Aerosol Generating Article

Description

TECHNICAL FIELD

The invention relates to an aerosol generating article.

TECHNICAL BACKGROUND

Aerosol generating articles have become popular as a replacement for conventional smoking articles. Such articles are expected by consumers to contain nicotine and/or tobacco and at the same time produce visible vapor.

In this context, EP 3 046 431 B1 is related to an aerosol generating system with a nicotine source which can be a liquid tobacco extract. WO 2021/053029 A1 is related to a plurality of aerosol generating substrates, and WO 2018/122375 A1 discloses a tobacco mousse. Finally, further aerosol generating articles are known from EP 3 462 935 B1, WO 2020/089067 A1 and WO 2020/089068 A1.

Nevertheless, there remains a need for an aerosol generating article, which is improved with regard to the production of visible vapor.

SUMMARY OF THE INVENTION

Therefore, the present invention provides an aerosol generating article, which is improved with regard to the production of visible vapor.

This is achieved by the subject matter of claim 1.

Accordingly, the novel aerosol generating article is configured for being heated but not burned and comprises an aerosol generating section and a filter section. At least the aerosol generating section is wrapped by a wrapper and comprises at least a tobacco-based aerosol generating substrate comprising homogenized tobacco material, such as reconstituted tobacco, and optionally tobacco lamina, e.g. up to 30 wt. % by weight of the tobacco-based aerosol generating substrate. The homogenized tobacco material may take the form of gathered sheet, shreds, or strips. The homogenized tobacco material may be manufactured into sheets or strips from a slurry by paper forming technology or casting, or from a slurry or dough by extrusion and lamination. The tobacco lamina may also be in the form of shreds. Additionally, a minor amount (e.g., 15 wt. % or less) of cut tobacco stems or stalks, cellulose fibre or expanded tobacco may be present. The aerosol generating section further comprises a porous aerosol generating reservoir containing a foam comprising an aerosol forming agent and a forming agent and, foam optionally a foam stabilizing agent.

By means of the tobacco-based aerosol generating substrate, tobacco taste and nicotine can be delivered, and by means of the additional aerosol generating reservoir, an increased amount of visible vapor can be produced. In this context, the foam contained in the aerosol generating reservoir can also be called a mousse or an e-mousse as it carries e-liquid similar to liquid of an e-cigarettes. As a side aspect, the tobacco substrate is essentially solid, preferably formed as a gathered sheet, shreds, strips and the like with high tobacco content, preferably tobacco in the form of agglomerated powder, and is at least preferably neither a tobacco mousse nor a capillary tobacco substrate.

The foam in the aerosol generating reservoir retains the aerosol forming agent in the mousse in a non-free liquid state and/or prevent it from leaking. In other words, there is no aerosol precursor in free-liquid state and preferably also no solid matrix or carrier in the aerosol generating reservoir. Thus, the desired effect of producing a high amount of visible vapor can be obtained without the risk of undesirable leakage of liquid of any kind from this reservoir. At the same time, by not requiring any solid matrix or carrier, (such as ceramic or porous plastic) the structure can be kept comparably simple, easily insertable in a paper wrapper (i.e., more deformable or shapable) and biodegradable.

The effect obtained by the invention can also be called a visible vapor booster which will lead to a satisfying vaping experience made by the users. As already indicated, this is essentially achieved by the reservoir containing an aerosol forming agent or humectant. In particular, the aerosol generating liquid can advantageously comprise at least one component having a boiling point above 160° C., preferably above 175° C., most preferably comprised between 185° C. and 295° C.

Providing an aerosol generating reservoir separate from the tobacco-based substrate overcomes the problem, that the amount of aerosol generating agent cannot be increased in the tobacco-based substrate due to manufacturability reasons. The manufacturability issues are related to the product becoming too sticky, difficult to handle and being wrapped and causing staining on the wrapper, when the amount of aerosol forming agent exceeds a certain value, for example 25 to 30 wt. % of the total weight of the substrate. Thus, an extra amount of visible vapor can essentially be produced by providing an aerosol generating reservoir in addition to and separate from the tobacco-based substrate. At the same time, heating of the aerosol generating reservoir can be ensured by avoiding any kind of heat barrier around or adjacent to it.

Preferred embodiments are described in the further claims.

In general, the aerosol generating reservoir can be positioned anywhere, where the desired high amount of vapor will be produced when heated. In particular, a position longitudinally and/or radially adjacent the tobacco-based substrate will be beneficial in order to ensure heating with a heater having relatively small dimensions while still covering the above-mentioned adjacent aerosol generating substrate and reservoir.

In a similar manner, the aerosol generating reservoir can have any suitable shape and can particularly be formed as a disc spanning the entire radial dimension of the wrapped inner volume of the aerosol generating article, which is typically a cylinder-shaped volume. However, the disc can also be oriented otherwise, in particular at an angle to the radial direction. Moreover, the foam can also be present in the shape of a rod, which may not necessarily cover the entire radial dimension of the article and can extend essentially in the longitudinal direction thereof or at an angle thereto. In preferred mode, the aerosol generating reservoir is formed of a cylindrical disc positioned adjacent the tobacco-based aerosol generating substrate and the ratio of the length of the aerosol generating reservoir to that of the tobacco-based aerosol generating substrate is comprised between 1:1 and 1:5, preferably 1:2 and 1:4.

For example, the length of the tobacco-based aerosol generating substrate is about 14 mm and the length of the aerosol generating reservoir is about 6 mm.

The aerosol generating reservoir can also comprise one or more longitudinal channels, in order to promote flow of aerosol through the reservoir.

It is currently expected that the compatibility of the tobacco-based substrate and the additional aerosol generating reservoir is particularly good, if the reservoir is positioned downstream of the substrate. Indeed, aerosol from the reservoir can be delivered more readily without being hindered by the mass of tobacco-based substrate.

Nevertheless, both the above-indicated disc as well as multiple discrete elements, such as beads or pellets, constituting the aerosol reservoir can advantageously be embedded in the tobacco-based substrate.

As a preferred embodiment of the aerosol generating reservoir being regularly adjacent the tobacco-based substrate, the reservoir can be a thin film essentially positioned between the substrate and the outer wrapper.

A well-established aerosol forming agent can be constituted by an aerosol generating liquid which will nevertheless be contained in a way preventing leakage as indicated above.

The general idea underlying the invention of increasing the amount of visible vapor is particularly reflected in the preferred measure of the content of aerosol forming agent in the foam of the reservoir being higher than the content of aerosol forming agent in the tobacco-based substrate.

Preferably, the foam-forming agent is selected from the group consisting of:

• • hydrocolloid selected from the group of agar, gellan gum,
  • an emulsifier selected from the group of lecithin, polyglycerol esters of fatty acids, glycerol esters of fatty acids, sorbitan esters of fatty acids,
  • and mixtures thereof. Preferably the foam-forming agent comprises or consists of gellan gum.

The amount of foam forming agent is preferably comprised between 1 and 15 wt. % in dry basis of the aerosol generating reservoir, more preferably between 2 and 10 wt. % in dry basis, most preferably between 3 and 8 wt. % in dry basis of the aerosol generating reservoir.

Also, preferably, the foam-stabilizing agent is selected from the group consisting of cellulose gum, hydroxyalkylated carbohydrates, derivatives thereof, and mixtures thereof, and/or the foam stabilizing agent comprises cellulose gum, in particular carboxymethylcellulose (CMC) or derivatives thereof and/or cellulose fibre.

The amount of foam-stabilizing agent is preferably comprised between 8 and 30 wt. % in dry basis of the aerosol generating reservoir, preferably between 10 and 28 wt. % in dry basis, most preferably between 15 and 25 wt. % in dry basis of the aerosol generating reservoir. In an example, the foam-stabilizing agent comprises between 8 and 12 wt. % in dry basis of cellulose fibre and between 8-12 wt. % in dry basis of carboxymethylcellulose in the aerosol generating reservoir. In another example, the foam-stabilizing agent comprises between 15 and 18 wt. % carboxymethylcellulose in the aerosol generating reservoir.

With all of the above-mentioned substances, superior results with regard to forming and stabilizing the foam will be obtained.

The foams include a porous structure which is open-pored, particularly wherein the structure is essentially formed from the foam forming agent and the foam stabilizing agent.

This also applies with regard to the forming of a sufficient amount of visible vapor, when the aerosol forming agent is present in an amount of at least 50 wt. %, preferably at least 60 wt. %, most preferred 70-85 wt. % of the total weight in dry basis of the aerosol reservoir.

Preferably, the aerosol forming agent comprises glycol derivatives, such as propylene glycol, or glycerin or glycerol or sebacate esters or a combination thereof and preferably comprises glycerol, and/or the aerosol forming agent comprises at least 30 wt. % glycerin, preferably at least 50 wt. % glycerin and most preferred about 63 wt. glycerin of the total weight in dry basis of aerosol forming agent. With these substances, in the described amount, a particularly good formation of visible vapor will be obtained.

The aerosol generating article described herein contains the above-described section wrapped in a wrapper. The article can further comprise a mouthpiece downstream of the tobacco-based aerosol generating substrate, which can also be contained in the wrapper. Further, the mouthpiece can comprise a filter and a spacing and/or cooling element provided between the aerosol generating section and the filter. The wrapper can for example be made from a cigarette paper and can be metallized or not. In either case, it can be designed to avoid scorching of the foam.

As regards the filter provided in the mouthpiece, this can be adapted to provide a relatively low, in any case, acceptable pressure drop, so that flavouring intensity and nicotine yield remain optimal. Additionally, the presence of the spacing and/or cooling element will, firstly, cool the generated aerosol, so that aerosol having an uncomfortably high temperature is prevented from entering the user's mouth. Moreover, by means of the spacing element the article according to the present invention can be provided with a size adapted to well-established aerosol generating devices, with which the article can be used. Due to the fact that the article described herein can be used with present aerosol generating devices, the users have the advantage that a single device is sufficient and only one device has to be maintained.

The spacing may comprise a hollow tubular member which may be formed of paper. As well, the cooling element may comprise a hollow tubular member which may be formed of paper. As regards the length of the hollow tubular member, 10 to 25 mm and preferably 18 to 22 mm are currently preferred. A further tubular member with an inner diameter smaller than the spacing and/or cooling member (i.e., a “center hole” segment) may be positioned between the cooling tubular member and the filter segment such as described in EP3881699A1.

In an example, the mouthpiece includes in the downstream direction the cooling element, a center hole segment and a filter segment. The center hole segment can be a segment positioned between the spacing and the filter segment. Since it is close to the mouth end, it can insulate the surface from the vapor.

The mouthpiece and the aerosol generation section are preferably individually wrapped by a wrapper and assembled by assembling wrapper, i.e., tipping paper.

A ventilation zone may be provided in the mouthpiece, preferably through the spacing and/or cooling element. The ventilation zone may be formed by a plurality of perforations provided through the wrapper and the hollow tubular member and/or through the wrapper and the center hole segment.

Whereas the aerosol generating substrate can have any appropriate extension, it will keep the article described herein compact, when the aerosol generating substrate extends from the upstream end towards the downstream end of the article. A preferred total length of the article is also between 50 mm and 70 mm, more preferably between 55 mm and 65 mm, even more preferably 58 mm to 62 mm; wherein a length of the aerosol generating section is preferably about 15 mm to 25 mm and a length of the mouthpiece is preferably about 30 and 45 mm.

A front plug may be added upstream of the tobacco-based aerosol generating substrate. The front plug may for instance act to prevent falling of tobacco substrate from the tobacco-based substrate and/or maintain the tobacco-based substrate compressed. The front plug may be a plain segment or hollow tubular segment made of fibrous material such as cellulose acetate or paper sheet or nonwoven.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter, the invention will be described with reference to non-limiting examples thereof, and with reference to the drawings, in which

FIGS. 1 to 7 show various embodiments of the aerosol generating article, and

FIG. 8 shows the effect obtained by the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

As can be taken from FIG. 1, the aerosol generating article 10 described herein is essentially rod or cylinder shaped, in which approximately a third to half of the length corresponds to an aerosol generating section which is heated by a heating zone demarcated by an external heater of the aerosol generating device indicated by 12. The aerosol generating section comprises a tobacco-based substrate 14 and an additional aerosol generating reservoir 16. Both are thus located in use in the heating zone 12. The aerosol generating article further comprises in the downstream direction of the aerosol flow path, a cooling tubular member 22 and a filter 24. The cooling tubular member 22 may comprise for instance a paper tube or any other at least partially rigid hollow structure enabling to give enough space and surface to the aerosol to cool down. A further tubular member with an inner diameter (i.e. a “center hole” segment) smaller than the cooling member may be positioned between the cooling tubular member 22 and the filter such as described in EP3881699A1.

The filter 24 may comprise one or several filter segments such as made of cellulose acetate or paper sheet. The filter may comprise a flavour release filter, e.g., a breakable capsule filter.

In the embodiment of FIG. 1, the tobacco-based substrate 14 is essentially divided into halves by the aerosol generating reservoir 16, in this case having the shape of a disc being located between the two halves. In other words, the aerosol generating reservoir has in this case a longitudinal extension, in other words an extension along the axis of the cylinder, which is significantly smaller, for example, only about 10 to 20% of one half of the tobacco-based substrate.

In an example, the article has a length of 40 to 80 mm, preferably 60 mm with a tobacco-based substrate having a length of 11 to 17 mm, preferably 14 mm, an aerosol generating reservoir of 4 to 8 mm, preferably 6 mm and a hollow tubular member comprising a paper tube of 15 to 25 mm, preferably 20 mm.

These dimensions essentially correspond to those shown for the embodiment of FIG. 2, in which the aerosol generating reservoir 16 is positioned downstream of the tobacco-based substrate 14. In both cases, both the substrate 14 and the reservoir 16 extend throughout the radial dimensions of the article 10 as a whole, the outside of which is essentially defined by the wrapper.

The described dimensions also apply to the embodiments of FIGS. 3 and 4, in which the embodiment of FIG. 3 has an essentially central hole or longitudinal channel 20. As a further example, the embodiment of FIG. 4 has plural, in the case shown four such longitudinal holes or channels 20. It goes without saying, that the discs of the embodiments of FIGS. 1, 3 and 4 do not have to be located exactly at the center of the tobacco-based substrate 14 in the longitudinal direction, but can be located further up or downstream, with a downstream position being preferred. Alternatively or in addition to the discs shown in FIGS. 1 to 4, the aerosol generating reservoir can also be formed of multiple discrete elements 18 as shown in FIG. 5.

As a further alternative, in the embodiment of FIG. 6, the aerosol generating reservoir 16 is formed as a thin film between the radially inner tobacco-based substrate 14 and the outer wrapper. The film can extend around the entire circumference, but it can also be shorter or longer, so as to overlap. Moreover, the film can have an axial extension corresponding to that of the tobacco-based substrate 14, but it can also be shorter or longer.

As a further alternative, in the embodiment of FIG. 7, the aerosol generating article 10 differs from the aerosol generating article 10 of the embodiment of FIG. 1 by a front plug 26. The front plug 26 is arranged so that the aerosol generating section is axially between the front plug 26 and the cooling tubular member 22. In other words, the front plug 26 is provided upstream of the tobacco-based aerosol generating substrate 14.

The front plug 26 may be plain or hollow. The front plug 26 may be made of fibrous material. In such case, the fibrous material may include at least one of cellulose acetate, paper sheet or nonwoven.

As well as in the embodiment of FIGS. 3 and 4, the aerosol generating article 10 of the embodiment of FIG. 7 may include an essentially central hole or longitudinal channel. Also, it may be contemplated that the aerosol generating article 10 of the embodiment of FIG. 7 includes an aerosol generating reservoir formed of multiple discrete elements or formed as a thin film as in the embodiment of FIGS. 5 and 6.

FIG. 8 essentially summarizes the effect obtained by the invention, which is a quick and extensive vapor generation as compared to current products.

Examples of recipes for the aerosol generating reservoir, i.e., (e-) mousse or foam are:

The e-mousse could comprise flavouring agents such as for example ethyl vanillin, menthol, spearmint oil, berry, fruit, root or plant extract or oil.

The e-mousse could comprise a pH adjusting agent e.g. chosen from one or more of sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, etc., and mixtures thereof.

Homogenized tobacco material in the context of the present disclosure denotes a material formed of agglomerated particulate tobacco (e.g. tobacco powder), aerosol forming agent, and optionally extrinsic binder (other than tobacco intrinsic binder).

The homogenized tobacco material may have any one more of the following characteristics:

• • Tobacco particle size D90: between about 20-1000 microns, preferably between 30 and 300 microns. D90 represents the maximum particle diameter below which 90% of the sample volume exists. It is measured using Malvern Mastersizer 3000 laser diffraction instrument using dry dispersion method.
  • The material is preferably formed into a sheet from a slurry by paper making process or cast sheet or slurry or dough by extrusion/lamination process.
  • The sheet can be inserted in a gathered form or cut or broken down into strands, shreds, strips, fragments, etc. The sheet can eventually be crimped.
    • Laminated sheet examples can be taken from: WO2021144676A1, WO2021144043A1, WO2020058814
    • Paper making sheet examples are shown in WO2017051034.
    • Cast sheet examples are given in: WO2016050471A1, WO2016050470A1, WO2012164009A1
  • Density (or mass-to-surface area ratio) in dry basis of the homogenized tobacco material: 800 to 1450 mg/cm3, preferably 900-1200 mg/cm3.
  • Content of aerosol forming agent in the sheet: 8-25 wt. %, preferably 10-18 wt. % in dry basis of the homogenized tobacco material.

The aerosol-forming agent can be: preferably polyhydric alcohol, which may include glycerin, propylene glycol, sorbitol, xylitol and erythritol. These polyhydric alcohols can be used alone or in combination of two or more.

• • The homogenized tobacco material may contain a binder (e.g. pectin, guar gum, locus bean gums, alginate, starches, CMC, dextran, etc.). The binder may be needed in particular for cast or extruded sheet when starting from a slurry or dough.
  • It is possible to blend different homogenized tobacco materials with tobacco of different origins/varieties (e.g. burley, virginia, oriental, etc.), and/or different making processes (cast, paper, laminated).
  • Possibly, also a blend of homogenized tobacco material with tobacco lamina, cellulose fibre, non-woven fibre, etc. can be provided.

The filling density of the tobacco-based aerosol generating substrate in the wrapper, may be at least 250 mg/cm3, preferably at least 300 mg/cm3 or usually 500 mg/cm3 or less, preferably 400 mg/cm3 or less, more preferably 350 cm3 or less.