Co-extruded aerosol-forming rod

Abstract

A co-extruded aerosol-forming rod is described comprising a sheath comprising aerosol-forming material; and an axially extending core region circumscribed by and contained within the sheath. The aerosol-forming rod finds use within an aerosol-forming article, for example a heated tobacco (HT) product.

Description

FIELD

[0001] The present disclosure relates to a co-extruded aerosol-forming rod. More specifically, the present disclosure relates to a co-extruded aerosol-forming rod comprising a sheath and an axially extending core region. Aerosol-forming articles containing such rods 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 a co-extruded aerosol-forming rod.

[0008] In some examples, the co-extruded aerosol-forming rod comprises a sheath comprising aerosol-forming material, and an axially-extending core region circumscribed by and contained within the sheath.

[0009] In this way the co-extruded aerosol-forming rod comprises two co-extruded layers: an inner layer which forms the axially extending core region and a layer concentric with and outside the inner layer which forms the sheath.

[0010] In some examples, the axially extending core region comprises a liquid section and a non-liquid section, wherein the liquid section is axially displaced from the non-liquid section.

[0011] By providing separate liquid and non-liquid sections within the axially extending core region of the co-extruded aerosol-forming rod, the functionality and versatility of the rod is improved and thereby the user experience is also improved. For instance, the liquid section may facilitate a greater generation of aerosol by the rod during use, creating a more significant "vapour cloud" which will improve the user experience. Alternatively or additionally, the liquid section may function as a vehicle for one or more property-modifying agents such as flavourants and / or active agents, allowing the rod to carry a larger quantity of such agents than would be possible for a rod lacking such a liquid section. Furthermore, by providing the non-liquid section axially displaced from the liquid section, the liquid section is axially contained, and unwanted egress of the liquid section along the rod is prevented or mitigated, providing control over the location and size of the liquid section and allowing the tailoring of the user experience as a result.

[0012] Another advantage of the presence of a liquid section in the core region is that the usable lifetime of the aerosol-forming article may be extended. In "traditional" aerosol-forming rods, the aerosol-forming material tends to be e.g. a solid tobacco material including a small amount of aerosol-former, e.g. glycerin or propylene glycol entrained within the solid material. As the aerosol-forming material is heated during use (e.g. using an "outside-in" heater arrangement) the amount of aerosol-former within the material is depleted, leading to a reduced vapour cloud and a belief by the user that the aerosol-forming rod is "spent" and must be disposed of and replaced. Given the small quantity of entrained aerosol former in traditional rods, the period of time until this occurs can be relatively short. By contrast, in the aerosol-forming rod of the invention, as aerosol former is "used up" in the outer volume of the sheath of the rod during use, additional aerosol-former is able to migrate (e.g. through capillary action) from the liquid section into the sheath and towards the outer heated surface of the rod. In this way the supply of aerosol-former is continuously "replenished" during use, maintaining the formation of aerosol upon heating and maintaining visible vapour for the user. As such, the aerosol-forming rod may be used for longer before the user feels that it is necessary to dispose of it.

[0013] The aerosol-forming rod is co-extruded. As used herein, the term "co-extruded" means that the aerosol-forming rod comprises a plurality of layers (e.g. concentrically arranged layers) formed by the simultaneous extrusion through a corresponding plurality of dies of an extruder.

[0014] One layer of the co-extruded rod comprises the sheath. The sheath is extruded in such a way as to define within it an inner, axially extending void into which the axially extending core region of the rod is extruded to form an inner layer of the co-extruded rod, concentric with the sheath. In some examples, the rod does not include any further layers outside the sheath (i.e. the sheath forms an outermost layer of the rod). In other examples, one or more further layers may lie upon the sheath, e.g. further co-extruded layers.

[0015] The geometry of the sheath is not limited provided that it defines an axially extending inner void in which the axially extending core region lies. In some examples the sheath has an annular cross-section, i.e. resulting from extrusion through a circular die (such that the sheath forms a circular hollow cylinder, with the hollow occupied by the axially extending core region). In some examples the sheath has a cross-section of non-circular geometry, e.g. a regular polygon such as a triangle, square, pentagon, hexagon, heptagon, octagon etc., or a non-regular shape. For example, a square cross-section would provide a sheath which forms a "hollow cuboid", or "rectangular tube", with the hollow occupied by the axially extending core region.

[0016] In some examples the sheath extends circumferentially around the entire axially-extending outer surface of the axially extending core region.

[0017] The sheath comprises aerosol-forming material. In some examples, the sheath consists of aerosol-forming material. In some examples, the aerosol-forming material of the sheath comprises or consists of an extruded composition comprising a particulate filler material and a binder. In some examples, the aerosol-forming material of the sheath comprises or consists of an extruded composition comprising plant fibres. In some examples, the aerosol-forming material of the sheath comprises or consists of an extruded composition comprising plant fibres and binder.

[0018] In some examples, the aerosol-forming material of the sheath comprises or consists of an extruded composition comprising filler material, binder, water and optionally one or more flavourants.

[0019] In some examples, the aerosol-forming material of the sheath comprises tobacco, for example milled tobacco.

[0020] 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 aerosol-forming material 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 filler material may comprise or consist of tea.

[0021] Suitable non-tobacco fillers are known in the art and may act to strengthen the material. Fillers may comprise fibrous (non-tobacco) fillers such as cellulose fibers, lignocellulose fibers (e.g. wood fibers), jute fibers and combinations thereof.

[0022] In some embodiments, the aerosol-forming material of the sheath 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 aerosol-forming material as a distinct ingredient. For example, when the aerosol-forming material contains non-tobacco particulate filler material, an active compound may also be present in the aerosol-forming material and may be introduced separately from the particulate filler material.

[0023] 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.

[0024] In some examples, the active compound comprises nicotine or a nicotine salt. In this way, the aerosol-forming material 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.

[0025] 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.

[0026] In some embodiments, the particulate filler material is present in an amount of at least 50 wt% based on the total weight of the aerosol-forming material, 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 aerosol-forming material, for example up to 80 wt% or up to 75 wt%.

[0027] 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 aerosol-forming material, for example from 55 to 80 wt%, from 60 to 80 wt% or from 65 to 75 wt%.

[0028] In some embodiments, the 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 aerosol-forming material.

[0029] In some embodiments, the 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 aerosol-forming material.

[0030] In some embodiments, the binder is present in an amount of from 0.4 to 1.0 wt% based on the total weight of the aerosol-forming material. For example, in some embodiments, the 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 aerosol-forming material. In some embodiments, the binder is present in an amount of from 0.5 to 1.0 wt% based on the total weight of the aerosol-forming material, for example from 0.5 to 0.9 wt%, or from 0.6 to 0.8 wt%.

[0031] In some embodiments, the binder comprises or consists of a polymer binder.

[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 binder comprises or consists of a gum. In some embodiments, the binder 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 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 density of the aerosol-forming material of the sheath, as determined after the extruded 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< .

[0035] The density of the 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.

[0036] In some embodiments, the density of the aerosol-forming material of the sheath 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< .

[0037] In some embodiments, the aerosol-forming material comprises a liquid carrier.

[0038] The liquid carrier is a liquid fraction of the aerosol-forming material which provides flowability and extrudability, enables the components of the composition to mix and facilitates the formation of aerosol by the aerosol-forming material after extrusion. In some embodiments, the liquid carrier comprises or consists of water. In some embodiments, the liquid carrier comprises or consists of water and one or more of glycerin and propylene glycol. In some embodiments, the liquid carrier comprises water and glycerin. In some embodiments, the liquid carrier comprises or consists of a mixture of water, glycerin and propylene glycol.

[0039] In some embodiments, the aerosol-forming material comprises the liquid carrier in an amount of at least 15 wt% based on the total weight of the aerosol-forming material, 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 aerosol-forming material comprises the liquid carrier in an amount of up to 40 wt% based on the total weight of the aerosol-forming material, 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 aerosol-forming material comprises the liquid carrier in an amount of from 15 to 40 wt% based on the total weight of the aerosol-forming material, 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%.

[0040] In some embodiments, the aerosol-forming material comprises glycerin in an amount of at least 10 wt% based on the total weight of the aerosol-forming material, 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 aerosol-forming material comprises glycerin in an amount of up to 25 wt% based on the total weight of the aerosol-forming material, 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 aerosol-forming material comprises glycerin in an amount of from 10 to 25 wt% based on the total weight of the aerosol-forming material, 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%.

[0041] In some embodiments, the aerosol-forming material comprises propylene glycol in an amount of at least 2 wt% based on the total weight of the aerosol-forming material, for example at least 3 wt%, at least 4 wt% or at least 5 wt%. In some embodiments, the aerosol-forming material comprises propylene glycol in an amount of up to 15 wt% based on the total weight of the aerosol-forming material, 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 aerosol-forming material comprises propylene glycol in an amount of from 2 to 15 wt% based on the total weight of the aerosol-forming material, 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%.

[0042] In some embodiments, the sheath has a thickness of from 1.5 mm to 3.5 mm, for example from 1.6 to 3.4 mm, from 1.7 to 3.3 mm, from 1.8 to 3.2 mm, from 1.9 to 3.1 mm or from 2 to 3 mm. Such thicknesses provide a sheath which provides a good balance of ease of extrusion, physical stability and ability to contain liquid within the axially extending core region, while ensuring an adequate "void" size to contain the axially-extending core region.

[0043] In some examples, the internal diameter of the sheath (i.e. the diameter of the "void" in the sheath which is occupied by the axially extending core region) is from 0.5 mm to 5 mm, for example from 0.5 mm to 4.5 mm, from 0.5 mm to 4 mm, from 0.6 mm to 3.5 mm, from 0.7 mm to 3.3 mm, from 0.8 mm to 3.2 mm, from 0.9 mm to 3.1 mm or from 1 mm to 3 mm.

[0044] The axially extending core region extends axially along the rod within the sheath of aerosol-forming material. In some examples, the axially extending core region is in contact with the sheath, i.e. there are no voids or co-extruded intervening layers between the sheath and the axially extending core region.

[0045] The axially extending core region has an inhomogeneous composition. The composition of the material within the axially extending core region changes when moving along the rod in an axial direction. This is because the axially extending core region comprises a liquid section and a non-liquid section, wherein the liquid section is axially displaced from the non-liquid section. As such, at one axial position within the rod the material within the axially extending core region is non-liquid, and at a second, axially displaced position within the rod the material within the axially extending core region is liquid.

[0046] In some examples, the axially extending core region comprises a plurality of non-liquid sections. In some examples, the axially extending core region comprises a single liquid section.

[0047] In some examples, the axially extending core region comprises at least one liquid section and at least two non-liquid sections, wherein one liquid section lies between two non-liquid sections. In this way, the axially extending core region contains at least one liquid section which is encapsulated on all sides, by the sheath and by the two non-liquid sections. In some examples, the axially extending core region comprises at least one liquid section and at least two non-liquid sections, wherein a non-liquid section lies at each end of the aerosol-forming rod. In this way, the terminal non-liquid sections form "plugs" which prevent or reduce any egress of liquid out of the aerosol-forming rod. The two terminal non-liquid sections may be the only non-liquid sections in the rod (with a liquid section between them), or there may be one or more further "internal" non-liquid sections, each sandwiched between two liquid sections.

[0048] In some examples, the axially extending core region comprises a plurality of liquid sections. In some examples, the axially extending core region comprises a plurality of non-liquid sections and a plurality of liquid sections. In some examples, the axially extending core region comprises two terminal non-liquid sections located at respective terminal ends of the rod, and one or a plurality of liquid sections located between the terminal non-liquid sections. In some examples, the axially extending core region comprises two terminal non-liquid sections located at respective terminal ends of the rod, and a plurality of liquid sections located between the terminal non-liquid sections, wherein the liquid sections are separated from one another by intermediate non-liquid sections.

[0049] In some examples, the axially extending core region comprises the liquid section located between a first non-liquid section and a second non-liquid section, such that the liquid section is encapsulated within the annular sheath and between the first non-liquid section and the second non-liquid section. In this way, egress of the liquid from the liquid section out of the rod is prevented or mitigated.

[0050] In some examples, the axially extending core region comprises a plurality of liquid sections and a plurality of non-liquid sections, wherein the liquid sections and non-liquid sections are located in an alternating arrangement along the axial length of the rod and wherein each terminal end of the rod comprises a non-liquid section.

[0051] In some examples, the sheath and the non-liquid section of the axially extending core region are substantially liquid-impermeable, such that the liquid section is contained within the axially extending core region. In this way, egress of the liquid out of the rod is mitigated or prevented.

[0052] However in some examples, the sheath is adapted to be at least partially liquid-permeable, to absorb at least some of the liquid contained within the one or more liquid sections after manufacture of the aerosol-forming rod. For example, some or all of the liquid may migrate through capillary action or other physical forces into a portion of the sheath which lies adjacent to the axially extending core region, or may migrate further and permeate the entire sheath. For example, the density, porosity and / or composition of the sheath can be tailored to facilitate such migration of liquid into the sheath. In this way, the contents of the liquid become part of the sheath and are able to impart the sheath and rod with desirable properties. For example, when using an "outside-in" heating arrangement during consumption of the aerosol-forming rod, a greater amount of aerosol may be generated due to the greater amount of liquid located within the material of the sheath. Alternatively or additionally, flavourant and / or active agent initially contained within the liquid section(s) may migrate into the sheath and as such will be released in greater quantities from the aerosol-forming rod upon heating, improving the user experience, and may extend the usable lifetime of the rod as explained above.

[0053] Furthermore, the properties of the product are easily tailored without any modification of the aerosol-forming article in the sheath being required before extrusion, since only the composition of the liquid section needs to be modified (e.g. to change the flavourant and / or active compound present).

[0054] In some examples, the liquid section comprises or consists of one or more of propylene glycol and glycerin. In some examples, the liquid section comprises or consists of one or more of propylene glycol, glycerin, and property modifying agent. In some examples, the liquid section comprises or consists of one or more of propylene glycol, glycerin, and flavourant. In some examples, the liquid section comprises or consists of one or more of propylene glycol, glycerin, and active agent. In some examples, the liquid section comprises or consists of one or more of propylene glycol, glycerin, flavourant and active agent. In some examples, the liquid section comprises or consists of propylene glycol, glycerin, and one or more of flavourant and active agent.

[0055] In some examples, the property modifying agent comprises or consists of one or more of nicotine and flavourant.

[0056] The non-liquid section within the axially extending core region may be a solid or a gel. The function of the non-liquid section is to remain in place to form a "plug" which facilitates the containment of the liquid section within the axially-extending core region.

[0057] Herein, the term "non-liquid" encompasses solids and semi-solids ("quasi-solids"). Semi-solids are materials existing in a state between a solid and a liquid, with a viscosity sufficient to enable the material to function as a plug or spacer adjacent the liquid section to prevent or mitigate the egress of liquid out of the liquid section.

[0058] In some examples, the non-liquid section comprises or consists of an extruded gel or paste. In some examples, the non-liquid section consists of an extruded gel. In some examples, the non-liquid section consists of an extruded paste, for example an extruded mixture of solid and liquid components. In some examples, the non-liquid section comprises or consists of a semi-solid material, i.e. a material which is able to flow sufficiently to facilitate extrusion, but has sufficient thickness / viscosity to ensure that it remains in place within the axially extending core region to form a spacer adjacent the liquid section.

[0059] In some examples, the non-liquid section may exist in a liquid or semi-solid state before and during extrusion to facilitate extrusion, but transition into a solid state (or transition from a liquid to a semi-solid state) after extrusion into the rod. For example, the non-liquid section may be extruded as a flowable paste but solidify after extrusion into the axially extending core region of the rod.

[0060] In some examples, the non-liquid section comprises or consists of hydrogel. The skilled person is aware of hydrogels and any suitable hydrogel may be used. The hydrogel may comprise a gelled material comprising a polymer phase and a liquid phase. The liquid phase may comprise water. Any suitable polymer which is able to form a gel may be used. Non-limiting examples of possible polymers include starches and / or celluloses 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.

[0061] In some examples, the non-liquid section comprises or consists of an aerosol-forming material. In some examples, the non-liquid section comprises an aerosol-forming material having a composition as described above for the aerosol-forming material of the sheath. In some examples, the non-liquid section and the sheath each comprise different aerosol-forming materials. In some examples, the non-liquid section and the sheath each comprise different aerosol-forming materials, wherein the aerosol-forming material of the non-liquid section has a higher content of liquid carrier than the aerosol-forming material of the sheath; in this way, the material of the non-liquid section is distinct from and "softer" than the material of the sheath.

[0062] In some examples, the non-liquid section comprises an aerosol-forming material having the same composition as the sheath, except that the non-liquid section comprises a greater proportion of a liquid carrier than the sheath, e.g. a greater proportion of glycerin and / or propylene glycol and / or water. In this way the rod contains consistent materials through its cross-section which differ only in the quantity of liquid carrier present, thereby providing predictable properties such as flavour, active agent content etc.

[0063] In some examples, the axially extending core region has a cross-sectional diameter of from 0.5 mm to 5 mm, for example from 0.5 mm to 4.5 mm, from 0.5 mm to 4 mm, from 0.6 mm to 3.5 mm, from 0.7 mm to 3.3 mm, from 0.8 mm to 3.2 mm, from 0.9 mm to 3.1 mm or from 1 mm to 3 mm. Such diameters provide an axially extending core region which is able to hold a meaningful quantity of liquid within the liquid section, without jeopardising the extrudability or physical properties of the sheath.

[0064] The present disclosure also provides a method of manufacturing an aerosol-forming rod by coextrusion, the method comprising: extruding an extrudable composition through a die to form a sheath of aerosol-forming material; simultaneously extruding a non-liquid composition within the sheath to form a non-liquid section circumscribed by and contained within the sheath; and introducing a liquid composition into the sheath to form a liquid section axially displaced from the non-liquid section within the sheath.

[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 any drying of the extruded aerosol-forming rod after extrusion. In some embodiments, the method does not include any elevated-temperature drying of the extruded aerosol-forming rod after extrusion.

[0067] In some examples, the aerosol-forming rod is an aerosol-forming rod as described above.

[0068] The sheath, aerosol-forming material of the sheath, non-liquid section and liquid section may each independently be selected based on any of the options and preferences already set out for these entities above in the context of the aerosol-forming rod product.

[0069] In some examples, the non-liquid composition and the liquid composition are alternately introduced into the sheath during the extrusion to produce a plurality of liquid sections and a plurality of non-liquid sections, wherein the liquid sections and non-liquid sections are located in an alternating arrangement along the axial length of the rod.

[0070] In some examples, the liquid composition is introduced into the sheath by extrusion through the same die through which the non-liquid composition is extruded.

[0071] In some examples, the non-liquid composition and the liquid composition are alternately introduced by the alternate switching on and off of an extruder pump. The pump may be a peristaltic pump.

[0072] In some embodiments, the method comprises extruding the extrudable composition through a first die, and extruding the non-liquid composition and the liquid composition through a second die, wherein the second die lies concentrically within the first die.

[0073] In some examples, the method comprises adjusting the ratio of the amounts of non-liquid composition and liquid composition introduced into the sheath to alter the amount of a liquid component (e.g. glycerin and / or propylene glycol) contained within the rod. In some examples, the method comprises adjusting the ratio of the amounts of non-liquid composition and liquid composition introduced into the sheath to alter the amount of a property modifying agent (e.g. active agent, such as nicotine, and / or flavourant) contained within the rod.

[0074] In some embodiments, the method comprises feeding one or more components of an aerosol-forming material into an extruder through one or more entry ports; feeding one or more components of a non-liquid composition into the extruder through one or more entry ports; and feeding one or more components of a liquid composition into the extruder through one or more entry ports. In some embodiments, each entry port to the extruder is associated with a pump, for example a peristaltic pump. In some embodiments, the method comprises controlling one or more of the pumps to vary the composition of the axially-extending core region of the aerosol-forming rod. In some embodiments, the method comprises changing (e.g. reducing) the pump rate of one or more of the pumps to vary the composition of the axially-extending core region of the aerosol-forming rod. In some embodiments, the method comprises temporarily reducing (e.g. to zero) the pump rate of one or more of the pumps to omit a component from the axially-extending core region of the aerosol-forming rod along a predetermined length of the aerosol-forming rod.

[0075] In some embodiments, the method comprises extruding the extrudable composition, liquid composition and non-liquid composition through a die to form the aerosol-forming 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 rod 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 rod 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 rods into sections is required.

[0076] The method may further comprise incorporating the aerosol-forming rod into an aerosol-forming article, for example assembling the aerosol-forming rod alongside one or more other components such as filter components, and circumscribing the aerosol-forming rod and one or more other components with one or more wrappers.

[0077] The method comprises extruding through a die, and the shape of the die will dictate the cross-sectional shape of the extruded aerosol-forming rod. For example, in some embodiments extrusion through a circular die forms 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).

[0078] The present disclosure also provides an aerosol-forming article comprising the aerosol-forming rod described herein.

[0079] 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.

[0080] 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 rod; and a cardboard tube located downstream of the aerosol-forming rod.

[0081] 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 rod which is a coextruded substrate as described herein, 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 a coextruded aerosol-forming rod 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.

[0082] Consequently, the aerosol-forming rod 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.

[0083] It will however be appreciated that in particularly suitable exemplary embodiments, the plant material is tobacco. Thus in some examples, the aerosol-forming rod 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.

[0084] 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 rod (e.g. tobacco rod) may be formed into a substantially cylindrical shape such that the article / consumable resembles a conventional cigarette. The aerosol-forming rod 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 rod 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).

[0085] In exemplary aspects and embodiments described herein, the aerosol-forming rod 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 rod or may be provided in isolated locations and / or varying concentrations throughout the aerosol-forming rod.

[0086] 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).

[0087] Suitable fillers are known in the art and may act to strengthen the aerosol-forming rod. Fillers may comprise fibrous (non-tobacco) fillers such as cellulose fibers, lignocellulose fibers (e.g. wood fibers), jute fibers and combinations thereof.

[0088] 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 rod (e.g. tobacco rod). 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).

[0089] In some exemplary aerosol-forming article embodiments described herein, in addition to an aerosol-forming rod, there may also be provided further components or elements combined with the aerosol-forming rod as is known in the art as well as described and claimed herein. Thus, the exemplary aerosol-forming article may include an aerosol-forming rod 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 rod 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.

[0090] 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 rod 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.

[0091] 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 rod 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.

[0092] 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 rod 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 rod. 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 rod (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.

[0093] 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.

[0094] Optionally, the aerosol-forming rod 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 rod. The cylindrical rod has a longitudinal axis, and the end faces are suitably perpendicular to the longitudinal axis.

[0095] In another aspect the present disclosure provides an aerosol-generating system comprising the aerosol-forming article, and an aerosol-generating apparatus comprising a heater.

[0096] 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.

[0097] 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).

[0098] 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.

[0099] The aerosol-forming article may be inserted into the cavity for aerosolising one or more components the aerosol-forming rod. 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 rod when inserted into the cavity.

[0100] 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 rod (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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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 rod.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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 rod, 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.

[0109] The aerosol-forming article may have an elongate shape, and optionally a rod shape (i.e., the aerosol-forming article forms a substantially cylindrical outer shape), the upstream and downstream ends of the aerosol-forming article can be air-permeable to allow an axial airflow through the aerosol-forming article.

[0110] 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.

[0111] 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 rod).

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] The heating element may have a length that is less than, or substantially the same as, an axial length of an aerosol-forming rod 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 rod, rather than other components of the aerosol-forming article. The heating element may penetrate the aerosol-forming rod for substantially the entire axial length of the aerosol-forming rod 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 rod, when penetrated by the heating element. That is, heat may be transferred radially outwardly (in the case of a cylindrical heating element).

[0117] 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 rod). In particular, the heating element may surround an aerosol-forming rod of the aerosol-forming article. That is, when an aerosol-forming article is engaged with the device, the aerosol-forming rod 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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 rod). That is, the aerosol-forming article may be inserted through the opening and into the cavity (so as to be engaged with the device).

[0122] 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.

[0123] 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).

[0124] 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.

[0125] 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).

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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).

[0130] 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.

[0131] 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.

[0132] 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).

[0133] 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.

[0134] 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

[0135] 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'; Figure 4 shows (a) an example of an aerosol-forming rod in longitudinal cross-section; and (b) another example of an aerosol-forming rod in longitudinal cross-section. DETAILED DESCRIPTION OF EMBODIMENTS

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] In this example, the device body 20 is a heat-not-burn device (HNB) configured to produce an aerosol by heating an aerosol-forming rod 10 (e.g. a solid precursor, such as tobacco material) to a temperature below its combustion temperature.

[0145] The term "aerosol-forming rod" refers to a rod of material capable of releasing volatile components that can form an aerosol, e.g. by releasing volatile compounds in the aerosol-forming rod 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 rod 10 in the aerosol-forming article 30 is a coextruded material, formed by coextruding compositions through a die, for example a die which forms part of a twin-screw extruder.

[0146] 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 rod 10 to a temperature lower than its combustion temperature such that an aerosol can be formed by evaporation, torrefaction and pyrolysis.

[0147] 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.

[0148] The article 30 defines an air passageway which transmits aerosol generated from the aerosol-forming rod 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 rod 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.

[0149] 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.

[0150] 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 rod 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 rod 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.

[0151] 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 rod 10. This may be referred to as an 'outside-in' heating arrangement.

[0152] In this example, the heating element 2a is a resistive heating element although it will be appreciated that the aerosol-forming rod 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] Figure 4(a) shows an aerosol-forming rod 5 according to the invention, in longitudinal cross-section. The aerosol-forming rod 5 has a cylindrical structure formed by the co-extrusion of an outer cylindrical sheath 50 and an inner axially-extending core made up of a liquid section 53 which is centrally located along the axial length of the aerosol-forming rod 5, and two non-liquid sections 51 and 52, which form "plugs" at each end of the aerosol-forming rod 5 to encapsulate the liquid section 53 within the aerosol-forming rod 5. The aerosol-forming rod 5 is 12 mm long and around 6.95 mm in diameter. Each of the liquid section 53 and two non-liquid sections 51 and 52 are 4 mm long. The axially-extending core region which contains the liquid and non-liquid sections has a diameter of 2 mm (and as such, the outer cylindrical sheath 50 has an internal diameter of 2 mm).

[0157] The aerosol-forming rod 5 has a curved, axially extending outer surface 54 and two planar terminal surfaces 55 and 56.

[0158] The aerosol-forming rod 5 is formed by co-extruding material from a twin-screw extruder, e.g. a Thermofisher Process 16 extruder. A paste containing milled tobacco and other ingredients is extruded through an annular die to form the sheath 50, and simultaneously a "softer" paste made from the same ingredients as the sheath-forming paste (but with a higher liquid content) is extruded concentrically within the sheath to form the non-liquid sections 51, 52. The central liquid section 53 is formed by temporarily switching off the peristaltic pump which feeds the "softer" paste to the extruder die, after the first non-liquid section 51 has formed, thereby creating a section with only liquid (e.g. glycerin) until the pump is switched back on to extrude the second non-liquid section 52.

[0159] The aerosol-forming rod 5 is a segment of a longer rod (not shown) formed by continuous co-extrusion. The longer rod is cut into smaller sections after extrusion to form a plurality of discrete aerosol-forming rods 5. It will be understood that the longer rod, before cutting, will contain alternating liquid and non-liquid sections, with the liquid sections being 4 mm long and the non-liquid sections being 8 mm long. By cutting the longer rod at the midway point along each non-liquid section, the result is a plurality of aerosol-forming rods 5, which each have two terminal non-liquid sections of 4 mm length, with a 4 mm long liquid section inbetween.

[0160] Figure 4(b) shows a second embodiment of an aerosol-forming rod 6 according to the invention, in longitudinal cross-section. The aerosol-forming rod 6 has generally the same structure and size as the aerosol-forming rod 5 of Figure 4(a), except that the aerosol-forming rod 6 has a greater number of liquid and non-liquid sections within the axially-extending core region along its length. Specifically, the aerosol-forming rod 6 has an alternating arrangement of five non-liquid sections 61, 62, 63, 64 and 65, and four liquid sections 66, 67, 68 and 69. The liquid sections 66, 67, 68 and 69 are each 1 mm long. Two terminal non-liquid sections 61 and 62 ("plugs") are each 1 mm long. Three internal non-liquid sections 63, 64 and 65 are each 2 mm long. This creates four "pockets" of encapsulated glycerin within the aerosol-forming rod 6. The aerosol-forming rod 6 is made by the same extrusion method as described for the rod of Figure 4(a), except that the pump supplying the "softer" paste is switched on and off more frequently to create the smaller liquid and non-liquid sections.

[0161] In Figures 4(a) and 4(b), the non-liquid sections 51, 52 and 61, 62, 63, 64, 65 are made from an aerosol-forming material (tobacco-containing extruded paste), however other materials are possible. In another embodiment, the non-liquid sections 51, 52 and 61, 62, 63, 64, 65 are instead made from a hydrogel, for example an alginate-based hydrogel.

[0162] Like the aerosol-forming rods of Figure 4(a), the aerosol-forming rod 6 of Figure 4(b) can be formed by continuous co-extrusion of a longer roc which is subsequently cut into sections to form a plurality of discrete aerosol-forming rods 6.EXAMPLES Example 1

[0163] A hollow cylindrical sheath of aerosol-forming material was extruded from an extrudable composition ("Composition 1") formed in situ within a Thermofisher Process 16 twin-screw extruder. Extrusion through an annular die created the cylindrical sheath of material. 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.

[0164] A "softer" aerosol-forming material was coextruded from another extrudable composition ("Composition 2") into the hollow of the sheath, in discrete sections. Between the discrete sections of Composition 2 within the sheath, a liquid composition ("Composition 3") was extruded. The liquid composition was "encapsulated" within the sheath between two sections of Composition 2.

[0165] To form Compositions 1 and 2, glycerin was fed to the extruder via a first liquid port; propylene glycol was optionally fed to the extruder via a second liquid port if necessary depending on the desired composition; and milled tobacco was fed to the extruder via a gravimetric feed hopper. Composition 2 was made "softer" than Composition 1 by increasing the amount of glycerin in Composition 2 relative to Composition 1. All of these ingredients were then mixed downstream of the ports within the extruder to form the extrudable compositions within the extruder, before extrusion of the respective compositions out of the dies.

[0166] 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 Composition 1 amount (based on total weight of composition) "Sheath" Composition 2 amount (based on total weight of composition) "Spacers" Milled tobacco75-80 wt%65-70 wt%Glycerin15-20 wt%25-30 wt%Water5 wt%5 wt%

[0167] Composition 3 was glycerin.

[0168] Alternating sections of Composition 2 and Composition 3 were created along the hollow centre of the sheath by periodically switching off the peristaltic pump which fed Composition 2 to the extruder, thereby feeding only the liquid Composition 3 through the extruder die until the pump was switched back on. Using this approach, 8 mm long sections of Composition 2 were extruded into the sheath, separated by 4 mm long sections of liquid Composition 3. In other words, the rod contained alternating sections of Compositions 2 and 3 along its centre, with the Composition 2 sections being 8 mm long and the Composition 3 sections being 4 mm long.

[0169] By subsequently dividing the continuous extruded rod at the halfway-point along each 8 mm long section of Composition 2, the result was separate rods, each 12 mm long, each including a central 4 mm long liquid section sandwiched between two terminal 4 mm long non-liquid sections.

[0170] The total rod diameter was 6.94 mm. The sheath was extruded to have an internal diameter of 2 mm, with a sheath thickness of 2.47 mm. Compositions 2 and 3 were extruded to form sections of 2 mm diameter, such that they "filled" the sheath.

[0171] The sheath and terminal non-liquid sections of Composition 2 adequately encapsulated the liquid glycerin section.

[0172] No drying step was carried out after extrusion.Example 2

[0173] The method of Example 1 was repeated, with the only change being that a flavourant (menthol) was added to Composition 3. Thus menthol-flavoured glycerin was extruded as the liquid sections within the aerosol-forming rod.Example 3

[0174] The method of Example 1 was repeated, with the only change being that a nicotine salt (nicotine bitartrate dihydrate) was added to Composition 3. Thus nicotine-containing glycerin was extruded as the liquid sections within the aerosol-forming rod.Example 4

[0175] The method of Example 1 was repeated, with the only change being that the lengths of the liquid and non-liquid sections extruded within the sheath were changed. To form the continuous extruded rod, 1 mm sections of liquid Composition 3 were extruded between 2 mm long sections of Composition 2. The continuous rod was then divided into 12 mm long discrete aerosol-forming rods, by cutting at the halfway-point along every fourth non-liquid section. The result was discrete rods, each containing 1 mm long terminal non-liquid "plugs" of Composition 2, with four 1 mm long liquid sections of Composition 3 within each rod, and three 2 mm long sections of non-liquid Composition 2 within each rod separating the liquid sections.

[0176] As a result, rods were formed having very small "pockets" of encapsulated glycerin within an outer sheath of aerosol-forming material.

Examples

second embodiment

[0160]Figure 4(b) shows an aerosol-forming rod 6 according to the invention, in longitudinal cross-section. The aerosol-forming rod 6 has generally the same structure and size as the aerosol-forming rod 5 of Figure 4(a), except that the aerosol-forming rod 6 has a greater number of liquid and non-liquid sections within the axially-extending core region along its length. Specifically, the aerosol-forming rod 6 has an alternating arrangement of five non-liquid sections 61, 62, 63, 64 and 65, and four liquid sections 66, 67, 68 and 69. The liquid sections 66, 67, 68 and 69 are each 1 mm long. Two terminal non-liquid sections 61 and 62 ("plugs") are each 1 mm long. Three internal non-liquid sections 63, 64 and 65 are each 2 mm long. This creates four "pockets" of encapsulated glycerin within the aerosol-forming rod 6. The aerosol-forming rod 6 is made by the same extrusion method as described for the rod of Figure 4(a), except that the pump supplying the "softer" paste is switched on an...

example 1

Example 1

[0163]A hollow cylindrical sheath of aerosol-forming material was extruded from an extrudable composition ("Composition 1") formed in situ within a Thermofisher Process 16 twin-screw extruder. Extrusion through an annular die created the cylindrical sheath of material. 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.

[0164]A "softer" aerosol-forming material was coextruded from another extrudable composition ("Composition 2") into the hollow of the sheath, in discrete sections. Between the discrete sections of Composition 2 within the sheath, a liquid composition ("Composition 3") was extruded. The liquid composition was "encapsulated" within the sheath between two sections of Composition 2.

[0165]To form Compositions 1 and 2, glycerin was fed to the extruder via a first liquid port; propylene glycol was optionally fed to the extruder via a second liqu...

example 2

Example 2

[0173]The method of Example 1 was repeated, with the only change being that a flavourant (menthol) was added to Composition 3. Thus menthol-flavoured glycerin was extruded as the liquid sections within the aerosol-forming rod.

FIELD

[0001] The present disclosure relates to a co-extruded aerosol-forming rod. More specifically, the present disclosure relates to a co-extruded aerosol-forming rod comprising a sheath and an axially extending core region. Aerosol-forming articles containing such rods 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 a co-extruded aerosol-forming rod.

[0008] In some examples, the co-extruded aerosol-forming rod comprises a sheath comprising aerosol-forming material, and an axially-extending core region circumscribed by and contained within the sheath.

[0009] In this way the co-extruded aerosol-forming rod comprises two co-extruded layers: an inner layer which forms the axially extending core region and a layer concentric with and outside the inner layer which forms the sheath.

[0010] In some examples, the axially extending core region comprises a liquid section and a non-liquid section, wherein the liquid section is axially displaced from the non-liquid section.

[0011] By providing separate liquid and non-liquid sections within the axially extending core region of the co-extruded aerosol-forming rod, the functionality and versatility of the rod is improved and thereby the user experience is also improved. For instance, the liquid section may facilitate a greater generation of aerosol by the rod during use, creating a more significant "vapour cloud" which will improve the user experience. Alternatively or additionally, the liquid section may function as a vehicle for one or more property-modifying agents such as flavourants and / or active agents, allowing the rod to carry a larger quantity of such agents than would be possible for a rod lacking such a liquid section. Furthermore, by providing the non-liquid section axially displaced from the liquid section, the liquid section is axially contained, and unwanted egress of the liquid section along the rod is prevented or mitigated, providing control over the location and size of the liquid section and allowing the tailoring of the user experience as a result.

[0012] Another advantage of the presence of a liquid section in the core region is that the usable lifetime of the aerosol-forming article may be extended. In "traditional" aerosol-forming rods, the aerosol-forming material tends to be e.g. a solid tobacco material including a small amount of aerosol-former, e.g. glycerin or propylene glycol entrained within the solid material. As the aerosol-forming material is heated during use (e.g. using an "outside-in" heater arrangement) the amount of aerosol-former within the material is depleted, leading to a reduced vapour cloud and a belief by the user that the aerosol-forming rod is "spent" and must be disposed of and replaced. Given the small quantity of entrained aerosol former in traditional rods, the period of time until this occurs can be relatively short. By contrast, in the aerosol-forming rod of the invention, as aerosol former is "used up" in the outer volume of the sheath of the rod during use, additional aerosol-former is able to migrate (e.g. through capillary action) from the liquid section into the sheath and towards the outer heated surface of the rod. In this way the supply of aerosol-former is continuously "replenished" during use, maintaining the formation of aerosol upon heating and maintaining visible vapour for the user. As such, the aerosol-forming rod may be used for longer before the user feels that it is necessary to dispose of it.

[0013] The aerosol-forming rod is co-extruded. As used herein, the term "co-extruded" means that the aerosol-forming rod comprises a plurality of layers (e.g. concentrically arranged layers) formed by the simultaneous extrusion through a corresponding plurality of dies of an extruder.

[0014] One layer of the co-extruded rod comprises the sheath. The sheath is extruded in such a way as to define within it an inner, axially extending void into which the axially extending core region of the rod is extruded to form an inner layer of the co-extruded rod, concentric with the sheath. In some examples, the rod does not include any further layers outside the sheath (i.e. the sheath forms an outermost layer of the rod). In other examples, one or more further layers may lie upon the sheath, e.g. further co-extruded layers.

[0015] The geometry of the sheath is not limited provided that it defines an axially extending inner void in which the axially extending core region lies. In some examples the sheath has an annular cross-section, i.e. resulting from extrusion through a circular die (such that the sheath forms a circular hollow cylinder, with the hollow occupied by the axially extending core region). In some examples the sheath has a cross-section of non-circular geometry, e.g. a regular polygon such as a triangle, square, pentagon, hexagon, heptagon, octagon etc., or a non-regular shape. For example, a square cross-section would provide a sheath which forms a "hollow cuboid", or "rectangular tube", with the hollow occupied by the axially extending core region.

[0016] In some examples the sheath extends circumferentially around the entire axially-extending outer surface of the axially extending core region.

[0017] The sheath comprises aerosol-forming material. In some examples, the sheath consists of aerosol-forming material. In some examples, the aerosol-forming material of the sheath comprises or consists of an extruded composition comprising a particulate filler material and a binder. In some examples, the aerosol-forming material of the sheath comprises or consists of an extruded composition comprising plant fibres. In some examples, the aerosol-forming material of the sheath comprises or consists of an extruded composition comprising plant fibres and binder.

[0018] In some examples, the aerosol-forming material of the sheath comprises or consists of an extruded composition comprising filler material, binder, water and optionally one or more flavourants.

[0019] In some examples, the aerosol-forming material of the sheath comprises tobacco, for example milled tobacco.

[0020] 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 aerosol-forming material 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 filler material may comprise or consist of tea.

[0021] Suitable non-tobacco fillers are known in the art and may act to strengthen the material. Fillers may comprise fibrous (non-tobacco) fillers such as cellulose fibers, lignocellulose fibers (e.g. wood fibers), jute fibers and combinations thereof.

[0022] In some embodiments, the aerosol-forming material of the sheath 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 aerosol-forming material as a distinct ingredient. For example, when the aerosol-forming material contains non-tobacco particulate filler material, an active compound may also be present in the aerosol-forming material and may be introduced separately from the particulate filler material.

[0023] 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.

[0024] In some examples, the active compound comprises nicotine or a nicotine salt. In this way, the aerosol-forming material 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.

[0025] 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.

[0026] In some embodiments, the particulate filler material is present in an amount of at least 50 wt% based on the total weight of the aerosol-forming material, 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 aerosol-forming material, for example up to 80 wt% or up to 75 wt%.

[0027] 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 aerosol-forming material, for example from 55 to 80 wt%, from 60 to 80 wt% or from 65 to 75 wt%.

[0028] In some embodiments, the 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 aerosol-forming material.

[0029] In some embodiments, the 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 aerosol-forming material.

[0030] In some embodiments, the binder is present in an amount of from 0.4 to 1.0 wt% based on the total weight of the aerosol-forming material. For example, in some embodiments, the 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 aerosol-forming material. In some embodiments, the binder is present in an amount of from 0.5 to 1.0 wt% based on the total weight of the aerosol-forming material, for example from 0.5 to 0.9 wt%, or from 0.6 to 0.8 wt%.

[0031] In some embodiments, the binder comprises or consists of a polymer binder.

[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 binder comprises or consists of a gum. In some embodiments, the binder 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 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 density of the aerosol-forming material of the sheath, as determined after the extruded 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< .

[0035] The density of the 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.

[0036] In some embodiments, the density of the aerosol-forming material of the sheath 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< .

[0037] In some embodiments, the aerosol-forming material comprises a liquid carrier.

[0038] The liquid carrier is a liquid fraction of the aerosol-forming material which provides flowability and extrudability, enables the components of the composition to mix and facilitates the formation of aerosol by the aerosol-forming material after extrusion. In some embodiments, the liquid carrier comprises or consists of water. In some embodiments, the liquid carrier comprises or consists of water and one or more of glycerin and propylene glycol. In some embodiments, the liquid carrier comprises water and glycerin. In some embodiments, the liquid carrier comprises or consists of a mixture of water, glycerin and propylene glycol.

[0039] In some embodiments, the aerosol-forming material comprises the liquid carrier in an amount of at least 15 wt% based on the total weight of the aerosol-forming material, 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 aerosol-forming material comprises the liquid carrier in an amount of up to 40 wt% based on the total weight of the aerosol-forming material, 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 aerosol-forming material comprises the liquid carrier in an amount of from 15 to 40 wt% based on the total weight of the aerosol-forming material, 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%.

[0040] In some embodiments, the aerosol-forming material comprises glycerin in an amount of at least 10 wt% based on the total weight of the aerosol-forming material, 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 aerosol-forming material comprises glycerin in an amount of up to 25 wt% based on the total weight of the aerosol-forming material, 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 aerosol-forming material comprises glycerin in an amount of from 10 to 25 wt% based on the total weight of the aerosol-forming material, 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%.

[0041] In some embodiments, the aerosol-forming material comprises propylene glycol in an amount of at least 2 wt% based on the total weight of the aerosol-forming material, for example at least 3 wt%, at least 4 wt% or at least 5 wt%. In some embodiments, the aerosol-forming material comprises propylene glycol in an amount of up to 15 wt% based on the total weight of the aerosol-forming material, 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 aerosol-forming material comprises propylene glycol in an amount of from 2 to 15 wt% based on the total weight of the aerosol-forming material, 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%.

[0042] In some embodiments, the sheath has a thickness of from 1.5 mm to 3.5 mm, for example from 1.6 to 3.4 mm, from 1.7 to 3.3 mm, from 1.8 to 3.2 mm, from 1.9 to 3.1 mm or from 2 to 3 mm. Such thicknesses provide a sheath which provides a good balance of ease of extrusion, physical stability and ability to contain liquid within the axially extending core region, while ensuring an adequate "void" size to contain the axially-extending core region.

[0043] In some examples, the internal diameter of the sheath (i.e. the diameter of the "void" in the sheath which is occupied by the axially extending core region) is from 0.5 mm to 5 mm, for example from 0.5 mm to 4.5 mm, from 0.5 mm to 4 mm, from 0.6 mm to 3.5 mm, from 0.7 mm to 3.3 mm, from 0.8 mm to 3.2 mm, from 0.9 mm to 3.1 mm or from 1 mm to 3 mm.

[0044] The axially extending core region extends axially along the rod within the sheath of aerosol-forming material. In some examples, the axially extending core region is in contact with the sheath, i.e. there are no voids or co-extruded intervening layers between the sheath and the axially extending core region.

[0045] The axially extending core region has an inhomogeneous composition. The composition of the material within the axially extending core region changes when moving along the rod in an axial direction. This is because the axially extending core region comprises a liquid section and a non-liquid section, wherein the liquid section is axially displaced from the non-liquid section. As such, at one axial position within the rod the material within the axially extending core region is non-liquid, and at a second, axially displaced position within the rod the material within the axially extending core region is liquid.

[0046] In some examples, the axially extending core region comprises a plurality of non-liquid sections. In some examples, the axially extending core region comprises a single liquid section.

[0047] In some examples, the axially extending core region comprises at least one liquid section and at least two non-liquid sections, wherein one liquid section lies between two non-liquid sections. In this way, the axially extending core region contains at least one liquid section which is encapsulated on all sides, by the sheath and by the two non-liquid sections. In some examples, the axially extending core region comprises at least one liquid section and at least two non-liquid sections, wherein a non-liquid section lies at each end of the aerosol-forming rod. In this way, the terminal non-liquid sections form "plugs" which prevent or reduce any egress of liquid out of the aerosol-forming rod. The two terminal non-liquid sections may be the only non-liquid sections in the rod (with a liquid section between them), or there may be one or more further "internal" non-liquid sections, each sandwiched between two liquid sections.

[0048] In some examples, the axially extending core region comprises a plurality of liquid sections. In some examples, the axially extending core region comprises a plurality of non-liquid sections and a plurality of liquid sections. In some examples, the axially extending core region comprises two terminal non-liquid sections located at respective terminal ends of the rod, and one or a plurality of liquid sections located between the terminal non-liquid sections. In some examples, the axially extending core region comprises two terminal non-liquid sections located at respective terminal ends of the rod, and a plurality of liquid sections located between the terminal non-liquid sections, wherein the liquid sections are separated from one another by intermediate non-liquid sections.

[0049] In some examples, the axially extending core region comprises the liquid section located between a first non-liquid section and a second non-liquid section, such that the liquid section is encapsulated within the annular sheath and between the first non-liquid section and the second non-liquid section. In this way, egress of the liquid from the liquid section out of the rod is prevented or mitigated.

[0050] In some examples, the axially extending core region comprises a plurality of liquid sections and a plurality of non-liquid sections, wherein the liquid sections and non-liquid sections are located in an alternating arrangement along the axial length of the rod and wherein each terminal end of the rod comprises a non-liquid section.

[0051] In some examples, the sheath and the non-liquid section of the axially extending core region are substantially liquid-impermeable, such that the liquid section is contained within the axially extending core region. In this way, egress of the liquid out of the rod is mitigated or prevented.

[0052] However in some examples, the sheath is adapted to be at least partially liquid-permeable, to absorb at least some of the liquid contained within the one or more liquid sections after manufacture of the aerosol-forming rod. For example, some or all of the liquid may migrate through capillary action or other physical forces into a portion of the sheath which lies adjacent to the axially extending core region, or may migrate further and permeate the entire sheath. For example, the density, porosity and / or composition of the sheath can be tailored to facilitate such migration of liquid into the sheath. In this way, the contents of the liquid become part of the sheath and are able to impart the sheath and rod with desirable properties. For example, when using an "outside-in" heating arrangement during consumption of the aerosol-forming rod, a greater amount of aerosol may be generated due to the greater amount of liquid located within the material of the sheath. Alternatively or additionally, flavourant and / or active agent initially contained within the liquid section(s) may migrate into the sheath and as such will be released in greater quantities from the aerosol-forming rod upon heating, improving the user experience, and may extend the usable lifetime of the rod as explained above.

[0053] Furthermore, the properties of the product are easily tailored without any modification of the aerosol-forming article in the sheath being required before extrusion, since only the composition of the liquid section needs to be modified (e.g. to change the flavourant and / or active compound present).

[0054] In some examples, the liquid section comprises or consists of one or more of propylene glycol and glycerin. In some examples, the liquid section comprises or consists of one or more of propylene glycol, glycerin, and property modifying agent. In some examples, the liquid section comprises or consists of one or more of propylene glycol, glycerin, and flavourant. In some examples, the liquid section comprises or consists of one or more of propylene glycol, glycerin, and active agent. In some examples, the liquid section comprises or consists of one or more of propylene glycol, glycerin, flavourant and active agent. In some examples, the liquid section comprises or consists of propylene glycol, glycerin, and one or more of flavourant and active agent.

[0055] In some examples, the property modifying agent comprises or consists of one or more of nicotine and flavourant.

[0056] The non-liquid section within the axially extending core region may be a solid or a gel. The function of the non-liquid section is to remain in place to form a "plug" which facilitates the containment of the liquid section within the axially-extending core region.

[0057] Herein, the term "non-liquid" encompasses solids and semi-solids ("quasi-solids"). Semi-solids are materials existing in a state between a solid and a liquid, with a viscosity sufficient to enable the material to function as a plug or spacer adjacent the liquid section to prevent or mitigate the egress of liquid out of the liquid section.

[0058] In some examples, the non-liquid section comprises or consists of an extruded gel or paste. In some examples, the non-liquid section consists of an extruded gel. In some examples, the non-liquid section consists of an extruded paste, for example an extruded mixture of solid and liquid components. In some examples, the non-liquid section comprises or consists of a semi-solid material, i.e. a material which is able to flow sufficiently to facilitate extrusion, but has sufficient thickness / viscosity to ensure that it remains in place within the axially extending core region to form a spacer adjacent the liquid section.

[0059] In some examples, the non-liquid section may exist in a liquid or semi-solid state before and during extrusion to facilitate extrusion, but transition into a solid state (or transition from a liquid to a semi-solid state) after extrusion into the rod. For example, the non-liquid section may be extruded as a flowable paste but solidify after extrusion into the axially extending core region of the rod.

[0060] In some examples, the non-liquid section comprises or consists of hydrogel. The skilled person is aware of hydrogels and any suitable hydrogel may be used. The hydrogel may comprise a gelled material comprising a polymer phase and a liquid phase. The liquid phase may comprise water. Any suitable polymer which is able to form a gel may be used. Non-limiting examples of possible polymers include starches and / or celluloses 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.

[0061] In some examples, the non-liquid section comprises or consists of an aerosol-forming material. In some examples, the non-liquid section comprises an aerosol-forming material having a composition as described above for the aerosol-forming material of the sheath. In some examples, the non-liquid section and the sheath each comprise different aerosol-forming materials. In some examples, the non-liquid section and the sheath each comprise different aerosol-forming materials, wherein the aerosol-forming material of the non-liquid section has a higher content of liquid carrier than the aerosol-forming material of the sheath; in this way, the material of the non-liquid section is distinct from and "softer" than the material of the sheath.

[0062] In some examples, the non-liquid section comprises an aerosol-forming material having the same composition as the sheath, except that the non-liquid section comprises a greater proportion of a liquid carrier than the sheath, e.g. a greater proportion of glycerin and / or propylene glycol and / or water. In this way the rod contains consistent materials through its cross-section which differ only in the quantity of liquid carrier present, thereby providing predictable properties such as flavour, active agent content etc.

[0063] In some examples, the axially extending core region has a cross-sectional diameter of from 0.5 mm to 5 mm, for example from 0.5 mm to 4.5 mm, from 0.5 mm to 4 mm, from 0.6 mm to 3.5 mm, from 0.7 mm to 3.3 mm, from 0.8 mm to 3.2 mm, from 0.9 mm to 3.1 mm or from 1 mm to 3 mm. Such diameters provide an axially extending core region which is able to hold a meaningful quantity of liquid within the liquid section, without jeopardising the extrudability or physical properties of the sheath.

[0064] The present disclosure also provides a method of manufacturing an aerosol-forming rod by coextrusion, the method comprising: extruding an extrudable composition through a die to form a sheath of aerosol-forming material; simultaneously extruding a non-liquid composition within the sheath to form a non-liquid section circumscribed by and contained within the sheath; and introducing a liquid composition into the sheath to form a liquid section axially displaced from the non-liquid section within the sheath.

[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 any drying of the extruded aerosol-forming rod after extrusion. In some embodiments, the method does not include any elevated-temperature drying of the extruded aerosol-forming rod after extrusion.

[0067] In some examples, the aerosol-forming rod is an aerosol-forming rod as described above.

[0068] The sheath, aerosol-forming material of the sheath, non-liquid section and liquid section may each independently be selected based on any of the options and preferences already set out for these entities above in the context of the aerosol-forming rod product.

[0069] In some examples, the non-liquid composition and the liquid composition are alternately introduced into the sheath during the extrusion to produce a plurality of liquid sections and a plurality of non-liquid sections, wherein the liquid sections and non-liquid sections are located in an alternating arrangement along the axial length of the rod.

[0070] In some examples, the liquid composition is introduced into the sheath by extrusion through the same die through which the non-liquid composition is extruded.

[0071] In some examples, the non-liquid composition and the liquid composition are alternately introduced by the alternate switching on and off of an extruder pump. The pump may be a peristaltic pump.

[0072] In some embodiments, the method comprises extruding the extrudable composition through a first die, and extruding the non-liquid composition and the liquid composition through a second die, wherein the second die lies concentrically within the first die.

[0073] In some examples, the method comprises adjusting the ratio of the amounts of non-liquid composition and liquid composition introduced into the sheath to alter the amount of a liquid component (e.g. glycerin and / or propylene glycol) contained within the rod. In some examples, the method comprises adjusting the ratio of the amounts of non-liquid composition and liquid composition introduced into the sheath to alter the amount of a property modifying agent (e.g. active agent, such as nicotine, and / or flavourant) contained within the rod.

[0074] In some embodiments, the method comprises feeding one or more components of an aerosol-forming material into an extruder through one or more entry ports; feeding one or more components of a non-liquid composition into the extruder through one or more entry ports; and feeding one or more components of a liquid composition into the extruder through one or more entry ports. In some embodiments, each entry port to the extruder is associated with a pump, for example a peristaltic pump. In some embodiments, the method comprises controlling one or more of the pumps to vary the composition of the axially-extending core region of the aerosol-forming rod. In some embodiments, the method comprises changing (e.g. reducing) the pump rate of one or more of the pumps to vary the composition of the axially-extending core region of the aerosol-forming rod. In some embodiments, the method comprises temporarily reducing (e.g. to zero) the pump rate of one or more of the pumps to omit a component from the axially-extending core region of the aerosol-forming rod along a predetermined length of the aerosol-forming rod.

[0075] In some embodiments, the method comprises extruding the extrudable composition, liquid composition and non-liquid composition through a die to form the aerosol-forming 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 rod 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 rod 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 rods into sections is required.

[0076] The method may further comprise incorporating the aerosol-forming rod into an aerosol-forming article, for example assembling the aerosol-forming rod alongside one or more other components such as filter components, and circumscribing the aerosol-forming rod and one or more other components with one or more wrappers.

[0077] The method comprises extruding through a die, and the shape of the die will dictate the cross-sectional shape of the extruded aerosol-forming rod. For example, in some embodiments extrusion through a circular die forms 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).

[0078] The present disclosure also provides an aerosol-forming article comprising the aerosol-forming rod described herein.

[0079] 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.

[0080] 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 rod; and a cardboard tube located downstream of the aerosol-forming rod.

[0081] 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 rod which is a coextruded substrate as described herein, 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 a coextruded aerosol-forming rod 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.

[0082] Consequently, the aerosol-forming rod 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.

[0083] It will however be appreciated that in particularly suitable exemplary embodiments, the plant material is tobacco. Thus in some examples, the aerosol-forming rod 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.

[0084] 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 rod (e.g. tobacco rod) may be formed into a substantially cylindrical shape such that the article / consumable resembles a conventional cigarette. The aerosol-forming rod 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 rod 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).

[0085] In exemplary aspects and embodiments described herein, the aerosol-forming rod 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 rod or may be provided in isolated locations and / or varying concentrations throughout the aerosol-forming rod.

[0086] 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).

[0087] Suitable fillers are known in the art and may act to strengthen the aerosol-forming rod. Fillers may comprise fibrous (non-tobacco) fillers such as cellulose fibers, lignocellulose fibers (e.g. wood fibers), jute fibers and combinations thereof.

[0088] 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 rod (e.g. tobacco rod). 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).

[0089] In some exemplary aerosol-forming article embodiments described herein, in addition to an aerosol-forming rod, there may also be provided further components or elements combined with the aerosol-forming rod as is known in the art as well as described and claimed herein. Thus, the exemplary aerosol-forming article may include an aerosol-forming rod 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 rod 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.

[0090] 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 rod 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.

[0091] 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 rod 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.

[0092] 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 rod 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 rod. 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 rod (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.

[0093] 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.

[0094] Optionally, the aerosol-forming rod 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 rod. The cylindrical rod has a longitudinal axis, and the end faces are suitably perpendicular to the longitudinal axis.

[0095] In another aspect the present disclosure provides an aerosol-generating system comprising the aerosol-forming article, and an aerosol-generating apparatus comprising a heater.

[0096] 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.

[0097] 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).

[0098] 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.

[0099] The aerosol-forming article may be inserted into the cavity for aerosolising one or more components the aerosol-forming rod. 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 rod when inserted into the cavity.

[0100] 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 rod (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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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 rod.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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 rod, 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.

[0109] The aerosol-forming article may have an elongate shape, and optionally a rod shape (i.e., the aerosol-forming article forms a substantially cylindrical outer shape), the upstream and downstream ends of the aerosol-forming article can be air-permeable to allow an axial airflow through the aerosol-forming article.

[0110] 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.

[0111] 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 rod).

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] The heating element may have a length that is less than, or substantially the same as, an axial length of an aerosol-forming rod 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 rod, rather than other components of the aerosol-forming article. The heating element may penetrate the aerosol-forming rod for substantially the entire axial length of the aerosol-forming rod 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 rod, when penetrated by the heating element. That is, heat may be transferred radially outwardly (in the case of a cylindrical heating element).

[0117] 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 rod). In particular, the heating element may surround an aerosol-forming rod of the aerosol-forming article. That is, when an aerosol-forming article is engaged with the device, the aerosol-forming rod 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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 rod). That is, the aerosol-forming article may be inserted through the opening and into the cavity (so as to be engaged with the device).

[0122] 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.

[0123] 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).

[0124] 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.

[0125] 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).

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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).

[0130] 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.

[0131] 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.

[0132] 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).

[0133] 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.

[0134] 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

[0135] 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'; Figure 4 shows (a) an example of an aerosol-forming rod in longitudinal cross-section; and (b) another example of an aerosol-forming rod in longitudinal cross-section. DETAILED DESCRIPTION OF EMBODIMENTS

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] In this example, the device body 20 is a heat-not-burn device (HNB) configured to produce an aerosol by heating an aerosol-forming rod 10 (e.g. a solid precursor, such as tobacco material) to a temperature below its combustion temperature.

[0145] The term "aerosol-forming rod" refers to a rod of material capable of releasing volatile components that can form an aerosol, e.g. by releasing volatile compounds in the aerosol-forming rod 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 rod 10 in the aerosol-forming article 30 is a coextruded material, formed by coextruding compositions through a die, for example a die which forms part of a twin-screw extruder.

[0146] 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 rod 10 to a temperature lower than its combustion temperature such that an aerosol can be formed by evaporation, torrefaction and pyrolysis.

[0147] 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.

[0148] The article 30 defines an air passageway which transmits aerosol generated from the aerosol-forming rod 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 rod 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.

[0149] 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.

[0150] 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 rod 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 rod 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.

[0151] 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 rod 10. This may be referred to as an 'outside-in' heating arrangement.

[0152] In this example, the heating element 2a is a resistive heating element although it will be appreciated that the aerosol-forming rod 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] Figure 4(a) shows an aerosol-forming rod 5 according to the invention, in longitudinal cross-section. The aerosol-forming rod 5 has a cylindrical structure formed by the co-extrusion of an outer cylindrical sheath 50 and an inner axially-extending core made up of a liquid section 53 which is centrally located along the axial length of the aerosol-forming rod 5, and two non-liquid sections 51 and 52, which form "plugs" at each end of the aerosol-forming rod 5 to encapsulate the liquid section 53 within the aerosol-forming rod 5. The aerosol-forming rod 5 is 12 mm long and around 6.95 mm in diameter. Each of the liquid section 53 and two non-liquid sections 51 and 52 are 4 mm long. The axially-extending core region which contains the liquid and non-liquid sections has a diameter of 2 mm (and as such, the outer cylindrical sheath 50 has an internal diameter of 2 mm).

[0157] The aerosol-forming rod 5 has a curved, axially extending outer surface 54 and two planar terminal surfaces 55 and 56.

[0158] The aerosol-forming rod 5 is formed by co-extruding material from a twin-screw extruder, e.g. a Thermofisher Process 16 extruder. A paste containing milled tobacco and other ingredients is extruded through an annular die to form the sheath 50, and simultaneously a "softer" paste made from the same ingredients as the sheath-forming paste (but with a higher liquid content) is extruded concentrically within the sheath to form the non-liquid sections 51, 52. The central liquid section 53 is formed by temporarily switching off the peristaltic pump which feeds the "softer" paste to the extruder die, after the first non-liquid section 51 has formed, thereby creating a section with only liquid (e.g. glycerin) until the pump is switched back on to extrude the second non-liquid section 52.

[0159] The aerosol-forming rod 5 is a segment of a longer rod (not shown) formed by continuous co-extrusion. The longer rod is cut into smaller sections after extrusion to form a plurality of discrete aerosol-forming rods 5. It will be understood that the longer rod, before cutting, will contain alternating liquid and non-liquid sections, with the liquid sections being 4 mm long and the non-liquid sections being 8 mm long. By cutting the longer rod at the midway point along each non-liquid section, the result is a plurality of aerosol-forming rods 5, which each have two terminal non-liquid sections of 4 mm length, with a 4 mm long liquid section inbetween.

[0160] Figure 4(b) shows a second embodiment of an aerosol-forming rod 6 according to the invention, in longitudinal cross-section. The aerosol-forming rod 6 has generally the same structure and size as the aerosol-forming rod 5 of Figure 4(a), except that the aerosol-forming rod 6 has a greater number of liquid and non-liquid sections within the axially-extending core region along its length. Specifically, the aerosol-forming rod 6 has an alternating arrangement of five non-liquid sections 61, 62, 63, 64 and 65, and four liquid sections 66, 67, 68 and 69. The liquid sections 66, 67, 68 and 69 are each 1 mm long. Two terminal non-liquid sections 61 and 62 ("plugs") are each 1 mm long. Three internal non-liquid sections 63, 64 and 65 are each 2 mm long. This creates four "pockets" of encapsulated glycerin within the aerosol-forming rod 6. The aerosol-forming rod 6 is made by the same extrusion method as described for the rod of Figure 4(a), except that the pump supplying the "softer" paste is switched on and off more frequently to create the smaller liquid and non-liquid sections.

[0161] In Figures 4(a) and 4(b), the non-liquid sections 51, 52 and 61, 62, 63, 64, 65 are made from an aerosol-forming material (tobacco-containing extruded paste), however other materials are possible. In another embodiment, the non-liquid sections 51, 52 and 61, 62, 63, 64, 65 are instead made from a hydrogel, for example an alginate-based hydrogel.

[0162] Like the aerosol-forming rods of Figure 4(a), the aerosol-forming rod 6 of Figure 4(b) can be formed by continuous co-extrusion of a longer roc which is subsequently cut into sections to form a plurality of discrete aerosol-forming rods 6.EXAMPLES Example 1

[0163] A hollow cylindrical sheath of aerosol-forming material was extruded from an extrudable composition ("Composition 1") formed in situ within a Thermofisher Process 16 twin-screw extruder. Extrusion through an annular die created the cylindrical sheath of material. 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.

[0164] A "softer" aerosol-forming material was coextruded from another extrudable composition ("Composition 2") into the hollow of the sheath, in discrete sections. Between the discrete sections of Composition 2 within the sheath, a liquid composition ("Composition 3") was extruded. The liquid composition was "encapsulated" within the sheath between two sections of Composition 2.

[0165] To form Compositions 1 and 2, glycerin was fed to the extruder via a first liquid port; propylene glycol was optionally fed to the extruder via a second liquid port if necessary depending on the desired composition; and milled tobacco was fed to the extruder via a gravimetric feed hopper. Composition 2 was made "softer" than Composition 1 by increasing the amount of glycerin in Composition 2 relative to Composition 1. All of these ingredients were then mixed downstream of the ports within the extruder to form the extrudable compositions within the extruder, before extrusion of the respective compositions out of the dies.

[0166] 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 Composition 1 amount (based on total weight of composition) "Sheath" Composition 2 amount (based on total weight of composition) "Spacers" Milled tobacco75-80 wt%65-70 wt%Glycerin15-20 wt%25-30 wt%Water5 wt%5 wt%

[0167] Composition 3 was glycerin.

[0168] Alternating sections of Composition 2 and Composition 3 were created along the hollow centre of the sheath by periodically switching off the peristaltic pump which fed Composition 2 to the extruder, thereby feeding only the liquid Composition 3 through the extruder die until the pump was switched back on. Using this approach, 8 mm long sections of Composition 2 were extruded into the sheath, separated by 4 mm long sections of liquid Composition 3. In other words, the rod contained alternating sections of Compositions 2 and 3 along its centre, with the Composition 2 sections being 8 mm long and the Composition 3 sections being 4 mm long.

[0169] By subsequently dividing the continuous extruded rod at the halfway-point along each 8 mm long section of Composition 2, the result was separate rods, each 12 mm long, each including a central 4 mm long liquid section sandwiched between two terminal 4 mm long non-liquid sections.

[0170] The total rod diameter was 6.94 mm. The sheath was extruded to have an internal diameter of 2 mm, with a sheath thickness of 2.47 mm. Compositions 2 and 3 were extruded to form sections of 2 mm diameter, such that they "filled" the sheath.

[0171] The sheath and terminal non-liquid sections of Composition 2 adequately encapsulated the liquid glycerin section.

[0172] No drying step was carried out after extrusion.Example 2

[0173] The method of Example 1 was repeated, with the only change being that a flavourant (menthol) was added to Composition 3. Thus menthol-flavoured glycerin was extruded as the liquid sections within the aerosol-forming rod.Example 3

[0174] The method of Example 1 was repeated, with the only change being that a nicotine salt (nicotine bitartrate dihydrate) was added to Composition 3. Thus nicotine-containing glycerin was extruded as the liquid sections within the aerosol-forming rod.Example 4

[0175] The method of Example 1 was repeated, with the only change being that the lengths of the liquid and non-liquid sections extruded within the sheath were changed. To form the continuous extruded rod, 1 mm sections of liquid Composition 3 were extruded between 2 mm long sections of Composition 2. The continuous rod was then divided into 12 mm long discrete aerosol-forming rods, by cutting at the halfway-point along every fourth non-liquid section. The result was discrete rods, each containing 1 mm long terminal non-liquid "plugs" of Composition 2, with four 1 mm long liquid sections of Composition 3 within each rod, and three 2 mm long sections of non-liquid Composition 2 within each rod separating the liquid sections.

[0176] As a result, rods were formed having very small "pockets" of encapsulated glycerin within an outer sheath of aerosol-forming material.

Examples

second embodiment

[0160]Figure 4(b) shows an aerosol-forming rod 6 according to the invention, in longitudinal cross-section. The aerosol-forming rod 6 has generally the same structure and size as the aerosol-forming rod 5 of Figure 4(a), except that the aerosol-forming rod 6 has a greater number of liquid and non-liquid sections within the axially-extending core region along its length. Specifically, the aerosol-forming rod 6 has an alternating arrangement of five non-liquid sections 61, 62, 63, 64 and 65, and four liquid sections 66, 67, 68 and 69. The liquid sections 66, 67, 68 and 69 are each 1 mm long. Two terminal non-liquid sections 61 and 62 ("plugs") are each 1 mm long. Three internal non-liquid sections 63, 64 and 65 are each 2 mm long. This creates four "pockets" of encapsulated glycerin within the aerosol-forming rod 6. The aerosol-forming rod 6 is made by the same extrusion method as described for the rod of Figure 4(a), except that the pump supplying the "softer" paste is switched on an...

example 1

Example 1

[0163]A hollow cylindrical sheath of aerosol-forming material was extruded from an extrudable composition ("Composition 1") formed in situ within a Thermofisher Process 16 twin-screw extruder. Extrusion through an annular die created the cylindrical sheath of material. 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.

[0164]A "softer" aerosol-forming material was coextruded from another extrudable composition ("Composition 2") into the hollow of the sheath, in discrete sections. Between the discrete sections of Composition 2 within the sheath, a liquid composition ("Composition 3") was extruded. The liquid composition was "encapsulated" within the sheath between two sections of Composition 2.

[0165]To form Compositions 1 and 2, glycerin was fed to the extruder via a first liquid port; propylene glycol was optionally fed to the extruder via a second liqu...

example 2

Example 2

[0173]The method of Example 1 was repeated, with the only change being that a flavourant (menthol) was added to Composition 3. Thus menthol-flavoured glycerin was extruded as the liquid sections within the aerosol-forming rod.

Claims

1. A co-extruded aerosol-forming rod comprising: a sheath comprising aerosol-forming material; and an axially extending core region circumscribed by and contained within the sheath; wherein the axially extending core region comprises a liquid section and a non-liquid section, wherein the liquid section is axially displaced from the non-liquid section.

2. The aerosol-forming rod according to claim 1, wherein the aerosol-forming material comprises an extruded composition comprising plant fibres, binder, water and optionally one or more flavourants.

3. The aerosol-forming rod according to claim 1 or 2, wherein the aerosol-forming material comprises tobacco.

4. The aerosol-forming rod according to any one of the preceding claims, wherein the axially extending core region comprises the liquid section located between a first non-liquid section and a second non-liquid section, such that the liquid section is encapsulated within the sheath and between the first non-liquid section and the second non-liquid section.

5. The aerosol-forming rod according to any one of the preceding claims, wherein the axially extending core region comprises a plurality of liquid sections and a plurality of non-liquid sections, wherein the liquid sections and non-liquid sections are located in an alternating arrangement along the axial length of the rod and wherein each terminal end of the rod comprises a non-liquid section.

6. The aerosol-forming rod according to any one of the preceding claims, wherein the sheath and the non-liquid section of the axially extending core region are substantially liquid-impermeable, such that the liquid section is contained within the axially extending core region.

7. The aerosol-forming rod according to any one of the preceding claims, wherein the liquid section comprises or consists of one or more of propylene glycol and glycerin, and optionally property modifying agent.

8. The aerosol-forming rod according to claim 7, wherein the property modifying agent comprises or consists of one or more of nicotine and flavourant.

9. The aerosol-forming rod according to any one of the preceding claims, wherein the non-liquid section comprises hydrogel.

10. A method of manufacturing an aerosol-forming rod according to any one of claims 1-9 by coextrusion, the method comprising: extruding an extrudable composition through a die to form a sheath of aerosol-forming material; simultaneously extruding a non-liquid composition within the sheath to form a non-liquid section circumscribed by and contained within the sheath; and introducing a liquid composition into the sheath to form a liquid section axially displaced from the non-liquid section within the sheath.

11. The method according to claim 10, wherein the non-liquid composition and the liquid composition are alternately introduced into the sheath during the extrusion to produce a plurality of liquid sections and a plurality of non-liquid sections, wherein the liquid sections and non-liquid sections are located in an alternating arrangement along the axial length of the rod.

12. The method according to claim 11, wherein the non-liquid composition and the liquid composition are alternately introduced by the alternate switching on and off of an extruder pump.

13. The method according to any one of claims 10-12, comprising adjusting the ratio of the amounts of non-liquid composition and liquid composition introduced into the sheath to alter the amount of a property modifying agent contained within the rod.

14. An aerosol-forming article comprising the aerosol-forming rod according to any one of claims 1-9.

15. The aerosol-forming article according to claim 14, which is a heat-not-burn product.

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