Aerosol-generating material

Abstract

An aerosol-generating material in the form of a body comprising two or more channels extending through the body, each channel of the two or more channels being defined by a continuous perimeter wall, wherein the body comprises a foaming agent.

Description

[0001] Aerosol-generating material

[0002] Technical Field

[0003] The present application relates to aerosol-generating compositions, articles for use in non-combustible aerosol provision devices comprising the aerosol-generating compositions and to non-combustible aerosol provision systems comprising such articles and devices.

[0004] Background

[0005] Aerosol-generating systems produce an aerosol during use, which is inhaled by a user. For example, tobacco heating devices heat an aerosol-generating material such as tobacco to form an aerosol by heating, but not burning, the aerosol-generating material.

[0006] Summary

[0007] According to a first aspect, there is provided an aerosol-generating material in the form of a body comprising two or more channels extending through the body, each channel of the two or more channels being defined by a continuous perimeter wall, wherein the body comprises a foaming agent.

[0008] In some embodiments, the foaming agent is in an amount of less than or equal to about 20 wt%. For example, the foaming agent is in an amount of less than or equal to about 10 wt, or less than or equal to about 5 wt%.

[0009] In some embodiments, the foaming agent is hydroxypropyl methylcellulose (HPMC).

[0010] In some embodiments, the foaming agent is a starch.

[0011] According to a second aspect, there is provided an aerosol-generating material in the form of a body comprising two or more channels extending through the body, each channel of the two or more channels being defined by a continuous perimeter wall, wherein the aerosol-generating material is porous.

[0012] In some embodiments, the body comprises an active, one or more binders and one or more aerosol formers. In some embodiments, the active comprises nicotine. For example, the active may comprise nicotine in an amount of less than about 5 wt%, for example less than about 3 wt% or less than about 2 wt%.

[0013] In some embodiments, the active consists of nicotine. For example, the active may consist of nicotine in an amount of less than about 5 wt%, for example less than about 4 wt%, less than about 3 wt%, or less than about 2 wt%.

[0014] In some embodiments, the aerosol-generating material comprises a botanical material.

[0015] In some embodiments, the botanical material comprises tobacco in an amount of about 50 to about 90 wt%. For example, the botanical material may comprise tobacco in an amount of about 60 wt% to 80 wt%.

[0016] In some embodiments, the botanical material comprises a non-tobacco material in an amount of about 20 to about 90 wt%. For example, the botanical material may comprise the non-tobacco material in an amount of about 30 to about 80 wt %. The botanical material may comprise the non-tobacco material in an amount of about 40 to about 60 wt%.

[0017] In some embodiments, the one or more aerosol formers are in an amount of about 5 to about 30 wt%. The one or more aerosol formers may be glycerol and propylene glycol, for example. The one or more aerosol formers may be in an amount of less than about 20 wt%.

[0018] In some embodiments, the body comprises one or more binders. For example, the body may comprise one or more binders in an amount of less than about 20 wt% or less than about 15 wt%. The one or more binders may be in an amount of about 10 wt%. The one or more binders may be in an amount of less than about 10 wt%. The one or more binders may comprise amylopectin, and a gum, such as Curdlan gum, for example. Optionally, the one or more binders may not comprise glucomannan.

[0019] In some embodiments, the body comprises water in an amount less than about 15 wt%. For example, the body may comprise water in an amount less than about 12 wt%, or less than about 10 wt%, or less than about 8 wt%, or less than about 6 wt%. The body may comprise water in an amount less than about 5 wt%, or less than about In some embodiments, the body comprises modified starch. For example, the body comprises modified starch in an amount of less than about 10 wt%, or less than about 8 wt%, or less than or equal to about 6 wt%.

[0020] In some embodiments, the body comprises calcium carbonate. For example, the calcium carbonate is in the form of chalk. The body may comprise chalk in an amount of less than about 10 wt %, or less than or equal to about 5 wt%.

[0021] In some embodiments, the body is an extruded body. Optionally, the extruded body is in the form of a rod.

[0022] In some embodiments, the body comprises a filler. Optionally, the filler may comprise carboxymethylcellulose (CMC). The body may comprise the filler in an amount of less than 10 wt%. For example, the body may comprise the filler in an amount of less than 5 wt%, or less than or equal to about 3 wt%.

[0023] In some embodiments, the body comprises a flavour. For example, the body may comprise a flavour in an amount of less than about 10 wt%.

[0024] In some embodiments, the body comprises a width / diameter of about 5 mm to about 12 mm and / or a length of about 3 mm to about 20 mm.

[0025] In some embodiments, the total surface area of the peripheral walls of the two or more channels is from about to about 40 mm2to about 1000 mm2per mm length of the body.

[0026] In some embodiments, the total surface area of the peripheral walls of the channels is from about 40mm2to about 1000mm2per mm length of the body.

[0027] In some embodiments, wherein two, or more than two, or all of the channels comprises a cross-sectional area of at least 0.1 mm2to about 1mm2. For example, the channels may have a cross-sectional area from about 0.05mm2to about 0.5mm2, or from about 0.1mm2to about 0.4mm2. The channels may have a cross-sectional area of from about 0.1mm2to about 0.3mm2.

[0028] In some embodiments, the volume of the two or more channels is from about 1mm3to about 5mm3. For example, the volume of the two or more channels may be from about 2 mm3to about 4 mm3, or about 3mm3. Optionally, the volume of the two or more channels may be from about 1mm3to about 5mm3, or from about 2mm3to about 4mm3, or about 3mm3when the body has a length of about 12mm.

[0029] In some embodiments, the body comprises a cavity for receiving an aerosol generator of an aerosol provision device.

[0030] In some embodiments, the cavity has a width or diameter of about 1mm to about 10mm. For example, the cavity may have a width or diameter of about 1.5mm to about 8mm. The cavity may have a width or diameter of from about 2mm to about 6mm.

[0031] In some embodiments, the cavity extends into the body by a length that is about 5% to about 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20% or 10% of the total length of the body.

[0032] In some embodiments, the cavity has a circular, square, triangular, hexagonal, pentagonal, heptagonal, octagonal, or oblong cross-sectional shape.

[0033] In some embodiments, the body comprises a series of radial walls and a series of bridging walls connecting the radial walls to form a series of concentric substantially circular walls. For example, the series of concentric substantially circular walls may comprise three or more concentric substantially circular walls.

[0034] In some embodiments, the series of concentric substantially circular walls comprises three substantially circular walls.

[0035] In some embodiments, the average weight of the body is less than or equal to 230mg. For example, the average weight of the body may be less than or equal to 225mg.

[0036] The average weight of the body may be less than or equal to 220mg. Optionally, the average weight of the body is less than or equal to 230mg when the body has a length of about 12mm.

[0037] According to a third aspect, there is provided an article for use with a non-combustible aerosol provision device, the article comprising the aerosol-generating material of any of the above embodiments. According to a fourth aspect, there is provided a process for preparing an aerosolgenerating material, the process comprising providing a precursor material comprising a foaming agent; and extruding the precursor material to provide the aerosolgenerating material. Optionally, the extruded precursor material is dried to provide the aerosol-generating material.

[0038] In some embodiments, extrusion of the precursor material is carried out at ambient temperature.

[0039] In some embodiments, the precursor material is a slurry. Optionally, the bulk density of the slurry is less than or equal to 0.35g / cm3. For example, the bulk density of the slurry may be less than or equal to 0.34g / cm3, 0.33g / cm3, 0.32g / cm3, 0.31g / cm3, or 0.30g / cm3. The bulk density of the slurry may be about 0.30g / cm3.

[0040] According to a fifth aspect, there is provided an aerosol-generating material produced by a process of any of the above embodiments.

[0041] According to a sixth aspect, there is provided a process for preparing an article according to the third aspect.

[0042] According to a seventh aspect, there is provided a system comprises an aerosolgenerating material according to the above embodiments and an aerosol-provision device or a system comprising an article comprising the aerosol-generating material and an aerosol-provision device.

[0043] According to an eighth aspect, there is provided a use of an aerosol-generating material according to the above embodiments with an aerosol provision system.

[0044] Brief Description of the Drawings

[0045] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0046] Figures la and lb are perspective views of two different bodies of aerosol generating material;

[0047] Figure 2 is an end-on view of the upstream ends of different bodies of aerosolgenerating material;

[0048] Figure 3 is a flow chart showing the key steps in process for preparing the aerosolgenerating material described herein; Figure 4 is a cross-sectional view of a consumable comprising aerosol-generating material as described herein;

[0049] Figure 5 is a cross-sectional view of an aerosol provision system comprising the consumable shown in Figure 4;

[0050] Figure 6 is a schematic view of a non-combustible aerosol provision device; and Figure 7 is a flow chart showing the steps in manufacturing a consumable comprising the aerosol-generating material as described herein.

[0051] Detailed Description

[0052] In the figures described herein, like reference numerals are used to illustrate equivalent features, articles or components.

[0053] Figure la is a perspective view of an aerosol generating material 1 in the form of a body 2. The body 2 comprises a cavity 3a for receiving an aerosol generator of an aerosol provision device, two channels 4a, 4b extending through the body 2, each channel 4a, 4b being defined by a continuous perimeter wall 5a, 5b.

[0054] The channels 4a, 4b extend from inlets 6a, 6b at an upstream end of the body 2, through the body 2 and terminate in outlets 7a, 7b at a downstream end of the body 2. The channels 6a, 6b are configured to allow fluid, such as air and / or aerosol, to pass through the body 2 between the upstream end and the downstream end. Although in this embodiment the body 2 comprises two channels 4a, 4b, additional channels may be provided in other embodiments. Increasing the number of channels increases the total surface area of the aerosol-generating material and therefore improves the efficiency of aerosol generation.

[0055] The terms 'upstream' and 'downstream' used herein are relative terms defined in relation to the direction of mainstream aerosol drawn through an aerosol-generating material, article or device in use.

[0056] The body 2 of aerosol-generating material 1 has a width, which is the longest straight line distance between a first point on the peripheral edge of the upstream end to a second point on the peripheral edge of the upstream end. Where the body 2 is in the form of a rod, the width is equivalent to the diameter of the upstream end of the rod.

[0057] In the present example, the body 2 of aerosol-generating material 1 is in the form of a rod which has a diameter of about 7 mm and a length of about 12 mm. The width / diameter of the body of aerosol-generating material may be from about 2 mm to about 20 mm, about 3 mm to about 16 mm, about 4 mm to about 14 mm, about 5 mm to about 12 mm or about 6 to about 10 mm.

[0058] The body of aerosol-generating material can have a length of from about 1 mm to about 30 mm, from about 2 mm to about 25 mm or from about 3 mm to about 20 mm. The body of aerosol-generating material can have a length of about 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm or 20 mm. The body of aerosol-generating material can be formed by cutting a longer body of aerosolgenerating material to the desired length.

[0059] In some embodiments the body of aerosol-generating material has a width / diameter of from about 5 mm to about 8 mm and a length of from about 5 mm to about 15 mm.

[0060] In the present example, the continuous perimeter wall 5a, 5b of the channels 4a, 4b is configured to fluidly isolate the channels 6a, 6b from each other. In embodiments comprising more than two channels, the continuous perimeter wall may be configured to fluidly isolate some or all of the channels from each other. Thus, some or all of the channels may be fluidly isolated from some or all of the other channels. For example, some or all of the channels may be configured such that fluid contained in one channel may not be able to pass into another channel without the fluid first exiting the body (e.g. through the outlets).

[0061] The cavity 3a for receiving an aerosol generator of an aerosol provision device comprises an opening 3b at the upstream end of the body 2 to allow for the aerosol generator to be inserted into the cavity 3a and is defined by a wall 3c extending from the perimeter edge of the opening 3b into the body 2. In the present example, the wall 3c of the cavity 3a extends along the full length of the body 2. In some embodiments, the wall 3c of the cavity 3a does not extend along the full length of the body 2, but terminates within the body 2 and so may be referred to as a blind cavity. The cavity 3a may extend into the body by a length that is equal to or about 5% to about 90%, 80%, 70%, 60%, 50%, 40%, 30% 20% or 10% of the total length of the body 2. The depth of the cavity and the width of the cavity may be adapted during manufacturing of the body 2 to suit the width and length of the aerosol-generator to be inserted into the cavity. The cavity 3a is configured (e.g. it has a suitable cross-sectional area and volume) to receive an aerosol generator, such as a heating pin or blade, of an aerosol provision device.

[0062] The cavity 3a may have a width / diameter of from about 1 mm to about 10 mm, about 1.5 mm to about 8 mm or from about 2 mm to about 6 mm. In some embodiments, the cavity has a width / diameter of from about 1.5 mm to about 5 mm or about 2 mm to about 4 mm. A cavity width of around 2 to about 4 mm may be a good compromise between the amount of volume occupied by the cavity and the aerosolgenerated in use by the aerosol-generating material.

[0063] In some embodiments the body of aerosol-generating material has a width / diameter of about 7 mm and a length of about 12 mm.

[0064] As set out previously, the cavity is suitable for receiving an aerosol generator of an aerosol provision device. An aerosol generator is an apparatus configured to cause aerosol to be generated from the aerosol-generating material. The aerosol generator can be a heater configured to subject the aerosol-generating material to heat energy, so as to release one or more volatiles from the aerosol-generating material to form an aerosol. The aerosol generator may be configured to cause an aerosol to be generated from the aerosol-generating material without heating. For example, the aerosol generator may be configured to subject the aerosol-generating material to one or more of vibration, increased pressure, or electrostatic energy.

[0065] When the aerosol generator is inserted into the cavity 3a, the aerosol generator can rapidly heat up the body 2 of aerosol generating material 1. The walls 5a, 5b of the channels 4a, 4b are relatively close to the aerosol generator and have a relatively large surface area. The heat generated by the aerosol generator causes the aerosolgenerating material 1 to release aerosol, which subsequently travels downstream through the channels 4a, 4b to the downstream end of the body.

[0066] The channels 4a, 4b are configured to convey a fluid from the upstream end to the downstream end the body 2. The fluid may be an aerosol. The aerosol-generating material generates an aerosol that flows from the upstream end of the body 2 to the downstream end of the body through the channels 4a, 4b.

[0067] The channels 4a, 4b are defined by the perimeter walls 5a, 5b, which extend from the upstream end to the downstream end of the body 1. The upstream end of the perimeter walls 5a, 5b also define, respectively, the inlets 6a, 6b. The downstream end of the perimeter walls 5a, 5b also define, respectively, the outlets 7a, 7b. The perimeter walls 5a, 5b produce aerosol when the aerosol-generating material is heated to a temperature that is sufficient to generate the aerosol.

[0068] As noted above, in the present example, the body 2 of aerosol-generating material 1 has a length of around 12 mm. The total surface area of the walls 5a, 5b can be calculated by adding the area of the walls 5a, 5b. The total surface area of walls 5a, 5b can be from about 50 mm2to around 10000 mm2, from around 100 mm2to around 5000 mm2or from around 500 mm2to about 3000 mm2. Increasing the number of channels may increase the total surface area of the walls and thus increase aerosol generation efficiency. A total surface area of around 1200 mm2to around 1400 mm2provided by 36 channels and a body 12 mm long has been found to be particularly effective at generating aerosol without compromising the structural integrity of the body. The 36 channels may be arranged between a series of concentric substantially circular walls. For example, the 36 channels may be arranged between a series of three concentric substantially circular walls. A body comprising three concentric substantially circular walls may each have a thickness which maintains rigidity of the body whilst also allowing improved release of aerosol. The thickness of each of the substantially circular walls may, for example, be from about 0.2mm to about 2mm. The thickness of each of the substantially circular walls may be from about 0.5mm to about 1mm. The concentric substantially circular walls may be connected by a series of radially extending walls. The radially extending walls (also termed 'radial walls') may have the same thickness as the concentric substantially circular walls. The radially extending walls may have a thickness less than the thickness of the concentrically substantially circular walls. The series of concentric substantially circular walls may be formed by a series of bridging walls which connect the radially extending walls. Each of the bridging walls may be straight such that the series of concentric walls have a cross-sectional shape which approximates to a circle. Each of the bridging walls may be arcuate such that the series of concentric walls have a circular cross-sectional shape. The channels of the body are located between the series of radial walls and the series of bridging walls.

[0069] The total surface area of the walls of the channels per mm length of the body can be from about 20 mm2to about 5000 mm2per mm length of body, from about 30 mm2to about 2000 mm2per mm length of body, from about 40 mm2to about 1000 mm2per mm length of body, from about 50 mm2to about 500 mm2per mm length of body, from about 60 mm2to about 250 mm2per mm length of body, or from about 80 mm2to 120 mm2.

[0070] The two or more channels may have a volume of from about 1mm3to about 5mm3, from about 2 mm3to about 4 mm3, or about 3mm3. Optionally, the two or more channels may have a volume of from about 1mm3to about 5mm3, or from about 2mm3to about 4mm3, or about 3mm3when the body has a length of about 12mm.

[0071] Compared to a body without channels (i.e. a body that only has a cavity for receiving the aerosol generator), the aerosol-generating material 1 produces aerosol more efficiently because aerosol can rapidly enter the channels 4a, 4b and move through the body towards the downstream end. Furthermore, as the aerosol generator heats the body 2 radially and the channels 4a, 4b are relatively close to the aerosol generator when it is inserted in the cavity 3a, the heat does not need to conduct through the complete volume of the body 2 in order for the aerosol to be released. Thus, the rate of aerosolisation may be improved.

[0072] Although not shown in Figure la or lb, the aerosol-generating material is porous. The porous body may comprise pores of a size that allow release of the aerosol from the aerosol-generating material. For example, the pores may have an average pore size of less than about 0.5mm, for example less than about 0.3mm, or less than about 0.1mm, or less than or equal to about 0.08mm, or less than or equal to about 0.06mm, or less than or equal to about 0.04mm, or less than or equal to about 0.02mm, or less than or equal to about 10pm, or less than or equal to about 5pm. The term 'average pore size' used herein relates to the smallest dimension within a given pore shape, that is, the diameter for a cylindrical pore and the width between two opposite walls for a slit-shaped pore. The term 'pore' used herein relates to regions of the porous body that are devoid of material. For example, the body comprises portions of aerosol-generating material forming the body and portions that are voids between the portions of the aerosol-generating material. The pore sizes may vary along the length and I or width of the body. Alternatively, the pore sizes may be substantially consistent along the length and I or width of the body.

[0073] The pores may be distributed uniformly along the length and I or width of the body. In this arrangement, aerosol can be readily released uniformly along the length and I or width of the body. The distribution of pores can be varied across the width of the body, for example, a central or inner portion of the body (nearest the cavity) may have a greater number of pores compared to an outer portion of the body. Thus, in this arrangement the inner or central portion of the body may generate aerosol more readily than the outer portion of the body. Alternatively, an outer portion of the body may have a greater number of pores compared to a central or inner portion of the body. Thus, the porosity characteristics of the body may be altered as desired.

[0074] The surface area to volume ratio is greater for a porous body compared to a body without pores. Thus, air that is drawn into the porous body may be heated quicker than in a non-porous body, which leads to improved aerosol generation. The surface area to volume ratio of the porous body may be at least 10 to 1. For example, the surface area to volume ratio of the porous body may be about 50 to 1, about 100 to 1, about 150 to 1, about 200 to 1, about 250 to 1, about 300 to 1, about 350 to 1, about 400 to 1, about 450 to 1, about 500 to 1, about 550 to 1, about 600 to 1, about 650 to 1, about 700 to 1.

[0075] In some embodiments, the porous body may have an open cell porosity. The term 'open cell porosity' refers to an arrangement in which the pores are at least partially connected. This is particularly favourable for fluid transport within the body. The body may comprise an open cell porosity of from about 20% to about 90% void volume to material volume. For example, the body may comprise an open cell porosity of from about 30% to about 80% void volume to material volume. The body may comprise an open cell porosity of about 40%, about 50%, about 60% or about 70% void volume to material volume. When the body comprises an open cell porosity of less than about 75% void volume to material volume, for example less than about 65% void volume to material volume, this may achieve a good compromise between providing improved aerosol generation and maintaining sufficient structural rigidity of the body.

[0076] The pores within the porous body may create a tortuous path through the body. This arrangement may allow fluid to meander through the body. The pores may connect with one or more channels. In some cases, the pores may allow two or more channels to interconnect. Thus, the body may provide both direct fluid paths through the channels, and indirect fluid paths through the pores.

[0077] The porous body may be less dense than a non-porous body. For example, the porous body may be from about 10 to about 50% less dense than a non-porous body. The body may be about 25% less dense than a non-porous body. The porous body may also be lighter than a non-porous body. For example, the porous body may be from about 5% to about 20% lighter than a non-porous body. The body may be about 10% lighter than a non-porous body. Whilst the porous body may advantageously have a lower density and weight compared to a non-porous body, the porous body maintains or increases the release of aerosol compared to the non-porous body, and thus the user experience is maintained or improved.

[0078] The cavity 3a may be shaped to receive the aerosol-generator such that when the aerosol-generator is received by the cavity 3a, the aerosol-generator is in contact with the wall 3c of the cavity 3a. This may improve the efficiency of heating of the aerosolgenerating material when the aerosol-generator is activated (e.g. when the aerosolgenerator is emitting heat). The cavity 3a and / or cavity opening 3b may be shaped to receive the aerosol-generator without deforming or damaging the body.

[0079] Where the body is rod-shaped, it may have a circular cross-section and the centre of the cavity may be approximately equidistant from an outer surface of the rod. Where the body has a non-circular cross-section, the cavity may be in the geometric centre, or centroid, of cross-section of the body. This may ensure that heat is distributed as evenly as possible throughout the aerosol-generating material when the aerosol generator is activated.

[0080] Figure lb is a perspective view of an aerosol generating material 1 in the form of a body 2. As with the embodiment shown in Figure la, the body 2 comprises two or more channels 4a, 4b, as previously described. Unlike the embodiment shown in Figure la, in the embodiment shown in Figure lb, the body 2 does not comprise a cavity for receiving an aerosol generator of an aerosol provision device. The aerosolgenerating material 1 may still be used with an aerosol provision device comprising an aerosol-generator in the form of a blade or pin, but rather than inserting the blade or pin into a cavity, the blade or pin can be inserted into the body 2 by deforming the aerosol-generating material. The channels 4a, 4b may facilitate the deformation of the body 2 during insertion of the blade or pin. Increasing the number of channels 4a, 4b may decrease the structural rigidity of the body 2 but improve the ease by which an aerosol generator may be inserted into the body 2 and yet still facilitate aerosol generation and delivery of the aerosol through the body 2. Further, since the body comprises a foaming agent, the pores within the body also facilitate the deformation of the body 2 during insertion of the blade or pin.

[0081] The aerosol-generating material 1 may also be used with an aerosol provision device that heats the aerosol-generating material from the "outside in" (i.e. by heating the outer surface of the body 2). When used with such an aerosol generating device, the aerosol generator heats the outer surface of the body 2. As the heat does not need to conduct through the complete volume of the body 2 in order for the aerosol to be released, aerosol may be more efficiently generated compared with a body that does not comprise channels.

[0082] In the embodiments described above, the aerosol-generating material is in the form of a rod. In some embodiments, the body may, for example, be in the form of a disc, a cube or a cuboid. The channels may confer the body with honeycomb or honeycomblike structure (e.g. the upstream end of the body 2 may have a honeycomb appearance when viewed from the upstream end of the body 2). The channels may have a regular cross-sectional shape or an irregular cross-sectional shape. The cross- sectional shape of the channels may be circular, square, hexagonal, pentagonal, heptagonal, octagonal or oblong. Decreasing the cross-sectional area of the channels 4a, 4b may reduce the volume of the channels 4a, 4b to allow for the body 2 to comprise more channels. Increasing the number of channels may increase the surface area of the body 2 and thus increase the efficiency of aerosol generation.

[0083] The channels may have a cross-sectional area of at least about 0.01 mm2to about 1 mm2, from about 0.05 mm2to about 0.5 mm2, from about 0.1 mm2to about 0.4 mm2or from about 0.1 mm2to about 0.3 mm2. One or more of the channels may have a different cross-sectional area from the other channels or each channel may have the same cross-sectional area.

[0084] Figure 2 shows the upstream end of various different bodies 2 of aerosol-generating material having different numbers and shapes of channels and channel inlets 6a. The cavity 3a may have any suitable cross-sectional area, but is typically larger in cross- sectional area than the cross-section area of each of the channels 4a, 4b in order to accommodate the aerosol generator. As shown, in these embodiments, the cavity 3a may be circular or have a hexagonal cross-section. The cross-sectional shape of the cavity may be, for example, circular, square, triangular, hexagonal, pentagonal, heptagonal, octagonal or oblong. These shapes may improve the structural rigidity of the body 2. The cavity may be defined by one or more cavity walls.

[0085] The body 2 may comprise a series of concentric substantially circular walls. The series of concentric substantially circular walls may comprise an outermost substantially circular wall forming an exterior surface of the body, and one or more inner substantially circular walls, whereby an innermost substantially circular wall may form a surface closest to the one or more cavity walls. As used herein, the term "aerosol-generating material" describes a material that is capable of generating aerosol, for example when heated, irradiated or energized in any other way. Aerosol-generating material may, for example, be in the form of a solid, liquid or semi-solid (such as a gel) which may or may not contain an active substance and / or flavourants.

[0086] The aerosol-generating material may comprise one or more active substances (sometimes referred to as "actives" herein) and / or flavours, one or more aerosolformer materials, filler and optionally one or more other functional material.

[0087] The aerosol-generating material may comprise a binder, such as a gelling agent, and an aerosol former. Optionally, a substance to be delivered and / or filler may also be present. Optionally, a solvent, such as water, is also present and one or more other components of the aerosol-generating material may or may not be soluble in the solvent. In some embodiments, the aerosol-generating material comprises a botanical material. In particular, in some embodiments, the aerosol-generating material is substantially tobacco free. In some embodiments, the aerosol-generating material comprises tobacco. In some embodiments, the aerosol-generating material comprises rooibos.

[0088] The binder may be selected from one or more compounds selected from the group comprising alginates, pectins, starches (and derivatives), amylose, amylopectin, celluloses (and derivatives), gums, silica or silicones compounds, clays, polyvinyl alcohol, a polysaccharide such as galactomannan or glucomannan, a gum such as acacia gum, curdlan gum, xanthan gum, pullulan, gellan gum, tragacanth gum, gum karaya, and combinations thereof.

[0089] Where present, the filler may include one or more organic fillers, such as wood pulp, cellulose, cellulose derivatives (e.g. microcrystalline cellulose, methylcellulose, ethyl cellulose, hydroxypropyl cellulose, and carboxymethylcellulose (CMC)) and a metal carbonate, such as calcium carbonate. In certain instances, the amorphous solid does not contain calcium carbonate, such as chalk.

[0090] The aerosol-generating material may comprise or be an "amorphous solid". In some embodiments. The amorphous solid may be a "monolithic solid". The amorphous solid may be substantially non-fibrous. In some embodiments, the amorphous solid may be a dried gel. The amorphous solid is a solid material that may retain some fluid, such as liquid, within it. The amorphous solid may be substantially tobacco free.

[0091] The aerosol-generating material may comprise an active. An active as used herein may be a physiologically active material, which is a material intended to achieve or enhance a physiological response. The active substance may for example be selected from nutraceuticals, nootropics, psychoactives. The active substance may be naturally occurring or synthetically obtained. The active substance may comprise for example nicotine, caffeine, taurine, theine, vitamins such as B6 or B12 or C, melatonin, cannabinoids, or constituents, derivatives, or combinations thereof. The active substance may comprise one or more constituents, derivatives or extracts of tobacco, cannabis or another botanical.

[0092] The active substance may be a legally permissible recreational drug.

[0093] The active substance may comprise nicotine. In some embodiments, the active substance comprises caffeine, melatonin or vitamin B12.

[0094] As noted, the active substance may comprise one or more constituents, derivatives or extracts of cannabis, such as one or more cannabinoids or terpenes.

[0095] The active substance may be CBD or a derivative thereof.

[0096] The active may be derived from one of more botanicals, such as one or more of the botanicals described herein. The active substance may comprise or be derived from one or more botanicals or constituents, derivatives or extracts thereof.

[0097] The aerosol-generating material may comprise, consist and / or be formed from a botanical material. As used herein, the term "botanical" includes any material derived from plants including, but not limited to, extracts, leaves, bark, fibres, stems, roots, seeds, flowers, fruits, pollen, husk, shells or the like. Alternatively, the material may comprise an active compound naturally existing in a botanical, obtained synthetically. The material may be in the form of liquid, gas, solid, powder, dust, crushed particles, granules, pellets, shreds, strips, sheets, or the like.

[0098] Example botanicals are tobacco, eucalyptus, star anise, hemp, cocoa, cannabis, fennel, lemongrass, peppermint, spearmint, rooibos, chamomile, flax, ginger, ginkgo biloba, hazel, hibiscus, laurel, licorice (liquorice), matcha, mate, orange skin, papaya, rose, sage, tea such as green tea or black tea, thyme, clove, cinnamon, coffee, aniseed (anise), basil, bay leaves, cardamom, coriander, cumin, nutmeg, oregano, paprika, rosemary, saffron, lavender, lemon peel, mint, juniper, elderflower, vanilla, Wintergreen, beefsteak plant, curcuma, turmeric, sandalwood, cilantro, bergamot, orange blossom, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, geranium, mulberry, ginseng, theanine, theacrine, maca, ashwagandha, damiana, guarana, chlorophyll, baobab or any combination thereof. The mint may be chosen from the following mint varieties: Mentha Arventis, Mentha c.v., Mentha niliaca, Mentha piperita, Mentha piperita citrata c.v., Mentha piperita c.v, Mentha spicata crispa, Mentha cardifolia, Memtha longifolia, Mentha suaveolens variegata, Mentha pulegium, Mentha spicata c.v. and Mentha suaveolens.

[0099] In particular, the botanical material may selected from tobacco, eucalyptus, star anise, cocoa and hemp, rooibos and fennel.

[0100] The aerosol-generating material may not comprise tobacco and / or may not comprise tobacco-derived material. In some embodiments, the aerosol-generating material is substantially free from tobacco or tobacco derived material.

[0101] The aerosol-generating material may comprise a flavour. As used herein, the terms "flavour" and "flavourant" refer to materials which, where local regulations permit, may be used to create a desired taste, aroma or other somatosensorial sensation in a product for adult consumers. They may include naturally occurring flavour materials, botanicals, extracts of botanicals, synthetically obtained materials, or combinations thereof (e.g., tobacco, cannabis, licorice (liquorice), hydrangea, eugenol, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, maple, matcha, menthol, Japanese mint, aniseed (anise), cinnamon, turmeric, Indian spices, Asian spices, herb, Wintergreen, cherry, berry, red berry, cranberry, peach, apple, orange, mango, clementine, lemon, lime, tropical fruit, papaya, rhubarb, grape, durian, dragon fruit, cucumber, blueberry, mulberry, citrus fruits, Drambuie, bourbon, scotch, whiskey, gin, tequila, rum, spearmint, peppermint, lavender, aloe vera, cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, khat, naswar, betel, shisha, pine, honey essence, rose oil, vanilla, lemon oil, orange oil, orange blossom, cherry blossom, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, wasabi, piment, ginger, coriander, coffee, hemp, a mint oil from any species of the genus Mentha, eucalyptus, star anise, cocoa, lemongrass, rooibos, flax, ginkgo biloba, hazel, hibiscus, laurel, mate, orange skin, rose, tea such as green tea or black tea, thyme, juniper, elderflower, basil, bay leaves, cumin, oregano, paprika, rosemary, saffron, lemon peel, mint, beefsteak plant, curcuma, cilantro, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, limonene, thymol, camphene), flavour enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and / or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example, liquid such as an oil, solid such as a powder, or gas.

[0102] In some embodiments, the flavour comprises menthol, spearmint and / or peppermint. In some embodiments, the flavour comprises flavour components of cucumber, blueberry, citrus fruits and / or redberry. In some embodiments, the flavour comprises eugenol. In some embodiments, the flavour comprises flavour components extracted from tobacco. In some embodiments, the flavour comprises flavour components extracted from cannabis.

[0103] In some embodiments, the flavour may comprise a sensate, which is intended to achieve a somatosensorial sensation which are usually chemically induced and perceived by the stimulation of the fifth cranial nerve (trigeminal nerve), in addition to or in place of aroma or taste nerves, and these may include agents providing heating, cooling, tingling, numbing effect. A suitable heat effect agent may be, but is not limited to, vanillyl ethyl ether and a suitable cooling agent may be, but not limited to eucolyptol or WS-3.

[0104] The flavour may be in the form of a flavour composition which comprises or consists of the flavour. The flavour composition may comprise the flavour and one or more other components, such as a flavour, or a solvent, such as water, ethanol, isopropanol, n- butanol, ethyl acetate, isopropyl acetate, butyl acetate, anisole, glycerol or propylene glycol. The inclusion of a solvent in the flavour composition may improve the homogeneity of the flavour in the aerosol-generating material and improve the absorption or adsorption of the flavour into the aerosol-generating material.

[0105] The aerosol-generating material may comprise an aerosol-former material. An aerosol-former material is a material that is capable of forming an aerosol. In some embodiments, the aerosol-former material may comprise one or more of glycerol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3- butylene glycol, erythritol, meso-Erythritol, ethyl vanillate, ethyl laurate, a diethyl suberate, triethyl citrate, triacetin, a diacetin mixture, benzyl benzoate, benzyl phenyl acetate, tributyrin, lauryl acetate, lauric acid, myristic acid, and propylene carbonate.

[0106] The aerosol-generating material may comprise one or more other materials. For example, the aerosol-generating material may comprise one or more of pH regulators, colouring agents, preservatives, binders, fillers, stabilizers, and / or antioxidants.

[0107] The aerosol-generating material may comprise particulate botanical material, such as tobacco or rooibos, a filler (e.g. microcrystalline cellulose or wood pulp), a binder (e.g. a cellulosic binder, such as carboxymethyl cellulose or a polysaccharide, such as glucomannan or amylopectin, or alginate) and aerosol former (e.g. glycerol and / or propylene glycol).

[0108] In some embodiments, the aerosol-generating material comprises a botanical material in an amount of 20 to 90% wt%, one or more binders in an amount of about 5 to 20 wt%, and one or more aerosol formers in an amount of about 5 to 30 wt%.

[0109] The aerosol-generating material comprises a foaming agent. The foaming agent aids in the formation of pores within the aerosol-generating material, thus forming a porous aerosol-generating material or body. The porous body may also be termed a foamed body, or a foam. The foaming agent generates gas bubbles which remain as pores within the aerosol-generating material and give rise to a sponge-like structure. In some embodiments, the foaming agent is in an amount of less than or equal to about 20 wt%. For example, the foaming agent is in an amount of less than or equal to about 15 wt%, 10 wt, 8 wt%, 6 wt% or 5 wt%.

[0110] The aerosol-generating material may comprise a foam stabilising agent. The foam stabilizing agent can reduce and even prevent breakdown of the foam after it has been formed. Put another way, the foam stabilizing agent can reduce the propensity of the surface tension of the liquid forming the bubbles of the foam to decrease.

[0111] The aerosol-generating material may comprise about lwt%, 1.5wt% or 2wt% to about 6 wt%, 8wt% or 10wt% of foam stabilising agent (all calculated on a dry weight basis). In exemplary embodiments, the aerosol-generating material comprises 1- 10wt%, 1.5-9wt% or 2-6wt% of foam stabilising agent (calculated on a dry weight basis). The foam stabilising agent may comprise one or more surfactants. In some embodiments, the one or more surfactants are each non-ionic, anionic or amphoteric. In some cases, the foam stabilising agent comprises sodium lauryl sulfate (SLS), Tween 60 (polyethylene glycol sorbitan monostearate), Tween 80 (polysorbate 80), Amphosol CA, Span 60 (sorbitan monosterate), Span 80 (sorbitan monooleate), lecithin or mixtures thereof.

[0112] The use of a foam stabilising agent can help formation of the foamed materials of the present invention. In particular, the foam stabilising agent can stabilise bubbles formed in the precursor material slurry and therefore help prevent the bubbles from collapsing when the slurry is dried. The use of a foam stabilising agent may therefore assist with the formation of porous aerosol-generating materials.

[0113] Surprisingly, when certain foam forming agents are used (e.g. HPMC), a foam stabilising agent is not needed, and a stable foam can be formed even without the use of a foam stabilising agent. Even when not essential, a foam stabilising agent may however still be used.

[0114] The aerosol-generating material may comprise an effervescent agent. The aerosolgenerating material may comprise from about lwt%, 2 wt% or 4wt% to about 7wt%, 8wt% or 10wt% of effervescent agent (all calculated on a dry weight basis). In exemplary embodiments, the aerosol-generating material comprises l-10wt%, 2- 8wt% or 4-7wt% of effervescent agent (all calculated on a dry weight basis).

[0115] The effervescent agent may comprise calcium carbonate, sodium carbonate, sodium bicarbonate, citric acid, tartaric acid, lactic acid, acetic acid, aluminium sulfate or mixtures thereof. Calcium carbonate may be used as a filler and an effervescent agent. When calcium carbonate is used in this way, it may be present in any amount, such as those disclosed above with respect to the filler.

[0116] By using an effervescent agent the precursor material slurry does not require mixing at high speed to aerate the slurry. This is particularly useful when a continuous process is used to form the aerosol-generating material.

[0117] Figure 3 is a flow chart showing the key steps in a process for preparing the aerosolgenerating material. A precursor material comprising a foaming agent is provided. The precursor material may additionally comprise an active, one or more binders and one or more aerosol formers. The precursor material is extruded to form the aerosol- generating material. Optionally, after the precursor material is extruded, the extruded material may be dried to provide the aerosol-generating material. In some embodiments, the extruded material may not need to be dried to form the aerosolgenerating material.

[0118] In some embodiments, water may be added to the precursor composition as a processing aid. For example, the presence of water may help to dissolve components of the precursor composition, and / or it may assist with binding or improve agglomeration. Water may be added in an amount of up to about 15 wt %, for example, about 12 wt%, about 11 wt%, about 10 wt%, about 9 wt%, about 8 wt%, about 7 wt%, about 6 wt%, about 5 wt%, about 4 wt% about 3 wt%, about 2 wt% or about 1 wt%.

[0119] In some embodiments, a flavour may be added to the precursor composition. The flavour may be added in an amount of up to about 10 wt%, for example, about 9 wt%, about 8 wt%, about 7 wt%, about 6 wt%, about 5 wt%, about 4 wt%, about 3 wt%, about 2 wt% or about 1%.

[0120] The precursor material comprises a foaming agent. The foaming agent creates pores in the aerosol-generating material, thus creating a porous body. The foaming agent may be a surfactant, for example sodium laureth sulfate (SLES) or a blowing agent, for example carbon dioxide. In some embodiments, the foaming agent may be hydroxypropyl methylcellulose (HPMC). In some embodiments, the foaming agent may be a starch. Examples of starches include corn starch, maize starch and oat starch. The starch may be provided in the form of particles or granules. The foaming agent advantageously reduces the density of the aerosol-generating material and increases the porosity of the aerosol-generating material.

[0121] All the components of the precursor material may be mixed together at ambient temperature before extrusion. The term 'ambient temperature' means that no heating is required. Typically, 'ambient temperature' is from about 15°C to about 25°C, for example, between about 18°C to 22°C. When the components of the precursor material which comprises the foaming agent are well mixed and extruded, this may produce an aerosol-generating material comprising homogeneously distributed pores throughout the length and / or width of the aerosol-generating material.

[0122] Extrusion may be performed using one of the main classes of extruders: screw, twin screw, sieve and basket, roll, and ram extruders. Forming the precursor material by extrusion has the advantage that this processing combines mixing, conditioning, homogenizing and moulding of the precursor composition.

[0123] During extrusion the mixture is forced though one or more orifices or openings to form an extruded material. In some embodiments, the extruded material has an elongated form and / or it may be cut into segments of a desired length as it exits the extruder. A rod-like extruded material may subsequently be cut into segments of desired length.

[0124] An extrusion die comprising one or more openings is selected to create the desired profile of the body. The die may, for example, comprise a series of radially extending openings and a series of openings that bridge between or connect the series of radially extending openings to form a series of concentric substantially circular openings. When the precursor material is forced through the openings of the die, the resulting extruded material comprises a series of concentric substantially circular walls connected by a series of radial walls. For example, one of the series of concentric substantially circular walls of the extruded material may form an outermost wall of the body of the aerosol-generating material. The die may also comprise solid regions which form channels within the extruded material. In particular, the channels may be formed between the concentric substantially circular walls of the extruded material. The extruded material may be formed such that the body comprises three or four concentric substantially circular walls, with one of the concentric substantially circular walls forming an outermost wall of the aerosol-generating material. The die may also comprise a central solid region which forms a cavity within the extruded material. The cavity may be defined by one or more cavity walls. As discussed previously, the cavity may not extend through the entire length of the aerosol-generating material. The central solid region of the die may have a circular, triangular, pentagonal, heptagonal or octagonal shaped cross section to form a cavity having the same cross- sectional shape.

[0125] The extruder may be operated without applying heat to the system (for example, at room / ambient temperature). The mixture may be exposed to pressures ranging from about 2 bar to about 200 bar, or from about 3 bar to about 100 bar, or from about 5 bar to about 60 bar, depending on the design of the die being used.

[0126] After the precursor material exits the die of the extruder, it may be dried, for example at room temperature, to provide the extruded material. The resulting extruded material is an aerosol-generating material comprising a porous body, for example, the porous body may be a foam. The extrusion may be a generally dry process, with the mixture being extruded being a substantially dry material.

[0127] The foaming agent may be added to the precursor material during the extrusion process. If the foaming agent is added continuously during the extrusion process, this may result in the pores being evenly distributed throughout the length and width of the aerosol-generating material.

[0128] Liquids may be added to the mixture during the extrusion process. For example, water may be added to the precursor composition, for example as a processing aid to assist dissolution or solubilisation of components of the composition, or to aid binding or agglomeration. Alternatively or additionally, a wetting agent may be added to the precursor composition.

[0129] The liquid may be an aerosol former material such as glycerol or others discussed herein. When liquid is added to the mixture in this manner, the liquid is applied not only on the surface, but, as a result of the extruder pressure combined with the intensive mixing by high shear forces, the extruded precursor material becomes impregnated with the liquid. Where the liquid is an aerosol former material, this can result in a high availability of the aerosol former material in the extruded precursor material to enhance evaporation of flavour components and other components of the final aerosol-forming material.

[0130] In some embodiments, the amount of aerosol former material incorporated into the precursor material and / or aerosol-generating material may be at least about 5% by weight, at least about 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% by weight, or at least about 20% by weight. In some embodiments, the amount of aerosol former material incorporated into the precursor material and / or aerosol-generating material may be up to about 15%, up to about 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29% by weight or up to about 30% by weight.

[0131] In some embodiments, aerosol former material is included in an amount of from about 5% to about 30% by weight of the precursor material and / or aerosol-generating material, for example, in an amount of from about 10% to about 30% by weight of the component. In some embodiments, the precursor material is a slurry. The term 'slurry' used herein means a semi-liquid mixture. Optionally, the bulk density of the slurry may be less than or equal to 0.35g / cm3. For example, the bulk density of the slurry may be less than or equal to 0.34g / cm3, 0.33g / cm3, 0.32g / cm3, 0.31g / cm3, or 0.30g / cm3.

[0132] The bulk density of the slurry may be about 0.30g / cm3.

[0133] The extruded precursor material may be shaped by the orifice or die through which it is forced. In some embodiments, the extruded precursor material is cut into pieces of desired length. The pieces formed in this way may be used as tobacco constituent releasing components or they may undergo further processing.

[0134] The orifice or die may be shaped to provide a strand of extruded precursor material. For example, the extruded precursor material may have the form of a cylindrical rod. Alternatively, the extruded precursor material may have different cross-sectional shapes, including oval, polygonal (such as triangular, square, etc.), and stars.

[0135] In some embodiments, the extruded precursor material is formed into a desired shape selected to enhance or promote the release of flavour, for example by providing a form having a large surface area per unit volume. This large surface area may be provided on the outer surface of the extruded precursor material, for example by selecting cross-sectional shapes with large perimeter.

[0136] The orifice or die may be shaped to provide an extruded precursor material with inner channels. As explained above, these inner channels provide further surface area and can enhance flavour release. The channel structure of the aerosol-generating material has enlarged inner surface area leading to improved heat and mass transfer. As a result, such components exhibit better, more uniform aerosol delivery. Furthermore, the structure with channels exhibits significantly improved strength in both the radial and axial directions, which is beneficial for the further processing of the aerosolgenerating material, for example when it is cut into segments.

[0137] By means of various die designs and / or different process parameters within the extruder, including the temperature, pressure and shear forces, extruded precursor materials with different physical properties may be prepared, including different heat transfer properties, draft resistance, and capable of producing different aerosols and / or of modifying aerosols being drawn through the extruded precursor material. The make up of the precursor composition can also play a significant role in determining the physical and mechanical properties of the extruded material and, as a consequence, of the tobacco constituent releasing components.

[0138] In some embodiments, the extruded precursor material is shaped upon discharge from the extruder. In some embodiments, the extruded precursor material is cut to an initial length, for example, 1 metre, before then being cut into sections of the desired length.

[0139] The aerosol-generating material may be incorporated into an article for use with a delivery system. An article is sometimes referred to as consumable throughout this disclosure.

[0140] As used herein, the term "delivery system" is intended to encompass systems that deliver at least one substance to a user, and includes non-combustible aerosol provision systems that release compounds from an aerosol-generating material without combusting the aerosol-generating material, such as electronic cigarettes, tobacco heating products, and hybrid systems to generate aerosol using a combination of aerosol-generating materials.

[0141] The article is for use in a non-combustible aerosol provision system. According to the present disclosure, a "non-combustible" aerosol provision system is one where a constituent aerosol-generating material of the aerosol provision system (or component thereof) is not combusted or burned in order to facilitate delivery of at least one substance to a user.

[0142] In some embodiments, the delivery system is a non-combustible aerosol provision system, such as a powered non-combustible aerosol provision system.

[0143] The non-combustible aerosol provision system can be an electronic cigarette, also known as a vaping device or electronic nicotine delivery system (END), although it is noted that the presence of nicotine in the aerosol-generating material is not a requirement.

[0144] The non-combustible aerosol provision system may be an aerosol-generating material heating system, also known as a heat-not-burn system. An example of such a system is a tobacco heating system. In some embodiments, the non-combustible aerosol provision system is a hybrid system to generate aerosol using a combination of aerosol-generating materials, one or a plurality of which may be heated. Each of the aerosol-generating materials may be, for example, in the form of a solid, liquid or gel and may or may not contain nicotine. In some embodiments, the hybrid system comprises a liquid or gel aerosolgenerating material and a solid aerosol-generating material. The solid aerosolgenerating material may comprise, for example, tobacco or a non-tobacco product.

[0145] Typically, the non-combustible aerosol provision system may comprise a noncombustible aerosol provision device and a consumable for use with the non- combustible aerosol provision device.

[0146] In some embodiments, the non-combustible aerosol provision system, such as a non- combustible aerosol provision device thereof, may comprise a power source and a controller. The power source may, for example, be an electric power source or an exothermic power source. In some embodiments, the exothermic power source comprises a carbon substrate which may be energised so as to distribute power in the form of heat to an aerosol-generating material or to a heat transfer material in proximity to the exothermic power source.

[0147] In some embodiments, the non-combustible aerosol provision system comprises an area for receiving the article for use in the non-combustible aerosol-provision system, a housing, a mouthpiece, a filter and / or an aerosol-modifying agent.

[0148] Referring to Figure 4, an article 16 includes aerosol-generating material as described herein. The aerosol-generating material 1 comprises a cavity 3a and channels 4a, 4b. The cavity 3a is located substantially centrally within the cross section of the aerosolgenerating material 1. The aerosol-generating material 1 is located within an aerosolgenerating material section 18, and thus the cavity 3a is located substantially centrally within the cross section of the aerosol-generating material section 18. The cavity 3a is suitable for receiving an aerosol-generator of a non-combustible aerosol provision device. Where cross-sections are referred to herein, these mean a cross-section taken in a plane perpendicular to the longitudinal direction through the article or component.

[0149] A first tubular element 17a defines a first portion of a hollow cavity 17c such that this overlaps with a portion of the cavity 3a and / or one or more channels 4a, 4b. For example, cavity 3a may entirely overlap with the first portion of the hollow cavity 17c defined by the first tubular element 17a, and channel 4b may overlap with the first portion of the hollow cavity 17c.

[0150] The cross-sectional area of overlap of the hollow cavity 17c of the tubular portion 17a, 17b and of the cavity 3a and the channels 4a, 4b is at least about 5mm2, at least about 6mm2, at least about 7mm2, or at least about 8mm2, optionally wherein the cross-sectional area of overlap is between 20% and 50% or between 30% and 45% of the total cross-sectional area of the cavity 3a and the channels 4a, 4b.

[0151] The article 16 comprises the aerosol-generating section 18 and a downstream section 19 downstream of the aerosol-generating section 18. The downstream section 19 can be or include a mouthpiece designed to be inserted into a user's mouth in use, or alternatively may be arranged to work with a separate mouthpiece such as one provided as a separate attachment to the downstream section 19 or as part of a noncombustible aerosol provision device. The downstream section 19 has an upstream end 19a and a downstream end 19b. In the present examples, the aerosol-generating section 18 comprises a source of aerosol-generating material in the form of a cylindrical rod of aerosol-generating material as described herein. The aerosolgenerating material can include at least 5% aerosol-former material by weight of the aerosol-generating material, calculated on a dry weight basis, the aerosol-former material being, for instance, one of the aerosol-former materials described herein.

[0152] Figure 5 is a cross-sectional illustration of the aerosol-generating material section 18 of Figure 4 respectively with the article in which it is provided inserted into a noncombustible aerosol provision device 21, illustrating the location of a pin heater 21a within the cavity 3a of section 18.

[0153] Referring to Figures 4 and 5, in the present examples, the receiving portion 20 is a recess in the device 21 including a pin-shaped heater 21a which penetrates the aerosol generating section 18. The pin-shaped heater 21a is resistively heated in the present example, although may alternatively be formed of a heating material as described herein which can be inductively heated, such as a susceptor, or make use of a pin-shaped heater which is heated in other ways. The pin-shaped heaters described herein can be in the general form of a cylinder which has a diameter of between 1.8 mm and 3 mm, or between 2.2 mm and 2.6 mm. The length of the pin-shaped heater can be between 11 mm and 20 mm, for instance between 15 mm and 18 mm. The length of the pin-shaped heater can be approximately 1 mm shorter than the combined length of the upstream body of material 22 and aerosol-generating material section 18. In other examples, the aerosol generating section 18 of the article 16 can include a heating material, for instance one which can be inductively heated, such as a susceptor.

[0154] The mouthpiece or downstream portion 19 includes the first tubular element 17a immediately downstream of the aerosol-generating material section 18, the first tubular element 17a defining a first portion of the hollow cavity 17c. In the present example, the first tubular element 17a is in an abutting relationship with the aerosolgenerating material. The first tubular element 17a has a first tubular wall. The mouthpiece or downstream portion 19 also includes a second tubular element 17b immediately downstream of the first tubular element 17a. In the present example, the second tubular element 17b is in an abutting relationship with the first tubular element 17a. The second tubular element 17b has a second tubular wall having a wall thickness of less than about 320 pm. The second tubular element 17b has an axial length of greater than about 15 mm, for instance between about 15 mm and about 25 mm. In the present example, a downstream body of material 23 is provided at the downstream end 19b of the downstream section 19. The first and second tubular elements 17a, 17b, and the downstream body of material 23, in the present example, each define a cylindrical outer shape and are arranged end-to-end on a common axis. The first and second tubular elements 17a, 17b, aerosol-generating material section 18 and body of material 23 have approximately the same outer diameter.

[0155] The upstream body of material 22 can be provided upstream of the aerosol-generating material section 18.

[0156] The first and second tubular elements 17a, 17b together define a chamber 17c into which aerosol formed in the aerosol-generating section 18 is drawn and expands and cools. The provision of discrete first and second tubular elements 17a, 17b enables these components to be designed to achieve different functional effects. For instance, the first tubular element 17a can be arranged to provide functions such as helping to reduce movement of the aerosol-generating material in use, as the article 16 is inserted into the recess 20 and the pin heater 21a penetrates the aerosol-generating material section 18. For this purpose, the first tubular element 17a can have a wall thickness of, for instance, between 1mm and 3.5mm, or between 1.5mm and 2.5mm. Alternatively or additionally, the first tubular element 17a can be arranged to help with providing rigidity to the article 16. Alternatively or additionally, the first tubular element 17a can be arranged to encourage aerosol to flow predominantly through an axial region of the second tubular element 17b, for instance to assist with aerosol formation. The second tubular element 17b can be designed to define a relatively large chamber as compared to the first tubular element 17a, providing greater space into which the aerosol formed in the aerosol-generating section 18 can be drawn to expand and cool. In addition, for a given weight of the second tubular element 17b, providing a relatively thin wall thickness of less than 320 pm enables material to be concentrated in the outer region of the second tubular element 17b, which can provide a higher bending stiffness as compared to components with thicker walls and the same weight. In some examples, articles may have the specific features set out in Table 1.0 below.

[0157] Table 1.0 Although in the present case, the downstream body of material 23 is provided at the mouth or downstream end 16b of the article 16, in other examples a further component can be provided downstream of the downstream body of material 23. For instance, a further body of material can be provided.

[0158] In the present examples, the first tubular element 17a has an axial length of about 7mm, but in other examples the first tubular element 17a can have an axial length between about 5mm and about 14mm. In the present examples, the first tubular element 17a has a wall thickness of about 1.6mm and an inner radius of the hollow cavity defined by the first tubular element 17a is about 1.95 mm. This results in a ratio between the thickness of the first tubular wall to the internal radius of the first hollow cavity of about 0.82. In other examples, the ratio of the thickness of the first tubular wall to the internal radius of the first hollow cavity can be between about 0.6 and about 1.1, or between about 0.7 and about 0.9.

[0159] In the present examples, the volume of the second portion of the hollow cavity 17c defined by the second tubular element 17b is about 588 mm3. The volume of the first portion of the hollow cavity 17c defined by the first tubular element 17a is about 84 mm3. The ratio of the volume of the second portion to the volume of the first portion is therefore about 7 times. The ratio of the volume of the second portion to the volume of the first portion can alternatively be between about 6.5 and about 8. This provides an arrangement in which aerosol can expand from a relatively small cavity within the first tubular element 17a into the much larger cavity of the second tubular element 17b. The second tubular element 17b can define a second portion of the hollow cavity 17c having a volume of at least about 520 mm3. The combined volumes of the first and second portions of the hollow cavity 17c can, for instance, be at least about 580 mm3, or at least about 620 mm3or at least about 650 mm3.

[0160] The second tubular wall can comprise at least first and second overlapping paper layers each extending around substantially the whole circumference of the second tubular element 17b. The at least first and second overlapping paper layers can each have a thickness of between 30 and 150 pm. Alternatively or in addition, the at least first and second overlapping paper layers can each have a basis weight of between 25 and 130 gsm. The at least first and second overlapping paper layers can be connected to each other by a layer of adhesive. The first and second overlapping paper layers can each be non-porous.

[0161] The aerosol-generating material section 18 can be in the form of a rod having an axial length which is less than or equal to the axial length of the second tubular element 17b. For instance, the aerosol-generating material section 18 can be in the form of a rod having an axial length which is between 50% and 80% of the axial length of the second tubular element 17b. These arrangements result in an article with a relatively large cavity size defined by the second tubular element 17b as compared to the volume occupied by the aerosol-generating material. Such a cavity can allow for improved expansion of the volume of aerosol passing though the article 16 and better aerosol formation. Preferably, ventilation apertures are provided into the wall of the second tubular element 17b such that cool air enters the cavity defined by the second tubular element 17b in use, further enhancing aerosol formation via condensation of aerosol components within the cavity 17c. The second tubular element 17b can have an axial length of greater than about 16mm or greater than about 16.5mm. For instance, in some examples, the second tubular element 17b can have an axial length which is at least 1.5 or at least 2 times greater than the axial length of the first tubular element 17a.

[0162] Use of a second tubular element 17b immediately downstream of the first tubular element 17a, which has a wall thickness of less than about 320 pm and an axial length of greater than about 15mm, can result in an article which has an overall weight which is lower than previous designs. In the present examples, the aerosol-generating material section 18 has a weight of between about 200 mg and about 280 mg and the non-aerosol-generating material components of the article 16 have a combined weight of about 320 mg. The total weight is therefore between about 520 grams and about 600 mg for an article 16 with an overall length of 54mm, resulting in an average weight of between 9.6 and 11.1 mg / mm. In some examples, the average weight per mm of axial length of the article can be less than about 12.5 mg / mm or less than about 12 mg / mm or less than about 11.5 mg / mm. In some examples, the average weight per mm of axial length of the article can be between 8.0 and 12.5 mg / mm, or between 9.0 and 11.5 mg / mm. The non-aerosol-generating material weight of the article can be between 45% and 55% of the overall article weight, for instance between 46% and 53%.

[0163] The tubular wall of the second tubular element 17b, in the present example, is formed from first and second overlapping paper sheets, resulting in an overall thickness of about 200pm. In alternative examples, the second tubular wall can have a thickness of between about 160pm and about 250 pm. The second hollow cavity defined by the second tubular element has a diameter of about 6.6mm and a radius 'r' of about 3.3mm. The second tubular wall can, for instance, have a thickness which is less than about 15% or less than about 10% of the internal radius 'r' of the second hollow cavity. As shown in Figure 6, the non-combustible aerosol provision device 21 and the article 16 together form a non-combustible aerosol provision system. The non-combustible aerosol provision device 21 includes a heating element 21a configured for insertion into the aerosol-generating material of the article 16. In the present example, the heating element 21a is a pin-shaped heater 21a which is insertable into the cavity 3a. The non-combustible aerosol provision device comprises a battery 21b, a processor 21c and a user interface 21d, such as a button, configured to operate the device 21. The device may comprise other components.

[0164] The non-combustible aerosol provision device 21 includes a housing 24 and an aperture 25 in the housing 24 into which the article 16 is inserted in use. The system is configured such that the second tubular element 17b extends partially within and partially outside the housing 24 when the article 16 is fully inserted into the non- combustible aerosol provision device 21, as shown in Figure 5. The system can be configured such that the second tubular element 17b extends at least about 5mm within and at least about 8mm outside the housing 24 when the article 16 is fully inserted into the non-combustible aerosol provision device 21. In the present example, the article 16 comprises aerosol-generating material section 18 having a length of about 12mm, a first tubular element 17a having a length of about 7mm and a second tubular element 17b having a length of about 17mm. The article 16 is inserted into the device 21 to an insertion depth of about 31mm, as shown by arrow 'B' in Figure 5. In the present case, about 6mm of the second tubular element 17b, between the upstream end 17b' of the second tubular element and the location 'B' on the article 16 aligned with the entrance to the recess 25 in the device 21, extends within the device. About 11mm of the second tubular element 17b, between the location 'B' on the article 16 aligned with the entrance to the recess 25 in the device 16 and the downstream end 17b" of the second tubular element 17b, extends outside the device 24 when the article 16 is fully inserted into the device 21.

[0165] The article 16 includes one or more ventilation apertures 16c extending through the second tubular element 17b at a location in the second tubular element 17b which is outside the housing 24 when the article 16 is fully inserted into the non-combustible aerosol provision device 24. The one or more ventilation apertures 16c can be provided as one or more rows of apertures, such as laser or mechanically formed perforations, circumscribing the article 16. In some examples, the level of ventilation is between about 10% and about 60%, for instance between about 20% and about 55% of the mainstream aerosol. In some examples, the body of aerosol-generating material 1 is a rod of aerosolgenerating material and is circumscribed by a wrapper 26. The wrapper 26 may be a moisture impermeable wrapper.

[0166] In the present example, the rod of aerosol-generating material has a circumference of about 22.7 mm. In alternative embodiments, the rod of aerosol-generating material may have any suitable circumference, for example between about 20 mm and about 26 mm.

[0167] The first tubular element 17a can be formed from filamentary tow, in the present example plasticised cellulose acetate tow. Other constructions can be used, such as a tubular element 17a formed having inner and outer paper tubes sandwiching a crimped paper sheet material. The wall of the first tubular element can be relatively non-porous, such that at least 80% of the aerosol generated by the aerosol generating material passes longitudinally through the hollow channels through the tube rather than through the wall material itself. For instance, at least 92% or at least 95% of the aerosol generated by the aerosol generating material can pass longitudinally through the first hollow cavity.

[0168] The filamentary tow forming the first tubular element 17a preferably has a total denier of between 25,000 and 45,000, preferably between 35,000 and 45,000. Preferably the cross-sectional shape of the filaments of tow are 'Y' shaped, although in other embodiments other shapes such as 'X' shaped filaments can be used.

[0169] The filamentary tow forming the first tubular element 17a preferably has a denier per filament between 4 and 10, more preferably between 4 and 9. In one example, the filamentary tow forming the first tubular element 17a has an 8Y40,000 tow formed from cellulose acetate and comprising 18% plasticiser, for instance triacetin.

[0170] Preferably, the density of the material forming the first tubular element 17a is at least about 0.20 grams per cubic centimetre (g / cc), more preferably at least about 0.25 g / cc. Preferably, the density of the material forming the first tubular element 17a is less than about 0.80 grams per cubic centimetre (g / cc), more preferably less than 0.6 g / cc. In some embodiments, the density of the material forming the first tubular element 17a is between 0.20 and 0.8 g / cc, more preferably between 0.3 and 0.6 g / cc, or between 0.4 g / cc and 0.6 g / cc or about 0.5 g / cc. These densities have been found to provide a good balance between improved firmness afforded by denser material and minimising the overall weight of the article. For the purposes of the present invention, the "density" of the material forming the first tubular element 17a refers to the density of any filamentary tow or other material forming the element with any plasticiser incorporated. The density may be determined by dividing the total weight of the material forming the first tubular element 17a by the total volume of the material forming the first tubular element 17a, wherein the total volume can be calculated using appropriate measurements of the material forming the first tubular element 17a taken, for example, using callipers. Where necessary, the appropriate dimensions may be measured using a microscope.

[0171] The first and second tubular elements 17a, 17b can be configured to provide a temperature differential of at least 40 degrees Celsius between a heated volatilised component entering a first, upstream end of the first and second tubular elements 17a, 17b and a heated volatilised component exiting a second, downstream end of the first and second tubular elements 17a, 17b. The first and second tubular elements 17a, 17b are preferably configured to provide a temperature differential of at least 60 degrees Celsius, preferably at least 80 degrees Celsius and more preferably at least 100 degrees Celsius between a heated volatilised component entering a first, upstream end of the first and second tubular elements 17a, 17b and a heated volatilised component exiting a second, downstream end of the first and second tubular elements 17a, 17b. This temperature differential across the length of the first and second tubular elements 17a, 17b protects the temperature sensitive downstream body of material 23 from the high temperatures of the aerosol-generating material when it is heated.

[0172] The aerosol-generating section 18 may exhibit a pressure drop of less than about 20 mm H2O. In some embodiments, the aerosol-generating section 18 exhibits a pressure drop across the aerosol-generating section 18 of from about 1 to about 15 mm H2O.

[0173] The resistance to draw or pressure drop through the length of a section, component or article as defined herein is determined according to the ISO standard method (ISO6565:2015). The resistance to draw or pressure drop refers to the 'closed pressure drop', in which any ventilation zones into the section, component or article under measurement are closed, unless otherwise stated.

[0174] The aerosol-generating material may have a packing density or bulk density of between about 400 mg / cm3and about 600 mg / cm3within the aerosol-generating section. A packing density higher than this may make it difficult to insert the aerosolgenerator of the aerosol provision device into the aerosol-generating material and increase the pressure drop. A packing density lower than 400 mg / cm3may reduce the rigidity of the article. Furthermore, if the packing density is too low, the aerosolgenerating material may not effectively grip the aerosol-generator of the aerosol provision device.

[0175] Between about 30% and about 50% of a volume of the aerosol-generating section 18 is composed of the aerosol-generating material. In some embodiments, from about 35% to about 45% of the volume of the aerosol-generating section 18 is filled with the aerosol-generating material, and the remainder is the cavity 3a and the channels 4a, 4b.

[0176] In the present embodiment, the moisture impermeable wrapper 26 which circumscribes the rod of aerosol-generating material comprises aluminium foil. In other embodiments, the wrapper 26 comprises a paper wrapper, optionally comprising a barrier coating to make the material of the wrapper substantially moisture impermeable. Where the wrapper comprises paper or a paper backing, i.e. a cellulose based material, the wrapper can have a basis weight greater than about 30 gsm. For example, the wrapper can have a basis weight in the range from about 40 gsm to about 70 gsm.

[0177] In the present example, the moisture impermeable wrapper 26 is also substantially impermeable to air. The wrapper 26 preferably has a permeability of less than 100 Coresta Units, more preferably less than 60 Coresta Units. It has been found that low permeability wrappers, for instance having a permeability of less than 100 Coresta Units, more preferably less than 60 Coresta Units, result in an improvement in the aerosol formation in the aerosol-generating material. The permeability of the wrapper 26 can be measured in accordance with ISO 2965:2009 concerning the determination of air permeability for materials used as cigarette papers, filter plug wrap and filter joining paper.

[0178] The downstream body of material 23 is wrapped in a first plug wrap 27. A second plug wrap 28 is provided to connect the downstream body of material 23 and second tubular element 17b. The upstream body of material 22 is wrapped in a third plug wrap 29. Preferably, the first, second and third plug wraps 27, 28, 29 each have a basis weight of less than 50 gsm, more preferably between about 20 gsm and 40 gsm. Preferably, the first, second and third plug wraps 27, 28, 29 each have a thickness of between 30 pm and 60 pm, more preferably between 35 pm and 45 pm. Preferably, the first, second and third plug wraps 27, 28, 29 are non-porous plug wraps, for instance having a permeability of less than 100 Coresta units, for instance less than 50 Coresta units. However, in other embodiments, the first, second and / or third plug wrap 27, 28, 29 can be a porous plug wrap, for instance having a permeability of greater than 200 Coresta Units.

[0179] A combining wrapper 30 is provided to connect the upstream body of material 22, aerosol generating material section 18 and first tubular element 17a. The combining wrapper 30 can have a basis weight of between about 30 gsm and about 70 gsm. Preferably, the combining wrapper 30 has a thickness of between 35 pm and 70 pm, more preferably between 40 pm and 60 pm. Preferably, the combining wrapper 30 is non-porous, for instance having a permeability of less than 100 Coresta units, for instance less than 50 Coresta units. However, in other embodiments, the combining wrapper 30 can be a porous wrapper, for instance having a permeability of greater than 200 Coresta Units.

[0180] The aerosol-generating material section 18 as described herein can be in the form of a cylinder comprising the aerosol-generating material. A first cylindrical element can be provided upstream of the aerosol-generating material section 18, for instance in the form of the upstream body of material 22. A second cylindrical element can be provided downstream of the aerosol-generating material section 18, for instance in the form of the first tubular element 17a. Advantageously, the first and second cylindrical elements can each have a diameter which is equal to or greater than the diameter of the aerosol-generating material section 18, thereby acting to protect the aerosolgenerating material section 18. For instance, the first and second cylindrical elements 17, 17a can act to support and / or protect the aerosol-generating material section 18 while it is wrapped in the combining wrapper 26. Furthermore, the first and second cylindrical elements 17, 17a can act to support and / or protect the aerosol-generating material section 18 while in use in the device 21, for instance reducing lateral forces on the aerosol-generating material section 18. For instance, the aerosol-generating material section 18 can be relatively fragile when formed from reconstituted botanical material or as a moulded component.

[0181] In some examples, the hardness of each of the first and second cylindrical elements 17, 17a is at least 78%, at least 80% or at least 82%. In some examples, the hardness of at least one of the first and second cylindrical elements 17, 17a is at least 86%, at least 90% or at least 92%. Such hardness levels can assist the first and second cylindrical elements 17, 17a in supporting and / or protecting the aerosolgenerating material section 18. Alternatively or in addition, the first and second cylindrical elements 17, 17a can each have a diameter which is greater than the diameter of the aerosol-generating material section 18, again helping to protect and / or support the section 18. For instance, the first and second cylindrical elements 17, 17a can each have a diameter which is at least 0.2 mm or 0.3 mm greater than the diameter of the aerosol-generating material section 18.

[0182] Figure 7 is a flow diagram illustrating a method of manufacturing an article for insertion into a non-combustible aerosol provision device to generate an aerosol. At step 100 an aerosol-generating material section 18 is provided in the form of a cylinder comprising aerosol-generating material, as well as first and second cylindrical elements each having a diameter equal to or greater than the diameter of the aerosolgenerating material section. At step 101, the aerosol-generating material section is arranged between the first and second cylindrical elements, for instance such that the first cylindrical element is upstream of the aerosol-generating material section and the second cylindrical element is downstream of the aerosol-generating material section. The first and second cylindrical elements can each have a diameter which is equal to or greater than the diameter of the aerosol-generating material section. At step 102, the aerosol-generating material section and the first and second cylindrical elements are wrapped in a combining wrapper. In further steps (not illustrated), the resulting combined rod can be aligned in an end-to-end configuration with a downstream portion 19, such as that described herein, and the combined rod and the downstream portion 19 connected using a further wrapper such as tipping paper 31.

[0183] Preferably, the length of the downstream body of material 23 is less than about 15 mm. More preferably, the length of the downstream body of material 23 is less than about 14 mm. In addition, or as an alternative, the length of the downstream body of material 23 is at least about 5 mm. Preferably, the length of the downstream body of material 23 is at least about 8 mm. In some preferred embodiments, the length of the downstream body of material 23 is from about 5 mm to about 15 mm, more preferably from about 8 mm to about 14 mm, even more preferably from about 10 mm to about 14 mm, most preferably about 10 mm, 11 mm or 12 mm. In the present example, the length of the downstream body of material 23 is 12 mm.

[0184] Preferably, the length of the upstream body of material 22 is less than about 10 mm. More preferably, the length of the upstream body of material 22 is less than about 8 mm. In addition, or as an alternative, the length of the upstream body of material 22 is at least about 5 mm. Preferably, the length of the upstream body of material 22 is at least about 6 mm. In some preferred embodiments, the length of the upstream body of material 22 is from about 5 mm to about 10 mm, more preferably from about 6 mm to about 8 mm. In the present example, the length of the upstream body of material 22 is 6 mm.

[0185] In the present example, the downstream body of material 23 is formed from filamentary tow. In the present example, the tow used in the downstream body of material 23 has a denier per filament (d.p.f.) of 3.5 and a total denier of 30,000. In the present example, the tow comprises plasticised cellulose acetate tow. The plasticiser used in the tow comprises about 8% by weight of the tow. In the present example, the plasticiser is triacetin. In other examples, different materials can be used to form the downstream body of material 23. For instance, rather than tow, the downstream body 23 can be formed from paper, for instance in a similar way to paper filters known for use in cigarettes. For instance, the paper, or other cellulose-based material, can be provided as one or more portions of sheet material which is folded and / or crimped to form the downstream body of material 23. The sheet material can have a basis weight of from 15gsm to 60gsm, for instance between 20 and 50 gsm. The sheet material can, for instance, have a basis weight in any of the ranges between 15 and 25 gsm, between 25 and 30 gsm, between 30 and 40 gsm, between 40 and 45 gsm and between 45 and 50 gsm. Additionally or alternatively, the sheet material can have a width of between 50mm and 200mm, for instance between 60mm and 170mm, or between 80mm and 150mm. For instance, the sheet material can have a basis weight of between 20 and 50 gsm and a width between 80mm and 180mm.

[0186] This can, for instance, enable the cellulose-based bodies to have appropriate pressure drops for an article having dimensions as described herein.

[0187] Alternatively, the downstream body 23 can be formed from tows other than cellulose acetate, for instance polylactic acid (PLA), other materials described herein for filamentary tow or similar materials. The tow is preferably formed from cellulose acetate. The tow, whether formed from cellulose acetate or other materials, preferably has a d.p.f. of at least 5. Preferably, to achieve a sufficiently uniform downstream body of material 23, the tow has a denier per filament of no more than 12 d.p.f., preferably no more than 11 d.p.f. and still more preferably no more than 10 d.p.f.

[0188] The total denier of the tow forming the downstream body of material 23 is preferably at most 35,000, more preferably at most 32,000 and still more preferably at most 30,000. These values of total denier provide a tow which takes up a reduced proportion of the cross-sectional area of the mouthpiece 19 which results in a lower pressure drop across the mouthpiece 19 than tows having higher total denier values. For appropriate firmness of the downstream body of material 23, the tow preferably has a total denier of at least 8,000 and more preferably at least 10,000. Preferably, the denier per filament is between 3 and 10 while the total denier is between 10,000 and 35,000. Preferably the cross-sectional shape of the filaments of tow are 'Y' shaped, although in other embodiments other shapes such as 'X' shaped filaments can be used, with the same d.p.f. and total denier values as provided herein.

[0189] Irrespective of the material used to form the downstream body 23, the pressure drop through the length of the downstream body 23, can, for instance, be between 0.3 and 5mmWG per mm of length of the downstream body 23, for instance between 0.5mmWG and 2.5mmWG per mm of length of the downstream body 23. The pressure drop can, for instance, be between 1.5 and 2.5mmWG / mm of length, on average. The total pressure drop across the downstream body 23 can, for instance, be between 12mmWG and 30mWG, or between 15mmWG and 25mmWG. Where the downstream body 23 includes an additive release component, the pressure drop refers to the average or total pressure drop prior to any rupture of that component.

[0190] The upstream body 22 can be formed from paper or other sheet material. For instance, the paper, or other cellulose-based material sheet, can be provided as one or more portions of sheet material which is folded and / or crimped to form the upstream body 22. The sheet material can have a basis weight of from 15gsm to 60gsm, for instance between 20 and 50 gsm, such as 36 gsm. The sheet material can, for instance, have a basis weight in any of the ranges between 15 and 25 gsm, between 25 and 30 gsm, between 30 and 40 gsm, between 40 and 45 gsm and between 45 and 50 gsm. Additionally or alternatively, the sheet material can have a width of between 50mm and 200mm, for instance between 80mm and 190mm, or between 100mm and 180mm. For instance, the sheet material can have a basis weight of between 20 and 50 gsm and a width between 120mm and 200mm. This can, for instance, enable the cellulose-based bodies to have appropriate pressure drops for an article having dimensions as described herein.

[0191] Irrespective of the material used to form the upstream body 22, the pressure drop through the length of the upstream body 22, can, for instance, be between 0.3 and 5mmWG per mm of length of the upstream body 22, for instance between 0.5mmWG and 2.5mmWG per mm of length of the upstream body 22. The pressure drop can, for instance, be between 1.0 and 2.0mmWG / mm of length, on average. The total pressure drop through the length of the upstream body 22 can, for instance, be between 6 mmH20 and 30 mmH20, or between 8 mmH20 and 20 mmH20, or between 6mmH2O and 12mmH2O. In some examples, the upstream body of material 22 has a resistance to draw through its length which is at least 15% or at least 20% of the resistance to draw through the length of the article 16. The resistance to draw and pressure drop of the upstream body of material 22 and of the aerosol-generating material section 18 as described herein are measured prior to the insertion of the article 16 into the non-combustible aerosol provision device 21.

[0192] The bulk density of the upstream body of material 22 can be between 0.1 and 0.3g / cm3, or between 0.15 and 0.25g / cm3. The upstream body of material 22 can be made from a sheet of material, such as paper or other fibrous material, having a width of between 100 mm and 240 mm, or between 150 mm and 200 mm.

[0193] The downstream body of material 23 downstream of the tubular portion 17a, 17b can define the downstream end 16b of the article 16. The upstream body of material 22 can define the upstream end 16a of the article 16. The resistance to draw through the length of the downstream body of material 23 can be higher than the resistance to draw through the length of the upstream body of material 22.

[0194] As illustrated in Figure 5, the device 21 can include a heating element 21a for insertion into the aerosol-generating material section 18 of the article 16 when the article 16 is inserted into the non-combustible aerosol provision device 21. The heating element 21a can be arranged for insertion into the aerosol-generating material section 18 of the article 16 when the article 16 is fully inserted into the non- combustible aerosol provision device 21. When this happens, the heating element 21a passes through the upstream body of material 22 and into the aerosol-generating material section 18. Advantageously, the resistance to draw through the length of the upstream body of material 22 can increase by at least 30%, at least 40% or at least 50% when the article 16 is fully inserted into the non-combustible aerosol provision device 21. This means that greater relative changes in pressure drop can be observed in the upstream body of material 22 than in the remainder of the article 16, making the change in pressure drop more predictable than that which may occur in the aerosol-generating material section 18. For instance, the percentage increase in the resistance to draw through the length of the upstream body of material 22 when the article 16 is fully inserted into the non-combustible aerosol provision device 21 can be greater than the overall percentage increase in the resistance to draw of the article 16 when fully inserted into the non-combustible aerosol provision device 21.

[0195] In some examples, when the article 16 is fully inserted into the non-combustible aerosol provision device 21 the article 16 has an insertion depth of at least 10 mm, for instance approximately 31 mm. Advantageously, the force required to insert the article 16 into the device 21 for the first time for each millimetre of the last 10 mm of the insertion depth changes by less than 300 grams force. By providing a stable insertion force in the final portion of the insertion depth, the consumer is provided with a clear tactile indication that the article can still be inserted further, up until the point at which the article is fully inserted. The force measurements can be made using a TA.XTPIusC Texture Analyser from Stable Micro Systems. The machine is set to Compression Mode with a pre-test speed of 1 mm / sec, a test speed of 2 mm / sec and a post-test speed of 5mm / sec and a Target Mode of 'Distance'.

[0196] The heating element 21a can have a width at its widest point of between about 1.5 mm and about 4 mm, or between about 2 mm and about 3 mm. The heating element 21a can have an insertion length of between about 10 mm and about 25 mm, or between about 15 mm and about 20 mm, for instance the portion of the heating element 21a which is within the article 16 when the article 16 is fully inserted into the device 21. The heating element 21a can, for instance, have an insertion length of at least 4 mm greater than the axial length of the aerosol-generating material section 18 of the article 16.

[0197] The average force required to insert the heating element 21a into each millimetre of length of the upstream body of material 22 can be less than 600 grams force, or less than 400 grams force or less than 300 grams force.

[0198] Having a relatively low insertion force means that the consumer is provided with a clearer tactile indication when the article 16 reaches the full insertion depth within the device 21 and the force required for further insertion is at that stage compressing the article 16. The relatively large increases in force from the low insertion forces to the relatively high compression force applied to the article once it is fully inserted, provide a clear indication to a consumer that they should stop applying force to the article. The force to compress the article axially by 2mm is advantageously at least 1500 grams force or at least 1800 grams force. A tipping paper 31 is wrapped around part of the downstream portion 19 and over part of the rod of aerosol-generating material and has an adhesive on its inner surface to connect the pre-combined downstream body 23 and second tubular element 17b, with the pre-combined first tubular element 17a, aerosol-generating material section 18 and upstream body of material 22. In the present example, the rod of aerosolgenerating material is wrapped in wrapper 26, which forms a first wrapping material, and the combining wrapper 30 forms an outer wrapper. In some examples, the tipping paper 31 can extend fully over the aerosol-generating material section 18.

[0199] In the present example, the tipping paper 31 extends 5 mm over the pre-combined first tubular element 17a, aerosol-generating material section 18 and upstream body of material 22, but it can alternatively extend between 3 mm and 10 mm over the rod, or more preferably between 4 mm and 6 mm, to provide a secure attachment. The tipping paper 31 can have a basis weight greater than 20 gsm, for instance greater than 25 gsm, or preferably greater than 30 gsm, for example 36 or 37 gsm. These ranges of basis weights have been found to result in tipping papers having acceptable tensile strength while being flexible enough to wrap around the article 16 and adhere to itself along a longitudinal lap seam on the paper.

[0200] The article 16 can have a ventilation level of about 20% of the total aerosol and ventilation drawn through the article 16. The article 16 preferably includes ventilation apertures provided into the second tubular element 17b. In alternative embodiments, the article 16 can have a ventilation level of between 10% and 60% of the total aerosol and ventilation drawn through the article 16, for instance between 20% and 50%.

[0201] An aerosol modifying agent is provided within the downstream body of material 23, in the present example in the form of an additive release component, in the present case a capsule 32. However, the capsule 32 can be omitted in other embodiments. In the case that the capsule 32 is provided, the first plug wrap 27 can be an oil-resistant first plug wrap 27. In other examples, the aerosol modifying agent can be provided in other forms, such as material injected into the downstream body of material 23 or provided on a thread, for instance the thread carrying a flavourant or other aerosol modifying agent, which may also be disposed within the downstream body of material 23.

[0202] The capsule 32 can comprise a breakable capsule, for instance a capsule which has a solid, frangible shell surrounding a liquid payload. In the present example, a single capsule 32 is used. The capsule 32 is entirely embedded within the body of material 23. In other words, the capsule 32 is completely surrounded by the material forming the body 23. In other examples, a plurality of breakable capsules may be disposed within the body of material 23, for instance 2, 3 or more breakable capsules. The length of the body of material 23 can be increased to accommodate the number of capsules required. In examples where a plurality of capsules is used, the individual capsules may be the same as each other, or may differ from one another in terms of size and / or capsule payload. In other examples, multiple bodies of material 23 may be provided, with each body containing one or more capsules.

[0203] The capsule 32 has a core-shell structure. In other words, the capsule 32 comprises a shell encapsulating a liquid agent, for instance a flavourant or other agent, which can be any one of the flavourants or aerosol modifying agents described herein. The shell of the capsule can be ruptured by a user to release the flavourant or other agent into the body of material 23.

[0204] In the present example, the capsule 32 is spherical and has a diameter of about 3 mm. In other examples, other shapes and sizes of capsule can be used. For example, the capsule may have a diameter less than 4 mm, or less than 3.5 mm, or less than 3.25 mm. In alternative embodiments, the capsule may have a diameter greater than about 3.25 mm, for example greater than 3.5 mm, or greater than 4 mm. The total weight of the capsule 32 may be in the range about 10 mg to about 50 mg.

[0205] In the present example, the capsule 32 is located at a non-longitudinally central position within the downstream body of material 23. In the present example, the capsule 32 is located closer to the upstream end of the body of material 23 than to the downstream end. That is, the capsule 32 is positioned so that its centre is 5 mm from the upstream end of the downstream body of material 23 and 7mm from the downstream end, which can assist with ensuring that the capsule cannot be seen from the downstream end of the article 16.

[0206] The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only, and are not exhaustive and / or exclusive. It is to be understood that advantages, embodiments, examples, functions, features, structures, and / or other aspects described herein are not to be considered limitations on the scope of the invention as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope of the claimed invention. Various embodiments of the invention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc, other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future.

Claims

Claims1. An aerosol-generating material in the form of a body comprising two or more channels extending through the body, each channel of the two or more channels being defined by a continuous perimeter wall, wherein the body comprises a foaming agent.

2. An aerosol-generating material according to claim 1, wherein the foaming agent is in an amount of less than or equal to about 20 wt%.

3. An aerosol-generating material according to claim 1 or 2, wherein the foaming agent is hydroxypropyl methylcellulose.

4. An aerosol-generating material according to claim 1 or 2, wherein the foaming agent is a starch.

5. An aerosol-generating material in the form of a body comprising two or more channels extending through the body, each channel of the two or more channels being defined by a continuous perimeter wall, wherein the aerosol-generating material is porous.

6. An aerosol-generating material according to any one of claims 1 to 5, wherein the body comprises: an active; one or more binders; and one or more aerosol formers.

7. An aerosol-generating material according to claim 6, wherein the active comprises nicotine.

8. An aerosol-generating material according to claim 6 or 7, wherein the aerosolgenerating material comprises a botanical material.

9. An aerosol-generating material according to claim 8, wherein the botanical material comprises tobacco in an amount of about 50 to about 90 wt%.

10. An aerosol-generating material according to claim 8 or 9, wherein the botanical material comprises a non-tobacco material in an amount of about 20 to about 90 wt%.

11. An aerosol-generating material according to any one of claims 6 to 10, wherein the one or more aerosol formers are in an amount of about 5 to about 30 wt%.

12. An aerosol-generating material according to any one of claims 1 to 11, wherein the body comprises a filler.

13. An aerosol-generating material according to any one of claims 1 to 12, wherein the body comprises water in an amount less than about 15 wt%.

14. An aerosol-generating material according to any one of claims 1 to 13, wherein the body is an extruded body.

15. An aerosol-generating material according to any one of claims 1 to 14, wherein the body comprises a width I diameter of about 5mm to about 12mm and / or a length of about 3mm to about 20mm.

16. An aerosol-generating material according to one of claims 1 to 15, wherein the total surface area of the peripheral walls of the two or more channels is from about 40 mm2to about 1000 mm2per mm length of the body.

17. An aerosol-generating material according to any one of claims 1 to 16, wherein two, or more than two, or all of the channels comprises a cross-sectional area of at least 0.1mm2to about 1mm2.

18. An aerosol-generating material according to any one of claims 1 to 17, wherein the body comprises a cavity for receiving an aerosol generator of an aerosol provision device.

19. An aerosol-generating material according to any one of claims 1 to 18, wherein the body comprises a series of radial walls and a series of bridging walls connecting the radial walls to form a series of concentric substantially circular walls.

20. An aerosol-generating material according to claim 19, wherein the series of concentric substantially circular walls comprises three substantially circular walls.

21. An aerosol-generating material according to any one of claims 1 to 20, wherein the average weight of the body is less than or equal to 230mg.

22. An article for use with a non-combustible aerosol provision device, the article comprising the aerosol-generating material according to any one of claims 1 to 21.

23. A process for preparing an aerosol-generating material, the process comprising: providing a precursor material comprising a foaming agent; and extruding the precursor material to provide the aerosol-generating material.

24. A process according to claim 23, wherein extrusion of the precursor material is carried out at ambient temperature.

25. An aerosol-generating material produced by a process according to claim 23 or

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