The present specification relates to a cleaning consumable for cleaning an aerosol- generating device having a heating element, to a method of cleaning an aerosol-generating device, and to an aerosol-generating system comprising an aerosol-generating device and a cleaning consumable.

Aerosol-generating articles in which an aerosol-forming substrate for generating an inhalable aerosol is heated, rather than combusted, are known in the art. The aim of such heated aerosol-generating articles is to reduce known harmful smoke constituents produced by the combustion and pyrolytic degradation of tobacco in conventional cigarettes. Typically in such heated aerosol-generating articles, an aerosol is generated by the transfer of heat from a heat source to a physically separate aerosol-forming substrate or material, which may be located within, around or downstream of the heat source. During smoking, volatile compounds are released from the aerosol-forming substrate by heat transfer from the heat source and entrained in air drawn through the smoking article. As the released compounds cool, they condense to form an aerosol that is inhaled by the consumer.

WO2013102614 discloses an example of an aerosol-generating device in which an aerosol-forming substrate of an aerosol-generating article is heated in direct contact with a heating element to form an inhalable aerosol. In such a device configuration, heat from a heating element may be conveyed almost instantaneously to at least a portion of the aerosol-forming substrate when the heating element is actuated, and this may facilitate the rapid generation of an aerosol. Furthermore, the overall heating energy required to generate an aerosol may be lower than would be the case in a system where the aerosol-forming substrate does not directly contact a heating element and initial heating of the substrate occurs by convection or radiation. Where a heating element is in direct contact with an aerosol-forming substrate, the initial heating of portions of the substrate that are in contact with the heating element will be effected by conduction.

When an aerosol-forming substrate, such as a tobacco substrate, is heated, volatile compounds are released. Volatile compounds and aerosol evolved by the heat from the heating element may become deposited on the aerosol-generating device and in particular on a surface of the heating element. Particles of the aerosol-forming substrate itself may also become adhered to the heating element, particularly if the heating element is in direct contact with the aerosol-forming substrate. For example, when using the device described in WO2013102614, a heating blade warms a tobacco substrate to temperatures in excess of 200°C, releasing volatile compounds, nicotine and glycerol, all of which form a respiratory aerosol for inhalation by the consumer. However, residues and dust tend to collect inside the device after smoking multiple aerosol-generating articles, which means that periodic cleaning of the device and the heating-blade is required.

Particles and compounds adhered to and deposited on the heating element of an aerosol-generating device may prevent the heating element from functioning in an optimal manner. These particles and compounds may also break down during use of the aerosol-generating device and impart unpleasant or bitter flavours to a user. For these reasons it is desirable to clean the heating element periodically.

Cleaning may be effected by a pyrolysis method, in which the heating element is heated to a temperature sufficiently high to burn any residues or deposits. Pyrolysis on its own may not always be effective, however. A brush or scraper may be used as an alternative to, or in addition to, pyrolysis. However, it may be a delicate operation to physically clean the heating element of an aerosol-generating device without damaging the heating element.

As described herein, a cleaning consumable may be provided for cleaning a heating element of an aerosol-generating device. The cleaning consumable comprises a solvent-evolving substrate capable of releasing a cleaning solvent when heated by the heating element. The cleaning solvent is released into contact with the heating element. The cleaning consumable is dimensioned to engage with the aerosol-generating device such that the heating element can heat the solvent-evolving substrate to evolve the cleaning solvent. Thus, it is preferred that the cleaning consumable is dimensioned, at least in part, substantially identically to an engageable portion of an aerosol-generating article for generating an inhalable aerosol when heated by the aerosol-generating device. The solvent-evolving substrate is configured to be penetrated by the heating element of the aerosol-generating device and the solvent-evolving substrate is encapsulated or sealed to prevent egress of the cleaning solvent until the cleaning consumable is engaged with the aerosol-generating device. In preferred embodiments the cleaning consumable is rod-shaped and resembles a cigarette.

The solvent-evolving substrate is configured to be penetrated by the heating element of the aerosol-generating device. Thus, by the act of penetration the heating element is brought into close proximity to, or contact with, the solvent-evolving substrate prior to the step of heating. The solvent that is evolved when the solvent-evolving substrate is heated then contacts the heating element and can act to dissolve or loosen unwanted residues and deposits on the heating element.

The cleaning solvent acts to at least partially dissolve or chemically alter one or more residue or deposit left on the aerosol-generating device by the heating of an aerosol-generating article. Preferably the cleaning solvent is a solvent that acts to at least partially dissolve or chemically alter one or more residue or deposit left by the heating of a tobacco based substrate of an aerosol generating article.

The cleaning solvent is preferably sufficiently volatile that it swiftly evaporates after removal of the cleaning consumable from the aerosol-generating device. Thus, the solvent should not contaminate the aerosol-generating device such that the user can detect an unwanted taste or flavour during consumption of their next aerosol-generating article.

The solvent-evolving substrate is encapsulated or sealed to prevent egress of the cleaning solvent until the cleaning consumable is engaged with the aerosol-generating device. For example, the solvent-evolving substrate may be hermetically sealed within a polymeric or foil wrapper such that the cleaning solvent is retained within the substrate. The wrapper may then be pierced on engagement with the aerosol-generating device in order to allow egress of the cleaning solvent from the substrate. A heating element of the aerosol- generating device may be used to pierce a wrapper encapsulating a solvent-evolving substrate, in which case the engagement with the aerosol-generating device may be made simply to cause the heating element to be inserted into the solvent-evolving substrate. The combination of an encapsulated or sealed substrate and the ability of the substrate to be penetrated by the heater allows the use of volatile cleaning solvents, which would evaporate if not encapsulated or sealed, and allows the delivery of those solvents directly to the heater to effect the cleaning.

As used herein, an 'aerosol-generating device' relates to a device that interacts with an aerosol-forming substrate to generate an aerosol. The aerosol-forming substrate may be part of an aerosol-generating article, for example part of a smoking article. An aerosol- generating device may comprise one or more components used to supply energy from a power supply to an aerosol-forming substrate to generate an aerosol.

An aerosol-generating device may be described as a heated aerosol-generating device, which is an aerosol-generating device comprising a heating element. The heating element or heater is used to heat an aerosol-forming substrate of an aerosol-generating article to generate an aerosol, or the solvent-evolving substrate of a cleaning consumable to form a cleaning solvent.

An aerosol-generating device may be an electrically heated aerosol-generating device, which is an aerosol-generating device comprising a heating element that is operated by electrical power to heat an aerosol-forming substrate of an aerosol-generating article to generate an aerosol. An aerosol-generating device may be a gas-heated aerosol-generating device. An aerosol-generating device may be a smoking device that interacts with an aerosol-forming substrate of an aerosol-generating article to generate an aerosol that is directly inhalable into a user's lungs thorough the user's mouth.

As used herein, the term 'aerosol-forming substrate' relates to a substrate capable of releasing volatile compounds that can form an inhalable aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. An aerosol-forming substrate may be adsorbed, coated, impregnated or otherwise loaded onto a carrier or support. An aerosol-forming substrate may conveniently be part of an aerosol-generating article or smoking article.

An aerosol-forming substrate may be solid or liquid and may comprise nicotine. An aerosol-forming substrate may comprise tobacco, for example may comprise a tobacco- containing material containing volatile tobacco flavour compounds, which are released from the aerosol-forming substrate upon heating. In preferred embodiments an aerosol-forming substrate may comprise homogenised tobacco material, for example cast leaf tobacco.

As used herein, the terms 'aerosol-generating article' and 'smoking article' refer to an article comprising an aerosol-forming substrate that is capable of releasing volatile compounds that can form an aerosol. For example, an aerosol-generating article may be a smoking article that generates an aerosol that is directly inhalable into a user's lungs through the user's mouth. An aerosol-generating article may be disposable.

As used herein, an aerosol-generating article is a heated aerosol-generating article, which is an aerosol-generating article comprising an aerosol-forming substrate that is intended to be heated rather than combusted in order to release volatile compounds that can form an aerosol. The aerosol formed by heating the aerosol-forming substrate may contain fewer known harmful constituents than would be produced by combustion or pyrolytic degradation of the aerosol-forming substrate. An aerosol-generating article may be, or may comprise, a tobacco stick.

As used herein, the term "cleaning consumable" relates to a consumable article that may be inserted into an aerosol-generating device to effect or facilitate cleaning of the aerosol-generating article. A cleaning consumable comprises a cleaning solvent that may be released or evolved from the cleaning consumable.

As used herein, the term 'solvent-evolving substrate' relates to a substrate capable of releasing volatile compounds that act as a cleaning solvent. Such volatile compounds may be released by heating the solvent-evolving substrate. A solvent-evolving substrate may be adsorbed, coated, impregnated or otherwise loaded onto a carrier or support.

The solvent-evolving substrate may be, or may comprise, a porous substrate material. The porous substrate material may be a foam, or may comprise matted fibres. A volatile cleaning solvent may be maintained within pores of the porous substrate material. For example, the solvent-evolving substrate may be a polymeric foam that is soaked with a cleaning solvent.

The solvent-evolving substrate may define a slot or hole for receiving the heating element during engagement between the cleaning consumable and the aerosol-generating device. Thus, the heating element may be sheathed within the solvent-evolving substrate when actuated to heat the solvent-evolving substrate. The solvent-evolving substrate may be pierceable by the heating element. For example, the solvent evolving substrate may comprise a foam that is pierceable by the heating element.

It may be particularly preferred that a portion of the cleaning consumable is configured to contact the heating element during engagement or dis-engagement between the cleaning consumable and the aerosol-generating device. The cleaning consumable may, for example, be arranged or configured to wipe the heating element during removal of the cleaning consumable from the aerosol-generating device. Thus, deposits and residues that have been acted on by the cleaning solvent may be removed by a physical interaction with the cleaning consumable. In preferred embodiments a portion of the solvent-evolving substrate interacts with eth heating element to wipe the heating element when the cleaning consumable is removed from the aerosol-generating device.

The heating element may conveniently be shaped as a needle, pin, rod, or blade that may be inserted into an aerosol-generating article and into a solvent-evolving substrate of a cleaning consumable. The aerosol-generating device may comprise more than one heating element and in this description reference to a heating element means one or more heating elements.

In preferred embodiments the solvent-evolving substrate may comprise one or more material selected from the list consisting of polyethylene, polypropylene, polyethylene- polypropylene, polyethyleneterephthalate, ethyl vinyl acetate, or natural cellulose sponge or fibre, or glass matted fibre.

In preferred embodiments the cleaning solvent may comprise, or may be, one or more solvent selected from the list consisting of 2-butoxyethanol, glycol ether, mineral oil, ethylacetate, isopropanol, ethanol, isoamylacetates, isoamylbutyrate, and hexane acid ethylester.

In addition to a cleaning solvent, the cleaning consumable may comprise a fragrance that may be evolved when the cleaning consumable is heated by the heating element. The fragrance may be released into the atmosphere and may act do mask any unpleasant odours caused by residues remaining on the aerosol-generating device after use. The fragrance may provide an air freshening effect by emitting pleasant odours and fragrances when the cleaning consumable is heated. Preferably the fragrance is sufficiently volatile that it swiftly evaporates after removal of the cleaning consumable from the aerosol-generating device. Thus, the fragrance should not contaminate the aerosol-generating device such that the user can detect an unwanted taste or flavour during consumption of their next aerosol- generating article.

In preferred embodiments the fragrance may include one or more fragrance ingredient selected from the list consisting of Amyl Cinnamal, Amylcinnamyl Alcohol, Benzyl Alcohol, Benzyl Salicylate, Cinnamyl Alcohol, Cinnamal, Citral, Coumarin, Eugenol, Geraniol, Hydroxycitronellal, Hyroxymethylpentylcyclohexenecarboxaldehyde, Isoeugenol, Anisyl Alcohol, Benzyl Benzoate, Benyl Cinnamate, Citronellol, Farnesol, Hexyl Cinnamaldehyde 2-methyl-3-(4-tert-butylbenzyl)propionaldehyde, d-Limonene, Linalool, Methyl heptine carbonate, and3-Methyl-4-(2,6,6-trimethyl-2-cyclohexen-1 -yl)-buten-2-one.

The fragrance may be absorbed or otherwise retained by the solvent-evolving substrate. Alternatively the fragrance may be absorbed or retained by a fragrance-evolving substrate that is separate from the solvent-evolving substrate. Materials stated above to be suitable for use as part of a solvent-evolving substrate are equally suitable for a flavour evolving substrate.

The cleaning consumable may comprise a plurality of elements, including the solvent-evolving substrate, assembled by a wrapper to form a rod. The rod is preferably of similar size and shape to an aerosol-generating article designed to be consumed with the aerosol-generating device. Thus, the cleaning consumable may have an external diameter of between approximately 5 millimetres and approximately 12 millimetres, for example of between approximately 6 millimetres and approximately 8 millimetres. In a preferred embodiment, the cleaning consumable has an external diameter of 7.2 millimetres +/- 10%.

The cleaning consumable may have a total length of between approximately 30 millimetres and approximately 100 millimetres. In preferred embodiments, the cleaning consumable has a total length of between 40 mm and 50 mm, for example approximately 45 millimetres.

Preferably the solvent-evolving substrate is in the form of a rod. Preferably the solvent-evolving substrate is located at a distal end of the rod for insertion into a cavity of the aerosol-generating device. A distal end of the rod may be penetrable by a heating element of the aerosol-generating device. For example, a distal end of the rod may define a slot or hole through which a heating element can be inserted. A distal end of the rod may be sealed by a foil or film that is penetrable by a heating element.

In preferred embodiments, the cleaning consumable is in the form of a rod comprising a cylindrical solvent-evolving substrate, a rigid cylindrical member and a tip. The rigid cylindrical member is of approximately the same diameter as the cylindrical solvent- evolving substrate and is located between the solvent-evolving substrate and the tip. The function of the rigid cylindrical member is to provide rigidity to the cleaning consumable to allow a user to engage the cleaning consumable with an aerosol-generating device. The rigid cylindrical member may be a hollow tube, for example a hollow acetate tube. The tip acts to terminate a proximal end of the rod. The tip may, for example, be a film or foil, or may be an insert such as a plastic insert.

The solvent evolving substrate may have a length of between approximately 5 mm and approximately 15 mm, for example between about 8 mm and about 12 mm. In one embodiment, the solvent evolving substrate may have a length of approximately 10 mm. In a preferred embodiment, the solvent evolving substrate has a length of approximately 12 mm.

The rigid cylindrical member may have a length of between approximately 5 millimetres and approximately 35 mm. In a preferred embodiment, the rigid cylindrical member has a length of approximately 25 millimetres.

The tip may have a length of between 1 mm and 10 mm, for example about 5 mm.

The wrapper may be a conventional cigarette paper. Advantageously, the elements of the cleaning consumable may be assembled using known cigarette assembly techniques. A method of cleaning an aerosol-generating device comprising a heating element for heating an aerosol-generating article, may comprise the steps of engaging a cleaning consumable with the aerosol-generating device, the cleaning consumable comprising a solvent-evolving substrate, and actuating the heating element such that the solvent-evolving substrate is heated and evolves a cleaning solvent. Preferably the cleaning solvent contacts the heating element.

The heating element of the aerosol-generating device penetrates the solvent- evolving substrate. Preferably the method comprises the step of removing the cleaning consumable from engagement with the aerosol-generating device, in which the heating element is wiped by the cleaning consumable as the cleaning consumable is removed from engagement with the aerosol-generating device. Thus, any residue or deposit on the heating element, for example a tobacco residue or deposit, may be loosened or partially dissolved by the cleaning solvent, and may then be wiped from the heating element by interaction with the solvent-evolving substrate.

The aerosol-generating device may be capable of actuating the heating element according to more than one heating profile. For example, there may be a first heating profile used for heating an aerosol-generating article to generate an inhalable aerosol and a second heating profile for heating a cleaning consumable. The heating profile for heating a cleaning consumable may have a lower maximum temperature than the heating profile for heating an aerosol-generating article. For example, the cleaning consumable may be heated to a maximum temperature that is lower than 150 °C, for example less than 120 °C, or less than 100 °C. In preferred embodiments the cleaning consumable may be heated to a temperature of between 60 °C and 120 °C.

Where an aerosol-generating device is capable of heating a heating element according to more than one heating profile, a user may be able to select which heating profile is used. For example, a user may be able to press a button that actuates the heating element according to a cleaning profile after a cleaning consumable has been inserted into the device. Alternatively, the aerosol-generating device may automatically detect the presence of the cleaning consumable and automatically actuate an appropriate cleaning profile. Thus, the cleaning consumable may be marked with a tag that can be detected by the aerosol-generating device, or may be slightly thicker or thinner than an aerosol- generating article, or may comprise other means for allowing detection of the cleaning consumable by the aerosol-generating device.

An aerosol-generating system may be provided comprising an aerosol-generating device having a heating element and a cleaning consumable for engagement with the aerosol-generating device. Preferably the cleaning consumable is a cleaning consumable as described above. The system may further comprise a plurality of aerosol-generating articles for generating an inhalable aerosol when heated by the aerosol-generating device.

Aerosol-generating articles may be packaged in a box or carton that contains a plurality of the aerosol-generating articles and a cleaning consumable. Thus, a user may be prompted to clean the aerosol-generating article on a regular basis before starting to consume a further box or carton of aerosol-generating articles.

Exemplary embodiments will now be described with reference to the figures, in which;

Figure 1 is a schematic cross-sectional diagram of a first embodiment of a cleaning consumable;

Figure 2 is a schematic cross-sectional diagram of the first embodiment of the cleaning consumable of Figure 1 engaged with an aerosol-generating device;

Figure 3 is a schematic cross-sectional diagram of a second embodiment of a cleaning consumable; and

Figure 4 is a schematic cross-sectional diagram of the second embodiment of the cleaning consumable of Figure 3 engaged with an aerosol-generating device.

Figure 1 illustrates a cleaning consumable 10 according to a first embodiment. The cleaning consumable 10 comprises a solvent-evolving substrate 20, a rigid support element 30, and a tip 40. These three elements are arranged sequentially and in coaxial alignment and are assembled by a cigarette paper 50 to form a rod. The rod has a proximal end 12, which terminates in the tip 40, and a distal end 13 located at the opposite end of the rod to the proximal end. When assembled, the cleaning consumable 10 is 45 millimetres long and has a diameter of 7.2 millimetres.

The solvent-evolving substrate 20 is 20 mm in length and is disposed towards the distal end 13 of the cleaning consumable 10. The solvent-evolving substrate 20 comprises a substantially cylindrical porous polyethylene foam, for example a porous wicking material as supplied by Porex®. A longitudinally disposed cylindrical cavity or hole 22 is defined in the foam. Pores in the foam retain a liquid component of the solvent evolving substrate comprising ethylacetate cleaning solvent. The liquid component also comprises a fragrance ingredient such as linalool. A foil seal 60 is disposed over the distal end 13 of the cleaning consumable 10 and acts to prevent egress of volatile elements of the solvent-evolving substrate 20.

The rigid support element 30 is a hollow acetate tube having a length of 18 mm. This element of the cleaning consumable extends the length of the consumable and facilitates the insertion and removal of the cleaning consumable with respect to an aerosol-generating device.

The tip is a polyethylene foam cylinder having a length of 7 millimetres. The tip 40 improves the appearance of the cleaning consumable.

The elements identified above are assembled by being tightly wrapped within the cigarette paper 50. The paper in this specific embodiment is a standard cigarette paper. The interface between the paper and each of the elements locates the elements and defines the rod of the cleaning consumable 10.

Figure 2 illustrates the cleaning consumable 10 when engaged with an aerosol- generating device. The aerosol-generating device 210 comprises a sheath 212 and a cavity 213 for receiving an aerosol-generating article (not shown) for consumption. The cavity may also receive a cleaning consumable 10. A heating element 290 is located within the cavity 213 and positioned to engage with a distal end of an aerosol-generating article and the distal end 13 of the cleaning consumable 10. The heating element 290 is formed from an electrically insulating ceramic material, such as alumina, with metallic tracks deposited on a surface of the ceramic. The metallic tracks are coupled to a power supply and heat by means of resistive heating. The heating element is shaped in the form of a blade.

When used to consume an aerosol-generating article, the aerosol-generating article is pushed into the cavity 213 such that the heating element 290 penetrates an aerosol- forming substrate of the aerosol-generating article. The heating element is then actuated to heat the aerosol-forming substrate and generate an inhalable aerosol. Thus, the aerosol- generating article is consumed. After consumption, the aerosol-generating article is removed from the cavity 213. Residues derived from the aerosol-forming substrate may adhere to the surface of the heating element and it is desirable to remove these residues periodically. To this end the aerosol-generating article may be engaged with a cleaning consumable 10, as shown in Figure 2.

The cleaning consumable 10 is engaged with the device 210 in the same manner as an aerosol-generating article is engaged with the device 210. The cleaning consumable 10 is inserted into the cavity 213 of the device 210 and, by applying a force to the cleaning consumable 10, the heating element 290 penetrates the foil seal 60 and enters the cavity 22. Once properly located, the heating element 290 is actuated and heats the cavity 22 of the cleaning consumable. The cleaning solvent retained within pores of the solvent-evolving substrate 20 is volatilised and interacts with residues on the heating element. This interaction may dissolve the residues and facilitate cleaning of the heating element.

In addition to the generation of a cleaning solvent, a fragrance is generated by volatilisation of the fragrance ingredient. This fragrance is dissipated into the atmosphere.

After a period of time power supply to the heating element is turned off and the cleaning consumable is removed from the aerosol-generating article. Any cleaning solvent or fragrance remaining on the heating element evaporates swiftly and the aerosol-generating device may be used for consuming further aerosol-generating articles.

Figure 3 illustrates an alternative embodiment of a cleaning consumable 310. The consumable is similar to the cleaning consumable described in relation to figure 1 and comprises a solvent-evolving substrate 320, a rigid support element 330, and a tip 340. These three elements are arranged sequentially and in coaxial alignment and are assembled by a cigarette paper 350 to form a rod. The rod has a proximal end 312, which terminates in the tip 340, and a distal end 313 located at the opposite end of the rod to the proximal end. When assembled, the cleaning consumable 310 is 45 millimetres long and has a diameter of 7.2 millimetres. The cleaning consumable 310 differs from that described in relation to figure 1 in that the solvent-evolving substrate 320 has no cavity.

The solvent-evolving substrate 320 is formed from a porous polyethylene foam that is penetrable by the heating element 290 of an aerosol-generating device 210. In use, as illustrated in figure 4, the cleaning consumable 310 is inserted into the cavity 213 of an aerosol-generating device 210. A force is applied to the cleaning consumable sufficient to cause the solvent-evolving substrate 310 to be penetrated by the heating element 290. Once inserted, the heating element 290 is activated and heats up. The solvent-evolving substrate is heated and cleaning solvent retained within pores of the solvent-evolving substrate is volatilised and can interact with any residues on the heating element.

After a period of time power supply to the heating element is turned off and the cleaning consumable is removed from the aerosol-generating article. Physical interaction between the solvent-evolving substrate 310 and the heating element 290 causes the heating element to be wiped as the cleaning consumable is removed. Thus, any deposits or residues that may have been partially-dissolved by the cleaning solvent may be wiped from the heating element on removal of the cleaning consumable. The exemplary embodiments described above illustrate but do not limit the invention. In view of the above discussed exemplary embodiments, other embodiments consistent with the above exemplary embodiments will now be apparent to one of ordinary skill in the art.