WO2019058134A1

WO2019058134A1 - A smoking article

Info

Publication number: WO2019058134A1
Application number: PCT/GB2018/052699
Authority: WO
Inventors: David Rushforth
Original assignee: British American Tobacco Investments Ltd IFI
Current assignee: British American Tobacco Investments Ltd IFI
Priority date: 2017-09-22
Filing date: 2018-09-21
Publication date: 2019-03-28
Anticipated expiration: 2020-03-22
Also published as: GB201715382D0

Abstract

L'invention concerne un article à fumer (1) comprenant une tige de substance pouvant être fumée (2) et un filtre (3, 4). La tige de substance pouvant être fumée et le filtre sont alignés sur un axe longitudinal commun et sont placés bout à bout. Le filtre comporte une cavité (5) destinée recevoir des cendres et de la substance pouvant être fumée résiduelle de la tige lors de l'extinction de l'article à fumer.The invention relates to a smoking article (1) comprising a smoke-capable rod (2) and a filter (3, 4). The smokable rod of substance and the filter are aligned on a common longitudinal axis and are placed end to end. The filter has a cavity (5) for receiving ash and residual smoke substance from the rod when the smoking article is extinguished.

Description

A Smoking Article

Technical Field

The present invention relates to a smoking article.

Background

Smoking articles such as cigarettes having a combustible tobacco rod and a rod of filter material are known. When the cigarette is alight, a user may inhale through the filter during smoking. After smoking, a consumer is left with a cigarette butt comprising the filter and any remaining ash generated as a result of combustion of the tobacco rod.

Summary

According to the invention there is provided a smoking article comprising a rod of smokeable material and a filter, the rod of smokeable material and filter being aligned to a common longitudinal axis and abutting; the filter comprising a cavity configured to receive ash and residual smokeable material from the rod during stubbing out of the smoking article.

The rod of smokeable material and the filter maybe wrapped in tipping paper.

A portion of the tipping paper wrapped around the rod of smokeable material may comprise a strength discontinuity configured to enable the portion of the tipping paper to collapse in a predetermined manner during stubbing out of the smoking article. The strength discontinuity may comprise at least one line of weakening.

The strength discontinuity may comprise a plurality of lines of weakening, the plurality of lines of weakening comprising discrete rings of weakening spaced apart along the longitudinal axis.

The or each line of weakening may comprise partial cuts that extend through at least a portion of the thickness of the tipping paper.

The or each line of weakening may comprise perforations. The strength discontinuity may be configured so that the portion of the tipping paper concertinas during stubbing out of the smoking article.

The strength discontinuity may comprise pre-folded sections of the tipping paper to facilitate concertinaing of the portion of the tipping paper.

The portion of the tipping paper and the cavity maybe equal in length in the direction of the longitudinal axis. The smoking article may further comprise heat sensitive material, the heat sensitive material being configured to fold inwards towards the longitudinal axis in response to heat from combustion of the smokable material to push ash and residual smokeable material from the rod into the cavity. The rod of smokeable material may comprise a paper tube, wherein a weakened area is provided in the paper tube where a portion of the rod of smokeable material extends adjacent the heat sensitive material.

The weakened area may comprise a plurality of slits in the paper tube extending parallel to the longitudinal axis.

The slits may be spaced apart around the circumference of the paper tube.

The heat sensitive material may be a coating.

The heat sensitive material may comprise a sheet wrapped around at least a portion of the rod of smokeable material.

The sheet may comprise a laminate having a first layer and a second layer, the second layer being disposed radially outward of the first layer, wherein the first layer is configured to shrink in response to the heat from combustion of the smokeable material at a greater rate than the second layer.

The sheet may be wrapped around the filter.

The sheet may be adhered to the filter. The filter may comprise a first portion and a second portion, each aligned to the common longitudinal axis and in abutting relation with each other, wherein the cavity is provided in the second portion.

An axial length of the second portion of the filter may be between 20% and 60% of an axial length of the first portion of the filter.

The rod of smokeable material may have a length at least 45 millimetres.

A diameter of the cavity may be between 55% and 65% of the overall diameter of the rod of smokeable material.

Brief Description of the Drawings

Embodiments of the invention will now be described, by way of example only, to the following drawings, in which:

Fig. 1 shows a cross section of a smoking article, according to an embodiment of the invention, taken along its longitudinal axis;

Fig. 2 shows a perspective view of the smoking article of Fig. 1;

Fig. 3A shows the smoking article of Fig. 1 in a partially smoked state;

Fig. 3B shows the smoking article of Fig. 1 following smoking;

Fig. 4 shows a cross section of a smoking article, according to another embodiment of the invention, taken along its longitudinal axis;

Fig. 5 shows the smoking article of Fig. 4 following smoking;

Fig. 6 shows a detail view of a smoking article according to another embodiment of the invention;

Fig. 7 shows a perspective view of a smoking article according to another embodiment of the invention; and

Fig. 8 shows a perspective view of a smoking article according to another embodiment of the invention.

Detailed Description

Fig. 1 shows a smoking article 1 according to an embodiment of the invention comprising a rod of smokebale material 2 - herein referred to as the tobacco rod 2 - and a filter 3, 4 providing a cavity 5 configured to receive ash and smokeable material from the rod during stubbing out of the smoking article 1. The tobacco rod 2 and filter 3, 4 are aligned to a common longitudinal axis A-A and held together by an outer layer of tipper paper 7 that extends over the filter 3, 4 and at least a portion of the tobacco rod 2. As shown in Fig. 2, a strength discontinuity is provided in the tipping paper 7 where it extends over the at least a portion of the tobacco rod 2. In this embodiment the strength discontinuity is formed of a plurality of lines of weakening 20, the lines of weakening may take the form of, for example, partial cuts, perforations, score lines, fold lines, pre-folded portions and the like. Alternatively, the strength discontinuity may be formed by increasing the strength of particular regions of the tipping paper by, for example, the addition of material such as structured varnish.

The lines of weakening 20 are configured to cause the tipping paper 7 to collapse in response to stubbing out of the smoking article 1 in which an axial force is applied in a direction towards the filter 3, 4 to push residual ash and smokeable material into the cavity 5.

Preferably, the lines of weakening 20 are configured so that the tipping paper 7 collapses in folds like a concertina, thus forming a concertinaed portion that at least partially extends across the open end of the cavity 5, as will be explained in more detail below.

The filter 3, 4 may be constructed from any suitable material known in the art, for example cellulose acetate or paper, and can be wrapped in conventional plug wrap paper 8 as shown in Fig. 1. Preferably the filter 3, 4 is constructed of two cellulose acetate portions, a first portion 3 and a second portion 4, each aligned to the common axis A-A and in abutting relation with each other: The first and second portions 3, 4 being held together by the plug wrap 8. The second portion 4 forms the cavity 5 between the first portion 3 and the tobacco rod 2 and may be constructed from hardened cellulose acetate or another suitable material. Ideally, the second portion 4 has sufficient stiffness to retain its shape when gripped by a smoker. The second portion 4 and the tobacco rod 2 may be held together by the tipping paper 7 as described above, or may be combined prior to application of the tipping paper 7 by the plug wrap 8, in which case the plug wrap 8 will extend to overlap the second portion 4, underneath the tipping paper 7. In the illustrations, the layers of tipping paper 7 and plug wrap 8 are shown slightly spaced apart for ease of reference.

For reasons set out below, it is desirable that the length of the cavity 5 is not less than the length of the tipping paper 7 extending over at least a portion of the tobacco rod 2, where length refers to distance measured along the longitudinal axis A- A.

An axial length of the second portion 4 of the filter 3, 4 may be between 20% and 60% of a total axial length of the filter 3, 4, that is to say, the axial length of the first and second filter portions combined 3, 4. Preferably, said axial length of the second portion 4 of the filter 3, 4 is between 40% and 60%, or more preferably between 50% and 60%, of the total length of the filter 3, 4. Therefore adequate filtration of the smoke is achieved. In the described embodiments, the tobacco rod 2 is conventionally constructed and will be familiar to anyone skilled in the art of cigarette manufacture. For example, and as illustrated, the tobacco rod 2 may comprise cut tobacco 9 wrapped in a tube of cigarette paper 10. The cigarette paper 10 may be held about the tobacco 9 by a strip of adhesive applied to overlapping edges of the paper 10. The tobacco rod 2 may have an axial length between 45 millimetres and 80 millimetres, or more preferably between 55 millimetres and 65 millimetres, therefore corresponding to the length of tobacco rods of conventional cigarettes sizes; such as: regular size, king size, slim, superslim and super king size, which will be apparent to a person skilled in the art. During use of the smoking article 1, the tobacco rod 2 is ignited and the tobacco 9 and cigarette paper 10 combust. The tobacco rod 2 burns down slowly as the tobacco rod 2 is smoked. The tobacco rod 2 in a partially smoked state is shown in FIG. 3A. The burnt tobacco 9 and cigarette paper 10, hereby referred to collectively as ash 11, fall away in the conventional way. Residual ash 11 is shown in cross hatch in FIG. 3A. The smouldering tobacco 9 and cigarette paper 10, is herein referred to as the smouldering portion 12 and shown in dot fill in FIG. 3A. After a period of smoking, the tobacco rod 2 burns at least to the edge of the tipping paper 7, whereupon if the smoker so wishes, they can then extinguish the smoking article 1 by stubbing it out in the normal fashion. The action of stubbing the smoking article 1 causes the tipping paper 7 to fold along the lines of weakening 20 and collapse, preferably into a concertinaed portion 21 (shown in Fig. 3B) which reduces the length of the remaining smoking article 1. Any residual smoking material such as tobacco 9 and ash 11 is compressed into the cavity 5 of the second portion 4 of the filter and the collapsed tipping paper 7 at least partially covers the opening to the cavity 5 to retain the residual smoking material therein. As the length of the cavity 5 may not be less than the length of the tipping paper 7 extending over at least a portion of the tobacco rod 2, any tobacco 9 and residual ash 11 within said at least a portion of the tobacco rod 2 is comfortably received with the cavity 5 following stubbing.

A diameter of the cavity 5 may be between 55% and 65% of the overall diameter of the second portion 4 of the filter 3, 4. In one example, the diameter of the cavity is 5 millimetres and the overall diameter of the second portion of the filter is

8mm.Therefore, the cavity 5 is sufficiently sized to comfortably receive residual smoking material. The overall diameter includes the thickness of the cigarette paper 10. It shall be appreciated that the lines of weakening 20 serve to both reduce the axial load required to fold the tipping paper 7 and ensure that the tipping paper 7 folds only along the lines of weakening 20. Without the lines of weakening 20, the tipping paper 7 would fold in a less predictable fashion and not properly form the concertinaed portion 21. Referring again to Fig. 2, the lines of weakening 20 extend around the tipping paper 7 in discreet rings that are spaced apart along the longitudinal axis A-A. Some or each of the lines of weakening 20 may be formed as partial cuts through a portion of the thickness of the tipping paper 7 or as lines of perforations. The lines of weakening 20 may also be formed as embossed fold lines. Other forms of weakening will be known to those skilled in the art.

Preferably, adjacent lines of weakening 20 are disposed on opposite sides of the tipping paper to encourage adjacent portions of the tipping paper 7 between the lines of weakening to fold in opposite directions, like a concertina.

Optionally, the lines of weakening 20 define pre-folded sections, so that each section is angled slightly relative to the longitudinal axis to further facilitate collapse of the tipping paper like a concertina. Longitudinal cuts 22 may further be provided in the tipping paper 7 extending parallel to the longitudinal axis A-A. The longitudinal cuts 22 extend through the tipping paper 7 where the tipping paper 7 overlaps the tobacco rod 2 so as to bisect the lines of weakening 20. The longitudinal cuts 22 allow the tipping paper 7 to splay as is it folds along the lines of weakening 20. This has the effect of further reducing the axial load required to fold the tipping paper 7.

FIG. 4 shows a smoking article 1 according to another embodiment of the invention, wherein like features retain the same reference numbers. In this embodiment, the lines of weakening 20 and longitudinal cuts 22 mentioned above are optional. In this embodiment, a layer of heat sensitive material 6 is provided around a length of the tobacco rod 2 adjacent the filter 3, 4 and underlying the tipping paper 7. The heat sensitive material 6 is configured to curl inwards towards the longitudinal axis A-A in response to heat from combustion of the tobacco rod 2 during use and after a period smoking. Specifically, when the tobacco rod 2 burns down so that the smouldering portion 12 is in close proximity to the heat sensitive material 6, as shown in FIG. 5, the heat from the smouldering portion 12 causes the heat sensitive material 6 to curl inwards toward the longitudinal axis of the smoking article A-A, cutting off the ash 11 and compressing any remaining tobacco 9 and the smouldering portion 12 into the cavity 5 of the second portion 4 of the filter 3, 4. The heat sensitive material 6 smothers and extinguishes the smouldering portion 12 as it is compressed into the cavity 5.

One advantage of this embodiment is that the smoking article 1 does not need to be stubbed out in order to push residual ash 11 and tobacco 9 into the cavity of the second portion 4 of the filter 3, 4, as this occurs simply as the result of the activation of the heat sensitive material 6.

Having extinguished the smouldering portion 12, the smoking article 1 is more easily disposed of while minimising the risk of combustion spreading to other material.

Further, loose tobacco 9 and any residual ash 11 is contained in the receiving space 5 by the heat sensitive material 6 so that the smoker may, if desired, place the used smoking article 1 in a pocket or other personal receptacle without creating excessive mess.

It is preferable, though not essential, that the band of heat sensitive material 6 overlaps at least a portion of the filter 3, 4, as shown in Figs. 4 and 5. In such embodiments, a portion of heat sensitive material 6 is adhered to the second portion 4 of the filter 3, 4 to provide a surface against which the heat sensitive material 6 can react to force the smouldering portion 12 and residual ash n into the cavity 5 of the second portion 4.

The heat sensitive material 6 may comprise a cellulose based polymer that is configured to shrink when heated by the smouldering portion 12. Specific examples of this material group include the Natureflex range, which is a trademark of Innovia Films.

Alternatively, the heat sensitive material 6 may comprise a substance applied to the paper wrapper 10 of the tobacco rod 2 to prevent combustion of the paper wrapper 10, instead causing it to curl inwards as described above. For example, a PTFE coating could be used.

It shall be appreciated that when the tobacco rod 2 burns down and the smouldering portion 12 is in close proximity to the heat sensitive material 6, the innermost surface of the heat sensitive material, that is the surface facing the smokeable material 9, reaches a higher temperature than the outermost surface, due to its closer proximity to the smouldering portion 12. This results in the innermost surface shrinking to greater degree than the outermost surface and is the reason the heat sensitive material 6 curls in towards the longitudinal axis of the smoking article as described above.

In one embodiment of the invention, shown in detail view in Fig. 6, in which the heat sensitive material comprises a cellulose based polymer layer as described above, like features retaining the same reference numbers, the heat sensitive material 6 is formed from a laminate having a first layer 13 and a second layer 14 each configured to shrink at different rates in response to heat exposure. In this embodiment, the second layer 14 is disposed outermost of the first layer 13 and the first layer 13 is configured to shrink in response to the heat of combustion of the smouldering portion 12 at a greater rate than the second layer 14. Therefore, the first layer 13 of the laminate becomes shorter following exposure to heat than the second layer 14, causing the laminate to curl inwards. Each layer 13, 14 of the laminate may be formed from a cellulose based polymer.

In another embodiment, shown in FIG. 7 in which like features retain the same reference numbers; the cigarette paper 10 of the portion of the tobacco rod 2 disposed beneath the heat sensitive material 6 is provided with a weakened area 15. The weakened area 15 prevents any unburnt cigarette paper 10 from resisting the inward curling motion of the heat sensitive material 6. It shall be appreciated that the weakened area 15 may be weakened in any conventional way. For example, and as illustrated, a plurality of slits 16 may be provided in the tube of cigarette paper 10 extending parallel to the longitudinal axis A-A of the smoking article 1. The slits 16 are spaced apart in regular intervals around the tube of cigarette paper 10 so that, as the tobacco rod 2 burns up to the weakened area 15 and the heat sensitive material 6 curls inwards, the portions of the cigarette paper 10 delimited by the slits 16 are free to fold inwards, towards the longitudinal axis A-A of the smoking article 1.

As an alternative to the slits 16 of FIG. 7, the weakened area 15 may be provided by a plurality of elongate cut out areas as shown in the embodiment of FIG. 8, wherein like features retain the same reference numbers. The cut out areas 17 extend in a direction parallel to the longitudinal axis A-A of the smoking article 1. The cut out areas 17 are spaced apart around the tube of cigarette paper 10 to reduce the total amount of paper underneath the heat sensitive material. The areas of cigarette paper 10 delimited by the cut out areas 17 are more easily folded inward by the heat sensitive material 16 when the tobacco rod 2 burns up to the weakened area 15 and the heat sensitive material 16 curls inwards. In some embodiments of the invention, the tipping paper 7 may be omitted and the filter 3, 4 and tobacco rod 2 are held together by the heat sensitive material 6. In such embodiments, the band of heat sensitive material 6 extends over the second portion 4 of the filter 3, 4 and into overlapping arrangement with the tobacco rod 2.

Claims

1. A smoking article comprising a rod of smokeable material and a filter, the rod of smokeable material and filter being aligned to a common longitudinal axis and abutting; the filter comprising a cavity configured to receive ash and residual smokeable material from the rod during stubbing out of the smoking article.

2. A smoking article according to claim l, wherein the rod of smokeable material and the filter are wrapped in tipping paper.

3. A smoking article according to claim 2, wherein a portion of the tipping paper wrapped around the rod of smokeable material comprises a strength discontinuity configured to enable the portion of the tipping paper to collapse in a predetermined manner during stubbing out of the smoking article.

4. A smoking article according to claim 3, wherein the strength discontinuity comprises at least one line of weakening.

5. A smoking article according to claim 4, wherein the strength discontinuity comprises a plurality of lines of weakening, the plurality of lines of weakening comprising discrete rings of weakening spaced apart along the longitudinal axis.

6. A smoking article according to claim 4 or claim 5, wherein the or each line of weakening comprises partial cuts that extend through at least a portion of the thickness of the tipping paper.

7. A smoking article according to any one of claims 4 to 6, wherein the or each line of weakening comprises perforations.

8. A smoking article according to any one of claims 3 to 7, wherein the strength discontinuity is configured so that the portion of the tipping paper concertinas during stubbing out of the smoking article.

9. A smoking article according to claim 8, wherein the strength discontinuity comprises pre-folded sections of the tipping paper to facilitate concertinaing of the portion of the tipping paper.

10. A smoking article according to any one of claims 3 to 9, wherein the portion of the tipping paper and the cavity are equal in length in the direction of the longitudinal axis.

11. A smoking article according to any one of claims 1 to 10, further comprising heat sensitive material, the heat sensitive material being configured to fold inwards towards the longitudinal axis in response to heat from combustion of the smokable material to push ash and residual smokeable material from the rod into the cavity.

12. A smoking article according to claim 11, wherein the rod of smokeable material comprises a paper tube, and wherein a weakened area is provided in the paper tube where a portion of the rod of smokeable material extends adjacent the heat sensitive material.

13. A smoking article according to claim 12, wherein the weakened area comprises a plurality of slits in the paper tube extending parallel to the longitudinal axis.

14. A smoking article according to claim 13, wherein the slits are spaced apart around the circumference of the paper tube.

15. A smoking article according to any one of claims 11 to 14, wherein the heat sensitive material is a coating.

16. A smoking article according to any one of claims 11 to 14, wherein the heat sensitive material comprises a sheet wrapped around at least a portion of the rod of smokeable material.

17. A smoking article according to claim 16, wherein the sheet comprises a laminate having a first layer and a second layer, the second layer being disposed radially outward of the first layer, wherein the first layer is configured to shrink in response to the heat from combustion of the smokeable material at a greater rate than the second layer.

18. A smoking article according to claim 16 or claim 17, wherein the sheet is wrapped around the filter.

19. A smoking article according to claim 18, wherein the sheet is adhered to the filter.

20. A smoking article according to any one of claims 1 to 19, wherein the filter comprises a first portion and a second portion, each aligned to the common

longitudinal axis and in abutting relation with each other, wherein the cavity is provided in the second portion.

21. A smoking article according to claim 20, wherein an axial length of the second portion of the filter is between 20% and 60% of an axial length of the first portion of the filter.

22. A smoking article according to any one of claims 1 to 21, wherein the rod of smokeable material has a length at least 45 millimetres.

23. A smoking article according to any one of claims 1 to 22, wherein a diameter of the cavity is between 55% and 65% of the overall diameter of the rod of smokeable material.