Extrudable composition and extruded aerosol-generating material

Abstract

An extrudable composition is described comprising: a particulate filler material; a liquid carrier; and a polyacrylic acid binder. Extruded aerosol-forming rods are also described, along with aerosol-forming articles, for example heated tobacco products, containing such rods.

Description

FIELD

[0001] The present disclosure relates to an extrudable composition. More specifically, the present disclosure relates to an extrudable composition comprising a particulate filler material, a liquid carrier and a polyacrylic acid binder. Extruded aerosol-forming materials and aerosol-forming articles containing such materials are also disclosed.BACKGROUND

[0002] A heat-not-burn (HNB) device, also known as a heated tobacco device, is a type of aerosol-generating system in which an aerosol precursor (e.g., a solid precursor such as tobacco) is heated by a heating system to produce an aerosol that can be inhaled by the user.

[0003] The aerosol precursor contains an aerosol-generating material, often including particulate tobacco or non-tobacco material (e.g. tea), along with aerosol-forming liquid components such as glycerin and / or propylene glycol. Other additives such as flavourants may also be present.

[0004] Some such aerosol precursors contain a collection or strands or shreds of sheet material, or pleated sheets of material. Others may be formed by extruding a paste containing a slurry of components, before drying the paste to produce the aerosol precursor.

[0005] Although extrusion is a convenient method to produce such aerosol precursors, there is a need for improved extrusion methods which lead to corresponding improved products having higher stability and an improved experience for the user.

[0006] It is against this background that the present invention has been developed.SUMMARY

[0007] The present disclosure provides an extrudable composition comprising a particulate filler material, a liquid carrier and a binder.

[0008] In some embodiments, the extrudable composition comprises a particulate filler material, a liquid carrier, and a polyacrylic acid binder.

[0009] It has been found that a polyacrylic acid binder is particularly suitable for extrudable compositions which are formed into aerosol precursors for a HNB article, because they are able to bind together the particulate filler material in a stable and homogeneous way which may provide a more consistent user experience. Furthermore, other common binders such as guar gum tend to form a solid mass after extrusion which hinders the ability of the aerosol precursor to produce aerosol when heated. By contrast, the polyacrylic acid binder remains in a flowable form, facilitating reliable aerosol production.

[0010] In some embodiments, the extrudable composition contains no water, or contains water in an amount of less than 3 wt% based on the total weight of the extrudable composition.

[0011] In this way, the extrudable composition can be described as "non-aqueous". Other extrudable compositions are prepared from a mixture which includes added water. This is necessary because many binders require additional water in order to "thicken" to facilitate proper binding of the particulate filler material. However a result of this high water content is that the first few puffs from a HNB article by a user tend to be very hot, due to the evaporation of steam from the aerosol-forming material upon heating. This experience is undesirable for the user.

[0012] It has surprisingly been found that by using the polyacrylic acid binder, it is not necessary to add water to the extrudable composition, such that the water content of the extrudable composition is below 3 wt%. The polyacrylic acid binder is able to bind the composition sufficiently well without the need to add any water to the composition, beyond the very small amount of water which may naturally be present within the other components. This provides a number of benefits. Firstly, the user experience is improved because the "hot initial puff' effect is mitigated or avoided. Secondly, no drying of the composition after extrusion is necessary due to the existing low water content. Drying of such compositions increases the cost and complexity of manufacture, and has detrimental effects on the product. For example, drying of an aqueous extruded product to remove water creates cracks (porosity) in the product and causes it to shrink, negatively impacting the dimensional stability of the product. The higher porosity means that the product may be more likely to absorb water from the environment (the average humidity inside the pocket of a user is 95-100%), again leading to poor dimensional stability since the dimensions of the product may change depending on the ambient humidity level. In addition, drying increases the brittleness of the product, increasing the likelihood that the product will be damaged during transport.

[0013] The extrudable composition of the invention may therefore be used to manufacture an aerosol precursor which has better stability, is less likely to be damaged during transport and provides an improved user experience.

[0014] In some embodiments, the particulate filler material comprises or consists of particulate tobacco. In this way, a tobacco-containing aerosol precursor is produced by extrusion of the extrudable composition, and heating of the aerosol precursor during use produces a nicotine-containing aerosol through volatilisation of nicotine from the tobacco. The particulate tobacco may comprise milled or ground tobacco material.

[0015] In some embodiments, the particulate filler material comprises or consists of particulate non-tobacco material. In some embodiments, the particulate filler material comprises or consists of particulate non-tobacco plant material. In some embodiments, the particulate filler material consists of particulate non-tobacco material, and the extrudable composition does not contain any tobacco material. Any suitable non-tobacco plant-based filler material may be used, for example one or more types of plant fiber. In some embodiments, the particulate filler material comprises or consists of particulate non-tobacco material comprising a psychoactive compound. For example, the particulate filler material may comprise or consist of tea.

[0016] In some embodiments, the extrudable composition comprises an active compound. In some embodiments, the active compound forms part of the particulate filler material. For example, tobacco contains nicotine as an active compound. However in other embodiments the active compound may be included in the extrudable composition as a distinct ingredient. For example, when the extrudable composition contains non-tobacco particulate filler material, an active compound may also be present in the extrudable composition and may be introduced separately from the particulate filler material.

[0017] The active compound may be any suitable biologically active, volatile compound which imparts a desired physical or psychological effect on the user. The active compound may be a stimulant. The active compound may be a depressant. Suitable active compounds include nicotine, cocaine, caffeine, THC, CBD, opiates and opioids, cathine and cathinone, cannabinoids, kavalactones, mysticin, beta-carboline alkaloids, salvinorin A, together with any combinations, functional equivalents to, and / or synthetic alternatives of the foregoing.

[0018] In some examples, the active compound comprises nicotine or a nicotine salt. In this way, the aerosol-generating article may deliver the user with a delayed hit of nicotine towards the end of a smoking session. In some examples, the active compound comprises nicotine (i.e. free base nicotine). In some examples, the active compound comprises a nicotine salt.

[0019] In some examples, the particulate filler material is a non-tobacco particulate filler material, for example non-tobacco plant fiber, and the active compound comprises nicotine or a nicotine salt.

[0020] In some embodiments, the particulate filler material is present in an amount of at least 50 wt% based on the total weight of the extrudable composition, for example at least 55 wt%, at least 60 wt% or at least 65 wt%. In some embodiments, the particulate filler material is present in an amount of up to 85 wt% based on the total weight of the extrudable composition, for example up to 80 wt% or up to 75 wt%.

[0021] In some embodiments, the particulate filler material is present in an amount of from 50 to 85 wt% based on the total weight of the extrudable composition, for example from 55 to 80 wt%, from 60 to 80 wt% or from 65 to 75 wt%.

[0022] In some embodiments, the polyacrylic acid binder is present in an amount of at least 0.1 wt%, for example at least 0.15 wt%, at least 0.2 wt%, at least 0.25 wt%, at least 0.3 wt%, at least 0.35 wt%, at least 0.4 wt%, at least 0.45 wt% or at least 0.5 wt%, based on the total weight of the extrudable composition.

[0023] In some embodiments, the polyacrylic acid binder is present in an amount of up to 2 wt%, for example up to 1.9 wt%, up to 1.8 wt%, up to 1.7 wt%, up to 1.6 wt%, up to 1.5 wt%, up to 1.4 wt%, up to 1.3 wt%, up to 1.2 wt%, up to 1.1 wt%, up to 1.0 wt%, up to 0.9 wt% or up to 0.8 wt%, based on the total weight of the extrudable composition.

[0024] In some embodiments, the polyacrylic acid binder is present in an amount of from 0.4 to 1.0 wt% based on the total weight of the extrudable composition. For example, in some embodiments, the polyacrylic acid binder is present in an amount of from 0.4 to 1.0 wt%, from 0.45 to 1.0 wt%, from 0.5 to 1.0 wt%, from 0.55 to 1.0 wt%, from 0.6 to 1.0 wt%, from 0.65 to 1.0 wt%, from 0.7 to 1.0 wt%, from 0.75 to 1.0 wt%, from 0.8 to 1.0 wt%, from 0.85 to 1.0 wt%, from 0.9 to 1.0 wt%, from 0.95 to 1.0 wt%, from 0.4 to 0.95 wt%, from 0.4 to 0.9 wt%, from 0.4 to 0.85 wt%, from 0.4 to 0.8 wt%, from 0.4 to 0.75 wt%, from 0.4 to 0.7 wt%, from 0.4 to 0.65 wt%, from 0.4 to 0.6 wt%, from 0.4 to 0.55 wt%, from 0.4 to 0.5 wt%, or from 0.4 to 0.45 wt%, based on the total weight of the extrudable composition. In some embodiments, the polyacrylic acid binder is present in an amount of from 0.5 to 1.0 wt% based on the total weight of the extrudable composition, for example from 0.5 to 0.9 wt%, or from 0.6 to 0.8 wt%.

[0025] In some embodiments, the polyacrylic acid binder comprises or consists of a polyacrylic acid polymer. In some embodiments, the polyacrylic acid binder comprises or consists of a polyacrylic acid polymer having cross-linked polymer chains. In some embodiments, the polyacrylic acid binder comprises or consists of a polyacrylic acid polymer having a number-average molecular weight, M n , of at least 1 x 10 9< Da, as determined by GPC. In some embodiments, the polyacrylic acid binder comprises or consists of a cross-linked polyacrylic acid polymer having a number-average molecular weight, M n , of at least 1 x 10 9< Da, as determined by GPC.

[0026] In some embodiments, the polyacrylic acid binder comprises or consists of a polyacrylic acid polymer having a logP value of greater than 0, wherein P is the octanol / water partition coefficient. The octanol / water partition coefficient provides an indication of the lipophilicity of a molecule: a positive value of logP means that the value of P is greater than 1, indicating that a molecule is more hydrophobic (lipophilic). The octanol / water partition coefficient is determined using the "shake flask" method, by dissolving a sample of the polymer in a biphasic mixture of n-octanol and water, and determining the resultant ratio of the concentrations of the polymer in the n-octanol and water phases.

[0027] The use of such a lipophilic polymer binder may provide a material with more stable binding of the particulate filler material and which is less likely to absorb water from the environment, thereby providing the benefits of low water content described above.

[0028] In some embodiments, the polyacrylic acid binder comprises or consists of a polyacrylic acid polymer having a viscosity of from 4000 to 11,000 cP, measured at 25 °C using a Brookfield RVT at 20 rpm, neutralized to pH 7.3-7.8, with 0.5 wt% mucilage and spindle #5.

[0029] In some embodiments, the polyacrylic acid binder comprises or consists of a polyacrylic acid polymer having: a viscosity of from 4000 to 11,000 cP, measured at 25 °C using a Brookfield RVT at 20 rpm, neutralized to pH 7.3-7.8, with 0.5 wt% mucilage and spindle #5; a number-average molecular weight, M n , of at least 1 x 10 9< Da, as determined by GPC; and a logP value of greater than 0.

[0030] Suitable polyacrylic acid binders include polymers sold under the trade name "Carbomer". One example of a suitable polyacrylic acid binder is the Carbomer sold by the Lubrizol Corporation under the name Carbopol 971P NF.

[0031] In some embodiments, the extrudable composition further comprises an auxiliary binder component. Such an auxiliary binder component may supplement the binding ability of the polyacrylic acid binder to improve the physical properties of the extrudable composition.

[0032] Suitable binders are known in the art and may act to bind together the components forming the extrudable material. Binders may comprise starches and / or cellulosic binders such as methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose and methyl cellulose, gums such as xanthan, guar, arabic and / or locust bean gum, organic acids and their salts such as alginic acid / sodium alginate, agar and pectins.

[0033] In some embodiments, the auxiliary binder component comprises or consists of a gum. In some embodiments, the auxiliary binder component comprises or consists of a natural gum. As used herein, a natural gum refers to polysaccharide materials of natural origin that have binding properties, and which are also useful as a thickening or gelling agents. Representative natural gums derived from plants, which are typically water soluble to some degree, include konjac gum, xanthan gum, guar gum, gum arabic, ghatti gum, gum tragacanth, karaya gum, locust bean gum, gellan gum, and combinations thereof.

[0034] In some embodiments, the auxiliary binder component comprises or consists of konjac gum. It has been found that konjac gum works particularly well alongside the polyacrylic acid binder to provide effective and stable binding of the particulate filler material without the need for any added water, and the resultant extruded aerosol precursor has good physical properties and reliably produces aerosol when heated.

[0035] In some embodiments, the extrudable composition comprises a binder component which consists of a mixture of the polyacrylic acid binder and a natural gum. In some embodiments, the extrudable composition comprises a binder component which consists of a mixture of the polyacrylic acid binder and konjac gum. In some embodiments, the extrudable composition comprises a binder component which consists of a mixture of a carbomer and konjac gum. In some embodiments, the extrudable composition comprises a binder component which consists of a mixture of Carbopol 971P NF and konjac gum.

[0036] In some embodiments, the auxiliary binder component is present in an amount of at least 0.1 wt%, for example at least 0.15 wt%, at least 0.2 wt%, at least 0.25 wt%, at least 0.3 wt%, at least 0.35 wt%, at least 0.4 wt%, at least 0.45 wt% or at least 0.5 wt%, based on the total weight of the extrudable composition.

[0037] In some embodiments, the auxiliary binder component is present in an amount of up to 2 wt%, for example up to 1.9 wt%, up to 1.8 wt%, up to 1.7 wt%, up to 1.6 wt%, up to 1.5 wt%, up to 1.4 wt%, up to 1.3 wt%, up to 1.2 wt%, up to 1.1 wt%, up to 1.0 wt%, up to 0.9 wt% or up to 0.8 wt%, based on the total weight of the extrudable composition.

[0038] In some embodiments, the auxiliary binder component is present in an amount of from 0.4 to 1.0 wt% based on the total weight of the extrudable composition. For example, in some embodiments, the auxiliary binder component is present in an amount of from 0.4 to 1.0 wt%, from 0.45 to 1.0 wt%, from 0.5 to 1.0 wt%, from 0.55 to 1.0 wt%, from 0.6 to 1.0 wt%, from 0.65 to 1.0 wt%, from 0.7 to 1.0 wt%, from 0.75 to 1.0 wt%, from 0.8 to 1.0 wt%, from 0.85 to 1.0 wt%, from 0.9 to 1.0 wt%, from 0.95 to 1.0 wt%, from 0.4 to 0.95 wt%, from 0.4 to 0.9 wt%, from 0.4 to 0.85 wt%, from 0.4 to 0.8 wt%, from 0.4 to 0.75 wt%, from 0.4 to 0.7 wt%, from 0.4 to 0.65 wt%, from 0.4 to 0.6 wt%, from 0.4 to 0.55 wt%, from 0.4 to 0.5 wt%, or from 0.4 to 0.45 wt%, based on the total weight of the extrudable composition. In some embodiments, the auxiliary binder component is present in an amount of from 0.5 to 1.0 wt% based on the total weight of the extrudable composition, for example from 0.5 to 0.9 wt%, or from 0.6 to 0.8 wt%.

[0039] In some embodiments, the weight ratio of the polyacrylic acid binder to the auxiliary binder component is from 2:1 to 1:2, for example from 1.5:1 to 1:1.5, for example from 1.2:1 to 1:1.2, for example from 1.1:1 to 1:1.1, for example about 1:1. Particularly good binding properties have been observed when the polyacrylic acid binder and the auxiliary binder component are present in approximately equal quantities by weight.

[0040] In some embodiments, the extrudable composition further comprises a structurant selected from plant fibres. As used herein, the term "structurant" refers to a solid material included in the composition primarily to provide structure, for example a particulate or fibrous material. In some embodiments, the extrudable composition does not contain any structurant other than the particulate filler material. In some embodiments, the extrudable composition comprises a structurant in addition to the particulate filler material. The structurant may be selected from plant fiber, for example one or more of wheat fiber, oat fiber and bamboo fiber. Suitable structurants are known in the art and may act to strengthen the material. Structurants may comprise fibrous (non-tobacco) fillers such as cellulose fibers, lignocellulose fibers (e.g. wood fibers), jute fibers and combinations thereof.

[0041] In some embodiments, the extrudable composition comprises a structurant (other than the particulate filler material described above) in an amount of up to 10 wt% based on the total weight of the extrudable composition, for example up to 9.5 wt%, up to 9 wt%, up to 8.5 wt% or up to 8 wt%. In some embodiments, the extrudable composition comprises a structurant (other than the particulate filler material described above) in an amount of from 0 to 10 wt%, for example from 0 to 9.5 wt%, from 0 to 9 wt%, from 0 to 8.5 wt%, from 0 to 8 wt%, from 0.1 to 8 wt%, from 0.5 to 8 wt% or from 1 to 8 wt%, based on the total weight of the extrudable composition.

[0042] In some embodiments, the density of the extrudable composition is greater than 1.0 g cm -3< , for example greater than 1.05 g cm -3< , greater than 1.10 g cm -3< , greater than 1.15 g cm -3< , greater than 1.20 g cm -3< , greater than 1.21 g cm -3< or greater than 1.22 g cm -3< .

[0043] In some embodiments, the density of the extrudable composition is from 1.0 g cm -3< to 1.5 g cm -3< , for example from 1.1 g cm -3< to 1.5 g cm -3< , from 1.2 g cm -3< to 1.5 g cm 3< , from 1.2 g cm -3< to 1.4 g cm -3< , from 1.2 g cm -3< to 1.3 g cm -3< , from 1.21 g cm -3< to 1.3 g cm -3< , from 1.22 g cm -3< to 1.3 g cm -3< , from 1.22 g cm -3< to 1.28 g cm -3< , from 1.22 g cm -3< to 1.26 g cm -3< , from 1.22 g cm -3< to 1.24 g cm -3< or from 1.22 g cm -3< to 1.23 g cm -3< .

[0044] The liquid carrier is a liquid fraction of the extrudable composition which provides flowability and extrudability, enables the components of the composition to mix and facilitates the formation of aerosol by the composition after extrusion. In some embodiments, the liquid carrier comprises or consists of one or more of glycerin and propylene glycol. In some embodiments, the liquid carrier comprises glycerin. In some embodiments, the liquid carrier comprises or consists of a mixture of glycerin and propylene glycol. In some embodiments, the liquid carrier consists of a mixture of glycerin and propylene glycol.

[0045] A mixture of glycerin and propylene glycol has been found to provide particularly good properties of the composition. Without wishing to be bound by theory, it is believed that the propylene glycol acts as a suitable carrier for the polyacrylic acid binder, with the polyacrylic acid binder thickening in the presence of the propylene glycol. The glycerin provides good aerosol formation in the form of a visible cloud of aerosol which is desirable to users. Thus a mixture of glycerin and propylene glycol provides a stable product with good properties during use.

[0046] In some embodiments, the extrudable composition comprises the liquid carrier in an amount of at least 15 wt% based on the total weight of the extrudable composition, for example at least 16 wt%, at least 17 wt%, at least 18 wt%, at least 19 wt% or at least 20 wt%. In some embodiments, the extrudable composition comprises the liquid carrier in an amount of up to 40 wt% based on the total weight of the extrudable composition, for example up to 35 wt%, up to 34 wt%, up to 33 wt%, up to 32 wt%, up to 31 wt% or up to 30 wt%. In some embodiments, the extrudable composition comprises the liquid carrier in an amount of from 15 to 40 wt% based on the total weight of the extrudable composition, for example from 16 to 35 wt%, from 17 to 34 wt%, from 18 to 33 wt%, from 18 to 32 wt%, from 19 to 31 wt% or from 20 to 30 wt%.

[0047] In some embodiments, the extrudable composition comprises glycerin in an amount of at least 10 wt% based on the total weight of the extrudable composition, for example at least 11 wt%, at least 12 wt%, at least 13 wt%, at least 14 wt% or at least 15 wt%. In some embodiments, the extrudable composition comprises glycerin in an amount of up to 25 wt% based on the total weight of the extrudable composition, for example up to 24 wt%, up to 23 wt%, up to 22 wt%, up to 21 wt% or up to 20 wt%. In some embodiments, the extrudable composition comprises glycerin in an amount of from 10 to 25 wt% based on the total weight of the extrudable composition, for example from 11 to 24 wt%, from 12 to 23 wt%, from 13 to 22 wt%, from 14 to 21 wt% or from 15 to 20 wt%.

[0048] In some embodiments, the extrudable composition comprises propylene glycol in an amount of at least 2 wt% based on the total weight of the extrudable composition, for example at least 3 wt%, at least 4 wt% or at least 5 wt%. In some embodiments, the extrudable composition comprises propylene glycol in an amount of up to 15 wt% based on the total weight of the extrudable composition, for example up to 14 wt%, up to 13 wt%, up to 12 wt%, up to 11 wt% or up to 10 wt%. In some embodiments, the extrudable composition comprises propylene glycol in an amount of from 2 to 15 wt% based on the total weight of the extrudable composition, for example from 3 to 14 wt%, from 3 to 13 wt%, from 3 to 12 wt%, from 4 to 11 wt% or from 5 to 10 wt%.

[0049] In some embodiments, the liquid carrier comprises or consists of glycerin and propylene glycol in a weight ratio of from 1:1 to 4:1, for example from 2:1 to 3:1.

[0050] In some embodiments, the extrudable composition comprises propylene glycol and the polyacrylic acid binder in a weight ratio of from 3:1 to 50:1, for example from 3:1 to 30:1, from 4:1 to 30:1 or from 5:1 to 25:1. Such ratios provide an acceptable level of viscosity for the extrudable composition which facilitates extrusion and homogeneous mixing of the components of the composition.

[0051] In some embodiments, the extrudable composition is a paste. In some embodiments, the extrudable composition is a deformable paste.

[0052] In some embodiments, the extrudable composition comprises: the particulate filler material, the liquid carrier comprising glycerin and propylene glycol, and the polyacrylic acid binder.

[0053] In some embodiments, the extrudable composition comprises: the particulate filler material comprising ground tobacco, the liquid carrier comprising glycerin and propylene glycol, and the polyacrylic acid binder.

[0054] In some embodiments, the extrudable composition comprises: the particulate filler material comprising ground tobacco, the liquid carrier comprising glycerin and propylene glycol, the polyacrylic acid binder, and the auxiliary binder component.

[0055] In some embodiments, the extrudable composition comprises: the particulate filler material comprising ground tobacco, the liquid carrier comprising glycerin and propylene glycol, the polyacrylic acid binder, and the auxiliary binder component comprising or consisting of konjac gum.

[0056] In some embodiments, the extrudable composition comprises: the particulate filler material comprising ground tobacco, the liquid carrier comprising glycerin and propylene glycol, the polyacrylic acid binder, the auxiliary binder component comprising or consisting of konjac gum, and a flavourant.

[0057] In some embodiments, the extrudable composition comprises: the particulate filler material comprising ground tobacco, the liquid carrier comprising glycerin and propylene glycol, the polyacrylic acid binder, the auxiliary binder component comprising or consisting of konjac gum, and a structurant.

[0058] In some embodiments, the extrudable composition comprises or consists of: 65 to 75 wt% particulate filler material comprising ground tobacco, 20 to 30 wt% liquid carrier comprising glycerin and propylene glycol, 0.4 to 1 wt% polyacrylic acid binder, 0 to 8 wt% structurant, 0 to 1 wt% auxiliary binder component comprising or consisting of konjac gum, and 0 to 1 wt% flavourant.

[0059] In some embodiments, the extrudable composition consists of: 65 to 75 wt% particulate filler material comprising ground tobacco, 20 to 30 wt% liquid carrier comprising glycerin and propylene glycol, 0.4 to 1 wt% polyacrylic acid binder, and 0 to 1 wt% auxiliary binder component comprising or consisting of konjac gum.

[0060] The present disclosure also provides a method of preparing the extrudable composition described herein. In some embodiments, the method comprises mixing a particulate filler material, a liquid carrier and a polyacrylic acid binder. In some embodiments, the method comprises mixing a particulate filler material, a liquid carrier and a polyacrylic acid binder, wherein the extrudable composition contains no water, or contains water in an amount of less than 3 wt% based on the total weight of the extrudable composition. In some embodiments, the method comprises mixing the aforementioned components within an extruder, for example a twin screw extruder. In some embodiments, the method comprises introducing one or more liquid components into one or more liquid ports of an extruder, and introducing one or more solid components into one or more solid feeders into the extruder. The solid feeder may comprise a gravimetric hopper feeder. The liquid ports may be connected with one or more peristaltic pumps.

[0061] The present disclosure also provides a method of preparing an aerosol-forming material. The method may comprise preparing an extrudable composition; and extruding the composition through a die. The method may comprise preparing an extrudable composition comprising a particulate filler material; a liquid carrier; and a polyacrylic acid binder; and extruding the composition through a die.

[0062] The method of preparing an aerosol-forming material, may comprise: preparing an extrudable composition comprising: a particulate filler material; a liquid carrier; and a polyacrylic acid binder; wherein the extrudable composition contains no water, or contains water in an amount of less than 3 wt% based on the total weight of the extrudable composition; and extruding the composition through a die.

[0063] In some embodiments, the method comprises mixing a particulate filler material, a liquid carrier and a polyacrylic acid binder. In some embodiments, the method comprises mixing a particulate filler material, a liquid carrier and a polyacrylic acid binder, wherein the extrudable composition contains no water, or contains water in an amount of less than 3 wt% based on the total weight of the extrudable composition. In some embodiments, the method comprises mixing the aforementioned components within an extruder, for example a twin screw extruder. In some embodiments, the method comprises introducing one or more liquid components into one or more liquid ports of an extruder, and introducing one or more solid components into one or more solid feeders into the extruder. The solid feeder may comprise a gravimetric hopper feeder. The liquid ports may be connected with one or more peristaltic pumps.

[0064] All of the options and preferences described above for the extrudable composition apply equally to the extrudable composition prepared within the method of preparing an aerosol-forming material. For example, all of the compositional preferences apply equally to the method.

[0065] In some embodiments, the method comprises extruding the composition using a twin screw extruder. One example of a suitable extruder is a Thermofisher Process 16 extruder.

[0066] In some embodiments, the method does not include the addition of any water to the extruder, beyond the water which may be unavoidably present in trace amounts within the components of the extrudable composition. For example, particulate filler materials such as ground tobacco would naturally contain a small amount of water, as would liquid carrier components such as glycerin and propylene glycol, and although a very small amount of water would thereby be introduced into the extruder, the method in some embodiments does not include any additional introduction of water into the extruder outside these trace amounts. For example, in some embodiments no aqueous compositions are added to the extruder. In some embodiments, no composition is added to the extruder which has a water content greater than 3 wt%. In some embodiments, each ingredient added to the extruder has a water content of less than 3 wt%, based on the total weight of that ingredient.

[0067] In some embodiments, the method does not include any drying of the extruded aerosol-forming material after extrusion. In some embodiments, the method does not include any elevated-temperature drying of the extruded aerosol-forming material after extrusion. The extrusion of aqueous compositions would require a drying step at elevated temperature to remove water from the composition, which would increase the energy consumption and complexity of the process, and cause shrinkage and cracking of the aerosol-forming material. By contrast, since the extrudable composition already contains a very low water content, no such drying step is required after extrusion and the resultant method is more efficient and the properties of the product may be improved due to less shrinkage and less cracking.

[0068] In some embodiments, the method comprises extruding the composition through a die to form an extruded product in the form of a rod. In some embodiments, the rod is a continuous rod and the method further comprises dividing the continuous rod into a plurality of sections, wherein each section is suitable for use as an aerosol-forming material within a single aerosol-forming article (e.g. a HNB article). In other embodiments, the method comprises extruding the composition through a die into a plurality of discrete rods, wherein each rod is suitable for use as an aerosol-forming material within a single aerosol-forming article (e.g. a HNB article). In other words, the extruder may operate to extrude discrete rods such that no further step of dividing the extruded material into sections is required.

[0069] The method may further comprise incorporating the aerosol-forming material into an aerosol-forming article, for example assembling the aerosol-forming material alongside one or more other components such as filter components, and circumscribing the aerosol-forming material and one or more other components with one or more wrappers.

[0070] The method comprises extruding the composition through a die, and the shape of the die will dictate the cross-sectional shape of the extruded aerosol-forming material. For example, in some embodiments the extrudable composition is extruded through a circular die to form a cylindrical rod. However the shape of the die and corresponding cross-sectional shape of the rod are not limited, and any suitable shape may be adopted, for example any regular polygon (resulting in a prismatic rod having corresponding regular polygon faces).

[0071] The present disclosure also provides an extruded aerosol-forming material comprising: a particulate filler material; a liquid carrier; and a polyacrylic acid binder; wherein the aerosol-forming material contains no water, or contains water in an amount of less than 3 wt% based on the total weight of the aerosol-forming material.

[0072] In some embodiments, the extruded aerosol-forming material is formed by extruding the extrudable composition described herein through a die. All of the options and preferences described above for the extrudable composition apply equally to the extruded aerosol-forming material, mutatis mutandis. For example, all of the compositional preferences apply equally to the extruded aerosol-forming material.

[0073] In some embodiments, the density of the extruded aerosol-forming material, as determined after the extruded aerosol-forming material has been left at 25 °C for 10 hours, is greater than 1.0 g cm -3< , for example greater than 1.05 g cm -3< , greater than 1.10 g cm -3< , greater than 1.15 g cm -3< , greater than 1.20 g cm 3< , greater than 1.21 g cm -3< or greater than 1.22 g cm -3< . The density of the extruded aerosol-forming material is determined by extruding a solid mass of the material, then leaving the extruded aerosol-forming material at 25 °C for 10 hours, before calculating the density of that solid mass based on the measured mass and volume. Extruded aerosol-forming materials made from an aqueous extrudable composition and then left at 25 °C for 10 hours tend to have higher porosity which results in lower density, due to drying of the material, whereas the non-aqueous compositions of the invention lead to extruded aerosol-forming materials of higher density.

[0074] In some embodiments, the density of the extruded aerosol-forming material, as determined after the extruded aerosol-forming material has been left at 25 °C for 10 hours, is from 1.0 g cm -3< to 1.5 g cm 3< , for example from 1.1 g cm -3< to 1.5 g cm 3< , from 1.2 g cm -3< to 1.5 g cm -3< , from 1.2 g cm -3< to 1.4 g cm -3< , from 1.2 g cm -3< to 1.3 g cm -3< , from 1.21 g cm -3< to 1.3 g cm -3< , from 1.22 g cm -3< to 1.3 g cm -3< , from 1.22 g cm -3< to 1.28 g cm 3< , from 1.22 g cm -3< to 1.26 g cm 3< , from 1.22 g cm -3< to 1.24 g cm -3< or from 1.22 g cm -3< to 1.23 g cm -3< .

[0075] In some embodiments, the difference in density between the extruded aerosol-forming material, as determined after the extruded aerosol-forming material has been left at 25 °C for 10 hours, and the extrudable composition, is less than 0.5 g cm -3< , for example less than 0.4 g cm -3< , less than 0.3 g cm -3< , less than 0.2 g cm -3< , less than 0.1 g cm -3< or less than 0.05 g cm -3< . Extruded aerosol-forming materials made from an aqueous extrudable composition may experience an increase in porosity and a resultant relatively large decrease in density upon drying, whereas the non-aqueous compositions of the invention experience very little change in density after extrusion since little or no drying occurs. In some embodiments, the difference in density between the extrudable composition and the extruded aerosol-forming material is from 0 to 0.5 g cm -3< , for example from 0.01 to 0.5 g cm -3< , from 0.01 to 0.4 g cm -3< , from 0.01 to 0.3 g cm -3< , from 0.01 to 0.2 g cm -3< , from 0.01 to 0.1 g cm -3< or from 0.01 to 0.05 g cm -3< .

[0076] The present disclosure also provides an aerosol-forming article comprising the aerosol-forming material described herein. In some embodiments, the aerosol-forming article is in the form of a heated tobacco (HT) stick. In some embodiments, the aerosol-forming article is a heat-not-burn (HNB) consumable.

[0077] In some examples, the aerosol-forming article further comprises one or more of: a mouthpiece segment at a downstream end of the aerosol-forming article; a hollow bore filter located downstream of the aerosol-forming material; and a cardboard tube located downstream of the aerosol-forming material.

[0078] In the exemplary aspects and embodiments described herein, the aerosol-forming article can be a consumable, e.g. a HT consumable, and the aerosol-forming apparatus can be a HT device as described above. The aerosol-forming article comprises an aerosol-forming material which is a solid (as opposed to liquid) extruded substrate capable of being heated to release at least one volatile compound that can form an aerosol. It will be appreciated that tobacco leaf is one such material, wherein an aerosol is generated by inhaling through the heated material. However, those skilled in the art will be aware that aerosol-generating systems might also be easily configured to heat non-tobacco organic material such as other plant material (e.g., cannabis leaf). Consequently, the aerosol-forming article (e.g. a HT consumable) is intended at its broadest to include an extruded aerosol-forming material comprising at least one volatile compound that is intended to be vaporised / aerosolised and that may provide the user with a recreational and / or medicinal effect when inhaled. Suitable chemical and / or physiologically active volatile compounds include the group consisting of: nicotine, cocaine, caffeine, THC, CBD, opiates and opioids, cathine and cathinone, cannabinoids, kavalactones, mysticin, beta-carboline alkaloids, salvinorin A, together with any combinations, functional equivalents to, and / or synthetic alternatives of the foregoing.

[0079] Consequently, the aerosol-forming material of the aerosol-forming article may comprise a plant material. The plant material may comprise at least one plant material selected from the list including Amaranthus dubius, Arctostaphylos uva-ursi (Bearberry), Argemone mexicana, Amica, Artemisia vulgaris, Yellow Tees, Galea zacatechichi, Canavalia maritima (Baybean), Cecropia mexicana (Guamura), Cestrum noctumum, Cynoglossum virginianum (wild comfrey), Cytisus scoparius, Damiana, Entada rheedii, Eschscholzia califomica (California Poppy), Fittonia albivenis, Hippobroma longiflora, Humulus japonica (Japanese Hops), Humulus lupulus (Hops), Lactuca virosa (Lettuce Opium), Laggera alata, Leonotis leonurus, Leonurus cardiaca (Motherwort), Leonurus sibiricus (Honeyweed), Lobelia cardinalis, Lobelia inflata (Indian-tobacco), Lobelia siphilitica, Nepeta cataria (Catnip), Nicotiana species (Tobacco), Nymphaea alba (White Lily), Nymphaea caerulea (Blue Lily), Opium poppy, Passiflora incamata (Passionflower), Pedicularis densiflora (Indian Warrior), Pedicularis groenlandica (Elephant's Head), Salvia divinorum, Salvia dorrii (Tobacco Sage), Salvia species (Sage), Scutellaria galericulata, Scutellaria lateriflora, Scutellaria nana, Scutellaria species (Skullcap), Sida acuta (Wireweed), Sida rhombifolia, Silene capensis, Syzygium aromaticum (Clove), Tagetes lucida (Mexican Tarragon), Tarchonanthus camphoratus, Tumera diffusa (Damiana), Verbascum (Mullein), Zamia latifolia (Maconha Brava) together with any combinations, functional equivalents to, and / or synthetic alternatives of the foregoing.

[0080] It will however be appreciated that in particularly suitable exemplary embodiments, the plant material is tobacco. Thus in some examples, the aerosol-forming material comprises tobacco or a tobacco derivative. Here, any type of tobacco may be used. This includes, but is not limited to, flue-cured tobacco, burley tobacco, Maryland Tobacco, dark-air cured tobacco, oriental tobacco, dark-fired tobacco, perique tobacco and rustica tobacco. This also includes blends of the above-mentioned tobaccos.

[0081] The tobacco may comprise one or more of leaf tobacco, stem tobacco, tobacco powder, tobacco dust, tobacco derivatives, expanded tobacco, homogenised tobacco, shredded tobacco, extruded tobacco, cut rag tobacco and / or reconstituted tobacco (e.g., slurry recon or paper recon). In each case, the aerosol-forming material may be formed into a rod of material. For instance, as termed herein, a tobacco rod. The aerosol-forming material (e.g. tobacco rod) may be formed into a substantially cylindrical shape such that the article / consumable resembles a conventional cigarette. The aerosol-forming material may have a diameter of between 5 and 10 mm (e.g., between 6 and 9 mm or 6 and 8 mm e.g., around 7 mm). The aerosol-forming material may have an axial length of between 10 and 25 mm (e.g., between 11 and 14 mm, such as around 12 or 13 mm).

[0082] In exemplary aspects and embodiments described herein, the aerosol-forming material may comprise one or more additives selected from humectants, flavourants, fillers, non-aqueous solvents and binders. Here, the flavourant may be provided in solid or liquid form. It may be selected from one or more of menthol, liquorice, chocolate, fruit flavour (including e.g., citrus, cherry etc.), vanilla, spice (e.g., ginger, cinnamon) and tobacco flavour. The flavourant may be evenly dispersed throughout the aerosol-forming material or may be provided in isolated locations and / or varying concentrations throughout the aerosol-forming material.

[0083] Humectants are provided as vapor generators - the resulting vapor helps carry the volatile active compounds and increases visible vapor. Suitable humectants include polyhydric alcohols (e.g. propylene glycol (PG), triethylene glycol, 1,2-butane diol and vegetable glycerin (VG)) and their esters (e.g. glycerol mono-, di- or tri-acetate).

[0084] Suitable fillers are known in the art and may act to strengthen the aerosol-forming material. Fillers may comprise fibrous (non-tobacco) fillers such as cellulose fibers, lignocellulose fibers (e.g. wood fibers), jute fibers and combinations thereof.

[0085] In some exemplary aspects and embodiments described herein, the aerosol-forming article can be specifically adapted for use with a HT device (either known devices or the HT devices described herein). In particular, a combustible cigarette is not specifically adapted for use with a HT device. Primarily, this is because insertion of a combustible cigarette into a HT device and subsequent operation of the HT device, would not generate an acceptable vapour for consumption by the user. In particular, an insufficient aerosol vapour would be generated. Consequently, in the exemplary embodiments of aerosol-forming articles (e.g. HT consumables) described and claimed herein, one specific adaption for use with a HT device is the incorporation of a carrier in the aerosol-forming material (e.g. tobacco material). Here, during use, a first vapour is produced from the tobacco material volatising the nicotine (or other active substance as described above) and a second vapour is produced from vaporisation of the carrier. Any known or suitable carrier is considered. For instance, the carrier added to the aerosol-forming material (e.g., the plant material such as tobacco) suitably comprises propylene glycol (PG), and / or vegetable glycerin (VG).

[0086] In some exemplary aerosol-forming article embodiments described herein, in addition to an aerosol-forming material, there may also be provided further components or elements combined with the aerosol-forming material as is known in the art as well as described and claimed herein. Thus, the exemplary aerosol-forming article may include an aerosol-forming material combined with one or more further components or elements by a wrapping paper which can include a combining paper and / or a tipping paper. The combining paper may circumscribe the aerosol-forming material and further components and may be glued or adhered to form a homogenous component or rod as is known in the art and as explained in the background section above. Therefore, except where incompatible, the addition or combination of features of the described and claimed aspects and embodiments of the consumables is expressly considered. Furthermore, as used herein, wrapping paper in its broadest is intended to include any suitable substrate that can be used to circumscribe the components of the aerosol-forming article to join or wrap one or more of the components. It is envisaged that suitable substrates are thin and flexible, with paper or similar materials being exemplary. Thus, as used herein, wrapping substrate is used interchangeably to reference wrapping paper in its broadest form even for instance when the aerosol-forming article paper is not combining components.

[0087] As will become apparent, the described aspects and embodiments can be suitable for use with a HT system wherein the HT consumable is intended to be used as described in the background section above. That is, the aerosol-forming article (e.g. a consumable) can be inserted into a cavity at a downstream end of the HT device. Or stated alternatively, the aerosol-generating article is insertable into the cavity in a downstream to upstream direction. Herein, such arrangements can be termed 'downstream' aerosol-forming article or consumable. Here, the aerosol-forming material is arranged at an upstream end and a distal, downstream end of the aerosol-forming article (e.g. the HT consumable) comprises a mouthpiece, for instance, a mouthpiece filter (e.g., a terminal filter arrangement). Here, suitably, the mouthpiece filter may comprise a monoacetate filter or a hollow bore filter. In some arrangements, the hollow bore filter may be a triple bore filter e.g., with three bores arranged in an equilateral triangle around a central axis. Alternatively or additionally, the mouthpiece filter may be comprised of cellulose acetate or polypropylene tow. Further alternatively or additionally, the mouthpiece filter element (e.g., the terminal filter element) may be comprised of activated charcoal or may be comprised of paper. In each case, the mouthpiece filter element is suitably at least partly (e.g., preferably, but not necessarily entirely) circumscribed with a plug wrap e.g., a paper plug wrap. In some arrangements of the downstream aerosol-forming articles, the mouthpiece filter may include flavourant. For instance, the mouthpiece filter can be formed with a capsule able to be fractured (fractureable) that a user can fracture to release a vapour or liquid (e.g., provided with a crush ball) as is known in the art.

[0088] In some exemplary downstream aerosol-forming articles, the mouthpiece filter (at the downstream end of the aerosol-forming article) is suitably joined to the upstream elements forming the aerosol-forming article and including at least the aerosol-forming material by a circumscribing tipping layer e.g., a tipping paper layer (which can be a component of the wrapping paper). The tipping paper may have an axial length longer than the axial length of the terminal filter element such that the tipping paper completely circumscribes the terminal filter element plus the wrapping layer surrounding any adjacent upstream element.

[0089] As explained, the aerosol-forming article may comprise further components and elements. For instance, in some exemplary downstream aerosol-forming articles, further elements can be arranged between the aerosol-forming material and the mouthpiece filter. Whereas in non-downstream embodiments which might not necessarily comprise a mouthpiece filter, the further elements may be provided to either or one side of the aerosol-forming material. For instance, in some embodiments, the aerosol-forming article comprises an aerosol-cooling element which is adapted to cool the aerosol generated from the aerosol-forming material (by heat exchange) before being inhaled by the user. That is, in some aerosol-forming articles, the cooling element regulates the temperature of vapour. In some exemplary arrangements, wherein the cooling element may suitably comprise a bore filter and a paper tube, each of the bore filter and the paper tube regulate the temperature of the vapour in use. In some arrangements, the bore filter may be a hollow bore filter. In some arrangements, the paper tube may be a spiral paper tube. In other words, the paper tube may be a continuous paper tube wound in a spiral or the paper tube may be a cardboard tube. In the exemplary embodiments, the paper tube itself may be impermeable to air but comprise a plurality of perforations e.g., formed by a laser. The plurality of perforations may be distributed circumferentially about the paper tube and correspond in number and location with the plurality of perforations of the tipping paper to provide ventilation into an internal cavity of the paper tube.

[0090] In some arrangements, as described herein, the exemplary HT consumable is configured as an upstream consumable. That is, a consumable for use with a HT device having a cavity at an upstream end for receiving the consumable, an air passage through the device to a mouthpiece at a downstream end.

[0091] Optionally, the aerosol-forming material may be an extruded cylindrical rod. Here, the cylindrical rod can have opposed end faces. Each end face may be a planar face. That is, the end face is said to be a planar face along the predominant plane of the aerosol-forming material. The cylindrical rod has a longitudinal axis, and the end faces are suitably perpendicular to the longitudinal axis.

[0092] In another aspect the present disclosure provides an aerosol-generating system comprising the aerosol-forming article, and an aerosol-generating apparatus comprising a heater.

[0093] At its most general, a heated tobacco (HT) system may comprise an aerosol-forming article (e.g. a HT consumable) and an aerosol-generating apparatus (e.g. a HT device) configured with a heating zone.

[0094] The aerosol-generating apparatus may include a cavity that may be configured to receive the aerosol-forming article. The cavity may be sized and / or dimensioned to conform with the outer dimensions of the aerosol-forming article (or vice versa). For example, the cavity may have the shape of a circular bore and the aerosol-forming article has the shape of a cylinder. A diameter of the cavity may the same as or slightly larger than the diameter of the aerosol-forming article. The cavity may be a blind hole in the aerosol-generating apparatus. The cavity may be provided by a bottom wall and a side wall that connects the bottom wall to an opening or aperture of the cavity. If the aerosol-forming article is fully inserted into the cavity, all outer surfaces of the aerosol-forming article that are arranged within the cavity may contact inner walls of the cavity (e.g. the bottom wall and the side wall).

[0095] The cavity may form the opening / aperture in a housing of the aerosol-generating apparatus. The aperture and / or the cavity may be closed by a lid, a cap, or other types of closing means if the consumable is not inserted into the cavity. If the aerosol-forming article is fully inserted into the cavity (for example by abutting against the bottom wall of the cavity), a part of the consumable (e.g. one or more filters) may protrude from the cavity. The aerosol-forming article may be sized so that the one or more filters are not arranged in the cavity so that they are not heated by the aerosol-generating unit.

[0096] The aerosol-forming article may be inserted into the cavity for aerosolising one or more components the aerosol-forming material. For example, the tobacco portion / section of the aerosol-forming article may be inserted into the cavity to be heated by the aerosol-generating unit. The aerosol-generating unit may be configured to generate heat for heating the aerosol-forming material when inserted into the cavity.

[0097] The components of the aerosol-generating unit that generate the heat may be arranged in and / or on the walls of the cavity so that the heat provided by the aerosol-generating unit is generated close to the aerosol-forming material (e.g. the precursor). A heat insulation may be provided around the cavity for reducing heat transfer from the aerosol-generating unit towards other parts of the aerosol-generating apparatus. The walls of the cavity may be made from a material with high thermal conductivity (e.g. metal) so that the heat that is generated by the aerosol-generating unit is quickly conducted along the walls of the cavity for uniformly heating the consumable.

[0098] The aerosol-generating unit defines a heating zone, where the heating zone is an area of the cavity over which the aerosol generating unit provides or generates heat.

[0099] The longitudinal direction of the cavity may be parallel or coincide with the longitudinal direction of the aerosol-generating apparatus and / or the aerosol-forming article when inserted into the cavity.

[0100] In some examples, the aerosol generating unit includes an inside-out heater having a heating element configured to penetrate the aerosol-generating substrate of the aerosol-forming article.

[0101] In one exemplary embodiment, the aerosol-generating apparatus, optionally the heating element, includes a resistive heater comprising a rod or blade that extends into the cavity. Here, the rod or blade is intended to be inserted into the aerosol-forming material.

[0102] In some examples, the aerosol generating unit includes an outside-in heater arranged in or on a side wall of the cavity for heating an outer surface of the aerosol-forming article when inserted into the cavity.

[0103] Thus, other embodiments of the aerosol generating unit are envisaged such as an outside-in heater. For instance, the outside-in heater may include a resistive heater and / or an infrared heater that is arranged to heat the sides of the aerosol-forming article.

[0104] The aerosol-generating unit may include the inside-out heater and the outside-in heater. Alternatively, embodiments are envisaged wherein the heating element is distributed in or on the consumable. For instance, the aerosol generating unit may include one or more induction heaters wherein a susceptor is provided in the aerosol-forming article. An electromagnetic source of the induction heater can be provided about the cavity.

[0105] Optionally, the stop is formed by the closed end of the cavity. However, in some embodiments, it is envisaged that the stop is provided as a ledge or ridge within the cavity. In particular, in embodiments including an aerosol-generating apparatus (e.g. the HT device) having a cavity at an upstream end such that air is drawn through the aerosol-forming material, the aerosol-generating apparatus can be configured to provide an airflow from the distal end of the cavity to a downstream mouthpiece on the aerosol-generating apparatus. Here, the distal end of the cavity can include a passageway. For instance, the passageway can be formed in a centre of a ledge. Here, a mesh can preferably be provided at the distal end of the cavity.

[0106] The aerosol-generating article may have an elongate shape, and optionally a rod shape (i.e., the aerosol-generating article forms a substantially cylindrical outer shape), the upstream and downstream ends of the aerosol-generating article can be air-permeable to allow an axial airflow through the aerosol-generating article.

[0107] In the exemplary aerosol-generating apparatuses (e.g. HT devices), and in relation to the aerosol-forming articles (e.g. HT consumables), the aerosol-generating apparatuses that the aerosol-forming articles are intended for use with, the aerosol-generating apparatus may comprise any one or more of the following exemplary features, except where those features are incompatible as apparent for the skilled person. This applies for both aerosol-generating apparatuses configured with a cavity configured to allow insertion of the aerosol-forming article in the upstream and downstream direction.

[0108] Optionally, the aerosol-generating apparatus may comprise an elongate housing (also referred to as a body). An end of the elongate body may be configured for engagement with an aerosol-forming article (e.g. a consumable). For example, the body may be configured for engagement with a heated tobacco consumable. Exemplary aerosol-generating apparatuses comprise a cavity that is configured for receipt of at least a portion of the aerosol-forming article (i.e., for engagement with the consumable). As explained, the aerosol-forming article is of the type that comprises an aerosol former (e.g., carried by an aerosol-forming material).

[0109] In exemplary embodiments, the heating element is rigidly mounted to the body. The heating element may be elongate so as to define a longitudinal axis and may, for example, have a transverse profile (i.e., transverse to a longitudinal axis of the heating element) that is substantially circular (i.e., the heating element may be generally cylindrical). Alternatively, the heating element may have a transverse profile that is rectangular (i.e., the heating element may be a "blade heater"). The heating element may alternatively be in the shape of a tube (i.e., the heating element may be a "tube heater"). The heating element may take other forms (e.g., the heating element may have an elliptical transverse profile). The shape and / or size (e.g., diameter) of the transverse profile of the heating element may be generally consistent for the entire length (or substantially the entire length) of the heating element.

[0110] In exemplary embodiments, the heating element is between 15 mm and 25 mm long, e.g., between 18 mm and 20 mm long, e.g., around 19 mm long. The heating element may have a diameter of between 1.5 mm and 2.5 mm, e.g., a diameter between 2 mm and 2.3 mm, e.g., a diameter of around 2.15 mm. The heating element may be formed of ceramic. The heating element may comprise a core (e.g., a ceramic core) comprising Al 2 O 3 . The core of the heating element may have a diameter of 1.8 mm to 2.1 mm, e.g., between 1.9 mm and 2 mm. The heating element may comprise an outer layer (e.g., an outer ceramic layer) comprising Al 2 O 3 . The thickness of the outer layer may be between 160 µm and 220 µm, e.g., between 170 µm and 190 µm, e.g., around 180 µm. The heating element may comprise a heating track, which may extend longitudinally along the heating element. The heating track may be sandwiched between the outer layer and the core of the heating element. The heating track may comprise tungsten and / or rhenium. The heating track may have a thickness of around 20 µm.

[0111] In exemplary embodiments, the heating element is located in the cavity (of the aerosol-generating apparatus), and may extend (e.g., along a longitudinal axis) from an internal base (i.e., distal end) of the cavity towards an opening of the cavity.

[0112] Optionally, the heating element may be in the form of a rod or blade that extends from the body and into the cavity. That is, the heating element extends from an end of the body that is configured for engagement with the consumable. Here, the heating element is configured for insertion into an aerosol-forming article (e.g., a HT consumable) when an aerosol-forming article is received in the cavity. In that respect, a distal end (i.e., distal from a base of the heating element where it is mounted to the aerosol-generating apparatus) of the heating element may comprise a tapered portion, which may facilitate insertion of the heating element into the aerosol-forming article. The heating element may fully penetrate an aerosol-forming article when the aerosol-forming article is received in the cavity. That is, the entire length, or substantially the entire length, of the heating element may be received in the aerosol-forming article.

[0113] The heating element may have a length that is less than, or substantially the same as, an axial length of an aerosol-forming material forming part of an aerosol-forming article (e.g., a HT consumable). Thus, when such an aerosol-forming article is engaged with the aerosol-generating apparatus, the heating element may only penetrate the aerosol-forming material, rather than other components of the aerosol-forming article. The heating element may penetrate the aerosol-forming material for substantially the entire axial length of the aerosol-forming material of the aerosol-forming article. Thus, heat may be transferred from (e.g., an outer circumferential surface of) the heating element to the surrounding aerosol-forming material, when penetrated by the heating element. That is, heat may be transferred radially outwardly (in the case of a cylindrical heating element).

[0114] Alternatively, the heating element can be configured to transfer heat radially inwardly (in the case of a tube heater). In exemplary embodiments where the heating element is a tube heater, the heating element of the tube heater may surround at least a portion of the cavity. When the portion of the aerosol-forming article (i.e., HT consumable) is received in the cavity, the heating element surrounds a portion of the aerosol-forming article (i.e., so as to heat that portion of the aerosol-forming article, for instance the aerosol-forming material). In particular, the heating element may surround an aerosol-forming material of the aerosol-forming article. That is, when an aerosol-forming article is engaged with the device, the aerosol-forming material of the aerosol-forming article may be located adjacent an inner surface of the (tubular) heating element. When the heating element is activated (by discharging a battery across the heating element), heat may be transferred radially inwardly from the inner surface of the heating element to heat the aerosol forming substrate.

[0115] In exemplary embodiments where the heating element is a tube heater, the cavity comprises a (e.g., circumferential) wall (or walls) and the (tubular) heating element extends around at least a portion of the wall(s). In this way, the wall may be located between the inner surface of the heating element and an outer surface of the aerosol-forming article. The wall (or walls) of the cavity may be formed from a thermally conductive material (e.g., a metal) to allow heat conduction from the heating element to the aerosol-forming article. Thus, heat may be conducted from the heating element, through the cavity wall (or walls), to the aerosol-generating substrate of an aerosol-forming article received in the cavity. Alternatively, here, the heating element may be an infrared (IR) heating element. A tubular IR heating element may be configured to emit more IR radiation across the wall (or walls) than is transmitted by conduction. The wall (or walls) is therefore suitably transmissive of the emitted IR radiation. The combination of the wall (or walls) with the tubular IR heating element may be referred to as an IR heating tube. That is, in exemplary embodiments, the cavity may be formed from an IR heating tube.

[0116] The aerosol-generating apparatus may further comprise a provision, preferably a mechanical means, to intrude into the cavity. For instance, o-rings or the like that are configured to slightly compress against the inserted aerosol-forming article in order to grip the aerosol-forming article and provide resistance to withdrawal (and in relation to the upstream configured cavities, to prevent the aerosol-forming article falling out under gravity in use). In embodiments comprising electrical connections between the device and the aerosol-forming article, the electrical connections may provide the resistance to withdrawal of the aerosol-forming article, or additional assist in doing so.

[0117] In some exemplary embodiments, the aerosol-generating apparatus comprises a cap disposed at the end of the body that is configured for engagement with the aerosol-forming article. Where the aerosol-generating apparatus comprises the heating element configured to be inserted into the aerosol-forming article, the cap may at least partially enclose the heating element. The cap may be moveable between an open position in which access is provided to the heating element, and a closed position in which the cap at least partially encloses the heating element. The cap may be slidably engaged (i.e., slid to engage) with the body of the aerosol-generating apparatus, and may be slidable (i.e., able to slide) between the open and closed positions. In the alternative, rather than or additional to opening and closing the cavity, the sliding between the open and closed position may act to lift the aerosol-forming article from heating element.

[0118] In exemplary embodiments, the cap defines at least a portion of the cavity of the device. That is, the cavity may be fully defined by the cap, or each of the cap and body may define a portion of the cavity. Where the cap fully defines the cavity, the cap may comprise an aperture for receipt of the heating element into the cavity (when the cap is in the closed position). The cap may comprise an opening to the cavity. The opening may be configured for receipt of at least a portion of the aerosol-forming article (and preferably at least the portion including the aerosol-forming material). That is, the aerosol-forming article may be inserted through the opening and into the cavity (so as to be engaged with the device).

[0119] In exemplary embodiments, the cap is configured such that when an aerosol-forming article is engaged with the device (e.g., received in the cavity), only a portion of the aerosol-forming article is received in the cavity. That is, a portion of the aerosol-forming article (not received in the cavity) may protrude from (i.e., extend beyond) the opening. In embodiments wherein the cavity is an upstream cavity, this (protruding) portion of the aerosol-forming article is a terminal (e.g., mouth) end of the aerosol-forming article, which is received in a user's mouth for the purpose of inhaling aerosol formed by the system.

[0120] In exemplary embodiments, the aerosol-generating apparatus comprises a power source or may be connectable to a power source (e.g., a power source separate to the aerosol-generating apparatus). Here, the power source is electrically connectable to the heating element. In that respect, altering (e.g., toggling) the electrical connection of the power source to the heating element may affect a state of the heating element. For example, toggling the electrical connection of the power source to the heating element may toggle the heating element between an on state and an off state (e.g., PWM control). The power source may be a power store. For example, the power source may be a battery or rechargeable battery (e.g., preferably a lithium-ion battery).

[0121] In exemplary embodiments, the aerosol-generating apparatus comprises an input connection (e.g., a USB port, Micro USB port, USB-C port, etc.). The input connection may be configured for connection to an external source of electrical power, such as a mains electrical supply outlet. The input connection may, in some cases, be used as a substitute for an internal power source (e.g., battery or rechargeable battery). That is, the input connection may be electrically connectable to the heating element (for providing power to the heating element). Hence, in some forms, the input connection may form at least part of the power source of the device. Where the power source comprises a rechargeable power source (such as a rechargeable battery), the input connection may be used to charge and recharge the power source.

[0122] In exemplary embodiments, the aerosol-generating apparatus comprises a user interface (UI). In some embodiments the UI may include input means to receive operative commands from the user. The input means of the UI may allow the user to control at least one aspect of the operation of the device. In some embodiments the input means may comprise a power button to switch the device between an on state and an off state. In some embodiments the UI may additionally or alternatively comprise output means to convey information to the user. In some embodiments the output means may comprise a light to indicate a condition of the device (and / or the aerosol-forming article) to the user. The condition of the device (and / or aerosol-forming article) indicated to the user may comprise a condition indicative of the operation of the heating element. For example, the condition may comprise whether the heating element is in an off state or an on state. In some embodiments, the UI unit may comprise at least one of a button, a display, a touchscreen, a switch, a light, and the like. For example, the output means may comprise one or more (e.g., two, three, four, etc.) light-emitting diodes ("LEDs") that may be located on the body of the device. In some exemplary embodiments, the device may further comprise a puff sensor (e.g., airflow sensor), which form part of the input means of the UI. The puff sensor may be configured to detect a user drawing on an end (i.e., a terminal (mouth) end) of the system. The puff sensor may, for example, be a pressure sensor or a microphone. The puff sensor may be configured to produce a signal indicative of a puff state. The signal may be indicative of the user drawing (an aerosol from the aerosol-generating article) such that it is e.g., in the form of a binary signal. Alternatively, or additionally, the signal may be indicative of a characteristic of the draw (e.g., a flow rate of the draw, length of time of the draw, etc).

[0123] In exemplary embodiments, the aerosol-generating apparatus comprises a controller, or may be connectable to a controller that may be configured to control at least one function of the device. The controller may comprise a microcontroller that may e.g., be mounted on a printed circuit board (PCB). The controller may also comprise a memory, e.g., non-volatile memory. The memory may include instructions, which, when implemented, may cause the controller to perform certain tasks or steps of a method. Where the device comprises an input connection, the controller may be connected to the input connection. The controller may be configured to control the operation of the heating element. Thus, the controller may be configured to control vaporisation of an aerosol forming part of an aerosol-forming article engaged with the device. The controller may be configured to control the voltage applied by power source to the heating element. For example, the controller may be configured to toggle between applying a full output voltage (of the power source) to the heating element and applying no voltage to the heating element. Alternatively, or additionally, the control unit may implement a more complex heating element control protocol. In exemplary embodiments, the controller includes a voltage regulator to regulate the output voltage supplied by the power source to form a regulated voltage. The regulated voltage may subsequently be applied to the heating element.

[0124] In some embodiments, where the aerosol-generating apparatus comprises a UI, the controller may be operatively connected to one or more components of the UI. The controller may be configured to receive command signals from an input means of the UI. The controller may be configured to control the heating element in response to the command signals. For example, the controller may be configured to receive "on" and "off" command signals from the UI and, in response, may control the heating element so as to be in a corresponding on or off state. The controller may be configured to send output signals to a component of the UI. The UI may be configured to convey information to a user, via an output means, in response to such output signals (received from the controller). For example, where the device comprises one or more LEDs, the LEDs may be operatively connected to the controller. Hence, the controller may be configured to control the illumination of the LEDs (e.g. in response to an output signal). For example, the controller may be configured to control the illumination of the LEDs according to (e.g., an on or off) state of the heating element.

[0125] Where the aerosol-generating apparatus comprises a sensor (e.g., a puff / airflow sensor), the controller may be operatively connected to the sensor. The controller may be configured to receive a signal from the sensor (e.g., indicative of a condition of the device and / or engaged aerosol-forming article). The controller may be configured to control the heating element, or an aspect of the output means, based on the signal from the sensor.

[0126] In some exemplary embodiments, the device may comprise a wireless interface configured to communicate wirelessly (e.g., via Bluetooth (e.g., a Bluetooth low-energy connection) or WiFi) with an external device. Similarly, the input connection may be configured for wired connection to an external device so as to provide communication between the device and the external device. The external device may be a mobile device. For example, the external device may be a smart phone, tablet, smart watch, or smart car. An application (e.g., app) may be installed on the external device (e.g., mobile device). The application may facilitate communication between the device and the external device via the wired or wireless connection. The wireless or wired interface may be configured to transfer signals between the external device and the controller of the device. In this respect, the controller may control an aspect of the device in response to a signal received from an external device. Alternatively, or additionally, an external device may respond to a signal received from the device (e.g., from the controller of the device).

[0127] As used herein, the terms "upstream" and "downstream" are intended to refer to the flow direction of the vapour / aerosol, i.e. with the downstream end of the article / consumable being the mouth end or outlet where the aerosol exits the consumable for inhalation by the user. The upstream end of the article / consumable is typically the opposing end to the downstream end. That is, where the airflow through the component or the system is substantially straight, the upstream end will be opposed to the downstream end. Where air inlets might be provided on the sides of the component, the downstream end is defined by the exit of the aerosol to the user and the upstream end is generally an opposed region including the inlets.

[0128] Another aspect the present disclosure provides the use of an aerosol-generating system comprising the aerosol-forming article describe herein, or the aerosol-generating system described herein, for the generation of an aerosol for inhalation by a user.

[0129] The present disclosure may provide a method of generating an aerosol, which may implement any one or more features disclosed herein. The method may comprise placing the aerosol-forming article in an aerosol-generating apparatus comprising a heater, as described herein (e.g. a HT device).

[0130] The preceding summary is provided for purposes of summarizing some examples to provide a basic understanding of aspects of the subject matter described herein. Accordingly, the above-described features should not be construed to narrow the scope of the subject matter described herein in any way. Moreover, the above and / or following examples may be combined in any suitable combination to provide further examples, except where such a combination is clearly impermissible or expressly avoided. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following text and the accompanying figures.BRIEF DESCRIPTION OF THE FIGURES

[0131] Aspects, features and advantages of the present disclosure will become apparent from the following description of examples in reference to the appended figures in which like numerals denote like elements. Figure 1 shows an example of an aerosol-generating system; Figure 2 shows the components of the aerosol-generating system in a 'disengaged state'; Figure 3 shows the components of the aerosol-generating system in an 'engaged state'. DETAILED DESCRIPTION OF EMBODIMENTS

[0132] It is to be understood that the present disclosure, which includes the specification and claim(s), is not limited by specific construction details or process steps. Rather, it will be clear to those skilled in the art that the systems, apparatuses, and methods described herein can be embodied and practiced in various alternative ways without departing from the scope of the invention.

[0133] Unless defined otherwise, scientific and technical terms used herein have their meanings commonly understood by those skilled in the art and that known techniques and procedures may be performed according to conventional methods.

[0134] In the present disclosure, the terms "a" and "an" may mean "one", "one or more", "at least one", and "one or more than one" unless the context clearly indicates otherwise. Likewise, plural terms shall include the singular unless otherwise required by context.

[0135] In the present disclosure, the term "or" means an inclusive "and / or" unless explicitly indicated to refer to alternatives only or unless the alternatives are mutually exclusive.

[0136] In the present disclosure, the terms "comprising, "having," "including," or "containing" (and any forms thereof, such as "comprise" and "comprises," "have" and "has," "includes" and "include," or "contains" and "contain," respectively) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0137] Unless stated otherwise, the features of examples disclosed herein, and of the claims, may be integrated together in any suitable arrangement such that combinations of features are not limited by the described forms, particularly the form (e.g. numbering) of example(s), embodiment(s), or dependency of claim(s). This also applies to the phrase "in one example", "according to an example" and the like, which are merely a stylistic form of wording not to be construed as limiting the features to a separate embodiment. This is to say, a reference to 'an,' 'one,' or 'some' examples(s) may be a reference to any one or more, and / or all examples, or combination(s) thereof, disclosed. Also, similarly, reference to "the" example may not be limited to the immediately preceding embodiment. Further, all references to one or more embodiments or examples are to be construed as non-limiting to the claims.

[0138] The present disclosure may be better understood in view of the following explanations, wherein the terms used that are separated by "or" may be used interchangeably.

[0139] Figure 1 shows an example of an aerosol-generating system 1 comprising a device body 20 and an aerosol-forming article 30 (alternatively referred to as a "consumable") for insertion into the device body 20. Figure 2 shows a schematic representation of the internal components of the device body 20 and aerosol-forming article 30, and shows the aerosol-forming article 30 in an "unwrapped" state, such that internal components of the aerosol-forming article are visible. The device body 20 and article 30 are shown in a "disengaged state" in which the article 30 is separated from the device body 20.

[0140] In this example, the device body 20 is a heat-not-burn device (HNB) configured to produce an aerosol by heating an aerosol-forming material 10 (e.g. a solid precursor, such as tobacco material) to a temperature below its combustion temperature.

[0141] The term "aerosol-forming material" refers to a material capable of releasing volatile components that can form an aerosol, e.g. by releasing volatile compounds in the aerosol-forming material 10. An "aerosol" is a dispersion of solid particles and / or liquid droplets dispersed in a gas. The aerosol may be visible or invisible. The aerosol-forming material 10 in the aerosol-forming article 30 is an extruded material, formed by extruding an extrudable composition through a die, for example a die which forms part of a twin-screw extruder.

[0142] The aerosol-generating system 1 has an aerosol-generating unit 2 in the form of a heating system. The heating system comprises a heating element 2a configured to penetrate the article 30. The heating element 2a heats the aerosol-forming material 10 to a temperature lower than its combustion temperature such that an aerosol can be formed by evaporation, torrefaction and pyrolysis.

[0143] The aerosol-generating system 1 includes a power source 4. In this example, the power source 4 includes a battery 4a configured to supply electrical energy to operate the aerosol-generating unit 2 and other components. The aerosol-generating system 1 may be powered, alternatively or in addition to the battery 4a, by an external power source.

[0144] The article 30 defines an air passageway which transmits aerosol generated from the aerosol-forming material 10 to a downstream end 32 (i.e. terminal end or mouth end) of the article 30. The article 30 may comprise one or more filter elements 34, one or more spacer elements 36, and one or more wrapping layers 38 (e.g. paper, foil or composite layers). One or more of the filter elements 34 and spacer elements 36 may define the air passageway. In the present example, the article 30 comprises an aerosol-forming material 10 at the upstream end 31 of the article 30, a filter element 34 at the downstream end 32, and a spacer element 36 positioned between them, all circumscribed by a wrapping layer 38.

[0145] Figure 3 shows the aerosol-generating system 1 in an "engaged state" in which the article 30 is inserted into an internal chamber 22 of the device body 20.

[0146] In this example, the heating element 2a is configured to penetrate the article 30. The heating element 2a is arranged to extend along a length of the aerosol-forming material 10 when inserted therein, such that when the heating element 2a is activated, heat is transferred radially outward from the heating element 2a to the aerosol-forming material 10 resulting in formation of an aerosol. This may be referred to as an 'inside-out' heating arrangement. The aerosol is subsequently entrained in an airflow produced by the action of the user drawing on the downstream end 32 of the article 30.

[0147] In alternative examples, the heating element 2a may be configured to at least partially encircle the article 30, such that when the heating element 2a is activated, heat is transferred radially inward from the heating element 2a to the aerosol-forming material 10. This may be referred to as an 'outside-in' heating arrangement.

[0148] In this example, the heating element 2a is a resistive heating element although it will be appreciated that the aerosol-forming material 10 may be heated by any suitable means. For instance, the heating element 2a may comprise a susceptor (not shown) configured to produce heat when penetrated by an alternating magnetic field.

[0149] The device body 20 may include any one or more of electrical circuitry, a memory, a wireless interface, and one or more other components. The device body 20 may include a printed circuit board (PCB) 25 on which components of the electrical circuitry, memory, wireless interface, and other components may be mounted.

[0150] The electrical circuitry may include a processing resource for controlling one or more operations of the body 20 and article 30, e.g. based on instructions stored in the memory. The wireless interface may be configured to communicate wirelessly with an external (e.g. mobile) device, e.g. via Bluetooth. The other component(s) may include one or more user interface devices configured to convey information to a user, a pressure sensor 15, and / or a charging port 18.

[0151] The aerosol-generating system 1 may comprise one or more input and / or output elements. The input and / or output elements may form part of a user interface (UI) of the system 1. For instance, Figure 1 shows an input element in the form of a button 16 and an output element in the form of a set of lights (LEDs) 17. The button 16 is configured to control at least one function of system 1, such as power supply to the heating element 2a. The lights 17 are configured to convey information to the user regarding the state of the system 1 and / or article. It will be appreciated that the input element(s) may be provided in various forms such as touch screens, switches, and sensors, and the output element(s) may be provided in various forms such as display screens, speakers, or a haptic output generated by a vibration generator.EXAMPLES Example 1

[0152] An extrudable composition was formed in situ within a Thermofisher Process 16 twin-screw extruder. Solid ingredients were fed into the extruder from gravimetric hopper feeders, and liquid / gel ingredients were fed into the extruder into liquid ports using peristaltic pumps.

[0153] The carbomer Carbopol 971P NF was added to propylene glycol to create a gel solution containing 4 wt% Carbopol 971P NF, which was then fed into the extruder.

[0154] The gel was fed to the extruder via a first liquid port; glycerin was fed to the extruder via a second liquid port; further propylene glycol was optionally fed to the extruder via a third liquid port if necessary depending on the desired composition; and milled tobacco was fed to the extruder via a gravimetric feed hopper. All of these ingredients were then mixed downstream of the ports within the extruder to form an extrudable composition within the extruder, before extrusion of the composition out of a die.

[0155] The ingredients were added to produce extrudable compositions containing the following components in quantities within the following ranges (where for any given product the amounts totalled 100%): Component Amount (based on total weight of extrudable composition) Milled tobacco65-75 wt%Glycerin15-20 wt%Propylene glycol5-10 wt%Carbopol 971P NF0.4-1 wt%

[0156] No water was added to the extruder.

[0157] The extrudable composition displayed acceptable stable binding of the milled tobacco and good extrusion from the die.

[0158] No drying step was required after extrusion due to the absence of water in the composition (other than inevitable trace amounts of water within the ingredients used). The resultant extruded non-aqueous composition was therefore dense, displaying no cracks or visible porosity due to the absence of a drying step.

[0159] The extrudable composition was extruded through a circular die into a continuous cylindrical rod, which was then divided into sections to form discrete rods of aerosol-forming material for use in an aerosol-forming article.

[0160] After leaving the extruded rod for 10 hours at 25 °C, the density was determined to be 1.224 g cm -3< .Example 2

[0161] The same method as Example 1 was used to produce an extruded aerosol-forming material, except that konjac gum was also added to the extruder as a solid powder through a solid gravimetric feed hopper.

[0162] The ingredients were added to produce extrudable compositions containing the following components in quantities within the following ranges (where for any given product the amounts totalled 100%): Component Amount (based on total weight of extrudable composition) Milled tobacco65-75 wt%Glycerin15-20 wt%Propylene glycol5-10 wt%Carbopol 971P NF0.4-1 wt%Konjac gum0.4-1 wt%

[0163] No water was added to the extruder.

[0164] The extrudable composition displayed acceptable stable binding of the milled tobacco and good extrusion from the die. The milled tobacco demonstrated improved binding relative to the composition of Example 1, with a smaller amount of visible milled tobacco residue around the die of the extruder, which suggested synergy between the binding properties of the Carbomer and konjac gum leading to an improved product.

[0165] No drying step was required after extrusion due to the absence of water in the composition (other than inevitable trace amounts of water within the ingredients used). The resultant extruded non-aqueous composition was therefore dense, displaying no cracks or visible porosity due to the absence of a drying step.

[0166] The extrudable composition was extruded through a circular die into a continuous cylindrical rod, which was then divided into sections to form discrete rods of aerosol-forming material for use in an aerosol-forming article.Example 3

[0167] The same method as Example 1 was used to produce an extruded aerosol-forming material, except that flavourant (menthol) was also added to the extruder through a separate liquid port.

[0168] The ingredients were added to produce extrudable compositions containing the following components in quantities within the following ranges (where for any given product the amounts totalled 100%): Component Amount (based on total weight of extrudable composition) Milled tobacco65-75 wt%Glycerin15-20 wt%Propylene glycol5-10 wt%Carbopol 971P NF0.4-1 wt%Flavourant0.1-1 wt%

[0169] No water was added to the extruder.

[0170] The extrudable composition displayed acceptable stable binding of the milled tobacco and good extrusion from the die.

[0171] No drying step was required after extrusion due to the absence of water in the composition (other than inevitable trace amounts of water within the ingredients used). The resultant extruded non-aqueous composition was therefore dense, displaying no cracks or visible porosity due to the absence of a drying step.

[0172] The extrudable composition was extruded through a circular die into a continuous cylindrical rod, which was then divided into sections to form discrete rods of aerosol-forming material for use in a flavoured aerosol-forming article.Example 4

[0173] The same method as Example 1 was used to produce an extruded aerosol-forming material, except that an additional structurant (wheat fibres; JELUCEL WF) was also added to the extruder through a separate gravimetric feed hopper.

[0174] The ingredients were added to produce extrudable compositions containing the following components in quantities within the following ranges (where for any given product the amounts totalled 100%): Component Amount (based on total weight of extrudable composition) Milled tobacco65-75 wt%Glycerin15-20 wt%Propylene glycol5-10 wt%Carbopol 971P NF0.4-1 wt%Wheat fibres0.1-8 wt%

[0175] No water was added to the extruder.

[0176] The extrudable composition displayed acceptable stable binding of the milled tobacco and wheat fibres, and good extrusion from the die. This demonstrated the ability of the Carbomer binder to bind solid filler materials of different types used in combination (tobacco and wheat fibres).

[0177] No drying step was required after extrusion due to the absence of water in the composition (other than inevitable trace amounts of water within the ingredients used). The resultant extruded non-aqueous composition was therefore dense, displaying no cracks or visible porosity due to the absence of a drying step.

[0178] The extrudable composition was extruded through a circular die into a continuous cylindrical rod, which was then divided into sections to form discrete rods of aerosol-forming material for use in an aerosol-forming article.Example 5

[0179] The same method as Example 1 was used to produce an extruded aerosol-forming material, except that a structurant (wheat fibres; JELUCEL WF) was added to the extruder through a separate gravimetric feed hopper instead of the milled tobacco, and nicotine was added by dissolving nicotine in the glycerin component in a suitable amount before feeding into the liquid port.

[0180] The ingredients were added to produce extrudable compositions containing the following components in quantities within the following ranges (where for any given product the amounts totalled 100%): Component Amount (based on total weight of extrudable composition) Glycerin15-20 wt%Propylene glycol5-10 wt%Carbopol 971P NF0.4-1 wt%Wheat fibres65-75 wt%Nicotine0.5-2 wt%

[0181] No water was added to the extruder.

[0182] The extrudable composition displayed acceptable stable binding of the wheat fibres, and good extrusion from the die. This demonstrated the ability of the Carbomer binder to bind wheat fibres, thereby producing a stable non-tobacco product containing nicotine.

[0183] No drying step was required after extrusion due to the absence of water in the composition (other than inevitable trace amounts of water within the ingredients used). The resultant extruded non-aqueous composition was therefore dense, displaying no cracks or visible porosity due to the absence of a drying step.

[0184] The extrudable composition was extruded through a circular die into a continuous cylindrical rod, which was then divided into sections to form discrete rods of aerosol-forming material for use in an aerosol-forming article.

Examples

example 1

Example 1

[0152]An extrudable composition was formed in situ within a Thermofisher Process 16 twin-screw extruder. Solid ingredients were fed into the extruder from gravimetric hopper feeders, and liquid / gel ingredients were fed into the extruder into liquid ports using peristaltic pumps.

[0153]The carbomer Carbopol 971P NF was added to propylene glycol to create a gel solution containing 4 wt% Carbopol 971P NF, which was then fed into the extruder.

[0154]The gel was fed to the extruder via a first liquid port; glycerin was fed to the extruder via a second liquid port; further propylene glycol was optionally fed to the extruder via a third liquid port if necessary depending on the desired composition; and milled tobacco was fed to the extruder via a gravimetric feed hopper. All of these ingredients were then mixed downstream of the ports within the extruder to form an extrudable composition within the extruder, before extrusion of the composition out of a die.

[0155]The ingredients were...

example 2

Example 2

[0161]The same method as Example 1 was used to produce an extruded aerosol-forming material, except that konjac gum was also added to the extruder as a solid powder through a solid gravimetric feed hopper.

[0162]The ingredients were added to produce extrudable compositions containing the following components in quantities within the following ranges (where for any given product the amounts totalled 100%):

Component Amount (based on total weight of extrudable composition)

Milled tobacco65-75 wt%

Glycerin15-20 wt%

Propylene glycol5-10 wt%

Carbopol 971P NF0.4-1 wt%

Konjac gum0.4-1 wt%

[0163]No water was added to the extruder.

[0164]The extrudable composition displayed acceptable stable binding of the milled tobacco and good extrusion from the die. The milled tobacco demonstrated improved binding relative to the composition of Example 1, with a smaller amount of visible milled tobacco residue around the die of the extruder, which suggested synergy between the binding properti...

example 3

Example 3

[0167]The same method as Example 1 was used to produce an extruded aerosol-forming material, except that flavourant (menthol) was also added to the extruder through a separate liquid port.

[0168]The ingredients were added to produce extrudable compositions containing the following components in quantities within the following ranges (where for any given product the amounts totalled 100%):

Component Amount (based on total weight of extrudable composition)

Milled tobacco65-75 wt%

Glycerin15-20 wt%

Propylene glycol5-10 wt%

Carbopol 971P NF0.4-1 wt%

Flavourant0.1-1 wt%

[0169]No water was added to the extruder.

[0170]The extrudable composition displayed acceptable stable binding of the milled tobacco and good extrusion from the die.

[0171]No drying step was required after extrusion due to the absence of water in the composition (other than inevitable trace amounts of water within the ingredients used). The resultant extruded non-aqueous composition was therefore dense, displayi...

FIELD

[0001] The present disclosure relates to an extrudable composition. More specifically, the present disclosure relates to an extrudable composition comprising a particulate filler material, a liquid carrier and a polyacrylic acid binder. Extruded aerosol-forming materials and aerosol-forming articles containing such materials are also disclosed.BACKGROUND

[0002] A heat-not-burn (HNB) device, also known as a heated tobacco device, is a type of aerosol-generating system in which an aerosol precursor (e.g., a solid precursor such as tobacco) is heated by a heating system to produce an aerosol that can be inhaled by the user.

[0003] The aerosol precursor contains an aerosol-generating material, often including particulate tobacco or non-tobacco material (e.g. tea), along with aerosol-forming liquid components such as glycerin and / or propylene glycol. Other additives such as flavourants may also be present.

[0004] Some such aerosol precursors contain a collection or strands or shreds of sheet material, or pleated sheets of material. Others may be formed by extruding a paste containing a slurry of components, before drying the paste to produce the aerosol precursor.

[0005] Although extrusion is a convenient method to produce such aerosol precursors, there is a need for improved extrusion methods which lead to corresponding improved products having higher stability and an improved experience for the user.

[0006] It is against this background that the present invention has been developed.SUMMARY

[0007] The present disclosure provides an extrudable composition comprising a particulate filler material, a liquid carrier and a binder.

[0008] In some embodiments, the extrudable composition comprises a particulate filler material, a liquid carrier, and a polyacrylic acid binder.

[0009] It has been found that a polyacrylic acid binder is particularly suitable for extrudable compositions which are formed into aerosol precursors for a HNB article, because they are able to bind together the particulate filler material in a stable and homogeneous way which may provide a more consistent user experience. Furthermore, other common binders such as guar gum tend to form a solid mass after extrusion which hinders the ability of the aerosol precursor to produce aerosol when heated. By contrast, the polyacrylic acid binder remains in a flowable form, facilitating reliable aerosol production.

[0010] In some embodiments, the extrudable composition contains no water, or contains water in an amount of less than 3 wt% based on the total weight of the extrudable composition.

[0011] In this way, the extrudable composition can be described as "non-aqueous". Other extrudable compositions are prepared from a mixture which includes added water. This is necessary because many binders require additional water in order to "thicken" to facilitate proper binding of the particulate filler material. However a result of this high water content is that the first few puffs from a HNB article by a user tend to be very hot, due to the evaporation of steam from the aerosol-forming material upon heating. This experience is undesirable for the user.

[0012] It has surprisingly been found that by using the polyacrylic acid binder, it is not necessary to add water to the extrudable composition, such that the water content of the extrudable composition is below 3 wt%. The polyacrylic acid binder is able to bind the composition sufficiently well without the need to add any water to the composition, beyond the very small amount of water which may naturally be present within the other components. This provides a number of benefits. Firstly, the user experience is improved because the "hot initial puff' effect is mitigated or avoided. Secondly, no drying of the composition after extrusion is necessary due to the existing low water content. Drying of such compositions increases the cost and complexity of manufacture, and has detrimental effects on the product. For example, drying of an aqueous extruded product to remove water creates cracks (porosity) in the product and causes it to shrink, negatively impacting the dimensional stability of the product. The higher porosity means that the product may be more likely to absorb water from the environment (the average humidity inside the pocket of a user is 95-100%), again leading to poor dimensional stability since the dimensions of the product may change depending on the ambient humidity level. In addition, drying increases the brittleness of the product, increasing the likelihood that the product will be damaged during transport.

[0013] The extrudable composition of the invention may therefore be used to manufacture an aerosol precursor which has better stability, is less likely to be damaged during transport and provides an improved user experience.

[0014] In some embodiments, the particulate filler material comprises or consists of particulate tobacco. In this way, a tobacco-containing aerosol precursor is produced by extrusion of the extrudable composition, and heating of the aerosol precursor during use produces a nicotine-containing aerosol through volatilisation of nicotine from the tobacco. The particulate tobacco may comprise milled or ground tobacco material.

[0015] In some embodiments, the particulate filler material comprises or consists of particulate non-tobacco material. In some embodiments, the particulate filler material comprises or consists of particulate non-tobacco plant material. In some embodiments, the particulate filler material consists of particulate non-tobacco material, and the extrudable composition does not contain any tobacco material. Any suitable non-tobacco plant-based filler material may be used, for example one or more types of plant fiber. In some embodiments, the particulate filler material comprises or consists of particulate non-tobacco material comprising a psychoactive compound. For example, the particulate filler material may comprise or consist of tea.

[0016] In some embodiments, the extrudable composition comprises an active compound. In some embodiments, the active compound forms part of the particulate filler material. For example, tobacco contains nicotine as an active compound. However in other embodiments the active compound may be included in the extrudable composition as a distinct ingredient. For example, when the extrudable composition contains non-tobacco particulate filler material, an active compound may also be present in the extrudable composition and may be introduced separately from the particulate filler material.

[0017] The active compound may be any suitable biologically active, volatile compound which imparts a desired physical or psychological effect on the user. The active compound may be a stimulant. The active compound may be a depressant. Suitable active compounds include nicotine, cocaine, caffeine, THC, CBD, opiates and opioids, cathine and cathinone, cannabinoids, kavalactones, mysticin, beta-carboline alkaloids, salvinorin A, together with any combinations, functional equivalents to, and / or synthetic alternatives of the foregoing.

[0018] In some examples, the active compound comprises nicotine or a nicotine salt. In this way, the aerosol-generating article may deliver the user with a delayed hit of nicotine towards the end of a smoking session. In some examples, the active compound comprises nicotine (i.e. free base nicotine). In some examples, the active compound comprises a nicotine salt.

[0019] In some examples, the particulate filler material is a non-tobacco particulate filler material, for example non-tobacco plant fiber, and the active compound comprises nicotine or a nicotine salt.

[0020] In some embodiments, the particulate filler material is present in an amount of at least 50 wt% based on the total weight of the extrudable composition, for example at least 55 wt%, at least 60 wt% or at least 65 wt%. In some embodiments, the particulate filler material is present in an amount of up to 85 wt% based on the total weight of the extrudable composition, for example up to 80 wt% or up to 75 wt%.

[0021] In some embodiments, the particulate filler material is present in an amount of from 50 to 85 wt% based on the total weight of the extrudable composition, for example from 55 to 80 wt%, from 60 to 80 wt% or from 65 to 75 wt%.

[0022] In some embodiments, the polyacrylic acid binder is present in an amount of at least 0.1 wt%, for example at least 0.15 wt%, at least 0.2 wt%, at least 0.25 wt%, at least 0.3 wt%, at least 0.35 wt%, at least 0.4 wt%, at least 0.45 wt% or at least 0.5 wt%, based on the total weight of the extrudable composition.

[0023] In some embodiments, the polyacrylic acid binder is present in an amount of up to 2 wt%, for example up to 1.9 wt%, up to 1.8 wt%, up to 1.7 wt%, up to 1.6 wt%, up to 1.5 wt%, up to 1.4 wt%, up to 1.3 wt%, up to 1.2 wt%, up to 1.1 wt%, up to 1.0 wt%, up to 0.9 wt% or up to 0.8 wt%, based on the total weight of the extrudable composition.

[0024] In some embodiments, the polyacrylic acid binder is present in an amount of from 0.4 to 1.0 wt% based on the total weight of the extrudable composition. For example, in some embodiments, the polyacrylic acid binder is present in an amount of from 0.4 to 1.0 wt%, from 0.45 to 1.0 wt%, from 0.5 to 1.0 wt%, from 0.55 to 1.0 wt%, from 0.6 to 1.0 wt%, from 0.65 to 1.0 wt%, from 0.7 to 1.0 wt%, from 0.75 to 1.0 wt%, from 0.8 to 1.0 wt%, from 0.85 to 1.0 wt%, from 0.9 to 1.0 wt%, from 0.95 to 1.0 wt%, from 0.4 to 0.95 wt%, from 0.4 to 0.9 wt%, from 0.4 to 0.85 wt%, from 0.4 to 0.8 wt%, from 0.4 to 0.75 wt%, from 0.4 to 0.7 wt%, from 0.4 to 0.65 wt%, from 0.4 to 0.6 wt%, from 0.4 to 0.55 wt%, from 0.4 to 0.5 wt%, or from 0.4 to 0.45 wt%, based on the total weight of the extrudable composition. In some embodiments, the polyacrylic acid binder is present in an amount of from 0.5 to 1.0 wt% based on the total weight of the extrudable composition, for example from 0.5 to 0.9 wt%, or from 0.6 to 0.8 wt%.

[0025] In some embodiments, the polyacrylic acid binder comprises or consists of a polyacrylic acid polymer. In some embodiments, the polyacrylic acid binder comprises or consists of a polyacrylic acid polymer having cross-linked polymer chains. In some embodiments, the polyacrylic acid binder comprises or consists of a polyacrylic acid polymer having a number-average molecular weight, M n , of at least 1 x 10 9< Da, as determined by GPC. In some embodiments, the polyacrylic acid binder comprises or consists of a cross-linked polyacrylic acid polymer having a number-average molecular weight, M n , of at least 1 x 10 9< Da, as determined by GPC.

[0026] In some embodiments, the polyacrylic acid binder comprises or consists of a polyacrylic acid polymer having a logP value of greater than 0, wherein P is the octanol / water partition coefficient. The octanol / water partition coefficient provides an indication of the lipophilicity of a molecule: a positive value of logP means that the value of P is greater than 1, indicating that a molecule is more hydrophobic (lipophilic). The octanol / water partition coefficient is determined using the "shake flask" method, by dissolving a sample of the polymer in a biphasic mixture of n-octanol and water, and determining the resultant ratio of the concentrations of the polymer in the n-octanol and water phases.

[0027] The use of such a lipophilic polymer binder may provide a material with more stable binding of the particulate filler material and which is less likely to absorb water from the environment, thereby providing the benefits of low water content described above.

[0028] In some embodiments, the polyacrylic acid binder comprises or consists of a polyacrylic acid polymer having a viscosity of from 4000 to 11,000 cP, measured at 25 °C using a Brookfield RVT at 20 rpm, neutralized to pH 7.3-7.8, with 0.5 wt% mucilage and spindle #5.

[0029] In some embodiments, the polyacrylic acid binder comprises or consists of a polyacrylic acid polymer having: a viscosity of from 4000 to 11,000 cP, measured at 25 °C using a Brookfield RVT at 20 rpm, neutralized to pH 7.3-7.8, with 0.5 wt% mucilage and spindle #5; a number-average molecular weight, M n , of at least 1 x 10 9< Da, as determined by GPC; and a logP value of greater than 0.

[0030] Suitable polyacrylic acid binders include polymers sold under the trade name "Carbomer". One example of a suitable polyacrylic acid binder is the Carbomer sold by the Lubrizol Corporation under the name Carbopol 971P NF.

[0031] In some embodiments, the extrudable composition further comprises an auxiliary binder component. Such an auxiliary binder component may supplement the binding ability of the polyacrylic acid binder to improve the physical properties of the extrudable composition.

[0032] Suitable binders are known in the art and may act to bind together the components forming the extrudable material. Binders may comprise starches and / or cellulosic binders such as methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose and methyl cellulose, gums such as xanthan, guar, arabic and / or locust bean gum, organic acids and their salts such as alginic acid / sodium alginate, agar and pectins.

[0033] In some embodiments, the auxiliary binder component comprises or consists of a gum. In some embodiments, the auxiliary binder component comprises or consists of a natural gum. As used herein, a natural gum refers to polysaccharide materials of natural origin that have binding properties, and which are also useful as a thickening or gelling agents. Representative natural gums derived from plants, which are typically water soluble to some degree, include konjac gum, xanthan gum, guar gum, gum arabic, ghatti gum, gum tragacanth, karaya gum, locust bean gum, gellan gum, and combinations thereof.

[0034] In some embodiments, the auxiliary binder component comprises or consists of konjac gum. It has been found that konjac gum works particularly well alongside the polyacrylic acid binder to provide effective and stable binding of the particulate filler material without the need for any added water, and the resultant extruded aerosol precursor has good physical properties and reliably produces aerosol when heated.

[0035] In some embodiments, the extrudable composition comprises a binder component which consists of a mixture of the polyacrylic acid binder and a natural gum. In some embodiments, the extrudable composition comprises a binder component which consists of a mixture of the polyacrylic acid binder and konjac gum. In some embodiments, the extrudable composition comprises a binder component which consists of a mixture of a carbomer and konjac gum. In some embodiments, the extrudable composition comprises a binder component which consists of a mixture of Carbopol 971P NF and konjac gum.

[0036] In some embodiments, the auxiliary binder component is present in an amount of at least 0.1 wt%, for example at least 0.15 wt%, at least 0.2 wt%, at least 0.25 wt%, at least 0.3 wt%, at least 0.35 wt%, at least 0.4 wt%, at least 0.45 wt% or at least 0.5 wt%, based on the total weight of the extrudable composition.

[0037] In some embodiments, the auxiliary binder component is present in an amount of up to 2 wt%, for example up to 1.9 wt%, up to 1.8 wt%, up to 1.7 wt%, up to 1.6 wt%, up to 1.5 wt%, up to 1.4 wt%, up to 1.3 wt%, up to 1.2 wt%, up to 1.1 wt%, up to 1.0 wt%, up to 0.9 wt% or up to 0.8 wt%, based on the total weight of the extrudable composition.

[0038] In some embodiments, the auxiliary binder component is present in an amount of from 0.4 to 1.0 wt% based on the total weight of the extrudable composition. For example, in some embodiments, the auxiliary binder component is present in an amount of from 0.4 to 1.0 wt%, from 0.45 to 1.0 wt%, from 0.5 to 1.0 wt%, from 0.55 to 1.0 wt%, from 0.6 to 1.0 wt%, from 0.65 to 1.0 wt%, from 0.7 to 1.0 wt%, from 0.75 to 1.0 wt%, from 0.8 to 1.0 wt%, from 0.85 to 1.0 wt%, from 0.9 to 1.0 wt%, from 0.95 to 1.0 wt%, from 0.4 to 0.95 wt%, from 0.4 to 0.9 wt%, from 0.4 to 0.85 wt%, from 0.4 to 0.8 wt%, from 0.4 to 0.75 wt%, from 0.4 to 0.7 wt%, from 0.4 to 0.65 wt%, from 0.4 to 0.6 wt%, from 0.4 to 0.55 wt%, from 0.4 to 0.5 wt%, or from 0.4 to 0.45 wt%, based on the total weight of the extrudable composition. In some embodiments, the auxiliary binder component is present in an amount of from 0.5 to 1.0 wt% based on the total weight of the extrudable composition, for example from 0.5 to 0.9 wt%, or from 0.6 to 0.8 wt%.

[0039] In some embodiments, the weight ratio of the polyacrylic acid binder to the auxiliary binder component is from 2:1 to 1:2, for example from 1.5:1 to 1:1.5, for example from 1.2:1 to 1:1.2, for example from 1.1:1 to 1:1.1, for example about 1:1. Particularly good binding properties have been observed when the polyacrylic acid binder and the auxiliary binder component are present in approximately equal quantities by weight.

[0040] In some embodiments, the extrudable composition further comprises a structurant selected from plant fibres. As used herein, the term "structurant" refers to a solid material included in the composition primarily to provide structure, for example a particulate or fibrous material. In some embodiments, the extrudable composition does not contain any structurant other than the particulate filler material. In some embodiments, the extrudable composition comprises a structurant in addition to the particulate filler material. The structurant may be selected from plant fiber, for example one or more of wheat fiber, oat fiber and bamboo fiber. Suitable structurants are known in the art and may act to strengthen the material. Structurants may comprise fibrous (non-tobacco) fillers such as cellulose fibers, lignocellulose fibers (e.g. wood fibers), jute fibers and combinations thereof.

[0041] In some embodiments, the extrudable composition comprises a structurant (other than the particulate filler material described above) in an amount of up to 10 wt% based on the total weight of the extrudable composition, for example up to 9.5 wt%, up to 9 wt%, up to 8.5 wt% or up to 8 wt%. In some embodiments, the extrudable composition comprises a structurant (other than the particulate filler material described above) in an amount of from 0 to 10 wt%, for example from 0 to 9.5 wt%, from 0 to 9 wt%, from 0 to 8.5 wt%, from 0 to 8 wt%, from 0.1 to 8 wt%, from 0.5 to 8 wt% or from 1 to 8 wt%, based on the total weight of the extrudable composition.

[0042] In some embodiments, the density of the extrudable composition is greater than 1.0 g cm -3< , for example greater than 1.05 g cm -3< , greater than 1.10 g cm -3< , greater than 1.15 g cm -3< , greater than 1.20 g cm -3< , greater than 1.21 g cm -3< or greater than 1.22 g cm -3< .

[0043] In some embodiments, the density of the extrudable composition is from 1.0 g cm -3< to 1.5 g cm -3< , for example from 1.1 g cm -3< to 1.5 g cm -3< , from 1.2 g cm -3< to 1.5 g cm 3< , from 1.2 g cm -3< to 1.4 g cm -3< , from 1.2 g cm -3< to 1.3 g cm -3< , from 1.21 g cm -3< to 1.3 g cm -3< , from 1.22 g cm -3< to 1.3 g cm -3< , from 1.22 g cm -3< to 1.28 g cm -3< , from 1.22 g cm -3< to 1.26 g cm -3< , from 1.22 g cm -3< to 1.24 g cm -3< or from 1.22 g cm -3< to 1.23 g cm -3< .

[0044] The liquid carrier is a liquid fraction of the extrudable composition which provides flowability and extrudability, enables the components of the composition to mix and facilitates the formation of aerosol by the composition after extrusion. In some embodiments, the liquid carrier comprises or consists of one or more of glycerin and propylene glycol. In some embodiments, the liquid carrier comprises glycerin. In some embodiments, the liquid carrier comprises or consists of a mixture of glycerin and propylene glycol. In some embodiments, the liquid carrier consists of a mixture of glycerin and propylene glycol.

[0045] A mixture of glycerin and propylene glycol has been found to provide particularly good properties of the composition. Without wishing to be bound by theory, it is believed that the propylene glycol acts as a suitable carrier for the polyacrylic acid binder, with the polyacrylic acid binder thickening in the presence of the propylene glycol. The glycerin provides good aerosol formation in the form of a visible cloud of aerosol which is desirable to users. Thus a mixture of glycerin and propylene glycol provides a stable product with good properties during use.

[0046] In some embodiments, the extrudable composition comprises the liquid carrier in an amount of at least 15 wt% based on the total weight of the extrudable composition, for example at least 16 wt%, at least 17 wt%, at least 18 wt%, at least 19 wt% or at least 20 wt%. In some embodiments, the extrudable composition comprises the liquid carrier in an amount of up to 40 wt% based on the total weight of the extrudable composition, for example up to 35 wt%, up to 34 wt%, up to 33 wt%, up to 32 wt%, up to 31 wt% or up to 30 wt%. In some embodiments, the extrudable composition comprises the liquid carrier in an amount of from 15 to 40 wt% based on the total weight of the extrudable composition, for example from 16 to 35 wt%, from 17 to 34 wt%, from 18 to 33 wt%, from 18 to 32 wt%, from 19 to 31 wt% or from 20 to 30 wt%.

[0047] In some embodiments, the extrudable composition comprises glycerin in an amount of at least 10 wt% based on the total weight of the extrudable composition, for example at least 11 wt%, at least 12 wt%, at least 13 wt%, at least 14 wt% or at least 15 wt%. In some embodiments, the extrudable composition comprises glycerin in an amount of up to 25 wt% based on the total weight of the extrudable composition, for example up to 24 wt%, up to 23 wt%, up to 22 wt%, up to 21 wt% or up to 20 wt%. In some embodiments, the extrudable composition comprises glycerin in an amount of from 10 to 25 wt% based on the total weight of the extrudable composition, for example from 11 to 24 wt%, from 12 to 23 wt%, from 13 to 22 wt%, from 14 to 21 wt% or from 15 to 20 wt%.

[0048] In some embodiments, the extrudable composition comprises propylene glycol in an amount of at least 2 wt% based on the total weight of the extrudable composition, for example at least 3 wt%, at least 4 wt% or at least 5 wt%. In some embodiments, the extrudable composition comprises propylene glycol in an amount of up to 15 wt% based on the total weight of the extrudable composition, for example up to 14 wt%, up to 13 wt%, up to 12 wt%, up to 11 wt% or up to 10 wt%. In some embodiments, the extrudable composition comprises propylene glycol in an amount of from 2 to 15 wt% based on the total weight of the extrudable composition, for example from 3 to 14 wt%, from 3 to 13 wt%, from 3 to 12 wt%, from 4 to 11 wt% or from 5 to 10 wt%.

[0049] In some embodiments, the liquid carrier comprises or consists of glycerin and propylene glycol in a weight ratio of from 1:1 to 4:1, for example from 2:1 to 3:1.

[0050] In some embodiments, the extrudable composition comprises propylene glycol and the polyacrylic acid binder in a weight ratio of from 3:1 to 50:1, for example from 3:1 to 30:1, from 4:1 to 30:1 or from 5:1 to 25:1. Such ratios provide an acceptable level of viscosity for the extrudable composition which facilitates extrusion and homogeneous mixing of the components of the composition.

[0051] In some embodiments, the extrudable composition is a paste. In some embodiments, the extrudable composition is a deformable paste.

[0052] In some embodiments, the extrudable composition comprises: the particulate filler material, the liquid carrier comprising glycerin and propylene glycol, and the polyacrylic acid binder.

[0053] In some embodiments, the extrudable composition comprises: the particulate filler material comprising ground tobacco, the liquid carrier comprising glycerin and propylene glycol, and the polyacrylic acid binder.

[0054] In some embodiments, the extrudable composition comprises: the particulate filler material comprising ground tobacco, the liquid carrier comprising glycerin and propylene glycol, the polyacrylic acid binder, and the auxiliary binder component.

[0055] In some embodiments, the extrudable composition comprises: the particulate filler material comprising ground tobacco, the liquid carrier comprising glycerin and propylene glycol, the polyacrylic acid binder, and the auxiliary binder component comprising or consisting of konjac gum.

[0056] In some embodiments, the extrudable composition comprises: the particulate filler material comprising ground tobacco, the liquid carrier comprising glycerin and propylene glycol, the polyacrylic acid binder, the auxiliary binder component comprising or consisting of konjac gum, and a flavourant.

[0057] In some embodiments, the extrudable composition comprises: the particulate filler material comprising ground tobacco, the liquid carrier comprising glycerin and propylene glycol, the polyacrylic acid binder, the auxiliary binder component comprising or consisting of konjac gum, and a structurant.

[0058] In some embodiments, the extrudable composition comprises or consists of: 65 to 75 wt% particulate filler material comprising ground tobacco, 20 to 30 wt% liquid carrier comprising glycerin and propylene glycol, 0.4 to 1 wt% polyacrylic acid binder, 0 to 8 wt% structurant, 0 to 1 wt% auxiliary binder component comprising or consisting of konjac gum, and 0 to 1 wt% flavourant.

[0059] In some embodiments, the extrudable composition consists of: 65 to 75 wt% particulate filler material comprising ground tobacco, 20 to 30 wt% liquid carrier comprising glycerin and propylene glycol, 0.4 to 1 wt% polyacrylic acid binder, and 0 to 1 wt% auxiliary binder component comprising or consisting of konjac gum.

[0060] The present disclosure also provides a method of preparing the extrudable composition described herein. In some embodiments, the method comprises mixing a particulate filler material, a liquid carrier and a polyacrylic acid binder. In some embodiments, the method comprises mixing a particulate filler material, a liquid carrier and a polyacrylic acid binder, wherein the extrudable composition contains no water, or contains water in an amount of less than 3 wt% based on the total weight of the extrudable composition. In some embodiments, the method comprises mixing the aforementioned components within an extruder, for example a twin screw extruder. In some embodiments, the method comprises introducing one or more liquid components into one or more liquid ports of an extruder, and introducing one or more solid components into one or more solid feeders into the extruder. The solid feeder may comprise a gravimetric hopper feeder. The liquid ports may be connected with one or more peristaltic pumps.

[0061] The present disclosure also provides a method of preparing an aerosol-forming material. The method may comprise preparing an extrudable composition; and extruding the composition through a die. The method may comprise preparing an extrudable composition comprising a particulate filler material; a liquid carrier; and a polyacrylic acid binder; and extruding the composition through a die.

[0062] The method of preparing an aerosol-forming material, may comprise: preparing an extrudable composition comprising: a particulate filler material; a liquid carrier; and a polyacrylic acid binder; wherein the extrudable composition contains no water, or contains water in an amount of less than 3 wt% based on the total weight of the extrudable composition; and extruding the composition through a die.

[0063] In some embodiments, the method comprises mixing a particulate filler material, a liquid carrier and a polyacrylic acid binder. In some embodiments, the method comprises mixing a particulate filler material, a liquid carrier and a polyacrylic acid binder, wherein the extrudable composition contains no water, or contains water in an amount of less than 3 wt% based on the total weight of the extrudable composition. In some embodiments, the method comprises mixing the aforementioned components within an extruder, for example a twin screw extruder. In some embodiments, the method comprises introducing one or more liquid components into one or more liquid ports of an extruder, and introducing one or more solid components into one or more solid feeders into the extruder. The solid feeder may comprise a gravimetric hopper feeder. The liquid ports may be connected with one or more peristaltic pumps.

[0064] All of the options and preferences described above for the extrudable composition apply equally to the extrudable composition prepared within the method of preparing an aerosol-forming material. For example, all of the compositional preferences apply equally to the method.

[0065] In some embodiments, the method comprises extruding the composition using a twin screw extruder. One example of a suitable extruder is a Thermofisher Process 16 extruder.

[0066] In some embodiments, the method does not include the addition of any water to the extruder, beyond the water which may be unavoidably present in trace amounts within the components of the extrudable composition. For example, particulate filler materials such as ground tobacco would naturally contain a small amount of water, as would liquid carrier components such as glycerin and propylene glycol, and although a very small amount of water would thereby be introduced into the extruder, the method in some embodiments does not include any additional introduction of water into the extruder outside these trace amounts. For example, in some embodiments no aqueous compositions are added to the extruder. In some embodiments, no composition is added to the extruder which has a water content greater than 3 wt%. In some embodiments, each ingredient added to the extruder has a water content of less than 3 wt%, based on the total weight of that ingredient.

[0067] In some embodiments, the method does not include any drying of the extruded aerosol-forming material after extrusion. In some embodiments, the method does not include any elevated-temperature drying of the extruded aerosol-forming material after extrusion. The extrusion of aqueous compositions would require a drying step at elevated temperature to remove water from the composition, which would increase the energy consumption and complexity of the process, and cause shrinkage and cracking of the aerosol-forming material. By contrast, since the extrudable composition already contains a very low water content, no such drying step is required after extrusion and the resultant method is more efficient and the properties of the product may be improved due to less shrinkage and less cracking.

[0068] In some embodiments, the method comprises extruding the composition through a die to form an extruded product in the form of a rod. In some embodiments, the rod is a continuous rod and the method further comprises dividing the continuous rod into a plurality of sections, wherein each section is suitable for use as an aerosol-forming material within a single aerosol-forming article (e.g. a HNB article). In other embodiments, the method comprises extruding the composition through a die into a plurality of discrete rods, wherein each rod is suitable for use as an aerosol-forming material within a single aerosol-forming article (e.g. a HNB article). In other words, the extruder may operate to extrude discrete rods such that no further step of dividing the extruded material into sections is required.

[0069] The method may further comprise incorporating the aerosol-forming material into an aerosol-forming article, for example assembling the aerosol-forming material alongside one or more other components such as filter components, and circumscribing the aerosol-forming material and one or more other components with one or more wrappers.

[0070] The method comprises extruding the composition through a die, and the shape of the die will dictate the cross-sectional shape of the extruded aerosol-forming material. For example, in some embodiments the extrudable composition is extruded through a circular die to form a cylindrical rod. However the shape of the die and corresponding cross-sectional shape of the rod are not limited, and any suitable shape may be adopted, for example any regular polygon (resulting in a prismatic rod having corresponding regular polygon faces).

[0071] The present disclosure also provides an extruded aerosol-forming material comprising: a particulate filler material; a liquid carrier; and a polyacrylic acid binder; wherein the aerosol-forming material contains no water, or contains water in an amount of less than 3 wt% based on the total weight of the aerosol-forming material.

[0072] In some embodiments, the extruded aerosol-forming material is formed by extruding the extrudable composition described herein through a die. All of the options and preferences described above for the extrudable composition apply equally to the extruded aerosol-forming material, mutatis mutandis. For example, all of the compositional preferences apply equally to the extruded aerosol-forming material.

[0073] In some embodiments, the density of the extruded aerosol-forming material, as determined after the extruded aerosol-forming material has been left at 25 °C for 10 hours, is greater than 1.0 g cm -3< , for example greater than 1.05 g cm -3< , greater than 1.10 g cm -3< , greater than 1.15 g cm -3< , greater than 1.20 g cm 3< , greater than 1.21 g cm -3< or greater than 1.22 g cm -3< . The density of the extruded aerosol-forming material is determined by extruding a solid mass of the material, then leaving the extruded aerosol-forming material at 25 °C for 10 hours, before calculating the density of that solid mass based on the measured mass and volume. Extruded aerosol-forming materials made from an aqueous extrudable composition and then left at 25 °C for 10 hours tend to have higher porosity which results in lower density, due to drying of the material, whereas the non-aqueous compositions of the invention lead to extruded aerosol-forming materials of higher density.

[0074] In some embodiments, the density of the extruded aerosol-forming material, as determined after the extruded aerosol-forming material has been left at 25 °C for 10 hours, is from 1.0 g cm -3< to 1.5 g cm 3< , for example from 1.1 g cm -3< to 1.5 g cm 3< , from 1.2 g cm -3< to 1.5 g cm -3< , from 1.2 g cm -3< to 1.4 g cm -3< , from 1.2 g cm -3< to 1.3 g cm -3< , from 1.21 g cm -3< to 1.3 g cm -3< , from 1.22 g cm -3< to 1.3 g cm -3< , from 1.22 g cm -3< to 1.28 g cm 3< , from 1.22 g cm -3< to 1.26 g cm 3< , from 1.22 g cm -3< to 1.24 g cm -3< or from 1.22 g cm -3< to 1.23 g cm -3< .

[0075] In some embodiments, the difference in density between the extruded aerosol-forming material, as determined after the extruded aerosol-forming material has been left at 25 °C for 10 hours, and the extrudable composition, is less than 0.5 g cm -3< , for example less than 0.4 g cm -3< , less than 0.3 g cm -3< , less than 0.2 g cm -3< , less than 0.1 g cm -3< or less than 0.05 g cm -3< . Extruded aerosol-forming materials made from an aqueous extrudable composition may experience an increase in porosity and a resultant relatively large decrease in density upon drying, whereas the non-aqueous compositions of the invention experience very little change in density after extrusion since little or no drying occurs. In some embodiments, the difference in density between the extrudable composition and the extruded aerosol-forming material is from 0 to 0.5 g cm -3< , for example from 0.01 to 0.5 g cm -3< , from 0.01 to 0.4 g cm -3< , from 0.01 to 0.3 g cm -3< , from 0.01 to 0.2 g cm -3< , from 0.01 to 0.1 g cm -3< or from 0.01 to 0.05 g cm -3< .

[0076] The present disclosure also provides an aerosol-forming article comprising the aerosol-forming material described herein. In some embodiments, the aerosol-forming article is in the form of a heated tobacco (HT) stick. In some embodiments, the aerosol-forming article is a heat-not-burn (HNB) consumable.

[0077] In some examples, the aerosol-forming article further comprises one or more of: a mouthpiece segment at a downstream end of the aerosol-forming article; a hollow bore filter located downstream of the aerosol-forming material; and a cardboard tube located downstream of the aerosol-forming material.

[0078] In the exemplary aspects and embodiments described herein, the aerosol-forming article can be a consumable, e.g. a HT consumable, and the aerosol-forming apparatus can be a HT device as described above. The aerosol-forming article comprises an aerosol-forming material which is a solid (as opposed to liquid) extruded substrate capable of being heated to release at least one volatile compound that can form an aerosol. It will be appreciated that tobacco leaf is one such material, wherein an aerosol is generated by inhaling through the heated material. However, those skilled in the art will be aware that aerosol-generating systems might also be easily configured to heat non-tobacco organic material such as other plant material (e.g., cannabis leaf). Consequently, the aerosol-forming article (e.g. a HT consumable) is intended at its broadest to include an extruded aerosol-forming material comprising at least one volatile compound that is intended to be vaporised / aerosolised and that may provide the user with a recreational and / or medicinal effect when inhaled. Suitable chemical and / or physiologically active volatile compounds include the group consisting of: nicotine, cocaine, caffeine, THC, CBD, opiates and opioids, cathine and cathinone, cannabinoids, kavalactones, mysticin, beta-carboline alkaloids, salvinorin A, together with any combinations, functional equivalents to, and / or synthetic alternatives of the foregoing.

[0079] Consequently, the aerosol-forming material of the aerosol-forming article may comprise a plant material. The plant material may comprise at least one plant material selected from the list including Amaranthus dubius, Arctostaphylos uva-ursi (Bearberry), Argemone mexicana, Amica, Artemisia vulgaris, Yellow Tees, Galea zacatechichi, Canavalia maritima (Baybean), Cecropia mexicana (Guamura), Cestrum noctumum, Cynoglossum virginianum (wild comfrey), Cytisus scoparius, Damiana, Entada rheedii, Eschscholzia califomica (California Poppy), Fittonia albivenis, Hippobroma longiflora, Humulus japonica (Japanese Hops), Humulus lupulus (Hops), Lactuca virosa (Lettuce Opium), Laggera alata, Leonotis leonurus, Leonurus cardiaca (Motherwort), Leonurus sibiricus (Honeyweed), Lobelia cardinalis, Lobelia inflata (Indian-tobacco), Lobelia siphilitica, Nepeta cataria (Catnip), Nicotiana species (Tobacco), Nymphaea alba (White Lily), Nymphaea caerulea (Blue Lily), Opium poppy, Passiflora incamata (Passionflower), Pedicularis densiflora (Indian Warrior), Pedicularis groenlandica (Elephant's Head), Salvia divinorum, Salvia dorrii (Tobacco Sage), Salvia species (Sage), Scutellaria galericulata, Scutellaria lateriflora, Scutellaria nana, Scutellaria species (Skullcap), Sida acuta (Wireweed), Sida rhombifolia, Silene capensis, Syzygium aromaticum (Clove), Tagetes lucida (Mexican Tarragon), Tarchonanthus camphoratus, Tumera diffusa (Damiana), Verbascum (Mullein), Zamia latifolia (Maconha Brava) together with any combinations, functional equivalents to, and / or synthetic alternatives of the foregoing.

[0080] It will however be appreciated that in particularly suitable exemplary embodiments, the plant material is tobacco. Thus in some examples, the aerosol-forming material comprises tobacco or a tobacco derivative. Here, any type of tobacco may be used. This includes, but is not limited to, flue-cured tobacco, burley tobacco, Maryland Tobacco, dark-air cured tobacco, oriental tobacco, dark-fired tobacco, perique tobacco and rustica tobacco. This also includes blends of the above-mentioned tobaccos.

[0081] The tobacco may comprise one or more of leaf tobacco, stem tobacco, tobacco powder, tobacco dust, tobacco derivatives, expanded tobacco, homogenised tobacco, shredded tobacco, extruded tobacco, cut rag tobacco and / or reconstituted tobacco (e.g., slurry recon or paper recon). In each case, the aerosol-forming material may be formed into a rod of material. For instance, as termed herein, a tobacco rod. The aerosol-forming material (e.g. tobacco rod) may be formed into a substantially cylindrical shape such that the article / consumable resembles a conventional cigarette. The aerosol-forming material may have a diameter of between 5 and 10 mm (e.g., between 6 and 9 mm or 6 and 8 mm e.g., around 7 mm). The aerosol-forming material may have an axial length of between 10 and 25 mm (e.g., between 11 and 14 mm, such as around 12 or 13 mm).

[0082] In exemplary aspects and embodiments described herein, the aerosol-forming material may comprise one or more additives selected from humectants, flavourants, fillers, non-aqueous solvents and binders. Here, the flavourant may be provided in solid or liquid form. It may be selected from one or more of menthol, liquorice, chocolate, fruit flavour (including e.g., citrus, cherry etc.), vanilla, spice (e.g., ginger, cinnamon) and tobacco flavour. The flavourant may be evenly dispersed throughout the aerosol-forming material or may be provided in isolated locations and / or varying concentrations throughout the aerosol-forming material.

[0083] Humectants are provided as vapor generators - the resulting vapor helps carry the volatile active compounds and increases visible vapor. Suitable humectants include polyhydric alcohols (e.g. propylene glycol (PG), triethylene glycol, 1,2-butane diol and vegetable glycerin (VG)) and their esters (e.g. glycerol mono-, di- or tri-acetate).

[0084] Suitable fillers are known in the art and may act to strengthen the aerosol-forming material. Fillers may comprise fibrous (non-tobacco) fillers such as cellulose fibers, lignocellulose fibers (e.g. wood fibers), jute fibers and combinations thereof.

[0085] In some exemplary aspects and embodiments described herein, the aerosol-forming article can be specifically adapted for use with a HT device (either known devices or the HT devices described herein). In particular, a combustible cigarette is not specifically adapted for use with a HT device. Primarily, this is because insertion of a combustible cigarette into a HT device and subsequent operation of the HT device, would not generate an acceptable vapour for consumption by the user. In particular, an insufficient aerosol vapour would be generated. Consequently, in the exemplary embodiments of aerosol-forming articles (e.g. HT consumables) described and claimed herein, one specific adaption for use with a HT device is the incorporation of a carrier in the aerosol-forming material (e.g. tobacco material). Here, during use, a first vapour is produced from the tobacco material volatising the nicotine (or other active substance as described above) and a second vapour is produced from vaporisation of the carrier. Any known or suitable carrier is considered. For instance, the carrier added to the aerosol-forming material (e.g., the plant material such as tobacco) suitably comprises propylene glycol (PG), and / or vegetable glycerin (VG).

[0086] In some exemplary aerosol-forming article embodiments described herein, in addition to an aerosol-forming material, there may also be provided further components or elements combined with the aerosol-forming material as is known in the art as well as described and claimed herein. Thus, the exemplary aerosol-forming article may include an aerosol-forming material combined with one or more further components or elements by a wrapping paper which can include a combining paper and / or a tipping paper. The combining paper may circumscribe the aerosol-forming material and further components and may be glued or adhered to form a homogenous component or rod as is known in the art and as explained in the background section above. Therefore, except where incompatible, the addition or combination of features of the described and claimed aspects and embodiments of the consumables is expressly considered. Furthermore, as used herein, wrapping paper in its broadest is intended to include any suitable substrate that can be used to circumscribe the components of the aerosol-forming article to join or wrap one or more of the components. It is envisaged that suitable substrates are thin and flexible, with paper or similar materials being exemplary. Thus, as used herein, wrapping substrate is used interchangeably to reference wrapping paper in its broadest form even for instance when the aerosol-forming article paper is not combining components.

[0087] As will become apparent, the described aspects and embodiments can be suitable for use with a HT system wherein the HT consumable is intended to be used as described in the background section above. That is, the aerosol-forming article (e.g. a consumable) can be inserted into a cavity at a downstream end of the HT device. Or stated alternatively, the aerosol-generating article is insertable into the cavity in a downstream to upstream direction. Herein, such arrangements can be termed 'downstream' aerosol-forming article or consumable. Here, the aerosol-forming material is arranged at an upstream end and a distal, downstream end of the aerosol-forming article (e.g. the HT consumable) comprises a mouthpiece, for instance, a mouthpiece filter (e.g., a terminal filter arrangement). Here, suitably, the mouthpiece filter may comprise a monoacetate filter or a hollow bore filter. In some arrangements, the hollow bore filter may be a triple bore filter e.g., with three bores arranged in an equilateral triangle around a central axis. Alternatively or additionally, the mouthpiece filter may be comprised of cellulose acetate or polypropylene tow. Further alternatively or additionally, the mouthpiece filter element (e.g., the terminal filter element) may be comprised of activated charcoal or may be comprised of paper. In each case, the mouthpiece filter element is suitably at least partly (e.g., preferably, but not necessarily entirely) circumscribed with a plug wrap e.g., a paper plug wrap. In some arrangements of the downstream aerosol-forming articles, the mouthpiece filter may include flavourant. For instance, the mouthpiece filter can be formed with a capsule able to be fractured (fractureable) that a user can fracture to release a vapour or liquid (e.g., provided with a crush ball) as is known in the art.

[0088] In some exemplary downstream aerosol-forming articles, the mouthpiece filter (at the downstream end of the aerosol-forming article) is suitably joined to the upstream elements forming the aerosol-forming article and including at least the aerosol-forming material by a circumscribing tipping layer e.g., a tipping paper layer (which can be a component of the wrapping paper). The tipping paper may have an axial length longer than the axial length of the terminal filter element such that the tipping paper completely circumscribes the terminal filter element plus the wrapping layer surrounding any adjacent upstream element.

[0089] As explained, the aerosol-forming article may comprise further components and elements. For instance, in some exemplary downstream aerosol-forming articles, further elements can be arranged between the aerosol-forming material and the mouthpiece filter. Whereas in non-downstream embodiments which might not necessarily comprise a mouthpiece filter, the further elements may be provided to either or one side of the aerosol-forming material. For instance, in some embodiments, the aerosol-forming article comprises an aerosol-cooling element which is adapted to cool the aerosol generated from the aerosol-forming material (by heat exchange) before being inhaled by the user. That is, in some aerosol-forming articles, the cooling element regulates the temperature of vapour. In some exemplary arrangements, wherein the cooling element may suitably comprise a bore filter and a paper tube, each of the bore filter and the paper tube regulate the temperature of the vapour in use. In some arrangements, the bore filter may be a hollow bore filter. In some arrangements, the paper tube may be a spiral paper tube. In other words, the paper tube may be a continuous paper tube wound in a spiral or the paper tube may be a cardboard tube. In the exemplary embodiments, the paper tube itself may be impermeable to air but comprise a plurality of perforations e.g., formed by a laser. The plurality of perforations may be distributed circumferentially about the paper tube and correspond in number and location with the plurality of perforations of the tipping paper to provide ventilation into an internal cavity of the paper tube.

[0090] In some arrangements, as described herein, the exemplary HT consumable is configured as an upstream consumable. That is, a consumable for use with a HT device having a cavity at an upstream end for receiving the consumable, an air passage through the device to a mouthpiece at a downstream end.

[0091] Optionally, the aerosol-forming material may be an extruded cylindrical rod. Here, the cylindrical rod can have opposed end faces. Each end face may be a planar face. That is, the end face is said to be a planar face along the predominant plane of the aerosol-forming material. The cylindrical rod has a longitudinal axis, and the end faces are suitably perpendicular to the longitudinal axis.

[0092] In another aspect the present disclosure provides an aerosol-generating system comprising the aerosol-forming article, and an aerosol-generating apparatus comprising a heater.

[0093] At its most general, a heated tobacco (HT) system may comprise an aerosol-forming article (e.g. a HT consumable) and an aerosol-generating apparatus (e.g. a HT device) configured with a heating zone.

[0094] The aerosol-generating apparatus may include a cavity that may be configured to receive the aerosol-forming article. The cavity may be sized and / or dimensioned to conform with the outer dimensions of the aerosol-forming article (or vice versa). For example, the cavity may have the shape of a circular bore and the aerosol-forming article has the shape of a cylinder. A diameter of the cavity may the same as or slightly larger than the diameter of the aerosol-forming article. The cavity may be a blind hole in the aerosol-generating apparatus. The cavity may be provided by a bottom wall and a side wall that connects the bottom wall to an opening or aperture of the cavity. If the aerosol-forming article is fully inserted into the cavity, all outer surfaces of the aerosol-forming article that are arranged within the cavity may contact inner walls of the cavity (e.g. the bottom wall and the side wall).

[0095] The cavity may form the opening / aperture in a housing of the aerosol-generating apparatus. The aperture and / or the cavity may be closed by a lid, a cap, or other types of closing means if the consumable is not inserted into the cavity. If the aerosol-forming article is fully inserted into the cavity (for example by abutting against the bottom wall of the cavity), a part of the consumable (e.g. one or more filters) may protrude from the cavity. The aerosol-forming article may be sized so that the one or more filters are not arranged in the cavity so that they are not heated by the aerosol-generating unit.

[0096] The aerosol-forming article may be inserted into the cavity for aerosolising one or more components the aerosol-forming material. For example, the tobacco portion / section of the aerosol-forming article may be inserted into the cavity to be heated by the aerosol-generating unit. The aerosol-generating unit may be configured to generate heat for heating the aerosol-forming material when inserted into the cavity.

[0097] The components of the aerosol-generating unit that generate the heat may be arranged in and / or on the walls of the cavity so that the heat provided by the aerosol-generating unit is generated close to the aerosol-forming material (e.g. the precursor). A heat insulation may be provided around the cavity for reducing heat transfer from the aerosol-generating unit towards other parts of the aerosol-generating apparatus. The walls of the cavity may be made from a material with high thermal conductivity (e.g. metal) so that the heat that is generated by the aerosol-generating unit is quickly conducted along the walls of the cavity for uniformly heating the consumable.

[0098] The aerosol-generating unit defines a heating zone, where the heating zone is an area of the cavity over which the aerosol generating unit provides or generates heat.

[0099] The longitudinal direction of the cavity may be parallel or coincide with the longitudinal direction of the aerosol-generating apparatus and / or the aerosol-forming article when inserted into the cavity.

[0100] In some examples, the aerosol generating unit includes an inside-out heater having a heating element configured to penetrate the aerosol-generating substrate of the aerosol-forming article.

[0101] In one exemplary embodiment, the aerosol-generating apparatus, optionally the heating element, includes a resistive heater comprising a rod or blade that extends into the cavity. Here, the rod or blade is intended to be inserted into the aerosol-forming material.

[0102] In some examples, the aerosol generating unit includes an outside-in heater arranged in or on a side wall of the cavity for heating an outer surface of the aerosol-forming article when inserted into the cavity.

[0103] Thus, other embodiments of the aerosol generating unit are envisaged such as an outside-in heater. For instance, the outside-in heater may include a resistive heater and / or an infrared heater that is arranged to heat the sides of the aerosol-forming article.

[0104] The aerosol-generating unit may include the inside-out heater and the outside-in heater. Alternatively, embodiments are envisaged wherein the heating element is distributed in or on the consumable. For instance, the aerosol generating unit may include one or more induction heaters wherein a susceptor is provided in the aerosol-forming article. An electromagnetic source of the induction heater can be provided about the cavity.

[0105] Optionally, the stop is formed by the closed end of the cavity. However, in some embodiments, it is envisaged that the stop is provided as a ledge or ridge within the cavity. In particular, in embodiments including an aerosol-generating apparatus (e.g. the HT device) having a cavity at an upstream end such that air is drawn through the aerosol-forming material, the aerosol-generating apparatus can be configured to provide an airflow from the distal end of the cavity to a downstream mouthpiece on the aerosol-generating apparatus. Here, the distal end of the cavity can include a passageway. For instance, the passageway can be formed in a centre of a ledge. Here, a mesh can preferably be provided at the distal end of the cavity.

[0106] The aerosol-generating article may have an elongate shape, and optionally a rod shape (i.e., the aerosol-generating article forms a substantially cylindrical outer shape), the upstream and downstream ends of the aerosol-generating article can be air-permeable to allow an axial airflow through the aerosol-generating article.

[0107] In the exemplary aerosol-generating apparatuses (e.g. HT devices), and in relation to the aerosol-forming articles (e.g. HT consumables), the aerosol-generating apparatuses that the aerosol-forming articles are intended for use with, the aerosol-generating apparatus may comprise any one or more of the following exemplary features, except where those features are incompatible as apparent for the skilled person. This applies for both aerosol-generating apparatuses configured with a cavity configured to allow insertion of the aerosol-forming article in the upstream and downstream direction.

[0108] Optionally, the aerosol-generating apparatus may comprise an elongate housing (also referred to as a body). An end of the elongate body may be configured for engagement with an aerosol-forming article (e.g. a consumable). For example, the body may be configured for engagement with a heated tobacco consumable. Exemplary aerosol-generating apparatuses comprise a cavity that is configured for receipt of at least a portion of the aerosol-forming article (i.e., for engagement with the consumable). As explained, the aerosol-forming article is of the type that comprises an aerosol former (e.g., carried by an aerosol-forming material).

[0109] In exemplary embodiments, the heating element is rigidly mounted to the body. The heating element may be elongate so as to define a longitudinal axis and may, for example, have a transverse profile (i.e., transverse to a longitudinal axis of the heating element) that is substantially circular (i.e., the heating element may be generally cylindrical). Alternatively, the heating element may have a transverse profile that is rectangular (i.e., the heating element may be a "blade heater"). The heating element may alternatively be in the shape of a tube (i.e., the heating element may be a "tube heater"). The heating element may take other forms (e.g., the heating element may have an elliptical transverse profile). The shape and / or size (e.g., diameter) of the transverse profile of the heating element may be generally consistent for the entire length (or substantially the entire length) of the heating element.

[0110] In exemplary embodiments, the heating element is between 15 mm and 25 mm long, e.g., between 18 mm and 20 mm long, e.g., around 19 mm long. The heating element may have a diameter of between 1.5 mm and 2.5 mm, e.g., a diameter between 2 mm and 2.3 mm, e.g., a diameter of around 2.15 mm. The heating element may be formed of ceramic. The heating element may comprise a core (e.g., a ceramic core) comprising Al 2 O 3 . The core of the heating element may have a diameter of 1.8 mm to 2.1 mm, e.g., between 1.9 mm and 2 mm. The heating element may comprise an outer layer (e.g., an outer ceramic layer) comprising Al 2 O 3 . The thickness of the outer layer may be between 160 µm and 220 µm, e.g., between 170 µm and 190 µm, e.g., around 180 µm. The heating element may comprise a heating track, which may extend longitudinally along the heating element. The heating track may be sandwiched between the outer layer and the core of the heating element. The heating track may comprise tungsten and / or rhenium. The heating track may have a thickness of around 20 µm.

[0111] In exemplary embodiments, the heating element is located in the cavity (of the aerosol-generating apparatus), and may extend (e.g., along a longitudinal axis) from an internal base (i.e., distal end) of the cavity towards an opening of the cavity.

[0112] Optionally, the heating element may be in the form of a rod or blade that extends from the body and into the cavity. That is, the heating element extends from an end of the body that is configured for engagement with the consumable. Here, the heating element is configured for insertion into an aerosol-forming article (e.g., a HT consumable) when an aerosol-forming article is received in the cavity. In that respect, a distal end (i.e., distal from a base of the heating element where it is mounted to the aerosol-generating apparatus) of the heating element may comprise a tapered portion, which may facilitate insertion of the heating element into the aerosol-forming article. The heating element may fully penetrate an aerosol-forming article when the aerosol-forming article is received in the cavity. That is, the entire length, or substantially the entire length, of the heating element may be received in the aerosol-forming article.

[0113] The heating element may have a length that is less than, or substantially the same as, an axial length of an aerosol-forming material forming part of an aerosol-forming article (e.g., a HT consumable). Thus, when such an aerosol-forming article is engaged with the aerosol-generating apparatus, the heating element may only penetrate the aerosol-forming material, rather than other components of the aerosol-forming article. The heating element may penetrate the aerosol-forming material for substantially the entire axial length of the aerosol-forming material of the aerosol-forming article. Thus, heat may be transferred from (e.g., an outer circumferential surface of) the heating element to the surrounding aerosol-forming material, when penetrated by the heating element. That is, heat may be transferred radially outwardly (in the case of a cylindrical heating element).

[0114] Alternatively, the heating element can be configured to transfer heat radially inwardly (in the case of a tube heater). In exemplary embodiments where the heating element is a tube heater, the heating element of the tube heater may surround at least a portion of the cavity. When the portion of the aerosol-forming article (i.e., HT consumable) is received in the cavity, the heating element surrounds a portion of the aerosol-forming article (i.e., so as to heat that portion of the aerosol-forming article, for instance the aerosol-forming material). In particular, the heating element may surround an aerosol-forming material of the aerosol-forming article. That is, when an aerosol-forming article is engaged with the device, the aerosol-forming material of the aerosol-forming article may be located adjacent an inner surface of the (tubular) heating element. When the heating element is activated (by discharging a battery across the heating element), heat may be transferred radially inwardly from the inner surface of the heating element to heat the aerosol forming substrate.

[0115] In exemplary embodiments where the heating element is a tube heater, the cavity comprises a (e.g., circumferential) wall (or walls) and the (tubular) heating element extends around at least a portion of the wall(s). In this way, the wall may be located between the inner surface of the heating element and an outer surface of the aerosol-forming article. The wall (or walls) of the cavity may be formed from a thermally conductive material (e.g., a metal) to allow heat conduction from the heating element to the aerosol-forming article. Thus, heat may be conducted from the heating element, through the cavity wall (or walls), to the aerosol-generating substrate of an aerosol-forming article received in the cavity. Alternatively, here, the heating element may be an infrared (IR) heating element. A tubular IR heating element may be configured to emit more IR radiation across the wall (or walls) than is transmitted by conduction. The wall (or walls) is therefore suitably transmissive of the emitted IR radiation. The combination of the wall (or walls) with the tubular IR heating element may be referred to as an IR heating tube. That is, in exemplary embodiments, the cavity may be formed from an IR heating tube.

[0116] The aerosol-generating apparatus may further comprise a provision, preferably a mechanical means, to intrude into the cavity. For instance, o-rings or the like that are configured to slightly compress against the inserted aerosol-forming article in order to grip the aerosol-forming article and provide resistance to withdrawal (and in relation to the upstream configured cavities, to prevent the aerosol-forming article falling out under gravity in use). In embodiments comprising electrical connections between the device and the aerosol-forming article, the electrical connections may provide the resistance to withdrawal of the aerosol-forming article, or additional assist in doing so.

[0117] In some exemplary embodiments, the aerosol-generating apparatus comprises a cap disposed at the end of the body that is configured for engagement with the aerosol-forming article. Where the aerosol-generating apparatus comprises the heating element configured to be inserted into the aerosol-forming article, the cap may at least partially enclose the heating element. The cap may be moveable between an open position in which access is provided to the heating element, and a closed position in which the cap at least partially encloses the heating element. The cap may be slidably engaged (i.e., slid to engage) with the body of the aerosol-generating apparatus, and may be slidable (i.e., able to slide) between the open and closed positions. In the alternative, rather than or additional to opening and closing the cavity, the sliding between the open and closed position may act to lift the aerosol-forming article from heating element.

[0118] In exemplary embodiments, the cap defines at least a portion of the cavity of the device. That is, the cavity may be fully defined by the cap, or each of the cap and body may define a portion of the cavity. Where the cap fully defines the cavity, the cap may comprise an aperture for receipt of the heating element into the cavity (when the cap is in the closed position). The cap may comprise an opening to the cavity. The opening may be configured for receipt of at least a portion of the aerosol-forming article (and preferably at least the portion including the aerosol-forming material). That is, the aerosol-forming article may be inserted through the opening and into the cavity (so as to be engaged with the device).

[0119] In exemplary embodiments, the cap is configured such that when an aerosol-forming article is engaged with the device (e.g., received in the cavity), only a portion of the aerosol-forming article is received in the cavity. That is, a portion of the aerosol-forming article (not received in the cavity) may protrude from (i.e., extend beyond) the opening. In embodiments wherein the cavity is an upstream cavity, this (protruding) portion of the aerosol-forming article is a terminal (e.g., mouth) end of the aerosol-forming article, which is received in a user's mouth for the purpose of inhaling aerosol formed by the system.

[0120] In exemplary embodiments, the aerosol-generating apparatus comprises a power source or may be connectable to a power source (e.g., a power source separate to the aerosol-generating apparatus). Here, the power source is electrically connectable to the heating element. In that respect, altering (e.g., toggling) the electrical connection of the power source to the heating element may affect a state of the heating element. For example, toggling the electrical connection of the power source to the heating element may toggle the heating element between an on state and an off state (e.g., PWM control). The power source may be a power store. For example, the power source may be a battery or rechargeable battery (e.g., preferably a lithium-ion battery).

[0121] In exemplary embodiments, the aerosol-generating apparatus comprises an input connection (e.g., a USB port, Micro USB port, USB-C port, etc.). The input connection may be configured for connection to an external source of electrical power, such as a mains electrical supply outlet. The input connection may, in some cases, be used as a substitute for an internal power source (e.g., battery or rechargeable battery). That is, the input connection may be electrically connectable to the heating element (for providing power to the heating element). Hence, in some forms, the input connection may form at least part of the power source of the device. Where the power source comprises a rechargeable power source (such as a rechargeable battery), the input connection may be used to charge and recharge the power source.

[0122] In exemplary embodiments, the aerosol-generating apparatus comprises a user interface (UI). In some embodiments the UI may include input means to receive operative commands from the user. The input means of the UI may allow the user to control at least one aspect of the operation of the device. In some embodiments the input means may comprise a power button to switch the device between an on state and an off state. In some embodiments the UI may additionally or alternatively comprise output means to convey information to the user. In some embodiments the output means may comprise a light to indicate a condition of the device (and / or the aerosol-forming article) to the user. The condition of the device (and / or aerosol-forming article) indicated to the user may comprise a condition indicative of the operation of the heating element. For example, the condition may comprise whether the heating element is in an off state or an on state. In some embodiments, the UI unit may comprise at least one of a button, a display, a touchscreen, a switch, a light, and the like. For example, the output means may comprise one or more (e.g., two, three, four, etc.) light-emitting diodes ("LEDs") that may be located on the body of the device. In some exemplary embodiments, the device may further comprise a puff sensor (e.g., airflow sensor), which form part of the input means of the UI. The puff sensor may be configured to detect a user drawing on an end (i.e., a terminal (mouth) end) of the system. The puff sensor may, for example, be a pressure sensor or a microphone. The puff sensor may be configured to produce a signal indicative of a puff state. The signal may be indicative of the user drawing (an aerosol from the aerosol-generating article) such that it is e.g., in the form of a binary signal. Alternatively, or additionally, the signal may be indicative of a characteristic of the draw (e.g., a flow rate of the draw, length of time of the draw, etc).

[0123] In exemplary embodiments, the aerosol-generating apparatus comprises a controller, or may be connectable to a controller that may be configured to control at least one function of the device. The controller may comprise a microcontroller that may e.g., be mounted on a printed circuit board (PCB). The controller may also comprise a memory, e.g., non-volatile memory. The memory may include instructions, which, when implemented, may cause the controller to perform certain tasks or steps of a method. Where the device comprises an input connection, the controller may be connected to the input connection. The controller may be configured to control the operation of the heating element. Thus, the controller may be configured to control vaporisation of an aerosol forming part of an aerosol-forming article engaged with the device. The controller may be configured to control the voltage applied by power source to the heating element. For example, the controller may be configured to toggle between applying a full output voltage (of the power source) to the heating element and applying no voltage to the heating element. Alternatively, or additionally, the control unit may implement a more complex heating element control protocol. In exemplary embodiments, the controller includes a voltage regulator to regulate the output voltage supplied by the power source to form a regulated voltage. The regulated voltage may subsequently be applied to the heating element.

[0124] In some embodiments, where the aerosol-generating apparatus comprises a UI, the controller may be operatively connected to one or more components of the UI. The controller may be configured to receive command signals from an input means of the UI. The controller may be configured to control the heating element in response to the command signals. For example, the controller may be configured to receive "on" and "off" command signals from the UI and, in response, may control the heating element so as to be in a corresponding on or off state. The controller may be configured to send output signals to a component of the UI. The UI may be configured to convey information to a user, via an output means, in response to such output signals (received from the controller). For example, where the device comprises one or more LEDs, the LEDs may be operatively connected to the controller. Hence, the controller may be configured to control the illumination of the LEDs (e.g. in response to an output signal). For example, the controller may be configured to control the illumination of the LEDs according to (e.g., an on or off) state of the heating element.

[0125] Where the aerosol-generating apparatus comprises a sensor (e.g., a puff / airflow sensor), the controller may be operatively connected to the sensor. The controller may be configured to receive a signal from the sensor (e.g., indicative of a condition of the device and / or engaged aerosol-forming article). The controller may be configured to control the heating element, or an aspect of the output means, based on the signal from the sensor.

[0126] In some exemplary embodiments, the device may comprise a wireless interface configured to communicate wirelessly (e.g., via Bluetooth (e.g., a Bluetooth low-energy connection) or WiFi) with an external device. Similarly, the input connection may be configured for wired connection to an external device so as to provide communication between the device and the external device. The external device may be a mobile device. For example, the external device may be a smart phone, tablet, smart watch, or smart car. An application (e.g., app) may be installed on the external device (e.g., mobile device). The application may facilitate communication between the device and the external device via the wired or wireless connection. The wireless or wired interface may be configured to transfer signals between the external device and the controller of the device. In this respect, the controller may control an aspect of the device in response to a signal received from an external device. Alternatively, or additionally, an external device may respond to a signal received from the device (e.g., from the controller of the device).

[0127] As used herein, the terms "upstream" and "downstream" are intended to refer to the flow direction of the vapour / aerosol, i.e. with the downstream end of the article / consumable being the mouth end or outlet where the aerosol exits the consumable for inhalation by the user. The upstream end of the article / consumable is typically the opposing end to the downstream end. That is, where the airflow through the component or the system is substantially straight, the upstream end will be opposed to the downstream end. Where air inlets might be provided on the sides of the component, the downstream end is defined by the exit of the aerosol to the user and the upstream end is generally an opposed region including the inlets.

[0128] Another aspect the present disclosure provides the use of an aerosol-generating system comprising the aerosol-forming article describe herein, or the aerosol-generating system described herein, for the generation of an aerosol for inhalation by a user.

[0129] The present disclosure may provide a method of generating an aerosol, which may implement any one or more features disclosed herein. The method may comprise placing the aerosol-forming article in an aerosol-generating apparatus comprising a heater, as described herein (e.g. a HT device).

[0130] The preceding summary is provided for purposes of summarizing some examples to provide a basic understanding of aspects of the subject matter described herein. Accordingly, the above-described features should not be construed to narrow the scope of the subject matter described herein in any way. Moreover, the above and / or following examples may be combined in any suitable combination to provide further examples, except where such a combination is clearly impermissible or expressly avoided. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following text and the accompanying figures.BRIEF DESCRIPTION OF THE FIGURES

[0131] Aspects, features and advantages of the present disclosure will become apparent from the following description of examples in reference to the appended figures in which like numerals denote like elements. Figure 1 shows an example of an aerosol-generating system; Figure 2 shows the components of the aerosol-generating system in a 'disengaged state'; Figure 3 shows the components of the aerosol-generating system in an 'engaged state'. DETAILED DESCRIPTION OF EMBODIMENTS

[0132] It is to be understood that the present disclosure, which includes the specification and claim(s), is not limited by specific construction details or process steps. Rather, it will be clear to those skilled in the art that the systems, apparatuses, and methods described herein can be embodied and practiced in various alternative ways without departing from the scope of the invention.

[0133] Unless defined otherwise, scientific and technical terms used herein have their meanings commonly understood by those skilled in the art and that known techniques and procedures may be performed according to conventional methods.

[0134] In the present disclosure, the terms "a" and "an" may mean "one", "one or more", "at least one", and "one or more than one" unless the context clearly indicates otherwise. Likewise, plural terms shall include the singular unless otherwise required by context.

[0135] In the present disclosure, the term "or" means an inclusive "and / or" unless explicitly indicated to refer to alternatives only or unless the alternatives are mutually exclusive.

[0136] In the present disclosure, the terms "comprising, "having," "including," or "containing" (and any forms thereof, such as "comprise" and "comprises," "have" and "has," "includes" and "include," or "contains" and "contain," respectively) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0137] Unless stated otherwise, the features of examples disclosed herein, and of the claims, may be integrated together in any suitable arrangement such that combinations of features are not limited by the described forms, particularly the form (e.g. numbering) of example(s), embodiment(s), or dependency of claim(s). This also applies to the phrase "in one example", "according to an example" and the like, which are merely a stylistic form of wording not to be construed as limiting the features to a separate embodiment. This is to say, a reference to 'an,' 'one,' or 'some' examples(s) may be a reference to any one or more, and / or all examples, or combination(s) thereof, disclosed. Also, similarly, reference to "the" example may not be limited to the immediately preceding embodiment. Further, all references to one or more embodiments or examples are to be construed as non-limiting to the claims.

[0138] The present disclosure may be better understood in view of the following explanations, wherein the terms used that are separated by "or" may be used interchangeably.

[0139] Figure 1 shows an example of an aerosol-generating system 1 comprising a device body 20 and an aerosol-forming article 30 (alternatively referred to as a "consumable") for insertion into the device body 20. Figure 2 shows a schematic representation of the internal components of the device body 20 and aerosol-forming article 30, and shows the aerosol-forming article 30 in an "unwrapped" state, such that internal components of the aerosol-forming article are visible. The device body 20 and article 30 are shown in a "disengaged state" in which the article 30 is separated from the device body 20.

[0140] In this example, the device body 20 is a heat-not-burn device (HNB) configured to produce an aerosol by heating an aerosol-forming material 10 (e.g. a solid precursor, such as tobacco material) to a temperature below its combustion temperature.

[0141] The term "aerosol-forming material" refers to a material capable of releasing volatile components that can form an aerosol, e.g. by releasing volatile compounds in the aerosol-forming material 10. An "aerosol" is a dispersion of solid particles and / or liquid droplets dispersed in a gas. The aerosol may be visible or invisible. The aerosol-forming material 10 in the aerosol-forming article 30 is an extruded material, formed by extruding an extrudable composition through a die, for example a die which forms part of a twin-screw extruder.

[0142] The aerosol-generating system 1 has an aerosol-generating unit 2 in the form of a heating system. The heating system comprises a heating element 2a configured to penetrate the article 30. The heating element 2a heats the aerosol-forming material 10 to a temperature lower than its combustion temperature such that an aerosol can be formed by evaporation, torrefaction and pyrolysis.

[0143] The aerosol-generating system 1 includes a power source 4. In this example, the power source 4 includes a battery 4a configured to supply electrical energy to operate the aerosol-generating unit 2 and other components. The aerosol-generating system 1 may be powered, alternatively or in addition to the battery 4a, by an external power source.

[0144] The article 30 defines an air passageway which transmits aerosol generated from the aerosol-forming material 10 to a downstream end 32 (i.e. terminal end or mouth end) of the article 30. The article 30 may comprise one or more filter elements 34, one or more spacer elements 36, and one or more wrapping layers 38 (e.g. paper, foil or composite layers). One or more of the filter elements 34 and spacer elements 36 may define the air passageway. In the present example, the article 30 comprises an aerosol-forming material 10 at the upstream end 31 of the article 30, a filter element 34 at the downstream end 32, and a spacer element 36 positioned between them, all circumscribed by a wrapping layer 38.

[0145] Figure 3 shows the aerosol-generating system 1 in an "engaged state" in which the article 30 is inserted into an internal chamber 22 of the device body 20.

[0146] In this example, the heating element 2a is configured to penetrate the article 30. The heating element 2a is arranged to extend along a length of the aerosol-forming material 10 when inserted therein, such that when the heating element 2a is activated, heat is transferred radially outward from the heating element 2a to the aerosol-forming material 10 resulting in formation of an aerosol. This may be referred to as an 'inside-out' heating arrangement. The aerosol is subsequently entrained in an airflow produced by the action of the user drawing on the downstream end 32 of the article 30.

[0147] In alternative examples, the heating element 2a may be configured to at least partially encircle the article 30, such that when the heating element 2a is activated, heat is transferred radially inward from the heating element 2a to the aerosol-forming material 10. This may be referred to as an 'outside-in' heating arrangement.

[0148] In this example, the heating element 2a is a resistive heating element although it will be appreciated that the aerosol-forming material 10 may be heated by any suitable means. For instance, the heating element 2a may comprise a susceptor (not shown) configured to produce heat when penetrated by an alternating magnetic field.

[0149] The device body 20 may include any one or more of electrical circuitry, a memory, a wireless interface, and one or more other components. The device body 20 may include a printed circuit board (PCB) 25 on which components of the electrical circuitry, memory, wireless interface, and other components may be mounted.

[0150] The electrical circuitry may include a processing resource for controlling one or more operations of the body 20 and article 30, e.g. based on instructions stored in the memory. The wireless interface may be configured to communicate wirelessly with an external (e.g. mobile) device, e.g. via Bluetooth. The other component(s) may include one or more user interface devices configured to convey information to a user, a pressure sensor 15, and / or a charging port 18.

[0151] The aerosol-generating system 1 may comprise one or more input and / or output elements. The input and / or output elements may form part of a user interface (UI) of the system 1. For instance, Figure 1 shows an input element in the form of a button 16 and an output element in the form of a set of lights (LEDs) 17. The button 16 is configured to control at least one function of system 1, such as power supply to the heating element 2a. The lights 17 are configured to convey information to the user regarding the state of the system 1 and / or article. It will be appreciated that the input element(s) may be provided in various forms such as touch screens, switches, and sensors, and the output element(s) may be provided in various forms such as display screens, speakers, or a haptic output generated by a vibration generator.EXAMPLES Example 1

[0152] An extrudable composition was formed in situ within a Thermofisher Process 16 twin-screw extruder. Solid ingredients were fed into the extruder from gravimetric hopper feeders, and liquid / gel ingredients were fed into the extruder into liquid ports using peristaltic pumps.

[0153] The carbomer Carbopol 971P NF was added to propylene glycol to create a gel solution containing 4 wt% Carbopol 971P NF, which was then fed into the extruder.

[0154] The gel was fed to the extruder via a first liquid port; glycerin was fed to the extruder via a second liquid port; further propylene glycol was optionally fed to the extruder via a third liquid port if necessary depending on the desired composition; and milled tobacco was fed to the extruder via a gravimetric feed hopper. All of these ingredients were then mixed downstream of the ports within the extruder to form an extrudable composition within the extruder, before extrusion of the composition out of a die.

[0155] The ingredients were added to produce extrudable compositions containing the following components in quantities within the following ranges (where for any given product the amounts totalled 100%): Component Amount (based on total weight of extrudable composition) Milled tobacco65-75 wt%Glycerin15-20 wt%Propylene glycol5-10 wt%Carbopol 971P NF0.4-1 wt%

[0156] No water was added to the extruder.

[0157] The extrudable composition displayed acceptable stable binding of the milled tobacco and good extrusion from the die.

[0158] No drying step was required after extrusion due to the absence of water in the composition (other than inevitable trace amounts of water within the ingredients used). The resultant extruded non-aqueous composition was therefore dense, displaying no cracks or visible porosity due to the absence of a drying step.

[0159] The extrudable composition was extruded through a circular die into a continuous cylindrical rod, which was then divided into sections to form discrete rods of aerosol-forming material for use in an aerosol-forming article.

[0160] After leaving the extruded rod for 10 hours at 25 °C, the density was determined to be 1.224 g cm -3< .Example 2

[0161] The same method as Example 1 was used to produce an extruded aerosol-forming material, except that konjac gum was also added to the extruder as a solid powder through a solid gravimetric feed hopper.

[0162] The ingredients were added to produce extrudable compositions containing the following components in quantities within the following ranges (where for any given product the amounts totalled 100%): Component Amount (based on total weight of extrudable composition) Milled tobacco65-75 wt%Glycerin15-20 wt%Propylene glycol5-10 wt%Carbopol 971P NF0.4-1 wt%Konjac gum0.4-1 wt%

[0163] No water was added to the extruder.

[0164] The extrudable composition displayed acceptable stable binding of the milled tobacco and good extrusion from the die. The milled tobacco demonstrated improved binding relative to the composition of Example 1, with a smaller amount of visible milled tobacco residue around the die of the extruder, which suggested synergy between the binding properties of the Carbomer and konjac gum leading to an improved product.

[0165] No drying step was required after extrusion due to the absence of water in the composition (other than inevitable trace amounts of water within the ingredients used). The resultant extruded non-aqueous composition was therefore dense, displaying no cracks or visible porosity due to the absence of a drying step.

[0166] The extrudable composition was extruded through a circular die into a continuous cylindrical rod, which was then divided into sections to form discrete rods of aerosol-forming material for use in an aerosol-forming article.Example 3

[0167] The same method as Example 1 was used to produce an extruded aerosol-forming material, except that flavourant (menthol) was also added to the extruder through a separate liquid port.

[0168] The ingredients were added to produce extrudable compositions containing the following components in quantities within the following ranges (where for any given product the amounts totalled 100%): Component Amount (based on total weight of extrudable composition) Milled tobacco65-75 wt%Glycerin15-20 wt%Propylene glycol5-10 wt%Carbopol 971P NF0.4-1 wt%Flavourant0.1-1 wt%

[0169] No water was added to the extruder.

[0170] The extrudable composition displayed acceptable stable binding of the milled tobacco and good extrusion from the die.

[0171] No drying step was required after extrusion due to the absence of water in the composition (other than inevitable trace amounts of water within the ingredients used). The resultant extruded non-aqueous composition was therefore dense, displaying no cracks or visible porosity due to the absence of a drying step.

[0172] The extrudable composition was extruded through a circular die into a continuous cylindrical rod, which was then divided into sections to form discrete rods of aerosol-forming material for use in a flavoured aerosol-forming article.Example 4

[0173] The same method as Example 1 was used to produce an extruded aerosol-forming material, except that an additional structurant (wheat fibres; JELUCEL WF) was also added to the extruder through a separate gravimetric feed hopper.

[0174] The ingredients were added to produce extrudable compositions containing the following components in quantities within the following ranges (where for any given product the amounts totalled 100%): Component Amount (based on total weight of extrudable composition) Milled tobacco65-75 wt%Glycerin15-20 wt%Propylene glycol5-10 wt%Carbopol 971P NF0.4-1 wt%Wheat fibres0.1-8 wt%

[0175] No water was added to the extruder.

[0176] The extrudable composition displayed acceptable stable binding of the milled tobacco and wheat fibres, and good extrusion from the die. This demonstrated the ability of the Carbomer binder to bind solid filler materials of different types used in combination (tobacco and wheat fibres).

[0177] No drying step was required after extrusion due to the absence of water in the composition (other than inevitable trace amounts of water within the ingredients used). The resultant extruded non-aqueous composition was therefore dense, displaying no cracks or visible porosity due to the absence of a drying step.

[0178] The extrudable composition was extruded through a circular die into a continuous cylindrical rod, which was then divided into sections to form discrete rods of aerosol-forming material for use in an aerosol-forming article.Example 5

[0179] The same method as Example 1 was used to produce an extruded aerosol-forming material, except that a structurant (wheat fibres; JELUCEL WF) was added to the extruder through a separate gravimetric feed hopper instead of the milled tobacco, and nicotine was added by dissolving nicotine in the glycerin component in a suitable amount before feeding into the liquid port.

[0180] The ingredients were added to produce extrudable compositions containing the following components in quantities within the following ranges (where for any given product the amounts totalled 100%): Component Amount (based on total weight of extrudable composition) Glycerin15-20 wt%Propylene glycol5-10 wt%Carbopol 971P NF0.4-1 wt%Wheat fibres65-75 wt%Nicotine0.5-2 wt%

[0181] No water was added to the extruder.

[0182] The extrudable composition displayed acceptable stable binding of the wheat fibres, and good extrusion from the die. This demonstrated the ability of the Carbomer binder to bind wheat fibres, thereby producing a stable non-tobacco product containing nicotine.

[0183] No drying step was required after extrusion due to the absence of water in the composition (other than inevitable trace amounts of water within the ingredients used). The resultant extruded non-aqueous composition was therefore dense, displaying no cracks or visible porosity due to the absence of a drying step.

[0184] The extrudable composition was extruded through a circular die into a continuous cylindrical rod, which was then divided into sections to form discrete rods of aerosol-forming material for use in an aerosol-forming article.

Examples

example 1

Example 1

[0152]An extrudable composition was formed in situ within a Thermofisher Process 16 twin-screw extruder. Solid ingredients were fed into the extruder from gravimetric hopper feeders, and liquid / gel ingredients were fed into the extruder into liquid ports using peristaltic pumps.

[0153]The carbomer Carbopol 971P NF was added to propylene glycol to create a gel solution containing 4 wt% Carbopol 971P NF, which was then fed into the extruder.

[0154]The gel was fed to the extruder via a first liquid port; glycerin was fed to the extruder via a second liquid port; further propylene glycol was optionally fed to the extruder via a third liquid port if necessary depending on the desired composition; and milled tobacco was fed to the extruder via a gravimetric feed hopper. All of these ingredients were then mixed downstream of the ports within the extruder to form an extrudable composition within the extruder, before extrusion of the composition out of a die.

[0155]The ingredients were...

example 2

Example 2

[0161]The same method as Example 1 was used to produce an extruded aerosol-forming material, except that konjac gum was also added to the extruder as a solid powder through a solid gravimetric feed hopper.

[0162]The ingredients were added to produce extrudable compositions containing the following components in quantities within the following ranges (where for any given product the amounts totalled 100%):

Component Amount (based on total weight of extrudable composition)

Milled tobacco65-75 wt%

Glycerin15-20 wt%

Propylene glycol5-10 wt%

Carbopol 971P NF0.4-1 wt%

Konjac gum0.4-1 wt%

[0163]No water was added to the extruder.

[0164]The extrudable composition displayed acceptable stable binding of the milled tobacco and good extrusion from the die. The milled tobacco demonstrated improved binding relative to the composition of Example 1, with a smaller amount of visible milled tobacco residue around the die of the extruder, which suggested synergy between the binding properti...

example 3

Example 3

[0167]The same method as Example 1 was used to produce an extruded aerosol-forming material, except that flavourant (menthol) was also added to the extruder through a separate liquid port.

[0168]The ingredients were added to produce extrudable compositions containing the following components in quantities within the following ranges (where for any given product the amounts totalled 100%):

Component Amount (based on total weight of extrudable composition)

Milled tobacco65-75 wt%

Glycerin15-20 wt%

Propylene glycol5-10 wt%

Carbopol 971P NF0.4-1 wt%

Flavourant0.1-1 wt%

[0169]No water was added to the extruder.

[0170]The extrudable composition displayed acceptable stable binding of the milled tobacco and good extrusion from the die.

[0171]No drying step was required after extrusion due to the absence of water in the composition (other than inevitable trace amounts of water within the ingredients used). The resultant extruded non-aqueous composition was therefore dense, displayi...

Claims

1. An extrudable composition comprising: a particulate filler material; a liquid carrier; and a polyacrylic acid binder; wherein the extrudable composition contains no water, or contains water in an amount of less than 3 wt% based on the total weight of the extrudable composition.

2. The extrudable composition according to claim 1, wherein the particulate filler material comprises or consists of particulate tobacco.

3. The extrudable composition according to claim 1 or 2, further comprising an auxiliary binder component.

4. The extrudable composition according to claim 3, wherein the auxiliary binder component comprises or consists of konjac gum.

5. The extrudable composition according to claim 3 or 4, wherein the auxiliary binder component is present in an amount of from 0.4 to 1.0 wt% based on the total weight of the extrudable composition.

6. The extrudable composition according to any one of the preceding claims, further comprising a structurant selected from plant fibres.

7. The extrudable composition according to any one of the preceding claims, wherein the density of the extrudable composition is greater than 1.20 g cm-3.

8. The extrudable composition according to any one of the preceding claims, wherein the liquid carrier comprises or consists of one or more of glycerin and propylene glycol.

9. The extrudable composition according to any one of the preceding claims, wherein the polyacrylic acid binder comprises a polyacrylic acid polymer having a logP value of greater than 0, wherein P is the octanol / water partition coefficient.

10. The extrudable composition according to any one of the preceding claims, wherein the polyacrylic acid binder comprises a polyacrylic acid polymer having a viscosity of from 4000 to 11,000 cP, measured at 25 °C using a Brookfield RVT at 20 rpm, neutralized to pH 7.3-7.8, with 0.5 wt% mucilage and spindle #5.

11. The extrudable composition according to any one of the preceding claims, wherein the polyacrylic acid binder is present in an amount of from 0.4 to 1.0 wt% based on the total weight of the extrudable composition.

12. A method of preparing an aerosol-forming material, the method comprising: preparing an extrudable composition comprising: a particulate filler material; a liquid carrier; and a polyacrylic acid binder; wherein the extrudable composition contains no water, or contains water in an amount of less than 3 wt% based on the total weight of the extrudable composition; and extruding the composition through a die.

13. An extruded aerosol-forming material comprising: a particulate filler material; a liquid carrier; and a polyacrylic acid binder; wherein the aerosol-forming material contains no water, or contains water in an amount of less than 3 wt% based on the total weight of the aerosol-forming material.

14. The extruded aerosol-forming material according to claim 13, wherein the density of the extruded aerosol-forming material is greater than 1.20 g cm-3.

15. An aerosol-forming article comprising the aerosol-forming material according to any one of claims 13 to 14, in the form of a heated tobacco stick.

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