Aerosol-generating article with free-flowing particles

Abstract

There is provided an aerosol-generating article (100) for use with an aerosol-generating device to generate an aerosol. The aerosol-generating article (100) comprises an airflow passage defined through the aerosol-generating article (100) between an air inlet (611) and an air outlet (612), a first plurality of free-flowing particles (741) located within the airflow passage, and a second plurality of free-flowing particles (742) located within the airflow passage. The first plurality of free-flowing particles (741) is defined by a first average particle diameter, the second plurality of free-flowing particles (742) are defined by a second average particle diameter. The first plurality of free-flowing particles (741) is located in a first portion (631) of the airflow passage. The second plurality of free-flowing particles (742) is located in a second portion (632) of the airflow passage different to the first portion (631) of the airflow passage. The second average particle diameter is greater in magnitude than the first average particle diameter.

Description

[0001] FTR3984PCT - P / 90969. WO01

[0002] 1

[0003] AEROSOL-GENERATING ARTICLE WITH FREE-FLOWING PARTICLES The present disclosure relates to an aerosol-generating article comprising an airflow passage having a plurality of free-flowing particles located therein.

[0004] A typical aerosol-generating article may appear similar to a conventional cigarette. For example, such an aerosol-generating article may be a substantially cylindrical article comprising an aerosolforming substrate and other components such as mouthpiece filter element, all wrapped in a cigarette paper. Dimensions of typical aerosol-generating articles are often similar to the dimensions of conventional cigarettes.

[0005] Research has shown that, in such a typical aerosol-generating article comprising a plug of aerosol-forming substrate, a significant portion of the plug of aerosol-forming substrate may not be sufficiently heated to form an aerosol during use. This is undesirable since this portion of the plug of aerosol-forming substrate contributes to the cost of manufacture and transport of the aerosolgenerating article but does not contribute to the aerosol delivered to an end user. This may be the case regardless of the way in which the aerosol-forming substrate is heated, for example regardless of whether a resistive or inductive heater is used and regardless of whether the plug of aerosol-forming substrate is heated from the inside or the outside.

[0006] It is an aim of the present disclosure to provide an aerosol-generating article, in which a greater portion of an aerosol-forming substrate of the aerosol-generating article is sufficiently heated to form an aerosol during use. It is also an aim to provide an aerosol-generating article in which the aerosolforming substrate is convenient to load into the article during manufacture and is retained within the article.

[0007] According to the present disclosure, there may be provided an aerosol-generating article for use with an aerosol-generating device to generate an aerosol. The aerosol-generating article may comprise an airflow passage defined through the aerosol-generating article between an air inlet and an air outlet. The aerosol-generating article may further comprise a first plurality of free-flowing particles located within the airflow passage. The first plurality of free-flowing particles may be defined by a first average particle diameter. The aerosol-generating article may further comprise a second plurality of free-flowing particles located within the airflow passage. The second plurality of free-flowing particles may be defined by a second average particle diameter. The first plurality of free-flowing particles may be located in a first portion of the airflow passage and the second plurality of free-flowing particles may be located in a second portion of the airflow passage different to the first portion of the airflow passage. The second average particle diameter is preferably greater in magnitude than the first average particle diameter.

[0008] In preferred examples there may be provided, an aerosol-generating article for use with an aerosol-generating device to generate an aerosol, the aerosol-generating article comprising; an airflow passage defined through the aerosol-generating article between an air inlet and an air outlet, and a first plurality of free-flowing particles located within the airflow passage, the first plurality of free-flowing particles being defined by a first average particle diameter, and a second plurality of free-flowingparticles located within the airflow passage, the second plurality of free-flowing particles being defined by a second average particle diameter, in which the first plurality of free-flowing particles is located in a first portion of the airflow passage and the second plurality of free-flowing particles is located in a second portion of the airflow passage different to the first portion of the airflow passage, and in which the second average particle diameter is greater in magnitude than the first average particle diameter.

[0009] The second plurality of free-flowing particles may act as a retaining means, for example a mechanical retaining means, for retaining the first plurality of free-flowing particles within the article. The use of the second plurality of particles as a retaining means may provide a benefit compared to other filter means, such as a mesh, in that clogging of the retaining means may be less problematic than clogging of a filter. Thus, there may be provided, an aerosol-generating article for use with an aerosol-generating device to generate an aerosol, the aerosol-generating article comprising; an airflow passage defined through the aerosol-generating article between an air inlet and an air outlet, and a first plurality of free-flowing particles located within the airflow passage, the first plurality of free-flowing particles being defined by a first average particle diameter, and a mechanical retaining means for retaining the a first plurality of free-flowing particles within the airflow passage, the mechanical retaining means comprising a second plurality of free-flowing particles defined by a second average particle diameter, in which the second average particle diameter is greater in magnitude than the first average particle diameter. For example, the first plurality of free-flowing particles may be located in a first portion of the airflow passage and the second plurality of free-flowing particles may be located in a second portion of the airflow passage different to the first portion of the airflow passage. The second plurality of free-flowing particles may block the passage of the first plurality of free-flowing particles to retain them within the first portion of the airflow passage.

[0010] The first plurality of free-flowing particles may comprise aerosol-forming material. The second plurality of free-flowing particles may comprise aerosol-forming material. Thus, in preferred examples, at least one of the first plurality of free-flowing particles and the second plurality of free-flowing particles comprises aerosol-forming material, for example both the first plurality of free-flowing particles and the second plurality of free-flowing particles may comprise aerosol-forming material.

[0011] Providing an aerosol-forming substrate in particulate form may have a number of advantages. Particles may be conveniently loaded into an aerosol-forming substrate by the step of pouring the particles, for example pouring a dose of the particles into a cavity of the article from a hopper or dispenser. The use of a free-flowing particulate substrate may facilitate accurate and repeatable dosing of the desired amount of aerosol-forming substrate into each of a large number of aerosolgenerating articles.

[0012] The free-flowing particles may be described as beads. The term “bead” as used herein refers to a discrete, solid particle which may be formed of aerosol-forming substrate. A bead may be a particle that has a rounded, typically spherical, form. Other terms may be used to define the free-flowing particles, such as, for example, “granules” or “pellets”. Thus, the first plurality of free-flowing particles and / or the second plurality of free-flowing particles may be described as pluralities of beads or pluralities of granules.The free-flowing particles are pluralities of discrete particles, that is the particles making up the first plurality of free-flowing particles and the second plurality of free flowing particles are not bound to one another but are, rather, individual particles. Preferably the discrete particles do not adhere to each other to any substantial degree such that aggregation of the particles is limited in extent.

[0013] The free-flowing particles are preferably particles having a morphology that facilitates the flow of a plurality of the particles. For example, it may be preferred that the outer surfaces of the particles are, in general, smooth rather than angular. For example, a plurality of smooth particles tends to glide past each other more freely, and therefore flow more easily when poured, than a plurality of angular particles. It may also be preferred that an aspect ratio of the particles is, in general, not large. For example, a plurality of low aspect ratio particles tends to glide past each other more freely, and therefore flow more easily when poured, compared to a plurality of high aspect ratio particles such as needles. It may be preferred that the particles making up the first plurality of free-flowing particles or the second plurality of free-flowing particles are predominantly smooth sided particles that are predominantly spheroid, for example a low aspect ration spheroid, for example substantially spherical particles.

[0014] The first plurality of free-flowing particles may be defined by an average particle length, an average particle width, and an average particle height. The ratio of the greatest of the average particle length, average particle width, and average particle height to the least of the average particle length, average particle width, and average particle height for the first plurality of free-flowing particles may be less than 3:1, for example less than 2.5:1, for example less than 2:1, for example less than 1.8:1, or less than 1.6:1 , or less than 1.5:1 , for example about 1:1. Alternatively, or in addition, the second plurality of free-flowing particles may be defined by an average particle length, an average particle width, and an average particle height. The ratio of the greatest of the average particle length, average particle width, and average particle height to the least of the average particle length, average particle width, and average particle height for the first plurality of free-flowing particles may be less than 3:1 , for example less than 2.5:1 , for example less than 2:1 , for example less than 1.8:1 , or less than 1.6:1, or less than 1.5: 1 , for example about 1:1.

[0015] The first plurality of free-flowing particles may be substantially spherical. Alternatively, or in addition, the second plurality of free-flowing particles may be substantially spherical. Alternatively, non-spherically shaped particles, such as ovoid or ellipsoid particles, may be used for either or both of the first plurality of free-flowing particles and the second plurality of free-flowing particles. Other shapes, such as cylindrical particles may be used for either or both of the first plurality of free-flowing particles and the second plurality of free-flowing particles. Thus, the first plurality of free-flowing particles may comprise, or consist of, particles having a different shape to particles in the second plurality of free-flowing particles.

[0016] Spherical particles, for example spherical beads, can advantageously be easily handled compared to other aerosol-forming substrates such as fine powders or cut filler. The spherical particles flow easily, and so can reliably and consistently fill a cavity of the aerosol-generating article during manufacture. This may allow a consistent and reproducible amount of aerosol-forming substrate to beloaded into each article during manufacture. Spherical particles may also be cleaner to handle than powders and cut fillers, which may cause dust in factories, and may leak from aerosol-generating articles in transit or in use. By selecting spherical particles with appropriate sizes and appropriate particle size distributions, air flow through the cavity of the aerosol-generating article may be controlled more reproducibly than would be the case for, say, a cut filler substrate. Spherical particles may have an average particle diameter.

[0017] Where a particle is not perfectly spherical, but a diameter of the particle is referred to, the term “diameter” may refer to the diameter of a perfectly spherical particle having the same volume as the not perfectly spherical particle.

[0018] The term “average particle diameter”, as used herein, may refer to a number average particle diameter.

[0019] Unless otherwise mentioned, values given for average particle diameters in this specification refer to a “number average particle diameter”. Specifically, a “number average particle diameter” is calculated as a sum of the diameters of the particles in a group divided by the number of particles in the group. Mathematically, this can be expressed as:

[0020] yn=7V n

[0021] — T

[0022] Number average particle diameter = - — -

[0023]

[0024] In the above equation, N is the total number of particles, and Dnis the diameter of the nthparticle.

[0025] The first plurality of free-flowing particles may have an average particle diameter of between 0.1 mm and 1.5 mm, for example between 0.2 mm and 1.25 mm, for example between 0.4 mm and 1 mm, for example between 0.5 mm and 0.8 mm. Alternatively, or in addition, first plurality of free-flowing particles may have an average particle diameter of less than 1 mm, for example less than 0.8 mm, for example less than 0.75 mm, for example less than 0.5 mm. The first plurality of free-flowing particles may preferably be in the form of a plurality of spherical beads.

[0026] The second plurality of free-flowing particles may have an average particle diameter of greater than 1 mm, for example greater than 1.2 mm, for example greater than 1.25 mm, for example greater than 1.5 mm. The second plurality of free-flowing particles may have an average particle diameter of between 1 mm and 4 mm, for example between 1.2 mm and 3 mm, for example between 1.5 mm and 2.5 mm, for example between 1.75 mm and 2 mm. The second plurality of free-flowing particles may preferably be in the form of a plurality of spherical beads.

[0027] The second average particle diameter may preferably be greater in magnitude than the first average particle diameter. The smaller first plurality of free-flowing particles of aerosol-forming substrate may generate aerosol more quickly and uniformly than the second plurality of free-flowing particles upon heating. Each of the particles in the first plurality of free-flowing particles may be larger than an interstitial gap size of the second plurality of free-flowing particles. This may advantageously allow the second plurality of free-flowing particles to act as a mechanical barrier to prevent the flow of particles from the first plurality of free-flowing particles through the interstitial gaps between each of the second plurality of free-flowing particles. The particle dimensions of the first plurality of free-flowingparticles and second plurality of free-flowing particles may be selected accordingly such that the particles flow easily and such that the volume of the particles is not so great that volatile components cannot be substantially completely liberated from each particle on heating fora short duration of time.

[0028] The first plurality of free-flowing particles may be defined by a particle size distribution having a D10 diameter and a D90 diameter. The first plurality of free-flowing particles may have a D10 diameter of less than 1 mm, for example less than 0.8 mm, for example less than 0.75 mm, for example less than 0.5 mm. The first plurality of free-flowing particles may have a D10 diameter of greater than 0.1 mm, for example greater than 0.5 mm, for example greater than 0.75 mm. Alternatively, or in addition, the first plurality of free-flowing particles may have a D90 diameter of less than 1.5 mm, for example less than 1 mm. The first plurality of free-flowing particles may have a D10 diameter within 25 % of the value of the D90 diameter.

[0029] The second plurality of free-flowing particles may be defined by a particle size distribution having a D10 diameter and a D90 diameter. The second plurality of free-flowing particles may have a D10 diameter of greater than 1 mm, for example greater than 1.2 mm, for example greater than 1.25 mm, for example greater than 1.5 mm. greater than 1 mm, for example greater than 1.5 mm, for example greater than 1.75 mm. Alternatively, or in addition, the second plurality of free-flowing particles may have a D90 diameter of less than 4 mm, for example less than 2 mm, or less than 2 mm. The second plurality of free-flowing particles may have a D10 diameter within 25 % of the value of the D90 diameter.

[0030] The size distribution of the first and / or second plurality of free-flowing particles may be a relatively narrow size distribution. This may facilitate the provision of a consistent amount of aerosolforming substrate in each article by helping to prevent settling and clumping within the plurality of free-flowing particles.

[0031] The first plurality of free-flowing particles and / or the second plurality of free-flowing particles preferably comprises plant material, for example tobacco. The plant material may be in the form of plant particles, that is small fragments of plant material, such as powdered plant material. The first plurality of free-flowing particles and / or the second plurality of free-flowing particles preferably comprises a binder, for example one or more hydrocolloid binders.

[0032] The first plurality of free-flowing particles and / or the second plurality of free-flowing particles preferably comprises an aerosol-former, for example an aerosol former selected from the list consisting of glycerine and propylene glycol. The aerosol-forming particles may have an aerosolformer content of at least 10 wt % on a dry weight basis, for example an aerosol-former content of greater than 20 wt % on a dry weight basis, for example greater than 25 wt %, or greater than 30 wt %, for example greater than 35 wt %. The first plurality of free-flowing particles and / or the second plurality of free-flowing particles may comprise one or more flavour compounds.

[0033] The first plurality of free-flowing particles and / or the second plurality of free-flowing particles may be formed by a process comprising steps of powder spherodising particles of aerosol-forming material, for example spherodising particles of tobacco, preferably in combination with a binder.Spherodising processes are highly controllable and may produce free-flowing particles that are substantially spherical and of controlled and consistent particle dimensions.

[0034] The first plurality of free-flowing particles and / or the second plurality of free-flowing particles may be formed by a process in which a dough of aerosol-forming material is formed and extruded and cut to for individual particles. These particles may then be spheronized and dried to for substantially spherical free-flowing particles suitable for used in articles according to the invention.

[0035] The first plurality of free-flowing particles and / or the second plurality of free-flowing particles may comprise at least 60 percent by weight of plant particles, for example at least 65 percent by weight of the plant particles, for example at least 70 percent by weight of the plant particles, for example at least 75 percent by weight of the plant particles, on a dry weight basis. The first plurality of free-flowing particles and / or the second plurality of free-flowing particles may comprise less than or equal to 95 percent by weight of the plant particles, for example less than or equal to 90 percent by weight of the plant particles, for example less than or equal to 85 percent by weight of the plant particles, on a dry weight basis.

[0036] An airflow passage may be defined through the aerosol-generating article from an air inlet to an air outlet. The airflow passage may alternatively be referred to as the airflow channel. The air inlet may be defined by one or more apertures allowing air flow into the aerosol-generating article. The air outlet may be defined by one or more apertures allowing airflow out of the aerosol-generating article.

[0037] The first plurality of free-flowing particles may be located in a first portion of the airflow passage and the second plurality of free-flowing particles may be located in a second portion of the airflow passage different to the first portion of the airflow passage. The first portion of the airflow passage may be upstream of the second portion of the airflow passage. Alternatively, the first portion of the airflow passage may be downstream of the second portion of the airflow passage.

[0038] The second plurality of free-flowing particles located within the airflow passage may be dimensioned such that they are substantially prevented from passing through the one or more apertures of the air outlet. For example, the average particle length or average particle diameter of the second plurality of free-flow particles may be larger than a thickness of the air outlet. This may advantageously prevent individual particles of the second plurality of particles from leaking out of the air outlet. The second plurality of free-flowing particles may act as a barrier to prevent the first plurality of free-flowing particles from exiting the aerosol-generating article through the inlet and / or the outlet. The second plurality of free-flowing particles may act as a mechanical retention means for retaining the first plurality of free-flowing particles within the aerosol-generating article. Advantageously, the second plurality of free-flowing particles may prevent individual particles of the first plurality of particles from leaking out of the air outlet and simultaneously generate aerosol upon heating.

[0039] The aerosol-generating article may comprise a first cavity and a second cavity arranged in series within the airflow passage. The second cavity may be located in series with and downstream of the first cavity. The first plurality of free-flowing particles may be located in the first cavity and the second plurality of free flowing particles may be located in the second cavity. The second plurality of freeflowing particles may thus act as a mechanical retaining means for preventing particles of the first plurality of free-flowing particles from flowing downstream into the second cavity.

[0040] A third cavity may be arranged in series with the first cavity and the second cavity within the airflow passage. The third cavity may be located in series with and upstream of the first cavity. A portion of the second plurality of free flowing particles may be located in the second cavity and a further portion of the second plurality of free flowing particles may be located in the third cavity. Thus, an aerosol-generating article according to the present disclosure may comprise a first cavity, a second cavity and a third cavity, in which the third cavity, first cavity and second cavity are arranged in series such that the third cavity is directly upstream from the first cavity, and the first cavity is directly upstream from the second cavity. The second plurality of free flowing particles may thus act as a mechanical retaining means for preventing particles of the first plurality of free-flowing particles from flowing downstream into in second cavity and / or upstream into the third cavity. Similarly, the second plurality of free flowing particles may thus act as a mechanical retaining means for preventing particles of the first plurality of free-flowing particles from flowing out of aerosol-generating article via the air inlet and / or air outlet.

[0041] The first cavity may have a different volume to the second cavity and / or the third cavity. For example, the volume of the first cavity may be greater than the volume of the second and / or third cavity. The first cavity may have a different length to the second cavity and / or the third cavity. For example, the length of the first cavity may be greater than the length of the second and / or third cavity.

[0042] The volume of the first cavity may be greater than 35 cubic millimetres, for example greater than 200 cubic millimetres, for example greater than 100 cubic millimetres, and in which the volume of the second cavity is greater than 35 cubic millimetres, for example greater than 60 cubic millimetres, for example greater than 100 cubic millimetres. The volume of the second cavity and / or third cavity may be the same as the first cavity. Alternatively, the volume of the second cavity and / or third cavity may be smaller than the volume of the first cavity.

[0043] Preferably, the first cavity, second cavity and / or third cavity comprises between 15 mg and 100 mg of the plurality of free-flowing particles, for example between 35 mg and 70 mg, for example between 40 mg and 60 mg, for example between 45 mg and 55 mg, for example about 40 mg, or about 50 mg or about 60 mg. By selecting free-flowing particles of appropriate particle size and distribution, utilisation of aerosol-forming compounds within the free-flowing particles may be optimised, allowing a relatively low mass of the free-flowing particles in each aerosol-forming article.

[0044] Preferably, the first cavity contains between 50% and 85% of the first plurality of free-flowing particles by volume. Preferably, the second and / or third cavity contains between 50% and 85% of the second plurality of free-flowing particles by volume. Each cavity may contain a plurality of free-flowing particles and between 15% and 50% free space. The cavity may contain a further component such as a corrugated element in addition to the plurality of free-flowing particles.

[0045] The aerosol-generating article may be a planar aerosol-generating article having a base defined by a length extending in an x direction, a width extending in a y direction, and a height or thickness extending in a z direction.According to the present disclosure, there may be provided an aerosol-generating article for use with an aerosol-generating device. By way of example, the aerosol-generating article may be as described in any of the preceding paragraphs. The aerosol-generating article may comprise a first external surface and a second external surface facing in substantially the opposite direction to the first external surface. The first external surface may be a substantially planar upper surface and the second external surface may be a substantially planar lower surface. The first external surface and the second external surface may be vertically spaced from each other by a height or thickness defined in a z direction. The first external surface and the second external surface may be parallel to each other.

[0046] The aerosol-generating article may further comprise one or more susceptor materials. The one or more susceptor materials may be arranged in thermal communication with the aerosol-forming substrate.

[0047] The substantially planar first external surface may be defined by a length extending in an x direction and a width extending in a y direction.

[0048] The substantially planar second external surface may be defined by a length extending in an x direction and a width extending in a y direction.

[0049] The one or more susceptor materials, if present, may serve as a heater for imparting heat to the aerosol-generating article. Heating of the one or more susceptor materials may occur when the aerosol-generating article is placed within a changing magnetic field, with the changing magnetic field resulting in heating of the susceptor material(s) by one or both of eddy current heating and magnetic hysteresis. Such a changing magnetic field may result from an alternating current being supplied to an inductor coil. Preferably, the inductor coil forms a component part of an aerosol-generating device to which the aerosol-generating article may be coupled.

[0050] The aerosol-generating article of the present disclosure is generally flat and thin. The article width and article length may each be greater than the article thickness. The provision of a generally flat and thin aerosol-generating article provides for rapid and efficient heating of the aerosol-forming substrate and improved uniformity in through-thickness heating. The primary source of aerosolforming substrate is in the form of free-flowing particles and preferably porous and / or of low density. Preferably, the aerosol-generating article is free of any single-use plastics, thereby providing an aerosol-generating article with improved sustainability.

[0051] The aerosol-generating article may extend over its length between a distal end and a proximal end. The proximal end may be a mouth end of the aerosol-generating article. The airflow passage may be defined through the aerosol-generating article between the distal end and proximal end. The air inlet may be located at the distal end of the aerosol-generating article. The air outlet may be located at the proximal end of the aerosol-generating article. One or more cavities as described above may be located within the aerosol-generating article between the upper surface and lower surface.

[0052] Aerosol-generating articles according to the present disclosure may preferably be substantially flat articles or substantially planar articles. Such articles have a large base area relative to the volume of the article. Advantageously, a larger base area may provide greater surface area for heating by a planar heater of an aerosol-generating device. Advantageously, a smaller height may allow a smallertemperature gradient or difference across the height of the aerosol-generating article during heating. For example, where the base of the aerosol-generating article is in contact with, and heated by, a planar heater, there may be a smaller temperature difference between the base and an upper surface opposing the base if the spacing, or height, between the base and the upper surface is smaller. Advantageously, this may allow heating of a greater proportion of the aerosol-forming substrate of the aerosol-generating article to a temperature at which an aerosol is released, whilst minimising the risk of burning the hottest portion of the substrate closest to the heater. Alternatively, or in addition, this may reduce a time required to heat the free-flowing particles of aerosol-forming substrate located within the cavity sufficiently to release an aerosol.

[0053] The aerosol-generating article may have an airflow passage defined through the aerosolgenerating article in an x / y plane from one side of the aerosol-generating article to the other side of the aerosol-generating article. The aerosol-generating article preferably has a resistance to draw (RTD) of less than 20 millimetre H2O, for example less than 10 millimetre H2O, in the direction of the airflow passage. Preferably, the aerosol-generating article has a RTD of less than 20 millimetre H2O, for example less than 10 millimetre H2O, in at least one direction in an x / y plane of the aerosolgenerating article. An aerosol-generating article with a low resistance airflow passage may allow for superior air-flow management and allow aerosol to be extracted more efficiently from the aerosolgenerating article and guided to a user.

[0054] Unless otherwise specified, the resistance to draw (RTD) is measured in accordance with ISO 6565-2015. The RTD refers to the pressure required to force airthrough the full length of a component, such as the aerosol-generating article. The terms “pressure drop” or “draw resistance” of a component or article may also refer to the “resistance to draw”. Such terms generally refer to the measurements made in accordance with ISO 6565-2015 and are normally carried out at under test at a volumetric flow rate of about 17.5 millilitres per second at the output or downstream end of the measured component at a temperature of about 22 degrees Celsius, a pressure of about 101 kPa (about 760 Torr) and a relative humidity of about 60%.

[0055] The aerosol-generating article according to any of the aspects disclosed herein may comprise substantially planar upper and lower surfaces. A vertical separation between the substantially planar upper and lower surfaces may define a height (for example, a z dimension) of the aerosol-generating article. An airflow passage may be defined between the substantially planar upper and lower surfaces. The height of the aerosol-generating article may be less than 5 millimetres, for example between 1.5 millimetres and 5 millimetres, for example between 1.5 millimetres and 4 millimetres, for example between 1.5 millimetres and 3 millimetres, for example between 1.5 millimetres and 2 millimetres. Although the free-flowing particles are the primary source of aerosol-forming substrate, one or both of the substantially planar upper and lower surfaces may comprise an additional aerosol-forming substrate. The aerosol-generating article may comprise upper and lower layers, at least one of the upper and lower layers comprising or consisting of additional aerosol-forming substrate, the upper layer forming the substantially planar upper surface and the lower layer forming the substantially planar lower surface.The aerosol-generating article may further comprise an intermediate layer arranged between an upper layer and a lower layer. The upper surface may define an external surface of the upper layer and the lower surface may define an external surface of the lower layer. An airflow passage may be defined through the aerosol-generating article in an x / y plane between a distal end and a proximal end of the aerosol-generating article. The intermediate layer may be located within the cavity. The intermediate layer may help define the cavity.

[0056] A resistance to draw (RTD) of the aerosol-generating article, along the airflow passage, may be less than 60 millimetres H2O, for example less than 50 millimetres H2O, or less than 40 millimetres H2O, or less than 30 millimetres H2O, for example less than 20 millimetres H2O.

[0057] One or both of the upper layer and the lower layer may comprise a sub-layer of aerosol-forming substrate laminated with a sub-layer of one or more susceptor materials. The sub-layer of aerosolforming substrate may define an inward-facing surface of the respective upper or lower layer.

[0058] The intermediate layer may comprise or consist of a paper-based substrate.

[0059] The intermediate layer may be free of aerosol-forming substrate.

[0060] The intermediate layer may comprise or consist of aerosol-forming substrate. The intermediate layer may further comprise one or more susceptor materials.

[0061] A plurality of longitudinally extending passages may be defined by corrugations between the upper layer and the intermediate layer and between the intermediate layer and the lower layer. The longitudinally extending passages may extend along in an x / y plane between the distal end and the proximal end. The corrugations may be located within the cavity and the free-flowing particles may be disposed in one or more of the corrugations.

[0062] The intermediate layer may be fixed relative to at least one of the upper layer and lower layer by an adhesive. For example, the adhesive may comprise guar gum. The adhesive may comprise an aerosol-forming material such as homogenised tobacco slurry.

[0063] The intermediate layer may comprise a corrugated element.

[0064] The intermediate layer may comprise a plurality of corrugated elements. Two or more of the plurality of corrugated elements may be arranged in vertical relationship to each other between the upper layer and the lower layer. One or more of the plurality of corrugated elements may comprise one or more susceptor materials and other one or ones of the plurality of corrugated elements may comprise aerosol-forming substrate. The intermediate layer may further comprise a planar element positioned between two of the plurality of corrugated elements. The planar element may comprise or consist of one or more susceptor materials.

[0065] According to the present disclosure, there may be provided an aerosol-generating article comprising a first planar layer, a second planar layer, and a corrugated layer arranged between the first planar layer and the second planar layer. The free-flowing particles may be located within one or more passages of the corrugated layer.

[0066] The use of a corrugated structure in the aerosol-generating article may advantageously allow the production of an aerosol-generating article that has extremely low RTD while still being sufficiently rigid to for a user to handle. Further, use of a corrugated structure may allow a low density, low RTD,aerosol-generating article to be produced using high speed production methods similar to those used for production of corrugated cardboard.

[0067] The aerosol-generating article may further comprise a planar frame positioned between an upper layer and a lower layer. The upper layer may comprise the first external surface. The lower layer may comprise the second external surface. The planar frame may define one or more cavities as described above. For example, side walls of the at least one cavity may be at least partially defined by the frame. An air flow passage may be defined through the aerosol-generating article in an x / y plane, the airflow passage extending through the cavity.

[0068] The upper layer and the lower layer may be coupled to opposing surfaces of the frame to overlie opposing ends of the cavity.

[0069] One or both of the upper layer and the lower layer may comprise or consist of one or more susceptor materials.

[0070] A corrugated element may be disposed within the cavity between the upper and lower layers. A plurality of longitudinally extending passages are defined by corrugations between the upper layer and the corrugated element and between the corrugated element and the lower layer. The longitudinally extending passages may extend along in an x / y plane between opposing ends of the frame.

[0071] The airflow passage may be at least partially defined by the frame. The frame may comprise an inlet airflow passage and an outlet airflow passage, the inlet airflow passage configured to permit a flow of air into the cavity and the outlet airflow passage configured to permit a flow of air to exit the cavity. The inlet airflow passage and the outlet airflow passage may be defined on opposing ends of the frame. The inlet airflow passage may be defined in a first width edge of the frame and the outlet airflow passage defined in a second width edge of the frame.

[0072] The frame may comprise a peripheral wall at least partially circumscribing or encircling the cavity. The frame may comprise a peripheral wall wholly circumscribing or encircling the cavity. The peripheral wall may be formed by a frame inner surface and a frame outer surface. The frame inner surface may define a cavity outer wall. The frame outer surface at least partially defines one or more external walls of the aerosol-generating article. The peripheral wall may have a radial thickness between 1 millimetre and 3 millimetres.

[0073] The frame may have a thickness greater than or equal to 80 percent of the thickness of the aerosol-generating article, for example between 80 percent and 95 percent of the thickness of the aerosol-generating article. The frame may have a thickness between 1 millimetre and 5.5 millimetres.

[0074] The aerosol-generating article may comprise a first planar external layer and a second planar external layer, in which the first planar external layer forms the first planar external surface, and the second planar external layer forms the second planar external surface. Optionally, at least one of the first planar external layer, the second planar external layer, and the frame may comprise or consist of additional aerosol-forming substrate.

[0075] A corrugated layer may be positioned within the cavity.The aerosol-generating article of any of the aspects of the present disclosure may have a length (for example, an x dimension) of between 10 millimetres and 100 millimetres, or between 10 millimetres and 50 millimetres, for example between 12 millimetres and 30 millimetres, for example between 14 millimetres and 26 millimetres, for example between 16 millimetres and 24 millimetres, for example between 18 millimetres and 22 millimetres, for example about 18 millimetres, or about 19 millimetres, or about 20 millimetres, or about 21 millimetres, or about 22 millimetres.

[0076] The aerosol-generating article may have a width (for example, a y dimension) of between 5 millimetres and 20 millimetres, for example between 8 millimetres and 18 millimetres, for example between 10 millimetres and 16 millimetres, for example between 11 millimetres and 15 millimetres, for example between 12 millimetres and 14 millimetres, for example about 13 millimetres.

[0077] The aerosol-generating article may have a height (for example, a z dimension) of between 1 millimetres and 10 millimetres, for example between 1.2 millimetres and 8 millimetres, for example between 1.4 millimetres and 7 millimetres, for example between 1.6 millimetres and 6 millimetres, for example between 1.7 millimetres and 5 millimetres, for example about 1.7 millimetres, or about 4.5 millimetres, or about 2 millimetres, or about 3 millimetres, or about 4 millimetres. Preferably, the thickness of the aerosol-generating article may be less than 50 percent of both the length and the width of the aerosol-generating article.

[0078] The aerosol-generating article of any of the aspects of the present disclosure when viewed in plan may have a shape defining a polygon, a quadrilateral (for example, a rectangle ora square), oval, or circle, ora combination thereof. Where the aerosol-generating article comprises substantially planar upper and lower surfaces, one or both of the upper and lower surfaces when viewed in plan may have a shape defining a polygon, a quadrilateral (for example, a rectangle ora square), an oval, a circle, or a combination thereof. A perimeter of the aerosol-generating article when viewed in plan may be formed of a plurality of straight sides, a plurality of curved sides, or a combination of straight and curved sides. Where the aerosol-generating article comprises substantially planar upper and lower surfaces, a perimeter of one or both of the upper and lower surfaces when viewed in plan may have a shape defining a polygon, a quadrilateral (for example, a rectangle ora square), an oval, a circle, or a combination thereof.

[0079] The aerosol-forming substrate may comprise nicotine. Nicotine may be present in the form of a tobacco material or may be in the form of a nicotine extract.

[0080] References to aerosol-forming substrate below may relate to either the aerosol-forming substrate of the free-flowing particles or any additional aerosol-forming substrate present in the article. The aerosol-forming substrate may comprise one or more aerosol-formers. Suitable aerosol-formers are well known in the art and include, but are not limited to, one or more aerosol-formers selected from: polyhydric alcohols, such as propylene glycol, polyethylene glycol, triethylene glycol, 1, 3-butanediol and glycerine; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. It may be particularly preferable for the aerosol-former to be or comprise glycerine.The aerosol-forming substrate may comprise at least 1, 2, 5, 10, or 15 weight percent aerosolformer. The aerosol-forming substrate may comprise greater than 15 weight percent aerosol-former, for example greater than 20 weight percent, or greater than 25 weight percent, or greater than 30 weight percent, or greater than 40 weight percent, or greater than 50 weight percent aerosol-former.

[0081] The aerosol-forming substrate may comprise less than or equal to 30 percent by weight of aerosol former, less than or equal to 25 percent by weight of aerosol former, or less than or equal to 20 percent by weight of aerosol former. That is, the aerosol-forming substrate may have an aerosol former content of less than or equal to 30 percent by weight, less than or equal to 25 percent by weight, or less than or equal to 20 percent by weight.

[0082] The aerosol-forming substrate may comprise between 1 percent and 30 percent by weight of aerosol former, between 1 percent and 25 percent by weight of aerosol former, or between 1 percent and 20 percent by weight of aerosol former.

[0083] The aerosol-forming substrate may comprise between 5 percent and 30 percent by weight of aerosol former, between 5 percent and 25 percent by weight of aerosol former, or between 5 percent and 20 percent by weight of aerosol former.

[0084] The aerosol-forming substrate may comprise between 10 percent and 30 percent by weight of aerosol former, between 10 percent and 25 percentby weight of aerosol former, or between 10 percent and 20 percent by weight of aerosol former.

[0085] The aerosol-forming substrate may comprise between 15 percent and 30 percent by weight of aerosol former, between 15 percent and 25 percentby weight of aerosol former, or between 15 percent and 20 percent by weight of aerosol former.

[0086] The aerosol-forming substrate may comprise at least 50 percent by weight of aerosol former, at least 60 percent by weight of aerosol former, or at least 70 percent by weight of aerosol former.

[0087] The aerosol-forming substrate may comprise less than or equal to 85 percent by weight of aerosol former, less than or equal to 80 percent by weight of aerosol former, or less than or equal to 75 percent by weight of aerosol former.

[0088] The aerosol-forming substrate may comprise between 50 percent and 85 percent by weight of aerosol former, between 50 percent and 80 percent by weight of aerosol former, or between 50 percent and 75 percent by weight of aerosol former.

[0089] The aerosol-forming substrate may comprise between 60 percent and 85 percent by weight of aerosol former, between 60 percent and 80 percent by weight of aerosol former, or between 60 percent and 75 percent by weight of aerosol former.

[0090] The aerosol-forming substrate may comprise between 70 percent and 85 percent by weight of aerosol former, between 70 percent and 80 percentby weight of aerosol former, or between 70 percent and 75 percent by weight of aerosol former.

[0091] The aerosol-forming substrate may comprise nicotine. The aerosol-forming material may comprise natural nicotine, or synthetic nicotine, or a combination of natural nicotine and synthetic nicotine.The aerosol-forming substrate may comprise at least 0.5 percent by weight of nicotine, at least 1 percent by weight of nicotine, at least 1.5 percent by weight of nicotine, or at least 2 percent by weight of nicotine. That is, the aerosol-forming substrate may have a nicotine content of at least 0.5 percent by weight, at least 1 percent by weight, at least 1.5 percent by weight, or at least 2 percent by weight.

[0092] The aerosol-forming substrate may comprise one or more cannabinoid compounds such as one or more of: tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiol (CBD), cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), cannabigerol monomethyl ether (CBGM), cannabivarin (CBV), cannabidivarin (CBDV), tetrahydrocannabivarin (THCV), cannabichromene (CBC), cannabicyclol (CBL), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabielsoin (CBE), cannabicitran (CBT). It may be preferable that the cannabinoid compound is CBD or THC. It may be particularly preferable that the cannabinoid compound is CBD.

[0093] The aerosol-forming substrate may comprise one or more flavourants. The one or more flavourants may comprise one or more of: one or more essential oils such as eugenol, peppermint oil and spearmint oil; one or both of menthol and eugenol; one or both of anethole and linalool; and an herbaceous material. Suitable herbaceous material includes herb leaf or other herbaceous material from herbaceous plants including, but not limited to, mints, such as peppermint and spearmint, lemon balm, basil, cinnamon, lemon basil, chive, coriander, lavender, sage, tea, coffee, thyme, and caraway. The one or more flavourants may comprise a tobacco material.

[0094] The aerosol-forming substrate may further comprise one or more carboxylic acids. Advantageously, where the active agent comprises nicotine, including one or more carboxylic acids in the aerosol-forming substrate may create a nicotine salt. The carboxylic acid may comprise one or more of lactic acid, levulinic acid, benzoic acid, fumaric acid or acetic acid. Preferably, the carboxylic acid is at least one of lactic acid or levulinic acid.

[0095] The aerosol-forming substrate may have a carboxylic acid content of at least 0.5 percent by weight, preferably at least 1 percent by weight, more preferably at least 2 percent by weight, on a dry weight basis.

[0096] The aerosol-forming substrate may have a carboxylic acid content of less than or equal to 10 percent by weight, preferably less than or equal to 8 percent by weight, more preferably less than or equal to 8 precent by weight, on a dry weight basis.

[0097] For example, the aerosol-forming substrate may comprise between about 0.5 percent by weight and about 10 percent by weight of the acid, or between about 1 percent by weight and about 8 percent by weight of the acid, or between about 2 percent by weight and about 6 percent by weight of the acid.

[0098] The aerosol-forming substrate may have a moisture content of about 5 to 25%, preferably of about 7 to 15%, at final product state. For example, the aerosol-forming substrate may be a homogenised tobacco material with a moisture of about 5 to 25%, preferably of about 7 to 15%, at final product state.

[0099] The aerosol-forming substrate may comprise tobacco leaf; for example, about 15 to 45%, preferably of about 20 to 35% of a blend of tobacco leaf, incorporating at least one of the followingtobacco types: bright tobacco; dark tobacco; aromatic tobacco. Tobacco material such as tobacco leaf is preferably ground and graded to a particle size of about 100 to 380 mesh, preferably of about 170 to 320 mesh. This tobacco material may, for example, be used to form the free-flowing particles of aerosol-forming substrate.

[0100] “Tobacco type” means one of the different varieties of tobacco, for example based on the distinct curing process that the tobacco undergoes before it is further processed in a tobacco product.

[0101] Examples of bright tobaccos are Flue-Cured Brazil, Indian Flue-Cured, Chinese Flue-Cured, US Flue-Cured such as Virginia tobacco, and Flue-Cured from Tanzania.

[0102] Examples of aromatic tobaccos are Oriental Turkey, Greek Oriental, semi-oriental tobacco but also Fire Cured, US Burley, such as Perique, and Rustica.

[0103] Examples of dark tobacco are Dark Cured Brazil Galpao, Burley Malawi or other African Burley, Sun Cured or Air Cured Indonesian Kasturi.

[0104] The aerosol-forming substrate may comprise Cellulose fibres. For example, the aerosol-forming substrate may comprise about 1 to 15% of cellulose fibres, preferably of about 3 to 7% of cellulose fibres. Preferably, cellulose fibres may have a length of about 10 to 250 pm, preferably of about 10 to 120 pm.

[0105] The aerosol-forming substrate may comprise organic fibres such as non-tobacco fibres, or tobacco fibres. For example, the aerosol-forming substrate may comprise about 5 to 20%, preferably about 7 to 15% of tobacco fibres. Tobacco fibres are preferably derived from stems and / or or stalks, graded to fibres of a length of about 10 to 350 pm, preferably of about 10 to 180 pm. The aerosolforming substrate may comprise about 10 to 30 %, preferably of about 15 to 25%, of a non-tobacco organic fibre. For example, organic fibres may derive from cellulose, cotton, wood, tea botanical varieties as sub-products, and sub-processed waste, the tea industry. Organic fibres are preferably of a length of about 10 to 400 pm, preferably of about 10 to 200 pm.

[0106] The aerosol-forming substrate may comprise a binder. For example, the aerosol-forming substrate may comprise about 1 to 10%, preferably of about 1 to 5%, of a binder such as any of common gums or pectins used in food and beverage (F&B) industries. Preferred binders may be natural pectins, such as fruit, for example citrus, or tobacco pectins; guar gums, land locust bean gums, such as hydroxyethyl and / or hydroxypropyl of those; starches, such as modified or derivatized starches; alginate; methyl, ethyl, ethylhydroxymethyl and carboxymethyl, celluloses; dextran; and xanthan gum. A preferable binder is guar.

[0107] The aerosol-forming substrate may comprise an organic botanical glycerite. For example, the aerosol-forming substrate may comprise about 15 to 55 %, preferably of about 20 to 35 %, of botanicals such as Clove, Echinacea sp., Fennel, Ginger, Hawthorn berry, Elderberry, Monarda, Mullein leaves, Nettle, Plantain, Turmeric, Yarrow, and compounds of those.

[0108] The aerosol-forming substrate may comprise organic botanical extracts. For example, the aerosol-forming substrate may comprise about 1 to 15 %, preferably of about 2 to 7 %, of any of the previously referred botanicals, as well as menthol (dl-Menthol, C10H20O, 2-lsopropyl-5-methylcyclohexanol) such as obtained from Chaerophyllum macrospermum, Mesosphaerumsidifolium, or other related botanic varieties, as well as P-menthan-3-ol, as any secondary alcohol as diastereoisomers of 5-methyl-2-(propan-2-yl)cyclohexan-1-ol.

[0109] The aerosol-forming substrate may comprise botanical essential oils, for example about 0.5 to 5 %, preferably of about 1 to 3 %, of a botanical essential oil, for example a botanical essential oil such as of palm, coconut, and wooden-based essential oils.

[0110] The aerosol-forming substrate preferably comprises an aerosol-former, for example about 5 to 35%, preferably of about 10 to 25%, of an aerosol former. Suitable aerosol-formers known in the art include: glycerine; monohydric alcohols like menthol, polyhydric alcohols, such as triethylene glycol; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyls of those.

[0111] As used herein, the term “aerosol-generating article” may refer to an article able to generate, or release, an aerosol.

[0112] As used herein, the term “aerosol-forming substrate” may refer to a substrate capable of releasing an aerosol or volatile compounds that can form an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. An aerosol-forming substrate may comprise an aerosol-forming material. An aerosol-forming substrate may be adsorbed, coated, impregnated, or otherwise loaded onto a carrier or support. An aerosol-forming substrate may conveniently be part of an aerosol-generating article or smoking article.

[0113] As used herein, the term “aerosol-generating device” may refer to a device for use with an aerosol-generating article to enable the generation, or release, of an aerosol.

[0114] As used herein, the term “aerosol generating system” refers to a combination of an aerosolgenerating device and one or more aerosol-forming articles for use with the device. An aerosolgenerating system may include additional components, such as a charging unit for recharging an onboard electric power supply in an electrically operated or electric aerosol-generating device.

[0115] As used herein, the term “aerosol former” may refer to any suitable known compound or mixture of compounds that, in use, facilitates formation of an aerosol. The aerosol may be a dense and stable aerosol. The aerosol may be substantially resistant to thermal degradation at the operating temperature of the aerosol-forming substrate or aerosol-generating article.

[0116] As used herein with reference to the invention, the term “nicotine”, is used to describe nicotine, nicotine base ora nicotine salt.

[0117] As used herein with reference to the invention, the terms “proximal”, “distal”, “upstream” and “downstream” are used to describe the relative positions of components, or portions of components, of the aerosol-generating article.

[0118] As used herein, the term “longitudinal” refers to the direction corresponding to the main longitudinal axis of the aerosol-generating article, which extends between the upstream and downstream ends of the aerosol-generating article. During use, air may be drawn through the aerosolgenerating article in the longitudinal direction.

[0119] As used herein, the term “sheet” denotes a laminar element having a width and length substantially greater than the thickness thereof. The width of a sheet may be greater than 10 mm,preferably greater than 20 mm or 30 mm. In certain embodiments, sheets of material for use in forming aerosol-forming substrates as described herein may have a thickness of between 10 pm and about 1000 pm, for example between 10 pm and about 300 pm.

[0120] As used herein, the term “homogenised tobacco material” encompasses any tobacco material formed by the agglomeration of particles of tobacco material. Sheets or webs of homogenised tobacco material are formed by agglomerating particulate tobacco obtained by grinding or otherwise powdering of one or both of tobacco leaf lamina and tobacco leaf stems. In addition, homogenised tobacco material may comprise a minor quantity of one or more of tobacco dust, tobacco fines, and other particulate tobacco by-products formed during the treating, handling and shipping of tobacco. The sheets of homogenised tobacco material may be produced by casting, extrusion, paper making processes or other any other suitable processes known in the art.

[0121] The term “cast leaf’ is used herein to refer to a product made by a casting process that is based on casting a slurry comprising plant particles (for example, clove particles or tobacco particles and clove particles in a mixture) and a binder (for example, guar gum) onto a supportive surface, such as a belt conveyor, drying the slurry and removing the dried sheet from the supportive surface. An example of the casting or cast leaf process is described in, for example, US-A-5,724,998 for making cast leaf tobacco. In a cast leaf process, particulate plant materials are produced by pulverizing, grinding, or comminuting parts of the plant. The particles produced from one or more plants are mixed with a liquid component, typically water, to form a slurry. Other components in the slurry may include fibres, a binder and an aerosol former. The particulate plant materials may be agglomerated in the presence of the binder. The slurry is cast onto a supportive surface and dried into a sheet of homogenized plant material. Preferably, homogenized plant material used in articles according to the present invention may be produced by casting. Such homogenized plant material may comprise agglomerated particulate plant material.

[0122] As used herein, resistance to draw is expressed with the units of pressure “mm H2O” or “mm WG” or “mm of water gauge” and may be measured in accordance with ISO 6565:2002.

[0123] The invention is defined in the claims. However, below there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0124] Ex1. An aerosol-generating article for use with an aerosol-generating device to generate an aerosol, the aerosol-generating article comprising;

[0125] an airflow passage defined through the aerosol-generating article between an air inlet and an air outlet, and

[0126] a first plurality of free-flowing particles located within the airflow passage, the first plurality of free-flowing particles being defined by a first average particle diameter, and

[0127] a second plurality of free-flowing particles located within the airflow passage, the second plurality of free-flowing particles being defined by a second average particle diameter, in which.

[0128] the first plurality of free-flowing particles is located in a first portion of the airflow passage and the second plurality of free-flowing particles is located in a second portion of the airflow passagedifferent to the first portion of the airflow passage, and in which the second average particle diameter is greater in magnitude than the first average particle diameter.

[0129] Ex1 a. An aerosol-generating article for use with an aerosol-generating device to generate an aerosol, for example an aerosol-generating device according to example Ex1 , the aerosol-generating article comprising;

[0130] an airflow passage defined through the aerosol-generating article between an air inlet and an air outlet, and

[0131] a first plurality of free-flowing particles located within the airflow passage, the first plurality of free-flowing particles being defined by a first average particle diameter, and

[0132] a mechanical retaining means for retaining a first plurality of free-flowing particles within the airflow passage, the mechanical retaining means comprising a second plurality of free-flowing particles defined by a second average particle diameter, in which the second average particle diameter is greater in magnitude than the first average particle diameter.

[0133] Ex1b. An aerosol-generating article according to example Ex1a, in which the first plurality of free-flowing particles is located in a first portion of the airflow passage and the second plurality of free-flowing particles is located in a second portion of the airflow passage different to the first portion of the airflow passage.

[0134] Ex2. An aerosol-generating article according to any preceding example in which the first plurality of free-flowing particles comprises aerosol-forming material.

[0135] Ex3. An aerosol-generating article according to any preceding example in which the second plurality of free-flowing particles comprises aerosol-forming material.

[0136] Ex3a. An aerosol-generating article according to any preceding example in which at least one of the first plurality of free-flowing particles and the second plurality of free-flowing particles comprises aerosol-forming material, for example in which both the first plurality of free-flowing particles and the second plurality of free-flowing particles comprises aerosol-forming material.

[0137] Ex4. An aerosol-generating article according to any preceding example in which the first plurality of free-flowing particles and / or the second plurality of free-flowing particles are low aspect ratio particles, for example spheroid particles, for example substantially spherical particles.

[0138] Ex4a. An aerosol-generating article according to example Ex4 in which the first plurality of free-flowing particles may be defined by an average particle length, an average particle width, and an average particle height, in which the ratio of the greatest of the average particle length, average particle width, and average particle height to the least of the average particle length, average particle width, and average particle height for the first plurality of free-flowing particles is less than 3:1, for example less than 2.5:1 , for example less than 2:1 , preferably less than 1.8:1 , or less than 1.6:1 , or less than 1.5:1, preferably about 1:1.

[0139] Ex5. An aerosol-generating article according to example Ex4 or Ex4a in which the second plurality of free-flowing particles may be defined by an average particle length, an average particle width, and an average particle height, in which the ratio of the greatest of the average particle length, average particle width, and average particle height to the least of the average particle length, averageparticle width, and average particle height for the second plurality of free-flowing particles is less than 3:1, for example less than 2.5:1, for example less than 2:1, preferably less than 1.8:1, or less than 1.6:1, or less than 1.5:1, preferably about 1:1.

[0140] Ex6. An aerosol-generating article according to any preceding example in which the first plurality of free-flowing particles and / or the second plurality of free-flowing particles are shaped to be poured into the aerosol-generating article during manufacture.

[0141] Ex7. An aerosol-generating article according to any preceding example in which the first plurality of free-flowing particles and / or the second plurality of free-flowing particles is defined by a particle size distribution having a D10 diameter and a D90 diameter.

[0142] Ex8. An aerosol-generating article according to example Ex7 in which the first plurality of free-flowing particles has a D10 diameter of less than 1 mm, for example less than 0.8 mm, for example less than 0.75 mm, for example less than 0.5 mm.

[0143] Ex8a. An aerosol-generating article according to example Ex7 or Ex8 in which the first plurality of free-flowing particles has an average particle diameter, for example a number average particle diameter, of less than 1 mm, for example less than 0.8 mm, for example less than 0.75 mm, for example less than 0.5 mm.

[0144] Ex8b. An aerosol-generating article according to example Ex7 or Ex8 in which the first plurality of free-flowing particles has an average particle diameter, for example a number average particle diameter, of between 0.1 mm and 1.5 mm, for example between 0.2 mm and 1.25 mm, for example between 0.4 mm and 1 mm, for example between 0.5 mm and 0.8 mm.

[0145] Ex9. An aerosol-generating article according to any of examples Ex7 to Ex8b in which the second plurality of free-flowing particles has a D10 diameter of greater than 1 mm, for example greater than 1.2 mm, for example greater than 1.25 mm, for example greater than 1.5 mm.

[0146] Ex9a. An aerosol-generating article according to any of examples Ex7 to Ex9 in which the second plurality of free-flowing particles has an average particle diameter, for example a number average particle diameter, of greater than 1 mm, for example greater than 1.2 mm, for example greater than 1.25 mm, for example greater than 1.5 mm.

[0147] Ex9b. An aerosol-generating article according to any of examples Ex7 to Ex9a in which the second plurality of free-flowing particles has an average particle diameter, for example a number average particle diameter, of between 1 mm and 4 mm, for example between 1.2 mm and 3 mm, for example between 1.5 mm and 2.5 mm, for example between 1.75 mm and 2 mm.

[0148] Ex10. An aerosol-generating article according to any preceding example in which, the air outlet is defined by one or more apertures allowing air flow out of the aerosol-generating article, in which the second plurality of free-flowing particles located within the airflow passage are dimensioned such that they are substantially prevented from passing through the one or more apertures of the air outlet.

[0149] Ex11. An aerosol-generating article according to any preceding example in which the second plurality of free-flowing particles functions as a barrier to prevent the first plurality of free-flowing particles from exiting the aerosol-generating article through the inlet and / or the outlet.Ex12. An aerosol-generating article according to any preceding example, in which the second plurality of free-flowing particles functions as a barrier to retain the first plurality of free-flowing particles within the aerosol-generating article, for example in which the second plurality of free-flowing particles are a mechanical retention means for retaining the first plurality of free-flowing particles within the aerosol-generating article.

[0150] Ex13. An aerosol-generating article according to any preceding example, comprising a first cavity and a second cavity arranged in series within the airflow channel, in which the first plurality of free-flowing particles is located in the first cavity and the second plurality of free flowing particles is located in the second cavity.

[0151] Ex14. An aerosol-generating article according to any preceding example, comprising a first cavity and a second cavity arranged in series within the airflow channel, the second cavity being located in series with and downstream of the first cavity, in which the first plurality of free-flowing particles is located in the first cavity and the second plurality of free flowing particles is located in the second cavity.

[0152] Ex15. An aerosol-generating article according to example Ex14, further comprising a third cavity arranged in series with the first cavity and the second cavity within the airflow channel, the third cavity being located in series with and upstream of the first cavity, in which a portion of the second plurality of free flowing particles is located in the second cavity and in which a further portion of the second plurality of free flowing particles is located in the third cavity.

[0153] Ex16. An aerosol-generating article according to any of examples Ex13 to Ex15, in which the first cavity has a different volume to the second cavity and / or the third cavity, for example in which the volume of the first cavity is greater than the volume of the second and / or third cavity.

[0154] Ex17. An aerosol-generating article according to any of examples Ex13 to Ex16, in which the volume of the first cavity is greater than 100 cubic millimetres, for example greater than 200 cubic millimetres, for example greater than 300 cubic millimetres, and in which the volume of the second cavity is greater than 100 cubic millimetres, for example greater than 200 cubic millimetres, for example greater than 300 cubic millimetres.

[0155] Ex18. An aerosol-generating article according to any of examples Ex13 to Ex17, in which the first cavity has a different length to the second cavity.

[0156] Ex19. An aerosol-generating article according to any preceding example in which the first plurality of free-flowing particles has a particle size distribution defined by a D10 diameter and a D90 diameter, in which the D10 diameter is greater than 0.1 mm, for example greater than 0.5 mm, for example greater than 0.75 mm, and the D90 diameter is less than 1.5 mm, for example less than 1 mm.

[0157] Ex20. An aerosol-generating article according to any preceding example in which the first plurality of free-flowing particles has a particle size distribution defined by a D10 diameter and a D90 diameter, in which the D10 diameter is within 25 % of the value of the D90 diameter.

[0158] Ex21. An aerosol-generating article according to any preceding example in which the second plurality of free-flowing particles has a particle size distribution defined by a D10 diameter and a D90diameter, in which the D10 diameter is greater than 1 mm, for example greater than 1.5 mm, for example greater than 1.75 mm, and the D90 diameter is less than 4 mm, for example less than 2 mm, or less than 2 mm.

[0159] Ex22. An aerosol-generating article according to any preceding example in which the second plurality of free-flowing particles has a particle size distribution defined by a D10 diameter and a D90 diameter, in which the D10 diameter is within 25 % of the value of the D90 diameter.

[0160] Ex23. An aerosol-generating article according to any preceding example in which the first plurality of free-flowing particles and / or the second plurality of free-flowing particles comprises plant material, for example tobacco, and a binder, for example one or more hydrocolloid binders, for example in which the plant material is in the form of plant particles.

[0161] Ex24. An aerosol-generating article according to any preceding example in which the first plurality of free-flowing particles and / or the second plurality of free-flowing particles comprise an aerosol-former, for example an aerosol former selected from the list consisting of glycerine and propylene glycol, for example in which the free-flowing particles have an aerosol-former content of greater than 20 wt % on a dry weight basis, for example greater than 25 wt %, or greater than 30 wt %, for example greater than 35 wt %.

[0162] Ex25. An aerosol-generating article according to any preceding example in which the first plurality of free-flowing particles and / or the second plurality of free-flowing particles comprises one or more flavour compounds.

[0163] Ex26. An aerosol-generating article according to any proceeding example in which the first plurality of free-flowing particles and / or the second plurality of free-flowing particles is formed by a process comprising steps of powder spherodising particles of aerosol-forming material, for example powder spherodising particles of tobacco, preferably in combination with a binder, or in which the first plurality of free-flowing particles and / or the second plurality of free-flowing particles is formed by a spheronization process, for example spheronization of a dough formed from aerosol-forming material.

[0164] Ex27. An aerosol-generating article according to any proceeding example in which the first plurality of free-flowing particles and / or the second plurality of free-flowing particles comprises at least 60 percent by weight of plant particles, for example at least 65 percent by weight of the plant particles, for example at least 70 percent by weight of the plant particles, for example at least 75 percent by weight of the plant particles, on a dry weight basis.

[0165] Ex28. An aerosol-generating article according to any proceeding example in which the first plurality of free-flowing particles and / or the second plurality of free-flowing particles comprises less than or equal to 95 percent by weight of the plant particles, for example less than or equal to 90 percent by weight of the plant particles, for example less than or equal to 85 percent by weight of the plant particles, on a dry weight basis.

[0166] Ex29. An aerosol-generating article according to any preceding claim in which the article comprises a first external surface and a second external surface facing in substantially the opposite direction to the first external surface, for example a first external surface and an opposing secondexternal surface, in which the airflow passage is defined through the aerosol-generating article between the air inlet and the air outlet.

[0167] Ex30. An aerosol-generating article according to example Ex29 in which one or more cavity is located within the aerosol-generating article between the first external surface and the second external surface.

[0168] Ex31. An aerosol-generating article according to any preceding example in which the aerosol-generating article is defined by an article length, an article width, and an article thickness, the article width being greater than the article thickness.

[0169] Ex32. An aerosol-generating article according to any of examples Ex29 to Ex31 in which the article comprises a frame positioned between the first external surface and the second external surface, the frame at least partially defining the airflow passage, for example in which side walls of the airflow passage are at least partially defined by the frame.

[0170] Ex33. An aerosol-generating article according to any of examples Ex29 to Ex32 in which the article comprises a frame positioned between the first external surface and the second external surface, the frame at least partially defining at least one cavity located within the airflow passage, for example in which side walls of the at least one cavity are at least partially defined by the frame.

[0171] Ex34. An aerosol-generating article according to any of examples Ex29 to Ex33 in which at least one of the first external surface and second external surface is a substantially planar surface, for example in which the first external surface is a substantially planar surface, for example in which both the first external surface and the second external surface is a substantially planar surface.

[0172] Ex35. An aerosol-generating article according to any of examples Ex29 to Ex34, wherein a thickness of the aerosol-generating article is less than 50 percent of both a length and a width of the aerosol-generating article.

[0173] Ex36. An aerosol-generating article according to any of examples Ex29 to Ex35, wherein the frame comprises a peripheral wall circumscribing or encircling the airflow passage, for example at least one cavity within the airflow passage.

[0174] Ex37. An aerosol-generating article according to example Ex36, wherein the peripheral wall is formed by a frame inner surface and a frame outer surface, and wherein the frame inner surface defines a cavity outer wall, and the frame outer surface at least partially defines one or more external walls of the aerosol-generating article.

[0175] Ex38. An aerosol-generating article according to Ex36 or Ex37, wherein the peripheral wall has a radial thickness between 1 millimetre and 3 millimetres.

[0176] Ex39. An aerosol-generating article according to any of examples Ex29 to Ex38, wherein the frame has a thickness greater than or equal to 80 percent of the thickness of the aerosol-generating article.

[0177] Ex40. An aerosol-generating article according to any of Ex29 to Ex39, wherein the frame has a thickness between 80 percent and 95 percent of the thickness of the aerosol-generating article.

[0178] Ex41. An aerosol-generating article according to any of examples Ex29 to Ex40, wherein the frame has a thickness between 1 millimetre and 5.5 millimetres.Examples will now be further described with reference to the figures in which:

[0179] Figure 1 is a perspective side view of an aerosol-generating article according to a first embodiment of the present disclosure;

[0180] Figure 2 is a perspective side view of an aerosol-generating article according to a second embodiment of the present disclosure;

[0181] Figure 3 is a schematic end view of an aerosol-generating article according to a third embodiment of the present disclosure;

[0182] Figure 4 is a schematic side view of the aerosol-generating article of figure 3;

[0183] Figure 5 is a schematic plan view of the aerosol-generating article of figure 3;

[0184] Figure 6 shows a schematic illustration of a corrugated element as used in the aerosolgenerating article of figure 3;

[0185] Figure 7 shows a perspective view of an aerosol-generating article according to an embodiment of the present disclosure;

[0186] Figure 8 shows an exploded perspective view of the aerosol-generating article of Figure 7; Figure 9 shows a further exploded perspective view of the aerosol-generating article of Figure 7;

[0187] Figure 10 shows a schematic transverse cross-sectional view of the aerosol-generating article of Figure 7; and

[0188] Figure 11 shows a schematic longitudinal cross-sectional view of the aerosol-generating article of Figure 7.

[0189] Figure 12 shows an exploded perspective view of an aerosol-generating article according to an embodiment of the present disclosure;

[0190] Figure 13 shows a schematic transverse cross-sectional view of the aerosol-generating article of Figure 12;

[0191] Figure 14 shows a schematic longitudinal cross-sectional view of the aerosol-generating article of Figure 12;

[0192] Figure 15 shows a schematic illustration of an apparatus for manufacturing the aerosolgenerating article of Figure 12;

[0193] Figure 1 illustrates a perspective side view of an aerosol-generating article 100 according to a first embodiment of the present disclosure. The aerosol-generating article 100 has upper and lower surfaces 110, 120 which are flat or planar.

[0194] The aerosol-generating article 100 comprises an internal cavity containing a first plurality of beads of aerosol-forming substrate (not shown) and a second plurality of beads of aerosol-forming substrate (not shown). In one embodiment, the aerosol-generating article 100 may consist substantially of aerosol-forming substrate in the form of the beads and other components. In another embodiment, the aerosol-forming substrate may be a subset of a plurality of component parts of the aerosol-generating article 100 (for example, only the beads). The aerosol-forming substrate is enclosed within an interior of the aerosol-generating article 100. Aerosol-forming substrate may at least partially define an exterior of the aerosol-generating article 100; for example, one or both of theupper and lower surfaces 110, 120 may comprise or consist of aerosol-forming substrate. One or more susceptor materials may be enclosed within an interior of the aerosol-generating article 100.

[0195] The aerosol-generating article 100 has a length, extending in an x dimension, of 80 millimetres, a width, extending in a y dimension, of 15 millimetres, and a height (which may also be referred to as a thickness), extending in a z dimension, of 3.6 millimetres.

[0196] Figure 2 illustrates a perspective side view of an aerosol-generating article 200 according to a second embodiment of the present disclosure, being a variant of aerosol-generating article 100. Features in common with aerosol-generating article 100 are referred to with like reference signs. An airflow path 230 is defined through the aerosol-generating article 200 between the upper and lower surfaces 110, 120. The airflow path 230 extends between opposed first and second ends 201 , 202 of the aerosol-generating article 200, and passes through a cavity 231 containing a first plurality of beads of aerosol-forming substrate 290 and a second plurality of beads of aerosol-forming substrate 295. The first end 201 may define a distal end of the aerosol-generating article 200, and the second end 202 may define a proximal end of the aerosol-generating article. The air flow path 230 may be directed towards a mouth of a user to allow a user to inhale aerosol generated. Parameters such as the total weight of aerosol-forming substrate 290, 295 within the cavity 230, density of aerosol-forming material within the cavity, and total porosity within the cavity, may be controlled by controlling the bead size and bead size distribution for the first plurality of beads 290 and a second plurality of 295.

[0197] In this specific embodiment, the beads of aerosol-forming substrate 290, 295 are substantially spherical beads. The first plurality of beads 290 have a mean diameter of 0.8 millimetres and a density of 1.3 grams per cubic centimetre. The second plurality of beads 295 have a mean diameter of 2 millimetres and a density of 1.3 grams per cubic centimetre. The total weight of beads 290, 295 in the substrate cavity 231 is approximately 150 mg. The beads 290, 295 are formed of an aerosol-forming substrate comprising plant particles, aerosol former and a hydrocolloid binder. An example of a suitable composition of the aerosol-forming substrate forming the beads is provided below.

[0198] Example

[0199] A suitable composition for forming beads of aerosol-forming substrate according to the invention is set out in Table 1 below:

[0200] Component Weight amount (%)

[0201] Tobacco particles 75.5

[0202] Glycerin 23.6

[0203] HPMC 0.9

[0204]

[0205] All amounts are shown as percentages by weight, on a dry weight basis, based on the total weight of the aerosol-generating element.

[0206] In order to make the beads, the tobacco particles are first mixed with glycerin. The HPMC binder is dispersed in glycerin and then water is added to form an aqueous binder solution. The binder solution is added to the mixture of tobacco particles and glycerin and all of the components are mixedto form a dough. The dough is extruded to form a plurality of discrete elements and the discrete elements are then spheronized at low speed to form spherical beads having an average diameter of 1.5 millimetres. The beads are dried in an oven to a desired moisture content. The dried beads can then be incorporated into a variety of different aerosol-generating articles, as described above.

[0207] When such beads were incorporated into an aerosol-generating article as described herein and heated, an aerosol was generated containing nicotine and glycerin from the aerosol-forming substrate. The ratio of nicotine to glycerin in each puff of aerosol was found to remain consistent over the duration of the heating. This is in contrast to the aerosol generated from an article having a similar construction but in which the aerosol-forming substrate is in the form of tobacco cast leaf. With the tobacco cast leaf substrate, the aerosol generated under the same conditions was found to have a much more variable ratio of nicotine to glycerin per puff. The provision of an aerosol with a more consistent ratio of nicotine to glycerin across puffs provides an optimal sensory experience to the consumer over the duration of the heating.

[0208] For exemplary purposes applicable to any of the embodiments described herein, a composition of aerosol-forming material that may be used to form the plurality of aerosol-forming beads may be as follows. Percentages are given in weight percent with respect to the product in its final state. The aerosol-forming substrate may have a moisture of about 5 to 25%, preferably of about 7 to 15%, at final product state. The aerosol-forming substrate may further comprise the following:

[0209] 1. Tobacco leaf; for example, about 15 to 45%, preferably of about 20 to 35% of a blend of tobacco leaf, incorporating at least one of the following tobacco types: bright tobacco; dark tobacco; aromatic tobacco. Tobacco material is ground and graded to a particle size of about 100 to 380 mesh, preferably of about 170 to 320 mesh.

[0210] 2. Cellulose fibres; for example, about 1 to 15%, preferably of about 3 to 7%, of cellulose fibres, of a length of about 10 to 250 pm, preferably of about 10 to 120 pm.

[0211] 3. Tobacco fibres; for example, about 5 to 20%, preferably of about 7 to 15% of tobacco fibres, as filler, of any tobacco type or a blend of tobacco types. Tobacco fibres are preferably derived from stems and / or or stalks, graded to fibres of a length of about 10 to 350 pm, preferably of about 10 to 180 pm.

[0212] 4. Binder; for example, about 1 to 10%, preferably of about 1 to 5%, of a binder such as any of common gums or pectins used in food and beverage (F&B) industries. Preferred binders may be natural pectins, such as fruit, for example citrus, or tobacco pectins; guar gums, land locust bean gums, such as hydroxyethyl and / or hydroxypropyl of those; starches, such as modified or derivatized starches; alginate; methyl, ethyl, ethylhydroxymethyl and carboxymethyl, celluloses; dextran; and xanthan gum. The preferable binder is guar.

[0213] 5. Aerosol-former; for example, about 5 to 35%, preferably of about 10 to 25%, of an aerosol former. Suitable aerosol-formers known in the art include: glycerine; monohydric alcohols like menthol, polyhydric alcohols, such as triethylene glycol; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyls of those.“Tobacco type” means one of the different varieties of tobacco, for example based on the distinct curing process that the tobacco undergoes before it is further processed in a tobacco product.

[0214] For exemplary purposes, a composition of a further aerosol-forming substrate, which may also be suitable for use as the aerosol-forming substrate in any of the embodiments described above is described below. Percentages are given in weight percent with respect to the product in its final state. The aerosol-forming substrate may comprise:

[0215] 1. An aerosol-former such as Glycerin; for example, about 10 to 40 %, preferably of about 20 to 30 %.

[0216] 2. Organic fibres; for example, about 10 to 30 %, preferably of about 15 to 25%, of any botanical variety suitable and with purity to comply with applicable FDA F&B grade requirements, as commonly available in the market. For example, organic fibres may derive from cellulose, cotton, wood, tea botanical varieties as sub-products, and sub-processed waste, of F&B tea industry. Organic fibres are preferably of a length of about 10 to 400 pm, preferably of about 10 to 200 pm.

[0217] 3. Organic botanical glycerite; for example, about 15 to 55 %, preferably of about 20 to 35 %, of botanicals such as Clove, Echinacea sp., Fennel, Ginger, Hawthorn berry, Elderberry, Monarda, Mullein leaves, Nettle, Plantain, Turmeric, Yarrow, and compounds of those. 4. Organic botanical extracts; for example about 1 to 15 %, preferably of about 2 to 7 %, of any of the previously referred botanicals, as well as menthol (dl-Menthol, C10H20O, 2-lsopropyl- 5-methylcyclohexanol) such as obtained from Chaerophyllum macrospermum, Mesosphaerum sidifolium, or other related botanic varieties, as well as P-menthan-3-ol, as any secondary alcohol as diastereoisomers of 5-methyl-2-(propan-2-yl)cyclohexan-1-ol. Alternatively, such aerosol-forming substrate may also contain botanical essential oils of about 0.5 to 5 %, preferably of about 1 to 3 %, such as of palm, coconut, and wooden-based essential oils.

[0218] A dough formed from any such aerosol-forming material may be extruded to form a plurality of discrete elements, and the discrete elements may then be spheronized at low speed to form substantially spherical beads having an average diameter of between 0.5 millimetres and 4 millimetres. The beads are dried in an oven to a desired moisture content. The dried beads can then be incorporated into a variety of different aerosol-generating articles, as described above.

[0219] Figures 3, 4, and 5 illustrate respectively an end view, a side view, and a plan view of an aerosolgenerating article 300 according to a third embodiment of the present disclosure. The aerosolgenerating article 300 comprises a planar upper layer 310, a planar lower layer 320, and an intermediate or separation layer 340 arranged between the upper layer 310 and lower layer 320.

[0220] The planar upper layer 310 is formed from a sheet of paper having a thickness of 100 microns. The planar lower layer 320 is formed from a sheet of paper having a thickness of 100 microns. The intermediate layer 340 is a corrugated element formed from a corrugated sheet of paper 345. A suitable aerosol-forming substrate may be beads of tobacco material 390 located within longitudinal cavities 361 , 362 formed by the corrugated sheet. The first plurality of beads of tobacco material 390 may be as described above in relation to figure 1.Figure 6 illustrates the corrugated sheet of paper 345. The corrugations have an amplitude 346 of 3 millimetres and a wavelength 347 of 3 millimetres. The corrugated sheet of paper 345 forming the intermediate layer 340 has a thickness of 150 microns.

[0221] Points of intersection 351, 352 between the upper layer 310 and the intermediate layer 340 and between the lower layer 320 and the intermediate layer 340 comprise an adhesive that joins the respective layers.

[0222] The aerosol-generating article 300 has a length, extending in an x dimension, of 80 millimetres, a width, extending in a y dimension, of 15 millimetres, and a height (or thickness), extending in a z dimension, of 3.6 millimetres.

[0223] Corrugations of the intermediate layer 340 form a first set of longitudinally extending cavities or channels 361 that are bounded by the upper layer 310 and the intermediate layer 340, and a second set of longitudinally extending cavities or channels 362 bounded by the lower layer 320 and the intermediate layer 340. The first and second sets of longitudinally extending channels 361 , 362 extend through the length of the corrugated sheet between a proximal end 371 of the sheet 345 and a distal end 372 of the sheet 345. The longitudinally extending channels 361, 362 contain beads of aerosolforming substrate 390 and also define an air-flow path through the sheet 345. The air-flow path, therefore, passes over of the beads of aerosol-forming substrate.

[0224] The corrugated sheet 345 may be a material other than paper, for example the corrugated sheet may be a sheet of any suitable aerosol-forming substrate.

[0225] Figure 7 shows an aerosol-generating article 600 according to an embodiment of the present disclosure but the aerosol-forming substrate is not shown in Figure 7 for clarity. The aerosolgenerating article 600 comprises a first planar external layer 624 forming a first planar external surface 621 , a second planar external layer 625 forming a second planar external surface 622, and a frame 650 positioned between the first planar external layer 624 and the second planar external layer 625. The second planar external surface 622 is positioned parallel to the first planar external surface 621.

[0226] Figures 8 and 9 show exploded views of the aerosol-generating article 600 of Figure 7. The frame 650 circumscribes and at least partially defines a cavity 630. Figure 8 shows the cavity 630 in an empty state. Figure 9 shows a first portion of the cavity 631 filled with a first plurality of beads of aerosol-forming substrate 741 and a second portion of the cavity 632 filled with a second plurality of beads of aerosol-forming substrate 742. The first portion of the cavity 631 occupies a greater volume of the cavity 630 than the second portion of the cavity 632.

[0227] Figures 10 and 11 show respective transverse and longitudinal cross-sectional views of the aerosol-generating article 600 through the first portion of the cavity 630 filled with the first plurality of beads of aerosol-forming substrate 741.

[0228] The first planar external layer 624 and the second planar external layer 625 are made from sheets of paper, and are in physical contact, with and bonded to, the frame 650. The first planar external layer 624 overlies a first end of the cavity 630 and forms a first cavity end wall 631. The second planar external layer 625 overlies a second end of the cavity 630 and forms a second cavity end wall 632, the second cavity end wall 632 being opposite to the first cavity end wall 631. That is,the frame 650, the first planar external layer 624 and the second planar external layer 625 collectively define the cavity 630.

[0229] The frame 650 has a hollow cuboid shape and is made from cardboard. The frame 650 defines an aperture extending through the height (also referred to as the thickness) of the frame 650 and the aperture at least partially forms the cavity 630 of the aerosol-generating article 600. The frame 650 comprises a peripheral wall 651 that circumscribes the cavity 630. The peripheral wall 651 includes a front wall 613 and a back wall 614. In more detail, the peripheral wall 651 is defined by an inner transverse surface 652 of the frame 450 and an outer transverse surface 653 of the frame 650. The inner transverse surface 652 of the peripheral wall 651 at least partially defines a perimeter of the cavity 630. The outer transverse surface 653 of the peripheral wall 651 at least partially defines a perimeter of the aerosol-generating article 600. The peripheral wall 651 has a radial thickness measured between the inner transverse surface 652 of the frame 650 and the outer transverse surface 653 of the frame 650 of about 5 millimetres.

[0230] An air inlet 611 and an air outlet 612 are defined by, and extend through, the peripheral wall 651 of the frame 650. More specifically, the air inlet 611 extends through the front wall 613 and the air outlet 612 extends through the back wall 614. The air inlet 611 and the air outlet 612 have an equivalent diameter of 5 millimetres. An airflow passage extends between the air inlet 611 and the air outlet 612 through the cavity 630. As shown in Figures 11 to 13, a first portion of the cavity 631 is filled with a first plurality of beads of aerosol-forming substrate 741 and a second portion of the cavity 632 is filled with a second plurality of beads of aerosol-forming substrate 742. The first plurality of beads of aerosol-forming substrate 741 and second plurality of beads of aerosol-forming substrate 742 comprise tobacco. The first plurality of beads of aerosol-forming substrate 741 are defined by a first average particle diameter of 0.75 millimetres. The second plurality of beads of aerosol-forming substrate 742 are defined by a second average particle diameter of 2 millimetres. As shown, the first plurality of beads of aerosol-forming substrate 741 and second plurality of beads of aerosol-forming substrate 742 fill the entire volume of the cavity 630, and airflow through the cavity is provided by interstices between free-flowing particles. Each of the beads in the first plurality of beads of aerosolforming substrate 741 may be larger than an interstitial gap size of the second plurality of beads of aerosol-forming substrate 742. This advantageously allows the second plurality of beads of aerosolforming substrate 742 to act as a mechanical barrier to prevent the flow of beads from the first plurality of beads of aerosol-forming substrate 742 through the interstitial gaps between each of the second plurality of beads of aerosol-forming substrate 742.

[0231] The aerosol-generating article 600 has a cuboid shape and has a height (or thickness) extending in a z dimension, as measured between the first planar external surface 621 and the second planar external surface 622, of 8 millimetres, a width extending in a y dimension of 40 millimetres and a length extending in an x dimension of 60 millimetres. The frame 650 has a height (or thickness) extending in a z dimension of 7.93 millimetres, a width extending in a y dimension of 40 millimetres and a length extending in an x dimension of 60 millimetres. The cavity 630 has a height (or thickness) extending ina z dimension of 7.93 millimetres, a width extending in a y dimension of 39.93 millimetres and a length extending in an x dimension of 52 millimetres.

[0232] Figure 12 shows an exploded view of an aerosol-generating article 700 according to another embodiment of the present disclosure. The aerosol-generating article 700 comprises a first planar external layer 724 forming a first planar external surface 721, a second planar external layer 725 forming a second planar external surface 722, and a frame 750 positioned between the first planar external layer 724 and the second planar external layer 725. The second planar external surface 722 is positioned parallel to the first planar external surface 721. The first planar external Iayer724, second planar external layer 725 are substantially the same as the first planar external layer 624, second planar external layer 625 of Figure 7.

[0233] The frame 750 is similar to the frame 650 of Figure 7, except that the frame 750 of Figures 12 to 14 defines three cavities 731, 732, 733 instead of one cavity. Therefore, Figures 12 to 14 will be described with respect to its differences only.

[0234] The article 700 defines an air flow passage between air inlet (not shown) and air outlet 712. The frame 750 circumscribes and at least partially defines a first cavity 731 , second cavity 732 and third cavity 733. Each of the first, second and third cavity 731, 732, 733 is located within the aerosolgenerating article 700 between the first external surface 721 and the second external surface 722. The first, second and third cavities 731, 732 and 733 are arranged in series such that the air flow passage in defined from the air inlet to the air outlet 712 through the third cavity 733, then the first cavity 731, then the second cavity 732. Each cavity 731, 732, 733 partially defines a portion of the air flow passage.

[0235] The frame 750 comprises a first dividing wall 761 , which separates the second cavity 732 and the first cavity 731. The first dividing wall 761 extends in the direction of the width of the article 700. The first dividing wall 761 defines a first opening 771 extending through the first dividing wall 761 from the second cavity 732 to the first cavity 731. The opening of the first dividing wall 761 defines at least a portion of the airflow passage between the air inlet and the air outlet 712. The frame 750 comprises a second dividing wall 762 which separates the third cavity 733 and the first cavity 731. The second dividing wall 762 extends in the direction of the width of the article 700. The second dividing wall 762 defines a second opening 772 extending through the second dividing wall 762 from the third cavity 733 to the first cavity 731. The opening of the second dividing wall 762 defines at least a portion of the airflow passage between the air inlet and the air outlet 712. In this embodiment, the first and second openings 771, 772 partition the first dividing wall 761 and second dividing wall 762, respectively.

[0236] The first cavity 731 is filled with a first plurality of beads of aerosol-forming substrate 741. The second cavity 732 and third cavity 733 are filled with a second plurality of beads of aerosol-forming substrate 742. The first plurality of beads of aerosol-forming substrate 741 may be substantially the same as the first plurality of beads of aerosol-forming substrate 741 of Figures 9 to 11. The second plurality of beads of aerosol-forming substrate 741 may be substantially the same as the second plurality of beads of aerosol-forming substrate 741 of Figures 9 to 11. Thus, the second plurality of beads of aerosol-forming substrate 742 act as barrier, or mechanical retaining means, for retainingthe first plurality of beads of aerosol-forming substrate 741 within the airflow passage. In this embodiment, the first and second plurality of beads 741, 742 are substantially spherical particles containing tobacco. The second average particle diameter is larger than a thickness of the air outlet 712 and a thickness of the air inlet, such that both the first and second plurality of beads 741, 742 are substantially prevented from passing through the air inlet or air outlet 712.

[0237] Figure 13 shows a transverse cross-section through the second cavity 732 of the aerosolgenerating article 700 of Figure 12. Figure 14 shows a longitudinal cross-sectional view of the aerosolgenerating article 700 of Figure 12.

[0238] When the aerosol-generating article 700 is in use, heat is applied to at least one of the first and / or second external surfaces 721 , 722 such that the first and second plurality of beads of aerosolforming substrate 741, 742 generate inhalable aerosol particles. A user may draw air along the airflow passage such air enters through the air inlet 711 and the inhalable aerosol particles generated by the first and second plurality of beads of aerosol-forming substrate 741 , 742 are entrained in the air flow before exiting at the air outlet 712.

[0239] Figure 15 is a schematic illustration of an apparatus 800 that may be used for the manufacture of the aerosol-generating article 700 of Figures 12 to 14. The apparatus 800 comprises a first dispenser 811, second dispenser 812, and third dispenser 813. The first dispenser is configured to dispense the first plurality of beads of aerosol-forming substrate 741 into the first cavity 731 of the aerosol-generating article 700. The second and third dispensers 812, 813 are configured to dispense the second plurality of beads of aerosol-forming substrate 742 into the second and third cavities 732, 733 of the aerosol-generating article 700, respectively. The second dispenser 812 is substantially the same as the third dispenser 813. In use, the dispensers 811 , 812 and 813 are configured to dispense the first and second plurality of beads 741 , 742 simultaneously.

[0240] For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term “about”. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number “A” is understood as “A” ± 10% of “A”. Within this context, a number “A” may be considered to include numerical values that are within general standard error for the measurement of the property that the number “A” modifies. The number “A”, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which “A” deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. The terms “in which” and “wherein” are used synonymously through this specification.

Claims

CLAIMS1. An aerosol-generating article for use with an aerosol-generating device to generate an aerosol, the aerosol-generating article comprising;an airflow passage defined through the aerosol-generating article between an air inlet and an air outlet, anda first plurality of free-flowing particles located within the airflow passage, the first plurality of free-flowing particles being defined by a first average particle diameter, anda second plurality of free-flowing particles located within the airflow passage, the second plurality of free-flowing particles being defined by a second average particle diameter, in which.the first plurality of free-flowing particles is located in a first portion of the airflow passage and the second plurality of free-flowing particles is located in a second portion of the airflow passage different to the first portion of the airflow passage, and in which the second average particle diameter is greater in magnitude than the first average particle diameter.

2. An aerosol-generating article for use with an aerosol-generating device to generate an aerosol, the aerosol-generating article, for example an aerosol-generating article according to claim 1, comprising;an airflow passage defined through the aerosol-generating article between an air inlet and an air outlet, anda first plurality of free-flowing particles located within the airflow passage, the first plurality of free-flowing particles being defined by a first average particle diameter, anda mechanical retaining means for retaining the first plurality of free-flowing particles within the airflow passage, the mechanical retaining means comprising a second plurality of free-flowing particles defined by a second average particle diameter, in which the second average particle diameter is greater in magnitude than the first average particle diameter.

3. An aerosol-generating article according to any preceding claim in which at least one of the first plurality of free-flowing particles and the second plurality of free-flowing particles comprises aerosolforming material.

4. An aerosol-generating article according to any preceding claim in which at least one of the first plurality of free-flowing particles and the second plurality of free-flowing particles are low aspect ratio particles, for example spheroid particles, for example substantially spherical particles.

5. An aerosol-generating article according to any preceding claim in which at least one of the first plurality of free-flowing particles and the second plurality of free-flowing particles may be defined by an average particle length, an average particle width, and an average particle height, in which the ratio of the greatest of the average particle length, average particle width, and average particle height tothe least of the average particle length, average particle width, and average particle height for the first plurality of free-flowing particles is less than 2:1.

6. An aerosol-generating article according to any preceding claim in which at least one of the first plurality of free-flowing particles and the second plurality of free-flowing particles is defined by a particle size distribution having a D10 diameter and a D90 diameter.

7. An aerosol-generating article according to any preceding claim in which the first plurality of free-flowing particles has a first average particle diameter of between 0.1 mm and 1.5 mm.

8. An aerosol-generating article according to any preceding claim in which the second plurality of free-flowing particles has an average particle diameter of between 1 mm and 4 mm.

9. An aerosol-generating article according to claim 7 and 8 in which the second average particle diameter is greater in magnitude than the first average particle diameter.

10. An aerosol-generating article according to any preceding claim in which the air outlet is defined by one or more apertures allowing air flow out of the aerosol-generating article, in which the second plurality of free-flowing particles located within the airflow passage are dimensioned such that they are substantially prevented from passing through the one or more apertures of the air outlet.

11. An aerosol-generating article according to any preceding claim, in which the second plurality of free-flowing particles functions as a barrier to retain the first plurality of free-flowing particles within the aerosol-generating article.

12. An aerosol-generating article according to any preceding claim comprising a first cavity and a second cavity arranged in series within the airflow channel, in which the second cavity is located in downstream of the first cavity, in which the first plurality of free-flowing particles is located in the first cavity and the second plurality of free flowing particles is located in the second cavity.

13. An aerosol-generating article according to claim 12 in which the first cavity has a different volume to the second cavity.

14. An aerosol-generating article according to claim 12 or 13, further comprising a third cavity arranged in series with the first cavity and the second cavity within the airflow channel, the third cavity being located in series with and upstream of the first cavity, in which a portion of the second plurality of free flowing particles is located in the second cavity and in which a further portion of the second plurality of free flowing particles is located in the third cavity.

15. An aerosol-generating article according to any preceding claim in which the article comprises a first external surface and a second external surface facing in substantially the opposite direction to the first external surface, for example a first external surface and an opposing second external surface, in which the airflow passage is defined through the aerosol-generating article between the air inlet and the air outlet.

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