Aerosol-generating article comprising a cavity containing an aerosol-generating element

Abstract

There is provided an aerosol-generating article for use with an aerosol-generating device to generate an aerosol. The aerosol-generating article is defined by an article length, an article width, and an article thickness. The article width is greater than the article thickness. The aerosol-generating article comprises a first external surface and an opposing second external surface, a cavity, a frame, an airflow passage and a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate. The cavity is located within the aerosol-generating article between the first external surface and the second external surface. The frame is positioned between the first external surface and the second external surface. The frame at least partially defines the cavity. The airflow passage is defined through the aerosol-generating article between an air inlet and an air outlet, the airflow passage extending through the cavity. The collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate is disposed within the cavity. Each shred, strip, strand or extrusion of the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate occupies less than 1 % of an enclosed volume of the cavity, for example less than 0.5% of the enclosed volume of the cavity, for example less than 0.2% of the enclosed volume of the cavity, for example less than 0.05% of the enclosed volume of the cavity; for example less than 0.01 % of the enclosed volume of the cavity.

Description

[0001] AEROSOL-GENERATING ARTICLE COMPRISING A CAVITY CONTAINING AN AEROSOLGENERATING ELEMENT

[0002] The present disclosure relates to an aerosol-generating article comprising a cavity and aerosol-generating element disposed within the cavity. 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 aerosol-generating device and the aerosolgenerating article. The present disclosure also relates to a method of manufacturing the aerosolgenerating 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.

[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.

[0007] According to the present disclosure, there is provided an aerosol-generating article. The aerosol-generating article may be for use with an aerosol-generating device to generate an aerosol. The aerosol-generating article may be defined by an article length, an article width, and an article thickness, the article width being greater than the article thickness. The aerosolgenerating article may comprise one or more aerosol-generating substrates. The aerosol- generating article comprises a first external surface and a second external surface. The first external surface and the second external surface may be described as opposing first and second surfaces, for example the second external surface may face in substantially the opposite direction to the first external surface.

[0008] The aerosol-generating article may comprise a cavity. The cavity may be located within the aerosol-generating article between the first external surface and the second external surface. The aerosol-generating article may comprise a frame positioned between the first external surface and the second external surface. The frame may at least partially define the cavity. The aerosolgenerating article may comprise an air inlet. The aerosol-generating article may comprise an air outlet. The aerosol-generating article may comprise an airflow passage extending between the air inlet and the air outlet. The airflow passage may be positioned between the first external surface and the second external surface. The airflow passage may extend between the air inlet and the air outlet through the cavity. A collection of unbound shreds, strips, strands or extrusions of aerosolforming substrate may be disposed within the cavity.

[0009] The collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate defines an aerosol-generating element of the aerosol-generating article. So, where the term “aerosol-generating element” is used within this specification, it will be understood that the aerosolgenerating element is preferably in the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate.

[0010] Thus, there may be provided an aerosol-generating article for use with an aerosolgenerating device to generate an aerosol, the aerosol-generating article being defined by an article length, an article width, and an article thickness, the article width being greater than the article thickness, the aerosol-generating article comprising a first external surface and an opposing second external surface; a cavity located within the aerosol-generating article between the first external surface and the second external surface; a frame positioned between the first external surface and the second external surface, the frame at least partially defining the cavity; and an airflow passage defined through the aerosol-generating article between an air inlet and an air outlet, the airflow passage extending through the cavity, wherein a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate is disposed within the cavity.

[0011] The collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate comprises, or is, aerosol-forming material. The collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may be the only source of aerosol-forming substrate within the article, or there may be other portions of the article that also comprise aerosol-forming substrate.

[0012] The collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may be fixed within the cavity, for example fixed by adhesion or fixed by mechanical means such as interference with one or more walls of the cavity. By fixing the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate within the cavity, any risk of the aerosol- forming substrate moving within the cavity and blocking or restricting airflow through the cavity is reduced.

[0013] The cavity is defined by internal dimensions, for example a cavity length, a cavity width, and a cavity height. Cavity height may also be termed cavity thickness. Preferably, the cavity width is greater than the cavity height / thickness.

[0014] The shreds, strips, strands or extrusions of aerosol-forming substrate may be aligned along a length direction of the aerosol-generating article. This may facilitate air flow through the aerosolgenerating article along the length direction of the article, with the shreds, strips, strands or extrusions of aerosol-forming substrate being aligned substantially in a desired direction of air flow.

[0015] The shreds, strips, stands or extrusions of aerosol-forming substrate may be aligned to extend between the air inlet and the air outlet. This may facilitate air flow through the cavity from the air inlet to the air outlet.

[0016] The aerosol-forming substrate may comprise or consist of tobacco, for example shreds, strips, stands or extrusions of cut filler.

[0017] The aerosol-forming substrate may comprise or consist of non-tobacco material, for example shredded non-tobacco plant material.

[0018] The aerosol-forming substrate may comprise an aerosol-former. Suitable aerosol-formers are known in the field of heated aerosol-generating articles, and some examples are set out herein. The aerosol-forming substrate may comprise an aerosol-former selected from the list consisting of glycerine and propylene glycol. The aerosol-forming substrate may comprise at least 10 percent by weight (wt %) of aerosol former on a dry weight basis. Preferably, the aerosol-forming substrate may have an aerosol-former content of greater than 20 wt % on a dry weight basis, for example greater than 25 wt %, or greater than 30 wt %, for example greater than 35 wt %. The aerosolgenerating element may comprise one or more flavour compounds in addition to any aerosolformer.

[0019] The aerosol-forming substrate may comprise cut filler impregnated with an aerosol-former, for example shredded plant material impregnated with an aerosol former.

[0020] The aerosol-forming substrate may comprise one or more flavour compounds.

[0021] The collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may have a mass in a range of between 50 mg and 300 mg, for example between 100 mg and 200 mg, for example between 125 mg and 175 mg, for example between 140 mg and 160 mg, for example about 140 mg, or about 150 mg or about 160 mg.

[0022] The collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may have a length in a range of between 0.5 and 30 millimetres, for example between 0.5 and 20 millimetres, for example between 0.5 and 15 millimetres, for example between 0.8 and 10 millimetres, for example between 0.8 and 5 millimetres.

[0023] A length of the collection of unbound shreds, strips, strands or extrusions of aerosolforming substrate may extend along between 15% and 100% of a length of the cavity, for example between 30% and 100% of a length of the cavity, for example between 50% and 100% of a length of the cavity, for example between 50% and 90% of a length of the cavity, for example between 50% and 80% of a length of the cavity, for example between 50% and 70% of a length of the cavity.

[0024] The collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may occupy between 15% and 100% of an interior volume of the cavity, for example between 30% and 100% of an interior volume of the cavity, for example between 50% and 100% of an interior volume of the cavity, for example between 50% and 90% of an interior volume of the cavity, for example between 50% and 80% of an interior volume of the cavity, for example between 50% and 70% of an interior volume of the cavity.

[0025] Each of the shreds, strips, strands of aerosol-forming substrate which form the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may have a length, a width and a thickness.

[0026] At least 80%, or at least 85%, or at least 90%, or at least 95%, or all of the shreds, strips, strands or extrusions of aerosol-forming substrate may have a length in a range of between 0.5 and 30 millimetres, for example between 0.5 and 20 millimetres, for example between 0.5 and 15 millimetres, for example between 0.8 and 10 millimetres, for example between 0.8 and 5 millimetres.

[0027] At least 80%, or at least 85%, or at least 90%, or at least 95%, or all of the shreds, strips, strands or extrusions of aerosol-forming substrate may have a width in a range of between 0.3 and 4 millimetres, for example between 0.3 and 3 millimetres, for example between 0.3 and 2 millimetres, for example between 0.6 and 1.2 millimetres, for example between 0.6 and 0.9 millimetres.

[0028] Preferably, the cavity contains a single unitary collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate. The cavity may, however, contain more than one collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate. For example, two or more collections of unbound shreds, strips, strands or extrusions of aerosolforming substrate may be arranged within the cavity in a side-by-side relationship. For example, two or more collections of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may be arranged within the cavity in a one on top of the other relationship. If there is more than one collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate within the cavity, they need not have an identical composition. That is, the aerosolforming substrate of one collection of unbound shreds, strips, strands or extrusions of aerosolforming substrate disposed within the cavity may be different in composition to another collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate disposed within the cavity, perhaps to facilitate optimisation of aerosol-delivery or flavour profile. For example, different volatile compounds may be evolved from first and second collections of unbound shreds, strips, strands or extrusions of aerosol-forming substrate disposed within the cavity, the first and second collections having different respective first and second compositions, thereby allowing a user of the aerosol-generating article to inhale aerosol containing a mixture of the different volatile compounds.

[0029] Preferably the collection of unbound shreds, strips, strands or extrusions of aerosolforming substrate is arranged to fill the cavity. This facilitates ensuring that air flow through the cavity must pass between individual shreds, strips, strands or extrusions of the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate, thereby enhancing entraining of the air flow with volatile compounds evolved from the aerosol-forming substrate under heating.

[0030] The cavity may comprise a filled portion and an empty portion, the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate confined to the filled portion of the cavity. The filled portion may be positioned closer to an upstream end of the cavity than the empty portion. The filled portion may define between 50% and 95% of an enclosed volume of the cavity, for example between 60% and 95% of the enclosed volume of the cavity, for example between 70% and 95% of the enclosed volume of the cavity, for example between 80% and 95% of the enclosed volume of the cavity.

[0031] The cavity may comprise a first filled portion and a second filled portion. The first and second filled portions may be filled with respective first and second collections of unbound shreds, strips, strands or extrusions of aerosol-forming substrate. The composition of the first collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may be different to the composition of the second collection of unbound shreds, strips, strands or extrusions of aerosolforming substrate. In this manner, different volatile compounds may be evolved from the first and second collections of unbound shreds, strips, strands or extrusions of aerosol-forming substrate, allowing a user of the aerosol-generating article to inhale aerosol containing a mixture of the different volatile compounds.

[0032] Each shred, strip, strand or extrusion of the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may occupy less than 10% of an enclosed volume of the cavity, for example less than 10% of an enclosed volume of the cavity, for example less than 1 % of an enclosed volume of the cavity, for example less than 0.5% of the enclosed volume of the cavity, for example less than 0.2% of the enclosed volume of the cavity, for example less than 0.05% of the enclosed volume of the cavity; for example less than 0.01 % of the enclosed volume of the cavity.

[0033] The collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate disposed within the cavity may have a bulk density of between 150 mg per cubic centimetre and 500 mg per cubic centimetre, for example between 175 mg per cubic centimetre and 475 mg per cubic centimetre, for example between 200 mg per cubic centimetre and 450 mg per cubic centimetre, for example between 225 mg per cubic centimetre and 425 mg per cubic centimetre, for example between 250 mg per cubic centimetre and 400 mg per cubic centimetre, for example between 275 mg per cubic centimetre and 375 mg per cubic centimetre, for example between 300 mg per cubic centimetre and 350 mg per cubic centimetre.

[0034] The collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate disposed within the cavity may have a bulk density of between 50 mg per cubic centimetre and 900 mg per cubic centimetre, for example between 100 mg per cubic centimetre and 800 mg per cubic centimetre, for example between 200 mg per cubic centimetre and 700 mg per cubic centimetre, for example between 200 mg per cubic centimetre and 600 mg per cubic centimetre, for example between 200 mg per cubic centimetre and 500 mg per cubic centimetre, for example between 200 mg per cubic centimetre and 400 mg per cubic centimetre.

[0035] The collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate disposed within the cavity may have a packing density between 0.3 and 0.9, for example between 0.4 and 0.9, for example between 0.5 and 0.9, for example between 0.5 and 0.8, for example between 0.5 and 0.7.

[0036] The collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may number between 30 and 2000 shreds, strips, strands or extrusions, for example between 30 and 1500 shreds, strips, strands or extrusions, for example between 30 and 1000 shreds, strips, strands or extrusions, for example between 30 and 500 shreds, strips, strands or extrusions, for example between 30 and 250 shreds, strips, strands or extrusions, for example between 30 and 100 shreds, strips, strands or extrusions.

[0037] Preferably, the shreds, strips, strands or extrusions of the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate are arranged to intermesh with each other. Such an intermeshing arrangement provides the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate with a structure better able to resist different ones of the shreds, strips, strands or extrusions from becoming separated from the collection of unbound shreds, strips, strands or extrusions when subject to an air flow through the cavity. For example, one or more first shreds, strips, strands or extrusions of the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may be aligned relative to one or more second shreds, strips, strands or extrusions of the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate at an acute angle of between 45 degrees and 90 degrees, for example between 60 degrees and 90 degrees, for example between 75 degrees and 90 degrees.

[0038] The first exterior wall and the second exterior wall may define respective first and second outwardly convex exterior surfaces, for example the first and second outwardly convex exterior surfaces collectively defining a lenticular profile.

[0039] Side walls of the cavity may be at least partially defined by the frame.

[0040] The frame may at least partially define the airflow passage. Advantageously, the first external surface and the second external surface allow for good contact with an external heater, particularly a planar external heater, of an aerosol-generating device, thereby providing optimum heating of the aerosol-generating substrate.

[0041] Advantageously, the first external surface and the second external surface may provide a large surface area for heating by an external heater of an aerosol-generating device, thereby allowing the aerosol-generating substrate to be quickly heated to a temperature sufficient for generating an aerosol.

[0042] 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.

[0043] 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. The collection of unbound shreds, strips, strands or extrusions of aerosolforming substrate may be located within the cavity during such a layering process.

[0044] In a preferred example, the aerosol-generating article comprises a first planar external surface and a second planar external surface, the aerosol-generating article further comprising a cavity within which one or more collections of unbound shreds, strips, strands or extrusions of aerosol-forming substrate are located, the aerosol-generating article further comprising a frame positioned between the first planar external surface and the second planar external surface, the frame at least partially defining the cavity. The aerosol-generating article further comprises an air inlet and an air outlet. The aerosol-generating article comprises an airflow passage extending between the air inlet and the air outlet through the cavity.

[0045] Advantageously, the frame may provide the aerosol-generating article with structural support. In particular, the frame may allow the aerosol-generating article to be relatively thin whilst maintaining structural rigidity.

[0046] The aerosol-generating article may have a length, a width and a thickness. The aerosolgenerating article may have an article length extending in an x-direction. The aerosol-generating article may have an article width extending in a y-direction. The aerosol-generating article may have an article thickness extending in a z-direction

[0047] Preferably, the cavity is defined by internal dimensions, the internal dimensions being a cavity length, a cavity width, and a cavity height. Preferably, the cavity length, cavity width, and cavity height extend in the x-direction, y-direction, and z-direction respectively.

[0048] The aerosol-generating article may comprise an x / y plane. The x / y plane may extend through the geometric centre of the aerosol-generating article. The x / y plane may define a plane of symmetry of the aerosol-generating article. The air inlet and air outlet may be symmetric, for example have a symmetric shape or position, about the x / y plane. The aerosol-generating article may comprise an x / z plane. The x / z plane may extend through the geometric centre of the aerosol-generating article. The x / z plane may define a plane of symmetry of the aerosol-generating article. The air inlet and air outlet may be symmetric, for example have a symmetric shape or position, about an x / z plane.

[0049] The aerosol-generating article may comprise a y / z plane. The y / z plane may extend through the geometric centre of the aerosol-generating article. The y / z plane may define a plane of symmetry of the aerosol-generating article. The air inlet and air outlet may be symmetric, for example have a symmetric shape or positioned, about the y / z plane.

[0050] Advantageously, a symmetric aerosol-generating article or an article with a symmetrically shaped or positioned air inlet and air outlet may allow the aerosol-generating article to be inserted into an aerosol-generating device in multiple orientations.

[0051] 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. Advantageously, this may allow heating of a greater proportion of the aerosol-generating substrate to a temperature at which an aerosol is released whilst minimising the risk of burning the hottest portion of the aerosolgenerating substrate closest to the heater. Advantageously, this may also reduce a time required to heat the aerosol-generating substrate sufficiently to release an aerosol.

[0052] The aerosol-generating article may have a 3-dimensional shape.

[0053] 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 cubic shape. The aerosol-generating article may have a cuboid shape. The aerosolgenerating article may have a rectangular cuboid shape. The aerosol-generating article may have a parallelepiped shape.

[0054] The aerosol-generating article may have a cylindrical shape. The aerosol-generating article may have a right-angled cylinder shape. The aerosol-generating article may have an elliptical cylinder shape.

[0055] The aerosol-generating article may have an oblong shape.

[0056] 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.

[0057] At least 50% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be paper or cardboard. At least 55% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be a cellulosic material. At least 60% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be a cellulosic material. At least 65% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be a cellulosic material. At least 70% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be a cellulosic material. At least 75% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be a cellulosic material. At least 80% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be a cellulosic material. At least 85% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be a cellulosic material. At least 90% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be a cellulosic material.

[0058] At least 50% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be paper or cardboard. At least 55% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be paper or cardboard. At least 60% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be paper or cardboard. At least 65% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be paper or cardboard. At least 70% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be paper or cardboard. At least 75% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be paper or cardboard. At least 80% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be paper or cardboard. At least 85% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be paper or cardboard. At least 90% of the mass of the aerosol-generating article, excluding the one or more aerosol-generating substrates, may be paper or cardboard.

[0059] Substantially the entirety of the aerosol-generating article, excluding the one or more aerosol-generating substrates and (if present) adhesive, may be paper or cardboard.

[0060] 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.

[0061] The frame may be a planar frame.

[0062] 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. The cross-section may have an annulus shape, such as a circular annulus shape, an elliptical annulus shape, a rectangular annulus shape, or a square annulus shape.

[0063] The frame may comprise a frame outer surface. The frame outer surface may extend in a transverse direction, for example between the first external surface and the second 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.

[0064] The frame may comprise a frame inner surface. The frame inner surface may extend in a transverse direction, for example between the first external surface and the second 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 outer surface may circumscribe or encircle the cavity.

[0065] 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.

[0066] The frame may define or form at least 75 percent of a perimeter of any cross-section, in an x / y plane, of the aerosol-generating article that extends through the frame. The frame may define or form at least 80 percent of a perimeter of any cross-section, in an x / y plane, of the aerosolgenerating article that extends through the frame. The frame may define or form at least 85 percent of a perimeter of any cross-section, in an x / y plane, of the aerosol-generating article that extends through the frame. The frame may define or form at least 90 percent of a perimeter of any crosssection, in an x / y plane, of the aerosol-generating article that extends through the frame. The frame may define or form at least 95 percent of a perimeter of any cross-section, in an x / y plane, of the aerosol-generating article that extends through the frame. The frame may define or form at least 99 percent of a perimeter of any cross-section, in an x / y plane, of the aerosol-generating article that extends through the frame.

[0067] Advantageously, providing a frame that forms at least 75 percent of a perimeter of any cross-section, in an x / y plane, of the aerosol-generating article that extends through the frame means that the frame extends around a significant portion of the aerosol-generating article. Therefore, the frame can provide the aerosol-generating article with good structural support.

[0068] Advantageously, providing a frame that forms at least 75 percent of a perimeter of any cross-section, in an x / y plane, of the aerosol-generating article that extends through the frame may mean that any air inlet or air outlet defined through the article is of a size that provides the aerosolgenerating article with a satisfactory resistance to draw.

[0069] Advantageously, providing a frame that forms at least 75 percent of a perimeter of any cross-section, in an x / y plane, of the aerosol-generating article that extends through the frame may allow the frame to act as a barrier that prevents egress of the shreds, strips, strands or extrusions of the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate from the aerosol-generating article.

[0070] The aerosol-generating article may comprise a cross-section in a first x / y plane that extends through the frame. The frame may form at least 99 percent of a perimeter of the crosssection in the first x / y plane. The frame may form at least 100 percent of the perimeter of the crosssection in the first x / y plane.

[0071] The aerosol-generating article may comprise a cross-section in a second x / y plane, spaced from the first x / y plane in the z-direction, that extends through the frame. The frame may form at least 99 percent of a perimeter of the cross-section in the second x / y plane. The frame may form 100 percent of the perimeter of the cross-section in the second x / y plane.

[0072] The air inlet may be positioned, in the z-direction, between the first x / y plane and the second x / y plane. The air outlet may be positioned, in the z-direction, between the first x / y plane and the second x / y plane.

[0073] The frame may comprise a first portion that is at least 30 percent of a thickness of the frame. The first portion may be at least 50 percent of the thickness of the frame. The first portion may be at least 70 percent of the thickness of the frame. The first portion may be at least 90 percent of the thickness of the frame. The frame forms 100 percent of a perimeter of any cross-section, in an x / y plane, of the aerosol-generating article that extends through the first portion of the frame.

[0074] The aerosol-generating article may comprise one or more external walls extending between the first external surface and the second 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.

[0075] The one or more external walls may circumscribe or encircle the cavity.

[0076] The frame may define at least 60 percent of the entire transverse external area of the aerosol-generating article. The frame may define at least 60 percent of the entire transverse external area of the aerosol-generating article. The frame may define at least 70 percent of the entire transverse external area of the aerosol-generating article. The frame may define at least 80 percent of the entire transverse external area of the aerosol-generating article. The frame may define at least 90 percent of the entire transverse external area of the aerosol-generating article.

[0077] 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. Advantageously, such a peripheral wall allows for a relatively large internal volume for an aerosol-generating substrate or aerosol formation whilst providing the structural strength to maintain the shape of the aerosol-generating article. 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.

[0078] 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.

[0079] 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 millimetre. 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 millimetres. The peripheral wall may have a radial thickness greater than or equal to 2.5 millimetres.

[0080] The peripheral wall may have a radial thickness less than or equal to 4 millimetres. 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 3 millimetres. The peripheral wall may have a radial thickness less than or equal to 2.5 millimetres. The peripheral wall may have a radial thickness less than or equal to 2 millimetres.

[0081] 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 3 millimetres. The peripheral wall may have a radial thickness between 0.5 millimetres and 2.5 millimetres. The peripheral wall may have a radial thickness between 1 millimetre and 3 millimetres. The peripheral wall may have a radial thickness between 1 millimetres and 2 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. Advantageously, a radial thickness between 0.5 millimetres and 3.5 millimetres may limit the amount of heat that is undesirably transferred to the frame rather than the aerosol-generating substrate.

[0082] The frame may be made from or comprise a biodegradable material. The frame may be made entirely from a biodegradable material.

[0083] 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.

[0084] The cellulosic material may have a grammage greater than or equal to 300 grams per square metre. The cellulosic material may have a grammage greater than or equal to 350 grams per square metre. The cellulosic material may have a grammage greater than or equal to 390 grams per square metre. The cellulosic material may have a grammage greater than or equal to 420 grams per square metre. The cellulosic material may have a grammage greater than or equal to 620 grams per square metre. The cellulosic material may have a grammage greater than or equal to 720 grams per square metre. The cellulosic material may have a grammage greater than or equal to 800 grams per square metre.

[0085] The cellulosic material may have a grammage less than or equal to 900 grams per square metre. The cellulosic material may have a grammage less than or equal to 800 grams per square metre. The cellulosic material may have a grammage less than or equal to 720 grams per square metre. The cellulosic material may have a grammage less than or equal to 620 grams per square metre. The cellulosic material may have a grammage less than or equal to 420 grams per square metre. The cellulosic material may have a grammage less than or equal to 390 grams per square metre. The cellulosic material may have a grammage less than or equal to 350 grams per square metre.

[0086] The cellulosic material may have a grammage between 300 grams per square metre and 900 grams per square metre. The cellulosic material may have a grammage between 300 grams per square metre and 800 grams per square metre. The cellulosic material may have a grammage between 350 grams per square metre and 800 grams per square metre. The cellulosic material may have a grammage between 400 grams per square metre and 700 grams per square metre.

[0087] The frame may be made from or comprise a fibrous material. The frame may be made from one or more of: natural fibres, synthetic fibres, polyester, bonded polyolefin, polyethylene, terylene, polypropylene, biopolymer fibres, nylon fibres, and ceramic fibres. The frame may comprise cellulosic fibres.

[0088] The frame may comprise a hydrophobic region. The hydrophobic region may comprise hydrophobic groups covalently bonded to the frame. The hydrophobic region may be positioned on, or form, at least a portion of the frame inner surface. Advantageously, a hydrophobic region may prevent or limit degradation of the frame in regions where the frame is regularly in contact with aerosol or liquids from the aerosol-generating substrate.

[0089] The hydrophobic region may be produced by a process comprising the steps of: applying a liquid composition comprising a fatty acid halide to a surface of the frame and maintaining the surface at a temperature of about 120 degrees Celsius to about 180 degrees Celsius. The fatty acid halide reacts in situ with protogenic groups of material in the hydrophobic region resulting in the formation of fatty acid esters.

[0090] The hydrophobic region may have a Cobb water absorption (ISO535:1991 ) value (at 60 seconds) less than or equal to 40 grams per square metre. The hydrophobic region may have a Cobb water absorption (ISO535:1991 ) value (at 60 seconds) of less than or equal to 35 grams per square metre. The hydrophobic region may have a Cobb water absorption (ISO535:1991 ) value (at 60 seconds) less than or equal to 30 grams per square metre. The hydrophobic region may have a Cobb water absorption (ISO535:1991 ) value (at 60 seconds) less than or equal to about 25 grams per square metre.

[0091] The hydrophobic region may have a water contact angle of greater than or equal to about 90 degrees. The hydrophobic region may have a water contact angle of greater than or equal to about 95 degrees. The hydrophobic region may have a water contact angle of greater than or equal to about 100 degrees. The hydrophobic region may have a water contact angle of greater than or equal to about 110 degrees. The hydrophobic region may have a water contact angle of greater than or equal to about 120 degrees. The hydrophobic region may have a water contact angle of greater than or equal to about 130 degrees. The hydrophobic region may have a water contact angle of greater than or equal to about 140 degrees. The hydrophobic region may have a water contact angle of greater than or equal to about 150 degrees. The hydrophobic region may have a water contact angle of greater than or equal to about 160 degrees. The hydrophobic region may have a water contact angle of greater than or equal to about 170 degrees.

[0092] Hydrophobicity is determined by utilizing the TAPPI T558 om-97 test and the result is presented as an interfacial contact angle and reported in “degrees” and can range from near zero degrees to near 180 degrees. Where no contact angle is specified along with the term hydrophobic, the water contact angle is at least 90 degrees.

[0093] The hydrophobic region may have a water contact angle of greater than or equal to 90 degrees and a Cobb water absorption (ISO535:1991 ) value (at 60 seconds) less than or equal to 40 grams per square metre.

[0094] 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 collection of unbound shreds, strips, strands or extrusions of aerosolforming substrate. The one or more susceptor materials may be dispersed within the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate. The one more susceptor materials may be in thermal contact with the airflow passage. The one more susceptor materials may be in thermal contact with the cavity. The one or more susceptor materials may be positioned in or on the frame inner surface. 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. Advantageously, the presence of one or more susceptor materials may allow the aerosol-generating article, and thus the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate, to be heated by engagement with a fluctuating electromagnetic field formed by an inductor.

[0095] 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. 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.

[0096] 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 60 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 80 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 aerosolgenerating article. The frame may have a thickness greater than or equal to 95 percent of the thickness of the aerosol-generating article.

[0097] 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 80 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.

[0098] 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 60 percent of the thickness of the aerosol-generating 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. The frame may have a thickness between 80 percent of the thickness of the aerosol-generating article and 95 percent of the thickness of the aerosolgenerating article.

[0099] The frame may have a thickness greater than or equal to 1 millimetre. The frame may have a thickness greater than or equal to 1 .5 millimetres. The frame may have a thickness greater than or equal to 2 millimetres. The frame may have a thickness greater than or equal to 2.5 millimetres. The frame may have a thickness greater than or equal to 3 millimetres. The frame may have a thickness greater than or equal to 3.5 millimetres. The frame may have a thickness greater than or equal to 4 millimetres. The frame may have a thickness greater than or equal to 4.5 millimetres.

[0100] The frame may have a thickness less than or equal to 5.5 millimetres. The frame may have a thickness less than or equal to 5 millimetres. The frame may have a thickness less than or equal to 4.5 millimetres. The frame may have a thickness less than or equal to 4 millimetres. The frame may have a thickness less than or equal to 3.5 millimetres. The frame may have a thickness less than or equal to 3 millimetres. The frame may have a thickness less than 2.5 millimetres. The frame may have a thickness less than 2 millimetres. The frame may have a thickness less than 1 .5 millimetres. The frame may have a thickness between 1 millimetre and 5.5 millimetres. The frame may have a thickness between 1 millimetre and 5 millimetres. Preferably, the frame may have a thickness between 1 .5 millimetres and 5 millimetres.

[0101] 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.

[0102] 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. The frame may have a width that is at least 90 percent of the width of the aerosol-generating article.

[0103] 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. Advantageously, the use of two or more layers allows producing, and rapidly adjusting, the desired thickness of the frame by adding or removing layers of sheet material. This may prevent the need to manufacture a single sheet of material having the desired thickness of the frame, which may subsequently need to be changed when the desired thickness of the frame changes.

[0104] 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 first frame layer may be an upper frame layer and the second frame layer may be a lower frame layer.

[0105] The frame may have a thickness equal to a sum of a thickness of the first frame layer and a thickness of the second frame layer. The frame aperture may be defined through both the first frame layer and the second frame layer.

[0106] 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. The first frame layer may be an upper frame layer, the second frame layer may be an intermediate frame layer, and the third frame layer may be a lower frame layer.

[0107] The first frame layer may be in physical contact with the second frame layer. The first frame layer may be bonded to the second frame layer with an adhesive. A lower surface of the first frame layer may be bonded to an upper surface of the second frame layer with an adhesive. The adhesive may extend at least 90% around the periphery of the intersection between the first frame layer and the second frame layer. The adhesive may extend at least 95% around the periphery of the intersection between the first frame layer and the second frame layer. The adhesive may extend at least 99% around the periphery of the intersection between the first frame layer and the second frame layer.

[0108] The second frame layer may be in physical contact with the third frame layer. The second frame layer may be bonded to the third frame layer with an adhesive. A lower surface of the second frame layer may be bonded to an upper surface of the third frame layer with an adhesive. The adhesive may extend at least 90% around the periphery of the intersection between the second frame layer and the third frame layer. The adhesive may extend at least 95% around the periphery of the intersection between the second frame layer and the third frame layer. The adhesive may extend at least 99% around the periphery of the intersection between the second frame layer and the third frame layer.

[0109] The frame may have a thickness equal to a sum of a thickness of the first frame layer, a thickness of the second frame layer and a thickness of the third frame layer. The frame aperture may be defined through the first frame layer, the second frame layer and the third frame layer.

[0110] The first frame layer may be planar.

[0111] The first frame layer may define a first frame layer aperture extending through the thickness of the first frame layer. The first frame layer aperture may at least partially define or form the cavity of the aerosol-generating article. For example, the first frame layer may have a hollow cuboid shape or a square hollow tube shape. As a further example, the first frame layer may have a crosssection that is annular in shape, preferably the cross-section in x / y plane is annular in shape. The cross-section may have an annulus shape, such as a circular annulus shape, an elliptical annulus shape, a rectangular annulus shape, or a square annulus shape.

[0112] The first frame layer may comprise a first frame layer outer surface. The first frame layer outer surface may extend in a transverse direction, for example between the first external surface and the second external surface. The first frame layer outer surface may at least partially define or form one or more external surfaces of the aerosol-generating article. For example, the first frame layer outer surface may at least partially define or form one or more external walls of the aerosolgenerating article. The first frame layer outer surface may circumscribe or encircle one or both: the first frame layer aperture and the frame aperture. The first frame layer outer surface may circumscribe or encircle the cavity.

[0113] The first frame layer may comprise a first frame layer inner surface. The first frame layer inner surface may extend in a transverse direction, for example between the first external surface and the second external surface. The first frame layer inner surface may define or form a first frame layer aperture outer wall. The first frame layer inner surface may at least partially define or form a cavity outer wall. The first frame layer inner surface may circumscribe or encircle one or both the first frame layer aperture and the frame aperture. The first frame layer outer surface may circumscribe or encircle the cavity. The first frame layer outer surface may circumscribe or encircle the first frame layer inner surface. The first frame layer inner surface and the first frame layer outer surface may be concentric with one another.

[0114] The first frame layer may comprise a first frame layer peripheral wall. The first frame layer peripheral wall may circumscribe or encircle one or both of: the frame aperture and the first frame layer aperture. The first frame layer peripheral wall may circumscribe or encircle the cavity.

[0115] The first frame layer peripheral wall may be defined or formed by the first frame layer outer surface and the first frame layer inner surface. The first frame layer peripheral wall may at least partially define or form one or more external surfaces or walls of the aerosol-generating article. The first frame layer peripheral wall may at least partially define or form the first frame layer aperture outer wall. The first frame layer peripheral wall may at least partially define or form the cavity outer wall.

[0116] The first frame layer may be made from or comprise any of the materials described above in relation to the frame. For example, the first frame layer may comprise the one or more susceptor materials.

[0117] The first frame layer may be made from or comprise a biodegradable material. The first frame layer may be entirely made from biodegradable material.

[0118] The first frame layer may be made from or comprise a cellulosic material. The cellulosic material may comprise a sheet of cellulosic material. The cellulosic material may comprise cellulosic fibres. The cellulosic material may be paper, paperboard, or cardboard. The first frame layer may be made from or comprise a plant material, such as tobacco. The first frame layer may be made entirely from a cellulosic material.

[0119] The cellulosic material may have any grammage or range of grammages as described above in relation to the frame.

[0120] The first frame layer may be made from a fibrous material. The first frame layer may be made from one or more of: natural fibres, synthetic fibres, polyester, bonded polyolefin, polyethylene, terylene, polypropylene, biopolymer fibres, nylon fibres, and ceramic fibres.

[0121] Where the frame comprises exactly two layers, the thickness of the first frame layer may be half (50 percent) the thickness of the frame. The first frame layer may have a thickness substantially the same as the second frame layer. Where the frame comprises exactly three layers, the thickness of the first frame layer may be one third (33.33 percent) the thickness of the frame. The first frame layer may have a thickness substantially the same as each of the second frame layer and the third frame layer.

[0122] The first frame layer may have a thickness greater than or equal to 0.5 millimetres. The frame may have a thickness greater than or equal to 1 millimetre. The first frame layer may have a thickness greater than or equal to 1 .5 millimetres. The first frame layer may have a thickness greater than or equal to 2 millimetres. The first frame layer may have a thickness greater than or equal to 2.5 millimetres. The first frame layer may have a thickness less than or equal to 3 millimetres. The first frame layer may have a thickness less than or equal to 2.5 millimetres. The first frame layer may have a thickness less than or equal to 2 millimetres. The first frame layer may have a thickness less than or equal to 1 .5 millimetres. The first frame layer may have a thickness less than or equal to 1 millimetres.

[0123] The first frame layer may have a thickness between 0.5 millimetres and 3 millimetres. The first frame layer may have a thickness between 0.5 millimetres and 2.5 millimetres. The first frame layer may have a thickness between 1 millimetres and 2.5 millimetres.

[0124] The second frame layer may be planar.

[0125] The second frame layer may define a second frame layer aperture extending through the thickness of the second frame layer. The second frame layer aperture may at least partially define or form the cavity of the aerosol-generating article. For example, the second frame layer may have a hollow cuboid shape or a square hollow tube shape. As a further example, the second frame layer may have a cross-section that is annular in shape, preferably the cross-section in x / y plane is annular in shape. The cross-section may have an annulus shape, such as a circular annulus shape, an elliptical annulus shape, a rectangular annulus shape, or a square annulus shape.

[0126] The second frame layer may comprise a second frame layer outer surface. The second frame layer outer surface may extend in a transverse direction, for example between the second external surface and the second external surface. The second frame layer outer surface may at least partially define or form one or more external surfaces of the aerosol-generating article. For example, the second frame layer outer surface may at least partially define or form one or more external walls of the aerosol-generating article. The second frame layer outer surface may circumscribe or encircle one or both: the second frame layer aperture and the frame aperture. The second frame layer outer surface may circumscribe or encircle the cavity.

[0127] The second frame layer may comprise a second frame layer inner surface. The second frame layer inner surface may extend in a transverse direction, for example between the second external surface and the second external surface. The second frame layer inner surface may define or form a second frame layer aperture outer wall. The second frame layer inner surface may at least partially define or form a cavity outer wall. The second frame layer inner surface may circumscribe or encircle one or both the second frame layer aperture and the frame aperture. The second frame layer outer surface may circumscribe or encircle the cavity.

[0128] The second frame layer outer surface may circumscribe or encircle the second frame layer inner surface. The second frame layer inner surface and the second frame layer outer surface may be concentric with one another.

[0129] The second frame layer may comprise a second frame layer peripheral wall. The second frame layer peripheral wall may circumscribe or encircle one or both of: the frame aperture and the second frame layer aperture. The second frame layer peripheral wall may circumscribe or encircle the cavity. The second frame layer peripheral wall may be defined or formed by the second frame layer outer surface and the second frame layer inner surface. The second frame layer peripheral wall may at least partially define or form one or more external surfaces or walls of the aerosolgenerating article. The second frame layer peripheral wall may at least partially define or form the second frame layer aperture outer wall. The second frame layer peripheral wall may at least partially define or form the cavity outer wall.

[0130] The second frame layer may be made from or comprise any of the materials described above in relation to the frame. For example, the second frame layer may comprise the one or more susceptor materials.

[0131] The second frame layer may be made from or comprise a biodegradable material. The second frame layer may be entirely made from biodegradable material.

[0132] The second frame layer may be made from or comprise a cellulosic material, as the cellulosic material may comprise a sheet of cellulosic material. The cellulosic material may be paper, paperboard, or cardboard. The second frame layer may be made from or comprise a plant material, such as tobacco. The second frame layer may be made entirely from a cellulosic material.

[0133] The cellulosic material may have any grammage or range of grammages as described above in relation to the frame.

[0134] The second frame layer may be made from a fibrous material. The second frame layer may be made from one or more of: natural fibres, synthetic fibres, polyester, bonded polyolefin, polyethylene, terylene, polypropylene, biopolymer fibres, nylon fibres, and ceramic fibres.

[0135] Where the frame comprises exactly two layers, the thickness of the second frame layer may be half (50 percent) the thickness of the frame. The second frame layer may have a thickness substantially the same as the first frame layer. Where the frame comprises exactly three layers, the thickness of the second frame layer may be one third (33.33 percent) the thickness of the frame. The second frame layer may have a thickness substantially the same as the first frame layer and the third frame layer.

[0136] The second frame layer may have a thickness greater than or equal to 0.5 millimetres. The frame may have a thickness greater than or equal to 1 millimetre. The second frame layer may have a thickness greater than or equal to 1 .5 millimetres. The second frame layer may have a thickness greater than or equal to 2 millimetres. The second frame layer may have a thickness greater than or equal to 2.5 millimetres.

[0137] The second frame layer may have a thickness less than or equal to 3 millimetres. The second frame layer may have a thickness less than or equal to 2.5 millimetres. The second frame layer may have a thickness less than or equal to 2 millimetres. The second frame layer may have a thickness less than or equal to 1 .5 millimetres. The second frame layer may have a thickness less than or equal to 1 millimetres. The second frame layer may have a thickness between 0.5 millimetres and 3 millimetres. The second frame layer may have a thickness between 0.5 millimetres and 2.5 millimetres. The second frame layer may have a thickness between 1 millimetres and 2.5 millimetres.

[0138] The third frame layer may be planar.

[0139] The third frame layer may define a third frame layer aperture extending through the thickness of the third frame layer. The third frame layer aperture may at least partially define or form the cavity of the aerosol-generating article. For example, the third frame layer may have a hollow cuboid shape or a square hollow tube shape. As a further example, the third frame layer may have a cross-section that is annular in shape, preferably the cross-section in x / y plane is annular in shape. The cross-section may have an annulus shape, such as a circular annulus shape, an elliptical annulus shape, a rectangular annulus shape, or a square annulus shape.

[0140] The third frame layer may comprise a third frame layer outer surface. The third frame layer outer surface may extend in a transverse direction, for example between the third external surface and the third external surface. The third frame layer outer surface may at least partially define or form one or more external surfaces of the aerosol-generating article. For example, the third frame layer outer surface may at least partially define or form one or more external walls of the aerosolgenerating article. The third frame layer outer surface may circumscribe or encircle one or both: the third frame layer aperture and the frame aperture. The third frame layer outer surface may circumscribe or encircle the cavity.

[0141] The third frame layer may comprise a third frame layer inner surface. The third frame layer inner surface may extend in a transverse direction, for example between the third external surface and the third external surface. The third frame layer inner surface may define or form a third frame layer aperture outer wall. The third frame layer inner surface may at least partially define or form a cavity outer wall. The third frame layer inner surface may circumscribe or encircle one or both the third frame layer aperture and the frame aperture. The third frame layer outer surface may circumscribe or encircle the cavity.

[0142] The third frame layer outer surface may circumscribe or encircle the third frame layer inner surface. The third frame layer inner surface and the third frame layer outer surface may be concentric with one another.

[0143] The third frame layer may comprise a third frame layer peripheral wall. The third frame layer peripheral wall may circumscribe or encircle one or both of: the frame aperture and the third frame layer aperture. The third frame layer peripheral wall may circumscribe or encircle the cavity.

[0144] The third frame layer peripheral wall may be defined or formed by the third frame layer outer surface and the third frame layer inner surface. The third frame layer peripheral wall may at least partially define or form one or more external surfaces or walls of the aerosol-generating article. The third frame layer peripheral wall may at least partially define or form the third frame layer aperture outer wall. The third frame layer peripheral wall may at least partially define or form the cavity outer wall. The third frame layer may be made from or comprise any of the materials described above in relation to the frame. For example, the third frame layer may comprise the one or more susceptor materials.

[0145] The third frame layer may be made from or comprise a biodegradable material. The third frame layer may be entirely made from biodegradable material.

[0146] The third frame layer may be made from or comprise a cellulosic material. The cellulosic material may comprise a sheet of cellulosic material. The cellulosic material may be paper, paperboard, or cardboard. The third frame layer may be made from or comprise a plant material, such as tobacco. The third frame layer may be made entirely from a cellulosic material.

[0147] The cellulosic material may have any grammage or range of grammages as described above in relation to the frame.

[0148] The third frame layer may be made from a fibrous material. The third frame layer may be made from one or more of: natural fibres, synthetic fibres, polyester, bonded polyolefin, polyethylene, terylene, polypropylene, biopolymer fibres, nylon fibres, and ceramic fibres.

[0149] Where the frame comprises exactly three layers, the thickness of the third frame layer may be one third (33.33 percent) the thickness of the frame. The third frame layer may have a thickness substantially the same as each of the first frame layer and the second frame layer.

[0150] The third frame layer may have a thickness greater than or equal to 0.5 millimetres. The frame may have a thickness greater than or equal to 1 millimetre. The third frame layer may have a thickness greater than or equal to 1 .5 millimetres. The third frame layer may have a thickness greater than or equal to 2 millimetres. The third frame layer may have a thickness greater than or equal to 2.5 millimetres.

[0151] The third frame layer may have a thickness less than or equal to 3 millimetres. The third frame layer may have a thickness less than or equal to 2.5 millimetres. The third frame layer may have a thickness less than or equal to 2 millimetres. The third frame layer may have a thickness less than or equal to 1 .5 millimetres. The third frame layer may have a thickness less than or equal to 1 millimetres.

[0152] The third frame layer may have a thickness between 0.5 millimetres and 3 millimetres. The third frame layer may have a thickness between 0.5 millimetres and 2.5 millimetres. The third frame layer may have a thickness between 1 millimetres and 2.5 millimetres.

[0153] Preferably, the collection of unbound shreds, strips, strands or extrusions of aerosolforming substrate disposed within the cavity is the primary source of aerosol-generating substrate within the article. In some examples, however, there may be one or more additional aerosolgenerating substrates. The one or more additional aerosol-generating substrates may comprise an aerosol-generating substrate layer. Advantageously, an aerosol-generating substrate layer can be made thin and, therefore, quickly heat up and release volatile compounds to form an aerosol. Advantageously, an aerosol-generating substrate layer can be positioned close to a heater of an aerosol-generating substrate. An 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.

[0154] The aerosol-generating substrate layer may be positioned between the frame and the first external surface. The aerosol-generating substrate layer may be positioned between the frame and the second external surface. The aerosol-generating substrate layer may be in physical contact with, and may be bonded to, the frame. The aerosol-generating substrate layer may be bonded to the frame with an adhesive.

[0155] 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. The aerosol-generating substrate layer may be bonded to both the frame and the outer wrapper with an adhesive.

[0156] The aerosol-generating substrate layer may be positioned between the frame and the first external layer. The aerosol-generating substrate layer may be positioned between the frame and the second external layer. The first external layer and the second 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 external layer. The aerosol-generating substrate layer may be bonded to both the frame and the first external layer with an adhesive. The aerosolgenerating substrate layer may in physical contact with, and may be bonded to, both the frame and the second external layer. The aerosol-generating substrate layer may be bonded to both the frame and the second external layer with an adhesive.

[0157] 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.

[0158] 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.

[0159] 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.

[0160] 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.

[0161] The first aerosol-generating substrate layer may be positioned between the frame and the first external surface. The first aerosol-generating substrate layer may be in physical contact with, and may be bonded to, the frame. For example, the first aerosol-generating substrate layer may be in physical contact with, and may be bonded to, the first frame layer. The first aerosol-generating substrate layer may be bonded to the frame with an adhesive. The first aerosol-generating substrate layer may be bonded to the first frame layer with an adhesive. A lower surface of the first aerosol-generating substrate layer may be bonded to an upper surface of the first frame layer with an adhesive.

[0162] 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. The first aerosol-generating substrate layer may be bonded to the frame and the outer wrapper with an adhesive.

[0163] The first aerosol-generating substrate layer may be positioned between the frame and the first external layer. The first aerosol-generating substrate layer may in physical contact with, and may be bonded to, both the frame and the first external layer. The first aerosol-generating substrate layer may be bonded to the frame and the first external layer with an adhesive.

[0164] The second aerosol-generating substrate layer may be positioned between the frame and the second external surface. The second aerosol-generating substrate layer may be in physical contact with, and may be bonded to, the frame. For example, the second aerosol-generating substrate layer may be in physical contact with, and may be bonded to, the second frame layer or third frame layer. The second aerosol-generating substrate layer may be bonded to the frame with an adhesive. The second aerosol-generating substrate layer may be bonded to the second frame layer or third frame layer with an adhesive. An upper surface of the second aerosol-generating substrate layer may be bonded to a lower surface of the second frame layer or third frame layer with an adhesive.

[0165] 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. The second aerosol-generating substrate layer may be bonded to the frame and the outer wrapper with an adhesive. The second aerosol-generating substrate layer may be positioned between the frame and the second external layer. The second aerosol-generating substrate layer may in physical contact with, and may be bonded to, both the frame and the second external layer. The second aerosolgenerating substrate layer may be bonded to the frame and the second external layer with an adhesive.

[0166] 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. In other words, the cavity may be defined by the frame, the first aerosol-generating substrate layer and the second aerosol-generating substrate layer.

[0167] The aerosol-generating substrate layer may be a planar aerosol-generating substrate layer. The planar aerosol-generating substrate layer may extend in the x-direction and the y- direction. That is, the planar aerosol-generating substrate layer may extend in the x / y plane.

[0168] The first aerosol-generating substrate layer may be a first planar aerosol-generating substrate layer. The first planar aerosol-generating substrate layer may extend in the x-direction and the y-direction. That is, first the planar aerosol-generating substrate layer may extend in the x / y plane.

[0169] The second aerosol-generating substrate layer may be a second planar aerosol-generating substrate layer. The second planar aerosol-generating substrate layer may extend in the x- direction and the y-direction. That is, the second planar aerosol-generating substrate layer may extend in the x / y plane.

[0170] The aerosol-generating substrate layer may have a thickness greater than or equal to 100 micrometres. The aerosol-generating substrate layer may have a thickness greater than or equal to 200 micrometres. The aerosol-generating substrate layer may have a thickness greater than or equal to 300 micrometres. The aerosol-generating substrate layer may have a thickness greater than or equal to 400 micrometres. The aerosol-generating substrate layer may have a thickness greater than or equal to 500 micrometres.

[0171] The aerosol-generating substrate layer may have a thickness less than or equal to 600 micrometres. The aerosol-generating substrate layer may have a thickness less than or equal to 500 micrometres. The aerosol-generating substrate layer may have a thickness less than or equal to 400 micrometres. The aerosol-generating substrate layer may have a thickness less than or equal to between 300 micrometres. The aerosol-generating substrate layer may have a thickness less than or equal to 200 micrometres.

[0172] The aerosol-generating substrate layer may have a thickness between 100 micrometres and 600 micrometres. The aerosol-generating substrate layer may have a thickness of between 200 micrometres and 500 micrometres. The aerosol-generating substrate layer may have a thickness of between 200 micrometres and 400 micrometres. The aerosol-generating substrate layer may have a thickness of between 200 micrometres and 300 micrometres.

[0173] One or both the first aerosol-generating substrate layer and the second aerosol-generating substrate layer may have a thickness greater than or equal to 100 micrometres. One or both the first aerosol-generating substrate layer and the second aerosol-generating substrate layer may have a thickness greater than or equal to 200 micrometres. One or both the first aerosol-generating substrate layer and the second aerosol-generating substrate layer may have a thickness greater than or equal to 300 micrometres. One or both the first aerosol-generating substrate layer and the second aerosol-generating substrate layer may have a thickness greater than or equal to 400 micrometres. One or both the first aerosol-generating substrate layer and the second aerosolgenerating substrate layer may have a thickness greater than or equal to 500 micrometres.

[0174] One or both the first aerosol-generating substrate layer and the second aerosol-generating substrate layer may have a thickness less than or equal to 600 micrometres. One or both the first aerosol-generating substrate layer and the second aerosol-generating substrate layer may have a thickness less than or equal to 500 micrometres. One or both the first aerosol-generating substrate layer and the second aerosol-generating substrate layer may have a thickness less than or equal to 400 micrometres. One or both the first aerosol-generating substrate layer and the second aerosol-generating substrate layer may have a thickness less than or equal to between 300 micrometres. One or both the first aerosol-generating substrate layer and the second aerosolgenerating substrate layer may have a thickness less than or equal to 200 micrometres.

[0175] One or both the first aerosol-generating substrate layer and the second aerosol-generating substrate layer may have a thickness between 100 micrometres and 600 micrometres. One or both the first aerosol-generating substrate layer and the second aerosol-generating substrate layer may have a thickness of between 200 micrometres and 500 micrometres. One or both the first aerosolgenerating substrate layer and the second aerosol-generating substrate layer may have a thickness of between 200 micrometres and 400 micrometres. One or both the first aerosolgenerating substrate layer and the second aerosol-generating substrate layer may have a thickness of between 200 micrometres and 300 micrometres.

[0176] 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.

[0177] 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.

[0178] 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. 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.

[0179] 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.

[0180] 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.

[0181] The first external surface may be an upper surface, for example a planar upper surface, and the second external surface may be a lower surface, for example a planar lower surface. The first external surface may be a top surface and the second external surface may be a bottom surface. The first external surface may be a ceiling surface and the second external surface may be a base surface.

[0182] The first external surface may be positioned substantially parallel to the second external surface. The first external surface may extend in the x-direction and the y-direction. That is, the first external surface may extend in the x / y plane. The second external surface may extend in the x-direction and the y-direction. That is, the second external surface may extend in the x / y plane.

[0183] The second external surface may be spaced from the first external surface in the z-direction or transverse direction. The distance, or maximum distance, between the first external surface and the second external surface in the z-direction or transverse direction may define the thickness of the aerosol-generating article. That is, a thickness of the aerosol-generating article may be defined by the maximum perpendicular distance between the first external surface and the second external surface.

[0184] The aerosol-generating article may comprise an outer wrapper. The outer wrapper may be hydrophobic. The outer wrapper may comprise a hydrophobic material.

[0185] The outer wrapper may define or form the first external surface. The outer wrapper may define or form the second external surface. The outer wrapper may define or form both the first external surface and the second external surface.

[0186] 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. In other words, the cavity may be defined by the frame and the outer wrapper.

[0187] 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. 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.

[0188] 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. The first planar external layer may be a top layer and the second planar external layer may be a bottom layer. The first planar external layer may be an ceiling layer and the second planar external layer may be a base layer.

[0189] The first planar external layer may define or form the first planar external surface. The first planar external layer may extend in the x-direction and the y-direction. That is, 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-direction and the y-direction. That is, the second planar external layer may extend in the x / y plane.

[0190] The first planar external layer may be in physical contact with, and may be bonded to, the frame. The first planar external layer may be bonded to the frame with an adhesive. The first planar external layer may be bonded to the first frame layer with an adhesive. A lower surface of the first planar external layer may be bonded to an upper surface of the first frame layer with an adhesive. The adhesive may extend at least 90% around the periphery of the intersection between the first planar external layer and the frame. The adhesive may extend at least 95% around the periphery of the intersection between the first planar external layer and the frame. The adhesive may extend at least 99% around the periphery of the intersection between the first planar external layer and the frame.

[0191] 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.

[0192] The second planar external layer may be in physical contact with, and may be bonded to, the frame. The second planar external layer may be bonded to the frame with an adhesive. The second planar external layer may be bonded to the second frame layer with an adhesive. An upper surface of the second planar external layer may be bonded to a lower surface of the second frame layer with an adhesive. The second planar external layer may be bonded to the third frame layer with an adhesive. An upper surface of the second planar external layer may be bonded to a lower surface of the third frame layer with an adhesive. The adhesive may extend at least 90% around the periphery of the intersection between the second planar external layer and the frame. The adhesive may extend at least 95% around the periphery of the intersection between the second planar external layer and the frame. The adhesive may extend at least 99% around the periphery of the intersection between the second planar external layer and the frame.

[0193] 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. 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. In other words, the cavity is defined by the frame, the first planar external layer and the second planar external layer.

[0194] 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. The first planar external layer may be bonded to the aerosol-generating substrate layer or the first aerosol-generating substrate layer with an adhesive.

[0195] 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 second planar external layer may be bonded to the aerosol-generating substrate layer or the second aerosolgenerating substrate layer with an adhesive.

[0196] 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.

[0197] Advantageously, adhesive bonding together components of the aerosol-generating article may provide for a tight seal between layers of the aerosol-generating article. In particular, the adhesive bonding one or both of the first planar external layer and the second planar external layer to the frame may provide for a tight seal between the first planar external layer and the frame or a tight seal between the second planar external layer and the frame.

[0198] Providing a tight seal between layers of the aerosol-generating article may improve air flow through the cavity. Improving air flow through the cavity may improve the user experience.

[0199] Advantageously, use of an adhesive to bond together components of the aerosolgenerating article may provide for an aerosol-generating article having a high structural integrity.

[0200] The adhesive may comprise a gum. The adhesive may comprise guar gum. The adhesive may comprise polyvinyl alcohol. The adhesive may comprise an aerosol-generating material. The adhesive may consist of an aerosol-generating material. For example, the adhesive may be a homogenised tobacco slurry. The adhesive may be, or may comprise, a flavourant and / or an aerosol-former. One or more of the outer wrapper, the first planar external layer and the second planar external layer may be made from a cellulosic material. One or more of the outer wrapper, the first planar external layer and the second planar external layer may comprise a cellulosic material. The cellulosic material may be paper, cardboard, wood, textile, natural fibres or artificial fibres.

[0201] Although preferably the primary source of aerosol-generating material is the aerosolgenerating element defined by the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate, one or more of the outer wrapper, the first planar external layer and the second planar external layer may be an additional aerosol-generating substrate comprising an aerosol-generating material. One or more of the outer wrapper, the first planar external layer and the second planar external layer may comprise an aerosol-generating material. The aerosolgenerating 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. For example, one or more of the outer wrapper, the first planar external layer and the second planar external layer may not comprise tobacco. One or more of the outer wrapper, the first planar external layer and the second planar external layer may be substantially nicotine-free.

[0202] One or more of the outer wrapper, the first external layer and the second external layer may comprise a paper material. For example, one or more of the outer wrapper, the first external layer and the second external layer may be paper, cardboard, cigarette paper or tobacco paper.

[0203] The cellulosic material may have a basis weight greater than 10 grams per square metre. The cellulosic material may have a basis weight greater than 20 grams per square metre. The cellulosic material may have a basis weight less than 30 grams per square metre. The cellulosic material may have a basis weight less than 25 grams per square metre. The cellulosic material may have a basis weight between 10 grams per square metre and 30 grams per square metre. The cellulosic material may have a basis weight between 15 grams per square metre and 25 grams per square metre.

[0204] One or more of the outer wrapper, the first external layer and the second external layer may comprise paper and non-paper components.

[0205] One or more of the outer wrapper, the first external layer and the second external layer may exhibit a range of permeabilities including not being permeable. The permeability is determined by utilizing the International Standard test method ISO 2965:2009 and the result is presented as cubic centimetres per minute per square centimetre and referred to as “CORESTA units”. One or more of the outer wrapper, the first external layer and the second external layer may have a permeability between 1 and 10 CORESTA units. One or more of the outer wrapper, the first external layer and the second external layer may have a permeability between 1 and 5 CORESTA units. One or more of the outer wrapper, the first external layer and the second external layer may have a permeability between 5 and 20 CORESTA units.

[0206] One or more of the outer wrapper, the first external layer and the second external layer may have a thickness greater than or equal to 25 micrometres. One or more of the outer wrapper, the first external layer and the second external layer may have a thickness greater than or equal to 30 micrometres. One or more of the outer wrapper, the first external layer and the second external layer may have a thickness greater than or equal to 35 micrometres. The outer wrapper may have a thickness greater than or equal to 40 micrometres. One or more of the outer wrapper, the first external layer and the second external layer may have a thickness greater than or equal to 45 micrometres.

[0207] One or more of the outer wrapper, the first external layer and the second external layer may have a thickness less than or equal to 55 micrometres. One or more of the outer wrapper, the first external layer and the second external layer may have a thickness greater than or equal to 50 micrometres. One or more of the outer wrapper, the first external layer and the second external layer may have a thickness greater than or equal to 45 micrometres. One or more of the outer wrapper, the first external layer and the second external layer may have a thickness greater than or equal to 40 micrometres. One or more of the outer wrapper, the first external layer and the second external layer may have a thickness greater than or equal to 35 micrometres.

[0208] One or more of the outer wrapper, the first external layer and the second external layer may have a thickness between 25 micrometres and 55 micrometres. One or more of the outer wrapper, the first external layer and the second external layer may have a thickness between 25 micrometres and 45 micrometres. One or more of the outer wrapper, the first external layer and the second external layer may have a thickness between 30 micrometres and 45 micrometres.

[0209] One or more of the outer wrapper, the first external layer and the second external layer may have a length substantially the same as the length of the frame. One or more of the outer wrapper, the first external layer and the second external layer may have a length substantially the same as the length of the aerosol-generating article. One or more of the outer wrapper, the first external layer and the second external layer may have a length of greater than or equal to 90 percent of the length of the frame. One or more of the outer wrapper, the first external layer and the second external layer may have a length of greater than or equal to 95 percent of the length of the frame.

[0210] One or more of the first external layer and the second external layer may have a width substantially the same as the width of the frame. One or more of the first external layer and the second external layer may have a width substantially the same as the width of the aerosolgenerating article. One or more of the outer wrapper, the first external layer and the second external layer may have a width of greater than or equal to 90 percent of the width of the frame. One or more of the outer wrapper, the first external layer and the second external layer may have a width of greater than or equal to 95 percent of the width of the frame. The cavity may comprise a first cavity end wall and a second cavity end wall positioned opposite the first cavity end wall. The first cavity end wall may be defined, or formed, by the outer wrapper, the first external layer or the first aerosol-generating substrate layer. The second cavity end wall may be defined, or formed, by the outer wrapper, the second external layer or the second aerosol-generating substrate layer. The cavity may be enclosed by the first cavity end wall, the second cavity end wall and the frame.

[0211] The cavity may comprise a cavity outer wall. The cavity outer wall may be defined, or formed, by the frame. The cavity outer wall may extend in a transverse direction. The cavity outer wall may extend in a transverse direction between the first cavity end wall and the second cavity end wall. The cavity outer wall may be defined, or formed, by the frame inner surface. The cavity outer wall may be defined, or formed, by the peripheral wall of the frame.

[0212] The cavity may have at least two corners extending between the first external surface and the second external surface. The at least two corners may be chamfered, or rounded or filleted. Preferably, all corners of the cavity extending between the first external surface and the second external surface are chamfered, or rounded or filleted.

[0213] Advantageously, a cavity having chamfered, rounded or filleted corners may make the cavity easier to heat. In particular, it may make it easier to heat an aerosol-generating substrate that is positioned within the cavity. Advantageously, a cavity having chamfered, rounded or filleted corners may make the aerosol-generating article stronger and less susceptible to damage. Advantageously, a cavity having chamfered, rounded or filleted corners may make the aerosolgenerating article easier to manufacture.

[0214] The cavity may have a thickness substantially the same as a thickness of the frame.

[0215] The cavity may have a thickness greater than or equal to 30 percent of the thickness of the aerosol-generating article. The cavity may have a thickness greater than or equal to 40 percent of the thickness of the aerosol-generating article. The cavity may have a thickness greater than or equal to 50 percent of the thickness of the aerosol-generating article. The cavity may have a thickness greater than or equal to 60 percent of the thickness of the aerosol-generating article. The cavity may have a thickness greater than or equal to 70 percent of the thickness of the aerosolgenerating article. The cavity may have a thickness greater than or equal to 80 percent of the thickness of the aerosol-generating article. The cavity may have a thickness greater than or equal to 90 percent of the thickness of the aerosol-generating article. The cavity may have a thickness greater than or equal to 95 percent of the thickness of the aerosol-generating article.

[0216] The cavity may have a thickness less than or equal to 95 percent of the thickness of the aerosol-generating article. The cavity may have a thickness less than or equal to 90 percent of the thickness of the aerosol-generating article. The cavity may have a thickness less than or equal to 80 percent of the thickness of the aerosol-generating article. The cavity may have a thickness less than or equal to 70 percent of the thickness of the aerosol-generating article. The cavity may have a thickness between 30 percent of the thickness of the aerosolgenerating article and 95 percent of the thickness of the aerosol-generating article. The cavity may have a thickness between 40 percent of the thickness of the aerosol-generating article and 95 percent of the thickness of the aerosol-generating article. The cavity may have a thickness between 50 percent of the thickness of the aerosol-generating article and 90 percent of the thickness of the aerosol-generating article. The cavity may have a thickness between 60 percent of the thickness of the aerosol-generating article and 90 percent of the thickness of the aerosolgenerating article. The cavity may have a thickness between 70 percent of the thickness of the aerosol-generating article and 90 percent of the thickness of the aerosol-generating article. The cavity may have a thickness between 80 percent of the thickness of the aerosol-generating article and 90 percent of the thickness of the aerosol-generating article.

[0217] 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 millimetre. 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 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 millimetres. The cavity may have a thickness greater than or equal to 3.5 millimetres. The cavity may have a thickness greater than or equal to 4 millimetres.

[0218] 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 4 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 2 millimetres. The cavity may have a thickness less than or equal to 1 .5 millimetres.

[0219] 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. The cavity may have a thickness between 2 millimetre and 4 millimetres. Preferably, the cavity may have a thickness between 2.8 millimetres and 3.3 millimetres.

[0220] The cavity may have a length greater than or equal to 30 percent of the length of the aerosol-generating article. The cavity may have a length greater than or equal to 40 percent of the length of the aerosol-generating article. The cavity may have a length greater than or equal to 50 percent of the length of the aerosol-generating article. The cavity may have a length greater than or equal to 60 percent of the length of the aerosol-generating article. The cavity may have a length greater than or equal to 70 percent of the length of the aerosol-generating article. The cavity may have a length greater than or equal to 80 percent of the length of the aerosol-generating article. The cavity may have a length greater than or equal to 90 percent of the length of the aerosolgenerating article.

[0221] The cavity may have a length less than or equal to 95 percent of the length of the aerosolgenerating article. The cavity may have a length less than or equal to 90 percent of the length of the aerosol-generating article. The cavity may have a length less than or equal to 80 percent of the length of the aerosol-generating article. The cavity may have a length less than or equal to 70 percent of the length of the aerosol-generating article. The cavity may have a length less than or equal to 60 percent of the length of the aerosol-generating article. The cavity may have a length less than or equal to 55 percent of the length of the aerosol-generating article.

[0222] The cavity may have a length between 30 percent and 95 percent of the length of the aerosol-generating article. The cavity may have a length between 40 percent and 95 percent of the length of the aerosol-generating article. The cavity may have a length between 50 percent and 90 percent of the length of the aerosol-generating article. The cavity may have a length between 55 percent and 90 percent of the length of the aerosol-generating article. The cavity may have a length between 60 percent and 90 percent of the length of the aerosol-generating article. The cavity may have a length between 70 percent and 90 percent of the length of the aerosol-generating article. The cavity may have a length between 80 percent and 90 percent of the length of the aerosol-generating article.

[0223] The cavity may have a length greater than or equal to 14 millimetres. The cavity may have a length equal to a greater than 16 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 26 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 34 millimetres. The cavity may have a thickness greater than or equal to 38 millimetres.

[0224] The cavity may have a length less than or equal to 40 millimetres. The cavity may have a length less than or equal to 38 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 30 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 26 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.

[0225] The cavity may have a length between 14 millimetres and 40 millimetres. The cavity may have a length between 14 millimetres and 38 millimetres. The cavity may have a length between 14 millimetres and 34 millimetres. The cavity may have a length between 14 millimetres and 30 millimetres. The cavity may have a length between 16 millimetres and 30 millimetres. The cavity may have a length between 18 millimetres and 30 millimetres. The cavity may have a length between 20 millimetres and 30 millimetres. The cavity may have a length between 24 millimetres and 28 millimetres.

[0226] The cavity may have a width greater than or equal to 30 percent of the width of the aerosolgenerating article. The cavity may have a width greater than or equal to 40 percent of the width of the aerosol-generating article. The cavity may have a width greater than or equal to 50 percent of the width of the aerosol-generating article. The cavity may have a width greater than or equal to 60 percent of the width of the aerosol-generating article. The cavity may have a width greater than or equal to 70 percent of the width of the aerosol-generating article. The cavity may have a width greater than or equal to 80 percent of the width of the aerosol-generating article. The cavity may have a width greater than or equal to 90 percent of the width of the aerosol-generating article.

[0227] The cavity may have a width less than or equal to 95 percent of the width of the aerosolgenerating article. The cavity may have a width less than or equal to 90 percent of the width of the aerosol-generating article. The cavity may have a width less than or equal to 80 percent of the width of the aerosol-generating article. The cavity may have a width less than or equal to 70 percent of the width of the aerosol-generating article. The cavity may have a width less than or equal to 60 percent of the width of the aerosol-generating article. The cavity may have a width less than or equal to 55 percent of the width of the aerosol-generating article.

[0228] The cavity may have a width between 30 percent and 95 percent of the width of the aerosolgenerating article. The cavity may have a width between 40 percent and 95 percent of the width of the aerosol-generating article. The cavity may have a width between 50 percent and 90 percent of the width of the aerosol-generating article. The cavity may have a width between 50 percent and 95 percent of the width of the aerosol-generating article. The cavity may have a width between 60 percent and 90 percent of the width of the aerosol-generating article. The cavity may have a width between 70 percent and 90 percent of the width of the aerosol-generating article. The cavity may have a width between 80 percent and 90 percent of the width of the aerosol-generating article.

[0229] 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 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 9 millimetres. The cavity may have a width greater than or equal to 11 millimetres.

[0230] The cavity may have a width less than or equal to 13 millimetres. 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 9 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.

[0231] The cavity may have a width between 4.5 millimetres and 13 millimetres. The cavity may have a width between 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.

[0232] 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.

[0233] 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.

[0234] 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. The cavity may have a volume of greater than or equal to 100 cubic millimetres. The cavity may have a volume greater than or equal to 200 cubic millimetres. The cavity may have a volume greater than or equal to 300 cubic millimetres. The cavity may have a volume greater than or equal to 400 cubic millimetres. The cavity may have a volume greater than or equal to 500 cubic millimetres. The cavity may have a volume greater than or equal to 600 cubic millimetres. The cavity may have a volume greater than or equal to 700 cubic millimetres. The cavity may have a volume greater than or equal to 800 cubic millimetres. The cavity may have a volume greater than or equal to 900 cubic millimetres. The cavity may have a volume greater than or equal to 1000 cubic millimetres. The cavity may have a volume greater than or equal to 1500 cubic millimetres. The cavity may have a volume greater than or equal to 2000 cubic millimetres. The cavity may have a volume greater than or equal to 2500 cubic millimetres. The cavity may have a volume greater than or equal to 3000 cubic millimetres.

[0235] The cavity may have a volume of less than or equal to 3500 cubic millimetres. The cavity may have a volume of less than or equal to 3000 cubic millimetres. The cavity may have a volume of less than or equal to 2500 cubic millimetres. The cavity may have a volume of less than or equal to 2000 cubic millimetres. The cavity may have a volume of less than or equal to 1500 cubic millimetres. The cavity may have a volume of less than or equal to 1000 cubic millimetres. The cavity may have a volume of less than or equal to 900 cubic millimetres. The cavity may have a volume less than or equal to 800 cubic millimetres. The cavity may have a volume less than or equal to 700 cubic millimetres. The cavity may have a volume less than or equal to 600 cubic millimetres. The cavity may have a volume less than or equal to 500 cubic millimetres. The cavity may have a volume less than or equal to 400 cubic millimetres. The cavity may have a volume less than or equal to 300 cubic millimetres.

[0236] The cavity may have a volume between 30 cubic millimetres and 3000 cubic millimetres. The cavity may have a volume between 30 cubic millimetres and 3000 cubic millimetres. The cavity may have a volume between 30 cubic millimetres and 2500 cubic millimetres. The cavity may have a volume between 30 cubic millimetres and 2350 cubic millimetres. The cavity may have a volume between 100 cubic millimetres and 2000 cubic millimetres. The cavity may have a volume between 100 cubic millimetres and 1500 cubic millimetres. The cavity may have a volume between 250 cubic millimetres and 1150 cubic millimetres. The cavity may have a volume between 100 cubic millimetres and 1000 cubic millimetres. The cavity may have a volume between 100 cubic millimetres and 900 cubic millimetres. The cavity may have a volume between 200 cubic millimetres and 800 cubic millimetres. Preferably, the cavity may have a volume between 300 cubic millimetres and 700 cubic millimetres. The cavity may have a volume between 400 cubic millimetres and 700 cubic millimetres. The cavity may have a volume between 500 cubic millimetres and 700 cubic millimetres. The cavity may have a volume greater than or equal to 1 percent of the external volume of the aerosol-generating article. The cavity may have a volume greater than or equal to 5 percent of the external volume of the aerosol-generating article. The cavity may have a volume greater than or equal to 1 percent of the external volume of the aerosol-generating article.

[0237] The cavity may have a volume less than or equal to 90 percent of the external volume of the aerosol-generating article. The cavity may have a volume less than or equal to 80 percent of the external volume of the aerosol-generating article. The cavity may have a volume less than or equal to 70 percent of the external volume of the aerosol-generating article.

[0238] The cavity may have a volume between 1 percent and 90 percent of the external volume of the aerosol-generating article. The cavity may have a volume between 5 percent and 80 percent of the external volume of the aerosol-generating article. The cavity may have a volume between 10 percent and 70 percent of the external volume of the aerosol-generating article.

[0239] The cavity may be a first cavity. The aerosol-generating article may comprise a second cavity. The second cavity may be positioned between the first external surface and the second external surface. The second cavity may have any of the features described in relation to the first cavity.

[0240] The frame may at least partially define or form the second cavity.

[0241] The frame may comprise a frame first aperture extending through the thickness of the frame. The frame first aperture may at least partially define or form the first cavity. The frame may define a frame second aperture extending through the thickness of the frame. The frame second aperture may at least partially define or form the second cavity.

[0242] The peripheral wall of the frame may comprise a frame first inner surface and a frame second inner surface. The frame first inner surface may define or form an outer wall of the first cavity. The frame second inner surface may define or form an outer wall of the second cavity.

[0243] The frame may comprise a dividing wall which separates the first cavity and the second cavity. The dividing wall may define or form an aperture. The aperture may extend from the first cavity to the second cavity. The aperture may define or form at least a portion of the airflow passage between the air inlet and the air outlet.

[0244] The outer wrapper may overlie opposing ends of the first cavity. The outer wrapper may overlie opposing ends of the second cavity. The outer wrapper may define or form opposing end walls of the first cavity. The outer wrapper may define or form opposing end walls of the second cavity. That is, the frame and the outer wrapper may collectively define the first cavity and the second cavity.

[0245] The first external layer and the second external layer may overlie opposing ends of the first cavity. The first external layer and the second external layer may overlie opposing ends of the second cavity. The first external layer and the second external layer may define or form opposing end walls of the first cavity. The first external layer and the second external layer may define or form opposing end walls of the second cavity. That is, the frame, the first external layer and the second external layer may collectively define the first cavity and the second cavity.

[0246] The first aerosol-generating substrate layer and the second aerosol-generating substrate layer may overlie opposing ends of the first cavity. The first aerosol-generating substrate layer and the second aerosol-generating substrate layer may overlie opposing ends of the second cavity. The first aerosol-generating substrate layer and the second aerosol-generating substrate layer may define or form opposing end walls of the first cavity The first aerosol-generating substrate layer and the second aerosol-generating substrate layer may define or form opposing end walls of the second cavity. That is, the frame, the first aerosol-generating substrate layer and the second aerosol-generating substrate layer may collectively define the first cavity and the second cavity.

[0247] The aerosol-generating article comprises an aerosol-generating element comprising or consisting of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate, as described herein, positioned within the cavity. The aerosol-generating element may fill the cavity. Advantageously, providing an aerosol-generating element which substantially fills the cavity enables the aerosol-generating element to provide mechanical support to the first external surface and the second external surface. The provision of additional mechanical support to the first external surface and the second external surface may improve the rigidity of the aerosol-generating article.

[0248] The aerosol-generating article may comprise a first collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate positioned within the first cavity. The first collection of unbound shreds, strips, strands or extrusions positioned within the cavity may fill the first cavity.

[0249] The aerosol-generating article may comprise a second collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate positioned within the second cavity.

[0250] Each of the first and second collections of unbound shreds, strips, strands or extrusions of aerosol-forming substrate define respective first and second aerosol-generating elements,

[0251] The aerosol-generating element positioned within the cavity, the first cavity or the second cavity comprises an aerosol-generating material. The aerosol-generating material may be any aerosol-generating material described herein.

[0252] The aerosol-generating article may comprise additional aerosol-generating material to the aerosol-generating element formed by the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate disposed within the cavity. Additional aerosol-generating material may be in the form of a sheet of aerosol-generating material. The sheet of aerosolgenerating 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. The sheet of aerosol-generating material may extend the entire length of the cavity, the first cavity or the second cavity. The sheet of aerosol-generating material may extend the entire width of the cavity, the first cavity or the second cavity.

[0253] 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.

[0254] 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.

[0255] 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 The plurality of parallel corrugations may be defined by a corrugation wavelength and a corrugation amplitude. The corrugation wavelength may be between 0.5 mm and 10 mm, for example between 1 mm and 10 mm, for example between 1 .5 mm and 8 mm, for example between 2 mm and 6 mm, for example between 2.5 mm and 5 mm, for example between 3 mm and 4 mm. The corrugation amplitude may be approximately the same as the thickness of the cavity.

[0256] 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 first cavity and the second cavity. The plurality of channels may be a plurality of longitudinally extending channels. That is, the plurality of channels may extend in a longitudinal direction of the aerosol-generating article. The plurality of channels may be a plurality of laterally extending channels. That is, the plurality of channels may extend in a lateral direction of the aerosol-generating article. The plurality of channels may define, or form, at least a portion of the airflow passage extending between the air inlet and air outlet of the aerosol-generating article.

[0257] The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a bulk density of greater than or equal to 0.05 milligrams per cubic millimetre. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a bulk density of greater than or equal to 0.1 milligrams per cubic millimetre. The aerosolgenerating element positioned within the cavity, the first cavity or the second cavity may have a bulk density of greater than or equal to 0.15 milligrams per cubic millimetre. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a bulk element of greater than or equal to 0.2 milligrams per cubic millimetre. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a bulk density of greater than or equal to 0.3 milligrams per cubic millimetre. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a bulk density of greater than or equal to 0.4 milligrams per cubic millimetre.

[0258] The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a bulk density of less than or equal to 0.5 milligrams per cubic millimetre. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a bulk density of less than or equal to 0.4 milligrams per cubic millimetre. The aerosolgenerating element positioned within the cavity, the first cavity or the second cavity may have a bulk density of less than or equal to 0.35 milligrams per cubic millimetre. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a bulk density of less than or equal to 0.3 milligrams per cubic millimetre.

[0259] The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a bulk density of between 0.05 milligrams per cubic millimetre and 0.5 milligrams per cubic millimetre. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a bulk density of between 0.1 milligrams per cubic millimetre and 0.4 milligrams per cubic millimetre. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a bulk density of between 0.1 and 0.3 milligrams per cubic millimetre. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a bulk density of between 0.2 and 0.3 milligrams per cubic millimetre.

[0260] The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a packing density greater than or equal to 0.3. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a packing density greater than or equal to 0.4. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a packing density greater than or equal to 0.5. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a packing density greater than or equal to 0.6. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a packing density greater than or equal to 0.7.

[0261] The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a packing density less than or equal to 0.9. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a packing density less than or equal to 0.8. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a packing density less than or equal to 0.7. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a packing density less than or equal to 0.6. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a packing density less than or equal to 0.5.

[0262] The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a packing density between 0.3 and 0.9. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a packing density between 0.4 and 0.9. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a packing density between 0.5 and 0.9. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a packing density between 0.5 and 0.8. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a packing density between 0.5 and 0.7.

[0263] Advantageously, providing an aerosol-generating element within the cavity having a high packing density may provide mechanical support to the first external surface and the second external surface. The provision of additional mechanical support to the first external surface and the second external surface may improve the rigidity of the aerosol-generating article. However, a packing density that is too high may restrict airflow through the aerosol-generating article and may provide the aerosol-generating article with an unsatisfactory resistance to draw.

[0264] Advantageously, providing an aerosol-generating element within the cavity having a packing density greater than or equal to 0.3 may promote heat conduction through the aerosolgenerating element. Increased heat conduction through the aerosol-generating element may reduce the time require to generate an aerosol.

[0265] Advantageously, providing an aerosol-generating element positioned within the cavity having a packing density less than or equal to 0.9 grams per cubic centimetre may promote the formation of air flow channels within the aerosol-generating element during use of the aerosolgenerating article. Increased provision of air flow channels within the aerosol-generating element may improve the vaporisation of the aerosol-generating element. Increased provision of air flow channels within the aerosol-generating element may also provide a satisfactory resistance to draw.

[0266] Advantageously, providing an aerosol-generating element positioned within the cavity having a packing density less than or equal to 0.9 grams per cubic centimetre may reduce the likelihood of the aerosol-generating substrate becoming compacted. Compaction of the aerosolgenerating element may increase the power required to heat the aerosol-generating substrate to a temperature sufficient to cause vaporisation.

[0267] Thus, the packing density may be a trade-off between heat conduction through the aerosolgenerating element, the provision of mechanical support for the first and second external surfaces, the promotion of air flow channels within the aerosol-generating substrate, and providing the aerosol-generating article with a satisfactory resistance to draw.

[0268] The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a volume greater than or equal to 150 cubic millimetres. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a volume greater than or equal to 200 cubic millimetres. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a volume greater than or equal to 250 cubic millimetres. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a volume greater than or equal to 350 cubic millimetres.

[0269] The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have less than or equal to 1000 cubic millimetres. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have less than or equal to 900 cubic millimetres. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have less than or equal to 800 cubic millimetres. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have less than or equal to 700 cubic millimetres.

[0270] The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a volume between 100 cubic millimetres and 1000 cubic millimetres. The aerosolgenerating element positioned within the cavity, the first cavity or the second cavity may have a volume between 200 cubic millimetres and 1000 cubic millimetres. The aerosol-generating element positioned within the cavity, the first cavity or the second cavity may have a volume between 350 cubic millimetres and 650 cubic millimetres.

[0271] Aerosol-generating substrates in aerosol-generating articles typically have a high density in order to promote heat conduction through the aerosol-generating substrate.

[0272] Advantageously, providing an aerosol-generating article with an aerosol-generating element having a relatively low density of less than or equal to 0.9 grams per cubic centimetre may allow for the aerosol-generating article to contain a reduced mass of aerosol-generating substrate. A reduced mass of aerosol-generating substrate may make the aerosol-generating article more convenient to handle and easier to manufacture.

[0273] Advantageously, providing a low density aerosol-generating element in the cavity of an aerosol-generating article comprising a first planar external surface, a second planar external surface and a frame positioned between the first planar external surface and the second planar external surface may allow for efficient heating of the aerosol-generating element while still providing the advantages of a low density aerosol-generating element as described above.

[0274] Advantageously, providing an aerosol-generating article with an aerosol-generating element less than or equal to 500 milligrams may reduce the amount of structural support that needs to be provided to the aerosol-generating article.

[0275] Advantageously, providing an aerosol-generating article with an aerosol-generating element greater than or equal 50 milligrams may allow the aerosol-generating element to provide some structural support to the aerosol-generating article.

[0276] Advantageously, providing an aerosol-generating article with a low mass of aerosolgenerating element may result in better heating efficiency because the mass of aerosol-generating element to be heated is relatively low. A relatively low mass of aerosol-generating element is particularly advantageous during the first puff with the aerosol-generating article because the first puff can be achieved much faster than with an aerosol-generating article having a high mass of aerosol-generating element.

[0277] Advantageously, providing an aerosol-generating article with a low mass of aerosolgenerating element may reduce the total water content of the aerosol-generating element. Reducing the total water content of the aerosol-generating element may reduce the temperature of the first puff.

[0278] The length of the aerosol-generating article may be defined in an x direction between a distal end and a proximal end of the aerosol-generating article. The aerosol-generating article may be divided over its length into a distal end portion and a proximal end portion. The distal end portion may extend from the distal end for 50% of the length of the aerosol-generating article and the proximal end portion may extend from the proximal end for 50% of the length of the aerosolgenerating article.

[0279] A ratio of the mass of the one or more aerosol-generating elements in the proximal end portion to the mass of the one or more aerosol-generating elements in the distal end portion may be within a range of between 0.77 and 1 .30.

[0280] A ratio of the mass of the one or more aerosol-generating elements in the proximal end portion to the mass of the one or more aerosol-generating elements in the distal end portion may be within a range of between 0.80 and 1.25, or between 0.83 and 1.2, or between 0.87 and 1.15; or between 0.91 and 1.10; or between 0.95 and 1.05.

[0281] The mass distribution of the one or more aerosol-generating elements in the proximal end portion in a lengthwise direction of the proximal end portion may be symmetric with the mass distribution of the one or more aerosol-generating elements in the distal end portion in a lengthwise direction of the distal end portion, relative to a midpoint of the length of the aerosol-generating article.

[0282] The one or more aerosol-generating elements in the proximal end portion may be arranged across a width of proximal end portion in first and second halves of the width of the proximal end portion, wherein the ratio of the mass of the one or more aerosol-generating elements in the first half of the width of the proximal end portion to the mass of aerosol-forming element in the second half of the width of the proximal end portion may be within a range of between 0.77 and 1 .30, or between 0.80 and 1 .25, or between 0.83 and 1 .2, or between 0.87 and 1.15; or between 0.91 and 1.10; or between 0.95 and 1.05.

[0283] The one or more aerosol-generating elements in the distal end portion may be arranged across a width of distal end portion in first and second halves of the width of the distal end portion. The ratio of the mass of the one or more aerosol-generating elements in the first half of the width of the distal end portion to the mass of the one or more aerosol-generating elements in the second half of the width of the distal end portion may be within a range of between 0.77 and 1 .30, or between 0.80 and 1 .25, or between 0.83 and 1 .2, or between 0.87 and 1.15; or between 0.91 and 1 .10; or between 0.95 and 1 .05.

[0284] The one or more aerosol-generating elements in the proximal end portion may be arranged across a height of proximal end portion in first and second halves of the height of the proximal end portion. The ratio of the mass of the one or more aerosol-generating elements in the first half of the height of the proximal end portion to the mass of the one or more aerosol-generating elements in the second half of the height of the proximal end portion may be within a range of between 0.77 and 1.30, or between 0.80 and 1.25, or between 0.83 and 1.2, or between 0.87 and 1.15; or between 0.91 and 1.10; or between 0.95 and 1.05.

[0285] The one or more aerosol-generating elements in the distal end portion may be arranged across a height of distal end portion in first and second halves of the height of the distal end portion. The ratio of the mass of the one or more aerosol-generating elements in the first half of the height of the distal end portion to the mass of the one or more aerosol-generating elements in the second half of the height of the distal end portion may be within a range of between 0.77 and 1 .30, or between 0.80 and 1 .25, or between 0.83 and 1 .2, or between 0.87 and 1.15; or between 0.91 and 1.10; or between 0.95 and 1.05.

[0286] The structure of the proximal end portion may be symmetric with the structure of the distal end portion, relative to a midpoint of the length of the aerosol-generating article.

[0287] The aerosol-generating article may comprise the outer wrapper and an aerosol-generating element as described herein positioned within the cavity.

[0288] The aerosol-generating article may comprise the outer wrapper, the frame, and an aerosolgenerating element as described herein positioned within the cavity.

[0289] The aerosol-generating article may comprise the outer wrapper and an additional aerosolgenerating substrate layer.

[0290] The aerosol-generating article may comprise the outer wrapper, the frame, and the additional aerosol-generating substrate layer.

[0291] The aerosol-generating article may comprise the outer wrapper, a first cavity, a second cavity and an additional aerosol-generating substrate layer. The first cavity may be empty or an aerosol-generating element as described herein may be positioned within the first cavity. The second cavity may be empty or an aerosol-generating element as described herein may be positioned within the second cavity.

[0292] The aerosol-generating article may comprise the outer wrapper, the frame, a first cavity, a second cavity and the additional aerosol-generating substrate layer. The first cavity may be empty or an aerosol-generating element as described herein may be positioned within the first cavity. The second cavity may be empty or an aerosol-generating element as described herein may be positioned within the second cavity.

[0293] The aerosol-generating article may comprise a first planar external layer, a second planar external layer, the frame, and an additional aerosol-generating substrate layer. An aerosolgenerating element as described herein is positioned within the cavity.

[0294] The aerosol generating element comprises aerosol-generating material. Preferably, the aerosol-generating element is in the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate. If present, the one or more additional aerosol-generating substrate comprises an aerosol-generating material. The, or each, 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.

[0295] 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.

[0296] The aerosol-generating element may comprise aerosol-generating material in the form of cut filler. The cut filler may be tobacco cut filler. The cut filler may comprise one or more of bright tobacco, dark tobacco, aromatic tobacco and filler tobacco. Examples of bright tobaccos are Flue- Cured Brazil, Indian Flue-Cured, Chinese Flue-Cured, US Flue-Cured such as Virginia tobacco, and Flue-Cured from Tanzania. Examples of aromatic tobaccos are Oriental Turkey, Greek Oriental, semi-oriental tobacco but also Fire Cured, US Burley, such as Perique, and Rustica. Examples of dark tobacco are Dark Cured Brazil Galpao, Burley Malawi or other African Burley, Sun Cured or Air Cured Indonesian Kasturi. 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, and homogenised plant material.

[0297] The cut filler suitable to be used with the present invention generally may resemble cut filler used for conventional smoking articles. The cut width of the cut filler preferably may be between 0.3 millimetres and 2.0 millimetres, or between 0.5 millimetres and 1 .2 millimetres, or between 0.6 millimetres and 1 .2 millimetres, or between 0.6 millimetres and 0.9 millimetres.

[0298] Preferably, shreds, strips, strands or extrusions of aerosol-forming substrate are employed having a length of between about 0.5 and 30 millimetres, for example between 0.5 and 20 millimetres, for example between 0.5 and 15 millimetres, for example between 0.8 and 10 millimetres, for example between 0.8 and 5 millimetres.

[0299] The cut filler may be, or comprise, shredded non-tobacco plant material. For example, the shredded non-tobacco plant material may comprise one or more of: tea, star anise, lavender, clove, peppermint, chamomile, rosemary, eucalyptus, ginger, dill seed, thyme, oregano and cumin.

[0300] Preferably, the cut filler is soaked with an aerosol former. Soaking the cut filler can be done by spraying or by other suitable application methods. Preferably, the aerosol former in the cut filler comprises one or more of glycerol and propylene glycol. The aerosol former may consist of glycerol or propylene glycol or of a combination of glycerol and propylene glycol. The cut filler may comprise at least 15 percent by weight of aerosol former, for example at least 17 percent by weight of aerosol former, on a dry weight basis based on the total weight of the cut filler.

[0301] The aerosol-generating material may comprise homogenised plant material, preferably a homogenised tobacco material. As used herein, the term “homogenised plant material” encompasses any plant material formed by the agglomeration of particles of plant. For example, sheets or webs of homogenised tobacco material for the aerosol-generating substrates of the present invention may be formed by agglomerating particles of tobacco material obtained by pulverising, grinding or comminuting plant material and optionally one or more of tobacco leaf lamina and tobacco leaf stems. The homogenised plant material may be produced by casting, extrusion, paper making processes or other any other suitable processes known in the art.

[0302] The homogenised plant material may be in the form of a plurality of strands, strips or shreds. As used herein, the term “strand” describes an elongate element of material having a length that is substantially greater than the width and thickness thereof.

[0303] The aerosol-generating material may comprise one or more cannabinoid compounds such as one or more of: tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiol (CBD), cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), cannabigerol monomethyl ether (CBGM), cannabivarin (CBV), cannabidivarin (CBDV), tetrahydrocannabivarin (THCV), cannabichromene (CBC), cannabicyclol (CBL), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabielsoin (CBE), cannabicitran (CBT). It may be preferable that the cannabinoid compound is CBD or THC. It may be particularly preferable that the cannabinoid compound is CBD.

[0304] 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 aerosolformer 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.

[0305] The aerosol-generating material may comprise organic fibres such as non-tobacco fibres, or tobacco fibres. For example, the aerosol-generating material may comprise about 5 to 20%, preferably about 7 to 15% of tobacco fibres. Tobacco fibres are preferably derived from stems and / or or stalks, graded to fibres of a length of about 10 to 350 pm, preferably of about 10 to 180 pm. The aerosol-generating material may comprise about 10 to 30 %, preferably of about 15 to 25%, of a non-tobacco organic fibre. For example, organic fibres may derive from cellulose, cotton, wood, tea botanical varieties as sub-products, and sub-processed waste, the tea industry. Organic fibres are preferably of a length of about 10 to 400 pm, preferably of about 10 to 200 pm.

[0306] The aerosol-generating element may additionally comprise one or more botanicals. For example, the aerosol-generating material may comprise botanicals such as Clove, Echinacea sp., Fennel, Ginger, Hawthorn berry, Elderberry, Monarda, Mullein leaves, Nettle, Plantain, Turmeric, Yarrow, and compounds of those. The aerosol-generating element may comprise organic botanical extracts. For example, the aerosol-generating material may comprise about 1 to 15 wt%, preferably of about 2 to 7 wt%, of any of the previously referred botanicals, as well as menthol (dl-Menthol, C10H20O, 2-lsopropyl- 5-methylcyclohexanol) such as obtained from Chaerophyllum macrospermum, Mesosphaerum sidifolium, or other related botanic varieties, as well as P-menthan-3-ol, as any secondary alcohol as diastereoisomers of 5-methyl-2-(propan-2-yl)cyclohexan-1 -ol.

[0307] The aerosol-generating element may comprise botanical essential oils, for example about 0.5 to 5 wt%, preferably of about 1 to 3 wt%, of a botanical essential oil, for example a botanical essential oil such as of palm, coconut, and wooden-based essential oils.

[0308] The aerosol-generating element may comprise particles of a functional material, for example particles of carbon, graphite, activated carbon, or expanded graphite. Such materials may, for example, increase the thermal conductivity of the aerosol-forming material and improve efficiency of aerosol generation.

[0309] The air inlet may be defined by the 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 the 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.

[0310] 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.

[0311] The air inlet may be defined by, or through, the first frame layer, the second frame layer or the third frame layer. The air inlet may be defined by, or through, the first frame layer and the second frame layer. The air inlet may be defined by, or through, the second frame layer and the third frame layer. The air inlet may be defined by, or through, the first frame layer, the second frame layer and the third frame layer.

[0312] The air outlet may be defined by, or through, the first frame layer, the second frame layer or the third frame layer. The air outlet may be defined by, or through, the first frame layer and the second frame layer. The air outlet may be defined by, or through, the second frame layer and the third frame layer. The air outlet may be defined by, or through, the first frame layer, the second frame layer and the third frame layer.

[0313] The air inlet may be defined by, and may extend through, the first 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 aerosolgenerating substrate layer. The air inlet may be defined by, and may extend through, the first external layer and the aerosol-generating substrate layer. The air inlet may be defined by, and may extend through, the first external layer and the first aerosol-generating substrate layer.

[0314] The air inlet may be defined by, and may extend through, the second external surface. The air inlet may be defined by, and may extend through, the outer wrapper and the second aerosolgenerating substrate layer. The air inlet may be defined by, and may extend through, the second external layer and the aerosol-generating substrate layer. The air inlet may be defined by, and may extend through, the second external layer and the second aerosol-generating substrate layer.

[0315] The air outlet may be defined by, and may extend through, the first 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 aerosolgenerating substrate layer. The air outlet may be defined by, and may extend through, the first external layer and the aerosol-generating substrate layer. The air outlet may be defined by, and may extend through, the first external layer and the first aerosol-generating substrate layer.

[0316] The air outlet may be defined by, and may extend through, the second 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 external layer and the aerosol-generating substrate layer. The air outlet may be defined by, and may extend through, the second external layer and the second aerosol-generating substrate layer. The air inlet may have an equivalent diameter greater than or equal to 0.1 millimetres. The air inlet may have an equivalent diameter greater than or equal to 0.4 millimetres. The air inlet may have an equivalent diameter greater than or equal to 0.7 millimetres. The air inlet may have an equivalent diameter greater than or equal to 1 .0 millimetres.

[0317] The air inlet may have an equivalent diameter less than or equal to 3 millimetres. The air inlet may have an equivalent diameter less than or equal to 2.7 millimetres. The air inlet may have an equivalent diameter less than or equal to 2.4 millimetres. The air inlet may have an equivalent diameter less than or equal to 2.1 millimetres. The air inlet may have an equivalent diameter less than or equal to 1 .8 millimetres. The air inlet may have an equivalent diameter less than or equal to 1 .5 millimetres.

[0318] The air inlet may have an equivalent diameter between 0.1 millimetres and 3 millimetres. The air inlet may have an equivalent diameter between 0.1 millimetres and 2.4 millimetres. The air inlet may have an equivalent diameter between 0.4 millimetres and 2.1 millimetres. The air inlet may have an equivalent diameter between 0.4 millimetres and 1.8 millimetres. The air inlet may have an equivalent diameter between 0.7 millimetres and 1 .5 millimetres. The air inlet may have an equivalent diameter between 1 .0 millimetres and 1 .5 millimetres.

[0319] The air outlet may have an equivalent diameter greater than or equal to 0.1 millimetres. The air outlet may have an equivalent diameter greater than or equal to 0.4 millimetres. The air outlet may have an equivalent diameter greater than or equal to 0.7 millimetres. The air outlet may have an equivalent diameter greater than or equal to 1 .0 millimetres.

[0320] The air outlet may have an equivalent diameter less than or equal to 3 millimetres. The air outlet may have an equivalent diameter less than or equal to 2.7 millimetres. The air outlet may have an equivalent diameter less than or equal to 2.4 millimetres. The air outlet may have an equivalent diameter less than or equal to 2.1 millimetres. The air outlet may have an equivalent diameter less than or equal to 1 .8 millimetres. The air outlet may have an equivalent diameter less than or equal to 1 .5 millimetres.

[0321] The air outlet may have an equivalent diameter between 0.1 millimetres and 3 millimetres. The air outlet may have an equivalent diameter between 0.1 millimetres and 2.4 millimetres. The air outlet may have an equivalent diameter between 0.4 millimetres and 2.1 millimetres. The air outlet may have an equivalent diameter between 0.4 millimetres and 1 .8 millimetres. The air outlet may have an equivalent diameter between 0.7 millimetres and 1 .5 millimetres. The air outlet may have an equivalent diameter between 1 .0 millimetres and 1 .5 millimetres.

[0322] 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.

[0323] The air inlet may a width of between 0.3 millimetres and 3 millimetres. The air inlet may a width of between 0.5 millimetres and 2 millimetres.

[0324] The air inlet may have a thickness of between 0.3 millimetres and 3 millimetres. The air outlet may have a thickness of between 0.5 millimetres and 2 millimetres

[0325] 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.

[0326] The air outlet may a width of between 0.3 millimetres and 3 millimetres. The air outlet may a width of between 0.5 millimetres and 2 millimetres.

[0327] The air outlet may have a thickness of between 0.3 millimetres and 3 millimetres. The air outlet may have a thickness of between 0.5 millimetres and 2 millimetres

[0328] 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.

[0329] Advantageously, an aerosol-generating article having an air inlet or an air outlet 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 good resistance to draw through the aerosol-generating article.

[0330] 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. 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.

[0331] 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.

[0332] The aerosol-generating article may comprise one or more air inlets. The aerosolgenerating 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.

[0333] The aerosol-generating article may comprise one or more air outlets. The aerosolgenerating 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.

[0334] The aerosol-generating article may comprise a filter element positioned downstream of the aerosol-generating element. 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.

[0335] The aerosol-generating article may comprise a filter element positioned upstream of the aerosol-generating element. 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.

[0336] 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.

[0337] The aerosol-generating article may comprise a front wall. The front wall may extend from the first external surface to the second external surface. That is, the front wall may extend in a transverse direction. The front wall may be a downstream wall and may be referred to as the downstream wall. The front wall may be defined by the frame, for example by the peripheral wall of the frame.

[0338] The aerosol-generating article may comprise a back wall. The back wall may extend from the first external surface to the second external surface. That is, the back wall may extend in a transverse direction. The backwall may be a upstream wall and may be referred to as the upstream wall. The back wall may be defined by the frame, for example by the peripheral wall of the frame.

[0339] The aerosol-generating article may comprise one or more side walls. The one or more side walls may comprise a first side wall and a second side wall, such as a left side wall and a right side wall. The first side wall and the second side wall may oppose one another. The one or more side walls may extend from the front wall to the back wall. The one or more side walls may extend from the first external surface to the second external surface. The one or more side walls, such as the first side wall and the second side wall, may be defined by the frame, for example by the peripheral wall of the frame.

[0340] Any two or more of the front wall, the back wall, the one or more side walls may be integral with one another. Advantageously, this structure may provide a robust article which is easy to manufacture.

[0341] The aerosol-generating article may comprise a first end face. The first end face may extend from the first external surface to the second external surface. The first end face may be defined or formed by an external wall of the aerosol-generating article, such as the front wall or the back wall.

[0342] The aerosol-generating article may comprise a second end face. The second end face may extend from the first external surface to the second external surface. The second end face may be defined or formed by an external wall or surface of the aerosol-generating article, such as the front wall or the back wall. The second end face may be positioned opposite the first end face. The second end face may be parallel to the first end face.

[0343] The aerosol-generating article may comprise a first side face. The first side face may extend from the first external surface to the second external surface. The first side face may be defined or formed by an external wall of the aerosol-generating article, such as the first side wall or the second side wall. The first side face may extend from the first end face to the second end face.

[0344] The aerosol-generating article may comprise a second side face. The second side face may extend from the first external surface to the second external surface. The second side face may be defined or formed by an external wall of the aerosol-generating article, such as the first side wall or the second side wall. The second side face may extend from the first end face to the second end face. The second side face may be positioned opposite the first side face. The second side face may be parallel to the first side face.

[0345] The first end face and the first side face may form an internal angle equal to or less than 90 degrees. The first end face and the second side face may form an internal angle equal to or less than 90 degrees.

[0346] The aerosol-generating article may comprise a first external corner extending from the first external surface to the second external surface. The first external corner may connect the first end face of the aerosol-generating article and the first side face of the aerosol-generating article.

[0347] The first external corner may be chamfered or rounded.

[0348] In embodiments where the first external corner is rounded, the first external corner may have a radius of curvature. The radius of curvature of the first external corner may be measured in the x / y plane. The radius of curvature of the first external corner may be between 1 .25 millimetres and 6.5 millimetres. The radius of curvature of the first external corner may be less than or equal to 50 percent of the width of the aerosol-generating article. The radius of curvature of the first external corner may be less than or equal to 30 percent of the width of the aerosol-generating article. The radius of curvature of the first external corner may be less than or equal to 20 percent of the width of the aerosol-generating article. The radius of curvature of the first external corner may be less than or equal to 10 percent of the width of the aerosol-generating article.

[0349] The radius of curvature of the first external corner may be greater than or equal to 1 percent of the width of the aerosol-generating article. The radius of curvature of the first external corner may be greater than or equal to 5 percent of the width of the aerosol-generating article. The radius of curvature of the first external corner may be greater than or equal to 10 percent of the width of the aerosol-generating article.

[0350] The radius of curvature of the first external corner may be between 1 percent and 50 percent of the width of the aerosol-generating article. The radius of curvature of the first external corner may be between 1 percent and 30 percent of the width of the aerosol-generating article. The radius of curvature of the first external corner may be between 5 percent and 30 percent of the width of the aerosol-generating article. The radius of curvature of the first external corner may be between 5 percent and 20 percent of the width of the aerosol-generating article.

[0351] In embodiments where the first external corner is chamfered, the first external corner may be chamfered at an angle between 30 degrees and 60 degrees as measured from the first end face. The first external corner may be chamfered at an angle between 40 degrees and 50 degrees as measured from the first end face. The first external corner may be chamfered at an angle of 45 degrees as measured from the first end face.

[0352] The first external corner may comprise a first corner surface connecting the first end face to the second side face. The first end face may connect to the first corner surface at a first corner transition region and, in any x / y plane, a first corner internal angle formed between a tangent of the first end face at the first corner transition region and a tangent of the first corner surface at the first corner transition region may be between 90 degrees and 180 degrees. The first corner internal angle may be between 120 degrees and 180 degrees. The first corner internal angle may be between 130 degrees and 180 degrees.

[0353] The aerosol-generating article may comprise a second external corner extending from the first external surface to the second external surface. The second external corner may connect the first end face of the aerosol-generating article and the second side face of the aerosol-generating article.

[0354] The second external corner may be chamfered or rounded.

[0355] In embodiments where the second external corner is rounded, the second external corner may have a radius of curvature. The radius of curvature of the second external corner may be measured in the x / y plane. The radius of curvature of the second external corner may be between 1 .25 millimetres and 6.5 millimetres. The radius of curvature of the second external corner may be less than or equal to 50 percent of the width of the aerosol-generating article. The radius of curvature of the second external corner may be less than or equal to 30 percent of the width of the aerosol-generating article. The radius of curvature of the second external corner may be less than or equal to 20 percent of the width of the aerosol-generating article. The radius of curvature of the second external corner may be less than or equal to 10 percent of the width of the aerosol-generating article.

[0356] The radius of curvature of the second external corner may be greater than or equal to 1 percent of the width of the aerosol-generating article. The radius of curvature of the second external corner may be greater than or equal to 5 percent of the width of the aerosol-generating article. The radius of curvature of the second external corner may be greater than or equal to 10 percent of the width of the aerosol-generating article.

[0357] The radius of curvature of the second external corner may be between 1 percent and 50 percent of the width of the aerosol-generating article. The radius of curvature of the second external corner may be between 1 percent and 30 percent of the width of the aerosol-generating article. The radius of curvature of the second external corner may be between 5 percent and 30 percent of the width of the aerosol-generating article. The radius of curvature of the second external corner may be between 5 percent and 20 percent of the width of the aerosol-generating article.

[0358] In embodiments where both first external corner and the second external corner are rounded, a radius of curvature of the first external corner may be the same as a radius of curvature of the second external corner.

[0359] In embodiments where the second external corner is chamfered, the second external corner may be chamfered at an angle between 30 degrees and 60 degrees as measured from the first end face. The second external corner may be chamfered at an angle between 40 degrees and 50 degrees as measured from the first end face. The second external corner may be chamfered at an angle of 45 degrees as measured from the first end face.

[0360] The second external corner may comprise a second corner surface connecting the first end face to the second side face. The first end face may connect to the second corner surface at a second corner transition region and, in any x / y plane, a second corner internal angle formed between a tangent of the first end face at the second corner transition region and a tangent of the second corner surface at the second corner transition region may be between 90 degrees and 180 degrees. The second corner internal angle may be between 120 degrees and 180 degrees. The second corner internal angle may be between 130 degrees and 180 degrees.

[0361] The aerosol-generating article may comprise a third external corner extending from the first external surface to the second external surface. The third external corner may connect the second end face of the aerosol-generating article and the first side face of the aerosol-generating article.

[0362] The third external corner may be chamfered or rounded. In embodiments where the third external corner is rounded, the third external corner may have a radius of curvature. The radius of curvature of the third external corner may be measured in the x / y plane. The radius of curvature of the third external corner may be between 1 .25 millimetres and 6.5 millimetres.

[0363] The radius of curvature of the third external corner may be less than or equal to 50 percent of the width of the aerosol-generating article. The radius of curvature of the third external corner may be less than or equal to 30 percent of the width of the aerosol-generating article. The radius of curvature of the third external corner may be less than or equal to 20 percent of the width of the aerosol-generating article. The radius of curvature of the third external corner may be less than or equal to 10 percent of the width of the aerosol-generating article.

[0364] The radius of curvature of the third external corner may be greater than or equal to 1 percent of the width of the aerosol-generating article. The radius of curvature of the third external corner may be greater than or equal to 5 percent of the width of the aerosol-generating article. The radius of curvature of the third external corner may be greater than or equal to 10 percent of the width of the aerosol-generating article.

[0365] The radius of curvature of the third external corner may be between 1 percent and 50 percent of the width of the aerosol-generating article. The radius of curvature of the third external corner may be between 1 percent and 30 percent of the width of the aerosol-generating article. The radius of curvature of the third external corner may be between 5 percent and 30 percent of the width of the aerosol-generating article. The radius of curvature of the third external corner may be between 5 percent and 20 percent of the width of the aerosol-generating article.

[0366] In embodiments where the third external corner is chamfered, the third external corner may be chamfered at an angle between 30 degrees and 60 degrees as measured from the second end face. The third external corner may be chamfered at an angle between 40 degrees and 50 degrees as measured from the third end face. The third external corner may be chamfered at an angle of 45 degrees as measured from the third end face.

[0367] The aerosol-generating article may comprise a fourth external corner extending from the first external surface to the second external surface. The fourth external corner may connect the second end face of the aerosol-generating article and the second side face of the aerosolgenerating article.

[0368] The fourth external corner may be chamfered or rounded.

[0369] In embodiments where the fourth external corner is rounded, the fourth external corner may have a radius of curvature. The radius of curvature of the fourth external corner may be measured in the x / y plane. The radius of curvature of the fourth external corner may be between 1 .25 millimetres and 6.5 millimetres.

[0370] The radius of curvature of the fourth external corner may be less than or equal to 50 percent of the width of the aerosol-generating article. The radius of curvature of the fourth external corner may be less than or equal to 30 percent of the width of the aerosol-generating article. The radius of curvature of the fourth external corner may be less than or equal to 20 percent of the width of the aerosol-generating article. The radius of curvature of the fourth external corner may be less than or equal to 10 percent of the width of the aerosol-generating article.

[0371] The radius of curvature of the fourth external corner may be greater than or equal to 1 percent of the width of the aerosol-generating article. The radius of curvature of the fourth external corner may be greater than or equal to 5 percent of the width of the aerosol-generating article. The radius of curvature of the fourth external corner may be greater than or equal to 10 percent of the width of the aerosol-generating article.

[0372] The radius of curvature of the fourth external corner may be between 1 percent and 50 percent of the width of the aerosol-generating article. The radius of curvature of the fourth external corner may be between 1 percent and 30 percent of the width of the aerosol-generating article. The radius of curvature of the fourth external corner may be between 5 percent and 30 percent of the width of the aerosol-generating article. The radius of curvature of the fourth external corner may be between 5 percent and 20 percent of the width of the aerosol-generating article.

[0373] In embodiments where the fourth external corner is chamfered, the fourth external corner may be chamfered at an angle between 30 degrees and 60 degrees as measured from the second end face. The fourth external corner may be chamfered at an angle between 40 degrees and 50 degrees as measured from the third end face. The fourth external corner may be chamfered at an angle of 45 degrees as measured from the third end face.

[0374] Advantageously, providing an aerosol-generating article having at least one external corner extending from the first external surface to the second external surface that is rounded or chamfered may make the aerosol-generating article easier to insert into an aerosol-generating device.

[0375] Advantageously, providing an aerosol-generating article having at least one external corner extending from the first external surface to the second external surface that is rounded or chamfered may make the aerosol-generating article less susceptible to damage, particularly during insertion of the aerosol-generating article into an aerosol-generating device.

[0376] Advantageously, providing an aerosol-generating article having at least one external corner extending from the first external surface to the second external surface that is rounded or chamfered may make the aerosol-generating article easier to manufacture.

[0377] 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. 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 3:1 . 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 4:1 . A ratio between the length and the thickness of the aerosol-generating article, and between the width and the thickness of the aerosolgenerating article may be greater than 5:1. 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 10:1. A ratio between the length and the thickness of the aerosolgenerating article, and between the width and the thickness of the aerosol-generating article may be greater than 12:1 . 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 15:1.

[0378] 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 . 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 12:1 . 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 10:1 . 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 5:1 . 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 4:1. 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 3:1 . 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 is less than 2.5:1 .

[0379] 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 . 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 12:1 . 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 10:1 . A ratio between the length and the thickness of the aerosol-generating article, and between the width and the thickness of the aerosolgenerating article may be between 3:1 and 10:1 . 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 4:1 and 10:1 . A ratio between the length and the thickness of the aerosolgenerating article, and between the width and the thickness of the aerosol-generating article may be between 5:1 and 10:1 .

[0380] A ratio between the length and the width of the aerosol-generating article may be greater than 1 :1 . A ratio between the length and the width of the aerosol-generating article may be greater than 1.25:1. A ratio between the length and the width of the aerosol-generating article may be greater than 1 .5:1 . A ratio between the length and the width of the aerosol-generating article may be greater than 2:1 . A ratio between the length and the width of the aerosol-generating article may be greater than 2.5:1 . A ratio between the length and the width of the aerosol-generating article may be greater than 3:1 . A ratio between the length and the width of the aerosol-generating article may be greater than 4:1 . A ratio between the length and the width of the aerosol-generating article may be greater than 5:1 .

[0381] A ratio between the length and the width of the aerosol-generating article may be less than 10:1 . A ratio between the length and the width of the aerosol-generating article may be less than

[0382] 8:1 . A ratio between the length and the width of the aerosol-generating article may be less than

[0383] 5:1 . A ratio between the length and the width of the aerosol-generating article may be less than

[0384] 4:1 . A ratio between the length and the width of the aerosol-generating article may be less than

[0385] 3.5:1 . A ratio between the length and the width of the aerosol-generating article may be less than 3:1 . A ratio between the length and the width of the aerosol-generating article may be less than 2.5:1 . A ratio between the length and the width of the aerosol-generating article may be less than 2:1.

[0386] A ratio between the length and the width of the aerosol-generating article may be between 1 :1 and 10:1. A ratio between the length and the width of the aerosol-generating article may be between 1 .5:1 and 5:1 . A ratio between the length and the width of the aerosol-generating article may be between 1 .5:1 and 4:1 . A ratio between the length and the width of the aerosol-generating article may be between 1.5:1 and 3:1. A ratio between the length and the width of the aerosolgenerating article may be between 2:1 and 4:1 . A ratio between the length and the width of the aerosol-generating article may be between 2:1 and 3:1 .

[0387] The aerosol-generating article may have a length greater than or equal to 15 millimetres.

[0388] The aerosol-generating article may have a length greater than or equal to 20 millimetres. The aerosol-generating article may have a length greater than or equal to 25 millimetres. The aerosolgenerating article may have a length greater than or equal to 30 millimetres. The aerosolgenerating article may have a length greater than or equal to 35 millimetres. The aerosolgenerating article may have a length greater than or equal to 40 millimetres.

[0389] The aerosol-generating article may have a length less than or equal to 45 millimetres. The aerosol-generating article may have a length less than or equal to 40 millimetres. The aerosol- generating article may have a length less than or equal to 35 millimetres. The aerosol-generating article may have a length less than or equal to 30 millimetres.

[0390] The aerosol-generating article may have a length between 15 millimetres and 45 millimetres. The aerosol-generating article may have a length between 20 millimetres and 40 millimetres. The aerosol-generating article may have a length between 20 millimetres and 35 millimetres. The aerosol-generating article may have a length between 25 millimetres and 30 millimetres.

[0391] The aerosol-generating article may have a width equal to greater than 3 millimetres. The aerosol-generating article may have a width greater than or equal to 5 millimetres. The aerosolgenerating article may have a width greater than or equal to 7.5 millimetres. The aerosolgenerating article may have a width greater than or equal to 9 millimetres. The aerosol-generating article may have a width greater than or equal to 11 millimetres. The aerosol-generating article may have a width greater than or equal to 13 millimetres.

[0392] The aerosol-generating article may have a width less than or equal to or equal to 17 millimetres. The aerosol-generating article may have a width less than or equal to 15 millimetres. The aerosol-generating article may have a width less than or equal to 12.5 millimetres. The aerosol-generating article may have a width less than or equal to 11 millimetres. The aerosolgenerating article may have a width less than or equal to 9 millimetres.

[0393] The aerosol-generating article may have a width between 3 millimetres and 17 millimetres. The aerosol-generating article may have a width between 5 millimetres and 15 millimetres. The aerosol-generating article may have a width between 7.5 millimetres and 12.5 millimetres. The aerosol-generating article may have a width between 9 millimetres and 11 millimetres.

[0394] The aerosol-generating article may have a thickness equal to greater than 1 millimetre. The aerosol-generating article may have a thickness greater than or equal to 1 .5 millimetres. The aerosol-generating article may have a thickness greater than or equal to 2 millimetres. The aerosolgenerating article may have a thickness greater than or equal to 2.5 millimetres. The aerosolgenerating article may have a thickness greater than or equal to 3 millimetres. The aerosolgenerating article may have a thickness greater than or equal to 3.5 millimetres. The aerosolgenerating article may have a thickness greater than or equal to 4 millimetres. The aerosolgenerating article may have a thickness greater than or equal to 4.5 millimetres.

[0395] The aerosol-generating article may have a thickness less than or equal to 5.5 millimetres. The aerosol-generating article may have a thickness less than or equal to 5 millimetres. The aerosol-generating article may have a thickness less than or equal to 4.5 millimetres. The aerosolgenerating article may have a thickness less than or equal to 4 millimetres. The aerosol-generating article may have a thickness less than or equal to 3.5 millimetres. The aerosol-generating article may have a thickness less than or equal to 3 millimetres. The aerosol-generating article may have a thickness less than 2.5 millimetres. The aerosol-generating article may have a thickness less than 2 millimetres.

[0396] The aerosol-generating article may have a thickness between 1 millimetres and 5 millimetres. The aerosol-generating article may have a thickness between 1 .5 millimetres and 5 millimetres. The aerosol-generating article may have a thickness between 2 millimetres and 4.5 millimetres. The aerosol-generating article may have a thickness between 2.5 millimetres and 4 millimetres. The aerosol-generating article may have a thickness between 3 millimetres and 3.5 millimetres.

[0397] The aerosol-generating article may have a length between 15 millimetres and 45 millimetres, a width between 5 millimetres and 15 millimetres, and a thickness between 1 millimetres and 5 millimetres. Preferably, the aerosol-generating article may have a length between 20 millimetres and 30 millimetres, a width between 7.5 millimetres and 12.5 millimetres, and a thickness between 2.5 millimetres and 4 millimetres.

[0398] More preferably, the aerosol-generating article may have a length of 30 millimetres, a width of 10 millimetres and a thickness of 3.1 millimetres.

[0399] Advantageously, providing an aerosol-generating article having a length of between 15 millimetres and 45 millimetres, a width of between 5 millimetres and 15 millimetres, and a thickness of between 1 millimetre and 5 millimetres may result in an aerosol-generating article that has a high ratio of external surface to volume. An aerosol-generating article having a high ratio of external surface to volume may be more efficiently heated, which may result in better vaporisation of an aerosol-generating substrate stored within the aerosol-generating article. Better vaporisation of an aerosol-generating substrate stored within the aerosol-generating article may lead to an improved user experience.

[0400] Advantageously, providing an aerosol-generating article having a length of between 15 millimetres and 45 millimetres, a width of between 5 millimetres and 15 millimetres, and a thickness of between 1 millimetre and 5 millimetres, with a cavity having a length of between 14 millimetres and 40 millimetres, a width of between 4.5 millimetres and 13 millimetres, and a thickness of between 0.5 millimetres and 4.5 millimetres, may result in the aerosol-generating article containing a large cavity and having a high cavity volume in proportion to external volume of the aerosolgenerating article.

[0401] The aerosol-generating article may have an external volume of between 75 cubic millimetres and 3375 cubic millimetres. The aerosol-generating article may have an external volume of between 375 cubic millimetres and 1750 cubic millimetres.

[0402] The aerosol-generating article may have a resistance to draw (RTD) of less than or equal to 20 millimetre H2O. The aerosol-generating article may have a resistance to draw (RTD) of less than or equal to 10 millimetre H2O. The aerosol-generating article may have a resistance to draw (RTD) of less than or equal to 8 millimetre H2O. The aerosol-generating article may have a resistance to draw (RTD) of less than or equal to 6 millimetre H2O. The aerosol-generating article may have a resistance to draw (RTD) of less than or equal to 4 millimetre H2O. The aerosolgenerating article may have a resistance to draw (RTD) of less than or equal to 2 millimetre H2O. The aerosol-generating article may have a resistance to draw (RTD) equal to, or close to, zero millimetres H2O.

[0403] The aerosol-generating article may have a resistance to draw (RTD) between 0 millimetres H2O and 9.9 millimetres H2O. The aerosol-generating article may have a resistance to draw (RTD) between 1 millimetre H2O and 8 millimetres H2O. The aerosol-generating article may have a resistance to draw (RTD) between 2 millimetres H2O and 6 millimetres H2O. The aerosolgenerating article may have a resistance to draw (RTD) between 3 millimetres H2O and 5 millimetres H2O. Unless otherwise specified, the resistance to draw (RTD) is measured in accordance with ISO 6565-2015. The RTD refers to the pressure required to force air through the aerosolgenerating article between the air inlet and the air outlet. The terms “pressure drop” or “draw resistance” of a component or article may also refer to the “resistance to draw”. Such terms generally refer to the measurements in accordance with ISO 6565-2015 are normally carried out at under test at a volumetric flow rate of about 17.5 millilitres per second at the output or downstream end of the measured component at a temperature of about 22 degrees Celsius, a pressure of about 101 kPa (about 760 Torr) and a relative humidity of about 60%.

[0404] According to the present disclosure, there may be provided a method of manufacturing a preferred example of an aerosol-generating article as described herein, the preferred example comprising a frame. The method comprises providing sheet material comprising: a first sheet of frame material, a second sheet of frame material, a third sheet of frame material, a first sheet of external layer material, and a second sheet of external layer material. The method may comprise bonding the first sheet of frame material, the second sheet of frame material and the third sheet of frame material to one another. The method comprises forming an aperture through the first sheet of frame material, the second sheet of frame material and the third sheet of frame material, for example after they have been bonded. The aperture forms a cavity. The method comprises positioning the first, second, and third sheets of frame material, between the first sheet of external layer material and the second sheet of external layer material, with a portion of an aerosolgenerating element as described herein located within the aperture. The method comprises bonding the sheet material to one another. The resulting article includes the aerosol-generating element positioned within a cavity of the article.

[0405] One or more of the first sheet of frame material, the second sheet of frame material, the third sheet of frame material in the methods of manufacturing described herein may be a sheet of paper or cardboard.

[0406] One or more of the first sheet of external layer material and the second sheet of external layer material in the methods of manufacturing described herein may be a sheet of cigarette paper.

[0407] According to the present disclosure, there is provided an aerosol-generating device for receiving an aerosol-generating article as disclosed herein. The aerosol-generating device comprises a cavity dimensioned to receive at least a portion of the aerosol-generating article. The aerosol-generating device comprises a heater or heating means, a power source for supplying power to the heater or heating means, and a controller to control a supply of power to the heater or heating means. The aerosol-generating device is configured to heat the aerosol-generating element to form an aerosol, for example an inhalable aerosol.

[0408] The cavity of the aerosol-generating device may comprise an opening into which an end, such as a longitudinal end, of the aerosol-generating article can be inserted. The cavity of the aerosol-generating device may have any suitable cross-sectional shape. For example, the cavity of the aerosol-generating device may have a rectangular transverse cross-section, for example a rectangular cross-section having opposed top and bottom sides that are greater in length than left and right sides.

[0409] Preferably, at least one internal surface of the cavity of the aerosol-generating device is a heating surface configured to heat the aerosol-generating article. The heating surface may comprise a heater, for example a resistance heater, or an infra-red heater, or a susceptor configured to be heated by engagement with an inductor. The heating surface may comprise an inductor, for example the surface may comprise a coil arranged to generate a fluctuating electromagnetic field within a space of the cavity of the aerosol-generating device. The heating surface may be a surface that is permeable to a fluctuating electromagnetic field, such that an inductor arranged outside the cavity can project a fluctuating electromagnetic field through the heating surface to engage with a susceptor arranged within the cavity of the aerosol-generating device.

[0410] Preferably, at least a lower surface of the cavity of the aerosol-generating device is a heating surface configured to heat an aerosol-generating article. Optionally, both the lower and an upper surface of the cavity of the aerosol-generating device are heating surfaces configured to heat an aerosol-generating article.

[0411] Preferably, at least a lower internal surface of the cavity of the aerosol-generating device is a substantially planar surface, preferably in which both lower and upper internal surfaces of the cavity of the aerosol-generating device are substantially planar. Preferably, upper and lower internal surfaces of the cavity of the aerosol-generating device are arranged in parallel relationship to one another.

[0412] Optionally, upper and lower internal surfaces may converge along a length of the cavity of the aerosol-generating device such that they are slightly closer spaced at a distal end of the cavity than at a proximal end of the cavity. This may allow the cavity of the aerosol-generating device to grip an aerosol-generating article inserted therein. Side internals surfaces may converge in a similar manner to achieve the result of gripping an aerosol-generating article. The upper and lower internal surfaces of the cavity of the aerosol-generating device, and / or opposing side surfaces of the cavity of the aerosol-generating device, may converge by between 1 degree and 10 degrees between the proximal end of the cavity and the distal end of the cavity, for example between 2 and 8 degrees, for example between 3 and 6 degree, for example between 4 and 5 degrees.

[0413] In some example, the lower internal surface and the upper internal surface may be movable relative to each other. For example, the lower internal surface and the upper internal surface may be configured to pivot relative to one another, or to move upward and downward relative to one another. This may allow an aerosol-generating article to be easily inserted into the cavity of the aerosol-generating device, while allowing the cavity walls of the aerosol-generating device to move to retain the substrate or article in position to be heated. For example, relative movement of upper and lower internal surfaces may result in an aerosol-generating article being gripped between the two surfaces to facilitate heating of the article and to help position the article appropriately within the device.

[0414] The cavity of the aerosol-generating device may be defined by a longitudinal dimension or length, a transverse dimension or width, and a depth dimension or height. The length and width are preferably greater in magnitude than the height, for example at least twice the magnitude of the height.

[0415] The aerosol-generating device may comprise a heating surface comprising a plurality of separately operable heating zones, for example two separately operable heating zones, or three separately operable heating zones, or four separately operable heating zones, or five separately operable heating zones, or six separately operable heating zones. The plurality of separably operable heating zones may be configured to be operated individually, or in any combination of two or more zones at once. In some examples, the plurality of separably operable heating zones may be longitudinally spaced within the cavity. In some example, the plurality of separably operable heating zones may be transversely spaced within the cavity. Different heating zones may be both transversely and longitudinally spaced from one another. Different heating zones may be arranged concentrically relative to one another.

[0416] The aerosol-generating device may comprise one or more resistance heaters, for example one or more resistance heaters integrated into walls of the cavity.

[0417] The device may comprise one or more inductors, for example one or more inductors integrated into walls of the cavity of the aerosol-generating device, or arranged to generate a fluctuating electromagnetic field in walls of the cavity of the aerosol-generating device, or within the cavity of the aerosol-generating device. One or more walls of the cavity of the aerosolgenerating device comprise or consist of susceptor material, such that the one or more walls of the cavity heat up on engagement with a fluctuating electromagnetic field, thereby heating an aerosol-generating article inserted within the cavity.

[0418] The aerosol-generating device may comprise one or more insertable heating elements arranged to project into the cavity of the aerosol-generating device for insertion into an aerosolgenerating article. The insertable heating elements may be resistance heaters. The insertable heating elements may be susceptors.

[0419] The aerosol-generating device may comprise a device body. The device body may comprise the heater. The aerosol-generating device may comprise a mouthpiece element. The device body may comprise a device body housing. The device body housing may define the cavity for receiving at least a portion of the aerosol-generating article. The device body and the mouthpiece element may be releasably connectable. The mouthpiece element may be releasably connectable with the device body, for example the device body housing.

[0420] The mouthpiece element may be releasably connectable with the device body, for example the device body housing, between a connected position and a disconnected position. In the connected position, the cavity of the aerosol-generating device may be at least partially covered, for example by the mouthpiece element. In the disconnected position, the cavity of the aerosolgenerating device may be at least partially exposed, for example so as to allow insertion of the article into the cavity of the aerosol-generating device. The mouthpiece element may be moveable, for example pivotable about a hinge, relative to the device body, for example between a first position and a second position. In the first position, the cavity of the aerosol-generating device may be at least partially covered, for example by the mouthpiece element. In the second position, the cavity may be at least partially exposed, for example so as to allow insertion of the article into the cavity of the aerosol-generating device. Advantageously, covering the cavity of the aerosolgenerating device, or the article in the cavity of the aerosol-generating device, may ensure most aerosol from the article travels along the desired flow path to the user, rather than escaping to the external environment.

[0421] The aerosol-generating device, for example the device body, may comprise a power source such as a battery. In use, the power source may provide power to the heater. The device, for example the device body, may comprise a controller. The controller may be configured to control power from the power supply to the heater.

[0422] The device body may comprise a distal end and a proximal end. The cavity of the aerosolgenerating device may be defined at the proximal end of the device body. The mouthpiece element may comprise a distal end and a proximal end. The distal end of the mouthpiece element may be configured to releasably connect to the proximal end of the device body.

[0423] The mouthpiece element, or at least a portion of the mouthpiece element, may be configured to be inserted into a mouth of a user. The proximal end of the mouthpiece element may be configured to be inserted into a mouth of a user.

[0424] The aerosol-generating device, for example one or both of the device body and the mouthpiece element, may comprise an air inlet. The device, for example the mouthpiece element, may comprise an air outlet. The device may comprise an air flow path fluidly connecting the air inlet to the air outlet. The air flow path may extend one or both of through and past the cavity of the aerosol-generating device. As such, in use, the device may be configured such that, when a negative pressure is applied to the air outlet, for example by a user drawing on the air outlet, air is drawn in through the air inlet, then past or through an aerosol-generating article received in the cavity, thereby entraining aerosol released from the aerosol-forming substrate of the article, then out through the air outlet.

[0425] According to the present disclosure, an aerosol-generating system comprises an aerosolgenerating device as disclosed herein and an aerosol-generating article as disclosed herein. The system may comprise a plurality of such articles for use with the aerosol-generating device.

[0426] As used herein, the term “aerosol-generating article” refers to an article comprising an aerosol-generating substrate. At least a portion of the aerosol-generating substrate is in the form of an aerosol-generating element located within the article. The article may be heated in use to produce and deliver an inhalable aerosol to a consumer. 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. The terms “aerosol-generating substrate” and “aerosol-forming substrate” are synonymous with each other.

[0427] 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.

[0428] 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.

[0429] As used herein, the term “transverse” refers to a direction extending between the first external surface and the second external surface.

[0430] As used herein, the term “longitudinal” refers to a direction that is perpendicular to the transverse direction. For example, a direction between the front wall and the back wall of the aerosol-generating article.

[0431] 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.

[0432] 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.

[0433] 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.

[0434] 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.

[0435] 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.

[0436] As used herein, the term “bulk density” may refer to the total weight of the aerosol-generating substrate divided by the bulk volume of the aerosol-generating substrate.

[0437] 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. As used herein, the term “aerosol former content” may refer to aerosol former content in percent on a dry weight basis, unless otherwise specified.

[0438] 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.

[0439] 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.

[0440] 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.

[0441] As used herein, the term “packing density” refers to a ratio of the total volume of the components, such as solid and liquid components, of an aerosol-generating substrate positioned within the cavity, the first cavity or the second cavity to the volume of the cavity that the aerosolgenerating substrate is positioned within.

[0442] 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.

[0443] Example Ex1 : An aerosol-generating article for use with an aerosol-generating device to generate an aerosol, the aerosol-generating article being defined by an article length, an article width, and an article thickness, the article width being greater than the article thickness, the aerosol-generating article comprising: a first external surface and an opposing second external surface; a cavity located within the aerosol-generating article between the first external surface and the second external surface; a frame positioned between the first external surface and the second external surface, the frame at least partially defining the cavity; and an airflow passage defined through the aerosol-generating article between an air inlet and an air outlet, the airflow passage extending through the cavity, wherein a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate is disposed within the cavity.

[0444] Example Ex2: An aerosol-generating article according to Ex1 , wherein the cavity is defined by internal dimensions, the internal dimensions being a cavity length, a cavity width, and a cavity height, the cavity width being greater than the cavity height. Example Ex3: An aerosol-generating article according to either one of Ex1 or Ex2, wherein the shreds, strips, strands or extrusions of aerosol-forming substrate are aligned along a length direction of the aerosol-generating article.

[0445] Example Ex4: An aerosol-generating article according to any one of Ex1 to Ex3, wherein the shreds, strips, stands or extrusions of aerosol-forming substrate are aligned to extend between the air inlet and the air outlet.

[0446] Example Ex5: An aerosol-generating article according to any one of Ex1 to Ex4, wherein the aerosol-forming substrate comprises or consists of tobacco, for example, shreds, strips, stands or extrusions of cut filler.

[0447] Example Ex6: An aerosol-generating article according to any one of Ex1 to Ex5, wherein the aerosol-forming substrate comprises or consists of non-tobacco material, for example shredded non-tobacco plant material.

[0448] Example Ex7: An aerosol-generating article according to any one of Ex1 to Ex6, wherein the aerosol-forming substrate comprises an aerosol-former, for example an aerosol former selected from the list consisting of glycerine and propylene glycol, for example in which the aerosolforming substrate has an aerosol-former content of at least 10 wt % on a dry weight basis, for example greater than 20 wt %, for example greater than 25 wt %, or greater than 30 wt %, for example greater than 35 wt %.

[0449] Example Ex8: An aerosol-generating article according to Ex7, wherein the aerosol-forming substrate comprises cut filler impregnated with an aerosol-former, for example shredded plant material impregnated with an aerosol former.

[0450] Example Ex9: An aerosol-generating article according to any one of Ex1 to Ex8, wherein the aerosol-forming substrate comprises one or more flavour compounds.

[0451] Example Ex10: An aerosol-generating article according to any one of Ex1 to Ex9, wherein the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate has a mass in a range of between 50 mg and 300 mg, for example between 100 mg and 200 mg , for example between 125 mg and 175 mg, for example between 140 mg and 160 mg, for example about 140 mg, or about 150 mg or about 160 mg.

[0452] Example Ex11 : An aerosol-generating article according to any one of Ex1 to Ex10, wherein the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate has a length in a range of between 0.5 and 30 millimetres, for example between 0.5 and 20 millimetres, for example between 0.5 and 15 millimetres, for example between 0.8 and 10 millimetres, for example between 0.8 and 5 millimetres.

[0453] Example Ex11 A: An aerosol-generating article according to any one of Ex1 to Ex11 , wherein a length of the collection of unbound shreds, strips, strands or extrusions of aerosolforming substrate extends along between 15% and 100% of a length of the cavity, for example between 30% and 100% of a length of the cavity, for example between 50% and 100% of a length of the cavity, for example between 50% and 90% of a length of the cavity, for example between 50% and 80% of a length of the cavity, for example between 50% and 70% of a length of the cavity.

[0454] Example Ex11 B: An aerosol-generating article according to any one of Ex1 to Ex11 A, wherein the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate occupy between 15% and 100% of an interior volume of the cavity, for example between 30% and 100% of an interior volume of the cavity, for example between 50% and 100% of an interior volume of the cavity, for example between 50% and 90% of an interior volume of the cavity, for example between 50% and 80% of an interior volume of the cavity, for example between 50% and 70% of an interior volume of the cavity.

[0455] Example Ex12: An aerosol-generating article according to any one of Ex1 to Ex11 B, wherein at least 80%, or at least 85%, or at least 90%, or at least 95%, or all of the shreds, strips, strands or extrusions of aerosol-forming substrate have a length in a range of between 0.5 and 30 millimetres, for example between 0.5 and 20 millimetres, for example between 0.5 and 15 millimetres, for example between 0.8 and 10 millimetres, for example between 0.8 and 5 millimetres.

[0456] Example Ex13: An aerosol-generating article according to any one of Ex1 to Ex12, wherein at least 80%, or at least 85%, or at least 90%, or at least 95%, or all of the shreds, strips, strands or extrusions of aerosol-forming substrate have a width in a range of between 0.3 and 4 millimetres, for example between 0.3 and 3 millimetres, for example between 0.3 and 2 millimetres, for example between 0.6 and 1 .2 millimetres, for example between 0.6 and 0.9 millimetres.

[0457] Example Ex14: An aerosol-generating article according to any one of Ex1 to Ex13, wherein the cavity contains a single unitary collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate.

[0458] Example Ex15: An aerosol-generating article according to any one of Ex1 to Ex13, wherein the cavity contains two or more collections of unbound shreds, strips, strands or extrusions of aerosol-forming substrate.

[0459] Example Ex16: An aerosol-generating article according to Ex15, wherein the composition of a first collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate disposed within the cavity is different to the composition of a second collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate disposed within the cavity.

[0460] Example Ex17: An aerosol-generating article according to any one of Ex1 to Ex16, wherein the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate is arranged to fill the cavity.

[0461] Example Ex18: An aerosol-generating article according to any one of Ex1 to Ex17, wherein the cavity comprises a filled portion and an empty portion, the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate confined to the filled portion of the cavity.

[0462] Example Ex19: An aerosol-generating article according to Ex18, wherein the filled portion is positioned closer to an upstream end of the cavity than the empty portion. Example Ex20: An aerosol-generating article according to either one of Ex18 or Ex19, wherein the filled portion defines between 50% and 95% of an enclosed volume of the cavity, for example between 60% and 95% of the enclosed volume of the cavity, for example between 70% and 95% of the enclosed volume of the cavity, for example between 80% and 95% of the enclosed volume of the cavity.

[0463] Example Ex21 : An aerosol-generating article according to any one of Ex1 to Ex20, wherein the cavity comprises a first filled portion and a second filled portion, the first and second filled portions filled with respective first and second collections of unbound shreds, strips, strands or extrusions of aerosol-forming substrate.

[0464] Example Ex22: An aerosol-generating article according to Ex21 , wherein the composition of the first collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate is different to the composition of the second collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate.

[0465] Example Ex22A: An aerosol-generating article according to any one of Ex1 to Ex22, wherein each shred, strip, strand or extrusion of the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate occupies less than 10% of an enclosed volume of the cavity, for example less than 5% of an enclosed volume of the cavity.

[0466] Example Ex23: An aerosol-generating article according to any one of Ex1 to Ex22A, wherein each shred, strip, strand or extrusion of the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate occupies less than 1 % of an enclosed volume of the cavity, for example less than 0.5% of the enclosed volume of the cavity, for example less than 0.2% of the enclosed volume of the cavity, for example less than 0.05% of the enclosed volume of the cavity; for example less than 0.01 % of the enclosed volume of the cavity.

[0467] Example Ex24: An aerosol-generating article according to any one of Ex1 to Ex23, wherein the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate disposed within the cavity has a bulk density of between 150 mg per cubic centimetre and 500 mg per cubic centimetre, for example between 175 mg per cubic centimetre and 475 mg per cubic centimetre, for example between 200 mg per cubic centimetre and 450 mg per cubic centimetre, for example between 225 mg per cubic centimetre and 425 mg per cubic centimetre, for example between 250 mg per cubic centimetre and 400 mg per cubic centimetre, for example between 275 mg per cubic centimetre and 375 mg per cubic centimetre, for example between 300 mg per cubic centimetre and 350 mg per cubic centimetre.

[0468] Example Ex25: An aerosol-generating article according to any one of Ex1 to Ex24, wherein the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate disposed within the cavity has a bulk density of between 50 mg per cubic centimetre and 900 mg per cubic centimetre, for example between 100 mg per cubic centimetre and 800 mg per cubic centimetre, for example between 200 mg per cubic centimetre and 700 mg per cubic centimetre, for example between 200 mg per cubic centimetre and 600 mg per cubic centimetre, for example between 200 mg per cubic centimetre and 500 mg per cubic centimetre, for example between 200 mg per cubic centimetre and 400 mg per cubic centimetre.

[0469] Example Ex26: An aerosol-generating article according to any one of Ex1 to Ex25, wherein the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate disposed within the cavity has a packing density between 0.3 and 0.9, for example between 0.4 and 0.9, for example between 0.5 and 0.9, for example between 0.5 and 0.8, for example between 0.5 and 0.7.

[0470] Example Ex27: An aerosol-generating article according to any one of Ex1 to Ex26, wherein the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate number between 30 and 2000 shreds, strips, strands or extrusions, for example between 30 and 1500 shreds, strips, strands or extrusions, for example between 30 and 1000 shreds, strips, strands or extrusions, for example between 30 and 500 shreds, strips, strands or extrusions, for example between 30 and 250 shreds, strips, strands or extrusions, for example between 30 and 100 shreds, strips, strands or extrusions.

[0471] Example Ex28: An aerosol-generating article according to any one of Ex1 to Ex27, wherein the shreds, strips, strands or extrusions of the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate are arranged to intermesh with each other.

[0472] Example Ex29: An aerosol-generating article according to Ex28, wherein one or more first shreds, strips, strands or extrusions of the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate is aligned relative to one or more second shreds, strips, strands or extrusions of the collection of unbound shreds, strips, strands or extrusions of aerosolforming substrate at an acute angle of between 45 degrees and 90 degrees, for example between 60 degrees and 90 degrees, for example between 75 degrees and 90 degrees.

[0473] Example Ex30: An aerosol-generating article according to any one of Ex1 to Ex29, wherein side walls of the cavity are at least partially defined by the frame.

[0474] Example Ex31 : An aerosol-generating article according to any one of Ex1 to Ex30, wherein the first exterior wall and the second exterior wall define respective first and second outwardly convex exterior surfaces, for example the first and second outwardly convex exterior surfaces collectively defining a lenticular profile.

[0475] Example Ex32: An aerosol-generating article according to any one of Ex1 to Ex31 , wherein one or more susceptor materials are arranged in thermal communication with the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate.

[0476] Example Ex33: An aerosol-generating article according to Ex32, wherein one or more susceptor materials are dispersed within the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate.

[0477] Example Ex34: An aerosol-generating article according to any one of Ex1 to Ex33, wherein at least one of the first external surface and the second external surface is a substantially planar surface, for example in which the first external surface is a substantially planar surface, for example in which both the first external surface and the second external surface is a substantially planar surface.

[0478] Example Ex35: An aerosol-generating article according to Ex34, wherein each of the first external surface and the second external surface is a substantially planar surface, the aerosolgenerating article further comprising a first aerosol-generating substrate layer positioned between the first planar external surface and the frame, and / or a second aerosol-generating substrate layer positioned between the second planar external surface and the frame.

[0479] Example Ex36: An aerosol-generating article according to Ex35, wherein one or both the first aerosol-generating substrate layer and the second aerosol-generating substrate layer comprises an aerosol-generating material in the form of a sheet of aerosol-generating material.

[0480] Example Ex37: An aerosol-generating article according to Ex36, wherein the sheet of aerosol-generating material is a sheet of homogenised tobacco material.

[0481] Example Ex38: An aerosol-generating article according to Ex36 or Ex37, wherein the sheet of aerosol-generating material comprises one or more aerosol-formers, such as one or both of glycerine and propylene glycol.

[0482] Example Ex39: An aerosol-generating article according to any one of Ex35 to Ex38, wherein the first aerosol-generating substrate layer and the second aerosol-generating substrate layer define opposing end walls of the cavity.

[0483] Example Ex40: An aerosol-generating article according to any one of Ex35 to Ex39, wherein one or both of the first aerosol-generating substrate layer and the second aerosolgenerating substrate layer has a thickness between 100 micrometres and 600 micrometres.

[0484] Example Ex41 : An aerosol-generating article according to any one of Ex35 to Ex40, wherein one or both the first aerosol-generating substrate layer and the second aerosol-generating substrate layer has a length substantially the same as the length of the aerosol-generating article.

[0485] Example Ex42: An aerosol-generating article according to any one of Ex35 to Ex41 , wherein one or both the first aerosol-generating substrate layer and the second aerosol-generating substrate layer has a width substantially the same as the width of the aerosol-generating article.

[0486] Example Ex43: An aerosol-generating article according to any one of Ex1 to Ex42, wherein the cavity has a width between 30 percent and 95 percent of the width of the aerosol-generating article.

[0487] Example Ex44: An aerosol-generating article according to any one of Ex1 to Ex43, wherein the cavity has a length between 30 percent and 95 percent of the length of the aerosol-generating article.

[0488] Example Ex45: An aerosol-generating article according to any one of Ex1 to Ex44, wherein the cavity has a thickness between 30 percent and 95 percent of the thickness of the aerosolgenerating article. Example Ex46: An aerosol-generating article according to any one of Ex1 to Ex45, wherein the cavity has 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.

[0489] Example Ex47: An aerosol-generating article according to any one of Ex1 to Ex46, wherein the cavity has 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.

[0490] Example Ex48: An aerosol-generating article according to any one of Ex1 to Ex47, wherein a thickness of the aerosol-generating article is less than 50 percent of both a length and a width of the aerosol-generating article.

[0491] Example Ex49: An aerosol-generating article according to any of Ex1 to Ex48, wherein the frame comprises a peripheral wall circumscribing or encircling the cavity.

[0492] Example Ex50: An aerosol-generating article according to Ex49, wherein the peripheral wall is formed by a frame inner surface and a frame outer surface, and wherein the frame inner surface defines a cavity outer wall and the frame outer surface at least partially defines one or more external walls of the aerosol-generating article.

[0493] Example Ex51 : An aerosol-generating article according to Ex49 or Ex50, wherein the peripheral wall has a radial thickness between 1 millimetre and 3 millimetres.

[0494] Example Ex52: An aerosol-generating article according to any of Ex1 to Ex51 , wherein the frame has a thickness greater than or equal to 80 percent of the thickness of the aerosol-generating article.

[0495] Example Ex53: An aerosol-generating article according to any of Ex1 to Ex52, wherein the frame has a thickness between 80 percent and 95 percent of the thickness of the aerosolgenerating article.

[0496] Example Ex54: An aerosol-generating article according to any of Ex1 to Ex53, wherein the frame has a thickness between 1 millimetre and 5.5 millimetres.

[0497] Example Ex55: An aerosol-generating article according to any of Ex1 to Ex54, wherein the frame comprises a cellulosic material.

[0498] Example Ex56: An aerosol-generating article according to Ex55, wherein the cellulosic material has a grammage between 300 grams per square metre and 900 grams per square metre.

[0499] Example Ex57: An aerosol-generating article according to Ex55 or Ex56, wherein the cellulosic material is paper, paperboard, or cardboard.

[0500] Example Ex58: An aerosol-generating article according to any of Ex1 to Ex57, wherein the frame is a unitary component.

[0501] Example Ex59: An aerosol-generating article according to any of Ex1 to Ex58, wherein the frame comprises a first frame layer and a second frame layer.

[0502] Example Ex60: An aerosol-generating article according to Ex59, wherein the first frame layer is bonded to the second frame layer with an adhesive. Example Ex61 : An aerosol-generating article according to Ex59 or Ex60, wherein the frame comprises a third frame layer.

[0503] Example Ex62: An aerosol-generating article according to Ex61 , wherein the second frame layer is positioned between the first frame layer and the third frame layer.

[0504] Example Ex63: An aerosol-generating article according to Ex61 or Ex62, wherein the second frame layer is bonded to the third frame layer with an adhesive.

[0505] Example Ex64: An aerosol-generating article according to any one of Ex1 to Ex63, comprising an outer wrapper defining the first external surface and the second external surface.

[0506] Example Ex65: An aerosol-generating article according to Ex64, wherein the first external surface is a planar surface and the second external surface is a planar surface.

[0507] Example Ex66: An aerosol-generating article according to any one of Ex1 to Ex65, comprising a first planar external layer and a second planar external layer, wherein the first planar external layer defines the first external surface and the second planar external layer defines the second external surface.

[0508] Example Ex67: An aerosol-generating article according to Ex66, wherein the first planar external layer and the second planar external layer overlie opposing ends of the cavity.

[0509] Example Ex68: An aerosol-generating article according to either one of Ex66 or Ex67, wherein one or both of the first planar external layer and the second planar external layer comprise a cellulosic material.

[0510] Example Ex69: An aerosol-generating article according to Ex68, wherein the cellulosic material is paper or cardboard.

[0511] Example Ex70: An aerosol-generating article according to any one of Ex66 to Ex69, wherein one or both of the first planar external layer and the second planar external layer has a length substantially the same as the length of the aerosol-generating article.

[0512] Example Ex71 : An aerosol-generating article according to any one of Ex66 to Ex70, wherein one or both of the first planar external layer and the second planar external layer has a width substantially the same as the width of the aerosol-generating article.

[0513] Example Ex72: An aerosol-generating article according to any one of Ex1 to Ex71 , wherein the air inlet is defined by the frame.

[0514] Example Ex73: An aerosol-generating article according to any one of Ex1 to Ex72, wherein the air inlet has an equivalent diameter between 0.1 millimetres and 3 millimetres.

[0515] Example Ex74: An aerosol-generating article according to any one of Ex1 to Ex73, wherein the air inlet has a width of between 0.3 millimetres and 3 millimetres.

[0516] Example Ex75: An aerosol-generating article according to any one of Ex1 to Ex74, wherein the air inlet has a thickness of between 0.3 millimetres and 3 millimetres.

[0517] Example Ex76: An aerosol-generating article according to any one of Ex1 to Ex75, wherein the air outlet is defined by the frame. Example Ex77: An aerosol-generating article according to any one of Ex1 to Ex76, wherein the air outlet has an equivalent diameter between 0.1 millimetres and 3 millimetres.

[0518] Example Ex78: An aerosol-generating article according to any one of Ex1 to Ex77, wherein the air outlet has a width of between 0.3 millimetres and 3 millimetres.

[0519] Example Ex79: An aerosol-generating article according to any one of Ex1 to Ex78, wherein the air outlet has a thickness of between 0.3 millimetres and 3 millimetres.

[0520] Example Ex80: An aerosol-generating article according to any one of Ex1 to Ex79, wherein 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 is between 2:1 and 15:1 .

[0521] Example Ex81 : An aerosol-generating article according to any one of Ex1 to Ex80, wherein a ratio between the length and the width of the aerosol-generating article is between 1 :1 and 10:1 .

[0522] Example Ex82: An aerosol-generating article according to any one of Ex1 to Ex81 , wherein the aerosol-generating article has a length between 15 millimetres and 45 millimetres, for example between 25 millimetres and 30 millimetres.

[0523] Example Ex83: An aerosol-generating article according to any one of Ex1 to Ex82, wherein the aerosol-generating article has a width between 3 millimetres and 17 millimetres, for example between 9 millimetres and 11 millimetres.

[0524] Example Ex84: An aerosol-generating article according to any one of Ex1 to Ex83, wherein the aerosol-generating article has a thickness between 1 millimetres and 5.5 millimetres, for example between 3 millimetres and 3.5 millimetres.

[0525] Example Ex85: An aerosol-generating article according to any one of Ex1 to Ex84, wherein the aerosol-generating article has a resistance to draw between 0 millimetres H2O and 9.9 millimetres H2O, for example in which the air flow path has a resistance to draw between 0 millimetres H2O and 9.9 millimetres H2O.

[0526] Examples will now be further described with reference to the figures in which:

[0527] Figure 1 shows a perspective view of an aerosol-generating article according to the present disclosure;

[0528] Figure 2 shows an exploded perspective view of the aerosol-generating article of Figure 1 ;

[0529] Figure 3 shows an exploded perspective view of an aerosol-generating article according to the present disclosure;

[0530] Figure 4 shows a transverse cross-sectional view of the aerosol-generating article of Figure 3;

[0531] Figure 5 shows a longitudinal cross-sectional view of the aerosol-generating article of Figure 3;

[0532] Figure 6A shows a longitudinal cross-sectional view of an embodiment of an aerosolgenerating element for use as part of the aerosol-generating article of Figures 1 to 5;

[0533] Figure 6B shows a longitudinal cross-sectional view of a further embodiment of an aerosolgenerating element for use as part of the aerosol-generating article of Figures 1 to 5; Figure 7 shows an exploded perspective view of an aerosol-generating article according to the present disclosure;

[0534] Figure 8 shows a transverse cross-sectional view of the aerosol-generating article of Figure 7;

[0535] Figure 9 shows a lateral cross-sectional view of the aerosol-generating article of Figure 7;

[0536] Figure 10 shows a perspective view of an aerosol-generating article according to the present disclosure;

[0537] Figure 11 shows a perspective view of the aerosol-generating article of Figure 10;

[0538] Figure 12 shows a perspective view of an aerosol-generating article according to the present disclosure;

[0539] Figure 13 shows an exploded perspective view of the aerosol-generating article of Figure 12;

[0540] Figure 14 shows an exploded perspective view of the aerosol-generating article of Figure 12;

[0541] Figure 15 show a perspective view of an aerosol-generating article according to the present disclosure;

[0542] Figure 16 shows an exploded perspective view of the aerosol-generating article of Figure 15;

[0543] Figure 17 shows an exploded perspective view of the aerosol-generating article of Figure 15;

[0544] Figure 18 shows a perspective view of an aerosol-generating article according to the present disclosure;

[0545] Figure 19 shows an exploded perspective view of the aerosol-generating article of Figure 18;

[0546] Figure 20 shows an exploded perspective view of an aerosol-generating article according to the present disclosure;

[0547] Figure 21 shows an exploded perspective view of an aerosol-generating article according to the present disclosure;

[0548] Figure 22 shows an exploded perspective view of an aerosol-generating article according to the present disclosure;

[0549] Figure 23 shows a perspective view of an aerosol-generating article according to the present disclosure;

[0550] Figure 24 shows an exploded perspective view of the aerosol-generating article of Figure 23;

[0551] Figure 25 shows an exploded perspective view of an aerosol-generating article according to the present disclosure;

[0552] Figure 26 shows an exploded perspective view of an aerosol-generating article according to the present disclosure; Figure 27 shows an exploded perspective view of an aerosol-generating article according to the present disclosure;

[0553] Figure 28 shows an exploded perspective view of an aerosol-generating article according to the present disclosure;

[0554] Figure 29 shows an exploded perspective view of an aerosol-generating article according to the present disclosure;

[0555] Figure 30 shows an exploded perspective view of an aerosol-generating article according to the present disclosure;

[0556] Figure 31 shows a perspective view of an aerosol-generating article according to the present disclosure;

[0557] Figure 32 shows a perspective view of the aerosol-generating article of Figure 31 ;

[0558] Figure 33 shows a perspective view of an aerosol-generating article according to the present disclosure;

[0559] Figure 34 shows a plan view of the aerosol-generating article of Figure 33;

[0560] Figure 35 shows an exploded perspective view of the aerosol-generating article of Figure

[0561] 33;

[0562] Figure 36 shows a cross-sectional view of the aerosol-generating article of Figure 33;

[0563] Figure 37 shows an exploded perspective view of an aerosol-generating article according to the present disclosure;

[0564] Figure 38 shows a perspective view of an aerosol-generating article according to the present disclosure;

[0565] Figure 39 shows a perspective view of an aerosol-generating article according to the present disclosure;

[0566] Figure 40 shows a perspective view of an aerosol-generating article according to the present disclosure;

[0567] Figure 41 shows a perspective view of an aerosol-generating article according to the present disclosure;

[0568] Figure 42 shows a schematic cross-sectional view of an aerosol-generating device according to the present disclosure;

[0569] Figure 43 shows a schematic cross-sectional view of the aerosol-generating device of Figure 42 in engagement with an aerosol-generating article of the present disclosure;

[0570] Figure 44 shows a method of manufacturing an aerosol-generating article according to the present disclosure;

[0571] Figure 45 shows a plan view of the method of manufacturing of Figure 44;

[0572] Figure 46 shows a method of manufacturing an aerosol-generating article according to the present disclosure;

[0573] Figure 47 shows a plan view of the method of manufacturing of Figure 46; Figure 48 shows a method of manufacturing an aerosol-generating article according to the present disclosure;

[0574] Figure 49 shows a plan view of the method of manufacturing of Figure 48;

[0575] Figure 50 shows a method of manufacturing an aerosol-generating article according to the present disclosure; and

[0576] Figure 51 shows a plan view of the method of manufacturing of Figure 50.

[0577] 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 may be formed from a non-aerosol forming material, such as paper or card. Alternatively, either of the first planar external layer 24 and the second planar external layer 25 may comprise an aerosol-generating substrate comprising an aerosol-generating material, for example tobacco.

[0578] 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.

[0579] The first planar external surface 21 and the second planar external surface 22 extend in the x-direction and the y-direction. That is, the first planar external surface 21 and the second planar external surface 22 extend in the x / y plane. The first planar external surface 21 is positioned parallel to the second planar external surface 22 and the first planar external surface 21 is spaced from the second planar external surface 22 in the z-direction or transverse direction. The distance between the first planar external surface 21 and the second planar external surface 22 in the z- direction or transverse direction corresponds to the thickness of the aerosol-generating article 10.

[0580] The aerosol-generating article 10 is a substantially flat aerosol-generating article or substantially planar aerosol-generating article. In particular, the thickness of the aerosol-generating article 10 is less than 50 percent of both the length and the width of the aerosol-generating article. That is, the thickness is less than 15 millimetres (less than 50 percent of the length of the aerosolgenerating article 10) and less than 5 millimetres (less than 50 percent of the width of the width of the aerosol-generating article 10). 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.

[0581] Figure 2 shows an exploded view of the aerosol-generating article 10 of Figure 1 .

[0582] 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. The cavity 30 serves as a location for containing an aerosol-forming substrate, for example an aerosol-generating element 40.

[0583] 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. The frame outer surface 53 encircles, and is concentric with, the frame inner surface 52. Thus, the frame 50 has a cross-section in the x / y plane that is annular in shape, in particular the cross-section is a rectangular annulus shape.

[0584] 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.

[0585] 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 overlies an end of the cavity 30 and forms a first cavity end wall 31 . The second planar external layer 25 overlies an opposite end of the cavity 30 and forms a second cavity end wall 32. That is, the frame 50, the first planar external layer 24 and the second planar external layer 25 collectively define the cavity 30.

[0586] 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.

[0587] The frame forms at least 95 percent of a perimeter of any cross-section, in an x / y plane, of the aerosol-generating article that extends through the frame. For example, the frame forms 100 percent of the perimeter of a cross-section, in an x / y plane, of the aerosol-generating article 10 taken between the first planar external layer 24 and the air outlet 12. On the other hand, the frame forms 95 percent of the perimeter of a cross-section, in an x / y plane, of the aerosol-generating article that extends through the air inlet 11 and the air outlet 12. This is because the perimeter of such a cross-section is formed by the frame, a width of the air inlet 11 and a width of the air outlet 12. Figure 3 shows an exploded view of the aerosol-generating article 10 of Figure 1 illustrating an aerosol-generating element 40 positioned within the cavity 30. The aerosol-generating element 40 is in the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate. The aerosol-forming substrate of the aerosol-generating element 40 is in the form of tobacco cut filler.

[0588] The unbound nature of the collection of shreds, strips, strands or extrusions which form the aerosol-generating element 40 allows the shreds, strips, strands or extrusions to be distributed within the cavity 30 in various manners. For the embodiment illustrated in Figures 3 to 5, the unbound shreds, strips, strands or extrusions of aerosol-forming substrate are distributed so as to fill the entire volume of the cavity 30. The mass of the aerosol-generating element 40 defined by the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate is approximately 150 mg.

[0589] Although the aerosol-generating element 40 is shown as filling the cavity 30 in Figures 3 to 5, in other embodiments the unbound collection of shreds, strips, strands or extrusions of aerosol-forming substrate may be arranged to occupy only a part of the interior volume of the cavity 30. For example, the unbound collection of shreds, strips, strands or extrusions of aerosol-forming substrate may occupy only a part of the length of the cavity 30 and / or a part of the width of the cavity 30. For example, the unbound collection of shreds, strips, strands or extrusions of aerosolforming substrate may be arranged to extend along only part of the length of the cavity 30, but across the full width of the cavity 30 such that opposing walls of the cavity 30 help to retain the unbound collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate in fixed position within the cavity 30.

[0590] In use, an air flow path through the cavity 30 would pass through the aerosol-generating element 40 defined by the collection of unbound shreds, strips, strands or extrusions of aerosolforming substrate. It will be understood that the level of air flow through the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate and the resistance to draw of the aerosol-generating article 10 will be affected by the number and level of compaction of the shreds, strips, strands or extrusions of aerosol-forming substrate within the cavity 30.

[0591] The shreds, strips, strands or extrusions of aerosol-forming substrate which form the aerosol-generating element 40 preferably each have a length in a range of between 0.8 millimetres and 10 millimetres and a width of between 0.6 millimetres and 1.2 millimetres. In other embodiments, at least 80% of the shreds, strips, strands or extrusions of aerosol-forming substrate which form the aerosol-generating element 40 have a length in a range of between 0.8 millimetres and 10 millimetres and a width of between 0.6 millimetres and 1.2 millimetres. Figures 4 and 5 show transverse and longitudinal cross-sectional views of the aerosol-generating article 10 of Figure 3, showing the aerosol-generating element 40 defined by the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate, located within the cavity 30. Figures 6A and 6B illustrate two different arrangements of a collection of unbound shreds, strips, strands or extrusions 401 of aerosol-forming substrate forming respective aerosolgenerating elements 40’, 40”.

[0592] Figure 6A shows aerosol-generating element 40’ formed of a collection of unbound shreds, strips, strands or extrusions 401 of aerosol-forming substrate aligned generally parallel to each other in an x direction. The aerosol-generating element 40’ of Figure 6A may be associated with providing an aerosol-generating article (such as aerosol-generating article 10) with a low level of resistance to draw.

[0593] Figure 6B shows aerosol-generating element 40” formed of a collection of unbound shreds, strips, strands or extrusions 401 of aerosol-forming substrate in two intermeshing groups 401 a, 401 b of shreds, strips, strands or extrusions 401 . Figure 6B shows the first group 401 a of shreds, strips, strands or extrusions 401 extending generally in an x direction, and the second group 401 b of shreds, strips, strands or extrusions 401 extending generally in a y direction. So, the intermeshing groups 401 a, 401 b of shreds, strips, strands or extrusions 401 form an intermeshing two dimensional arrangement. The aerosol-generating element 40” of Figure 6B, with its intermeshing groups 401 a, 401 b of shreds, strips, strands or extrusions 401 of aerosol-forming substrate, may be associated with providing structural stability to the collection of unbound shreds, strips, strands or extrusions 401 forming aerosol-generating element 40”. Although not shown in Figure 6B, in other embodiments there may be a third group of shreds, strips, strands or extrusions 401 extending generally in a z direction, with the first, second and third groups of shreds, strips, strands or extrusions 401 collectively forming an intermeshing three dimensional lattice arrangement.

[0594] Figure 7 shows an exploded view of an aerosol-generating 10 that is similar to the aerosolgenerating article 10 of Figure 3 except that the cavity 30 contains an aerosol-generating substrate 47 in the form of a sheet of aerosol-generating material, in particular a corrugated sheet of homogenised tobacco material. Figures 8 and 9 show transverse and lateral cross-sectional views of the aerosol-generating article 10 of Figure 7, respectively. It is noted that the cavity 30 may additionally contain one or more aerosol-generating elements in the form of one or more collections of unbound shreds, strips, strands or extrusions of aerosol-forming substrate, in a similar manner to as described for Figures 1 to 5. For example, an aerosol-generating element in the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may be positioned in one or more channels 45, 46 defined by the corrugated sheet of homogenised tobacco material 47; the channels 45, 46 are shown in Figure 8.

[0595] The corrugated sheet of homogenised tobacco material comprises a plurality of parallel corrugations having a plurality of substantially parallel peaks 43 and troughs 44. The plurality of parallel corrugations are defined by a corrugation profile which, as seen in Figure 8, is sinusoidal. The plurality of parallel corrugations have a corrugation wavelength of about 0.92 millimetres. The corrugation amplitude is approximately the same as the thickness of the cavity, as shown by the peaks 43 and troughs 44 coinciding with the first cavity end wall 31 and the second cavity end wall 32, respectively.

[0596] The plurality of parallel corrugations form plurality of channels 45 between the sheet of aerosol-generating material and the first cavity end wall 31 , and plurality of channels 46 between the sheet of aerosol-generating material and the second cavity end wall 32. The plurality of channels extend in a longitudinal direction of the aerosol-generating article 10 and form at least a portion of the airflow passage extending between the air inlet 11 and the air outlet 12.

[0597] Figure 10 shows an aerosol-generating article 10 similar to the aerosol-generating article 10 of Figures 1 , 3 and 7 except that the aerosol-generating article 10 of Figure 10 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. Figure 11 shows, for illustration purposes, the aerosol-generating article 10 of Figure 10 in which the outer wrapper 23 has been unwrapped to expose a portion of the peripheral wall 51 of the frame 50. The outer wrapper 23 is cigarette paper.

[0598] Figure 12 shows an aerosol-generating article 10 similar to the aerosol-generating article 10 of Figure 1 , except that the frame 50 of the aerosol-generating article 10 of Figure 12 comprises a first frame layer 54 and a second frame layer 55. Figure 13 shows an exploded view of the first planar external layer 24, the frame 50 and the second planar external layer 25 of the aerosolgenerating article 10 of Figure 12. Figure 14 shows a yet further exploded view of the first planar external layer 24, the first frame layer 54, the second frame layer 55, and the second planar external layer 25 of the aerosol-generating article 10 of Figure 12. An aerosol-generating element 40 in the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may be located in the cavity 30 of the article 10 of Figures 12 to 14.

[0599] The first planar external layer 24 is in physical contact with the first frame layer 54 and are bonded together with an adhesive 15. The first frame layer 54 is in physical contact with the second frame layer 55 and are bonded together with an adhesive 15. The second planar external layer 25 is in physical contact with the second frame layer 55 and are bonded together with an adhesive 15.

[0600] The aerosol-generating article 10 has the same dimensions as the aerosol-generating article 10 of Figure 1. The frame 50 has the same dimensions as the frame 50 of Figure 1. The thickness of the frame 50 is equal to the sum of the thickness of the first frame layer 54 and the second frame layer 55, which both have the same thickness. The air inlet 11 and air outlet 12 are formed by both the first frame layer 54 and the second frame layer 55.

[0601] Figure 15 shows an aerosol-generating article 10 similar to the aerosol-generating article 10 of Figure 1 except that the frame 50 of the aerosol-generating article 10 of Figure 15 comprises a first frame layer 54, a second frame layer 55 and a third frame layer 56 positioned between the first frame layer 54 and the second frame layer 55. Figure 16 shows an exploded view of the first planar external layer 24, the frame 50 and the second planar external layer 25 of the aerosol- generating article 10 of Figure 15. Figure 17 shows a yet further exploded view of the first planar external layer 24, the first frame layer 54, the second frame layer 55, the third frame layer 56 and the second planar external layer 25 of the aerosol-generating article 10 of Figure 15. An aerosolgenerating element 40 in the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may be located in the cavity 30 of the article 10 of Figures 15 to 17.

[0602] The first planar external layer 24 is in physical contact with the first frame layer 54 and are bonded together with an adhesive 15. The first frame layer 54 is in physical contact with the second frame layer 55 and are bonded together with an adhesive 15. The second frame layer 55 is in physical contact with the third frame layer 56 and are bonded together with an adhesive 15. The second planar external layer 25 is in physical contact with the third frame layer 56 and are bonded together with an adhesive 15.

[0603] The aerosol-generating article 10 has the same dimensions as the aerosol-generating article 10 of Figure 1 . The frame 50 has the same dimensions as the frame 50 in Figure 1 . The thickness of the frame 50 is equal to the sum of the thickness of the first frame layer 54, the second frame layer 55 and the third frame layer 56. The air inlet 11 and air outlet 12 extend through the second frame layer 55.

[0604] Figure 18 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 18 further comprises a first aerosol-generating substrate layer 41 and a second aerosol-generating substrate layer 42. Figure 19 shows an exploded view of the aerosol-generating article 10 of Figure 18. The first aerosolgenerating 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 aerosolgenerating 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.

[0605] 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 overlies an end of the cavity 30 and forms a first cavity end wall 31 . The second aerosol-generating layer 42 overlies an opposite end of the cavity 30 and forms a second cavity end wall 32. That is, the frame 50, the first aerosolgenerating substrate layer 41 and the second aerosol-generating substrate layer 42 collectively define the cavity 30.

[0606] 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.

[0607] The frame 50 is depicted as a unitary component. However, the frame may be a two layer frame as shown in Figure 12 or a three layer frame as shown in Figure 15.

[0608] Figure 20 shows an exploded view of an aerosol-generating article 10 that is similar to the aerosol-generating article 10 of Figure 18 except that an aerosol-generating element 40 is positioned within the cavity 30 as described in relation to Figure 3. As previously described, the aerosol-generating element 40 is in the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate.

[0609] Figure 21 shows an exploded view of an aerosol-generating article 10 that is similar to the aerosol-generating article 10 of Figure 20, except that the cavity 30 contains an aerosol-generating substrate 47 in the form of a sheet of aerosol-generating material, in particular a corrugated sheet of homogenised tobacco material as described in relation to Figure 7. It will be appreciated that an aerosol-generating element in the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may be positioned in one or more channels defined by the corrugated sheet of homogenised tobacco material 47.

[0610] Figure 22 shows an exploded view of an aerosol-generating article 10 that is similar to the aerosol-generating article 10 of Figure 20 except that the aerosol-generating article 10 further comprises a filter element 60 positioned within the cavity 30.

[0611] The filter element 60 is positioned immediately upstream of the air outlet 12. The filter element 60 is made from cellulose acetate. The filter element 60 has a thickness and a width approximately the same as the thickness and width of the cavity 30, respectively. The filter element 60 has a length of about 6 millimetres. The collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate defining aerosol-generating element 40 fills the remaining volume of the cavity 30.

[0612] Figure 23 shows an aerosol-generating article 10 that is similar to the aerosol-generating article 10 of Figure 1 except that the aerosol-generating article 10 of Figure 23 comprises a first cavity 33 and a second cavity 34. Figure 24 shows an exploded view of the aerosol-generating article 10 of Figure 23.

[0613] The first cavity 33 is substantially empty and the second cavity 34 is substantially empty. The first cavity 33 has a length of 12 millimetres, a width of 6 millimetres, and a thickness of 2.7 millimetres. The second cavity 34 has a length of 12 millimetres, a width of 6 millimetres, and a thickness of 2.7 millimetres.

[0614] The frame 50 defines a frame first aperture extending through the thickness of the frame 50 and the frame first aperture at least partially forms the first cavity 33. The frame 50 defines a frame second aperture extending through the thickness of the frame 50 and the frame second aperture at least partially forms the second cavity 34. The frame 50 comprises dividing wall 57 which separates the first cavity 33 and the second cavity 34. The dividing wall 57 defines an aperture extending from the first cavity 33 to the second cavity 34. The aperture of the dividing wall 57 defines at least a portion of the airflow passage between the air inlet 11 and the air outlet 12.

[0615] The first planar external layer 24 overlies an end of the first cavity 33 and the second planar external layer 25 overlies an opposite end of the first cavity 33. That is, the frame 50, the first planar external layer 24 and the second planar external layer 25 collectively define the first cavity 33. The first planar external layer 24 overlies an end of the second cavity 34 and the second planar external layer 25 overlies an opposite end of the second cavity 34. That is, the frame 50, the first planar external layer 24 and the second planar external layer 25 collectively define the second cavity 34.

[0616] Figure 25 shows an exploded view of an aerosol-generating article 10 that is similar to the aerosol-generating article 10 of Figure 23 except that a first cavity aerosol-generating element 45 is positioned within the first cavity 33 and a second cavity aerosol-generating element 46 is positioned within the second cavity 34. Each of the aerosol-generating elements 45, 46 are in the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate.

[0617] Figure 26 shows an exploded view of an aerosol-generating article 10 that is similar to the aerosol-generating article 10 of Figure 25 except that the first cavity contains an aerosol-generating substrate 47 in the form of a sheet of aerosol-generating material, in particular a corrugated sheet of homogenised tobacco material, and the second cavity also contains an aerosol-generating substrate 47 in the form of a sheet of aerosol-generating material, in particular a corrugated sheet of homogenised tobacco material. It will be appreciated that an aerosol-generating element in the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may be positioned in one or more channels defined by the corrugated sheet of homogenised tobacco material 47 for one or both of the first and second cavities.

[0618] Figure 27 shows an exploded view of an aerosol-generating article 10 that is similar to the aerosol-generating article 10 of Figure 23 except that a first cavity aerosol-generating element 45 is positioned within the first cavity 33, a filter element 60 is positioned within the first cavity 33, and a second cavity aerosol-generating substrate 47 is positioned within the second cavity 34.

[0619] The filter element 60 is positioned immediately upstream of the air outlet 12. The filter element is made from cellulose acetate. The filter element 60 has a thickness and a width approximately the same as the thickness and width of the first cavity 33, respectively. The filter element 60 has a length of about 4 millimetres.

[0620] It will be appreciated that the first cavity aerosol-generating element 45 may be in the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate. It will also be appreciated that an aerosol-generating element in the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate may be positioned within the second cavity 34 to overlie or be overlaid by the second cavity aerosol-generating substrate 47. Figure 28 shows an exploded view of an aerosol-generating article 10 that is similar to the aerosol-generating article 10 of Figure 23 except that a filter element 60 is positioned within the air outlet 12 and a second cavity aerosol-generating element 46 is positioned within the second cavity 34. The filter element 60 is made from cellulose acetate and has the same dimensions as the air outlet 12. The first cavity 33 is empty. The second cavity aerosol-generating element 46 has the same form as the aerosol-generating element 40 of Figures 1 to 5.

[0621] Figure 29 shows an exploded view of an aerosol-generating article 10 that is similar to the aerosol-generating article 10 of Figure 23 except that the aerosol-generating article 10 further comprises a first aerosol-generating substrate layer 41 and a second aerosol-generating substrate layer 42 as described in relation to Figure 18.

[0622] 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.

[0623] 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 overlies an end of the first cavity 33 and the second aerosol-generating substrate layer 42 overlies an opposite end of the first cavity 33. That is, the frame 50, the first aerosol-generating substrate layer 41 and the second aerosolgenerating substrate layer 42 collectively define the first cavity 33. The first aerosol-generating substrate layer 41 overlies an end of the second cavity 34 and the second aerosol-generating substrate layer 42 overlies an opposite end of the second cavity 34. That is, the frame 50, the first aerosol-generating substrate layer 41 and the second aerosol-generating substrate layer 42 collectively define the second cavity 34. An aerosol-generating element in the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate (for example, as described for the aerosol-generating element 40 of Figures 1 to 5) may be located in one or both cavities 33, 34.

[0624] Figure 30 shows an exploded view of an aerosol-generating article 10 similar to the aerosol-generating article 10 of Figure 29 except that a first cavity aerosol-generating element 45 is positioned within the first cavity 33 and a second cavity aerosol-generating element 46 is positioned within the second cavity 34. It will be appreciated that one or both aerosol-generating elements 45, 46 may be in the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate - for example, as described for the aerosol-generating element 40 of Figures 1 to 5. The first cavity aerosol-generating element 45 may comprise an aerosol-generating material in the form of tobacco cut filler and have an aerosol-former content of 5 percent by weight on a dry weight basis. The first cavity aerosol-generating element 45 fills the entire volume of the first cavity 33. The second cavity aerosol-generating element 46 may comprise an aerosolgenerating material in the form of tobacco cut filler and have an aerosol-former content of 5 percent by weight on a dry weight basis. The second cavity aerosol-generating element 46 fills the entire volume of the second cavity 34.

[0625] Figure 31 shows an aerosol-generating article 10 similar to the aerosol-generating article 10 of Figures 18 and 29 except that the aerosol-generating article 10 of Figure 31 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. Figure 32 shows, for illustration purposes, the aerosol-generating article 10 of Figure 31 in which the outer wrapper 23 has been unwrapped to expose a portion of the peripheral wall 51 of the frame 50. The outer wrapper 23 is cigarette paper.

[0626] Figure 33 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 33 comprises a first external corner 71 and a second external corner 72 that are rounded. However, it would be understood that one or both of the first external corner 71 and the second external corner 72 could be chamfered. Figures 34 and 35 show a plan view and an exploded view of the aerosol-generating article 10 of Figure 33, respectively.

[0627] The first external corner 71 extends from the first planar external surface 21 to the second planar external surface 22 and comprises a first corner surface 76 connecting a first end face 73 of the aerosol-generating article 10 and a first side face 74 of the aerosol-generating article 10. In more detail, the first end face 73 connects to the first corner surface 76 at a first corner transition region 82. A first corner internal angle 01 formed between a tangent 81 of the first end face 73 at the first corner transition region 82 and a tangent 83 of the first corner surface 76 at the first corner transition region 82 is between 90 degrees and 180 degrees.

[0628] The second external corner 72 extends from the first planar external surface 21 to the second planar external surface 22 and comprises a second corner surface 77 connecting the first end face 73 of the aerosol-generating article 10 and a second side face 75 of the aerosolgenerating article 10. In more detail, the first end face 73 connects to the second corner surface 77 at a second corner transition region 85. A second corner internal angle 02 formed between a tangent 84 of the first end face 73 at the second corner transition region 85 and a tangent 86 of the second corner surface 77 at the second corner transition region 85 is between 90 degrees and 180 degrees.

[0629] Figure 36 shows a cross-sectional view in the x / y plane of the aerosol-generating article 10 of Figure 33 taken through the intersection between the first planar external layer 24 and the frame 50. The cavity 30 comprises a first corner 35, a second corner 36, a third corner 37 and a fourth corner 38 which each extend in the z-direction and are rounded.

[0630] Figure 37 shows an exploded view of an aerosol-generating article that is similar to the aerosol-generating article 10 of Figure 33 except that an aerosol-generating element 40 is positioned within the cavity 30. The aerosol-generating element 40 is in the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate (for example, as described in relation to the embodiment of Figures 1 to 5).

[0631] Figure 38 shows an aerosol-generating article 10 similar to the aerosol-generating article 10 of Figures 33 and 37 except that the aerosol-generating article 10 of Figure 38 further comprises a first aerosol-generating substrate layer 41 and a second aerosol-generating substrate layer 42 as described in relation to Figure 18.

[0632] Figure 39 shows an aerosol-generating article 10 similar to the aerosol-generating article 10 of Figure 1 except that the air inlet 11 is defined by the first planar external surface 21 and extends through the first planar external layer 24.

[0633] Figure 40 shows an aerosol-generating article 10 similar to the aerosol-generating article 10 of Figure 10 except that the air inlet 11 is defined by the first planar external surface 21 and extends through the outer wrapper 23.

[0634] Figure 41 shows an aerosol-generating article 10 similar to the aerosol-generating article 10 of Figure 18 except that the air inlet 11 is defined by the first planar external surface 21 and extends through the first planar external layer 24 and the first aerosol-generating substrate layer 41.

[0635] Figure 42 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.

[0636] Figure 43 shows a schematic cross-sectional view of the aerosol-generating device 90 of Figure 42 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 aerosol-generating article 10 and the second heater 96 heats the second planar external surface 22 of the aerosolgenerating article, and as a result the aerosol-generating element 40 located within the article 10 is heated. Volatile components of the aerosol-generating element 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 aerosol-generating element has been depleted of volatile components, the aerosolgenerating article 10 is removed from the cavity 1000 and disposed of.

[0637] Figure 44 depicts a schematic illustration of a method of manufacturing 1100 an aerosolgenerating article 10 as described herein and, in particular, a method of manufacturing the aerosolgenerating article 10 of Figure 3. The method comprises punching and bonding a first sheet of frame material 1201 , a first sheet of external layer material 1301 and a second sheet of external layer material 1302. Figure 45 depicts a schematic plan view of the method of Figure 44 but for illustration purposes the manufacturing equipment is not depicted. The dotted line 1101 in Figure 45 is for illustration purposes and represents the eventual cross-sectional perimeter of the aerosolgenerating article 10.

[0638] The first sheet of frame material 1201 is fed from a bobbin 1102 between a first pair of rollers 1103 and a second pair of rollers 1104. An aperture punching device 1105 punches a frame aperture 1400 through the first sheet of frame material 1201 . The frame aperture 1400 will at least partially form the cavity 30 of the aerosol-generating article 10. An adhesive applying device 1106 applies an adhesive to a lower surface of the first sheet of frame material 1201 . The first sheet of external layer material 1301 is fed from a bobbin 1102 via a roller 1107 and is bonded to the first sheet of frame material 1201 by the adhesive applied to the lower surface of the first sheet of frame material 1201. An aerosol-generating substrate dispensing device 1108 dispenses an aerosolgenerating element 40 into the frame aperture 1400, the aerosol-generating element 40 having the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate. An adhesive applying device 1109 applies an adhesive 1110 to an upper surface of the first sheet of frame material 1201 . The second sheet of external layer material 1302 is fed from a bobbin 1102 via a roller 1107 and is bonded to the first sheet of frame material 1201 by the adhesive 1110 applied to the upper surface of the first sheet of frame material 1201 . An aperture punching device 1111 punches an aperture 1410 through the first sheet of frame material 1201 , the first sheet of external layer material 1301 and the second sheet of external layer material 1302 so as to eject an aerosol-generating article 10. The air inlet and air outlet may be formed before or after the aerosol-generating article 10 has been ejected. In some embodiments, one or more of the first sheet of frame material 1201 , the first sheet of external layer material 1301 and the second sheet of external layer material 1302 comprises an aerosol-generating substrate.

[0639] Figure 46 depicts a schematic illustration of a method of manufacturing 1100 an aerosolgenerating article 10 as described herein and, in particular, a method of manufacturing the aerosolgenerating article 10 of Figure 18. The method comprises punching and bonding a first sheet of frame material 1201 , a first sheet of aerosol-generating material 1501 , a second sheet of aerosolgenerating material 1502, a first sheet of external layer material 1301 and a second sheet of external layer material 1302. Figure 47 depicts a schematic plan view of the method of Figure 46 but for illustration purposes the manufacturing equipment is not depicted. The dotted line 1101 in Figure 47 is for illustration purposes and represents the eventual cross-sectional perimeter of the aerosol-generating article 10.

[0640] The first sheet of frame material 1201 fed from a bobbin 1102 between a first pair of rollers 1103 and a second pair of rollers 1104. An aperture punching device 1105 punches a frame aperture 1400 through the first sheet of frame material 1201 . The frame aperture 1400 will at least partially form the cavity 30 of the aerosol-generating article 10.

[0641] An adhesive applying device 1106 applies an adhesive 1110 to a lower surface of the first sheet of frame material 1201 and to an upper surface of the first sheet of frame material 1201 .

[0642] The first sheet of aerosol-generating material 1501 is fed from a bobbin 1102 via a roller 1107 and is bonded to the first sheet of frame material 1201 by the adhesive applied to the lower surface of the first sheet of frame material 1201 . The second sheet of aerosol-generating material 1502 is fed from a bobbin 1102 via a roller 1107 and is bonded to the first sheet of frame material 1201 by the adhesive 1110 applied to the upper surface of the first sheet of frame material 1201.

[0643] An adhesive applying device 1109 applies an adhesive 1110 to a lower surface of the first sheet of aerosol-generating material 1501 and to an upper surface of the second sheet of aerosolgenerating material 1502.

[0644] The first sheet of external layer material 1301 is fed from a bobbin 1102 via a roller 1107 and is bonded to the first sheet of aerosol-generating material 1501 by the adhesive applied to the lower surface of the first sheet of aerosol-generating material 1501 . The second sheet of external layer material 1302 is fed from a bobbin 1102 via a roller 1107 and is bonded to the second sheet of aerosol-generating material 1502 by the adhesive 1110 applied to the upper surface of the second sheet of aerosol-generating material 1502.

[0645] An aperture punching device 1111 punches an aperture 1410 through the first sheet of frame material 1201 , the first sheet of aerosol-generating material 1501 , the second sheet of aerosol-generating material 1502, the first sheet of external layer material 1301 and the second sheet of external layer material 1302 so as to eject the aerosol-generating article 10. The air inlet and air outlet may be formed before or after the aerosol-generating article 10 has been ejected. Figure 48 depicts a schematic illustration of a method of manufacturing 1100 an aerosolgenerating article 10 as described herein and, in particular, a method of manufacturing the aerosolgenerating article 10 of Figure 12 comprising an aerosol-generating element 40 positioned within the cavity 30. The method comprises punching and bonding a first sheet of frame material 1201 , a second sheet of frame material 1202, a first sheet of external layer material 1301 and a second sheet of external layer material 1302. Figure 49 depicts a schematic plan view of the method of Figure 48 but for illustration purposes the manufacturing equipment is not depicted. The dotted line 1101 in Figure 49 is for illustration purposes and represents the eventual cross-sectional perimeter of the aerosol-generating article 10.

[0646] The first sheet of frame material 1201 is fed from a bobbin 1102 between a first pair of rollers 1103 and a second pair of rollers 1104. An adhesive applying device 1106 applies an adhesive 1110 to an upper surface of the first sheet of frame material 1201. The second sheet of frame material 1202 is fed from a bobbin 1102 via a roller 1107 and is bonded to the first sheet of frame material 1201 by the adhesive 1110 applied to the upper surface of the first sheet of frame material 1201 .

[0647] An aperture punching device 1105 punches a frame aperture 1400 through the first sheet of frame material 1201 and the second sheet of frame material 1202. The frame aperture 1400 will at least partially form the cavity 30 of the aerosol-generating article 10.

[0648] An adhesive applying device 1106 applies an adhesive to a lower surface of the first sheet of frame material 1201 . The first sheet of external layer material 1301 is fed from a bobbin 1102 via a roller 1107 and is bonded to the first sheet of frame material 1201 by the adhesive applied to the lower surface of the first sheet of frame material 1201 .

[0649] An aerosol-generating element dispensing device 1108 dispenses an aerosol-generating element 40 into the frame aperture 1400, the aerosol-generating element 40 having the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate. An adhesive applying device 1109 applies an adhesive 1110 to an upper surface of the second sheet of frame material 1202. The second sheet of external layer material 1302 is fed from a bobbin 1102 via a roller 1107 and is bonded to the second sheet of frame material 1202 by the adhesive 1110 applied to the upper surface of the second sheet of frame material 1202.

[0650] An aperture punching device 1111 punches an aperture 1410 through the first sheet of frame material 1201 , the second sheet of frame material 1202, the first sheet of external layer material 1301 and the second sheet of external layer material 1302 so as to eject an aerosolgenerating article 10. The air inlet and air outlet may be formed before or after the aerosolgenerating article 10 has been ejected.

[0651] In some embodiments, one or more of the first sheet of frame material 1201 , the second sheet of frame material 1202, the first sheet of external layer material 1301 and the second sheet of external layer material 1302 comprises an aerosol-generating substrate. Figure 50 depicts a schematic illustration of a method of manufacturing 1100 an aerosolgenerating article 10 as described herein and, in particular, a method of manufacturing the aerosolgenerating article 10 of Figure 15 comprising an aerosol-generating element 40 positioned within the cavity 30. The method comprises punching and bonding a first sheet of frame material 1201 , a second sheet of frame material 1202, a third sheet of frame material 1203, a first sheet of external layer material 1301 and a second sheet of external layer material 1302. Figure 51 depicts a schematic plan view of the method of Figure 50 but for illustration purposes the manufacturing equipment is not depicted. The dotted line 1101 in Figure 51 is for illustration purposes and represents the eventual cross-sectional perimeter of the aerosol-generating article 10.

[0652] The first sheet of frame material 1201 is fed from a bobbin 1102 between a first pair of rollers 1103 and a second pair of rollers 1104. An aperture punching device 1112 punches an air inlet aperture 1610 and an air outlet aperture 1620 through the first sheet of frame material 1201 .

[0653] An adhesive applying device 1106 applies an adhesive 1110 to a lower surface of the first sheet of frame material 1201 and to an upper surface of the first sheet of frame material 1201 .

[0654] The second sheet of frame material 1202 is fed from a bobbin 1102 via a roller 1107 and is bonded to the first sheet of frame material 1201 by the adhesive applied to the lower surface of the first sheet of frame material 1201 . The third sheet of frame material 1203 is fed from a bobbin 1102 via a roller 1102 and is bonded to the first sheet of frame material 1201 by the adhesive 1110 applied to the upper surface of the first sheet of frame material 1201 .

[0655] An aperture punching device 1105 punches a frame aperture 1400 through the first sheet of frame material 1201 , the second sheet of frame material 1202 and the third sheet of frame material 1203. The frame aperture will at least partially form the cavity 30 of the aerosol-generating article 10.

[0656] An adhesive applying device 1106 applies an adhesive to a lower surface of the second sheet of frame material 1202. The first sheet of external layer material 1301 is fed from a bobbin 1102 via a roller 1107 and is bonded to the second sheet of frame material 1202 by the adhesive applied to the lower surface of the second sheet of frame material 1202.

[0657] An aerosol-generating element dispensing device 1108 dispenses an aerosol-generating element 40 into the frame aperture 1400, the aerosol-generating element 40 having the form of a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate. An adhesive applying device 1109 applies an adhesive 1110 to an upper surface of the third sheet of frame material 1203. The second sheet of external layer material 1302 is fed from a bobbin 1102 via a roller 1107 and is bonded to the third sheet of frame material 1203 by the adhesive 1110 applied to the upper surface of the third sheet of frame material 1203.

[0658] An aperture punching machine 1111 punches an aperture 1410 through the first sheet of frame material 1201 , the second sheet of frame material 1202, the third sheet of frame material 1203, the first sheet of external layer material 1301 and the second sheet of external layer material 1302 so as to eject the aerosol-generating article 10. 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 being defined by an article length, an article width, and an article thickness, the article width being greater than the article thickness, the aerosol-generating article comprising: a first external surface and an opposing second external surface; a cavity located within the aerosol-generating article between the first external surface and the second external surface; a frame positioned between the first external surface and the second external surface, the frame at least partially defining the cavity; and an airflow passage defined through the aerosol-generating article between an air inlet and an air outlet, the airflow passage extending through the cavity, wherein a collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate is disposed within the cavity, wherein each shred, strip, strand or extrusion of the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate occupies less than 1 % of an enclosed volume of the cavity, for example less than 0.5% of the enclosed volume of the cavity, for example less than 0.2% of the enclosed volume of the cavity, for example less than 0.05% of the enclosed volume of the cavity; for example less than 0.01 % of the enclosed volume of the cavity.

2. An aerosol-generating article according to claim 1 , wherein the shreds, strips, strands or extrusions of aerosol-forming substrate are aligned along a length direction of the aerosolgenerating article.

3. An aerosol-generating article according to either one of claim 1 or claim 2, wherein the shreds, strips, stands or extrusions of aerosol-forming substrate are aligned to extend between the air inlet and the air outlet.

4. An aerosol-generating article according to any one of claims 1 to 3, wherein the aerosolforming substrate comprises or consists of tobacco, for example, shreds, strips, stands or extrusions of cut filler.

5. An aerosol-generating article according to any one of claims 1 to 4, wherein the aerosolforming substrate comprises or consists of non-tobacco material, for example shredded nontobacco plant material.

6. An aerosol-generating article according to any one of claims 1 to 5, wherein the aerosolforming substrate comprises an aerosol-former, for example an aerosol former selected from the list consisting of glycerine and propylene glycol, for example in which the aerosol-forming substrate has an aerosol-former content of at least 10 wt % on a dry weight basis, for example greater than 20 wt %, for example greater than 25 wt %, or greater than 30 wt %, for example greater than 35 wt %.

7. An aerosol-generating article according to any one of claims 1 to 6, wherein the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate has a mass in a range of between 50 mg and 300 mg, for example between 100 mg and 200 mg , for example between 125 mg and 175 mg, for example between 140 mg and 160 mg, for example about 140 mg, or about 150 mg or about 160 mg.

8. An aerosol-generating article according to any one of claims 1 to 7, wherein at least one of the following criteria are met: a) at least 80%, or at least 85%, or at least 90%, or at least 95%, or all of the shreds, strips, strands or extrusions of aerosol-forming substrate have a length in a range of between 0.5 and 30 millimetres, for example between 0.5 and 20 millimetres, for example between 0.5 and 15 millimetres, for example between 0.8 and 10 millimetres, for example between 0.8 and 5 millimetres; and / or. b) at least 80%, or at least 85%, or at least 90%, or at least 95%, or all of the shreds, strips, strands or extrusions of aerosol-forming substrate have a width in a range of between 0.3 and 4 millimetres, for example between 0.3 and 3 millimetres, for example between 0.3 and 2 millimetres, for example between 0.6 and 1 .2 millimetres, for example between 0.6 and 0.9 millimetres.

9. An aerosol-generating article according to any one of claims 1 to 8, wherein the cavity contains a single unitary collection of unbound shreds, strips, strands or extrusions of aerosolforming substrate.

10. An aerosol-generating article according to any one of claims 1 to 9, wherein the cavity contains two or more collections of unbound shreds, strips, strands or extrusions of aerosolforming substrate, for example wherein the composition of a first collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate disposed within the cavity is different to the composition of a second collection of unbound shreds, strips, strands or extrusions of aerosolforming substrate disposed within the cavity.

11. An aerosol-generating article according to any one of claims 1 to 10, wherein the cavity comprises a filled portion and an empty portion, the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate confined to the filled portion of the cavity.

12. An aerosol-generating article according to any one of claims 1 to 11 , wherein the shreds, strips, strands or extrusions of the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate are arranged to intermesh with each other, preferably wherein one or more first shreds, strips, strands or extrusions of the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate is aligned relative to one or more second shreds, strips, strands or extrusions of the collection of unbound shreds, strips, strands or extrusions of aerosolforming substrate at an acute angle of between 45 degrees and 90 degrees, for example between 60 degrees and 90 degrees, for example between 75 degrees and 90 degrees.

13. An aerosol-generating article according to any one of claims 1 to 12, wherein the first exterior wall and the second exterior wall define respective first and second outwardly convexexterior surfaces, for example the first and second outwardly convex exterior surfaces collectively defining a lenticular profile.

14. An aerosol-generating article according to any one of claims 1 to 13, wherein one or more susceptor materials are arranged in thermal communication with the collection of unbound shreds, strips, strands or extrusions of aerosol-forming substrate.

15. An aerosol-generating article according to any one of claims 1 to 14, wherein at least one of the first external surface and the second external surface is a substantially planar surface, for example in which the first external surface is a substantially planar surface, for example in which both the first external surface and the second external surface is a substantially planar surface.

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