Smoking article comprising a filter with enhanced flavourant release

Abstract

There is provided a smoking article (10) comprising a tobacco rod (12) and a filter (14) axially aligned in an abutting end-to-end relationship. The filter (14) consists of a single segment of filtration material having an overall length (L) and extending from a mouth end (16) to a tobacco rod end (18). The smoking article (10) comprises a ventilation zone (20) at a location at a first distance (V) from the mouth end (16) of the filter; and an additive delivery element (22) upstream of the ventilation zone (20) and at a second distance (C) from the mouth end (16) of the filter (14). The ventilation zone (20) is at least 5 mm apart from the additive delivery element (22). The overall length (L) of the filter is from 20 mm to 30 mm; the first distance (V) is from 11 mm to 22 mm; and the second distance (C) is from 16 mm to 27 mm.

Claims

1. A smoking article comprising: a tobacco rod; a filter axially aligned in an abutting end-to-end relationship with the tobacco rod, the filter consisting of a single segment of filtration material having an overall length (L) and extending from a mouth end to a tobacco rod end; a ventilation zone at a location along the filter segment at a first distance (V) from the mouth end of the filter; an additive delivery element at a location along the filter segment upstream of the ventilation zone and at a second distance (C) from the mouth end of the filter, such that the ventilation zone is at least 5 millimetres apart from the additive delivery element; wherein: the overall length (L) of the filter is from 20 millimetres to 36 millimetres; the first distance (V) between the ventilation zone and the mouth end of the filter is from 11 millimetres to 28 millimetres; and the second distance (C) between the additive delivery element and the mouth end of the filter is from 16 millimetres to 33 millimetres; wherein a third distance (E) between the additive delivery element and the tobacco rod end of the filter is at least 3 millimetres and less than 10 millimetres.

2. A smoking article according to claim 1, wherein the overall length (L) of the filter is at least 25 millimetres.

3. A smoking article according to claim 1, wherein the difference between the second distance (C) and the first distance (V) is at least 18 millimetres.

4. A smoking article according to claim 1, wherein the ratio ((C−V)/L) between the difference between the second distance (C) and the first distance (V) and the overall length (L) is at least 0.45.

5. A filter for a smoking article, the filter being formed of a single segment of filtration material having an overall length (L) and extending from a first end to a second end; the filter comprising a ventilation zone at a location along the filter segment between the first end and the second end; an additive delivery element at a location along the filter segment between the ventilation zone and the second end, such that the additive delivery element is at least 5 millimetres apart from the ventilation zone; wherein: the overall length (L) of the filter is from 20 millimetres to 36 millimetres; a first distance between the ventilation zone and the first end of the filter is from 11 mm to 28 millimetres; and a second distance (C) between the additive delivery element and the first end of the filter is from 16 millimetres to 33 millimetres; wherein a third distance (E) between the additive delivery element and the second end of the filter is at least 3 millimetres and less than 10 millimetres.

Description

(1) The invention will be further described, by way of example only, with reference to the drawings of the accompanying Figures, wherein:

(2) FIG. 1 illustrates a schematic sectional view of a smoking article in accordance with the present invention;

(3) FIG. 2 is a schematic side view of a filter of a reference smoking article showing locations along the filter where temperature has been measured during smoking (Example 1);

(4) FIG. 3 is a chart showing how temperature varies during smoking of the reference smoking article at the locations of FIG. 2;

(5) FIG. 4 is a bar chart comparing features of a smoking article in accordance with the present invention with the corresponding features of a reference smoking article in accordance with the prior art; and

(6) FIG. 5 shows a an exemplary method of forming a filter for a smoking article in accordance with the present invention.

(7) FIG. 1 shows a smoking article 10 comprising a tobacco rod 12 and a filter 14. The filter 14 is axially aligned in an abutting end-to-end relationship with the tobacco rod 12, and is formed of a single segment of filtration material extending from a mouth end 16 to a tobacco rod end 18. The overall length L of the filter 12 is of about 27 millimetres.

(8) The smoking article 10 comprises a ventilation zone 20 comprising a plurality of holes disposed about the circumference of the filter. The ventilation zone 20 is at a location along the filter 12 at a distance V of about 12 millimetres from the mouth end 16. Further, the smoking article 10 comprises an additive delivery element 22 at a location along the filter segment upstream of the ventilation zone 20 and at a second distance C of about 18 millimetres from the mouth end 16. Thus, the ventilation zone 20 is about 6 millimetres apart from the additive delivery element 22. Further, the additive delivery element 22 is at a third distance E of about 9 mm from the tobacco rod end 18. The additive delivery element 22 is provided as a frangible capsule having a diameter of about 4.2 millimetres and containing menthol.

(9) Temperature Profile Assessment

(10) Variations in the temperature profile within the filter of a smoking article during smoking have been assessed under the Health Canada Intense (HCl) smoking regime. To this purpose, measurements have been carried out on a reference smoking article 20 (8 mg tar (ISO)) comprising a tobacco rod 22 of about 57 millimetres and a single-segment filter 24 of about 27 millimetres has been used, the tobacco rod and the filter having a diameter of about 7.9 millimetres. In the reference smoking article, the tobacco rod is circumscribed by a wrapper having a permeability of about 45 Coresta units. The filter is attached to the tobacco rod by a band of tipping having a permeability of 298 Coresta Units.

(11) As shown schematically in FIG. 2, thermocouples have been set to measure the temperature at different locations along the filter, namely at points:

(12) P: 5 millimetres from the mouth end;

(13) Q: 10 millimetres from the mouth end;

(14) R: 15 millimetres from the mouth end;

(15) S: 20 millimetres from the mouth end; and

(16) T: 25 millimetres from the mouth end.

(17) The reference smoking article has been smoked under the HCl regime, which entails the following parameters:

(18) Ventilation: 100 percent blocked;

(19) Puff frequency: 30 seconds;

(20) Puff duration: 2 seconds;

(21) Puff volume: 55 cubic centimetres.

(22) The graph of FIG. 3 illustrates how temperature varies over time during smoking, that is, with the number of puffs. Different curves have been plotted for the locations P-T along the filter. Unsurprisingly, temperature generally increases at all locations with every additional puff, as the length of the tobacco rod decreases and the combustion front becomes progressively nearer to the tobacco rod/filter interface. However, it has been surprisingly found that, from the third puff onward, temperature increases much faster and reaches significantly higher values at locations R to T, that is from about 15 millimetres to about 25 millimetres from the mouth end, compared with locations P and Q. In addition, from the sixth puff onward, a further significant distinction in the temperature profile becomes apparent between locations S-T, that is from about 20 millimetres to about 25 millimetres from the mouth end, and the other downstream locations.

(23) The highest temperature is consistently reached at location T. While at locations P-R temperature appears to approximate a plateau around the ninth or tenth puff, a monotonically increasing trend is observed past at locations S and T.

(24) Thus, locations at least about 20 millimetres from the mouth end—that is, at 7 millimetres or less from the tobacco rod end—not only reach generally higher temperatures compared with more downstream locations, but are also exposed to greater temperature gradients, such that higher temperatures are reached sooner than at more downstream locations, and such that temperatures continue to increase substantially during smoking, even when temperature essentially stabilises at more downstream location.

(25) On the other hand, at locations from about 10 millimetres to about 15 millimetres from the mouth end—that is, at positions centred around the midpoint (13.5 millimetres from the mouth end of the filter—temperatures are not only consistently lower during the whole smoking test, but also increase at a progressively lower rate from the sixth/seventh puff onward.

(26) It should be clear that the whole section of the filter of a smoking article in accordance with the invention upstream of the ventilation zone would be essentially identical to the filter of the reference smoking article described above. Accordingly, without wishing to be bound to theory, it can reasonably be assumed that, at least in qualitative terms, a similar trend would be observed during smoking of a smoking article in accordance with the invention. In particular, these experimental results confirm that the transfer of an additive into the mainstream smoke can be thermally enhanced most significantly by arranging the delivery element at locations from 2 millimetres to 12 millimetres from the tobacco rod end.

EXAMPLE 1

(27) A smoking article in accordance with the present invention (see the description of smoking article 10 above) has been subjected to a smoking test and the menthol delivery into the mainstream smoke (MIS) as well as the tar delivery (TAR), along with other characteristics of the mainstream smoke, have been measured.

COMPARATIVE EXAMPLE

(28) The behaviour of the smoking article of Example 1 has been compared with a reference smoking article that is substantially identical to the smoking article 10 and only differs from the smoking article of Example 1 insofar as the additive delivery element is arranged at a centred location along the longitudinal axis of the filter, whilst the ventilation zone is upstream from the additive delivery system. In other words, in the comparative smoking article, L=27 millimetres, V=18 millimetres and C=13.5 millimetres.

(29) Quantitative determination of the menthol content in the mainstream smoke is carried out by GC-FID. The mainstream smoke of cigarettes smoked on a smoking machine is collected on glass fibre filter pads. An alcohol extract of smoke trapped on these filters is analysed.

(30) To this purpose, the smoking article is smoked in accordance with Q0309 “Determination of Total Particulate Matter and Carbon Monoxide (CO) in Mainstream Smoke Using a Non-Automatic Linear Smoking Machine” or equivalent when a 20-channel linear smoking machine (Cerulean) is used and to Q0338 “Determination of Total Particulate Matter and Carbon Monoxide in Mainstream Smoke using an RM-200 or RM20 Smoking Machine” or equivalent when a rotary smoking machine (Borgwaldt) is used. However, in the determination of menthol content, the following exceptions concerning the preparation and conditioning of the cigarette samples apply: a sample of at least 80 cigarettes must be subjected to the test; on the day of the test, 40 acceptable cigarettes must be selected from the conditioned packs, so as to eliminate obvious nonconformities (such as void ends, torn rods, badly attached filters etc.), and stored in a closed container until they are smoked (the maximum storage time is 12 hours); menthol has to be released from the additive delivery element (for example, by crushing, in the case of a frangible capsule) prior to smoking; smoking must start within 5 minutes of release.

(31) Further, reference can be made to ISO 13110 “Cigarettes—Determination of menthol in smoke condensates—Gas chromatographic method”.

(32) The content of carbon monoxide may be determined in accordance with the CORESTA Recommended Method No. 5—Determination of Carbon Monoxide in the Mainstream Smoke of Cigarettes by Non-Dispersive Infrared Analysis (second edition, September 1993). The content of nicotine is determined in accordance with the CORESTA Recommended Method No. 7—Determination of Nicotine in the Mainstream Smoke of Cigarettes by Gas Chromatographic Analysis (second edition, August 1991). Ventilation may be determined in accordance with the CORESTA Recommended Method No. 6—Determination of Ventilation: Definitions and Measurement Principles (second edition, March 2000). Resistance To Draw (RTD) may be determined in accordance with the CORESTA Recommended Method No. 41—Determination of the Draw Resistance of Cigarettes and Filter Rods (second edition, June 2007). The content of Total Particulate Matter (TPM) may be determined in accordance with the CORESTA Recommended Method No. 23—Determination of Total Particulate Matter and Preparation for Water and Nicotine Measurements (second edition, August 1991).

(33) The following Table 1 contains data obtained from the smoking test. The bar chart of FIG. 4 visually illustrates the differences between the behaviour of the smoking article 10 according to the present invention and the comparative smoking article in accordance with the prior art.

(34) TABLE-US-00001 TABLE 1 CO Nicotine TAR TPM H.sub.2O No. MIS RTD Ventilation [mg] [mg] [mg] [mg] [mg] Puffs [mg] [mmH.sub.2O] [percent] Example 1 6.46 0.40 6.61 7.59 0.59 7.47 1.22 84 55 Comparative 5.59 0.42 6.22 7.29 0.65 7.71 0.90 93 60 Example

(35) As can be seen, an increase of about 35 percent in the menthol delivery is obtained with a smoking article in accordance with the present invention with respect to the comparative smoking article. As shown in the chart of FIG. 4, this leads to an enhanced flavour impact which is easily perceived by the consumer, not only in terms of intensity of the minty and cooling notes, but also in terms of persistence of the cooling sensation during smoking of the smoking article. This has been assessed by means of a routine testing test involving a panel of regular smokers.

EXAMPLE 2

(36) An additional set of smoking articles (A, B, C) in accordance with the present inventions was also subjected to the same smoking test. The smoking articles A, B, C of Example 2 differ from the smoking article of Example 1 in that the additive delivery element 22 is provided as a frangible capsule with a diameter of 3.5 millimetres. Further, the smoking articles A, B, C of Example 2 are designed to have different levels of TAR delivery (about 2 milligrams, 7 milligrams and 13 milligrams, respectively). For each smoking article A, B, C in accordance with the present invention, a corresponding reference smoking article with L=27 millimetres, V=18 millimetres and C=13.5 millimetres was also smoked.

(37) The following Table 2 contains data obtained from the smoking test.

(38) TABLE-US-00002 TABLE 2 MIS CO TAR No. MIS Nicotine variation [mg] [mg] Puffs [mg] [mg] [%] Example 2 (A) 2.7 2.2 8.7 0.40 0.16 +30 Comparative 2.2 2.3 8.8 0.31 0.17 = = = Example (A) Example 2 (B) 7.7 7 7.7 0.91 0.49 +29 Comparative 6.9 6.9 7.7 0.70 0.50 = = = Example (B) Example 2 (C) 12.5 12.7 7.1 1.32 0.60 +18 Comparative 12.0 13.2 6.9 1.12 0.91 = = = Example (C)

(39) These experimental results confirm that with smoking articles in accordance with the present invention the transfer of menthol into the mainstream smoke is significantly enhanced, regardless of the TAR content. In particular, the increase in the menthol release remains substantially constant at about 30 percent as the TAR content increases from about 2 milligrams to about 7 milligrams.

(40) FIG. 5 illustrates a process for forming a plurality of filters for smoking articles in accordance with the present invention. In a substantially continuous rod 100 of filtration material additive delivery elements 20 are embedded such that consecutive additive delivery elements are spaced apart in the longitudinal direction of the rod 100 alternatively by a first distance D1 of about 36 millimetres and a second distance D2 of about 18 millimetres. The additive delivery elements 20 are surrounded on all sides by the filtration material.

(41) The substantially continuous filter rod 100 at cut lines spaced longitudinally by a third distance D3, of about 27 millimetres to produce filter segments 12 of filtration material. Thus, each filter segment 12 includes an additive delivery element 20 embedded in the filter segment. The additive delivery element 20 is at about 18 mm (0.5 times D1) from one end of the filter segment 12 and at about 9 millimetres (0.5 times D2) from the opposite end of the filter segment. It shall be appreciated that the second distance C corresponds to 0.5 times D1 and the third distance E corresponds to 0.5 times D2.