SMOKING ARTICLE WITH FRONT-PLUG AND METHOD

Abstract

A smoking article for an aerosol-generating device including a heating element is provided, the article retaining an aerosol-forming substrate in fixed relation to and in contact with a cigarette paper of the article after shrinkage of the substrate, the article including cylindrical elements including a front-plug and the substrate assembled in contact with the paper forming a rod having mouth and distal ends, the substrate contacting the heating element when the plug is penetrated by the heating element via the distal end, and in which the article has a first unheated state in which the cigarette paper retains the cylindrical elements in position by an interference interaction in which the paper grips and holds the cylindrical elements within the rod, and a second heated state in which the substrate has shrunk relative to the first state and the paper retains the cylindrical elements in position by the interference interaction.

Claims

1. (canceled)

2. A smoking article for an aerosol-generating device comprising a heating element, the smoking article being configured to retain an aerosol-forming substrate of the smoking article in fixed relation to and in contact with a cigarette paper of the smoking article after shrinkage of the aerosol-forming substrate, the smoking article comprising: a plurality of cylindrical elements, including a front-plug and the aerosol-forming substrate, assembled in contact with the cigarette paper to form a rod, the rod having a mouth end and a distal end upstream from the mouth end, wherein the front-plug is located upstream of the aerosol-forming substrate within the rod, the aerosol-forming substrate coming into contact with the heating element when the front-plug is penetrated by the heating element via the distal end, and wherein the smoking article has two states, including: a first state in which the aerosol-forming substrate is unheated, and in which the cigarette paper retains the plurality of cylindrical elements in position by an interference interaction in which the cigarette paper grips the plurality of cylindrical elements and holds the plurality of cylindrical elements in position within the rod, and a second state, different from the first state, in which the aerosol-forming substrate is heated and has shrunk relative to the first state, and in which the cigarette paper still retains the plurality of cylindrical elements in position by the interference interaction in which the cigarette paper grips the plurality of cylindrical elements and holds the plurality of cylindrical elements in position within the rod.

3. The smoking article according to claim 2, wherein the front-plug has a length of between 1 mm and 10 mm.

4. The smoking article according to claim 2, wherein the front-plug has a diameter approximately equal to a diameter of the smoking article.

5. The smoking article according to claim 2, wherein the front-plug has a diameter of greater than or equal to 5 mm and less than or equal to 10 mm, and a length of between 2 mm and 10 mm.

6. The smoking article according to claim 2, wherein the front-plug has a hole or slit defined therethrough.

7. The smoking article according to claim 6, wherein the aerosol-forming substrate comes into contact with the heating element when the hole or slit of the front-plug is penetrated by the heating element.

8. The smoking article according to claim 2, wherein the front-plug comprises a filter material.

9. The smoking article according to claim 2, further comprising a filter disposed at the mouth end of the rod.

10. The smoking article according to claim 2, wherein a material of the aerosol-forming substrate comprises processed tobacco.

11. The smoking article according to claim 2, wherein the front-plug is configured to wipe a surface of the heating element as the heating element is withdrawn from the smoking article.

12. A method of using a smoking article with an aerosol-generating device comprising a heating element, the smoking article comprising a plurality of cylindrical elements, including a front-plug and an aerosol-forming substrate, assembled in contact with a cigarette paper to form a rod, the rod having a mouth end and a distal end upstream from the mouth end, the front-plug located upstream of the aerosol-forming substrate within the rod, the method comprising: inserting the heating element through the front-plug via the distal end such that the aerosol-forming substrate comes into contact with the heating element; and raising a temperature of the heating element to heat the aerosol-forming substrate from a first state to a second state, the second state being different from the first state, wherein in the first state the aerosol-forming substrate is unheated, and the cigarette paper retains the plurality of cylindrical elements in position by an interference interaction in which the cigarette paper grips the plurality of cylindrical elements and holds the plurality of cylindrical elements in position within the rod, and wherein in the second state the aerosol-forming substrate is heated and has shrunk relative to the first state, and the cigarette paper still retains the plurality of cylindrical elements in position by the interference interaction in which the cigarette paper grips the plurality of cylindrical elements and holds the plurality of cylindrical elements in position within the rod.

13. The method according to claim 12, further comprising: withdrawing the heating element from the smoking article, wherein the front-plug prevents egress of the aerosol-forming substrate when the heating element is withdrawn from the smoking article.

14. The method according to claim 12, wherein the step of inserting the heating element through the front-plug via the distal end such that the aerosol-forming substrate comes into contact with the heating element comprises piercing the front-plug with the heating element.

15. The method according to claim 12, wherein the step of inserting the heating element through the front-plug via the distal end such that the aerosol-forming substrate comes into contact with the heating element comprises inserting the heating element through a hole or slit defined in the front-plug.

16. The method according to claim 12, further comprising: withdrawing the heating element from the smoking article; and wiping a surface of the heating element as the heating element is withdrawn from the smoking article.

Description

[0048] Specific embodiments will now be described with reference to the figures, in which;

[0049] FIG. 1 is a schematic cross-sectional diagram of a smoking article according to a first embodiment engaged with an aerosol-generating device;

[0050] FIG. 2 is a schematic diagram illustrating a front-end projection of the smoking article according to the first embodiment, showing penetration of the front-plug of the smoking article by a heating element;

[0051] FIG. 3A is a schematic diagram illustrating a front-end projection of a smoking article according to a second embodiment, showing penetration of the front-plug of the smoking article by a heating element;

[0052] FIG. 3B is a schematic diagram illustrating a front-end projection of a smoking article according to a third embodiment, showing penetration of the front-plug of the smoking article by a heating element; and

[0053] FIG. 3C is a schematic diagram illustrating a front-end projection of a smoking article according to a fourth embodiment, showing penetration of the front-plug of the smoking article by a heating element.

[0054] FIG. 1 illustrates a smoking article 1 according to a first embodiment. The smoking article 1 comprises five elements, a front-plug 2, an aerosol-forming substrate 7, a hollow cellulose acetate tube 6, a transfer section 4, and a mouthpiece filter 3. These five elements are arranged sequentially and in coaxial alignment and are assembled by a cigarette paper 5 to form a rod 15. The rod has a mouth-end 20, which a user inserts into his or her mouth during use, and a distal end 30 located at the opposite end of the rod 15 to the mouth end 20. Elements located between the mouth-end 20 and the distal end 30 can be described as being upstream of the mouth-end 20 or, alternatively, downstream of the distal end 30.

[0055] When assembled, the rod 15 is 52 millimetres long and has a diameter of 7.2 millimetres.

[0056] The front-plug 2 is a cylindrical portion of cellulose acetate tow having a length of 7 millimetres. The fibres of the cellulose acetate tow are aligned with the longitudinal direction of the rod 15.

[0057] The aerosol-forming substrate 7 is located downstream of the front-plug 2 and comprises a bundle of crimped cast-leaf tobacco wrapped in a filter paper. The cast-leaf tobacco includes additives, including glycerine as an aerosol-forming additive.

[0058] The tube 6 is located immediately downstream of the aerosol-forming substrate 7 and is formed from cellulose acetate. The tube 6 defines an aperture having a diameter of 3.3 millimetres. One function of the tube 6 is to locate the aerosol-forming substrate 7 towards the distal end 30 of the rod 15 so that it can be contacted with a heating element. The tube 6 acts to prevent the aerosol-forming substrate 7 from being forced along the rod 15 towards the mouth-end 20 when a heating element is inserted.

[0059] The transfer section 4 comprises a thin-walled tube of 18 millimetres in length. The transfer section 4 allows volatile substances released from the aerosol-forming substrate 7 to pass along the rod 15 towards the mouth end 20. The volatile substances may cool within the transfer section 4 to form an aerosol.

[0060] The mouthpiece filter 3 is a conventional mouthpiece filter formed from cellulose acetate, tow and having a length of 7 millimetres.

[0061] The five elements identified above are assembled by being tightly wrapped within a cigarette paper 5. The cigarette paper 5 in this specific embodiment is a conventional cigarette paper. For example, the cigarette paper may be a porous material with a non-isotropic structure comprising cellulose fibres (crisscross of fibres interlinked by hydrogen bonds), one or more fillers and one or more combustion agents. The one or more fillers may be, for example, calcium carbonate (CaCO.sub.3) and the one or more combustion agents may be, for example, one or more of the following: potassium/sodium citrate; sodium acetate; mono-ammonium phosphate (MAP); and di-sodium phosphate (DSP). The final composition of the cigarette paper per square metre may be approximately 25 g cellulose fibres, 10 g calcium carbonate, and 0.2 g combustion agent. The porosity of the cigarette paper may be between approximately 0 Coresta and approximately 120 Coresta. The interface between the cigarette paper 5 and each of the elements locates the elements and defines the rod 15 of the smoking article 1.

[0062] Although the specific embodiment described above and illustrated in FIG. 1 has five elements assembled in a cigarette paper, it will now be clear to one of ordinary skill in the art that a smoking article according to the embodiments discussed here may have additional elements and these elements may be assembled in an alternative cigarette wrapper or equivalent. Likewise, a smoking article according to the embodiments discussed here may have fewer elements. Moreover, it will now be apparent to one of ordinary skill in the art that various dimensions for the elements discussed in relation to the various embodiments discussed here are merely exemplary, and that suitable alternative dimensions for the various elements may be chosen without deviating from the spirit of the embodiments discussed herein.

[0063] The smoking article of the first embodiment is consumed or smoked in conjunction with a suitable aerosol-generating device. FIG. 1 illustrates the smoking article when engaged with such a device 11 for consumption.

[0064] The aerosol-generating device 11 comprises a sheath 12 for receiving the smoking article 1 for consumption. A heating element 8 is located within the sheath 12 and positioned to engage with the distal end 30 of the smoking article 1. The heating element 8 is shaped in the form of a blade terminating in a point 40.

[0065] As the smoking article 1 is pushed into the sheath 12 the point 40 of the heating element 8 engages with an outer surface of the front-plug 2. By applying a force to the smoking article 1, the heating element 8 penetrates the front plug 2 and the point 40 of the heating element 8 is then brought into contact with the aerosol-forming substrate 7. The application of further pressure causes the heating element 8 to penetrate into the aerosol-forming substrate 7. Further penetration is prevented as the distal end 30 of the smoking article 1 abuts an end wall of the sheath 12, which acts as a stop.

[0066] When the smoking article 1 is properly engaged with the aerosol-generating device 11, the heating element 8 has been inserted through the front-plug 2 and is located within the aerosol-forming substrate 7 in contact with aerosol-forming material. An insulating collar 9 may surround a portion of the heating element 8 that is in contact with the front-plug 2. The collar 9 may alternatively be a cool zone provided on the length of the heating element 8. Such a collar may prevent the heating element 8 from burning or melting the front-plug 2.

[0067] FIG. 2 is a front-end view of the smoking article 1 when engaged with the heating element 8. This view shows the cigarette paper 5 in contact with the front-plug 2. The heating element 8, which can be seen to have a blade shaped cross-section, has been inserted through the front-plug 2. The heating element 8 has deformed the cellulose acetate material forming the front-plug 2 slightly, and the resilience of this cellulose acetate material results in there being a firm contact between the front-plug 2 and outer surfaces of the heating element 8.

[0068] The aerosol-generating device 11 comprises a power supply and electronics (not shown) that allow the heating element 8 to be actuated. Such actuation may be manually operated or may occur automatically in response to a user drawing on the smoking article 1. When the heating element 8 is actuated, the aerosol-forming substrate 7 is heated and volatile substances are generated or evolved. As a user draws on the mouth end 20 of the smoking article 1, air is drawn into the smoking article 1 and the volatile substances condense to form an inhalable aerosol. This aerosol passes through the mouth-end 20 of the smoking article 1 and into the user's mouth.

[0069] The heating element 8 is heated to a temperature of about 375 degrees Celsius in order to generate an aerosol from the aerosol-forming substrate 7. As volatile substances are driven off the aerosol-forming substrate 7 by heat, the aerosol-forming substrate 7 dries out and shrinks. This can result in the aerosol-forming substrate 7 gripping the heating element 8. Simultaneously, the shrinkage of the aerosol-forming substrate 7 may cause a loss in contact with the cigarette paper 5. In the first embodiment the aerosol-forming substrate 7 is in the form of a plug, and the shrinkage causes this plug to become loose within the rod 15 of the smoking article 1.

[0070] After use, the user withdraws the smoking article 1 from the aerosol-generating device 11. The smoking article 1 is withdrawn from the sheath 12 and the heating element 8 slides out of the front-plug 2. Because the adherence between the heating element 8 and the aerosol-forming substrate 7 is greater than the adherence between the aerosol-forming substrate 7 and the cigarette paper 5, the aerosol-forming substrate 7 moves towards the distal end 30 with the heating element 8. However, the front-plug 2 blocks the path of the aerosol-forming substrate 7. This allows the heating element 8 to be withdrawn from the aerosol-forming substrate 7 without removing the aerosol-forming substrate 7 from the smoking article 1.

[0071] Particles of the aerosol-forming substrate 7 or residues derived from the aerosol-forming substrate 7 may become stuck to the heating element 8 during operation. As the heating element 8 is withdrawn from the smoking article 1, the outer surface of the heating element 8 is wiped by the front-plug 2. Thus, the heating element 8 is automatically cleaned by wiping every time a smoking article 1 is removed from the aerosol-generating device 11.

[0072] The first embodiment described above with reference to FIGS. 1 and 2 describes a smoking article 1 having its distal end 30 closed by a solid front-plug 2. Such a front-plug 2 requires a heating element 8 to be forced through the front-plug 2 to contact the aerosol-forming substrate 7.

[0073] A second embodiment of a smoking article 100 is illustrated in FIG. 3A (end view only). The smoking article 100 of FIG. 3A is identical to the smoking article 1 of the first embodiment described above apart from the configuration of the front-plug 102. The front-plug 102 is formed from cellulose acetate and is assembled in contact with a cigarette paper 5, but the front-plug 102 defines a substantially circular through-hole 103 allowing through-access to a heating element of an aerosol-generating device. The heating element can pass through the front-plug 102 with minimal insertion force required. The circular shape of the hole 103 means that there is no special orientation relationship required between the smoking article 100 and the heating element in order to engage the smoking article 100 with the aerosol-generating device.

[0074] In use, the front-plug 102 of the smoking article 100 acts in the same way as described above to prevent egress of an aerosol-forming substrate from the smoking article 100.

[0075] A third embodiment of a smoking article 200 is illustrated in FIG. 3B (end view only). The smoking article 200 of FIG. 3B is identical to the smoking article 1 of the first embodiment described above apart from the configuration of the front-plug 202. The front-plug 202 is formed from cellulose acetate and is assembled in contact with a cigarette paper 5, but the front-plug 202 defines a number of slits 203 allowing through-access to a heating element of an aerosol-generating device. The slits 203 lower the insertion force required to insert a heating element into the smoking article 200.

[0076] In use, the front-plug 202 of the smoking article 200 acts in the same way as described above to prevent egress of an aerosol-forming substrate from the smoking article 200. Furthermore, the slits 203 impinge on the heating element and effectively wipe an outer surface of the heating element when the heating element is removed from the smoking article 200, providing a cleaning effect as described above.

[0077] A fourth embodiment of a smoking article 300 is illustrated in FIG. 3C (end view only). The smoking article 300 of FIG. 3C is identical to the smoking article 1 of the first embodiment described above apart from the configuration of the front-plug 302. The front-plug 302 is formed from cellulose acetate and is assembled in contact with a cigarette paper 5, but the front-plug defines a star-shaped hole 303 allowing through-access to a heating element of an aerosol-generating device. The hole lowers the insertion force required to insert a heating element into the smoking article 300. The shape of the hole 303 allows the heating element to engage with the front-plug 302 of the smoking article 300 and prevent rotation of the smoking article 300 while it is being consumed.

[0078] In use, the front-plug 302 of the smoking article 300 acts in the same way as described above to prevent egress of an aerosol-forming substrate from the smoking article 300.

[0079] Although described above as formed from cellulose acetate, it will now be clear to one of ordinary skill in the art that the front-plugs 2, 102, 202, and 302 of the smoking articles could alternatively be formed of any suitable material or combination of materials. For example, the front-plug may be solely comprised of tobacco, a substantially tobacco comprised material, or a combination of tobacco or a substantially tobacco comprised material with another suitable material. Such materials and suitable combinations of materials will now be apparent to one of ordinary skill in the art.

[0080] The exemplary embodiments described above are not limiting. In view of the above discussed exemplary embodiments, other embodiments consistent with the above exemplary embodiments will now be apparent to one of ordinary skill in the art.