Aerosol-generating article comprising an aerosol-generating substrate and a capsule

Abstract

The aerosol-generating article (100) for generating an inhalable aerosol upon heating comprises an aerosol-generating element (101) including a first aerosol-generating substrate and a capsule (102) located downstream of the aerosol-generating element (101). The capsule (102) contains a second aerosol-generating substrate. The second aerosol-generating substrate contains nicotine. The capsule (102) includes at least one capsule air inlet (103) located at the upstream end of the capsule (102) and at least one capsule air outlet (104) located at the downstream end of the capsule (102). The downstream end of the capsule (102) is at least 10 millimeters from the downstream end of the aerosol-generating article (100).

Description

[Technical Field]

[0001] The present invention relates to an aerosol-generating article comprising an aerosol-generating element and a capsule located downstream of the aerosol-generating element, in particular, the aerosol-generating article comprising an aerosol-generating element and a capsule located downstream of the aerosol-generating element, the capsule including at least one capsule air inlet and at least one capsule air outlet. [Background technology]

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

[0003] Numerous prior art documents disclose aerosol generating devices for consuming aerosol-generating articles. Such devices include, for example, electrically heated aerosol generating devices in which aerosol is generated by heat transfer from one or more electric heater elements of the aerosol generating device to an aerosol-generating substrate of a heated aerosol-generating article. For example, electrically heated aerosol generating devices have been proposed that include an internal heater blade adapted to be inserted into the aerosol-generating substrate.

[0004] The use of aerosol-generating articles in combination with external heating systems is also known. For example, WO 2020 / 115151 describes the provision of one or more heating elements arranged around the periphery of the aerosol-generating article when the aerosol-generating article is received in a cavity of an aerosol generating device. Alternatively, WO 2015 / 176898 proposes an inductively heatable aerosol-generating article comprising an aerosol-generating substrate and a susceptor arranged within the aerosol-generating substrate.

[0005] The duration of the consumer experience when using a known aerosol-generating article can be determined by the amount of aerosol-generating substrate used. The amount of aerosol-generating substrate can be increased, for example, by increasing the size or density of the aerosol-generating substrate. However, there is an upper limit to how large or dense the aerosol-generating substrate can be. A longer aerosol-generating substrate may be more difficult to heat or require a longer and more powerful heater. In addition, providing a larger or denser aerosol-generating substrate may increase the water content of the aerosol-generating substrate. This may increase the temperature of the aerosol during use of an aerosol-generating article containing a large or dense aerosol-generating substrate, especially during the first inhalation. This further increases power consumption requirements and leads to the need for more complex electronics within the device. In addition, when the aerosol-generating substrate is longer, the downstream portion of the aerosol-generating substrate may filter a portion of the aerosol generated by the upstream portion of the aerosol-generating substrate. This is known as self-filtration and may reduce the amount of aerosol delivered to the user. Similarly, increasing the density of the aerosol-generating substrate may also require a more powerful heater, increase battery consumption, and increase the complexity of the electronics required for the device. In addition, downstream portions of the aerosol-generating substrate having a higher density may disadvantageously filter aerosol generated further upstream of the aerosol-generating substrate.

[0006] It is therefore desirable to provide new aerosol-generating articles that can provide a longer-lasting user experience without the need to increase the complexity or power consumption of the associated device's electronics, and while avoiding or reducing self-filtration within the aerosol-generating substrate. Summary of the Invention

[0007] The present disclosure relates to an aerosol-generating article for generating an inhalable aerosol upon heating. The aerosol-generating article may include an aerosol-generating element. The aerosol-generating element may include a first aerosol-generating substrate. The aerosol-generating article may include a capsule located downstream from the aerosol-generating element. The capsule may contain a second aerosol-generating substrate. The capsule may include at least one capsule air inlet located at an upstream end of the capsule. The capsule may include at least one capsule air outlet located at a downstream end of the capsule.

[0008] According to a first aspect of the present invention, there is provided an aerosol-generating article for generating an inhalable aerosol upon heating. The aerosol-generating article comprises an aerosol-generating element including a first aerosol-generating substrate. The aerosol-generating article comprises a capsule located downstream from the aerosol-generating element, the capsule containing a second aerosol-generating substrate. The capsule includes at least one capsule air inlet located at an upstream end of the capsule and at least one capsule air outlet located at a downstream end of the capsule.

[0009] Providing an aerosol-generating article that includes both a first aerosol-generating substrate and a downstream capsule containing a second aerosol-generating substrate can advantageously enable an extended user experience and aerosol delivery without the technical difficulties described above. In particular, using a capsule to contain the second aerosol-generating substrate can enable the use of a second aerosol-generating substrate that emits aerosol at a lower temperature than prior art aerosol-generating substrates. This may advantageously allow the second aerosol-generating substrate to generate aerosol without the need for larger, more complex heaters and electronics, and without increasing the power consumption of the aerosol-generating device. This may advantageously mean that the size of the aerosol-generating device does not need to be increased to accommodate a larger battery. This may also mean that a user may be able to use the device more times before recharging the aerosol-generating device's battery. Additionally, providing a capsule that includes at least one capsule air inlet and at least one air outlet can mean that the capsule has a relatively low resistance to withdrawal, meaning that the capsule does not act to filter the aerosol generated by the first aerosol-generating substrate.

[0010] Furthermore, the provision of a downstream capsule containing a second aerosol-generating substrate that emits an aerosol at a lower temperature than the prior art aerosol-generating substrate may advantageously allow the aerosol-generating article to be similar in size to prior art aerosol-generating articles, which may further advantageously allow the aerosol-generating article of the present invention to be used in combination with prior art aerosol-generating devices.

[0011] During use, the aerosol-generating article may be inserted into an aerosol-generating device, and the heater of the aerosol-generating device may be activated. The heater of the aerosol-generating device may be positioned to efficiently heat a first aerosol-generating substrate of the aerosol-generating element, thereby generating an aerosol that travels downstream along the interior of the aerosol-generating article. The aerosol from the first aerosol-generating substrate enters the capsule through at least one capsule air inlet, and heat from the aerosol also indirectly heats the second aerosol-generating substrate by convection. The heated second aerosol-generating substrate generates additional aerosol. The aerosol from the first aerosol-generating substrate and the second aerosol-generating substrate leave the capsule through at least one capsule air outlet and then exit the downstream end of the aerosol-generating article.

[0012] As used herein, the term "aerosol-generating article" refers to an article that heats an aerosol-generating substrate to generate an inhalable aerosol for delivery to a consumer. As used herein, the term "aerosol-generating substrate" refers to a substrate that has the ability to release volatile compounds upon heating to generate an aerosol.

[0013] As used herein, the term "aerosol-generating device" refers to a device that includes a heater element that interacts with an aerosol-generating substrate of an aerosol-generating article to generate an aerosol.

[0014] As used herein, the term "longitudinal" refers to a direction corresponding to the main longitudinal axis of the aerosol-generating article or device extending between the upstream and downstream ends of the aerosol-generating article or device. As used herein, the terms "upstream" and "downstream" describe the relative position of an element, or portion of an element, of the aerosol-generating article or device with respect to the direction in which aerosol travels through the aerosol-generating article or device during use.

[0015] During use, air is drawn longitudinally through the aerosol-generating article. The terms "transverse" or "radial" refer to directions perpendicular to the longitudinal axis. Any reference to a "cross section" of an aerosol-generating article or a component of an aerosol-generating article refers to a transverse cross section, unless otherwise specified.

[0016] The term "length" refers to the dimension of a component of an aerosol-generating article in its longitudinal direction. For example, it may be used to refer to the dimension of a rod or elongated tubular element in its longitudinal direction.

[0017] The aerosol-generating elements may have a diameter of at least 3 millimeters. For example, the aerosol-generating elements may have a diameter of at least 4 millimeters, at least 5 millimeters, or at least 6 millimeters.

[0018] The aerosol-generating element may have a diameter of 12 millimeters or less. For example, the aerosol-generating element may have a diameter of 10 millimeters or less, 9 millimeters or less, or 8 millimeters or less.

[0019] The aerosol-generating element may have a diameter of 3 millimeters to 12 millimeters. For example, the aerosol-generating element may have a diameter of 3 millimeters to 10 millimeters, 3 millimeters to 9 millimeters, or 3 millimeters to 8 millimeters.

[0020] The aerosol-generating element may have a diameter of 4 millimeters to 12 millimeters. For example, the aerosol-generating element may have a diameter of 4 millimeters to 10 millimeters, 4 millimeters to 9 millimeters, or 4 millimeters to 8 millimeters.

[0021] The aerosol-generating element may have a diameter of 5 millimeters to 12 millimeters. For example, the aerosol-generating substrate may have a diameter of 5 millimeters to 10 millimeters, 5 millimeters to 9 millimeters, or 5 millimeters to 8 millimeters.

[0022] The aerosol-generating element may have a diameter of 6 millimeters to 12 millimeters. For example, the aerosol-generating element may have a diameter of 6 millimeters to 10 millimeters, 6 millimeters to 9 millimeters, or 6 millimeters to 8 millimeters.

[0023] The aerosol-generating element may have a diameter of 3.7 millimeters to 9 millimeters, 5.7 millimeters to 7.9 millimeters, or 6 millimeters to 7.5 millimeters.

[0024] In particularly preferred embodiments, the aerosol-generating element may have a diameter of less than about 7.5 millimeters, for example, the aerosol-generating element may have a diameter of about 7.2 millimeters.

[0025] It has generally been observed that the smaller the diameter of the aerosol-generating element, the lower the temperature required to raise the core temperature of the first aerosol-generating substrate, and the more vaporized species that are released from the first aerosol-generating substrate to form the desired amount of aerosol. At the same time, without wishing to be bound by theory, it is understood that the smaller the diameter of the aerosol-generating element, the faster the heat supplied to the aerosol-generating article can penetrate the entire volume of the first aerosol-generating substrate. Nevertheless, if the diameter of the aerosol-generating substrate is too small, the volume-to-surface area ratio of the aerosol-generating substrate becomes unfavorable as the amount of available aerosol-generating substrate decreases.

[0026] Aerosol-generating element diameters within the ranges described herein are particularly advantageous in terms of the balance between energy consumption and aerosol delivery. This advantage is particularly felt when an aerosol-generating article including an aerosol-generating element having a diameter described herein is used in combination with an external heater disposed around the periphery of the aerosol-generating article. Under such operating conditions, it has been observed that less thermal energy is required to achieve a sufficiently high temperature at the core of the aerosol-generating substrate, typically at the core of the article. Therefore, when operating at a lower temperature, the desired target temperature at the core of the first aerosol-generating substrate can be achieved within a desirably reduced time frame and with less energy consumption.

[0027] The aerosol-generating element may have a diameter approximately equal to the outer diameter of the aerosol-generating article.

[0028] The aerosol-generating element may have a length of 80 millimeters or less. For example, the aerosol-generating element may have a length of 65 millimeters or less, 60 millimeters or less, 55 millimeters or less, 50 millimeters or less, 40 millimeters or less, 35 millimeters or less, 25 millimeters or less, 20 millimeters or less, or 15 millimeters or less.

[0029] The aerosol-generating element may have any length. The aerosol-generating element may have a length of at least 5 millimeters, at least 7 millimeters, at least 10 millimeters, or at least 12 millimeters.

[0030] The aerosol-generating element may have a length of 5 mm to 80 mm. For example, the aerosol-generating element may have a length of 5 mm to 65 mm, 5 mm to 60 mm, 5 mm to 55 mm, 5 mm to 50 mm, 5 mm to 40 mm, 5 mm to 35 mm, 5 mm to 25 mm, 5 mm to 20 mm, or 5 mm to 15 mm.

[0031] The aerosol-generating element may have a length of 7 mm to 80 mm. For example, the aerosol-generating element may have a length of 7 mm to 65 mm, 7 mm to 60 mm, 7 mm to 55 mm, 7 mm to 50 mm, 7 mm to 40 mm, 7 mm to 35 mm, 7 mm to 25 mm, 7 mm to 20 mm, or 7 mm to 15 mm.

[0032] The aerosol-generating element may have a length of 5 mm to 80 mm. For example, the aerosol-generating element may have a length of 10 mm to 65 mm, 10 mm to 60 mm, 10 mm to 55 mm, 10 mm to 50 mm, 10 mm to 40 mm, 10 mm to 35 mm, 10 mm to 25 mm, 10 mm to 20 mm, or 10 mm to 15 mm.

[0033] The aerosol-generating element may have a length of 5 mm to 80 mm. For example, the aerosol-generating element may have a length of 12 mm to 65 mm, 12 mm to 60 mm, 12 mm to 55 mm, 12 mm to 50 mm, 12 mm to 40 mm, 12 mm to 35 mm, 12 mm to 25 mm, 12 mm to 20 mm, or 12 mm to 15 mm.

[0034] Preferably, the aerosol-generating element may have a length of about 16 millimeters, or about 11.5 millimeters.

[0035] Providing an aerosol-generating element with a length within the above range can prevent the upstream end of the aerosol-generating element from heating to a temperature significantly higher than the downstream end of the aerosol-generating element. This, in turn, can prevent less volatile components, such as the aerosol former, from condensing in the downstream portion of the aerosol-generating element during use. This can advantageously help to deliver a consistent aerosol to the user that contains the correct proportion of volatile components from the first aerosol-generating substrate.

[0036] The aerosol-generating element may have a density of 1 gram per cubic centimeter or less. For example, the aerosol-generating element may have a density of 0.5 grams per cubic centimeter or 0.7 grams per cubic centimeter.

[0037] As used herein, the "density" of an aerosol-generating element refers to the mass of the aerosol-generating element divided by the volume taken up by the aerosol-generating element when it is in an aerosol-generating article. The "mass" of the aerosol-generating element includes the mass of the aerosol-generating substrate and any packaging material surrounding the first aerosol-generating substrate. The "volume" taken up by the aerosol-generating element includes the volume of the first aerosol-generating substrate and the volume of any packaging material surrounding the aerosol-generating substrate.

[0038] In preferred embodiments, the aerosol-generating element may have a density of 0.45 grams per cubic centimeter or less, 0.4 grams per cubic centimeter or less, 0.34 grams per cubic centimeter or less, 0.3 grams per cubic centimeter or less, or 0.25 grams per cubic centimeter or less.

[0039] The aerosol-generating element may have a density of at least 0.1 grams per cubic centimeter. For example, the aerosol-generating substrate may have a density of at least 0.15 grams per cubic centimeter, at least 0.2 grams per cubic centimeter, or at least 0.24 grams per cubic centimeter.

[0040] The aerosol-generating element may have a density of 0.1 grams per cubic centimeter to 0.45 grams per cubic centimeter. For example, the aerosol-generating element may have a density of 0.1 grams per cubic centimeter to 0.4 grams per cubic centimeter, 0.1 grams per cubic centimeter to 0.34 grams per cubic centimeter, 0.1 grams per cubic centimeter to 0.3 grams per cubic centimeter, or 0.1 grams per cubic centimeter to 0.34 grams per cubic centimeter.

[0041] The aerosol-generating elements may have a density of 0.15 grams per cubic centimeter to 0.45 grams per cubic centimeter. For example, the aerosol-generating elements may have a density of 0.15 grams per cubic centimeter to 0.4 grams per cubic centimeter, 0.15 grams per cubic centimeter to 0.34 grams per cubic centimeter, 0.15 grams per cubic centimeter to 0.3 grams per cubic centimeter, or 0.15 grams per cubic centimeter to 0.34 grams per cubic centimeter.

[0042] The aerosol-generating elements may have a density of 0.2 grams per cubic centimeter to 0.45 grams per cubic centimeter. For example, the aerosol-generating elements may have a density of 0.2 grams per cubic centimeter to 0.4 grams per cubic centimeter, 0.21 grams per cubic centimeter to 0.34 grams per cubic centimeter, 0.2 grams per cubic centimeter to 0.3 grams per cubic centimeter, or 0.2 grams per cubic centimeter to 0.34 grams per cubic centimeter.

[0043] The aerosol-generating element may have a density of 0.24 grams per cubic centimeter to 0.45 grams per cubic centimeter. For example, the aerosol-generating element may have a density of 0.24 grams per cubic centimeter to 0.4 grams per cubic centimeter, 0.24 grams per cubic centimeter to 0.34 grams per cubic centimeter, 0.24 grams per cubic centimeter to 0.3 grams per cubic centimeter, or 0.24 grams per cubic centimeter to 0.34 grams per cubic centimeter.

[0044] Preferably, the aerosol-generating element may have a density of about 0.29 grams per cubic centimeter.

[0045] The capsule may include an outer capsule wall defining an interior cavity containing the aerosol-generating substrate.

[0046] The capsule outer wall may be made of any suitable material. Preferably, the capsule outer wall is made of an impermeable material, most preferably an impermeable polymeric material. This ensures that air does not pass through the capsule outer wall during use, except through holes specifically provided for airflow. Thus, airflow through the capsule during use can be effectively controlled.

[0047] The capsule wall may comprise a polymeric or cellulosic material. For example, the capsule wall may be made of one or more polymers that are compatible with nicotine, including medical-grade polymers such as ALTUGLAS® medical resin polymethyl methacrylate (PMMA), Chevron Phillips K-Resin® styrene butadiene copolymer (SBC), Arkema special performance polymers Pebax®, Rilsan®, and Rilsan® Clear, DOW (Health+™) low-density polyethylene (LDPE), DOW™ LDPE91003, DOW™ LDPE91020 (MFI 2.0; density 923), ExxonMobil™ polypropylene (PP) PP1013H1, PP1014H1, and PP9074MED, Trinseo CALIBRE™ polycarbonate (PC) 2060-SERIES, etc.

[0048] Alternatively, the capsule outer wall may be formed from one or more materials selected from polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), gelatin, and hydroxypropyl methylcellulose (HPMC).

[0049] The capsule is preferably in the form of a spherical cylinder, with the cylindrical portion defined by a cylindrical wall and a rounded, hemispherical end wall at each end of the cylindrical portion. This type of capsule is commonly used in the pharmaceutical industry. Alternatively, the capsule may be spherical or ovoid.

[0050] The capsule is preferably a two-part capsule having two separate parts that fit together to close the capsule and retain the contents. The two separate parts may fit together by a friction fit without the use of an adhesive. Alternatively, an adhesive may be used to seal the two parts together.

[0051] The capsule preferably includes a first part and a second part, the second part having a smaller diameter than the first part so that an end of the second part can be inserted into the open end of the first part to close the capsule.

[0052] In such an embodiment, the outer diameters of the first and second portions of the capsule may be adapted so that only the second portion of the capsule can be received within the hollow tubular element. The outer diameter of the first portion of the capsule is adapted to be larger than the inner diameter of the hollow tubular element so that the first portion of the capsule cannot be received within the hollow tubular element and remains outside the hollow tubular element. Preferably, the second portion of the capsule is held within the hollow tubular element by a friction fit.

[0053] Alternatively, the capsule may be inserted completely into the hollow tubular element, and the outer diameters of the first and second portions of the capsule may be adapted so that the outer diameter of the second portion is smaller than the inner diameter of the hollow tubular element. This provides a space between the second portion of the capsule and the wall of the hollow tubular element, allowing airflow around the second portion of the capsule. Such an arrangement may be beneficial in embodiments where it is desirable to position an air outlet on the cylindrical wall of the capsule, as described below.

[0054] The capsule's internal cavity has a volume of at least 250 cubic millimeters, corresponding to 0.25 millimeters. This corresponds to the capsule's internal volume, or capacity. The capsule's internal cavity preferably has a volume of at least 400 cubic millimeters (0.4 milliliters), more preferably at least 500 cubic millimeters (0.5 milliliters), and even more preferably at least 600 cubic millimeters (0.6 milliliters). The capsule's internal cavity may be less than 2000 cubic millimeters (2 milliliters), or less than 1500 cubic millimeters (1.5 milliliters), or less than 1000 cubic millimeters (1 milliliter). For example, standard capsule sizes 000, 00, 0, 0, 1, 2, and 3 may be suitable.

[0055] The capsules may have any length. The capsules may have a length of at least 10 mm. More preferably, the capsules may have a length of at least 12 mm, more preferably at least 15 mm, and more preferably at least 18 mm. The capsule length is preferably less than 30 mm, more preferably less than 28 mm, and more preferably less than 25 mm. For example, the capsule length may be 10 mm to 30 mm, or 12 mm to 28 mm, or 15 mm to 25 mm, or 18 mm to 25 mm. The capsule length may be approximately 20 mm.

[0056] Preferably, the capsule has a maximum diameter of at least 5 mm, more preferably at least 5.5 mm, more preferably at least 6 mm, more preferably at least 6.5 mm. Preferably, the maximum diameter of the capsule is less than 9 mm, more preferably less than 8.5 mm, more preferably less than 8 mm, more preferably less than 7.5 mm. For example, the maximum diameter of the capsule may be 5 mm to 9 mm, or 5.5 mm to 8.5 mm, or 6 mm to 6 mm, or 6.5 mm to 7.5 mm. The maximum diameter of the capsule may be about 7 mm.

[0057] The ratio between the length of the capsule and the length of the aerosol-generating element may be at least 1.

[0058] For example, the ratio of the capsule length to the aerosol-generating element length can be at least 1, at least 1.25, at least 1.5, at least 1.75, at least 2, or at least 2.25.

[0059] The ratio of the length of the aerosol-generating element to the length of the capsule may be 3 or less.

[0060] Because the first aerosol-generating substrate may have a higher density than the second aerosol-generating substrate, it may be advantageous for the capsule to be longer than the aerosol-generating elements. If there is a need to provide a similar amount of first aerosol-generating substrate to the second aerosol-generating substrate, this may be achieved by providing a capsule that is longer than the aerosol-generating elements.

[0061] For example, the ratio of the capsule length to the aerosol-generating element length may be 2.75 or less, 2.5 or less, 2.25 or less, 2 or less, 1.75 or less.

[0062] The length of the capsule may be the same as the length of the aerosol-generating element.The length of the aerosol-generating element may be the same as the length of the capsule.

[0063] The capsule may include multiple capsule air inlets, for example, 2 to 6 capsule air inlets.

[0064] The capsule may include multiple capsule air outlets. For example, the capsule may include 2 to 6 capsule air outlets. The number of capsule air outlets may be the same as or different from the number of capsule air inlets.

[0065] The ratio of the number of capsule air inlets to the number of capsule air outlets may be greater than 0.5. For example, the ratio of the number of capsule air inlets to the number of capsule air outlets may be greater than 0.75, greater than 1, greater than 1.25, greater than 1.5, greater than 1.75, or greater than 2.

[0066] The ratio of the number of capsule air inlets to the number of capsule air outlets may be at least one.

[0067] The ratio of the number of capsule air inlets to the number of capsule air outlets may be equal to or less than 2. For example, the ratio of the number of capsule air inlets to the number of capsule air outlets may be equal to or less than 1.75, equal to or less than 1.5, equal to or less than 1.25, equal to or less than 1, equal to or less than 0.75, or equal to or less than 0.5.

[0068] Since the capsule air outlets must allow aerosol generated within the capsule to pass from the capsule into the hollow tubular element, it may be advantageous to provide more capsule air outlets than capsule air inlets.

[0069] It may be advantageous to provide more capsule air inlets than capsule air outlets because in doing so, the air leaving the capsule is forced to accelerate its exit from the capsule, which may reduce the pressure of the air exiting the capsule which promotes aerosol condensation and nucleation.

[0070] The number and size of the capsule air inlets and capsule air outlets may also be adjusted to control the airflow through the capsule and the resistance to draw (RTD) of the aerosol-generating article. In certain embodiments, the capsule provides the primary source of RTD within the article, and therefore the overall RTD of the aerosol-generating article is likely to be highly dependent on the RTD of the capsule.

[0071] Each capsule air inlet and each capsule air outlet are preferably in the form of holes through the outer capsule wall. Each hole is preferably spherical, although other shapes may also be suitable. The diameter of each hole should be large enough that it cannot be easily blocked, for example, by dust. However, the diameter of each hole should also be adapted to the shape and nature of the solid aerosol-generating substrate so that the solid aerosol-generating substrate is not lost from the internal cavity through the holes.

[0072] Preferably, each hole forming an air inlet or an air outlet has a diameter of at least 0.2 mm, more preferably at least 0.25 mm, more preferably at least 0.3 mm, more preferably at least 0.35 mm, more preferably at least 0.4 mm, and more preferably at least 0.5 mm. The diameter of each hole may be less than 2 mm, or less than 1.8 mm, or less than 1.6 mm, or less than 1.4 mm, or less than 1.2 mm, or less than 1 mm, or less than 0.9 mm, or less than 0.8 mm. For example, the diameter of each hole may be 0.2 mm to 2 mm, or 0.25 mm to 1.8 mm, or 0.3 mm to 1.6 mm, or 0.35 mm to 1.4 mm, or 0.4 mm to 1.2 mm, or 0.45 mm to 1 mm, or 0.5 mm to 0.9 mm, or 0.5 mm to 0.8 mm.

[0073] If multiple capsule air inlets or outlets are provided, the holes should be sufficiently spaced apart so that their presence does not adversely affect the structural integrity of the capsule, e.g., the holes are preferably spaced at least 1 millimeter apart from each other.

[0074] The at least one capsule air outlet is preferably at least 5 mm downstream of the at least one air inlet, more preferably at least 8 mm downstream of the at least one air inlet, and more preferably at least 10 mm downstream of the at least one air inlet, This spacing allows for maximizing the length of the airflow path through the capsule.

[0075] The at least one capsule air outlet is preferably located at the downstream end of the capsule. If the capsule has a conventional capsule shape with an elongated cylindrical body and rounded end walls, the at least one capsule air outlet is preferably provided on the downstream end wall.

[0076] At least one capsule air inlet may be located at the upstream end of the capsule. For example, if the capsule has the conventional capsule shape described above, at least one capsule air inlet may be provided on the upstream end wall. However, in certain embodiments, it may be advantageous to position at least one capsule air inlet a specific distance downstream from the upstream end. For example, at least one capsule air inlet may be provided at least 2 millimeters downstream from the upstream end of the capsule, or at least 3 millimeters downstream from the upstream end of the capsule, or at least 4 millimeters downstream from the upstream end of the capsule, or at least 5 millimeters downstream from the upstream end of the capsule. If multiple capsule air inlets are provided, all of the air inlets should be located at least this distance from the upstream end, even if the positions of the capsule air inlets along the length of the capsule vary.

[0077] In a preferred embodiment, the capsule comprises a cylindrical wall and rounded end walls at the upstream and downstream ends of the cylindrical wall (as in conventional capsule shapes), and at least one capsule air inlet may advantageously be provided in the cylindrical wall downstream of the upstream end wall.

[0078] Locating the at least one capsule air inlet away from the upstream end of the capsule can be particularly beneficial when the solid aerosol-generating substrate is in the form of a gel composition or any other type of substrate that melts or becomes more viscous upon heating. Locating the at least one capsule air inlet away from the upstream end of the cavity where molten substrate may concentrate ensures that the risk of the aerosol-generating substrate leaking from the capsule is minimized. The risk of blockage of the capsule air inlet by the aerosol-generating substrate is also reduced.

[0079] The at least one capsule air outlet may include a plurality of air outlets located at a downstream end of the capsule, the plurality of air outlets being arranged around a circle centered on the longitudinal axis of the capsule, the circle having a diameter smaller than the diameter of the aerosol-generating article.

[0080] The aerosol-generating article may further include a hollow tubular element located downstream from the aerosol-generating element, the capsule being located within the hollow tubular element.

[0081] As used herein, the term "hollow tubular element" refers to a generally elongated element that defines a cavity or airflow passage along its longitudinal axis. In particular, the term "tubular" is used hereinafter with reference to a tubular element that has a substantially cylindrical cross-section and defines at least one airflow conduit 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 cross-sectional shapes) of the tubular element may be possible.

[0082] The hollow tubular element has a capsule containing an aerosol-generating substrate mounted at its upstream end, as described above. Furthermore, the hollow tubular element may have a length greater than the length of the hollow tubular element itself. As a result, the hollow tubular element may define an upstream cavity upstream of the capsule, a downstream cavity downstream of the capsule, or both an upstream cavity and a downstream cavity. In some embodiments, the downstream cavity extends entirely from the capsule to the downstream end of the aerosol-generating article. Alternatively, one or more filter segments may be provided within the hollow tubular element at its downstream end, as described in more detail below.

[0083] The aerosol-generating element may also be disposed within a hollow tubular element, in which case the hollow tubular element may extend to the upstream end of the aerosol-generating article, which may advantageously provide structural support for the aerosol-generating article.

[0084] Where the hollow tubular element extends to the upstream end of the aerosol-generating article, it preferably has a total length of at least 25 millimeters, more preferably at least 28 millimeters, more preferably at least 30 millimeters, more preferably at least 32 millimeters, more preferably at least 34 millimeters. The length of the hollow tubular element may be less than 50 millimeters, or less than 48 millimeters, or less than 45 millimeters, or less than 42 millimeters, or less than 40 millimeters. For example, the total length of the hollow tubular element may be between 25 millimeters and 50 millimeters, or between 28 millimeters and 48 millimeters, or between 30 millimeters and 45 millimeters, or between 32 millimeters and 42 millimeters, or between 34 millimeters and 40 millimeters.

[0085] The hollow tubular element downstream of the aerosol-generation element has a length of at least 10 millimeters, more preferably at least 12 millimeters, and even more preferably at least 14 millimeters. The length of the hollow tubular element downstream of the aerosol-generation element may be up to 40 millimeters, or up to 30 millimeters, or up to 25 millimeters. For example, the hollow tubular element downstream of the aerosol-generation element may have a length of 10 to 40 millimeters, or 12 to 30 millimeters, or 14 to 25 millimeters.

[0086] The capsule may extend to the downstream end of the aerosol-generating article, in which case the downstream end of the capsule may be aligned with the downstream end of the aerosol-generating article.

[0087] The capsule may extend to the downstream end of the aerosol-generating article. In this case, the downstream end of the capsule may be spaced apart from the downstream end of the aerosol-generating article. For example, the downstream end of the capsule may be at least 2 millimeters, at least 5 millimeters, at least 10 millimeters, at least 15 millimeters, at least 20 millimeters, or at least 25 millimeters from the downstream end of the aerosol-generating article.

[0088] Spacing the capsule away from the downstream end of the aerosol-generating article may advantageously allow the capsule to be heated at least to some extent by the aerosol-generating device when the aerosol-generating article is in use. If the capsule extends to the downstream end of the aerosol-generating article, at least a portion of the capsule will be close to the user's lips. This means that the capsule cannot be directly heated by the aerosol-generating device and that the temperature to which the capsule is heated must be limited to avoid discomfort to the user.

[0089] Alternatively, the aerosol-generating element may be located upstream of the upstream end of the hollow tubular element, which may advantageously allow the first aerosol-generating substrate to be heated more easily when the article is used in combination with an external heater, as heat does not have to penetrate the hollow tubular element.

[0090] The upstream end of the hollow tubular element may abut the downstream end of the aerosol-generation element.

[0091] When the aerosol-generating element is located upstream of the upstream end of the hollow tubular element, the hollow tubular element preferably has a total length of at least 10 millimeters, more preferably at least 12 millimeters, and even more preferably at least 14 millimeters. The length of the hollow tubular element may be up to about 40 millimeters, or up to 30 millimeters, or up to 25 millimeters. For example, the hollow tubular element may have a length of 10 millimeters to 40 millimeters, or 12 millimeters to 30 millimeters, or 14 millimeters to 25 millimeters.

[0092] The hollow tubular element may have an outer diameter of 5 millimeters to 12 millimeters, for example 5 millimeters to 10 millimeters, or 6 millimeters to 8 millimeters. In one preferred embodiment, the hollow tubular element has an outer diameter of 7.2 millimeters plus or minus 10 percent.

[0093] The inner diameter of the hollow tubular element is preferably constant along the length of the hollow tubular element. The lumen or cavity of the hollow tubular segment may have any cross-sectional shape. The lumen of the hollow tubular segment may have a circular cross-sectional shape.

[0094] Preferably, the inner diameter of the hollow tubular element is at least 5 millimeters, more preferably at least 5.5 millimeters, more preferably at least 6 millimeters, more preferably at least 6.5 millimeters. The inner diameter of the hollow tubular element is preferably less than 9 millimeters, more preferably less than 8.5 millimeters, more preferably less than 8 millimeters, more preferably less than 7.5 millimeters. For example, the inner diameter may be between 5 millimeters and 9 millimeters, or between 5.5 millimeters and 8.5 millimeters, or between 6 millimeters and 6 millimeters, or between 6.5 millimeters and 7.5 millimeters. The inner diameter may be approximately 7 millimeters.

[0095] The hollow tubular element preferably has a wall thickness of at least 100 micrometers, more preferably at least 150 micrometers, more preferably at least 200 micrometers, more preferably at least 250 micrometers, and more preferably at least 500 micrometers. The wall thickness of the hollow tubular element may be less than 2 millimeters, preferably less than 1.5 millimeters, and even more preferably less than 1.25 mm. The wall thickness of the hollow tubular element may be less than 1 millimeter. For example, the wall thickness of the hollow tubular element may be 100 micrometers to 2 millimeters, or 150 micrometers to 1.5 millimeters, or 200 micrometers to 1.25 millimeters, or 250 millimeters to 1 millimeter, or 500 micrometers to 1 millimeter.

[0096] The hollow tubular segment may comprise a paper-based material. The hollow tubular segment may comprise at least one layer of paper. The paper may be very stiff paper. The paper may be a crimped paper, such as crimped heat-resistant paper or crimped parchment paper. Advantageously, the crimped paper may form one or more air flow channels extending around the exterior of the capsule. One or more air flow channels may be particularly advantageous in embodiments where the capsule includes at least one of an air inlet and an air outlet on the cylindrical wall of the capsule.

[0097] Preferably, the hollow tubular element is formed from cardboard. The hollow tubular element may be a cardboard tube. Advantageously, cardboard is a cost-effective material that provides a balance between being deformable to provide ease of insertion of the article into the aerosol generating device and being sufficiently rigid to provide proper engagement of the article with the interior of the device. Thus, a cardboard tube may provide adequate resistance to deformation or compression during use.

[0098] The hollow tubular segment may be a paper tube. The hollow tubular segment may be a tube formed from spirally wound paper. The hollow tubular segment may be formed from multiple layers of paper. The paper may have a basis weight of at least about 50 grams per square meter, at least about 60 grams per square meter, at least about 70 grams per square meter, or at least about 90 grams per square meter.

[0099] The hollow tubular segment may comprise a polymeric material. For example, the hollow tubular segment may comprise a polymeric film. The polymeric film may comprise a cellulose film. The hollow tubular segment may comprise low-density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. The hollow tube may comprise cellulose acetate tow.

[0100] When the hollow tubular segment comprises cellulose acetate tow, the cellulose acetate tow may have a denier per filament of from about 2 to about 4 and a total denier of from about 25 to about 40.

[0101] The capsule may be disposed within a capsule section of the hollow tubular element, which may extend from the downstream end of the aerosol-generating element to either the downstream end of the aerosol-generating article or the upstream end of the mouthpiece filter, if present.

[0102] The length of the capsule section may be greater than the length of the capsule. The ratio of the length of the capsule section to the length of the capsule may be at least 1.05, at least 1.1, at least 1.3, or at least 1.5.

[0103] The ratio of the length of the capsule section to the length of the capsule may be 2.5 or less, 2.2 or less, 2 or less, 1.8 or less.

[0104] When the length of the capsule section is greater than the length of the capsule, the capsule may be positioned substantially equidistant between the upstream and downstream ends of the capsule section. As described above, this arrangement may result in empty cavities upstream and downstream of the capsule. The empty cavities upstream and downstream of the capsule may act to cool the vapor generated by the first and second aerosol-generating substrates. This may advantageously promote aerosol condensation and nucleation, which facilitates aerosol generation.

[0105] The hollow tubular element may include at least one stop, such as a flange or protrusion, extending inwardly from the inner surface at the downstream end of the capsule to prevent the capsule from being forced further downstream into the hollow tubular element. For example, the hollow tubular element may include an annular flange extending from the inner surface.

[0106] The hollow tubular element may include both upstream and downstream stops, such as upstream and downstream flanges, to prevent the capsule from moving longitudinally within the capsule section of the hollow tubular element.

[0107] The hollow tubular element may include a first ventilation zone, which may be provided downstream of the downstream end of the aerosol-generation element but upstream of the upstream end of the capsule.

[0108] The hollow tubular element may include a second ventilation zone, which may be provided downstream of the downstream end of the capsule.

[0109] The provision of a first ventilation zone may allow ambient air to be drawn into the hollow tubular element immediately downstream of the aerosol-generating element. The provision of ambient air may facilitate aerosol generation from the first aerosol-generating substrate.

[0110] The upstream end of the first ventilation zone may be located no more than 10 millimeters from the downstream end of the aerosol-generating element.

[0111] The provision of a second ventilation zone may allow ambient air to be drawn into the hollow tubular element immediately downstream of the capsule, which may facilitate aerosol generation from the second aerosol-generating substrate.

[0112] The upstream end of the second ventilation zone may be located no more than 10 millimeters from the downstream end of the capsule.

[0113] "Ventilation zone" features described below refer to optional features of either the first ventilation zone or the second ventilation zone, or both the first and second ventilation zones.

[0114] The ventilation zone may include at least one ventilation perforation. The ventilation zone may include multiple perforations through the hollow tubular element. The ventilation zone may include at least two ventilation perforations. For example, the ventilation zone may include at least two, at least three, at least five, or at least ten ventilation perforations through the hollow tubular element.

[0115] Providing a greater number of ventilation perforations than this may advantageously improve aerosol generation.

[0116] The ventilation zone may include no more than 35 ventilation perforations. For example, the ventilation zone may include no more than 30, no more than 25, no more than 20, or no more than 15 ventilation perforations through the hollow tubular element.

[0117] The plurality of vent perforations can include at least one perforation having a width of 200 micrometers or less. For example, the plurality of vent perforations can include at least one perforation having a width of 175 micrometers or less, 150 micrometers or less, 125 micrometers or less, or 120 micrometers or less.

[0118] The plurality of vent perforations can include at least one perforation having a width of 2 millimeters or less. For example, the plurality of vent perforations can include at least one perforation having a width of 1.5 millimeters or less, 1 millimeter or less, 500 micrometers or less, or 250 micrometers or less.

[0119] The plurality of vent perforations may include at least one perforation having a width of at least 50 micrometers. The plurality of vent perforations may include at least one perforation having a width of at least 50 micrometers. For example, the plurality of vent perforations may include at least one perforation having a width of at least 65 micrometers, at least 80 micrometers, at least 90 micrometers, or at least 100 micrometers.

[0120] The plurality of vent perforations may include at least one perforation having a length of at least 400 micrometers. The plurality of vent perforations may include at least one perforation having a length of 1 millimeter or less. The plurality of vent perforations may form an array of perforations surrounding the hollow tubular element. The ventilation zone may include a porous portion of the hollow tubular element.

[0121] The ventilation level of the aerosol-generating article provided by the ventilation zone may be at least 20 percent.

[0122] The aerosol-generating article may further comprise at least one capsule downstream stop protruding from the inner surface of the hollow tubular element to prevent the capsule from moving further downstream than the at least one capsule downstream stop.

[0123] Providing at least one capsule downstream stop may advantageously help to keep the capsule in place within the hollow tubular element, in particular the at least one capsule downstream stop may advantageously prevent the capsule from moving too far downstream and may prevent the capsule from blocking the ventilation zone and allowing ambient air to enter the hollow tubular element.

[0124] At least one capsule downstream stop may be located upstream of the ventilation zone.

[0125] The at least one capsule downstream stop may be any type of stop. The at least one capsule downstream stop may limit the inner diameter of the hollow tubular element at a certain point. The inner diameter of the hollow tubular element at the at least one capsule downstream stop may be smaller than the outer diameter of the capsule, thereby preventing the capsule from moving further downstream than the at least one capsule downstream stop.

[0126] At least one capsule downstream stop may include an embossed portion of the hollow tubular element that extends into the interior of the hollow tubular element.

[0127] At least one capsule downstream stop may comprise a thicker portion of the hollow tubular element, thereby reducing the inner diameter of the hollow tubular element and preventing the capsule from moving further downstream than the thicker portion.

[0128] At least one capsule downstream stop may comprise a flange attached within the hollow tubular element to prevent the capsule from moving further downstream.

[0129] The aerosol-generating article may further comprise at least one capsule downstream stop protruding from the inner surface of the hollow tubular element to prevent the capsule from moving further upstream than the at least one stop.

[0130] The features of the at least one capsule downstream stop described above may be equally applicable to the at least one capsule upstream stop.

[0131] The aerosol-generating article may further comprise a wrapper surrounding at least the downstream portion of the aerosol-generating element and the upstream portion of the hollow tubular element.

[0132] If the hollow tubular element does not extend further upstream than the upstream end of the capsule section of the hollow tubular element, the provision of a wrapper may advantageously attach the aerosol-generating element to the hollow tubular element. The wrapper may surround the entire length of the aerosol-generating element. This may advantageously provide greater strength and a more secure connection between the aerosol-generating element and the hollow tubular element.

[0133] The wrapper may be attached to one or more of the aerosol-generating element and the hollow tubular element by an adhesive applied between the wrapper and one or more of the aerosol-generating element and the hollow tubular element.

[0134] The aerosol-generating article may further include a thermally conductive element for transferring heat from the aerosol-generating element to the capsule.

[0135] The provision of a thermally conductive element may advantageously allow heat from the aerosol-generating element, which may be heated directly by a heater in the aerosol-generating device, to be efficiently transferred by conduction to the capsule, which may advantageously improve aerosol generation by the second aerosol-generating substrate.

[0136] The thermally conductive element may include a thermally conductive material.

[0137] As used herein in connection with the present invention, the term "thermally conductive material" is used to describe a material that has a bulk thermal conductivity of at least about 10 Watts per meter Kelvin (W / (m K)) at 23°C and a relative humidity of 50% as measured using the modified transient plane heat source (MTPS) method.

[0138] The thermally conductive element may include a metal. For example, the thermal conductor may include at least one of aluminum, steel, nimonic, and inconel. Preferably, the thermally conductive element includes aluminum.

[0139] The thermally conductive element may be provided within the hollow tubular element.The thermally conductive element may be provided on the outer surface of the hollow tubular element.

[0140] The thermally conductive element may include a portion of a wrapper formed from a thermally conductive material.

[0141] The thermally conductive element may include a metal foil surrounding at least a portion of the aerosol-generating element and a portion of the capsule.

[0142] The thermally conductive element may comprise a rod or pin of thermally conductive material extending from the aerosol-generating element to the capsule. The thermally conductive element may extend into the capsule.

[0143] The outer diameter of the capsule may be approximately the same as the inner diameter of the hollow tubular element so that air cannot pass from the upstream end of the hollow tubular element to the downstream end of the hollow tubular element without passing through the capsule.

[0144] In this way, air is substantially prevented from passing from the upstream end of the hollow tubular element to the downstream end of the hollow tubular element without passing through the capsule.

[0145] Without wishing to be bound by theory, it is expected that the airflow through the aerosol-generating article slows down significantly as the air exits the capsule through the at least one capsule air outlet and enters the interior of the hollow tubular element. This is because the diameter of the hollow tubular element is larger than the diameter of the at least one capsule air outlet. This slowing down of the airflow is also a pressure reduction that can further facilitate the desired nucleation of aerosols. In addition, the slowing down of the airflow can also improve cooling of the airflow by ambient air entering through the ventilation zone. This can advantageously further facilitate aerosol generation.

[0146] The capsule's internal cavity preferably contains at least 50 milligrams of the second aerosol-generating substrate, more preferably at least 100 milligrams, and even more preferably at least 150 milligrams. The capsule's internal cavity may contain up to 1000 milligrams of the second aerosol-generating substrate, or up to 750 milligrams of the second aerosol-generating substrate, or up to 500 milligrams of the second aerosol-generating substrate, or up to 250 milligrams of the second aerosol-generating substrate. For example, the capsule's internal cavity may contain 50 milligrams to 1000 milligrams of the second aerosol-generating substrate, or 100 milligrams to 750 milligrams of the second aerosol-generating substrate, or 150 milligrams to 500 milligrams of the second aerosol-generating substrate, or 150 milligrams to 250 milligrams of the second aerosol-generating substrate.

[0147] According to the present invention, the density of the second aerosol-generating substrate within the capsule corresponds to at least 0.1 milligrams per cubic millimeter of the internal cavity. This corresponds to the total weight of the second aerosol-generating substrate divided by the total volume of the internal cavity. Preferably, the density of the second aerosol-generating substrate within the capsule corresponds to at least 0.12 milligrams per cubic millimeter of the internal cavity, more preferably at least 0.15 milligrams per cubic millimeter of the internal cavity, more preferably at least 0.18 milligrams per cubic millimeter of the internal cavity, more preferably at least 0.2 milligrams per cubic millimeter, more preferably at least 0.22 milligrams per cubic millimeter, more preferably at least 0.25 milligrams per cubic millimeter, more preferably at least 0.28 milligrams per cubic millimeter, more preferably at least 0.3 milligrams per cubic millimeter, more preferably at least 0.32 milligrams per cubic millimeter, more preferably at least 0.35 milligrams per cubic millimeter, more preferably at least 0.38 milligrams per cubic millimeter, and more preferably at least 0.4 milligrams per cubic millimeter. Preferably, the density of the second aerosol-generating substrate within the capsule corresponds to less than 2 milligrams per cubic millimeter of the internal cavity, more preferably less than 1.9 milligrams per cubic millimeter, more preferably less than 1.8 milligrams per cubic millimeter, more preferably less than 1.7 milligrams per cubic millimeter, more preferably less than 1.6 milligrams per cubic millimeter, more preferably less than 1.5 milligrams per cubic millimeter, more preferably less than 1.4 milligrams per cubic millimeter, more preferably less than 1.3 milligrams per cubic millimeter, more preferably less than 1.2 milligrams per cubic millimeter, more preferably less than 1.1 milligrams per cubic millimeter, more preferably less than 1 milligram per cubic millimeter.For example, the density of the second aerosol-generating substrate within the capsule may be between 0.1 milligrams per cubic millimeter and 2 milligrams per cubic millimeter within the internal cavity, or between 0.12 milligrams per cubic millimeter and 1.9 milligrams per cubic millimeter within the internal cavity, or between 0.15 milligrams per cubic millimeter and 1.8 milligrams per cubic millimeter within the internal cavity, or between 0.18 milligrams per cubic millimeter and 1.7 milligrams per cubic millimeter within the internal cavity, or between 0.2 milligrams per cubic millimeter and 1.6 milligrams per cubic millimeter within the internal cavity, or between 0.22 milligrams per cubic millimeter and 1.5 milligrams per cubic millimeter within the internal cavity, or between 0.25 milligrams per cubic millimeter and 1.6 milligrams per cubic millimeter within the internal cavity. This may correspond to milligrams / cubic millimeter to 1.4 milligrams / cubic millimeter, or 0.28 milligrams / cubic millimeter to 1.3 milligrams / cubic millimeter of the internal cavity, or 0.3 milligrams / cubic millimeter to 1.2 milligrams / cubic millimeter of the internal cavity, or 0.32 milligrams / cubic millimeter to 1.1 milligrams / cubic millimeter of the internal cavity, or 0.35 milligrams / cubic millimeter to 1 milligram / cubic millimeter of the internal cavity, or 0.38 milligrams / cubic millimeter to 1 milligram / cubic millimeter of the internal cavity, or 0.4 milligrams / cubic millimeter to 1 milligram / cubic millimeter of the internal cavity.

[0148] The fill rate of the capsule with the second aerosol-generating substrate is preferably at least 50 percent, more preferably at least 60 percent, and even more preferably at least 70 percent. The fill rate is preferably less than 90 percent. The fill rate corresponds to the percentage of the capsule's internal cavity that is occupied by the second aerosol-generating substrate. It may be advantageous to retain some empty space within the internal cavity to allow airflow through the internal cavity and to allow for even heating of the second aerosol-generating substrate.

[0149] The first and second aerosol-generating substrates may be configured to generate first and second aerosols, respectively, upon heating.

[0150] The first aerosol and the second aerosol can be the same aerosol. The first aerosol and the second aerosol can be different aerosols.

[0151] The temperature at which the second aerosol-generating substrate generates the aerosol may be lower than the temperature at which the first aerosol-generating substrate generates the aerosol.

[0152] The first aerosol-generating substrate is capable of generating an aerosol when the first aerosol-generating substrate is heated above a first temperature, and the second aerosol-generating substrate is capable of generating an aerosol when the second aerosol-generating substrate is heated above a second temperature.

[0153] The first temperature may be higher than the second temperature, for example, the first temperature may be at least 5 degrees Celsius, at least 10 degrees Celsius, at least 20 degrees Celsius, at least 30 degrees Celsius, or at least 50 degrees Celsius higher than the second temperature.

[0154] The first and second temperatures may both be higher than ambient temperature. The first and second temperatures may both be higher than room temperature. The first and second temperatures may both be higher than 20 degrees Celsius, 30 degrees Celsius, 35 degrees Celsius, 40 degrees Celsius, 50 degrees Celsius, 60 degrees Celsius, or 100 degrees Celsius. The second temperature may be higher than ambient temperature. For example, the second temperature may be higher than 20 degrees Celsius, 30 degrees Celsius, 35 degrees Celsius, 40 degrees Celsius, 50 degrees Celsius, 60 degrees Celsius, or 100 degrees Celsius.

[0155] As mentioned above, this may advantageously allow efficient aerosol generation by the second aerosol-generating substrate even when the second aerosol-generating substrate is not directly heated by the heater of the aerosol-generating device.

[0156] The aerosol-generating article may further include a downstream filter segment located downstream of the capsule, the downstream filter segment comprising a filter material.

[0157] Where the hollow tubular element extends to the downstream end of the aerosol-generating article, the downstream filter segment may comprise a segment of filter material mounted within the hollow tubular element at the downstream end of the hollow tubular segment.

[0158] In this case, the segment of filter material preferably has an outer diameter approximately equal to the inner diameter of the hollow tubular element so that the segment of filter material is retained within the hollow tubular element by a friction fit.

[0159] Preferably, the outer diameter of the downstream filter segment is between 5 mm and 12 mm, more preferably between 6 mm and 10 mm, more preferably between 7 mm and 8 mm.

[0160] The filter segment may extend to the downstream end of the hollow tubular element.

[0161] The downstream end of the downstream filter segment may define the downstream end of the aerosol-generating article. The inclusion of a downstream filter segment can be useful for providing a desired level of RTD in the aerosol-generating article.

[0162] The filter material of the downstream filter segment is preferably a solid plug, which may also be described as a "plain" plug, and is non-tubular. Thus, the filter material preferably has a substantially uniform cross-section.

[0163] The filter material is preferably formed of a fibrous filter material. The fibrous filter material may be for filtering aerosols generated from the first and second aerosol-generating substrates. Suitable fibrous filter materials will be known to those skilled in the art. It is particularly preferred that the filter material comprises cellulose acetate tow.

[0164] The downstream filter segment may optionally include a flavoring agent, which may be provided in any suitable form, for example, the downstream filter segment may comprise one or more capsules, beads, or granules of flavoring agent, or one or more flavor-loaded threads or filaments.

[0165] The downstream filter segment preferably has a low particle filtration efficiency.

[0166] Unless otherwise specified, the resistance to draw (RTD) of a component or aerosol-generating article is measured in accordance with ISO 6565-2015. RTD refers to the pressure required to force air through the entire length of the component. The terms "pressure drop" or "draw resistance" of a component or article can also refer to "resistance to draw." These terms generally refer to measurements in accordance with ISO 6565-2015 being performed successfully under test conditions of 22 degrees Celsius, 101 kPa (approximately 760 Torr), and 60% relative humidity, with a volumetric flow rate of 17.5 milliliters per second at the output or downstream end of the measured component. Smoking conditions and smoking machine specifications are provided in ISO Standard 3308 (ISO 3308:2000). Conditioning and testing atmospheres are provided in ISO Standard 3402 (ISO 3402:1999).

[0167] The resistance to draw (RTD) of the downstream filter segment may be at least 0 millimeters of H2O, or at least 3 millimeters of H2O, or at least 6 millimeters of H2O.

[0168] The RTD of the downstream filter segment may be 12 millimeters H2O or less, or 11 millimeters H2O or less, or 10 millimeters H2O or less.

[0169] As described above, the downstream filter segment can be formed from a fibrous filtration material. The downstream filter segment can be formed from a porous material. The downstream filter segment can be formed from a biodegradable material. The downstream filter segment can be formed from a cellulose material, such as cellulose acetate. For example, the downstream filter segment can be formed from a bundle of cellulose acetate fibers having 10-15 denier per filament. For example, the downstream filter segment can be formed from a relatively low density cellulose acetate tow, such as a cellulose acetate tow containing 12 denier fibers per filament.

[0170] The downstream filter segment may be formed of a polylactic acid-based material. The downstream filter segment may be formed of a bioplastic material, preferably a starch-based bioplastic material. The downstream filter segment may be fabricated by injection molding or extrusion. Bioplastic-based materials are advantageous because they can provide a downstream filter segment structure that is simple and inexpensive to manufacture, with a particular complex cross-sectional profile that may include multiple relatively large airflow channels extending through the downstream filter segment material, providing favorable RTD characteristics.

[0171] The length of the downstream filter segment may be at least 5 millimeters, or at least 8 millimeters, or at least 10 millimeters. The length of the downstream filter segment may be less than 20 millimeters, or less than 15 millimeters, or less than 12 millimeters. For example, the length of the downstream filter segment may be between 5 millimeters and 20 millimeters, or between 8 millimeters and 15 millimeters, or between 8 millimeters and 12 millimeters, or between 10 millimeters and 12 millimeters.

[0172] In alternative embodiments of the present invention, a downstream filter segment may be provided downstream of the hollow tubular element. The downstream filter segment may extend between the hollow tubular element and the downstream end of the aerosol-generating article. In such embodiments, the downstream filter segment may be connected to the hollow tubular element by a tipping wrapper.

[0173] The overall RTD of the aerosol-generating article may be at least 1 millimeter of H O. For example, the overall RTD of the aerosol-generating article may be at least 2 millimeters of H O, at least 3 millimeters of H O, at least 4 millimeters of H O, at least 5 millimeters of H O, at least 6 millimeters of H O, at least 7 millimeters of H O, at least 8 millimeters of H O, at least 9 millimeters of H O, at least 10 millimeters of H O, at least 15 millimeters of H O, at least 20 millimeters of H O, at least 30 millimeters of H O, at least 40 millimeters of H O, or at least 50 millimeters of H O.

[0174] The overall RTD of the aerosol-generating article may be 180 millimeters HO or less. For example, the overall RTD of the aerosol-generating article may be 170 millimeters HO or less, 160 millimeters HO or less, 150 millimeters HO or less, or 140 millimeters HO or less.

[0175] The overall RTD of the aerosol-generating article may be between 1 millimeter HO and 180 millimeter HO. For example, the overall RTD of the aerosol-generating article may be between 5 millimeter HO and 170 millimeter HO, between 10 millimeter HO and 160 millimeter HO, between 20 millimeter HO and 150 millimeter HO, or between 50 millimeter HO and 140 millimeter HO.

[0176] Aerosol-generating articles according to the invention may have an overall length of at least 40 millimetres, or at least 50 millimetres, or at least 60 millimetres.

[0177] Aerosol-generating articles of the present invention may have an overall length of 90 millimeters or less, 85 millimeters or less, or 80 millimeters or less.

[0178] In some embodiments, the total length of the aerosol-generating article is preferably between 40 millimeters and 70 millimeters, more preferably between 45 millimeters and 70 millimeters. In other embodiments, the total length of the aerosol-generating article is preferably between 40 millimeters and 60 millimeters, more preferably between 45 millimeters and 60 millimeters. In further embodiments, the total length of the aerosol-generating article is preferably between 40 millimeters and 50 millimeters, more preferably between 45 millimeters and 50 millimeters. In an exemplary embodiment, the total length of the aerosol-generating article is about 45 millimeters.

[0179] The aerosol-generating article may have an outer diameter of at least 5 millimeters, at least 6 millimeters, or at least 7 millimeters.

[0180] The aerosol-generating article may have an outer diameter of about 12 millimeters or less, about 10 millimeters or less, or about 8 millimeters or less.

[0181] In some embodiments, the aerosol-generating article has an outer diameter of about 5 millimeters to about 12 millimeters, preferably about 6 millimeters to about 12 millimeters, and more preferably about 7 millimeters to about 12 millimeters. In other embodiments, the aerosol-generating article has an outer diameter of about 5 millimeters to about 10 millimeters, preferably about 6 millimeters to about 10 millimeters, and more preferably about 7 millimeters to about 10 millimeters. In further embodiments, the aerosol-generating article has an outer diameter of about 5 millimeters to about 8 millimeters, preferably about 6 millimeters to about 8 millimeters, and more preferably about 7 millimeters to about 8 millimeters. In other embodiments, the aerosol-generating article has an outer diameter of less than 7 millimeters.

[0182] The outer diameter of the aerosol-generating article may be substantially constant along the entire length of the article. Alternatively, different portions of the aerosol-generating article may have different outer diameters.

[0183] The aerosol-generating element may further include a susceptor element.

[0184] As used herein, the term "susceptor element" refers to an element comprising a material capable of converting electromagnetic energy into heat. When the susceptor element is positioned within an alternating electromagnetic field, the susceptor is heated. Heating of the susceptor element can be the result of at least one of hysteresis losses and eddy currents induced within the susceptor, depending on the electrical and magnetic properties of the susceptor material. An aerosol-generating article according to the present invention may be used with an aerosol-generating device including an induction coil for inducing electrical currents within corresponding susceptor elements within the aerosol-generating element.

[0185] The susceptor element can be positioned such that when an aerosol-generating article is received within the cavity of the aerosol-generating device, the oscillating electromagnetic field generated by the inductor coil induces current flow in the susceptor element, heating the susceptor element. In these embodiments, the aerosol-generating device is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of 1 to 5 kiloamperes per meter (kA / m), preferably 2 to 3 kA / m, e.g., about 2.5 kA / m. Electrically operated aerosol-generating devices are preferably capable of generating a fluctuating electromagnetic field having a frequency of 1 to 30 MHz, e.g., 1 to 10 MHz, e.g., 5 to 7 MHz.

[0186] The susceptor element is preferably located in contact with the first aerosol-generating substrate. The susceptor element may be located within the first aerosol-generating substrate.

[0187] In some embodiments, the susceptor element is arranged to heat the outer surface of the first aerosol-generating substrate, hi some embodiments, the susceptor element is arranged to be inserted into the first aerosol-generating substrate when the aerosol-generating substrate is received in the cavity.

[0188] The susceptor elements may comprise any suitable material. They may be formed from any material that can be inductively heated to a temperature sufficient to release volatile compounds from the aerosol-generating substrate. Suitable materials for the elongated susceptor elements include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium, and composites of metallic materials. Some susceptor elements comprise metal or carbon. Advantageously, the susceptor elements may comprise or consist of ferromagnetic materials, such as ferritic iron, ferromagnetic steel, or stainless steel, ferromagnetic alloys, ferromagnetic particles, and ferrites. Suitable susceptor elements may be or contain aluminum. The susceptor elements preferably comprise more than about 5 percent, preferably more than about 20 percent, and more preferably more than about 50 percent or more than about 90 percent ferromagnetic or paramagnetic material. Some elongated susceptor elements may be heated to temperatures greater than about 250 degrees Celsius.

[0189] The susceptor element may comprise a non-metallic core having a metallic layer disposed thereon, for example, the susceptor element may include a ceramic core or metallic tracks formed on the outer surface of the substrate.

[0190] The susceptor element may extend the entire length of the aerosol-generating element.

[0191] In other words, the upstream end of the susceptor element may be aligned with the upstream end of the aerosol-generation element, and the downstream end of the susceptor element may be aligned with the downstream end of the aerosol-generation element.

[0192] Providing a susceptor element that extends the entire length of the aerosol-generating element may advantageously ensure maximum aerosol generation of the first aerosol-generating substrate.

[0193] The first aerosol-generating substrate may be a solid aerosol-generating substrate.

[0194] The first aerosol-generating substrate may comprise homogenized plant material.The first aerosol-generating substrate may comprise tobacco.The first aerosol-generating substrate may comprise homogenized tobacco material.

[0195] 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 an aerosol-generating 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.

[0196] The homogenized plant material can be provided in any suitable form.

[0197] For example, the homogenized plant material may be in the form of one or more sheets. As used herein in connection with the present invention, the term "sheet" describes a laminar element having a width and length that substantially exceeds its thickness.

[0198] The homogenized plant material may be in the form of a plurality of pellets or granules.

[0199] The homogenized plant material may be in the form of multiple 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 morphology. 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.

[0200] In some embodiments, the strands may be formed in situ within the first aerosol-generating substrate as a result of splitting or breaking down the sheet of homogenized plant material during the formation of the aerosol-generating substrate, e.g., as a result of crimping. The strands of homogenized plant material within the first aerosol-generating substrate may be separated from one another. Alternatively, each strand of homogenized plant material within the first aerosol-generating substrate may be at least partially connected to an adjacent strand or strands along its 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 a sheet of homogenized plant material during the manufacture of the aerosol-generating substrate, as described above.

[0201] When the first aerosol-generating substrate comprises homogenized plant material, the homogenized plant material may typically be provided in the form of one or more sheets. In particular, the sheets of homogenized plant material may be produced by a casting process. Preferably, the sheets of homogenized plant material may be produced by a papermaking process.

[0202] The first aerosol-generating substrate may comprise a cut filler.The first aerosol-generating substrate may comprise a cut tobacco filler.

[0203] As used herein, the term "cut filler" is used to specifically describe a blend of shredded plant material, such as tobacco plant material, including one or more of leaf blades, processed stems and veins, and homogenized plant material.

[0204] The cut filler may include other aftercuts, filler tobacco, or casings.

[0205] Preferably, the cut filler comprises at least 25 percent of the plant leaf blades, more preferably at least 50 percent of the plant leaf blades, even more preferably at least 75 percent of the plant leaf blades, and most preferably at least 90 percent of the plant leaf blades. Preferably, the plant material is one of tobacco, mint, tea, and cloves. However, the present invention is equally applicable to other plant materials capable of releasing, upon heating, a substance capable of subsequently forming an aerosol, as described in more detail below.

[0206] Preferably, the cut filler comprises tobacco plant material including the blades of one or more of bright tobacco, dark tobacco, aromatic tobacco, and filler tobacco. For purposes of the present invention, the term "tobacco" describes any plant of the genus Nicotiana.

[0207] Bright tobacco is generally a tobacco with large, light-colored leaves. Throughout this specification, the term "bright tobacco" is used to refer to flue-cured tobacco. Examples of bright tobacco include Chinese flue-cured tobacco, Brazilian flue-cured tobacco, American flue-cured tobacco (such as Virginia tobacco), Indian flue-cured tobacco, Tanzanian flue-cured tobacco, or other African flue-cured tobacco. Bright tobacco is characterized by a high sugar-to-nitrogen ratio. From a sensory perspective, bright tobacco is a tobacco type that, after curing, has a spicy, lively sensation. In the context of the present invention, bright tobacco is tobacco having a reducing sugar content of about 2.5 percent to about 20 percent based on dry weight of the leaf and a total ammonia content of less than about 0.12 percent based on dry weight of the leaf. Reducing sugars include, for example, glucose or fructose. Total ammonia includes, for example, ammonia and ammonia salts.

[0208] Dark tobacco is generally tobacco with large, dark-colored leaves. Throughout this specification, the term "dark tobacco" is used to refer to air-cured tobacco. Additionally, dark tobacco may be fermented. This category also includes tobaccos primarily used for chewing tobacco, snuff, cigars, and pipe blends. Typically, these dark tobaccos are air-cured and, in some cases, fermented. From a sensory perspective, dark tobacco is a tobacco type associated with a smoky, dark cigar-type sensation after curing. Dark tobacco is characterized by a low sugar-to-nitrogen ratio. Examples of dark tobacco are Malawi or other African burley, dark-cured Brazilian galpao, san-cured, or air-cured Indonesian kasturi. According to the present invention, dark tobacco is tobacco with a reducing sugar content of less than about 5 percent based on dry weight of the leaf and a total ammonia content of about 0.5 percent or less based on dry weight of the leaf.

[0209] Aromatic tobaccos are often tobaccos with small, light-colored leaves. Throughout this specification, the term "aromatic tobacco" is used in contrast to other tobaccos with a high aromatic content, e.g., essential oil content. From a sensory perspective, aromatic tobaccos are tobacco types associated with a spicy and fragrant sensation after curing. Examples of aromatic tobaccos include Greek Orient, Turkish Orient, and Semi-Orient tobaccos, as well as fire-cured, US Burley (e.g., Perique), Rustica, US Burley, or Maryland. Filler tobacco is not a specific tobacco type, but includes tobacco types used in blends and primarily to complement other tobacco types that do not contribute a specific characteristic aroma direction to the final product. Examples of filler tobaccos are the stems, midribs, or petioles of other tobacco types. A specific example would be flue-cured stems of the lower petiole of Brazilian flue-cured petioles.

[0210] The cut filler suitable for use in the present invention may generally be similar to the cut filler used in conventional smoking articles. The cut width of the cut filler is preferably 0.3 mm to 2.0 mm, more preferably 0.5 mm to 1.2 mm, and most preferably 0.6 mm to 0.9 mm. The cut width may play a role in the distribution of heat within the aerosol-generating element. The cut width may also play a role in the resistance to draw (RTD) of the article. Furthermore, the cut width may affect the overall density of the aerosol-generating substrate as a whole.

[0211] Because the length of the strands depends on the overall size of the object from which they are cut, the strand length of the cut filler is somewhat random. Nevertheless, longer strands can be cut by conditioning the material before cutting, for example, by controlling the moisture content and overall fineness of the material. Preferably, the strands have a length of about 10 millimeters to about 40 millimeters, and the strands are then bundled together to form the aerosol-generating element. Obviously, if the strands are longitudinally arranged in an aerosol-generating element with a longitudinal extension of less than 40 millimeters, the final aerosol-generating element may have strands that are, on average, shorter than the initial strand length. Preferably, the strand length of the cut filler is such that about 20 percent to 60 percent of the strands extend along the entire length of the aerosol-generating element. This prevents the strands from easily falling off the aerosol-generating element.

[0212] The first aerosol-generating substrate may contain any amount of cut filler, for example, at least 80 milligrams of cut filler, at least 100 milligrams of cut filler, at least 150 milligrams of cut filler, or at least about 170 milligrams of cut filler.

[0213] The first aerosol-generating substrate may contain 400 milligrams or less of cut filler. For example, the first aerosol-generating substrate may contain 300 milligrams or less of cut filler, 250 milligrams or less of cut filler, or 220 milligrams or less of cut filler.

[0214] The first aerosol-generating substrate may contain 80 milligrams to 400 milligrams of cut filler. For example, the first aerosol-generating substrate may contain 100 milligrams to 300 milligrams of cut filler, 150 milligrams to 250 milligrams of cut filler, or 170 milligrams to 220 milligrams of cut filler.

[0215] Preferably, the first aerosol-generating substrate may contain about 200 milligrams of cut filler. This amount of cut filler typically allows for sufficient material for the formation of an aerosol. In addition, given the aforementioned constraints on diameter and size, this allows for a balance of the density of the aerosol-generating element between the energy uptake, the RTD, and the fluid path of the aerosol-generating element where the aerosol-generating substrate contains plant material.

[0216] The first aerosol-generating substrate may comprise at least one of shredded tobacco material, cast leaf tobacco material, homogenized tobacco material, tobacco cut filler, or reconstituted tobacco material.

[0217] The first aerosol-generating substrate may include at least one aerosol former.

[0218] When the first aerosol-generating substrate includes a cut filler, the cut filler may be immersed in the aerosol former. The immersion of the cut filler may be achieved by spraying or other suitable application methods. The aerosol former may be added to the blend during preparation of the cut filler. For example, the aerosol former may be applied to the blend in a direct conditioning casing cylinder (DCCC). Conventional machinery may be used to add the aerosol former to the cut filler. The aerosol former may be any suitable known compound or mixture of compounds that promotes the formation of a dense, stable aerosol during use. The aerosol former may promote the aerosol to be substantially resistant to thermal decomposition at temperatures typically encountered during use of the aerosol-generating article. Suitable aerosol formers are, for example, polyhydric alcohols (such as triethylene glycol, 1,3-butanediol, propylene glycol, and glycerin), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate), aliphatic esters of monocarboxylic, dicarboxylic, or polycarboxylic acids (such as dimethyl dodecanedioate and dimethyl tetradecanedioate), and combinations thereof.

[0219] The aerosol former preferably comprises one or more of glycerin and propylene glycol. The aerosol former may consist of glycerin, or propylene glycol, or a combination of glycerin and propylene glycol.

[0220] The first aerosol-generating substrate may contain any amount of aerosol formers, for example, the aerosol-generating substrate may contain at least 5 weight percent aerosol formers, at least 6 weight percent aerosol formers, at least 8 weight percent aerosol formers, or at least 10 weight percent aerosol formers.

[0221] The first aerosol-generating substrate may comprise 20 percent or less of aerosol formers. For example, the aerosol-generating substrate may comprise 18 percent or less of aerosol formers, or 15 percent or less of aerosol formers.

[0222] The first aerosol-generating substrate may contain between 5 percent and 20 percent aerosol formers by weight. For example, the first aerosol-generating substrate may contain between 6 percent and 18 percent aerosol formers by weight, between 8 percent and 15 percent aerosol formers by weight, or between 10 percent and 15 percent aerosol formers by weight.

[0223] Preferably, the first aerosol-generating substrate comprises about 13 weight percent aerosol former, the weight percentage of aerosol former being provided based on the dry weight of the cut filler.

[0224] The most effective amount of aerosol former also depends on the cut filler and whether the cut filler comprises plant blades or homogenized plant material. For example, the type of cut filler, among other factors, determines the extent to which the aerosol former can facilitate release of material from the cut filler.

[0225] The second aerosol-generating substrate may comprise a solid aerosol-generating substrate.

[0226] The second aerosol-generating substrate may comprise at least one aerosol former.

[0227] The second aerosol-generating substrate may comprise nicotine.

[0228] The second aerosol-generating substrate may be a solid aerosol-generating substrate contained within a capsule. The solid aerosol-generating substrate may comprise nicotine and an aerosol former, but may take a variety of different forms.

[0229] The second aerosol-generating substrate may comprise at least 15 percent by weight of aerosol formers on a dry weight basis. Preferably, the second aerosol-generating substrate comprises at least 20 percent by weight of aerosol formers on a dry weight basis. More preferably, the second aerosol-generating substrate comprises at least 25 percent by weight of aerosol formers on a dry weight basis. More preferably, the second aerosol-generating substrate comprises at least 30 percent by weight of aerosol formers on a dry weight basis. More preferably, the second aerosol-generating substrate comprises at least 35 percent by weight of aerosol formers on a dry weight basis. More preferably, the second aerosol-generating substrate comprises at least 40 percent by weight of aerosol formers on a dry weight basis. More preferably, the aerosol-generating substrate comprises at least 45 percent by weight of aerosol formers on a dry weight basis. More preferably, the second aerosol-generating substrate comprises at least 50 percent by weight of aerosol formers on a dry weight basis.

[0230] More preferably, the second aerosol-generating substrate comprises 80% or less by weight on a dry weight basis. More preferably, the second aerosol-generating substrate comprises 75% or less by weight on a dry weight basis. More preferably, the second aerosol-generating substrate comprises 70% or less by weight on a dry weight basis.

[0231] For example, the second aerosol-generating substrate may provide an aerosol former content of from 15 weight percent to 80 weight percent, or from 20 weight percent to 80 weight percent, or from 25 weight percent to 80 weight percent, or from 30 weight percent to 75 weight percent, or from 35 weight percent to 75 weight percent, or from 40 weight percent to 70 weight percent, or from 45 weight percent to 70 weight percent, or from 50 weight percent to 70 weight percent, on a dry weight basis.

[0232] In certain preferred embodiments, the second aerosol-forming material in the aerosol-generating substrate may be present in an amount of from 40 to 80 percent by weight, or from 45 to 75 percent by weight, or from 50 to 70 percent by weight, on a dry weight basis. In such embodiments, the second aerosol-generating substrate therefore has a relatively high aerosol-forming material content.

[0233] Aerosol formers suitable for inclusion in the second aerosol-generating substrate 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).

[0234] The second aerosol-generating substrate preferably comprises glycerol as an aerosol former.

[0235] The second aerosol-generating substrate further comprises nicotine. As used herein in connection with the present invention, the term "nicotine" is used to describe nicotine, nicotine base, or nicotine salt. In embodiments in which the second aerosol-generating substrate comprises nicotine base or nicotine salt, the amount of nicotine recited herein is the amount of free base nicotine or the amount of protonated nicotine, respectively.

[0236] The second aerosol-generating substrate may comprise natural or synthetic nicotine. The nicotine may comprise one or more nicotine salts. The one or more nicotine salts may be selected from the list consisting of nicotine lactate, nicotine citrate, nicotine pyruvate, nicotine bitartrate, nicotine benzoate, nicotine pectinate, nicotine alginate, and nicotine salicylate.

[0237] The nicotine may comprise an extract of tobacco.

[0238] Preferably, the second aerosol-generating substrate contains at least 0.5 weight percent nicotine on a dry weight basis. More preferably, the second aerosol-generating substrate contains at least 1 weight percent nicotine on a dry weight basis. Even more preferably, the second aerosol-generating substrate contains at least 2 weight percent nicotine on a dry weight basis. Additionally or alternatively, the second aerosol-generating substrate preferably contains less than 10 weight percent nicotine on a dry weight basis. More preferably, the second aerosol-generating substrate contains less than 8 weight percent nicotine on a dry weight basis. More preferably, the second aerosol-generating substrate contains less than 6 weight percent nicotine on a dry weight basis.

[0239] For example, the second aerosol-generating substrate may contain, on a dry weight basis, 0.5 to 10 percent nicotine, or 1 to 8 percent nicotine, or 2 to 6 percent nicotine.

[0240] The second aerosol-generating substrate may comprise one or more carboxylic acids. Advantageously, including one or more carboxylic acids in the second aerosol-generating substrate may produce nicotine salts.

[0241] The one or more carboxylic acids include one or more of lactic acid and levulinic acid. Advantageously, the inventors have discovered that lactic acid and levulinic acid are particularly good carboxylic acids for producing nicotine salts.

[0242] Preferably, the second aerosol-generating substrate comprises at least 0.5 weight percent carboxylic acid on a dry weight basis, more preferably at least 1 weight percent carboxylic acid on a dry weight basis, and more preferably at least 2 weight percent carboxylic acid on a dry weight basis.

[0243] Additionally or alternatively, the second aerosol-generating substrate preferably contains 15 weight percent or less of the carboxylic acid on a dry weight basis. More preferably, the second aerosol-generating substrate contains less than 10 weight percent of the carboxylic acid on a dry weight basis. More preferably, the second aerosol-generating substrate contains less than 5 weight percent of the carboxylic acid on a dry weight basis. For example, the aerosol-generating substrate may contain 0.5 to 15 weight percent of the carboxylic acid, or 1 to 10 weight percent of the carboxylic acid, or 2 to 5 weight percent of the carboxylic acid.

[0244] In certain preferred embodiments, the second aerosol-generating substrate is in the form of an aerosol-generating film comprising a cellulosic film-forming agent, nicotine, and an aerosol former. The aerosol-generating film may further comprise a cellulosic reinforcing agent. The aerosol-generating film may further comprise less than 30 weight percent water.

[0245] The term "film" as used herein is used to describe a solid layered element having a thickness smaller than its width or length. The film can be self-supporting. In other words, even if the film is obtained by casting a film-forming formulation on a support surface, it can have cohesive and mechanical properties that allow it to be separated from the support surface. Alternatively, the film can be placed on a support or sandwiched between other materials. This can enhance the mechanical stability of the film.

[0246] The second aerosol-generating substrate may be provided in any suitable form. Preferably, a capsule contains a plurality of particles of the second aerosol-generating substrate. For example, the capsule may contain a plurality of beads, pellets, granules, pieces, fragments, or flakes of the second aerosol-generating substrate.

[0247] The second aerosol-generating substrate may comprise a plurality of beads, pellets, granules, strips, pieces, or flakes of aerosol-generating material.

[0248] The second aerosol-generating substrate may comprise a particulate aerosol-generating material.

[0249] In certain embodiments, the maximum dimension of each particle is preferably at least 0.05 millimeters, more preferably at least 0.1 millimeters, more preferably at least 0.15 millimeters, more preferably at least 0.2 millimeters, more preferably at least 0.25 millimeters, more preferably at least 0.5 millimeters, more preferably at least 0.75 millimeters, and more preferably at least 1 millimeter. The maximum dimension of each particle is preferably 10 millimeters or less, more preferably 9 millimeters or less, more preferably 8 millimeters or less, more preferably 6 millimeters or less, and more preferably 5 millimeters or less. Providing relatively large particles within these ranges may be preferable when holes are provided in the capsule wall to form air inlets and outlets, as described below. The relatively large maximum dimension of the particles then ensures that the particles are not lost through the holes in the capsule wall.

[0250] The largest dimension of a particle corresponds to the largest outer diameter of the particle, and if the particle is substantially spherical, the largest dimension of the particle corresponds to the diameter of the particle.

[0251] In such embodiments, the capsule preferably contains at least 2 particles of the second aerosol-generating substrate, more preferably at least 5 particles of the second aerosol-generating substrate, more preferably at least 10 particles of the second aerosol-generating substrate, more preferably at least 20 particles of the aerosol-generating substrate, and more preferably at least 30 particles. The capsule may contain up to 200 particles.

[0252] In other embodiments, the second aerosol-generating substrate may be in the form of a powder having a greater number of smaller particles. For example, in such embodiments, the powder may be formed from particles having a D50 particle size of 50 micrometers to 80 micrometers, 50 micrometers to 75 micrometers, 55 micrometers to 75 micrometers, 55 micrometers to 70 micrometers, or 60 micrometers to 70 micrometers.

[0253] As used herein in connection with the present invention, the term "D50 particle size" refers to the median particle size of a particulate material or powder. The D50 particle size is the particle size that divides the distribution in half, with half of the particles being larger than the D50 particle size and half of the particles being smaller than the D50 particle size. The particle size distribution can be determined by laser diffraction. For example, the particle size distribution can be determined by laser diffraction using a Malvern Mastersizer 3000 laser diffraction particle size analyzer according to the manufacturer's instructions.

[0254] The powder may be formed from particles having a D95 particle size of 80 micrometers to 130 micrometers, 90 micrometers to 125 micrometers, 100 micrometers to 120 micrometers, or 110 micrometers to 120 micrometers.

[0255] As used herein in connection with the present invention, the term "D95 particle size" is the particle size below which 95 percent of the mass fraction of particles has a particle size.

[0256] The powder may be formed from particles having a maximum diameter of 50 micrometers to 250 micrometers, 80 micrometers to 225 micrometers, or 100 micrometers to 125 micrometers.

[0257] In embodiments in which the capsule contains a plurality of particles, the mass of each particle is preferably at least 0.05 micrograms, more preferably at least 0.1 micrograms, more preferably at least 0.2 micrograms, more preferably at least 0.3 micrograms, more preferably at least 0.4 micrograms, more preferably at least 0.5 micrograms, more preferably at least 0.6 micrograms, more preferably at least 0.7 micrograms, more preferably at least 0.8 micrograms, more preferably at least 0.9 micrograms, more preferably at least 1 microgram, more preferably at least 10 micrograms, more preferably at least 100 micrograms, more preferably at least 200 micrograms, more preferably at least 500 micrograms, and more preferably at least 1 milligram. The mass of each particle is preferably 600 milligrams or less, more preferably 500 milligrams or less, more preferably 400 milligrams or less, more preferably 300 milligrams or less, more preferably 200 milligrams or less, more preferably 100 milligrams or less, more preferably 50 milligrams or less, and more preferably 10 milligrams or less.

[0258] Alternatively, the second aerosol-generating substrate may be in the form of one or more sheets. As used herein in connection with the present invention, the term "sheet" describes a laminar element having a width and length that substantially exceed its thickness.

[0259] The one or more sheets as described herein may be one or more of crimped, folded, gathered, and pleated. The one or more sheets may be cut into strands.

[0260] Alternatively, the aerosol-generating element may comprise an upstream capsule. The first aerosol-generating substrate may be contained within the upstream capsule. The upstream capsule may include any of the features of the capsules described above and may also be referred to as a downstream capsule.

[0261] When the first aerosol-generating element may include an upstream capsule, the hollow tubular element preferably extends substantially to the upstream end of the aerosol-generating article. The upstream capsule preferably has the same diameter as the downstream capsule. In this way, both the upstream capsule and the downstream capsule may be provided within the hollow tubular element.

[0262] When the first aerosol-generating substrate is contained within the upstream capsule, the first aerosol-generating substrate may include any of the features or components described above in relation to the second aerosol-generating substrate.

[0263] Where the first aerosol-generating substrate is contained within the upstream capsule, the aerosol-generating article may further comprise at least one aerosol-generating element stop protruding from the inner surface of the hollow tubular element to prevent the aerosol-generating element from moving further downstream than the at least one aerosol-generating element stop.

[0264] The features of the at least one capsule downstream stop described above may be equally applicable to the at least one aerosol-generating element stop.

[0265] According to a second aspect of the present invention, there is provided an aerosol generating system comprising an aerosol-generating article according to the first aspect of the present invention and an aerosol generating device comprising a heating chamber for receiving the aerosol-generating article and a heating element provided within or near the periphery of the heating chamber.

[0266] The aerosol-generating device may include an upstream end and a downstream end. The aerosol-generating device may include a body. The body or housing of the aerosol-generating device may define a heating chamber at the downstream end of the device for removably receiving an aerosol-generating article. The aerosol-generating device includes a heating element or heater for heating the aerosol-generating substrate when the aerosol-generating article is received in the heating chamber.

[0267] The heating chamber may extend between an upstream end and a downstream end. The upstream end of the heating chamber may be a closed end, and the downstream end of the heating chamber may be an open end. The aerosol-generating article may be inserted into the heating chamber through the open end of the heating chamber. The heating chamber may be cylindrical in shape to fit the same shape of the aerosol-generating article.

[0268] The phrase "received within" may refer to the fact that a component or element is completely or partially received within another component or element. For example, the phrase "the aerosol-generating article is received within the heating chamber" refers to the aerosol-generating article being completely or partially received within the heating chamber of the aerosol-generating article. When the aerosol-generating article is received within the heating chamber, the aerosol-generating article may abut against the upstream end of the heating chamber. When the aerosol-generating article is received within the heating chamber, the aerosol-generating article may be substantially adjacent to the upstream end of the heating chamber. The upstream end of the heating chamber may be defined by an end wall.

[0269] The length of the heating chamber may be between 15 millimeters and 80 millimeters, or between 20 millimeters and 70 millimeters, or between 25 millimeters and 60 millimeters, or between 25 millimeters and 50 millimeters.

[0270] The length of the heating chamber may be between 25 millimeters and 29 millimeters, or between 26 millimeters and 29 millimeters, or between 27 millimeters and 28 millimeters.

[0271] When the aerosol-generating article is received in the heating chamber, the aerosol-generating element is preferably completely within the device cavity to optimize heating of the first aerosol-generating substrate within the aerosol-generating element, and therefore the length of the device cavity is preferably greater than the length of the aerosol-generating element.

[0272] The diameter of the heating chamber may be 4 mm to 10 mm. The diameter of the heating chamber may be 5 mm to 9 mm. The diameter of the heating chamber may be 6 mm to 8 mm. The diameter of the heating chamber may be 6 mm to 7 mm.

[0273] The diameter of the heating chamber may be substantially the same as or larger than the diameter of the aerosol-generating article, and may be the same as the diameter of the aerosol-generating article to establish a tight fit therewith.

[0274] The heating chamber may be configured to establish a tight fit with an aerosol-generating article received within the heating chamber. A tight fit may refer to a snug fit. The aerosol-generating device may include a peripheral wall. Such a peripheral wall may define the heating chamber. The peripheral wall defining the heating chamber may be configured to engage in a tight fit with an aerosol-generating article received within the heating chamber such that, when received within the device, there are substantially no gaps or empty spaces between the peripheral wall defining the heating chamber and the aerosol-generating article.

[0275] Such a tight fit may establish an airtight fit or configuration between the heating chamber and the aerosol-generating article received therein.

[0276] In such an airtight configuration, there will be substantially no gaps or empty spaces between the peripheral walls defining the heating chamber and the aerosol-generating article for air to flow through.

[0277] A tight fit with the aerosol-generating article may be established along the entire length of the heating chamber or along a portion of the length of the heating chamber.

[0278] The aerosol generating device may include an airflow channel extending between the channel inlet and the channel outlet. The airflow channel may be configured to establish fluid communication between the interior of the heating chamber and the exterior of the aerosol generating device. The airflow channel of the aerosol generating device may be defined within the housing of the aerosol generating device to enable fluid communication between the interior of the heating chamber and the exterior of the aerosol generating device. When an aerosol-generating article is received within the heating chamber, the airflow channel may be configured to provide air flowing into the article to deliver the generated aerosol to a user who inhales from a downstream end of the article.

[0279] The airflow channel of the aerosol generating device may be defined within or by the peripheral wall of the housing of the aerosol generating device. In other words, the airflow channel of the aerosol generating device may be defined within the thickness of the peripheral wall, or by the inner surface of the peripheral wall, or a combination of both. The airflow channel may be partially defined by the inner surface of the peripheral wall, or partially defined within the thickness of the peripheral wall. The inner surface of the peripheral wall defines the periphery of the device cavity.

[0280] The airflow channel of the aerosol generation device may extend from an inlet located at the downstream end of the aerosol generation device to an outlet located away from the downstream end of the device. The airflow channel may extend along a direction parallel to the longitudinal axis of the aerosol generation device.

[0281] The heater may be of any suitable type. In the present invention, the heater is preferably an external heater that heats the aerosol-generating element. Such an external heater may surround the aerosol-generating article when inserted or received within the aerosol-generating device.

[0282] Alternatively, the heater may be an elongated heater blade adapted to be inserted into the aerosol-generating element to internally heat the first aerosol-generating substrate.

[0283] The heater may include at least one heating element. The at least one heating element may be any suitable type of heating element. In some embodiments, the device includes only one heating element. In some embodiments, the device includes multiple heating elements.

[0284] The heating element may be a resistive heating element.

[0285] Suitable materials for forming the resistive heating element include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide), carbon, graphite, metals, metal alloys, and composites made of ceramic and metallic materials. Such composites may include doped or undoped ceramics. An example of a suitable doped ceramic is doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel-, cobalt-, chromium-, aluminum-, titanium-, zirconium-, hafnium-, niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese-, and iron-containing alloys, as well as nickel-, iron-, cobalt-, and stainless steel-based superalloys, Timetal®, and iron-manganese-aluminum-based alloys.

[0286] In some embodiments, the resistive heating element comprises one or more stamped portions of an electrically resistive material (such as stainless steel), or alternatively, at least one resistive heating element may include a heating wire or filament (e.g., Ni-Cr (nickel-chromium), platinum, tungsten, or alloy wire).

[0287] In some embodiments, the heating element comprises an electrically insulating substrate, and at least one resistive heating element is provided on the electrically insulating substrate.

[0288] The electrically insulating substrate may comprise any suitable material. For example, the electrically insulating substrate may comprise one or more of paper, glass, ceramic, anodized metal, coated metal, and polyimide. The ceramic may comprise mica, alumina (Al2O3), or zirconia (ZrO2). The electrically insulating substrate preferably has a thermal conductivity of about 40 watts per meter Kelvin or less, preferably about 20 watts per meter Kelvin or less, and ideally about 2 watts per meter Kelvin or less.

[0289] The heater may comprise a heating element comprising a rigid, electrically insulating substrate having one or more conductive tracks or wires disposed on its surface. The size and shape of the electrically insulating substrate may allow the heater to be inserted directly into the aerosol-generating substrate. If the electrically insulating substrate is not sufficiently rigid, the heating element may comprise further reinforcing means. Electric current may be passed through one or more conductive tracks to heat the heating element and the aerosol-generating substrate.

[0290] In some embodiments, the heater comprises an induction heating arrangement. The induction heating device may comprise an inductor coil and a power source configured to provide a high-frequency oscillating current to the inductor coil. As used herein, high-frequency oscillating current means an oscillating current having a frequency between about 500 kHz and about 30 MHz. The heater may advantageously comprise a DC / AC inverter for converting DC current provided by a DC power source into alternating current. The inductor coil may be arranged to generate a high-frequency oscillating electromagnetic field upon receiving the high-frequency oscillating current from the power source. The inductor coil may be positioned to generate a high-frequency oscillating electromagnetic field within the device cavity. In some embodiments, the inductor coil may substantially surround the device cavity. The inductor coil may extend at least partially along the length of the device cavity.

[0291] The provision of a heater including an induction heating arrangement may be advantageously used in combination with an aerosol-generating article including a susceptor element as described above.

[0292] The heater may include an induction heating element. The induction heating element may be a susceptor element. The susceptor element may be positioned such that when an aerosol-generating article is received within the cavity of the aerosol-generating device, an oscillating electromagnetic field generated by the inductor coil induces a current in the susceptor element, heating the susceptor element. In these embodiments, the aerosol-generating device is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of 1 to 5 kiloamperes per meter (kA / m), preferably 2 to 3 kA / m, e.g., about 2.5 kA / m. Electrically operated aerosol-generating devices are preferably capable of generating a fluctuating electromagnetic field having a frequency of 1 to 30 MHz, e.g., 1 to 10 MHz, e.g., 5 to 7 MHz.

[0293] In these embodiments, the susceptor element is preferably positioned in contact with the first aerosol-generating substrate. In some embodiments, the susceptor element is positioned within the aerosol-generating device. In these embodiments, the susceptor element may be positioned within a cavity. The aerosol-generating device may include only one susceptor element. The aerosol-generating device may include multiple susceptor elements. In some embodiments, the susceptor element is preferably positioned to heat the outer surface of the aerosol-generating substrate.

[0294] The susceptor element may comprise any suitable element.

[0295] In some embodiments, the aerosol generating device may comprise at least one resistive heating element and at least one inductive heating element, hi some embodiments, the aerosol generating device may comprise a combination of resistive and inductive heating elements.

[0296] In use, the heater can be controlled to operate within a defined operating temperature range that is less than the maximum operating temperature. The operating temperature range within the heating chamber (or device cavity) is preferably from about 150 degrees Celsius to about 300 degrees Celsius. The operating temperature range of the heater may be from about 150 degrees Celsius to about 250 degrees Celsius.

[0297] During use, the system may be configured to heat the aerosol-generating element and the capsule such that the first aerosol-generating substrate and the second aerosol-generating substrate are heated. The system may be configured to heat the first aerosol-generating substrate to a first temperature. The system may be configured to heat the second aerosol-generating substrate to a second temperature. The first temperature may be higher than the second temperature. For example, the first temperature may be at least 5 degrees Celsius, at least 10 degrees Celsius, at least 20 degrees Celsius, at least 30 degrees Celsius, or at least 50 degrees Celsius higher than the second temperature.

[0298] The first and second temperatures may both be higher than ambient temperature. The first and second temperatures may both be higher than room temperature. The first and second temperatures may both be higher than 20 degrees Celsius, 30 degrees Celsius, 35 degrees Celsius, 40 degrees Celsius, 50 degrees Celsius, 60 degrees Celsius, or 100 degrees Celsius. The second temperature may be higher than ambient temperature. For example, the second temperature may be higher than 20 degrees Celsius, 30 degrees Celsius, 35 degrees Celsius, 40 degrees Celsius, 50 degrees Celsius, 60 degrees Celsius, or 100 degrees Celsius.

[0299] The aerosol generating device may include a power source. The power source may be a DC power source. In some embodiments, the power source is a battery. The power source may be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery (e.g., a lithium-cobalt, lithium iron phosphate, or lithium polymer battery). However, in some embodiments, the power source may be another form of charge storage device, such as a capacitor. The power source may require recharging and may have a capacity that allows for the storage of sufficient energy for one or more user operations, such as one or more aerosol generation experiences.

[0300] The aerosol-generating device may include a piercing device for piercing the capsule when the aerosol-generating article is inserted into the device cavity. As noted above, piercing the capsule may be necessary to establish one or more airflow paths through the capsule.

[0301] According to a third aspect of the present invention, there is provided a method for operating an aerosol-generating system. The method includes the steps of inserting an aerosol-generating article into a heating chamber of an aerosol-generating device and activating a heating element to heat the aerosol-generating article. During heating of the aerosol-generating article, a first aerosol-generating substrate and a second aerosol-generating substrate may be heated. The first aerosol-generating substrate may be heated to a first temperature. The second aerosol-generating substrate may be heated to a second temperature. The first temperature may be higher than the second temperature. For example, the first temperature may be at least 5 degrees Celsius, at least 10 degrees Celsius, at least 20 degrees Celsius, at least 30 degrees Celsius, or at least 50 degrees Celsius higher than the second temperature.

[0302] The first and second temperatures may both be higher than ambient temperature. The first and second temperatures may both be higher than room temperature. The first and second temperatures may both be higher than 20 degrees Celsius, 30 degrees Celsius, 35 degrees Celsius, 40 degrees Celsius, 50 degrees Celsius, 60 degrees Celsius, or 100 degrees Celsius. The second temperature may be higher than ambient temperature. For example, the second temperature may be higher than 20 degrees Celsius, 30 degrees Celsius, 35 degrees Celsius, 40 degrees Celsius, 50 degrees Celsius, 60 degrees Celsius, or 100 degrees Celsius. [Brief explanation of the drawings]

[0303] [Figure 1] FIG. 1 shows a schematic cross-sectional side view of an aerosol-generating article according to a first embodiment of the present invention. [Figure 2] FIG. 2 shows a schematic cross-sectional side view of an aerosol-generating article according to a second embodiment of the present invention. [Figure 3]FIG. 3 is a graph showing how the level of aerosol delivered varies over time during use of a prior art aerosol generating system. [Figure 4] FIG. 4 is a graph showing how the level of aerosol delivered varies over time during use of an aerosol generating system according to the present invention. [Figure 5] FIG. 5 is a graph showing how the level of aerosol delivered varies over time during use of an aerosol generating system according to the present invention. [Figure 6] FIG. 6 is a graph showing how the level of aerosol delivered varies over time during use of an aerosol generating system according to the present invention. [Figure 7] FIG. 7 shows a schematic cross-sectional side view of an aerosol-generating article according to a third embodiment of the present invention. [Figure 8] FIG. 8 shows a schematic cross-sectional side view of an aerosol generation system according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0304] The following provides a non-exhaustive list of non-limiting examples, any one or more of the features of which may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0305] Example 1: 1. An aerosol-generating article for generating an inhalable aerosol upon heating, the article comprising: an aerosol-generating element including a first aerosol-generating substrate; and a capsule located downstream of the aerosol-generating substrate, the capsule containing a second aerosol-generating substrate, the capsule including at least one capsule air inlet located at an upstream end of the capsule and at least one capsule air outlet located downstream of the capsule. Example 1a: 1. An aerosol-generating article for generating an inhalable aerosol upon heating, the article comprising: an aerosol-generating element including a first aerosol-generating substrate; and a capsule located downstream of the aerosol-generating substrate, the capsule containing a second aerosol-generating substrate, the second aerosol-generating substrate containing nicotine, the capsule comprising at least one capsule air inlet located at an upstream end of the capsule and at least one capsule air outlet located at a downstream end of the capsule, the downstream end of the capsule being at least 10 millimeters from the downstream end of the aerosol-generating article. Example 2: The aerosol-generating article of Example 1 or Example 1a, wherein the aerosol-generating element has a length of at least 5 mm. Example 3: An aerosol-generating article according to any preceding example, wherein the capsule has a length of at least 10 mm. Example 4: An aerosol-generating article according to any preceding embodiment, wherein the ratio of the capsule length to the aerosol-generating element length is at least 1. Example 5: An aerosol-generating article according to any preceding embodiment, wherein the ratio of the number of capsule air inlets to capsule air outlets is at least 1. Example 6: 10. The aerosol-generating article of any preceding embodiment, further comprising a hollow tubular element located downstream of the aerosol-generating element, the capsule being located within the hollow tubular element. Example 7: 7. The aerosol-generating article of example 6, wherein the upstream end of the hollow tubular element abuts the downstream end of the aerosol-generating element. Example 8: The aerosol-generating article of example 6 or example 7, further comprising a wrapper surrounding at least the downstream portion of the aerosol-generating element and the upstream portion of the hollow tubular element. Example 9: An aerosol-generating article described in any one of Examples 6 to 8, wherein the outer diameter of the capsule is approximately the same as the inner diameter of the hollow tubular element so that air cannot pass from the upstream end of the hollow tubular element to the downstream end of the hollow tubular element without passing through the capsule. Example 10: An aerosol-generating article according to any preceding example, further comprising a thermally conductive element for transferring heat from the aerosol-generating element to the capsule. Example 11: 10. The aerosol-generating article of example 9, wherein the thermally conductive element comprises a portion of a wrapper formed from a thermally conductive material. Example 12: 10. The aerosol-generating article of example 9, wherein the thermally conductive element comprises a rod of thermally conductive material extending from the aerosol-generating element to the capsule. Example 13: An aerosol-generating article according to any preceding example, wherein the first aerosol-generating substrate and the second aerosol-generating substrate are configured to generate first and second aerosols, respectively, upon heating. Example 14: An aerosol-generating article as described in Example 13, wherein the temperature at which the second aerosol-generating substrate generates an aerosol is lower than the temperature at which the first aerosol-generating substrate generates an aerosol. Example 15: 14. The aerosol-generating article of Example 13, wherein the first aerosol-generating substrate generates an aerosol when heated above a first temperature, and the second aerosol-generating substrate generates an aerosol when heated above a second temperature, the first temperature being greater than the second temperature. Example 16: The aerosol-generating article of example 15, wherein the first and second temperatures are greater than 20 degrees Celsius. Example 17: The aerosol-generating article of any preceding example, further comprising a downstream filter segment located downstream of the capsule, the downstream filter segment comprising a filter material. Example 18: The aerosol-generating article of any preceding example, wherein the aerosol-generating element further comprises a susceptor element. Example 19: 19. The aerosol-generating article of example 18, wherein the susceptor element extends the entire length of the aerosol-generating element. Example 20: An aerosol-generating article according to any preceding embodiment, wherein the first aerosol-generating substrate comprises tobacco. Example 21: 21. The aerosol-generating article of Example 20, wherein the first aerosol-generating substrate comprises at least one of cut tobacco material, cast leaf tobacco material, homogenized tobacco material, tobacco cut filler, or reconstituted tobacco material. Example 22: An aerosol-generating article according to any preceding embodiment, wherein the first aerosol-generating substrate comprises at least one aerosol former. Example 23: An aerosol-generating article according to any preceding embodiment, wherein the second aerosol-generating substrate is a solid aerosol-generating substrate. Example 24: An aerosol-generating article according to any preceding embodiment, wherein the second aerosol-generating substrate is a particulate aerosol-generating material. Example 25: The aerosol-generating article of any preceding embodiment, wherein the second aerosol-generating substrate comprises a plurality of beads, pellets, granules, strips, pieces, or flakes of aerosol-generating material. Example 26: An aerosol-generating article according to any preceding embodiment, wherein the second aerosol-generating substrate comprises at least one aerosol former. Example 27: An aerosol-generating article according to any preceding example, wherein the second aerosol-generating substrate comprises nicotine. Example 28: 10. The aerosol-generating article of any preceding embodiment, wherein the hollow tubular element comprises a first vent zone provided downstream of the downstream end of the aerosol-generating element but upstream of the upstream end of the capsule. Example 29: An aerosol-generating article according to any preceding example, wherein the hollow tubular element further comprises a second vent zone provided downstream of the downstream end of the capsule. Example 30: An aerosol-generating article as described in any of the preceding examples, further comprising at least one capsule downstream stop protruding from the inner surface of the hollow tubular element to prevent the capsule from moving further downstream than the at least one capsule downstream stop. Example 31: An aerosol-generating article according to any of the preceding embodiments, further comprising at least one capsule upstream stop protruding from the inner surface of the hollow tubular element to prevent the capsule from moving further upstream than the at least one capsule upstream stop. Example 32: An aerosol generating system comprising an aerosol-generating article described in any one of Examples 1 to 27, and an aerosol generating device including a heating chamber for receiving the aerosol-generating article, and a heating element provided within or near the periphery of the heating chamber. Example 33: 33. An aerosol-generating system as described in Example 32, wherein the system is configured to heat a first aerosol-generating substrate to a first temperature and the system is configured to heat a second aerosol-generating substrate to a second temperature. Example 34: 34. The aerosol generating system of Example 33, wherein the first temperature is higher than the second temperature. Example 35: An aerosol generating system as described in Example 33 or Example 34, wherein the first and second temperatures are greater than 20 degrees Celsius. Example 36: A method for operating an aerosol generating system described in any one of Examples 33 to 35, comprising the steps of inserting an aerosol-generating article into a heating chamber of the aerosol generating device and activating a heating element to heat the aerosol-generating article. Example 37: 37. The method of example 36, wherein a first aerosol-generating substrate is heated to a first temperature and a second aerosol-generating substrate is heated to a second temperature. Example 38: 38. The aerosol generating system of Example 37, wherein the first temperature is higher than the second temperature. Example 39: An aerosol generating system as described in Example 37 or Example 38, wherein the first and second temperatures are greater than 20 degrees Celsius.

[0306] The invention will now be further described with reference to the drawings of the accompanying drawings, in which:

[0307] The aerosol-generating article 100 shown in Figure 1 comprises an aerosol-generating element 101 and a capsule 102 located downstream of the aerosol-generating element 101. The aerosol-generating element 101 comprises a first aerosol-generating substrate. The aerosol-generating article 100 further comprises a hollow tubular element 105 extending from the upstream end of the aerosol-generating article 100 to the downstream end of the aerosol-generating article 100. The aerosol-generating element 101 and the capsule 102 are mounted inside the hollow tubular element 105. The aerosol-generating element 101 is mounted at the upstream end of the aerosol-generating article 101. The capsule 102 is mounted downstream of the downstream end of the aerosol-generating element 101.

[0308] The aerosol-generating article 100 further comprises a downstream filter segment 108 mounted inside the hollow tubular element 105 at the downstream end of the aerosol-generating article 100. The downstream filter segment 108 is formed from cellulose acetate tow. The downstream filter segment 108 has a length of 10 millimeters and a diameter of 6.7 millimeters.

[0309] The hollow tubular element 105 is formed from cardboard and has a cylindrical shape extending from the upstream end to the downstream end. The hollow tubular element 105 has a constant outer diameter of approximately 7.2 millimeters and a constant inner diameter of approximately 6.7 millimeters. Thus, the hollow tubular element 105 has a wall thickness of approximately 0.25 millimeters. The hollow tubular element 105 has a length of approximately 40 millimeters.

[0310] In the embodiment shown in FIG. 1 , the first aerosol-generating substrate comprises a solid aerosol-generating substrate containing tobacco cut filler impregnated with approximately 12 weight percent of an aerosol former, such as glycerin. The tobacco cut filler comprises 90 weight percent tobacco lamina. The tobacco cut filler has a cut width of approximately 0.7 millimeters. The aerosol-generating substrate contains approximately 130 milligrams of tobacco cut filler. The first aerosol-generating substrate has a density of approximately 0.28 grams per cubic centimeter. The aerosol-generating element 101 further comprises a susceptor element 111. The susceptor element 111 comprises a length of aluminum material embedded in the first aerosol-generating substrate and extending from the upstream end of the aerosol-generating element to the downstream end of the aerosol-generating element 105.

[0311] The aerosol-generating element 101 has a length of about 10 millimeters and an outer diameter of about 6.7 millimeters, which is therefore similar to the inner diameter of the hollow tubular element 105 such that the aerosol-generating element 101 is held within the hollow tubular element 105 by a friction fit.

[0312] The capsule 102 is disposed within the capsule section. The capsule section of the hollow tubular element 105 extends from the downstream end of the aerosol-generation element 101 to the upstream end of the downstream filter segment 108. The capsule 102 is disposed at the center of the capsule section. The length of the capsule section is greater than the length of the capsule, providing an upstream cavity 106 upstream of the capsule 102 and a downstream cavity 107 downstream of the capsule 102.

[0313] The capsule 102 includes an outer wall formed from an impermeable polymer such as HPMC. The capsule 102 has an elongated capsule (spherocylindrical) shape with a round cross-section. The capsule 102 includes an outer capsule wall defining an interior cavity containing a plurality of beads of a first aerosol-generating substrate (not shown in FIG. 1). The first aerosol-generating substrate includes nicotine and glycerin as an aerosol former. The outer capsule wall is defined by a cylindrical wall and opposing hemispherical end walls at the upstream and downstream ends of the capsule 102. The capsule 102 has a length of approximately 10 millimeters and an outer diameter of approximately 6.7 millimeters. The outer diameter of the capsule 102 is therefore similar to the inner diameter of the hollow tubular element 105 such that the capsule 102 is retained within the hollow tubular element 105 by a friction fit.

[0314] Capsule 102 has an internal volume of about 600 cubic millimeters and contains about 200 milligrams of solid aerosol-generating substrate. Thus, capsule 102 contains approximately 0.33 milligrams of aerosol-generating substrate per cubic millimeter of internal cavity.

[0315] The capsule 102 includes, at an upstream end of the capsule 102, a plurality of capsule air inlets 103 on a hemispherical upstream end wall of the capsule 102. The capsule 102 includes, at a downstream end of the capsule 102, a plurality of capsule air outlets 104 on a hemispherical downstream end wall of the capsule 102. The arrangement of the capsule air inlets 103 and capsule air outlets 104 will be described in more detail below.

[0316] The hollow tubular element 105 includes a first ventilation zone that allows outside air to enter the aerosol-generating article 100. The first ventilation zone is provided downstream of the downstream end of the capsule 102.

[0317] The first ventilation zone includes ten ventilation perforations 110 extending through the hollow tubular element 104. The ventilation perforations 110 are evenly spaced from one another and arranged in a line surrounding the hollow tubular element 105. The ventilation perforations 110 are all the same size. Each ventilation perforation 110 has a width of 100 micrometers and a length of 600 micrometers. The first ventilation zone provides a ventilation level of at least 20 percent.

[0318] The aerosol-generating article 100 further comprises at least one capsule downstream stop 112 protruding from the inner surface of the hollow tubular element 105 to prevent the capsule 102 from traveling further downstream than the at least one downstream stop 112. The at least one capsule downstream stop 112 comprises an annular flange attached to and extending from the inner surface of the hollow tubular element 105. The inner diameter of the flange is smaller than the outer diameter of the capsule 102, thereby preventing the capsule 102 from traveling further downstream than the stop 112. The at least one capsule downstream stop 112 is located upstream of the ventilation zone.

[0319] The aerosol-generating article 100 further comprises at least one capsule upstream stop 109 protruding from the inner surface of the hollow tubular element 105 to prevent the capsule 102 from moving further upstream than the at least one capsule upstream stop 109. The at least one capsule upstream stop 109 comprises an annular flange attached to and extending from the inner surface of the hollow tubular element 105. The inner diameter of the flange is smaller than the outer diameter of the capsule 102, thereby preventing the capsule 102 from moving further upstream than the stop 109.

[0320] Figure 2 shows a second aerosol-generating article 200 according to the present invention. The aerosol-generating article 200 includes many features in common with the aerosol-generating article 100 of Figure 1. These common features are identified by the same reference numerals.

[0321] The second aerosol-generating article 200 differs from the first aerosol-generating article 100 in that the aerosol-generating element 202 of the second aerosol-generating article 200 comprises a capsule. The capsule aerosol-generating element 202 is identical to the capsule 102 and comprises a plurality of air inlets 203 and air outlets 204. The capsule aerosol-generating element 202 contains a first aerosol-generating substrate.

[0322] The aerosol-generating article 200 further comprises at least one aerosol-generating element downstream stop 113 protruding from the inner surface of the hollow tubular element 105 to prevent the aerosol-generating element 202 from moving further downstream than the at least one capsule downstream stop 113. The at least one capsule downstream stop 113 comprises an annular flange attached to and extending from the inner surface of the hollow tubular element 105. The inner diameter of the flange is smaller than the outer diameter of the aerosol-generating element 202, thereby preventing the aerosol-generating element 202 from moving further downstream than the stop 113.

[0323] 3 is a graph showing how the amount of aerosol generated by an aerosol generating system including an aerosol-generating article changes over the course of use of the aerosol generating system. The aerosol-generating article used is a prior art aerosol generating article, not one according to the present invention. The aerosol-generating article differs from the present invention only in that it does not include a capsule containing a second aerosol-generating substrate. The aerosol-generating element is located upstream of an elongated cavity within a hollow tubular element. A downstream filter segment is located downstream of the elongated cavity.

[0324] The graph plots aerosol level 301 against time 302 for use of a single aerosol-generating article. A heater within the aerosol-generating device is turned on at time 303 and turned off at time 304. Line 305 indicates the minimum concentration level (MCL) of the aerosol; aerosol delivery below the MCL is not considered sufficient for an acceptable user experience.

[0325] As can be seen from graph plot 306, when the heater is first turned on, aerosol delivery begins to increase as heat from the heater generates aerosol from the first aerosol-generating substrate. The aerosol level crosses the MCL, and the rate of aerosol increase begins to decrease. Eventually, the aerosol delivery level begins to drop, even though the heater is turned on. This is because the aerosol-generating substrate begins to be depleted. Eventually, the aerosol generation level falls below the MCL. At this point, the heater is turned off because it is no longer possible to generate an acceptable amount of aerosol from the aerosol-generating substrate. The aerosol-generating substrate then cools, and aerosol delivery ceases.

[0326] 4 is a graph showing how the amount of aerosol generated by an aerosol generating system comprising an aerosol-generating article varies over use of the aerosol generating system, the aerosol-generating article being an aerosol generator according to the present invention.

[0327] The graph plots aerosol level 401 versus time 402 for use of a single aerosol-generating article in the same manner as in FIG. 3 , with similar reference numbers used to refer to the same features of the graph. Additionally, line 406 indicates the aerosol level generated from the first aerosol-generating substrate, line 407 indicates the aerosol level generated from the second aerosol-generating substrate, and line 408 indicates the total aerosol level generated by the aerosol-generating article. As can be seen, the heater is turned on and off at the same time points as in FIG. 3 . In particular, the heater is turned off when the aerosol delivery from the first aerosol-generating substrate falls below the MCL 405. The aerosol level provided by the first aerosol-generating substrate 406 is the same as the corresponding level in FIG. 3 . Additionally, once the heater has been on for a while, the aerosol level generated from the second aerosol-generating substrate begins to increase. This is because the capsule is not directly heated, and it takes time for the capsule to reach a temperature sufficient to generate aerosol from the second aerosol-generating substrate. As can be seen, the level of aerosol generated from the second aerosol-generating substrate increases and peaks at approximately the same time that the level of aerosol generated from the second aerosol-generating substrate begins to drop. As a result, the total aerosol generated increases toward the end of the total aerosol experience. Thus, total aerosol delivery can be increased compared to prior art aerosol delivery while maintaining the same heating profile.

[0328] 5 is a graph showing how the amount of aerosol generated by an aerosol generating system comprising an aerosol-generating article varies over use of the aerosol generating system, the aerosol-generating article being an aerosol generator according to the present invention.

[0329] The graph plots aerosol level 501 against time 502 for use of a single aerosol-generating article in the same manner as in Figure 4, and like reference numerals are used to refer to like features of the graph. The heating profile shown in Figure 5 differs from those shown in Figures 3 and 4 because the point in time 504 at which the heater is turned off occurs after the aerosol delivery from the first aerosol-generating substrate 506 is below the MCL 505.

[0330] As can be seen, the aerosol delivery profile is similar to that shown in Figure 4. However, in the example of Figure 5, the heater continues to heat even after the first aerosol-generating substrate is essentially depleted. This is intended to heat the second aerosol-generating substrate, which is heated only by convection as warm air passes through the capsule. As can be seen, the result is that the second aerosol-generating substrate delivers aerosol for a longer period of time 507. While this heating profile is intended to maximize aerosol delivery from the second aerosol-generating substrate, it can be disadvantageous because it requires heating the first aerosol-generating substrate when it is already below the MCL 505.

[0331] 6 is a graph showing how the amount of aerosol generated by an aerosol generating system comprising an aerosol-generating article varies over use of the aerosol generating system, the aerosol-generating article being an aerosol generator according to the present invention.

[0332] The graph plots aerosol level 601 against time 602 for use of a single aerosol-generating article in the same manner as in Figure 5, and like reference numerals are used to refer to like features of the graph. The heating profile shown in Figure 6 differs from the profiles shown in Figures 3, 4, and 5 because the heater is repeatedly turned on and off. Each time the heater is turned on is identified by line 603, and each time the heater is turned off is identified by line 604.

[0333] As can be seen, the level 607 of aerosol generated by the second aerosol-generating substrate begins to increase slower than the level of aerosol generated by the first aerosol-generating substrate, as in Figures 4 and 5. However, if the heater is then turned off, the level of aerosol generated by the first aerosol-generating substrate immediately drops, while the level of aerosol generated by the second aerosol-generating substrate continues to rise. This delay occurs because the second aerosol-generating substrate is heated only by convection as warm air passes through the capsule. As a result of this alternating on-off switching of the heater, the levels of aerosol generated by both the first and second aerosol-generating substrates change over the course of use of the aerosol-generating article. However, because the second aerosol-generating substrate is not directly heated, the peaks and troughs of aerosol delivery from the first and second aerosol-generating substrates are out of phase. The advantage of this is that the total aerosol 608 generated by the aerosol-generating substrates is smoothed despite the repeated on-off switching of the heater.

[0334] Figure 7 shows a third aerosol-generating article 700 according to the present invention. The aerosol-generating article 700 includes many features in common with the aerosol-generating article 100 of Figure 1. These common features are identified by the same reference numerals.

[0335] The third aerosol-generating article 700 differs from the first aerosol-generating article 100 in that the hollow tubular element 105 does not extend to the upstream end of the aerosol-generating article 700. Instead, the hollow tubular element 105 extends only from the downstream end of the aerosol-generating article 700 to the upstream end of the capsule section. The aerosol-generating element 101 is upstream of and abuts the upstream end of the hollow tubular element 105. The aerosol-generating element 101 is connected to the hollow tubular element 105 by a wrapper 701 that surrounds the entire length of the aerosol-generating element 101 and the upstream portion of the hollow tubular element 105.

[0336] The third aerosol-generating article 700 further comprises a thermally conductive element 702 extending from the downstream end of the aerosol-generating element 101, through the upstream cavity 106, and into the upstream portion of the capsule 102. The thermally conductive element 702 comprises an aluminum rod. The thermally conductive element is not aligned with the longitudinal center of the aerosol-generating article 700.

[0337] 8 shows an aerosol-generating system 800 according to the present invention. The system 800 comprises an aerosol-generating article 100 as described above. The system 800 further comprises an aerosol-generating device 801. The aerosol-generating device 801 includes a device housing 802. The housing 802 defines a heating chamber 803 for receiving the upstream end of the aerosol-generating article 100. The heating chamber 803 has an inner diameter that substantially corresponds to the outer diameter of the aerosol-generating article 100. The heating chamber 803 has a length of approximately 30 millimeters.

[0338] The aerosol-generating apparatus 801 further includes a heating element or heater 805 for heating the first aerosol-generating substrate when the aerosol-generating article 100 is received within the heating chamber 803. The heater 805 is an inductor coil that is part of an induction heating arrangement. The heater 603 is connected to a power source (not shown) and controlled using a control circuit (not shown).

[0339] The aerosol generating device 801 further includes a plurality of device air inlets 804 for allowing air to enter the heated chamber 803 of the device 801 .

[0340] In use, the upstream end of the aerosol-generating article 100 is inserted into the heating chamber 803 of the aerosol-generating device 801. The heater 805 is activated and the inductor coil generates an oscillating electromagnetic field. The electromagnetic field induces a current in the susceptor element 111, which heats the susceptor element 111. The heat from the susceptor element 111 heats the first aerosol-generating substrate of the aerosol-generating element 101, which generates vapor.

[0341] When a pressure drop is applied across the downstream end of the aerosol-generating article 100, ambient air is drawn into the upstream end of the aerosol-generating article 100 through the device air inlet 804. Here, the air, entrained with vapor, leaves the aerosol-generating element 101 and passes into the upstream cavity 106. As the vapor passes into the upstream cavity 106, it condenses to form an aerosol, which then passes into the capsule 102 through the capsule air inlet 103. The warm air and aerosol heat a second aerosol-generating substrate within the capsule 102, generating a second vapor. The aerosol, vapor, and air mixture leaves the capsule 102 through the capsule air outlet 104 and enters the downstream cavity 107. Here, the air mixes with ambient air drawn through the ventilation perforations 110, which cools the vapor and promotes aerosol nucleation and condensation. The aerosol then passes through the downstream filter segment 108 and exits the downstream end of the aerosol-generating article 100.

[0342] 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. Accordingly, in this context, the number A is understood as A ± 10%. 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 instances, 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. 1. An aerosol-generating article for generating an inhalable aerosol upon heating, said article comprising: an aerosol-generating element comprising a first aerosol-generating substrate; a capsule located downstream of the aerosol-generating element, the capsule containing a second aerosol-generating substrate, the second aerosol-generating substrate containing nicotine; the capsule includes at least one capsule air inlet located at an upstream end of the capsule and at least one capsule air outlet located at a downstream end of the capsule; An aerosol-generating article, wherein the downstream end of the capsule is at least 10 millimeters from the downstream end of the aerosol-generating article.

2. 10. The aerosol-generating article of claim 1, wherein the aerosol-generating element has a length of at least 5 mm.

3. 3. The aerosol-generating article of claim 1 or claim 2, wherein the capsule has a length of at least 10 mm.

4. 10. An aerosol-generating article according to any preceding claim, wherein the ratio of the length of the capsule to the length of the aerosol-generating element is at least 1.

5. 10. An aerosol-generating article according to any preceding claim, wherein the ratio of the number of capsule air inlets to the number of capsule air outlets is at least 1.

6. 10. An aerosol-generating article according to any preceding claim, further comprising a hollow tubular element located downstream of the aerosol-generating element, the capsule being located within the hollow tubular element.

7. 7. The aerosol-generating article of claim 6, wherein the upstream end of the hollow tubular element abuts the downstream end of the aerosol-generating element.

8. 8. The aerosol-generating article of claim 6 or claim 7, further comprising a wrapper surrounding at least the downstream portion of the aerosol-generating element and the upstream portion of the hollow tubular element.

9. 9. An aerosol-generating article according to any one of claims 6 to 8, wherein the outer diameter of the capsule is approximately the same as the inner diameter of the hollow tubular element, such that air cannot pass from the upstream end of the hollow tubular element to the downstream end of the hollow tubular element without passing through the capsule.

10. 10. An aerosol-generating article according to any preceding claim, further comprising a thermally conductive element for transferring heat from the aerosol-generating element to the capsule.

11. 10. The aerosol-generating article of claim 9, wherein the thermally conductive element comprises a portion of the wrapper formed from a thermally conductive material.

12. 10. The aerosol-generating article of claim 9, wherein the thermally conductive element comprises a rod of thermally conductive material extending from the aerosol-generating element to the capsule.

13. 10. An aerosol-generating article according to any preceding claim, wherein the first aerosol-generating substrate and the second aerosol-generating substrate are configured to generate first and second aerosols, respectively, upon heating.

14. 14. The aerosol-generating article according to claim 13, wherein the temperature at which the second aerosol-generating substrate generates an aerosol is lower than the temperature at which the first aerosol-generating substrate generates an aerosol.

15. 1. An aerosol generating system comprising: An aerosol-generating article according to any one of claims 1 to 14; an aerosol generating device including a heating chamber for receiving the aerosol-generating article, and a heating element provided within or near the periphery of the heating chamber.

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