AEROSOL-GENERATING ARTICLE WITH LOW RESISTANCE TO DRAW AND IMPROVED FLAVOUR DELIVERY

Abstract

An aerosol-generating article extending from a mouth end to a distal end is provided, including: an aerosol-generating element; and a downstream section located downstream of the aerosol-generating element, the downstream section extending from a downstream end of the aerosol-generating element to the mouth end of the aerosol-generating article, a resistance to draw (RTD) of the downstream section being less than 10 mm H.sub.2O, between about 5 percent and about 35 percent of a length of the downstream section includes a first section defining a first empty region for air to flow, at least about 65 percent of the length of the downstream section further includes a second section defining a second empty region for air to flow, and a total cross-sectional area of the first empty region defined by the first section being less than a total cross-sectional area of the second empty region defined by the second section.

Claims

1.-15. (canceled)

16. An aerosol-generating article extending from a mouth end to a distal end, comprising: an aerosol-generating element; and a downstream section located downstream of the aerosol-generating element, the downstream section extending from a downstream end of the aerosol-generating element to the mouth end of the aerosol-generating article, wherein a resistance to draw (RTD) of the downstream section is less than 10 mm H.sub.2O, wherein between about 5 percent and about 35 percent of a length of the downstream section comprises a first section defining a first empty region for air to flow, wherein at least about 65 percent of the length of the downstream section further comprises a second section defining a second empty region for air to flow, and wherein a total cross-sectional area of the first empty region defined by the first section is less than a total cross-sectional area of the second empty region defined by the second section.

17. The aerosol-generating article according to claim 16, wherein the second empty region comprises at least one cavity, the at least one cavity providing an unrestricted air flow channel extending along a longitudinal direction of the aerosol-generating article.

18. The aerosol-generating article according to claim 16, wherein the second section of the downstream section comprises at least one hollow tubular element, and wherein the second empty region is defined by the at least one hollow tubular element.

19. The aerosol-generating article according to claim 18, wherein a peripheral wall thickness of the at least one hollow tubular element is less than about 1.5 millimetres.

20. The aerosol-generating article according to claim 16, wherein the first section comprises a first segment, the first segment defining at least one segment air flow channel extending along a longitudinal direction of the first segment, and wherein the first empty region is defined by the at least one segment air flow channel.

21. The aerosol-generating article according to claim 16, wherein between about 5 percent and about 25 percent of the length of the downstream section further comprises the first section defining the first empty region for air to flow, and wherein at least about 75 percent of the length of the downstream section further comprises the second section defining the second empty region for air to flow.

22. The aerosol-generating article according to claim 16, wherein the RTD per unit length of the downstream section is between about 0 mm H.sub.2O per mm and about 3 mm H.sub.2O per mm.

23. The aerosol-generating article according to claim 16, wherein the RTD per unit length of the first section is between about 0 mm H.sub.2O per mm and about 3 mm H.sub.2O per mm.

24. The aerosol-generating article according to claim 16, wherein a ratio of a total cross-sectional area of the second empty region to a total cross-sectional area of the first empty region is at least about 1.1.

25. The aerosol-generating article according to claim 16, wherein a ratio of a total cross-sectional area of the first empty region defined by the first section to a total cross-sectional area of the downstream section is least about 5 percent.

26. The aerosol-generating article according to claim 16, wherein a ratio of a total cross-sectional area of the second empty region defined by the second section to a total cross-sectional area of the downstream section is least about 25 percent.

27. The aerosol-generating article according to claim 16, wherein the downstream section further comprises a ventilation zone at a location along the second section.

28. The aerosol-generating article according to claim 16, wherein the aerosol-generating element comprises tobacco cut filler.

29. The aerosol-generating article according to claim 16, wherein an aerosol former content in the aerosol-generating element is at least about 10 percent by weight.

30. The aerosol-generating article according to claim 16, wherein the second section of the downstream section has a length of at least about 25 millimetres.

Description

[0378] In the following, the invention will be further described with reference to the drawings of the accompanying Figures, wherein:

[0379] FIG. 1 shows a schematic side sectional view of an aerosol-generating article in accordance with an embodiment of the invention;

[0380] FIG. 2 shows a schematic side sectional view of another aerosol-generating article in accordance with another embodiment of the invention;

[0381] FIG. 3a shows a schematic side sectional view of another aerosol-generating article in accordance with an embodiment of the invention;

[0382] FIG. 3b shows a schematic side sectional view of another aerosol-generating article in accordance with an embodiment of the invention; and

[0383] FIGS. 4a-4f each show front elevation views of different examples of a mouthpiece segment 50, which can be used in the aerosol-generating articles shown in FIGS. 3a and 3b.

[0384] 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. Thus, the aerosol-generating article 10 extends from an upstream or distal end 16which substantially coincides with an upstream end of the rod 12to a downstream or mouth end 18, which coincides with a downstream end of the downstream section 14.

[0385] The aerosol-generating article 10 has an overall length of about 45 millimetres.

[0386] The rod of aerosol-generating substrate 12 comprises tobacco cut filler impregnated with about 12 percent by weight of an aerosol former, such as glycerin. The tobacco cut filler comprises 90 percent by weight of tobacco leaf lamina. The cut width of the tobacco cut filler is about 0.7 millimetres. The rod of aerosol-generating substrate 12 comprises about 130 milligrams of tobacco cut filler.

[0387] The downstream section 14 comprises a hollow tubular element 20 located immediately downstream of the rod 12 of aerosol-generating substrate, the hollow tubular element 20 being in longitudinal alignment with the rod 12. In the embodiment of FIG. 1, the upstream end of the hollow tubular element 20 abuts the downstream end of the rod 12 of aerosol-generating substrate.

[0388] The hollow tubular element 20 defines a hollow section of the aerosol-generating article 10. The hollow tubular element does not substantially contribute to the overall RTD of the aerosol-generating article. In more detail, an RTD of the downstream section is about 0 mm H.sub.2O.

[0389] The hollow tubular element 20 is provided in the form of a hollow cylindrical tube made of cellulose acetate or of stiff paper, such as paper having a grammage (basis weight) of at least about 90 grams per square metre. The hollow tubular element 20 defines an internal cavity 22 that extends all the way from an upstream end 24 of the hollow tubular segment to a downstream end 26 of the hollow tubular element 20. The internal cavity 22 is substantially empty, and so substantially unrestricted airflow is enabled along the internal cavity 22. The hollow tubular element 20 does not substantially contribute to the overall RTD of the aerosol-generating article 10.

[0390] The hollow tubular element 20 has a length of about 33 millimetres, an external diameter (D.sub.E) of about 7.3 millimetres, and an internal diameter (Di) of about 7.1 millimetres. Thus, a thickness of a peripheral wall of the hollow tubular element 20 is about 0.1 millimetres.

[0391] The aerosol-generating article 10 comprises a ventilation zone 30 provided at a location along the hollow tubular element 20. In more detail, the ventilation zone 30 is provided at about 18 millimetres from the downstream end 26 of the hollow tubular element 20. As such, in the embodiment of FIG. 1 the ventilation zone 30 is effectively provided at 18 millimetres from the mouth end 18 of the aerosol-generating article 10. A ventilation level of the aerosol-generating article 10 is about 40 percent.

[0392] In the embodiment of FIG. 1, the aerosol-generating article does not comprise any additional component upstream of the rod of aerosol-generating substrate 12 or downstream of the hollow tubular segment 20.

[0393] The aerosol-generating article 100 shown in FIG. 2 differs from the aerosol-generating article 10 described above only by the provision of an upstream section at a location upstream of the aerosol-generating element. Accordingly, the aerosol-generating article 100 will only be described insofar as it differs from the aerosol-generating article 10.

[0394] On top of a rod 12 of aerosol-generating substrate and a downstream section 14 at a location downstream of the rod 12, the aerosol-generating article 100 comprises an upstream section 40 at a location upstream of the rod 12. As such, the aerosol-generating article 10 extends from a distal end 16 substantially coinciding with an upstream end of the upstream section 40 to a mouth end or downstream end 18 substantially coinciding with a downstream end of the downstream section 14.

[0395] The upstream section 40 comprises an upstream element 42 located immediately upstream of the rod 12 of aerosol-generating substrate, the upstream element 42 being in longitudinal alignment with the rod 12. In the embodiment of FIG. 2, the downstream end of the upstream element 42 abuts the upstream end of the rod 12 of aerosol-generating substrate. The upstream element 42 is provided in the form of a cylindrical plug of cellulose acetate circumscribed by a stiff wrapper. The upstream element 42 has a length of about 5 millimetres. The RTD of the upstream element 42 is about 30 millimetres H.sub.2O.

[0396] The embodiments of FIGS. 3a & 3b show an aerosol-generating article, similar to that shown in FIG. 1, but comprising an additional component downstream of the rod of aerosol-generating substrate 24. Such an additional component consists of a mouthpiece segment 50.

[0397] The aerosol-generating articles 200, 300 shown in FIGS. 3a & 3b differ from the aerosol-generating article 10 described above in that the downstream section 14 consists of a first section 58 and a second section 56. The first section 58 comprises the mouthpiece segment 50 and the second section 56 comprises all, or a portion, of the hollow tubular element 20. The mouthpiece segment 50 has a length of about 6 mm and is located at least 1 mm downstream from the ventilation zone 30, which is provided along the hollow tubular element and at about 18 mm from the downstream end 18 of the aerosol-generating articles 200, 300. The mouthpiece segment 50 of the first section 58 defines a first empty region (not shown) and the hollow tubular element 20 defines a second empty region 52, which corresponds to the internal cavity 22.

[0398] In the aerosol-generating article 200 shown in FIG. 3a, the mouthpiece segment 50 is located immediately downstream of the hollow tubular element 20, which has a length of about 27 mm. The mouthpiece segment 50 extends from the downstream end of the hollow tubular element 20 to the downstream end of the downstream section 14, which coincides with the mouth end 18 of the aerosol-generating article 200.

[0399] In the aerosol-generating article 300 shown in FIG. 3b, the mouthpiece segment 50 is located within the hollow tubular element 20 and at a position along the hollow tubular element 20. The placement of the mouthpiece segment 50 within the hollow tubular element defines two internal cavities 22a, 22b within the hollow tubular element 20 and at either side of the mouthpiece segment 50. The external surface of the mouthpiece segment 50 forms an airtight fit with the internal wall surface of the hollow tubular element 20.

[0400] The second section 56a, 56b of the downstream section 14 comprises two portions 56a, 56b defining two portions 52a, 52b of the second empty region, which correspond to internal cavities 22a, 22b defined downstream and upstream of the mouthpiece segment 50. Such two portions 52a, 52b together define the second empty region 52 that is defined by the second section 56 of the downstream section 14. As shown in FIG. 3b, the length of the hollow tubular element 20 is the same as the length of the downstream section 14, which is about 33 mm. The downstream cavity portion 22b defines a recess cavity of the aerosol-generating article 300. The length of such a recess cavity is about 6 mm. The upstream cavity portion 22a defines a cavity between the mouthpiece segment 50 and the rod of aerosol-generating substrate 24. The length of the upstream cavity portion 22a is about 21 mm.

[0401] FIG. 4a shows a mouthpiece segment 50a formed from a bundle of fibres of polylactic acid or cellulose acetate tow extending longitudinally along the mouthpiece segment 50a. The gaps amongst the fibres effectively provide air flow channels and such air flow channels define the first empty region 54a. The cross-sectional area of the mouthpiece segment 50a occupied by the fibres is about 90% of the total cross-sectional area of the mouthpiece segment 50a, which is the same as the total cross-sectional area of the downstream section 14. The RTD per unit length of the mouthpiece segment 50a is about 0.6 mm H.sub.2O per mm.

[0402] FIG. 4b shows a mouthpiece segment 50b comprising a roll of crimped sheet of a paper-based material. Longitudinally-extending gaps within the rolled, crimped sheet material are defined throughout the length of the mouthpiece segment 50b. Such gaps define a first empty region 54b, which is defined by and within the mouthpiece segment 50b. The RTD per unit length of the mouthpiece segment 50 is about 0.25 mm H.sub.2O per mm.

[0403] FIG. 4c shows a mouthpiece segment 50c comprising a single Y-shaped segment air flow channel 53c. The Y-shaped segment channel 53c can be considered to consist of three channels joined together along the central axis of the mouthpiece segment 50c by a central channel to form a single Y-shaped air flow channel 53c. The channel 53c defines the first empty region 54c of the mouthpiece segment 50c. The cross-sectional area of the first empty region 54c is about 25% of the total cross-sectional area of the mouthpiece segment 50c, which is the same as the total cross-sectional area of the downstream section 14. The mouthpiece segment 50c is formed from cellulose acetate tow. The RTD per unit length of the mouthpiece segment 50c is about 0.02 mm H.sub.2O per mm.

[0404] FIG. 4d shows a mouthpiece segment 50d comprising three segment air flow channels 53d. As shown in FIG. 4d, the air flow channels 53d are circular and are arranged in a triangular formation. The air flow channels 53d define the first empty region 54d of the mouthpiece segment 50d. The total cross-sectional area of the air flow channels 50d is at least about 10% of the total cross-sectional area of the mouthpiece segment 50d, which is the same as the total cross-sectional area of the downstream section 14. The mouthpiece segment 50d is formed from cellulose acetate tow.

[0405] FIG. 4e shows a mouthpiece segment 50e comprising five segment air flow channels 53e. As shown in FIG. 4e, the air flow channels 53e are in the shape of annular sectors and are evenly circumferentially distributed in the vicinity of the outer periphery of the mouthpiece segment 50e. The air flow channels 53e define the first empty region 54e of the mouthpiece segment 50e. The total cross-sectional area of the air flow channels 53e is about 20% of the total cross-sectional area of the mouthpiece segment 50e, which is the same as the total cross-sectional area of the downstream section 14. The mouthpiece segment 50e is formed from cellulose acetate tow. The RTD per unit length of the mouthpiece segment 50e is about 0.05 mm H.sub.2O per mm.

[0406] FIG. 4f shows a mouthpiece segment 50f comprising seven air flow channels 53f. The air flow channels 53f define the first empty region 54f of the mouthpiece segment 50f. The total cross-sectional area of the air flow channels 53f is at least about 80% of the total cross-sectional area of the mouthpiece segment 50f, which is the same as the total cross-sectional area of the downstream section 14. The mouthpiece segment 50f is formed from a bioplastic material. The RTD per unit length of the mouthpiece segment 50f is about 0.01 mm H.sub.2O per mm.

[0407] For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term about. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A10% of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.