Patent Description:
Smoking articles such as cigarettes, cigars and the like burn tobacco during use to create tobacco smoke. Attempts have been made to provide alternatives to these smoking articles by creating products that release compounds without actually combusting and hence which do not create smoke or an aerosol as a result of degradation of, for example, tobacco by combustion or the process of burning. Examples of such products are so-called heat-not-burn products, tobacco heating products or tobacco heating devices which release compounds, which may form an aerosol, by heating, but not burning, aerosol generating material. The aerosol generating material may be for example tobacco or other non-tobacco products, which may or may not contain nicotine.

<CIT> discloses a disposable aerosol generator comprising at lest one receptacle containing fluid aerosol generating material.

<CIT> discloses a method of preparing a tobacco material for use in a smoking article.

<CIT> discloses a method for producing a vaporisable material wherein cut plant fibres are mixed with a humectant and dried prior disposition thereof in a capsule.

<CIT> disclose an electronic smoking article.

The present invention provides a method as claimed in claim <NUM>.

As used herein, the term "aerosol generating material" includes materials that provide volatilised components upon heating. "Aerosol generating material" includes any tobacco-containing material and may, for example, include one or more of tobacco, tobacco derivatives including tobacco extracts, expanded tobacco, reconstituted tobacco or tobacco substitutes. "Aerosol generating material" also may include other, non-tobacco, products, including for example flavourants, which, depending on the product, may or may not contain nicotine, filler materials such as chalk and/or sorbent materials, glycerol, propylene glycol or triacetin. The aerosol generating material may also include a binding material, for example, sodium alginate.

Referring to <FIG>, there is shown a perspective view of an example of an apparatus <NUM> arranged to heat aerosol generating material (not shown in <FIG>) to volatise at least one component of the aerosol generating material. The apparatus <NUM> is a so-called "heat-not-burn" apparatus. The apparatus <NUM> in this example is generally elongate, having a generally cuboidal outer housing <NUM> of rectangular cross-section and comprising a lid 2a. The apparatus <NUM> may comprise any suitable material or materials, for example, the outer housing <NUM> may comprise plastic or metal. The apparatus <NUM> has a mouthpiece <NUM> through which a user can draw material that has been volatised in the apparatus <NUM>. The mouthpiece <NUM> (or at least the tip of the mouthpiece <NUM>) may comprise a material that feels comfortable to the lips, for example, suitable plastics or silicone rubber based materials.

Referring particularly to the cross-sectional view of <FIG>, the apparatus <NUM> has a heating chamber <NUM> which in use contains a receptacle <NUM> for containing the aerosol generating material <NUM> to be heated and volatised. The heating chamber <NUM> is in fluid flow communication with the mouthpiece <NUM>. The heating chamber <NUM> further contains a heater arrangement <NUM> for heating the aerosol generating material <NUM>. An aerosol formation and condensation zone <NUM> may be provided between the heating chamber <NUM> and the mouthpiece <NUM> (or as part of the mouthpiece <NUM>).

The apparatus <NUM> further has an electronics/power chamber <NUM> which in this example contains electrical control circuitry <NUM> and a power source <NUM>. In this example, the heating chamber <NUM> and the electronics/power chamber <NUM> are adjacent each other along the longitudinal axis of the apparatus <NUM>. The electrical control circuitry <NUM> may include a controller, such as a microprocessor arrangement, configured and arranged to control the heater arrangement <NUM> as discussed further below.

The power source <NUM> may be a battery, which may be a rechargeable battery or a non-rechargeable battery. Examples include nickel cadmium batteries although any suitable batteries may be used. The battery <NUM> is electrically coupled to the heater arrangement <NUM> (to be discussed further below) of the heating chamber <NUM> to supply electrical power when required and under control of the electrical control circuitry <NUM> to heat the aerosol generating material <NUM> (as discussed, to volatize the aerosol generating material <NUM> without causing the aerosol generating material <NUM> to combust or undergo pyrolysis).

The apparatus <NUM> may further comprise one or other or, as is illustrated in <FIG>, both of a manual actuator <NUM>, for example, a push button, and a control sensor <NUM>, for example an air flow sensor, each operably coupled to the control circuitry <NUM>. The manual actuator <NUM> may be located on the lid 2a of the housing <NUM> where it can be operated by a user of the article <NUM>. In this example, the sensor <NUM> is an airflow sensor and is located in the heating chamber <NUM> towards the rear of the apparatus <NUM>.

The apparatus <NUM> may further comprise one or more air inlets <NUM> formed through the housing <NUM>, in this example, through a rear wall 2b of the housing <NUM> and through a base wall 2c of the housing <NUM> towards the mouthpiece <NUM> end.

In one example, the receptacle <NUM> is a thin sheet of suitable material having at least one cavity, for example a recess 7a, pressed or etched or otherwise formed, therein for containing aerosol generating material <NUM>. As used herein, the word cavity is intended to encompass any hollow space, recess, indent, or the like at least partly defined by the receptacle and for containing aerosol generating material <NUM>.

The receptacle <NUM> may, for example, be formed of a metal sheet, for example, copper, aluminium, stainless steel, silver, gold or an alloy or from a ceramic material or a metal-plated material.

As perhaps best seen in <FIG>, in one example, the receptacle <NUM> comprises a plurality of recesses 7a formed therein, each recess 7a for containing aerosol generating material <NUM>. The recesses 7a may be arranged in a regular matrix or array, for example, an array of nine as shown in <FIG>. In the example of <FIG>, the array of nine recesses 7a comprises three 'rows' of three recesses 7a arranged parallel with the longitudinal axis of the receptacle <NUM> and three 'columns' of three recesses 7a arranged perpendicular to that longitudinal axis.

A layer of aerosol generating material <NUM> coats, partially or completely, an inner surface of each recess 7a.

In one example of the apparatus <NUM>, the heater arrangement <NUM> comprises one or more heater elements 11a and is located in the heating chamber <NUM> close to the underside of the receptacle <NUM>. The heater arrangement <NUM> further comprises power connections 11b for connecting the heater elements 11a to the electrical control circuitry <NUM>.

In one example, the heater arrangement <NUM> comprises a plurality of heater elements 11a arranged in an array that matches the array of recesses 7a formed in the receptacle <NUM>. Accordingly, in the example of <FIG>, the heater arrangement <NUM> comprises nine heater elements 11a in a matching array to the array of recesses 7a so that each heater element 11a is positioned for heating aerosol generating material <NUM> in a respective one of the recesses 7a.

The electrical control circuitry <NUM> and the power connections 11b to the heater elements 11a are preferably arranged such that at least two, and more preferably all, of the heater elements 11a can be powered independently of each other, for example in turn (over time) or together (simultaneously) as desired.

In an example, the heater elements 11a may be resistive heating elements, comprising, for example, resistive electrical wiring wound as a coil or formed as a mesh. In other examples, the heater elements 11a may comprise a ceramics material. Examples include aluminium nitride and silicon nitride ceramics, which may be laminated and sintered. Other heating arrangements are possible, including for example the heater elements 11a being infra-red heater elements which heat by emitting infra-red radiation or inductive heater elements. An inductive heater element may, for example, comprise an induction coil and a susceptor element. Under the control of the electrical control circuitry <NUM> the induction coil generates an alternating magnetic field which causes eddy current heating and/or, if the susceptor element is magnetic, magnetic hysteresis heating of the susceptor element. The susceptor element may take any suitable form (e.g. it may itself be a coil) and be formed of any suitable material.

An advantage of the arrangement illustrated in <FIG> in which the receptacle <NUM> is separate from the heating arrangement <NUM> is that the receptacle <NUM> may be removed by a user from the housing <NUM> once all the aerosol generating material <NUM> in the receptacle <NUM> has been consumed and replaced with a replacement. The receptacle <NUM> may therefore be a consumable article separate from the remainder of the apparatus <NUM> and can be disposed of after it has been exhausted. In this way, a new aerosol generating receptacle <NUM> may be inserted into the heating chamber <NUM> as required.

To replace a receptacle <NUM>, a user may simply open the lid 2a of the housing <NUM>, remove the spent receptacle <NUM> and then insert a replacement. The lid 2a may be attached to the housing <NUM> by any suitable means, for example, by a hinge, magnetically, or by a recessed lockable sliding arrangement.

In one example, the housing <NUM> incorporates, or is lined with, insulating material (not shown in the Figures) of sufficient heat transmission retarding qualities that the outer surface of the housing remains sufficiently cool to facilitate comfortable holding. Internally, insulation may be positioned to protect the electrical control circuitry <NUM> and the power source <NUM> from elevation of temperature above ambient. In this way the electrical control circuitry <NUM> and power supply <NUM> may be protected from potential thermal damage by proximity to the heating arrangement <NUM>.

In some examples, the mouthpiece <NUM> is removeable from the housing <NUM> so that should a mouthpiece that has been repeatedly used encounter depositions to the extent that it cannot easily be cleaned, it can be replaced with a new replacement mouthpiece.

In use, heat produced by a heating element 11a heats the aerosol generating material <NUM> in the recess 7a above that heating element 11a to generate aerosol and/or a gas or vapour. As a user inhales on the mouth piece <NUM>, air is drawn into the heating chamber <NUM> through the one or more air inlets <NUM> (as shown by the broken arrows in <FIG>) and the combination of the drawn air and aerosol and/or gas or vapour passes into the aerosol formation and condensation zone <NUM> which cools the hot gas or vapours to form further aerosol and condenses some aerosol so that aerosol is cool entering the mouthpiece <NUM> for inhalation by a user.

In this example, at least some of the air drawn through the housing <NUM> when a user inhales passes directly over the heating elements 11a and is thus heated and so is hot when mixing with aerosol and/or gas or vapour.

In other examples, air is not drawn over the heating elements 11a and passes over the receptacle <NUM> only.

In yet another example, the apparatus <NUM> is arranged such that the total volume of inlet air flow is directed over the heating elements 11a prior to flowing across the recesses 7a, hence ensuring pre-heated air at elevated temperature interacts with the aerosol generating material <NUM>, promoting more effective aerosol generation.

In some examples, the apparatus <NUM> is arranged so that the total volume of inlet air flow is admitted directly from exterior to the apparatus <NUM> and is therefore initially at external ambient temperature on entry into the apparatus <NUM> to flow over the recesses 7a. In this case, the air temperature becomes elevated during flow across the recesses 7a which may be desirable when volatile flavours or other volatile substances which have sensorial activity are present in the aerosol generating material <NUM>.

In one example, when taking each draw on the mouth piece <NUM>, in order to initiate heating, a user may actuate the actuator <NUM> to cause the power supply <NUM> under the control of the control circuitry <NUM> to supply power to one or more of the heating elements 11a.

In one example, heating may be initiated automatically each time a user takes a draw on the mouth piece <NUM> by means of the sensor <NUM>, for example, an air flow sensor, causing the power supply <NUM> under the control of the control circuitry <NUM> to supply power to one or more of the heating elements 11a.

In another example, heating may be initiated manually prior to each draw, and the sensor <NUM> automatically switches electrical power off after each draw has been completed and air flow reverts to near zero in the apparatus <NUM>. In this way battery power may be preserved, but the user can manually control switching the heating elements 11a to the on position.

In examples in which the heater elements 11a can be powered independently of each other, the particular heating element <NUM>1a or combination of heating elements 11a that are powered on each given draw may vary from draw to draw in accordance with a predetermined power control sequence controlled by the control circuitry <NUM>.

Preferably, the heating elements 11a can be powered sequentially, one per draw by a user, such that aerosol and/or gas is generated in a consistent basis on each draw.

Activation of each heating element 11a preferably results in a flash vaporisation of the aerosol generating material <NUM> in the recess 7a being heated by a heating element 11a. To this end, as an example only, activation of each heating element 11a heats the aerosol generating material <NUM> in the recess 7a being heated to between <NUM> to <NUM> degrees Celsius and preferably to between <NUM> degrees to <NUM> degrees Celsius. It will be appreciated that a heating element 11a itself may be controlled so as to reach any temperature between <NUM> to <NUM> degrees Celsius and that temperature may be tailored to meet the requirements for aerosol generation in a particular case.

The electrical power drawn by each heating element 11a can be controlled by pre-programming the electrical control circuitry <NUM> to suit the individual heating requirements of each of the plurality of recesses 7a containing aerosol generating material <NUM> formed in the receptacle <NUM>.

It will be appreciated that any combination of materials discussed herein could be placed in any given recess 7a.

In one example, the aerosol generating material <NUM> in at least one of the recesses 7a comprises a flavourant material, for example, menthol. In this example, the aerosol generating material <NUM> in the at least one of the recesses 7a may comprise a flavourant material and little or no tobacco based material. It will be appreciated that a heating element 11a arranged to heat aerosol generating material <NUM> in a recess 7a that comprises flavourant but no tobacco based material need not heat the aerosol generating material <NUM> to the same temperature or extent as that required for aerosol generating material <NUM> that does comprise a tobacco based material. For example, temperatures as low as <NUM> to <NUM> degrees C may be sufficient to cause the release of an acceptable amount of flavour.

The aerosol generating material <NUM> in different recesses 7a may comprise different flavourants.

In one example, one or more of the heating elements 11a are automatically controlled upon the sensor <NUM> detecting a draw being taken and one or more other of the heating elements 11a are manually controlled by the actuator <NUM>.

The manually controlled heating elements 11a may be for heating a particular flavourant which the user may wish to control when that flavourant is released.

The temperature to which aerosol generating material <NUM> comprising flavourant is heated may also be varied (for example, by the user varying the duration for which the actuator is actuated) to vary the taste intensity of the flavourant experienced by the user.

Although in <FIG> each heater element 11a is illustrated as being generally linear in shape this need not be the case. In one example, each heater element has a curved shape the curvature of which generally matches that of the recess that it is arranged to heat. This arrangement facilitates a uniform heating of the aerosol generating material in a recess and may provide a good heating rate.

In an example, the receptacle <NUM> may comprise a protective layer (not shown) overlying the recess or recesses 7a to seal the aerosol generating material <NUM> in the recess or recesses 7a. A user may remove the protective layer, for example, by peeling it off, to expose the aerosol generating material <NUM> in each recess or recesses 7a, either prior to or after fitting the receptacle <NUM> into the housing <NUM>. Once the replacement receptacle <NUM> has been fitted into the housing <NUM>, the user can close the lid 2a of the housing <NUM> so that the apparatus is ready for use.

The protective layer (not shown) may comprise any suitable material, for example, a polyimide such as Kapton™, paper, polymer, cellophane or aluminium foil and may be attached to the receptacle <NUM> by any suitable means, for example, glue.

The protective layer is preferably heat resistant and does not contribute adversely to the taste of the aerosol generating material <NUM> perceived by a user.

In examples in which the receptacle <NUM> is fitted into the housing <NUM> and the lid 2a is closed without the user first being required to remove the protective layer, the apparatus <NUM> is provided with means for rupturing the protective layer above each of the recesses 7a to expose the aerosol generating material <NUM> in the recesses 7a prior to the recesses 7a being heating for aerosol generation.

In one example, the receptacle <NUM> is in the form of a so called `blister pack' with the regions of the protective layer above the recesses 7a being easily rupturable to expose the aerosol generating material <NUM> in the recesses 7a. The underside of the lid 2a of the housing <NUM> may define a pattern of formations (not shown) having the same spatial arrangement as the recesses 7a and which when the lid 2a is pressed down into the closed position by a user ruptures those regions of the protective layer above the recesses 7a to expose the aerosol generating material <NUM> in the recesses 7a.

In another example, a rupture mechanism is included in the apparatus <NUM> which ruptures the protective layer above one or more of recesses 7a each time a user actuates the actuator <NUM> or automatically each time the sensor <NUM> detects that a user is taking a draw on the mouth piece <NUM>.

Referring now to <FIG> and <FIG>, there is illustrated an alternative example of a receptacle <NUM>' and heating arrangement <NUM>'. In this example, the receptacle <NUM>' is similar to the receptacle <NUM> described above and the heating arrangement <NUM>' comprises one or more heating elements <NUM>'a but heating element <NUM>'a is located inside a respective one of the recesses <NUM>'a. In this example, the aerosol generating material <NUM> in a recess <NUM>'a coats the heating element <NUM>'a that is in that recess <NUM>'a.

In this example, each heating element <NUM>'a is a coil (for example a flat or hemispherical or spiral coil) or mesh formed of resistive electrical wiring. In this example, the aerosol generating material <NUM> in each recess <NUM>'a coats the coil or mesh heating element <NUM>'a in that recess 7a. An advantage of this arrangement is that it facilitates consistent flash vaporisation of the aerosol generating material in a recess <NUM>'a. Furthermore, with this configuration, for example, the length of each coil or mesh may be selected so as to achieve a particular heat transfer characteristic.

As illustrated in <FIG>, in this alternative example of a receptacle <NUM>', a pair of holes <NUM> are formed through the receptacle <NUM>' in each of the recesses <NUM>'a to enable the power connections 11b to be connected to the heater elements <NUM>'a.

Referring now to <FIG>, a receptacle <NUM> may comprise a first plurality of walls <NUM> extending upright from the base of the receptacle <NUM> and running parallel to the longitudinal axis of the receptacle and a second plurality of walls <NUM> also extending upright from the base of the receptacle and running perpendicular to the longitudinal axis of the receptacle and which together define a plurality of compartments <NUM> each containing a respective one of the cavities 7a, in this example, recesses 7a. Sufficient headspace is provided between the compartments <NUM> and the underside of the lid 2a of the housing <NUM> to allow for circulation of aerosol and/or gas.

Alternatively, the first plurality of walls <NUM> the second plurality of walls <NUM> that define the compartments <NUM> may be part of the internal structure of the housing <NUM> rather than being integral with the receptacle <NUM>.

Advantageously, the walls <NUM> and <NUM> may act as heat barriers. Accordingly, providing each recess in a separate compartment in this way may inhibit the conduction of heat away from the recesses 7a so that the aerosol generating material <NUM> is efficiently heated.

As is schematically illustrated in <FIG>, in some examples, particularly those in which the receptacle <NUM> comprises an electrically conductive material, an electrical insulator <NUM>, <NUM> may be provided between the heating elements 11a and the receptacle <NUM> to prevent electrical shorts occurring between them. The electrical insulator <NUM>, <NUM> may, for example, comprise a polyimide such as Kapton™. As illustrated in the example of <FIG>, the electrical insulator <NUM> may be in the form of a layer of electrically insulating tape attached to the underside (i.e. the side facing the heating elements 11a) of the receptacle <NUM>. Alternatively, as illustrated in <FIG>, an electrical insulator <NUM> may be provided that is separate from the receptacle <NUM> but which forms a barrier between the heating elements 11a and the underside of the receptacle <NUM>. The barrier may be in the form of a continuous sheet that separates substantially all of the underside of the receptacle <NUM> from the heating elements 11a or, as is illustrated in <FIG>, a plurality of discrete sections, each of which sections is positioned between a heating element 11a and the part of the underside of the receptacle <NUM> that that heating element 11a is for heating.

As is illustrated in <FIG>, in some examples, a thermal barrier <NUM> (represented by pairs of vertical lines) is located around the periphery of each recess of the receptacle <NUM> so as to inhibit the conduction of heat away from the recesses to ensure that the aerosol generating material <NUM> is sufficiently heated.

Examples of suitable materials for thermal barriers include: ceramics, aerogel materials (incorporating a foamed internal structure - foamed silica aerogels) fibrous insulating materials for example inorganic fibres.

Referring now to <FIG>, there is schematically illustrated an example of an alternative receptacle <NUM> that can be used in the apparatus <NUM> instead of the receptacle <NUM>.

The receptacle <NUM> comprises a flat plate <NUM> and a blister pack <NUM> attached to a surface of the flat plate <NUM> to define a lid. The blister pack <NUM> comprises a plurality of generally hemispherical blisters <NUM> arranged in an array, in this example, an array comprising two rows and four columns. Each blister <NUM> covers a respective part of the surface of the flat plate <NUM> and co-operates with that part of the surface to define a cavity <NUM> containing aerosol generating material <NUM>. The aerosol generating material <NUM> rests on the surface within each cavity <NUM>.

The flat plate <NUM> may comprise any suitable heat conductive and resistant material, for example, a polyimide such as Kapton™, or a metal such as aluminium. The blister pack <NUM> may comprise any suitable heat resistant material, for example, a suitable polymer, a foil, or laminated films.

The blister pack <NUM> may be attached to the flat plate <NUM> by attachment means <NUM>. In one example, the attachment means <NUM> is an adhesive, for example a glue such as Polyvinyl acetate (PVA).

As schematically illustrated in <FIG>, the adhesive <NUM> may be located between the surface of the flat plate <NUM> and the blister pack <NUM> as a grid of criss-crossing adhesive tracks (illustrated by dotted lines in <FIG>) which securely fix the blister pack <NUM> to the surface of the flat plate <NUM>.

During the manufacturing of the receptacle <NUM>, a stencil (not shown) may be used to ensure a correct placement of the aerosol generating material <NUM> and of the tracks of adhesive <NUM>.

In use, the receptacle <NUM> is placed within the heating chamber <NUM> of the apparatus <NUM> (as described in the example above in respect of the receptacle <NUM>), so that each cavity <NUM> is above a respective one of the heater elements 11a of the heater arrangement <NUM>. The heater arrangement <NUM> and its associated control circuitry <NUM> may be used to heat the receptacle <NUM> in any of the ways described above in respect of the receptacle <NUM>. As illustrated in <FIG>, each blister <NUM> has one or more holes 76a to allow aerosol and/or a gas or vapour from the aerosol generating material <NUM> to exit a cavity <NUM>.

In one example, the one or more holes 76a are formed in the blisters <NUM> prior to the receptacle <NUM> being inserted into the housing <NUM>. For example, the one or more holes may be formed during the manufacturing of the receptacle <NUM> or by a user. In another example, the apparatus itself is provided with a means of forming the one or more holes 76a when the receptacle <NUM> is in the housing <NUM>.

One advantage of an entirely sealed blister pack is that shelf life/freshness of the aerosol generating material <NUM> is preserved.

An advantage of the type of receptacle <NUM> in this example is that it allows for the aerosol generating material <NUM> to be heated to a temperature sufficient to generate an aerosol without undesirable heat damage being caused to the blister pack <NUM> itself.

Referring now to <FIG> and <FIG>, there is schematically illustrated an example of another alternative receptacle <NUM> that can be used in the apparatus <NUM> instead of the receptacle <NUM>.

The receptacle <NUM> comprises a strip of flexible material <NUM> comprising one or more cavities <NUM> each provided by forming, for example etching, pressing or indenting a recess into the strip <NUM>. As illustrated in <FIG> and <FIG>, a plurality of such cavities <NUM> may be positioned at regular intervals longitudinally along the strip <NUM>.

Each of the cavities <NUM> may contain aerosol generating material <NUM> as described in the previous embodiments.

The strip <NUM> may, for example, comprise a thin metal sheet of, for example, copper, aluminium, stainless steel, silver, gold or an alloy, or comprises a thin metal plated sheet or a ceramic sheet.

The receptacle <NUM> may further comprise a protective sealing strip or film (not shown in the <FIG> and <FIG>) which overlies the strip <NUM> to seal the aerosol generating material <NUM> within the cavities <NUM>. The sealing strip may be attached to the strip <NUM> in any suitable way, for example, by being heat sealed or by being glued. The sealing strip may comprise any suitable heat resistive material, for example, a polyimide such as Kapton™, or metal such as those listed in the previous paragraph, or a suitable polymer or foil.

The receptacle <NUM> further comprises a pair of spaced apart cylindrical spools <NUM>, <NUM> to which the strip <NUM> is attached. The strip <NUM> is wrapped from one of its ends around a first of the spools <NUM> and wrapped from its other end around a second of the spools <NUM>.

In use, the receptacle <NUM> is mounted within the heating chamber <NUM> of the apparatus <NUM> and one of the first <NUM> and second <NUM> spools, in this example the first spool <NUM>, is connected by a motor drive link <NUM> to a motor <NUM> located in the housing, for example, in the electronics/power chamber <NUM>, which, when activated rotatably drives the first spool <NUM>. As the first spool <NUM> rotates, a further amount of the strip <NUM> is wound around the first spool <NUM> and a corresponding amount of the strip <NUM> is wound off the second spool <NUM> as the strip <NUM> is drawn onto the first spool <NUM> as indicated by the direction of travel arrow in <FIG>.

Each of a plurality of cavities <NUM> containing aerosol generating material <NUM> (not shown in <FIG> and <FIG>) may be positioned directly above a respective heating element <NUM>1a of a plurality of heating elements <NUM>1a, as illustrated in <FIG> and <FIG>, so that when a required heating element 11a or elements 11a are activated, aerosol and/or gas/vapour is generated accordingly. Once the aerosol generating material in one or more of the cavities <NUM> has been used, activating the motor <NUM> to rotate the first spool <NUM> causes the section of the strip <NUM> having the spent cavity or cavities <NUM> to be wound around the first spool <NUM> and a new section of the strip <NUM> having one or more un-used cavities <NUM> to be unwound from the second spool <NUM> thus positioning one or more fresh unused cavities <NUM> containing aerosol generating material over the heating elements 11a.

The movement of the strip <NUM> may automatically occur following one or more of the heating elements 11a being activated, either in response to a user manually actuating the actuator <NUM> or the sensor <NUM> detecting a draw on the mouth piece <NUM>.

As schematically illustrated in <FIG>, the power supply <NUM> may be used to power the motor <NUM> and, via power connections 11b, the heating elements 11a. The control circuitry <NUM> may be configured to ensure that there is a correct timing between the activation of the heating elements 11a and the motor <NUM>.

Once all of the cavities <NUM> in the receptacle <NUM> have been exhausted of aerosol generating material <NUM>, the receptacle <NUM> can be removed from the housing <NUM> and replaced with a new one.

If the receptacle <NUM> comprise a protective sealing strip or film which overlies the strip <NUM> which seals the aerosol generating material in the cavities <NUM>, then the apparatus <NUM> may be provided with a means for perforating the sealing strip above each cavity <NUM> to provide one or more holes to allow aerosol and/or a gas or vapour from the aerosol generating material <NUM> to exit the cavity <NUM>.

In the examples described above, the housing <NUM> of the apparatus <NUM> is provided with a lid 2a to provide access to the heating chamber <NUM> in order to allow user to insert and remove a receptacle <NUM>. In an alternative example, illustrated schematically in <FIG>, the apparatus <NUM> is modular and comprises a power chamber 13a containing a power supply (e.g. battery), an electronics chamber 13b containing the control circuitry, the heating chamber <NUM> and a combined aerosol formation (cooling) chamber and mouth piece <NUM>. At least the section of the apparatus <NUM> that defines the heating chamber <NUM> is separable from another section of the apparatus <NUM> to enable a receptacle <NUM> (not shown in <FIG>) to be inserted into the heating chamber <NUM> for use and then removed after all of the aerosol generating material <NUM> has been consumed.

The section of the apparatus <NUM> that defines the power chamber 13a may also be separable to enable batteries to be inserted into or removed and to provide access to the control circuitry. Finally, as already mentioned above, the mouthpiece/aerosol formation chamber <NUM> may be separable from the rest of the apparatus <NUM> in order to facilitate cleaning of the apparatus <NUM>.

As is illustrated in <FIG>, the arrows X indicate air flow through the heating chamber <NUM> during a draw taken by a user and the arrows Y indicate air flow through the aerosol formation chamber and mouthpiece <NUM> during a draw.

In the example described in <FIG>, the apparatus <NUM> is predominantly rectangular in cross section. In alternative examples, the apparatus <NUM> may comprise any suitable shape, for example, a generally oval cross section as illustrated in <FIG>, a generally circular cross section as illustrated in <FIG> and a polygonal cross section, for example, hexagonal as illustrated in <FIG>.

Although in the above described examples, the apparatus <NUM> comprises a single receptacle <NUM>, <NUM>, <NUM> in the heating chamber <NUM>, in alternative examples, the apparatus <NUM> comprises a plurality of receptacles arranged, for example, in a stacked configuration in the heating chamber <NUM>.

As is schematically illustrated in <FIG>, in one such stacked arrangement, a plurality of receptacles <NUM> and a plurality of heater arrangements <NUM> are provided with each heater arrangement <NUM> being for heating a respective one of the receptacles <NUM>. Each heater arrangement <NUM> again comprises a plurality of heater elements 11a (for clarity only two are labelled in <FIG>) each positioned to heat a cavity 270a in its associated receptacle <NUM>. Each receptacle <NUM> may take, for example, the form of any of the previously described receptacles and comprises one or more cavities 270a (for clarity only two are labelled in <FIG>) for containing, for example, any of the previously described aerosol generating materials. Again, each receptacle <NUM> may be provided with a sealing cover (not shown in <FIG>) for sealing the aerosol generating material in the cavities 270a. Any sealing cover may be removed or punctured by a user prior to use or the apparatus <NUM> may be provided with means for puncturing the sealing cover to enable aerosol and/or gas to be generated in use.

Each receptacle <NUM> and its associated heater arrangement <NUM> define a pair and the pairs of receptacles <NUM> and heater arrangements <NUM> are stacked one above the other in the heating chamber (not shown in <FIG>) at regular intervals. Each receptacle <NUM> and heater arrangement <NUM> pair may be positioned between barrier layers <NUM> which provide thermal and/or electrical insulation between pairs. Each barrier layer <NUM> may comprise any suitable material for thermally and/or electrically insulating a receptacle <NUM> and heater arrangement <NUM> pair, for example, metal, alloy, plated metal or heat resistant plastics.

Each of the heater arrangements <NUM> is connected to the electrical control circuitry <NUM> (not shown in <FIG>) of the apparatus <NUM>. The electrical control circuitry <NUM> may be arranged so that each of the heater elements 11a in any given heater arrangement <NUM> are controllable in any of the ways described previously.

The electrical control circuitry <NUM> may be arranged so that each heating arrangement <NUM> is independently operable from the other heater arrangements <NUM>. The electrical control circuitry <NUM> may be arranged so that plural heater elements 11a in the same heater arrangement <NUM> are simultaneously operable and/or plural heater elements 11a in different heater arrangements <NUM> are simultaneously operable.

In one example, the electrical control circuitry <NUM> is arranged so that use is made of one of the heater arrangements <NUM> until all of (or most of) the aerosol generating material in that heater arrangement's <NUM> receptacle <NUM> has been consumed at which time the electrical control circuitry <NUM> is used to switch to using a different one of the heater arrangements <NUM> and so on until all of (or most of) the aerosol generating material in the apparatus <NUM> has been consumed. In some examples, a user may manually control the control circuitry <NUM> to switch from making use of one heating arrangement <NUM> to another of the heating arrangements <NUM> when that user discerns that the currently used receptacle <NUM> is no longer producing sufficient aerosol. In other examples, the control circuitry <NUM> may automatically switch from using one heating arrangement <NUM> to another of the heating arrangements <NUM> in response to a sensor <NUM> indicating that the currently used receptacle <NUM> is no longer producing sufficient aerosol.

It will be appreciated that with such stacked arrangements, the time period between a user having to replace receptacles in the apparatus <NUM> is increased.

Although in the above examples, the cavities are illustrated as being generally oval in plan-view it will be appreciated that this is for the purpose of ease or illustration only and that the cavities may have any suitable shape (for example circular or a flattened oval in plan-view).

In each of the described embodiments above, the heating elements may take any suitable form, including the examples of resistive heating elements, infra-red heating elements and inductive heating elements as previously described.

Referring to <FIG>, there will now be described an example of steps in a method of providing a receptacle, such as the previously described receptacle <NUM>, containing material for generating an aerosol.

In a first step, a plurality of recesses 57a arranged in a matrix or array in a receptacle <NUM> are filled with a wet aerosol generating material <NUM>. The aerosol generating material <NUM> may comprise, for example, a combination of one or more of glycerol, tobacco extract, nicotine, tobacco extract flavour, binders, thickeners such as alginate, gums and chalk. The aerosol generating material <NUM> is in the form of a wet gel, slurry, liquid or the like and comprises a relatively large percentage per weight of water.

The aerosol generating material may comprise, for example:
On a dry weight basis.

In a second step, the receptacle <NUM> is placed in a drying environment, for example, in an oven (not shown), for drying in order to reduce the percentage per weight of water of the aerosol generating material <NUM> to a relatively small amount, resulting in a dry aerosol generating material <NUM> (similar to that described above) in which the percentage per weight of water is relatively small compared to that of the wet aerosol generating material <NUM>. In one example, the receptacle <NUM> is placed in an oven at around <NUM> degrees Celsius over a few hours, for example, <NUM> to <NUM> hours. In another example, the receptacle is placed in an oven at around <NUM> to <NUM> degrees Celsius, for <NUM> to <NUM> minutes or dried at <NUM> to <NUM> degrees Celsius for <NUM> to <NUM> minutes.

Typically, the percentage of water of the aerosol generating material <NUM> is reduced from a start percentage per weight of around <NUM> to <NUM>% to an end percentage per weight of around <NUM> to <NUM>%.

The dry aerosol generating material <NUM> may for example comprise a dried gel.

In some examples, if not already present, tobacco extract is sprayed or otherwise deposited on the dry aerosol generating material <NUM>. In other examples, if not already present, tobacco extract is sprayed or otherwise deposited on the aerosol generating material <NUM> prior to drying.

In a third step, the receptacle <NUM> is cut into a plurality of smaller sections (not shown), each smaller section comprising a matrix or array of recesses containing the dry aerosol generating material <NUM>. The matrix or array of recesses may for example be a <NUM> x <NUM> matrix or array as described above.

In a fourth step, a protective layer <NUM> is provided to overlie the recess or recesses 57a of each smaller section to seal the aerosol generating material <NUM> in those recess or recesses 57a in order to preserve the flavoursome properties of the aerosol generating material <NUM>.

The protective layer may take the same form as any of the protective layers previously described above in respect of the receptacle <NUM>.

Although in the above example the wet aerosol generating material <NUM> is treated by heating to reduce the percentage of water that it contains, it should be appreciated that other treatments can be used to the same effect. For example, the wet aerosol generating material <NUM> in the recesses 57a may be freeze dried to reduce the percentage of water that it contains.

Claim 1:
A method of preparing a receptacle (<NUM>) with an aerosol generating material, the method comprising:
providing one or more cavities (7a) of the receptacle (<NUM>) with a relatively wet aerosol generating material (<NUM>), the relatively wet aerosol generating material (<NUM>) comprising a percentage of water;
treating said relatively wet aerosol generating material (<NUM>) to reduce the percentage of water of said relatively wet aerosol generating material (<NUM>) to generate a relatively dry aerosol generating material (<NUM>) in the one or more cavities (7a).