A SUBSTITUTE SMOKING CONSUMABLE

Abstract

 Disclosed is a consumable for a smoking substitute system. The consumable comprises an aerosol-forming substrate formed of a moulded porous freeze-dried mixture comprising a plant material. Also disclosed is a smoking substitute system and a method for forming the consumable.

Description

Field of the disclosure

[0001] The present disclosure relates to a consumable for a smoking substitute system. It also relates to a consumable for a smoking substitute system, and a method of forming an aerosol-forming substrate of the consumable.

Background

[0002] The "smoking" of tobacco is generally considered to expose a smoker to potentially harmful substances. It is generally thought that a significant amount of the potentially harmful substances are generated through the heat caused by the burning and/or combustion of the tobacco and the constituents of the burnt tobacco in the tobacco smoke itself.

[0003] Conventional combustible smoking articles, such as cigarettes, typically comprise a cylindrical rod of tobacco comprising shreds of tobacco which is surrounded by a wrapper, and usually also a cylindrical filter axially aligned in an abutting relationship with the wrapped tobacco rod. The filter typically comprises a filtration material which is circumscribed by a plug wrap. The wrapped tobacco rod and the filter are joined together by a wrapped band of tipping paper that circumscribes the entire length of the filter and an adjacent portion of the wrapped tobacco rod. A conventional cigarette of this type is used by lighting the end opposite to the filter, and burning the tobacco rod. The smoker receives mainstream smoke into their mouth by drawing on the mouth end or filter end of the cigarette.

[0004] Combustion of organic material such as tobacco is known to produce tar and other potentially harmful by-products. There have been proposed various smoking substitute systems (or "substitute smoking systems") in order to avoid the smoking of tobacco.

[0005] Such smoking substitute systems can form part of nicotine replacement therapies aimed at people who wish to stop smoking and overcome a dependence on nicotine.

[0006] Smoking substitute systems include electronic systems that permit a user to simulate the act of smoking by producing an aerosol (also referred to as a "vapour") that is drawn into the lungs through the mouth (inhaled) and then exhaled. The inhaled aerosol typically bears nicotine and/or flavourings without, or with fewer of, the odour and health risks associated with traditional smoking.

[0007] In general, smoking substitute systems are intended to provide a substitute for the rituals of smoking, whilst providing the user with a similar experience and satisfaction to those experienced with traditional smoking and with combustible tobacco products. Some smoking substitute systems use smoking substitute articles that are designed to resemble a traditional cigarette and are cylindrical in form with a mouthpiece at one end.

[0008] The popularity and use of smoking substitute systems has grown rapidly in the past few years. Although originally marketed as an aid to assist habitual smokers wishing to quit tobacco smoking, consumers are increasingly viewing smoking substitute systems as desirable lifestyle accessories.

[0009] There are a number of different categories of smoking substitute systems, each utilising a different smoking substitute approach.

[0010] One approach for a smoking substitute system is the so-called "heat not burn" ("HNB") approach in which tobacco (rather than an "e-liquid") is heated or warmed to release vapour. The tobacco may be leaf tobacco or reconstituted tobacco. The vapour may contain nicotine and/or flavourings. In the HNB approach the intention is that the tobacco is heated but not burned, i.e. the tobacco does not undergo combustion.

[0011] A typical HNB smoking substitute system may include a device and a consumable. The consumable may include the tobacco material. The device and consumable may be configured to be physically coupled together. In use, heat may be imparted to the tobacco material by a heating element of the device, wherein airflow through the tobacco material causes moisture in the tobacco material to be released as vapour. A vapour may also be formed from a carrier in the tobacco material (this carrier may for example include propylene glycol and/or vegetable glycerine) and additionally volatile compounds released from the tobacco. The released vapour may be entrained in the airflow drawn through the tobacco.

[0012] As the vapour passes through the consumable (entrained in the airflow) from an inlet to a mouthpiece (outlet), the vapour cools and condenses to form an aerosol for inhalation by the user. The aerosol will normally contain the volatile compounds.

[0013] In HNB smoking substitute systems, heating as opposed to burning the tobacco material is believed to cause fewer, or smaller quantities, of the more harmful compounds ordinarily produced during smoking. Consequently, the HNB approach may reduce the odour and/or health risks that can arise through the burning, combustion and pyrolytic degradation of tobacco.

[0014] A first existing implementation of the HNB approach is the IQOS™ device from Philip Morris Ltd. The IQOS™ device uses a consumable, including reconstituted tobacco contained within a metallic foil and paper wrapper. The consumable is a cylindrical, rod-shaped consumable designed to resemble a traditional cigarette which is inserted into a heater device. The heater device has a thermally conductive heating blade which penetrates the reconstituted tobacco of the consumable, when the consumable is inserted into the heating device. Activation of the heating device heats the heating element, which, in turn, heats the tobacco in the consumable. The heating of the tobacco causes it to release nicotine vapour and flavours which may be drawn through the mouthpiece by the user through inhalation.

[0015] A second existing implementation of the HNB approach is the device known as Glo™ from British American Tobacco. Glo™ also uses a rod-shaped consumable similar in appearance to a traditional cigarette. The consumable includes reconstituted tobacco in a paper wrapping which is heated in a heating device. When the consumable is placed in the heating device, the tobacco is surrounded by a heating element. Activation of the heating device heats the heating element, which, in turn, heats the tobacco in the consumable. The heating of the tobacco causes it to release nicotine vapour and flavours which may be drawn through the consumable by the user through inhalation. The tobacco, when heated by the heating device, is configured to produce vapour when heated rather than when burned (as in a traditional cigarette). The tobacco may contain high levels of aerosol formers (carrier), such as vegetable glycerine ("VG") or propylene glycol ("PG").

[0016] Common to both the IQOS™ and Glo™ systems is uneven and incomplete heating of the tobacco, or possible burning of some regions of the tobacco.

[0017] Both devices also fail to conceal the residues which remain in the consumable after heating, these residues being both aesthetically unpleasing and also presenting a contamination risk to the user during removal of the consumable from the device.

[0018] Furthermore, the aerosol formers may leach from the consumable to stain and/or dampen the paper wrapping which is aesthetically unappealing and which can lead to transfer of the aerosol formers to contaminate the user.

[0019] Aspects and embodiments of the disclosure were devised with the foregoing in mind.

Summary

[0020] At its most general, the present disclosure relates to an aerosol-forming article e.g. a smoking substitute article such as an HNB consumable having a moulded porous plant material substrate arranged between an inlet and outlet of the consumable for airflow therethrough.

[0021] In a first aspect, there is provided a consumable for a smoking substitute system, the consumable comprising an aerosol-forming substrate formed of a moulded mixture comprising a plant material, the substrate having a porosity of between 20% and 70%.

[0022] The provision of a moulded porous mixture may allow for the passage of airflow or vapour flow through the mixture. In this way, components of the substrate may be entrained in the airflow or vapour flow as it passes through the substrate.

[0023] The term "porosity" is used to describe the fraction of volume of voids with respect to total volume of the substrate. The porosity may be measured by the computed tomography method (i.e. using a CT scan to determine the volume of voids and total volume), or by the gas expansion method.

[0024] Optional features will now be set out. These are applicable singly or in any combination with any aspect.

[0025] In some embodiments, the porosity of the substrate may be between 40% and 50%.

[0026] The moulded mixture of the aerosol substrate may be freeze-dried. In other words, the aerosol-forming substrate may be formed of a moulded porous freeze-dried mixture comprising a plant material.

[0027] The provision of a consumable having an aerosol-forming substrate comprising a freeze-dried plant material may provide the consumable with a longer life span (i.e. shelf life) than a product that is not freeze-dried. Components of the freeze-dried material may then be released by passing e.g. vapour through the aerosol-forming substrate (i.e. during use of the consumable). The components of the freeze-dried material may be entrained in the airflow or vapour flow through the aerosol-forming substrate.

[0028] The aerosol-forming substrate may be capable of releasing at least one volatile compound that can form an aerosol. The freeze-dried mixture may comprise at least one volatile compound. The freeze-dried mixture may comprise nicotine.

[0029] The aerosol-forming substrate of the consumable may be an extruded aerosol-forming substrate. That is, the substrate may be formed by way of an extrusion process in which the material forming the substrate is moved (e.g. pushed or pulled) through a die.

[0030] The aerosol-forming substrate may alternatively be e.g. die-pressed, rolled, etc.

[0031] The aerosol-forming substrate may have a porosity of between 20% and 70%. For example, the aerosol-forming substrate may have a porosity of between 40% and 50%.

[0032] An airflow path may extend through the consumable between an inlet and an outlet of the consumable (e.g. a housing of the consumable). The inlet may be at an upstream end of the consumable and the outlet may be at a downstream end of the consumable (e.g. housing). The airflow path may pass through at least a portion of the aerosol-forming substrate. Thus, the aerosol-forming substrate may be disposed between the inlet and the outlet.

[0033] As used herein, the terms "upstream" and "downstream" are intended to refer to the flow direction of the vapour/aerosol i.e. with the downstream end of the consumable being the mouth end or outlet where the aerosol exits the consumable for inhalation by the user. The upstream end of the consumable is the opposing end to the downstream end.

[0034] The aerosol-forming substrate may comprise upper and lower surfaces spaced by opposing longitudinally-extending transverse surfaces wherein the depth of the substrate (between the upper and lower surfaces) and the width of the substrate (between the opposing transverse surfaces) are unequal e.g. the width is greater than the depth. In other embodiments, the substrate may be cylindrical (i.e. rod-shaped).

[0035] In some embodiments, the upper and lower surfaces are substantially planar and may be equally spaced by the transverse surfaces (i.e. the upper and lower surfaces are parallel to one another) such that the substrate is a planar substrate.

[0036] The opposing transverse surfaces may be planar and substantially parallel to one another. Where the upper and lower surfaces are planar, the planar transverse surfaces may be substantially perpendicular to the upper and lower surfaces such that the planar substrate has a substantially rectangular transverse cross section i.e. the substrate is a cuboid substrate.

[0037] The transverse cross section is defined by a face having edges defining the width and depth i.e. the term "transverse cross section" is used to denote a cross section through the consumable perpendicular to the longitudinal axis/length of the planar substrate/consumable. The substrate has opposing longitudinal end faces (an upstream end face and a downstream end face) which will each comprise a transverse cross section.

[0038] The substrate may have a greater width and length than depth. The length and width may be equal but, preferably, the length is greater than the width such that the substrate has substantially rectangular upper and lower surfaces. The length of the substrate (between the upstream and downstream end faces) may be between 10 and 20 mm e.g. between 10 and 15 mm. The width of the substrate (between opposing transverse surfaces) may be between 7 and 18 mm e.g. between 8 and 14 mm or 10 and 12 mm. The depth of the substrate (between the upper and lower surfaces) may be between 1 and 8 mm, e.g. between 2 and 7 mm e.g. around 2 mm or around 6 mm.

[0039] In some embodiments, the consumable comprises a single aerosol-forming substrate e.g. a single planar substrate as described above. In this case, the depth of the substrate is preferably between 5 and 7 mm e.g. around 6 mm.

[0040] The substrate may have a hollow core. In such an embodiment, air may flow through the hollow core and through the (porous) body of the substrate. In such an embodiment, the airflow downstream of the substrate may be a combination of airflow through the substrate and airflow through the hollow core of the substrate.

[0041] The consumable may further comprise a filter downstream of the substrate. The filter may have a non-circular transverse cross-section. The transverse cross-section of the filter may match the transverse cross-section of the substrate.

[0042] The filter may comprise upper and lower surfaces spaced by opposing longitudinally-extending transverse surfaces wherein the depth of the filter (between the upper and lower surfaces) and the width of the filter (between the opposing transverse surfaces) are unequal.

[0043] In some embodiments, the upper and lower surfaces are substantially planar and may be equally spaced by the transverse surfaces (i.e. the upper and lower surfaces are parallel to one another) such that the filter is a planar filter.

[0044] The opposing transverse surfaces may be substantially parallel to one another and substantially perpendicular to the upper and lower surfaces such that the planar filter has a substantially rectangular transverse cross section i.e. the filter is a cuboid filter.

[0045] The filter preferably has a greater width and length than depth. The depth of the filter may be between 4 and 8 mm, e.g. between 5 and 7 mm e.g. around 6 mm. The width of the filter may be between 7 and 18 mm e.g. between 8 and 14 mm or 10 and 12 mm. The length of the filter may be between 2mm and 25 mm e.g. between 3mm and 22mm.

[0046] The filter has an upstream longitudinal end face which faces and may abut the downstream longitudinal end face of the substrate.

[0047] The downstream longitudinal end face of the filter may comprises a curved/rounded surface (e.g. a convex surface such as a semi-circular surface).

[0048] The filter may comprise a hollow bore. The hollow bore may extend from the upstream longitudinal end face of the filter to the downstream longitudinal face of the filter. The hollow bore may have a circular, rectangular or obround transverse cross sectional area. The bore may have a uniform transverse cross-sectional area.

[0049] The filter may be comprised of cellulose acetate or polypropylene tow. The filter may be comprised of activated charcoal. The filter may be comprised of paper. The filter may be comprised of plant material e.g. extruded or pressed plant material. The filter may be circumscribed with a plug wrap e.g. a paper plug wrap.

[0050] In some embodiments, the filter and/or the substrate may comprise at least one liquid release member.

[0051] The liquid release member can comprise an envelope for containing the liquid. The envelope can be rigid and fragmentable under pressure (e.g. upon contact with the heating element). Alternatively, the envelope can be meltable upon application of heat.

[0052] The consumable may comprise a spacer e.g. a paper/cardboard spacer interposed between the filter and the substrate. The spacer defines a space or cavity or chamber downstream from the aerosol-forming substrate. For example, it may be provided between the aerosol-forming substrate and the filter. The spacer acts to allow both cooling and mixing of the aerosol.

[0053] The spacer may be a planar spacer e.g. having a substantially rectangular or substantially obround transverse cross section. The spacer may have a transverse cross-section matching the transverse cross section of the substrate and/or filter.

[0054] The spacer preferably has a greater width and length than depth. The length and width may be equal but, preferably, the width is greater than the length. The depth of the spacer may be between 4 and 8 mm, e.g. between 5 and 7 mm e.g. around 6 mm. The width of the spacer may be between 7 and 18 mm e.g. between 8 and 14 mm or 10 and 12 mm.

[0055] The consumable may further comprise a wrapping e.g. a paper or cardboard wrapping that encloses the upper and lower surfaces and the transverse walls of the substrate (and filter/spacer where present).

[0056] As is set forth above, the consumable comprises a housing that at least partly encloses the substrate. The housing may have a non-circular transverse cross-section. The transverse cross-section of the housing may match the transverse cross-section of the substrate.

[0057] The housing may be self-supporting. The term "self-supporting" is intended to refer to a housing formed of a material that does not flex or bend under its own weight. Preferably, the housing is formed of a material that is substantially rigid or semi-rigid i.e. it is not easily flexible.

[0058] The paper wrappers provided on the prior art consumables are relatively thin and flimsy. Whilst physically containing the plant material before and after use of the consumable, they may not effectively contain residues in the spent consumable and handling of the spent consumable can result in residue transfer to the user. By providing a more structurally robust (self-supporting) housing, the consumable may become more akin to a cartridge or "pod" that effectively contains residue after use to protect a user from contamination.

[0059] At least a portion and preferably the whole of the housing has a wall thickness in the range of 0.8 to 8.0 mm, e.g. 1.5 to 5.0 mm.

[0060] The housing may have an inner surface defining a chamber housing the substrate wherein the inner surface is textured e.g. it may have a mesh texture.

[0061] The housing may be formed at least partly and preferably entirely of a biodegradable material such as cornstarch, bamboo, wood, palm, sugarcane, cardboard or paperboard, recycled or recyclable (thermoplastic) polymer material.

[0062] It may be formed of moulded pulp material e.g. natural fibre pulp material. The housing may be at least partly formed of moulded tobacco cellulose pulp, wood pulp, bamboo pump, palm pulp or bagasse pulp. Bagasse pulp is most preferred.

[0063] The housing may comprise upper and lower walls spaced by opposing longitudinally-extending transverse walls wherein the depth of the housing (between the upper and lower walls) and the width of the housing (between the opposing transverse walls) are unequal e.g. the width is greater than the depth.

[0064] In some embodiments, the upper and lower walls are substantially planar and may be equally spaced by the transverse walls (i.e. the upper and lower walls are parallel to one another) such that the housing is a planar housing.

[0065] The opposing transverse walls may be planar and substantially parallel to one another. Where the upper and lower walls are planar, the planar transverse walls may be substantially perpendicular to the upper and lower walls such that the planar housing has a substantially rectangular transverse cross section i.e. the housing is a cuboid housing.

[0066] Preferably, the transverse cross-section of the housing and the chamber matches the transverse cross-section of the substrate.

[0067] The housing may have an at least partly open upstream longitudinal end face. Alternatively, as discussed below, the upstream longitudinal end face may comprise an upstream end wall that at least partly (and preferably fully) obscures the substrate from view.

[0068] The housing may have an opposing downstream longitudinal end wall. The downstream longitudinal end wall may comprise the outlet/mouthpiece aperture. The downstream longitudinal end wall may comprise a curved/rounded (e.g. a convex/semi-circular) end wall.

[0069] The inner surface of the downstream longitudinal end wall of the housing may abut the downstream longitudinal end surface of the filter.

[0070] At least one (and optionally both) of the opposing transverse walls of the housing may comprise a longitudinally-extending junction such that the housing can be opened to expose the chamber within. The downstream longitudinal end /wall may also comprise a junction. For example, both of the opposing transverse walls and the downstream longitudinal end wall could comprise a respective junction such that the housing can be split into two opposing parts allowing for easy insertion during manufacture of the substrate (and filter/spacer where present).

[0071] Alternatively, one of the opposing transverse walls and the upstream longitudinal end wall may contain the junctions and the other transverse wall may contain a longitudinally extending hinge portion such that the housing may be opened along the junctions by pivoting of the two opposing parts about the hinge portion.

[0072] As discussed above, the downstream longitudinal end of the housing comprises a downstream longitudinal end wall. The filter is typically provided adjacent e.g. with its downstream longitudinal end face abutting this longitudinal end wall of the housing. Thus the downstream longitudinal end wall at least partly (and preferably completely) obscures/conceals the filter from view by the user.

[0073] By concealing the filter from view, the user is not exposed to the residues remaining in the filter/consumable after use thus improving the aesthetic appeal of the consumable after use and avoiding transfer of residue to the user.

[0074] Although the downstream longitudinal end wall may comprise one or more outlet(s)/mouthpiece aperture(s), this/these are typically small enough that visual inspection of the filter is significantly impeded compared to the prior art consumable where the end face of the filter is completely exposed. Thus whilst the downstream longitudinal wall may be discontinuous, it preferably covers (e.g. overlies or abuts) at least 20% e.g. at least 30 or 40 % and preferably at least 50%, e.g. at least 70% such as at least 80% or 90% of the surface area of the downstream longitudinal end face of the filter.

[0075] Similarly, the upstream longitudinal end face may comprise an upstream longitudinal end wall that at least partly obscures the substrate from view at least prior to use.

[0076] The upstream longitudinal end face of the housing may comprise an upstream longitudinal end wall for at least partly overlying (e.g. abutting) the upstream longitudinal end face of the substrate. The upstream longitudinal end wall may comprise an aperture (e.g. into which air may enter the housing).

[0077] The upstream longitudinal end wall may be a perimeter wall i.e. it may extend only around one or more of the edges of the upstream longitudinal end face of the housing. For example, it may extend around all edges to form a frame defining the aperture (into which the heating element can be inserted).

[0078] In other embodiments, the upper longitudinal end wall of the housing may extend along the upper and lower edges to form rails defining the aperture therebetween.

[0079] The upstream longitudinal end face of the housing may additionally or alternatively comprise a pierceable or peelable membrane such as a metallic foil or plastic membrane. The membrane may be mounted across the entire open upstream longitudinal end face of the housing or it may be mounted on the upstream longitudinal end wall across the aperture. The membrane seals the upstream longitudinal end face prior to use and is pierced to mount the consumable on the heating element.

[0080] In order to generate an aerosol, the substrate comprises at least one volatile compound that is intended to be vaporised/aerosolised and that may provide the user with a recreational and/or medicinal effect when inhaled. Suitable chemical and/or physiologically active volatile compounds include the group consisting of: nicotine, cocaine, caffeine, opiates and opoids, cathine and cathinone, kavalactones, mysticin, beta-carboline alkaloids, salvinorin A together with any combinations, functional equivalents to, and/or synthetic alternatives of the foregoing.

[0081] The plant material may comprise least one plant material selected from the list including Amaranthus dubius, Arctostaphylos uva-ursi (Bearberry), Argemone mexicana, Amica, Artemisia vulgaris, Yellow Tees, Galea zacatechichi, Canavalia maritima (Baybean), Cecropia mexicana (Guamura), Cestrum noctumum, Cynoglossum virginianum (wild comfrey), Cytisus scoparius, Damiana, Entada rheedii, Eschscholzia califomica (California Poppy), Fittonia albivenis, Hippobroma longiflora, Humulus japonica (Japanese Hops), Humulus lupulus (Hops), Lactuca virosa (Lettuce Opium), Laggera alata, Leonotis leonurus, Leonurus cardiaca (Motherwort), Leonurus sibiricus (Honeyweed), Lobelia cardinalis, Lobelia inflata (Indian-tobacco), Lobelia siphilitica, Nepeta cataria (Catnip), Nicotiana species (Tobacco), Nymphaea alba (White Lily), Nymphaea caerulea (Blue Lily), Opium poppy, Passiflora incamata (Passionflower), Pedicularis densiflora (Indian Warrior), Pedicularis groenlandica (Elephant's Head), Salvia divinorum, Salvia dorrii (Tobacco Sage), Salvia species (Sage), Scutellaria galericulata, Scutellaria lateriflora, Scutellaria nana, Scutellaria species (Skullcap), Sida acuta (Wireweed), Sida rhombifolia, Silene capensis, Syzygium aromaticum (Clove), Tagetes lucida (Mexican Tarragon), Tarchonanthus camphoratus, Tumera diffusa (Damiana), Verbascum (Mullein), Zamia latifolia (Maconha Brava) together with any combinations, functional equivalents to, and/or synthetic alternatives of the foregoing.

[0082] Preferably, the plant material is tobacco. Any type of tobacco may be used. This includes, but is not limited to, flue-cured tobacco, burley tobacco, Maryland Tobacco, dark-air cured tobacco, oriental tobacco, dark-fired tobacco, perique tobacco and rustica tobacco. This also includes blends of the above mentioned tobaccos.

[0083] Any suitable parts of the tobacco plant may be used. This includes leaves, stems, roots, bark, seeds and flowers.

[0084] Extruded tobacco can produced by forming a liquid mixture of powered tobacco and optionally a binding agent such as a gum (e.g. xanthan, guar, arabic and/or locust bean gum). The liquid mixture is heated and then extruded through a die. The extrudate is then freeze-dried. Flavouring may be added to the liquid mixture prior to extrusion and freeze drying to provide a flavoured extruded substrate e.g. a flavoured extruded hollow core substrate.

[0085] The flavourant may be provided in solid or liquid form. It may include menthol, liquorice, chocolate, fruit flavour (including e.g. citrus, cherry etc.), vanilla, spice (e.g. ginger, cinnamon) and tobacco flavour.

[0086] The aerosol-forming substrate may comprise one or more additives selected from humectants, flavourants, fillers, aqueous/non-aqueous solvents and binders.

[0087] Humectants are provided as vapour generators - the resulting vapour helps carry the volatile active compounds and increases visible vapour. Suitable humectants include polyhydric alcohols (e.g. propylene glycol (PG), triethylene glycol, 1,2-butane diol and vegetable glycerine (VG)) and their esters (e.g. glycerol mono-, di- or tri-acetate). They may be present in the aerosol-forming substrate in an amount between 1 and 50 wt%.

[0088] The humectant content of the aerosol-forming substrate may have a lower limit of at least 1 % by weight of the plant material, such as at least 2 wt %, such as at least 5 wt %, such as at least 10 wt %, such as at least 20 wt %, such as at least 30 wt %, or such as least 40 wt %.

[0089] The humectant content of the aerosol-forming substrate may have an upper limit of at most 50 % by weight of the plant material, such as at most 40 wt %, such as at most 30 wt %, or such as at most 20 wt %.

[0090] Preferably, the humectant content is 1 to 40 wt % of the aerosol-forming substrate, such as 1 to 20 wt %
Suitable binders are known in the art and may act to bind together the components forming the aerosol-forming substrate. Binders may comprise starches and/or cellulosic binders such as methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose and methyl cellulose, gums such as xanthan, guar, arabic and/or locust bean gum, organic acids and their salts such as alginic acid/ sodium alginate, agar and pectins.

[0091] Preferably the binder content is 5 to 10 wt% of the aerosol-forming substrate e.g. around 6 to 8 wt%.

[0092] Suitable fillers are known in the art and may act to strengthen the aerosol-forming substrate. Fillers may comprise fibrous (non-tobacco) fillers such as cellulose fibres, lignocellulose fibres (e.g. wood fibres), jute fibres and combinations thereof.

[0093] Preferably, the filler content is 5 to 10 wt% of the aerosol-forming substrate e.g. around 6 to 9 wt%.

[0094] The aerosol-forming substrate may comprise an aqueous and/or non-aqueous solvent. In some embodiments, the aerosol forming substrate has a water content of between 5 and 10 wt% e.g. between 6-9 wt% such as between 7-9 wt%.

[0095] The flavourant may be provided in solid or liquid form. It may include menthol, liquorice, chocolate, fruit flavour (including e.g. citrus, cherry etc.), vanilla, spice (e.g. ginger, cinnamon) and tobacco flavour. The flavourant may be evenly dispersed throughout the aerosol-forming substrate or may be provided in isolated locations and/or varying concentrations throughout the aerosol-forming substrate.

[0096] In a second aspect, there is provided a consumable for a smoking substitute system, the consumable comprising an aerosol-forming substrate formed of a moulded porous freeze-dried mixture comprising a plant material.

[0097] The consumable of the second aspect may be as otherwise described above with respect to the first aspect. Thus, for example, the substrate may have a porosity of between 20% and 70%.

[0098] In a third aspect there is provided a smoking substitute system comprising:

a consumable as described above with respect to the first or second aspect; and

a vapour generating article upstream of the consumable and in fluid communication with the substrate of the consumable

[0099] The vapour generating article may comprise a passage for fluid flow therethrough. The passage may extend through (at least a portion of) the vapour generating article, between openings that may define an inlet and an outlet of the passage. The passage may be fluidly connected to the airflow path of the consumable. In this respect, the outlet of the passage may be in fluid communication (and may be adjacent to) the substrate of the consumable. In this respect, a user may draw fluid (e.g. air) into and through the passage by inhaling at the outlet of the consumable (i.e. using the mouthpiece). The air may pass from the passage and through the substrate to the outlet.

[0100] The vapour generating article may comprise a tank (reservoir) for containing a vaporisable liquid (e.g. an e-liquid). The e-liquid may, for example, comprise a base liquid and e.g. nicotine. The base liquid may include propylene glycol and/or vegetable glycerine.

[0101] The e-liquid may further comprise a flavourant. The flavourant may be natural or synthetic. For example, the flavourant may include menthol, liquorice, chocolate, fruit flavour (including e.g. citrus, cherry etc.), vanilla, spice (e.g. ginger, cinnamon) and tobacco flavour. The flavourant may be evenly dispersed or may be provided in isolated locations and/or varying concentrations.

[0102] The tank may be defined by a tank housing. At least a portion of the tank housing may be translucent. For example, the tank housing may comprise a window to allow a user to visually assess the quantity of e-liquid in the tank. The tank may be referred to as a "clearomizer" if it includes a window, or a "cartomizer" if it does not. A passage may extend longitudinally within the tank and a passage wall may define the inner wall of the tank. In this respect, the tank may surround the passage e.g. the tank may be annular. The passage wall may comprise longitudinal ribs extending therealong. These ribs may provide support to the passage wall. The ribs may extend for the full length of the passage wall. The ribs may project (e.g. radially outwardly) into the tank.

[0103] The vapour generating article may comprise a vaporiser. The vaporiser may comprise a wick. The vaporiser may further comprise a heater. The wick may comprise a porous material. A portion of the wick may be exposed to fluid flow in the passage. The wick may also comprise one or more portions in contact with liquid stored in the reservoir. For example, opposing ends of the wick may protrude into the reservoir and a central portion (between the ends) may extend across the passage so as to be exposed to fluid flow in the passage. Thus, fluid may be drawn (e.g. by capillary action) along the wick, from the reservoir to the exposed portion of the wick.

[0104] The heater may comprise a heating element, which may be in the form of a filament wound about the wick (e.g. the filament may extend helically about the wick). The filament may be wound about the exposed portion of the wick. The heating element may be electrically connected (or connectable) to a power source. Thus, in operation, the power source may supply electricity to (i.e. apply a voltage across) the heating element so as to heat the heating element. This may cause liquid stored in the wick (i.e. drawn from the tank) to be heated so as to form a vapour and become entrained in fluid flowing through the passage. In some cases, this vapour may subsequently cool to form an aerosol in the passage.

[0105] This vapour (or aerosol) may then pass through the substrate (i.e. downstream of the vapour generating article). Upon passing through the substrate, the vapour may at least partially rehydrate the freeze-dried material such that one or more components (e.g. nicotine) of the substrate become entrained in the vapour. The combined vapour/aerosol may then pass out of the consumable via the outlet so as to be inhaled by a user.

[0106] In some embodiments, the consumable and the vapour generating article may be enclosed in a shared housing (e.g. such as the housing described above with respect to the first aspect). In such an embodiment, the vapour generating article may be disposed at an upstream end of the housing and an airflow path may be defined through the vapour generating article and the consumable to an outlet of the housing. In this respect, the vapour generating article may form part of the consumable.

[0107] Alternatively, in other embodiments the vapour generating may be separate form, but engageable with, the vapour generating article (e.g. by way of an interference fit, snap-engagement, etc.). In this respect, the consumable and vapour generating articles may be interchangeable with other consumables/vapour generating articles.

[0108] The system may further comprise a main body. The main body and the vapour generating article may be configured to be physically coupled together. For example, the vapour generating article may be at least partially received in a recess of the main body, such that there is snap engagement between the main body and the vapour generating article. Alternatively, the main body and the vapour generating article may be physically coupled together by screwing one onto the other, or through a bayonet fitting.

[0109] Thus, the vapour generating article and/or consumable may comprise one or more engagement portions for engaging with a main body. In this way, one end of the vapour generating article (i.e. the inlet end) may be coupled with the main body, whilst an opposing end (i.e. the outlet end) of the vapour generating article may define a mouthpiece.

[0110] The main body and the vapour generating article and/or consumable may be configured to be physically coupled together. For example, the vapour generating article may be at least partially received in a recess of the main body, such that there is snap engagement between the main body and the vapour generating article. Alternatively, the main body and the vapour generating article may be physically coupled together by screwing one onto the other, or through a bayonet fitting.

[0111] Thus, the vapour generating article may comprise one or more engagement portions for engaging with a main body. In this way, one end of the vapour generating article (i.e. the inlet end) may be coupled with the main body, whilst an opposing end of the vapour generating article may be coupled with the consumable.

[0112] The main body, consumable or the vapour generating article may comprise a power source or be connectable to a power source. The power source may be electrically connected (or connectable) to the heater. The power source may be a battery (e.g. a rechargeable battery). An external electrical connector in the form of e.g. a USB port may be provided for recharging this battery.

[0113] The vapour generating article may comprise an electrical interface for interfacing with a corresponding electrical interface of the main body. One or both of the electrical interfaces may include one or more electrical contacts. Thus, when the main body is engaged with the vapour generating article, the electrical interface may be configured to transfer electrical power from the power source to a heater of the vapour generating article. The electrical interface may also be used to identify the vapour generating article from a list of known types. The electrical interface may additionally or alternatively be used to identify when the vapour generating article and/or the consumable is connected (e.g. directly or indirectly) to the main body.

[0114] The main body may alternatively or additionally be able to detect information about the consumable via an RFID reader, a barcode or QR code reader. This interface may be able to identify a characteristic (e.g. a type) of the consumable. In this respect, the consumable may include any one or more of an RFID chip, a barcode or QR code, or memory within which is an identifier and which can be interrogated via the interface.

[0115] The vapour generating article, consumable or main body may comprise a controller, which may include a microprocessor. The controller may be configured to control the supply of power from the power source to the heater (e.g. via the electrical contacts). A memory may be provided and may be operatively connected to the controller. The memory may include non-volatile memory. The memory may include instructions which, when implemented, cause the controller to perform certain tasks or steps of a method.

[0116] The vapour generating article, consumable or main body may comprise a wireless interface, which may be configured to communicate wirelessly with another device, for example a mobile device, e.g. via Bluetooth®. To this end, the wireless interface could include a Bluetooth® antenna. Other wireless communication interfaces, e.g. WiFi®, are also possible. The wireless interface may also be configured to communicate wirelessly with a remote server.

[0117] An airflow (i.e. puff) sensor may be provided that is configured to detect a puff (i.e. inhalation from a user). The airflow sensor may be operatively connected to the controller so as to be able to provide a signal to the controller that is indicative of a puff state (i.e. puffing or not puffing). The airflow sensor may, for example, be in the form of a pressure sensor or an acoustic sensor. The controller may control power supply to the heater in response to airflow detection by the sensor. The control may be in the form of activation of the heater in response to a detected airflow. The airflow sensor may form part of the consumable or the main body.

[0118] In an alternative embodiment the vapour generating article may be integral with the main body. In such embodiments, an aerosol former (e.g. e-liquid) of the vapour generating article may be replenished by re-filling the tank of the vapour generating article (rather than replacing the vapour generating article). Access to the tank (for re-filling of the e-liquid) may be provided via e.g. an opening to the tank that is sealable with a closure (e.g. a cap).

[0119] The vapour generating article may be in the form of an e-cigarette consumable (e.g. pod). The main body may be an e-cigarette device.

[0120] In a fourth aspect, there is provided a method of forming an aerosol-forming substrate for a smoking substitute system, the method comprising:

forming a mixture including plant material, a volatile compound, and water;

moulding the mixture to form a desired shape; and

freeze-drying the moulded mixture.

[0121] Moulding the mixture may comprise extruding the mixture (i.e. forcing the mixture through a die) and/or die-pressing the mixture. The moulding may be performed so as to form a moulded mixture having a circular or rectangular cross-sectional shape.

[0122] Where the moulding comprises extrusion, the moulding may form an elongate moulded body. The method may thus further comprise a cutting process for cutting the elongate moulded body into a plurality of moulded mixture portions. The cutting process may be performed prior to or after the freeze drying.

[0123] Freeze drying the mixture may be performed so as to substantially remove all moisture from the moulded mixture. The freeze drying process may be performed so as to result in a solid (e.g. self-supporting) body. The freeze drying process may be performed as to produce a porous body. That is the removal of moisture from the moulded moisture may form gaps in the moulded mixture. The freeze drying may be performed so as to provide a freeze-dried moulded mixture having a porosity of between 20% and 70% (or between 40% and 50%).

[0124] The volatile compound of the mixture may be nicotine. The mixture may comprise a plurality of volatile compounds. For example, the mixture may comprise one or more of the volatile compounds listed above with respect to the first aspect.

[0125] The plant material may be tobacco. The mixture may comprise a plurality of plant materials. For example, the mixture may comprise one or more of the plant materials (or tobaccos) listed above with respect to the first aspect.

[0126] The mixture may comprise one or more additives selected from humectants, flavourants, fillers, solvents and binders. These may be as described above with respect to the first aspect.

[0127] In a fifth aspect, there is provided a method of using a substitute smoking system according to the third aspect, the method comprising:

engaging the consumable with the vapour generating article;

generating a vapour using the vapour generating article; and

causing the vapour to flow through the aerosol-forming substrate of the consumable.

[0128] Once consumed the consumable may be released from the vapour generating article and a further consumable may subsequently be (releasably) engaged with the vapour generating article for receipt of vapour.

[0129] The disclosure includes the combination of the aspects and preferred features described except where such a combination is clearly impermissible or expressly avoided.

Summary of the figures

[0130] So that the disclosure may be more readily understood, and so that further features thereof may be appreciated, embodiments and experiments illustrating the principles of the disclosure will now be described by way of example with reference to the accompanying figures in which:

Figure 1 shows a first embodiment of a consumable comprising a planar freeze-dried tobacco substrate;

Figure 2 shows a cuboid brick of freeze-dried plant product;

Figures 3a - 3c show a second embodiment of a consumable;

Figures 4a and 4b show a third embodiment of a consumable;

Figures 5a and 5b show a fourth embodiment of a consumable;

Figures 6a and 6b show a fifth embodiment of a consumable; and

Figure 7a and 7b are schematic views of a smoking substitute system including the consumable of the fourth embodiment.

Detailed Description

[0131] Aspects and embodiments of the disclosure will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art.

[0132] Figure 1 shows a perspective view of a first embodiment of a smoking substitute consumable 1 comprising a planar substrate 2 formed of a freeze-dried tobacco mixture such that the consumable 1 has a substantially rectangular transverse cross section. Whilst not apparent from the figure, the mixture has a porosity of between 20% and 70%.

[0133] The planar substrate 2 has a substantially rectangular upper surface 3, and has a length of around 12 mm, a width of around 8 mm and a depth of around 6 mm.

[0134] The consumable further comprises a filter 4. The filter 4 is also formed as a planar slab having a substantially rectangular transverse cross section. The filter 4 typically has a width of around 8 mm, a depth of around 6 mm and a length of around 3 mm.

[0135] The filter 4 has an upstream longitudinal end face 5 which faces (but is spaced from) the downstream longitudinal end face 6 of the planar slab 2 of freeze-dried tobacco.

[0136] The consumable 1 further comprises a paper spacer 7 interposed between the filter 4 and the plant product 2. The spacer 7 typically has a width of around 8 mm, a depth of around 6 mm and a length of around 5 mm.

[0137] The consumable 1 further comprises a paper wrapper 8 which is shown open in Figure 1 but which is wrapped around to fully enclose the upper surface 3, lower surface and the opposing transverse surfaces of the consumable 1.

[0138] As will be described further below, the consumable 1 of Figure 1 may receive vapour from a vapour generating article. The vapour may at least partly rehydrate the freeze-dried tobacco of the planar slab 2, such that material of the planar slab 2 is entrained in the vapour.

[0139] Figure 2 shows a portion of freeze-dried tobacco extruded into a cuboid brick 9. The cuboid brick has an upper surface 3' and a lower surface (not visible) spaced by opposing transverse surfaces 15 (only one visible). The outer surfaces of the cuboid brick 9 are coated with a hydrophobic/liquid impermeable coating.

[0140] The length of the cuboid brick is typically around 12 mm, with a depth of around 6 mm and width of around 10 mm.

[0141] The cuboid brick 9 has a hollow core defined by a cuboid recess 10 extending in a length direction from the upstream longitudinal end face 11 of the cuboid brick 9 to the opposing downstream longitudinal end face 12. Vapour, from a vapour generating article, may pass through the hollow core.

[0142] The cuboid recess 10 is defined by upper and lower inner surfaces 13a, 13b and opposing inner transverse surfaces 14a, 14b. The cuboid recess has a depth of around 1 mm, a width of around 8 mm and a length of around 12 mm.

[0143] As can be seen in Figures 3a-3c, the cuboid brick 9 can be inserted and glued into a substantially rigid, self-supporting housing 16 having walls of a uniform thickness of around 2 mm formed of moulded bagasse pulp to form the consumable 1'. The housing 16 has a textured e.g. meshed inner surface 17 facing the freeze-dried tobacco. The outer surface of the housing 16 is substantially smooth.

[0144] The housing 16 has an open upstream longitudinal end 19 having a rectangular transverse cross-section. It has a rounded opposing downstream longitudinal end wall 21 which has at least one mouthpiece aperture (not visible).

[0145] The consumable 1' has a filter 4' having a rounded downstream longitudinal end face for abutment with the inside surface of the downstream longitudinal end wall 21 of the housing 16.

[0146] The downstream longitudinal end wall 21 at least partly (and preferably completely) obscures the filter 4' from view by a user.

[0147] By concealing the filter 4' from view, the user is not exposed to the residues remaining in the filter 4'/consumable 1' after use thus improving the aesthetic appeal of the consumable after use and avoiding transfer of residue to the user.

[0148] The housing 16 comprises an upper wall 22 and lower wall 23 spaced by opposing transverse walls 24. One of the opposing transverse walls 24 comprises a longitudinally extending junction 25 and the downstream longitudinal end wall 21 also comprises a junction such that the housing can be opened to expose the cuboid chamber as shown in figures 3a-3c.

[0149] The other opposing transverse wall 24' comprises a longitudinally extending hinge portion 26 such that the housing 16 may be opened along the junctions by pivoting of the upper wall 22 and lower wall 23 about the hinge portion 26.

[0150] In this way, the cuboid brick 9 and the filter 4' can be fitted (and glued) into the opened housing 16 and then the housing closed (by pivoting about the hinge portion 26 as shown in Figure 3c). The junctions can be sealed e.g. with glue.

[0151] The closed housing 16 has the shape that is the same as that of the embodiment shown in figures 5a and 5b, and with such a housing 16, the consumable 1' becomes more akin to a cartridge or "pod" that effectively contains residue after use to protect a user from contamination.

[0152] Figures 4a-4b shown another embodiment in which the consumable 1" comprises two planar substrates 2', 2" of freeze-dried tobacco, each having a depth of around 2 mm, a length of around 12 mm and a width of around 10 mm.

[0153] The two planar substrates 2', 2" are vertically and horizontally aligned and spaced from one another to define a planar recess 27 (visible in Figure 7). The housing 16 is as described previously and the two planar substrates 2', 2" are each glued into a respective half of the housing 16 (see Figure 6b) before closing the housing 16 by pivoting along the hinge portion 26 to form the planar recess 27. The tobacco at or proximal the inner surface (facing the planar recess 27) on one or both of the planar slabs 2', 2" is dosed with e-liquid as described above. The junctions around the housing 16 are sealed using glue.

[0154] A further embodiment of a consumable 1"' is shown in figures 5a and 5b where the housing 16 and filter 4' are as previously described. The freeze-dried tobacco is formed as single planar substrate 2 having a substantially rectangular upper surface 3. The substrate 2 has a length of around 12 mm, a width of around 8 mm and a depth of around 6 mm.

[0155] The upstream longitudinal end 19 of the housing 16 is provided with a pierceable or peelable membrane such as a metallic foil or plastic membrane 29. Such a membrane may be provided on any of the previously described embodiments and is provided to at least partly obscure the freeze-dried tobacco from view by a user prior to use. When the consumable 1"' is used, the membrane can be removed to allow vapour flow through the substrate 2.

[0156] Figures 6a and 6b show a perspective internal view of an eighth embodiment of a consumable 1"".

[0157] The planar substrate 2'" formed of a freeze-dried tobacco mixture comprises a planar upper surface 3' and a planar lower surface 53 spaced by opposing longitudinally-extending transverse surfaces 54a, 54b. The depth of the substrate 2"' (between the upper and lower surfaces, 3', 53) and the width of the substrate 2'" (between the opposing transverse surfaces 54a, 54b) are unequal with the width being greater than the depth.

[0158] The opposing transverse surfaces 54a, 54b each comprise a longitudinally-extending upper concave portion 55a, 55b and lower concave portion 56a, 56b which meet at a longitudinally-extending ridge 57a, 57b.

[0159] The concave portions are spaced from the upper surface 3' and lower surface 53 by opposing convex portions 58a, 58a', 58b, 58b' such that the transverse cross-section through the substrate 2'" is a modified obround where the opposing transverse surfaces 54a, 54b each take the form of a curly brace/bracket i.e. "{" and "}".

[0160] The length of the substrate 2'" (between the upstream end face 59 and downstream end face 60) is around 12 mm long. The width of the substrate 2"' (between opposing transverse surfaces 54a, 54b) may be around 12 mm. The depth of the substrate 2"' (between the upper and lower surfaces) may be around 6 mm.

[0161] The substrate 2"' is formed of cast leaf slurry recon tobacco. It may alternatively be formed as extruded tobacco e.g. with added flavouring.

[0162] The consumable further comprises a planar filter 4". The filter 4' comprises a substantially planar upper surface 61 and a substantially planar lower surface 62 equally spaced by opposing longitudinally-extending transverse surfaces 63a, 63b.

[0163] The opposing transverse surfaces 63a, 63b each comprise a substantially convex surface (a semi-circular surface) such that the planar filter 4" has a substantially obround transverse cross section i.e. the filter 4" is an obround cylindrical filter.

[0164] The filter 4" has greater width and length than depth. The length is around 22mm and the width is around 12 mm. The depth is around 6mm.

[0165] The filter 4" has a hollow bore 64. The hollow bore 64 extends from the upstream longitudinal end face 5' of the filter 4" to the downstream longitudinal end face 6' of the filter 4".

[0166] The hollow bore 64 has an obround transverse cross sectional area. The bore 64 has a uniform transverse cross-sectional area. The bore is 64 dimensioned such that there is a thickness of filter material of around 1.5mm from the bore to the upper lower surfaces 61, 62 and the opposing transverse surfaces 63a, 63b.

[0167] The upstream longitudinal end face 5' of the filter 4" faces and abuts the downstream longitudinal end face 65 of the substrate 2"'.

[0168] The filter 4" is comprised of cellulose acetate or polypropylene tow. The filter 4" is circumscribed with a paper plug wrap (not shown).

[0169] The substrate 2"' and filter 4" are contained within a rigid bagasse housing 16'.

[0170] The housing 16' comprises upper and lower walls 22', 23' (see Figure 16) spaced by opposing longitudinally-extending transverse surfaces 24a', 24b'. The housing 16' has a wall thickness in the range of around 0.8 mm.

[0171] The upper and lower walls 22', 23' are substantially planar and equally spaced by the transverse surfaces 24a', 24b', (i.e. the upper and lower walls 22', 23' are parallel to one another).

[0172] The opposing transverse surfaces 24a', 24b' each comprise upper and lower concave portions 66a, 66a', 66b, 66b' which meet at a longitudinally-extending ridge 67.

[0173] The concave portions 66a, 66a', 66b, 66b' are spaced from the upper and lower surfaces by opposing convex portions 68a, 68a', 68b, 68b' such that the transverse cross-section of the housing 16' is a modified obround.

[0174] The chamber within and defined by the inner surfaces of the housing walls 22', 23', 24a', 24b' is a modified obround cylindrical chamber, i.e. the transverse cross-section of the chamber within the housing 16' matches the transverse cross section of the substrate 2"'.

[0175] The housing 16' may have a length of around 42 mm, a height of around 6 mm and a width of around 15mm.

[0176] The housing 16' has open upstream longitudinal end face which may be sealed by a metallic foil or a plastic membrane, which can be removed prior to use. This foil or membrane obscures the substrate 2'" from view.

[0177] The downstream longitudinal end of the housing 16' is shown in Figure 6b. The downstream longitudinal end wall 21' conceals the filter 4" from view by the user.

[0178] Although the downstream longitudinal end wall 21' comprises a mouthpiece aperture 69, this is small enough (with a maximum depth of 0.6 mm and a width of 7.3 mm) that visual inspection of the filter 4" is significantly impeded.

[0179] The consumable 1"" may be engaged with a vapour generating article (as will be described further below). Vapour from the vapour generating article may pass through the planar substrate 3'.

[0180] Figures 7a and 7b show a smoking substitute system 70, which includes a consumable 1"'. The illustrated consumable 1"' is the same as that shown in figures 5a and 5b, but could alternatively be a consumable of other embodiments described above.

[0181] The system 70 also comprises a vapour generating article 71, which is integral with the main body of a smoking substitute device 72 (i.e. an e-cigarette device). The vapour generating article 71 comprises a recess 73, into which the consumable 1"' can be received and engaged by way of an interference fit. Figure 7b shows the consumable 1"' in an engaged position, whilst Figure 7a shows the consumable 1"' in a disengaged position.

[0182] The vapour generating article 71 further comprises a passage 74 for fluid flow therethrough. The passage 74 extends through the vapour generating article, between openings that define an inlet and an outlet of the passage 74. The passage 74 is surrounded and defined by a tank 75 containing a vaporisable liquid (e.g. an e-liquid). The e-liquid may, for example, include propylene glycol and/or vegetable glycerine.

[0183] This e-liquid can be vaporised by a vaporiser of the vapour generating article 71. The vaporiser comprises a wick 76 and a heater 77. The wick 76 is formed of a porous material and extends across the passage 75 such that opposing ends of the wick 76 extend into the tank 75, whilst a central portion of the wick 76 is exposed to fluid flow in the passage 75. In this way, e-liquid stored in the tank 75 is drawn from the ends of the wick 76 to the central portion of the wick 76 by capillary action.

[0184] The heater 77 comprises a heating filament that is wound about the wick 76. The heater 77 is connected electrically to a power source of the device 72 (not shown in the present figures). When power is supplied to the heating filament of the heater 77, the heating filament rises in temperature so as to heat the wick 76 and the e-liquid in the wick 76. When heated, the e-liquid forms a vapour, which is entrained in an airflow flowing through the passage 73.

[0185] The passage 73 of the vapour generating article 71 is fluidly connected between inlets 78 of the vapour generating article 71 and an outlet 79 formed in the longitudinal end wall 21 of the consumable 1"'. Thus, as may be appreciated from Figure 7b in particular, when the consumable 1"' is engaged with the vapour generating article 71, a user can draw air through the vapour generating article 71 and the consumable 1"' (from the inlets 78). That is, a user can inhale through the mouthpiece outlet 79, which draws air through the passage 73 and subsequently through the consumable 1"'.

[0186] As the air passes across the wick 76, vapour (produced by heating e-liquid) is entrained in the air. This vapour is carried through the passage 73 and then through the freeze-dried (moulded) tobacco substrate 2 of the consumable 1"'. The porous nature of the substrate 2 allows the vapour to pass therethrough. As the vapour passes through the substrate 2 it rehydrates the substrate 2, which causes material (such as nicotine) of the substrate 2 to become entrained in the airflow/vapour. The vapour may subsequently cool to form an aerosol and pass through the filter 4' before being discharged from the consumable 1"' through the outlet 79 (i.e. so as to be inhaled by a user).

[0187] While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the scope of the invention.

[0188] Throughout this specification, including the claims which follow, unless the context requires otherwise, the word "comprise" and "include", and variations such as "comprises", "comprising", and "including" will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

Claims

1. A consumable for a smoking substitute system, the consumable comprising an aerosol-forming substrate formed of a moulded mixture comprising a plant material, the substrate having a porosity of between 20% and 70%.

2. A consumable according to claim 1 wherein the moulded mixture is a freeze-dried mixture.

3. A consumable according to claim 1 or 2 wherein the aerosol-forming substrate comprises nicotine.

4. A consumable according to any one of the preceding claims wherein the plant material is tobacco.

5. A consumable according to any one of the preceding claims comprising an airflow path that extends from an inlet at an upstream end of the consumable to an outlet at a downstream end of the consumable, the aerosol-forming substrate disposed between the inlet and outlet such that the airflow path passes through at least a portion of the aerosol-forming substrate.

6. A consumable according to claim 5 comprising a housing at least partly enclosing the aerosol-forming substrate, the inlet and outlet formed in the housing.

7. A consumable according to claim 5 or 6 comprising a filter downstream of the aerosol-forming substrate.

8. A smoking substitute system comprising:

a consumable according to any one of the preceding claims; and

a vapour generating article upstream of the consumable and in fluid communication with the aerosol-forming substrate of the consumable.

9. A smoking substitute system according to claim 8 wherein the vapour generating article is engageable with the consumable.

10. A smoking substitute system according to claim 8 or 9 comprising:

a tank for containing a vaporisable liquid;

a vaporiser to vaporise the vaporisable liquid; and

a passage fluidly connecting the vaporiser to the aerosol-forming substrate of the consumable.

11. A smoking substitute system according to claim 10 wherein the vaporiser comprises:

a porous wick having a first portion extending into the tank and a second portion exposed to fluid flow through the passage; and

a heater for heating the porous wick.

12. A method of using a smoking substitute system according to any one of claims 8 to 11 comprising:

engaging the consumable with the vapour generating article;

generating a vapour using the vapour generating article; and

causing the vapour to flow through the aerosol-forming substrate of the consumable.

13. A method of forming an aerosol-forming substrate for a smoking substitute system consumable, the method comprising:

forming a mixture including plant material, a volatile compound and water;

moulding the mixture to form a desired shape; and

freeze-drying the moulded mixture.

14. A method according to claim 13 wherein moulding the mixture comprises extruding the mixture.

15. A method according to claim 13 or 14 wherein the freeze-drying is performed so as to provide a moulded mixture having a porosity of between 20% and 70%.

Drawing