RODS FOR USE IN SMOKING ARTICLES

Abstract

A smoking article is provided, including an aerosol-generating substrate, the aerosol-generating substrate being a rod including a gathered sheet of homogenised tobacco material circumscribed by a wrapper, the gathered sheet of homogenised tobacco material including one or more aerosol-formers and having an aerosol-former content of greater than 5% on a dry weight basis, and the rod having a length of between 5 mm and 20 mm.

Claims

1. (canceled)

2. A smoking article comprising an aerosol-generating substrate, wherein the aerosol-generating substrate is a rod comprising a gathered sheet of homogenised tobacco material circumscribed by a wrapper, wherein the gathered sheet of homogenised tobacco material comprises one or more aerosol-formers and has an aerosol-former content of greater than 5% on a dry weight basis, and wherein the rod has a length of between 5 mm and 20 mm.

3. The smoking article according to claim 2, wherein the gathered sheet of homogenised tobacco material has a thickness of at least 50 μm.

4. The smoking article according to claim 2, wherein the gathered sheet of homogenised tobacco material has a thickness of between 120 μm and 260 μm.

5. The smoking article according to claim 2, wherein the gathered sheet of homogenised tobacco material of has a width of at least about 25 mm.

6. The smoking article according to claim 2, wherein the gathered sheet of homogenised tobacco material has a width of between 110 mm and 134 mm.

7. The smoking article according to claim 2, wherein the gathered sheet of homogenised tobacco material has a tobacco content of at least 50% by weight on a dry weight basis.

8. The smoking article according to claim 2, wherein the gathered sheet of homogenised tobacco material has a tobacco content of at least 70% by weight on a dry weight basis.

9. The smoking article according to claim 2, wherein the gathered sheet of homogenised tobacco material comprises between 1% and 5% non-tobacco fibers by weight on a dry weight basis.

10. The smoking article according to claim 2, wherein the gathered sheet of homogenised tobacco material is convoluted.

11. The smoking article according to claim 2, wherein the gathered sheet of homogenised tobacco material is formed by a casting process.

12. The smoking article according to claim 2, wherein the gathered sheet of homogenised tobacco material is formed by agglomerating particulate tobacco.

13. The smoking article according to claim 2, wherein the gathered sheet of homogenised tobacco material has a grammage of between 100 g/m.sup.2 and 300 g/m.sup.2.

14. The smoking article according to claim 2, wherein the smoking article is for an electrically heatable aerosol-generating system.

15. The smoking article according to claim 2, wherein the aerosol-generating substrate further comprises a thread, yarn, tape, or filament to which one or more additives have been applied, the thread, yam, tape, or filament being incorporated into the gathered sheet of homogenised tobacco material.

16. The smoking article according to claim 2, wherein the one or more aerosol-formers comprises a polyhydric alcohol, an ester of a polyhydric alcohol, or an aliphatic ester of a mono-, di-, or poly-carboxylic acid.

17. The smoking article according to claim 2, wherein the one or more aerosol-formers comprises an aerosol-former selected from the list consisting of triethylene glycol, 1,3-butanediol, glycerine, glycerol monoacetate, glycerol diacetate, glycerol triacetate, dimethyl dodecanedioate, and dimethyl tetradecanedioate.

Description

[0120] The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

[0121] FIG. 1 shows a schematic cross-section of apparatus for forming a rod according to the invention;

[0122] FIG. 2 shows the density of rods according to a first embodiment of the invention formed using the apparatus shown in FIG. 1; and

[0123] FIG. 3 shows the density of rods comprising shreds of tobacco material.

[0124] The apparatus shown in FIG. 1 generally comprises: supply means for providing a continuous sheet of homogenised tobacco material; crimping means for crimping the continuous sheet of homogenised tobacco material; rod forming means for gathering the continuous crimped sheet of homogenised tobacco material and circumscribing the gathered continuous crimped sheet of homogenised tobacco material with a wrapper to form a continuous rod; and cutting means for severing the continuous rod into a plurality of discrete rods. The apparatus also comprises transport means for transporting the continuous sheet of homogenised tobacco material downstream through the apparatus from the supply means to the rod forming means via the crimping means.

[0125] As shown in FIG. 1, the supply means comprises a continuous sheet of homogenised tobacco material 2 mounted on a bobbin 4 and the crimping means comprises a pair of rotatable crimping rollers 6. In use, the continuous sheet of homogenised tobacco material 2 is drawn from the bobbin 4 and transported downstream to the pair of crimping rollers 6 by the transport mechanism via a series of guide and tensioning rollers. As the continuous sheet of homogenised tobacco material 2 is fed between the pair of crimping rollers 6, the crimping rollers engage and crimp the continuous sheet of homogenised tobacco material 2 to form a continuous crimped sheet of homogenised tobacco material 8 having a plurality of spaced-apart ridges or corrugations substantially parallel to the longitudinal axis of the sheet of homogenised tobacco material through the apparatus.

[0126] The continuous crimped sheet of homogenised tobacco material 8 is transported downstream from the pair of crimping rollers 6 to the rod forming means by the transport mechanism where it is fed through a converging funnel or horn 10. The converging funnel 10 gathers the continuous crimped sheet of homogenised tobacco material 8 transversely relative to the longitudinal axis of the sheet of homogenised tobacco material. The continuous crimped sheet of homogenised tobacco material 8 assumes a substantially cylindrical configuration as it passes through the converging funnel 10.

[0127] Upon exiting the converging funnel 10, the gathered continuous crimped sheet of homogenised tobacco material is wrapped in a continuous sheet of wrapping material 12. The continuous sheet of wrapping material is fed from a bobbin 14 and enveloped around the gathered continuous crimped sheet of homogenised tobacco material by an endless belt conveyor or garniture. As shown in FIG. 1, the rod forming means comprises an adhesive application means 16 that applies adhesive to one of the longitudinal edges of the continuous sheet of wrapping material, so that when the opposed longitudinal edges of the continuous sheet of wrapping material are brought into contact they adhere to one other to form a continuous rod.

[0128] The rod forming means further comprises a drying means 18 downstream of the adhesive application means 16, which in use dries the adhesive applied to the seam of the continuous rod as the continuous rod is transported downstream from the rod forming means to the cutting means.

[0129] The cutting means comprises a rotary cutter 20 that severs the continuous rod into a plurality of discrete rods of unit length or multiple unit length.

[0130] The apparatus shown in FIG. 1 further comprises an additive application means 24 located between the crimping means and the rod forming means for applying solid or liquid additives such as, for example, flavourants, to the continuous crimped sheet of homogenised tobacco material 8 before it is gathered transversely relative to the longitudinal axis thereof by the converging funnel 10.

[0131] In one alternative embodiment (not shown), the additive application means is located between the supply means and the crimping means for applying solid or liquid additives to the continuous sheet of homogenised tobacco material before it is crimped.

[0132] In another alternative embodiment (not shown), the additive application means is located adjacent to the converging funnel 10 of the rod forming means and is adapted to apply solid or liquid additives to the gathered continuous crimped sheet of homogenised tobacco material before it is wrapped in the continuous sheet of wrapping material 12.

[0133] In a further embodiment (not shown) the apparatus further comprises means located between the crimping means and the rod forming means for incorporating a continuous element to which one or more additives have been applied into the continuous crimped sheet of homogenised tobacco material 8 as it is gathered by the converging funnel 10.

Example 1

[0134] Rods according to a first embodiment of the invention comprising a gathered crimped sheet of homogenised tobacco material circumscribed by a paper wrapper and having a length of 120 mm and diameters of between 6.9 mm and 7.2 mm were produced at rates of between 20 m/min and 25 m/min using apparatus of the type shown in FIG. 1. Continuous sheets of tobacco material produced by a casting process having a width of between 110 mm and 134 mm, a thickness of 120 μm to 260 μm, a grammage of between 167 g/m.sup.2 and 201 g/m.sup.2 and a moisture content of between 5% and 12% were used to form the rods.

[0135] The density of five rods according to the first embodiment of the invention was measured at positions between 10 mm and 110 mm along the length of the rods using a C.sup.2 cigarette testing unit available from Cerulean, a trading name of Molins PLC of Milton Keynes, United Kingdom. The results of the density measurements are shown in FIG. 2.

[0136] For the purpose of comparison, the density of five rods of the same dimensions but comprising shreds of homogenised tobacco material circumscribed by a paper wrapper was also measured at positions between 10 mm and 110 mm along the length of the rods using standard techniques. The results of the density measurements are shown in FIG. 3.

[0137] As shown in FIG. 2, for the five rods according to the first embodiment of the invention the minimum density value is about 410 mg/cm.sup.3, the maximum density value is about 450 mg/cm.sup.3 and the average density value is about 430 mg/cm.sup.3 with a standard deviation of about 9 mg/cm.sup.3 and a coefficient of variation (CV) of about 2%.

[0138] As shown in FIG. 3, for the five rods comprising shreds of homogenised tobacco material the minimum density value is about 360 mg/cm.sup.3, the maximum density value is about 470 mg/cm.sup.3 and the average density value is about 410 mg/cm.sup.3 with a standard deviation of about 29 mg/cm.sup.3 and a CV of about 7%.

[0139] As illustrated by the data presented in FIGS. 2 and 3, the rods according to the first embodiment of the invention advantageously exhibit more uniform densities than the rods comprising shreds of homogenised tobacco material.

Example 2

[0140] Rods according to a second embodiment of the invention having a length of 12 mm and diameters of between 6.9 mm and 7.2 mm for use as aerosol-generating substrates in electrically heated smoking articles were produced by severing the rods according to the first embodiment of the invention produced in Example 1.