EP4666875A1

EP4666875A1 - Aerosol generating materials and methods of preparing the same

Info

Publication number: EP4666875A1
Application number: EP24183004.1A
Authority: EP
Inventors: Maria Sofianopoulos
Original assignee: Nicoventures Trading Ltd
Current assignee: Nicoventures Trading Ltd
Priority date: 2024-06-19
Filing date: 2024-06-19
Publication date: 2025-12-24
Also published as: WO2025262110A1

Abstract

An aerosol-generating material comprising a gelling agent and an aerosol-former material is provided, wherein the gelling agent is homogeneously distributed within the aerosol-generating material. Methods are also provided for ensuring the homogenous distribution of the gelling agent within the aerosol-generating material.

Description

Technical Field

The present invention relates to aerosol-generating materials comprising a gelling agent and an aerosol-former material is provided, wherein the gelling agent is homogeneously distributed within the aerosol-generating material. Methods are also provided for ensuring the homogenous distribution of the gelling agent within the aerosol-generating material.

Background

Certain tobacco industry products produce an aerosol during use, which is inhaled by a user. For example, tobacco heating devices heat an aerosol-generating material such as tobacco to form an aerosol by heating, but not burning, the substrate. Such tobacco industry products commonly include consumables containing aerosol-generating material for use in a heating device.

Summary

In accordance with a first aspect of the invention, there is provided an aerosol-generating composition comprising a gelling agent and an aerosol-former material, wherein the gelling agent is homogeneously distributed within the aerosol-generating material.
In some embodiments, one or more properties of the aerosol-generating material is homogenous, the properties being selected from the group consisting of: thickness; porosity/permeability; area density; volume density; surface roughness; conductance; and visual appearance.
In some embodiments, the homogeneous property of the aerosol-generating material is measured over an area of from about 10 to about 100 mm².
In some embodiments, the homogeneous property of the aerosol-generating material is measured over the entire area of the sheet or piece of aerosol-generating material.
In some embodiments, the property is considered homogenous where the variance of the property over the measured area is no more than 10%, no more than 5% or no more than 3%.
In some embodiments, the aerosol-generating material is a cast sheet. In some embodiments, the cast sheet is cut or shredded.
In some embodiments, the gelling agent comprises one or more selected from the group consisting of: alginates, pectins, starches, starch derivatives, cellulose, cellulose derivates, pullulan, xanthan gum, guar gum, carrageenan, agar, agarose, acacia gum, silica and silicone compounds, clays and polyvinyl alcohol.
In some embodiments, the aerosol-generating material comprises from about 0.5 to about 60 wt%, or from about 4 to about 25 wt%, of the gelling agent on a dry weight basis.
In some embodiments, the gelling agent hydrates and swells on contact with water.
In some embodiments, the gelling agent comprises an alginate.
In some embodiments, the aerosol-former material comprises one or more selected from the group consisting of: glycerine, 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, and propylene carbonate. In some embodiments, the aerosol former is glycerine, glycerol or propylene glycol.
In some embodiments, the aerosol-former material comprises glycerol.
In some embodiments, the aerosol-generating material comprises from about 5 to about 60 wt% of the aerosol-former material on a dry weight basis.
According to a second aspect of the invention, there is provided an article for use in an aerosol-provision system, the article comprising an aerosol-generating material according to the first aspect.
In some embodiments, the article comprises a filter and/or cooling element.
According to a third aspect, there is provided an aerosol provision system comprising an article according to the second aspect.
According to a fourth aspect, there is provided a method of manufacturing an aerosol-generating material comprising a gelling agent and an aerosol-former material, the method comprising:

solubilising the gelling agent in the aerosol-former material and in the absence of water to form a homogenous premix;
adding water to the premix form a hydrated mixture;
casting the hydrated mixture to form a layer; and
forming a dry sheet of the aerosol-generating material from the cast layer of the hydrated mixture.

In some embodiments, the solubilised gelling agent is hydrated on addition of water to form a gel.
In some embodiments, the gelling agent is an alginate or alginate derivative.
In some embodiments, the aerosol-former material is a solvent in which the gelling agent readily dissolves.
In some embodiments, the hydrated mixture is formed by mixing at a speed on no more than 1000 rpm.
In some embodiments, further water soluble components of the aerosol-generating material are added after the gelling agent has been solubilised in the aerosol-former material.
In some embodiments, further components of the aerosol-generating material that are soluble in the aerosol-former material are included in the mixture of the gelling agent and the aerosol-former material.

Brief Description of the Drawings

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a flow chart showing the steps of a method according to the present disclosure;
Figure 2 is a side-on cross-sectional view of an article for use in an aerosol provision system, according to one embodiment;
Figure 3 is a side-on cross-sectional view of an article according to another embodiment;
Figure 4 is a side-on cross-sectional view of an article according to an alternative embodiment;
Figure 5 is a side-on cross-sectional view of an article according to a further embodiment;
Figure 6 is a perspective illustration of a non-combustible aerosol provision device for generating aerosol from an article according to the present disclosure;
Figure 7a is a photograph of a gel compositions prepared using a conventional method cast as a layer;
Figure 7b is a photograph of a dried sheet of aerosol-generating material formed by drying a gel composition prepared using a conventional method;
Figure 8a is a photograph of a dried sheet of aerosol-generating material formed by drying a gel composition prepared using a method according to the described invention;
Figures 9a, 10a and 11a are graphs depicting particles of different size ranges present during the preparation of a gel composition using a conventional method; and
Figures 9b, 10b and 11b are graphs depicting particles of different size ranges present during the preparation of a gel composition using a method according to the described invention.

Detailed Description

The present invention relates generally to an aerosol-generating material for use in an aerosol-generating article which is configured to heat (but not burn) the material to generate an aerosol for inhalation.
The aerosol-generating material comprises a thin film. Specifically, the aerosol-generating material comprises a gelling agent and an aerosol-former material, wherein the gelling agent is homogeneously distributed within the aerosol-generating material.
The aerosol-generating material is to be heated during use to generate a vapour and/or aerosol. The homogeneity of the distribution of the gelling agent also ensures that the aerosol-generating properties of the thin film are consistent across the material and that the aerosol generated in consistent and predictable. The homogeneity of the distribution of the gelling agent within the aerosol-generating material is key to ensuring that a usable thin film is formed with consistent physical properties across the material. The homogeneity of the distribution of the gelling agent within the aerosol-generating material is also key to ensuring that a usable thin film is formed with consistent chemical make-up and properties across the material.
In some embodiments, the aerosol-generating material has one or more homogeneous properties selected from the group consisting of: thickness; porosity; permeability; area density; volume density; surface roughness; conductance; and visual appearance.
When heated, the aerosol-generating material may provide a source of flavours and active substances in a vapour and/or aerosol. In some embodiments, the aerosol-generating material provides a concentrated source of such substances. In some embodiments, the aerosol-generating material provides volatile components, including flavour components such as those that may be part of a botanical extract, in a stabilised form.
The aerosol-generating material may also represent a source of an aerosol-former material in large enough amounts to provide the desired aerosol body and visible aerosol when heated.
In embodiments of the invention, the aerosol-generating material may provide flavours and/or active substances in a concentrated form. This means that the amount of such aerosol-generating material included in the aerosol-generating articles may be reduced compared to the amounts of conventional aerosol-generating compositions. For example, in some embodiments, the aerosol-generating material disclosed herein is combined with one or more other aerosol-generating compositions, for example tobacco or other botanical material.
A reproducible and consistent homogeneity of the aerosol-generating material affords additional flexibility in terms of how this material is incorporated in the aerosol-generating composition and in the design of articles incorporating the aerosol-generating composition. This allows articles to be designed that permit controlled heating of the aerosol-generating material and controlled generation of a consistent and predictable vapour and/or aerosol.
Homogeneity of the distribution of the gelling agent also ensures that the aerosol-generating properties of the thin film are consistent across the material and therefore provides greater consistency of aerosol generation and delivery of components such as flavours and active substances, with the resultant sensory attributes and user satisfaction.
Homogeneous distribution of the gelling agent also ensures efficient casting of thin film material and may prevent formulation issues in the later stages of manufacturing when other substances are introduced into the composition.

Aerosol-generating material

As referred to herein, the aerosol-generating material is a material that may be heated to form an aerosol. In some embodiments, the aerosol-generating material is in the form of a sheet. For example, the aerosol-generating material may be a thin film which may alternatively be referred to as a "dried gel". The aerosol-generating material is a solid material that may retain some fluid, such as liquid, within it. In some embodiments, the aerosol-generating material or thin film is optionally cast or extruded to form the sheet.
The aerosol-generating material comprises a gelling agent and an aerosol-former material, wherein the gelling agent is homogeneously distributed within the aerosol-generating material. Optionally, a substance to be delivered and/or filler may also be present. In some embodiments, the aerosol-generating material comprises a particulate botanical material. Optionally, a solvent, such as water, is also present and one or more other components of the aerosol-generating material may or may not be soluble in the solvent.
In some embodiments, the homogeneous property of the aerosol-generating material is measured over an area of at least about 10 mm². In some embodiments, the homogeneous property of the aerosol-generating material is measured over an area of at least about 15, at least about 20, at least about 25, at least about 30, at least about 35, at least about 40, at least about 45, at least about 50, at least about 55, at least about 60, at least about 65, at least about 70, at least about 75, at least about 80, at least about 85, at least about 90, at least about 95, or at least about 100 mm².
In some embodiments, the homogeneous property of the aerosol-generating material is measured over the entire area of the sheet or piece of aerosol-generating material. In some embodiments, the property is considered homogenous where the variance of the property over the measured area is no more than about 10%, about 9%, about 8%, about 7%, about 6%, about 5%, about 4% or no more than about 3%.
In some embodiments, the aerosol-generating material has one or more homogeneous properties selected from the group consisting of: thickness; porosity; permeability; area density; volume density; surface roughness; conductance; and visual appearance.
The aerosol-generating material may have a thickness of about 0.015 mm to about 2 mm. For example, the thickness may be in the range of from about 0.05 mm, about 0.1 mm or about 0.15 mm to about 1.5 mm or about 1 mm.
The aerosol-generating material may comprise more than one layers or films, and the thickness described herein may refer to the aggregate thickness of those layers or films.
The aerosol-generating material may have any suitable area density, such as from about 30 g/m² to about 120 g/m². In some embodiments, aerosol-generating material may have an area density of from about 30 to about 70 g/m², or from about 40 to about 60 g/m². In some embodiments, the aerosol-generating material may have an area density of from about 80 to about 120 g/m², or from about 70 to about 110 g/m², or particularly from about 90 to about 110 g/m². 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.
In some examples, the aerosol-generating material in sheet form may have a tensile strength of from about 200 N/m to about 900 N/m. In some examples, such as where the thin film does not comprise a filler, the aerosol-generating material may have a tensile strength of from about 200 N/m to about 400 N/m, or from about 200 N/m to about 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 aerosol-generating material comprises a filler, the thin film may have a tensile strength of from about 600 N/m to about 900 N/m, or from about 700 N/m to about 900 N/m, or about 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 wrapper or as a rolled sheet, suitably in the form of a tube.
The aerosol-generating material may be continuous. For example, 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 plug or section of gathered sheet, or it may be shredded to form a plug or section comprising shredded sheet alone or combined with one or more further material. The shredded sheet may comprise one or more strands or strips of the aerosol-generating material.
The aerosol-generating material comprises a number of components, including a binder that binds the components together to form a cohesive whole. The binder may be a gelling agent.
In some embodiments, the aerosol-generating material may comprise from about 0.5 wt% to about 60 wt% gelling agent. For example, the aerosol-generating material may comprise at least about 0.5 wt%, at least about 1 wt%, at least about 5 wt%, at least about 10 wt%, at least about 15 wt%, at least about 20 wt%, at least about 25 wt%, at least about 30 wt%. additional or alternatively, the aerosol-generating material may comprise no more than about 60 wt%, no more than about 55 wt%, no more than about 50 wt%, no more than about 45 wt%, no more than about 40 wt%, no more than about 35 wt% or no more than about 30 wt% of a gelling agent (all calculated on a dry weight basis). For example, the aerosol-generating material may comprise from about 4 to about 25 wt%, from about 25 to about 50 wt%, from about 30 to about 45 wt% or from about 35 to about 40 wt% of the gelling agent. In some embodiments, the gelling agent comprises a hydrocolloid.
In some embodiments, the gelling agent comprises (or is) one or more compounds selected from polysaccharide gelling agents, such as alginate, pectin, starch or a derivative thereof, cellulose or a derivative thereof, pullulan, carrageenan, agar and agarose; gelatin; gums, such as xanthan gum, guar gum and acacia gum; silica or silicone compounds, such as PDMS and sodium silicate; clays, such as kaolin; and polyvinyl alcohol.
In some embodiments, the gelling agent hydrates and swells on contact with water.
In some embodiments the gelling agent comprises (or is) one or more polysaccharide gelling agents.
In some embodiments, the polysaccharide gelling agent is selected from alginate, pectin, starch or a derivative thereof, or cellulose or a derivative thereof. In some embodiments the polysaccharide gelling agent is selected from alginate and a cellulose derivative.
In some embodiments, the gelling agent is a polysaccharide gelling agent, optionally wherein the polysaccharide gelling agent is selected from alginate and a cellulose derivative.
In some embodiments, the alginate is sodium alginate.
In some embodiments the gelling agent is not crosslinked. The absence of crosslinks in the gelling agent facilitates quicker delivery of the botanical constituent, derivative or extract (and any optional additional active substances and/or flavours) from the second aerosol-generating material.
Examples of cellulosic gelling agents (also referred to herein as cellulose derivatives) include, but are not limited to, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethylcellulose (CMC), hydroxypropyl methylcellulose (HPMC), methyl cellulose, ethyl cellulose, cellulose acetate (CA), cellulose acetate butyrate (CAB), and cellulose acetate propionate (CAP). In some embodiments the cellulose or derivative thereof is selected from hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethylcellulose (CMC), hydroxypropyl methylcellulose (HPMC), methyl cellulose, ethyl cellulose, cellulose acetate (CA), cellulose acetate butyrate (CAB), and cellulose acetate propionate (CAP). In some embodiments, the cellulose derivative is CMC.
For example, in some embodiments, the gelling agent comprises (or is) one or more of alginate, pectin, 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 embodiments, the gelling agent comprises (or is) one or more of hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethylcellulose, guar gum, acacia gum, alginate and/or pectin.
In some cases, the gelling agent comprises (or is) alginate and/or pectin, and may be combined with a setting agent (such as a calcium source) during formation of the thin film. In some cases, the aerosol-generating material may comprise a calcium-crosslinked alginate and/or a calcium-crosslinked pectin.
In some embodiments, the gelling agent comprises (or is) alginate, optionally wherein the alginate is present in the aerosol-generating material in an amount of from about 0.5 to about 40 wt%, for example from about 5 to about 25 wt% or from about 10 to about 10 wt%, of the aerosol-generating material (calculated on a dry weight basis).
In some embodiments, alginate is the only gelling agent present in the aerosol-generating material.
In other embodiments, the gelling agent comprises alginate and at least one further gelling agent, such as pectin.
In particular embodiments, the gelling agent is carboxymethylcellulose, optionally wherein the carboxymethylcellulose (CMC) is present in an amount of from about 15 to about 50 wt%, for example from about 20 to about 40 wt% or about 30 wt%. In some embodiments, CMC is the only gelling agent present in the aerosol-generating material.
In some embodiments, the aerosol-generating material comprises botanical material.
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 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 Arventis, Mentha c.v., Mentha niliaca, Mentha piperita, Mentha piperita citrata c.v., Mentha piperita c.v., Mentha spicata crispa, Mentha cardifolia, Mentha longifolia, Mentha suaveolens variegata, Mentha pulegium, Mentha spicata c.v. and Mentha suaveolens.
In some embodiments, the botanical is tobacco. 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.
In some embodiments, the aerosol-generating material may comprise up to about 60 wt%, about 50 wt%, about 40 wt%, about 30 wt%, about 20 wt%, about 15 wt% or about 10 wt% of the botanical material. In some cases, the aerosol-generating material may comprise at least about 10 wt%, about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt% or about 40 wt% of the botanical material (all calculated on a dry weight basis). For example, the aerosol-generating material may comprise from about 10 wt% to about 60 wt%, from about 20 wt% to about 50 wt% or from about 30 wt% to about 40 wt% of the botanical material.
In some embodiments, the botanical material is tobacco material. The term "tobacco material" may include one or more of tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco, or tobacco-containing substitute materials.
The tobacco material may comprise one or more of ground tobacco, tobacco fibre, cut tobacco, tobacco leaf, tobacco lamina, extruded tobacco, tobacco stem, reconstituted tobacco and/or tobacco extract. The reconstituted tobacco material may comprise tobacco fibres, and may be formed by casting, a Fourdrinier-based paper making-type approach with back addition of tobacco extract, or by extrusion.
The aerosol generating material may comprise any type of tobacco, such as single grades or blends, cut rag or whole leaf. In some embodiments, the tobacco material is cut rag tobacco or reconstituted tobacco.
The tobacco material may comprise tobacco particle 'fines' or dust, expanded tobacco, stems, expanded stems, and other processed stem materials, such as cut rolled stems.
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.
In some embodiments, the botanical material in particulate form. In some embodiments, then botanical material is ground and comprises fine particles. In some embodiments that may be particularly preferred, the botanical material is in the form of ground tobacco.
In some embodiments, the botanical material may be in the form of a botanical extract.
To enhance the aerosol-generation, the aerosol-generating material may preferably comprise an aerosol-former material. The aerosol-former material may comprise one or more constituents capable of forming an aerosol.
The aerosol-generating material may comprise from about 5 wt%, about 10 wt%, about 15%, about 20 wt%, about 25 wt%, about 27 wt% or about 30 wt% to about 60 wt%, about 55 wt%, about 50 wt%, about 45 wt%, about 40 wt%, or about 35 wt% of an aerosol-former material (DWB). For example, the aerosol-generating material may comprise from about 10 wt% to about 60 wt%, from about 20 wt% to about 50 wt%, from about 25 wt% to about 40 wt% or from about 30 wt% to about 35 wt% of an aerosol-former material.
Suitably, the aerosol-generating material may comprise from about 0.1 wt%, about 0.5 wt%, about 1 wt%, about 3 wt%, about 5 wt%, about 7 wt% or about 10 wt% to about 50 wt%, about 45 wt%, about 40 wt%, about 35 wt%, about 30 wt% or about 25 wt% of an aerosol-former material (all calculated on a dry weight basis). For example, the aerosol-generating material may comprise from about 0.5 wt% to about 40 wt%, from about 3 wt% to about 35 wt% or from about 10 wt% to about 25 wt% of an aerosol-former material.
In some embodiments, the aerosol-former material may comprise one or more of glycerine, 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, and propylene carbonate.
In some cases, the aerosol-former material comprises one or more compound selected from erythritol, propylene glycol, glycerol, triacetin, sorbitol and xylitol. In some cases, the aerosol-former material comprises, consists essentially of, or consists of, glycerol.
In some embodiments, the aerosol-former material comprises a mixture of glycerol and propylene glycol in a weight ratio of glycerol to propylene glycol of from about 3:1 to about 1:3, from about 2:1 to about 1:2, from about 1.5:1 to about 1:1.5, from about 55:45 to about 45:55, or about 45:55.
The aerosol-former material may act as a plasticiser. It has been established that if the content of the aerosol-former material is too high, the aerosol-generating material may absorb water (as the aerosol-former material is hygroscopic) resulting in a material that does not create an appropriate consumption experience in use. It has also been established that if the aerosol-former material content is too low, the aerosol-generating material may be brittle and easily broken (as the aerosol-former material may act as a plasticiser). The aerosol-former material content specified herein provides the aerosol-generating material with flexibility which allows the material to be wound onto a bobbin, which is useful in manufacture of aerosol generating articles.
The aerosol-generating material may comprise from about 10 wt%, about 20 wt%, about 30 wt%, about 40 wt% or about 45 wt% to about 90 wt%, about 85 wt%, about 80 wt%, about 75 wt%, about 70 wt%, about 65 wt%, about 60 wt%, about 55 wt% or about 50 wt% of botanical extract (DWB). For example, the aerosol-generating material may comprise from about 20 to about 60 wt%, from about 40 to about 55 wt% or from about 45 to about 50 wt% of botanical extract (DWB).
In some embodiments, the botanical extract is a liquid or solid that has been isolated from a botanical material. For example, the extract may be prepared by processing techniques such as expression (such as juicing or pressing) or solvent extraction. Optionally, the extract is concentrated and/or purified, for example by distillation. In some embodiments, the botanical material is macerated, frequently without heating, to soften and degrade the material prior to extraction.
In some cases, the botanical extract is an aqueous extract, obtained by extraction with water. Additionally or alternatively, other solvents may be used, including supercritical fluids.
In some embodiments, the botanical extract included in the thin film is an extract of one or more of any of the botanical materials discussed herein.
In some embodiments, the botanical extract comprises or consists of a tobacco extract.
In some embodiments, the aerosol-generating material comprises from about 1 wt%, about 1.5 wt% or about 2 wt% to about 6 wt%, about 5 wt%, about 4 wt% or about 3 wt% of nicotine (DWB). In some cases, there may be no nicotine in the aerosol-generating material other than that which results from the tobacco extract.
In some embodiments, the aerosol-generating material comprises an additional or added flavour and/or active substance, in addition to the flavour and/or active substance present in the botanical extract. Suitably, the aerosol-generating material may comprise up to about 60 wt%, about 50 wt%, about 40 wt%, about 30 wt%, about 20 wt%, about 10 wt% or about 5 wt% of such an additional flavour and/or active substance. In some cases, the aerosol-generating material may comprise at least about 0.5 wt%, about 1 wt%, about 2 wt%, about 5 wt%, about 10 wt%, about 20 wt% or about 30 wt% of an additional flavour and/or active substance (all calculated on a dry weight basis). For example, the aerosol-generating material may comprise from about 10 wt% to about 60 wt%, from about 20 wt% to about 50 wt% or from about 30 wt% to about 40 wt% of an additional flavour and/or active substance.
Suitably, the aerosol-generating material may comprise up to about 60 wt%, about 50 wt%, about 40 wt%, about 30 wt%, about 20 wt%, about 10 wt% or about 5 wt% of an additional or added flavour. In some cases, the aerosol-generating material may comprise at least about 0.5 wt%, about 1 wt%, about 2 wt%, about 5 wt%, about 10 wt%, about 20 wt% or about 30 wt% of an additional flavour (all calculated on a dry weight basis). For example, the aerosol-generating material may comprise from about 10 wt% to about 60 wt%, from about 20 wt% to about 50 wt% or from about 30 wt% to about 40 wt% of an additional flavour. In some cases, the additional flavour (if present) comprises, consists essentially of, or consists of, menthol.
In some cases, the aerosol-generating material does not comprise an added flavour and/or active substance. In some cases, the aerosol-generating material does not comprise an additional flavour. In some cases, the aerosol-generating material does not comprise a further active substance.
In some embodiments, the aerosol-generating material comprises nicotine. In some embodiments, the aerosol-generating material has a nicotine content of from about 1.5 wt% to about 7 wt% of the aerosol-generating material (DWB).
In some cases, the aerosol-generating material may comprise at least about 1.5 wt%, about 2 wt%, about 2.5 wt%, about 3 wt%, about 3.5 wt%, about 4 wt%, about 4.5 wt% or about 5 wt% of nicotine (DWB). The aerosol-generating material may comprise no more than about 7 wt%, about 6.5 wt%, about 6 wt%, about 5.5 wt%, about 5 wt%, about 4.5 wt%, about 4 wt%, about 3.5 wt% or about 3 wt% of nicotine (DWB). For example, the aerosol-generating material may comprise from about 2 wt% to about 6 wt%, or from about 4 wt% to about 5 wt% nicotine by weight of the thin film (DWB).
In some embodiments, the aerosol-generating material comprises a filler. The filler may be present to adjust the physical and/or chemical properties of the material. For example, in some embodiments, the filler may increase the tensile strength of the aerosol-generating material and render it more suitable for large scale manufacture of aerosol-generating articles. On the other hand, inclusion of a filler may add to the cost, weight and density of the aerosol-generating material. Adding to the mass of the aerosol-generating material potentially adds to the energy and time required to heat the material to generate the desired aerosol.
In some embodiments, the aerosol-generating material comprises no more than about 60 wt% of a filler, such as from about 1 wt% to about 60 wt%, or from about 5 wt% to about 50 wt%, or from about 5 wt% to about 30 wt%, or from about 10 wt% to about 20 wt%.
In other embodiments, the aerosol-generating material comprises no more than about 20 wt%, suitably no more than about 10 wt% or no more than about 5 wt% of a filler. In some cases, the aerosol-generating material comprises no more than about 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; tobacco pulp; hemp fibre; starch and starch derivatives, such as maltodextrin; chitosan; and cellulose and cellulose derivatives, such as microcrystalline cellulose and nanocrystalline cellulose. In particular cases, the aerosol-generating material 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 fibre, cellulose or cellulose derivatives. In some embodiments, the fibrous filler is wood pulp. Without wishing to be bound by theory, it is believed that including fibrous filler in the aerosol-generating material may increase the tensile strength of the material. This may be particularly advantageous in examples wherein the aerosol-generating material is provided as a sheet, such as when a sheet of the aerosol-generating material circumscribes a rod of aerosolisable material.
In some embodiments, the aerosol-generating material does not comprise tobacco fibres. In particular embodiments, the aerosol-generating material does not comprise fibrous material.
In some embodiments, the gelling agent is CMC and is used together with wood pulp as a filler.
The aerosol-generating material may, in some cases, comprise water. In some instances, the aerosol-generating material is a hydrogel. In some embodiments, the aerosol-generating material comprises no more than about 20 wt%, about 15 wt%, about 12 wt% or about 10 wt% water. In some cases, the thin film may comprise at least about 1 wt%, about 2 wt% or about 5 wt% of water. The aerosol-generating material may comprise about 10 wt% water. In some cases, the aerosol-generating material comprises from about 5 wt% to about 10 wt% water, or from about 5 wt% to about 7 wt%. Suitably, the water content of the aerosol-generating material may be about 5 wt%.
In some cases, the aerosol-generating material may consist essentially of, or consist of, one or more gelling agents, an aerosol-former material, a botanical material, water, and one or more fillers. In some cases, the aerosol-generating material may consist essentially of, or consist of, glycerol, guar gum and/or cellulose, a botanical material and a filler such as wood pulp. In some cases, the aerosol-generating material may consist essentially of, or consist of, glycerol, alginate, a botanical material and a filler such as wood pulp. In some examples, the gelling agents include a cross-linking agent, such as a metal ion.
In some embodiments, the aerosol-generating material comprises:

1-10 wt% alginate;
10-30 wt% glycerol; and
10-60 wt% of ground tobacco; and

In some embodiments, the aerosol-generating material comprises:

1-10 wt% guar gum;
10-30 wt% glycerol;
10-60 wt% of ground tobacco; and
1-10 wt% wood pulp;

In some cases, the aerosol-generating material may additionally comprise a carrier on which the aerosol-generating material is provided. This carrier may ease manufacture and/or handling through, for example, (a) providing a surface onto which a gel composition may be cast (and which the gel composition does not need to be separated from later), (b) providing a non-tacky surface for the aerosol-generating material, (c) providing some rigidity to the aerosol-generating material.
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 botanical 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 flavour carrier. For example, the carrier may be impregnated with a flavourant or with botanical extract.
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 in use, 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 carrier in the aerosol-generating article may comprise or consist of a porous layer that abuts the aerosol-generating material. For example, the porous layer may be a paper layer. In some particular cases, the aerosol-generating material is disposed in direct contact with the porous layer; the porous layer abuts the aerosol-generating material and forms a strong bond. The aerosol-generating material is formed by setting or drying a gel composition and, without being limited by theory, it is thought that the gel composition partially impregnates the porous layer (e.g. paper) so that when the gel composition sets and forms cross-links, the porous layer is partially bound into the aerosol-generating material. This provides a strong binding between the aerosol-generating material and the porous layer.
Additionally, surface roughness may contribute to the strength of bond between the aerosol-generating material and the carrier. The paper roughness (for the surface abutting the carrier) may suitably be in the range of from about 50 to about 1000 Bekk seconds, suitably from about 50 to about 150 Bekk seconds, suitably about 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 aerosol-generating material 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 aerosol-generating material and a smoother side facing away from the aerosol-generating material.
In one particular case, the carrier may be a paper-backed foil; the paper layer abuts the aerosol-generating material 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 aerosol-generating material.
In another case, the foil layer of the paper-backed foil abuts the aerosol-generating material. The foil is substantially impermeable, thereby preventing water provided in the aerosol-generating material from being absorbed into the paper which could weaken its structural integrity.
In some cases, the carrier is formed from or comprises metal foil, such as aluminium foil. A metallic carrier may allow for better conduction of thermal energy to the aerosol-generating material. 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 no more than about 20 µm, such as from about 1 µm to about 10 µm, suitably about 5 µm.
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 aerosol-generating material 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 aerosol-generating material may comprise embedded heating means, such as resistive or inductive heating elements.

Method

Significant problems are encountered when forming cast sheets from gels with simple compositions, as discussed herein. The results are highly inconsistent and unpredictable, even when creating gels with the same composition and following the same process. The gel compositions may, in some cases, be uncastable or may result in sheets that are highly variable and so are not suitable for use in an aerosol-generating system due to the unpredictability of the aerosol generated upon heating, or due to the resultant sheet material simply being unsuitable for incorporation into a consumable.
A particular source of these problems appears to be the clumping of particulate materials when mixing the components. Such clumps can be very difficult to break up, not least because this would ordinarily be achieved by vigorous blending which can introduce air bubbles into the gel, creating further problems and inconsistencies in the cast sheet produced from such aerated gels.
Clumps in the gel mixture can lead to an irregular, non-uniform sheet being produced when the gel is cast and dried. This is characterised by an uneven surface and thickness of the sheet and a varied appearance, for example, with opaque spots.
A further problem observed with convention processes for preparing the aerosol-generating material was phase separation. This manifested itself by liquid separating out from the gel phase, either before or after the formation of a dried sheet.
The following is an industry standard method for dispersing and hydrating alginates, which are available in powdered and granular form, both of which have a strong tendency to form lumps when added to water. Calcium interferes with the creation of the gel structure and so it is recommended that alginates be dispersed in deionized water.

Step 1 - charge the process vessel with deionised water and start agitator or stirrer.
Step 2 - Prepare any premix of the alginate with any other powdered ingredient such as salt or sugar.
Step 3 - Add the alginate into the vortex created by the agitator at a controlled rate to try and reduce the formation of agglomerates.
Step 4 - Mixing is continued until the alginate has been fully dispersed and hydrated.
Step 5 - A filtration step may be required to remove any agglomerates and/or unhydrated alginate.

The inventors have identified that the sequence in which the components of the aerosol-generating material are mixed can be selected so as to ensure that the solid particles are uniformly distributed in the gel composition and a homogenous and stable gel is formed. In some embodiments, this uniform mixture is achieved without the need for vigorous mixing which can introduce unwanted air bubbles into the gel.
In addition to achieving uniform dispersion of the particulate materials in the gel composition, it is also important that the gelling agent is completely and consistently hydrated during the preparation of the gel composition. It can be simultaneous dispersion of the particulate and liquid materials and the hydration of the gelling agent that can cause the problems and lead to clumping.
In view of this discovery, the inventors have identified that it is essential that the gelling agent is solubilised in the aerosol-former material and a uniform mixture with other components is formed before the gelling agent is hydrated by adding water to this mixture.
Thus, a uniform mixture of the components should be formed before water is added to hydrate the gelling agent.
An aerosol-generating material comprising a gelling agent and an aerosol-former material is formed the method comprising:

solubilising the gelling in the aerosol-former material and in the absence of water to form a homogenous premix;
adding water to the premix form a hydrated mixture;
casting the hydrated mixture to form a layer; and
forming a dry sheet of the aerosol-generating material from the cast layer of the hydrated mixture.

In some embodiments, an aerosol-former material is selected that is a solvent in which the gelling agent readily dissolves. In such embodiments, the gelling agent may be fully dissolved in the aerosol-former material before the water is added and the gelling agent is hydrated.
In some embodiments, a co-solvent or a solubility enhancer may be added to the premix. The premix comprising the gelling agent and the aerosol-former material is preferably substantially or completely free of water.
In some embodiments, other components of the aerosol-generating material may be soluble in the aerosol-former material and these components may also be solubilised in the aerosol-former material before the gelling agent is hydrated.
In some embodiments, other components of the aerosol-generating material are water-soluble. These water soluble components may be added after the gelling agent has been solubilised in the aerosol-former material. In some embodiments, these water-soluble components may be added to the water before the water is added to the premix comprising aerosol-former material and gelling agent.
In some embodiments, other components of the aerosol-generating material are added to the hydrated mixture before it is cast.
The solubilisation of the gelling agent in the aerosol-former material prior to its hydration means that the process of making the gel composition to be cast and dried does not require vigorous blending as clumping of particles is reduced or prevented altogether. Therefore, the method involves mixing or blending the hydrated mixture at a speed on no more than 1000 rpm. In some embodiments, the mixing of the gelling agent and the aerosol-former material is carried out at 650 rpm.
In some specific embodiments, the method comprises mixing a gelling agent, such as an alginate, with an aerosol-former material, such as glycerol and/or propylene glycol. A liquid premix is thus made, in which the gelling agent is dissolved in the aerosol-former material. In some embodiments, this formation of the premix may involve mixing or blending, for example at 650 rpm.
The inventors have established that the gelling agent is generally easily solubilised in the aerosol-former material and so it is not necessary to increase the amount of aerosol-former material used in order to achieve the desired degree of solubilisation for the methods described herein. Thus, in some embodiments, the ratio of the gelling agent to aerosol-former material may be from about 1:2 to about 1:5. For example, the ratio may be 1:3, meaning that the mixture comprises 10 g alginate to 30 g glycerol.
Once the gelling agent is fully dispersed in the aerosol-former material, water, for example deionised water, is added to the premix and the gelling agent is allowed to fully hydrate. In some embodiments, this hydration of the gelling agent may involve mixing or blending, for example at 650 rpm. In some embodiments, this hydration step takes from about 30 seconds to about 15 minutes. In some embodiments, the hydration step takes no more than about 14 minutes, no more than about 13 minutes, no more than about 12 minutes, no more than about 11 minutes, no more than about 10 minutes, no more than about 9 minutes, no more than about 8 minutes, no more than about 7 minutes, no more than about 6 minutes, no more than about 5 minutes, no more than about 4 minutes, no more than about 3 minutes, no more than about 2 minutes, or no more than about minute.
In some embodiments, completion of the hydration of the gelling agent is assessed by counting the number of particles within the mixture. When particles having a size of up to 1000 µm number 1000 or less and the number has plateaued for at least 2 minutes, the mixture is considered to be hydrated. At this point, the majority of the particles detected are most likely air bubbles. This assessment may be carried out using particle track data.
Finally, further components of the aerosol-generating material may then be added to the hydrated gel composition. Such additional components may include, for example, one or more of: a filler and one or more substances to be delivered. Suitable fillers include wood pulp, and the substance to be delivered may be in the form of a botanical material, such as a ground botanical material, or an extract therefrom. The botanical material may be tobacco and the substance to be delivered may be nicotine or tobacco-derived flavours.
These additional components, which may include solid materials, may be mixed into the hydrated gel mixture at an rpm of from about 3,500 to about 25,000. In some embodiments, the mixing is conducted at an rpm of at least about 4,000, at least about 5,000, at least about 6,000, at least about 7,000, at least about 8,000, at least about 9,000, at least about 10,000, at least about 11,000, at least about 12,000, at least about 13,000, at least about 14,000, at least about 15,000, at least about 16,000, at least about 17,000, at least about 18,000, at least about 19,000, at least about 20,000, at least about 21,000, at least about 22,000, at least about 23,000, or at least about 24,000 rpm. Additionally or alternatively, the mixing is conducted at an rpm of no more than about 25,000, no more than about 24,000, no more than about 23,000, no more than about 22,000, no more than about 21,000, no more than about 20,000, no more than about 19,000, no more than about 18,000, no more than about 17,000, no more than about 16,000, no more than about 15,000, no more than about 14,000, no more than about 13,000, no more than about 12,000, no more than about 11,000, no more than about 10,000, no more than about 9,000, no more than about 8,000, no more than about 7,000, no more than about 6,000, no more than about 5,000, no more than about 4,000 rpm.
The additional components may be mixed into the hydrated gel mixture for a period of from about 1 to about 25 minutes and usually for a period of from about 5 to about 20 minutes. In some embodiments, the mixing is conducted for a period of at least about 1 minute, at least about 2 minutes, at least about 3 minutes, at least about 4 minutes, at least about 5 minutes, at least about 6 minutes, at least about 7 minutes, at least about 8 minutes, at least about 9 minutes, at least about 10 minutes, at least about 11 minutes, at least about 12 minutes, at least about 13 minutes, at least about 14 minutes, at least about 15 minutes, at least about 16 minutes, at least about 17 minutes, at least about 18 minutes, or at least about 19 minutes. Alternatively or additionally, the mixing is conducted for a period of no more than about 20 minutes, no more than about 19 minutes, no more than about 18 minutes, no more than about 17 minutes, no more than about 16 minutes, no more than about 15 minutes, no more than about 14 minutes, no more than about 13 minutes, no more than about 12 minutes, no more than about 11 minutes, no more than about 10 minutes, no more than about 9 minutes, no more than about 8 minutes, no more than about 7 minutes, no more than about 6 minutes, no more than about 5 minutes, no more than about 4 minutes, no more than about 3 minutes, no more than about 2 minutes.
The mixing steps may be carried out at room temperature.
In some embodiments, the gelling agent may be crosslinked and this may require the addition of a cross-linking agent. The cross-linking agent may be added with or after the addition of the additional components such as the filler or botanical material.
Where the gelling agent is an alginate, this may be cross-linked by the addition of calcium ions (Ca²⁺). Such ions are present in tobacco and so the alginate may be cross-linked by the addition of ground tobacco or a tobacco extract. Alternatively, the alginate may be cross-linked by the addition of a Ca²⁺ source, such as calcium formate.
The total amount of the setting agent, such as a calcium source, may be from about 0.5 to about 5 wt% (calculated on a dry weight basis). The addition of too little setting agent may result in a dried gel which does not stabilise the components within it and results in these components dropping out of the gel. The addition of too much setting agent results in an aerosol-generating material that is very tacky and consequently has poor handleability. Too much calcium may also cause issues with phase separation of gel and water. The rate of reaction of calcium with alginate may also be impacted.
It is important that the cross-linking agent is not added before the gelling agent is solubilised. Preferably, the gelling agent is solubilised and then hydrated before the cross-linking agent is added. Preferably, the gelling agent is solubilised and then hydrated before any substance to be delivered (such as botanical material or extract) is added. Preferably, the gelling agent is solubilised and then hydrated before any filler is added.
When the cross-linking agent is added, the mixture may be mixed or blended at a higher rpm, such as 800 to 3,500 rpm using a mixer such as a Robot Coupe Robot Cook Cutter mixer or equivalent. Mixing may be carried out for a period of from about 5 to about 20 minutes.
The process has been found to result in consistent sheet materials with excellent homogeneity in chemical and physical characteristics. In addition, the resultant gel composition and cast sheet did not exhibit phase separation (where a liquid is observed to separate from the gel phase). Such separation is clearly undesirable and is indicative of a non-homogenous aerosol-generating material.
In some examples, the hydrated gel composition 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. In some examples, the gel composition may have an elastic modulus of from about 5 to about 1200 Pa (also referred to as storage modulus); in some cases, the gel composition may have a viscous modulus of from about 5 to about 600 Pa (also referred to as loss modulus).
Once the hydrated gel composition, optionally with further added components, has been formed into a layer, it is dried to form the aerosol-generating material. In some embodiments, drying is conducted at a temperature of from about 60 to about 120°C. In some embodiments, drying is conducted for a period of from about 10 minutes to about 2 hours.
In some embodiments, the hydrated gel composition is heated to volatilise at least some of the water, to form the sheet of aerosol-generating material. For example, the gel composition may be heated to remove at least about 60 wt%, about 70 wt%, about 80 wt%, about 85 wt% or about 90 wt% of the water.
Figure 1 is a flow chart showing the sequence in which the steps of preparing the aerosol-generating material are carried out.

Article

An article for use in an aerosol provision system comprises an aerosol-generating portion comprising the aerosol-generating composition described herein.
In some embodiments, the aerosol generating article may be circumscribed by a wrapping material such as paper.
In some cases, the article may additionally comprise a filter and/or cooling element. In some embodiments, the filter and/or cooling element and the aerosol-generating portion are joined by tipping paper that circumscribes at least a portion of both of these parts of the article.
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. In some embodiments, the cooling segment comprises a longitudinally extending air channel for cooling the flow of air therethrough.
The filter, if present, may comprise any suitable filter known in the art such as a cellulose acetate plug or a paper plug, and optionally including capsule.
In some embodiments, the article comprises a mouth end hollow tubular body. The one or more sections selected from the mouth end tubular body, filter plug and cooling element may be combined by a wrapping material to form a mouthpiece of the article. The mouthpiece may be attached to the aerosol-generating portion, for example by a tipping paper.
In some embodiments, the aerosol-generating article and/or the aerosol-generating portion thereof comprises the aerosol-generating material in the form of a sheet.
In some cases, the aerosol-generating material may be included as a bunched or gathered sheet, as a crimped sheet, or as a rolled sheet (i.e., in the form of a tube or as a rolled plug).
In some embodiments, the aerosol-generating material may be included as a sheet circumscribing a rod of a further aerosol-generating material. In some other cases, the aerosol-generating material may be formed as a sheet and then shredded and incorporated into the article. In some cases, the shredded sheet may be mixed with a further aerosol-generating material and incorporated into the article. In such cases, the aerosol-generating material may have a mass per unit area that is selected to be comparable to the density of the further aerosol-generating material, so the mixture components do not separate. For example, the aerosol-generating material may have a mass per unit area of from about 80 g/m² to about 120 g/m² so that it has a density comparable to cut rag tobacco.
In some embodiments, the aerosol generating portion of the article comprises two or more sections, each comprising an aerosol-generating material having a different form or composition.
In some embodiments, the article comprises a paper wrapper circumscribing the aerosol-generating composition, wherein the aerosol-generating material according to the invention is positioned between a plug of aerosol-generating material and the wrapper. In some embodiments, the aerosol-generating material is a sheet which is positioned between the wrapper and the plug of aerosol generating material. In some embodiments, the aerosol-generating material is provided on the inner surface of the wrapper circumscribing the plug of aerosol-generating material.
Figure 2 is a side-on cross-sectional view of an article 1 for use in an aerosol provision system. In the present case, the article comprises a consumable for a non-combustible aerosol provision system.
The article comprises an aerosol generating portion, in the present case a cylindrical aerosol-generating portion 2, and a mouthpiece 3 downstream from and connected to the aerosol-generating portion 2.
The aerosol-generating portion 2 comprises a rod or segment of aerosol-generating composition 20 wrapped in a rod wrapper 10.
In Figure 2, the rod of aerosol-generating composition 20 comprises the aerosol-generating material according to the present disclosure and a further, different aerosol-generating material, for example, shredded botanical material, such as cut rag tobacco. In this embodiment, the two materials are cut or shredded and the two different shredded materials are blended and formed into a rod segment. In this embodiment, the two aerosol-generating materials are fairly evenly distributed within the rod and along the length of the rod.
The article 1 also comprises a mouthpiece 3 which has a mouth end 3b and a distal end 3a that abuts the aerosol-generating portion 2.
The mouthpiece 3 illustrated in Figure 2 is located at the mouth end of the article 1 and comprises three elements, a mouthpiece body 14 downstream of a cooling section 13, and a hollow tubular element 15 downstream of the mouthpiece body 14. In other embodiments, one or two of these different mouthpiece elements may be omitted or duplicated, and/or the elements may be provided in a different sequence. For example, the hollow tubular element 15 may be omitted, and the mouthpiece body 14 may form the mouth end of the article. In some examples where the hollow tubular element 15 is omitted, the length of the mouthpiece body 14 may be increased, or a further body of material may be provided at the mouth end.
In an alternative arrangement that is not illustrated, the mouthpiece comprises a mouthpiece body at the mouth end of the mouthpiece, optionally comprising a plug of cellulose acetate tow or paper, and optionally including capsule. Adjacent to this mouthpiece body is a first tube, optionally formed from paper, which abuts at its other end a further tubular section, optionally comprising cellulose acetate.
In the mouthpiece shown in Figure 2, the cooling section 13, mouthpiece body 14 and hollow tubular element 15 are connected by a combining wrapping material 11.
As shown in Figure 2, tipping paper 9 is wrapped around the full length of the mouthpiece 3 and over part of the aerosol generating portion 2. The tipping paper 9 has an adhesive on its inner surface (not shown) to connect the mouthpiece 3 and rod 2. In the illustrated embodiment, the tipping paper 9 extends 5 mm over the rod of aerosol generating material 2 but it can alternatively extend from about 3 mm to about 15 mm over the rod 2, or from about 4 mm to about 6 mm, to provide a secure attachment between the mouthpiece 3 and rod 2.
In the illustrated embodiment, the article 1 is provided with first and second parallel rows of perforations 12 through the tipping material 9, combining wrapping material 11 and cooling section 13, providing ventilation into the mouthpiece 3 at the cooling section 13. The perforations 12 shown are formed as laser perforations, at positions about 18 mm and about 19 mm respectively from the downstream, mouth-end 3b of the mouthpiece 3. In other examples, the ventilation can be provided into the mouthpiece 3 at other locations.
Figure 3 shows an article 1 with a similar overall construction to the article shown in Figure 2 and described above. Specifically, the mouthpiece and wrappers are the same.
In Figure 3, the rod comprising the aerosol-generating composition is different to that shown in Figure 1. In this embodiment, the aerosol-generating portion comprises a rod or segment comprising a plug of a first aerosol-generating material 21. This may be a rod of shredded botanical material, such as tobacco. The entire length of this rod or segment is surrounded by a sheet 22 of an aerosol-generating material according to the present disclosure. In this embodiment, the two aerosol-generating materials are provided together but they are not blended and they are present in the aerosol-generating portion in different and distinct or separate forms. In the embodiment illustrated in Figure 3, both of the two aerosol-generating materials are present along the entire length of the aerosol-generating portion 2.
Figure 4 shows an article 1 with a similar overall construction to the article shown in Figure 3 and described above. Specifically, the mouthpiece and wrappers are the same.
In Figure 4, the aerosol-generating portion 2 differs from that shown in Figure 2 in that only part of the length of the rod or segment comprising the first aerosol-generating material 21 is surrounded by a sheet 22 of a second aerosol-generating material. Once again, the first aerosol-generating material 21 may be shredded botanical material. Thus, in the embodiment illustrated in Figure 4, only the first aerosol-generating material 21 is present along the entire length of the aerosol-generating portion 2. The second aerosol-generating material 22 is present over only part of the length of the aerosol-generating portion 2. This arrangement means that the second aerosol-generating material 22 may be heated and generate an aerosol at specific times during the overall use of the article.
Figure 5 shows an article 1 with a different construction of aerosol-generating portion 2. Once again, the mouthpiece and wrappers are the same as shown in the foregoing figures and are as described above.
In Figure 5, the aerosol-generating portion 2 comprises two separate segments. The first segment is a rod or plug comprising the first aerosol-generating material 21, such as cut rag tobacco. This segment abuts the distal end 3a of the mouthpiece 3. The second segment of the aerosol-generating portion 2 is a rod or plug comprising the second aerosol-generating material 22 which is a sheet material according to the present disclosure. This second segment is formed from a roll of a sheet of the second aerosol-generating material forming a plug. In alternative embodiments, the rod or plug may comprise a folded or gathered sheet of the second aerosol-generating material 22, aligned strips of the second aerosol-generating sheet material, or a plug of cut or shredded second aerosol-generating sheet material.
In the embodiment illustrated in Figure 5, the first aerosol-generating material 21 and second aerosol-generating material 22 are present at different locations along the length of the aerosol-generating portion 2. This will allow them to be separately or independently heated, if desired.
In Figure 5, the two segments of the aerosol-generating portion 2 are separately wrapped by wrappers 10 and 6. The two segments are held together by a tipping paper 7 which is wrapped around the full length of the segment comprising the second aerosol-generating material 22 and over part of the segment comprising the first aerosol generating material 21. The tipping paper 7 has an adhesive on its inner surface (not shown) to connect the segments of the aerosol-generating portion 2. In the illustrated embodiment, the tipping paper 7 extends 5 mm over the segment comprising the first aerosol generating material 21 but it can alternatively extend over the entire length of the aerosol-generating portion 2, or even over the entire length of the article 1.

Assembly

The invention also relates to an aerosol generating assembly comprising an aerosol generating article described herein and a heater configured to heat but not burn the aerosol-generating composition (also referred to herein as the aerosolisable material).
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. The heater may be a combustible heat source or a chemical heat source which undergoes an exothermic reaction to product heat in use. The aerosol generating assembly may comprise a plurality of heaters. The heater(s) may be powered by a battery.
In some cases, the heater may heat, without burning, the aerosolisable material to a temperature of from about 120°C to about 350°C in use. In some cases, the heater may heat, without burning, the aerosolisable material to from about 140°C to about 250°C in use. In some cases in use, substantially all of the second aerosol-generating composition is no more than about 4 mm, about 3 mm, about 2 mm or about 1 mm from the heater. In some cases, the second aerosol-generating composition is disposed from about 0.01 mm to about 2 mm from the heater, suitably from about 0.02 mm to about 1.0 mm, suitably from about 0.1 mm to about 0.5 mm. These minimum distances may, in some cases, reflect the thickness of a carrier that supports the thin film. In some cases, a surface of the thin film and/or of the second aerosol-generating composition may directly abut the heater.
In some cases, the heater may be embedded in the aerosol-generating composition. 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 composition, which is heated by induction.
In some cases, the aerosol generating assembly may be a heat-not-burn device. That is, it may contain a solid aerosol-generating composition and no liquid aerosolisable material. In some cases, the aerosol-generating composition may comprise 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 aerosol-generating composition and a liquid aerosolisable material. In some cases, the solid aerosol-generating composition may comprise nicotine. In some cases, the solid aerosol-generating composition may comprise a tobacco material. In some cases, the solid aerosol-generating composition may comprise a tobacco material and a separate nicotine source. The separate aerosolisable materials may be heated by separate heaters, the same heater or, in one case, a downstream solid aerosol-generating composition may be heated by a hot aerosol which is generated from the upstream aerosolisable material. An electronic hybrid device is disclosed in WO 2016/135331 A1 , which is incorporated by reference in its entirety.
The aerosol generating article or assembly 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 volatilised components thereby cooling the aerosol.
The ventilation enhances the generation of visible heated volatilised components from the article when it is heated in use. The heated volatilised components are made visible by the process of cooling the heated volatilised components such that supersaturation of the heated volatilised components occurs. The heated volatilised components then undergo droplet formation, otherwise known as nucleation, and eventually the size of the aerosol particles of the heated volatilised components increases by further condensation of the heated volatilised components and by coagulation of newly formed droplets from the heated volatilised components.
In some cases, the ratio of the cool air to the sum of the heated volatilised components and the cool air, known as the ventilation ratio, is at least about 15%. A ventilation ratio of about 15% enables the heated volatilised components to be made visible by the method described above. The visibility of the heated volatilised components enables the user to identify that the volatilised components have been generated and adds to the sensory experience of the smoking experience.
In another example, the ventilation ratio is from about 50% to about 85% to provide additional cooling to the heated volatilised components. In some cases, the ventilation ratio may be at least about 60% or about 65%.
The assembly may comprise an integrated aerosol generating article and heater, or may comprise a heater device into which the article is inserted in use. In either case, the heater is configured to heat but not burn the aerosol-generating composition.
Figure 6 shows an example of a non-combustible aerosol provision device 100 for generating aerosol from an aerosol-generating composition of an article or consumable 110, as described herein. For example, the article 110 may be any one of the articles 1 shown in Figures 2 to 5.
In broad outline, the device 100 may be used to heat a replaceable article 110 comprising the aerosol-generating composition as described herein, for instance an article as described elsewhere herein, to generate an aerosol or other inhalable medium which is inhaled by a user of the device 100. The device 100 and replaceable article 110 together form a system.
The device 100 comprises a housing 102 (in the form of an outer cover) which surrounds and houses various components of the device 100. The device 100 has an opening 104 in one end, through which the article 110 may be inserted for heating by a heating assembly. In use, the article 110 may be fully or partially inserted into the heating assembly where it may be heated by one or more components of the heater assembly. The article 110 is illustrated having a rod-shape, like the articles 1 illustrated in Figures 2 to 5.
The device 100 of this example comprises a first end member 106 which comprises a lid 108 which is moveable relative to the first end member 106 to close the opening 104 when no article 110 is in place. In Figure 6, the lid 108 is shown in an open configuration, however the lid 108 may move into a closed configuration. For example, a user may cause the lid 108 to slide in the direction of arrow "B".
The device 100 may also include a user-operable control element 112, such as a button or switch, which operates the device 100 when pressed. For example, a user may turn on the device 100 by operating the switch 112. This switch may also actuate the means for opening the container inserted into the device, in readiness for its use.
The device 100 may also comprise an electrical component, such as a socket/port 114, which can receive a cable to charge a battery of the device 100. For example, the socket 114 may be a charging port, such as a USB charging port.

Example

Two processes were used to create samples an aerosol-generating material from a mixture having the following composition:

Components wt% (WWB)

Alginate (gelling agent) 1.65%

Glycerol (aerosol-former material) 3%

Water 95.35%
To assess the homogeneity of the mixtures and the dissolution and dispersion of the alginate within the aerosol-former material and water, a Particle Track was used to detect particles within the mixture during the mixing step. An Easyviewer camera was also used to obtain images of the mixture.
The first samples were produced using a conventional process. This involved adding the alginate (in the form of a solid powder) to the water and then subsequently adding the glycerol. This mixture was then agitated using a blender to disperse the alginate homogenously. In the test, an IKA digital mixer with a dissolver stirrer (80 mm diameter R1300 Dissolver Stirrer) was used to stir the mixture in a 2 litre vial, operating at 650 rpm.
The data from the Particle Viewer is shown in Figures 9a, 10a and 11a. Figure 9a shows the count of particles with a size of up to 10 µm. Figure 10a shows the count of particles with a size of from 10 to 100 µm. Figure 11a shows the count of particles with a size of from 100 to 1000 µm. The addition of the alginate after 2 minutes gave rise to particles in the mixture whose size was detected and which were counted.
The graph of Figure 9a shows that the number of particles having a particle size of up to 10 µm dropped from an initial peak of around 900 on addition of the alginate to the mixture. The number of these small particles then rose again to a higher peak of about 2000 after about 3 to 5 minutes as the mixture was blended at 650 rpm. Then, the number of small particles in the mixture dropped to a lower level, eventually plateauing at a count of less than 100 some 9 minutes after the addition of the alginate.
The graph of Figure 10a shows the number of mid-range sized particles having a particle size of from 10 to 100 µm. The number of these particles in the mixture peaked at over 3000 on addition of the alginate after 2 minutes and then dropped to a lower plateau of from about 400 to 1000 counts for several minutes before finally dropping to a final plateau of about 300 counts some 7 minutes after the addition of the alginate to the mixture.
The graph of Figure 11a shows the number of large particles having a particle size of 100 to 1000 µm) in the mixture. This number peaked at over 600 when the alginate was first added to the mixture after two minutes. The number of large particles then fluctuated wildly between 50 and 550 for about seven minutes before finally dropping to a plateau of about 50-60 counts.
Only after at least 15 minutes of mixing at 650 rpm following the addition of the alginate did the mixture prepared using the conventional sequence of adding the components show a significant reduction in the number of particles of all sizes (up to about 1000 µm). Thus, the data suggest that the mixing for a period of at least about 15 minutes following the addition of the alginate was necessary to properly disperse the particles and to solubilise the alginate.
The visual appearance of the mixture changed during the 15 minutes of mixing. Initially, the mixture was generally colourless and opaque, with visible clumps. After 15 minutes of mixing following the addition of the alginate, the mixture was more uniform in appearance with no visible large clumps.
When samples prepared by this method were cast onto a metal surface to form a layer for drying, some of the cast layers showed signs of phase separation. At the edge of the layer, a liquid was seen separating from the gel, as shown in the photograph of Figure 7a. In addition, careful observation of other layers showed the presence of some smaller regions of increased opacity within the gel which appeared to represent small clumps of alginate. Rather than forming a smooth, uniform sheet, the cast layer has an uneven appearance, as shown in the photograph of Figure 7b. Using a Hegman gauge, the particle size in the final slurry was assessed and was found to be below 100 µm.
The second samples were produced using a process according to the method described herein. This involved adding the alginate (in the form of a solid powder) to the glycerol in the absence of any water. This premix comprising the alginate and glycerol was gently stirred to enhance solubilisation of the alginate in the glycerol. At this point, the alginate was fully dissolved in the glycerol so that no solid particles were visible.
Next, the premix was added to the deionised water and the mixture was agitated using a blender to assist hydration of the alginate. In the test, an IKA mixer with attached propeller was used, operating at 650 rpm.
The data from the Particle Viewer is shown in Figures 9b, 10b and 11b. Figure 9b shows the count of particles with a size of up to 10 µm. Figure 10b shows the count of particles with a size of from 10 to 100 µm. Figure 11b shows the count of particles with a size of from 100 to 1000 µm.
The addition of the alginate/glycerol premix after 1.5 minutes gave rise to the brief spike in the number of particles of all sizes. The graphs each show that the number of particles and their size quickly decreased to a low plateau, indicating the almost total absence of particles in the mixture. The mixture did not require extensive or prolonged mixing to disperse and dissolve particles. Indeed, the mixture was ready for further processing within less than 30 second after the introduction of the premix into the water.
The visual appearance of the mixture was clear and uniform throughout the processing. When samples prepared by this method were cast onto a metal surface to form a layer for drying, the cast layers showed no signs of phase separation and, once again, the appearance of the cast mixture was clear and uniform.
When the layer was dried, no irregularities were visible. Rather, the sheet of aerosol-generating material had a highly homogeneous appearance, as shown in the photograph of Figure 8a.
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

An aerosol-generating material comprising a gelling agent and an aerosol-former material, wherein the gelling agent is homogeneously distributed within the aerosol-generating material.
An aerosol-generating material as claimed in claim 1, wherein one or more properties of the aerosol-generating material is homogenous, the properties being selected from the group consisting of:
thickness;

porosity/permeability;

area density;

volume density;

surface roughness;

conductance; and

visual appearance.
An aerosol-generating material as claimed in claim 2, wherein the homogeneous property of the aerosol-generating material is measured over an area of from about 10 to about 100 mm².
An aerosol-generating material as claimed in claim 2 or claim 3, wherein the homogeneous property of the aerosol-generating material is measured over the entire area of the sheet or piece of aerosol-generating material, and/or wherein the property is considered homogenous where the variance of the property over the measured area is no more than 10%, no more than 5% or no more than 3%.
An aerosol-generating material as claimed in any one of claims 1 to 4, wherein the aerosol-generating material is a cast sheet, optionally, wherein the cast sheet is cut or shredded.
An aerosol-generating material as claimed in any one of claims 1 to 5, wherein the gelling agent comprises one or more selected from the group consisting of:
alginates, pectins, starches, starch derivatives, cellulose, cellulose derivates, pullulan, xanthan gum, guar gum, carrageenan, agar, agarose, acacia gum, silica and silicone compounds, clays and polyvinyl alcohol.
An aerosol-generating material as claimed in any one of claims 1 to 6, comprising from about 0.5 to about 60 wt%, or from about 4 to about 25 wt%, of the gelling agent on a dry weight basis, optionally wherein the gelling agent comprises an alginate.
An aerosol-generating material as claimed in any one of claims 1 to 7, wherein the gelling agent hydrates and swells on contact with water, optionally wherein the gelling agent comprises an alginate.
An aerosol-generating material as claimed in any one of claims 1 to 8, wherein the aerosol-former material comprises one or more selected from the group consisting of: glycerine, 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, and propylene carbonate. In some embodiments, the aerosol former is glycerine, glycerol or propylene glycol, optionally wherein the aerosol-former material comprises glycerol.
An aerosol-generating material as claimed in any one of claims 1 to 9, comprising from about 5 to about 60 wt% of the aerosol-former material on a dry weight basis.
An article for use in an aerosol-provision system, the article comprising an aerosol-generating material as claimed in any one of claims 1 to 10, and optionally comprising a filter and/or cooling element.
An aerosol provision system comprising an article as claimed in claim 11.
A method of manufacturing an aerosol-generating material comprising a gelling agent and an aerosol-former material, the method comprising:
solubilising the gelling agent in the aerosol-former material and in the absence of water to form a homogenous premix;

adding water to the premix form a hydrated mixture;

casting the hydrated mixture to form a layer; and

forming a dry sheet of the aerosol-generating material from the cast layer of the hydrated mixture.
A method as claimed in claim 13, wherein the solubilised gelling agent is hydrated on addition of water to form a gel, and/or wherein the gelling agent is an alginate or alginate derivative, and/or wherein the aerosol-former material is a solvent in which the gelling agent readily dissolves.
A method as claimed in claims 13 or claim 14, wherein:
(i) the hydrated mixture is formed by mixing at a speed on no more than 1000 rpm;

(ii)
further water soluble components of the aerosol-generating material are added after the gelling agent has been solubilised in the aerosol-former material; and/or

(iii)
further components of the aerosol-generating material that are soluble in the aerosol-former material are included in the mixture of the gelling agent and the aerosol-former material.