AEROSOL-GENERATING ARTICLE WITH COMBUSTION PREVENTING WRAPPER

Abstract

An aerosol-generating article is provided for producing an inhalable aerosol upon heating, the article including: a rod of aerosol-generating substrate extending from a rod proximal end to a rod distal end upstream from the proximal end, the substrate an aerosol-former, an aerosol former content of the substrate being at least 10 percent on a dry weight basis; a downstream section located downstream of the rod; and a wrapper circumscribing the rod, the wrapper including a wrapping base material having a dry basis weight, in which a treated portion of the wrapper extending between the proximal and distal ends includes a flame retardant composition including flame retardant compounds, such that the treated portion has an overall dry basis weight greater than that of the wrapping base material, and in which the treated portion includes at least about 2 g/m.sup.2 of the flame retardant compounds of surface area of the treated portion.

Claims

1-18. (canceled)

19. An aerosol-generating article for producing an inhalable aerosol upon heating, the aerosol-generating article comprising: a rod of aerosol-generating substrate extending from a rod proximal end to a rod distal end upstream from the rod proximal end, wherein the aerosol-generating substrate comprises at least an aerosol-former, an aerosol former content of the aerosol-generating substrate being at least 10 percent on a dry weight basis; a downstream section at a location downstream of the rod of aerosol-generating substrate; and a wrapper circumscribing at least the rod of aerosol-generating substrate, the wrapper comprising a wrapping base material having a dry basis weight, wherein at least a treated portion of the wrapper extending between the rod proximal end and the rod distal end comprises a flame retardant composition comprising one or more flame retardant compounds, such that the treated portion of the wrapper has an overall dry basis weight greater than a dry basis weight of the wrapping base material, and wherein the treated portion comprises at least about 2 grams of the one or more flame retardant compounds per square meter of surface area of the treated portion.

20. The aerosol-generating article according to claim 19, wherein the treated portion further comprises at least about 3 grams of the one or more flame retardant compounds per square meter of surface area of the treated portion.

21. The aerosol-generating article according to claim 19, wherein the treated portion further comprises less than or equal to about 12 grams of the one or more flame retardant compounds per square meter of surface area of the treated portion.

22. The aerosol-generating article according to claim 19, wherein the dry basis weight of the wrapping base material is at least about 20 grams per square meter.

23. The aerosol-generating article according to claim 19, wherein the dry basis weight of the wrapping base material is less than or equal to about 40 grams per square meter.

24. The aerosol-generating article according to claim 19, wherein the treated portion extends over at least about 90 percent of an outer surface area of the rod of aerosol-generating substrate.

25. The aerosol-generating article according to claim 19, wherein a length of the treated portion is at least about 90 percent of a length of the rod of aerosol-generating substrate.

26. The aerosol-generating article according to claim 19, wherein the wrapper further comprises a layer comprising the flame retardant composition provided on a surface of the wrapping base material facing the aerosol-generating substrate, a surface of the wrapping base material facing away from the aerosol-generating substrate, or both.

27. The aerosol-generating article according to claim 19, wherein the flame retardant composition further comprises a polymer and a mixed salt based on at least one mono, di- and/or tri-carboxylic acid, at least one polyphosphoric, pyrophosphoric, and/or phosphoric acid, and a hydroxide or a salt of an alkali or an alkaline earth metal, where the at least one mono, di- and/or tri-carboxylic acid and the hydroxide or salt form a carboxylate and the at least one polyphosphoric, pyrophosphoric, and/or phosphoric acid and the hydroxide or salt form a phosphate.

28. The aerosol-generating article according to claim 27, wherein the flame retardant composition further comprises a carbonate of an alkali or an alkaline earth metal.

29. The aerosol-generating article according to claim 19, wherein the flame retardant composition further comprises cellulose modified with at least one C.sub.10 or higher fatty acid, tall oil fatty acid (TOFA), phosphorylated linseed oil, phosphorylated downstream corn oil.

30. The aerosol-generating article according to claim 19, wherein the wrapper does not comprise metal.

31. The aerosol-generating article according to claim 19, wherein the rod of aerosol-generating substrate has a length of less than about 40 millimeters.

32. The aerosol-generating article according to claim 19, wherein the rod of aerosol-generating substrate comprises a gathered sheet of homogenised tobacco material or a gel composition, the gel composition comprising at least one gelling agent, at least one of an alkaloid compound and a cannabinoid compound, and an aerosol former.

33. The aerosol-generating article according to claim 19, wherein the rod of aerosol-generating substrate further comprises a susceptor element arranged within the aerosol-generating substrate.

34. A method of manufacturing an aerosol-generating article for generating an inhalable aerosol upon heating, the method comprising: providing a continuous rod of aerosol-generating substrate, an aerosol former content of the aerosol-generating substrate being at least 10 percent on a dry weight basis; circumscribing the continuous rod of aerosol-generating substrate with a wrapper, the wrapper comprising a wrapping base material having a dry basis weight; treating at least a portion of the wrapper with a flame retardant composition comprising one or more flame retardant compounds, so as to provide a treated portion of the wrapper having an overall dry basis weight greater than the dry basis weight of the wrapping base material; and cutting the treated wrapped continuous rod of aerosol-generating substrate into discrete rods, each discrete rod extending from a discrete rod proximal end to a discrete rod distal end upstream from the discrete rod proximal end, such that in each discrete rod a treated portion of the wrapper comprises at least about 2 grams of the one or more flame retardant compounds per square meter of surface area of the treated portion.

35. The method according to claim 34, wherein a layer of the flame retardant composition is applied onto at least one side of the wrapping base material by an application process based on size pressing, spraying, printing, or coating.

36. An aerosol-generating system comprising an electrically operated aerosol-generating device and an aerosol-generating article according to claim 19, the electrically operated aerosol-generating device comprising means for heating the rod of aerosol-generating substrate to a temperature sufficient to generate an aerosol from the aerosol-generating substrate.

Description

[0313] In the following, the invention will be further described with reference to the drawings of the accompanying Figures, wherein:

[0314] FIG. 1 shows a schematic side sectional view of an aerosol-generating article in accordance with an embodiment of the invention; and

[0315] FIG. 2 shows a schematic side sectional view of another aerosol-generating article in accordance with another embodiment of the invention.

[0316] The aerosol-generating article 10 shown in FIG. 1 comprises a rod 12 of aerosol-generating substrate 12 and a downstream section 14 at a location downstream of the rod 12 of aerosol-generating substrate. Further, the aerosol-generating article 10 comprises an upstream section 16 at a location upstream of the rod 12 of aerosol-generating substrate. Thus, the aerosol-generating article 10 extends from an upstream or distal end 18 to a downstream or mouth end 20.

[0317] The aerosol-generating article has an overall length of about 45 millimetres.

[0318] The downstream section 14 comprises a support element 22 located immediately downstream of the rod 12 of aerosol-generating substrate, the support element 22 being in longitudinal alignment with the rod 12. In the embodiment of FIG. 1, the upstream end of the support element 18 abuts the downstream end of the rod 12 of aerosol-generating substrate. In addition, the downstream section 14 comprises an aerosol-cooling element 24 located immediately downstream of the support element 22, the aerosol-cooling element 24 being in longitudinal alignment with the rod 12 and the support element 22. In the embodiment of FIG. 1, the upstream end of the aerosol-cooling element 24 abuts the downstream end of the support element 22. In the embodiment of FIG. 1, the support element 22 and the aerosol-cooling element 24 together define an intermediate hollow section 50 of the aerosol-generating article 10.

[0319] The support element 22 comprises a first hollow tubular segment 26. The first hollow tubular segment 26 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The first hollow tubular segment 26 defines an internal cavity 28 that extends all the way from an upstream end 30 of the first hollow tubular segment to an downstream end 32 of the first hollow tubular segment 20. The internal cavity 28 is substantially empty, and so substantially unrestricted airflow is enabled along the internal cavity 28.

[0320] The first hollow tubular segment 26 has a length of about 8 millimetres, an external diameter of about 7.25 millimetres, and an internal diameter of about 1.9 millimetres. Thus, a thickness of a peripheral wall of the first hollow tubular segment 26 is about 2.67 millimetres.

[0321] The aerosol-cooling element 24 comprises a second hollow tubular segment 34. The second hollow tubular segment 34 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The second hollow tubular segment 34 defines an internal cavity 36 that extends all the way from an upstream end 38 of the second hollow tubular segment to a downstream end 40 of the second hollow tubular segment 34. The internal cavity 36 is substantially empty, and so substantially unrestricted airflow is enabled along the internal cavity 36.

[0322] The second hollow tubular segment 34 has a length of about 8 millimetres, an external diameter of about 7.25 millimetres, and an internal diameter of about 3.25 millimetres. Thus, a thickness of a peripheral wall of the second hollow tubular segment 34 is about 2 millimetres. Thus, a ratio between the internal diameter of the first hollow tubular segment 26 and the internal diameter of the second hollow tubular segment 34 is about 0.75.

[0323] The aerosol-generating article 10 comprises a ventilation zone 60 provided at a location along the second hollow tubular segment 34. In more detail, the ventilation zone is provided at about 2 millimetres from the upstream end of the second hollow tubular segment 34. A ventilation level of the aerosol-generating article 10 is about 25 percent.

[0324] In the embodiment of FIG. 1, the downstream section 14 further comprises a mouthpiece element 42 at a location downstream of the intermediate hollow section 50. In more detail, the mouthpiece element 42 is positioned immediately downstream of the aerosol-cooling element 24. As shown in the drawing of FIG. 1, an upstream end of the mouthpiece element 42 abuts the downstream end 40 of the aerosol-cooling element 18.

[0325] The mouthpiece element 42 is provided in the form of a cylindrical plug of low-density cellulose acetate. The mouthpiece element 42 has a length of about 12 millimetres and an external diameter of about 7.25 millimetres.

[0326] The rod 12 comprises an aerosol-generating substrate of one of the types described above. A density of the aerosol-generating substrate is about 600 milligrams per cubic centimetre.

[0327] The rod 12 of aerosol-generating substrate has an external diameter of about 7.25 millimetres and a length of about 12 millimetres.

[0328] The aerosol-generating article 10 further comprises an elongate susceptor 44 within the rod 12 of aerosol-generating substrate. In more detail, the susceptor 44 is arranged substantially longitudinally within the aerosol-generating substrate, such as to be approximately parallel to the longitudinal direction of the rod 12. As shown in the drawing of FIG. 1, the susceptor 44 is positioned in a radially central position within the rod and extends effectively along the longitudinal axis of the rod 12. In more detail, the susceptor 44 is in thermal contact with the aerosol-generating substrate. The susceptor 44 extends all the way from an upstream end to a downstream end of the rod 12. In effect, the susceptor 44 has substantially the same length as the rod 12 of aerosol-generating substrate.

[0329] In the embodiment of FIG. 1, the susceptor 44 is provided in the form of a strip and has a length of about 12 millimetres, a thickness of about 60 micrometres, and a width of about 4 millimetres.

[0330] The upstream section 16 comprises an upstream element 46 located immediately upstream of the rod 12 of aerosol-generating substrate, the upstream element 46 being in longitudinal alignment with the rod 12. In the embodiment of FIG. 1, the downstream end of the upstream element 46 abuts the upstream end of the rod 12 of aerosol-generating substrate. This advantageously prevents the susceptor 44 from being dislodged. Further, this ensures that the consumer cannot accidentally contact the heated susceptor 44 after use.

[0331] The upstream element 46 is provided in the form of a cylindrical plug of cellulose acetate circumscribed by a stiff wrapper. The upstream element 46 has a length of about 5 millimetres. The RTD of the upstream element 46 is about 30 millimetres H.sub.2O.

[0332] As shown in the drawing of FIG. 1, the aerosol-generating article 10 further comprises a wrapper 70 circumscribing the rod 12 of aerosol-generating substrate. The wrapper 70 comprises a wrapping base material having a basis weight of about 90 grams per square metre. Further, the wrapper 70 comprises a flame retardant composition comprising one or more flame retardant compounds.

[0333] In more detail, the flame retardant composition is provided at least in a treated portion 72 of the wrapper extending between the proximal end and the distal end of the rod 12 of aerosol-generating substrate. The treated portion 72 comprises about 3.5 grams of the one or more flame retardant compounds per square metre of surface area of the treated portion 72. Thus, the treated portion 72 of the wrapper 70 has an overall basis weight greater than the basis weight of the wrapping base material. In the embodiment of FIG. 1, the treated portion 72 has a length substantially matching the length of the rod 12 of aerosol-generating substrate, and extends substantially over the whole outer surface area of the rod 12 of aerosol-generating substrate.

[0334] The aerosol-generating article 110 shown in FIG. 2 has a number of features in common with the aerosol-generating article 10 of FIG. 1, and will be described below insofar as it differs from the aerosol-generating article 10.

[0335] As shown in FIG. 2, the aerosol-generating article 110 comprises a rod 12 of aerosol-generating substrate 12 and a modified downstream section 114 at a location downstream of the rod 12 of aerosol-generating substrate. Further, the aerosol-generating article 110 does not comprise an upstream section.

[0336] Like the downstream section 14 of the aerosol-generating article 10, the modified downstream section 114 of the aerosol-generating article 110 comprises a support element 22 located immediately downstream of the rod 12 of aerosol-generating substrate, the support element 22 being in longitudinal alignment with the rod 12, wherein the upstream end of the support element 22 abuts the downstream end of the rod 12 of aerosol-generating substrate.

[0337] Further, the modified downstream section 114 comprises an aerosol-cooling element 124 located immediately downstream of the support element 22, the aerosol-cooling element 124 being in longitudinal alignment with the rod 12 and the support element 22. In more detail, the upstream end of the aerosol-cooling element 124 abuts the downstream end of the support element 22.

[0338] In contrast to the downstream section 14 of the aerosol-generating article 10, the aerosol-cooling element 124 of the modified downstream section 114 comprises a plurality of longitudinally extending channels which offer a low or substantially null resistance to the passage of air through the rod. In more detail, the aerosol-cooling element 124 is formed from a preferably non-porous sheet material selected from the group comprising a metallic foil, a polymeric sheet, and a substantially non-porous paper or cardboard. In particular, in the embodiment illustrated in FIG. 2, the aerosol-cooling element 124 is provided in the form of a crimped and gathered sheet of polylactic acid (PLA). The aerosol-cooling element 124 has a length of about 8 millimetres, and an external diameter of about 7.25 millimetres.

[0339] Similar to the embodiment of FIG. 1, the aerosol-generating article 110 of FIG. 2 further comprises a wrapper 70 circumscribing the rod 12 of aerosol-generating substrate. The wrapper 70 comprises a wrapping base material having a basis weight of about 90 grams per square metre. Further, the wrapper 70 comprises a flame retardant composition comprising one or more flame retardant compounds.

[0340] In more detail, the flame retardant composition is provided at least in a treated portion 72 of the wrapper extending between the proximal end and the distal end of the rod 12 of aerosol-generating substrate. The treated portion 72 comprises about 3.5 grams of the one or more flame retardant compounds per square metre of surface area of the treated portion 72. Thus, the treated portion 72 of the wrapper 70 has an overall basis weight greater than the basis weight of the wrapping base material. In the embodiment of FIG. 1, the treated portion 72 has a length substantially matching the length of the rod 12 of aerosol-generating substrate, and extends substantially over the whole outer surface area of the rod 12 of aerosol-generating substrate.