WO2016184978A1

WO2016184978A1 - Aerosol generating material and devices including the same

Info

Publication number: WO2016184978A1
Application number: PCT/EP2016/061314
Authority: WO
Inventors: Walid Abi Aoun; Bryan ALLBUTT; Edward Dennis John
Original assignee: British American Tobacco (Investments) Limited
Priority date: 2015-05-20
Filing date: 2016-05-19
Publication date: 2016-11-24
Also published as: GB201508670D0

Abstract

There is provided a component (1) for aerosol generation by electrical heating, the component (1) comprising a solid aerosol generating material (3) and a plurality of resistive wires (2), each of which is at least partially embedded in the solid aerosol generating material (3).

Description

Aerosol Generating Material and Devices Including the Sam e

Field

The present invention relates to aerosol generating material which emits an aerosol and/ or gas on heating.

Backgro und

Tobacco material is heated in smoki ng articles for the purpose of releasing substances contained in the material and deliveri ng these as an aerosol .

I n many smoking articles, combustion of tobacco material releases thermal energy which in turn releases a smoke aerosol from the tobacco material . Combustion causes various physico-chemical degradation processes, which may be a combination of oxidative degradation, pyrolysis, pyrosynthesis, and distillation. The thermal energy generated by combustion tends to be high, however, and the amount of heat released is often difficult to control .

I n other smoking articles, the heat providing the thermal energy needed to release an aerosol is provided by electrical heati ng.

H eat not burn devices (also known as tobacco heating devices or tobacco heating products) are non-combustion type smoki ng articles, developed as an alternative to conventional , combustible cigarettes. These devices volatilise components of tobacco by heating the tobacco material , suitably by electrical heating (although other means of heating could be used) ; pyrolysis or combustion of the tobacco or volati les is avoided. The volati lised components condense to form an inhal able aerosol .

Sum m ary

According to a first aspect of the present invention, there is provided a component for aerosol generation by electrical heati ng, the component comprisi ng a solid aerosol generati ng material and a plurality of resistive wires, each of which is at least partially embedded i n the solid aerosol generati ng material . According to a second aspect of theinvention, there is provided a device for generating an inhal able aerosol and/ or gas, the device comprisi ng a component for aerosol generation by electrical heating, thecomponent comprising a solid aerosol generating material and a plurality of resistive wires, each of which is at least partially embedded in the solid aerosol generating material. In other words, accordingto the second aspect of theinvention there is provided a device for generating an inhal able aerosol and/ or gas, the device comprising a component for aerosol generation accordingto the first aspect.

In use, the aerosol generating material is heated by direct contact with the resistive wires. In some cases, one or more of the wires may be heated to generate at least one delivery of an inhal able aerosol and/ or gas. Each wire can be heated individually to heat a certain portion of the aerosol generating material. In other cases, one or more of the wires may be heated to generate multiple deliveries of an inhal able aerosol and/ or gas.

In some embodiments, the wires are separate resistive wires. By "separate", it ismeant that the wires geneally do not interconnect within thecomponent for aerosol generation, and in particular, do not form amesh. In some embodiments, some incidental contact between separate wires is not excluded.

In some embodiments, the aerosol generating material may be repeatedly heated by the wires to generate multiple deliveries of inhal able aerosol and/ or gas.

In some embodiments, the aerosol generating material comprises an aerosol generating agent.

In some embodiments, the aerosol generating material comprises nicotine.

In some embodiments, the aerosol generating material comprises tobacco material, suitably tobacco extract.

In some embodiments, the aerosol generating material comprises a filler material. In some embodiments, the aerosol generating material comprises a binder. In some embodiments, the wires are at least partially embedded or arefully embedded in the solid aerosol generating material. In some embodiments, the wires are at least partly coated by or are coated by thesolid aerosol generating material. In some embodiments, the majority of or substantially all of the wires are embedded in or coated by thesolid aerosol generating material. In some embodiments, all of thewires are embedded in or coated by thesolid aerosol generating material except for a portion of wire necessary to allow electrical contact with a power source.

In some embodiments, a first portion of the aerosol generating material may be heated independently from a second portion of the aerosol generating material.

In some embodiments, the device is configured such that it ispossibleto heat thewires independently of each other. That is, current may be selectively passed through one or morewiressuch that only those wires heat up, thereby allowing controlled heating of one or moreportionsof the aerosol generating material. In other words, in some embodiments it ispossibleto individually address particular wires so that, of the plurality of resistive wires, only theaddressed wires heat up.

In some embodiments, the device is configured such that different potential differences can be applied across individual wires (or selected groups of wires) within the plurality of wires; thus, the temperature response of the individual wires (or the selected group of wires) can be selectively controlled and can differ from other wires. In some embodiments, this meansthat the temperature response of individual wires (or the selected group of wires) within the plurality of wires can be controlled such that they heat up at different rates and/ or to different temperatures.

In some embodiments, the heating response of one or morewireson application of a current may differ from one or more of the other wires, thereby allowing controlled heating of the aerosol generating material. The heating response of the wires is affected by thewirecross section, thewirelength and the wire material composition. In other words, thewires may differ from one another in the material used and/ or in their length and/ or in the wire cross section.

In various embodiments, the wire cross section may be circular, oval, rectangular or square and may differ between different wires within the pi ural ity of wires. In some cases, thewires may all have a substantially similar cross section shape, but the size of the cross section may differ between different wires within the plurality of wires. In some cases, the wires all have a substantially circular cross section, but thewire diameter may differ between different wires within the plurality of wires.

Thewires may comprise any suitable electrically conducting medium, i.e. so that a current can be applied across the wires. In some embodiments, thewires may comprise a conducting ceramic material. In some embodiments, the wires comprise a metal or metal alloy; these are excellent conductors of electricity and thermal energy. Suitable metals include but are not limited to: copper, aluminium, platinum, tungsten, gold, silver, and titanium. Suitable metal alloys include but are not limited to: nichrome and stain I ess st eel. In some embodiments, different wires within the plurality of wires have different material compositions. In some such embodiments, different wires comprise different metals or metal alloys. In some embodiments, the wires comprise, substantially consist of or consist of nichrome.

Thewires may be substantially linear. The wires may be substantially parallel to each other. The wires may be substantially parallel to an axis of the component for aerosol generation by electrical heating.

Thecomponent for aerosol generation by electrical heating may be in the form of a sheet. The sheet may be flat or substantially flat when incorporated into the devices of the present invention. In other embodiments, the sheet may be rolled so that it forms a wound/ rolled configuration. In thewound configuration, theend profile may resemble a spiral shape and the overall shape is approximately cylindrical. In thewound configuration, the plurality of wires may be disposed substantially parallel to the axis around which the sheet is roiled. In some embodiments, the sheet may be formed as a substantially planar sheet, which may then be rolled into thewound configuration.

In some alternative embodiments, the plurality of wires may at least partially surround the aerosol generating material and beat least partially embedded in the surface of the aerosol generating material. Thewires may be spaced at regular intervals around the aerosol generating material surface. In such embodiments, aerosol generating material may be in a monolithicform. The monolithicform may have been formed by an extrusion process. For example, the aerosol generating material may be extruded into a rod, cylinder or tube. The rod or tube may have any suitable cross section (such as circular, elliptical, square and rectangular). The wires may be embedded in a surface of the rod, cylinder or tube and extend parallel to the axis of the rod, cylinder or tube.

In some embodiments, different portions of the aerosol generating material may have different chemical compositions. In such embodiments, the wires may be configured such that it ispossibleto heat the different portions independently during use.

In some embodiments, actuating means are provided which allow theuser of the device to initiateor control heating of the aerosol generating material by the at least partly embedded wires.

In some embodiments, the device is a heat not burn or tobacco heating device, or tobacco heating product. A device of thistype is a non-combustion type smoking article, developed as an alternative to conventional, combustibleci gar ettes. These devices vol ati I ise components of tobacco by heating the tobacco material; pyrolysisor combustion of thetobacco or volatiles is avoided. The volatilised components condense to form an inhal able aerosol. The aerosol often comprises water, a humect ant, nicotine and optionally other tobacco components such as flavours and aromas. Thus, in some embodiments, the device is one in which tobacco is heated to volatilise components without pyrolysisor combustion of thetobacco.

According to a third aspect of thepresent invention, there is provided a method for fabricating a component for aerosol generation of thefirst aspect (which may be incorporated into a device for generating an inhal able aerosol and/ or gas according to the second aspect), wherein the method comprises applying a slurry of aerosol generating material to a plurality of resistive wires.

In some embodiments, theslurry isapplied by casting the slurry onto the piuraiity of wires. In some embodiments, theslurry isapplied by spraying the slurry onto the plurality of wires. In some embodiments, theslurry isapplied by dipping the plurality of wiresinto theslurry. In some embodiments, theslurry is extruded with or onto the plurality of wires.

In some embodiments, the component for aerosol generation by electrical heating, fabricated according to the second aspect of thepresent invention, isin the form of a sheet. In some embodiments, the method also includes a step of rolling the sheet into a wound configuration.

According to a fourth aspect of the present invention, there is provided the use of a device according to the second aspect for the generation of an aerosol and/ or gas comprising nicotine.

According to a fifth aspect of the present invention, there is provided the use of a component for aerosol generation by electrical heating, the component comprisinga solid aerosol generating material and a plurality of resistive wires, each of which is at least partially embedded in the solid aerosol generating material.

To the extent that they are compatible, optional or preferable features of each aspect of the invention may be combined with other aspects of the invention defined herein. Specifically, features of thecomponent described herein may be applicableto the first and second aspects of theinvention, irrespective of whether they aredescribed in relation tothedeviceor thecomponent per se.

In some embodiments, different portionsof thecomponent may be heated

independently by separate power sources or by switching the supply of power from one portion to another.

Brief Description of Dra ings

Embodimentsof theinvention will now be described, by way of example only, with reference to accompanying drawings, in which:

Figure 1 shows a schematic perspective view of a first embodiment of the invention. Figure 2 shows a schematic perspective view of a second embodiment of theinvention. Figure 3 shows a schematic perspective view of a test rig apparatus used to evaluate aerosol generation.

Figure 4 is a graph of surface temperature against timefor a sample component made accordingto Example 2. The data were collected asset out in Example 4.

Figure 5 is a graph of surface temperature against timefor a sample component made accordingto Example 3. The data were collected asset out in Example4.

Figure 6 shows a schematic perspective view of athird embodiment of theinvention. Detailed Description

The present invention relates to devices for forming an inhal able aerosol and/ or gas, thedevices comprising aerosol generating material that may be heated to emit an inhal able aerosol.

More specifically, thepresent invention provides a device for generating an inhal able aerosol and/ or gas, the device comprising a component for aerosol generation by electrical heating, thecomponent comprising a solid aerosol generating material and a plurality of resistive wires, each of which is at least partially embedded in the solid aerosol generating material.

The resistive wires conduct an applied current in use. Electrical resistance in the wires transduces electrical energy into thermal energy which heats the aerosol generating material.

Thus, thepresent invention provides a device for generating an inhal able aerosol and/ or gas, the device comprising an integrated electrically resistive heating element, wherein the heating element comprises a plurality of wires. In other words, the aerosol generating material and plurality of wires form asingleunit or unitary structure. This means that the aerosol generating material and the wires are provided as a single piece or item. Thus, in components of the present invention, at least two resistive wires are at least partially embedded in the same body of aerosol generating material. The aerosol generating material in the unitary structure may, for example, be extruded, cast or molded. The structure or coating may be formed from a slurry which isdried to provide the aerosol generating material in a solid form. In some embodiments, the slurry isdried in contact with theresi stive wires so that the aerosol generating material isin a solid form and adheres to the wires.

In some embodiments, thewiresareat least partially coated by the aerosol generating material. In some embodiments, the wires at least partially surround the aerosol generating material.

In some embodiments, the heating of the aerosol generating material does not result in any significant combustion of the material. In some embodiments, the heating results in no combustion or essentially no combustion of the aerosol generating material. In some embodi ments, the device is a heat not burn or tobacco heating device, or a tobacco heating product.

Usi ng electricity to heat aerosol generati ng material i n a smoki ng article has many advantages. I n particular, it has many advantages over using combustion.

Combustion is a complex process that generates aerosols by a combination of interactive physico-chemical processes which may i nclude oxidative degradation, pyrolysis, pyrosyn thesis, and distillation. I t generally leads to the generation of complex aerosols. For example, smoke arising from a combustible smoki ng article comprisi ng tobacco is a complex, dynamic mixture of more than 5000 identified constituents.

The exothermic processes of combustion may be self-sustai ning, and may result in heat generation rates, and heat output quantities, sufficient for degradation of the combustible matrix. I n some cases, the matrix may be completely degraded to an ash residue which may comprise inorganic, non-combustible materials. Very high temperatures can be reached in burni ng cigarettes due to the exothermic reaction of combustion. I n between taking puffs of a cigarette (the inter-puff smouldering period), the centre of the burni ng zone in the tobacco rod of the cigarette can reach

temperatures as high as 800°C. During taki ng a puff of a cigarette, the periphery of the burning zone in the tobacco rod of the cigarette can reach temperatures as high as 910°C.

Usi ng electrical resistance heati ng systems (such as the resistive wires of the present invention) is advantageous because the rate of heat generation is easier to control , and lower levels of heat are easier to generate, compared with using combustion for heat generation.

The use of electrical heati ng systems therefore allows greater control over the generation of an aerosol and/ or gas from aerosol generating materials. Furthermore, it allows for aerosol and/ or gas to be generated without combustion taki ng place, rather than through combustive degradation. Electrical heati ng systems can also fad litate the generation of an aerosol and/ or gas from inherently non-combustible materials, such as inorganic sorbents with i ngredients that generate an aerosol and/ or gas when heated. In the devices of the invention, the resistive wires provide a medium for conducting electricity and generating heat. When an electric current passes through thewires, the temperature of the wires increases, and the aerosol generating material in contact with those wiresisheated.

The effect delivered by the aerosol generating material when heated by the wires will depend on thechemical composition of the aerosol generating material, as well as the temperature to which it is heated.

The aerosol generating material included in the devices of the invention may have any suitable chemical composition.

In some embodiments, the devices of the invention areableto provide multiple deliveries or doses of aerosol and/ or gas. This meansthat the aerosol generating material may be heated to produce sufficient aerosol and/ or gas to allow multiplepuffs. This may be achieved by heating the aerosol generating material for a period of time sufficient to produce a volume of aerosol and/ or gas suitable for multipledeliveries. In some embodiments, thismay involve heating the aerosol generating material constantly. Alternatively, this may involve successive, shorter periods of heating the aerosol generating material, optionally with each period producing a single delivery or dose of aerosol and/ or gas. In the latter embodiments, the same aerosol generating material may be repeatedly heated by the same resistive wires to produce multiple deliveries or doses of aerosol and/ or gas. Alternatively, selected resistive wires can be heated sequentially so that heating each wire provides sufficient aerosol for a single puff.

In some embodiments, thedevices of theinvention may, in addition to thecomponent for aerosol generation, comprise further aerosol generating materials.

In some embodiments, the aerosol generating material may comprise an aerosol generating agent. In thiscontext, an "aerosol generating agent" isan agent that promotes the generation of an aerosol. An aerosol generating agent may promotethe generation of an aerosol by promoting an initial vapourisation and/ or the condensation of a gas to an inhal able solid and/ or liquid aerosol. In some embodiments, an aerosol generating agent may improvethedelivery of flavour from the aerosol generating material. Any suitable aerosol generating agent or agents may be included in the aerosol generating material of the invention. Suitable aerosol generating agents include, but are not limited to: apolyol such as sorbitol, glycerol, and glycols like propylene glycol or triethylene glycol; a non-polyol such as monohydric alcohols, high boiling point hydrocarbons, acids such as lactic acid, glycerol derivatives, esters such asdiacetin, triacetin, triethylene glycol diacetate, triethyl citrate or myri states including ethyl myri state and isopropyl myristateand aliphaticcarboxylicacid esters such as methyl st ear ate, dimethyl dodecanedioateand dimethyl tetradecanedioate.

In some embodiments, the aerosol generating material may comprise between about 5- 50%, about 8-20% or about 10- 15% aerosol generating agent by weight. In some of these embodiments, the aerosol generating agent may be glycerol.

In some embodiments, the aerosol generating material may comprise one or more compounds for the purpose of lowering the boiling point of one or more other substances in the aerosol generating material. In some of these embodiments, the aerosol generating material may comprise one or more compounds for the purpose of forming an azeotrope with one or more other substances in the aerosol generating material.

In some embodiments, the aerosol generating material may comprise one or more flavou rants. As used herein, the terms "flavour" and "flavourant" refer to materials which, where local regulations permit, may be used to create a desired taste or aroma in a product for adult consumers.

The terms "flavour" and "flavourant" may include extracts (e.g., licorice, hydrangea, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, menthol, Japanese mint, aniseed, cinnamon, herb, wintergreen, cherry, berry, peach, apple, Drambuie, bourbon, scotch, whiskey, spearmint, peppermint, lavender, cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, honey essence, rose oil, vanilla, lemon oil, orange oil, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, piment, ginger, anise, coriander, coffee, or amint oil from any species of thegenus Mentha), flavour enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and/ or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredientsor blends thereof. They may be in any suitable form, for example, oil, liquid, or powder.

In some embodiments, the aerosol generating material may comprise one or more colourants. The aerosol generating material may be coloured, as required. In some embodiments, the aerosol generating material may be coloured such that it resembles components of a conventional, combustible cigarette. In some embodi ments a caramel colourant may be included in the aerosol generating material.

In some embodiments, the aerosol generating material may comprise nicotine. In some embodiments, the aerosol generating material may comprise more than about 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1% nicotine by weight. In some embodiments, the material may comprise less than about 25%, 20%, 15%, 10%, 5%, 2%, 1.5%, or 1% nicotine by weight. In some embodiments, the material may comprise about 0.1-25%, 0.3- 10% or 0.5-1.5% nicotine by weight. In some

embodiments, the material may comprise about 1% nicotine by weight.

In some embodiments, the aerosol generating material may comprise tobacco material, wherein tobacco material isany material comprising tobacco or derivatives thereof. The tobacco material may comprise one or more of ground tobacco, tobacco fibre, cut tobacco, extruded tobacco, tobacco stem, reconstituted tobacco and/ or tobacco extract. In some embodiments, the aerosol generating material may comprise a tobacco substitute.

Thetobacco used in the aerosol generating material or treated to produce tobacco material, such as a tobacco extract, for usein the aerosol generating material may be any suitable tobacco, such as single grades or blends, cut rag or whole leaf, including Virginia and/ or Burley and/ or Oriental. It may also be tobacco particle 'fines^' or dust, expanded tobacco, stems, expanded stems, and other processed stem materials, such as cut rolled stems. Thetobacco material used in the aerosol generating material may be a ground tobacco or a reconstituted tobacco material. The reconstituted tobacco material may comprise tobacco fibres, and may be formed by casting, a Fourdrinier-based paper making-type approach with back addition of tobacco extract, or by extrusion. I n embodiments where the aerosol generating material comprises tobacco material , the tobacco material may have any suitable chemical composition and may have been prepared according to any suitable process. I n some embodi ments, the tobacco material may comprise one or more substances in the solid and/ or liquid phase. I n these embodiments, the tobacco material may have any suitable solid and liquid content.

I n some embodiments, the tobacco material may comprise more than about 0.1%, 0.5%, 1%, 1.5%, 2%, 3%, 4%, 5%, or 10% nicoti ne by weight. I n some embodiments, the tobacco material may comprise less than about 25%, 20%, 15%, 10%, 7%, 5%, or 4% nicotine by weight. I n some embodi ments, the material may comprise about 0.1-25%, 1- 15% or 2-7% nicoti ne by weight.

I n some embodiments, the tobacco material may comprise a tobacco extract. A tobacco extract is a composition of tobacco that is obtai ned by a method comprisi ng the treatment of tobacco with a solvent, along with any other suitable extraction processes. I n some embodiments, the aerosol generati ng material may comprise between about 1- 90%, 1-50%, about 2-35%, about 5-35%, about 5-20%, about 5-15%, about 10- 15% or about 5-10% of tobacco extract by weight.

I n some embodiments, the tobacco extract may be obtained by a method comprisi ng the treatment of tobacco with water. I n some embodiments, the treatment of tobacco with water may comprise addi ng water to tobacco, separati ng the resulting water-based liquid extract from the insoluble portion of tobacco feedstock, and optionally removi ng excess water to form a tobacco extract. Any suitable fi Itration methods may be used, such as centrifugal soiids fiitration or vacuum fluidised bed filtration. Any suitable evaporative concentration methods may be used, such as vacuum spinni ng disk, vacuum falli ng, or risi ng fi lm evaporation. Techniques including spray-drying or freeze- dryi ng may also be uti lised to reduce/ remove water content. Such processes would be known to those skilled in the art of fi ltration and evaporative concentration.

I n some embodiments, tobacco extract may be obtained by a method comprisi ng extraction usi ng a supercritical fluid, e.g. supercritical carbon dioxide. I n some other embodiments, tobacco extract may be obtai ned by a method comprising extraction with a solvent which may comprise a polyol or other suitable higher boili ng liquids. I n some cases, the extraction solvent may comprise glycerol and/ or propylene glycol (and optionally water).

I n some embodiments, the tobacco extract may be prepared by a method comprising steps for removi ng or reducing the concentration of certain substances. For example, the tobacco extract may be treated with bentonite to reduce protei n content, and/ or polyvinylpolypyrrolidone to reduce polyphenol content.

I n some embodiments, the tobacco extract may be prepared by a method comprising steps for addi ng or i ncreasi ng the concentration of one or more substances. I n some of these embodi ments, aerosol generating agents and/ or flavourants may be added, for example.

A tobacco extract i ncluded in the aerosol generating material i n the devices of the invention may have any suitable chemical composition. I t may have any suitable solid and liquid content. The solid content of the tobacco extract may have a significant effect on the structural stability of the aerosol generati ng material when added to the resistive wires, and may have a significant effect on how the material is affected when heated.

I n some embodiments, the aerosol generati ng material may be prepared by drying a slurry of the aerosol generating material comprisi ng a tobacco extract with a solid content of at least about 2%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% 50%, 60%, 75%, 80%, 85%, 90% or 95% by weight.

I n some embodiments, the aerosol generati ng material may comprise any suitable substances in place of, or i n addition to, a tobacco extract. Examples of suitable substances include, but are not li mited to: water, a bi nder, an inorganic filier material , and an aerosol generati ng agent. Generally, components of the aerosol generati ng material wil l be i ncluded in a slurry which is dried to form the component of the present invention.

I n some embodiments, the aerosol generati ng material may comprise tobacco in place of, or in addition to, a tobacco extract. Suitably, the tobacco may be ground tobacco, with a particle size of 250 pm or less or with a particle size of 80 μιτι or less. (This means that all particles pass through a si eve of appropriate size.) I n some

embodiments, the aerosol generating material is in the form of a sheet and comprises tobacco, suitably ground tobacco. I n some embodiments which comprise ground tobacco, the aerosol generating material may further comprise a bi nder (suitably an algi nate), an aerosol generating agent (such as glycerol or propylene glycol) and an inorganic carrier (suitably chalk). Optionally, the aerosol generati ng material may additionally comprise cellulose fibres, suitably woodpulp or tobacco fibres. The aerosol generating material can be formed from a slurry containing tobacco, suitably ground tobacco.

I n some embodiments, the resistive wi res may be at least partially embedded i n a reconstituted tobacco material which is the aerosol generating material . The reconstituted tobacco material may comprise further substances, includi ng one or more of a bi nder (suitably an algi nate), an aerosol generating agent (such as glycerol or propylene glycol) and an inorganic carrier (suitably chalk). Such substances may be added duri ng the process of preparing a reconstituted tobacco material , i .e. by addition to the tobacco fibres, suitably using a slurry, solution or a supercritical fluid contai ning the substances. Suitably, the reconstituted tobacco material which is the aerosol generati ng material may be formed as a sheet.

I n some embodiments in which the reconstituted tobacco is made using a Fourdrinier paper maki ng-type process and is the aerosol generating material , the reconstituted tobacco may comprise an aerosol generati ng agent (such as glycerol or propylene glycol) and an i norganic carrier (suitably chalk) . Colourants or flavours may also be added. I n some such embodiments, the aerosol generati ng material may include no bi nder.

I n some embodiments, the component for aerosol generation comprising an aerosol generati ng material and a plurality of wires may not include nicotine. Suitably, in such embodiments, an alternative nicotine source may be provided. This may be a solid or liquid nicotine source.

I n some embodiments, the aerosol generati ng material may comprise one or more inorganic fi ller materials. The aerosol generating material may comprise any suitable inorganic fi ller materials. Suitable i norganic filler materials i nclude, but are not li mited to: calci um carbonate (i .e. chalk), perlite, vermiculite, diatomaceous earth, colloidal silica, magnesium oxide, magnesi um sulphate, magnesi um carbonate, and suitable inorganic sorbents, such as molecular sieves. Calci um carbonate is particularly suitable. In somecases, thefiller comprises an organic material such as wood pulp, cellulose and cellulose derivatives. I norganic f i I ier materials are generally more preferred.

A filler material may be included in the aerosol generating material for any suitable purpose. In some embodiments, it may act asasorbent and/ or support for other substances in the aerosol generating material. In some embodiments, it may act as a structure for adsorbing other substances before releasing them on heating. In some embodiments, it may act asasorbent and/ or support for an aerosol generating agent, such as glycerol, and/ or any other substances that influence the sensory characteristics of the aerosol generated on heating.

In some embodiments, a filler material may be included in the aerosol generating material to provide additional strength. In some embodiments, it may be included together with a tobacco extract, in which case it may be included to help retain the tobacco extract within the aerosol generating material and to provide an aerosol generating material with suitable strength for subsequent processing-' utilisation.

A filler material may be included in the aerosol generating material in any suitable quantity and concentration. In some embodiments, it may be advantageous to include a large quantity and concentration of filler material in the aerosol generating material to increase its strength and/ or processability. In some embodiments, the aerosol generating material may comprise between about 1-90%, 10-50%, 20-90%, 35-90% 45- 90%, 50-90%, 55-85%, 60-80%, or 65-75% filler material, suitably i norganic fi I Ier material, by weight. In some of these embodiments, the inorganic filler material may be calcium carbonate, suitably chalk.

In some embodiments, the aerosol generating material may comprise one or more binders. The aerosol generating material may comprise any suitable binder. In some embodiments, the binder comprises one or more of an alginate, celluloses or modified celluloses, polysaccharides, starches or modified starches, and natural gums.

Suitable binders include, but are not limited to: alginate salts comprising any suitable cation, such as sodium alginate, calcium alginate, and potassium alginate; celluloses or modified celluloses, such as hydroxypropyl cellulose and carboxymethyl cellulose; starches or modified starches; polysaccharides such as pectin salts comprising any suitable cation, such as sodium, potassium, calcium or magnesium pectate; xanthan gum, guar gum, and any other suitable natural gums.

A binder may be included in the aerosol generating material in any suitable quantity and concentration. The quantity and concentration of thebinder included in the material may vary depending on the composition of the material, the nature of the resistive wires and the properties desired of the device into which it is incorporated.

In some embodiments, the aerosol generating material may comprise between about 0.5-50%, 3-40%, 5-20%. or 5- 10% binder by weight. In some of these embodiments, thebinder may be sodium alginate.

In some embodiments, the aerosol generating material may comprise water. Water may be included for any suitable purpose, and may be included having been purified using any suitable method of purification, such as reverse osmosis, distillation, and/ or ion exchange. In some embodiments, it may be included to moisten thematerial.

Alternatively or in addition, it may be included to modify the sensory characteristics of the aerosol and/ or gas generated from thematerial on heating.

Any suitable quantity of water may be included in the aerosol generating material. For example, in some embodiments, the aerosol generating material may comprise about 1- 25%, 1-15%, 3-15%, 3-10%, 7- 10% or about 3-7% water by weight.

In some embodiments, as discussed in greater detail below, the aerosol generating material may be applied to the resistive wires in theform of a slurry which isdried to form a solid coating or layer, or monolithicform. The slurry may include water, some of which is removed as the slurry dries.

In some embodiments, the aerosol generating material may comprise one or more of thefollowing in any possible combination: an aerosol generating agent, such as glycerol; a filler material, such as chalk; a binder, such as sodium alginate; aflavourant or colourant; atobacco material such as tobacco per se, tobacco extract or nicotine; and water.

In some embodiments, the aerosol generating material may comprise heat-conducting particles. These may improve the rate of heat transfer from the resistive wires to the aerosol generating material. Alternatively or in addition, they may improve the rate of heat transfer from one region of the aerosol generating material to another region of the aerosol generating material.

As used herein, a slurry isaliquid, gel, solution, suspension or emulsion. It does not necessarily include solid particles of matter. It is, in some embodiments, in a form which may be readily applied to the surface of a heat source so that, upon drying, it forms a coating or encases the heat source.

Thus, in some embodiments, theslurry has a consistency and/ or water content that renders it suitablefor casting or dipping or spraying onto the resistive wires. Theslurry may have a water content of about 25-90%, about 40-90%, about 50-90% about 60- 85% or about 70-80% by weight. In further embodiments, theslurry may have a consistency and/ or water content that renders it suitablefor extrusion, for example, to form a rod of aerosol generating material around which the heat source may be placed or formed. In some embodiments, in which theslurry is extruded to form the component of the present invention, theslurry may have a water content of less than about 60%, 50%, 40%, 30% Or 25% by weight.

In some embodiments, additional ingredients may be included in the aerosol generating material for amelioration of sensory char act eristics of the aerosols generated. In some cases, water, flavourings, casings, or substances which may be acidic or basic in character may alter the taste, flavour, and sensory impact of the aerosol. In some embodiments, these additional ingredients may lead to a milder or mellow effect. In some embodiments, they may lead to more pronounced sensory effects.

In some embodiments, the aerosol generating material may be heated to a temperature sufficient to significantly increase the rate of evaporation and/ or sublimation of a substance in the aerosol generating material, but insufficient to initiatecombustion. This may be the case when thedevicesof theinvention are heat not burn or tobacco heating devices or tobacco heating products. In some other embodiments, the aerosol generating material may be heated to a temperature sufficient to initiatecombustion. This may be the case when the device is a combustible device. In some embodiments, the device may be configured to heat the aerosol generating material to a temperature of between about 50-400°C, 100-350°C, 150-350°C, 150- 330 °C, or 180-300°C.

The plurality of wires may comprise 2 or more, 3 or more, 4 or more, 5 or more, or 10 or more wires. In some embodiments, the plurality of wires may comprise fewer than 15, 12 or 10 wires. In some embodiments the plurality of wires comprises 2- 15, 4-12 or 5-10 wires. In some embodiments, the plurality of wires comprises 6, 7, 8 or 9 wires. The plurality of wires may be spaced from each other by lessthan about 2 cm, 1.5cm, 1cm or 0.75cm.

The wires may be substantially linear. The wires may be arranged substantially parallel to each other. In some embodiments, the wires may consist of aplurality of

substantially linear wires, which may be arranged substantially parallel to each other.

In some embodiments, the wires are separate from oneanother. By "separate", it is meant that thewiresdo not interconnect within thecomponent for aerosol generation, and in particular, do not form a mesh. In other words, they are individual wires. This means that the plurality of wires are not in electrical contact within thecomponent for aerosol generation. In other words, thereis no electrically conducting path between the separate wires. Thewiresdo not form a mesh within thecomponent for aerosol generation. However, in some embodiments, the wires being separate as defined does not preclude the existence of incidental contact of some of the wires within the component for aerosol generation.

One or morefurther electrically resistive heating elements may be included in the devices of the invention. In embodiments wherein one or morefurther heating elements is included, each one may be the same or may be different. Where there is more than one heating element, the second or more heating element isnot particularly limited and may have any suitabieform; it isnot limited to aplurality of wires, and may be a metal mesh, sheet or plate, for example.

In some embodiments, it is possible to the heat wires independently of each other. That is, current may be selectively applied to one or more wires such that only those wires heat up, thereby allowing controlled heating of one or moreportionsof the aerosol generating material. In other words, in some embodiments it ispossibleto individually address particular wires so that, of the plurality of wires, only the addressed wires heat up. In some embodiments, adjacent wires may be heated sequentially.

In some embodiments, different portionsof the aerosol generating material may have different chemical compositions. In such embodiments, the plurality of wires may be configured such that it ispossibleto heat thedifferent portions at different times during use, thereby resulting in different aerosols and/ or gases being generated at different times. In such embodiments, different portionsof the aerosol generating material may be able to generate different flavours, and/ or provide different sensory experiences. In some embodiments, the user of the device may be able to initiate and/ or control which of the portions is heated, and so which aerosols and/ or gases are generated. In some embodiments, a single body of aerosol generating material may be provided, in which different portions have different compositions. Alternatively, more than one body of aerosol generating material may be provided, with discrete bodies of aerosol generating material optionally being separated by insulating means; in such embodiments, at least one of the bodies has embedded in it at least two resistive wires.

The plurality of wires may comprise any suitable conducting medium. I n some embodiments, the wires comprise a metal or metal alloy. It may be advantageous for the wires to comprise a metal or metal alloy because metals are excellent conductors of electricity and thermal energy.

Suitable met als include but are not limited to: copper, aluminium, platinum, tungsten, gold, silver, and titanium. Suitable metal alloys include but are not limited to: nichrome and stain I ess st eel. Nichrome been shown to be effective in experiments, as discussed in the Examples section below.

In some embodiments, the heating response of one or morewireson application of a current may differ from one or more of the other wires, thereby allowing controlled heating of the aerosol generating material. The heating response of the wires is affected by the wire diameter and material composition. In some embodiments, the wires may differ from each other; suitably different wires may have different diameters or may be made from different materials. In some embodiments, one or more of, or all of, the plurality of wires may comprise nichrome, wherein the alloy composition of the wires may be the same for each wireor may differ between wires. In some embodiments, the plurality of wi res substantially consist of or consist of nichrome. I n some

embodiments, each of the plurality of wi res is substantially the same or is the same.

Suitable nichrome wire compositions may i nclude from about 50%, 60%, 70%, 80% or 90% nickel by weight and about 10%, 20%, 30%, 40% or 50% chromium by weight. I n some embodi ments, nichrome wi res may be used which (substantially) consist of 80% nickel and 20% chromi um by weight.

I n some embodiments, the metal or metal alloy may be coated i n another material which is more resistant to corrosion than the metal or metal alloy. I n some

embodiments, this material may also be a metal or metal alloy, such as gold or silver.

I n some embodiments, it may be advantageous for the wires to have a large surface area to volume ratio in order to promote the dissipation of thermal energy, and the heati ng of the aerosol generati ng material . The diameter of each wi re may be the same or the diameter may differ between wi res. I n some embodi ments, the wire diameter may be less than about 1 mm, 0.5 mm, 0.4 mm , or 0.3 mm.

I n some embodiments, it may be advantageous for the wires to have high electrical conductivity; in other embodi ments, it may be advantageous for them to have low electrical conductivity. This is because the electrical conductivity of the wires dictates the electric current generated at any given voltage, which itself dictates two things: the rate at which the element emits heat, and the rate at which it consumes electricity.

I n embodiments wherei n the wi res have high electrical conductivity, the rate of heat emission wi ll be high and the rate of electricity consumption will be high. This is because the current will be high, leading to the emission of more heat and the consumption of more electricity. I n embodi ments where the wires have a low electrical conductivity, the rate of heat emission will be low and the rate of electricity

consumption will be low. This is because the current will be low, leading to the emission of less heat and the consumption of less electricity. I n some embodi ments, an electric current may be passed through the wi res with a magnitude of between about 0.3-8 A, 2-6 A, or 4-6 A. I n other embodi ments, the battery may produce a current of greater than about 8 A. In some embodiments, thecomponent for aerosol generation may be in theform of a sheet. An example of such a sheet is schematically represented in Figure 1, in which the sheet 1 comprises a plurality of linear wires 2 partly embedded within an aerosol generating material 3. In theembodiment depicted the wires are arranged parallel to oneanother.

The sheet may be flat or substantially flat when incorporated into the devices of the present invention. In other embodiments, the sheet may be rolled or wrapped so that it formsawound configuration. One such embodiment is shown in Figure 2. In the wound configuration, theend profile resembles a spiral shape 4 and the overall shape is approximately cylindrical 6. In such embodiments, thewires2 may be disposed approximately parallel to the axis around which the sheet is roiied. In some

embodiments, the sheet 1 may be formed as a substantially planar structure, which may then be rolled into the wound configuration 6. The wound configuration isa particularly convenient way in which to incorporate the component for aerosol generation into a device. This is because the wires are then both (a) in direct contact with the immediately surrounding aerosol generating material and (b) proximal to other layers of the rolled sheet; thus, on heating a sheet in a wound configuration, the wires can each heat a wider area of the aerosol generating material, and so heating is particularly efficient and power consumption is lower. Conveniently, in thewound configuration, thewires2 protrude from the sheet at each end and contact each other to form a single electrical contact 5 at each end of thecylinder 6.

In some embodiments, the sheet may comprise a single layer of aerosol generating material and a plurality of substantially linear, substantially parallel wires. In some embodiments, the sheet may have alaminate structure comprisi ng two or more layers in which each layer comprises a plurality of substantially linear, substantially parallel wires. In some embodiments, thewiresin one layer may be approximately parallel to the wires in another layer.

In some embodiments, the sheet may comprise portions of aerosol generating material which may be independently heated. One or more of the plurality of wires may pass through a different portion of the aerosol generating material from one or more of the other wires. In some embodiments, the sheet may comprise more than one body of solid aerosol generating material, each body optionally being separated by insulating means, and in which each body has an integrated electrically resistive heating element; at least one body comprises a plurality of resistive wi res, which are at least partially embedded i n that body.

Any suitable means may be used to pass an electric current through the resistive wi res in the devices of the invention. The wi res may be constantly i n contact with the power source, or they may come i nto contact with the power source only when the device is i n use and the aerosol generating material is to be heated.

I n some embodiments, the aerosol generati ng material comprises two or more portions and the aerosol generati ng material may be moved i n order to facilitate the sequential heati ng of two or more portions of the aerosol generati ng material . For example, the movement may engage one or more resistive wi res associated with any given portion of aerosol generati ng material with a power source. I n some such embodiments, the portions of aerosol generati ng material have the same composition. I n other such embodiments, the portions of aerosol generating material have different compositions.

I n alternative embodiments i n which the sheet is i n a wound configuration, the device may be configured to allow the wound sheet to be unwound by the user. I n some embodiments, the sheet may be unwound in order to connect a new portion of aerosol generating material to the power source, which portion has not yet been heated. I n some embodi ments, the sheet may be unwound to reveal fresh aerosol generati ng material after the material which has already been exposed has already been heated. This may increase the amount of material which can be heated and so extend the length of time over which the device may be used. I n some embodi ments, the sheet may be wrapped around a spool , which may make it easier to unwi nd the sheet. I n some embodiments, the spool may have a cyli ndrical shape. I n some cases, a second spool may be provided, parallel to the first. The spent or consumed material may be wound onto the second spool i n use. The two spools and sheet can be combi ned in a "cassette". Either spool may be driven to move the sheet. I n such cassette embodi ments, the wi res suitably extend parallel to the longitudi nal axis of the spools and protrude from the sides of the sheet. The protrudi ng wires sequentially contact electrodes as the spools are driven, which electrodes are connected to a power source. The spools may be driven by hand, or i n some embodi ments, may be driven by a motor. I n some cases, the material may become frangible after heati ng, and so a support material may be provided underneath the exposed portion between the two spools. An example of the "cassette" structure isdepicted in Figure 6, in which a sheet 1, comprising electrically resistive wires 2 embedded in an aerosol generating material 3, is wrapped around two spaced spools 61. Two electrodes 63 are arranged adjacent to the sheet 1 in the gap between the two spools. These electrodes are connected to a power source 62. The resistive wires 2 extend parallel to the spools longitudinal axes and protrude from the edges of the sheet 1 such that, as the spools are rotated, adjacent wires sequentially contact the electrodes 63 and heat up.

In some embodiments, different wires within the plurality of resistive wires may be independently powered, to allowtheportionsof the aerosol generating material associated with those different wires to be heated independently and/ or sequentially. In some embodiments, thedifferent wires are independently powered by virtue of the parts having separate power sources, such as separate batteries. In some embodiments, thedifferent wires are independently powered by virtue of one or more switches linking the parts to a single power source.

In some embodiments, one or more batteries may be used to provide a potential difference and pass a direct electric current through the resistive wires. In these embodiments, one or more batteries may be connected to the resistive wires in any suitable way, for example by using of wires and/ or clips. In embodiments wherein more than one battery is used to provide more than one power supply, the batteries may be thesameor may bedifferent.

A battery used in thedevicesof theinvention may have any suitable properties. For example, it may be rechargeable or non-rechargeable and may be replaceableor non- replaceable.

A battery used in thedevices of theinvention may have any suitable voltage. In some embodiments, a battery with a high voltage may be preferred over a battery with a low voltage because this will generate a higher electric current and the resistive wires will emit heat at a higher rate. In some embodiments, a battery i ncorporated into the devices of theinvention has a voltage of between about 0.5-10 V, 2-8 V, or 4-6 V. In other embodiments, the battery may have a higher voltage, e.g.10 V or more may be used. The voltage of a battery used in thedevicesmay be chosen based on the size of the electric current which needs to passthrough the resistive wires. In embodiments where the resistive wires have high electrical resistance, the battery may have a high voltage; in embodiments where the resistive wires have low electrical resistance, the battery may have alow voltage.

A battery used in thedevicesmay have any suitable charge capacity. In some embodiments, a battery with a high charge capacity may be preferred over a battery with alow charge capacity because this will allow the battery to deliver a potential difference for a longer period of time.

In some alternative embodiments, the plurality of wires may at least partially surround the aerosol generating material and beat least partially embedded in the surface of the aerosol generating material. The wires may be spaced at regular intervals around the aerosol generating material surface. In such embodiments, aerosol generating material may be in amonolithicform. Themonolithicform may have been formed by an extrusion process. For example, the aerosol generating material may be extruded into a rod, cylinder or tube. The wires may be embedded in a surface of the rod, cylinder or tube and extend parallel to the longitudinal axis of the rod, cylinder or tube.

In some embodiments, thecomponent comprising aerosol generating material and the resistive wires may be provided in a cartridge, and the cartridge may be inserted into a device. In someof these embodiments, thiscartridge may be replaceable.

In some embodiments, the cartridge may comprise one or more areas on itssurfacefor connecting the resistive wires of the cartridge to a power source in thedevice. In some embodiments, these areas may be covered by a cover, such as a cap, when thecartridge has not been added to the device. In some embodiments, the cartridge may comprise one or more orifices for the passage of air, gas, and/ or aerosol. In some embodiments, these orifices may be covered by a cover, such as a cap, when the cartridge has not been added to thedevice.

In embodiments where the component is provided in a cartridge, thecartridge may be combined with other parts of the aerosol generating device in any suitable way. In some embodiments, it may be attached to other parts of the device by a friction fit and/ or a screw fit and/ or a press fit. In some embodiments, the devices may comprise an actuator, wherein the actuator may be actuated to initiatetheheat source by initiating the passing of electricity through at least part of theresi stive wiresto generate heat. In some cases, the actuator may be manually activated in use. In some of these embodiments, the actuator may be, or may be connected to, a switch in an electrical circuit.

In some embodiments, heating may be initiated when a pressure gradient isproduced within the device. This pressure gradient may, for example, be produced when puffing on or inhaling through the device. In some embodiments, the resistive wires may be heated when puffing or inhaling.

In some embodiments, the device may comprise an indicator, wherein the indicator indicates one or more properties of the resistive wires and/ or aerosol generating material. For example, thedevice may comprise an indicator for indicating the temperature of the resi stive wi res and/ or aerosol generating material. For example, the device may comprise an indicator for indicating the extent to which the aerosol generating material has released an aerosol and/ or gas.

In some embodiments, thedevice may comprise temperature controlling feedback circuitry to regulate the temperature of the resistive wires. This may be used to provide the optimum temperature for aerosol generation by heating.

In some embodiments, the device may comprise an insulating layer between the outside of the device and the heating element (i.e. the resi stive wires).

According to a second aspect of the invention, there is provided a method for fabricating the component for aerosol generation by electrical heating which is incorporated into aerosol generating devices of the invention. The method comprises applying a slurry of aerosol generating material to a plurality of wires. In some embodiments, this involves casting or coating a slurry of aerosol generating material onto the plurality of wires and/ or dipping the plurality of wires into a slurry of aerosol generating material. In other embodiments, this involves extruding a slurry of aerosol generating material onto the plurality of wires. In some embodiments, thecomponent for aerosol generation isfabricated in sheet form; that is, it isfabricated as a substantially planar body (i.e. sheet), which may optionally be rolled into awound configuration.

Any suitable process or processes may be used to prepare the plurality of wires and the slurry of aerosol generating material before combining them. In some embodiments, the aerosol generating material isformed from a slurry which isapplied to the plurality of wires and then allowed to dry. In some embodiments, the aerosol generating material, and theslurry used to prepare it, comprise a tobacco material.

In some embodiments, the aerosol generating material is prepared by a method comprising the formati on of a slurry. To form theslurry, the components of the aerosol generating material may be added in any suitable order. In some embodiments, the slurry may undergo mixing during and/ or after the addition of its components and, in these embodiments, may undergo mixingfor any suitable length of time. The length of time over which theslurry undergoes mixing will depend on its composition and volume, and may be varied accordingly. In some embodiments, theslurry may undergo mixing as necessary to make the composition of theslurry substantially homogeneous before being combined with the pi ural ity of wires.

In embodiments wherein the aerosol generating material comprises sodium alginate, glycerol, chalk and optionally tobacco extract and/ or optionally caramel colourant, the method may comprise the steps of (1) addingsodium alginate to the water and hydrating the alginate to form a smooth paste, (2) adding glycerol (and optionally caramel colourant), (3) adding chalk, (4) mixing thoroughly to form a smooth slurry, and optionally (5) adding tobacco extract. Generally, themethod will comprise adding at least one of caramel colourant and tobacco extract. In some embodiments, no colourant will be included.

In some embodiments, a method of making the slurry may comprises

(1) suspending dispersing the binder in glycerol (aerosol generating agent) and then

(2) hydrating the suspension with water and mixing. This isfollowed by (3) optionally adding caramel and adding chalk, (4) mixing thoroughly to form a smooth slurry, and optionally (5) adding tobacco extract. Generally, themethod will comprise adding at least one of caramel colourant and tobacco extract. In some embodiments, no colourant will be included. In some embodiments, the slurry of aerosol generating material may be formed by a process comprising adding one or more additives, such asflavourants.

In embodiments wherein the slurry of aerosol generating material is cast onto the resistive wires, thewiresmay be placed onto a plate before the slurry is poured onto it. Alternatively, thewiresmay be placed onto the band of abandcasting machine. In some embodiments, the slurry may be poured onto the wires so that it is evenly spread over the heat source with any suitable thickness or depth. A casting knife may be used to ensure even thickness. In some embodiments, the slurry may be poured onto the wires so that it has a thickness or depth of about 0.5-6 mm, 0.6-5 mm, 0.7-4 mm, 0.8-3 mm, 0.9-2.5 mm or 1-2 mm. In some embodiments, the slurry may be poured onto the resistive wires so that it isspread evenly and has a thickness or depth of about 2 mm.

After beingcombined with the heat source, the slurry may bedried, and may bedried using any suitable method of drying. In some embodiments, the slurry may bedried at room temperature (i.e. about 20-25°C). In some embodiments, theslurry may bedried in warm air (i.e. an oven). In these embodiments, theslurry may bedried at any suitable temperature for any suitable length of time. In some embodiments, theslurry may bedried at a temperature of about 30-100°C, 60-100°C, 40-75°C, 45-60°Cor 45- 55°C.

In embodiments where the slurry of aerosol generating material has been cast onto the resistive wires on a plate, theresulting structure (in which the wires are at least partially embedded in the aerosol generating material) is removed from the plate. In some embodiments, the structure may be removed using an item for accessingthe space between structure and the plate, such as a knife or blade (a "doctoring knife"). Alternatively or in addition, the structure may be removed by increasing the temperature of the contact point between the structure and the plate. In some such embodiments, the structure may be removed from the plate using steam which, in addition to increasing the temperature of the contact point between the structure and the plate, causes sorption of water by the aerosol generating material which aids its removal.

In some embodiments, the component for aerosol generation may be conditioned after being removed from the plate. In some embodiments, thecomponent may be conditioned at about a temperature of about 20-25°C, such as about 22°C. Alternatively or i n addition, the component may be conditioned in ai r with a relative humidity of about 50-80%, such as about 60%. Commonly, conditioning is carried out at 22°C and a relative humidity of 60% for an appropriate ti me period, e.g. 48 hours.

I n some embodiments, the component may then be stored (e.g. in a sealed contai ner) at a temperature below room temperature (e.g. 4-20°C) and at any suitable humidity for any suitable length of ti me, before being incorporated into the device of the invention.

Once the slurry of aerosol generati ng material has been combi ned with the resistive wires, dried, conditioned, and stored, the resulting structure may be divided into separate pieces. These separate pieces may then be incorporated into one or more devices. I n some of these embodi ments, the resulti ng structure may be in the form of a sheet or strip and may be cut into separate pieces using any suitable method of cutti ng. I n some cases, these separate pieces are stored in sealed capsules or other suitable sealed packagi ng to prevent or mi ni mise degradation prior to use.

Exam les

The invention wi ll now be i llustrated by reference to examples.

"Solids" and "Solid(s) Content" refer to the whole of the extract or slurry other than the water, and may i nclude components which by themselves are liquid at room

temperature and pressure, such as glycerol .

The term Wet Weight Basis (WWB) refers to an alyte concentration data calculated for material weights i ncludi ng water; Dry Weight Basis (DWB) refers to analyte

concentration data for material weights corrected for water content.

I n the Examples, Reverse Osmosis [ RO] quality water refers to softened water which is additionally purified by reverse osmosis.

Example 1: Tobacco extraction and extract composition

Seven batches of whole leaf Burley tobacco (4.5 kg per batch) were extracted with 80kg water (RO quality) at 60° C for 25 - 30 minutes with gentle agitation. The resulti ng mixture was fi ltered and centrifuged and the combi ned resulting extracts (480 I) were concentrated util ising an evaporative concentration process to 41.1% solids content (i n this context, 'solids content^' refers to the non-aqueous portion of the water extract). Table 1 shows the composition of the resulting tobacco extract.

Table 1: Composition of tobacco extract

The density of the concentrated extract was 1.21 g cm³.

After the process 9.12 kg of concentrated extract was obtained and stored frozen until required.

This tobacco extract was used in the manufacture of an aerosol generating material i n Example 3 (below) .

Example 2: Aerosol generati ng material without tobacco extract - manufacturi ng procedure and composition

Approxi mately 500g water (reverse osmosis purified) was placed i n a high shear mixer. Whilst mixi ng, sodium algi nate powder (22.5g) was slowly added, ensuring even mixing and full hydration to a smooth, viscous fluid. Water (reverse osmosis purified) was used where necessary to ensure complete transfer of other ingredients i nto the high shear mixer. For example, glycerol (37.5g) was added to the high shear mixer with conti nuous mixing and complete transfer from the vessel originally containi ng glycerol effected by washi ng with water aliquots. Simi larly, caramel (colourant) (4.5g) was added to the high shear mixer with conti nuous mixing and the remaini ng water used to ensure complete transfer from the vessel origi nally containi ng the caramel . The total water added to ensure complete transfer of ingredients was approxi mately 200g, so the total batch water weighed 70 Og. Chalk (235.5g) was fi nally added in a slow powder stream with continuous high shear mixi ng.

After a smooth, free flowing slurry had been formed, the material was ready for casti ng into sheet.

A series of approximately parallel nichrome wires (35 SWG - see Table 2 below) were strung the length of a stai n I ess steel casti ng plate. The slurry was then cast onto the stain I ess steel plates at 2mm thickness using acasting knife. This provided a constant thickness of theslurry which was then dried. Drying can be effected by air drying at ambient conditionsfor approximately 24 hours or in an oven at ca.90 °Cfor about 30 - 60 minutes. Thedried sheet was then removed from the plate and conditioned by exposure at 22 °Cand 60% relative humidity (RH), for 48 hours. In some cases, the dried sheet was cut off the casti ng plate usi ng a "doctori ng" knife.

In all experimental runs, the specifications of the nichrome wire were as indicated in Table 2.

Table 2: Nichrome wire specification

Example 3: Aerosol generating material with tobacco extract - manufacturing procedure and composition

The tobacco extract based aerosol generating material was prepared utilising the following procedure. The tobacco extract in Table 1 was used to prepare this material.

Water (756g - reverse osmosis purified) was placed in a high shear mixer. Whilst mixing, sodium alginate powder (15.01g) was slowly added, ensuring even mixing and full hydration to asmooth, viscousfluid. Glycerol (24.99g) was added to the high shear mixer with continuous mixing. Chalk (156.99g) was then added in a slow powder stream with continuous high shear mixing. Finally, tobacco extract (61.26g) was added with continuoushigh shear mixing until asmooth, free flowing slurry was formed.

After asmooth, free flowing slurry had been formed, the material was ready for casting into sheet.

A seriesof approximately parallel nichrome wires (35 SWG - see Table 2 above) were strung the length of a stain I ess steel casting plate. The slurry wasthen cast onto the stain I ess steel plates at 2mm thickness using acasting knife. This provided a constant thickness of theslurry which wasthen dried. Drying can be effected by air drying at ambient conditionsfor approximately 24 hours or in an oven at about 45-55 °Cfor 0.5- 5 hours (minimum timeused to reduce loss of volatiles). Thedried sheet was then removed from the plate and conditioned by exposure at 22 °Cand 60% relative humidity (RH), for 48 hours. In some cases, thedried sheet was cut off the casting plate using a "doctoring" knife.

Theformed aerosol generating materialsfrom Examples 2 and 3 were analysed for water, nicotineand glycerol content and the results are shown in Table 3.

Table 3: Aerosol generating material analysis

Note: WWB: Wet Weight Basis (data calculated for material weights including water content); DWB: Dry Weight Basis (corrected for water content)

Example 4: Aerosol generation

Sample configuration

The sheets of aerosol generating material manufactured in Examples 2 and 3 were cut into strips measuring 3cm x 5cm. Each strip contained 7 wires, each of which isabout 7cm long and each of which protruded from both sides of the strip by about 2cm.

These strips were then rolled to form an approximately cylindrical shape (theend profile of which resembles a spiral). The length of thecylinder was approximately 3cm and thediameter approximately 1cm. In thisconfiguration, the embedded nichrome wires were disposed approximately parallel to the longitudinal axis of that cylinder.

The wire conductors protruded from each side of theroll of aerosol generating material and wereconnected totheterminalsof theaerosol generation test rig.

The rolled configuration is depicted in Figure 2, in which the sheet 1, comprising a plurality of wires 2 embedded within theaerosol generating material 3, iswound to form an approximately cylindrical shape 6. Theend profile4 of thecylinder resembles a spiral. The wires 2 protrude from the sheet at each end, and contact one another 5 for subsequently contacting electrodes to allow power delivery. Aerosol generation test rig apparatus and aerosol propensity evaluation

The aerosol generation test rig apparatus was used to assess aerosol generation of the aerosol generation materials manufactured in Examples 2 and 3.

The apparatus is il lustrated i n Figure 3 and i nciudes a tubuiar glass chamber 10 formed from a glass tube 101 and two glass end caps 102. Two tungsten electrodes 11 extend through the chamber wall from the outside to the i nside of the ch amber. I n use, a rolled sample 6 prepared as set out in the preceding section is connected to the electrodes i nside the chamber. An electrical power supply 12 (Weir Model 413D) is connected to the electrodes outside of the chamber.

An upstream air inlet 103 is provided in the upstream end cap 102. A downstream outlet 104 in the downstream end cap 102 is connected to a f i Iter chamber 13, i n which a Cambridge particle fi lter 131 is provided.

Downstream of the f i iter 131 an outlet from the filter chamber 13 connects to a liquid trap 14. The outiet from the iiquid gas trap is connected to a continuous draw pump 15 (SKC 224-PCMTX8). A thermocouple 16 (H ANNA H I 93532 K) is arranged to measure the surface temperature of the sample 6.

When collecting data, the sample 6 being tested was connected to the electrodes 11 inside the chamber 10. The ai r flow rate was set at 1.95 l/ min with air flowing F from the upstream air inlet 103 to the conti nuous draw pump 15. At time zero, the pump 15 and power supply 12 were switched on. The temperature was noted at approxi mately one minute intervals from the thermocouple 16 reading, and aerosol formation was noted via observation of opacity within the equipment.

The power supply 12 was switched off after 15 mi nutes, and the equipment allowed to cool for 4 minutes. After a total run time of 19 minutes, the pump 15 was switched off. Particulate aerosol was trapped on the Cambridge fi lter 131 and volatiles passing through the fi lter were trapped in the iiquid trap 14.

The interior surfaces of the glass chamber 10 and fi lter chamber 13 were wiped clean using further, unused portions of Cambridge particle fi lter pad. The Cambridge fi lter pads (both those used to wipe clean the apparatus and that used as the trap for particulate aerosol) and the contents of the liquid gas trap were added to a flask, which was placed on a shaker for 20min then analyzed by gas chromatography to determi ne the aerosol nicotine and glycerol content.

Before subjecting the sample to testing, the weight of the aerosol generating material was measured and the available quantity of glycerol and nicotine for aerosol formation calculated. Efficiency of transfer of these components to the aerosol could then be calculated.

All experi ments were conducted i n a control led atmosphere laboratory (22°C and 60% relative humidity). Blank experiments (i n which no sample was placed in the glass chamber 10) were conducted to determine background levels of each component. The measured values for each sample were corrected accordingly.

Duri ng the experiments it was found that, on reachi ng a threshold temperature, substances i n the aerosol generating material are released. These were observed to form a free aerosol on subsequent cool ing, which appeared as a visible white cloudy mist.

Several experiments were conducted usi ng rolled samples of each of the materials manufactured in Example 2 and 3.

I n one experi ment, a rolled sample of the material made in Example 2 was subjected to an approximately constant 5 Amp current (current held approximately constant by adjusting the voltage) . Observations and data are provided i n Table A1 and in Figure 4.

I n another experi ment, a rol led sample of the material made in Example 3 was subjected to an approximately constant 5 Amp current (current held approximately constant by adjusting the voltage) . The observations and data are provided in Table A2 and i n Figure 5. Table 4 indicates the aerosol composition that resulted in some of the experiments.

Table 4: Resulting aerosol composit

Note on Table 4: The weight of analyte i n aerosol collected is calculated from combi ned particle phase (Cambridge fi lter) and vapour phase (liquid trap).

Table 5 below i ndicates the percentage transfer of nicoti ne and glycerol from the aerosol generati ng material to the aerosol following the application of electrical power.

Table 5: Percentage transfer of selected substances to form aerosol

Discussion

Shortly after application of a potential difference across the nichrome wires (during which period they were heati ng up) , an aerosol could be observed as white cloudy mist withi n the glass chamber of the aerosol generation test rig. The aerosol was carried to the Cambridge fi lter / liquid trap collection system by ai r pumped through the apparatus. Aerosol formation occurred throughout a substantial period of the heati ng time, as indicated in Tables A1 & A2. I t can be seen that there is a substantial transfer of nicotine and glycerol from the aerosol generati ng material to form a free aerosol on application of electrical power heati ng to the resistive wires. The data indicate that under these conditions, despite both substances having high boiling poi nts, the transfer of nicotine is shown to exceed that of glycerol in the material of Example 3.

The various embodiments described herei n are presented only to assist in

understandi ng and teachi ng the clai med features. These em bodi ments are provided as a representative sample of embodi ments only, and are not exhaustive and/ or exclusive. I t is to be understood that advantages, embodiments, examples, functions, features, structures, and/ or other aspects described herein are not to be considered limitations on the scope of the invention as defined by the clai ms or li mitations on equivalents to the clai ms, and that other embodi ments may be uti lised and modifications may be made without departing from the scope of thedaimed invention. Various embodiments of theinvention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein. In addition, this disclosure may include other inventions not presently daimed, but which may be claimed in future.

Table A1: Observations and data from test with material manufactured in Example 2.

Table A2: Observations and data from test with material manufactured i n Example 3.

Claims

1. A component for aerosol generation by electrical heating, thecomponent comprising a solid aerosol generating material and a plurality of resistive wires, each of which is at least partially embedded in the solid aerosol generating material.

2. A component according to claim 1, wherein the wires are separate resistive wires.

3. A component according to claim 1 or claim 2, wherein the wires are embedded in or coated by the solid aerosol generating material.

4. A component accordingto any preceding claim, wherein thecomponent isin the form of a sheet.

5. A component accordingto claim 4, wherein thecomponent isin the form of a rolled sheet.

6. A component accordingto any preceding claim, wherein thewiresare substantially linear.

7. A component accordingto any preceding claim, wherein the wires comprise metal or metal alloy.

8. A component accordingto any preceding claim, wherein the wires have a diameter of lessthan about 1 mm.

9. A component accordingto any preceding claim, wherein the aerosol generating material comprises an aerosol generating agent.

10. A component according to any preceding claim, wherein the aerosol generating material comprises nicotine.

11. A component accordingto any preceding claim, wherein aerosol the generating material comprises tobacco material, such as ground tobacco, tobacco fibre, cut tobacco, extruded tobacco, tobacco stem, reconstituted tobacco and/ or tobacco extract.

12. A component according to any preceding claim, wherein the aerosol generating material comprisesafiller material, and/ or wherein the aerosol generating material comprises a binder.

13. A component according to any preceding claim, wherein the aerosol generating material is a cast or extruded material.

14. A component according to any preceding claim, wherein thecomponent is configured to allow one or more of the wires to be heated independently of one or more other wires.

15. A component according to claim 14, wherein different portionsof the aerosol generating material have different chemical compositions and wherein thecomponent isconfigured to allow thedifferent portions to be heated independently from each other during use.

16. A device for generating an inhal able aerosol and/ or gas, the device comprising a component for aerosol generation by electrical heating, thecomponent comprising a solid aerosol generating material and a plurality of resistive wires, each of which is at least partially embedded in the solid aerosol generating material.

17. A device according claim 16, wherein the device is a tobacco heating product.

18. A method for fabricating a component according to any one of claims 1 to 15 or a device according to claim 16 or claim 17, wherein the method comprises applying a slurry of aerosol generating material to a plurality of resistive wires.

19. A method accordingto claim 18, wherein thecomponent isformed as a sheet, and optionally wherein the sheet is roiied into a wound configuration after theslurry hasdried.

20. A method according to claim 19, wherein theslurry iscast or extruded onto the wiresto form a sheet, or wherein the wires are dipped into theslurry of the aerosol generating material to form a sheet.