AEROSOL-GENERATING ARTICLE HAVING A LOW-RTD SUBSTRATE AND AN UPSTREAM SECTION

Abstract

An aerosol-generating article is provided, including: a rod of aerosol-generating substrate having a length of between 8 millimetres and 16 millimetres and a resistance-to-draw (RTD) of between 4 millimetres H.sub.2O and 10 millimetres H.sub.2O; a downstream section provided downstream of the rod of aerosol-generating substrate, the downstream section including at least one hollow tubular segment; and an upstream element provided upstream of the rod of aerosol-generating substrate and abutting an upstream end of the rod of aerosol-generating substrate, the upstream element having a length of between 2 millimetres and 8 millimetres and being formed of a hollow tubular segment defining a longitudinal cavity providing an unrestricted flow channel.

Claims

1.-15. (canceled)

16. An aerosol-generating article, comprising: a rod of aerosol-generating substrate having a length of between 8 millimetres and 16 millimetres and a resistance-to-draw (RTD) of between 4 millimetres H.sub.2O and 10 millimetres H.sub.2O; a downstream section provided downstream of the rod of aerosol-generating substrate, the downstream section comprising at least one hollow tubular segment; and an upstream element provided upstream of the rod of aerosol-generating substrate and abutting an upstream end of the rod of aerosol-generating substrate, the upstream element having a length of between 2 millimetres and 8 millimetres and being formed of a hollow tubular segment defining a longitudinal cavity providing an unrestricted flow channel.

17. The aerosol-generating article according to claim 16, wherein the upstream element has an RTD of less than 1.5 millimetres H.sub.2O per 5 millimetres length.

18. The aerosol-generating article according to claim 16, wherein the upstream element has an RTD of less than 2 millimetres H.sub.2O.

19. The aerosol-generating article according to claim 16, wherein the hollow tubular segment of the upstream element has a wall thickness of less than 1 millimetre.

20. The aerosol-generating article according to claim 16, wherein the longitudinal cavity of the hollow tubular segment of the upstream element has a diameter of at least 5 millimetres.

21. The aerosol-generating article according to claim 16, wherein the aerosol-generating article has an RTD of between 20 millimetres H.sub.2O and 22 millimetres H.sub.2O.

22. The aerosol-generating article according to claim 16, wherein a combined RTD of the upstream element and the rod of aerosol-generating substrate is less than 10 millimetres H.sub.2O.

23. The aerosol-generating article according to claim 16, further comprising a ventilation zone at a location along the at least one hollow tubular segment of the downstream section, wherein an RTD of a portion of the aerosol-generating article upstream of the ventilation zone is between 10 millimetres H.sub.2O and 12 millimetres H.sub.2O.

24. The aerosol-generating article according to claim 16, wherein the at least one hollow tubular segment of the downstream section has a length of between 17 millimetres and 25 millimetres.

25. The aerosol-generating article according to claim 16, wherein the downstream section further comprises a mouthpiece element having a length of between 5 millimetres and 9 millimetres.

26. The aerosol-generating article according to claim 25, wherein an RTD of the mouthpiece element is between 6 millimetres H.sub.2O and 10 millimetres H.sub.2O.

27. The aerosol-generating article according to claim 16, wherein the aerosol-generating substrate comprises shredded tobacco material.

28. The aerosol-generating article according to claim 27, wherein the shredded tobacco material has a density of between 150 mg per cubic centimetre and 500 mg per cubic centimetre.

29. The aerosol-generating article according to claim 16, wherein the upstream element has a length of between 4 millimetres and 6 millimetres.

30. The aerosol-generating article according to claim 16, wherein the aerosol-generating substrate comprises one or more aerosol formers and wherein the content of aerosol former in the aerosol-forming substrate is at least 10 percent by weight, on a dry weight basis.

Description

[0381] In the following, the invention will be further described with reference to the drawings of the accompanying Figures, wherein:

[0382] FIG. 1 shows a schematic side perspective view of an aerosol-generating article in accordance with an embodiment of the invention;

[0383] FIG. 2 shows a schematic side sectional view of the aerosol-generating article in accordance with an embodiment of the invention; and

[0384] FIG. 3 shows a schematic side sectional view of the aerosol-generating system comprising an aerosol-generating article in accordance with an embodiment of the invention and an aerosol-generating device.

[0385] The aerosol-generating article 10 shown in FIG. 1 comprises a rod 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 16—which substantially coincides with an upstream end of the rod 12—to a downstream or mouth end 18, which coincides with a downstream end of the downstream section 14. The downstream section 14 comprises a hollow tubular element 20 and a mouthpiece element 50.

[0386] The aerosol-generating article 10 has an overall length of about 45 millimetres and an outer diameter of about 7.2 mm.

[0387] The rod of aerosol-generating substrate 12 comprises a shredded tobacco material. The rod of aerosol-generating substrate 12 comprises 150 milligrams of a shredded tobacco material comprising from 13 percent by weight to 16 percent by weight of glycerine. The density of the aerosol-generating substrate is about 300 mg per cubic centimetre. The RTD of the rod of aerosol-generating substrate 12 is between about 6 to 8 mm H.sub.2O. The rod of aerosol-generating substrate 12 is individually wrapped by a plug wrap (not shown).

[0388] The hollow tubular element 20 is located immediately downstream of the rod 12 of aerosol-generating substrate, the hollow tubular element 20 being in longitudinal alignment with the rod 12. The upstream end of the hollow tubular element 20 abuts the downstream end of the rod 12 of aerosol-generating substrate.

[0389] 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 hollow tubular element 20 is about 0 mm H.sub.2O.

[0390] As shown in FIG. 2, the hollow tubular element 20 is provided in the form of a hollow cylindrical tube made of cardboard. The hollow tubular element 20 defines an internal cavity 22 that extends all the way from an upstream end of the hollow tubular element 20 to a downstream end 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.

[0391] The hollow tubular element 20 has a length of about 21 millimetres, an external diameter of about 7.2 millimetres, and an internal diameter of about 6.7 millimetres. Thus, a thickness of a peripheral wall of the hollow tubular element 20 is about 0.25 millimetres.

[0392] 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 16 millimetres from the downstream end 18 of the article 10. The ventilation zone 30 is provided at about 12 mm downstream from the downstream end of the rod 12 of aerosol-generating substrate. The ventilation zone 30 is provided at about 9 mm upstream from the upstream end of the mouthpiece element 50. The ventilation zone 30 comprises a circumferential row of openings or perforations circumscribing the hollow tubular element 20. The perforations of the ventilation zone 30 extend through the wall of the hollow tubular element 20, in order to allow fluid ingress into the internal cavity 22 from the exterior of the article 10. A ventilation level of the aerosol-generating article 10 is about 16 percent.

[0393] 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.

[0394] 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. 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 hollow cylindrical plug of cellulose acetate tow having a wall thickness of about 1 mm and defining an internal cavity 23. The upstream element 42 has a length of about 5 millimetres. An external diameter of the upstream element 42 is about 7.1 mm. An internal diameter of the upstream element 42 is about 5.1 mm.

[0395] The mouthpiece element 50 extends from the downstream end of the hollow tubular element 20 to the downstream or mouth end of the aerosol-generating article 10. The mouthpiece element 50 has a length of about 7 mm. An external diameter of the mouthpiece element 50 is about 7.2 mm. The mouthpiece element 50 comprises a low-density, cellulose acetate filter segment. The RTD of the mouthpiece element 50 is about 8 mm H.sub.2O. The mouthpiece element 50 may be individually wrapped by a plug wrap (not shown).

[0396] As shown in FIGS. 1 & 2, the article 10 comprises an upstream wrapper 44 circumscribing the upstream element 42, the aerosol-generating substrate 12 and the hollow tubular element 20. The ventilation zone 30 may also comprise a circumferential row of perforations provided on the upstream wrapper 44. The perforations of the upstream wrapper 44 overlap the perforations provided on the hollow tubular element 20. Accordingly, the upstream wrapper 44 overlies the perforations of the ventilation zone 30 provided on the hollow tubular element 20.

[0397] The article 10 also comprises a tipping wrapper 52 circumscribing the hollow tubular element 20 and the mouthpiece element 50. The tipping wrapper 52 overlies the portion of the upstream wrapper 44 that overlies the hollow tubular element 20. This way the tipping wrapper 52 effectively joins the mouthpiece element 50 to the rest of the components of the article 10. The width of the tipper wrapper 52 is about 26 mm. Additionally, the ventilation zone 30 may comprise a circumferential row of perforations provided on the tipping wrapper 52. The perforations of the tipping wrapper 52 overlap the perforations provided on the hollow tubular element 20 and the upstream wrapper 44. Accordingly, the tipping wrapper 52 overlies the perforations of the ventilation zone 30 provided on the hollow tubular element 20 and the upstream wrapper 44.

[0398] FIG. 3 illustrates an aerosol-generating system 100 comprising an exemplary aerosol-generating device 1 and the aerosol-generating article 10, equivalent to that shown in FIGS. 1 & 2. FIG. 3 illustrates a downstream, mouth end portion of the aerosol-generating device 1 where the device cavity is defined and the aerosol-generating article 10 can be received. The aerosol-generating device 1 comprises a housing (or body) 4, extending between a mouth end 2 and a distal end (not shown). The housing 4 comprises a peripheral wall 6. The peripheral wall 6 defines a device cavity for receiving an aerosol-generating article 10. The device cavity is defined by a closed, distal end and an open, mouth end. The mouth end of the device cavity is located at the mouth end of the aerosol-generating device 1. The aerosol-generating article 10 is configured to be received through the mouth end of the device cavity and is configured to abut a closed end of the device cavity.

[0399] A device air flow channel 5 is defined within the peripheral wall 6. The air-flow channel 5 extends between an inlet 7 located at the mouth end of the aerosol-generating device 1 and the closed end of the device cavity. Air may enter the aerosol-generating substrate 12 via an aperture (not shown) provided at the closed end of the device cavity, ensuring fluid communication between the air flow channel 5 and the aerosol-generating substrate 12.

[0400] The aerosol-generating device 1 further comprises a heater (not shown) and a power source (not shown) for supplying power to the heater. A controller (not shown) is also provided to control such supply of power to the heater. The heater is configured to controllably heat the aerosol-generating article 10 during use, when the aerosol-generating article 1 is received within the device 1. The heater is preferably arranged to externally heat the aerosol-generating substrate 12 for optimal aerosol generation. The ventilation zone 30 is arranged to be exposed when the aerosol-generating article 10 is received within the aerosol-generating device 1.

[0401] In the embodiment shown in FIG. 3, the device cavity defined by the peripheral wall 6 is 28 mm in length. When the article 10 is received within the device cavity, the upstream section 40, the rod of aerosol-generating substrate 12 and an upstream portion of the hollow tubular element 20 are received within the device cavity. Such an upstream portion of the hollow tubular element 20 is 11 mm in length. Accordingly, about 28 mm of the article 10 is received within the device 1 and about 17 mm of the article 10 is located outside of the device 1. In other words, about 17 mm of the article 10 protrudes from the device 1 when the article 10 is received therein. Such a length PL of the article 10 protruding from the device 1 is shown in FIG. 3.

[0402] As a result, the ventilation zone 30 is advantageously located outside of the device 1 when the article 10 is inserted in the device 1. Where the device cavity is 28 mm long, the ventilation zone 30 is located 1 mm downstream from the mouth end 2 of the device 1 when the article 10 is received within the device 1. 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 A±10% 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.