Patent ID: 12257383

DETAILED DESCRIPTION

As used herein, the term “aerosol generating agent” includes agents that provide volatilized components upon heating. “Aerosol generating agent” includes any tobacco-containing material and may, for example, include one or more of tobacco, tobacco derivatives including tobacco extracts, expanded tobacco, reconstituted tobacco or tobacco substitutes. “Aerosol generating agent” may also include other, non-tobacco, products, including for example flavorants, which, depending on the product, may or may not contain nicotine, filler materials such as chalk and/or sorbent materials, glycerol, propylene glycol or triacetin. The aerosol generating agent may also include a binding material, for example, sodium alginate. The aerosol generating agent may include tobacco particles or leaves in solid form within the agent. In one example the aerosol generating agent is an aerosol forming gel. The aerosol generating gel may be a solid, jelly like material. The aerosol generating gel may be a newtonian or non-newtonian gel. In one example the gel is a thermoplastic gel. In one example, the aerosol generating gel has a viscosity of between 0.1 and 100 Ns/m2.

Referring toFIGS.1to2, there is shown an article100for use with an apparatus for heating aerosol generating agent to volatilize at least one component of the aerosol generating agent. The article100includes a support layer102and a layer of aerosol generating agent104. The aerosol generating agent104is located on a first surface106of the support layer102. The aerosol generating agent104forms a layer of material on the support layer102as shown inFIGS.1and2, for example the layer of aerosol generating agent104is bonded to the support layer102.

In the examples of the articles100shown inFIGS.1to6, the support layer102has a substantially smooth first surface106on which the aerosol generating agent104is located. An example of a support layer102which has a smooth surface is aluminum foil.

The article100is designed to be used with an apparatus for heating aerosol generating agent to volatilize at least one component of the aerosol generating agent, such as a so-called tobacco heating product, which includes a heater. An example of a heating apparatus is shown inFIG.3. In one example, the apparatus50comprises a substantially flat heating surface52upon which, in use, the article100is placed such that the support layer102lies on the heating surface. In other examples, the heater may take the form of a cylindrical heater or a blade heater. In other example, the apparatus may comprise a heater to heat air which will subsequently pass over the surface of the aerosol generating agent to heat it. The heater may comprise a resistive heater, in another example, the heater may be an inductive heater and the article may be placed on a susceptor within the apparatus. In the example of the induction heating, the support layer102may be formed of a magnetic material and act as an additional susceptor so that an eddy current is generated when the support layer102is subjected to a varying magnetic field. The apparatus50is configured to heat the article100to volatilize at least one component of the aerosol generating agent. In the example ofFIG.3, the apparatus50includes a mouthpiece54through which the volatilized components may flow. However, in other examples, the apparatus does not include the mouthpiece54.

In the example of the aerosol forming agent104comprising an aerosol forming gel, the aerosol forming gel104may be formed by mixing a concentrated tobacco extract with water in a high shear mixer with a binding agent, such as sodium alginate, to form a paste or slurry. An aerosol generating material, such as glycerol, is added and the paste is wet cast on as a thin film on a support layer102, such as aluminum or paper. The thin film is then dried by applying heat to remove excess water from the film. In the drying phase, the articles100may be subject to a temperature of approximately 60 to 100 degrees Celsius for approximately 20 minutes to 5 hours. Depending on the chemicals used in the formulation of the thin films, the thin films exhibit a sticky surface that makes handling them in a commercial environment problematic. The thin films may also exhibit poor adhesion to the support layer102on which they have been cast, which may lead to problems during the drying phase and also when the article100is heated in use in the aerosol generating apparatus, which will be described in more detail below.

In one example, the aerosol forming agent104has a thickness of between 100 μm and 350 μm.

It has been observed that upon heating of the article, the aerosol generating agent104tends to become delaminated from the support layer102. In addition, when the article100is placed on a heating surface52of the apparatus, the support layer102tends to curl, which results in a separation between the support layer102and the heating surface52. The consequence of both of these examples is poor heat transfer from the heating surface52to the aerosol generating agent104, which results in a poor aerosol delivery.

A first mechanism for delamination between the aerosol generating agent104and the support layer102is shown inFIGS.4A and4B.FIG.4Ashows an example of the article100during heating. The heating process causes water and or other components within the aerosol generating agent104to evaporate causing the agent to contract as shown by the arrows inFIG.3A. The support layer102may be formed from a solid material, such as aluminum or paper and thus would not contract upon heating. As there is some adhesion between the aerosol generating material104and the support layer102, the differential contraction between the aerosol generating agent layer104and the support layer102causes the article100to curl as shown inFIG.3A. The self-weight of the support layer102causes the support layer102to resist the contraction of the aerosol generating agent104. As the aerosol generating agent104continues to contract, the central part of the aerosol generating agent104may separate from the support layer102resulting in delamination of the aerosol generating agent104and the support layer102. The degree of curling versus delamination depends on the level of adhesion between the aerosol generating agent104and the support layer102, the stiffness of the support layer102and the stiffness of the aerosol forming agent104.

A second mechanism for delamination between the aerosol generating agent104and the support layer102is shown inFIG.5.FIG.5shows an example of the article100during heating. The heating process causes water and or other components within the aerosol generating agent104to evaporate. If the support layer102is placed on a heating surface52of an apparatus, then the surface of the aerosol generating agent104that is proximate to the first surface106of the support layer102(and hence the heating surface) will be heated faster compared with the surface of the aerosol forming agent104that is further from the heating surface52. As a result, the surface of the aerosol generating agent104that is proximate to the first surface106of the support layer102will lose more water compared with the surface of the aerosol forming agent that is further from the heating surface and therefore will contract more as shown inFIG.5.

A third mechanism for delamination between the aerosol generating agent104and the support layer102is shown inFIG.6. As the aerosol generating agent104is heated, at least one component of the aerosol generating agent104is volatilized. If there is not a flow path between the volatilized component and the outer surface of the aerosol generating agent104, then a build-up of volatilized components will act to separate the aerosol generating agent104from the support layer102. There may also be air bubbles that get trapped in the aerosol generating agent104during the drying process that will expand upon heating and act to cause a delamination between the aerosol generating agent104and the support layer102.

There is a need to improve heat transfer between a heater of the apparatus50and the article100, which will improve the generation of volatilized components. Surprisingly, it was found that improving the adhesion sufficiently improves heat transfer for aerosol generating agents and results in a more efficient aerosol generating. One way of improving heat transfer is to improve adhesion between the aerosol generating agent104and the support layer102to reduce the delamination between the aerosol generating agent104and the support layer102. One option for improving the adhesion between the aerosol generating agent104and the support layer102would be through the use of chemical additives to the aerosol generating agent104and the support layer102. Powdered additives may be used to reduce the stickiness of the aerosol generating agent104to improve the handling of the agent. However, the use of additives has a number of drawbacks because components from the additives may be volatilized upon heating and be inhaled by a user, which may be undesirable. Further, the use of additives will increase the costs of creating the article100.

FIGS.7A and7Bshow an example of a support layer202in the form of a substrate having a first surface206, wherein at least a portion of the first surface206is rough to provide an uneven or irregular surface. The first surface206is sufficiently rough to prevent or inhibit the delamination of the aerosol generating agent204from the first surface206of the support layer202.

In one example, the first surface206is made rough by making a number of holes in the support layer202. The holes may be made by penetrating the first surface206with a pin or series of pins.

The support layer202may be formed of any material suitable for receiving and holding the aerosol generating agent204. In one example, the support layer202is formed from a heat conducting material, for example a metal such as aluminum. The support layer202may be, for example a metal foil such as aluminum foil.

In the example of the support layer202being formed of aluminum, the aluminum can have a thickness of between 5 μm to 25 μm. The aluminum thickness may be 7 μm, 10 μm or 20 μm, such as 6 μm to 8 μm.

In other examples, the support layer202is formed from a paper material, such as tipping paper, porous plug wrap, cigarette paper or tea bag paper. The paper may be a porous paper. When an aerosol generating gel is used as the aerosol generating agent, the gel may flow into the pores of the porous paper to improve adhesion. In the example of the support layer being formed from a paper material, the paper can have a weight of between 20 gsm and 100 gsm.

The aerosol forming agent204(not shown) will be located on the first surface206of the support layer202. In the example shown inFIGS.7A and7B, the first surface206is rough due to the fact that there is a plurality of protuberances208. Protuberances208are elements that protrude from the first surface206of the support layer202. In the example shown inFIGS.7A and7B, the protuberances take the form of cylinders, however, any shape that projects from the first surface206of the support layer202may be used, such as cubes, pyramids and irregular shapes. It is not necessary for the protuberances208to be formed of the same shape. The protuberance208inFIGS.7A and7Bare shown as covering most of the first surface206of the support layer202, but in other example, the protuberances208only cover part of the first surface206of the support layer202. In one example protuberances208may be formed by adding additional material or removing some material from the first surface206of the support later.

In one example the protuberances have a height of between 0.1 mm and 0.2 mm and a width of between 0.2 mm and 0.4 mm, such as a height of 0.15 mm and a width of 0.3 mm.

In one example, the first surface206of the support layer202is embossed to create the surface roughness. The support layer202may be embossed by stamping the support layer202with a mould to cause the first surface206of support layer202to have a three-dimensional or raised effect on selected areas. In some examples, the embossing procedure requires the use of two dies: one that is raised and one that is recessed. The dies fit into each other so that when the support layer202is pressed between them, the raised die forces the support layer202into the recessed die and creates the embossed surface.

The protuberances208may also be formed by embossing. Embossing the first surface206of the support layer202is a simple and repeatable way of creating a rough surface. The first surface202may be made rough by including one or more ridges, folds, indents, raised sections, holes.

The first surface206may be embossed using various patterns, such as one or more of spirals, lines; squares; circles; and/or rectangles.

The rough first surface206of the support layer202, as shown inFIGS.7A and7B, acts to increase the contact surface area between the aerosol generating agent204and the support layer202. An example of article200formed from the support layer202with a rough first surface206and aerosol generating agent204is shown inFIG.7C. The increased surface area will increase the adhesion between the aerosol forming agent204and the support layer202, and hence reduce the effects of the first two separation mechanisms described above. In relation to the first mechanism, the increased adhesion means that as the aerosol generating agent204contracts, it will be less likely to separate from the support layer202. In relation to the second mechanism, the aerosol forming agent204is less likely to separate from the inner surface of the heat conducting layer because it will have a stronger adhesion to the inner surface. As the adhesion is increased, the aerosol forming agent204is less likely to delaminate from the support layer202and therefore when the article200is heated by a heating apparatus, more aerosol generating agent204will be heated.

The article200may be manufacturing by providing a support layer202having a first surface206, wherein at least a portion of the first surface206is rough; and providing an aerosol generating agent204on the portion of the first surface206that is rough. As described above, the first surface206may be made rough by one or more of embossing the first surface206, providing protuberances208, or other means of roughening the surface.

In the further example shown inFIG.8, the first surface306of the support layer302is made rough by having one or more score lines310formed in the first surface306. The score lines may be formed by known processes such as running a cutting element over the first surface306of the support layer306to provide one or more cuts or indents in the first surface306of the support layer302.

FIG.8shows the support layer302with six score lines310applied to the first surface306, however, in some examples there are fewer score lines and in other examples there are more than six score lines310applied to the first surface306. As with the protuberances208shown inFIG.7B, score lines310perform the function of adding a surface roughness to the first surface of the support layer310, which increases the adhesion between the aerosol generating agent304and the support layer302. In one example, the surface roughness of the first surface306of the support layer302is provided by the score lines310. In other examples, the surface roughness of the first surface306of the support layer is provided by a combination of one or more of the protuberances208, embossment and the score lines310.

As shown inFIG.9, the score lines310may also be applied to the aerosol generating agent304. Applying score lines310to the aerosol generating agent304results in the aerosol generating agent304being pooled into one or more separate sections delineated by the score lines310. Separating the aerosol generating agent304into separate sections provides more flow paths for any volatilized components and the outer surface of the aerosol generating agent304. Therefore, the third mechanism of delamination between the aerosol generating agent304and the support layer302described above is less likely to occur. Further, separating the aerosol generating agent304into one or more separate sections helps reduce the curling effect described above.

Aerosol generating agents104,204,304may be formed from different tobacco extracts, such as Burley, Virgina and Oriental. Aerosol generating agents204,304formed from different tobacco extracts may have different properties, for example, agents formed from Burley tobacco is more brittle, whereas agents formed from Virginia and Oriental is more pliable. Providing a first surface306of a support later302, where at least a portion of the first surface is rough provides the best results when an aerosol generating agent304formed from an oriental tobacco is used.

T-Peel tests were carried out on a selection of samples. A T-Peel test involves testing the peel strength between the aerosol generating agent304and the support layer302. Result of the T-Peel Test are shown below:

LayerAgentSupport LayertypeThicknessUnembossedEmbossedBurley20 μm4.5 +/− 0.8N/mm6.4 +/− 0.6N/mmOriental10 μm2.3 +/− 0.3N/mm3.9 +/− 0.8N/mm

In a yet further example, the support layer402may be formed from paper, such as tipping paper, porous plug wrap, cigarette paper or tea bag paper. As paper is a fibrous substrate, the surface of the paper will be irregular. When an aerosol generating agent is applied to the surface of the paper, the aerosol generating agent will contact the irregular surface and will adhere to a first surface of the paper substrate. The inventors found that surprisingly, the aerosol generating agent404did not weaken the thin paper support and upon casting, the paper retained its integrity and after drying, the thin film adhered strongly to the paper substrate. This makes an article400that uses a paper substrate as the support layer an ideal system for use in a heating apparatus because the paper is thin enough not to act as a significant “insulation layer” so heat transfer is acceptable.

In one example, the apparatus for heating aerosol generating agent to volatilize at least one component of the aerosol generating agent may be sold in a kit, together with the article according to any of the examples described above.

The examples above show an aerosol generating agent on a first surface of a support layer, however, in other examples the support layer may include a first surface and a second surface, wherein at least a portion of the first surface is rough; and at least a portion of the second surface is rough. The second surface may be arranged on the opposite side of the support layer to the first surface. An aerosol generating agent is applied to the portion of the first surface that is rough and to the portion of the second surface that is rough. This arrangement enables more aerosol generating agent to be held by the support layer. Alternatively, the article may comprise a second support layer, such that the aerosol generating agent is located in between the first and second support layers. As with the first support layer the second support layer may comprise a first and/or second surface that are rough.

FIG.10shows an example of an article according to any of the example above, wherein the article500is in the form of a cartridge that can be inserted into the apparatus50for heating aerosol generating agent to volatilize at least one component of the aerosol generating agent. The article500includes a support layer having a first surface (not shown) wherein at least a portion of the first surface is rough. An aerosol generating agent is be applied to the portion of the first surface that is rough.

The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only, and are not exhaustive and/or exclusive. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects described herein are not to be considered limitations on the scope of the invention as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilized and modifications may be made without departing from the scope of the claimed invention. Various embodiments of the invention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc, other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future.