upstream opening 32 of the tubular element 30 is offset from the radial central axis of the aerosol-generating article 1, while the downstream opening 34 is located at the radial center of the downstream end wall 33 of the tubular element 30.

[0280] 6 shows an aerosol-generating article 1 according to a sixth embodiment, comprising a plurality of elements assembled in the form of a rod, the plurality of elements including a first tubular element 30, a second tubular element 90, and a capsule 100 containing an aerosol-forming substrate.

[0281] The upstream end of the first tubular element 30 is in physical contact with the downstream end of the second tubular element 90, and there is no gap between the first tubular element 30 and the second tubular element 90. In addition, the first tubular element 30 is positioned at the downstream-most end 3 of the aerosol-generating article 1.

[0282] The second tubular element 90 is constructed in a similar manner to the first tubular element 30, except that the second tubular element 90 only has an upstream end wall 91. The upstream end wall 91 defines an opening 92 to allow fluid communication between the interior of the second tubular element 90 and the exterior of the second tubular element 90. The second tubular element 90 extends from the upstream end 2 of the aerosol-generating article 1 to the upstream end wall 31 of the first tubular element 30. The second tubular element 90 comprises a cavity 93 extending from the upstream end wall 91 to the downstream end of the second tubular element 90.

[0283] In contrast to the first to fifth embodiments, in the sixth embodiment, the aerosol-generating article 1 comprises a capsule 100 containing an aerosol-forming substrate in the form of an inhalable dry powder. During use, a consumer inserts a rupturing element, such as a needle, through the opening 92 to rupture the capsule 100. The upstream end wall 31 of the first tubular element 30 restricts the downstream movement of the capsule 100, thereby assisting in the capsule rupture process. Once the capsule ruptures, the aerosol-forming substrate within the capsule 100 is released when the consumer sucks on the downstream end 3 of the aerosol-generating article 1.

[0284] Figure 7 shows a perspective view of the tubular element 30 according to Figure 1. The upstream end wall 31 extends substantially transversely to the longitudinal direction of the aerosol-generating article 1 and the longitudinal direction of the tubular element 30. The upstream opening 33 has an equivalent diameter of about 3 millimeters.

[0285] 8A-8D show a tubular element 30 of an aerosol-generating article according to the present disclosure through different stages in its formation, and thus illustrate a method of forming a tubular element such as the tubular element 30 of FIG.

[0286] As shown in FIG. 8A, the method begins by providing a tubular element precursor 300 having a tubular body 301 defining a cavity 304 extending along a longitudinal axis from a first end of the tubular body to a second end of the tubular body, a first end 302 adjacent to and integrally formed with the first end of the tubular body 301, and a second end 303 adjacent to and integrally formed with the second end of the tubular body.

[0287] To form the upstream end wall 31, a folding force is applied to the precursor tubular element 300, bending the first end 302 around the folding point 305. The folding force deflects the first end 302 inward relative to the tubular body 301 (as indicated by the dashed curved arrow in Figures 8B and 8C), toward the cavity 304. The folding force continues to be applied until the first end 302 is folded at an angle greater than 90 degrees, as measured relative to the wall of the tubular body. The folding force is then released. Due to the inherent elastic properties of the paper material (such as paper, paperboard, or cardboard) of the precursor tubular element 300, the first end 302 partially returns along its folding path until it reaches a position where it extends substantially transverse to the longitudinal axis of the tubular body 301. This position is shown in Figure 8D.

[0288] To form the downstream end wall 33, a folding force is applied to the precursor tubular element 300, bending the second end portion 303 about the folding point 306. The folding force deflects the second end portion 303 inward relative to the tubular body 300 (as indicated by the dashed curved arrows in FIGS. 8B and 8C ), toward the cavity 304. The folding force continues to be applied until the second end portion 303 is folded at an angle greater than 90 degrees, as measured relative to the wall of the tubular body. The folding force is then released. Due to the inherent elastic properties of the paper material (such as paper, paperboard, or cardboard) of the precursor tubular element 300, the second end portion 303 partially returns along its folding path until it reaches a position where it extends substantially transverse to the longitudinal axis of the tubular body 301. This position is shown in FIG. 8D.

[0289] 9 illustrates an alternative method for forming a tubular element according to the present disclosure. In a first step 401, a cellulosic material, such as paper, is mixed with water to form a pulp. Typically, the water has a temperature of about 40 to 70 degrees Celsius. In a second step 402, the pulp is inserted into a mold to produce the desired shape of the tubular element. In a third step 403, the molded pulp is ejected from the mold and dried to remove moisture from the molded pulp, thereby forming the tubular element.

[0290] For purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like are understood to be modified in all instances by the term "about." Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein. Thus, in this context, the number A is understood as A ± 5%. Within this context, the number A may be considered to include a numerical value that is within the typical standard error for measurement of the property that the number A modifies. In some cases, as used in the appended claims, the number A may deviate by the percentages recited above, provided that the amount by which A deviates does not materially affect the basic and novel characteristics of the claimed invention. Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein.

Claims

1. An aerosol generating article comprising a plurality of elements assembled in the form of a rod, wherein the plurality of elements are Aerosol-forming substrate and, A tubular element positioned downstream of the aerosol-forming substrate, An upstream end wall defining an upstream opening to enable fluid communication between the inside of the tubular element and the outside of the tubular element, an aerosol generating article comprising a tubular element having a downstream end wall that defines a downstream opening for enabling fluid communication between the inside of the tubular element and the outside of the tubular element.

2. The aerosol generating article according to claim 1, wherein any element positioned downstream of the tubular element has a draw resistance smaller than the draw resistance of the tubular element.

3. Any element positioned downstream of the tubular element is approximately 10 mmH 2 Drawback resistance less than 0, preferably about 0 mmH 2 An aerosol generating article according to claim 1 or 2, having an O extraction resistance.

4. The aerosol generating article according to claim 1 or 2, wherein a filter element made of cellulose acetate is not positioned downstream of the tubular element.

5. The aerosol generating article according to claim 1 or 2, wherein a filter element is not positioned downstream of the tubular element.

6. The aerosol generating article according to claim 1 or 2, wherein the tubular element is the downstream element of the aerosol generating article.

7. The aerosol generating article according to claim 1 or 2, wherein the tubular element is located at the downstream end of the aerosol generating article.

8. The aerosol generating article according to claim 1 or 2, wherein the downstream end wall is located less than 15 millimeters from the downstream end of the aerosol generating article.

9. The aerosol generating article according to claim 1 or 2, wherein the upstream end wall is in physical contact with the downstream end of the aerosol forming substrate.

10. The aerosol generating article according to claim 1 or 2, wherein the tubular element extends from the downstream end of the aerosol forming substrate to the downstream end of the aerosol generating article.

11. The aerosol generating article according to claim 1 or 2, wherein the tubular element comprises a cavity extending from the upstream end wall to the downstream end wall, and the cavity is empty.

12. The aerosol generating article according to claim 1 or 2, wherein the upstream end wall defines a plurality of openings for enabling fluid communication between the inside of the tubular element and the outside of the tubular element.

13. The aerosol generating article according to claim 1 or 2, wherein the upstream end wall is formed by a first folded end, and preferably the downstream end wall is formed by a second folded end.

14. The aerosol generating article according to claim 1 or 2, further comprising a ventilation zone located between the upstream end and the downstream end of the aerosol generating article.

15. The aerosol generating article according to claim 1 or 2, further comprising a susceptor element positioned in thermal contact with the aerosol-forming substrate.

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