US20240407422A1 - Aerosol generation - Google Patents

Abstract

Described herein is an aerosol generating assembly comprising an aerosol generating substrate and a heater which is configured to heat but not burn the aerosol generating material. The aerosol generating substrate comprises an aerosol generating material, the aerosol generating material comprising an amorphous solid. The amorphous solid comprises 1-60 wt % of a gelling agent, 0.1-50 wt % of an aerosol generating agent, and 0.1-80 wt % of a flavor, wherein these weights are calculated on a dry weight basis.

Description

PRIORITY CLAIM
• The present application is a divisional application of U.S. patent application Ser. No. 17/263,926, filed on Jan. 28, 2021, which is a National Phase entry of International Application No. PCT/EP2019/070725, filed Jul. 31, 2019, which claims priority from GB Patent Application No. 1812497.4, filed Jul. 31, 2018, each of which is hereby fully incorporated herein by reference.
TECHNICAL FIELD
• The present disclosure relates to aerosol generation.
BACKGROUND
• Smoking articles such as cigarettes, cigars and the like burn tobacco during use to create tobacco smoke. Alternatives to these types of articles release an inhalable aerosol or vapor by releasing compounds from a substrate material by heating without burning. These may be referred to as non-combustible smoking articles or aerosol generating assemblies.
• One example of such a product is a heating device which release compounds by heating, but not burning, a solid aerosolizable material. This solid aerosolizable material may, in some cases, contain a tobacco material. The heating volatilizes at least one component of the material, typically forming an inhalable aerosol. These products may be referred to as heat-not-burn devices, tobacco heating devices or tobacco heating products. Various different arrangements for volatilizing at least one component of the solid aerosolizable material are known.
• As another example, there are e-cigarette/tobacco heating product hybrid devices, also known as electronic tobacco hybrid devices. These hybrid devices contain a liquid source (which may or may not contain nicotine) which is vaporized by heating to produce an inhalable vapor or aerosol. The device additionally contains a solid aerosolizable material (which may or may not contain a tobacco material) and components of this material are entrained in the inhalable vapor or aerosol to produce the inhaled medium.
SUMMARY
• A first aspect of the disclosure provides an aerosol generating assembly comprising an aerosol generating substrate and a heater which is configured to heat but not burn the aerosol generating substrate, wherein the aerosol generating substrate comprises an aerosol generating material, the aerosol generating material comprising an amorphous solid, the amorphous solid comprising:
• • 1-60 wt % of a gelling agent;
  • 0.1-50 wt % of an aerosol generating agent; and
  • 0.1-80 wt % of a flavor;
    wherein these weights are calculated on a dry weight basis.
• In some embodiments, the amorphous solid comprises 1-80 wt % of a flavor (dry weight basis).
• In some embodiments, the amorphous solid comprising:
• • 1-50 wt % of a gelling agent;
  • 0.1-50 wt % of an aerosol generating agent; and
  • 30-60 wt % of a flavor;
    wherein these weights are calculated on a dry weight basis.
• In some embodiments, the amorphous solid is a hydrogel and comprises less than about 15 wt % of water calculated on a wet weight basis.
• In some embodiments, the gelling agent comprises a hydrocolloid. In some cases, the hydrocolloid comprises one or more compounds selected from the group comprising alginates, cellulose derivatives, gums, silica or silicones compounds, clays and combinations thereof. In some cases, the gelling agent comprises alginate and/or pectin, and may be combined with a setting agent (such as a calcium source) during formation of the amorphous solid. In some cases, the amorphous solid may comprise a calcium-crosslinked alginate and/or a calcium-crosslinked pectin.
• In some embodiments, the amorphous solid additionally comprises an active substance. In some embodiments, the active substance comprises a tobacco material and/or nicotine. In some embodiments, the amorphous solid comprises powdered tobacco and/or nicotine and/or a tobacco extract.
• In some embodiments, the flavor comprises menthol.
• In some embodiments, the amorphous solid is formed as a sheet. In some cases, the sheet may be incorporated into the assembly in sheet form. In other cases, the sheet may be shredded and then incorporated into the assembly, suitably mixed into an aerosolizable material such as cut rag tobacco. The sheet may have a mass per unit area of 80-120 g/m², suitably about 100 g/m².
• In some cases, the aerosol generating assembly may be a heat-not-burn device.
• In some cases, the aerosol generating assembly may be an electronic tobacco hybrid device.
• A second aspect of the disclosure provides an aerosol generating article for use in an aerosol generating assembly, the article comprising an aerosol generating substrate, the substrate comprising an aerosol generating material, the aerosol generating material comprising an amorphous solid, the amorphous solid comprising:
• • 1-60 wt % of a gelling agent;
  • 0.1-50 wt % of an aerosol generating agent; and
  • 0.1-80 wt % of a flavor;
    wherein these weights are calculated on a dry weight basis.
• In some embodiments, the amorphous solid comprises 1-80 wt % of a flavor (dry weight basis).
• In some embodiments, the amorphous solid comprises:
• • 1-50 wt % of a gelling agent;
  • 0.1-50 wt % of an aerosol generating agent; and
  • 30-60 wt % of a flavor;
    wherein these weights are calculated on a dry weight basis.
• A third aspect of the disclosure provides a method of making the assembly according to the first aspect. This method comprises a method of making the amorphous solid and incorporating the amorphous solid into the assembly.
• The method may comprise (a) forming a slurry comprising components of the amorphous solid or precursors thereof, (b) forming a layer of the slurry, and (c) setting the slurry to form a gel, (d) drying to form an amorphous solid, and (e) incorporating the resulting amorphous solid into the assembly.
• The step (c) of setting the gel may comprise the addition of a setting agent to the slurry.
• A further aspect of the disclosure provides an aerosol generating substrate, the substrate comprising an aerosol generating material, wherein the aerosol generating material comprises an amorphous solid, the amorphous solid comprising:
• • 1-60 wt % of a gelling agent;
  • 0.1-50 wt % of an aerosol generating agent; and
  • 0.1-80 wt % of a flavor;
    the weights being calculated on a dry weight basis.
• In some embodiments, the amorphous solid comprises 1-80 wt % of a flavor (dry weight basis).
• In some embodiments, the amorphous solid comprises:
• • 1-50 wt % of a gelling agent;
  • 0.1-50 wt % of an aerosol generating agent; and
  • 30-60 wt % of a flavor;
    the weights being calculated on a dry weight basis.
• A further aspect of the disclosure provides a slurry comprising:
• • 1-60 wt % of a gelling agent;
  • 0.1-50 wt % of an aerosol generating agent; and
  • 0.1-80 wt % of a flavor;
    the weights being calculated on a dry weight basis, and
  • solvent.
• In some embodiments, the slurry comprises 1-80 wt % of a flavor (dry weight basis).
• In some embodiments, the slurry comprises:
• • 1-50 wt % of a gelling agent;
  • 0.1-50 wt % of an aerosol generating agent; and
  • 30-60 wt % of a flavor;
    the weights being calculated on a dry weight basis, and
  • a solvent.
• A further aspect of the disclosure provides a method of making an aerosol generating material, the aerosol generating material comprising an amorphous solid, the method comprising:
• • (a) providing molten menthol;
  • (b) combining the molten menthol with gelling agent, aerosol generating agent and solvent to form a slurry;
  • (c) forming a layer of the slurry;
  • (d) setting the slurry to form a gel; and
  • (e) drying the gel to form an amorphous solid.
• In some embodiments, the slurry comprises:
• • 1-60 wt % gelling agent;
  • 0.1-50 wt % aerosol generating agent; and
  • 0.1-80 wt % menthol
    the weights being calculated on a dry weight basis, and
  • solvent.
• In some embodiments, the slurry comprises 0.1-80 wt % menthol. In some embodiments, the slurry comprises 30-60 wt % menthol.
• To the extent that they are combinable, features described herein in relation to the one aspect of the disclosure are explicitly disclosed in combination with each and every other aspect.
• Further aspects of the disclosure described herein may provide the use of the aerosol generating substrate, the aerosol generating article or the aerosol generating assembly, in the generation of an inhalable aerosol.
• Further features and advantages of the disclosure will become apparent from the following description, given by way of example only, and with reference to the accompanying figures.
BRIEF DESCRIPTION OF THE FIGURES
• FIG.1 shows a section view of an example of an aerosol generating article.
• FIG.2 shows a perspective view of the article ofFIG.1.
• FIG.3 shows a sectional elevation of an example of an aerosol generating article.
• FIG.4 shows a perspective view of the article ofFIG.3.
• FIG.5 shows a perspective view of an example of an aerosol generating assembly.
• FIG.6 shows a section view of an example of an aerosol generating assembly.
• FIG.7 shows a perspective view of an example of an aerosol generating assembly.
DETAILED DESCRIPTION
• As noted above, the disclosure provides an aerosol generating assembly comprising an aerosol generating substrate and a heater which is configured to heat but not burn the aerosol generating substrate, wherein the substrate comprises an aerosol generating material, where the aerosol generating material comprises an amorphous solid, the amorphous solid comprising:
• • 1-60 wt % of a gelling agent;
  • 0.1-50 wt % of an aerosol generating agent; and
  • 0.1-80 wt % of a flavor;
    wherein these weights are calculated on a dry weight basis.
• In some embodiments, the amorphous solid comprises:
• • 1-50 wt % of a gelling agent;
  • 0.1-50 wt % of an aerosol generating agent; and
  • 30-60 wt % of a flavor;
    wherein these weights are calculated on a dry weight basis.
• The amorphous solid material is formed from a dried gel. The inventors have found that using these component proportions means as the gel sets, flavor compounds are stabilized within the gel matrix allowing a higher flavor loading to be achieved than in non-gel compositions. The flavoring (e.g. menthol) is stabilized at high concentrations and the products have a good shelf life.
• In some cases, the amorphous solid may have a thickness of about 0.015 mm to about 1.0 mm. Suitably, the thickness may be in the range of about 0.05 mm, 0.1 mm or 0.15 mm to about 0.5 mm or 0.3 mm. The inventors have found that a material having a thickness of 0.2 mm is particularly suitable. The amorphous solid may comprise more than one layer, and the thickness described herein refers to the aggregate thickness of those layers.
• The inventors have established that if the aerosol-forming amorphous solid is too thick, then heating efficiency is compromised. This adversely affects the power consumption in use. Conversely, if the aerosol-forming amorphous solid is too thin, it is difficult to manufacture and handle; a very thin material is harder to cast and may be fragile, compromising aerosol formation in use.
• The inventors have established that the amorphous solid thicknesses stipulated herein optimize the material properties in view of these competing considerations.
• The thickness stipulated herein is a mean thickness for the material. In some cases, the amorphous solid thickness may vary by no more than 25%, 20%, 15%, 10%, 5% or 1%.
• Suitably, the amorphous solid may comprise from about 1 wt %, 5 wt %, 10 wt %, 15 wt %, 20 wt % or 25 wt % to about 60 wt %, 50 wt %, 45 wt %, 40 wt % or 35 wt % of a gelling agent (all calculated on a dry weight basis). For example, the amorphous solid may comprise 1-50 wt %, 5-45 wt %, 10-40 wt % or 20-35 wt % of a gelling agent.
• In some embodiments, the gelling agent comprises a hydrocolloid. In some embodiments, the gelling agent comprises 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 gelling agent 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 gelling agent comprises alginate and/or pectin, and may be combined with a setting agent (such as a calcium source) during formation of the amorphous solid. In some cases, the amorphous solid may comprise a calcium-crosslinked alginate and/or a calcium-crosslinked pectin.
• In some embodiments, the gelling agent comprises alginate, and the alginate is present in the amorphous solid in an amount of from 10-30 wt % of the amorphous solid (calculated on a dry weight basis). In some embodiments, alginate is the only gelling agent present in the amorphous solid. In other embodiments, the gelling agent comprises alginate and at least one further gelling agent, such as pectin.
• In some embodiments the amorphous solid may include gelling agent comprising carrageenan.
• Suitably, the amorphous solid may comprise from about 0.1 wt %, 0.5 wt %, 1 wt %, 3 wt %, 5 wt %, 7 wt % or 10% to about 50 wt %, 45 wt %, 40 wt %, 35 wt %, 30 wt % or 25 wt % of an aerosol generating agent (all calculated on a dry weight basis). The aerosol generating agent may act as a plasticizer. For example, the amorphous solid may comprise 0.5-40 wt %, 3-35 wt % or 10-25 wt % of an aerosol generating agent. In some cases, the aerosol generating agent comprises one or more compound selected from erythritol, propylene glycol, glycerol, triacetin, sorbitol and xylitol. In some cases, the aerosol generating agent comprises, consists essentially of or consists of glycerol. The inventors have established that if the content of the plasticizer is too high, the amorphous solid may absorb water resulting in a material that does not create an appropriate consumption experience in use. The inventors have established that if the plasticizer content is too low, the amorphous solid may be brittle and easily broken. The plasticizer content specified herein provides an amorphous solid flexibility which allows the sheet to be wound onto a bobbin, which is useful in manufacture of aerosol generating articles.
• The amorphous solid comprises a flavor. Suitably, the amorphous solid may comprise up to about 80 wt %, 70 wt %, 60 wt %, 55 wt %, 50 wt % or 45 wt % of a flavor. In some cases, the amorphous solid may comprise at least about 0.1 wt %, 1 wt %, 10 wt %, 20 wt %, 30 wt %, 35 wt % or 40 wt % of a flavor (all calculated on a dry weight basis). For example, the amorphous solid may comprise 1-80 wt %, 10-80 wt %, 20-70 wt %, 30-60 wt %, 35-55 wt % or 30-45 wt % of a flavor. In some cases, the flavor comprises, consists essentially of or consists of menthol.
• In some cases, the amorphous solid may additionally comprise an emulsifying agent, which emulsified molten flavor during manufacture. For example, the amorphous solid may comprise from about 5 wt % to about 15 wt % of an emulsifying agent (calculated on a dry weight basis), suitably about 10 wt %. The emulsifying agent may comprise acacia gum.
• In some embodiments, the amorphous solid is a hydrogel and comprises less than about 20 wt % of water calculated on a wet weight basis. In some cases, the hydrogel may comprise less than about 15 wt %, 12 wt % or 10 wt % of water calculated on a wet weight basis. In some cases, the hydrogel may comprise at least about 1 wt %, 2 wt % or at least about 5 wt % of water (WWB).
• In some embodiments, the amorphous solid additionally comprises an active substance. For example, in some cases, the amorphous solid additionally comprises a tobacco material and/or nicotine. In some cases, the amorphous solid may comprise 5-60 wt % (calculated on a dry weight basis) of a tobacco material and/or nicotine. In some cases, the amorphous solid may comprise from about 1 wt %, 5 wt %, 10 wt %, 15 wt %, 20 wt % or 25 wt % to about 70 wt %, 60 wt %, 50 wt %, 45 wt %, 40 wt %, 35 wt %, or 30 wt % (calculated on a dry weight basis) of an active substance. In some cases, the amorphous solid may comprise from about 1 wt %, 5 wt %, 10 wt %, 15 wt %, 20 wt % or 25 wt % to about 70 wt %, 60 wt %, 50 wt %, 45 wt %, 40 wt %, 35 wt %, or 30 wt % (calculated on a dry weight basis) of a tobacco material. For example, the amorphous solid may comprise 10-50 wt %, 15-40 wt % or 20-35 wt % of a tobacco material. In some cases, the amorphous solid may comprise from about 1 wt %, 2 wt %, 3 wt % or 4 wt % to about 20 wt %, 18 wt %, 15 wt % or 12 wt % (calculated on a dry weight basis) of nicotine. For example, the amorphous solid may comprise 1-20 wt %, 2-18 wt % or 3-12 wt % of nicotine.
• In some cases, the amorphous solid comprises an active substance such as tobacco extract. In some cases, the amorphous solid may comprise 5-60 wt % (calculated on a dry weight basis) of tobacco extract. In some cases, the amorphous solid may comprise from about 5 wt %, 10 wt %, 15 wt %, 20 wt % or 25 wt % to about 60 wt %, 50 wt %, 45 wt %, 40 wt %, 35 wt %, or 30 wt % (calculated on a dry weight basis) tobacco extract. For example, the amorphous solid may comprise 10-50 wt %, 15-40 wt % or 20-35 wt % of tobacco extract. The tobacco extract may contain nicotine at a concentration such that the amorphous solid comprises 1 wt % 1.5 wt%, 2 wt % or 2.5 wt % to about 6 wt %, 5 wt %, 4.5 wt % or 4 wt % (calculated on a dry weight basis) of nicotine. In some cases, there may be no nicotine in the amorphous solid other than that which results from the tobacco extract.
• In some embodiments the amorphous solid comprises no tobacco material but does comprise nicotine. In some such cases, the amorphous solid may comprise from about 1 wt %, 2 wt %, 3 wt % or 4 wt % to about 20 wt %, 18 wt %, 15 wt % or 12 wt % (calculated on a dry weight basis) of nicotine. For example, the amorphous solid may comprise 1-20 wt %, 2-18 wt % or 3-12 wt % of nicotine.
• In some cases, the total content of active substance and/or flavor may be at least about 0.1 wt %, 1 wt %, 5 wt %, 10 wt %, 20 wt %, 25 wt % or 30 wt %. In some cases, the total content of active substance and/or flavor may be less than about 90 wt %, 80 wt %, 70 wt %, 60 wt %, 50 wt % or 40 wt % (all calculated on a dry weight basis).
• In some cases, the total content of tobacco material, nicotine and flavor may be at least about 0.1 wt %, 1 wt %, 5 wt %, 10 wt %, 20 wt %, 25 wt % or 30 wt %. In some cases, the total content of active substance and/or flavor may be less than about 90 wt %, 80 wt %, 70 wt %, 60 wt %, 50 wt % or 40 wt % (all calculated on a dry weight basis).
• The amorphous solid may be made from a gel, and this gel may additionally comprise a solvent, included at 0.1-50 wt %. However, the inventors have established that the inclusion of a solvent in which the flavor is soluble may reduce the gel stability and the flavor may crystallize out of the gel. As such, in some cases, the gel does not include a solvent in which the flavor is soluble.
• In some embodiments, the amorphous solid comprises less than 60 wt % of a filler, such as from 1 wt % to 60 wt %, or 5 wt % to 50 wt %, or 5 wt % to 30 wt %, or 10 wt % to 20 wt %.
• In other embodiments, the amorphous solid comprises less than 20 wt %, suitably less than 10 wt % or less than 5 wt % of a filler. In some cases, the amorphous solid comprises less than 1 wt % of a filler, and in some cases, comprises no filler.
• The filler, if present, may comprise one or more inorganic filler materials, such as calcium carbonate, perlite, vermiculite, diatomaceous earth, colloidal silica, magnesium oxide, magnesium sulphate, magnesium carbonate, and suitable inorganic sorbents, such as molecular sieves. The filler may comprise one or more organic filler materials such as wood pulp, cellulose and cellulose derivatives. In particular cases, the amorphous solid comprises no calcium carbonate such as chalk.
• In particular embodiments which include filler, the filler is fibrous. For example, the filler may be a fibrous organic filler material such as wood pulp, hemp fiber, cellulose or cellulose derivatives. Without wishing to be bound by theory, it is believed that including fibrous filler in an amorphous solid may increase the tensile strength of the material. This may be particularly advantageous in examples wherein the amorphous solid is provided as a sheet, such as when an amorphous solid sheet circumscribes a rod of aerosolizable material.
• In some embodiments, the amorphous solid does not comprise tobacco fibers. In particular embodiments, the amorphous solid does not comprise fibrous material.
• In some embodiments, the aerosol generating material does not comprise tobacco fibers. In particular embodiments, the aerosol generating material does not comprise fibrous material.
• In some embodiments, the aerosol generating substrate does not comprise tobacco fibers. In particular embodiments, the aerosol generating substrate does not comprise fibrous material.
• In some embodiments, the aerosol generating article does not comprise tobacco fibers. In particular embodiments, the aerosol generating article does not comprise fibrous material.
• In some examples, the amorphous solid in sheet form may have a tensile strength of from around 200 N/m to around 900 N/m. In some examples, such as where the amorphous solid does not comprise a filler, the amorphous solid may have a tensile strength of from 200 N/m to 400 N/m, or 200 N/m to 300 N/m, or about 250 N/m. Such tensile strengths may be particularly suitable for embodiments wherein the aerosol generating material is formed as a sheet and then shredded and incorporated into an aerosol generating article. In some examples, such as where the amorphous solid comprises a filler, the amorphous solid may have a tensile strength of from 600 N/m to 900 N/m, or from 700 N/m to 900 N/m, or around 800 N/m. Such tensile strengths may be particularly suitable for embodiments wherein the aerosol generating material is included in an aerosol generating article/assembly as a rolled sheet, suitably in the form of a tube.
• In some cases, the amorphous solid may consist essentially of, or consist of a gelling agent, water, an aerosol generating agent, a flavor, and optionally an active substance.
• In some cases, the amorphous solid may consist essentially of, or consist of a gelling agent, water, an aerosol generating agent, a flavor, and optionally a tobacco material and/or a nicotine source.
• In some cases, the aerosol-forming amorphous solid layer has a thickness of about 0.015 mm to about 1.5 mm, suitably about 0.05 mm to about 1.5 mm or 0.05 mm to about 1.0 mm. Suitably, the thickness may be in the range of from about 0.1 mm or 0.15 mm to about 1.0 mm, 0.5 mm or 0.3 mm. The inventors have found that a material having a thickness of 0.2 mm is particularly suitable.
• The inventors have established that if the aerosol-forming amorphous solid is too thick, then heating efficiency is compromised. This adversely affects the power consumption in use. Conversely, if the aerosol-forming amorphous solid is too thin, it is difficult to manufacture and handle; a very thin material is harder to cast and may be fragile, compromising aerosol formation in use. The inventors have established that the amorphous solid thicknesses stipulated herein optimize the material properties in view of these competing considerations.
• The thickness values stipulated herein are mean values for the thickness in question. In some cases, the thickness may vary by no more than 25%, 20%, 15%, 10%, 5% or 1%.
• In some embodiments, the amorphous solid is formed as a sheet. In some cases, the amorphous solid sheet may be incorporated into the assembly or article in sheet form. The amorphous solid sheet may be incorporated as a planar sheet, as a gathered or bunched sheet, as a crimped sheet, or as a rolled sheet (i.e. in the form of a tube). In some such cases, the amorphous solid of these embodiments may be included in an aerosol generating article/assembly as a sheet, such as a sheet circumscribing a rod of aerosolizable material (e.g. tobacco). For example, the amorphous solid sheet may be formed on a wrapping paper which circumscribes an aerosolizable material such as tobacco. In other cases, the sheet may be shredded and then incorporated into the assembly, suitably mixed into an aerosolizable material such as cut rag tobacco.
• The aerosol generating material comprising the amorphous solid may have any suitable area density, such as from 30 g/m²to 120 g/m². In some cases, the sheet may have a mass per unit area of 80-120 g/m², or from about 70 to 110 g/m², or particularly from about 90 to 110 g/m², or suitably about 100 g/m²(so that it has a similar density to cut rag tobacco and a mixture of these substances will not readily separate). Such area densities may be particularly suitable where the aerosol-generating material is included in an aerosol generating article/assembly in sheet form, or as a shredded sheet (described further hereinbelow).In some cases, the sheet may have a mass per unit area of about 30 to 70 g/m², 40 to 60 g/m², or 25-60 g/m²and may be used to wrap an aerosolizable material such as tobacco.
• The aerosol generating substrate may comprise a carrier on which the amorphous solid is provided. The carrier functions as a support on which the amorphous solid layer forms, easing manufacture. The carrier may provide tensile strength to the amorphous solid layer, easing handling.
• In some cases, the carrier may be formed from materials selected from metal foil, paper, carbon paper, greaseproof paper, ceramic, carbon allotropes such as graphite and graphene, plastic, cardboard, wood or combinations thereof. In some cases, the carrier may comprise or consist of a tobacco material, such as a sheet of reconstituted tobacco. In some cases, the carrier may be formed from materials selected from metal foil, paper, cardboard, wood or combinations thereof. In some cases, the carrier itself be a laminate structure comprising layers of materials selected from the preceding lists. In some cases, the carrier may also function as a flavor carrier. For example, the carrier may be impregnated with a flavorant or with tobacco extract.
• In some cases, the carrier may be magnetic. This functionality may be used to fasten the carrier to the assembly in use, or may be used to generate particular amorphous solid shapes. In some cases, the aerosol generating material may comprise one or more magnets which can be used to fasten the material to an induction heater in use.
• In some cases, the carrier may be substantially or wholly impermeable to gas and/or aerosol. This prevents aerosol or gas passage through the carrier layer, thereby controlling the flow and ensuring it is delivered to the user. This can also be used to prevent condensation or other deposition of the gas/aerosol in use on, for example, the surface of a heater provided in an aerosol generating assembly. Thus, consumption efficiency and hygiene can be improved in some cases.
• In some cases, the surface of the carrier that abuts the amorphous solid may be porous. For example, in one case, the carrier comprises paper. The inventors have found that a porous carrier such as paper is particularly suitable for the present invention; the porous (e.g. paper) layer abuts the amorphous solid layer and forms a strong bond. The amorphous solid is formed by drying a gel and, without being limited by theory, it is thought that the slurry from which the gel is formed partially impregnates the porous carrier (e.g. paper) so that when the gel sets and forms cross-links, the carrier is partially bound into the gel. This provides a strong binding between the gel and the carrier (and between the dried gel and the carrier).
• Additionally, surface roughness may contribute to the strength of bond between the amorphous material and the carrier. The inventors have found that the paper roughness (for the surface abutting the carrier) may suitably be in the range of 50-1000 Bekk seconds, suitably 50-150 Bekk seconds, suitably 100 Bekk seconds (measured over an air pressure interval of 50.66-48.00 kPa). (A Bekk smoothness tester is an instrument used to determine the smoothness of a paper surface, in which air at a specified pressure is leaked between a smooth glass surface and a paper sample, and the time (in seconds) for a fixed volume of air to seep between these surfaces is the “Bekk smoothness”.)
• Conversely, the surface of the carrier facing away from the amorphous solid may be arranged in contact with the heater, and a smoother surface may provide more efficient heat transfer. Thus, in some cases, the carrier is disposed so as to have a rougher side abutting the amorphous material and a smoother side facing away from the amorphous material.
• In one particular case, the carrier may be a paper-backed foil; the paper layer abuts the amorphous solid layer and the properties discussed in the previous paragraphs are afforded by this abutment. The foil backing is substantially impermeable, providing control of the aerosol flow path. A metal foil backing may also serve to conduct heat to the amorphous solid.
• In another case, the foil layer of the paper-backed foil abuts the amorphous solid. The foil is substantially impermeable, thereby preventing water provided in the amorphous solid to be absorbed into the paper which could weaken its structural integrity.
• In some cases, the carrier is formed from or comprises metal foil, such as aluminum foil. A metallic carrier may allow for better conduction of thermal energy to the amorphous solid. Additionally, or alternatively, a metal foil may function as a susceptor in an induction heating system. In particular embodiments, the carrier comprises a metal foil layer and a support layer, such as cardboard. In these embodiments, the metal foil layer may have a thickness of less than 20 μm, such as from about 1 μm to about 10 μm, suitably about 5 μm.
• In some cases, the carrier may have a thickness of between about 0.010 mm and about 2.0 mm, suitably from about 0.015 mm, 0.02 mm, 0.05 mm or 0.1 mm to about 1.5 mm, 1.0 mm, or 0.5 mm.
Aerosol Generating Article and Assembly
• The aerosol generating assembly comprises a heater configured to heat but not burn the aerosol generating substrate. The heater may be, in some cases, a thin film, electrically resistive heater. In other cases, the heater may comprise an induction heater or the like. In yet further cases, the heater may be a combustible heat source or a chemical heat source which undergoes an exothermic reaction to product heat in use.
• In some cases, the heater may heat but not burn the aerosolizable material(s) to between 120° C. and 350° C. in use. In some cases, the heater may heat but not burn the aerosolizable material(s) to between 140° C. and 250° C. in use. In some cases in use, substantially all of the amorphous solid is less than about 4 mm, 3 mm, 2 mm or 1 mm from the heater. In some cases, the solid is disposed between about 0.017 mm and 2.0 mm from the heater, suitably between about 0.1 mm and 1.0 mm. These minimum distances may, in some cases, reflect the thickness of a carrier that supports the amorphous solid. In some cases, a surface of the amorphous solid may directly abut the heater.
• In some cases, the heater may be embedded in the aerosol generating substrate. In some such cases, the heater may be an electrically resistive heater (with exposed contacts for connection to an electrical circuit). In other such cases, the heater may be a susceptor embedded in the aerosol generating substrate, which is heated by induction.
• The aerosol generating assembly may additionally comprise a cooling element and/or a filter. The cooling element, if present, may act or function to cool gaseous or aerosol components. In some cases, it may act to cool gaseous components such that they condense to form an aerosol. It may also act to space the very hot parts of the apparatus from the user. The filter, if present, may comprise any suitable filter known in the art such as a cellulose acetate plug.
• In some cases, the aerosol generating assembly may be a heat-not-burn device. That is, it may contain a solid tobacco-containing material (and no liquid aerosolizable material). In some cases, the amorphous solid may comprise the tobacco material. A heat-not-burn device is disclosed in WO 2015/062983 A2, which is incorporated by reference in its entirety.
• In some cases, the aerosol generating assembly may be an electronic tobacco hybrid device. That is, it may contain a solid aerosolizable material and a liquid aerosolizable material. In some cases, the amorphous solid may comprise nicotine. In some cases, the amorphous solid may comprise a tobacco material. In some cases, the amorphous solid may comprise a tobacco material and a separate nicotine source. The separate aerosolizable materials may be heated by separate heaters, the same heater or, in one case, a downstream aerosolizable material may be heated by a hot aerosol which is generated from the upstream aerosolizable material. An electronic tobacco hybrid device is disclosed in WO 2016/135331 A1, which is incorporated by reference in its entirety.
• The disclosure also provides an aerosol generating article comprising an aerosol generating substrate, the aerosol generating substrate comprising an aerosol generating material, wherein the aerosol generating material comprises an amorphous solid, the amorphous solid comprising:
• • 1-60 wt % of a gelling agent;
  • 0.1-50 wt % of an aerosol generating agent; and
  • 0.1-80 wt % of a flavor;
    wherein these weights are calculated on a dry weight basis.
• In some embodiments, the amorphous solid comprise:
• • solid comprising:
    • 1-50 wt % of a gelling agent;
    • 0.1-50 wt % of an aerosol generating agent; and
    • 30-60 wt % of a flavor;
  • wherein these weights are calculated on a dry weight basis.
• The article may alternatively be referred to herein as a cartridge. The article may be adapted for use in a THP, an electronic tobacco hybrid device or another aerosol generating device. In some cases, the article may additionally comprise a filter and/or cooling element, as described previously. In some cases, the aerosol generating article may be circumscribed by a wrapping material such as paper.
• The aerosol generating article may additionally comprise ventilation apertures. These may be provided in the sidewall of the article. In some cases, the ventilation apertures may be provided in the filter and/or cooling element. These apertures may allow cool air to be drawn into the article during use, which can mix with the heated volatilized components thereby cooling the aerosol.
• The ventilation enhances the generation of visible heated volatilized components from the article when it is heated in use. The heated volatilized components are made visible by the process of cooling the heated volatilized components such that supersaturation of the heated volatilized components occurs. The heated volatilized components then undergo droplet formation, otherwise known as nucleation, and eventually the size of the aerosol particles of the heated volatilized components increases by further condensation of the heated volatilized components and by coagulation of newly formed droplets from the heated volatilized components.
• In some cases, the ratio of the cool air to the sum of the heated volatilized components and the cool air, known as the ventilation ratio, is at least 15%. A ventilation ratio of 15% enables the heated volatilized components to be made visible by the method described above. The visibility of the heated volatilized components enables the user to identify that the volatilized components have been generated and adds to the sensory experience of the smoking experience.
• In another example, the ventilation ratio is between 50% and 85% to provide additional cooling to the heated volatilized components. In some cases, the ventilation ratio may be at least 60% or 65%.
• Referring toFIGS.1 and2, there are shown a partially cut-away section view and a perspective view of an example of anaerosol generating article101. Thearticle101 is adapted for use with a device having a power source and a heater. Thearticle101 of this embodiment is particularly suitable for use with the device51 shown inFIGS.5 to7, described below. In use, thearticle101 may be removably inserted into the device shown inFIG.5 at aninsertion point20 of the device51.
• Thearticle101 of one example is in the form of a substantially cylindrical rod that includes a body ofaerosol generating material103 and afilter assembly105 in the form of a rod. The aerosol generating material comprises the amorphous solid material described herein. In some embodiments, it may be included in sheet form. In some embodiments it may be included in the form of a shredded sheet. In some embodiments, the aerosol generating material described herein may be incorporated in sheet form and in shredded form.
• Thefilter assembly105 includes three segments, acooling segment107, afilter segment109 and amouth end segment111. Thearticle101 has afirst end113, also known as a mouth end or a proximal end and asecond end115, also known as a distal end. The body ofaerosol generating material103 is located towards thedistal end115 of thearticle101. In one example, thecooling segment107 is located adjacent the body ofaerosol generating material103 between the body ofaerosol generating material103 and thefilter segment109, such that thecooling segment107 is in an abutting relationship with theaerosol generating material103 and thefilter segment103. In other examples, there may be a separation between the body ofaerosol generating material103 and thecooling segment107 and between the body ofaerosol generating material103 and thefilter segment109. Thefilter segment109 is located in between the coolingsegment107 and themouth end segment111. Themouth end segment111 is located towards theproximal end113 of thearticle101, adjacent thefilter segment109. In one example, thefilter segment109 is in an abutting relationship with themouth end segment111. In one embodiment, the total length of thefilter assembly105 is between 37 mm and 45 mm, more preferably, the total length of thefilter assembly105 is 41 mm.
• In one example, the rod ofaerosol generating material103 is between 34 mm and 50 mm in length, suitably between 38 mm and 46 mm in length, suitably 42 mm in length.
• In one example, the total length of thearticle101 is between 71 mm and 95 mm, suitably between 79 mm and 87 mm, suitably 83 mm.
• An axial end of the body ofaerosol generating material103 is visible at thedistal end115 of thearticle101. However, in other embodiments, thedistal end115 of thearticle101 may comprise an end member (not shown) covering the axial end of the body ofaerosol generating material103.
• The body ofaerosol generating material103 is joined to thefilter assembly105 by annular tipping paper (not shown), which is located substantially around the circumference of thefilter assembly105 to surround thefilter assembly105 and extends partially along the length of the body ofaerosol generating material103. In one example, the tipping paper is made of 58GSM standard tipping base paper. In one example the tipping paper has a length of between 42 mm and 50 mm, suitably of 46 mm.
• In one example, thecooling segment107 is an annular tube and is located around and defines an air gap within the cooling segment. The air gap provides a chamber for heated volatilized components generated from the body ofaerosol generating material103 to flow. Thecooling segment107 is hollow to provide a chamber for aerosol accumulation yet rigid enough to withstand axial compressive forces and bending moments that might arise during manufacture and whilst thearticle101 is in use during insertion into the device51. In one example, the thickness of the wall of thecooling segment107 is approximately 0.29 mm.
• Thecooling segment107 provides a physical displacement between theaerosol generating material103 and thefilter segment109. The physical displacement provided by thecooling segment107 will provide a thermal gradient across the length of thecooling segment107. In one example thecooling segment107 is configured to provide a temperature differential of at least 40 degrees Celsius between a heated volatilized component entering a first end of thecooling segment107 and a heated volatilized component exiting a second end of thecooling segment107. In one example thecooling segment107 is configured to provide a temperature differential of at least 60 degrees Celsius between a heated volatilized component entering a first end of thecooling segment107 and a heated volatilized component exiting a second end of thecooling segment107. This temperature differential across the length of thecooling element107 protects the temperaturesensitive filter segment109 from the high temperatures of theaerosol generating material103 when it is heated by the device51. If the physical displacement was not provided between thefilter segment109 and the body ofaerosol generating material103 and the heating elements of the device51, then the temperature sensitive filter segment may109 become damaged in use, so it would not perform its required functions as effectively.
• In one example the length of thecooling segment107 is at least 15 mm. In one example, the length of thecooling segment107 is between 20 mm and 30 mm, more particularly 23 mm to 27 mm, more particularly 25 mm to 27 mm, suitably 25 mm.
• Thecooling segment107 is made of paper, which means that it is comprised of a material that does not generate compounds of concern, for example, toxic compounds when in use adjacent to the heater of the device51. In one example, thecooling segment107 is manufactured from a spirally wound paper tube which provides a hollow internal chamber yet maintains mechanical rigidity. Spirally wound paper tubes are able to meet the tight dimensional accuracy requirements of high-speed manufacturing processes with respect to tube length, outer diameter, roundness and straightness.
• In another example, thecooling segment107 is a recess created from stiff plug wrap or tipping paper. The stiff plug wrap or tipping paper is manufactured to have a rigidity that is sufficient to withstand the axial compressive forces and bending moments that might arise during manufacture and whilst thearticle101 is in use during insertion into the device51.
• Thefilter segment109 may be formed of any filter material sufficient to remove one or more volatilized compounds from heated volatilized components from the aerosol generating material. In one example thefilter segment109 is made of a mono-acetate material, such as cellulose acetate. Thefilter segment109 provides cooling and irritation-reduction from the heated volatilized components without depleting the quantity of the heated volatilized components to an unsatisfactory level for a user.
• In some embodiments, a capsule (not illustrated) may be provided infilter segment109. It may be disposed substantially centrally in thefilter segment109, both across thefilter segment109 diameter and along thefilter segment109 length. In other cases, it may be offset in one or more dimension. The capsule may in some cases, where present, contain a volatile component such as a flavorant or aerosol generating agent.
• The density of the cellulose acetate tow material of thefilter segment109 controls the pressure drop across thefilter segment109, which in turn controls the draw resistance of thearticle101. Therefore the selection of the material of thefilter segment109 is important in controlling the resistance to draw of thearticle101. In addition, the filter segment performs a filtration function in thearticle101.
• In one example, thefilter segment109 is made of a 8Y15 grade of filter tow material, which provides a filtration effect on the heated volatilized material, whilst also reducing the size of condensed aerosol droplets which result from the heated volatilized material.
• The presence of thefilter segment109 provides an insulating effect by providing further cooling to the heated volatilized components that exit thecooling segment107. This further cooling effect reduces the contact temperature of the user's lips on the surface of thefilter segment109.
• In one example, thefilter segment109 is between 6 mm to 10 mm in length, suitably 8 mm.
• Themouth end segment111 is an annular tube and is located around and defines an air gap within themouth end segment111. The air gap provides a chamber for heated volatilized components that flow from thefilter segment109. Themouth end segment111 is hollow to provide a chamber for aerosol accumulation yet rigid enough to withstand axial compressive forces and bending moments that might arise during manufacture and whilst the article is in use during insertion into the device51. In one example, the thickness of the wall of themouth end segment111 is approximately 0.29 mm. In one example, the length of themouth end segment111 is between 6 mm to 10 mm, suitably 8 mm.
• Themouth end segment111 may be manufactured from a spirally wound paper tube which provides a hollow internal chamber yet maintains critical mechanical rigidity. Spirally wound paper tubes are able to meet the tight dimensional accuracy requirements of high-speed manufacturing processes with respect to tube length, outer diameter, roundness and straightness.
• Themouth end segment111 provides the function of preventing any liquid condensate that accumulates at the exit of thefilter segment109 from coming into direct contact with a user.
• It should be appreciated that, in one example, themouth end segment111 and thecooling segment107 may be formed of a single tube and thefilter segment109 is located within that tube separating themouth end segment111 and thecooling segment107.
• Referring toFIGS.3 and4, there are shown a partially cut-away section and perspective views of an example of anarticle301. The reference signs shown inFIGS.3 and4 are equivalent to the reference signs shown inFIGS.1 and2, but with an increment of200.
• In the example of thearticle301 shown inFIGS.3 and4, aventilation region317 is provided in thearticle301 to enable air to flow into the interior of thearticle301 from the exterior of thearticle301. In one example theventilation region317 takes the form of one or more ventilation holes317 formed through the outer layer of thearticle301. The ventilation holes may be located in thecooling segment307 to aid with the cooling of thearticle301. In one example, theventilation region317 comprises one or more rows of holes, and preferably, each row of holes is arranged circumferentially around thearticle301 in a cross-section that is substantially perpendicular to a longitudinal axis of thearticle301.
• In one example, there are between one to four rows of ventilation holes to provide ventilation for thearticle301. Each row of ventilation holes may have between 12 to 36 ventilation holes317. The ventilation holes317 may, for example, be between 100 to 500 μm in diameter. In one example, an axial separation between rows of ventilation holes317 is between 0.25 mm and 0.75 mm, suitably 0.5 mm.
• In one example, the ventilation holes317 are of uniform size. In another example, the ventilation holes317 vary in size. The ventilation holes can be made using any suitable technique, for example, one or more of the following techniques: laser technology, mechanical perforation of thecooling segment307 or pre-perforation of thecooling segment307 before it is formed into thearticle301. The ventilation holes317 are positioned so as to provide effective cooling to thearticle301.
• In one example, the rows ofventilation holes317 are located at least 11 mm from theproximal end313 of the article, suitably between 17 mm and 20 mm from theproximal end313 of thearticle301. The location of the ventilation holes317 is positioned such that user does not block the ventilation holes317 when thearticle301 is in use.
• Providing the rows of ventilation holes between 17 mm and 20 mm from theproximal end313 of thearticle301 enables the ventilation holes317 to be located outside of the device51, when thearticle301 is fully inserted in the device51, as can be seen inFIGS.6 and7. By locating the ventilation holes outside of the device, non-heated air is able to enter thearticle301 through the ventilation holes from outside the device51 to aid with the cooling of thearticle301.
• The length of thecooling segment307 is such that thecooling segment307 will be partially inserted into the device51, when thearticle301 is fully inserted into the device51. The length of thecooling segment307 provides a first function of providing a physical gap between the heater arrangement of the device51 and the heatsensitive filter arrangement309, and a second function of enabling the ventilation holes317 to be located in the cooling segment, whilst also being located outside of the device51, when thearticle301 is fully inserted into the device51. As can be seen fromFIGS.6 and7, the majority of thecooling element307 is located within the device51. However, there is a portion of thecooling element307 that extends out of the device51. It is in this portion of thecooling element307 that extends out of the device51 in which the ventilation holes317 are located.
• Referring now toFIGS.5 to7 in more detail, there is shown an example of a device51 arranged to heat aerosol generating material to volatilize at least one component of said aerosol generating material, typically to form an aerosol which can be inhaled. The device51 is a heating device which releases compounds by heating, but not burning, the aerosol generating material.
• A first end53 is sometimes referred to herein as the mouth or proximal end53 of the device51 and a second end55 is sometimes referred to herein as the distal end55 of the device51. The device51 has an on/off button57 to allow the device51 as a whole to be switched on and off as desired by a user.
• The device51 comprises a housing59 for locating and protecting various internal components of the device51. In the example shown, the housing59 comprises auni-body sleeve11 that encompasses the perimeter of the device51, capped with atop panel17 which defines generally the ‘top’ of the device51 and abottom panel19 which defines generally the ‘bottom’ of the device51. In another example the housing comprises a front panel, a rear panel and a pair of opposite side panels in addition to thetop panel17 and thebottom panel19.
• Thetop panel17 and/or thebottom panel19 may be removably fixed to theuni-body sleeve11, to permit easy access to the interior of the device51, or may be “permanently” fixed to theuni-body sleeve11, for example to deter a user from accessing the interior of the device51. In an example, thepanels17 and19 are made of a plastics material, including for example glass-filled nylon formed by injection moulding, and theuni-body sleeve11 is made of aluminum, though other materials and other manufacturing processes may be used.
• Thetop panel17 of the device51 has anopening20 at the mouth end53 of the device51 through which, in use, thearticle101,301 including the aerosol generating material may be inserted into the device51 and removed from the device51 by a user.
• The housing59 has located or fixed therein aheater arrangement23,control circuitry25 and apower source27. In this example, theheater arrangement23, thecontrol circuitry25 and thepower source27 are laterally adjacent (that is, adjacent when viewed from an end), with thecontrol circuitry25 being located generally between theheater arrangement23 and thepower source27, though other locations are possible.
• Thecontrol circuitry25 may include a controller, such as a microprocessor arrangement, configured and arranged to control the heating of the aerosol generating material in thearticle101,301 as discussed further below.
• Thepower source27 may be for example a battery, which may be a rechargeable battery or a non-rechargeable battery. Examples of suitable batteries include for example a lithium-ion battery, a nickel battery (such as a nickel-cadmium battery), an alkaline battery and/or the like. Thebattery27 is electrically coupled to theheater arrangement23 to supply electrical power when required and under control of thecontrol circuitry25 to heat the aerosol generating material in the article (as discussed, to volatilize the aerosol generating material without causing the aerosol generating material to burn).
• An advantage of locating thepower source27 laterally adjacent to theheater arrangement23 is that a physicallylarge power source25 may be used without causing the device51 as a whole to be unduly lengthy. As will be understood, in general a physicallylarge power source25 has a higher capacity (that is, the total electrical energy that can be supplied, often measured in Amp-hours or the like) and thus the battery life for the device51 can be longer.
• In one example, theheater arrangement23 is generally in the form of a hollow cylindrical tube, having a hollow interior heating chamber29 into which thearticle101,301 comprising the aerosol generating material is inserted for heating in use. Different arrangements for theheater arrangement23 are possible. For example, theheater arrangement23 may comprise a single heating element or may be formed of plural heating elements aligned along the longitudinal axis of theheater arrangement23. The or each heating element may be annular or tubular, or at least part-annular or part-tubular around its circumference. In an example, the or each heating element may be a thin film heater. In another example, the or each heating element may be made of a ceramics material. Examples of suitable ceramics materials include alumina and aluminum nitride and silicon nitride ceramics, which may be laminated and sintered. Other heating arrangements are possible, including for example inductive heating, infrared heater elements, which heat by emitting infrared radiation, or resistive heating elements formed by for example a resistive electrical winding.
• In one particular example, theheater arrangement23 is supported by a stainless steel support tube and comprises a polyimide heating element. Theheater arrangement23 is dimensioned so that substantially the whole of the body ofaerosol generating material103,303 of thearticle101,301 is inserted into theheater arrangement23 when thearticle101,301 is inserted into the device51.
• The or each heating element may be arranged so that selected zones of the aerosol generating material can be independently heated, for example in turn (over time, as discussed above) or together (simultaneously) as desired.
• Theheater arrangement23 in this example is surrounded along at least part of its length by athermal insulator31. Theinsulator31 helps to reduce heat passing from theheater arrangement23 to the exterior of the device51. This helps to keep down the power requirements for theheater arrangement23 as it reduces heat losses generally. Theinsulator31 also helps to keep the exterior of the device51 cool during operation of theheater arrangement23. In one example, theinsulator31 may be a double-walled sleeve which provides a low pressure region between the two walls of the sleeve. That is, theinsulator31 may be for example a “vacuum” tube, i.e. a tube that has been at least partially evacuated so as to minimize heat transfer by conduction and/or convection. Other arrangements for theinsulator31 are possible, including using heat insulating materials, including for example a suitable foam-type material, in addition to or instead of a double-walled sleeve.
• The housing59 may further comprises variousinternal support structures37 for supporting all internal components, as well as theheating arrangement23.
• The device51 further comprises acollar33 which extends around and projects from theopening20 into the interior of the housing59 and a generallytubular chamber35 which is located between thecollar33 and one end of thevacuum sleeve31. Thechamber35 further comprises a cooling structure35f, which in this example, comprises a plurality of cooling fins35fspaced apart along the outer surface of thechamber35, and each arranged circumferentially around outer surface of thechamber35. There is anair gap36 between thehollow chamber35 and thearticle101,301 when it is inserted in the device51 over at least part of the length of thehollow chamber35. Theair gap36 is around all of the circumference of thearticle101,301 over at least part of thecooling segment307.
• Thecollar33 comprises a plurality ofridges60 arranged circumferentially around the periphery of theopening20 and which project into theopening20. Theridges60 take up space within theopening20 such that the open span of theopening20 at the locations of theridges60 is less than the open span of theopening20 at the locations without theridges60. Theridges60 are configured to engage with anarticle101,301 inserted into the device to assist in securing it within the device51. Open spaces (not shown in the Figures) defined by adjacent pairs ofridges60 and thearticle101,301 form ventilation paths around the exterior of thearticle101,301. These ventilation paths allow hot vapors that have escaped from thearticle101,301 to exit the device51 and allow cooling air to flow into the device51 around thearticle101,301 in theair gap36.
• In operation, thearticle101,301 is removably inserted into aninsertion point20 of the device51, as shown inFIGS.5 to7. Referring particularly toFIG.6, in one example, the body ofaerosol generating material103,303, which is located towards thedistal end115,315 of thearticle101,301, is entirely received within theheater arrangement23 of the device51. Theproximal end113,313 of thearticle101,301 extends from the device51 and acts as a mouthpiece assembly for a user.
• In operation, theheater arrangement23 will heat thearticle101,301 to volatilize at least one component of the aerosol generating material from the body ofaerosol generating material103,303.
• The primary flow path for the heated volatilized components from the body ofaerosol generating material103,303 is axially through thearticle101,301, through the chamber inside thecooling segment107,307, through thefilter segment109,309, through themouth end segment111,313 to the user. In one example, the temperature of the heated volatilized components that are generated from the body of aerosol generating material is between 60° C. and 250° C., which may be above the acceptable inhalation temperature for a user. As the heated volatilized component travels through thecooling segment107,307, it will cool and some volatilized components will condense on the inner surface of thecooling segment107,307.
• In the examples of thearticle301 shown inFIGS.3 and4, cool air will be able to enter thecooling segment307 via the ventilation holes317 formed in thecooling segment307. This cool air will mix with the heated volatilized components to provide additional cooling to the heated volatilized components.
Method of Manufacture
• A third aspect of the disclosure provides a method of making the assembly according to the first aspect. This method comprises a method of making the amorphous solid and incorporating the amorphous solid into the assembly.
• The method may comprise (a) forming a slurry comprising components of the amorphous solid or precursors thereof, (b) forming a layer of the slurry, and (c) setting the slurry to form a gel, (d) drying to form an amorphous solid, and (e) incorporating the resulting amorphous solid into the assembly.
• The step (b) of forming a layer of the slurry may comprise spraying, casting or extruding the slurry, for example. In some cases, the layer is formed by electrospraying the slurry. In some cases, the layer is formed by casting the slurry.
• In some cases, the steps (b) and/or (c) and/or (d) may, at least partially, occur simultaneously (for example, during electrospraying). In some cases, these steps may occur sequentially.
• In some cases, a setting agent (such as a calcium source) may be added to the slurry before or during step (b). This is appropriate in instances where gelation occurs relatively slowly (e.g. with alginate gelling agent), and thus the slurry may be, e.g. cast, after the setting agent is added.
• In other cases, the step (c) of setting the slurry as a gel may comprise the addition of a setting agent to the slurry layer. The setting agent may be sprayed onto the gel, for example, or may be preloaded onto the surface on which the slurry is layered.
• For example, a setting agent comprising a calcium source (such as calcium chloride or calcium citrate), may be added to a slurry containing alginate and/or pectin to form a calcium-crosslinked alginate/pectin gel. In some cases where gelation occurs rapidly (such as those in which a pectin gelling agent is used), the calcium should be added after casting (because the gel is too viscous to cast).
• The total amount of the setting agent, such as a calcium source, may be 0.5-5 wt % (calculated on a dry weight basis). The inventors have found that the addition of too little setting agent may result in a gel which does not stabilize the flavor and results in the flavor dropping out of the gel. The inventors have found that the addition of too much setting agent results in a gel that is very tacky and consequently has poor handleability.
• Alginate salts are derivatives of alginic acid and are typically high molecular weight polymers (10-600 kDa). Alginic acid is a copolymer of β-D-mannuronic (M) and α-L-guluronic acid (G) units (blocks) linked together with (1,4)-glycosidic bonds to form a polysaccharide. On addition of calcium cations, the alginate crosslinks to form a gel. The inventors have determined that alginate salts with a high G monomer content more readily form a gel on addition of the calcium source. In some cases therefore, the gel-precursor pay comprise an alginate salt in which at least about 40%, 45%, 50%, 55%, 60% or 70% of the monomer units in the alginate copolymer are α-L-guluronic acid (G) units.
• In some cases, the slurry may be warmed prior to and during casting. This can slow gelation, improving handleability and easing the casting process. Further, warming the slurry may melt the flavor components (e.g. menthol) easing handleability.
• In some cases, menthol (or other flavors) may be distributed through the slurry in powder form. In some cases, menthol (or other flavors) may be molten in the slurry (where it is warmed). In such cases, an emulsifying agent such as acacia gum may be added to disperse molten menthol in the slurry.
• In some cases, the slurry may be cast onto a bandcast sheet. The sheet may be loaded with a releasing agent, such as lecithin, which can aid separation of the bandcast and the amorphous solid.
• The slurry may also form part of the invention. In some cases, the invention provides a slurry comprising
• • 1-60 wt % of a gelling agent;
  • 0.1-50 wt % of an aerosol generating agent; and
  • 0.1-80 wt % of a flavor;
    wherein these weights are calculated on a dry weight basis, and
  • a solvent.
• In some embodiments, the slurry comprises:
• • a slurry comprising
    • 1-50 wt % of a gelling agent;
    • 0.1-50 wt % of an aerosol generating agent; and
    • 30-60 wt % of a flavor;
  • wherein these weights are calculated on a dry weight basis, and
    • a solvent.
• In some cases, the slurry solvent may consist essentially of or consist of water.
• In some cases, the slurry may comprise from about 50 wt %, 60 wt %, 70 wt %, 80 wt % or 90 wt % of solvent (WWB).
• In some examples, the slurry has a viscosity of from about 10 to about 20 Pa·s at 46.5° C., such as from about 14 to about 16 Pa·s at 46.5° C.
• A further aspect of the present disclosure provides a method of making an aerosol generating material, the aerosol generating material comprising an amorphous solid, the method comprising:
• • (a) providing molten menthol;
  • (b) combining the molten menthol with gelling agent, aerosol generating agent and solvent to form a slurry;
  • (c) forming a layer of the slurry;
  • (d) setting the slurry to form a gel; and
  • (e) drying the gel to form an amorphous solid.
• Surprisingly, the inventors have identified that the use of molten menthol in a manufacturing process (as opposed to menthol in powder form) may reduce contamination of other machinery in the manufacturing location with menthol. In particular, providing menthol in molten form before combining at least some or all of the other components of the slurry may reduce contamination of other machinery (i.e. menthol is molten before all of the components in the slurry are combined). The use of molten menthol may also allow for improved dispersion of the menthol throughout the resulting amorphous solid, and/or providing an amorphous solid wherein more of the starting menthol present in the slurry is retained in the amorphous solid.
• In some embodiments, the slurry comprises:
• • 1-60 wt % gelling agent;
  • 0.1-50 wt % aerosol generating agent; and
  • 0.1-80 wt % menthol
    the weights being calculated on a dry weight basis, and
  • solvent.
• The gelling agent may be any suitable gelling agent. In some embodiments, the gelling agent comprises alginate and/or pectin.
• In cases where the solvent consists of water, the dry weight content of the slurry will match the dry weight content of the amorphous solid. Thus, the discussion herein relating to the solid composition is explicitly disclosed in combination with any slurry aspect of the invention.
Exemplary Embodiments
• In some embodiments, the amorphous solid comprises menthol.
• Particular embodiments comprising a menthol-containing amorphous solid may be particularly suitable for including in an aerosol generating article/assembly as a shredded sheet. In these embodiments, the amorphous solid may have the following composition (DWB): gelling agent (preferably comprising alginate, more preferably comprising a combination of alginate and pectin) in an amount of from about 20 wt % to about 40 wt %, or about 25 wt % to 35 wt %; menthol in an amount of from about 35 wt % to about 60 wt %, or from about 40 wt % to 55 wt %; aerosol generating agent (preferably comprising glycerol) in an amount of from about 10 wt % to about 30 wt %, or from about 15 wt % to about 25 wt % (DWB).
• In one embodiment, the amorphous solid comprises about 32-33 wt % of an alginate/pectin gelling agent blend; about 47-48 wt % menthol flavorant; and about 19-20 wt % glycerol aerosol generating agent (DWB).
• As noted above, the amorphous solid of these embodiments may be included in an aerosol generating article/assembly as a shredded sheet. The shredded sheet may be provided in the article/assembly blended with cut tobacco. Alternatively, the amorphous solid may be provided as a non-shredded sheet. Suitably, the shredded or non-shredded sheet has a thickness of from about 0.015 mm to about 1 mm, preferably from about 0.02 mm to about 0.07 mm.
• Particular embodiments of the menthol-containing amorphous solid may be particularly suitable for including in an aerosol generating article/assembly as a sheet, such as a sheet circumscribing a rod of aerosolizable material (e.g. tobacco). In these embodiments, the amorphous solid may have the following composition (DWB): gelling agent (preferably comprising alginate, more preferably comprising a combination of alginate and pectin) in an amount of from about 5 wt % to about 40 wt %, or about 10 wt % to 30 wt %; menthol in an amount of from about 10 wt % to about 50 wt %, or from about 15 wt % to 40 wt %; aerosol generating agent (preferably comprising glycerol) in an amount of from about 5 wt % to about 40 wt %, or from about 10 wt % to about 35 wt %; and optionally filler in an amount of up to 60 wt %—for example, in an amount of from 5 wt % to 20 wt %, or from about 40 wt % to 60 wt % (DWB).
• In one of these embodiments, the amorphous solid comprises about 11 wt % of an alginate/pectin gelling agent blend, about 56 wt % woodpulp filler, about 18% menthol flavorant and about 15 wt % glycerol (DWB).
• In another of these embodiments, the amorphous solid comprises about 22 wt % of an alginate/pectin gelling agent blend, about 12 wt % woodpulp filler, about 36% menthol flavorant and about 30 wt % glycerol (DWB).
• As noted above, the amorphous solid of these embodiments may be included as a sheet. In one embodiment, the sheet is provided on a carrier comprising paper. In one embodiment, the sheet is provided on a carrier comprising metal foil, suitably aluminum metal foil. In this embodiment, the amorphous solid may abut the metal foil.
• In one embodiment, the sheet forms part of a laminate material with a layer (preferably comprising paper) attached to a top and bottom surface of the sheet. Suitably, the sheet of amorphous solid has a thickness of from about 0.015 mm to about 1 mm.
• In some embodiments, the amorphous solid comprises a flavorant which does not comprise menthol. In these embodiments, the amorphous solid may have the following composition (DWB): gelling agent (preferably comprising alginate) in an amount of from about 5 to about 40 wt %, or from about 10 wt % to about 35 wt %, or from about 20 wt % to about 35 wt %; flavorant in an amount of from about 0.1 wt % to about 40 wt %, of from about 1 wt % to about 30 wt %, or from about 1 wt % to about 20 wt %, or from about 5 wt % to about 20 wt %; aerosol generating agent (preferably comprising glycerol) in an amount of from 15 wt % to 75 wt %, or from about 30 wt % to about 70 wt %, or from about 50 wt % to about 65 wt %; and optionally filler (suitably woodpulp) in an amount of less than about 60 wt %, or about 20 wt %, or about 10 wt %, or about 5 wt % (preferably the amorphous solid does not comprise filler) (DWB).
• In one of these embodiments, the amorphous solid comprises about 27 wt % alginate gelling agent, about 14 wt % flavorant and about 57 wt % glycerol aerosol generating agent (DWB).
• In another of these embodiments, the amorphous solid comprises about 29 wt % alginate gelling agent, about 9 wt % flavorant and about 60 wt % glycerol (DWB).
• The amorphous solid of these embodiments may be included in an aerosol generating article/assembly as a shredded sheet, optionally blended with cut tobacco. Alternatively, the amorphous solid of these embodiments may be included in an aerosol generating article/assembly as a sheet, such as a sheet circumscribing a rod of aerosolizable material (e.g. tobacco). Alternatively, the amorphous solid of these embodiments may be included in an aerosol generating article/assembly as a layer portion disposed on a carrier.
EXAMPLES
• In a first example, a slurry having the following composition was formed in a high-shear mixer. Water and glycerol were first mixed, and the alginate and ground menthol powder then added. The alginate was fully hydrated before the calcium citrate was added. The slurry was cast at 2 mm thickness at room temperature and allowed to set as a gel. The gel was then dried in an oven (60° C. for 1-3 hrs).

• 		Final composition
  	Slurry Composition	(after drying)
  Component	(wt % − WWB)	(wt % − WWB)

  Alginate	3.12	Unmeasured*
  Calcium citrate	0.18	Unmeasured*
  Menthol	7.2	50.2
  Glycerol	1.5	15.0
  Water	88	8.2
  *Total % of alginate and calcium citrate in final composition is 26.6%.

• In a second example, a slurry having the following composition was formed in a high-shear mixer. Water and glycerol were first mixed, and the pectin and ground menthol powder then added. The slurry was warmed during mixing to 50-80° C. to melt menthol and reduce the slurry viscosity.
• The warmed slurry was cast at 2 mm thickness. An aqueous solution of calcium chloride (2.1 g calcium chloride dissolved in water) was sprayed onto the cast to effect gelation. The gel was then dried in an oven (60° C. for 1-3 hrs).

• 		Final composition
  	Slurry Composition	(after drying)
  Component	(wt % − WWB)	(wt % − WWB)

  Pectin	4.2	~33
  Menthol	6.0	~40
  Glycerol	1.8	~20
  Water	88	~7

• In this second example, the calcium source was added after casting due to the speed of gelation of the pectin gelling agent. If calcium were to be added prior to casting, gelation would occur rapidly and the material could not be easily cast.
• The slurry may comprise molten menthol in this second example because the pectin gelling agent has groups along the polysaccharide chain that emulsify the menthol in the slurry. In the case of the first example, the alginate gelling agent does not have these emulsifying properties, and so menthol is used in dry powder form.
Definitions
• The aerosol generating material described herein comprises an “amorphous solid”, which may alternatively be referred to as a “monolithic solid” (i.e. non-fibrous), or as a “dried gel”. The amorphous solid is a solid material that may retain some fluid, such as liquid, within it. In some cases, the aerosol generating the material comprises from 50 wt %, 60 wt % or 70 wt % of amorphous solid, to about 90 wt %, 95 wt % or 100 wt % of amorphous solid. In some cases, the aerosol generating material consists of amorphous solid.
• 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 comprises 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.
• Cannabinoids are a class of natural or synthetic chemical compounds which act on cannabinoid receptors (i.e., CB1 and CB2) in cells that repress neurotransmitter release in the brain. Cannabinoids may be naturally occurring (phytocannabinoids) from plants such as cannabis, from animals (endocannabinoids), or artificially manufactured (synthetic cannabinoids). Cannabis species express at least 85 different phytocannabinoids, and are divided into subclasses, including cannabigerols, cannabichromenes, cannabidiols, tetrahydrocannabinols, cannabinols and cannabinodiols, and other cannabinoids. Cannabinoids found in cannabis include, without limitation: 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 monomethyl ether (CBGM), cannabinerolic acid, cannabidiolic acid (CBDA), Cannabinol variant (CBNV), propyl cannabitriol (CBO), tetrahydrocannabmolic acid (THCA), and tetrahydrocannabivarinic acid (THCV A).
• As noted herein, the active substance may comprise or be derived from one or more botanicals or constituents, derivatives or extracts thereof. As used herein, the term “botanical” includes any material derived from plants including, but not limited to, extracts, leaves, bark, fibers, 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 tobacco, 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 arvensis, Menthac.v.,Mentha niliaca, Mentha piperita, Mentha piperita citratac.v.,Mentha piperitac.v.,Mentha spicata crispa, Mentha cordifolia, Mentha longifolia, Mentha suaveolens variegata, Mentha pulegium, Mentha spicatac.v. andMentha suaveolens.
• In some embodiments, the botanical is selected from eucalyptus, star anise, cocoa and hemp.
• In some embodiments, the botanical is selected from rooibos and fennel.
• As used herein, the terms “flavor” and “flavorant” 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 flavor 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), flavor 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.
• The flavor may suitably comprise one or more mint-flavors suitably a mint oil from any species of the genus Mentha. The flavour may suitably comprise, consist essentially of or consist of menthol.
• In some embodiments, the flavor comprises menthol, spearmint and/or peppermint.
• In some embodiments, the flavor comprises flavour components of cucumber, blueberry, citrus fruits and/or redberry.
• In some embodiments, the flavor comprises eugenol.
• In some embodiments, the flavor comprises flavor components extracted from tobacco.
• In some embodiments, the flavor comprises flavor components extracted from cannabis.
• In some embodiments, the flavor 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 eucalyptol, WS-3.
• As used herein, the term “aerosol generating agent” refers to an agent that promotes the generation of an aerosol. An aerosol generating agent 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.
• Suitable aerosol generating agents include, but are not limited to: a polyol such as erythritol, 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. The aerosol generating agent may suitably have a composition that does not dissolve menthol. The aerosol generating agent may suitably comprise, consist essentially of or consist of glycerol.
• As used herein, the term “tobacco material” refers to any material comprising tobacco or derivatives therefore. 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 fiber, cut tobacco, extruded tobacco, tobacco stem, reconstituted tobacco and/or tobacco extract.
• The tobacco used to produce tobacco material may be any suitable tobacco, such as single grades or blends, cut rag or whole leaf, including Virginia and/or Burley and/or Oriental. It may also be tobacco particle ‘fines’ or dust, expanded tobacco, stems, expanded stems, and other processed stem materials, such as cut rolled stems. The tobacco material may be a ground tobacco or a reconstituted tobacco material. The reconstituted tobacco material may comprise tobacco fibers, and may be formed by casting, a Fourdrinier-based paper making-type approach with back addition of tobacco extract, or by extrusion.
• All percentages by weight described herein (denoted wt %) are calculated on a dry weight basis, unless explicitly stated otherwise. All weight ratios are also calculated on a dry weight basis. A weight quoted on a dry weight basis refers to the whole of the extract or slurry or material, other than the water, and may include components which by themselves are liquid at room temperature and pressure, such as glycerol. Conversely, a weight percentage quoted on a wet weight basis refers to all components, including water.
• For the avoidance of doubt, where in this specification the term “comprises” is used in defining the invention or features of the invention, embodiments are also disclosed in which the invention or feature can be defined using the terms “consists essentially of” or “consists of” in place of “comprises”. Reference to a material “comprising” certain features means that those features are included in, contained in, or held within the material.
• The above embodiments are to be understood as illustrative examples of the invention. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.

Claims (20)

1. An aerosol generating substrate comprising an aerosol generating material, the aerosol generating material comprising an amorphous solid, the amorphous solid comprising:

1-60 wt % of a gelling agent; and

0.1-50 wt % of an aerosol generating agent;

wherein these weights are calculated on a dry weight basis.

2. The aerosol generating substrate according toclaim 1, wherein the amorphous solid further comprises 0.1-80 wt % of a flavor calculated on a dry weight basis.

3. The aerosol generating substrate according toclaim 1, wherein the amorphous solid is a hydrogel and comprises less than about 15 wt % of water calculated on a wet weight basis.

4. The aerosol generating substrate according toclaim 1, wherein the gelling agent comprises a hydrocolloid.

5. The aerosol generating substrate according toclaim 4, wherein the hydrocolloid comprises one or more compounds selected from the group comprising alginates, cellulose derivatives, gums, silica or silicones compounds, clays and combinations thereof.

6. The aerosol generating substrate according toclaim 5, wherein the amorphous solid comprises a calcium-crosslinked alginate and/or a calcium-crosslinked pectin.

7. The aerosol generating substrate according toclaim 1, wherein the amorphous solid additionally comprises an active substance.

8. The aerosol generating substrate according toclaim 7, wherein the amorphous solid comprises powdered tobacco and/or nicotine and/or a tobacco extract.

9. The aerosol generating substrate ofclaim 1, wherein the amorphous solid comprises no tobacco material but does comprise nicotine.

10. The aerosol generating substrate ofclaim 9, wherein the aerosol generating material consists of the amorphous solid.

11. The aerosol generating substrate ofclaim 10, wherein the amorphous solid is in the form of a shredded sheet.

12. The aerosol generating substrate according toclaim 2, wherein the flavor comprises menthol.

13. The aerosol generating substrate according toclaim 1, wherein the amorphous solid is formed as a sheet.

14. The aerosol generating substrate according toclaim 13, wherein the sheet has a mass per unit area of 80-120 g/m².

15. The aerosol generating substrate according toclaim 1, wherein the aerosol generating material has a mass per unit area of from 30 to 120 g/m².

16. An aerosol generating assembly comprising the aerosol generating substrate according toclaim 1 and a heater which is configured to heat but not burn the aerosol generating material.

17. An aerosol generating assembly according toclaim 13, wherein the amorphous solid is provided in the aerosol generating device in sheet form or as a shredded sheet.

18. An aerosol generating article for use in an aerosol generating assembly, the article comprising the aerosol generating substrate according toclaim 1.

19. A method of making the aerosol generating substrate according toclaim 1, the method comprising (a) forming a slurry comprising components of the amorphous solid or precursors thereof, (b) forming a layer of the slurry, and (c) setting the slurry to form a gel, and (d) drying to form the amorphous solid.

20. A method of making the aerosol generating substrate according toclaim 12, the method comprising:

(a) providing the menthol as molten menthol;

(b) combining the molten menthol with the gelling agent, the aerosol generating agent and solvent to form a slurry;

(c) forming a layer of the slurry;

(d) setting the slurry to form a gel; and

(e) drying the gel to form the amorphous solid.

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