Aerosol generating article equipped with capsule and susceptor

Abstract

An aerosol generating article (10) for generating an inhalable aerosol when heated is provided, the aerosol generating article (10) comprising a capsule (14;414). The capsule (14;414) comprises a capsule outer wall (20) defining an internal cavity (22) and a plurality of first particles (24) within the internal cavity (22). Each of the first particles (24) comprises an aerosol-forming substrate. The capsule (14;414) further comprises a plurality of second particles (25;225;325) within the internal cavity (22), each of which comprises a susceptor material and does not contain an aerosol-forming substrate, or only one of a plurality of second particles (25;225;325) or a single susceptor element (425) within the internal cavity (22). Also provided are an aerosol generating system (100) comprising an aerosol generating article (10), and a method for forming a capsule (14;414) for the aerosol generating article (10).

Description

Technical Field

[0001] The present invention relates to an aerosol-generating article comprising a capsule, wherein the capsule comprises a plurality of first particles of an aerosol-forming substrate and a susceptor. The present invention also relates to an aerosol-generating system comprising the aerosol-generating article and a method of forming the capsule.

Background Art

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

[0003] Several prior art documents disclose aerosol generators for consuming aerosol-generating articles. Such devices include, for example, electrically heated aerosol generators in which aerosols are generated by heat transfer from one or more electric heater elements of the aerosol generator to an aerosol-forming substrate of a heated aerosol-generating article. For example, an electrically heated aerosol generator comprising a resistance heating element has been proposed, which generates heat for heating the aerosol-forming substrate. Other electrically heated aerosol generators comprising an induction heating system have been proposed, in which an inductor coil generates a variable magnetic field for heating a susceptor element, and the susceptor element is arranged to heat the aerosol-forming substrate. For example, an inductionally heated aerosol-generating article comprising an aerosol-forming substrate and a susceptor disposed within the aerosol-forming substrate is proposed in International Publication No. 2015 / 176898. [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Certain types of aerosol-forming substrates containing nicotine and relatively high aerosol-forming content, such as nicotine-containing gels and films, are known. Such substrates are typically very stable during storage and, advantageously, provide very consistent delivery of nicotine to consumers when heated. They also, advantageously, can generate aerosols at lower temperatures than other solid substrates. However, problems can also arise from the use of this type of aerosol-forming substrate. Relatively high aerosol-forming content increases the risk of aerosol-forming material leaking from the substrate during storage and use. Furthermore, certain substrates, such as gel compositions, generally melt when heated in an aerosol-generating device during use. Consequently, the viscosity of the gel composition increases significantly, making it more difficult to control the movement of the gel composition, particularly to retain the gel composition within the aerosol-generating article. Leakage of aerosol-forming material or molten gel composition from the aerosol-generating article is undesirable because it may leak into the heating chamber of the aerosol-generating device and contaminate the device. Leakage of aerosol-forming materials or gel compositions can also be potentially unpleasant for consumers.

[0005] Furthermore, even solid aerosol-forming substrates may contain one or more volatile compounds, such as aerosol-forming agents, which may leak out of the aerosol-generating article over time if the article is not stored properly.

[0006] Therefore, it would be desirable to provide a novel aerosol generating article having an arrangement that provides improved retention of the aerosol-forming substrate and volatile compounds within the aerosol generating article during storage and use. It would be even more desirable to provide such an aerosol generating article that allows the aerosol-forming substrate to be efficiently heated so that aerosols can be generated from the aerosol-forming substrate in an efficient and consistent manner. [Brief explanation of the drawing]

[0007] [Figure 1]Figure 1 shows a cross-sectional view of an aerosol-generating article according to one embodiment of the present invention. [Figure 2] Figure 2 shows a cross-sectional view of the capsule of the aerosol-generating article shown in Figure 1. [Figure 3] Figure 3 shows a cross-sectional view of an aerosol generation system comprising an aerosol generator and the aerosol generating article shown in Figure 1, which is received within the aerosol generator. [Figure 4] Figure 4 shows a cross-sectional view of an alternative second particle for the capsule in Figure 2. [Figure 5] Figure 5 shows a perspective view of the second particle in Figure 4. [Figure 6] Figure 6 shows a perspective view of a further alternative second particle for the capsule in Figure 2. [Figure 7] Figure 7 shows a perspective view of the second particle from Figure 6, nested within a plurality of first particles, each having a spherical shape. [Figure 8] Figure 8 shows a cross-sectional view of an alternative capsule for the aerosol-generating article shown in Figure 1. [Modes for carrying out the invention]

[0008] This disclosure relates to an aerosol generating article for generating an inhalable aerosol when heated. The aerosol generating article may comprise a capsule. The capsule may comprise a capsule outer wall defining an internal cavity. The capsule may comprise a plurality of first particles within the internal cavity. Each of the first particles may comprise an aerosol-forming substrate. The capsule may further comprise a single susceptor element within the internal cavity. The capsule may further comprise a plurality of second particles within the internal cavity. Each of the second particles may comprise a susceptor material and may not comprise an aerosol-forming substrate.

[0009] The present invention provides an aerosol generating article for generating an inhalable aerosol when heated, the aerosol generating article comprising a capsule. The capsule comprises a capsule outer wall defining an internal cavity and a plurality of first particles within the internal cavity. Each of the first particles comprises an aerosol-forming substrate. The capsule further comprises a plurality of second particles within the internal cavity, each of which comprises a susceptor material and does not contain an aerosol-forming substrate, or only one of a plurality of second particles or a single susceptor element within the internal cavity.

[0010] As used herein, the term "aerosol-generating article" is used to refer to an article comprising an aerosol-forming substrate that is heated in order to generate and deliver an inhalable aerosol to a consumer. As used herein, the term "aerosol-forming substrate" means a substrate that has the ability to release volatile compounds upon heating in order to generate an aerosol.

[0011] As used herein, the term "aerosol generator" refers to a device comprising a heater element that interacts with an aerosol-forming substrate of an aerosol-generating article in order to generate an aerosol.

[0012] As used herein, the term "longitudinal axis" refers to the direction corresponding to the main longitudinal axis of the aerosol generating article, extending between the upstream and downstream ends of the aerosol generating article. As used herein, the terms "upstream" and "downstream" indicate the relative position of an element (or part of an element) of the aerosol generating article with respect to the direction in which aerosols are transported through the aerosol generating article during use.

[0013] During use, air is drawn in along the long axis through the aerosol-generating object. The term "transverse direction" refers to the direction perpendicular to the long axis.

[0014] The term "length" refers to the dimensions of the components of an aerosol-generating article in the direction of its long axis. For example, it may be used to mean the dimensions of a hollow tubular element or capsule in the direction of its long axis.

[0015] As used herein, the term “solid” refers to a non-flowing aerosol-forming substrate that retains its shape and forms at room temperature, rather than being a liquid or gas. In the context of the present invention, the term “solid” encompasses gel materials and compositions.

[0016] As used herein, the terms “susceptor,” “susceptor element,” and “susceptor material” refer to a material that can be inductively heated. That is, a susceptor material can absorb electromagnetic energy and convert it into heat.

[0017] Advantageously, by providing particles of the susceptor material or a single susceptor element within the internal cavity of the capsule, direct contact is provided between the susceptor and the particles of the aerosol-forming substrate. Advantageously, this direct contact between the susceptor and the aerosol-forming substrate provides efficient heating of the aerosol-forming substrate. Advantageously, this direct contact between the susceptor and the aerosol-forming substrate facilitates rapid heating of the aerosol-forming substrate at the start of the heating cycle. Advantageously, the rapid heating of the aerosol-forming substrate facilitates rapid aerosol delivery to the user.

[0018] Advantageously, the manufacture of aerosol-generating articles can be simplified by providing the aerosol-forming substrate to multiple second particles of the susceptor material, or to multiple first particles distinct from a single susceptor element. For example, it may be easier to manufacture the first particles of the aerosol-forming substrate separately from a single susceptor element or multiple second particles of the susceptor material.

[0019] Advantageously, by positioning the first particles of the aerosol-forming substrate within the internal cavity of the capsule by means of a single susceptor element or a plurality of second particles of susceptor material, a uniform distribution of the aerosol-forming substrate with respect to the susceptor can be facilitated. Advantageously, the uniform distribution of the aerosol-forming substrate with respect to the susceptor can facilitate uniform heating of the aerosol-forming substrate and thus uniform aerosol delivery throughout the heating cycle. Advantageously, the uniform distribution of the aerosol-forming substrate with respect to the susceptor can facilitate uniform heating of the aerosol-forming substrate such that the aerosol generation profile of the aerosol-generating article is independent of the orientation of the capsules within the aerosol-generating article and independent of the orientation of the aerosol-generating article within the aerosol-generating device.

[0020] Advantageously, by providing the susceptor as part of the aerosol-generating article, the heater can be made replaceable each time the aerosol-generating article is replaced. Advantageously, this removes the problem of heater contamination specific to aerosol-generating devices comprising a resistive heater that is repeatedly used to heat a plurality of aerosol-generating articles.

[0021] The capsule may comprise a plurality of second particles. The plurality of first particles are preferably mixed with the plurality of second particles. Advantageously, mixing the second particles with the first particles can facilitate a uniform distribution of the aerosol-forming substrate with respect to the susceptor material. Advantageously, this can facilitate more efficient heat transfer from the susceptor material to the aerosol-forming substrate.

[0022] The plurality of first particles can have any suitable form. The plurality of first particles may comprise a plurality of beads, pellets, granules, flakes, pieces, or laminae.

[0023] The plurality of second particles can have any suitable form. The plurality of second particles may comprise a plurality of beads, pellets, granules, flakes, pieces, or laminae.

[0024] Each of the first particles may have an outer surface including the first shape. Each of the second particles may have an outer surface including the second shape.

[0025] The first shape and the second shape may be the same.

[0026] The second shape may be different from the first shape. A part of the second shape may be configured to engage with a part of the first shape. In other words, a part of the second shape may be complementary to a part of the first shape. A part of the second shape may be configured to receive a part of the first shape. A part of the second shape may be configured to be received by a part of the first shape. In other words, a part of the first shape may be configured to receive a part of the second shape.

[0027] Advantageously, by providing first and second shapes configured to engage with each other, contact between the first and second particles can be increased or maximized. Advantageously, increasing or maximizing contact between the first and second particles may facilitate efficient heat transfer from the susceptor material to the aerosol-forming substrate.

[0028] The first shape is preferably configured to reduce or prevent engagement between the first particles. In other words, the first shape is preferably configured so that it cannot engage with or accept any part of itself. Advantageously, this may facilitate mixing of the first and second particles.

[0029] The second shape is preferably configured to reduce or prevent engagement between the second particles. In other words, the second shape is preferably configured so that it cannot engage with or accept any part of itself. Advantageously, this may facilitate mixing of the first and second particles.

[0030] Preferably, each of the second particles has at least one of a size and shape that reduces or minimizes the interlocking of the second particles. Advantageously, reducing or minimizing the interlocking of the second particles may facilitate mixing of the second particles with the first particles.

[0031] Preferably, each of the second particles has at least one of a size and shape that increases or maximizes contact between the second particle and the first particle. Advantageously, increasing or maximizing contact between the second particle and the first particle may facilitate heat transfer from the susceptor material to the aerosol-forming substrate.

[0032] The first shape may be convex. The first shape may be a sphere, an ellipse, or an egg. The first shape may be a polyhedron. The first shape may be a stellated polyhedron.

[0033] The second shape may be convex. The second shape may be a sphere, an ellipse, or an egg. The second shape may be a polyhedron. The second shape may be a stellated polyhedron.

[0034] Each of the first and second shapes may be spherical, ellipsoidal, or oval. Advantageously, providing each of the first and second particles with a spherical, ellipsoidal, or oval shape may simplify the manufacturing of the first and second particles. Advantageously, providing each of the first and second particles with a spherical, ellipsoidal, or oval shape may facilitate mixing of the second and first particles.

[0035] The first shape may be a sphere, an ellipsoid, or an egg shape, and the second shape may be a stellated polyhedron. Advantageously, by providing each of the first particles with a spherical, ellipsoidal, or egg shape and each of the second particles with a stellated polyhedron, contact between the first and second particles can be increased or maximized.

[0036] Each of the first particles may have a first size, and each of the second particles may have a second size.

[0037] The first size may differ from the second size.

[0038] The first size may be identical to the second size.

[0039] Advantageously, by providing identical first and second sizes, a homogeneous distribution of multiple first particles within multiple second particles can be facilitated. Advantageously, this homogeneous distribution of multiple first particles within multiple second particles may facilitate efficient heat transfer from the susceptor material to the aerosol-forming substrate.

[0040] Each of the first particles may have a first cross-sectional dimension. To accommodate variations in the size of the first particles due to intentional or manufacturing tolerances, the first cross-sectional dimension is a number-average cross-sectional dimension.

[0041] Each of the second particles may have a second cross-sectional dimension. To accommodate variations in the size of the second particles due to intent or manufacturing tolerances, the second cross-sectional dimension is a number-average cross-sectional dimension.

[0042] The first and second cross-sectional dimensions are preferably the maximum cross-sectional dimensions of the first and second particles, respectively. For particles with a spherical shape, the maximum cross-sectional dimension is the diameter of the sphere. For particles with an elliptical or egg shape, the maximum cross-sectional dimension is the major axis of the elliptical or egg shape.

[0043] The first cross-sectional dimension may differ from the second cross-sectional dimension.

[0044] The first cross-sectional dimension may be identical to the second cross-sectional dimension. Advantageously, providing identical first and second cross-sectional dimensions can facilitate a homogeneous distribution of multiple first particles within multiple second particles. Advantageously, a homogeneous distribution of multiple first particles within multiple second particles may facilitate efficient heat transfer from the susceptor material to the aerosol-forming substrate.

[0045] The maximum first cross-sectional dimension of the first particle is preferably at least 0.05 mm, more preferably at least 0.1 mm, more preferably at least 0.15 mm, more preferably at least 0.2 mm, more preferably at least 0.25 mm, more preferably at least 0.5 mm, more preferably at least 0.75 mm, and more preferably at least 1 mm. The maximum first cross-sectional dimension of the first particle is preferably 10 mm or less, more preferably 9 mm or less, more preferably 8 mm or less, more preferably 6 mm or less, and more preferably 5 mm or less. Providing relatively large first particles within these ranges may be preferable when holes are provided in the outer wall of the capsule for forming air intakes and outlets, as described below. The relatively large maximum dimension of the first particle may ensure that the first particle is not lost through the holes in the outer wall of the capsule.

[0046] The maximum second cross-sectional dimension of the second particle is preferably at least 0.05 mm, more preferably at least 0.1 mm, more preferably at least 0.15 mm, more preferably at least 0.2 mm, more preferably at least 0.25 mm, more preferably at least 0.5 mm, more preferably at least 0.75 mm, and more preferably at least 1 mm. The maximum second cross-sectional dimension of the second particle is preferably 10 mm or less, more preferably 9 mm or less, more preferably 8 mm or less, more preferably 6 mm or less, and more preferably 5 mm or less. Providing relatively large second particles within these ranges may be preferable when holes are provided in the outer wall of the capsule for forming air intakes and outlets, as described below. The relatively large maximum dimension of the second particle may ensure that the second particle is not lost through the holes in the outer wall of the capsule.

[0047] Each of the first particles may have a first mass. To accommodate variations in the mass of the first particles due to intentional or manufacturing tolerances, the first mass is the number-average mass.

[0048] Each of the second particles may have a second mass. To accommodate variations in the mass of the second particles due to intentional or manufacturing tolerances, the second mass is the number-average mass.

[0049] The first mass may be different from the second mass.

[0050] The difference between the first mass and the second mass is preferably less than 10 percent of the first mass. Most preferably, the first mass may be the same as the second mass. Advantageously, providing identical first and second masses can facilitate a homogeneous distribution of multiple first particles within multiple second particles. Advantageously, a homogeneous distribution of multiple first particles within multiple second particles may facilitate efficient heat transfer from the susceptor material to the aerosol-forming substrate.

[0051] The first mass 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 first mass 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.

[0052] The second mass 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 second mass 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.

[0053] Each of the first particles may have a first density. To accommodate variations in the density of the first particles due to intentional or manufacturing tolerances, the first density is the number-average density.

[0054] Each of the second particles may have a second density. To accommodate variations in the density of the second particles due to intentional or manufacturing tolerances, the second density is the number-average density.

[0055] The first density may be different from the second density.

[0056] The difference between the first density and the second density is preferably less than 10 percent of the first density. Most preferably, the first density may be the same as the second density. Advantageously, providing identical first and second densities can facilitate a homogeneous distribution of multiple first particles within multiple second particles. Advantageously, a homogeneous distribution of multiple first particles within multiple second particles may facilitate efficient heat transfer from the susceptor material to the aerosol-forming substrate.

[0057] The first density is preferably at least 0.1 milligrams / cubic millimeter, more preferably at least 0.2 milligrams / cubic millimeter, more preferably at least 0.25 milligrams / cubic millimeter, more preferably at least 0.3 milligrams / cubic millimeter, more preferably at least 0.35 milligrams / cubic millimeter, more preferably at least 0.4 milligrams / cubic millimeter, more preferably at least 0.45 milligrams / cubic millimeter, more preferably at least 0.5 milligrams / cubic millimeter, more preferably at least 0.55 milligrams / cubic millimeter, more preferably at least 0.6 milligrams / cubic millimeter, more preferably at least 0.65 milligrams / cubic millimeter, more preferably at least 0.7 milligrams / cubic millimeter, more preferably at least 0.75 milligrams / cubic millimeter, and more preferably at least 0.8 milligrams / cubic millimeter. The first density is preferably 2 milligrams per cubic millimeter or less, more preferably 1.95 milligrams / cubic millimeter or less, more preferably 1.9 milligrams / cubic millimeter or less, more preferably 1.85 milligrams / cubic millimeter or less, more preferably 1.8 milligrams / cubic millimeter or less, more preferably 1.75 milligrams / cubic millimeter or less, more preferably 1.7 milligrams / cubic millimeter or less, more preferably 1.65 milligrams / cubic millimeter or less, more preferably 1.6 milligrams / cubic millimeter or less, more preferably 1.55 milligrams / cubic millimeter or less, more preferably 1.5 milligrams / cubic millimeter or less, more preferably 1.45 milligrams / cubic millimeter or less, more preferably 1.4 milligrams / cubic millimeter or less, more preferably 1.35 milligrams / cubic millimeter or less, more preferably 1.3 milligrams / cubic millimeter or less, more preferably 1.25 milligrams / cubic millimeter or less, and more preferably 1.2 milligrams / cubic millimeter or less.

[0058] The second density is preferably at least 0.1 milligrams / cubic millimeter, more preferably at least 0.2 milligrams / cubic millimeter, more preferably at least 0.25 milligrams / cubic millimeter, more preferably at least 0.3 milligrams / cubic millimeter, more preferably at least 0.35 milligrams / cubic millimeter, more preferably at least 0.4 milligrams / cubic millimeter, more preferably at least 0.45 milligrams / cubic millimeter, more preferably at least 0.5 milligrams / cubic millimeter, more preferably at least 0.55 milligrams / cubic millimeter, more preferably at least 0.6 milligrams / cubic millimeter, more preferably at least 0.65 milligrams / cubic millimeter, more preferably at least 0.7 milligrams / cubic millimeter, more preferably at least 0.75 milligrams / cubic millimeter, and more preferably at least 0.8 milligrams / cubic millimeter. The second density is preferably 2 milligrams per cubic millimeter or less, more preferably 1.95 milligrams / cubic millimeter or less, more preferably 1.9 milligrams / cubic millimeter or less, more preferably 1.85 milligrams / cubic millimeter or less, more preferably 1.8 milligrams / cubic millimeter or less, more preferably 1.75 milligrams / cubic millimeter or less, more preferably 1.7 milligrams / cubic millimeter or less, more preferably 1.65 milligrams / cubic millimeter or less, more preferably 1.6 milligrams / cubic millimeter or less, more preferably 1.55 milligrams / cubic millimeter or less, more preferably 1.5 milligrams / cubic millimeter or less, more preferably 1.45 milligrams / cubic millimeter or less, more preferably 1.4 milligrams / cubic millimeter or less, more preferably 1.35 milligrams / cubic millimeter or less, more preferably 1.3 milligrams / cubic millimeter or less, more preferably 1.25 milligrams / cubic millimeter or less, and more preferably 1.2 milligrams / cubic millimeter or less.

[0059] Preferably, the ratio of the total number of first particles to the total number of second particles in the internal cavity is 0.2 to 1 to 5 to 1, more preferably 0.3 to 1 to 4 to 1, more preferably 0.4 to 1 to 3.5 to 1, more preferably 0.5 to 1 to 3 to 1, more preferably 0.6 to 1 to 2.5 to 1, more preferably 0.7 to 1 to 2 to 1, more preferably 0.8 to 1 to 1.5 to 1, more preferably 0.9 to 1.1 to 1, and most preferably about 1 to 1. Advantageously, providing a ratio of the total number of first particles to the total number of second particles within these ranges may facilitate efficient and uniform heating of the aerosol-forming substrate by the susceptor material.

[0060] Preferably, the ratio of the total mass of the first particles to the total mass of the second particles in the internal cavity is 0.2:1 to 5:1, more preferably 0.3:1 to 4:1, more preferably 0.4:1 to 3.5:1, more preferably 0.5:1 to 3:1, more preferably 0.6:1 to 2.5:1, more preferably 0.7:1 to 2:1, more preferably 0.8:1 to 1.5:1, more preferably 0.9:1 to 1.1:1, and most preferably about 1:1. Advantageously, providing a ratio of the total mass of the first particles to the total mass of the second particles within these ranges may facilitate efficient and uniform heating of the aerosol-forming substrate by the susceptor material.

[0061] Each of the second particles may have a homogeneous structure. Advantageously, a homogeneous structure can simplify the manufacturing of the second particles. Each of the second particles may contain solid particles of the susceptor material. Each of the second particles may have a uniform density.

[0062] Each of the second particles may have a heterogeneous structure. Advantageously, the heterogeneous structure makes it easier to provide each second particle with at least one of the desired size, mass, and density. Each of the second particles may have a heterogeneous density.

[0063] Each of the second particles may comprise a shell of susceptor material and a void defined by the shell of the susceptor material. The void may be at least partially filled with non-susceptor material. The shell of the susceptor material may have a first density, and the non-susceptor material may have a second density, the second density being less than the first density. The non-susceptor material may include non-conductive foam. The void may not contain solid or liquid material. The void may be filled with gas. The gas may include air. The gas may include an inert gas. The void may contain a partial vacuum or a vacuum.

[0064] Each of the second particles may contain multiple layers of susceptor material. The multiple layers of susceptor material may comprise a first layer containing the first susceptor material and a second layer containing the second susceptor material, wherein the first susceptor material is different from the second susceptor material. The first susceptor material may have a first density, and the second susceptor material may have a second density, wherein the first density is different from the second density.

[0065] Each of the second particles may have at least one of a size and shape that increases the surface area of ​​the second particle. Advantageously, increasing the surface area of ​​each second particle may facilitate heat transfer from the susceptor material to the aerosol-forming substrate.

[0066] Each of the second particles may include a plurality of fins. Each fin is preferably formed from a susceptor material. Each of the second particles may include a plurality of disks or plates of susceptor material, each disk or plate forming one of the plurality of fins. The following optional or preferred features for embodiments in which each of the second particles includes a plurality of disks can be equally applied to embodiments in which each of the second particles includes a plurality of plates. The disks are preferably arranged in a stacked manner. The disks are preferably spaced apart from each other. The disks are preferably connected to each other by a central column. The central column is preferably formed from a susceptor material.

[0067] A capsule may comprise a single susceptor element, which comprises a susceptor material. As used herein, the term "single susceptor element" refers to the susceptor element that is the only susceptor element within the capsule.

[0068] The first particle may include either of the optional or preferred features described above.

[0069] A single susceptor element may have any preferred shape and size. A single susceptor element may have a convex shape. A single susceptor element may have a planar shape. A single susceptor element may have an elongated shape. A single susceptor element may have a shape selected from rods, pins, cylinders, spheres, ellipsoids, ovals, sheets, discs, cones, and truncated cones.

[0070] Further optional and preferred features described below are applicable to embodiments in which the capsule comprises multiple second particles and embodiments in which the capsule comprises a single susceptor element.

[0071] The susceptor material preferably contains at least one metal. The susceptor material may contain at least one metal alloy. The susceptor material may contain a foam.

[0072] The susceptor material preferably includes a ferromagnetic metallic material. The susceptor material may include at least one of ferrite iron, ferromagnetic steel, stainless steel, and aluminum. Different materials will generate different amounts of heat when positioned in an electromagnetic field with similar frequency and magnetic field strength values. Therefore, the susceptor material can be selected to provide the desired power loss within a known electromagnetic field.

[0073] In embodiments where the susceptor material includes stainless steel, the susceptor material may include at least one 400 series stainless steel. Preferred 400 series stainless steels include grades 410, 420, and 430.

[0074] The susceptor material may include metallic wool. The metallic wool may be formed from any of the metallic susceptor materials described herein.

[0075] The susceptor material may include a metal foam. The metal foam may be formed from any of the metal susceptor materials described herein.

[0076] The susceptor material may include a protective coating that encloses the surface of the susceptor material. The protective coating may prevent direct contact between the susceptor material and the aerosol-forming substrate. Advantageously, this may prevent undesirable chemical reactions between the susceptor material and the aerosol-forming substrate. The protective coating may include at least one of glass and ceramic.

[0077] Preferably, each of the first particles does not contain susceptor material. Advantageously, providing first particles that do not contain susceptor material can simplify the manufacturing of the first particles.

[0078] The aerosol-forming substrate preferably includes a solid aerosol-forming substrate.

[0079] The aerosol-forming substrate preferably contains at least one of nicotine and tobacco. The aerosol-forming substrate preferably contains nicotine.

[0080] As used herein in relation to the present invention, the term "nicotine" is used to describe nicotine, nicotine base, or nicotine salt. In embodiments in which the aerosol-forming substrate comprises a nicotine base or nicotine salt, the amounts of nicotine listed herein are, respectively, amounts of free base nicotine or amounts of protonated nicotine.

[0081] The aerosol-forming substrate may contain natural or synthetic nicotine. The nicotine may contain one or more nicotine salts. One or more nicotine salts may be selected from a list consisting of nicotine lactate, nicotine citrate, nicotine pyruvate, nicotine beetartrate, nicotine benzoate, nicotine pectinate, nicotine alginate, and nicotine salicylate.

[0082] Nicotine may be present in tobacco extracts.

[0083] Preferably, the aerosol-forming substrate contains at least 0.5 weight percent of nicotine on a dry weight basis. More preferably, the aerosol-forming substrate contains at least 1 weight percent of nicotine on a dry weight basis. Even more preferably, the aerosol-forming substrate contains at least 2 weight percent of nicotine on a dry weight basis. Additionally or alternatively, it is preferable that the aerosol-forming substrate contains less than 10 weight percent of nicotine on a dry weight basis. More preferably, the aerosol-forming substrate contains less than 8 weight percent of nicotine on a dry weight basis. More preferably, the aerosol-forming substrate contains less than 6 weight percent of nicotine on a dry weight basis.

[0084] The aerosol-forming substrate may contain one or more carboxylic acids. Advantageously, by including one or more carboxylic acids in the aerosol-forming substrate, a nicotine salt can be produced.

[0085] One or more carboxylic acids include one or more of lactic acid and levulinic acid. Advantageously, the inventors have found that lactic acid and levulinic acid are particularly good carboxylic acids for producing nicotine salts.

[0086] Preferably, the aerosol-forming substrate contains at least 0.5 weight percent of carboxylic acid on a dry weight basis. More preferably, the aerosol-forming substrate contains at least 1 weight percent of carboxylic acid on a dry weight basis. More preferably, the aerosol-forming substrate contains at least 2 weight percent of carboxylic acid on a dry weight basis.

[0087] In addition, or alternatively, the aerosol-forming substrate preferably contains less than 15 weight percent of carboxylic acid on a dry weight basis. More preferably, the aerosol-forming substrate preferably contains less than 10 weight percent of carboxylic acid on a dry weight basis. More preferably, the aerosol-forming substrate preferably contains less than 5 weight percent of carboxylic acid on a dry weight basis. For example, the aerosol-forming substrate may contain 0.5 to 15 weight percent of carboxylic acid, or 1 to 10 weight percent of carboxylic acid, or 2 to 5 weight percent of carboxylic acid.

[0088] The aerosol-forming substrate may contain at least one aerosol-forming material. The aerosol-forming substrate may contain at least 15 weight percent of aerosol-forming materials on a dry weight basis. Preferably, the aerosol-forming substrate contains at least 20 weight percent of aerosol-forming materials on a dry weight basis. More preferably, the aerosol-forming substrate contains at least 25 weight percent of aerosol-forming materials on a dry weight basis. More preferably, the aerosol-forming substrate contains at least 30 weight percent of aerosol-forming materials on a dry weight basis. More preferably, the aerosol-forming substrate contains at least 35 weight percent of aerosol-forming materials on a dry weight basis. More preferably, the aerosol-forming substrate contains at least 40 weight percent of aerosol-forming materials on a dry weight basis. More preferably, the aerosol-forming substrate contains at least 45 weight percent of aerosol-forming materials on a dry weight basis. More preferably, the aerosol-forming substrate contains at least 50 weight percent of aerosol-forming materials on a dry weight basis.

[0089] Preferably, the aerosol-forming substrate contains 80% by weight or less on a dry weight basis. More preferably, the second aerosol-forming substrate contains 75% by weight or less on a dry weight basis. More preferably, the second aerosol-forming substrate contains 70% by weight or less on a dry weight basis.

[0090] Suitable aerosol-forming materials to be included in the aerosol-forming 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 dodecanedioic acid and dimethyl tetradecanedioic acid).

[0091] The aerosol-forming substrate may comprise a gel composition containing nicotine, at least one gelling agent, and an aerosol-forming body. Preferably, the gel composition is substantially free of tobacco.

[0092] The gel composition preferably contains at least 50 weight percent of aerosol-forming material, more preferably at least 60 weight percent, and more preferably at least 70 weight percent, on a dry weight basis. The gel composition may contain up to 80 weight percent of aerosol-forming material. The aerosol-forming material in the gel composition is preferably glycerol.

[0093] The gel composition preferably contains at least one gelling agent. Preferably, the gel composition contains a total amount of gelling agent ranging from about 0.4% to about 10% by weight, or about 0.5% to about 8% by weight, or about 1% to about 6% by weight, or about 2% to about 4% by weight, or about 2% to about 3% by weight.

[0094] The term "gelling agent" refers to a compound that, when added homogeneously to a mixture of 50% water and 50% glycerol in an amount of approximately 0.3% by weight, forms a solid medium or supporting matrix, leading to the formation of a gel. Examples of gelling agents, though not limited to them, include hydrogen-linked gelling agents and ionic-linked gelling agents.

[0095] The term "hydrogen bond crosslinking gelling agent" refers to a gelling agent that forms non-covalent or physical crosslinks via hydrogen bonds.

[0096] The hydrogen bonding crosslinking gelling agent may contain one or more of galactomannan, gelatin, agarose, konjac gum, or agar. It is preferable that the hydrogen bonding crosslinking gelling agent contains agar.

[0097] The term "ionic crosslinking gelling agent" refers to a gelling agent that forms non-covalent or physical crosslinks via ionic bonding.

[0098] The ion-crosslinking gelling agent may include low-acylgellan, pectin, kappa-carrageenan, iota-carrageenan, or alginate. It is preferable that the ion-crosslinking gelling agent may include low-acylgellan.

[0099] The gelling agent may contain one or more biopolymers. The biopolymers may be formed from polysaccharides.

[0100] Examples of biopolymers include gellan gum (natural gellan gum, low-acyl gellan gum, and high-acyl gellan gum having low-acyl gellan gum are preferred), xanthan gum, alginate (alginic acid), agar, and guar gum. The composition may preferably contain xanthan gum. The composition may contain two biopolymers. The composition may contain three biopolymers. The composition may contain two biopolymers in substantially equal weights. The composition may contain three biopolymers in substantially equal weights.

[0101] The gel composition may further contain a thickening agent. Remarkably, thickening agents combined with hydrogen-bonding crosslinking gelling agents appear to support the solid medium and maintain the gel composition even when it contains high levels of glycerol.

[0102] The term "thickener" refers to a compound that, when uniformly added in an amount of 0.3 weight percent to a mixture of 50 weight percent water and 50 weight percent glycerol at 25 degrees Celsius, increases viscosity without causing gel formation, causing the mixture to remain in a fluid state or to stay fluid.

[0103] The gel composition preferably contains a thickening agent in an amount ranging from about 0.2% to about 5% by weight, or about 0.5% to about 3% by weight, or about 0.5% to about 2% by weight, or about 1% to about 2% by weight.

[0104] The thickener may contain one or more of the following: xanthan gum, carboxymethylcellulose, microcrystalline cellulose, methylcellulose, gum arabic, guar gum, lambda carrageenan, or starch. It is preferable that the thickener contains xanthan gum.

[0105] The gel composition may further contain divalent cations. Preferably, the divalent cations include calcium ions such as calcium lactate in solution. Divalent cations (such as calcium ions) can assist in gel formation in compositions containing gelling agents, such as ion-crosslinking gelling agents. Ionic effects may assist in gel formation. Divalent cations may be present in the gel composition in an amount ranging from about 0.1 to about 1 weight percent, or about 0.5 weight percent.

[0106] The gel composition may further contain an acid. The acid may contain a carboxylic acid. The carboxylic acid may contain a ketone group. Preferably, the carboxylic acid may contain a ketone group having less than 10 carbon atoms, such as levulinic acid or lactic acid, or less than 6 carbon atoms or less than 4 carbonate atoms. Preferably, this carboxylic acid has three carbon atoms (such as lactic acid).

[0107] The gel composition preferably contains some water. The gel composition is more stable when it contains some water.

[0108] Preferably, the gel composition contains about 8% to about 32% by weight of water, or about 15% to about 25% by weight of water, or about 18% to about 22% by weight of water, or about 20% by weight of water.

[0109] The capsule outer wall can be formed from any suitable material. Preferably, the capsule outer wall is formed from an impermeable material, and most preferably from an impermeable polymer material. This ensures that air does not pass through the capsule outer wall except through pores specifically provided for airflow during use. Therefore, the airflow through the capsule during use can be effectively controlled.

[0110] The capsule outer wall may contain polymeric or cellulosic materials. For example, the capsule outer wall may be made of one or more nicotine-compatible polymers, including medical-grade polymers such as ALTUGLAS® medical resin polymethyl methacrylate (PMMA), Chevron Phillips K-Resin® styrene-butadiene copolymer (SBC), Arkema specialty performance polymers Pebax®, Rilsan®, and Rilsan® Clear, DOW (Health+®) low-density polyethylene (LDPE), DOW® LDPE91003, DOW® LDPE91020 (MFI2.0; density 923), ExxonMobil® polypropylene (PP) PP1013H1, PP1014H1, and PP9074MED, and Trinseo CALIBRE® polycarbonate (PC) 2060-SERIES.

[0111] Alternatively, the outer wall of the capsule 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).

[0112] The capsule is preferably spherical-cylindrical in shape, with a cylindrical portion defined by a cylindrical wall and rounded hemispherical end walls 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 oval in shape.

[0113] The capsule is preferably a two-part capsule having two separate parts that fit together to close the capsule and hold its contents. The two separate parts can be fitted together by friction without adhesive, or an adhesive may be used to seal the two parts together.

[0114] The capsule preferably comprises a first part and a second part, the second part having a smaller outer diameter than the first part so that the end of the second part can be inserted into the open end of the first part in order to close the capsule. When the capsule is mounted within a hollow tubular element, the second part of the capsule is preferably provided downstream of the first part.

[0115] In such embodiments, the outer diameters of the first and second portions of the capsule can be adapted such 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 such that the first portion of the capsule cannot be received within the hollow tubular element and remains outside the hollow tubular element at its upstream end. The second portion of the capsule is preferably held within the hollow tubular element by friction fitting. The first component prevents the capsule from being further pushed into the hollow tubular element.

[0116] Alternatively, in such embodiments, the capsule may be fully inserted into a hollow tubular element, and the outer diameters of the first and second portions of the capsule may be fitted such that the outer diameter of the second portion is smaller than the inner diameter of the hollow tubular element. This provides 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 the air outlet on the cylindrical wall of the capsule, as described below. The outer diameter of the first portion of the capsule is preferably fitted such that the first portion of the capsule is held in place within the hollow tubular article by friction fitting. Alternatively, the first portion of the capsule may be held in place by a suitable adhesive. Either of these arrangements is preferable to substantially prevent airflow around the first portion of the capsule from being downstream of the second portion of the capsule.

[0117] The internal cavity of the capsule preferably has a volume of at least 250 cubic millimeters, corresponding to 0.25 millimeters. This corresponds to the internal volume or capacity of the capsule. The internal cavity of the capsule preferably has a volume of at least 400 cubic millimeters (0.4 milliliters), more preferably at least 500 cubic millimeters (0.5 milliliters), and more preferably at least 600 cubic millimeters (0.6 milliliters). The internal cavity of the capsule 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.

[0118] The capsule preferably has a length of at least 10 millimeters, more preferably at least 12 millimeters, more preferably at least 15 millimeters, and more preferably at least 18 millimeters. The capsule length is preferably less than 30 millimeters, more preferably less than 28 millimeters, and more preferably less than 25 millimeters. For example, the capsule length may be 10 to 30 millimeters, or 12 to 28 millimeters, or 15 to 25 millimeters, or 18 to 25 millimeters. The capsule length may also be about 20 millimeters.

[0119] 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, and 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, and more preferably less than 7.5 mm. For example, the maximum diameter of the capsule may be between 5 mm and 9 mm, or between 5.5 mm and 8.5 mm, or between 6 mm and 6 mm, or between 6.5 mm and 7.5 mm. The maximum diameter of the capsule may be about 7 mm.

[0120] The internal cavity of the capsule preferably contains at least 50 milligrams of aerosol-forming substrate, more preferably at least 100 milligrams, and more preferably at least 150 milligrams. The internal cavity may contain up to 1000 milligrams of aerosol-forming substrate, or up to 750 milligrams, or up to 500 milligrams, or up to 250 milligrams. For example, the internal cavity of the capsule may contain 50 to 1000 milligrams of aerosol-forming substrate, or 100 to 750 milligrams, or 150 to 500 milligrams, or 150 to 250 milligrams.

[0121] The weight of the aerosol-forming substrate inside the capsule is preferably at least 0.1 milligrams per cubic millimeter of the internal cavity. This corresponds to the total weight of the aerosol-forming substrate divided by the total volume of the internal cavity. The weight of the aerosol-forming substrate inside the capsule is preferably at least 0.15 milligrams per cubic millimeter of the internal cavity, and more preferably at least 0.2 milligrams per cubic millimeter of the internal cavity. The weight of the aerosol-forming substrate inside the capsule may be less than 2 milligrams per cubic millimeter of the internal cavity, or less than 1 milligram per cubic millimeter of the internal cavity, or less than 0.5 milligrams per cubic millimeter of the internal cavity. For example, the weight of the aerosol-forming substrate inside the capsule may be between 0.1 milligrams and 2 milligrams per cubic millimeter of the internal cavity, or between 0.15 milligrams and 1 milligram per cubic millimeter of the internal cavity, or between 0.2 milligrams and 0.5 milligrams per cubic millimeter of the internal cavity.

[0122] The filling rate of the capsule with the first and second particles, or the first particle and a single susceptor element, is preferably at least 50 percent, more preferably at least 60 percent, and more preferably at least 70 percent. The filling rate is preferably less than 90 percent. The filling rate corresponds to the proportion of the internal cavity of the capsule occupied by the first and second particles, or the first particle and a single susceptor element. In other words, the filling rate corresponds to the proportion of the volume of the internal cavity occupied by the first and second particles, or the first particle and a single susceptor element. It may be advantageous to retain some empty space within the internal cavity to allow airflow through the internal cavity and to heat the aerosol-forming substrate evenly.

[0123] The capsule may be configured such that, during heating, one or more airflow paths are provided through the capsule. Advantageously, the one or more airflow paths allow aerosols generated from the aerosol-forming substrate to be drawn out through the aerosol-generating article and delivered to the consumer.

[0124] The capsule may be sealed and airtight in the initial stage, but when the aerosol generating article is inserted into the aerosol generating device, it may be adapted so that an airflow path is created, for example, by inserting an internal heating element or through a penetrating element that penetrates the outer wall of the capsule.

[0125] Alternatively, and more preferably, the capsule comprises at least one air intake and at least one air outlet within the outer wall of the capsule. The at least one air intake and at least one air outlet preferably define one or more airflow paths through the internal cavity of the capsule between the at least one air intake and at least one air outlet. The at least one air outlet is provided downstream of the at least one air intake.

[0126] Preferably, each of the first particles is larger than each of at least one air intake and at least one air outlet. Advantageously, this can prevent the first particles from being lost from the capsule through at least one air intake and at least one air outlet.

[0127] Preferably, each of the second particles is larger than each of at least one air intake and at least one air outlet. Advantageously, this can prevent the second particles from being lost from the capsule through at least one air intake and at least one air outlet.

[0128] The capsule preferably has multiple air intakes. For example, the capsule may have 2 to 6 air intakes.

[0129] The capsule preferably has multiple air outlets. For example, the capsule may have 2 to 6 air outlets. The number of air outlets may be the same as or different from the number of air intakes. It may be advantageous to provide more air outlets than air intakes, as the air outlets need to allow aerosols generated inside the capsule to escape from the capsule into the hollow tubular element.

[0130] The number and size of the air intakes and outlets can be adjusted to control the airflow through the capsule and the draw resistance (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.

[0131] Each air intake and each air outlet is preferably in the form of a hole passing through the outer wall of the capsule. Each hole is preferably cylindrical, but other shapes may also be suitable. The diameter of each hole should be sufficiently large, for example, so that the hole cannot be easily blocked by dust. However, the diameter of each hole should also be adapted according to the shape and properties of the aerosol-forming substrate so that the aerosol-forming substrate is not lost from the internal cavity through the hole.

[0132] Each hole forming the air intake or air outlet preferably 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 1.7 mm, or less than 1.6 mm, or less than 1.5 mm, or less than 1.4 mm, or less than 1.3 mm, or less than 1.2 mm, or less than 1.1 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.

[0133] If multiple air intakes or outlets are provided, each pore should be sufficiently spaced apart so that its presence does not adversely affect the structural integrity of the capsule. For example, it is preferable that the pores be spaced at least 1 millimeter apart from each other.

[0134] At least one air outlet is preferably at least 5 millimeters downstream of at least one air intake, more preferably at least 8 millimeters downstream of at least one air intake, and more preferably at least 10 millimeters downstream of at least one air intake. This spacing allows for maximizing the length of the airflow path through the capsule.

[0135] Preferably, at least one air outlet is 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, it is preferable that at least one air outlet is provided on the downstream end wall.

[0136] At least one air intake can be positioned at the upstream end of the capsule. For example, if the capsule has the conventional capsule shape as described above, at least one air intake may be provided on the upstream end wall. However, in certain embodiments, it may be advantageous to position at least one air intake at a specific distance downstream of the upstream end. For example, at least one air intake may be provided at least 2 millimeters downstream of the upstream end of the capsule, or at least 3 millimeters downstream of the upstream end of the capsule, or at least 4 millimeters downstream of the upstream end of the capsule, or at least 5 millimeters downstream of the upstream end of the capsule. If multiple air intakes are provided, all air intakes should be provided at least this distance from the upstream end, even if the position of the air intakes along the length of the capsule varies.

[0137] In a preferred embodiment, the capsule includes a cylindrical wall and rounded end walls at the upstream and downstream ends of the cylindrical wall (as in a conventional capsule shape), and at least one air intake may be advantageously provided in the cylindrical wall downstream of the upstream end wall.

[0138] Positioning at least one air intake away from the upstream end of the capsule in this manner may be particularly beneficial when the aerosol-forming substrate is in the form of a gel composition or any other type of substrate that melts or becomes more viscous upon heating. By positioning at least one air intake away from the upstream end of a cavity into which molten substrate can be collected, the risk of the aerosol-forming substrate leaking from the capsule is reduced or minimized. The risk of the aerosol-forming substrate blocking the air intake is also reduced or minimized.

[0139] The aerosol-generating article may comprise a hollow tubular element. The capsule may be positioned within the hollow tubular element. The capsule may be held within the hollow tubular element by an interference fit.

[0140] The capsule may be positioned within a hollow tubular element, in particular when at least one air intake is provided on the cylindrical wall of the capsule, such that at least one air intake is not covered or blocked by the wall of the hollow tubular element. There are various preferred ways to achieve this, as described below.

[0141] The hollow tubular element may have one or more holes extending through its peripheral wall, the one or more holes being positioned to coincide with one or more air intakes on the capsule. With such an arrangement, air can pass from the outside of the hollow tubular element, through its peripheral wall, to at least one air intake.

[0142] The capsule may be mounted within a hollow tubular element such that a portion of the capsule extends from the upstream end of the hollow tubular element, and as a result, at least one air intake is positioned outside the hollow tubular element. Preferably, at least 20 percent of the length of the capsule protrudes from the hollow tubular element, and more preferably at least 30 percent of the length of the capsule. Preferably, 50 percent or less of the length of the capsule protrudes from the hollow tubular element. Preferably, the majority of the capsule is within the hollow tubular element so that the capsule can be firmly held within the hollow tubular element. The hollow tubular element may have a flange or projection extending inward from its inner surface at the downstream end of the capsule to prevent the capsule from being pushed further downstream into the hollow tubular element. For example, the hollow tubular element may have an annular flange extending from its inner surface.

[0143] The capsule may be provided with an outer diameter smaller than the inner diameter of the hollow tubular element. This arrangement provides a space between the outer surface of the capsule and the inner surface of the hollow tubular element so that air can pass between the capsule and the hollow tubular element to at least one air intake. In such embodiments, it may be necessary to block the airflow from the upstream end of the hollow tubular element to at least one air outlet within the capsule wall. Thus, the main airflow path is defined through the capsule and not around the outside of the capsule. This can be achieved, for example, by providing an annular sealing ring around the capsule, within the hollow tubular element, sealing the space between the capsule and the inner surface of the hollow tubular element at a position downstream of at least one air intake. Advantageously, the annular sealing ring also facilitates retention of the capsule within the hollow tubular element.

[0144] In this embodiment, the outer diameter of the capsule is preferably at least 0.2 millimeters smaller than the inner diameter of the hollow tubular element, more preferably at least 0.5 millimeters smaller, and more preferably at least 0.8 millimeters smaller. The outer diameter of the capsule may be up to 2 millimeters smaller than the inner diameter of the hollow tubular element.

[0145] The inner surface of the hollow tubular element may be corrugated at the upstream end of the hollow tubular element, defining a plurality of longitudinal channels arranged circumferentially so as to substantially coincide with at least one air intake. Such arrangement allows air to enter the hollow tubular element through the longitudinal channels defined by the corrugated surface and pass along the capsule to at least one air intake. Preferably, the hollow tubular element is corrugated only along a portion of its length from the upstream end, and not along its entire length. Therefore, it is preferable that the longitudinal channels extend to a position upstream of at least one air outlet so that there is no airflow from the upstream end of the hollow tubular element to at least one air outlet. In this way, the main airflow path is defined through the capsule and not around the outside of the capsule.

[0146] Therefore, it is preferable that the hollow tubular element extends to the downstream end of the aerosol-generating article.

[0147] As used herein, the term “hollow tubular element” means a substantially elongated element that defines a lumen or channel along the longitudinal axis of the hollow tubular element. In particular, the term “tubular” is used herein with respect to a tubular element having a substantially cylindrical cross-section and defining at least a channel extending between the upstream end and the downstream end of the tubular element. However, it will be understood that alternative geometric shapes (e.g., alternative cross-sectional shapes) of tubular elements may be possible.

[0148] The capsule may be positioned at the upstream end of the hollow tubular element, as described above. The hollow tubular element may define a hollow cavity downstream of the capsule, which extends along part or all of the length of the hollow tubular element. The hollow cavity may extend all the way from the capsule to the downstream end of the aerosol generating article. Thus, in such embodiments, the aerosol generating article may be formed by only two elements: the capsule and the hollow tubular element. Alternatively, one or more filter segments may be provided within the hollow tubular element, at the downstream end of the hollow tubular element, or adjacent to the downstream end of the hollow tubular element, as will be described in more detail below.

[0149] The empty cavity defined within the hollow tubular element downstream of the capsule preferably has a length of at least 10 mm, more preferably at least 12 mm, and more preferably at least 14 mm. The length of the empty cavity may be up to 40 mm, or up to 30 mm, or up to 25 mm. For example, the empty cavity may have a length of 10 mm to 40 mm, or 12 mm to 30 mm, or 14 mm to 25 mm.

[0150] Preferably, the hollow tubular element has a total length of at least 25 mm, more preferably at least 28 mm, more preferably at least 30 mm, more preferably at least 32 mm, and more preferably at least 34 mm. The length of the hollow tubular element may be less than 50 mm, less than 48 mm, less than 45 mm, or less than 42 mm or less than 40 mm. For example, the total length of the hollow tubular element may be 25 mm to 50 mm, or 28 mm to 48 mm, or 30 mm to 45 mm, or 32 mm to 42 mm, or 34 mm to 40 mm.

[0151] The hollow tubular element may have an outer diameter of 5 to 12 mm, for example, 5 to 10 mm, or 6 to 8 mm. In one preferred embodiment, the hollow tubular element has an outer diameter of 7.2 mm plus or minus 10 percent.

[0152] The inner diameter of the hollow tubular element is preferably constant along its length. The lumen or cavity of the hollow tubular element may have any cross-sectional shape. The lumen of the hollow tubular element may have a circular cross-sectional shape.

[0153] Preferably, the inner diameter of the hollow tubular element is at least 5 mm, more preferably at least 5.5 mm, more preferably at least 6 mm, and more preferably at least 6.5 mm. Preferably, the inner diameter of the hollow tubular element is less than 9 mm, more preferably less than 8.5 mm, more preferably less than 8 mm, and more preferably less than 7.5 mm. For example, the inner diameter 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 inner diameter may be about 7 mm.

[0154] 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 micrometers to 1 millimeter, or 500 micrometers to 1 millimeter.

[0155] The hollow tubular element may contain a paper-based material. The hollow tubular element may comprise at least one layer of paper. The paper may be very rigid. The paper may be crimped paper, such as crimped heat-resistant paper or crimped sulfuric acid paper. Advantageously, the crimped paper may form one or more airflow channels extending around the outside of the capsule. One or more airflow channels may be particularly advantageous in embodiments in which the capsule comprises at least one of an air intake and an air outlet on the cylindrical wall of the capsule.

[0156] 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 generator and being rigid enough to provide proper engagement of the article with the inside of the device. Thus, the cardboard tube may provide good resistance to deformation or compression during use.

[0157] The hollow tubular element may be a paper tube. The hollow tubular element may be a tube formed from spirally wound paper. The hollow tubular element 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.

[0158] The hollow tubular element may contain polymer materials. For example, the hollow tubular element may contain a polymer film. The polymer film may include a cellulose film. The hollow tubular element may contain low-density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. The hollow tube may contain cellulose acetate tow.

[0159] If the hollow tubular element contains cellulose acetate tow, the cellulose acetate tow may have about 2 to about 4 deniers per filament and a total of about 25 to about 40 deniers per filament.

[0160] In the aerosol generating article according to the present invention, the hollow tubular element preferably provides a negligible level of drawdown resistance (RTD). The term “negligible level of RTD” is used to describe an RTD of less than 1 mmH2O per 10 mm length hollow tubular element or hollow tubular element, preferably less than 0.4 mmH2O per 10 mm length hollow tubular element or hollow tubular element, and more preferably less than 0.1 mmH2O per 10 mm length hollow tubular element or hollow tubular element.

[0161] The RTD of the hollow tubular element is preferably about 10 mmH2O or less. More preferably, the RTD of the hollow tubular element is about 5 mmH2O or less. Even more preferably, the RTD of the hollow tubular element is about 2.5 mmH2O or less. Even more preferably, the RTD of the hollow tubular element is about 2 mmH2O or less. Even more preferably, the RTD of the hollow tubular element is about 1 mmH2O or less.

[0162] The RTD of the hollow tubular element may be at least 0 mmH2O, or at least about 0.25 mmH2O, or at least about 0.5 mmH2O, or at least about 1 mmH2O.

[0163] In some embodiments, the RTD of the hollow tubular element is about 0 mmH2O to about 10 mmH2O, preferably about 0.25 mmH2O to about 10 mmH2O, and more preferably about 0.5 mmH2O to about 10 mmH2O. In other embodiments, the RTD of the hollow tubular element is about 0 mmH2O to about 5 mmH2O, preferably about 0.25 mmH2O to about 5 mmH2O, and more preferably about 0.5 mmH2O to about 5 mmH2O. In yet another embodiment, the RTD of the hollow tubular element is about 1 mmH2O to about 5 mmH2O. In yet another embodiment, the RTD of the hollow tubular element is about 0 mmH2O to about 2.5 mmH2O, preferably about 0.25 mmH2O to about 2.5 mmH2O, and more preferably about 0.5 mmH2O to about 2.5 mmH2O. In further embodiments, the RTD of the hollow tubular element is about 0 mmH2O to about 2 mmH2O, preferably about 0.25 mmH2O to about 2 mmH2O, and more preferably about 0.5 mmH2O to about 2 mmH2O. In a particularly preferred embodiment, the RTD of the hollow tubular element is about 0 mmH2O.

[0164] The aerosol-generating article may include a downstream filter segment, as described above. The downstream filter segment may be mounted within the hollow tubular element at the downstream end of the hollow tubular element. The downstream filter segment may extend to the downstream end of the hollow tubular element. The downstream end of the downstream filter segment may define the downstream end of the aerosol-generating article. Including the downstream filter segment within the hollow tubular element may be useful in providing the aerosol-generating article with a desired level of RTD.

[0165] The downstream filter segment is located downstream of the capsule. Preferably, the capsule and the downstream filter segment have a gap in the longitudinal direction such that a cavity is defined between the capsule and the downstream filter segment. The downstream filter segment is preferably located at least 5 millimeters downstream from the downstream end of the capsule, more preferably at least 8 millimeters downstream, more preferably at least 10 millimeters downstream, and more preferably at least 15 millimeters downstream. The downstream filter segment is preferably located less than 30 millimeters downstream from the downstream end of the capsule, and more preferably less than 25 millimeters downstream. The distance defined between the downstream end of the capsule and the downstream filter segment corresponds to the length of the cavity between the capsule and the downstream filter segment.

[0166] The downstream filter segment is preferably a solid plug, which may also be described as a “plain” plug and is non-tubular. The filter segment preferably has a substantially uniform cross-sectional area.

[0167] The downstream filter segment is preferably formed of a fibrous filter material. The fibrous filter material may be for filtering aerosols generated from the aerosol-forming substrate. Suitable fibrous filter materials will be known to those skilled in the art. Particularly preferably, at least one downstream filter segment includes a cellulose acetate filter segment formed from cellulose acetate tow.

[0168] The downstream filter segment may optionally include flavoring agents, which can be provided in any preferred form. For example, the downstream filter segment may comprise one or more capsules, beads, or granules of the flavoring agent, or threads or filaments filled with one or more flavoring agents.

[0169] The downstream filter segment preferably has a low particle filtration efficiency.

[0170] The downstream filter segment preferably has an outer diameter approximately equal to the inner diameter of the hollow tubular element, so that the downstream filter segment is held within the hollow tubular element by friction fitting.

[0171] Preferably, the outer diameter of the downstream filter segment is 5 mm to 12 mm, more preferably 6 mm to 10 mm, and more preferably 7 mm to 8 mm.

[0172] Unless otherwise specified, the draw resistance (RTD) of a component or aerosol-generating article shall be measured in accordance with ISO 6565-2015. RTD refers to the pressure required to pump air through the entire length of the component. The terms “pressure drop” or “draw resistance” for a component or article may also refer to “resistance to draw.” Such terms generally refer to measurements performed in accordance with ISO 6565-2015, successfully executed under a test of a volumetric flow rate of 17.5 ml / s at the output or downstream end of the measured component, at a temperature of 22 degrees Celsius, a pressure of 101 kPa (approximately 760 Torr), and a relative humidity of 60%. The conditions for smoking and the specifications of the smoking machine are presented in ISO standard 3308 (ISO 3308:2000). The atmosphere for adjustment and testing is presented in ISO standard 3402 (ISO 3402:1999).

[0173] The draw-out resistance (RTD) of the downstream filter segment may be at least 0 mmH2O, or at least 3 mmH2O, or at least 6 mmH2O.

[0174] The RTD of the downstream filter segment may be 12 mmH2O or less, or 11 mmH2O or less, or 10 mmH2O or less.

[0175] As described above, the downstream filter segment may be formed from a fibrous filtration material. The downstream filter segment may be formed from a porous material. The downstream filter segment may be formed from a biodegradable material. The downstream filter segment may be formed from a cellulose material such as cellulose acetate. For example, the downstream filter segment may be formed from a bundle of cellulose acetate fibers having 10 to 15 denier per filament. For example, the downstream filter segment may be formed from a relatively low-density cellulose acetate tow, such as cellulose acetate tow containing fibers with 12 denier per filament.

[0176] The downstream filter segment may be formed from a polylactic acid-based material. The downstream filter segment may also be formed from a bioplastic material, preferably a starch-based bioplastic material. The downstream filter segment may be manufactured by injection molding or extrusion molding. Bioplastic materials are advantageous because they can provide a downstream filter segment structure that is easy and inexpensive to manufacture, with a specific complex cross-sectional profile that may include multiple relatively large airflow channels extending through the downstream filter segment material, providing suitable RTD properties.

[0177] 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.

[0178] The 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. The downstream filter segment may be connected to the hollow tubular element by a chipping wrapper.

[0179] The overall RTD of an aerosol-generating article may be at least 1 milliH2O. For example, the overall RTD of an aerosol-generating article may be at least 2 milliH2O, at least 3 milliH2O, at least 4 milliH2O, at least 5 milliH2O, at least 6 milliH2O, at least 7 milliH2O, at least 8 milliH2O, at least 9 milliH2O, at least 10 milliH2O, at least 15 milliH2O, at least 20 milliH2O, at least 30 milliH2O, at least 40 milliH2O, or at least 50 milliH2O.

[0180] The overall RTD of an aerosol-generating article may be 180 mmH2O or less. For example, the overall RTD of an aerosol-generating article may be 170 mmH2O or less, 160 mmH2O or less, 150 mmH2O or less, or 140 mmH2O or less.

[0181] The overall RTD of an aerosol-generating article may range from 1 mmH2O to 180 mmH2O. For example, the overall RTD of an aerosol-generating article may range from 5 mmH2O to 170 mmH2O, 10 mmH2O to 160 mmH2O, 20 mmH2O to 150 mmH2O, or 50 mmH2O to 140 mmH2O.

[0182] The aerosol-generating article may have an overall length of at least 40 millimeters, or at least 50 millimeters, or at least 60 millimeters.

[0183] The total length of the aerosol-generating article may be 90 millimeters or less, or 85 millimeters or less, or 80 millimeters or less.

[0184] In some embodiments, the total length of the aerosol-generating article is preferably 40 to 70 millimeters, more preferably 45 to 70 millimeters. In other embodiments, the total length of the aerosol-generating article is preferably 40 to 60 millimeters, more preferably 45 to 60 millimeters. In further embodiments, the total length of the aerosol-generating article is preferably 40 to 50 millimeters, more preferably 45 to 50 millimeters. In exemplary embodiments, the total length of the aerosol-generating article is about 45 millimeters.

[0185] The aerosol-generating article may have an outer diameter of at least 5 millimeters, at least 6 millimeters, or at least 7 millimeters.

[0186] The aerosol-generating article may have an outer diameter of approximately 12 mm or less, approximately 10 mm or less, or approximately 8 mm or less.

[0187] In some embodiments, the aerosol-generating article has an outer diameter of about 5 mm to about 12 mm, preferably about 6 mm to about 12 mm, and more preferably about 7 mm to about 12 mm. In other embodiments, the aerosol-generating article has an outer diameter of about 5 mm to about 10 mm, preferably about 6 mm to about 10 mm, and more preferably about 7 mm to about 10 mm. In further embodiments, the aerosol-generating article has an outer diameter of about 5 mm to about 8 mm, preferably about 6 mm to about 8 mm, and more preferably about 7 mm to about 8 mm. In other embodiments, the aerosol-generating article has an outer diameter of less than 7 mm.

[0188] The outer diameter of an aerosol-generating article may be substantially constant along its entire length. Alternatively, different parts of the aerosol-generating article may have different outer diameters.

[0189] The present invention also relates to an aerosol generating system comprising an aerosol generating article according to the present invention, relating to any embodiment described herein. The aerosol generating system also comprises an aerosol generating device comprising a device cavity for receiving an aerosol generating article and an induction heating device for induction heating a plurality of second particles of a single susceptor element.

[0190] The aerosol generator may have a distal end and an oral end opposite the distal end. The aerosol generator may include a housing. The housing of the aerosol generator may define a device cavity. Preferably, the device cavity is located at the oral end of the aerosol generator.

[0191] The device cavity may be referred to as the heating chamber of the aerosol generator. The device cavity may extend between a distal end and a mouth (or proximal) end. The distal end of the device cavity may be a closed end, and the mouth (or proximal) end may be an open end. The aerosol generating article may be inserted into the device cavity through the open end of the device cavity. The device cavity may be cylindrical in shape to conform to the same shape as the aerosol generating article.

[0192] The expression "internalized" may refer to the fact that a component or element is fully or partially contained within another component or element. For example, the expression "aerosol-generating article is contained within the device cavity" means that the aerosol-generating article is fully or partially contained within the device cavity of the aerosol-generating article. When an aerosol-generating article is contained within a device cavity, the aerosol-generating article may abut against the distal end of the device cavity. When an aerosol-generating article is contained within a device cavity, the aerosol-generating article may be substantially close to the distal end of the device cavity. The distal end of the device cavity may be defined by an end wall. When an aerosol-generating article is contained within a device cavity, the oral end of the aerosol-generating article may protrude from the oral end of the device cavity.

[0193] The length of the cavity in the device may be 15 mm to 80 mm, or 20 mm to 70 mm, or 25 mm to 60 mm, or 25 mm to 50 mm.

[0194] The length of the cavity in the device may be 25 to 29 millimeters, 26 to 29 millimeters, or 27 to 28 millimeters.

[0195] When an aerosol-generating article is received within the device cavity, it is preferable that the capsule be completely contained within the device cavity to optimize the heating of the aerosol-forming substrate within the capsule. Therefore, it is preferable that the length of the device cavity be greater than the length of the capsule.

[0196] The diameter of the device cavity may be 4 mm to 10 mm. The diameter of the device cavity may be 5 mm to 9 mm. The diameter of the device cavity may be 6 mm to 8 mm. The diameter of the device cavity may be 6 mm to 7 mm.

[0197] The diameter of the device cavity may be substantially the same as, or larger than, the diameter of the aerosol generating article. The diameter of the device cavity may be the same as the diameter of the aerosol generating article in order to establish a tight fit with the aerosol generating article.

[0198] The device cavity may be configured to establish a tight fit with the aerosol generating article received within the device cavity. A tight fit may refer to a blind fit. The aerosol generating device may have a peripheral wall. Such a peripheral wall may define a device cavity or a heating chamber. The peripheral wall defining the device cavity may be configured to engage in a tight fit with the aerosol generating article received within the device cavity, such that when received within the device, there is substantially no gap or empty space between the peripheral wall defining the device cavity and the aerosol generating article.

[0199] Such a tight fit can establish an airtight fit or configuration between the device cavity and the aerosol-generating article received therein.

[0200] This airtight configuration effectively eliminates any gaps or empty spaces between the peripheral walls defining the device cavity and the aerosol-generating articles through which air flows.

[0201] A tight fit with the aerosol-generating article may be established along the entire length of the device cavity or along a portion of the length of the device cavity.

[0202] An aerosol generator may include an airflow channel extending between a channel inlet and a channel outlet. The airflow channel may be configured to establish fluid communication between the inside of the device cavity and the outside of the aerosol generator. The airflow channel of the aerosol generator may be defined within the housing of the aerosol generator to enable fluid communication between the inside of the device cavity and the outside of the aerosol generator. When an aerosol-generating article is received in the device cavity, the airflow channel may be configured to provide airflow to the article in order to deliver the generated aerosol to a user who draws it in from the mouth end of the article.

[0203] The airflow channel of the aerosol generator may be defined within or by the peripheral wall of the housing of the aerosol generator. In other words, the airflow channel of the aerosol generator may be defined within the thickness of the peripheral wall, 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.

[0204] The airflow channel of the aerosol generator may extend from an inlet located at the mouth end or proximal end of the aerosol generator to an outlet located away from the mouth end of the device. The airflow channel may extend along a direction parallel to the longitudinal axis of the aerosol generator.

[0205] An induction heating device may comprise an inductor coil and a power supply configured to supply a high-frequency oscillating current to the inductor coil. As used herein, “high-frequency oscillating current” means an oscillating current having a frequency of about 500 kHz to about 30 MHz. An aerosol generator may comprise a DC / AC inverter for converting the DC current supplied by the DC power supply into an AC current. The inductor coil may be configured to generate a high-frequency oscillating electromagnetic field upon receiving the high-frequency oscillating current from the power supply. During use, the high-frequency oscillating electromagnetic field induces heating of the susceptor material of the aerosol generating article. Preferably, the inductor coil is configured to generate the high-frequency oscillating electromagnetic field within the device cavity. The inductor coil may substantially surround the device cavity. The inductor coil may extend at least partially along the length of the device cavity.

[0206] During use, the induction heating device may be controlled to heat the susceptor material within a specified operating temperature range below the maximum operating temperature. The operating temperature range within the heating chamber (or device cavity) is preferably about 150°C to about 300°C. The operating temperature range of the heater may be about 150°C to about 250°C.

[0207] The aerosol generator may be equipped with a power supply. The power supply may be a DC power supply. In some embodiments, the power supply is a battery. The power supply may be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery (e.g., lithium cobalt, lithium iron phosphate, or lithium polymer battery). However, in some embodiments, the power supply may be another form of charge storage device, such as a capacitor. The power supply 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.

[0208] The aerosol generator may be equipped with a penetration device for penetrating a capsule when an aerosol generating article is inserted into the device cavity. As described above, penetration of the capsule may be necessary to establish one or more airflow paths through the capsule.

[0209] The present invention also relates to a method for forming capsules for an aerosol generating article to generate an inhalable aerosol when heated. The method comprises providing a plurality of first particles, each comprising an aerosol-forming substrate, and providing a plurality of second particles, each comprising a susceptor material and not comprising an aerosol-forming substrate. The method further comprises mixing the plurality of first particles with the plurality of second particles to form a particle mixture. The method also comprises providing a capsule outer wall defining an internal cavity, and inserting the particle mixture into the internal cavity to form a capsule comprising the capsule outer wall and the particle mixture inside the internal cavity. The capsule may have any of the preferred or optional features of the capsule described above.

[0210] The present invention also relates to another method for forming a capsule for an aerosol generating article to generate an inhalable aerosol when heated. The method includes providing a plurality of first particles, each comprising an aerosol-forming substrate, and a single susceptor element. The method further includes providing a capsule outer wall defining an internal cavity, and inserting the plurality of first particles and the single susceptor element into the internal cavity to form a capsule comprising the capsule outer wall and the plurality of first particles and the single susceptor element within the internal cavity. The capsule may have any of the preferred or optional features of the capsule described above.

[0211] [Examples] A non-exclusive list of non-limiting embodiments is provided below. One or more features of these embodiments may be combined with one or more features of other embodiments, models, or aspects described herein.

[0212] Example 1: An aerosol generating article for generating an inhalable aerosol when heated, wherein the aerosol generating article comprises a capsule, and the capsule is The outer wall of the capsule defines the internal cavity, A plurality of first particles within an internal cavity, each of which contains an aerosol-forming substrate, comprising: The capsule is Multiple second particles within an internal cavity, each of which contains a susceptor material and does not contain an aerosol-forming substrate, or An aerosol-generating article further comprising only one of the single susceptor elements within an internal cavity. Example 2: The capsule is an aerosol-generating article as described in Example 1, comprising a plurality of second particles. Example 3: The aerosol generating article according to Example 2, wherein multiple second particles are mixed with multiple first particles. Example 4: The aerosol generating article according to Example 2 or 3, wherein each of the first particles has an outer surface including a first shape, and each of the second particles has an outer surface including a second shape, wherein a portion of the second shape is configured to engage with a portion of the first shape. Example 5: The aerosol generating article according to Example 4, wherein a portion of the first shape is configured to receive a portion of the second shape. Example 6: The aerosol-generating article according to Example 4 or 5, wherein a portion of the second shape is configured to receive a portion of the first shape. Example 7: An aerosol-generating article according to any of Examples 2 to 6, wherein each of the first particles has a first cross-sectional dimension, each of the second particles has a second cross-sectional dimension, and the first and second cross-sectional dimensions are the same. Example 8: The aerosol generating article according to Example 7, wherein each of the first particles has a spherical shape, each of the second particles has a spherical shape, the first cross-sectional dimension is the diameter of each of the first particles, and the second cross-sectional dimension is the diameter of each of the second particles. Example 9: An aerosol generating article according to any of Examples 2 to 8, wherein each of the first particles has a first mass, each of the second particles has a second mass, and the first mass and the second mass are the same. Example 10: An aerosol-generating article according to any of Examples 2 to 9, wherein each of the first particles has a first density, each of the second particles has a second density, and the first and second densities are the same. Example 11: The aerosol-generating article according to any of Examples 2 to 10, wherein the ratio of the total number of first particles to the total number of second particles is 0.9 to 1 to 1.1 to 1. Example 12: Each of the second particles has a homogeneous structure, as described in any of Examples 2 to 11. Example 13: Each of the second particles has a heterogeneous structure, as described in any of Examples 2 to 11. Example 14: Each of the second particles comprises an aerosol-generating article according to any of Examples 2 to 11, comprising multiple layers of susceptor material. Example 15: The aerosol generating article according to Example 14 comprises a first layer containing a first susceptor material and a second layer containing a second susceptor material, wherein the first susceptor material is different from the second susceptor material. Example 16: Each of the second particles has a non-uniform density, as described in any of Examples 2 to 15. Example 17: Each of the second particles comprises an aerosol-generating article according to any of Examples 2 to 16, comprising a shell of susceptor material. Example 18: The aerosol generating article described in Example 17, wherein the shell of the susceptor material defines a void inside the shell of the susceptor material. Example 19: The aerosol-generating article according to Example 18, wherein the void is filled with one of the following: air, an inert gas, a partial vacuum, and a vacuum. Example 20: The aerosol-generating article described in Example 18, wherein the void is filled with a non-susceptor material. Example 21: The aerosol-generating article according to Example 20, wherein the shell of the susceptor material has a first density, and the non-susceptor material has a second density, the second density being less than the first density. Example 22: The non-susceptor material is an aerosol-generating article as described in Example 20 or 21, comprising a non-conductive foam. Example 23: An aerosol generating article according to any of Examples 2 to 22, wherein each of the second particles has at least one of a size and shape for increasing the surface area of ​​the second particle. Example 24: Each of the second particles comprises a plurality of fins, the aerosol generating article according to any of Examples 2 to 23. Example 25: Each fin is formed from a susceptor material in the aerosol generating article described in Example 24. Example 26: The aerosol-generating article according to Example 24 or 25, wherein each of the second particles comprises a plurality of discs, each disc forming one of a plurality of fins. Example 27: The discs are arranged in a stacked manner in the aerosol-generating article described in Example 26. Example 28: The aerosol generating article according to Example 27, wherein the disks are interconnected by a central column. Example 29: The central column is formed from a susceptor material, and is an aerosol generating article as described in Example 28. Example 30: The discs are separated from each other by gaps, as described in any of Examples 26 to 29, in an aerosol-generating article. Example 31: An aerosol generating article according to any of Examples 2 to 30, wherein each of the second particles has at least one of a size and shape for minimizing the interaction of the second particles with each other. Example 32: An aerosol generating article according to any of Examples 2 to 31, wherein each of the second particles has at least one of a size and shape to maximize contact between the second particle and the first particle. Example 33: An aerosol-generating article according to any of Examples 2 to 32, wherein each of the first particles has a first size, and each of the second particles has a second size, the second size being different from the first size. Example 34: An aerosol-generating article according to any of Examples 2 to 32, wherein each of the first particles has a first size, and each of the second particles has a second size, the second size being the same as the first size. Example 35: An aerosol-generating article according to any of Examples 2 to 34, wherein each of the first particles has a first shape, and each of the second particles has a second shape, the second shape being different from the first shape. Example 36: An aerosol generating article according to any of Examples 2 to 34, wherein each of the first particles has a first shape, and each of the second particles has a second shape, the second shape being identical to the first shape. Example 37: An aerosol-generating article according to any of Examples 2 to 36, wherein each of the first particles has a first mass, each of the second particles has a second mass, and the difference between the first mass and the second mass is less than 10 percent of the first mass. Example 38: An aerosol-generating article according to any of Examples 2 to 37, wherein each of the first particles has a first density, each of the second particles has a second density, and the difference between the first density and the second density is less than 10 percent of the first density. Example 39: Each of the first particles has a convex shape, an aerosol generating article according to any one of Examples 1 to 38. Example 40: An aerosol-generating article according to any of Examples 1 to 39, wherein each of the first particles has a spherical, elliptical, or egg-shaped form. Example 41: Each of the second particles has a convex shape, an aerosol generating article according to any of Examples 2 to 40. Example 42: The aerosol-generating article according to any of Examples 2 to 41, wherein each of the second particles has a spherical, elliptical, or egg-shaped form. Example 43: Each of the second particles has a star-shaped polyhedron, the aerosol generating article according to any of Examples 2 to 40. Example 44: The aerosol generating article according to Example 1, wherein the capsule comprises a single susceptor element, and the single susceptor element comprises a susceptor material. Example 45: The susceptor material is an aerosol-generating article according to any one of Examples 1 to 44, comprising at least one metal. Example 46: The susceptor material is an aerosol-generating article according to any one of Examples 1 to 45, comprising at least one metal alloy. Example 47: The susceptor material is an aerosol-generating article as described in any of Examples 1 to 46, which includes a foam. Example 48: Each of the first particles is an aerosol-generating article according to any of Examples 1 to 47, which does not contain susceptor material. Example 49: The aerosol-forming substrate is an aerosol-generating article according to any one of Examples 1 to 48, which includes a solid aerosol-forming substrate. Example 50: The aerosol-forming substrate is an aerosol-generating article according to any one of Examples 1 to 49, comprising at least one of tobacco and nicotine. Example 51: The capsule outer wall is formed of an impermeable material, an aerosol generating article as described in any of Examples 1 to 50. Example 52: The aerosol generating article according to any one of Examples 1 to 51, wherein the capsule comprises at least one air intake port extending through the outer wall of the capsule and at least one air outlet extending through the outer wall of the capsule. Example 53: The aerosol generating article according to Example 52, wherein at least one air intake and at least one air outlet are positioned to define at least one airflow path through an internal cavity between at least one air intake and at least one air outlet. Example 54: The aerosol generating article according to Example 52 or 53, wherein each of the first particles is larger than each of at least one air intake and at least one air outlet. Example 55: An aerosol generating article according to Example 52, 53, or 54, combined with Example 2, wherein each of the second particles is larger than each of at least one air intake and at least one air outlet. Example 56: The aerosol-generating article according to any of Examples 1 to 55, wherein the internal cavity of the capsule has volume, and the first particle and the second particle or a single susceptor element together occupy at least 70 percent of the volume of the internal cavity. Example 57: An aerosol generating article according to any one of Examples 1 to 56, further comprising a hollow tubular element, wherein the capsule is positioned within the hollow tubular element. Example 58: The aerosol generating article according to Example 57, wherein the capsule is positioned at the upstream end of a hollow tubular element. Example 59: The aerosol-generating article according to Example 57 or 58, wherein the hollow tubular element is formed from at least one of paper and cardboard. Example 60: The aerosol generating article according to Examples 57, 58, or 59, wherein the capsule is held within a hollow tubular element by a tight fit. Example 61: An aerosol generating article according to any one of Examples 57 to 60, further comprising a filter element positioned downstream of a hollow tubular element. Example 62: The aerosol generating article according to Example 61, wherein the filter element is positioned adjacent to the downstream end of a hollow tubular element. Example 63: The aerosol generating article according to Example 61 or 62, wherein the filter element is positioned at the downstream end of the aerosol generating article. Example 64: The aerosol generating article according to Examples 61, 62, or 63, wherein the filter element is separated from the capsule through a gap to define a cavity between the capsule and the filter element. Example 65: Aerosol generation system, an aerosol generating article described in any of Examples 1 to 64, Aerosol generator, A device cavity for receiving at least a portion of an aerosol-generating article, An aerosol generating system comprising an aerosol generating device, which includes an induction heating device for inductively heating multiple second particles or a single susceptor element; and an aerosol generating device. Example 66: A method for forming a capsule for an aerosol generating article that generates an aerosol that can be inhaled when heated, To provide a plurality of first particles, each containing an aerosol-forming substrate, To provide a plurality of second particles, each containing a susceptor material and not containing an aerosol-forming substrate, To form a mixture of particles, multiple first particles are mixed with multiple second particles. To provide a capsule outer wall that defines the internal cavity, and A method for forming a capsule containing a particle mixture in an internal cavity and an outer wall of the capsule. Example 67: A method for forming a capsule for an aerosol generating article that generates an aerosol that can be inhaled when heated, To provide a plurality of first particles, each containing an aerosol-forming substrate, To provide a single susceptor element, To provide a capsule outer wall that defines the internal cavity, and A method comprising inserting a plurality of first particles and a single susceptor element into an internal cavity in order to form a capsule comprising a capsule outer wall and an internal cavity containing a plurality of first particles and a single susceptor element. Example 68: The method according to Example 66 or Example 67, wherein the capsule is a capsule having any of the features of Examples 1 to 64.

[0213] The present invention will now be further described with reference to the attached drawings.

[0214] Figure 1 shows an aerosol generating article 10 comprising a hollow tubular element 12 and a capsule 14 attached to the upstream end of the hollow tubular element 12. The aerosol generating article 10 extends from an upstream or distal end 16 to a downstream or mouth end 18. The upstream end 16 coincides with the upstream end of the capsule 14. The downstream end 18 coincides with the downstream end of the hollow tubular element 12.

[0215] The aerosol generating article 10 has an overall length of approximately 45 mm and an outer diameter of approximately 7.2 mm.

[0216] The hollow tubular element 12 is formed from a cylindrical cardboard tube with a wall thickness of approximately 0.25 millimeters. The hollow tubular element 12 defines an internal channel. The hollow tubular element 12 has a length of approximately 45 millimeters, an outer diameter of approximately 7.2 millimeters, and an inner diameter of approximately 6.7 millimeters. The capsule 14 is mounted at the upstream end within the internal channel of the hollow tubular element 12.

[0217] Figure 2 shows a more detailed cross-sectional view of a suitable capsule 14 for use in the aerosol generating article 10 of Figure 1.

[0218] The capsule 14 is a two-part capsule formed from an impermeable polymer such as HPMC. The capsule 14 has an elongated capsule (spherical cylindrical) shape with a round cross-section. The capsule comprises a capsule outer wall 20 defining an internal cavity 22 containing a plurality of first particles 24 and a plurality of second particles 25 mixed with the plurality of first particles 24. Each of the first particles 24 contains an aerosol-forming substrate, which is a solid aerosol-forming substrate containing nicotine. Each of the second particles 25 contains a susceptor material, which includes stainless steel. The capsule outer wall 20 is defined by a cylindrical wall 26 and opposing hemispherical end walls 28, 29 formed integrally with the cylindrical wall 26. The capsule 14 has a length of approximately 20 millimeters and an outer diameter of approximately 6.7 millimeters. Thus, the outer diameter of the capsule 14 is similar to the inner diameter of the hollow tubular element 12, and as a result, the capsule is held within the hollow tubular element 12 by friction fitting.

[0219] The downstream filter segment 50 extends from the capsule 14 through a gap and defines an empty cavity 52 inside the hollow tubular element 12. The empty cavity 52 has a length of approximately 25 millimeters. The downstream filter segment 50 extends to the downstream end of the hollow tubular element 12, and as a result, the downstream end of the downstream filter segment 50 substantially coincides with the downstream end 18 of the aerosol generating article 10.

[0220] The downstream filter segment 50 has a length of approximately 10 millimeters and comprises a low-density cellulose acetate filter segment. The RTD of the downstream filter segment 50 is approximately 10 mmH2O.

[0221] The capsule 14 is mounted inside the hollow tubular element 12 such that approximately 30 percent of the capsule 14 extends beyond the upstream end of the hollow tubular element 12. Thus, the capsule 14 protrudes from the upstream end of the hollow tubular element 12, and the upstream end of the capsule 14 defines the upstream end 16 of the aerosol generating article 10.

[0222] The capsule has an internal volume of approximately 600 cubic millimeters and contains approximately 200 milligrams of aerosol-forming substrate. Therefore, the capsule contains approximately 0.33 milligrams of aerosol-forming substrate per cubic millimeter of internal cavity 22.

[0223] The capsule 14 is equipped with a plurality of air outlets 30, each of which is in the form of a hole extending through the outer wall 20 of the capsule, each having a diameter of approximately 0.5 millimeters. The plurality of air intakes 30 are separated by gaps in a circular formation on the upstream end wall 28 of the capsule 14.

[0224] The capsule 14 further comprises a plurality of air outlets 32, each of which is in the form of a hole extending through the outer wall 20 of the capsule, each having a diameter of approximately 0.5 millimeters. The plurality of air outlets 32 are separated by gaps in a circular formation on the downstream end wall 29 of the capsule 14.

[0225] The projection of the hollow tubular element 12 of the capsule 14 from the upstream end means that the air intake 30 is located outside the hollow tubular element 12.

[0226] The air intake port 30 and the air outlet port 32 are arranged at opposing ends of the capsule 14 so as to be substantially symmetrical to each other.

[0227] The arrangement of the air intake port 30 and the air outlet port 32 defines multiple airflow paths through the internal cavity 22 of the capsule 14 so that, during heating, ambient air can pass through the capsule 14 and come into contact with and be drawn out of the first particles 24 of the solid first aerosol-forming substrate. The aerosol generated from the first particles 24 of the solid first aerosol-forming substrate during heating is drawn out of the capsule 14 along the hollow tubular element 12, together with the ambient air, through the air outlet port 32 to the downstream end 18 of the aerosol-generating article 10.

[0228] Each of the first particles 24 of the solid first aerosol-forming substrate contained within the capsule 14 is elliptical in shape with a major axis of 0.8 millimeters. Those skilled in the art will understand that other shapes and sizes of the first particles 24 may be used. For example, in an alternative embodiment, each of the first particles is substantially spherical in shape with a diameter of 0.8 millimeters. Each of the first particles 24 of the aerosol-forming substrate is formed from a gel composition having the following composition: [Table 1] JPEG2026512622000002.jpg4075

[0229] Figure 3 shows an aerosol generating system 100 according to one embodiment of the present invention. The aerosol generating system 100 comprises an aerosol generating article 10 as described above. The aerosol generating system 100 further comprises an aerosol generating device 102. The aerosol generating device 102 comprises a device housing 145. The device housing 145 defines a device cavity 142 for receiving the upstream end of the aerosol generating article 10. The device cavity 142 has an inner diameter substantially corresponding to the outer diameter of the aerosol generating article 10. The aerosol generating device 102 further comprises an induction heating device 141 comprising an inductor surrounding a portion of the device cavity 142. When the aerosol generating article 10 is received within the device cavity 142, the capsule 14 is positioned within the inductor coil. During use, a control device (not shown) supplies alternating current from a power source (not shown) to the inductor coil so that the inductor coil generates a changing magnetic field. The changing magnetic field inductively heats the susceptor material of the second particle 25, which in turn heats the first particle 24 to generate an aerosol from the solid aerosol-forming substrate. The apparatus housing 145 defines a plurality of apparatus air intakes 150 communicating with the apparatus cavity 142. Thus, the aerosol generation system 100 has an airflow path that extends from the apparatus air intakes 150 through the capsule 14 via the capsule air intake 30 and capsule air outlet 32, and through a hollow tubular element 12 and a downstream filter segment 50 for delivering the aerosol to the user.

[0230] Figures 4 and 5 show alternative configurations of the second particles of the capsule 14. In particular, Figures 4 and 5 show second particles 225 comprising disks 227 with multiple gaps between them, each disk 227 being formed of a susceptor material including stainless steel. The disks 227 are interconnected by a central column 229, which is preferably also formed of a susceptor material such as stainless steel. The stacking of disks 227 with gaps between them significantly increases the surface area of ​​the second particles 225 compared to spherical particles of the same size. The increased surface area increases the rate of heat radiation from the second particles 225, which provides more efficient heating of the first particles 24.

[0231] Figures 6 and 7 show further alternative forms of the second particle of the capsule 14. In particular, Figures 6 and 7 show a second particle 325 having a star-shaped polyhedron formed from a susceptor material including stainless steel. As shown in Figure 7, which shows the second particle 325 together with a plurality of first particles 24, each having a spherical shape, the star-shaped polyhedron of the second particle 325 facilitates the nesting of the second particle 325 among the plurality of first particles 24. The increased nesting facilitates the mixing of the first particles 24 and the second particle 325 within the capsule 14 and facilitates heat transfer from the second particle 325 to the first particles 24.

[0232] Figure 8 shows a cross-sectional view of an alternative capsule 414 for use in the aerosol generating article 10 of Figure 1. The capsule 414 in Figure 8 is similar to the capsule 14 in Figure 2, where the same reference numerals indicate the same parts. Instead of multiple second particles 25, the capsule 414 includes a single susceptor element 425 formed of a susceptor material including stainless steel. The single susceptor element 425 is rod-shaped and extends along substantially the entire length of the internal cavity 22 of the capsule 414. During use, the single susceptor element 425 is surrounded by multiple first particles 24 so that heat is transferred from the single susceptor element 425 to the first particles 24.

Claims

1. An aerosol generating article for generating an inhalable aerosol when heated, wherein the aerosol generating article comprises a capsule, and the capsule is The outer wall of the capsule defines the internal cavity, A plurality of first particles within the internal cavity, each of which contains an aerosol-forming substrate, The plurality of second particles in the internal cavity, each of which contains a susceptor material and does not contain an aerosol-forming substrate, comprises The aforementioned capsule is Each of the first particles having a first cross-sectional dimension, and each of the second particles having a second cross-sectional dimension, wherein the first and second cross-sectional dimensions are the same, each of the first particles is spherical, each of the second particles is spherical, the first cross-sectional dimension is the diameter of each of the first particles, and the second cross-sectional dimension is the diameter of each of the second particles, each of the first particles having a first cross-sectional dimension, and each of the second particles having a second cross-sectional dimension, Each of the first particles having a first mass and each of the second particles having a second mass, wherein the first mass and the second mass are the same, Each of the first particles having a first density and each of the second particles having a second density, wherein the first density and the second density are the same, The ratio of the total number of first particles to the total number of second particles is 0.2 to 1 to 5 to 1, or An aerosol-generating article further comprising at least one of the ratios of the total mass of a first particle to the total mass of a second particle, ranging from 0.2:1 to 5:

1.

2. The aerosol generating article according to claim 1, wherein the plurality of second particles are mixed with the plurality of first particles.

3. The aerosol generating article according to claim 1 or 2, wherein each of the first particles has an outer surface including a first shape, and each of the second particles has an outer surface including a second shape, wherein a portion of the second shape is configured to engage with a portion of the first shape.

4. The aerosol generating article according to claim 3, wherein a part of the first shape is configured to receive a part of the second shape.

5. The aerosol generating article according to claim 3 or 4, wherein a part of the second shape is configured to receive a part of the first shape.

6. The aerosol generating article according to any one of claims 1 to 5, wherein each of the first particles does not contain susceptor material.

7. Aerosol generation system, an aerosol generating article according to any one of claims 1 to 6, Aerosol generator, A device cavity for receiving at least a portion of the aerosol generating article, An aerosol generating system comprising an aerosol generating device, which includes an induction heating device for induction heating of the plurality of second particles or a single susceptor element.

8. A method for forming a capsule for an aerosol generating article that generates an aerosol that can be inhaled when heated, To provide a plurality of first particles, each containing an aerosol-forming substrate, To provide a plurality of second particles, each containing a susceptor material and not containing an aerosol-forming substrate, Mixing the plurality of first particles with the plurality of second particles in order to form a mixture of particles, To provide a capsule outer wall that defines the internal cavity, and To form a capsule comprising the outer wall of the capsule and the particle mixture in the internal cavity, the particle mixture is inserted into the internal cavity, and the capsule is formed Each of the first particles having a first cross-sectional dimension, and each of the second particles having a second cross-sectional dimension, wherein the first and second cross-sectional dimensions are the same, each of the first particles is spherical, each of the second particles is spherical, the first cross-sectional dimension is the diameter of each of the first particles, and the second cross-sectional dimension is the diameter of each of the second particles, each of the first particles having a first cross-sectional dimension, and each of the second particles having a second cross-sectional dimension, Each of the first particles having a first mass and each of the second particles having a second mass, wherein the first mass and the second mass are the same, Each of the first particles having a first density and each of the second particles having a second density, wherein the first density and the second density are the same, The ratio of the total number of first particles to the total number of second particles is 0.2 to 1 to 5 to 1, or A method comprising insertion, further comprising at least one of the ratios of the total mass of a first particle to the total mass of a second particle, ranging from 0.2:1 to 5:1.

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