AEROSOL-GENERATING ARTICLE HAVING A VENTILATED CAVITY

Abstract

An aerosol-generating article for producing an inhalable aerosol upon heating is provided, the article including: a rod of aerosol-generating substrate; a mouthpiece segment including a plug of filtration material and being downstream of the rod and in longitudinal alignment with the rod; a hollow tubular segment between and in longitudinal alignment with the rod and the mouthpiece segment, the hollow tubular segment defining a cavity extending to an upstream end of the mouthpiece segment; and a ventilation zone along the hollow tubular segment and including one or more rows of perforations formed through a peripheral wall of the hollow tubular segment at less than about 18 millimetres from an upstream end of the hollow tubular segment, the rod including at least an aerosol former, and the aerosol-generating article having a ventilation level of at least about 10 percent.

Claims

1.-14. (canceled)

15. An aerosol-generating article for producing an inhalable aerosol upon heating, the aerosol-generating article comprising: a rod of aerosol-generating substrate; a mouthpiece segment comprising a plug of filtration material, the mouthpiece segment being disposed downstream of the rod and in longitudinal alignment with the rod; a hollow tubular segment at a location between the rod and the mouthpiece segment, the hollow tubular segment being in longitudinal alignment with the rod and the mouthpiece segment, wherein the hollow tubular segment defines a cavity extending to an upstream end of the mouthpiece segment; and a ventilation zone at a location along the hollow tubular segment, the ventilation zone comprising one or more rows of perforations formed through a peripheral wall of the hollow tubular segment at less than about 18 millimetres from an upstream end of the hollow tubular segment, wherein the ventilation zone is at less than 45 millimetres from an upstream end of the aerosol-generating article; wherein a thickness of the peripheral wall of the hollow tubular segment is less than about 1.5 millimetres, wherein the rod of aerosol-generating substrate comprises at least an aerosol former, the rod of aerosol-generating substrate having an aerosol former content of at least about 10 percent on a dry weight basis, and wherein the aerosol-generating article has a ventilation level of at least about 10 percent.

16. The aerosol-generating article according to claim 15, wherein the hollow tubular segment comprises a wrapper circumscribing the rod and the mouthpiece segment.

17. The aerosol-generating article according to claim 15, wherein the hollow tubular segment comprises a tube formed from a polymeric material or a cellulosic material, and wherein the heated aerosol-generating article further comprises a wrapper circumscribing the rod, the tube, and the mouthpiece segment.

18. The aerosol-generating article according to claim 15, wherein the ventilation zone is at a location along the hollow tubular segment at least 2 millimetres from the upstream end of the mouthpiece segment.

19. The aerosol-generating article according to claim 18, wherein the ventilation zone is at a location along the hollow tubular segment less than 25 millimetres from a downstream end of the mouthpiece segment.

20. The aerosol-generating article according to claim 15, wherein the aerosol-generating article has a ventilation level of less than about 60 percent.

21. The aerosol-generating article according to claim 15, wherein the rod has a length of less than about 15 millimetres.

22. The aerosol-generating article according to claim 15, wherein the hollow tubular segment has a length of between about 10 millimetres and about 30 millimetres.

23. The aerosol-generating article according to claim 15, wherein an overall length of the aerosol-generating article is from about 40 millimetres to about 70 millimetres.

24. The aerosol-generating article according to claim 15, wherein a thickness of the hollow tubular segment is at least about 100 micrometres.

25. The aerosol-generating article according to claim 15, wherein an internal equivalent diameter of the hollow tubular segment at the location of the ventilation zone is at least about 4 millimetres.

26. The aerosol-generating article according to claim 15, wherein an RTD of the aerosol-generating article is between about 30 millimetres H.sub.2O and about 90 millimetres H.sub.2O.

27. The aerosol-generating article according to claim 15, wherein the ventilation zone comprises a single row of holes formed through the peripheral wall of the hollow tubular segment.

28. A pack comprising at least ten aerosol-generating articles according to claim 15, wherein a difference between an RTD of the aerosol-generating article having the highest RTD among the at least ten aerosol-generating articles and an RTD of the aerosol-generating article having the lowest RTD among the at least ten aerosol-generating articles is less than 10 mm H.sub.2O.

Description

[0127] In the following, the invention will be further described with reference to the drawings of the accompanying figures, in which:

[0128] FIG. 1 shows a schematic side sectional view of an aerosol-generating article in accordance with the invention;

[0129] FIG. 2 shows a schematic side sectional view of another example of an aerosol-generating article in accordance with the invention; and

[0130] FIG. 3 shows a schematic side sectional view of a further example an aerosol-generating article in accordance with the invention.

[0131] The aerosol-generating article 10 shown in FIG. 1 comprises a rod of aerosol-generating substrate 12, a hollow cellulose acetate tube 14, a hollow tubular segment 16 and a mouthpiece segment 18. These four elements are arranged in end-to-end, longitudinal alignment and are circumscribed by a wrapper 20 to form the aerosol-generating article 10. The aerosol-generating article 10 has a mouth end 22 and an upstream, distal end 24 located at the opposite end of the article to the mouth end 22. The aerosol-generating article 10 shown in FIG. 1 is particularly suitable for use with an electrically operated aerosol-generating device comprising a heater for heating the rod of aerosol-generating substrate.

[0132] The rod of aerosol-generating substrate 12 has a length of about 12 millimetres and a diameter of about 7 millimetres. The rod 12 is cylindrical in shape and has a substantially circular cross-section. The rod 12 comprises a gathered sheet of homogenised tobacco material. The sheet of homogenised tobacco material comprises 10 percent by weight on a dry basis of glycerine. The hollow cellulose acetate tube 14 has a length of about 8 millimetres and a thickness of 1 millimetre.

[0133] The mouthpiece segment 18 comprises a plug of cellulose acetate tow of 8 denier per filament and has a length of about 7 millimetres.

[0134] The hollow tubular segment 14 is provided as a cylindrical tube having a length of about 18 millimetres and a thickness of the tube wall is about 100 micrometres.

[0135] In more detail, the hollow tubular segment 16 may for example be formed from a paper having a basis weight of 110 gsm and has a weight of 45 milligrams (that is, 2.5 milligrams/millimetre of length). An equivalent internal diameter of the hollow tubular segment 16 is about 7 millimetres. Thus, a volume of the cavity internally defined by the hollow tubular segment 16 is about 693 cubic millimetres. As such, a ratio between the weight of the hollow tubular segment and the volume of the internal cavity defined by the hollow tubular segment 16 is about 0.065.

[0136] The aerosol-generating article 10 comprises a ventilation zone 26 provided at about 5 millimetres from an upstream end of the mouthpiece segment 18. Thus, the ventilation zone 26 is at about 12 millimetres from the downstream end of the aerosol-generating article, and about 13 millimetres from the upstream end of the hollow tubular segment. Thus, the ventilation zone 26 is at about 21 millimetres from a downstream end of the rod 12.

[0137] FIG. 2 illustrates another example of an aerosol-generating article in accordance with the invention. The aerosol-generating article 30 of FIG. 2 has the same structure of the aerosol-generating article 10 of FIG. 1 and differs from the aerosol-generating article 10 substantially only in the length of certain components, and will be described below only insofar as it differs from the aerosol-generating article 10. In the following the same reference numerals will be used, wherever possible, for corresponding components having the same structural or functional function.

[0138] In the aerosol-generating article 30 of FIG. 2, the rod 12 and the hollow cellulose acetate tube 14 have the same length as in the aerosol-generating article 10 of FIG. 1. However, the mouthpiece segment comprises a plug of cellulose acetate tow of 11 denier per filament and having a length of about 12 millimetres, and a hollow tubular segment 14 having a length of about 13 millimetres. The ventilation zone 26 is provided at about 6 millimetres from the upstream end of the mouthpiece segment 18, and at about 7 millimetres from the upstream end of the hollow tubular segment. Thus, the ventilation zone 26 is at about 15 millimetres from a downstream end of the rod 12.

[0139] In the embodiment of FIG. 2, the hollow tubular segment 16 may for example be provided as a cylindrical tube of cellulose acetate having a length of about 18 millimetres and a peripheral wall thickness of about 1 millimetre, with a weight of 171 milligrams (that is, 9.5 milligrams/millimetre of length).

[0140] An equivalent internal diameter of the hollow tubular segment 16 may be about 5.3 millimetres. Thus, a volume of the cavity internally defined by the hollow tubular segment 16 is about 397 cubic millimetres. As such, a ratio between the weight of the hollow tubular segment and the volume of the internal cavity defined by the hollow tubular segment 16 is about 0.43.

[0141] FIG. 3 illustrates yet another example of an aerosol-generating article in accordance with the invention. The aerosol-generating article 40 of FIG. 3 differs structurally from the aerosol-generating articles 10 of FIGS. 1 and 30 of FIG. 2 in that it does not include a hollow cellulose acetate tube as a support element. Accordingly, the lengths of the three main components are also different. In the following the same reference numerals will be used, wherever possible, for corresponding components having the same structural or functional function.

[0142] In the aerosol-generating article 40 of FIG. 3, the rod 12 has a length of about 12 millimetres, the hollow tubular segment 14 has a length of about 26 millimetres, and the mouthpiece segment 18 comprises a plug of cellulose acetate tow has a length of about 12 millimetres and 11 denier per filament. The ventilation zone 26 is provided at about 5 millimetres from the upstream end of the mouthpiece segment 18, and at about 21 millimetres from the upstream end of the hollow tubular segment, which in this embodiment coincides with the downstream end of the rod 12.

[0143] The following example records experimental results obtained during tests carried out on a specific embodiment of an aerosol-generating article in accordance with the present invention. Conditions for smoking and smoking machine specifications are set out in ISO Standard 3308 (ISO 3308:2000). The atmosphere for conditioning and testing is set out in ISO Standard 3402.

[0144] EXAMPLE 1 This experiment is performed to assess the effect of incorporation of a hollow tubular segment wherein a ventilation zone is provided at a location along the hollow tubular segment in accordance with the present invention. The experiment investigates the effect of the ventilation level on the delivery of nicotine and aerosol former (glycerin). A comparative measurement with a reference aerosol-generating article without ventilation is also provided.

[0145] Materials and Methods

[0146] Article A is an aerosol-generating article formed of: a rod of aerosol-generating substrate comprising a gathered sheet of homogenised tobacco material and about 18 percent on a dry weight basis of glycerin, the rod having a length of 12 millimetres; a support element in the form of a hollow cellulose acetate tube in alignment with and immediately downstream of the rod, the support element having a length of 8 millimetres; a hollow tubular segment in the form of a cardboard tube in alignment with and immediately downstream of the rod, the hollow tubular segment having a length of 13 millimetres; a mouthpiece segment of filtration material in alignment with and immediately downstream of the hollow tubular segment, the mouthpiece segment having a length of 12 millimetres. A ventilation zone is provided at a location along the hollow tubular segment at 18 millimetres from a downstream end of the mouthpiece segment. A level of ventilation of aerosol-generating article A is 30 percent.

[0147] Article B is a reference aerosol-generating article having the same structure of article A, but without the ventilation zone. Thus, a level of ventilation of aerosol-generating article B is 0 percent.

[0148] Nicotine and glycerin deliveries are measured by gas chromatography/time-of-flight mass spectrometry (GC/MS-TOF) on the nicotine and glycerin collected on a Cambridge filter pad. Runs were performed as described in example 1

[0149] Results. The average nicotine and glycerin deliveries from Article A and Article B are shown in the following Table 1.

TABLE-US-00001 TABLE 1 Effect of ventilation level on nicotine and glycerin deliveries. Nicotine Ventilation delivery Glycerin [%] [mg] [mg] Article A 30 1.41 5.6 Article B 0 1.17 3.5