An aerosol generating material

Abstract

Described herein is an aerosol generating material comprising: a first fibrous material comprising a botanical material, a second fibrous material, an active, and a binder, wherein the first fibrous material and the second fibrous material are different, a rod comprising the aerosol generating material, an article and device comprising the 5 aerosol generating material, and a process for preparing an aerosol generating material.

Description

[0001]An Aerosol Generating Material Technical Field The present disclosure relates to an aerosol generating material comprising a fibrous material and non-combustible aerosol-provision systems comprising the aerosol generating material. Background Aerosol generating materials are typically heated, for example by a non-combustible aerosol-provision system, to form an aerosol, which may be inhaled by a consumer. Aerosol generating materials may be made from various different sources, including from tobacco material and / or non-tobacco material. Summary According to a first aspect, there is described an aerosol generating material comprising: a first fibrous material comprising a botanical material, a second fibrous material, an active, and a binder, wherein the first fibrous material and the second fibrous material are different. According to a second aspect, there is described an aerosol generating rod comprising an aerosol generating material according to the first aspect. According to a third aspect, there is described a delivery system comprising an aerosol generating material according to the first aspect or the aerosol generating rod according to the second aspect. According to a fourth aspect, there is described a process for preparing an aerosol generating material, the process comprising: combining a first fibrous material comprising a botanical material, a second fibrous material, an active, a binder, and water to form a slurry; processing the slurry so as to form a sheet of aerosolisable material, and drying the sheet of aerosolisable material, wherein the first fibrous material and the second fibrous material are different. According to a fifth aspect, there is described an aerosol generating material obtained or obtainable from a process according to the fourth aspect. According to a sixth aspect, there is described the use of an aerosol generating material according to the first aspect, in an article or delivery system. Description of Drawings Embodiments of the invention are described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a flowchart for a method of making an aerosol generating material. Detailed Description The invention relates to aerosol generating materials. The invention also relates to a method of manufacturing an aerosol generating material, the use of an aerosol generating material, an article for use in a delivery system, and a system comprising an aerosol generating material and a device. Aerosol generating materials comprise aerosolisable components. In use, the aerosol generating material produces an aerosol, for example a suspension of liquid droplets or particulates in a gas. The aerosol comprises nicotine as well as other components generated by the aerosol generating material. In use, the user inhales the aerosol. As such, it is important that the aerosol generating material produces an aerosol that delivers an appropriate user experience and satisfaction. The composition of the aerosol contributes to the user’s experience and satisfaction. One attribute that contributes to the user’s experience and satisfaction is the nicotine content in the aerosol. Another attribute that contributes to the user’s experience and satisfaction is the perceived harshness of the aerosol. It is therefore important to control the content of the active and harshness of an aerosol. Certain actives may produce an aerosol with a perceived harshness which is too high for a consumer. In some instances, it has been found that an aerosol generating material comprising nicotine and one, or more, organic acids produces an aerosol that has a favourable perceived harshness. The present inventors noted that an aerosol generating material containing pure nicotine, for example free base nicotine, produces an aerosol which may be perceived as too harshness by certain consumers. It therefore may be of interest to produce an aerosol which has a lower perceived harshness. Addition of an organic acid, in the presence of free base nicotine, reduced the perceived harshness to a favourable level. In some instances, it has been noticed that an aerosol generating material comprising nicotine and one, or more, organic acids produces an aerosol that exhibits a favourable overall flavour profile. In other instances, it has been found that an aerosol generating material comprising a nicotine salt produces an aerosol which has a favourable perceived harshness. As used herein, the term “delivery system” is intended to encompass systems that deliver a substance to a user, and includes: combustible aerosol provision systems, such as cigarettes, cigarillos, cigars, and tobacco for pipes or for roll-your-own or for make-your-own cigarettes (whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco, tobacco substitutes or other smokable material); non-combustible aerosol provision systems that release compounds from an aerosol-generating material without combusting the aerosol-generating material, such as electronic cigarettes, tobacco heating products, and hybrid systems to generate aerosol using a combination of aerosol-generating materials; and aerosol-free delivery systems, such as lozenges, gums, patches, articles comprising inhalable powders, and smokeless tobacco products such as snus and snuff, which deliver a material to a user without forming an aerosol. According to the present disclosure, a “combustible” aerosol provision system is one where a constituent aerosol-generating material of the aerosol provision system (or component thereof) is combusted or burned during use in order to facilitate delivery of at least one substance to a user. In some embodiments, the delivery system is a combustible aerosol provision system, such as a system selected from the group consisting of a cigarette, a cigarillo and a cigar. In some embodiments, the disclosure relates to a component for use in a combustible aerosol provision system, such as a filter, a filter rod, a filter segment, a tobacco rod, a spill, an aerosol-modifying agent release component such as a capsule, a thread, or a bead, or a paper such as a plug wrap, a tipping paper or a cigarette paper. According to the present disclosure, a “non-combustible” aerosol provision system is one where a constituent aerosol-generating material of the aerosol provision system (or component thereof) is not combusted or burned in order to facilitate delivery to a user. In some embodiments, the delivery system is a non-combustible aerosol provision system, such as a powered non-combustible aerosol provision system. In some embodiments, the non-combustible aerosol provision system is an electronic cigarette, also known as a vaping device or electronic nicotine delivery system (END). In some embodiments, the non-combustible aerosol provision system is a tobacco heating system, also known as a heat-not-burn system. In some embodiments, the non-combustible aerosol provision system is a hybrid system to generate aerosol using a combination of aerosol-generating materials, one or a plurality of which may be heated. Each of the aerosol-generating materials may be, for example, in the form of a solid, liquid or gel. In some embodiments, the hybrid system comprises a liquid or gel aerosol-generating material and a solid aerosol- generating material. The solid aerosol-generating material may comprise, for example, tobacco material or a non-tobacco product. Typically, the non-combustible aerosol provision system may comprise a non- combustible aerosol provision device, also referred to herein as an aerosol generation device, and a consumable for use with the non-combustible aerosol provision system. In some embodiments, the disclosure relates to consumables comprising aerosol- generating material and configured to be used with non-combustible aerosol provision devices. These consumables are sometimes referred to as articles throughout the disclosure. In some embodiments, it is envisaged that consumables which themselves comprise a means for powering an aerosol generating component may themselves form the non- combustible aerosol provision system. In some embodiments, the non-combustible aerosol provision system may comprise a power source and a controller. The power source may be an electric power source or an exothermic power source. In some embodiments, the exothermic power source comprises a carbon substrate which may be energised so as to distribute power in the form of heat to an aerosol-generating material or heat transfer material in proximity to the exothermic power source. In some embodiments, the power source, such as an exothermic power source, is provided in the article so as to form the non-combustible aerosol provision system. In some embodiments, the non-combustible aerosol provision system may comprise an area for receiving the consumable, an aerosol generator, an aerosol generation area, a housing, a mouthpiece, a filter and / or an aerosol-modifying agent. In some embodiments, the consumable for use with the non-combustible aerosol provision device may comprise aerosol-generating material, an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol generator, an aerosol generation area, a housing, a wrapper, a filter, a mouthpiece, and / or an aerosol-modifying agent. In some embodiments, the substance to be delivered comprises an active substance. The active substance as used herein may be a physiologically active material, which is a material intended to achieve or enhance a physiological response. The active substance may for example be selected from nutraceuticals, nootropics, psychoactives. The active substance may be naturally occurring or synthetically obtained. The active substance may comprise for example nicotine, caffeine, taurine, theine, vitamins such as B6 or B12 or C, melatonin, cannabinoids, or constituents, derivatives, or combinations thereof. The active substance may comprise one or more constituents, derivatives or extracts of tobacco, cannabis or another botanical. In some embodiments the active substance is a legally permissible recreational drug. In some embodiments, the active substance comprises nicotine, such as a nicotine salt or free base nicotine. In some embodiments, the active substance comprises caffeine, melatonin or vitamin B12. As noted herein, the active substance may comprise one or more constituents, derivatives or extracts of cannabis, such as one or more cannabinoids or terpenes. In some embodiments, the aerosol generating material comprises a cannabinoid selected from the list consisting of cannabigerol (CBG), cannabichromene (CBC), cannabidiol (CBD), tetrahydrocannabinol (THC), cannabinol (CBN), cannabinodiol (CBDL), cannabicyclol (CBL), cannabivarin (CBV), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabigerol monomethylether (CBGM), cannabinerolic acid, cannabidiolic acid (CBDA), cannabinol propyl variant (CBNV), cannbitriol (CBO), tetrahydrocannabinolic acid (THCA), and tetrahydrocannabivarinic acid (THCV A), and mixtures thereof. The active substance may be CBD or a derivative thereof. As used herein, the term "botanical" includes any material derived from plants including, but not limited to, extracts, leaves, bark, fibres, stems, roots, seeds, flowers, fruits, pollen, husk, shells or the like. Alternatively, the material may comprise an active compound naturally existing in a botanical, obtained synthetically. The material may be in the form of liquid, gas, solid, powder, dust, crushed particles, granules, pellets, shreds, strips, sheets, or the like. Example botanicals are eucalyptus, star anise, hemp, cocoa, cannabis, fennel, lemongrass, peppermint, spearmint, rooibos, chamomile, flax, ginger, ginkgo biloba, hazel, hibiscus, laurel, licorice (liquorice), matcha, mate, orange skin, papaya, rose, sage, tea such as green tea or black tea, thyme, clove, cinnamon, coffee, aniseed (anise), basil, bay leaves, cardamom, coriander, cumin, nutmeg, oregano, paprika, rosemary, saffron, lavender, lemon peel, mint, juniper, elderflower, vanilla, wintergreen, beefsteak plant, curcuma, turmeric, sandalwood, cilantro, bergamot, orange blossom, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, geranium, mulberry, ginseng, theanine, theacrine, maca, ashwagandha, damiana, guarana, chlorophyll, baobab or any combination thereof. The mint may be chosen from the following mint varieties: Mentha Arventis, Mentha c.v.,Mentha niliaca, Mentha piperita, Mentha piperita citrata c.v.,Mentha piperita c.v, Mentha spicata crispa, Mentha cardifolia, Memtha longifolia, Mentha suaveolens variegata, Mentha pulegium, Mentha spicata c.v. and Mentha suaveolens In some embodiments, the active substance comprises or is derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is selected from eucalyptus, cocoa and hemp. In some embodiments, the active substance comprises or derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is selected from star anise, rooibos, mint, and fennel. An aerosol is a suspension of particles of liquid, solid, or both, within a gas. In some embodiments, the fibrous material comprises rooibos. In some embodiments, the botanical material comprises rooibos. In some embodiments, the substance to be delivered comprises a flavour. As used herein, the terms "flavour" and "flavourant" refer to materials which, where local regulations permit, may be used to create a desired taste, aroma or other somatosensorial sensation in a product for adult consumers. They may include naturally occurring flavour materials, botanicals, extracts of botanicals, synthetically obtained materials, or combinations thereof (e.g., tobacco, cannabis, licorice (liquorice), hydrangea, eugenol, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, maple, matcha, menthol, Japanese mint, aniseed (anise), cinnamon, turmeric, Indian spices, Asian spices, herb, wintergreen, cherry, berry, red berry, cranberry, peach, apple, orange, mango, clementine, lemon, lime, tropical fruit, papaya, rhubarb, grape, durian, dragon fruit, cucumber, blueberry, mulberry, citrus fruits, Drambuie, bourbon, scotch, whiskey, gin, tequila, rum, spearmint, peppermint, lavender, aloe vera, cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, khat, naswar, betel, shisha, pine, honey essence, rose oil, vanilla, lemon oil, orange oil, orange blossom, cherry blossom, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, wasabi, piment, ginger, coriander, coffee, hemp, a mint oil from any species of the genus Mentha, eucalyptus, star anise, cocoa, lemongrass, rooibos, flax, ginkgo biloba, hazel, hibiscus, laurel, mate, orange skin, rose, tea such as green tea or black tea, thyme, juniper, elderflower, basil, bay leaves, cumin, oregano, paprika, rosemary, saffron, lemon peel, mint, beefsteak plant, curcuma, cilantro, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, limonene, thymol, camphene), flavour enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and / or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example, liquid such as an oil, solid such as a powder, or gas. In some embodiments, the flavour comprises menthol, spearmint and / or peppermint. In some embodiments, the flavour comprises flavour components of cucumber, blueberry, citrus fruits and / or redberry. In some embodiments, the flavour comprises eugenol. In some embodiments, the flavour comprises flavour components extracted from tobacco. In some embodiments, the flavour comprises flavour components extracted from cannabis, such as terpenes. In some embodiments, the flavour may comprise a sensate, which is intended to achieve a somatosensorial sensation which are usually chemically induced and perceived by the stimulation of the fifth cranial nerve (trigeminal nerve), in addition to or in place of aroma or taste nerves, and these may include agents providing heating, cooling, tingling, numbing effect. A suitable heat effect agent may be, but is not limited to, vanillyl ethyl ether and a suitable cooling agent may be, but not limited to eucolyptol, WS-3. In some embodiments, the flavour comprises menthol, spearmint and / or peppermint. In some embodiments, the flavour comprises flavour components of berry fruits, citrus fruits, and / or tropical fruits. In some embodiments, the flavour may comprise cucumber, blueberry, citrus fruits, pineapple, strawberry, and / or redberry. In some embodiments, the flavour added to an aerosol generating material may be selected to enhance the underlying aroma properties of the aerosol generating material. For example, as described herein, it may be preferable that the fibrous material does not contain tobacco material. Instead, a botanical material may be selected as a major component of the fibrous material. In such instances, the botanical material may produce a particularly neutral aroma profile, for example when rooibos, fennel, star anise, and / or mint are utilised in the aerosol generating material, it is noted that the resulting aerosol is relatively neutral in aroma. When one, or more, of rooibos, fennel, star anise, and / or mint are used, the aroma produced may be enhanced when paired with a flavour such as menthol, spearmint, peppermint; berry fruits, citrus fruits, and / or tropical fruits, or any combination of these flavours. An aerosol generating material is a material that is capable of generating aerosol, for example when heated, irradiated or energized in any other way. Aerosol generating materials may, for example, be in the form of a solid, liquid or semi- solid (such as a gel) which may or may not contain an active substance and / or flavourants. The aerosol-generating material may comprise one or more active substances and / or flavours, one or more aerosol-former materials, and optionally one or more other functional material. The aerosol generating material may comprise, or be, a continuous sheet of material. The sheet may be in the form of a wrapper, it may be gathered to form a gathered sheet or it may be shredded to form a shredded sheet. The shredded sheet may comprise one or more strands or strips of aerosol generating material. The sheet or shredded sheet comprises a first surface and a second surface opposite the first surface. The dimensions of the first and second surfaces are congruent. The first and second surfaces of the sheet or shredded sheet may have any shape. For example, the first and second surfaces may be square, rectangular, oblong or circular. Irregular shapes are also envisaged. The first and / or second surfaces of the sheet or shredded sheet may be relatively uniform (e.g. they may be relatively smooth) or they may be uneven or irregular. For example, the first and / or second surfaces of the sheet may be textured or patterned to define a relatively coarse surface. In some embodiments, the first and / or second surfaces are relatively rough. The smoothness of the first and second surfaces may be influenced by a number of factors, such as the area density of the sheet or shredded sheet, the nature of the components that make up the aerosolisable material or whether the surfaces of the material have been manipulated, for example embossed, scored or otherwise altered to confer them with a pattern or texture. The areas of the first and second surfaces are each defined by a first dimension (e.g. a width) and a second dimension (e.g. a length). The measurements of the first and second dimensions may have a ratio of 1:1 or greater than 1:1 and thus the sheet or shredded sheet may have an “aspect ratio” of 1:1 or greater than 1:1. As used herein, the term “aspect ratio” is the ratio of a measurement of a first dimension of the first or second surface to a measurement of a second dimension of the first or second surface. An “aspect ratio of 1:1” means that a measurement of the first dimension (e.g. width) and a measurement of the second dimension (e.g. length) are identical. An “aspect ratio of greater than 1:1” a measurement of the first dimension (e.g. width) and a measurement of the second dimension (e.g. length) are different. In some embodiments, the first and second surfaces of the sheet or shredded sheet have an aspect ratio of greater than 1:1, such as 1:2, 1:3, 1:4, 1:5, 1:6, 1:7 or more. The shredded sheet may comprise one or more strands or strips of the aerosolisable material. In some embodiments, the shredded sheet comprises a plurality (e.g. two or more) strands or strips of the aerosolisable material. The strands or strips of aerosolisable material may have an aspect ratio of 1:1. In an embodiment, the strands or strips of aerosolisable material have an aspect ratio of greater than 1:1. In some embodiments, the strands or strips of aerosolisable material have an aspect ratio of from about 1:5 to about 1:16, or about 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11 or 1:12. Where the aspect ratio of the strands or strips is greater than 1:1, the strands or strips comprises a longitudinal dimension, or length, extending between a first end of the strand or strip and a second end of the strand or strip. Where the shredded sheet comprises a plurality of strands or strips of material, the dimensions of each strand or strip may vary between different strands or strips. For example, the shredded sheet may comprise a first population of strands or strips and a second population of strands or strips, wherein the dimensions of the strands or strips of the first population are different to the dimensions of the strands or strips of the second population. In other words, the plurality of strands or strips may comprise a first population of strands or strips having a first aspect ratio and a second population of strands or strips having a second aspect ratio that is different to the first aspect ratio. A first dimension, or cut width, of the strands or strips of aerosolisable material is between 0.9 mm and 1.5 mm. When strands or strips of aerosolisable material have a cut width of below 0.9 mm are incorporated into an article for use in a non-combustible aerosol provision system, the pressure drop across the article may be increased to a level that renders the article unsuitable for use in a non-combustible aerosol-provision device. However, if the strands or strips have a cut width above 2 mm (e.g. greater than 2 mm), then it may be challenging to insert the strands or strips of aerosolisable material into the article during its manufacture. In a preferred embodiment, the cut width of the strands or strips of aerosolisable material is between about 1 mm and 1.5 mm. The strands or strips of material are formed by shredding the sheet of aerosolisable material. The sheet of aerosolisable material may be cut width-wise, for example in a cross-cut type shredding process, to define a cut length for the strands or strips of aerosolisable material, in addition to a cut width. The cut length of the shredded aerosolisable material is preferably at least 5 mm, for instance at least 10 mm, or at least 20 mm. The cut length of the shredded aerosolisable material can be less than 60 mm, less than 50 mm, or less than 40 mm. In some embodiments, a plurality of strands or strips of aerosolisable material is provided and at least one of the plurality of strands or strips of aerosolisable material has a length greater than about 10 mm. At least one of the plurality of strands or strips of aerosolisable material can alternatively or in addition have a length between about 10 mm and about 60 mm, or between about 20 mm and about 50 mm. Each of the plurality of strands or strips of aerosolisable material can have a length between about 10 mm and about 60 mm, or between about 20 mm and about 50 mm. A consumable is an article comprising or consisting of aerosol-generating material, part or all of which is intended to be consumed during use by a user. In some embodiments, the consumable for use with a non-combustible aerosol provision device may comprise one or more other components, such as, an aerosol- generating material storage area, an aerosol-generating material transfer component, an aerosol generator, an aerosol generation area, a housing, a wrapper, a filter, a mouthpiece, and / or an aerosol-modifying agent. A consumable may also comprise an aerosol generator, such as a heater, that emits heat to cause the aerosol-generating material to generate aerosol in use. The heater may, for example, comprise combustible material, a material heatable by electrical conduction, or a susceptor. A susceptor is a material that is heatable by penetration with a varying magnetic field, such as an alternating magnetic field. The susceptor may be an electrically- conductive material, so that penetration thereof with a varying magnetic field causes induction heating of the heating material. The heating material may be magnetic material, so that penetration thereof with a varying magnetic field causes magnetic hysteresis heating of the heating material. The susceptor may be both electrically-conductive and magnetic, so that the susceptor is heatable by both heating mechanisms. The device that is configured to generate the varying magnetic field is referred to as a magnetic field generator, herein. An aerosol generator is a heater capable of interacting with the aerosol-generating material so as to release one or more volatiles from the aerosol-generating material to form an aerosol. In some embodiments, the aerosol generator is capable of generating an aerosol from the aerosol-generating material without heating. For example, the aerosol generator may be capable of generating an aerosol from the aerosol-generating material without applying heat thereto, for example via one or more of vibrational, mechanical, pressurisation or electrostatic means. In some embodiments, the fibrous material comprises a botanical material. A fibrous material comprising a botanical material may supplement the flavour profile of any aerosol produced. For example, a botanical material may be selected which has a relatively neutral flavour profile. A neutral flavour profile may be described as a flavour profile which contains few intense flavours and / or one which readily accepts the loading of top flavours, without significantly affecting their perception. For example, a fibrous material containing reconstituted tobacco material may be described as producing an aerosol with a relatively neutral flavour profile. It may be advantageous to be able to produce an aerosol which has a similarly neutral flavour profile to that of reconstituted tobacco, but without using tobacco material. In some embodiments, the fibrous material may be called a substrate. It may be preferable for the substrate to be made from a non-tobacco material, such that a consumer may reduce their use of tobacco-based materials. However, consumers may wish to retain the physiological effects provided by nicotine. Therefore, providing a substrate made from a non-tobacco botanical material which includes nicotine may be of interest to certain consumers. In some embodiments, an aerosol generating material comprises a first fibrous material comprising a botanical material, a second fibrous material, an active, and a binder, wherein the first fibrous material and the second fibrous material are different. In certain circumstances, consumers may wish to experience the effects of an active other than nicotine, such as one or more of those described hereinabove. In some embodiments, the botanical material may be any non-tobacco botanical material. For example, the material may be derived from species which are members of the Asteracae family, the Fabaceae family, the Myrtaceae family, Apiaceae family, Camellia taliensis, the Solanaceae family, the Brassicaceae family, the Caricaceae family, the Asclepiadaceae family, the Equisetaceae family, the Oleaceae family, the Lamiaceae family, and tisanes. For example, the non-tobacco botanical material may be selected from the Matricaria species, such as chamomile; the Pimpinella anisum species, such as anise; the Foeniculum vulgare species, such as fennel; jasmine; lavender; cloves; eucalyptus, and the species Aspalathus linearis, such as rooibos. In some embodiments, the non-tobacco botanical material is selected from a botanical material which comprises favourable aroma properties for use in a non-combustible aerosol provision system. For example, the non-tobacco botanical material may comprise relatively few aroma compounds compared to a traditional tobacco material; therefore, an aerosol produced from a non-tobacco botanical material may have a different profile of volatile compounds compared to an aerosol produced from a tobacco material. The non-tobacco botanical material may deliver an aerosol which is considered favourable by a consumer of tobacco-based delivery systems. In some embodiments, a non-tobacco botanical material may produce an aerosol, when heated, with a sensorial experience that is comparable to that provided by a conventional combustible product, such as a cigarette. In some embodiments, the non-tobacco botanical material is selected from seed-producing plants which do not develop persistent woody tissue and which are often valued for their medicinal or sensorial characteristics. In some embodiments, it may be preferable to provide an aerosol generating material, for use in a non-combustible aerosol provision system which does not comprise any tobacco plant material. As used herein, the term “tobacco material” refers to any material comprising tobacco or derivatives or substitutes thereof. The tobacco material may be in any suitable form. The term “tobacco material” may include one or more of tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes. The tobacco material may comprise one or more of ground tobacco, tobacco fibre, cut tobacco, extruded tobacco, tobacco stem, tobacco lamina, and / or reconstituted tobacco. The present inventors have identified that the aerosol produced from an aerosol generating material comprising a first fibrous material comprising a botanical material, a second fibrous material, a nicotine source, and a binder, where the first and second fibrous material are different is particularly favourable. In particular, the perceived harshness is at a desirable level and comparable to that provided from a conventional combustible product. The aerosol generating material comprises a binder. The binder is arranged to bind the components of the aerosol generating material together to form, for example, a sheet or shredded sheet. The binder may at least partially coat the surface of the first fibrous material and the second fibrous material. Alternatively, the binder may hold the first fibrous material and the second fibrous material together in a matrix. The binder may be selected from one or more compounds selected from the group comprising alginates, pectins, starches (and derivatives), celluloses (and derivatives), gums, silica or silicones compounds, clays, polyvinyl alcohol and combinations thereof. For example, in some embodiments, the binder comprises one or more of alginates, pectins, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethylcellulose, pullulan, xanthan gum, guar gum, carrageenan, agarose, acacia gum, fumed silica, PDMS, sodium silicate, kaolin and polyvinyl alcohol. In some cases, the binder comprises alginate and / or pectin or carrageenan. In a preferred embodiment, the binder comprises guar gum. The binder may be present in an amount of from about 1 to about 20% by weight of the sheet or shredded sheet, or in an amount of from 1 to about 10% by weight of the sheet or shredded sheet of aerosolisable material. For example, the binder may be present in an amount of about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10% by weight of the sheet or shredded sheet of aerosolisable material. In some embodiments, the aerosol generating material comprises a total fibrous material content of between about 30% and about 95% by weight on a dry basis. For example, the total fibrous material content may be between about 35% and about 95%, such as between about 40% and about 95%, such as between about 45% and about 95%, such as between about 50% and about 95%, such as between about 55% and about 95%, such as between about 60% and about 95%, such as between about 65% and about 95%, such as between about 65% and about 90%, such as between about 65% and about 85%, such as between about 65% and about 80%, such as between about 70% and about 80% by weight on a dry basis. In some embodiments, the total fibrous material content of the aerosol generating material is about 65%, by weight on a dry basis. In some embodiments, the total fibrous material content of the aerosol generating material is about 70%, by weight on a dry basis. In some embodiments, the total fibrous material content of the aerosol generating material is about 75%, by weight on a dry basis. In some embodiments, the fibrous material comprises first and second fibrous materials. In some embodiments, the first and second fibrous materials are different. When the first and second fibrous materials are different, the properties of the aerosol generating material, e.g. the aerosol generated, may be modified. For example, two different fibrous materials could be combined which complement each other and provide an aerosol that is particularly pleasant / favourable to a consumer. In some embodiments, the first fibrous material comprises a botanical material and the second fibrous material comprises wood fibres / wood pulp. Used herein, wood fibres and wood pulp may be used to describe a cellulose material derived from a cellulose material which has little, or substantially no, noticeable aroma. For example, wood fibre and wood pulp may be of similar nature to wood fibre / wood pulp used to make paper. Wood fibre and wood pulp are obtained from a non-tobacco material based source. In some embodiments, the first fibrous material comprises a botanical material and the second fibrous material comprises a different botanical material. When the second fibrous material comprises a botanical material, as well as the first fibrous material, the aerosol may be able to be modified to a greater extent. In particular, when two different botanical materials are utilised, each shall produce its own specific aroma. Selecting appropriate botanical materials which complement each other may therefore produce a favourable aerosol. In some embodiments, a ratio between the first fibrous material and the second fibrous material may be from about 20:1 to about 2:1. For example, the ratio between the first fibrous material and the second fibrous material may be from about 18:1 to about 2:1; such as from about 16:1 to about 2:1; such as from about 14:1 to about 2:1; such as from about 12:1 to about 2:1; such as from about 10:1 to about 2:1. For example, the ratio may be from about 9:1 to about 2:1; such as from about 8:1 to about 3:1; such as from about 7:1 to about 3:1; such as from about 6:1 to about 3:1; such as from about 5:1 to about 3:1. In some embodiments, a ratio between the first fibrous material and the second fibrous material may be about 4:1. In some embodiments, a ratio between the first fibrous material and the second fibrous material may be about 5:1. In some embodiments, a ratio between the first fibrous material and the second fibrous material may be about 6:1. When a ratio between the first fibrous material and the second material is from about 20:1 to about 2:1, the aerosol produced may be particularly favourable. Furthermore, botanical materials are generally more difficult and more costly to obtain compared to wood pulp / wood fibres, which are cheap and readily available due to their use in the manufacture of paper. Therefore, it may be desirable to combine a botanical material with wood fibres / wood pulp to produce an aerosol containing the aroma compounds from the botanical material but manufactured more cost efficiently compared to a fibrous material containing 100% botanical material. It has been found that addition of wood fibres / wood pulp in the ratios described above has little, to no impact on the sensorial properties of an aerosol, and any impact could be corrected / covered / adjusted by the use of flavours. In some embodiments, modifying the amount of a first fibrous material, comprising, for example, a botanical material; and a second fibrous material, comprising, for example, wood fibres / wood pulp, enables the aerosol to be modified / tailored to a specific desirable profile. For example, one may increase the relative amount of a botanical material, compared to wood fibre / wood pulp, therefore increasing the amount of aroma compounds derived from the botanical material in an aerosol. Alternatively, reducing the amount of botanical material in the fibrous material may produce an aerosol with fewer aroma compounds. When an aerosol contains fewer aroma compounds, any further flavours added to the aerosol generating material may be more prominent and perceived to a greater extent by a user. Alternatively, producing an aerosol with fewer aroma compounds may allow the use of flavours which are particularly subtle, for example flavours derived from berry fruits, tropical fruits, and citrus fruits. The correct amount of an organic acid to be used in an aerosol-generating material can be defined in a number of ways. For example, the amount of organic acid used may be defined in relation to the aerosol generating material, for example as a weight percentage of the aerosol generating material. Alternatively, the amount of organic acid may be defined in relation to the nicotine content of the aerosol generating material, for example by reference to a ratio of the moles of nicotine to the moles of acid. Without wishing to be bound by any particular theory, it is understood that when the amount of acid in the aerosol-generating material is as described herein, the aerosol produced by the aerosol-generating material contains a ratio of nicotine in the gas phase to nicotine in the particulate / liquid phase (nicotine (gas):nicotine (particulate / liquid)) that is particularly beneficial. That is, the ratio of nicotine (gas):nicotine (particulate / liquid) in the aerosol produced by the present aerosol generating materials provides an improved user experience and satisfaction. This is believed to be because using an amount of acid as defined herein allows for optimal protonation of the nicotine (for example, by altering the ratio of free-base nicotine to protonated nicotine). Without wishing to be bound by theory, it is hypothesised that protonation of the nicotine in the aerosol-generating material changes the ratio of nicotine (gas):nicotine (particulate / liquid) by increasing the amount of nicotine present in the particulate / liquid phase. The aerosols produced by the aerosol-generating materials described herein deliver an appropriate amount of nicotine to the user. Furthermore, users report that such aerosol-generating materials are neither too harsh, nor not harsh enough. As such, the aerosol-generating materials comprising acid as described herein produce an aerosol with an appropriate nicotine content and perceived harshness. The addition of acids may additionally improve the overall flavour profile of a consumable. In some embodiments, the acid is selected from the group consisting of levulinic acid, lactic acid, benzoic acid, citric acid, 2-methylbutyric acid, or 2-methylvaleric acid. In some embodiments, the acid is benzoic acid. In some embodiments, the acid is levulinic acid. In some embodiments, the acid is a combination of benzoic acid and levulinic acid. In particular, it is understood that the total amount of acid as defined herein represents the lowest amount of acid required to provide the appropriate nicotine level and sensory experience. Using an amount of acid lower than that described herein results in a non-optimal amount of nicotine reaching the user. It is further understood that the total amount of acid as defined herein represents the greatest amount of acid required to provide the appropriate nicotine level and sensory experience. Using an amount of acid greater than that described herein results in no better performance and is therefore considered to be wasted. In some embodiments, the aerosol generating material comprises an organic acid. The total amount of the acid is from about 0.1% to about 5% by weight of the aerosol- generating material. For example, the total amount of the acid is from about 0.1% to about 5%, from about 0.5% to about 5%, from about 1% to about 5%, from about 1.5% to about 5%, from about 2% to about 5%, or from about 2.5% to about 5% by weight of the aerosol-generating material. For example, the total amount of the acid is from about 2.5% to about 5%, from about 2.5% to about 4.5%, from about 2.5% to about 4%, from about 2.5% to about 3.5%, or from about 2.5% to about 3% by weight of the aerosol-generating material. In some embodiments, the aerosol generating material comprises two or more, different organic acids. When the aerosol generating material comprises two or more, different organic acids, the total amount of the combined organic acids may be from about 0.1% to about 5% by weight of the aerosol-generating material. For example, the total amount of the combined acid may be from about 0.5% to about 5%, from about 1% to about 5%, from about 1% to about 4.5%, from about 1% to about 4%, from about 1% to about 3.5%, from about 1% to about 3%, from about 1% to about 2.5%, from about 1% to about 2%, from about 1% to about 1.75%, or from about 1.3% to about 1.6% by weight of the aerosol-generating material. In some embodiments, the aerosol generating material comprises an acid, or two or more different organic acids, wherein the total amount of acid is included in an amount (i.e. moles of acid) from about 50%, about 60%, about 70%, about 80%, about 90%, about 100%, about 110%, about 120%, about 130%, about 140%, about 150%, about 160%, about 170%, about 180%, or about 190% to about 200% relative to the moles of nicotine. In some embodiments, the aerosol generating material comprises an acid, or two or more different organic acids, in an amount (i.e. moles of acid) from about 50% to about 250%, relative to the moles of nicotine, such as free base nicotine. For example, from about 50% to about 200%; such as from about 75% to about 175%; such as from about 75% to about 150%; such as from 100% to about 150%; such as from about 100% to about 125%, relative to the moles of nicotine, such as free base nicotine. The skilled person would readily understand that the amount of acid that may be included can be described in many other alternative ways. For example, the aerosol generating material may comprise an acid, or two or more different organic acids, in an amount of between about 0.5 and about 2.5 moles, relative to the moles of nicotine, such as free base nicotine; such as from about 0.5 to about 2.0 moles; such as from about 0.75 to about 1.75 moles; such as from about 0.75 to about 1.50 moles; such as from about 1.0 to about 1.50 moles; such as from about 1.0 to about 1.25 moles, relative to the moles of nicotine, such as free base nicotine. In some embodiments, the aerosol generating material comprises an extract derived from a botanical material. The aerosol generating material comprises an aerosol former / aerosol former material. The total amount of aerosol former may be from about 5% to about 35% by weight on a dry weight basis. In some embodiments, the total amount of the aerosol former is from about 10% to about 30% by dry weight basis. In some embodiments, the total amount of the aerosol former is from about 10% to about 25%; such as from about 12% to about 2%; such as from about 15% to about 25%; such as from about 17% to about 23%; such as from about 18% to about 22%, by dry weight basis. In some embodiments, the total amount of the aerosol former material is about 20%, by weight based on a dry weight basis. In some embodiments, the total amount of the aerosol former material is about 25%, by weight on a dry weight basis. In some embodiments, the total amount of aerosol former is about 17%, by weight on a dry weight basis. In this context, an "aerosol former " is an agent, or material, that promotes the generation of an aerosol. An aerosol former may promote the generation of an aerosol by promoting an initial vaporisation and / or the condensation of a gas to an inhalable solid and / or liquid aerosol. In some embodiments, an aerosol former may improve the delivery of flavour from the aerosol generating material. The aerosol former material has been found to improve the sensory performance of an article for use with an aerosol generation device comprising the aerosol generating material, by helping to transfer compounds such as flavour compounds from the fibrous material to the consumer. In some embodiments, the aerosol former material described herein is flavoured and / or comprises a flavour as described herein. In general, any suitable aerosol former may be included in the aerosol generating material of the invention. Suitable aerosol formers include, but are not limited to: a polyol such as sorbitol, glycerol, and glycols like propylene glycol or triethylene glycol; a non-polyol such as monohydric alcohols, high boiling point hydrocarbons, acids such as lactic acid, glycerol derivatives, esters such as diacetin, triacetin, triethylene glycol diacetate, triethyl citrate or myristates including ethyl myristate and isopropyl myristate and aliphatic carboxylic acid esters such as methyl stearate, dimethyl dodecanedioate and dimethyl tetradecanedioate. In some embodiments, the aerosol former is selected from the group consisting of glycerol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3- butylene glycol, erythritol, meso-Erythritol, ethyl vanillate, ethyl laurate, a diethyl suberate, triethyl citrate, triacetin, a diacetin mixture, benzyl benzoate, benzyl phenyl acetate, tributyrin, lauryl acetate, lauric acid, myristic acid, propylene carbonate, and mixtures thereof. In some embodiments, the aerosol former comprises glycerol in amount from about 10% to about 90% by weight of the aerosol former. In some embodiments, a ratio of aerosol former to the total fibrous material is from about 1:7 to about 1:3. For example, from about 1:6 to about 1:4, such as about 1:5. When the ratio of aerosol former to fibrous material is within this range, the aerosol generating material exhibits favourable storage properties and generates a favourable aerosol. In some embodiments, a ratio of aerosol former to the first fibrous material is from about 1:6 to about 1:2, such as from about 1:5 to about 1:2, such as from about 1:3 to about 1:2. In some embodiments, a ratio of aerosol former to the first fibrous material is about 1:1. In some embodiments, a ratio of aerosol former to the second fibrous material is from about 3:1 to about 1:3, such as from about 2:1 to about 1:2, such as from about 1.5:1 to about 1:1.5. In some embodiments, a ratio of aerosol former to the second fibrous material is about 1:1. In some embodiments, the aerosol generating material comprises particles of a first fibrous material and a second fibrous material. Alternatively, it may be described that the aerosol generating material comprises particulate fibrous material. Each particle of fibrous material may have a maximum dimension. As used herein, the term “maximum dimension” refers to the longest straight line distance from any point on the surface of a particle of fibrous material, or on a particle of fibrous material, to any other surface point on the same particle of fibrous material, or particle surface. The maximum dimension of a particle of particulate fibrous material may be measured using scanning electron microscopy (SEM). The maximum dimension of each particle of fibrous material can be up to about 250 μm. In some embodiments, the maximum dimension of each particle of fibrous material can be up to about 200 μm, such as up to about 150 μm, such as up to about 100 μm, such as up to about 75 μm. In some embodiments, the maximum dimension of each particle of fibrous material can be up to about 1 mm. A population of particles of fibrous material may have a specific, targeted particle size distribution. Particle size distribution can be defined by referring to the D10, D50, and D90 values of a sample; and sieve analysis can be used to determine the particle size distribution of the particles of fibrous material. In some embodiments, a population of particles of the fibrous material, i.e. the first fibrous material and the second fibrous material, may have a particle size distribution (D90) of at least about 100 μm. In some embodiments, a population of particles of the fibrous material has a particle size distribution (D90) of at least about 110 μm, such as at least about 120 μm, such as at least about 130 μm, such as at least about 140 μm, such as at least about 150 μm. In some embodiments, a population of particles of the fibrous material, i.e. the first fibrous material and the second fibrous material, may have a particle size distribution (D90) of at least about 200 μm, such as at least about 300 μm, such as at least about 400 μm, such as at least about 500 μm, such as at least about 600 μm, such as at least about 700 μm, such as at least about 800 μm, such as at least about 900 μm, such as at least about 1000 μm. In some embodiments, a population of particles of the fibrous material, i.e. the first fibrous material and the second fibrous material, may have a particle size distribution (D50), of between about 25 μm and about 125 μm. In some embodiments, a population of particles of the fibrous material has a particle size distribution (D50) of between about 35 μm and about 115 μm, such as between about 45 μm and about 105 μm, such as between about 50 μm and about 100 μm. In some embodiments, a population of particles of the fibrous material, i.e. the first fibrous material and the second fibrous material, may have a particle size distribution (D10), of between about 25 μm and about 75 μm. In some embodiments, a population of particles of the fibrous material has a particle size distribution (D10) of between about 30 μm and about 70 μm, such as between about 35 μm and about 65 μm, such as between about 40 μm and about 60 μm, such as between about 45 μm and about 50 μm. In some embodiments, a population of particles of the fibrous material, i.e. the first fibrous material and the second fibrous material, may have a particle size distribution D10 of <50 μm, D50 of 50 μm to 100 μm, and a D90 of 100 μm to 150 μm. In some embodiments, a population of particles of the fibrous material, i.e. the first fibrous material and the second fibrous material, may have a particle size distribution D10 of 50 μm to 100 μm, a D50 of 50 μm to 100 μm, and a D90 of 50 μm to 100 μm. For example, a population of particles of fibrous material may have a particle size distribution D10 of 50 μm to 60 μm, a D50 of 60 μm to 80 μm, and a D90 of 80 μm to 100 μm. When the D10, D50, and D90 are similar, then the population distribution may be described as being narrow. In other words, such a particle size distribution contains a very small variation in particle size. The maximum dimension of a particle and the particle size distribution impact the thickness of any aerosol generating material produced from said particles. The inventors have found that providing a particle size distribution such as that described herein, e.g. having a D90 of at least about 100 μm; or having a D50 of between about 25 μm and about 125 μm; or having a D10 of between about 25 μm and about 75 μm; or having a D10 of <50 μm, a D50 of about 50 μm to about 100 μm, and a D90 of about 100 μm to about 150 μm; or a D10 of about 50 μm to about 60 μm, a D50 of about 60 μm to about 80 μm, and a D90 of about 80 μm to about 100 μm, allows better mixing, which improves bonding and chemical interactions between particles. In addition, providing particles within these ranges allows the skilled person to more extensively adjust the thickness of any sheet prepared from the particles. The particle size of the particulate fibrous material can also influence the roughness of the sheet or shredded sheet of aerosol generating material. In some embodiments, the aerosol generating material has a thickness from about 50 μm to about 450 μm. In some embodiments, the aerosol generating material has a thickness from about 50 μm to about 400 μm, such as from about 75 μm to about 350 μm, such as from about 75 μm to about 300 μm, such as from about 75 μm to about 250 μm, such as from about 75 μm to about 200 μm, such as from about 100 μm to about 200 μm, such as from about 100 μm to about 175 μm, such as from about 100 μm to about 150 μm. In some embodiments, the aerosol generating material has a water content of between about 3% to about 15%. For example, the aerosol generating material has a water content of between about 3% and about 12%, such as between about 3% and about 10%, such as between about 3% and about 9%, such as between about 3% and about 8%, such as between about 4% to about 7%, for example between about 5% and about 6%. In some embodiments, the aerosol generating material comprises a water content of about 5%. In some embodiments, the aerosol generating material has a filling value from about 2 cm3 / g to about 10 cm3 / g. In some embodiments, the aerosol generating material has a filling value of from about 3 cm3 / g to about 8 cm3 / g, for example the aerosol generating material may have a filling value of from about 4 cm3 / g to about 7 cm3 / g, such as from about 4 cm3 / g to about 6 cm3 / g. In some embodiments, the aerosol generating material has a filling value of about 5 cm3 / g. When the filling value is between about 2 cm3 / g to about 10 cm3 / g, for example about 5 cm3 / g, a consumable containing the aerosol generating material can achieve the same firmness using less material. Therefore, the overall weight of material used to achieve the same / required filling value, is less, which can provide a saving to the cost of goods. In some embodiments, the aerosol generating material exhibits a bursting strength of between about 5 KPa and about 40 KPa. In some embodiments, the aerosol generating material exhibits a bursting strength of between about 10 KPa and about 30 KPa. In some embodiments, the aerosol generating material exhibits a bursting strength of between about 15 KPa and about 25 KPa, for example between about 20 KPa and about 25 KPa. In some embodiments, the bursting strength is about 20 KPa. In an embodiment, the nicotine salt is selected from nicotine benzoate, nicotine citrate, and nicotine lactate, nicotine levulinate, or mixtures thereof. According to an aspect of the disclosure, there is provided a process for manufacturing an aerosol generating material as described herein. The process comprises combining a first fibrous material comprising a botanical material, a second fibrous material, a nicotine source, a binder, and water to form a slurry. The slurry is then processed to form a sheet of aerosolisable material comprising the first fibrous material, the second fibrous material, the nicotine source, and the binder. The slurry may be processed by forming a layer of the slurry on a surface and then drying the slurry to remove at least some of the water and form a sheet of aerosol generating material. The water may be removed by allowing the water to evaporate from the slurry at ambient temperature and pressure (e.g.25 °C and 101 kPa.) Alternatively, the water may be removed by applying heat to the slurry (e.g. by heating it to about 25 °C) and / or reducing the atmospheric pressure surrounding the slurry (e.g. to less than 101 kPa). Alternatively, the water may be removed by applying heat to a cast sheet by heating the material to between about 100 °C to about 120 °C. In some embodiments, the slurry is processed by band casting it. After drying, the sheet of aerosolisable material can be cut into strips or strands of aerosolisable material. The strips or strands of aerosolisable material can be gathered and formed into an article for use in a non-combustible aerosol provision system. A suitable process for cutting the sheet of aerosolisable material and gathering it into the article is found in WO 2019 / 057796. Optionally, the aerosolisable material can be crimped prior to being gathered and formed into the article. Figure 1 illustrates how an article for use in a non-combustible aerosol provision system comprising the aerosol generating material may be manufactured. A slurry comprising a first and second fibrous material, a nicotine source, water and binder is formed. Optionally, an aerosol former is added at this point. A layer of the slurry is formed on a surface. The layer of slurry is dried on the surface to form a sheet of aerosolisable material. A single thickness of the sheet of aerosolisable material is fed into a shredding apparatus. This can be achieved, for example, by providing a bobbin of sheet material which can be continuously fed into a shredding apparatus. Alternatively, a discrete portion of the aerosolisable material in sheet form, such as a sheet known to those skilled in the art as a flag, can be fed into a shredding apparatus. The sheet of aerosolisable material is shredded to form strands or strips of aerosolisable material. Optionally the aerosolisable material may be subject to a second cutting step (not shown), such as in a cross-cut type shredding process, to obtain a defined cut length. The strands or strips of aerosolisable material are gathered together to form an aerosol- generating section of an article. In some embodiments, the aerosol generating material is in the form of a sheet or shredded sheet and has an area density of from about 60 g / m2to about 400 g / m2. The sheet or shredded sheet may have an area density of from about 110 g / m2to about 240 g / m2, from about 120 g / m2to about 230 g / m2, from about 130 g / m2to about 220 g / m2or from about 140 g / m2to about 210 g / m2. In some embodiments, the sheet or shredded sheet has an area density of from about 130 g / m2to about 190 g / m2, from about 140 g / m2to about 180 g / m2, from about 150 g / m2to about 170 g / m2. In some embodiments, the sheet or shredded sheet has an area density of about 160 g / m2, 170 g / m2, 180 g / m2, 190 g / m2or 200 g / m2. In a preferred embodiment, the sheet or shredded sheet has an area density of about 160 g / m2. The area density of about 100 g / m2to about 250 g / m2is thought to contribute to the strength and flexibility of the sheet or shredded sheet. Furthermore, the inventors have found that a rod comprising a shredded sheet of aerosolisable material having an area density of around 180 gsm and a minimum thickness of 220–230 μm can be can be packed such that the aerosolisable material stays in place within the rod whilst maintaining a desired weight of tobacco material within the rod (e.g. around 300 mg) and delivering acceptable organoleptic properties (e.g. taste and smell) when heated in a non-combustible aerosol provision device. In an embodiment, the aerosol generating material is in the form of a rod. The aerosol generating rod may have a total weight of between about 250 mg and about 350 mg. In an embodiment, the aerosol generating rod may be wrapped in a wrapper having a permeability of less than 100 Coresta Units. The aerosol generating rod may have an outer circumference of at least about 19 mm, preferably between about 19 mm and about 23 mm or about 21 mm. This may facilitate insertion of the article into an aerosol generation device. As used herein, the term “rod” is used to describe a generally cylindrical element of substantially circular, oval, or elliptical cross section. In the compositions described herein, where amounts are given in % by weight, for the avoidance of doubt this refers to a dry weight basis, unless specifically indicated to the contrary. Thus, any water that may be present in the aerosol-generating material, or in any component thereof, is entirely disregarded for the purposes of the determination of the weight %. The water content of the aerosol-generating material described herein may vary and may be, for example, from 5 to 15% by weight. The water content of the aerosol-generating material described herein may vary according to, for example, the temperature, pressure and humidity conditions at which the compositions are maintained. The water content can be determined by Karl-Fisher analysis, as known to those skilled in the art. On the other hand, for the avoidance of doubt, even when the aerosol-former material is a component that is in liquid phase, such as glycerol or propylene glycol, any component other than water is included in the weight of the aerosol-generating material. In some embodiments, the system comprises an article as described herein and the aerosol generation device is arranged to receive at least a portion of the article comprising the aerosol-generating material and to heat the portion of the article comprising the aerosol-generating material and generate an aerosol from the aerosol- generating material. In some embodiments, the aerosol generating material may be positioned in an aerosol generating section of an article. When in use, the aerosol generating section may exhibit a pressure drop of from about 15 to about 40 mm H2O. In some embodiments, the aerosol generating section exhibits a pressure drop across the aerosol generating section of from about 15 to about 30 mm H2O. In some embodiments, the article comprises a mouthpiece, and a cylindrical rod of aerosol generating material connected, either directly or indirectly, to the mouthpiece. A mouthpiece wrapper, also described herein as a tipping paper, may be wrapped around the full length of the mouthpiece and over part of the rod of aerosol generating material and has an adhesive on its inner surface to connect the mouthpiece and rod. In some embodiments, the tipping paper extends 5 mm over the rod of aerosol generating material but it can alternatively extend between 3 mm and 10 mm over the rod 3, or more preferably between 4 mm and 6 mm, to provide a secure attachment between the mouthpiece and rod. The tipping paper can have a basis weight which is higher than the basis weight of plug wraps used in the article for use with an aerosol generation device, for instance a basis weight of 40 gsm to 80 gsm, more preferably between 50 gsm and 70 gsm, and in the present example 58 gsm. These ranges of basis weights have been found to result in tipping papers having acceptable tensile strength while being flexible enough to wrap around the article 1 and adhere to itself along a longitudinal lap seam on the paper. The outer circumference of the tipping paper, once wrapped around the mouthpiece, may be about 21mm. According to some embodiments, there is provided an article for use in an aerosol provision system, the article including an aerosol generating material or substrate, a mouthpiece downstream of the aerosol generating material and a wrapper, wherein the wrapper comprises a sensate material. A portion of the mouthpiece wrapper close to the downstream end of the mouthpiece comes into contact with the consumer’s lips during use. The mouthpiece wrapper may be arranged to wrap around and enclose the mouthpiece in a region between the upstream end and downstream end of the mouthpiece. The mouthpiece wrapper may be arranged such that, when the article is inserted into a heating device, a portion of the mouthpiece wrapper is heated to the same or a similar temperature as the aerosol generating material. In some embodiments, the mouthpiece wrapper comprises a sensate material. The sensate material may comprise a flavourant, as herein described. In some embodiments, the flavourant may suitably be liquorice, rose oil, vanilla, lemon oil, orange oil, a mint- flavour, suitably menthol and / or a mint oil from any species of the genus Mentha such as peppermint oil and / or spearmint oil, or lavender, fennel or anise. In preferred embodiments, the sensate material comprises sugars and / or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol). Additionally or alternatively, the sensate material may comprise a material that delivers a cooling, heating or sour sensation to the consumer during use of the article. In some embodiments, the sensate material may comprise one or more of pH regulators, stabilizers, and / or antioxidants. These materials may help to increase the shelf-life of the mouthpiece wrapper and thus the article. The sensate material can be encapsulated in an encapsulating material. For instance, the sensate material can be provided in the form of microcapsules which are applied to the wrapper. The mouthpiece wrapper may comprise an inwardly facing surface and an outwardly facing surface and the sensate material may be present on at least a portion of the inwardly facing surface and / or the outwardly facing surface of the wrapper. For example, the sensate material may be disposed on an outwardly facing surface of the mouthpiece wrapper in an area which comes into contact with the consumer’s lips during use. By disposing the sensate material on the outwardly facing surface of the mouthpiece wrapper, the sensate material may be transferred to the consumer’s lips during use. Transfer of the sensate material to the consumer’s lips during use of the article may modify the organoleptic properties (e.g. taste) of the aerosol generated by the aerosol generating substrate. For example, the sensate material may impart flavour to the aerosol generated by the aerosol generating substrate. The sensate material may be at least partially soluble in water such that it may be transferred to the user via the consumer’s saliva. Advantageously, a relatively low amount of sensate material may be required in order to modify the sensory properties delivered to the consumer during use of the article, although this will, to some extent, depend on the properties of the senate material because the minimum amount that is needed to modify the sensory properties will vary between different sensate materials. This may have the advantage that the addition of the sensate material to the mouthpiece wrapper may not significantly increase the overall weight of the article. Example 1 An aerosol generating material was prepared having the composition illustrated in Table 1. Table 1 The aerosol generating material was prepared by adding rooibos, wood pulp / wood fibres, glycerol, nicotine, benzoic acid, and guar gum, to water to form a slurry. The slurry was subsequently cast into a sheet and dried to form an aerosol generating material. Example 2 An aerosol generating material was prepared having the composition illustrated in Table 2 The aerosol generating material of Example 2 was prepared in a similar manner to that of Example 1, i.e. rooibos, wood pulp / wood fibres, glycerol, nicotine, benzoic acid, levulinic acid, and guar gum were added to water to form a slurry. The slurry was subsequently cast into a sheet and dried to form an aerosol generating material. The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only, and are not exhaustive and / or exclusive. It is to be understood that advantages, embodiments, examples, functions, features, structures, and / or other aspects described herein are not to be considered limitations on the scope of the invention as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope of the claimed invention. Various embodiments of the invention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc, other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future.

Claims

Claims 1. An aerosol generating material comprising: a first fibrous material comprising a botanical material, a second fibrous material, an active, and a binder, wherein the first fibrous material and the second fibrous material are different.

2. The aerosol generating material according to claim 1, wherein the aerosol generating material is free of, or substantially free of, tobacco material.

3. The aerosol generating material according to claim 1 or claim 2, wherein the botanical material is selected from the list consisting of rooibos, star anise, fennel, mint, and combinations thereof.

4. The aerosol generating material according to claim 3, wherein the botanical material is rooibos.

5. The aerosol generating material according to claim 3, wherein the botanical material is star anise, fennel or mint, and combinations thereof.

6. The aerosol generating material according to any one of claims 1 to 5, wherein the second fibrous material comprises wood fibres / wood pulp.

7. The aerosol generating material according to any one of claims 1 to 6, wherein a ratio between the first fibrous material and the second fibrous material is from about 20:1 to about 2:

1.

8. The aerosol generating material according to any one of claims 1 to 5, wherein the binder is a natural gum binder selected from the list consisting of alginates, pectins, starches, celluloses, natural gums, silica, silicone compounds, clays, polyvinyl alcohol.

9. The aerosol generating material according to any one of claims 1 to 8, wherein the binder is selected from the list consisting of hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethylcellulose, pullulan, xanthan gum, guargum, carrageenan, agarose, acacia gum, fumed silica, PDMS, sodium silicate, kaolin, and polyvinyl alcohol.

10. The aerosol generating material according to any one of claims 1 to 9, wherein the binder is included in an amount of from about 1% to about 20% on a dry weight basis.

11. The aerosol generating material according to any one of claims 1 to 10, wherein the active comprises a nicotine salt.

12. The aerosol generating material according to claim 11, wherein the nicotine salt is selected from the list consisting of nicotine benzoate, nicotine levulinate, nicotine citrate, nicotine lactate, or combinations thereof.

13. The aerosol generating material according to any one of claims 1 to 10, wherein the active comprises free base nicotine and an organic acid.

14. The aerosol generating material according to claim 13, wherein the organic acid is selected from the list consisting of lactic acid, levulinic acid, benzoic acid, citric acid, 2-methylbutyric acid, 2-methylvaleric acid, and mixtures thereof.

15. The aerosol generating material according to claim 14, wherein the organic acid is included in a ratio of between about 0.5 and about 2.5 moles, relative to the moles of free base nicotine.

16. The aerosol generating material according to any one of claims 1 to 15, wherein the active is a non-nicotine active.

17. The aerosol generating material according to any one of claims 1 to 16, further comprising an aerosol former material.

18. The aerosol generating material according to claim 17, wherein the aerosol former material is included in an amount from about 5% to about 35% on a dry weight basis.

19. The aerosol generating material according to claim 17 or claim 18, wherein the aerosol former material is selected from the list consisting of glycerine, glycerol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3- butylene glycol, erythritol, meso-Erythritol, ethyl vanillate, ethyl laurate, adiethyl suberate, triethyl citrate, triacetin, a diacetin mixture, benzyl benzoate, benzyl phenyl acetate, tributyrin, lauryl acetate, lauric acid, myristic acid, and propylene carbonate.

20. The aerosol generating material according to any one of claims 1 to 19, wherein the aerosol generating material comprises a total fibrous material content of between about 70% and about 95% by weight on a dry basis.

21. The aerosol generating material according to any one of claims 1 to 20, wherein the aerosol generating material has a thickness of about 100 μm to about 450 μm.

22. The aerosol generating material according to any one of claims 1 to 21, wherein the aerosol generating material has a filling value of between about 2 cm3 / g to about 10 cm3 / g.

23. An aerosol generating rod comprising an aerosol generating material according to any one of claims 1 to 22.

24. A delivery system comprising an aerosol generating material according to any one of claims 1 to 22, or the aerosol generating rod according to claim 23.

25. A process for preparing an aerosol generating material, the process comprising: combining a first fibrous material comprising a botanical material, a second fibrous material, an active, a binder, and water to form a slurry; processing the slurry so as to form a sheet of aerosolisable material, and drying the sheet of aerosolisable material, wherein the first fibrous material and the second fibrous material are different.

26. The process according to claim 25, wherein the process comprises shredding the sheet to for a shredded sheet comprising a plurality of strips of the aerosolisable material, and / or wherein the step of processing the slurry comprises casting the sheet on a band caster.

27. An aerosol generating material obtained or obtainable from a process according to claim 25 or claim 26.

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