Patent ID: 12225932

DETAILED DESCRIPTION

In the context of the present disclosure, an aerosol and a vapour can be considered interchangeable expressions. That is, an aerosol is a vapour and a vapour is an aerosol. An aerosol for smoking may refer to an aerosol with particle sizes of 0.5-7 microns. The particle size may be less than 10 or 7 microns.

FIGS.1A and1Bare perspective views of an aerosol generating device2in an open configuration.FIGS.2A and2Bare perspective views of the aerosol generating device2in a closed configuration. The aerosol generating device2includes a hinged lid4that can be opened for insertion or removal of a cartridge6which contains an aerosol generating substrate such as tobacco. The hinged lid4can be closed in order to grip the cartridge6and secure it in position. With the hinged lid4in its open position, a depleted cartridge6can be removed, and a fresh cartridge6can be fitted in its place.

The aerosol generating device2includes an internal cavity which is shaped and sized to receive the cartridge6. The cartridge6is sized such that it fits within the internal cavity and projects through an opening8in the housing of the aerosol generating device2in order to form a mouthpiece20.

Further details of the cartridge6are apparent fromFIGS.4to6. The cartridge6includes an aerosol generating substrate10that includes tobacco. The aerosol generating substrate10can be solid or semi-solid. Example types of vapour generating solids include powder, granules, pellets, shreds, strands, porous material, foam or sheets.

In a preferred arrangement the aerosol generating substrate10is tobacco foam, which may be a semi-solid mousse. Tobacco foam typically comprises a plurality of fine tobacco particles and can typically also comprise a volume of water and/or a moisture additive, such as a humectant. The tobacco foam may be porous, and may allow a flow of air and/or vapour through the foam.

The aerosol generating substrate10may comprise an aerosol-former. Examples of aerosol-formers include polyhydric alcohols and mixtures thereof such as glycerine or propylene glycol. Typically, the aerosol generating substrate may comprise an aerosol-former content of between approximately 5% and approximately 50% on a dry weight basis. Preferably, the aerosol generating substrate may comprise an aerosol-former content of approximately 15% on a dry weight basis.

The aerosol generating substrate10is a slab of material having a shape which is a substantial cuboid or rectangular prism. The aerosol generating substrate10has two major surfaces12a,b, two edge surfaces14a,b, and front and rear end surfaces16a,b. The aerosol generating substrate10typically has a length of 10 mm to 40 mm, more preferably 10 mm to 20 mm, a width of 10 mm to 50 mm, more preferably 10 mm to 30 mm and a thickness of 0.5 mm to 3.0 mm. The surface area of each major surface is between 100 mm2and 2000 mm2, more preferably from 100 mm2to 1600 mm2, more preferably from 100 mm2to 1000 mm2, and even more preferably from 100 mm2to 600 mm2.

The slab of aerosol generating substrate10is provided within a wrapper18, which may be an air permeable material, and is preferably made of paper having a thickness of between 10 nm and 1000 nm. The wrapper18extends around the two major surfaces12a,band the two edge surfaces14a,b. The wrapper18includes a paper fold at the vertices between the major surfaces12a,band the edge surfaces14a,b, and this paper fold can advantageously improve the overall rigidity of the cartridge6to reduce the risk of bending and to help maintain the major surfaces12a,bin a flat configuration. The front and rear end surfaces16a,bare not covered by the wrapper18so that they can be exposed to an airflow within the aerosol generating device2. The wrapper18can advantageously prevent the aerosol generating substrate10from adhering to a heater30,32within the aerosol generating device2. Glue (or some other adhesive) can be provided between the wrapper18and the aerosol generating substrate10. The wrapper18may not be air permeable in some arrangements, but may have holes or perforations that can allow an air flow.

In one embodiment the wrapper18includes an overlapping portion on one of the edge surfaces14a,b. In this way, the wrapper18can be secured in position by adhering the overlapping portion of the wrapper18to the remainder of the wrapper along one of the edge surface14a,b. Advantageously the overlapping portion is only on one of the edge surfaces14a,band does not extend onto either of the major surfaces12a,b. This ensures that the wrapper18has even thickness along the major surfaces12a,bso that heat can be evenly received by the aerosol generating substrate10through the major surfaces12a,b. The overlapping portion of the wrapper18can also advantageously improve the rigidity of the aerosol generating substrate10, reducing the likelihood of bending.

In another embodiment the wrapper18does not include an overlapping portion. In such a configuration the wrapper18can have two ends which face one another without overlapping. In this way, the wrapper18can have a consistent thickness around the two major surfaces12a,band the two edge surfaces14a,b. This means that the wrapper18presents a substantially equal thickness around the aerosol generating substrate18. In another embodiment the wrapper18may be configured as a continuous sleeve which extends around the aerosol generating substrate10. In other embodiments the wrapper18may be implemented as a cover or film which is provided only on the major surfaces12a,b, or only on one of the major surfaces12a,b.

In yet another configuration, the wrapper18can have two ends which are provided on one of the major surfaces12a,b. The ends can be provided in an overlapping configuration or otherwise. This may improve the integrity of the wrapper18and reduce the risk of the wrapper18unpeeling. This approach may improve the ease of manufacture because it may be simpler to join the two wrapper ends against one of the major surfaces12a,bthan against one of the edge surfaces14a,b, since these edge surfaces may be relatively small.

The cartridge6includes a mouthpiece portion20extending from the front end surface16aof the aerosol generating substrate10. The mouthpiece portion20is formed by the wrapper18extending around a first corrugated paper block22, which helps the mouthpiece portion20maintain the same cross-sectional shape as that of the aerosol generating substrate10. The first corrugated paper block22helps to maintain the shape of the mouthpiece portion20so that it is resistant to crushing when received in a user's mouth. The first corrugated paper block22also helps to maintain the structural rigidity of the thin aerosol generating substrate10within the overall cartridge6to reduce the likelihood of bending. In other embodiments the first corrugated paper block22may be replaced by other kinds of material that similarly permit an airflow from the front end surface16aof the aerosol generating substrate10to the open end of the mouthpiece portion20; for example, the first corrugated paper block22may be replaced by a block of porous filter material or a plurality of struts, each of which can help to maintain the cross-sectional shape of the mouthpiece portion20, and to provide a structure that the wrapper18can bear against while it is wrapped around the aerosol generating substrate10. The mouthpiece portion20has a length of approximately 10 mm to 25 mm, more preferably 10 mm to 20 mm, from the front end surface16aof the aerosol generating substrate10to the open end of the cartridge6. The mouthpiece portion20can separate the user's mouth from the slab of aerosol generating substrate10, and this can permit some cooling of the generated aerosol in the mouthpiece portion20before it is received in the user's mouth. It has been found that this cooling effect can improve the user experience.

The cartridge6also includes an air inlet portion24extending from the rear end surface16bof the aerosol generating substrate10. The air inlet portion24is formed by the wrapper18extending around a second corrugated paper block26which helps the air inlet portion24maintain the same cross-sectional shape as that of the aerosol generating substrate10. In a similar way, as described above in relation to the first corrugated paper block22, the second corrugated paper block26can help to maintain the structural rigidity of the thin aerosol generating substrate10within the overall cartridge6to reduce the likelihood of bending. The second corrugated paper block26could also be replaced by another material that permits an air flow. In use, an air flow can be carried into the cartridge6through the air inlet portion24. The air inlet portion24has a length of approximately 5 mm to 10 mm, from the rear end surface16bof the aerosol generating substrate10to the open rear end of the cartridge6.

FIG.7Ais a top view of a plurality of cartridges6produced in a single line in an embodiment of the invention.FIG.7Bshows the plurality of cartridges6ofFIG.7Aafter they have been separated. The cartridges6are produced by providing a plurality of slabs of aerosol generating substrate10in a line, separated from one another with corrugated paper blocks25. The slabs of aerosol generating substrate10and corrugated paper blocks25are wrapped in the wrapper18in one long, thin line. The cartridges6are separated from one another by cutting. This may be achieved, for example, using a mechanical cutting device or an optical cutting device such as a laser. The cutting is performed at a position in the corrugated paper blocks25, thereby to form individual cartridges6having a mouthpiece portion20with a first corrugated paper block22and an air inlet portion24with a second corrugated paper block26. The present design means that the accuracy required in the position of the cutting line in the corrugated paper block25is not particularly high; for example, an accuracy may be provided of ±2 mm. This is possible because the cartridge6has a first corrugated paper block22and a second corrugated paper block26.

This design is preferable because it avoids the need to position a cutting line close to the front or rear end surfaces16a,bof the slab of aerosol generating material10, since this would require high accuracy, which would add to manufacturing cost and increase the amount of time required in the manufacturing process.

FIG.8is a schematic cross-sectional side view of the aerosol generating device2, in an embodiment of the invention, with the cartridge6installed within. As can be appreciated, the mouthpiece portion20of the cartridge6extends through the hole8in the housing of the aerosol generating device2to be received by a user's mouth. In this embodiment the aerosol generating device2includes a first heater30and a second heater32. The first heater30has a surface area which is between 100 mm2and 2000 mm2, which is approximately equal to the surface area of the bottom major surface12bof the slab of aerosol generating material10. The second heater32has the same surface area, which is between 100 mm2and 2000 mm2, and is positioned adjacent the top major surface12aof the slab of aerosol generating material10. The aerosol generating device2includes a battery and printed circuit board (PCB)34which includes control electronics. In use, a user can activate the first and second heaters30,32in a conventional way, for example using an activation button (not shown) or using an airflow sensor (not shown). The first and second heaters30,32electrically activated using electrical energy supplied by the battery34and the heat generated by the first and second heaters30,32is supplied to the aerosol generating substrate10by conduction, convection, radiation or some combination of these. The aerosol generating substrate10is thereby heated and this causes generation of an aerosol which can be inhaled by a user via the mouthpiece portion20. The aerosol generating device2includes air inlet holes36. When a user inhales through the mouthpiece portion20air can be drawn into the air inlet hole36and through or past the aerosol generating substrate10. In this way, generated aerosol can be entrained in the airflow that is received in the user's mouth.

FIG.9is a schematic cross-sectional side view of the aerosol generating device2with a cartridge6installed in another embodiment of the invention. In this arrangement only the first heater30is present. Heat can therefore be supplied to the aerosol generating substrate10from one major surface12a,bonly.

FIGS.10to13are perspective views of cartridges6in a number of embodiments showing different designs that can facilitate an airflow from one end of the cartridge6to the other, through or past the slab of aerosol generating substrate10. The perspective views inFIGS.10to13include a cut-away portion so that internal features of the cartridges6are visible, beneath the wrapper18. InFIG.10the slab of aerosol generating substrate10includes longitudinal channels40on one of the major surfaces12a,b, extending from the rear end face16bto the front end face16a. InFIG.11the slab of aerosol generating substrate10includes a longitudinal channel42in one or both of its edge surfaces14a,b, extending from the rear end face16bto the front end face16a. InFIG.12the slab of aerosol generating substrate10includes a cross-hatch pattern of channels44in at least one of its major surfaces12a,b, to provide an airflow path from the rear end face16bto the front end face16a. The channels40,42,44provide an airflow path between the aerosol generating substrate10and the wrapper18from the rear end face16bto the front end face16aof the aerosol generating substrate10. In other words, the channels40,42,44are internal to the wrapper18. In this way, aerosol that is generated by the aerosol generating substrate10can be entrained in the airflow that extends in the channels40,42,44so that the aerosol can be gathered efficiently and delivered to a user. Any combination of these kinds of channels40,42,44may be provided to achieve a similar effect.

InFIG.13the slab of aerosol generating substrate10includes a plurality of through-holes46which extend from one major surface12ato the other major surface12b. These through-holes46facilitate an internal airflow in the slab of aerosol generating substrate10that can be effective in improving delivery of aerosol to the user. In other embodiments through-holes may be provided between the front and rear end faces16a,bor the edge surfaces14a,b. The through-holes46may be provided together with the channels40,42,44disclosed above in any combination.

FIG.14is a cross-sectional end view of the aerosol generating device2shown inFIG.9including a cartridge6in an alternative embodiment. In this arrangement a number of grooves48are provided on the outer surface of the wrapper18on one of the major surfaces12a,b. This may be achieved by providing a wrapper18having different thicknesses across the major surface12a,b. For example, the wrapper18may have ridges, indentations, grooves or other surface features. This arrangement can create an airflow path between the first heater30and the wrapper18, extending from the rear end face16bto the front end face16aof the aerosol generating substrate10. This provides another technique for gathering generated aerosol in an airflow and delivering it to a user.

FIG.15is a cross-sectional end view of the aerosol generating device2shown inFIG.9including a cartridge6in a further alternative embodiment. In this arrangement a number of grooves50are provided on the inner surface of the wrapper18on the major surfaces12a,b. This may be achieved by providing a wrapper18having an internal surface profile on the major surfaces12a,bincluding ridges, indentations, grooves or other surface features. This arrangement can create an airflow path between the aerosol generating substrate10and the wrapper18, extending from the rear end face16bto the front end face16a. This provides a further technique for gathering generated aerosol in an airflow and delivering it to a user.

The present techniques provide a cartridge6which is thin, having a thickness of 0.5 mm to 3.0 mm. The surface area of the major surface12a,bof the aerosol generating substrate10within the cartridge6is between 100 mm2and 2000 mm2. This arrangement provides an aerosol generating substrate10with a small total volume and major surface area which is large, relative to the total volume. In other words, the ratio of major surface area to volume is high. In use, heat can be applied through at least one of the major surfaces12a,b. Heat can be applied across a large surface area, and this can allow the relatively small volume to be heated rapidly, allowing the aerosol generating substrate10to produce a vapour with minimal delay. In some arrangements it has been found that a vapour can be produced within around 10 seconds from the time at which heat is first applied.