CN110913709A

CN110913709A - Tobacco component releasing member

Info

Publication number: CN110913709A
Application number: CN201880047978.XA
Authority: CN
Inventors: D.弗兰克; O.格吕纳; J.克诺特; T.克尼希; V.库尔; M.林克; F.普吕克汉
Original assignee: British American Tobacco Investments Ltd
Current assignee: Nicoventures Trading Ltd
Priority date: 2017-07-18
Filing date: 2018-07-17
Publication date: 2020-03-24
Also published as: EP3654782A1; RU2730722C1; BR112020001173A2; AU2018304943B2; CA3069653C; CA3069653A1; JP6968974B2; US20200163377A1; PH12020550016A1; MY190330A; KR20200024926A; AU2018304943A1; KR102403078B1; GB201717408D0; MX2020000635A; CL2020000025A1; GB201711534D0; JP2020527947A; WO2019016535A1; AU2018304943B9

Abstract

The present invention relates to a tobacco component release member for inclusion in an aerosol provision device, the tobacco component release member comprising tobacco particles, optionally in a coalesced structure. The invention also relates to an apparatus comprising a tobacco component releasing member, and to a method of manufacturing a tobacco component releasing member.

Description

Tobacco component releasing member

Technical Field

The present invention relates to a tobacco component release member for inclusion in an aerosol supply, such as an apparatus for heating smokable material to volatilise at least one component of the smokable material, the tobacco component release member comprising tobacco particles, optionally in a coalesced structure. The invention also relates to an apparatus comprising a tobacco component releasing member, and to a method of manufacturing a tobacco component releasing member.

Background

Smoking articles such as cigarettes, cigars and the like burn tobacco during use to form tobacco smoke. Attempts have been made to provide alternatives to these articles by making products that release compounds without burning. Examples of such products are so-called "heat non-combustible" products or tobacco heating devices or products which release a compound by heating rather than burning smokable material.

It is also known to include flavourants in smoking articles to add a particular desired flavour to the aerosol generated by the smoking article. This has been achieved in a number of different ways, including the use of crushable capsules containing perfume compositions.

Disclosure of Invention

According to a first aspect of the present invention there is provided a tobacco component release member for inclusion in an aerosol provision device, the tobacco component release member having a coalescing structure formed from a precursor composition comprising tobacco particles, wherein the pH of the precursor composition has been adjusted to an alkaline pH.

In some embodiments, the pH is increased by the addition of one or more bases or an alkaline buffer system.

Alternatively, there is provided a tobacco component release member for inclusion in an aerosol provision device, the tobacco component release member comprising tobacco particles and one or more bases or an alkaline buffer system, the tobacco component release member having an alkaline pH.

In some embodiments, the one or more bases are selected from the group consisting of hydroxide, carbonate, and bicarbonate. In some embodiments, the one or more bases are selected from the group consisting of: potassium hydroxide, sodium carbonate and sodium bicarbonate.

In some embodiments, the pH of the precursor composition is at least about 7.5.

In some embodiments, the tobacco particles have an average diameter of no greater than 3mm, no greater than 1mm, no greater than 0.5 mm, or no greater than 0.3 mm.

In some embodiments, one or more aerosol-forming agents are included. In some embodiments, the aerosol former is selected from the group consisting of glycerin, propylene glycol, and glycerol triacetate.

In some embodiments, one or more binding agents are included. In some embodiments, the one or more binding agents are selected from the group consisting of: thermally reversible gelling agents, such as gelatin; starch; a polysaccharide; pectin, cellulose; cellulose derivatives such as carboxymethyl cellulose; and alginates.

In some embodiments, one or more aroma modulators are included.

In some embodiments, the precursor composition is pelletized or rounded to form a coalesced structure.

In some embodiments, the precursor composition is extruded to form a coalesced structure.

In some embodiments, the component is in the form of particles.

In some embodiments, the components have an elongated or rod-shaped form.

In some embodiments, the member has a cross-sectional shape for increasing the surface area of the tobacco component releasing member.

According to a second aspect of the present invention there is provided an aerosol provision device comprising a tobacco component release member according to the first aspect of the present invention.

In some embodiments, the device is a tobacco heating product comprising a tobacco segment heated to volatilize constituents and optionally a filter or filter element.

In some embodiments, the device is a blended product comprising a tobacco segment to be heated to volatilize components and a liquid to be heated to form a vapor and optionally a filter or filter element.

In some embodiments, the tobacco component releasing component is located in a filter or filter element of the device. In some embodiments, the one or more tobacco component releasing members are surrounded by a filter material in a filter or filter element. In other embodiments, one or more tobacco component releasing members are located in the cavity of the multi-segment filter.

In some embodiments, one or more tobacco component releasing components are located in the tobacco segment. In some embodiments, the tobacco segment is comprised of one or more tobacco component releasing members.

In some embodiments, the device is a blended product comprising a tobacco segment to be heated to volatilize components and a liquid to be heated to form a vapor, wherein one or more tobacco component releasing members are located in the tobacco segment, and wherein the tobacco segment is heated by the vapor. In some embodiments, the liquid is a nicotine-free liquid. In some embodiments, the apparatus comprises means for heating the liquid to form the vapour, but does not comprise separate means for heating the smokeable material.

According to a third aspect of the present invention there is provided a method of manufacturing a tobacco component releasing component comprising: preparing a precursor composition comprising tobacco microparticles; adjusting the pH of the precursor composition to an alkaline pH; and treating the precursor composition to form a coalesced structure.

In some embodiments, the precursor composition is extruded to form a coalesced structure. In some embodiments, the extruded agglomerates are cooled during or after extrusion. In some embodiments, the extrusion creates internal channels within the extruded agglomerates.

According to a fourth aspect of the present invention there is provided apparatus for heating smokable material to volatilise at least one component of the smokable material and heating a nicotine-free liquid to be heated to form a vapour, wherein the smokable material comprises tobacco particles having an alkaline pH, and wherein the smokable material is heated by the vapour.

In some embodiments, the apparatus comprises means for heating the liquid to form a vapour, but does not comprise separate means for heating the smokeable material.

In some embodiments, the pH of the tobacco microparticles is at least about 7.5.

Drawings

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

FIG. 1 is a flow diagram illustrating key steps of a process according to an embodiment of the invention;

fig. 2a, 2b and 2c show examples of nozzle designs for forming extruded agglomerates with internal passages, while fig. 2d and 2e show how such nozzles may be used for shaping extruded agglomerates;

FIG. 3 is a photograph of some extruded agglomerates showing different cross-sectional geometries for forming internal channels;

fig. 4a shows an example of a die for producing particles by extrusion, while fig. 4b shows how such a die may be used to form extruded agglomerates;

FIG. 5 is a schematic representation of some extruded pellets;

figure 6 is a schematic cross-sectional view of a tobacco heating product including a tobacco component releasing member for heating smokable material to volatilise at least one component of the smokable material;

figure 7 is a schematic view of a mixing device including a tobacco component releasing component for heating smokable material to volatilise at least one component of the smokable material; and the number of the first and second groups,

figure 8 is a schematic cross-sectional view of an example of a cartridge containing a plurality of tobacco component releasing members.

Detailed Description

The present invention relates to a tobacco component releasing member formed of tobacco particles. These components can, for example, release tobacco components including flavors and nicotine when heated.

At least some of the released ingredients are directly derived from the tobacco particles used to form the component. In some embodiments, other materials may be added to the component for release. These other materials may, for example, also include added tobacco components to supplement those derived directly from the tobacco particles. Alternatively or additionally, the other material added to the component for release may not be derived from tobacco. For example, in some embodiments, the components may also carry and release other flavors, including flavors not derived from tobacco.

In some embodiments, the tobacco component releasing element is a coalescing structure. This means that they are blocks or clusters formed by fusing or bonding a plurality of microparticles to each other. The constituent particles comprise tobacco particles. In some embodiments, particles of other materials may also be included.

pH adjustment

In some embodiments, the coalescing structure is formed from a precursor composition comprising tobacco microparticles, wherein the pH of the precursor composition has been adjusted to a basic pH. For example, the pH may be adjusted to at least about 7.5. The pH may be adjusted by the addition of one or more bases. Alternatively, the pH may be adjusted by using a buffer solution.

In some embodiments, the tobacco component releasing component comprises tobacco particles and one or more bases or an alkaline buffer system such that the tobacco component releasing component has an alkaline pH. For example, the pH may be at least about 7.5.

The purpose of adjusting the pH of the tobacco particles and/or precursor composition is to provide the tobacco component in a chemical form, which means that the tobacco component is readily released from the release means, and/or the tobacco component is readily transferred to the aerosol generated by the smoking article. Adjusting the pH of tobacco changes the natural balance of those acid-base reactions that bind certain types of chemicals in tobacco. For example, in natural tobacco leaves, nicotine tends to bind to organic acids present in the leaves, and thus nicotine is more stable and less volatile when exposed to mild heating. This reduces the natural association of nicotine with acid if the pH of the leaves is raised. This unbound "free" nicotine is more volatile. The same principle applies to other chemical equilibria in tobacco.

In some embodiments, the pH of the precursor composition is adjusted to at least about 7.5, at least about 8, at least about 8.5, at least about 9, at least about 9.5, or at least about 10. In some embodiments, the pH is adjusted to be no greater than about 14, no greater than about 13.5, no greater than about 13, no greater than about 12.5, no greater than about 12, no greater than about 11.5, no greater than about 11, no greater than about 10.5, or no greater than about 10. In some embodiments, the pH of the precursor composition is adjusted from about 8 to about 10 or from about 8.5 to about 9.5.

In some embodiments, the pH of the tobacco component releasing component is at least about 7.5, at least about 8, at least about 8.5, at least about 9, at least about 9.5, or at least about 10. In some embodiments, the pH is not greater than about 14, not greater than about 13.5, not greater than about 13, not greater than about 12.5, not greater than about 12, not greater than about 11.5, not greater than about 11, not greater than about 10.5, or not greater than about 10. In some embodiments, the pH of the tobacco component releasing component is adjusted from about 8 to about 10 or from about 8.5 to about 9.5.

In some embodiments, the pH is adjusted from about 7.5 to about 10 or from about 8 to about 9 or to about 8.5, about 9, about 9.5, or about 10.

In some embodiments, the base used to adjust the pH is a hydroxide or a carbonate. The hydroxide used may be a monobasic, dibasic or tribasic acid. Suitable bases include, for example, potassium hydroxide, calcium hydroxide, silver hydroxide, ammonium hydroxide, magnesium hydroxide, sodium carbonate, sodium bicarbonate (also known as sodium bicarbonate), and potassium carbonate.

The base may be added to the precursor composition in liquid form (such as an aqueous or non-aqueous solution or suspension) or in solid form (such as a powder).

The precursor composition includes a mixture of tobacco particles and a pH adjuster. In some embodiments in which the tobacco particulates and pH adjuster are dry, for example, in which the base is in the form of a dry powder, the pH of the precursor composition will be adjusted upon addition of water to the composition (as compared to the pH of the tobacco particulates without the pH adjuster).

As used herein, where the composition or component is dry, the pH of the precursor composition or tobacco ingredient releasing component refers to the pH when water is added to the composition or component.

In some embodiments, the buffering system used to adjust the pH is a mixture of a weak base and its conjugate acid. Suitable buffering systems include, for example, buffering systems having a pH of at least about 7.5, at least about 8, at least about 8.5, or at least about 9. In some embodiments, the pH of the buffer system is from about 8 to about 10 or from about 8.5 to about 9.5. Suitable buffering systems include, for example, buffering systems based on ammonia, carbonates or hydroxides, and suitable counterions. An example of a specific buffer system is a mixture of aqueous ammonia and ammonium chloride.

Tobacco particles

The tobacco particles present in the precursor composition are of a sufficiently small size to ensure that a plurality of such particles can coalesce to form a tobacco component releasing component of a desired size based on its intended use.

Smaller tobacco particles have a greater surface area to volume ratio and therefore they may exhibit enhanced release of tobacco constituents compared to larger sized particles.

In addition, the size of the tobacco particles (and other particles in the precursor composition) will have an effect on the porosity and density of the coalescing structure and the tobacco component releasing means. Thus, the size of the tobacco particles can be selected to produce a more porous, coalesced structure, which will have an effect on the release of the tobacco constituents. Thus, the size of the tobacco particles is another factor that can be adjusted to affect the release of tobacco constituents, particularly where the agglomerated structure is formed by granulation rather than extrusion.

The preferred size of the tobacco particles may also depend on the method used to form the agglomerated structure. For example, the extrusion process can be sensitive to the size of the microparticles in the composition being extruded. In particular, in embodiments in which the precursor composition is extruded to form a coalesced structure, it may be desirable for the particles (including tobacco particles) in the precursor composition to have an average particle size of no greater than about 3mm, no greater than 1mm, no greater than about 0.5 mm, or to have an average particle size of no greater than about 0.3 mm, as measured by sieving.

In some embodiments, it may be desirable for the tobacco particulates in the precursor composition and/or in the tobacco component releasing component to have an average particulate size of no greater than about 3mm, no greater than 1mm, no greater than about 0.5 mm, or to have an average particulate size of no greater than about 0.3 mm, as measured by sieving. In some embodiments, the average particle size is in the range of about 0.1 to about 3mm, about 0.1 to about 1mm, about 0.1 to about 0.5 mm, about 0.1 to about 0.4 mm, or in the range of about 0.2 to about 0.3 mm. In some embodiments, at least about 90% of the particles of the precursor composition will have a particle size in the range of about 0.1 to about 3mm, or about 0.1 to about 1mm, or about 0.1 to about 0.5 mm. In some embodiments, at least about 90% of the tobacco particles of the precursor composition will have a particle size in the range of about 0.1 to about 3mm, or about 0.1 to about 1mm, or about 0.1 to 0.5 mm. In some embodiments, none of the particles in the precursor composition have a particle size greater than 5mm, greater than 4mm, greater than 2mm, greater than 1.5mm, or greater than about 1 mm.

The particles of the desired size may be formed by grinding, shredding, cutting or crushing the tobacco material. Suitable machines for producing such tobacco particles include, for example, shredders, cutters, or grinders, such as hammer mills, roller mills, or other types of commercially available grinding machines. The size of the tobacco particles is selected to provide particles that can be readily prepared from a variety of different types of tobacco materials, which particles can be formed into agglomerated structures using the processes described herein, and which have the properties described herein, and which provide a source of readily releasable tobacco constituents.

Without wishing to be bound by any one particular theory, it is speculated that chopping the tobacco to form tobacco particles enhances the release of tobacco components including volatile flavors and aroma components, as well as nicotine. The increased surface area of the tobacco particles is also believed to aid in volatilization. Smaller tobacco particles also improve the homogeneity of the conglomerate structure formed by the tobacco particles together with other components.

The tobacco material used to form the tobacco particles can be any type of tobacco and can be any part of a tobacco plant, including tobacco lamina, stem, stalk, veins (rib), scraps and short pieces or mixtures of two or more thereof. Suitable tobacco materials include the following types: virginia or flue-cured, burley, oriental or blends of tobacco materials, optionally including those listed herein. The tobacco may be expanded, such as Dry Ice Expanded Tobacco (DIET), or processed by any other means. In some embodiments, the tobacco material may be a reconstituted tobacco material. The tobacco may or may not be pre-processed and may for example be a Solid Stem (SS); minced dried stems (SDS); steam treating the stems (STS); or any combination thereof. The tobacco material may be fermented, cured, uncured, cured, or otherwise pre-treated.

Other Components of the precursor composition

The tobacco component releasing member having a coalescing structure is formed from a precursor composition comprising tobacco particles.

In some embodiments, the precursor composition and/or the tobacco component releasing component do not comprise a binding agent or binding additive. In other embodiments, the precursor composition includes a binder or binding additive. The binding additive may be selected to aid in the formation of the agglomerated structure by helping to bind the tobacco particles to each other and to other components in the composition. Suitable bonding additives include, for example: thermally reversible gelling agents, such as gelatin; starch; a polysaccharide; pectin; an alginate; wood pulp; cellulose; cellulose derivatives, such as carboxymethyl cellulose.

In some embodiments, the precursor composition and/or the tobacco component releasing component further comprises a diluent. The diluent may be in solid or liquid form. In some embodiments, the diluent is inert or substantially inert.

In some embodiments, the coalesced structure formed from the precursor composition may have an increased surface area by including particles of an inert filler material in the precursor composition. Suitable inert fillers may be porous or non-porous.

In some embodiments, the precursor composition and/or the tobacco component releasing component further comprises at least one aerosol former, which may for example be a polyol aerosol generator or a non-polyol aerosol generator, preferably a non-polyol aerosol generator. It may be solid or liquid at room temperature, but preferably is liquid at room temperature. Suitable polyols include sorbitol, glycerol and glycerol alcohols like propylene glycol or triethylene glycol. Suitable non-polyols include monohydric alcohols, high boiling hydrocarbons, acids and esters such as lactic acid (such as diacetin, triacetin, triethyl citrate or isopropyl myristate). Combinations of aerosol-formers may be used in the same or different proportions. Glycerol and propylene glycol are particularly preferred.

In some embodiments, the precursor composition and/or the tobacco component releasing component can include a flavor modulator to modulate the flavor or add flavor provided by the tobacco particles. In some embodiments, a fragrance modulator can be included in the precursor composition. Alternatively or additionally, flavour modulators may be added or applied to the coalescing structure. Flavour modulators include, for example, shell materials, as well as "flavour" and "fragrance agent" materials, which may be used to develop a desired taste or aroma in products intended for adult consumers, where local regulations permit. It may include extracts (e.g. licorice, hydrangea, japanese white bark lily leaves, chamomile, fenugreek, clove, menthol, japanese mint, anise, cinnamon, vanilla, wintergreen, cherry, berry, peach, apple, jungle brand liqueur, bourbon whisky, scotland whisky, spearmint, mint, lavender, cardamom, celery, caltrop, nutmeg, sandalwood, bergamot, geranium, honey essence, rose oil, vanilla, lemon oil, orange oil, cinnamon, caraway, cognac brandy, jasmine, ylang, sage, fennel, allspice, ginger, fennel, coriander, coffee or peppermint oil from any species of the genus mentha), flavour enhancers, bitter receptor site blockers, sensory receptor site activators or stimulators, sugars and/or sugar substitutes (e.g. sucralose, acesulfame potassium, Aspartame, saccharin, cyclamate, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives, such as charcoal, chlorophyll, minerals, botanicals, or breath fresheners. It may be a simulated, synthetic or natural ingredient or a blend thereof. It may be in any suitable form, such as an oil, liquid, gel, wax or powder.

In some embodiments, the precursor composition and/or the tobacco component releasing component further comprises a preservative. Suitable preservatives will be readily known to those skilled in the art and will include, for example, those which can be safely used in products for the production of inhalable aerosols. Examples of preservatives that may be used include: propylene glycol, carvacrol, thymol, L-menthol, 1, 8-cineole, phenoxyethanol, herbicides, sorbic acid and its salts, sodium hydroxymethylglycinate, ethylhexylglycerol, parabens and vitamins such as vitamin E or vitamin C.

In some embodiments, neither the precursor composition nor the tobacco component releasing component comprises a gelling agent.

In the form of conglomerate structures

In some embodiments, the tobacco component releasing component is in particulate form, being small individual particles. In most embodiments, a plurality of particles will be incorporated into the device so as to have a desired effect on the aerosol of the device.

In some embodiments, the particulate tobacco component-releasing component has an average size (as measured by sieving) of from about 0.5 mm to about 4 mm. In some embodiments, it is preferred that the particles have an average size of from about 0.7 mm to about 3 mm. In the case where, for example, the particles are to be dispersed within the filter material of the filter element (as in a Dalmatian-type filter element), the particles may preferably have an average size of from about 0.3 mm to about 1 mm. For example, where the particles are to be included in a cavity (such as a cavity within a filter), the particles may preferably have an average size of from about 0.5 mm to about 4 mm.

In other embodiments, the tobacco component releasing member is in unitary form, being a larger article. In most embodiments, a single integral component will be incorporated into the device so as to have a desired effect on the aerosol of the device.

In some embodiments, the shape of the unitary component is generally spherical or cylindrical. It may have a diameter of from about 4mm to about 10 mm. In some embodiments, the diameter may be from about 5mm to about 8 mm. The cylindrical member may furthermore have a length of from about 5mm to about 80 mm, from about 15 mm to about 50 mm or from about 20 mm to about 30 mm.

Forming a coalesced structure

FIG. 1 is a flow chart showing key steps in the process of the present invention. Tobacco raw material, which may be pre-treated or pre-processed, is ground to a desired particle size. The pH is adjusted by adding one or more bases or by adding a buffer solution to the tobacco particles. Any additional components may be added to the tobacco material. These additional components may be in liquid form or in solid form. The additional solid component is preferably in particulate or powder form. Additional components may be added before, during or after the pH adjustment step. The agglomerated structure is then formed from the resulting precursor composition by binding the pH-adjusted tobacco particles and optional other components to form a multi-particulate entity.

In some embodiments, water may be added to the precursor composition as a processing aid. For example, the presence of water may help to dissolve components of the precursor composition, such as pH adjusters and sugars, and/or it may assist in binding or improving coalescence.

In some embodiments, the coalesced structure may be formed from the precursor composition by a process comprising one or more steps selected from the group consisting of pelletization, extrusion, and spheronization.

Granulating

Granulation of the precursor composition involves combining or fusing the microparticles of the precursor composition together to form a larger multi-microparticle entity, referred to herein as a conglomerate structure. The multiparticulate entity formed by granulation is referred to as a granule, and the granule may have various geometries including, for example, a general form of sphere, cylinder, etc.

In one embodiment, the granulation step used is wet granulation. In wet granulation, granules are formed by adding a granulation liquid to a powder bed. Agitation in the system in conjunction with wetting of the components in the precursor composition causes the microparticles to coalesce to produce wet granules. The granulation liquid may be at least partially removed by drying to provide dry granules. The granulation liquid may be water-based or solvent-based. Suitable granulation liquids include, for example, water, glycerol, ethanol, and isopropanol, alone or in combination. In some embodiments, the granulation liquid comprises an aerosol former, such as glycerin or one of the other agents mentioned herein and/or a binding agent or binder. In some embodiments, water is not added to the precursor composition to aid in granulation.

In another embodiment, the granulation step used is dry granulation. In dry granulation, granules are formed without the use of a granulation liquid. This type of process has the following advantages: it does not expose the precursor composition to moisture and therefore there is no need to expose the particles to heat in order to dry them. Forming granules by dry granulation involves compacting and densifying the precursor composition, typically at high pressure.

Extrusion

Extrusion of the precursor composition involves feeding the precursor composition through an orifice to produce an extruded agglomerate. The process of applying pressure to the precursor composition in combination with the shear force results in a coalesced structure.

Extrusion can be performed using one of the following main types of extruders: screw, screen and basket, roller, ram and pin barrel extruders. Single or twin screw extruders may be used. The formation of the tobacco component releasing member by extrusion has the following advantages: this processing combines mixing, conditioning, homogenizing and molding of the precursor composition.

In some embodiments, during extrusion, the free-flowing precursor composition is exposed to elevated pressure and temperature and forced through an orifice, such as a shaping nozzle or die, to form an extruded agglomerate. In some embodiments, the extruded agglomerates have a rod-like form, and/or they may be cut into segments of a desired length upon exiting the orifice. The rod-shaped extruded agglomerates may then be cut into segments of a desired length.

In some embodiments, the precursor composition comprising tobacco microparticles is exposed to a temperature of from about 40 ℃ to about 150 ℃, or from about 80 ℃ to about 130 ℃, or from about 60 ℃ to about 95 ℃ within the extruder. In some embodiments, including those using twin extrusion, the precursor composition is exposed to a temperature of from about 70 ℃ to about 95 ℃ within the extruder. In some embodiments, including those using single extrusion, the precursor composition is exposed to a temperature of from about 60 ℃ to about 80 ℃ within the extruder. Depending on the design of the die or nozzle used, the composition may be exposed to pressures ranging from about 2bar to about 100bar or from about 5bar to about 60bar (just prior to the die or nozzle).

In some embodiments, the tobacco component delivery element formed from the extruded agglomerates exhibits good heat and mass transfer due to the relatively high density of the extruded agglomerates and the relatively open surface of the tobacco particles therein, which has a positive impact on the delivery of tobacco components such as flavors and nicotine.

In some embodiments, extrusion may be a substantially dry process, wherein the precursor composition is a dry or substantially dry material comprising tobacco particulates and optionally other particulate materials including, for example, alkalis, diluents, solid aerosol formers, solid flavor modifiers, and the like.

In some embodiments, the liquid may be added to the precursor composition during the extrusion process. For example, water may be added to the precursor composition as a processing aid to aid in the dissolution or solubilization, or to aid in the binding or agglomeration of the components of the composition. Alternatively or additionally, a wetting agent may be added to the precursor composition.

In some embodiments, the liquid may be an aerosol former, such as glycerin or others discussed herein. When liquid is added to the precursor composition in this manner, the liquid is not only applied to the surface, but the extruded agglomerates are impregnated with the liquid due to the combination of extruder pressure and intensive mixing caused by high shear forces. Where the liquid is an aerosol former, this can result in high availability of the aerosol former in the agglomerated product, thereby enhancing evaporation of flavour components from the tobacco particles and other components of the agglomerated structure, thereby enhancing release of the tobacco component from the resulting extruded tobacco component release component.

In some embodiments, considering that the extruded agglomerates are impregnated with aerosol-forming agent, a greater volume of this additive can be incorporated into the tobacco component release component than if the aerosol-forming agent was applied only to the surface of the precursor composition or extruded agglomerates. In some embodiments, the amount of aerosol-former incorporated into the tobacco component-releasing component can be at least about 1% by weight, at least about 1.5% by weight, at least about 2% by weight, at least about 3% by weight, at least about 5% by weight, at least about 10% by weight, at least about 15% by weight, or at least about 20% by weight. In some embodiments, the amount of aerosol former incorporated into the tobacco component release member can be up to about 30% by weight, and even up to about 40% by weight. The amount of high aerosol former, such as at least about 10% or at least about 20% by weight, may be advantageous in cases where the tobacco component releasing means is used to generate an aerosol in addition to releasing the tobacco component. In cases where the primary function of the tobacco component releasing component is to release tobacco components or other flavourants carried by the component into an existing aerosol or air stream, smaller amounts of aerosol former, such as up to about 5% by weight, may be sufficient.

The extruded agglomerates will be shaped by a nozzle or die through which they are forced. In some embodiments, the extruded agglomerates are cut into pieces of a desired length. The sheet formed in this manner may be used as a tobacco component releasing member, or it may undergo further processing.

In some embodiments, the nozzle or die is shaped to provide a strand of solid extruded agglomerates. For example, the extruded agglomerates may have the form of solid cylindrical rods. Alternatively, the extruded agglomerates may have different cross-sectional shapes, including oval, polygonal (such as triangular, square, etc.), and star shapes.

In some embodiments, the extruded composition is formed into a desired shape selected to enhance or promote the release of the scent, for example, by providing a form having a large surface area per unit volume. This large surface area may be provided on the outer surface of the extruded agglomerate, for example by selecting a cross-sectional shape with a large circumference. Alternatively or additionally, a large surface area may be provided by forming channels within the extruded agglomerates.

In some embodiments, the nozzle is shaped to provide extruded agglomerates having internal channels. These internal channels provide more surface area and can enhance ingredient release.

Examples of some nozzle designs are shown in fig. 2a, 2b and 2 c. These nozzles 1 have orifices 2 through which the extruded composition is forced to pass to produce extruded agglomerates having a wheel-like spoke structure. As shown in fig. 2d and 2e, these nozzles are used in extruders, in which fig. 2d and 2e the flow direction of the extruded material is indicated by arrow a.

FIG. 3 is a photograph of some extruded rod-shaped agglomerates showing different cross-sectional geometries including internal channels. Some of these extruded agglomerates have been formed using the nozzle designs of fig. 2a, 2b and 2 c.

Fig. 4a shows an example of a die for producing particles by extrusion. The die 3 has a plurality of orifices 4 through which the extrusion composition is forced to produce an extruded agglomerate that exits the die in the form of a number of solid cylindrical rods that are cut at the die to form extruded particles of the desired length. The diameter of the particles is driven primarily by the diameter of the orifice 4. Such a die can be used in an extruder and the flow direction of the extruded material is indicated by arrow a in fig. 4b, which fig. 4b comprises a side view of the die 3.

Fig. 5 is a schematic of some extruded agglomerates in the form of granules.

The tobacco component releasing element formed from such shaped extruded agglomerate sections has an internal channel structure with advantageous adjustable bundle ventilation properties and a significantly enlarged inner surface, which results in improved heat and mass transfer. Thus, by evaporation, these components exhibit a better, more uniform fragrance release. Furthermore, the structure with internal channels shows a significantly improved strength both in radial and axial direction, which facilitates further processing of the extruded agglomerates, for example when cutting them into segments.

By means of various nozzle or die designs and/or different process parameters (including temperature, pressure and shear forces) within the extruder, extruded agglomerates having different physical properties, including different heat transfer properties, aeration resistance, and the ability to generate different aerosols and/or modify the aerosols drawn through the extruded agglomerates can be prepared.

In some embodiments, the extruded agglomerates are shaped as they exit the extruder. In some embodiments, the extruded agglomerates are cut to an initial length, for example 1 meter, and allowed to cool before being later cut into sections of a desired length to provide a tobacco component delivery member of a desired size.

In some embodiments, the extruded agglomerates may be cooled just prior to or just as they exit the extruder. In some embodiments, the cooling is severe and involves exposing the extruded agglomerates (which will be at a high temperature, e.g., from about 30 ℃ to about 100 ℃ or from about 40 ℃ to about 70 ℃) to a cooling device that will reduce the temperature to within a range from about 0 ℃ to about 70 ℃, from about 0 ℃ to about 50 ℃, from about 5 ℃ to about 25 ℃, or from about 5 ℃ to about 15 ℃. This rapid cooling of the extruded agglomerates may enhance the internal and external stability of the extruded agglomerates. In some embodiments, the nozzle or mold is cooled to achieve this effect.

In some embodiments, it may be desirable to control the temperature of the precursor composition during extrusion, including prior to feeding the composition through a nozzle or die. This is particularly the case when the precursor composition comprises a temperature sensitive component, such as an aerosol former (such as glycerol). Thus, in some embodiments, the extrusion of the precursor composition comprises: the temperature of the precursor composition is reduced before the precursor composition reaches the nozzle or the mold. Such cooling of the precursor composition may result in the formation of extruded agglomerates having beneficial properties or may improve the beam forming process, for example, where channels are to be formed within the extruded agglomerate beam.

In some embodiments, a spheronization process is used to further process the extruded segments. The segments are generally cylindrical and are cut or broken to uniform lengths after extrusion. Which is then gradually transformed into a spherical shape by a spheronization method. This shaping, which occurs as a result of plastic deformation and rounding, can lead to spherical conglomerate structures, which usually have a more or less uniform diameter.

Incorporated into the apparatus

One or more tobacco component releasing components may be incorporated into the aerosol provision device, such as a device for heating the smokable material to volatilise at least one component of the smokable material.

As used herein, aerosol provision means include vapour means such as an e-cigarette, means for heating smokable material (such as tobacco heating means) and mixing means.

As used herein, an apparatus for heating smokable material to volatilise at least one component of the smokable material comprises a so-called "heat non-combustible" product or tobacco heating device or product which releases the compound by heating rather than burning the smokable material. It also includes other nicotine delivery products such as aerosol-generating devices including electronic cigarettes, and hybrid products in which a liquid, such as a nicotine-containing liquid or a nicotine-free liquid, is heated to form an aerosol, and this aerosol is then drawn through a smokable material (such as a tobacco segment) to pick up tobacco flavour, or in which a separate aerosol is formed by heating the smokable material. The apparatus may be provided with a filter for the aerosol drawn by the user.

The tobacco component releasing component may be positioned within the apparatus or device such that the released tobacco component is entrained in an aerosol generated by the apparatus or device in use, thereby modifying the properties of the aerosol (e.g. by applying a tobacco component comprising a tobacco flavour to the aerosol). Additionally or alternatively, the tobacco component release component may itself generate an aerosol during use, the aerosol comprising the released tobacco component.

In some embodiments, an apparatus or device may be provided with a filter having a tobacco component releasing component located within the filter. This may be in addition to or in place of an apparatus or device that includes other tobacco component releasing components.

In some embodiments, the filter or filter element may comprise a filter material having a filtering effect. Suitable filter materials may include, for example, tow comprising or consisting of cellulose acetate, polylactic acid, and/or other suitable polymers, or a filter or filter element may include a stiff material such as plastic with holes.

In some embodiments in which a plurality of tobacco component releasing members are incorporated into the filter, this may be in a "Dalmatian" type filter section in which the tobacco component releasing members are interspersed within the fibrous filter plug material. Alternatively, the tobacco component releasing member may be located in a cavity within the filter. The cavity may be, for example, a cavity section positioned between two (or more) adjacent filter plugs, or the cavity may be a fluted cavity defined within a filter plug. In such embodiments, the tobacco component releasing member may be of small size, for example in particulate form.

In other embodiments, a larger single tobacco component release member is incorporated into the filter. For example, a single tobacco component releasing member may be embedded in the fibrous filter plug material.

Alternatively, the tobacco component releasing member may be incorporated into a multi-segment filter, the tobacco component releasing member itself constituting one filter segment. In such embodiments, the tobacco component releasing member may be of any shape or size, but it may be advantageous for the member to have a cylindrical shape and a size similar or compatible with the size of the filter segment. In some embodiments, the tobacco component releasing member may be surrounded by a filter material, such as a layer of fibrous filter tow, to form a filter segment. In other embodiments, the tobacco component releasing member may be sized as a filter plug and it may be incorporated into a filter having one or more adjacent filter plugs. Alternatively, the tobacco component releasing component may be included in a cavity section positioned between two (or more) adjacent filter plugs.

In some embodiments, the tobacco component release member may itself be a filter element in the aerosol provision device that is capable of filtering condensate and other particulate matter in the aerosol before the aerosol is inhaled by the user.

According to some embodiments, one or more tobacco component releasing components are included in an aerosol provision device or apparatus for heating smokable material to volatilise at least one component of the smokable material, in which the tobacco segment is heated but not combusted (i.e. a tobacco heating product or a so-called heated non-combustible product). In some of these products, the tobacco segment is heated to generate an aerosol.

One option is to include one or more tobacco component releasing components in the filter of such products. In some embodiments, a plurality of tobacco component releasing members are incorporated into a filter of a tobacco heating product. In other embodiments, a single tobacco component releasing member is incorporated into the filter of the tobacco heating product.

Another option is to include one or more tobacco component releasing components in the tobacco segment of such products. In some embodiments, one or more tobacco component releasing components may be incorporated into a tobacco material to form a tobacco segment. For example, one or more tobacco component releasing members may be dispersed within a tobacco material, such as cut tobacco or reconstituted tobacco, to contribute to the flavor imparted by the tobacco. In other embodiments, the tobacco included in the tobacco segment of the tobacco heating product is comprised of or consists essentially of one or more tobacco component releasing components. In one embodiment, the tobacco segment heated by the tobacco heating product is comprised of or consists essentially of one or more tobacco component releasing members. The tobacco component releasing member may be heated directly. Where the tobacco segment is a multiple tobacco component releasing member, these tobacco component releasing members may be held in a container or cartridge. At least a portion of the container or cartridge may be air permeable to allow air to flow over or through the tobacco component releasing member.

Figure 6 shows a cross-sectional view of an example of a tobacco heating product for heating smokable material. The apparatus 11 has a heating chamber 14, the heating chamber 14 containing, in use, smokable material to be heated and volatilised. In this embodiment, the smokable material is in the form of a unitary tobacco component releasing member 13. The smokable material may however be a plurality of tobacco component releasing members held in a heating chamber or provided in a cartridge similar to that shown in figure 8.

The apparatus 11 of fig. 6 also has an electronics/power chamber 16, which may for example contain electrical control circuitry and/or a power source (not shown). The electrical control circuit may comprise a controller, such as a microprocessor device, configured and arranged to control heating of the smokable material via a heating element (not shown). The electrical control circuit may in use receive a signal from, for example, a smoke actuation sensor which is sensitive to changes in pressure or changes in the rate of air flow, for example, which occur when a user starts to puff the device 11. The electrical control circuit can then operate to cause heating of the smokable material "on demand". Various devices for smoke actuation sensors are available, including, for example, sensors based on thermistors, electromechanical devices, mechanical devices, optical devices, opto-electro-mechanical devices, and micro-electro-mechanical systems (MEMS). Alternatively, the device may have a manually operable switch for the user to initiate smoking.

A heating chamber 14 is contained within the housing 12. There may be supports and/or insulation means (not shown) positioned between the heating chamber 14 and the housing 12, for example to assist in thermally insulating the housing 12 from the heating chamber 14 so that the housing 12 does not heat up or at least does not become too hot to touch during use.

The housing 12 includes an inlet 15 through which air is drawn into the device. The housing 12 also includes an outlet 17 at a mouthpiece 18 of the device 11. Air is drawn into the device 11 through the inlet 15, travels through the device, picks up tobacco components released by the tobacco component release component 13, and the resulting aerosol generated by the device 11 exits the device 11 through the outlet 19 and is inhaled by the user.

According to some embodiments, one or more tobacco component releasing components are included in a so-called blended product for heating the smokable material to volatilise at least one component of the smokable material. In some of these products, in addition to the heating of a liquid (such as a nicotine-containing liquid or a nicotine-free liquid, which is heated by a heat source to form an aerosol or vapor), the tobacco segment is heated to generate an aerosol. In some blended products, an aerosol or vapor formed from a liquid is drawn through the tobacco segment or through the tobacco segment, thereby picking up the tobacco flavor. In other embodiments, the aerosol or vapor formed from the liquid is not drawn through the tobacco segment or is not drawn through the tobacco segment.

In a hybrid product comprising a filter, one option is to include a tobacco component releasing member in the filter of such a product in a manner similar to that described for the tobacco heating product. In some embodiments, a plurality of tobacco component releasing members are incorporated into a filter of the blended product. In other embodiments, a single tobacco component releasing member is incorporated into the filter of the blended product.

In case the smoking article is a so-called hybrid product, another option is to include the tobacco component releasing means in the tobacco section of such a product. In some embodiments, one or more tobacco component releasing components may be incorporated into a tobacco material to form a tobacco segment. For example, one or more tobacco component releasing members may be dispersed within a tobacco material, such as cut tobacco or reconstituted tobacco, to contribute to the flavor imparted by the tobacco. In other embodiments, the tobacco included in the tobacco segment of the blended product is comprised of one or more tobacco component releasing members. In one embodiment, the tobacco segment in the blended product is comprised of or consists essentially of one or more tobacco component releasing members.

Figure 7 shows a cross-sectional view of an example of a mixed product for heating smokable material and liquid. The apparatus 21 has a housing 22 containing a chamber 24, the chamber 24 containing, in use, smokable material to be heated and volatilised. In this embodiment, the smokable material is in the form of a unitary tobacco component releasing member 23. The smokable material may however be a plurality of tobacco component releasing members held in a chamber or provided in a cartridge similar to the cartridge shown in figure 8. The housing 22 further contains a liquid reservoir 25, the liquid reservoir 25 containing a liquid 26 to be heated to form a vapor.

The apparatus 21 also has an electronics/power chamber 27 which may, for example, contain electrical control circuitry and/or a power source (not shown). The electrical control circuit may include a controller, such as a microprocessor device, configured and arranged to control heating of the smokable material and liquid 26 via one or more heating elements (not shown). The electronic control circuitry may allow the device 21 to be smoke activated so as to cause "on demand" heating of the smokable material. Alternatively, the device 22 may have a manually operable switch for the user to initiate smoking.

The housing 22 also includes an inlet 28 through which air is drawn into the device. The housing 22 also includes an outlet 29 at a mouthpiece 30 of the device 21. Air is drawn into the device 21 through the inlet 28, travels through the device, picks up vapour formed by heating the liquid 26 in the liquid reservoir 25 and tobacco components released by the tobacco component release component 23, and the resulting aerosol generated by the device 21 exits the device 21 through the outlet 29 and is inhaled by the user.

The mixing device 21 schematically shown in fig. 7 represents exactly one possible configuration of such an apparatus. The relative positions of the liquid reservoir 25 and the smokable material chamber 24 can be varied, as can the path of air through the apparatus.

In one embodiment, the liquid reservoir is positioned upstream of the smokable material to be volatilised. Alternatively, the liquid reservoir may be located downstream of the smokable material to be volatilised. In still other arrangements, the two aerosol sources in the apparatus may be arranged side-by-side, etc.

In some embodiments, the vapour generated by heating the liquid in the liquid reservoir flows over or through the smokable material comprising or consisting of one or more tobacco component releasing components. In some embodiments, the high temperature of the vapor causes the tobacco component to be released. Alternatively or in addition, the smokable material may be heated separately by heating means.

In some embodiments, a mixing device is provided in which the smokable material is heated by a vapour formed from heating a liquid so as to volatilise at least one component of the smokable material. In some embodiments, the liquid is a nicotine-free liquid. In other embodiments, the liquid comprises nicotine. Where the smokable material is heated by vapour to volatilise at least one component of the smokable material, in certain embodiments the apparatus does not comprise a separate means for heating the smokable material. The smokable material may comprise or consist of at least one tobacco component releasing member.

In other embodiments, the vapour generated by heating the liquid in the liquid reservoir does not flow over or through the smokable material comprising or consisting of one or more tobacco component releasing components. Rather, the vapour and aerosol generated by heating the smokable material are mixed only after both vapour and aerosol are formed.

The tobacco heating and mixing products described herein may in some embodiments comprise tobacco segments in the form of containers or cartridges containing one or more tobacco component releasing members. These containers or cartridges may be removable. They may replace both the chamber holding the smokable material and the smokable material in the apparatus described above with reference to figures 6 and 7 and in the alternative embodiments discussed.

Referring to fig. 8, a tobacco segment cartridge 31 is shown which includes a housing 32, the housing 32 defining a cavity within which one or more tobacco component releasing members (not shown) according to the present invention are retained. The housing 32 may be made, for example, of molded plastic or the like. To allow air drawn through the device to enter the cartridge 31 and pass over or through the one or more tobacco component releasing members and then exit the cartridge 31, ventilation holes 33 are provided in the housing 32 of the cartridge 31. In some embodiments, the cartridge 31 may further comprise heating means which may be heated by suitable means to heat the one or more tobacco component releasing members retained therein.

Mixed product

An apparatus is provided for heating smokable material to volatilise at least one component of the smokable material and heating a nicotine-free liquid to be heated to form a vapour, wherein the smokable material comprises tobacco particles having an alkaline pH, and wherein the smokable material is heated by the vapour. This is a so-called synthesizer.

In some embodiments, the apparatus comprises means for heating the liquid to form a vapour, but does not comprise separate means for heating the smokeable material. Thus, the heat of vaporisation of at least one component of the smokable material is from a vapour formed by heating a nicotine-free liquid (commonly referred to as e-liquid in such devices).

The pH of the tobacco particles is adjusted. This can be achieved by adding a pH adjuster to the tobacco particles or to a composition comprising the tobacco particles. The pH can be increased, for example, by the addition of one or more bases or alkaline buffer systems. Any base and buffer system mentioned herein may be suitable. Further, the pH may be adjusted to any of the pH values or ranges mentioned herein.

In some embodiments, the tobacco particles have an average diameter of no greater than 3mm, no greater than 1mm, no greater than 0.5 mm, or no greater than 0.3 mm, as measured by sieving. Again, the particle size may be as described above.

The smokable material comprising the tobacco particles may comprise other materials.

In some embodiments, the smokable material does not include a binding agent or binding additive. In other embodiments, the smokable material comprises a binder or binding additive. Suitable bonding additives include, for example: thermally reversible gelling agents, such as gelatin; starch; a polysaccharide; pectin; an alginate; wood pulp; cellulose; and cellulose derivatives such as carboxymethyl cellulose.

In some embodiments, the smokable material further comprises a diluent. The diluent may be in solid or liquid form. In some embodiments, the diluent is inert or substantially inert.

In some embodiments, the smokable material further comprises at least one aerosol former, which may for example be a polyol aerosol generator or a non-polyol aerosol generator, preferably a non-polyol aerosol generator. It may be solid or liquid at room temperature, but preferably is liquid at room temperature. Suitable polyols include sorbitol, glycerol and glycerol alcohols like propylene glycol or triethylene glycol. Suitable non-polyols include monohydric alcohols, high boiling hydrocarbons, acids and esters such as lactic acid, such as diacetin, triacetin, triethyl citrate or isopropyl myristate. Combinations of aerosol-formers may be used in the same or different proportions. In some embodiments, glycerin and propylene glycol are particularly preferred.

In some embodiments, the smokable material may comprise flavour modulating agents to modulate the flavour provided by the tobacco particles or to add flavour. Suitable flavour modulators are discussed in detail above.

In some embodiments, the smokable material further comprises a preservative, as discussed above. In other embodiments, the smokable material is free of any preservatives.

In some embodiments, as discussed in detail above, the smokable material comprises tobacco particles in the form of one or more agglomerated structures. Alternatively, such a coalesced structure may be formed by extrusion.

To address various problems and advance the art, the entire disclosure shows by way of illustration various embodiments in which one or more of the claimed inventions may be practiced and which provide superior tobacco component delivery components and smoking articles. The advantages and features of the present disclosure are merely representative examples of embodiments and are not exhaustive and/or exclusive. They are presented merely to aid in understanding and teaching the claimed features. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the present disclosure are not to be considered limitations on the present disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilized and modifications may be made without departing from the scope and/or spirit of the present disclosure. Various embodiments may suitably comprise, consist of, or consist essentially of various combinations of the disclosed elements, components, features, parts, steps, means, and the like. Furthermore, this disclosure includes other inventions not presently claimed, but which may be claimed in the future.

Claims

1. A tobacco component release member for inclusion in an aerosol provision device, the tobacco component release member having a coalescing structure formed from a precursor composition comprising tobacco particles, wherein the pH of the precursor composition has been adjusted to an alkaline pH.

2. The component of claim 1, wherein the pH is increased by the addition of one or more bases or an alkaline buffer system.

3. A tobacco component release member for inclusion in an aerosol provision device, the tobacco component release member comprising tobacco particles and one or more bases or an alkaline buffer system, the tobacco component release member having an alkaline pH.

4. The component of claim 3, wherein the one or more bases are selected from the group consisting of hydroxides, carbonates, and bicarbonates.

5. The component of any one of claims 2 to 4, wherein the one or more bases are selected from the group consisting of: potassium hydroxide, sodium carbonate and sodium bicarbonate.

6. The component of any one of the preceding claims, wherein the precursor composition has a pH of at least about 7.5.

7. The component of any one of the preceding claims, wherein the tobacco particles have an average diameter of no greater than 3mm, no greater than 1mm, no greater than 0.5 mm, or no greater than 0.3 mm.

8. The component of any one of the preceding claims, further comprising: one or more aerosol forming agents.

9. The component of claim 8, wherein the aerosol former is selected from the group consisting of glycerin, propylene glycol, and glycerol triacetate.

10. The component of any one of the preceding claims, further comprising: one or more binding agents.

11. The component of claim 10, wherein the one or more binding agents are selected from the group consisting of: thermally reversible gelling agents, such as gelatin; starch; a polysaccharide; pectin, cellulose; cellulose derivatives such as carboxymethyl cellulose; and alginates.

12. The component of any one of the preceding claims, further comprising: one or more flavour modulators.

13. The component of any one of the preceding claims, wherein the precursor composition is pelletized or spheronized to form the conglomerate structure.

14. The component of any one of the preceding claims, wherein the precursor composition is extruded to form the coalesced structure.

15. The component of any one of the preceding claims in particulate form.

16. A component according to any of the preceding claims, having an elongated or rod-shaped form.

17. A component according to any preceding claim, wherein the component has a cross-sectional shape for increasing the surface area of the tobacco component releasing component.

18. An aerosol provision device comprising a tobacco component release member according to any preceding claim.

19. The device of claim 18, wherein the device is a tobacco heating product comprising a tobacco segment to be heated to volatilise components and optionally a filter or filter element.

20. The device of claim 18, wherein the device is a blended product comprising a tobacco section to be heated to volatilize components and a liquid to be heated to form a vapor and optionally a filter or filter element.

21. A device according to any one of claims 18 to 20, wherein the tobacco component release means is located in a filter or filter element of the device.

22. The apparatus of claim 21, wherein one or more tobacco component releasing members are surrounded by filter material in the filter or filter element.

23. The apparatus of claim 21, wherein the one or more tobacco component releasing members are located in the cavity of the multi-segment filter.

24. Apparatus according to claim 19 or claim 20, wherein one or more tobacco component releasing members are located in the tobacco section.

25. The apparatus of claim 24, wherein the tobacco segment is comprised of one or more tobacco component releasing members.

26. The device of claim 18, wherein the device is a blended product comprising a tobacco segment to be heated to volatilize constituents and a liquid to be heated to form a vapor, wherein one or more tobacco constituent releasing components are located in the tobacco segment, and wherein the tobacco segment is heated by the vapor.

27. The device of claim 26, wherein the liquid is a nicotine-free liquid.

28. Apparatus according to claim 26 or claim 27, wherein the apparatus includes means for heating the liquid to form a vapour, but does not include separate means for heating the tobacco section.

29. A method of making a tobacco component releasing member comprising: preparing a precursor composition comprising tobacco microparticles; adjusting the pH of the precursor composition to a basic pH; and treating the precursor composition to form a coalesced structure.

30. The method of claim 29, wherein the precursor composition is pelletized or rounded to form the coalesced structure.

31. The method of claim 29, wherein the precursor composition is extruded to form the coalesced structure.

32. The method of claim 31, wherein the extruded agglomerates are cooled during or after extrusion.

33. The method of claim 31 or 32, wherein the extruding forms internal channels within the extruded agglomerates.

34. An apparatus for heating smokable material to volatilise at least one component of the smokable material and heating a nicotine-free liquid to be heated to form a vapour, wherein the smokable material comprises tobacco particles having an alkaline pH, and wherein the smokable material is heated by the vapour.

35. Apparatus according to claim 34, comprising means for heating the liquid to form a vapour but not comprising separate means for heating the smokable material.

36. The apparatus of claim 34 or claim 35, wherein the pH is increased by the addition of one or more bases or an alkaline buffer system.

37. The apparatus of any one of claims 34 to 36, wherein the pH of the tobacco particles is at least about 7.5.

38. The apparatus of any one of claims 34 to 37, wherein the tobacco particles have an average diameter of no greater than 3mm, no greater than 1mm, no greater than 0.5 mm, or no greater than 0.3 mm.