Aerosol-generating article comprising an airflow pathway

Abstract

There is provided an aerosol-generating article (10). The aerosol-generating article (10) is for use with an aerosol-generating device to generate an aerosol. The aerosol-generating article (10) comprises a first planar external surface (21) and a second planar external surface (22). The aerosol-generating article (10) comprises a cavity (30) and a frame (150) at least partially defining the cavity (30). The aerosol-generating article (10) comprises an air inlet (11) and an air outlet (12). The aerosol-generating article (10) comprises an aerosol-generating substrate (40) positioned within the cavity (30) between the air inlet (11) and the air outlet (12). The aerosol-generating article (10) defines an airflow pathway extending through the cavity (30) from the airflow inlet (11) to the airflow outlet (12). The aerosol-generating article (10) has a length (158) extending between a first end of the aerosol-generating article (10) and a second end of the generating article (10), wherein the length (158) is the largest dimension of the aerosol-generating article (10). A length (156) of the airflow pathway is less than the length (158) of the aerosol-generating article (10).

Description

[0001] AEROSOL-GENERATING ARTICLE COMPRISING AN AIRLFOW PATHWAY

[0002] The present disclosure relates to an aerosol-generating article. The present disclosure also relates to an aerosol-generating device for use with the aerosol-generating article. The present disclosure also relates to an aerosol-generating system comprising the aerosolgenerating device and the aerosol-generating article.

[0003] A typical aerosol-generating system comprises an aerosol-generating device and an aerosol-generating article comprising an aerosol-generating substrate. In use, the aerosolgenerating device is arranged to heat a heating element that is positioned near, or in contact with, the aerosol-generating substrate which causes the aerosol-generating substrate to heat up and release volatile compounds. These volatile compounds are then entrained in air that is drawn through the aerosol-generating article. As the volatile compounds cool, they condense to form an aerosol that can be inhaled by a consumer.

[0004] A typical aerosol-generating article may appear similar and have similar dimensions to a conventional cigarette. For example, such an aerosol-generating article may be substantially cylindrical and comprise an aerosol-generating substrate in addition to other components such as mouthpiece filter element and a cooling element, which are arranged in the form of a rod and wrapped in a cigarette paper.

[0005] However, a significant portion of the aerosol-generating substrate in these cylindrical aerosol-generating articles may not be sufficiently heated to form an aerosol during use. This is undesirable since the insufficiently heated portion of the aerosol-generating substrate contributes to the cost of manufacture and transport of the aerosol-generating article but does not contribute to the aerosol delivered to the consumer. Moreover, the components of these cylindrical aerosolgenerating articles normally need to have the same or very similar outer diameters so that they can be brought together, accurately positioned in axial alignment and wrapped in a cigarette paper. This can lead to increased cost and complexity of manufacture. Furthermore, at least one of insufficient heating and poorly managed airflow through the aerosol-generating article may result in undesirable condensation of aerosol within the aerosol-generating article or an aerosolgenerating device during use.

[0006] It is an objective of the present disclosure to provide an aerosol-generating article in which a greater portion of the aerosol-generating substrate is sufficiently heated to form an aerosol during use. It is also an objective of the present disclosure to provide an aerosol-generating article that can be manufactured relatively efficiently and cheaply. It is also an objective of the present disclosure to provide an aerosol-generating article that reduces or minimises the condensation of aerosol inside the aerosol-generating article or an aerosol-generating device during use.

[0007] According to the present disclosure, there is provided an aerosol-generating article. The aerosol-generating article is for use with an aerosol-generating device to generate an aerosol. The aerosol-generating article comprises a first planar external surface and a second planar external surface. The aerosol-generating article comprises a cavity and a frame at least partially defining the cavity. The aerosol-generating article comprises an air inlet and an air outlet. The aerosol-generating article comprises an aerosol-generating substrate positioned within the cavity between the air inlet and the air outlet. The aerosol-generating article defines an airflow pathway extending through the cavity from the airflow inlet to the airflow outlet. The aerosol-generating article has a length extending between a first end of the aerosol-generating article and a second end of the generating article, wherein the length is the largest dimension of the aerosol-generating article. A length of the airflow pathway is less than the length of the aerosol-generating article.

[0008] Advantageously, the frame may allow the aerosol-generating article to be relatively thin whilst maintaining structural rigidity.

[0009] Advantageously, the first planar external surface and the second planar external surface allow for good contact with an external heater, particularly an external heater, of an aerosolgenerating device, thereby providing optimum heating of the aerosol-generating substrate.

[0010] Advantageously, aerosol-generating articles of the present disclosure may be heated along substantially their entire length and width, thereby allowing the entire aerosol-generating substrate to be sufficiently heated to generate an aerosol.

[0011] Advantageously, aerosol-generating articles of the present disclosure may be manufactured by layering sheet materials which can be achieved through a continuous manufacturing process, thereby resulting in an aerosol-generating article that is relatively easy and cheap to manufacture.

[0012] Aerosol-generating articles of the present disclosure define an airflow pathway through a cavity from an airflow inlet to an airflow outlet, wherein a length of the airflow pathway is less than the length of the aerosol-generating article. This arrangement may provide a number of advantages.

[0013] Advantageously, the short airflow pathway may reduce or eliminate void space within the cavity, wherein void space refers to one or more spaces within the cavity that are not occupied by the aerosol-generating substrate. Advantageously, reducing or eliminating void space within the cavity may reduce or minimise condensation of aerosol within the cavity during use.

[0014] In embodiments in which the airflow exiting the aerosol-generating article is mixed with ventilation air, it may be preferable to maintain a large temperature difference between the higher temperature airflow exiting the aerosol-generating article and the lower temperature ventilation air to improve aerosol nucleation. Advantageously, the short airflow pathway may help to maintain a relatively high temperature of the airflow exiting the aerosol-generating article.

[0015] Advantageously, maintaining a relatively high temperature of the airflow exiting the aerosol-generating article may allow a configuration in which a ventilation airflow is moved downstream of the aerosol-generating article. Advantageously, this may facilitate providing one or more ventilation airflow apertures on an aerosol-generating device or a reusable mouthpiece rather than providing the one or more ventilation airflow apertures on the aerosol-generating article. Advantageously, this may reduce the manufacturing costs of the aerosol-generating article. Advantageously, providing one or more ventilation airflow apertures on a reusable aerosol-generating device or a reusable mouthpiece may facilitate more precise formation of the one or more ventilation airflow apertures.

[0016] The passage of airflow through the airflow inlet and the airflow outlet may result in turbulent airflow, which may promote undesirable condensation of aerosol within the aerosol-generating article. Advantageously, the short airflow pathway may facilitate positioning of the air inlet and the air outlet as close as possible to the aerosol-generating substrate. This may be particularly advantageous in embodiments in which the aerosol-generating substrate is heated during use, since it may position the air inlet and the air outlet as close as possible to the heat source. Advantageously, this may increase or maximise the temperature of the airflow through the air inlet and the air outlet, which may reduce or minimise condensation of aerosol that may otherwise occur as a result of turbulent airflow at the air inlet and the air outlet.

[0017] Preferably, the length of the airflow pathway is the shortest airflow distance through the cavity from the airflow inlet to the airflow outlet. Preferably, the shortest airflow distance through the cavity from the airflow inlet to the airflow outlet is a straight line. Advantageously, a straight line may promote laminar airflow through the cavity and reduce turbulent airflow within the aerosol-generating article. Advantageously, reducing turbulent airflow may reduce or minimise condensation of aerosol within the aerosol-generating article.

[0018] The length of the airflow pathway may be equal to or less than 90 percent of the length of the aerosol-generating article, optionally equal to or less than 80 percent of the length of the aerosol-generating article, optionally equal to or less than 70 percent of the length of the aerosolgenerating article, optionally equal to or less than 60 percent of the length of the aerosolgenerating article, or optionally equal to or less than 50 percent of the length of the aerosolgenerating article.

[0019] The aerosol-generating substrate may be arranged in the cavity so that the airflow pathway extends through the aerosol-generating substrate. Advantageously, arranging the aerosol-generating substrate in the cavity so that the airflow passes through the aerosolgenerating may reduce or eliminate void space within the cavity. Advantageously, reducing or eliminating void space in the cavity may reduce or minimise the risk of condensation of aerosol within the cavity.

[0020] The aerosol-generating substrate may have a length extending parallel with the airflow pathway. Preferably, the length of the aerosol-generating substrate is at least 80 percent of the length of the airflow pathway, preferably at least 90 percent of the length of the airflow pathway, preferably wherein the length of the aerosol-generating substrate is the same as the length of the airflow pathway. Advantageously, providing an aerosol-generating substrate with a length that is similar to or the same as the length of the airflow pathway may reduce or minimise void space within the cavity.

[0021] The length of the airflow pathway may be perpendicular to the length of the aerosolgenerating article. The length of the airflow pathway may extend in a direction parallel to a width of the aerosol-generating article. Advantageously, arranging the length of the airflow pathway perpendicular to the length of the aerosol-generating article may reduce the length of the airflow pathway while maintaining an overall size and shape of the aerosol-generating article when compared to an aerosol-generating article in which a length of an airflow pathway extends parallel with the length of the aerosol-generating article.

[0022] The frame may at least partially define the first end and the second end of the aerosolgenerating article. The frame may at least partially define a first side of the aerosol-generating article extending between the first end and the second end. The frame may at least partially define a second side of the aerosol-generating article extending between the first end and the second end. The air inlet may extend through the first side of the aerosol-generating article and the air outlet may extend through the second side of the aerosol-generating article. Each of the first planar surface and the second planar surface may be perpendicular to each of the first end, the second end, the first side, and the second side.

[0023] The cavity may be a first cavity, the aerosol-generating article further comprising a second cavity, wherein the frame at least partially defines the second cavity.

[0024] The aerosol-generating substrate may be a first aerosol-generating substrate, the aerosolgenerating article further comprising a second aerosol-generating substrate positioned within the second cavity.

[0025] The air inlet may be a first air inlet and the air outlet may be a second air outlet. The aerosol-generating article may further comprise a second air inlet and a second air outlet, wherein the second aerosol-generating substrate is positioned within the second cavity between the second air inlet and the second air outlet. The airflow pathway may be a first airflow pathway, wherein the aerosol-generating article defines a second airflow pathway extending through the second cavity from the second airflow inlet to the second airflow outlet, and wherein a length of the second airflow pathway is less than the length of the aerosol-generating article.

[0026] Preferably, the length of the second airflow pathway is the shortest airflow distance through the second cavity from the second airflow inlet to the second airflow outlet. Preferably, the shortest airflow distance through the second cavity from the second airflow inlet to the second airflow outlet is a straight line.

[0027] Preferably, the length of the second airflow pathway is equal to or less than 90 percent of the length of the aerosol-generating article, optionally equal to or less than 80 percent of the length of the aerosol-generating article, optionally equal to or less than 70 percent of the length of the aerosol-generating article, optionally equal to or less than 60 percent of the length of the aerosol-generating article, or optionally equal to or less than 50 percent of the length of the aerosol-generating article.

[0028] Preferably, the second aerosol-generating substrate is arranged in the second cavity so that the second airflow pathway extends through the second aerosol-generating substrate,

[0029] The second aerosol-generating substrate may have a length extending parallel with the second airflow pathway. Preferably, the length of the second aerosol-generating substrate is at least 80 percent of the length of the second airflow pathway, preferably at least 90 percent of the length of the second airflow pathway, preferably wherein the length of the second aerosolgenerating substrate is the same as the length of the second airflow pathway,

[0030] The length of the second airflow pathway may be perpendicular to the length of the aerosol-generating article. The length of the airflow pathway may extend in a direction parallel to a width of the aerosol-generating article.

[0031] The frame may at least partially define the first end and the second end of the aerosolgenerating article. The frame may at least partially define a first side of the aerosol-generating article extending between the first end and the second end. The frame may at least partially define a second side of the aerosol-generating article extending between the first end and the second end. The second air inlet may extend through the first side of the aerosol-generating article and the second air outlet may extend through the second side of the aerosol-generating article. Each of the first planar surface and the second planar surface may be perpendicular to each of the first end, the second end, the first side, and the second side.

[0032] The length of the airflow pathway may be parallel with the length of the aerosol-generating article.

[0033] The aerosol-generating article may comprise an inlet chamber at least partially defined by the frame, wherein the inlet chamber has an open end at the first end of the aerosol-generating article and a second end spaced apart from the open end, and wherein the air inlet provides fluid communication between the second end of the inlet chamber and the cavity. Advantageously, the inlet chamber may facilitate the manufacture of an aerosol-generating article having a device length while also facilitating the positioning of the air inlet away from the first end of the aerosolgenerating article to provide the short airflow pathway length between the air inlet and the air outlet. The aerosol-generating article may comprise an inlet opening defining the open end of the inlet chamber. Preferably, a ratio of a maximum cross-sectional area of the inlet opening to a maximum cross-sectional area of the inlet chamber parallel to the inlet opening is at least 0.8 to 1 , preferably at least 0.9 to 1 , preferably at least 1 to 1. Advantageously, the relatively large inlet opening may facilitate a desired airflow into the inlet chamber during use.

[0034] The aerosol-generating article may comprise an outlet chamber at least partially defined by the frame, wherein the outlet chamber has an open end at the second end of the aerosol- generating article and a second end spaced apart from the open end, and wherein the air outlet provides fluid communication between the cavity and the second end of the outlet chamber. Advantageously, the outlet chamber may facilitate the manufacture of an aerosol-generating article having a device length while also facilitating the positioning of the air outlet away from the second end of the aerosol-generating article to provide the short airflow pathway length between the air inlet and the air outlet. The aerosol-generating article may comprise an outlet opening defining the open end of the outlet chamber. Preferably, a ratio of a maximum cross-sectional area of the outlet opening to a maximum cross-sectional area of the outlet chamber parallel to the outlet opening is at least 0.8 to 1 , preferably at least 0.9 to 1 , preferably at least 1 to 1. Advantageously, the relatively large outlet opening may facilitate a desired airflow out of the outlet chamber during use.

[0035] The frame may comprise a first longitudinal portion extending between the first and second ends of the aerosol-generating article. The frame may comprise a second longitudinal portion extending between the first and second ends of the aerosol-generating article, wherein the second longitudinal portion is spaced apart from the first longitudinal portion. The frame may comprise a first lateral portion spaced apart from the first end of the aerosol-generating article, wherein the first lateral portion extends between the first and second longitudinal portions. The frame may comprise a second lateral portion spaced apart from the second end of the aerosol-generating article, wherein the second lateral portion extends between the first and second longitudinal portions. The second lateral portion may be spaced apart from the first lateral portion so that the cavity is at least partially defined between the first and second longitudinal portions and between the first and second lateral portions.

[0036] The aerosol-generating article may comprise at least one of a taggant and a machine readable indicium positioned at the first end of the aerosol-generating article. The aerosolgenerating article may comprise at least one of a taggant and a machine readable indicium positioned at the second end of the aerosol-generating article. The at least one of a taggant and a machine readable indicium may facilitate identification of the aerosol-generating article by an aerosol-generating device.

[0037] According to the present disclosure there is also provided an aerosol-generating system comprising an aerosol-generating article according to any of the examples or embodiments described herein. The aerosol-generating system also comprises an aerosol-generating device, the aerosol-generating device comprising a chamber for receiving at least a portion of the aerosolgenerating article, and an electric heater arranged to heat at least part of the aerosol-generating article when the aerosol-generating article is received within the chamber.

[0038] Preferably, the aerosol-generating device comprises a controller to control a supply of power to the heater. Preferably, the aerosol-generating device is configured to heat at least one of the one or more aerosol-generating substrates to form an aerosol, for example an inhalable aerosol. The aerosol-generating device may be configured to heat each of the one or more aerosol-generating substrates to form an aerosol, for example an inhalable aerosol.

[0039] The aerosol-generating article has a length extending in an x-direction. The aerosolgenerating article may have a width extending in a y-direction. The aerosol-generating article may have a thickness extending in a z-direction.

[0040] The aerosol-generating article may be a substantially flat aerosol-generating article or a substantially planar aerosol-generating article. In particular, a thickness of the aerosol-generating article may less than 50 percent of both a length and a width of the aerosol-generating article. Advantageously, a smaller thickness may provide a small temperature gradient or difference across the thickness of the aerosol-generating substrate during heating.

[0041] The aerosol-generating article may have a quadrilaterally-faced hexahedron shape. The aerosol-generating article may have a rectangular prism shape. The aerosol-generating article may have a cuboid shape. The aerosol-generating article may have a cylindrical shape. The aerosol-generating article may have a right-angled cylinder shape.

[0042] The aerosol-generating article may have a laminated structure, for example the aerosolgenerating article may comprise or be formed from at least two layers. In particular, the aerosolgenerating article may comprise at least two of: a first external layer, a second external layer, a frame, a first frame layer, a second frame layer, a third frame layer, a first aerosol-generating substrate layer, and a second aerosol-generating substrate layer as discussed in more detail below.

[0043] Substantially the entirety of the aerosol-generating article, excluding the one or more aerosol-generating substrates (if present) and (if present) adhesive, may be paper or cardboard.

[0044] The aerosol-generating article may have a cellulose acetate content of less than 5 percent. The aerosol-generating article may have a cellulose acetate content of less than 3 percent. The aerosol-generating article may have a cellulose acetate content of less than 1 percent.

[0045] The frame may be a planar frame.

[0046] The frame may define a frame aperture extending through the thickness of the frame. The frame aperture may define or form the airflow passage of the aerosol-generating article. The frame aperture may define or form the cavity of the aerosol-generating article. For example, the frame may have a hollow cuboid shape or a square hollow tube shape. As a further example, the frame may have a cross-section that is annular in shape, preferably the cross-section in an x / y plane is annular in shape.

[0047] The frame may comprise a frame outer surface. The frame outer surface may extend in a transverse direction, for example between the first planar external surface and the second planar external surface. The frame outer surface may at least partially define or form one or more external surfaces of the aerosol-generating article. For example, the frame outer surface may at least partially define or form one or more external walls of the aerosol-generating article. The frame outer surface may circumscribe or encircle the frame aperture. The frame outer surface may circumscribe or encircle the cavity.

[0048] The frame may comprise a frame inner surface. The frame inner surface may extend in a transverse direction, for example between the first planar external surface and the second planar external surface. The frame inner surface may define or form a frame aperture outer wall. The frame inner surface may define or form a cavity outer wall. The frame inner surface may circumscribe or encircle the frame aperture extending through the thickness of the frame. The frame inner surface may circumscribe or encircle the cavity.

[0049] The frame outer surface may circumscribe or encircle the frame inner surface. The frame inner surface and the frame outer surface may be concentric with one another.

[0050] The aerosol-generating article may comprise one or more external walls extending between the first planar external surface and the second planar external surface. The one or more external walls may collectively define an entire transverse external area of the aerosol-generating article. The frame may at least partially define each of the one or more external walls. The one or more external walls may circumscribe or encircle the cavity. The frame may define at least 60 percent, at least 70 percent, at least 80 percent, or at least 90 percent of the entire transverse external area of the aerosol-generating article.

[0051] The frame may comprise a peripheral wall. The peripheral wall may circumscribe or encircle at least a portion of the frame aperture extending through the thickness of the frame. The peripheral wall may circumscribe or encircle at least a portion of the cavity. The peripheral wall may circumscribe or encircle the frame aperture extending through the thickness of the frame. The peripheral wall may circumscribe or encircle the cavity.

[0052] The peripheral wall may be defined or formed by the frame outer surface and the frame inner surface. The peripheral wall may at least partially define or form one or more external surfaces or walls of the aerosol-generating article. The peripheral wall may define or form a frame aperture outer wall. The peripheral wall may define or form a cavity outer wall.

[0053] The peripheral wall may have a radial thickness. The radial thickness may be defined as the minimum distance between the frame outer surface and the frame inner surface, such as in the x / y plane.

[0054] The peripheral wall may have a radial thickness greater than or equal to 0.5 millimetres. The peripheral wall may have a radial thickness greater than or equal to 1.5 millimetres. The peripheral wall may have a radial thickness greater than or equal to 2.5 millimetres.

[0055] The peripheral wall may have a radial thickness less than or equal to 3.5 millimetres. The peripheral wall may have a radial thickness less than or equal to 2.5 millimetres.

[0056] The peripheral wall may have a radial thickness between 0.5 millimetres and 3.5 millimetres. The peripheral wall may have a radial thickness between 0.5 millimetres and 2.5 millimetres. Advantageously, the peripheral wall having a radial thickness between 0.5 millimetres and 3.5 millimetres has been found to provide good structural strength for the aerosol-generating article whilst not using excess amounts of material which may increase manufacturing costs, and may limit the amount of heat that is undesirably transferred to the frame rather than the aerosolgenerating substrate.

[0057] The frame may be made from or comprise a biodegradable material. The frame may be made entirely from a biodegradable material.

[0058] The frame may be made from or comprise a cellulosic material. The cellulosic material may comprise a sheet of cellulosic material. The cellulosic material may comprise cellulose fibres. The cellulosic material may be paper, paperboard, or cardboard. The frame may be made from or comprise a plant material, such as tobacco. The frame may be made entirely from a cellulosic material.

[0059] The aerosol-generating article may comprise one or more susceptor materials. The frame may comprise one or more susceptor materials. The one more susceptor materials may be in thermal contact with the aerosol-generating substrate. The one more susceptor materials may be in thermal contact with the cavity. The one or more susceptor materials may be incorporated within the material of the frame. For example, the one or more susceptor material may be incorporated within the peripheral wall of the frame.

[0060] The one or more susceptor materials may be one or more particles, strips, threads, or wires of susceptor material. The one or more susceptor materials may be one or more sheets or layers of susceptor material. The one of more sheets or layers of susceptor material may be in the form of a mesh of susceptor material.

[0061] The susceptor material, in whatever form, may comprise one or more materials selected from the list consisting of: aluminium, iron and iron alloys, nickel and nickel alloys, cobalt alloys, stainless steel alloys, copper alloys, carbon, expanded carbon, and graphite.

[0062] The frame may have a thickness greater than or equal to 50 percent of the thickness of the aerosol-generating article. The frame may have a thickness greater than or equal to 70 percent of the thickness of the aerosol-generating article. The frame may have a thickness greater than or equal to 90 percent of the thickness of the aerosol-generating article. The frame may have a thickness greater than or equal to 95 percent of the thickness of the aerosol-generating article.

[0063] The frame may have a thickness less than or equal to 95 percent of the thickness of the aerosol-generating article. The frame may have a thickness less than or equal to 90 percent of the thickness of the aerosol-generating article. The frame may have a thickness less than or equal to 70 percent of the thickness of the aerosol-generating article.

[0064] The frame may have a thickness between 50 percent of the thickness of the aerosolgenerating article and 95 percent of the thickness of the aerosol-generating article. The frame may have a thickness between 70 percent of the thickness of the aerosol-generating article and 95 percent of the thickness of the aerosol-generating article.

[0065] The frame may have a thickness greater than or equal to 1 millimetre, greater than or equal to 2 millimetres, greater than or equal to 3 millimetres, or greater than or equal to 4 millimetres. The frame may have a thickness less than or equal to 5.5 millimetres, less than or equal to 4.5 millimetres, less than or equal to 3.5 millimetres, less than or equal to 2.5 millimetres, or less than or equal to 1.5 millimetres. The frame may have a thickness between 1 millimetre and 5.5 millimetres. Preferably, the frame may have a thickness between 1.5 millimetres and 5.5 millimetres.

[0066] The frame may have a length that is equal to the length of the aerosol-generating article. The frame may have a length that is at least 90 percent of the length of the aerosol-generating article. The frame may have a length that is at least 95 percent of the length of the aerosolgenerating article.

[0067] The frame may have a width that is equal to the width of the aerosol-generating article. The frame may have a width that is at least 90 percent of the width of the aerosol-generating article.

[0068] The frame may be a unitary component. Alternatively, the frame may comprise two or more layers. That is, the frame may have a laminated structure. Advantageously, the properties of each layer may be individually optimised depending on the relative distance between the layer and aerosol-generating substrate or heater of the aerosol-generating device.

[0069] The frame may comprise a first frame layer and a second frame layer. The first frame layer and the second frame layer may be the only layers of the frame. That is, the frame may comprise no more than two layers or may comprise exactly two layers. The frame aperture may be defined through both the first frame layer and the second frame layer.

[0070] The frame may comprise a first frame layer, a second frame layer and a third frame layer. The second frame layer may be positioned between the first frame layer and the third frame layer. The first frame layer, the second frame layer and the third frame layer may be the only layers of the frame. That is, the frame may comprise no more than three layers or may comprise exactly three layers.

[0071] The one or more aerosol-generating substrates may comprise an aerosol-generating substrate layer. Advantageously, the aerosol-generating substrate layer can be made thin and, therefore, quickly heat up and release volatile compounds to form an aerosol. Advantageously, the aerosol-generating substrate layer can be positioned close to a heater of an aerosolgenerating device.

[0072] The aerosol-generating substrate layer may comprise an aerosol-generating material. The aerosol-generating material may be any aerosol-generating material described herein. The aerosol-generating material may be in the form of a sheet of aerosol-generating material. The sheet of aerosol-generating material may be any sheet of aerosol-generating material described herein. The aerosol-generating substrate layer may be, and may be made entirely of, a sheet of aerosol-generating material.

[0073] The aerosol-generating substrate layer may be positioned between the frame and the first planar external surface. The aerosol-generating substrate layer may be positioned between the frame and the second planar external surface. The aerosol-generating substrate layer may be in physical contact with, and may be bonded to, the frame.

[0074] The aerosol-generating substrate layer may be positioned between the frame and the outer wrapper. The outer wrapper is discussed in more detail below. The aerosol-generating substrate layer may in physical contact with, and may be bonded to, both the frame and the outer wrapper.

[0075] The aerosol-generating substrate layer may be positioned between the frame and the first planar external layer. The aerosol-generating substrate layer may be positioned between the frame and the second planar external layer. The first planar external layer and the second planar external layer are discussed in more detail below. The aerosol-generating substrate layer may in physical contact with, and may be bonded to, both the frame and the first planar external layer. The aerosol-generating substrate layer may in physical contact with, and may be bonded to, both the frame and the second planar external layer.

[0076] The aerosol-generating substrate layer may overlie an end of the cavity. The aerosolgenerating substrate layer may define or form a wall of the cavity, such as the first cavity end wall or the second cavity end wall. Advantageously, the aerosol-generating substrate layer may therefore be in, or at least partially define or form, the airflow passage thereby allowing released volatile compounds to quickly form an aerosol.

[0077] The one or more aerosol-generating substrates may comprise a first aerosol-generating substrate layer and a second aerosol-generating substrate layer. Advantageously, a first and a second aerosol-generating substrate layer may allow rapid generation of a satisfactory volume of aerosol compared with using a single aerosol-generating substrate layer.

[0078] The first aerosol-generating substrate layer may comprise an aerosol-generating material. The aerosol-generating material may be any aerosol-generating material described herein. The aerosol-generating material may be in the form of a sheet of aerosol-generating material. The sheet of aerosol-generating material may be any sheet of aerosol-generating material described herein. The first aerosol-generating substrate layer may be, and may be made entirely of, a sheet of aerosol-generating material.

[0079] The second aerosol-generating substrate layer may comprise an aerosol-generating material. The aerosol-generating material may be any aerosol-generating material described herein. The aerosol-generating material may be in the form of a sheet of aerosol-generating material. The sheet of aerosol-generating material may be any sheet of aerosol-generating material described herein. The second aerosol-generating substrate layer may be, and may be made entirely of, a sheet of aerosol-generating material.

[0080] The first aerosol-generating substrate layer may be positioned between the frame and the first planar external surface. The first aerosol-generating substrate layer may be in physical contact with, and may be bonded to, the frame.

[0081] The first aerosol-generating substrate layer may be positioned between the frame and the outer wrapper. The first aerosol-generating substrate layer may in physical contact with, and may be bonded to, both the frame and the outer wrapper.

[0082] The first aerosol-generating substrate layer may be positioned between the frame and the first planar external layer. The first aerosol-generating substrate layer may in physical contact with, and may be bonded to, both the frame and the first planar external layer.

[0083] The second aerosol-generating substrate layer may be positioned between the frame and the second planar external surface. The second aerosol-generating substrate layer may be in physical contact with, and may be bonded to, the frame.

[0084] The second aerosol-generating substrate layer may be positioned between the frame and the outer wrapper. The second aerosol-generating substrate layer may in physical contact with, and may be bonded to, both the frame and the outer wrapper.

[0085] The second aerosol-generating substrate layer may be positioned between the frame and the second planar external layer. The second aerosol-generating substrate layer may in physical contact with, and may be bonded to, both the frame and the second planar external layer.

[0086] The first aerosol-generating substrate layer and the second aerosol-generating substrate layer may overlie opposing ends of the cavity. The first aerosol-generating substrate layer and the second aerosol-generating substrate layer may define or form opposing end walls of the cavity. That is, the frame, the first aerosol-generating substrate layer and the second aerosol-generating substrate layer may collectively define the cavity.

[0087] One or more of the aerosol-generating substrate layer, the first aerosol-generating substrate layer and the second aerosol-generating substrate layer may have a thickness greater than or equal to 100 micrometres, greater than or equal to 200 micrometres, greater than or equal to 300 micrometres, greater than or equal to 400 micrometres, or greater than or equal to 500 micrometres.

[0088] One or more of the aerosol-generating substrate layer, the first aerosol-generating substrate layer and the second aerosol-generating substrate layer may have a thickness less than or equal to 600 micrometres, less than or equal to 500 micrometres, less than or equal to 400 micrometres, less than or equal to 300 micrometres, or less than or equal to 300 micrometres.

[0089] One or more of the aerosol-generating substrate layer, the first aerosol-generating substrate layer and the second aerosol-generating substrate layer may have a thickness between 100 micrometres and 600 micrometres, between 200 micrometres and 500 micrometres, between 200 micrometres and 400 micrometres, or between 200 micrometres and 300 micrometres.

[0090] The aerosol-generating substrate layer may have a length substantially the same as the length of the frame. The aerosol-generating substrate layer may have a length substantially the same as the length of the aerosol-generating article.

[0091] The first aerosol-generating substrate layer may have a length substantially the same as the length of the frame. The first aerosol-generating substrate layer may have a length substantially the same as the length of the aerosol-generating article.

[0092] The second aerosol-generating substrate layer may have a length substantially the same as the length of the frame. The second aerosol-generating substrate layer may have a length substantially the same as the length of the aerosol-generating article.

[0093] The aerosol-generating substrate layer may have a width substantially the same as the width of the frame. The aerosol-generating substrate layer may have a width substantially the same as the width of the aerosol-generating article.

[0094] The first aerosol-generating substrate layer may have a width substantially the same as the width of the frame. The first aerosol-generating substrate layer may have a width substantially the same as the width of the aerosol-generating article.

[0095] The second aerosol-generating substrate layer may have a width substantially the same as the width of the frame. The second aerosol-generating substrate layer may have a width substantially the same as the width of the aerosol-generating article.

[0096] The first planar external surface may be a planar upper surface and the second planar external surface may be a planar lower surface. The first planar external surface may be positioned parallel to the second planar external surface. The first planar external surface may extend in the x / y plane. The second planar external surface may extend in the x / y plane. The second planar external surface may be spaced from the first planar external surface in the z- direction or transverse direction. The distance between the first planar external surface and the second planar external surface in the z-direction or transverse direction may define the thickness of the aerosol-generating article.

[0097] The aerosol-generating article may comprise an outer wrapper. The outer wrapper may be hydrophobic. The outer wrapper may comprise a hydrophobic material.

[0098] The outer wrapper may define or form the first planar external surface. The outer wrapper may define or form the second planar external surface. The outer wrapper may define or form both the first planar external surface and the second planar external surface.

[0099] The outer wrapper may circumscribe or encircle the frame. The outer wrapper may be in physical contact with, and may be bonded to, the frame. The outer wrapper may overlie opposing ends of the cavity. The outer wrapper may define or form opposing end walls of the cavity, such as the first cavity end wall and the second cavity end wall. That is, the frame and the outer wrapper may collectively define the cavity.

[0100] The outer wrapper may circumscribe or encircle the frame and the aerosol-generating substrate layer. The outer wrapper may be in physical contact with, and may be bonded to, both the frame and the aerosol-generating substrate layer.

[0101] The outer wrapper may circumscribe or encircle the frame, the first aerosol-generating substrate layer and the second aerosol-generating substrate layer. The outer wrapper may be in physical contact with, and may be bonded to, both the first aerosol-generating substrate layer and the second aerosol-generating substrate layer.

[0102] The aerosol-generating article may comprise a first planar external layer and a second planar external layer. The first planar external layer may be an upper layer and the second planar external layer may be a lower layer.

[0103] The first planar external layer may define or form the first planar external surface. The first planar external layer may extend in the x / y plane. The second planar external layer may define or form the second planar external surface. The second planar external layer may extend in the x / y plane.

[0104] The first planar external layer may be in physical contact with, and may be bonded to, the frame. The first planar external layer may overlie an end of the cavity. The first planar external layer may define or form a wall of the cavity, such as the first cavity end wall.

[0105] The second planar external layer may be in physical contact with, and may be bonded to, the frame. The second planar external layer may overlie an end of the cavity. The second planar external layer may define or form a wall of the cavity, such as the second cavity end wall.

[0106] The first planar external layer and the second planar external layer may overlie opposing ends of the cavity. The first planar external layer and the second planar external layer may define or form opposing end walls of the cavity, such as the first cavity end wall and the second cavity end wall. That is, the frame, the first planar external layer and the second planar external layer may collectively define the cavity.

[0107] The first planar external layer may be spaced, such as in a transverse direction, from the frame. For example, the aerosol-generating substrate layer or the first aerosol-generating substrate layer may be positioned between the first planar external layer and the frame. The first planar external layer may be in physical contact with, and may be bonded to, the aerosolgenerating substrate layer or the first aerosol-generating substrate layer.

[0108] The second planar external layer may be spaced, such as in a transverse direction, from the frame. For example, the aerosol-generating substrate layer or the second aerosol-generating substrate layer may be positioned between the second planar external layer and the frame. The second planar external layer may be in physical contact with, and may be bonded to, the aerosolgenerating substrate layer or the second aerosol-generating substrate layer. The first planar external layer may be hydrophobic. The first planar external layer may comprise a hydrophobic material. The second planar external layer may be hydrophobic. The second planar external layer may comprise a hydrophobic material.

[0109] One or more of the outer wrapper, the first planar external layer and the second planar external layer may comprise, or be made from, a cellulosic material. The cellulosic material may be paper, cigarette paper, tobacco paper, cardboard, wood, textile, natural fibres or artificial fibres.

[0110] One or more of the outer wrapper, the first planar external layer and the second planar external layer may be an aerosol-generating substrate comprising an aerosol-generating material. The aerosol-generating material may be any aerosol-generating material described herein. In particular, the aerosol-generating material may be in the form of a sheet of aerosol-generating material. The sheet of aerosol-generating material may be any sheet of aerosol-generating material described herein. Alternatively, one or more of the outer wrapper, the first planar external layer and the second planar external layer may not comprise any aerosol-generating material, particularly in embodiments comprising an aerosol-generating substrate layer, a first aerosolgenerating substrate layer, a second aerosol-generating substrate layer or an aerosol-generating substrate positioned within the cavity. One or more of the outer wrapper, the first planar external layer and the second planar external layer may be substantially nicotine-free.

[0111] One or more of the outer wrapper, the first planar external layer and the second planar external layer may have a thickness greater than or equal to 25 micrometres, greater than or equal to 30 micrometres, greater than or equal to 35 micrometres, greater than or equal to 40 micrometres, or greater than or equal to 45 micrometres.

[0112] One or more of the outer wrapper, the first planar external layer and the second planar external layer may have a thickness less than or equal to 55 micrometres, less than or equal to 50 micrometres, less than or equal to 45 micrometres, less than or equal to 40 micrometres, or less than or equal to 35 micrometres.

[0113] One or more of the outer wrapper, the first planar external layer and the second planar external layer may have a thickness between 25 micrometres and 55 micrometres, between 25 micrometres and 45 micrometres, or between 30 micrometres and 45 micrometres.

[0114] One or more of the outer wrapper, the first planar external layer and the second planar external layer may have a length substantially the same as the length of the frame. One or more of the outer wrapper, the first planar external layer and the second planar external layer may have a length substantially the same as the length of the aerosol-generating article.

[0115] One or more of the first planar external layer and the second planar external layer may have a width substantially the same as the width of the frame. One or more of the first planar external layer and the second planar external layer may have a width substantially the same as the width of the aerosol-generating article. The cavity may have a thickness greater than or equal to 0.5 millimetres. The cavity may have a thickness greater than or equal to 1.5 millimetres. The cavity may have a thickness greater than or equal to 2.5 millimetres. The cavity may have a thickness greater than or equal to 3.5 millimetres.

[0116] The cavity may have a thickness less than or equal to 4.5 millimetres. The cavity may have a thickness less than or equal to 3.5 millimetres. The cavity may have a thickness less than or equal to 2.5 millimetres. The cavity may have a thickness less than or equal to 1.5 millimetres.

[0117] The cavity may have a thickness between 0.5 millimetres and 4.5 millimetres. The cavity may have a thickness between 1 millimetre and 4.5 millimetres. Preferably, the cavity may have a thickness between 2.8 millimetres and 3.3 millimetres.

[0118] The cavity may have a length greater than or equal to 14 millimetres. The cavity may have a length equal to a greater than 18 millimetres. The cavity may have a length greater than or equal to 22 millimetres. The cavity may have a thickness greater than or equal to 30 millimetres. The cavity may have a thickness greater than or equal to 38 millimetres.

[0119] The cavity may have a length less than or equal to 40 millimetres. The cavity may have a thickness less than or equal to 34 millimetres. The cavity may have a thickness less than or equal to 28 millimetres. The cavity may have a thickness less than or equal to 22 millimetres. The cavity may have a thickness less than or equal to 18 millimetres.

[0120] The cavity may have a length between 14 millimetres and 40 millimetres. The cavity may have a length between 14 millimetres and 34 millimetres. . The cavity may have a length between 24 millimetres and 28 millimetres.

[0121] The cavity may have a width greater than or equal to 4.5 millimetres. The cavity may have a width greater than or equal to 7 millimetres. The cavity may have a width greater than or equal to 11 millimetres.

[0122] The cavity may have a width less than or equal to 13 millimetres. The cavity may have a width less than or equal to 11 millimetres. The cavity may have a width less than or equal to 7 millimetres. The cavity may have a width less than or equal to 5 millimetres.

[0123] The cavity may have a width between 4.5 millimetres and 13 millimetres. The cavity may have a width between 7 millimetres and 10 millimetres. The cavity may have a width between 7.5 millimetres and 8.5 millimetres.

[0124] The cavity may have a length between 14 millimetres and 40 millimetres, a width between 4.5 millimetres and 13 millimetres, and a thickness between 0.5 millimetres and 4.5 millimetres.

[0125] Preferably, the cavity may have a length between 20 millimetres and 30 millimetres, a width between 7 millimetres and 10 millimetres, and a thickness between 2.5 millimetres and 4 millimetres.

[0126] Most preferably, the cavity may have a length of 26 millimetres, a width of 8 millimetres, and a thickness of 3.1 millimetres. The cavity may have a volume of greater than or equal to 30 cubic millimetres, greater than or equal to 100 cubic millimetres, greater than or equal to 300 cubic millimetres, greater than or equal to 500 cubic millimetres, greater than or equal to 700 cubic millimetres, greater than or equal to 900 cubic millimetres, greater than or equal to 1000 cubic millimetres, greater than or equal to 2000 cubic millimetres, or greater than or equal to 30 cubic millimetres.

[0127] The cavity may have a volume of less than or equal to 3500 cubic millimetres, less than or equal to 2500 cubic millimetres, less than or equal to 1500 cubic millimetres, less than or equal to 1000 cubic millimetres, less than or equal to 800 cubic millimetres, less than or equal to 600 cubic millimetres, less than or equal to 500 cubic millimetres, less than or equal to 400 cubic millimetres, or less than or equal to 300 cubic millimetres.

[0128] The cavity may have a volume between 30 cubic millimetres and 3500 cubic millimetres. The cavity may have a volume between 30 cubic millimetres and 2500 cubic millimetres. The cavity may have a volume between 100 cubic millimetres and 1500 cubic millimetres. The cavity may have a volume between 100 cubic millimetres and 1000 cubic millimetres.

[0129] The cavity may be substantially empty.

[0130] The one or more aerosol-generating substrates may comprise an aerosol-generating substrate positioned within the cavity. The aerosol-generating substrate positioned within the cavity may fill the cavity.

[0131] The aerosol-generating substrate positioned within the cavity may comprise an aerosolgenerating material. The aerosol-generating material may be any aerosol-generating material described herein. For example, the aerosol-generating material may be in the form of shredded aerosol-generating material.

[0132] The aerosol-generating material may be in the form of a sheet of aerosol-generating material. The sheet of aerosol-generating material may be any sheet of aerosol-generating material described herein. For example, the sheet of aerosol-generating material may be a sheet of homogenised tobacco material.

[0133] The sheet of aerosol-generating material may extend the entire length of the cavity. The sheet of aerosol-generating material may extend the entire width of the cavity.

[0134] The sheet of aerosol-generating material may be a gathered sheet of aerosol-generating material. That is, the sheet of aerosol-generating material may be convoluted, folded, or otherwise compressed or constricted substantially perpendicular to the transverse direction of the aerosolgenerating article.

[0135] The sheet of aerosol-generating material may be a crimped sheet of aerosol-generating material. The sheet of aerosol-generating material may be a corrugated sheet of aerosolgenerating material. The crimped sheet of aerosol-generating material or the corrugated sheet of aerosol-generating material may comprise a plurality of parallel corrugations. For example, the crimped sheet of aerosol-generating material may comprise a plurality of substantially parallel peaks and troughs.

[0136] The plurality of parallel corrugations may be defined by a corrugation profile, in which the corrugation profile is sinusoidal, or triangular, or rectangular, or trapezoidal, or toroidal, or parabolic.

[0137] The plurality of parallel corrugations may define, or form, a plurality of channels between the sheet of aerosol-generating material and one or more walls of the cavity. The plurality of channels may be a plurality of longitudinally extending channels. The plurality of channels may be a plurality of laterally extending channels. The plurality of channels may defined, or form, at least a portion of the airflow passage extending between the air inlet and air outlet of the aerosolgenerating article.

[0138] The aerosol-generating material may comprise one or more organic materials such as tobacco, mint, tea and cloves. The aerosol-generating material may comprise one or more of: herb leaf, tobacco leaf, fragments of tobacco ribs, reconstituted tobacco, homogenised tobacco such as cast leaf, extruded tobacco, expanded tobacco, aerosol-generating films and gel compositions.

[0139] The aerosol-generating material may be in the form of shredded aerosol-generating material. The shredded aerosol-generating material may comprise one or more of: strips and strands of aerosol-generating material, such as strips and strands of tobacco or homogenised tobacco material. The shredded aerosol-generating material may be in the form of a shredded sheet of homogenised tobacco material.

[0140] The aerosol-generating material may be cut filler. The aerosol-generating material may be tobacco cut filler. As used herein, the term “cut filler” is used to describe to a blend of shredded plant material, such as tobacco plant material, including, in particular, one or more of leaf lamina, processed stems and ribs, homogenised plant material.

[0141] The aerosol-generating material may be in the form of a sheet of aerosol-generating material. As used herein, the term “sheet” describes a laminar element having a width and length substantially greater than the thickness thereof. The sheet of aerosol-generating material may be a sheet of plant material. The sheet of aerosol-generating material may be a sheet of tobacco material. The sheet of aerosol-generating material may be a sheet of homogenised tobacco material, such as a cast leaf sheet.

[0142] The aerosol-generating material may comprise one or more aerosol-formers. Suitable aerosol-formers are well known in the art and include, but are not limited to, one or more aerosolformers selected from: polyhydric alcohols, such as propylene glycol, polyethylene glycol, triethylene glycol, 1 , 3-butanediol and glycerine; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. It may be particularly preferable for the aerosol- former to be or comprise one or both of glycerine and propylene glycol. The aerosol former may consist of glycerine or propylene glycol or of a combination of glycerine and propylene glycol.

[0143] The aerosol-generating material may have an aerosol-former content greater than or equal to 1 , 2, 5, 10, or 15 percent by weight on a dry weight basis. The aerosol-generating material may have an aerosol-former content greater than or equal to 15 percent by weight on a dry weight basis, for example greater than 20 by weight on a dry weight basis, or greater than 25 by weight on a dry weight basis, or greater than 30 by weight on a dry weight basis, or greater than 40 by weight on a dry weight basis, or greater than 50 by weight on a dry weight basis.

[0144] The aerosol-generating material may have an aerosol-former content less than or equal to 30 percent by weight on a dry weight basis, less than or equal to 25 percent by weight on a dry weight basis, or less than or equal to 20 percent by weight on a dry weight basis.

[0145] The aerosol-generating material may have an aerosol-former content between 5 percent and 30 percent by weight on a dry weight basis, between 5 percent and 25 percent by weight on a dry weight basis, or between 5 percent and 20 percent by weight on a dry weight basis.

[0146] The aerosol-generating material may have an aerosol-former content between 10 percent and 30 percent by weight on a dry weight basis, between 10 percent and 25 percent by weight on a dry weight basis, or between 10 percent and 20 percent by weight on a dry weight basis.

[0147] The aerosol-generating material may comprise nicotine. The aerosol-generating material may comprise natural nicotine, or synthetic nicotine, or a combination of natural nicotine and synthetic nicotine.

[0148] The aerosol-generating material may comprise at least 0.5 percent by weight of nicotine, at least 1 percent by weight of nicotine, at least 1.5 percent by weight of nicotine, or at least 2 percent by weight of nicotine. That is, the aerosol-generating material may have a nicotine content of at least 0.5 percent by weight, at least 1 percent by weight, at least 1.5 percent by weight, or at least 2 percent by weight.

[0149] The aerosol-generating material may be in the form of a plurality of beads. The plurality of beads may have an average particle diameter of between 0.1 mm and 4 mm, for example between 0.5 mm and 4 mm.

[0150] The term “bead” refers to a discrete, solid particle formed of the aerosol-generating substrate. A bead may have a rounded, typically spherical, form. Other terms may be used to define the substrate such as, for example, “granule”.

[0151] Providing the aerosol-generating material as a plurality of beads may provide certain advantages. Beads can be easily handled compared to other aerosol-forming substrates such as fine powders or cut filler. The beads flow easily, and so can reliably and consistently fill the cavity of the aerosol-generating article during manufacture. This may allow a consistent and reproducible amount of aerosol-forming substrate to be loaded into each article during manufacture. Beads may also be cleaner to handle than powders and cut fillers, which may cause dust in factories, and may leak from aerosol-generating articles in transit or in use. By selecting beads with appropriate bead sizes and appropriate particle size distributions, air flow through the cavity of the aerosol-generating article may be controlled more reproducibly than would be the case for, say, a cut filler substrate.

[0152] Where a particle is not perfectly spherical, but a diameter of the particle is referred to, the term “diameter” may refer to a largest dimension of the particle. Alternatively, the term “diameter” may refer to the diameter of a perfectly spherical particle having the same volume as the not perfectly spherical particle.

[0153] The term “average particle diameter”, as used herein, may refer to a number average particle diameter. Other methods of determining average particle diameter are known. Thus, the average particle diameter may be, for example, a volume average particle diameter.

[0154] The aerosol-generating material may be in form of a wrapped body of aerosol-generating material, the wrapped body comprising a wrapper at least partially enclosing aerosol-generating material.

[0155] The wrapped body of aerosol-generating material may occupy between 15% and 100% of the interior volume of the cavity. The wrapped body of aerosol-generating material may occupy between 30% and 100% of the interior volume of the cavity. The wrapped body of aerosolgenerating material may occupy between 50% and 100% of the interior volume of the cavity. The wrapped body of aerosol-generating material may occupy between 50% and 80% of the interior volume of the cavity. The wrapped body of aerosol-generating material may occupy between 50% and 70% of the interior volume of the cavity.

[0156] The air inlet may be defined by a front wall of the aerosol-generating article. The air inlet may be defined by, and may extend through, the frame. The air inlet may be defined by the peripheral wall of the frame. The air inlet may extend through the peripheral wall of the frame. The air outlet may be defined by a back wall of the aerosol-generating article. The air outlet may be defined by, and may extend through, the frame. The air outlet may be defined by the peripheral wall of the frame. The outlet may extend though the peripheral wall of the frame.

[0157] The air inlet may have a round cross-section, a circular cross-section, an oval crosssection, a square cross-section, or a rectangular cross-section. The air outlet may have a round cross-section, a circular cross-section, an oval cross-section, a square cross-section, or a rectangular cross-section.

[0158] The air inlet may be defined by, and may extend through, the first planar external surface. The air inlet may be defined by, and may extend through, the outer wrapper. The air inlet may be defined by, and may extend through, the outer wrapper and the aerosol-generating substrate layer. The air inlet may be defined by, and may extend through, the outer wrapper and the first aerosol-generating substrate layer. The air inlet may be defined by, and may extend through, the first planar external layer and the aerosol-generating substrate layer. The air inlet may be defined by, and may extend through, the first planar external layer and the first aerosol-generating substrate layer.

[0159] The air inlet may be defined by, and may extend through, the second planar external surface. The air inlet may be defined by, and may extend through, the outer wrapper and the second aerosol-generating substrate layer. The air inlet may be defined by, and may extend through, the second planar external layer and the aerosol-generating substrate layer. The air inlet may be defined by, and may extend through, the second planar external layer and the second aerosol-generating substrate layer.

[0160] The air outlet may be defined by, and may extend through, the first planar external surface. The air outlet may be defined by, and may extend through, the outer wrapper. The air outlet may be defined by, and may extend through, the outer wrapper and the aerosol-generating substrate layer. The air outlet may be defined by, and may extend through, the outer wrapper and the first aerosol-generating substrate layer. The air outlet may be defined by, and may extend through, the first planar external layer and the aerosol-generating substrate layer. The air outlet may be defined by, and may extend through, the first planar external layer and the first aerosol-generating substrate layer.

[0161] The air outlet may be defined by, and may extend through, the second planar external surface. The air outlet may be defined by, and may extend through, the outer wrapper and the second aerosol-generating substrate layer. The air outlet may be defined by, and may extend through, the second planar external layer and the aerosol-generating substrate layer. The air outlet may be defined by, and may extend through, the second planar external layer and the second aerosol-generating substrate layer.

[0162] One or both of the air inlet and the air outlet may have an equivalent diameter greater than or equal to 0.1 millimetres, greater than or equal to 0.4 millimetres, greater than or equal to 0.7 millimetres, or greater than or equal to 1.0 millimetres.

[0163] One or both of the air inlet and the air outlet may have an equivalent diameter less than or equal to 3 millimetres, less than or equal to 2.7 millimetres, less than or equal to 2.4 millimetres, less than or equal to 2.1 millimetres. The air inlet may have an equivalent diameter less than or equal to 2.7 millimetres, less than or equal to 1.8 millimetres, or less than or equal to 1.5 millimetres.

[0164] One or both of the air inlet and the air outlet may have an equivalent diameter between 0.1 millimetres and 3 millimetres, between 0.1 millimetres and 2.4 millimetres, between 0.4 millimetres and 2.1 millimetres, between 0.4 millimetres and 1.8 millimetres, between 0.7 millimetres and 1.5 millimetres, or between 1.0 millimetres and 1.5 millimetres.

[0165] The air inlet may have a width less than a width of the cavity. The air outlet may have a width less than a width of the cavity. The air inlet may have a thickness less than a thickness of the cavity. The air outlet may have a thickness less than a thickness of the cavity. One or both of the air inlet and the air outlet may a width of between 0.3 millimetres and 3 millimetres or between 0.5 millimetres and 2 millimetres.

[0166] One or both of the air inlet and the air outlet may have a thickness of between 0.3 millimetres and 3 millimetres or between 0.5 millimetres and 2 millimetres.

[0167] Preferably, the air inlet may have a width of between 0.3 millimetres and 3 millimetres, and a thickness of between 0.3 millimetres and 3 millimetres.

[0168] Preferably, the air outlet may have a width of between 0.3 millimetres and 3 millimetres, and a thickness of between 0.3 millimetres and 3 millimetres.

[0169] Advantageously, an aerosol-generating article having an air outlet or air inlet with a width of between 0.3 millimetres and 3 millimetres and a thickness of between 0.3 millimetres and 3 millimetres may provide for a relatively large inlet or outlet opening while allowing for improved retention of the aerosol-generating substrate within the aerosol-generating article. Improved retention of the aerosol-generating substrate within the aerosol-generating article may reduce the risk of aerosol-generating substrate falling out of the aerosol-generating article.

[0170] A ratio of the width of the air inlet to the thickness of the air inlet may be between 0.33 and 3. A ratio of the width of the air inlet to the thickness of the air inlet may be between 0.5 and 1.5. A ratio of the width of the air inlet to the thickness of the air inlet may be between 0.75 and 1.25.

[0171] A ratio of the width of the air outlet to the thickness of the air outlet may be between 0.33 and 3. A ratio of the width of the air outlet to the thickness of the air outlet may be between 0.5 and 1.5. A ratio of the width of the air outlet to the thickness of the air outlet may be between 0.75 and 1.25.

[0172] The aerosol-generating article may comprise a plurality of air inlets. One or each of the air inlets may have one or more of the features of the air inlet described herein.

[0173] The aerosol-generating article may comprise a plurality of air outlets. One or each of the air outlets may have one or more of the features of the air outlet described herein.

[0174] The aerosol-generating article may comprise a filter element positioned downstream of the aerosol-forming substrate. The aerosol-generating article may comprise a filter element positioned downstream of the cavity. The aerosol-generating article may comprise a filter element at least partially positioned within the air outlet. The aerosol-generating article may comprise a filter element positioned within, and may be positioned at a downstream end of, the cavity.

[0175] The aerosol-generating article may comprise a filter element positioned upstream of the aerosol-forming substrate. The aerosol-generating article may comprise a filter element positioned upstream of the cavity. The aerosol-generating article may comprise a filter element at least partially positioned within the air inlet. The aerosol-generating article may comprise a filter element positioned within, and may be positioned at an upstream end of, the cavity. The filter element may comprise one or more segments of a fibrous filtration material. Suitable fibrous filtration materials would be known to the skilled person. The filter element may comprise a cellulose acetate.

[0176] A ratio between the length and the thickness of the aerosol-generating article, and between the width and the thickness of the aerosol-generating article may be greater than 2:1 , greater than 5:1 , greater than 10:1 , greater than 12:1 , or greater than 15:1.

[0177] A ratio between the length and the thickness of the aerosol-generating article, and between the width and the thickness of the aerosol-generating article may be less than 15:1 , less than 12:1 , less than 10:1 , less than 5:1 , or less than 2.5:1

[0178] A ratio between the length and the thickness of the aerosol-generating article, and between the width and the thickness of the aerosol-generating article may be between 2:1 and 15:1 , between 2:1 and 12:1 , between 2:1 and 10:1 , or between 5:1 and 10:1.

[0179] A ratio between the length and the width of the aerosol-generating article may be greater than 1 :1 , greater than 2: 1 , greater than 3: 1 , greater than 4: 1 , or greater than 5: 1.

[0180] A ratio between the length and the width of the aerosol-generating article may be less than 10:1 , less than 8: 1 , less than 5: 1 , less than 4: 1 , less than 3:1 , or less than 2:1.

[0181] A ratio between the length and the width of the aerosol-generating article may be between 1 :1 and 10:1 , between 1 :1 and 5:1 , between 1 :1 and 4:1 , between 1 :1 and 3:1 , between 2:1 and 4:1 , or between 2:1 and 3: 1 .

[0182] The aerosol-generating article may have a length greater than or equal to 15 millimetres, greater than or equal to 20 millimetres, greater than or equal to 25 millimetres, greater than or equal to 30 millimetres, greater than or equal to 35 millimetres, or greater than or equal to 40 millimetres.

[0183] The aerosol-generating article may have a length less than or equal to 45 millimetres, less than or equal to 40 millimetres, less than or equal to 35 millimetres, or less than or equal to 30 millimetres.

[0184] The aerosol-generating article may have a length between 15 millimetres and 45 millimetres, between 20 millimetres and 40 millimetres, between 20 millimetres and 35 millimetres, or between 25 millimetres and 30 millimetres.

[0185] The aerosol-generating article may have a width equal to greater than 3 millimetres, greater than 5 millimetres, greater than 7.5 millimetres, greater than 9 millimetres, greater than 11 millimetres, or greater than 13 millimetres.

[0186] The aerosol-generating article may have a width less than or equal to 17 millimetres, less than or equal to 15 millimetres, less than or equal to 12.5 millimetres, less than or equal to 11 millimetres, or less than or equal to 9 millimetres. The aerosol-generating article may have a width between 3 millimetres and 17 millimetres, between 5 millimetres and 15 millimetres, between 7.5 millimetres and 12.5 millimetres, or between 9 millimetres and 11 millimetres.

[0187] The aerosol-generating article may have a thickness equal to greater than 1 millimetre, greater than or equal to 1.5 millimetres, greater than or equal to 2 millimetres, greater than or equal to 2.5 millimetres, greater than or equal to 3 millimetres, greater than or equal to 3.5 millimetres, greater than or equal to 4 millimetres, or greater than or equal to 4.5 millimetres.

[0188] The aerosol-generating article may have a thickness less than or equal to 5.5 millimetres, less than or equal to 5 millimetres, less than or equal to 4.5 millimetres, less than or equal to 4 millimetres, less than or equal to 3.5 millimetres, less than or equal to 3 millimetres, less than or equal to 2.5 millimetres, or less than or equal to 2 millimetres.

[0189] The aerosol-generating article may have a thickness between 1 millimetres and 5 millimetres, between 1.5 millimetres and 5 millimetres, between 2 millimetres and 4.5 millimetres, between 2.5 millimetres and 4 millimetres, or between 3 millimetres and 3.5 millimetres.

[0190] As used herein, the term “aerosol-generating article” refers to an article comprising an aerosol-generating substrate. The article may be heated in use to produce and deliver an inhalable aerosol to a consumer.

[0191] As used herein, the term “aerosol-generating substrate” refers to a substrate capable of releasing volatile compounds upon heating, for example compounds which, in use, cool and condense to generate an aerosol.

[0192] As used herein, the term “aerosol-generating device” refers to a device that, in use, interacts with, for example heats, an aerosol-generating substrate of an aerosol-generating article to generate an aerosol.

[0193] As used herein, the term “planar” refers to a feature generally formed in a single Euclidean plane and not wrapped around or otherwise conformed to fit a curved or other non-planar shape. A planar surface may extend in two dimensions in a single Euclidean plane. A planar object may extend in two dimensions in a single Euclidean plane substantially more than in a third dimension perpendicular to the plane. More specifically, a planar object may extend in a first dimension and a second dimension perpendicular to the first dimension at least two, five or ten times further than the object extends in a third dimension perpendicular to the first and second dimensions.

[0194] As used herein, the term “transverse” refers to a direction extending between the first planar external surface and the second planar external surface. The transverse direction may also be referred to as the “z-direction”.

[0195] As used herein, the term “longitudinal” refers to a direction that is perpendicular to the transverse direction. For example, a direction between a front wall and a back wall of the aerosolgenerating article. The longitudinal direction may also be referred to as the “x-direction”. As used herein, the term “lateral” refers to a direction that is perpendicular to the transverse direction and the longitudinal direction. For example, a direction from a first side wall to a second side wall of the aerosol-generating article. The lateral direction may also be referred to as the “y-direction”.

[0196] As used herein, the term “thickness” refers to a maximum dimension of the aerosolgenerating article or a component of the aerosol-generating article in the transverse direction.

[0197] As used herein, the term “length” refers to a maximum dimension of the aerosol-generating article or a component of the aerosol-generating article in the longitudinal direction.

[0198] As used herein, the term “width” refers to a maximum dimension of the aerosol-generating article or a component of the aerosol-generating article in the lateral direction.

[0199] As used herein, the terms “upstream” and “downstream” refer to the relative positions of components, or portions of components, of the aerosol-generating article in relation to the direction in which the air or aerosol is transported through the aerosol-generating article during use.

[0200] As used herein, the term “bulk density” may refer to the total weight of the aerosolgenerating substrate divided by the bulk volume of the aerosol-generating substrate.

[0201] As used herein, the term “aerosol former” may refer to any suitable known compound or mixture of compounds that, in use, facilitates formation of an aerosol. The aerosol may be a dense and stable aerosol. The aerosol may be substantially resistant to thermal degradation at the operating temperature of the aerosol-generating substrate or aerosol-generating article.

[0202] As used herein, the term “aerosol former content” may refer to aerosol former content in percent on a dry weight basis, unless otherwise specified.

[0203] As used herein, a "susceptor" refers to a conductive element that heats up when subjected to a changing magnetic field. This may be the result of eddy currents induced in the susceptor element and / or hysteresis losses.

[0204] As used herein, the term “hydrophobic” refers to a surface exhibiting water repelling properties. One useful way to determine this is to measure the water contact angle. The “water contact angle” is the angle, conventionally measured through the liquid, where a liquid / vapour interface meets a solid surface. It quantifies the wettability of a solid surface by a liquid via the Young equation.

[0205] As used herein, the term “equivalent diameter” of an opening or an aperture is used herein to denote the diameter of a circular opening or aperture having the same cross-sectional area as the opening or aperture.

[0206] The invention is defined in the claims. However, below there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein. Example 1 : An aerosol-generating article for use with an aerosol-generating device to generate an aerosol, the aerosol-generating article comprising: a first planar external surface and a second planar external surface; a cavity; a frame at least partially defining the cavity; an air inlet and an air outlet; an aerosol-generating substrate positioned within the cavity between the air inlet and the air outlet; and wherein the aerosol-generating article defines an airflow pathway extending through the cavity from the airflow inlet to the airflow outlet; wherein the aerosol-generating article has a length extending between a first end of the aerosol-generating article and a second end of the generating article, wherein the length is the largest dimension of the aerosol-generating article; and wherein a length of the airflow pathway is less than the length of the aerosol-generating article.

[0207] Example 2: An aerosol-generating article according to Example 1 , wherein the length of the airflow pathway is the shortest airflow distance through the cavity from the airflow inlet to the airflow outlet.

[0208] Example 3: An aerosol-generating article according to Example 1 or 2, wherein the length of the airflow pathway is equal to or less than 90 percent of the length of the aerosol-generating article, optionally equal to or less than 80 percent of the length of the aerosol-generating article, optionally equal to or less than 70 percent of the length of the aerosol-generating article, optionally equal to or less than 60 percent of the length of the aerosol-generating article, or optionally equal to or less than 50 percent of the length of the aerosol-generating article.

[0209] Example 4: An aerosol-generating article according to Example 1 , 2 or 3, wherein the aerosolgenerating substrate is arranged in the cavity so that the airflow pathway extends through the aerosol-generating substrate.

[0210] Example 5: An aerosol-generating article according to any preceding Example, wherein the aerosol-generating substrate has a length extending parallel with the airflow pathway, and wherein the length of the aerosol-generating substrate is at least 80 percent of the length of the airflow pathway, preferably at least 90 percent of the length of the airflow pathway, preferably wherein the length of the aerosol-generating substrate is the same as the length of the airflow pathway.

[0211] Example 6: An aerosol-generating article according to any preceding Example, wherein the length of the airflow pathway is perpendicular to the length of the aerosol-generating article.

[0212] Example 7: An aerosol-generating article according to any preceding Example, wherein the frame at least partially defines the first end and the second end of the aerosol-generating article, wherein the frame at least partially defines a first side of the aerosol-generating article extending between the first end and the second end, wherein the frame at least partially defines a second side of the aerosol-generating article extending between the first end and the second end, wherein the air inlet extends through the first side of the aerosol-generating article, and wherein the air outlet extends through the second side of the aerosol-generating article.

[0213] Example 8: An aerosol-generating article according to Example 7, wherein each of the first planar surface and the second planar surface is perpendicular to each of the first end, the second end, the first side, and the second side.

[0214] Example 9: An aerosol-generating article according to any preceding Example, wherein the cavity has a length extending parallel with the length of the aerosol-generating article, wherein the aerosol-generating substrate has a width extending parallel with the length of the cavity, and wherein the width of the aerosol-generating substrate is the same as the length of the cavity.

[0215] Example 10: An aerosol-generating article according to any preceding Example, wherein the cavity has a length extending parallel with the length of the aerosol-generating article, wherein the air inlet has a width extending parallel with the length of the cavity, and wherein the width of the air inlet is the same as the length of the cavity.

[0216] Example 11 : An aerosol-generating article according to any preceding Example, wherein the cavity has a length extending parallel with the length of the aerosol-generating article, wherein the air outlet has a width extending parallel with the length of the cavity, and wherein the width of the air outlet is the same as the length of the cavity.

[0217] Example 12: An aerosol-generating article according to any of Examples 1 to 8, wherein the cavity has a length extending parallel with the length of the aerosol-generating article, wherein the aerosol-generating substrate has a width extending parallel with the length of the cavity, and wherein the width of the aerosol-generating substrate is less than the length of the cavity.

[0218] Example 13: An aerosol-generating article according to Example 9, wherein the width of the aerosol-generating substrate is equal to or less than 90 percent of the length of the cavity, optionally equal to or less than 80 percent of the length of the cavity, optionally equal to or less than 70 percent of the length of the cavity, optionally equal to or less than 60 percent of the length of the cavity, or optionally equal to or less than 50 percent of the length of the cavity.

[0219] Example 14: An aerosol-generating article according to any of Examples 1 to 8, 12 or 13, wherein the cavity has a length extending parallel with the length of the aerosol-generating article, wherein the air inlet has a width extending parallel with the length of the cavity, and wherein the width of the air inlet is less than the length of the cavity.

[0220] Example 15: An aerosol-generating article according to Example 14, wherein the width of the air inlet is equal to or less than 90 percent of the length of the cavity, optionally equal to or less than 80 percent of the length of the cavity, optionally equal to or less than 70 percent of the length of the cavity, optionally equal to or less than 60 percent of the length of the cavity, or optionally equal to or less than 50 percent of the length of the cavity.

[0221] Example 16: An aerosol-generating article according to any of Examples 1 to 8, or any of Examples 12 to 15, wherein the cavity has a length extending parallel with the length of the aerosol-generating article, wherein the air outlet has a width extending parallel with the length of the cavity, and wherein the width of the air outlet is less than the length of the cavity.

[0222] Example 17: An aerosol-generating article according to Example 16, wherein the width of the air outlet is equal to or less than 90 percent of the length of the cavity, optionally equal to or less than 80 percent of the length of the cavity, optionally equal to or less than 70 percent of the length of the cavity, optionally equal to or less than 60 percent of the length of the cavity, or optionally equal to or less than 50 percent of the length of the cavity.

[0223] Example 18: An aerosol-generating article according to any of Examples 14 to 17, wherein the width of the air outlet is the same as the width of the air inlet.

[0224] Example 19: An aerosol-generating article according to any preceding Example, wherein the cavity is a first cavity, the aerosol-generating article further comprising a second cavity, and wherein the frame at least partially defines the second cavity.

[0225] Example 20: An aerosol-generating article according to Example 19, wherein the aerosolgenerating substrate is a first aerosol-generating substrate, the aerosol-generating article further comprising a second aerosol-generating substrate positioned within the second cavity.

[0226] Example 21 : An aerosol-generating article according to Example 20, wherein the air inlet is a first air inlet, wherein the air outlet is a second air outlet, wherein the aerosol-generating article further comprises a second air inlet and a second air outlet, wherein the second aerosolgenerating substrate is positioned within the second cavity between the second air inlet and the second air outlet, wherein the airflow pathway is a first airflow pathway, and wherein the aerosolgenerating article defines a second airflow pathway extending through the second cavity from the second airflow inlet to the second airflow outlet

[0227] Example 22: An aerosol-generating article according to Example 21 , wherein the length of the second airflow pathway is the shortest airflow distance through the second cavity from the second airflow inlet to the second airflow outlet.

[0228] Example 23: An aerosol-generating article according to Example 21 or 22, wherein the length of the second airflow pathway is equal to or less than 90 percent of the length of the aerosol- generating article, optionally equal to or less than 80 percent of the length of the aerosol- generating article, optionally equal to or less than 70 percent of the length of the aerosol- generating article, optionally equal to or less than 60 percent of the length of the aerosolgenerating article, or optionally equal to or less than 50 percent of the length of the aerosolgenerating article. Example 24: An aerosol-generating article according to Example 21 , 22 or 23, wherein the second aerosol-generating substrate is arranged in the second cavity so that the second airflow pathway extends through the second aerosol-generating substrate.

[0229] Example 25: An aerosol-generating article according to any of Examples 21 to 24, wherein the second aerosol-generating substrate has a length extending parallel with the second airflow pathway, and wherein the length of the second aerosol-generating substrate is at least 80 percent of the length of the second airflow pathway, preferably at least 90 percent of the length of the second airflow pathway, preferably wherein the length of the second aerosol-generating substrate is the same as the length of the second airflow pathway.

[0230] Example 26: An aerosol-generating article according to any of Examples 21 to 25, wherein the length of the second airflow pathway is perpendicular to the length of the aerosol-generating article.

[0231] Example 27: An aerosol-generating article according to any of Examples 21 to 26, wherein the frame at least partially defines the first end and the second end of the aerosol-generating article, wherein the frame at least partially defines a first side of the aerosol-generating article extending between the first end and the second end, wherein the frame at least partially defines a second side of the aerosol-generating article extending between the first end and the second end, wherein the second air inlet extends through the first side of the aerosol-generating article, and wherein the second air outlet extends through the second side of the aerosol-generating article.

[0232] Example 28: An aerosol-generating article according to Example 27, wherein each of the first planar surface and the second planar surface is perpendicular to each of the first end, the second end, the first side, and the second side.

[0233] Example 29: An aerosol-generating article according to any of Examples 21 to 28, wherein the second cavity has a length extending parallel with the length of the aerosol-generating article, wherein the second aerosol-generating substrate has a width extending parallel with the length of the second cavity, and wherein the width of the second aerosol-generating substrate is the same as the length of the second cavity.

[0234] Example 30: An aerosol-generating article according to any of Examples 21 to 29, wherein the second cavity has a length extending parallel with the length of the aerosol-generating article, wherein the second air inlet has a width extending parallel with the length of the second cavity, and wherein the width of the second air inlet is the same as the length of the second cavity.

[0235] Example 31 : An aerosol-generating article according to any of Examples 21 to 30, wherein the second cavity has a length extending parallel with the length of the aerosol-generating article, wherein the second air outlet has a width extending parallel with the length of the second cavity, and wherein the width of the second air outlet is the same as the length of the second cavity.

[0236] Example 32: An aerosol-generating article according to any of Examples 19 to 21 , further comprising a third cavity, and wherein the frame at least partially defines the third cavity. Example 33: An aerosol-generating article according to Example 32, further comprising a third aerosol-generating substrate positioned within the third cavity.

[0237] Example 34: An aerosol-generating article according to Example 33, further comprises a third air inlet and a third air outlet, wherein the third aerosol-generating substrate is positioned within the third cavity between the third air inlet and the third air outlet, and wherein the aerosolgenerating article defines a third airflow pathway extending through the third cavity from the third airflow inlet to the third airflow outlet

[0238] Example 35: An aerosol-generating article according to Example 34, wherein the length of the third airflow pathway is the shortest airflow distance through the third cavity from the third airflow inlet to the third airflow outlet.

[0239] Example 36: An aerosol-generating article according to Example 34 or 35, wherein the length of the third airflow pathway is equal to or less than 90 percent of the length of the aerosol- generating article, optionally equal to or less than 80 percent of the length of the aerosol- generating article, optionally equal to or less than 70 percent of the length of the aerosol- generating article, optionally equal to or less than 60 percent of the length of the aerosol- generating article, or optionally equal to or less than 50 percent of the length of the aerosolgenerating article.

[0240] Example 37: An aerosol-generating article according to Example 34, 35 or 36, wherein the third aerosol-generating substrate is arranged in the third cavity so that the third airflow pathway extends through the third aerosol-generating substrate.

[0241] Example 38: An aerosol-generating article according to any of Examples 34 to 37, wherein the third aerosol-generating substrate has a length extending parallel with the third airflow pathway, and wherein the length of the third aerosol-generating substrate is at least 80 percent of the length of the third airflow pathway, preferably at least 90 percent of the length of the third airflow pathway, preferably wherein the length of the third aerosol-generating substrate is the same as the length of the third airflow pathway.

[0242] Example 39: An aerosol-generating article according to any of Examples 34 to 38, wherein the length of the third airflow pathway is perpendicular to the length of the aerosol-generating article. Example 40: An aerosol-generating article according to any of Examples 34 to 39, wherein the frame at least partially defines the first end and the second end of the aerosol-generating article, wherein the frame at least partially defines a first side of the aerosol-generating article extending between the first end and the second end, wherein the frame at least partially defines a second side of the aerosol-generating article extending between the first end and the second end, wherein the third air inlet extends through the first side of the aerosol-generating article, and wherein the third air outlet extends through the second side of the aerosol-generating article. Example 41 : An aerosol-generating article according to Example 40, wherein each of the first planar surface and the second planar surface is perpendicular to each of the first end, the second end, the first side, and the second side.

[0243] Example 42: An aerosol-generating article according to any of Examples 34 to 41 , wherein the third cavity has a length extending parallel with the length of the aerosol-generating article, wherein the third aerosol-generating substrate has a width extending parallel with the length of the third cavity, and wherein the width of the third aerosol-generating substrate is the same as the length of the third cavity.

[0244] Example 43: An aerosol-generating article according to any of Examples 34 to 42, wherein the third cavity has a length extending parallel with the length of the aerosol-generating article, wherein the third air inlet has a width extending parallel with the length of the third cavity, and wherein the width of the third air inlet is the same as the length of the third cavity.

[0245] Example 44: An aerosol-generating article according to any of Examples 34 to 43, wherein the third cavity has a length extending parallel with the length of the aerosol-generating article, wherein the third air outlet has a width extending parallel with the length of the third cavity, and wherein the width of the third air outlet is the same as the length of the third cavity.

[0246] Example 45: An aerosol-generating article according to any of Examples 1 to 5, wherein the length of the airflow pathway is parallel with the length of the aerosol-generating article.

[0247] Example 46: An aerosol-generating article according to Example 45, further comprising an inlet chamber at least partially defined by the frame, wherein the inlet chamber has an open end at the first end of the aerosol-generating article and a second end spaced apart from the open end, and wherein the air inlet provides fluid communication between the second end of the inlet chamber and the cavity.

[0248] Example 47: An aerosol-generating article according to Example 46, further comprising an inlet opening defining the open end of the inlet chamber, wherein a ratio of a maximum cross-sectional area of the inlet opening to a maximum cross-sectional area of the inlet chamber parallel to the inlet opening is at least 0.8 to 1 , preferably at least 0.9 to 1 , preferably at least 1 to 1.

[0249] Example 48: An aerosol-generating article according to Example 45, 46 or 47, further comprising an outlet chamber at least partially defined by the frame, wherein the outlet chamber has an open end at the second end of the aerosol-generating article and a second end spaced apart from the open end, and wherein the air outlet provides fluid communication between the cavity and the second end of the outlet chamber.

[0250] Example 49: An aerosol-generating article according to Example 48, further comprising an outlet opening defining the open end of the outlet chamber, wherein a ratio of a maximum cross- sectional area of the outlet opening to a maximum cross-sectional area of the outlet chamber parallel to the outlet opening is at least 0.8 to 1 , preferably at least 0.9 to 1 , preferably at least 1 to 1. Example 50: An aerosol-generating article according to any of Examples 45 to 49, wherein the frame comprises: a first longitudinal portion extending between the first and second ends of the aerosolgenerating article; a second longitudinal portion extending between the first and second ends of the aerosolgenerating article, wherein the second longitudinal portion is spaced apart from the first longitudinal portion; a first lateral portion spaced apart from the first end of the aerosol-generating article, wherein the first lateral portion extends between the first and second longitudinal portions; and a second lateral portion spaced apart from the second end of the aerosol-generating article, wherein the second lateral portion extends between the first and second longitudinal portions, and wherein the second lateral portion is spaced apart from the first lateral portion so that the cavity is at least partially defined between the first and second longitudinal portions and between the first and second lateral portions.

[0251] Example 51 : An aerosol-generating article according to Example 50, wherein the first and second longitudinal portions and the first and second lateral portions are all formed integrally with each other.

[0252] Example 52: An aerosol-generating article according to Example 50, wherein the first lateral portion is formed integrally with the first longitudinal portion, wherein the second lateral portion is formed integrally with the second longitudinal portion.

[0253] Example 53: An aerosol-generating article according to Example 52, wherein the first longitudinal portion and the first lateral portion together form a first subframe, wherein the second longitudinal portion and the second lateral portion together form a second subframe, wherein the second subframe is formed separately from the first subframe, and wherein the first subframe and the second subframe together form the frame.

[0254] Example 54: An aerosol-generating article according to any preceding Example, further comprising at least one of a taggant and a machine readable indicium positioned at the first end of the aerosol-generating article or the second end of the aerosol-generating article.

[0255] Example 55: An aerosol-generating article according to Example 54, wherein the at least one of a taggant and a machine readable indicium is arranged on at least one of the first planar external surface and the second planar external surface.

[0256] Example 56: An aerosol-generating system comprising: an aerosol-generating article according to any preceding Example; and an aerosol-generating device, the aerosol-generating device comprising: a chamber for receiving at least a portion of the aerosol-generating article; and an electric heater arranged to heat at least part of the aerosol-generating article when the aerosol-generating article is received within the chamber. Examples will now be further described with reference to the figures in which:

[0257] Figure 1 shows a perspective view of an aerosol-generating article according to the present disclosure;

[0258] Figure 2 shows an exploded perspective view of the aerosol-generating article of Figure 1 ;

[0259] Figure 3 shows an exploded perspective view of an aerosol-generating article according to the present disclosure;

[0260] Figure 4 shows a perspective view of an aerosol-generating article according to the present disclosure;

[0261] Figure 5 shows a perspective view of an aerosol-generating article according to the present disclosure;

[0262] Figure 6 shows an exploded perspective view of an aerosol-generating article according to the present disclosure;

[0263] Figure 7 shows a perspective view of an aerosol-generating article according to the present disclosure;

[0264] Figure 8 shows a perspective view of an alternative frame for an aerosol-generating device according to the present disclosure;

[0265] Figure 9 shows a perspective view of an aerosol-generating article comprising the frame of Figure 8;

[0266] Figure 10 shows a perspective view of a further alternative frame for an aerosol-generating device according to the present disclosure;

[0267] Figure 11 shows a perspective view of a further alternative frame for an aerosol-generating device according to the present disclosure;

[0268] Figure 12 shows a perspective view of an aerosol-generating article comprising the frame of Figure 11 ;

[0269] Figure 13 shows a perspective view of a further alternative frame for an aerosol-generating device according to the present disclosure;

[0270] Figure 14 shows a perspective view of an aerosol-generating article comprising the frame of Figure 13;

[0271] Figure 15 shows a schematic cross-sectional view of an aerosol-generating device according to the present disclosure;

[0272] Figure 16 shows a schematic cross-sectional view of the aerosol-generating device of Figure 15 in engagement with an aerosol-generating article of the present disclosure; and

[0273] Figure 17 shows a schematic cross-sectional view of an aerosol-generating article comprising the frame of Figure 13 in engagement with a convective heater and a mouthpiece.

[0274] Figure 1 shows an aerosol-generating article 10 comprising a first planar external layer 24 forming a first planar external surface 21 , a second planar external layer 25 forming a second planar external surface 22, and a frame 50 positioned between the first planar external layer 24 and the second planar external layer 25. The first planar external layer 24 and the second planar external layer 25 both comprise an aerosol-generating substrate comprising an aerosolgenerating material, namely tobacco. However, it will be understood that in some embodiments only one of the first planar external layer 24 and the second planar external layer 25 may comprise an aerosol-generating substrate. Alternatively, or additionally, the aerosol-generating substrate may be positioned elsewhere within the aerosol-generating article 10.

[0275] The aerosol-generating article 10 has a length extending in the x-direction, a width extending in the y-direction and a thickness extending in the z-direction. The aerosol-generating article 10 has a length of 30 millimetres, a width of 10 millimetres, and a thickness of 3.1 millimetres.

[0276] The aerosol-generating article 10 is substantially flat aerosol-generating article or substantially planar aerosol-generating article. In particular, the thickness of the aerosolgenerating article 10 is less than 50 percent of both the length and the width of the aerosolgenerating article. The aerosol-generating article 10 has a generally rectangular cuboid shape and a laminated structure formed by the first planar external layer 24, the frame 50 and the second planar external layer 25. The first planar external layer 24, the frame 50 and the second planar external layer 25 are bonded together with an adhesive, in particular guar gum, as discussed in more detail below in relation to Figure 2.

[0277] Figure 2 shows an exploded view of the aerosol-generating article 10 of Figure 1.

[0278] The frame 50 has a length of 30 millimetres, a width of 10 millimetres, and a thickness of 2.7 millimetres. The frame 50 is made from cardboard and defines a frame aperture extending through the thickness of the frame 50. The frame aperture at least partially forms a cavity 30. The cavity 30 has length of 26 millimetres, a width of 6 millimetres, and a thickness of 2.7 millimetres. Therefore, the cavity 30 has a volume of about 421.2 cubic millimetres. In this embodiment, the cavity 30 is substantially empty.

[0279] The frame 50 has a frame inner surface 52 extending in the z-direction or the transverse direction between the first planar external surface 21 and the second planar external surface 22. The frame inner surface 52 defines a cavity outer wall. The frame 50 has a frame outer surface 53 extending in the z-direction or the transverse direction between the first planar external surface 21 and the second planar external surface 22. The frame outer surface 53 at least partially defines one or more external surfaces of the aerosol-generating article, such as the front wall 13 and the back wall 14.

[0280] The frame 50 comprises a peripheral wall 51 that circumscribes the cavity 30. In more detail, the peripheral wall 51 is defined by the frame inner surface 52 and the frame outer surface 52. The peripheral wall 51 has a radial thickness, as measured between the frame inner surface 52 and the frame outer surface 53 in the x / y plane, of about 2 millimetres. The first planar external layer 24 and the second planar external layer 25 have a thickness of 200 micrometres and are in physical contact with the frame 50. The first planar external layer 24 and the second planar external layer 25 are bonded to the frame with an adhesive 15. The first planar external layer 24 defines at least a portion of the cavity 30. The second planar external layer 25 defines at least a portion of the cavity 30.

[0281] The aerosol-generating article 10 comprises an air inlet 11 and an air outlet 12. The air inlet 11 and the air outlet 12 are defined by, and extend through, the peripheral wall 51 of the frame 50. The air inlet 11 and the air outlet 12 each have a rectangular cross-section, a width of 2 millimetres, and a thickness of 0.9 millimetres. An airflow passage extends between the air inlet 11 and the air outlet 12 through the cavity 30.

[0282] Figure 3 shows an exploded view of an aerosol-generating article that is similar to the aerosol-generating article 10 of Figure 1 except that the first planar external layer 24 and the second planar external layer 25 do not comprise an aerosol-generating substrate. Instead, an aerosol-generating substrate 40 is positioned within the cavity 30. The aerosol-generating substrate 40 comprises an aerosol-generating material in the form of tobacco cut filler and has an aerosol-former content of 5 percent by weight on a dry weight basis. As shown, the aerosolgenerating substrate 40 fills the entire volume of the cavity 30. In the example of Figure 3, the aerosol-generating substrate 40 has a packing density of about 0.87, a density of about 0.3 grams per cubic centimetre, and a mass of about 110 milligrams. In another example, the aerosolgenerating substrate 40 may have a different packing density, a different density and a different mass. For example, aerosol-generating substrate may have a packing density of 0.64, a density of 0.35 grams per cubic centimetre, and a mass of about 95 milligrams.

[0283] Figure 4 shows an aerosol-generating article 10 similar to the aerosol-generating article 10 of Figures 1 and 3 except that the aerosol-generating article 10 of Figure 4 comprises an outer wrapper 23 defining the first planar external surface 21 and the second planar external surface 22 instead of the first planar external layer 24 and the second planar external layer 25.

[0284] Figure 5 shows an aerosol-generating article 10 similar to the aerosol-generating article 10 of Figure 1 except that the aerosol-generating article 10 of Figure 5 further comprises a first aerosol-generating substrate layer 41 and a second aerosol-generating substrate layer 42. The first aerosol-generating substrate layer 41 and the second aerosol-generating substrate layer 42 are formed from a sheet of aerosol-generating material. In particular, a sheet of homogenised tobacco material having an aerosol-former content of 5 percent by weight on a dry weight basis. The first aerosol-generating substrate layer 41 and the second aerosol-generating substrate layer 42 each have a length equal to the length of the aerosol-generating article 10, a width equal to the width of the aerosol-generating article 10 and a thickness of 200 micrometres. That is, the aerosol-generating article 10 has a length of 30 millimetres, a width of 10 millimetres, and a thickness of 3.5 millimetres. The first aerosol-generating substrate layer 41 and the second aerosol-generating substrate layer 42 are in physical contact with the frame 50 and are bonded to the frame with an adhesive 15. The first aerosol-generating substrate layer 41 defines at least a portion of the cavity 30. The second aerosol-generating layer 42 defines at least a portion of the cavity 30.

[0285] The first planar external layer 24 is in physical contact with the first aerosol-generating substrate layer 41 and are bonded together with an adhesive 15. The second planar external layer 25 is in physical contact with the second aerosol-generating substrate layer 42 and are bonded together with an adhesive 15.

[0286] Figure 6 shows an exploded view of an aerosol-generating article 10 that is similar to the aerosol-generating article 10 of Figure 5 except that an aerosol-generating substrate 40 is positioned within the cavity 30 as described in relation to Figure 3. The aerosol-generating substrate 40 comprises an aerosol-generating material in the form of tobacco cut filler and has an aerosol-former content of 5 percent by weight on a dry weight basis. As shown, the aerosolgenerating substrate 40 fills the entire volume of the cavity 30. Figure 7 shows an aerosolgenerating article 10 similar to the aerosol-generating article 10 of Figure 5 except that the aerosol-generating article 10 of Figure 7 comprises an outer wrapper 23 defining the first planar external surface 21 and the second planar external surface 22 instead of the first planar external layer 24 and the second planar external layer 25.

[0287] Figure 8 shows a perspective view of an alternative frame 150 for use in aerosolgenerating articles according to the present disclosure, including the aerosol-generating articles 10 of Figures 1 to 7. The frame 150 shares features with the frame 50 and like reference numerals are used to designate like parts.

[0288] The frame 150 differs from the frame 50 by the location of the air inlet 11 and the air outlet 12. In particular, the air inlet 11 is positioned on a first side wall 152 of the frame 150 and the air inlet 12 is positioned on a second side wall 154 of the frame 150. The frame 150 defines an airflow pathway extending in the y-direction from the air inlet 11 to the air outlet 12. The airflow pathway has a length 156 corresponding to the distance between the inner surfaces of the first and second side walls 152, 154.

[0289] The frame 150 has a length 158 extending in the x-direction. The length 158 of the frame 150 corresponds to the distance between the outer surfaces of the front wall 13 and the back wall 14. When the frame 150 forms part of an aerosol-generating article such as the aerosolgenerating articles of Figures 1 to 7, the length 158 of the frame 150 may correspond to the length of the aerosol-generating article. Therefore, the length 156 of the airflow pathway is less than the length 158 of the frame 150 and the aerosol-generating article.

[0290] Figure 9 shows a perspective view of an aerosol-generating article 180 comprising the frame 150 and an aerosol-generating substrate 40 positioned within the cavity 30 between the air inlet 11 and the air outlet 12. The aerosol-generating substrate 40 abuts the air inlet 11 and the air outlet 12, which reduces the flow of aerosol into void spaces 31 within the frame 150. Advantageously, reducing the flow of aerosol into the void space 31 may reduce or prevent the condensation of aerosol in the void spaces 31.

[0291] Figure 10 shows a perspective view of a further alternative frame 250 for use in an aerosolgenerating article of the present disclosure. For example, the frame 250 may be used in place of the frame 150 in the aerosol-generating article 180 of Figure 10. The frame 250 is substantially the same as the frame 150 of Figure 8 and like reference numerals designate like parts. The frame 250 differs by the addition of a first lateral portion 252 and a second lateral portion 254 each extending between the first side wall 152 and the second side wall 154. The first and second lateral portions 252, 254 separate the cavity 30 from void spaces 31 within the frame 250. Advantageously, the separation provided by the first and second lateral portions 252, 254 may reduce or prevent the condensation in the void spaces 31 of aerosol generated from the substrate 40.

[0292] Figure 11 shows a perspective view of a further alternative frame 350 for use in an aerosolgenerating article of the present disclosure. For example, the frame 350 may be used in place of the frame 150 in the aerosol-generating article 180 of Figure 10. The frame 350 is similar to the frame 150 of Figure 8 and like reference numerals designate like parts.

[0293] The frame 350 differs by the addition of a lateral portion 352 extending between the first side wall 152 and the second side wall 154. The lateral portion 352 divides the inside of the frame 350 into a first cavity 330 and a second cavity 333. The first side wall 152 of the frame 350 defines a first air inlet 311 in fluid communication with the first cavity 330 and a second air inlet 321 in fluid communication with the second cavity 333. The second side wall 154 of the frame 350 defines a first air outlet 312 in fluid communication with the first cavity 330 and a second air outlet 322 in fluid communication with the second cavity 333.

[0294] The frame 350 defines a first airflow pathway extending in the y-direction from the first air inlet 311 to the first air outlet 312. The first airflow pathway has a length 356 corresponding to the distance between the inner surfaces of the first and second side walls 152, 154.

[0295] The frame 350 defines a second airflow pathway extending in the y-direction from the second air inlet 321 to the second air outlet 322. The second airflow pathway has a length 357 corresponding to the distance between the inner surfaces of the first and second side walls 152, 154. Therefore, the length 356 of the first airflow pathway is the same as the length 357 of the second airflow pathway.

[0296] The frame 350 has a length 158 extending in the x-direction. The length 158 of the frame 350 corresponds to the distance between the outer surfaces of the front wall 13 and the back wall 14. When the frame 350 forms part of an aerosol-generating article such as the aerosolgenerating articles of Figures 1 to 7, the length 158 of the frame 350 may correspond to the length of the aerosol-generating article. Therefore, the length 356 of the first airflow pathway and the length 357 of the second airflow pathway are both less than the length 158 of the frame and the aerosol-generating article.

[0297] Figure 12 shows a perspective view of an aerosol-generating article 380 comprising the frame 350. The aerosol-generating article 380 also comprises a first aerosol-generating substrate 340 positioned within the first cavity 330 between the first air inlet 311 and the first air outlet 312. The aerosol-generating article 380 also comprises a second aerosol-generating substrate 341 positioned within the second cavity 333 between the second air inlet 321 and the second air outlet 322. The first aerosol-generating substrate 340 substantially fills the volume of the first cavity 330 and the second aerosol-generating substrate 341 substantially fills the volume of the second cavity 333. Advantageously, this substantially eliminates void space from the frame 350, which may reduce or prevent the condensation of aerosol in the frame 350.

[0298] Figure 13 shows a perspective view of an alternative frame 450 for use with aerosolgenerating articles according to the present disclosure, including the aerosol-generating articles of Figures 1 to 7. The frame 450 shares features with the frame 50 and like reference numerals are used to designate like parts.

[0299] The frame 450 has an H-shape comprising a first longitudinal portion 452, a second longitudinal portion 454, a first lateral portion 456, and a second lateral portion 458. The first and second longitudinal portions 452, 454 and the first and second lateral portions 456, 458 are formed integrally with each other. The cavity 30 is defined between the first and second longitudinal portions 452, 454 and the first and second lateral portions 456, 458. The first lateral portion 456 defines the air inlet 11 and the second lateral portion 458 defines the air outlet 12. An airflow pathway extends in the x-direction from the air inlet 11 to the air outlet 12. The airflow pathway has a length 457 corresponding to the distance between the inner surfaces of the first and second lateral portions 456, 458.

[0300] The frame 450 has a length 459 extending in the x-direction. The length 459 of the frame 450 corresponds to the distance between first and second ends of the frame 450. When the frame 450 forms part of an aerosol-generating article such as the aerosol-generating articles of Figures 1 to 7, the length 459 of the frame 450 may correspond to the length of the aerosolgenerating article. Therefore, the length 457 of the airflow pathway is less than the length 459 of the frame 450 and the aerosol-generating article.

[0301] The frame 450 also defines a first chamber 460 at the first end of the frame 450 and a second chamber 462 at the second end of the frame 450.

[0302] The first chamber 460 has an open end 464 and a closed end 466. A first opening 468 at the open end 464 of the first chamber 460 extends across the full width of the first chamber 460 and allows airflow to enter the first chamber 460 during use. The air inlet 11 provides fluid communication between the first chamber 460 and the cavity 30 at the closed end 466 of the first chamber 460. The second chamber 462 has an open end 470 and a closed end 472. A second opening 474 at the open end 470 of the second chamber 462 extends across the full width of the second chamber 462 and allows airflow to exit the second chamber 462 during use. The air outlet 12 provides fluid communication between the cavity 30 and the second chamber 462 at the closed end 472 of the second chamber 462.

[0303] Figure 14 shows a perspective view of an aerosol-generating article 480 comprising the frame 450 of Figure 13. The aerosol-generating article 480 also comprises a first planar external layer 24 and a second planar external layer 25 attached to the top and bottom of the frame 450 to enclose the cavity 30, the first chamber 460 and the second chamber 462. An aerosolgenerating substrate 40 is positioned within the cavity 30. The aerosol-generating substrate 40 substantially fills the volume of the cavity 30. Advantageously, this substantially eliminates void space from the cavity 30, which may reduce or prevent the condensation of aerosol in the cavity 30.

[0304] A taggant 482 is arranged on the first planar external surface 21 defined by the first planar external layer 24. Advantageously, the taggant 482 facilitates identification of the aerosolgenerating article 480 by an aerosol-generating device. Advantageously, the H-shape of the frame 450 facilitates positioning of the taggant 482 away from the aerosol-generating substrate 40, which may reduce or eliminate heating of the taggant 482 by the heater of an aerosolgenerating device during use.

[0305] Figure 15 shows a schematic cross-sectional view of an aerosol-generating device 90 configured for use with an aerosol-generating article 10 described herein. The aerosol-generating device 90 is an elongate aerosol-generating device extending between a proximal end 91 and a distal end 92. The aerosol-generating device 90 comprises a battery 93, a controller 94, a first heater 95 and a second heater 96 located within a housing 97. The controller 94 controls supply of power from the battery 93 to the first heater 95 and the second heater 96. A cavity 1000 is defined in the device 90, the cavity 1000 having an opening 1010 defined in the proximal end 91 of the device 90. The opening 1010 is rectangular in shape and is dimensioned to accommodate the transverse cross-section of the aerosol-generating article 10. The cavity 1000 comprises an upper planar surface 1020 and a lower planar surface 1030. The first heater 95 is located in the upper planar surface 1020 to heat the first planar external surface 21 of an aerosol-generating article 10 inserted into the cavity 1000, and the second heater 96 is located in the lower planar surface 1030 to heat the second planar external surface 22 of an aerosol-generating article 10 inserted into the cavity 1000. The device 90 comprises an air inlet 98 defining an air-flow path configured to allow air to flow into the cavity 1000 from outside the device.

[0306] Figure 16 shows a schematic cross-sectional view of the aerosol-generating device 90 of Figure 15 in engagement with the aerosol-generating article 10 of Figure 1 . There is little tolerance between the first planar external surface 21 and the second planar external surface 22 of the aerosol-generating article 10 and the internal surfaces 1020, 1030 of the cavity 1000. Thus, there is a snug fit between the aerosol-generating article 10 and the aerosol-generating device 90. When a consumer has inserted the aerosol-generating article 10 into the cavity 1000, the device can be operated. The first heater 95 heats the first planar external surface 21 of the aerosolgenerating article 10 and the second heater 96 heats the second planar external surface 22 of the aerosol-generating article, and as a result the aerosol-generating substrate is heated. Volatile components of the aerosol-generating substrate are evaporated and condense in the cavity 30 of the aerosol-generating article 10 to form an aerosol. The consumer inhales the aerosol by drawing on the end of the aerosol-generating article 10 comprising the air outlet 12. Once the aerosolgenerating substrate has been depleted of volatile components, the aerosol-generating article 10 is removed from the cavity 1000 and disposed of.

[0307] Figure 17 shows a schematic cross-sectional view of an aerosol-generating article comprising the frame 450 of Figure 13 in engagement with a convective heater 1100 of an aerosolgenerating device and a mouthpiece 1102. The convective heater 1100 is received within the first chamber 460 and the mouthpiece 1102 is received within the second chamber 462. The convective heater 1100 comprises a heater housing 1104 defining an inlet airflow passage 1106 extending through the heater housing 1104. The convective heater 1100 also comprises a resistive heater 1108 arranged within the inlet airflow passage 1106 to heat airflow passing through the inlet airflow passage 1106 and into the cavity 30 of the aerosol-generating article via the air inlet 11. The heated airflow heats the aerosol-generating substrate 40 positioned within the cavity 30 to generate an aerosol. The aerosol flows out of the cavity 30 via the air outlet 12 and into an outlet air passageway 1110 defined by the mouthpiece 1102. The aerosol is mixed with ventilation airflow entering the outlet air passageway 1110 through a plurality of ventilation air inlets 1112 before being delivered to the consumer.

[0308] For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ± 10% of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

Claims

Claims1. An aerosol-generating article for use with an aerosol-generating device to generate an aerosol, the aerosol-generating article comprising: a first planar external surface and a second planar external surface; a cavity; a frame at least partially defining the cavity; an air inlet and an air outlet; an aerosol-generating substrate positioned within the cavity between the air inlet and the air outlet; and wherein the aerosol-generating article defines an airflow pathway extending through the cavity from the airflow inlet to the airflow outlet; wherein the aerosol-generating article has a length extending between a first end of the aerosol-generating article and a second end of the generating article, wherein the length is the largest dimension of the aerosol-generating article; and wherein a length of the airflow pathway is less than the length of the aerosol-generating article.

2. An aerosol-generating article according to claim 1 , wherein the length of the airflow pathway is the shortest airflow distance through the cavity from the airflow inlet to the airflow outlet.

3. An aerosol-generating article according to claim 1 or 2, wherein the length of the airflow pathway is equal to or less than 90 percent of the length of the aerosol-generating article, optionally equal to or less than 80 percent of the length of the aerosol-generating article, optionally equal to or less than 70 percent of the length of the aerosol-generating article, optionally equal to or less than 60 percent of the length of the aerosol-generating article, or optionally equal to or less than 50 percent of the length of the aerosol-generating article.

4. An aerosol-generating article according to claim 1 , 2 or 3, wherein the aerosol-generating substrate is arranged in the cavity so that the airflow pathway extends through the aerosolgenerating substrate.

5. An aerosol-generating article according to any preceding claim, wherein the aerosolgenerating substrate has a length extending parallel with the airflow pathway, and wherein the length of the aerosol-generating substrate is at least 80 percent of the length of the airflowpathway, preferably at least 90 percent of the length of the airflow pathway, preferably wherein the length of the aerosol-generating substrate is the same as the length of the airflow pathway.

6. An aerosol-generating article according to any preceding claim, wherein the length of the airflow pathway is perpendicular to the length of the aerosol-generating article.

7. An aerosol-generating article according to any preceding claim, wherein the frame at least partially defines the first end and the second end of the aerosol-generating article, wherein the frame at least partially defines a first side of the aerosol-generating article extending between the first end and the second end, wherein the frame at least partially defines a second side of the aerosol-generating article extending between the first end and the second end, wherein the air inlet extends through the first side of the aerosol-generating article, and wherein the air outlet extends through the second side of the aerosol-generating article, optionally wherein each of the first planar surface and the second planar surface is perpendicular to each of the first end, the second end, the first side, and the second side.

8. An aerosol-generating article according to any preceding claim, wherein the cavity is a first cavity, the aerosol-generating article further comprising a second cavity, and wherein the frame at least partially defines the second cavity, optionally wherein the aerosol-generating substrate is a first aerosol-generating substrate, the aerosol-generating article further comprising a second aerosol-generating substrate positioned within the second cavity.

9. An aerosol-generating article according to claim 8, wherein the air inlet is a first air inlet, wherein the air outlet is a second air outlet, wherein the aerosol-generating article further comprises a second air inlet and a second air outlet, wherein the second aerosol-generating substrate is positioned within the second cavity between the second air inlet and the second air outlet, wherein the airflow pathway is a first airflow pathway, wherein the aerosol-generating article defines a second airflow pathway extending through the second cavity from the second airflow inlet to the second airflow outlet, and wherein a length of the second airflow pathway is less than the length of the aerosol-generating article, optionally wherein the length of the second airflow pathway is the shortest airflow distance through the second cavity from the second airflow inlet to the second airflow outlet, optionally wherein the length of the second airflow pathway is equal to or less than 90 percent of the length of the aerosol-generating article, optionally equal to or less than 80 percent of the length of the aerosol-generating article, optionally equal to or less than 70 percent of the length of the aerosol-generating article, optionally equal to or less than 60 percent of the lengthof the aerosol-generating article, or optionally equal to or less than 50 percent of the length of the aerosol-generating article, optionally wherein the second aerosol-generating substrate is arranged in the second cavity so that the second airflow pathway extends through the second aerosol-generating substrate, optionally wherein the second aerosol-generating substrate has a length extending parallel with the second airflow pathway, and wherein the length of the second aerosol-generating substrate is at least 80 percent of the length of the second airflow pathway, preferably at least 90 percent of the length of the second airflow pathway, preferably wherein the length of the second aerosol-generating substrate is the same as the length of the second airflow pathway, optionally wherein the length of the second airflow pathway is perpendicular to the length of the aerosol-generating article.

10. An aerosol-generating article according to claim 8 or 9, wherein the frame at least partially defines the first end and the second end of the aerosol-generating article, wherein the frame at least partially defines a first side of the aerosol-generating article extending between the first end and the second end, wherein the frame at least partially defines a second side of the aerosolgenerating article extending between the first end and the second end, wherein the second air inlet extends through the first side of the aerosol-generating article, and wherein the second air outlet extends through the second side of the aerosol-generating article, optionally wherein each of the first planar surface and the second planar surface is perpendicular to each of the first end, the second end, the first side, and the second side.

11. An aerosol-generating article according to any preceding claim, wherein the length of the airflow pathway is parallel with the length of the aerosol-generating article, optionally wherein the aerosol-generating article further comprises an inlet chamber at least partially defined by the frame, wherein the inlet chamber has an open end at the first end of the aerosol-generating article and a second end spaced apart from the open end, and wherein the air inlet provides fluid communication between the second end of the inlet chamber and the cavity, optionally wherein the aerosol-generating article further comprises an inlet opening defining the open end of the inlet chamber, wherein a ratio of a maximum cross-sectional area of the inlet opening to a maximum cross-sectional area of the inlet chamber parallel to the inlet opening is at least 0.8 to 1 , preferably at least 0.9 to 1 , preferably at least 1 to 1.

12. An aerosol-generating article according to claim 11 , further comprising an outlet chamber at least partially defined by the frame, wherein the outlet chamber has an open end at the second end of the aerosol-generating article and a second end spaced apart from the open end, andwherein the air outlet provides fluid communication between the cavity and the second end of the outlet chamber, optionally wherein the aerosol-generating article further comprises an outlet opening defining the open end of the outlet chamber, wherein a ratio of a maximum cross- sectional area of the outlet opening to a maximum cross-sectional area of the outlet chamber parallel to the outlet opening is at least 0.8 to 1 , preferably at least 0.9 to 1 , preferably at least 1 to 1.

13. An aerosol-generating article according to claim 11 or 12, wherein the frame comprises: a first longitudinal portion extending between the first and second ends of the aerosolgenerating article; a second longitudinal portion extending between the first and second ends of the aerosolgenerating article, wherein the second longitudinal portion is spaced apart from the first longitudinal portion; a first lateral portion spaced apart from the first end of the aerosol-generating article, wherein the first lateral portion extends between the first and second longitudinal portions; and a second lateral portion spaced apart from the second end of the aerosol-generating article, wherein the second lateral portion extends between the first and second longitudinal portions, and wherein the second lateral portion is spaced apart from the first lateral portion so that the cavity is at least partially defined between the first and second longitudinal portions and between the first and second lateral portions.

14. An aerosol-generating article according to any preceding claim, further comprising at least one of a taggant and a machine readable indicium positioned at the first end of the aerosolgenerating article or the second end of the aerosol-generating article, optionally wherein the at least one of a taggant and a machine readable indicium is arranged on at least one of the first planar external surface and the second planar external surface.

15. An aerosol-generating system comprising: an aerosol-generating article according to any preceding claim; and an aerosol-generating device, the aerosol-generating device comprising: a chamber for receiving at least a portion of the aerosol-generating article; and an electric heater arranged to heat at least part of the aerosol-generating article when the aerosolgenerating article is received within the chamber.

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