Method of making tobacco cut filler

Abstract

A tobacco cut filler comprises a first tobacco material cut in accordance with a first cut specification, wherein the first cut specification sets at least predetermined first cut width and first cut length.

Claims

1. A tobacco cut filler comprising a first tobacco material cut into strips in accordance with a first cut specification, wherein the first cut specification sets at least predetermined first cut width and first cut length corresponding to a final cut width and a final cut length in the tobacco cut filler when used in a tobacco product, wherein a cut length distribution among the cut strips of the first tobacco material is at least bimodal.

2. A tobacco cut filler according to claim 1, further comprising a second tobacco material cut in accordance with a second cut specification differing from the first cut specification for at least one of cut length and cut width.

3. A tobacco cut filler according to claim 1, wherein the first tobacco material is a pre-processed tobacco material.

4. A tobacco cut filler according to claim 1, wherein the first tobacco material is a reconstituted tobacco sheet.

5. A tobacco cut filler according to claim 2, wherein the second tobacco material is a natural tobacco leaf material.

6. A tobacco cut filler according to claim 1, wherein the first tobacco material is shredded into strips having a cut length from about 5 mm to about 60 mm.

7. A tobacco cut filler according to claim 1, wherein the cut length distribution among the cut strips of the first tobacco material is trimodal.

8. A tobacco cut filler according to claim 1, wherein the first tobacco material is shredded into strips having a cut width from about 0.2 mm to about 1 mm.

9. A tobacco cut filler according to claim 1, wherein the first tobacco material is shredded into strips from a sheet material having a thickness from about 0.05 mm to about 1 mm.

10. A tobacco cut filler according to claim 1, wherein the first tobacco material is shredded into strips having a sinusoidal shape, wherein a wave length of the sinusoidal shape is from about 1 mm to about 15 mm.

11. A tobacco cut filler according to claim 1, wherein the first tobacco material is shredded into strips each comprising at least a first strip structure comprising a branching node from which a further strip structure branches off, forming an angle with the first strip structure.

12. A tobacco cut filler according to claim 1, wherein the first tobacco material is shredded into strips each comprising at least a first, a second and a third strip structures, wherein the first strip structure comprises a node from which the second strip structure branches off, the second strip structure comprises a second node from which the third strip structure branches off.

13. A tobacco cut filler according to claim 1 having a filling power of at least 3.5 cubic centimetres per gram at a reference moisture value of 12.5 percent oven volatiles.

14. A smoking article comprising a rod of a tobacco cut filler according to claim 1.

15. A method of making tobacco cut filler comprising: providing a first tobacco material; cutting the first tobacco material into strips in accordance with a first cut specification setting at least predetermined first cut width and first cut length, a cut length distribution among the cut strips being at least bimodal.

16. A method according to claim 15, comprising: providing a second tobacco material; cutting the second tobacco material separately from the first tobacco material and in accordance with a second cut specification, the second cut specification differing from the first cut specification for at least one of cut length and cut width; and blending the cut first tobacco material and the cut second tobacco material.

17. A method according to claim 15, wherein the first tobacco material is a pre-processed tobacco material.

18. A method according to claim 15, wherein the second tobacco material is a reconstituted tobacco sheet.

19. A method according to claim 15, further comprising conditioning the first tobacco material prior to cutting the first tobacco material.

20. A method according to claim 18, comprising controlling the moisture content of the cut filler by adjusting the moisture content of the first tobacco material.

21. A method according to claim 15, further comprising adjusting the moisture content of the second tobacco material.

Description

(1) FIGS. 1 and 2 illustrate sinusoidal strips. In more detail, FIG. 1 shows a zigzag-shaped strip and FIG. 2 shows a wave-shaped strip. Where the cut strip is zigzag-shaped or wave-shaped, it is possible to measure a wave length of the cut strip, which substantially corresponds to the strip cut length divided by the number of repetitions of the zigzag or wave. For instance, in the cut strip of FIG. 1 the zigzag is repeated 10 times. In the cut strip of FIG. 2 the wave is repeated 6 times. Preferably, a wave length of the sinusoidal shape is from about 1 mm to about 15 mm, more preferably from about 2 mm to about 12 mm, even more preferably from 4 mm to 10 mm.

(2) FIG. 3 shows a Y-shaped strip.

(3) FIG. 4 shows a star-shaped strip.

(4) FIG. 5 illustrates an oval shaped strip.

(5) A fishbone-shaped strip is shown in FIG. 6, whereas

(6) FIGS. 7 and 8 show two embodiments of rectangular strips.

(7) FIGS. 9 and 11 illustrate two examples of strips having a more complex, “hybrid” shape, wherein strip structures having the same or different shape substantially branch off one another. In particular, one such strip may comprise at least a first strip structure comprising a branching node from which a further strip structure branches off, forming an angle with the first strip structure.

(8) Preferably, in a cut filler according to the present invention, the first tobacco material is shredded into cut strips comprising at least a first, a second and a third strip structures, wherein the first strip structure comprises a node from which the second strip structure branches off, the second strip structure comprises a second node from which the third strip structure branches off.

(9) By way of example, the cut strip of FIG. 9 comprises a first Y-shaped structure including a first branching node from which a second Y-shaped structure branches off. Further, the second Y-shaped structure comprises a second branching node from which a rectangular structure branches off. In the embodiment of FIG. 11, the cut strip comprises a first Y-shaped structure including a first branching node from which a second Y-shaped structure branches off. Further, the second Y-shaped structure comprises a second branching node from which a third Y-shaped structure branches off. In turn, the third Y-shaped structure comprises a third branching node from which a rectangular structure branches off. In the embodiments of both FIGS. 9 and 11 the sectional cut width within all the structures forming the cut strips is substantially constant.

(10) FIGS. 10 and 12 show two examples of cut strips including one or more V-shaped structure. Each V structure comprises two substantially straight elements forming an angle. In the embodiment of FIG. 10, the two straight elements are substantially perpendicular. The cut strip of FIG. 12 may be regarded as comprising three V-shaped structures of the type illustrated in FIG. 1, wherein adjacent V-shaped structures are connected by the ends of respective straight elements. In the embodiments of both FIGS. 10 and 12 the sectional cut width within all the structures forming the cut strips is substantially constant.

(11) Preferably, the cut filler has a filling power of at least about 3.5 cubic centimetres per gram at a reference moisture value of 12.5 percent oven volatiles. More preferably, the cut filler has a filling power of at least about 4 cubic centimetres per gram at a reference moisture value of 12.5 percent oven volatiles. In addition, or as an alternative, the cut filler preferably has a filling power of less than about 8 cubic centimetres per gram at a reference moisture value of 12.5 percent oven volatiles. More preferably, the cut filler has a filling power of less than about 7 cubic centimetres per gram at a reference moisture value of 12.5 percent oven volatiles. In some particularly preferred embodiments, the cut filler has a filling power of from about 3.5 cubic centimetres per gram to about 8 cubic centimetres per gram at a reference moisture value of 12.5 percent oven volatiles.

(12) Tobacco cut filler in accordance with the present invention may be incorporated into a variety of smoking articles. In some embodiments, tobacco cut filler according to the invention may be used in the tobacco rod of a combustible smoking article, such as a filter cigarette, cigarillo or cigar. Alternatively, the cut filler may be used to provide the tobacco aerosol generating substrate in a distillation based smoking article, or an electrically heated smoking system. Alternatively, the cut filler may be used as a roll-your-own or make-your-own product, or loose tobacco product for use in a pipe.

(13) Tobacco cut fillers according to the present invention may be prepared by a method comprising providing a first tobacco material and cutting the first tobacco material in accordance with a first cut specification setting at least predetermined first cut width and first cut length.

(14) Preferably, the method further comprises providing a second tobacco material and cutting the second tobacco material separately from the first tobacco material and in accordance with a second cut specification, the second cut specification differing from the first cut specification for at least one of cut length and cut width. Further, the method preferably comprises the step of blending the cut first tobacco material and the cut second tobacco material. This is particularly advantageous because, since the first tobacco material is cut separately from the second tobacco material and may thus not be exposed to the same operating conditions and treatment steps to which the second tobacco material is subjected, the features of the first tobacco material can effectively be preserved when it is ultimately blended, in a shredded state, with the cut second tobacco material to form the cut filler.

(15) The method may further comprise a step of conditioning the first tobacco material prior to cutting the first tobacco material. Further, the method may comprise a step of controlling the moisture content of the cut filler by adjusting the moisture content of the first tobacco material. In addition or as an alternative, the method may further comprise a step of adjusting the moisture content of the second tobacco material.

(16) The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

(17) FIGS. 1 to 12 depict schematic top views of cut strips of a tobacco material for forming a tobacco cut filler in accordance with the present invention; and

(18) FIG. 13 depicts a schematic view of an apparatus for forming a tobacco cut filler in accordance with the present invention.

(19) FIGS. 1 to 12 shows cut strips of a first tobacco material for incorporation in a cut filler according to the present invention. The strips have been cut from a sheet of reconstituted tobacco having a thickness from about 0.05 mm to about 1 mm in accordance with a first cut specification, wherein the first cut specification sets a predetermined first cut width CW1 and a predetermined first cut length CL1. In addition, the first cut specification may further set a predetermined first sectional cut width SCW1.

(20) FIG. 13 illustrates an apparatus 30 for the manufacture of a tobacco cut filler in accordance with the present invention. A web 32 of reconstituted tobacco having a thickness T is unwound off a bobbin 34 and fed to a shredding device 36. The shredding device is configured to cut the reconstituted tobacco in accordance to a first cut specification, whereby both cut width and cut length are predetermined. The cut strips are dropped onto a conveyor belt 38 arranged beneath the shredding device 36 and defining a collection surface upon which the cut strips fall out of the shredding device. Additional means T may be provided for tensioning the web of reconstituted tobacco as it is unwound off the bobbin. Further, the apparatus 30 may comprise sensors 40 for detecting the moisture content of the web of reconstituted tobacco upstream of the shredding device 36. In addition, the apparatus 30 may comprise mass flow controllers 42, 44 adapted to adjust the speed at which the web of reconstituted tobacco is fed to the shredding device 36 and the speed of the conveyor belt 38. Sensors 40 and mass flow controllers 42, 44, if present, are operatively connected with a control unit 46 configured to control the operation of the apparatus. In particular, the control unit 46 adjusts the speed to the conveyor belt 38 in view of variations in the speed at which the web of reconstituted tobacco is fed to the shredding device 36, so as to prevent any undesirable accumulation of cut strips on the conveyor belt. The cut strips are then advanced to a further station (not shown) wherein they are blended with a second tobacco material cut in accordance with a second cut specification, such that at least one of cut width and cut length of the cut strips of the second tobacco material differs from a corresponding one of cut width and cut length of the cut strips of the first tobacco material.

EXAMPLE 1 BASIC CUT SPECIFICATIONS

(21) Experiments were carried out in order to assess the impact of different shapes and cut specifications to key parameters of tobacco cut filler particles, such as the filling power.

(22) In a first stage, the CCV was measured at a reference moisture value of 12.5 percent oven volatiles for pure samples each containing tobacco particles cut from a sheet of reconstituted tobacco (basis weight: about 150 grams/square metre) in accordance with a predetermined shape and cut specification. The following Table 1 lists the various cut specifications tested. For each sample, reference is made to the corresponding Figure illustrating the shape. In each Figure, CL1 represents the cut length of the particle, CW1 the overall width or the particle, and SCW1 the cut width of the particle. For the rectangular shapes of FIGS. 7 and 8 the overall width of the particle coincides with the cut width of the particle.

(23) TABLE-US-00001 TABLE 1 Cut specifi- Length Width Cut width cation No. Shape (CL1) (CW1) (SCW1) 1 FIG. 1 20 mm 3.5 mm 0.9 mm 2 FIG. 2 20 mm 3.5 mm 0.9 mm 3 FIG. 3 20 mm 6.3 mm 0.9 mm 4 FIG. 4 20 mm 6.3 mm 0.9 mm 5 FIG. 5 20 mm 6.3 mm 0.9 mm 6 FIG. 6 20 mm 6.3 mm 0.9 mm 7 FIG. 7 20 mm 0.9 mm 0.9 mm 8 FIG. 8 40 mm 0.9 mm 0.9 mm

(24) Table 2 below lists the values of CCV (expressed in cubic centimetres per gram) measured at a reference moisture value of 12.5 percent oven volatiles for each sample. Before each measurement was taken, tobacco particles cut in accordance with the various cut specifications were stored in a conditioned room for 24 hours. The CCV was measured on 5 samples of 20 g for each specification. For each specification, three measurements (CCV1, CCV2 and CCV3) of the CCV were taken on the five samples, and then the total average was calculated and assumed as the effective CCV of the specification. Between repetitions of the measurements, the samples were prepared by detangling the individual strands, so that any compaction occurred during the previous measurement would have as little influence as possible on the subsequently measured CCV.

(25) TABLE-US-00002 TABLE 2 Cut Specifi- CCV cation No. CCV1 CCV2 CCV3 (Average) 1 4.59 4.75 4.74 4.69 2 3.65 3.69 3.83 3.72 3 5.33 5.27 5.32 5.31 4 4.63 4.49 4.65 4.59 5 4.20 4.34 4.20 4.25 6 4.03 3.91 3.85 3.93 7 4.44 4.38 4.70 4.51 8 7.43 7.38 7.40 7.40

EXAMPLE 2 HYBRID CUT SPECIFICATIONS

(26) The highest CCV values were obtained for cut specification no. 3, which substantially corresponds to particles having a Y-shape. However, it was found that when particles were produced from the same sheet of reconstituted tobacco according to cut specification no. 3 are produced, a significant fraction of the tobacco material went to waste. Accordingly, two further hybrid cut specifications were tested. These correspond to the shapes illustrated in FIGS. 9 and 10, respectively, for which the values of CCV listed in the following Table 3 were measured.

(27) TABLE-US-00003 TABLE 3 Cut Specifi- CCV cation No. CCV1 CCV2 CCV3 (Average) 9 5.09 4.79 4.99 4.96 10 5.18 5.12 5.16 5.15

(28) Based on these results, the cut specification no. 10 was identified as the one with the highest CCV and, accordingly, as the most promising for use in a cut filler for the manufacture of a smoking article.

EXAMPLE 3 SMOKING ARTICLES

(29) In a third experiment, the cut specification no. 10 was slightly modified with a view to improving the resistance of the particles to the stresses involved by the cigarette-making process. In particular, there was concern that during the cigarette-making process the tobacco particle would be exposed to high tensions and frictions which might cause particles prepared in accordance with the cut specification no. 10 to break. This may have reduced the benefit coming from the V-shape and shown by the CCV measurements described above.

(30) Accordingly, tobacco particles were prepared from the same sheet of reconstituted tobacco according to the cut specification illustrated in FIG. 12, wherein the cut width SCW1 is of 0.9 millimetres, the cut length CL1 is of 4.94 millimetres and the global width CW1 is of 12.50 millimetres. Should one such particle break at a location in the central V-shaped portion, the two resulting parts of the particles would still be effectively V-shaped.

(31) In addition, the cut specification no. 9 was also slightly modified. Since the CCV measurements appeared to indicate that there is an advantage in terms of filling power coming with V-shaped particles, particles were prepared from a sheet of reconstituted tobacco according to the cut specification illustrated in FIG. 11, wherein the cut width SCW1 is of 0.9 millimetres, the cut length CL1 is of 17.60 millimetres and the global width CW1 is of 6.08 millimetres. An angle of 90 degrees was considered to be undesirable, in that it would lead essentially to a shape quite similar to the shape of FIG. 6, and so an angle of 60 degrees was chosen for the “V” elements.

(32) Tobacco rods were prepared from a tobacco cut filler using tobacco particles cut in accordance with the specifications of FIGS. 11 and 12. In particular, a first couple of blends were used, that contained 85 percent by weight of natural tobacco particles and 15 percent by weight of reconstituted tobacco particles cut in accordance with specifications of FIGS. 11 and 12, respectively. In addition, a second couple of blends was used, that contained 70 percent by weight of natural tobacco particles and 30 percent by weight of reconstituted tobacco particles cut in accordance with the specifications of FIGS. 11 and 12, respectively.