Patent Publication Number: US-2020288774-A1

Title: Article for use with apparatus for heating smokable material

Description:
PRIORITY CLAIM 
     This application is a continuation of application Ser. No. 15/772,394 filed Apr. 30, 2018, which in turn is a National Phase entry of PCT Application No. PCT/EP2016/075737, filed Oct. 26, 2016, which claims priority from U.S. patent application Ser. No. 14/927,539, filed Oct. 30, 2015, each of which is hereby fully incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to articles for use with apparatus for heating smokable material to volatilize at least one component of the smokable material, and to systems comprising such apparatus and such articles. 
     BACKGROUND 
     Smoking articles such as cigarettes, cigars and the like burn tobacco during use to create tobacco smoke. Attempts have been made to provide alternatives to these articles by creating products that release compounds without combusting. Examples of such products are so-called “heat not burn” products or tobacco heating devices or products, which release compounds by heating, but not burning, material. The material may be, for example, tobacco or other non-tobacco products, which may or may not contain nicotine. 
     SUMMARY 
     A first aspect of the present disclosure provides an article for use with apparatus for heating smokable material to volatilize at least one component of the smokable material, the article comprising: a sheet comprising smokable material; and heating material that is heatable by penetration with a varying magnetic field to heat the smokable material. 
     In an exemplary embodiment, the heating material is in contact with the sheet. 
     In an exemplary embodiment, the heating material is on a surface of the sheet. 
     In an exemplary embodiment, the heating material is embedded within the sheet. 
     In an exemplary embodiment, the smokable material comprises reconstituted smokable material. 
     In an exemplary embodiment, the sheet consists entirely or substantially entirely of the reconstituted smokable material. 
     In an exemplary embodiment, the sheet is planar or substantially planar. 
     In an exemplary embodiment, the sheet is a rolled sheet. 
     In an exemplary embodiment, an axial length of the rolled sheet is greater than a diameter of the rolled sheet. 
     In an exemplary embodiment, the article comprises at least one connector comprising heating material that is heatable by penetration with a varying magnetic field, wherein the rolled sheet is elongate in an axial direction, and wherein the, or each, connector is located at a longitudinal end of the rolled sheet so that the heating material of the, or each, connector contacts the heating material that is heatable by penetration with a varying magnetic field to heat the smokable material. 
     In an exemplary embodiment, the article comprises a mass of smokable material discrete from, and encircled by, the rolled sheet. 
     In an exemplary embodiment, the article comprises adhesive adhering two portions of the rolled sheet to each other. 
     In an exemplary embodiment, all or substantially all of a surface of the sheet is covered by the heating material. 
     In an exemplary embodiment, a surface of the sheet is only partially covered by the heating material. 
     In an exemplary embodiment, the article comprises a plurality of discrete bodies on a surface of the sheet, wherein each of the discrete bodies comprises the heating material. 
     In an exemplary embodiment, each of the discrete bodies comprises a tube comprising the heating material. In an exemplary embodiment, each of the tubes is a carbon tube. 
     In an exemplary embodiment, each of the discrete bodies comprises a strip or track comprising the heating material. 
     In an exemplary embodiment, the heating material is in the form of at least one spiral. 
     In an exemplary embodiment, the heating material is in the form of at least one closed circuit. 
     In an exemplary embodiment, the article comprises ink on the sheet, wherein the ink comprises the heating material. 
     In an exemplary embodiment, the heating material comprises one or more materials selected from the group consisting of: an electrically-conductive material, a magnetic material, and a magnetic electrically-conductive material. 
     In an exemplary embodiment, the heating material comprises a metal or a metal alloy. 
     In an exemplary embodiment, the heating material comprises one or more materials selected from the group consisting of: aluminum, gold, iron, nickel, cobalt, conductive carbon, graphite, plain-carbon steel, stainless steel, ferritic stainless steel, copper, and bronze. 
     In an exemplary embodiment, the heating material is in contact with the smokable material. 
     In an exemplary embodiment, the smokable material comprises tobacco and/or one or more humectants. 
     A second aspect of the present disclosure provides an article for use with apparatus for heating smokable material to volatilize at least one component of the smokable material, the article comprising: a sheet comprising smokable material; and an adhesive surface for adhering the sheet to a carrier. 
     In an exemplary embodiment, the adhesive surface comprises adhesive on a surface of the sheet. 
     In an exemplary embodiment, the adhesive surface is a surface of the sheet. 
     In an exemplary embodiment, the sheet is a rolled sheet. 
     In an exemplary embodiment, the smokable material comprises reconstituted smokable material. 
     In an exemplary embodiment, the sheet consists entirely or substantially entirely of the reconstituted smokable material. 
     In an exemplary embodiment, the article comprises a backing sheet, wherein the adhesive surface is in contact with the backing sheet. 
     In an exemplary embodiment, the backing sheet is removable from the adhesive surface to expose the adhesive surface. 
     In an exemplary embodiment, the backing sheet comprises glass fibers and/or carbon fibers. 
     A third aspect of the present disclosure provides a system, comprising: apparatus for heating smokable material to volatilize at least one component of the smokable material; and an article for use with the apparatus, the article comprising a sheet comprising smokable material, and heating material that is heatable by penetration with a varying magnetic field to heat the smokable material; wherein the apparatus comprises a heating zone for receiving at least a portion of the article, and a magnetic field generator for generating a varying magnetic field to be used in heating the smokable material when the portion of the article is in the heating zone. 
     In an exemplary embodiment, the smokable material comprises reconstituted smokable material. 
     In an exemplary embodiment, the apparatus comprises heating material that is heatable by penetration with the varying magnetic field to heat the smokable material when the portion of the article is in the heating zone. 
     In an exemplary embodiment, the article of the system is the article of the first aspect of the present disclosure. The article of the system may have any one or more of the features discussed above as being present in respective exemplary embodiments of the article of the first aspect of the present disclosure. 
     In an exemplary embodiment, the article of the system is the article of the second aspect of the present disclosure. The article of the system may have any one or more of the features discussed above as being present in respective exemplary embodiments of the article of the second aspect of the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1  shows a schematic perspective view of an example of an article for use with apparatus for heating smokable material to volatilize at least one component of the smokable material. 
         FIG. 2  shows a schematic perspective view of an example of another article for use with apparatus for heating smokable material to volatilize at least one component of the smokable material. 
         FIG. 3  shows a schematic perspective view of an example of another article for use with apparatus for heating smokable material to volatilize at least one component of the smokable material. 
         FIG. 4  shows a schematic front view of an example of another article for use with apparatus for heating smokable material to volatilize at least one component of the smokable material. 
         FIG. 5  shows a schematic front view of an example of another article for use with apparatus for heating smokable material to volatilize at least one component of the smokable material. 
         FIG. 6  shows a schematic side view of an example of another article for use with apparatus for heating smokable material to volatilize at least one component of the smokable material. 
         FIG. 7  shows a schematic perspective view of an example of another article for use with apparatus for heating smokable material to volatilize at least one component of the smokable material. 
         FIG. 8  shows a schematic perspective view of an example of another article for use with apparatus for heating smokable material to volatilize at least one component of the smokable material. 
         FIG. 9  shows a schematic cross-sectional view of an example of a system comprising the article of  FIG. 2  and apparatus for the heating smokable material of the article to volatilize at least one component of the smokable material. 
     
    
    
     DETAILED DESCRIPTION 
     As used herein, the term “smokable material” includes materials that provide volatilized components upon heating, typically in the form of vapor or an aerosol. “Smokable material” may be a non-tobacco-containing material or a tobacco-containing material. “Smokable material” may, for example, include one or more of tobacco per se, tobacco derivatives, expanded tobacco, reconstituted tobacco, tobacco extract, homogenized tobacco or tobacco substitutes. The smokable material can be in the form of ground tobacco, cut rag tobacco, extruded tobacco, reconstituted tobacco, reconstituted smokable material, liquid, gel, gelled sheet, powder, or agglomerates, or the like. “Smokable material” also may include other, non-tobacco, products, which, depending on the product, may or may not contain nicotine. “Smokable material” may comprise one or more humectants, such as glycerol or propylene glycol. 
     As used herein, the term “heating material” or “heater material” refers to material that is heatable by penetration with a varying magnetic field. 
     As used herein, the term “reconstituted smokable material” refers to reconstituted tobacco (sometimes itself referred to as tobacco “recon”), such as reconstituted tobacco sheet, or other reconstituted smokable material. The reconstituted smokable material may comprise a plurality of different types of tobacco or other smokable material, which may have been selected to improve the transmission of tobacco tastes and flavors to a user in use. For example, the reconstituted smokable material may comprise one or more of sun-cured tobacco, dark air-cured tobacco, fire-cured tobacco or any other suitable tobacco type. The reconstituted smokable material may be produced by subjecting smokable material to one or more processes comprising drying the smokable material, milling the dried smokable material to a particle size suitable for making a sheet, optionally adding fiber, a binding agent and/or a humectant, and/or forming the resultant product into a reconstituted sheet. In some embodiments, the reconstituted smokable material may be produced by subjecting smokable material to one or more processes comprising mixing the smokable material with a solvent such as an aqueous solvent, separating a soluble portion of the smokable material from an insoluble portion, mechanically refining the insoluble portion to produce a pulp, forming the sheet into a pulp, removing excess liquid from the pulp, concentrating the soluble portion such as by evaporation, recombining the concentrated solubles with the sheet, and then drying the resultant product. 
     As used herein, the terms “flavor” and “flavorant” refer to materials which, where local regulations permit, may be used to create a desired taste or aroma in a product for adult consumers. They may include extracts (e.g., licorice, hydrangea, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, menthol, Japanese mint, aniseed, cinnamon, herb, wintergreen, cherry, berry, peach, apple, Drambuie, bourbon, scotch, whiskey, spearmint, peppermint, lavender, cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, honey essence, rose oil, vanilla, lemon oil, orange oil, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, piment, ginger, anise, coriander, coffee, or a mint oil from any species of the genus Mentha), flavor enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and/or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example, oil, liquid, gel, powder, or the like. 
     Induction heating is a process in which an electrically-conductive object is heated by penetrating the object with a varying magnetic field. The process is described by Faraday&#39;s law of induction and Ohm&#39;s law. An induction heater may comprise an electromagnet and a device for passing a varying electrical current, such as an alternating current, through the electromagnet. When the electromagnet and the object to be heated are suitably relatively positioned so that the resultant varying magnetic field produced by the electromagnet penetrates the object, one or more eddy currents are generated inside the object. The object has a resistance to the flow of electrical currents. Therefore, when such eddy currents are generated in the object, their flow against the electrical resistance of the object causes the object to be heated. This process is called Joule, ohmic, or resistive heating. An object that is capable of being inductively heated is known as a susceptor. 
     It has been found that, when the susceptor is in the form of a closed circuit, magnetic coupling between the susceptor and the electromagnet in use is enhanced, which results in greater or improved Joule heating. 
     Magnetic hysteresis heating is a process in which an object made of a magnetic material is heated by penetrating the object with a varying magnetic field. A magnetic material can be considered to comprise many atomic-scale magnets, or magnetic dipoles. When a magnetic field penetrates such material, the magnetic dipoles align with the magnetic field. Therefore, when a varying magnetic field, such as an alternating magnetic field, for example as produced by an electromagnet, penetrates the magnetic material, the orientation of the magnetic dipoles changes with the varying applied magnetic field. Such magnetic dipole reorientation causes heat to be generated in the magnetic material. 
     When an object is both electrically-conductive and magnetic, penetrating the object with a varying magnetic field can cause both Joule heating and magnetic hysteresis heating in the object. Moreover, the use of magnetic material can strengthen the magnetic field, which can intensify the Joule heating. 
     In each of the above processes, as heat is generated inside the object itself, rather than by an external heat source by heat conduction, a rapid temperature rise in the object and more uniform heat distribution can be achieved, particularly through selection of suitable object material and geometry, and suitable varying magnetic field magnitude and orientation relative to the object. Moreover, as induction heating and magnetic hysteresis heating do not require a physical connection to be provided between the source of the varying magnetic field and the object, design freedom and control over the heating profile may be greater, and cost may be lower. 
     Referring to  FIG. 1  there is shown a schematic perspective view of an example of an article according to an embodiment of the disclosure. The article  1  comprises a sheet  10  comprising reconstituted smokable material, and heating material  20  that is heatable by penetration with a varying magnetic field to heat the smokable material. Examples of such heating material are described below. The article  1  is for use with apparatus for heating the smokable material to volatilize at least one component of the smokable material without burning the smokable material. Such an apparatus may comprise a magnetic field generator for generating a varying magnetic field to be used in heating the heating material. An example such apparatus  100  is shown in  FIG. 9  and described below. 
     In this embodiment, the sheet  10  is planar, or substantially planar. However, the sheet  10  is bendable or rollable so as to from a rolled sheet. By “rolled sheet”, it is meant that the sheet  10  is curved, such as without folding, so that the sheet  10  has an elongate spiral or tubular shape. Such a rolled sheet may be less prone to damage, more convenient to store and handle, and better suited for use with the apparatus than the planar sheet. 
     In this embodiment, the heating material  20  is in contact with the sheet  10 . More specifically, in this embodiment, the heating material  20  is on a surface of the sheet  10 . Still more specifically, in this embodiment, all or substantially all of a surface of the sheet  10  is covered by a layer that comprises the heating material  20 . The layer may be a foil layer. However, as will be apparent from the description below, in other embodiments the surface of the sheet  100  may be only partially covered by the heating material  20 . Further, in some embodiments, the heating material  20  may be on both opposite surfaces of the sheet  10 . For example, in some embodiments, all, substantially all, a majority, or only a portion of each of two opposite surfaces of the sheet  10  may be covered by heating material  20 . 
     Referring to  FIG. 2  there is shown a schematic perspective view of an example of another article according to an embodiment of the disclosure. The article  2  of  FIG. 2  is identical to the article  1  described above with reference to  FIG. 1 , other than the manner in which heating material is provided in the article  2 . Any of the herein-described possible variations to the article  1  of  FIG. 1  may be made to the article  2  of  FIG. 2  to form separate respective embodiments. 
     In this embodiment, the heating material  20  again is on a surface of the sheet  10  comprising reconstituted smokable material. However, in this embodiment, the article  2  comprises a plurality of discrete bodies  22   a ,  22   b ,  22   c ,  22   d  on a surface of the sheet  10 , and each of the discrete bodies  22   a ,  22   b ,  22   c ,  22   d  comprises the heating material  20 . In this embodiment, each of the discrete bodies  22   a ,  22   b ,  22   c ,  22   d  comprises a strip or track  22   a ,  22   b ,  22   c ,  22   d  on a surface of the surface of the sheet  10 . 
     In this embodiment, the strips  22   a ,  22   b ,  22   c ,  22   d  are parallel to each other, but in other embodiments this may not be the case. Further, in this embodiment, the strips  22   a ,  22   b ,  22   c ,  22   d  are all on one surface of the sheet  10 , but in other embodiments there may be one or more such strips on both opposite surfaces of the sheet  10 . In some embodiments, there may be only one such strip  22   a ,  22   b ,  22   c ,  22   d  on a surface of the sheet  10 . 
     In this embodiment, the strips  22   a ,  22   b ,  22   c ,  22   d  are linear. In other embodiments, some or all of the strips  22   a ,  22   b ,  22   c ,  22   d  may be non-linear, such as curved or wavy. 
     In this embodiment, the strips  22   a ,  22   b ,  22   c ,  22   d  are of substantially equal width in a direction perpendicular to their respective elongate dimensions, and substantially equal thicknesses in a direction normal to the surface on which they are provided. In other embodiments, the strips  22   a ,  22   b ,  22   c ,  22   d  may be of different respective widths and/or thicknesses. Regions of the smokable material adjacent the wider or thicker tracks may then be heated to a lesser degree by the application of a given varying magnetic field than regions of the smokable material adjacent the narrower tracks. Moreover, in some embodiments, the width and/or thickness of one or more of the strips  22   a ,  22   b ,  22   c ,  22   d  may vary along the path the strip follows. Therefore, in some embodiments, one or more portions of the heating material  20  is/are able to heat first region(s) of the smokable material relatively quickly to initialize volatilization of at least one component of the smokable material and formation of vapor in the first region(s) of the smokable material, and one or more portions of the heating material  20  is/are able to heat second region(s) of the smokable material relatively slowly to initialize volatilization of at least one component of the smokable material and formation of vapor in the second region(s) of the smokable material. Accordingly, vapor is able to be formed relatively rapidly for inhalation by a user, and vapor can continue to be formed thereafter for subsequent inhalation by the user even after the first region(s) of the smokable material may have ceased generating vapor. A given region of the smokable material may cease generating the vapor when the region becomes exhausted of volatilizable components of the smokable material. 
     In each of the embodiments discussed herein, the heating material  20  may have a skin depth, which is an exterior zone within which most of an induced electrical current and/or induced reorientation of magnetic dipoles occurs. By providing that the component comprising the heating material  20  has a relatively small thickness, a greater proportion of the heating material  20  may be heatable by a given varying magnetic field, as compared to heating material in a component having a depth or thickness that is relatively large as compared to the other dimensions of the component. Thus, a more efficient use of material is achieved. In turn, costs are reduced. 
     In some embodiments, the strip or strips  22   a ,  22   b ,  22   c ,  22   d  is/are in the form ink comprising the heating material  20 . During manufacture, the ink may be printed on the sheet  10 , for example using gravure printing. Ink may have a small thickness. Therefore, induced electrical current and/or induced reorientation of magnetic dipoles in the ink when subjected to a varying magnetic field may penetrate most or all of the ink, rather than be confined to just a “skin” thereof as can be the case when a component comprising heating material has too great a thickness. Thus, a more efficient use of material is achieved and, in turn, costs are reduced. In other embodiments, the strip or strips  22   a ,  22   b ,  22   c ,  22   d  may be adhered or otherwise provided on the surface of the sheet  10  in a different manner. 
     Referring to  FIG. 3  there is shown a schematic perspective view of an example of another article according to an embodiment of the disclosure. The article  3  of  FIG. 3  is identical to the article  2  described above with reference to  FIG. 2 , other than the manner in which heating material is provided in the article  3 . Any of the herein-described possible variations to the article  2  of  FIG. 2  may be made to the article  3  of  FIG. 3  to form separate respective embodiments. 
     In this embodiment, the article  3  again comprises a plurality of discrete bodies  24   a ,  24   b ,  24   c  on a surface of the sheet  10 , and each of the discrete bodies  24   a ,  24   b ,  24   c  again comprises the heating material  20 . However, in this embodiment, each of the discrete bodies  24   a ,  24   b ,  24   c  comprises a tube  24   a ,  24   b ,  24   c  on a surface of the sheet  10 . The tubes  24   a ,  24   b ,  24   c  may be affixed to the surface of the sheet  10  by an adhesive or the like. In this embodiment, the tubes  24   a ,  24   b ,  24   c  are aligned axially parallel to each other. In some embodiments, the tubes  24   a ,  24   b ,  24   c  are aligned magnetically with each other. That is, magnetic dipoles within the tubes  24   a ,  24   b ,  24   c  are aligned magnetically with each other. It has been found that, when the tubes  24   a ,  24   b ,  24   c  are aligned magnetically with each other, magnetic coupling between the tubes  24   a ,  24   b ,  24   c  and an electromagnet of the apparatus may be enhanced in use, which results in greater or improved Joule heating of the tubes  24   a ,  24   b ,  24   c , and thus greater or improved heating of the smokable material. In other embodiments, the tubes  24   a ,  24   b ,  24   c  may be aligned at different relative orientations. 
     In this embodiment, the tubes  24   a ,  24   b ,  24   c  are all on one surface of the sheet  10 . In other embodiments there may be one or more such tubes  24   a ,  24   b ,  24   c  on both opposite surfaces of the sheet  10 . In some embodiments, there may be only one such tube  24   a ,  24   b ,  24   c  on a surface of the sheet  10 . 
     In some embodiments, the, or each, tube  24   a ,  24   b ,  24   c  may be a carbon tube. In some embodiments, the, or each, tube  24   a ,  24   b ,  24   c  may have an outer diameter that is within the range of 0.05 to 2.0 millimeters, or within the range of 0.1 to 1.0 millimeters, such as approximately 0.5 millimeters. 
     In this embodiment, each of the tubes  24   a ,  24   b ,  24   c  comprises a closed circuit of heating material that is heatable by penetration with a varying magnetic field. In some embodiments, this can result in magnetic coupling between the tubes  24   a ,  24   b ,  24   c  and an electromagnet of the apparatus in use being enhanced, which results in greater or improved Joule heating. 
     A tubular element can have a small cross-sectional area to diameter ratio. Therefore, the circulating current in the tube when subjected to a varying magnetic field may penetrate most or all of the tube, rather than be confined to just a “skin” thereof as can be the case when a component comprising heating material has too greater a thickness. Thus, a more efficient use of material is achieved and, in turn, costs are reduced. 
     In this embodiment, each of the tubes  24   a ,  24   b ,  24   c  consists entirely, or substantially entirely, of the heating material. However, in other embodiments, one or more of the tubes  24   a ,  24   b ,  24   c  may comprise a carrier that is free of heating material and that carries the heating material. For example, one or more of the tubes  24   a ,  24   b ,  24   c  may comprise a tubular carrier free of heating material with a closed-circuit of the heating material coated thereon. 
     In some variations to this embodiment, some or all of the tubes  24   a ,  24   b ,  24   c  may be replaced with a loop-shaped or ring-shaped element comprising a closed circuit of heating material, or a carrier that is free of heating material and that carries the closed circuit of heating material. A loop-shaped element may be of any shape that defines a path that starts and ends at the same point so as to create a closed circuit, whereas a ring-shaped element necessarily is circular or substantially circular. 
     Referring to  FIG. 4  there is shown a schematic perspective view of an example of another article according to an embodiment of the disclosure. The article  4  of  FIG. 4  is identical to the article  2  described above with reference to  FIG. 2 , other than the manner in which heating material is provided in the article  4 . Any of the herein-described possible variations to the article  2  of  FIG. 2  may be made to the article  4  of  FIG. 4  to form separate respective embodiments. 
     In this embodiment, the article  4  again comprises a plurality of discrete bodies  26   a ,  26   b ,  26   c  on a surface of the sheet  10 , and each of the discrete bodies  26   a ,  26   b ,  26   c  again comprises the heating material  20 . However, in this embodiment, each of the discrete bodies  26   a ,  26   b ,  26   c  comprises a closed circuit  26   a ,  26   b ,  26   c  of the heating material  20 . Again, in some embodiments, such a closed circuit of heating material can result in magnetic coupling between the closed circuit(s)  26   a ,  26   b ,  26   c  and an electromagnet of the apparatus in use being enhanced, which results in greater or improved Joule heating. 
     In this embodiment, the closed circuits  26   a ,  26   b ,  26   c  are arranged concentrically with one another. This can make efficient use of the space on the sheet  10 . In other embodiments, the closed circuits  26   a ,  26   b ,  26   c  are arranged non-concentrically with one another. For example, in some embodiments the closed circuits  26   a ,  26   b ,  26   c  may be arranged so that each of the closed circuits  26   a ,  26   b ,  26   c  is outside of each other of the closed circuits  26   a ,  26   b ,  26   c.    
     Further, in this embodiment, the closed circuits  26   a ,  26   b ,  26   c  are all on one surface of the sheet  10 , but in other embodiments there may be one or more such closed circuits  26   a ,  26   b ,  26   c  on both opposite surfaces of the sheet  10 . In some embodiments, there may be only one such closed circuit  26   a ,  26   b ,  26   c  on a surface of the sheet  10 . 
     In some embodiments, the closed circuit(s)  26   a ,  26   b ,  26   c  is/are in the form ink comprising the heating material  20 . The ink may be printed on the sheet  10 , for example using gravure printing. In other embodiments, the closed circuit(s)  26   a ,  26   b ,  26   c  may be adhered or otherwise provided on a surface of the sheet  10  in a different manner. 
     Referring to  FIG. 5  there is shown a schematic perspective view of an example of another article according to an embodiment of the disclosure. The article  5  of  FIG. 5  is identical to the article  4  described above with reference to  FIG. 4 , other than the manner in which heating material is provided in the article  5 . Any of the herein-described possible variations to the article  4  of  FIG. 4  may be made to the article  5  of  FIG. 5  to form separate respective embodiments. 
     In this embodiment, the article  5  comprises a spiral  28  of the heating material  20  on a surface of the sheet  10 . In some embodiments, more than one such spiral  28  may be provided on the surface of the sheet  10 . In this embodiment the spiral  28  covers a majority of a surface of the sheet  10 . In some embodiments there may be one or more such spirals  28  on both opposite surfaces of the sheet  10 . 
     In some embodiments, the spiral(s)  28  is/are in the form ink comprising the heating material  20 . The ink may be printed on the sheet  10 , for example using gravure printing. In other embodiments, the spiral(s)  28  may be adhered or otherwise provided on a surface of the sheet  10  in a different manner. 
     In each of the above-described embodiments, the sheet  10  is planar, or substantially planar. However, in some embodiments, the sheet  10  may be bendable or rollable so as to from a rolled sheet. Such a rolled sheet may be less prone to damage, more convenient to store and handle, and better suited for use with the apparatus. 
     In some embodiments the articles  1 ,  2 ,  3 ,  4 ,  5  may be provided to a user in the respective states shown in  FIGS. 1 to 5 . In other embodiments, the respective articles  1 ,  2 ,  3 ,  4 ,  5  may be provided to a user with the sheet  10  in the form of a rolled sheet  10 . In some such embodiments, an axial length of the rolled sheet  10  may be greater than a diameter (or width perpendicular to the axial length) of the rolled sheet  10 . The article  1 ,  2 ,  3 ,  4 ,  5  may have overall proportions approximating those of a cigarette. In some embodiments, the sheet  10  may be rolled so that the sheet  10  defines an outer surface of the article  1 ,  2 ,  3 ,  4 ,  5 , which may contact the apparatus in use. In some embodiments, the sheet  10  may be rolled so that the sheet  10  lies between the heating material and an exterior of the article  1 ,  2 ,  3 ,  4 ,  5 . In some embodiments, the article may comprise an adhesive (not shown) that adheres overlapped portions of the sheet  10  to each other to help prevent the rolled sheet  10  from unraveling. The adhesive may comprise one or more of, for example, gum Arabic, natural or synthetic resins, starches, hydroxyl propyl methyl cellulose, and varnish. In other embodiments, the adhesive may be omitted. 
     Referring to  FIG. 6  there is shown a schematic perspective view of an example of another article according to an embodiment of the disclosure. The article  6  of  FIG. 6  comprises a rolled sheet  10 , which is formed from the sheet  10  of the article  1  described above with reference to  FIG. 1 . Any of the herein-described possible variations to the article  1  of  FIG. 1  may be made to the article  6  of  FIG. 6  to form separate respective embodiments. Further, the rolled sheet  10  of the article  6  of  FIG. 6  may be replaced by a rolled version of the sheet  10  of any of the other embodiments described herein to form separate respective embodiments. 
     In this embodiment, the article  6  is elongate and cylindrical with a substantially circular cross section. The rolled sheet  10  of the article  6  has an axial length that is greater than a diameter (or width perpendicular to the axial length) of the rolled sheet  10 . The sheet  10  is arranged so that the sheet  10  lies between the heating material and an exterior of the article  6 . This helps to retain heat that is generated in the heating material  20  within the article  6 . In some embodiments, the article  6  may comprise an adhesive (not shown) that adheres overlapped portions of the sheet  10  to each other to help prevent the rolled sheet  10  from unraveling. The adhesive may comprise one or more of the possible adhesives discussed above, but in other embodiments such adhesive may be omitted. 
     The article  6  comprises two connectors  32 ,  34 , which are located at opposite longitudinal ends of the rolled sheet  10 . In this embodiment, each of the connectors  32 ,  34  comprises a carrier and one or more bodies of heating material on the carrier. In this embodiment, the carrier is made from paper, but in other embodiments the carrier may be made of a material other than paper, such as an alternative electrically-insulating material. In other embodiments, one or each of the connectors  32 ,  34  may instead consist entirely or substantially entirely of heating material. 
     In this embodiment, the connectors  32 ,  34  are adhered to the sheet  10  by an adhesive (not shown), which may comprise one or more of the possible adhesives discussed above, but in other embodiments such adhesive may be omitted. In this embodiment, the combination of the sheet  10  and the connectors  32 ,  34  defines an outer surface of the article  6 , which may contact the apparatus in use. 
     In this embodiment, the connectors  32 ,  34  abut respective longitudinal ends of the sheet  10  of reconstituted smokable material, so as to form respective longitudinal ends of the article  6 . In this embodiment, the connectors  32 ,  34  are arranged so that the heating material of the connectors  32 ,  34  contacts the heating material  20  that is heatable to heat the smokable material. As the heating material  20  on the surface of the sheet  10  of reconstituted smokable material is in the shape of an elongate spiral, the heating material of the connectors  32 ,  34  acts to connect otherwise spaced-apart portions of the heating material  20  on the surface of the sheet  10 , so as to define one or more closed circuits of heating material. As noted elsewhere herein, the provision of a closed circuit of heating material can result in magnetic coupling between the closed circuit and an electromagnet of the apparatus in use being enhanced, which results in greater or improved Joule heating. 
     In a variation to the illustrated embodiment, the article  6  may be formed from the article  2  of  FIG. 2 , for example. That is, the sheet  10  of the article  2  of  FIG. 2  may be rolled and then the connectors  32 ,  34  attached to opposite longitudinal ends of the rolled sheet  10 . The strips  22   a ,  22   b ,  22   c ,  22   d  comprising heating material may be arranged so as to be parallel to the longitudinal axis of the rolled sheet  10 . The connectors  32 ,  34  may be arranged so that the heating material of the connectors  32 ,  34  contacts the strips  22   a ,  22   b ,  22   c ,  22   d  of heating material  20  so as to define one or more closed circuits of heating material. 
     In some embodiments, the heating material  20  may be U-shaped, with the free ends of the arms of the U located at one longitudinal end of the article  6  and the base of the U located away from that longitudinal end of the article  6 . In such a variation, only one of the connectors  32 ,  34  need be provided at that one longitudinal end of the article  6  to create one or more closed circuits comprising the heating material  20  and the heating material of the one connector  32 ,  34 . 
     In some embodiments, the connector(s)  32 ,  34  may be movable or rotatable relative to the heating material  20 . Such rotation may enable the number of connections between portions of the heating material  20  made by the connector(s)  32 ,  34  to be changed, thereby to vary the amount of heating material present in a circuit or circuits. This may vary the intensity of heating provided to the smokable material. In some embodiments, the heating material  20  on the surface of the sheet  10  may comprise strips or tracks of different thicknesses and/or widths, so that different heating profiles may be created by rotating the connector(s)  32 ,  34  to different rotational positions relative to the tracks. 
     Referring to  FIG. 7  there is shown a schematic perspective view of an example of another article according to an embodiment of the disclosure. The article  7  of  FIG. 7  comprises a rolled sheet  10 , which is formed from the sheet  10  of the article  1  described above with reference to  FIG. 1 . Any of the herein-described possible variations to the article  1  of  FIG. 1  may be made to the article  7  of  FIG. 7  to form separate respective embodiments. Further, the rolled sheet  10  of the article  7  of  FIG. 7  may be replaced by a rolled version of the sheet  10  of any of the other embodiments described herein to form separate respective embodiments. 
     In this embodiment, the article  7  is elongate and cylindrical with a substantially circular cross section. The rolled sheet  10  of the article  7  has an axial length L that is greater than a diameter (or width perpendicular to the axial length) D of the rolled sheet  10 . 
     In this embodiment, the article  7  comprises an adhesive  50  that adheres overlapped portions of the sheet  10  to each other to help prevent the rolled sheet  10  from unraveling. The adhesive  50  may comprise one or more of the possible adhesives discussed above, but in other embodiments such adhesive may be omitted. It is to be noted that the size of the adhesive  50  relative to the rest of the article  7  is accentuated in  FIG. 7  for clarity. 
     The article  7  of this embodiment also comprises a mass of smokable material  40  that is discrete from, and encircled by, the rolled sheet  10 . The sheet  10  is arranged so that the sheet  10  lies between the heating material and an exterior of the article  7 , and so that the heating material is closer to the mass of smokable material  40 . This helps to retain within the article  7  heat that is generated in the heating material  20  in use. This also helps to enable the generated heat to heat the mass of smokable material  40  in use. In this embodiment, all of the mass of smokable material  40  is located at the centre of the rolled sheet  10 . However, in other embodiments, this may not be true. For example, in some embodiments, at least a portion of the mass of smokable material  40  may be sandwiched between overlapping portions of the sheet  10 . In some embodiments, the mass of smokable material  40  may be annular in shape or omitted, and the article  7  may be annular in shape. 
     In each of the above embodiments, the heating material  20  is located on a surface of the sheet  10  comprising reconstituted smokable material. However, in other embodiments, the heating material  20  may be embedded in the sheet  10 . For example, in some embodiments, the heating material  20  may be in the form of one or more strips, wires or tracks that are embedded within the sheet  10 . In some embodiments, the heating material  20  may be out of contact with the sheet  10 , but in thermal communication with the sheet  10  so as still to be heatable to heat the smokable material. 
     In each of the above embodiments, the heating material  20  is in contact with the smokable material. Thus, when the heating material  20  is heated by penetration with a varying magnetic field, heat may be transferred directly from the heating material  20  to the smokable material. In other embodiments, the heating material  20  may be kept out of contact with the smokable material. For example, in some embodiments, the article may comprise a thermally-conductive barrier that is free of heating material and that spaces the heating material  20  from the smokable material. In some embodiments, the thermally-conductive barrier may be a coating on the heating material  20 . The provision of such a barrier may be advantageous to help to dissipate heat to alleviate hot spots in the heating material. 
     In some embodiments, which may be respective variations to the embodiments discussed above, a first portion of the heating material  20  of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  may be more susceptible to eddy currents being induced therein by penetration with a varying magnetic field than a second portion of the heating material  20  of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 . The first portion of the heating material  20  may be more susceptible as a result of the first portion of the heating material  20  being made of a first material, the second portion of the heating material  20  being made of a different second material, and the first material being of a higher susceptibility to eddy currents being induced therein than the second material. For example, one of the first and second portions may be made of iron, and the other of the first and second portions may be made of graphite. Alternatively or additionally, the first portion of the heating material  20  may be more susceptible as a result of a first portion of a component comprising the first portion of the heating material  20  having a different thickness to the second portion of the component that comprises the second portion of the heating material  20 . 
     Such varying susceptibility of the heating material  20  to eddy currents being induced therein can help achieve progressive heating of the smokable material, and thereby progressive generation of vapor. For example, the higher susceptibility portion may be able to heat a first region of the smokable material relatively quickly to initialize volatilization of at least one component of the smokable material and formation of vapor in the first region of the smokable material. The lower susceptibility portion may be able to heat a second region of the smokable material relatively slowly to initialize volatilization of at least one component of the smokable material and formation of vapor in the second region of the smokable material. Accordingly, vapor is able to be formed relatively rapidly for inhalation by a user, and vapor can continue to be formed thereafter for subsequent inhalation by the user even after the first region of the smokable material may have ceased generating vapor. The first region of the smokable material may cease generating the vapor when it becomes exhausted of volatilizable components of the smokable material. 
     In other embodiments, all of the heating material  20  of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  may be equally, or substantially equally, susceptible to eddy currents being induced therein by penetration with a varying magnetic field. In some embodiments, the heating material  20  may not be susceptible to such eddy currents. In such embodiments, the heating material  20  may be a magnetic material that is non-electrically-conductive, and thus may be heatable by the magnetic hysteresis process discussed above. 
     In some embodiments, which may be respective variations to the embodiments discussed above, a plurality of the articles  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  may be arranged in a stack. The articles may be adhered to one another in the stack. Each of the articles  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  in the stack may be identical to each other of the articles  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  in the stack. Alternatively, one or more of the articles  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  in the stack may differ in construction from one or more other of the articles  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  in the stack. For example, any one or more of the articles in the stack may be one of the articles  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  discussed above, and one or more other of the articles in the stack may be a different one of the articles  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  discussed above. Smokable material may then be sandwiched between two bodies of heating material. 
     In some embodiments, which may be respective variations to the embodiments discussed above, the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  may comprise a plurality of bodies, wherein each of the bodies comprises heating material  20  that is heatable by penetration with a varying magnetic field. At least one of the plurality of bodies may be more susceptible to eddy currents being induced therein by penetration with a varying magnetic field than at least one of the other of the plurality of bodies. This may be effected by the bodies being made of different heating materials and/or having different thicknesses, for example, as discussed above. Again, such varying susceptibility of the bodies can help achieve progressive heating of the smokable material, and thereby progressive generation of vapor, in a manner corresponding to that described above. The plurality of bodies may be coplanar. In some embodiments, the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  may comprise a catalytic material on at least a portion of the heating material  20 . The catalytic material may take the form of a coating on the heating material  20 . The catalytic material may be provided on all surface(s) of the heating material  20 , or on only some of the surface(s) of the heating material  20 . The provision of such a catalytic material on the heating material  20  means that, in use, the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  may have a heated, chemically active surface. In use, the catalytic material may act to convert, or increase the rate of conversion of, a potential irritant to something that is less of an irritant. 
     In some embodiments, which may be respective variations to the embodiments discussed above, the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  may comprise a mouthpiece defining a passageway that is in fluid communication with the reconstituted smokable material. The mouthpiece may be made of any suitable material, such as a plastics material, cardboard, cellulose acetate, paper, metal, glass, ceramic, or rubber. In use, when the smokable material is heated, volatilized components of the smokable material can be readily inhaled by a user. In embodiments in which the article is a consumable article, once all or substantially all of the volatilizable component(s) of the smokable material of the article has/have been spent, the user may dispose of the mouthpiece together with the rest of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 . This can be more hygienic than using the same mouthpiece with multiple articles, can help ensure that the mouthpiece is correctly aligned with the smokable material, and presents a user with a clean, fresh mouthpiece each time they wish to use another article. The mouthpiece, when provided, may comprise or be impregnated with a flavorant. The flavorant may be arranged so as to be picked up by heated vapor as the vapor passes through the passageway of the mouthpiece in use. 
     Referring to  FIG. 8  there is shown a schematic perspective view of an example of another article according to an embodiment of the disclosure. The article  8  of this embodiment comprises a sheet  10  comprising reconstituted smokable material, and adhesive  60  on a surface of the sheet  10  for adhering the sheet  10  to a carrier. 
     In this embodiment, the sheet  10  is a rolled sheet  10 . This may make the sheet  10  less prone to damage and more convenient to store and handle. However, in variations to the illustrated embodiment, the sheet  10  may instead be planar or substantially planar. 
     The adhesive  60  may comprise one or more of, for example, gum Arabic, natural or synthetic resins, starches, hydroxyl propyl methyl cellulose, and varnish. 
     In this embodiment, the article  8  comprises a backing sheet  70 . The adhesive  60  is located between the sheet  10  comprising reconstituted smokable material and the backing sheet  70 . The article  8  thus comprises a rolled structure having three layers  10 ,  60 ,  70 . 
     The backing sheet  70  may comprise any material suitable for ensuring that overlapping layers of the rolled sheet  10  do not become adhered to each other by the adhesive  60  while the sheet  10  remains rolled. For example, the backing sheet  70  may comprise glass fibers, carbon fibers, silk, paper, grease-proof paper, or the like. 
     In this embodiment, the backing sheet  70  is removable from the adhesive  60  and the sheet  10  comprising reconstituted smokable material to expose the adhesive  60  on a surface of the sheet  10  comprising reconstituted smokable material. In the present embodiment, once the backing sheet  70  has been removed, the sheet  10  may be cut or torn and then adhered to a carrier by a user using the adhesive  60 . Such adhesion may reduce or avoid air gaps present between the sheet  10  and the carrier, and provide good thermal coupling between the sheet  10  and the carrier. The article  8  is free of heating material that is heatable by penetration with a varying magnetic field, and it is envisaged that the carrier would comprise such heating material. Accordingly, once the sheet  10  has been adhered to such a carrier, the combination of the sheet  10  and the carrier may be used with apparatus comprising a magnetic field generator for generating a varying magnetic field to be used in heating the heating material of the carrier, and thus the smokable material of the sheet  10 . An example such apparatus  100  is that shown in  FIG. 9  and described below. 
     In a variation to this embodiment, the adhesive  60  may be removable with the backing sheet  70  from the sheet  10  comprising reconstituted smokable material. In such a variation, it may be necessary for the user to use a separate adhesive to adhere the sheet  10  comprising reconstituted smokable material to the carrier. Such a separate adhesive may be present on the carrier, or may need to be applied to the carrier and/or to the sheet  10  comprising reconstituted smokable material by a user. 
     In further variations to this embodiment, the adhesive surface may be a surface of the sheet  10 . That is, a surface of the sheet  10  may be inherently tacky or adhesive. In some such embodiments, the article may or may not comprise a backing sheet  70  in contact with the adhesive surface of the sheet  10  and removable to expose the adhesive surface of the sheet  10 . 
     In some embodiments, the surface of the backing sheet  70  opposite from the surface facing the sheet  10  comprising smokable material may be coated or treated to be a non-stick surface. 
     In a further variation to this embodiment, the backing sheet  70  may be omitted from the article  8 . In such further variations, preferably the adhesive  60  is suitable for ensuring that overlapping layers of the rolled sheet  10  do not become adhered to each other by the adhesive  60  while the sheet  10  remains rolled. 
     In some embodiments, a series of longitudinally-spaced lines of weakness, such as perforations, may extend across the width of the sheet  10  comprising smokable material, and optionally also the backing sheet  70  when provided. These may help a user to detach a predetermined length of the sheet  10  from the rest of the sheet  10  for attachment to the carrier. 
     In each of the above embodiments, the sheet  10  comprises reconstituted smokable material. However, in other embodiments, the sheet  10  may comprise smokable material in a different form. 
     For example, in some embodiments, the sheet  10  may carry tobacco extract. A tobacco extract is a composition of tobacco that is obtained by a method comprising the treatment of tobacco with a solvent, and may comprise other treatment steps such as concentration. 
     The sheet  10  may be a cast or extruded material, suitably formed from a slurry. The sheet  10  may, for example, comprise paper, card, cardboard, or the like. The sheet may comprise a filler and a binder. The filler may be an organic material such as wood pulp, cellulose and cellulose derivatives. The filler may be an inorganic material such as calcium carbonate, perlite, vermiculite, diatomaceous earth, colloidal silica, magnesium oxide, magnesium sulphate and magnesium carbonate. The binder may comprise alginate, polysaccharides, celluloses or modified celluloses, starches or modified starches, or natural gums. 
     In each of the above embodiments, the sheet  10  comprising reconstituted smokable material may consist entirely or substantially entirely of the reconstituted smokable material. However, in other embodiments, the sheet  10  may comprise one or more materials or ingredients in addition to the reconstituted smokable material. 
     In each of the above embodiments, the sheet  10  itself is free of heating material. However, in other embodiments, the sheet  10  may comprise heating material in addition to the reconstituted smokable material. 
     In each of the embodiments discussed above, the sheet  10  or rolled sheet  10  is smooth or substantially smooth. However, in other embodiments, this may not be the case. For example, in some embodiments, the sheet  10  may be corrugated, have protrusions thereon, and/or have indentations therein. 
     In each of the embodiments discussed above with reference to  FIGS. 1 to 5 , the sheet  10  is planar or substantially planar. However, in other embodiments, this may not be the case. For example, in some embodiments, the sheet  10  may be corrugated, follow a wavelike or wavy path, be twisted, have protrusions thereon, have indentations therein, and/or have a non-uniform non-planar shape. 
     Such non-smooth or non-planar shapes may help air passing through the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8  in use to pick up the volatilized material created when the smokable material is heated. Such shapes can provide a tortuous path for air to follow, creating turbulence in the air and causing better heat transfer from the heating material  20  to the smokable material. 
     In some embodiments, the article may comprise a mass of thermal insulation radially outwards of the rolled sheet  10 . The thermal insulation may comprise one or more materials selected from the group consisting of: aerogel, vacuum insulation, wadding, fleece, non-woven material, non-woven fleece, woven material, knitted material, nylon, foam, polystyrene, polyester, polyester filament, polypropylene, a blend of polyester and polypropylene, cellulose acetate, paper or card, and corrugated material such as corrugated paper or card. The thermal insulation may additionally or alternatively comprise an air gap. Such thermal insulation can help prevent heat loss to components of the apparatus, and provide more efficient heating of the smokable material of the sheet  10 . In some embodiments, the insulation may have a thickness of up to one millimeter, such as up to 0.5 millimeters. 
     In each of the embodiments discussed above, the heating material  20  is aluminum. However, in other embodiments, the heating material  20  may comprise one or more materials selected from the group consisting of: an electrically-conductive material, a magnetic material, and a magnetic electrically-conductive material. In some embodiments, the heating material  20  may comprise a metal or a metal alloy. In some embodiments, the heating material  20  may comprise one or more materials selected from the group consisting of: aluminum, gold, iron, nickel, cobalt, conductive carbon, graphite, plain-carbon steel, stainless steel, ferritic stainless steel, copper, and bronze. Other heating material(s) may be used in other embodiments. In some embodiments, the heating material  20  may be magnetic. It has also been found that, when magnetic electrically-conductive material is used as the heating material  20 , magnetic coupling between the magnetic electrically-conductive material and an electromagnet of the apparatus may be enhanced in use. In addition to potentially enabling magnetic hysteresis heating, this can result in greater or improved Joule heating of the heating material  20 , and thus greater or improved heating of the smokable material. 
     In each of the above-described embodiments that comprise adhesive, it is advantageous for the adhesive to be thermally stable and to retain its functionality at the operating temperatures of the apparatus with which the article is to be used. Example operating temperatures are described elsewhere herein. 
     Each of the above-described articles  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8  and described variants thereof may be used with an apparatus for heating the smokable material to volatilize at least one component of the smokable material. The apparatus may be to heat the smokable material to volatilize the at least one component of the smokable material without burning the smokable material. Any one of the article(s)  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8  and such apparatus may be provided together as a system. The system may take the form of a kit, in which the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8  is separate from the apparatus. Alternatively, the system may take the form of an assembly, in which the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8  is combined with the apparatus. An example such system will now be described with reference to  FIG. 9 . 
     Referring to  FIG. 9  there is shown a schematic cross-sectional view of an example of a system according to an embodiment of the disclosure. The system  1000  of this embodiment comprises an article  2  and apparatus  100 . The article  2  comprises a sheet  10  comprising reconstituted smokable material, and heating material  22   a ,  22   b ,  22   c ,  22   d  that is heatable by penetration with a varying magnetic field to heat the smokable material. The apparatus  100  is for heating the smokable material of the article  2  to volatilize at least one component of the smokable material. 
     In this embodiment, the article  2  of the system  1000  is the article  2  of  FIG. 2 , rolled in such a way that the sheet  10  of the article  2  is a rolled sheet  10  and the strips  22   a ,  22   b ,  22   c ,  22   d  comprising heating material  20  are arranged so as to be parallel to the longitudinal axis of the rolled sheet  10 . However, in other embodiments, the article of the system  1000  may be an article other than the article  2  of  FIG. 2 , such as any one of the other articles described above. Broadly speaking, the apparatus  100  comprises a heating zone  111  for receiving at least a portion of the article and a magnetic field generator  112  for generating a varying magnetic field to be used in heating the smokable material when the portion of the article is in the heating zone  111 . 
     The apparatus  100  of this embodiment comprises a body  110  and a mouthpiece  120 . The mouthpiece  120  defines a channel  122  therethrough. The mouthpiece  120  is locatable relative to the body  110  so as to cover an opening into the heating zone  111 . When the mouthpiece  120  is so located relative to the body  110 , the channel  122  of the mouthpiece  120  is in fluid communication with the heating zone  111 . In use, the channel  122  acts as a passageway for permitting volatilized material to pass from the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  inserted in the heating zone  111  to an exterior of the apparatus  100 . In this embodiment, the mouthpiece  120  of the apparatus  100  is releasably engageable with the body  110  so as to connect the mouthpiece  120  to the body  110 . In other embodiments, the mouthpiece  120  and the body  110  may be permanently connected, such as through a hinge or flexible member. The mouthpiece  120  of the apparatus  100  may comprise or be impregnated with a flavorant. The flavorant may be arranged so as to be picked up by heated vapor as the vapor passes through the channel  122  of the mouthpiece  120  in use. In some embodiments, such as embodiments in which the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  itself comprises a mouthpiece, the mouthpiece  120  of the apparatus  100  may be omitted. 
     In this embodiment, the body  110  comprises the heating zone  111 . In this embodiment, the heating zone  111  comprises a recess  111  for receiving at least a portion of the article  2 . In other embodiments, the heating zone  111  may be other than a recess, such as a shelf, a surface, or a projection, and may require mechanical mating with the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  in order to co-operate with, or receive, the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 . In this embodiment, the heating zone  111  is elongate, and is sized and shaped to receive the article  2 . In this embodiment, the heating zone  111  accommodates the whole article  2 . In other embodiments, the heating zone  111  may be dimensioned to receive only a portion of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 . 
     In some embodiments, the apparatus  100  may comprise a mechanism for compressing an article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  when the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  is located in the heating zone  114 . Such compression of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  may compress the smokable material, so as to increase the thermal conductivity of the smokable material. In other words, compression of the smokable material can provide for higher heat transfer through the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 . Such compression should not be so great as to break the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  or to prevent a user to be able to draw volatilized material from the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 . 
     In this embodiment, the magnetic field generator  112  comprises an electrical power source  113 , a coil  114 , a device  116  for passing a varying electrical current, such as an alternating current, through the coil  114 , a controller  117 , and a user interface  118  for user-operation of the controller  117 . 
     In this embodiment, the electrical power source  113  is a rechargeable battery. In other embodiments, the electrical power source  113  may be other than a rechargeable battery, such as a non-rechargeable battery, a capacitor, a battery-capacitor hybrid, or a connection to a mains electricity supply. 
     The coil  114  may take any suitable form. In this embodiment, the coil  114  is a helical coil of electrically-conductive material, such as copper. In some embodiments, the magnetic field generator  112  may comprise a magnetically permeable core around which the coil  114  is wound. Such a magnetically permeable core concentrates the magnetic flux produced by the coil  114  in use and makes a more powerful magnetic field. The magnetically permeable core may be made of iron, for example. In some embodiments, the magnetically permeable core may extend only partially along the length of the coil  114 , so as to concentrate the magnetic flux only in certain regions. 
     In this embodiment, the coil  114  of the magnetic field generator  112  extends along a longitudinal axis that is substantially coincident with a longitudinal axis of the heating zone  111 . In other embodiments, these axes may be aligned with each other by being parallel to each other, or may be oblique to each other. 
     In this embodiment, an impedance of the coil  114  of the magnetic field generator  112  is equal, or substantially equal, to an impedance of each of the strips  22   a ,  22   b ,  22   c ,  22   d  comprising heating material  20  of the article  1 . If the impedance of one of the strips  22   a ,  22   b ,  22   c ,  22   d  of the article  2  were instead lower than the impedance of the coil  114 , then the voltage generated across the strip in question in use may be lower than the voltage that may be generated across that strip when the impedances are matched. Alternatively, if the impedance of one of the strips  22   a ,  22   b ,  22   c ,  22   d  of the article  2  were instead higher than the impedance of the coil  114 , then the electrical current generated in that strip in use may be lower than the current that may be generated in that strip when the impedances are matched. In embodiments of the system  1000  comprising one of the articles  1 ,  3 ,  4 ,  5 ,  6 ,  7  of  FIGS. 1 and 3 to 7 , similarly the impedance of the coil  114  may be equal, or substantially equal, to an impedance of the part of the article  1 ,  3 ,  4 ,  5 ,  6 ,  7  comprising heating material. Matching the impedances may help to balance the voltage and current to maximize the heating power generated at the heating material of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  when heated in use. 
     In this embodiment, the device  116  for passing a varying current through the coil  114  is electrically connected between the electrical power source  113  and the coil  114 . In this embodiment, the controller  117  also is electrically connected to the electrical power source  113 , and is communicatively connected to the device  116  to control the device  116 . More specifically, in this embodiment, the controller  117  is for controlling the device  116 , so as to control the supply of electrical power from the electrical power source  113  to the coil  114 . In this embodiment, the controller  117  comprises an integrated circuit (IC), such as an IC on a printed circuit board (PCB). In other embodiments, the controller  117  may take a different form. In some embodiments, the apparatus may have a single electrical or electronic component comprising the device  116  and the controller  117 . The controller  117  is operated in this embodiment by user-operation of the user interface  118 . In this embodiment, the user interface  118  is located at the exterior of the body  110 . The user interface  118  may comprise a push-button, a toggle switch, a dial, a touchscreen, or the like. In other embodiments, the user interface  118  may be remote and connected to the rest of the apparatus wirelessly, such as via Bluetooth. 
     In this embodiment, operation of the user interface  118  by a user causes the controller  117  to cause the device  116  to cause an alternating electrical current to pass through the coil  114 , so as to cause the coil  114  to generate an alternating magnetic field. When the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  is located in the heating zone  111 , the coil  114  of the apparatus  100  and the heating material  20  of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  are suitably relatively positioned so that the alternating magnetic field produced by the coil  114  penetrates the heating material  20  of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 . When the heating material  20  of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  is an electrically-conductive material, this may cause the generation of one or more eddy currents in the heating material  20 . The flow of eddy currents in the heating material  20  against the electrical resistance of the heating material  20  causes the heating material  20  to be heated by Joule heating. As mentioned above, when the heating material  20  is made of a magnetic material, the orientation of magnetic dipoles in the heating material  20  changes with the changing applied magnetic field, which causes heat to be generated in the heating material  20 . 
     The apparatus  100  of this embodiment comprises a temperature sensor  119  for sensing a temperature of the heating zone  111 . The temperature sensor  119  is communicatively connected to the controller  117 , so that the controller  117  is able to monitor the temperature of the heating zone  111 . In some embodiments, the temperature sensor  119  may be arranged to take an optical temperature measurement of the recess, heating zone or article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 . In some embodiments, the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  may comprise a temperature detector, such as a resistance temperature detector (RTD), for detecting a temperature of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 . For example, the temperature detector may be located in or on the sheet  10  of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 . The article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  may further comprise one or more terminals connected, such as electrically-connected, to the temperature detector. The terminal(s) may be for making connection, such as electrical connection, with a temperature monitor of the apparatus  100  when the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  is in the heating zone  111 . The controller  117  may comprise the temperature monitor. The temperature monitor of the apparatus  100  may thus be able to determine a temperature of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  during use of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  with the apparatus  100 . 
     In some embodiments, by providing that a component of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  comprising the heating material  20  has a suitable resistance, the response of the heating material  20  to a change in temperature could be sufficient to give information regarding temperature inside the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 . The temperature sensor  119  of the apparatus  100  may then comprise a probe for analyzing the heating material. 
     On the basis of one or more signals received from the temperature sensor  119  or temperature detector, the controller  117  may cause the device  116  to adjust a characteristic of the varying or alternating electrical current passed through the coil  114  as necessary, in order to ensure that the temperature of the heating zone  111  remains within a predetermined temperature range. The characteristic may be, for example, amplitude or frequency. Within the predetermined temperature range, in use the smokable material within an article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  located in the heating zone  111  is heated sufficiently to volatilize at least one component of the smokable material without combusting the smokable material. Accordingly, the controller  117 , and the apparatus  100  as a whole, is arranged to heat the smokable material to volatilize the at least one component of the smokable material without combusting the smokable material. In some embodiments, the temperature range is about 50° C. to about 300° C., such as between about 50° C. and about 250° C., between about 50° C. and about 150° C., between about 50° C. and about 120° C., between about 50° C. and about 100° C., between about 50° C. and about 80° C., or between about 60° C. and about 70° C. In some embodiments, the temperature range is between about 170° C. and about 220° C. In other embodiments, the temperature range may be other than this range. In some embodiments, the temperature sensor  119  may be omitted. 
     The apparatus  100  may define an air inlet that fluidly connects the heating zone  111  with the exterior of the apparatus  100 . Such an air inlet may be defined by the body  110  of the apparatus  100  and/or by the mouthpiece  120  of the apparatus  100 . A user may be able to inhale the volatilized component(s) of the smokable material by drawing the volatilized component(s) through the channel  122  of the mouthpiece  120 . As the volatilized component(s) are removed from the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 , air may be drawn into the heating zone  111  via the air inlet of the apparatus  100 . 
     The apparatus may provide haptic feedback to a user. The feedback could indicate that heating is taking place, or be triggered by a timer to indicate that greater than a predetermined proportion of the original quantity of volatilizable component(s) of the smokable material of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  has/have been spent, or the like. The haptic feedback could be created by interaction of the coil  114  with the heating material of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  (e.g. magnetic response), by interaction of an electrically-conductive element with the coil  114 , by rotating an unbalanced motor, by repeatedly applying and removing a current across a piezoelectric element, or the like. 
     The apparatus  100  may comprise more than one coil. The plurality of coils of the apparatus  100  could be operable to provide progressive heating of the smokable material in an article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 , and thereby progressive generation of vapor. For example, one coil may be able to heat a first region of the heating material  20  relatively quickly to initialize volatilization of at least one component of the smokable material and formation of a vapor in a first region of the smokable material. Another coil may be able to heat a second region of the heating material  20  relatively slowly to initialize volatilization of at least one component of the smokable material and formation of a vapor in a second region of the smokable material. Accordingly, a vapor is able to be formed relatively rapidly for inhalation by a user, and vapor can continue to be formed thereafter for subsequent inhalation by the user even after the first region of the smokable material may have ceased generating vapor. The initially-unheated second region of smokable material could act as a heat sink, to reduce the temperature of created vapor or make the created vapor mild, during heating of the first region of smokable material. 
     In some embodiments, the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  may comprise a plurality of discrete portions of heating material  20  that is heatable by penetration with a varying magnetic field to heat the smokable material of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 . The plurality of discrete portions of heating material  20  may be substantially separately heatable by varying magnetic fields produced by a respective plurality of coils  114  of the apparatus  100 . One of the plurality of discrete portions of heating material  20  may be more susceptible to eddy currents being induced therein by penetration with a varying magnetic field than other(s) of the plurality of discrete portions of heating material  20 . Such a structure could be operable to provide progressive heating of the smokable material of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 , and thereby progressive generation of vapor, in a similar way to that described above. 
     In some embodiments, a component comprising the heating material  20  may comprise discontinuities or holes therein. Such discontinuities or holes may act as thermal breaks to control the degree to which different regions of the smokable material are heated in use. Areas of the heating material  20  with discontinuities or holes therein may be heated to a lesser extent that areas without discontinuities or holes. This may help progressive heating of the smokable material, and thus progressive generation of vapor, to be achieved. Such discontinuities or holes may, on the other hand, be used to optimize the creation of complex eddy currents in use. 
     In each of the above described embodiments, the smokable material comprises tobacco. However, in respective variations to each of these embodiments, the smokable material may consist of tobacco, may consist substantially entirely of tobacco, may comprise tobacco and smokable material other than tobacco, may comprise smokable material other than tobacco, or may be free of tobacco. In some embodiments, the smokable material may comprise a vapor or aerosol forming agent or a humectant, such as glycerol, propylene glycol, triacetin, or diethylene glycol. 
     An article embodying the present disclosure may be a cartridge, for example. 
     In each of the above described embodiments, the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8  is a consumable article. Once all, or substantially all, of the volatilizable component(s) of the smokable material of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8  has/have been spent, the user may dispose of the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 . The user may subsequently re-use the apparatus with another of the articles  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 . However, in other respective embodiments, the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8  may be non-consumable, and the apparatus and the article  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8  may be disposed of together once the volatilizable component(s) of the smokable material has/have been spent. 
     In some embodiments, the apparatus discussed above is sold, supplied or otherwise provided separately from the articles  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8  with which the apparatus is usable. However, in some embodiments, the apparatus and one or more of the articles  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8  may be provided together as a system, such as a kit or an assembly, possibly with additional components, such as cleaning utensils. 
     Embodiments of the disclosure could be implemented in a system comprising any one of the articles discussed herein, and any one of the apparatuses discussed herein, wherein the apparatus itself has heating material, such as in a susceptor, for heating by penetration with the varying magnetic field generated by the magnetic field generator. Heat generated in the heating material of the apparatus could be transferred to the article to heat, or further heat, the smokable material therein when the portion of the article is in the heating zone  111 . 
     In order to address various issues and advance the art, the entirety of this disclosure shows by way of illustration and example various embodiments in which the claimed invention may be practiced and which provide for superior articles for use with apparatus for heating smokable material to volatilize at least one component of the smokable material, and superior systems comprising such apparatus and such articles. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are presented only to assist in understanding and teach the claimed and otherwise disclosed features. It is to be understood that advantages, embodiments, examples, functions, features, structures and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilized and modifications may be made without departing from the scope and/or spirit of the disclosure. Various embodiments may suitably comprise, consist of, or consist in essence of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. The disclosure may include other inventions not presently claimed, but which may be claimed in future.