Aerosol-generating article having rod with multiple longitudinal elongate elements of non-tobacco material

Abstract

To provide an aerosol-generating article (10) for producing an inhalable aerosol upon heating.SOLUTION: A heated aerosol-generating article (10) comprises a rod of aerosol-generating substrate (12), wherein the rod of aerosol-generating substrate comprises from about 20 to about 200 strands (30) of non-tobacco material comprising and adapted to release at least one aerosol former, each strand (30) having an equivalent diameter of at least about 0.1 millimetres. The plurality of strands (30) are assembled such that the strands extend in the longitudinal direction. Further, the aerosol-generating substrate (12) comprises a wrapper (32) circumscribing the plurality of strands (30).SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an aerosol-generating article comprising an aerosol-generating substrate and to a method for producing such an aerosol-generating article. [Background technology]

[0002] Aerosol-generating articles in which an aerosol-generating substrate, such as a tobacco-containing substrate, is heated rather than combusted are well known in the art. Typically, in such heated smoking articles, the aerosol is generated by transferring heat from a heat source to a physically separated aerosol-generating substrate or material, which may be located in contact with, within, around, or downstream of the heat source. During use of the aerosol-generating article, volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source and are entrained in the air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol.

[0003] Numerous prior art documents disclose aerosol generating devices for consuming aerosol-generating articles, including, for example, electrically heated aerosol generating devices in which the aerosol is generated by heat transfer from one or more electric heating elements of the aerosol generating device to the aerosol-generating substrate of the heated aerosol-generating article.

[0004] Substrates for heated aerosol-generating articles have typically been produced using randomly oriented pieces, strands, or strips of tobacco material. Forming rods for heated smoking articles or aerosol-generating articles from pieces of tobacco material has many disadvantages. For example, the process of shredding tobacco material undesirably produces tobacco fines and other waste. Rods containing pieces of tobacco material may exhibit "loose ends," i.e., loss of tobacco material fragments from the ends of the rod. Rods containing pieces of tobacco material may exhibit large standard deviations in weight, in part because the rods tend to exhibit loose ends. Rods containing pieces of tobacco material also tend to exhibit non-uniform density, i.e., density along the length of the rod tends to be inconsistent due to variations in the amount of tobacco material at different locations along the rod. Furthermore, loose ends can disadvantageously lead to the need for more frequent cleaning of aerosol-generating devices and manufacturing equipment used with aerosol-generating articles.

[0005] As an example, International Patent Application No. WO-A-2012 / 164009 discloses a rod for a heated aerosol-generating article formed from an assembly of tobacco material sheets. The rod disclosed in WO-A-2012 / 164009 has longitudinal porosity that allows air to be drawn through the rod. In effect, folds within the assembly of tobacco material sheets define longitudinal channels through the rod. The use of a rod formed from an assembly of homogenized tobacco material sheets addresses some of the problems associated with forming aerosol-generating substrates from shredded tobacco. However, assembling sheets to form a rod can have drawbacks, as such sheets typically have relatively low tensile strength. International Patent Application WO-A-2011 / 101164 discloses an alternative rod for a heated aerosol-generating article formed from strands of homogenized tobacco material, which may be formed by casting, rolling, calendering, or extruding a mixture comprising particulate tobacco and at least one aerosol former to form a sheet of homogenized tobacco material. In an alternative embodiment, the rod of WO-A-2011 / 101164 may be formed from strands of homogenized tobacco material obtained by extruding a mixture comprising particulate tobacco and at least one aerosol former to form a continuous length of homogenized tobacco material.

[0006] However, achieving consistent and precise control of the amount of tobacco substrate within rods of the above-described type can be difficult, especially when operating at high speeds. Furthermore, depending on the shape and arrangement of the homogenized tobacco sheets or strands, it can be difficult to control the porosity and resistance to draw (RTD) of the aerosol-generating article. Furthermore, while addressing some of the problems associated with forming aerosol-generating substrates from shredded tobacco, rods formed from aggregates of homogenized tobacco material sheets can have drawbacks during handling and manufacturing because such sheets typically have relatively low tensile strength.

[0007] It would therefore be desirable to provide an aerosol-generating article that does not use tobacco sheet material. At the same time, it would be desirable to provide a substrate for such an aerosol-generating article that facilitates insertion of a heater into the substrate during use. It would also be desirable to provide such a substrate or rod that can be manufactured efficiently and rapidly, and to provide a method for manufacturing such a rod. Summary of the Invention

[0008] According to an aspect of the present invention, there is provided a heated aerosol-generating article for producing an inhalable aerosol, the heated aerosol-generating article comprising a rod of aerosol-generating substrate, the rod of aerosol-generating substrate comprising about 20 to about 200 strands of non-tobacco material containing at least one aerosol former and adapted to emit the at least one aerosol former, each strand having an equivalent diameter of at least about 0.1 millimeters and assembled so that the strands extend longitudinally, and a wrapper surrounding the strands.

[0009] According to a further aspect of the present invention, there is provided a method of making a rod for use as an aerosol-generating substrate in an aerosol-generating article, the method comprising the steps of providing a plurality of strands of non-tobacco material adapted to hold and release an aerosol former, each strand having an equivalent diameter of at least about 0.1 millimeters; assembling about 20 to about 200 strands such that the assembled strands extend longitudinally; surrounding the assembled strands with a wrapper to form a continuous rod; and cutting the continuous rod into a plurality of individual rods.

[0010] According to another aspect of the present invention, there is provided a rod for use as an aerosol-generating substrate in an aerosol-generating article, the rod including about 20 to about 200 strands of a non-tobacco material containing at least one aerosol former and adapted to emit the at least one aerosol former, each strand having an equivalent diameter of at least about 0.1 millimeter, assembled so that the strands extend longitudinally, and a wrapper surrounding the strands.

[0011] An equivalent diameter of 0.1 millimeters for strands of non-tobacco material has advantages over smaller diameter strands because it increases the ratio of the collective volume of the strands present within the rod to the surface area of the strands present within the rod.

[0012] The external surface area of each strand increases linearly with increasing diameter. Meanwhile, the cross-sectional surface area and volume of each individual strand increase substantially quadratically with the diameter of the individual strand. Without wishing to be bound by theory, it is understood that as the diameter of each individual strand increases, the number of strands present within a rod of a given diameter decreases. Therefore, an increase in the diameter of an individual strand is generally accompanied by a very small or nearly negligible change in the collective volume of the strands contained within the rod, because the effect of reducing the number of strands within the rod is substantially canceled by the increase in the cross-sectional area of the individual strands. In contrast, an increase in the diameter of an individual strand is generally associated with a decrease in the collective external surface of multiple strands, because the linear growth in the surface area of each strand is not sufficient to compensate for the effect of reducing the number of strands within the rod. The inventors have found that for equivalent diameters of 0.1 millimeters or greater, the amount of material that can be trapped within the strands (e.g., the amount of aerosol former), which is proportional to the collective volume of the strands, is significantly improved over the amount of material that can be trapped in the gaps between the strands. The release of material trapped within the strands can be better controlled than the release of material trapped on the outer surface of the strands, and therefore a larger equivalent diameter generally leads to improved control of the release of the aerosol former of an aerosol-generating article according to the present invention.

[0013] It will be appreciated that any feature described in relation to one aspect of the invention is equally applicable to any other aspect of the invention.

[0014] As used herein, the term "aerosol-generating article" refers to both an article in which an aerosol-generating substrate is heated and an article in which an aerosol-generating substrate is combusted (such as a conventional cigarette). As used herein, the term "aerosol-generating substrate" refers to a substrate that has the ability to release volatile compounds when heated to produce an aerosol.

[0015] In heated aerosol-generating articles, aerosols are generated by heating a flavor-generating substrate (such as tobacco) without combustion. Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles in which an aerosol is generated by the transfer of heat from a combustible fuel element or heat source to a physically separated aerosol-forming material. For example, the aerosol-generating article according to the present invention finds particular application in aerosol-generating systems comprising an electrically heated aerosol-generating device having an internal heater blade adapted to be inserted into the rod of the aerosol-generating substrate. This type of aerosol-generating article is described in the prior art, for example, in European Patent No. EP 0822670. The term "aerosol-generating device" as used herein refers to a device comprising a heater element that interacts with the aerosol-generating substrate of the aerosol-generating article to generate an aerosol. Alternatively, the aerosol-generating article according to the present invention may comprise a combustible carbon heat source for heating the aerosol-generating substrate during use. This type of aerosol-generating article is described in the prior art, for example, in International Patent Application No. WO 2009 / 022232. Aerosol-generating articles are also known in which a nicotine-containing aerosol is produced from tobacco material, tobacco extracts, or other nicotine sources without combustion, and in some cases without heat, e.g., by a chemical reaction. During smoking, volatile compounds are released from the aerosol-forming substrate by heat transfer from the fuel element and are entrained in the air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol.

[0016] As used herein, the term "strand" means a strip, piece, filament, rod or other elongated element.

[0017] The term "length" refers to the dimension of a component of an aerosol-generating article in its longitudinal direction. For example, it can be used to refer to the dimension of a rod or strand of non-tobacco material in its longitudinal direction.

[0018] As used herein, the term "longitudinal" refers to a direction corresponding to the major longitudinal axis of the aerosol-generating article extending between the upstream and downstream ends of the aerosol-generating article. During use, air is drawn longitudinally through the aerosol-generating article. The term "transverse" refers to a direction perpendicular to the longitudinal axis. All references to a "cross section" of an aerosol-generating article or a component of an aerosol-generating article refer to a transverse cross section, unless otherwise specified.

[0019] As used herein, the term "equivalent diameter of a strand" means the diameter of a circle having the same surface area as the transverse cross-section of the strand. For strands having a circular transverse cross-section, the equivalent diameter is the diameter of the cross-section of the strand.

[0020] As used herein, the terms "upstream" and "downstream" describe the relative position of an element (or part of an element) of an aerosol-generating article with respect to the direction in which aerosol is transported through the aerosol-generating article during use.

[0021] As briefly described above, the aerosol-generating article of the present invention incorporates a rod of aerosol-generating substrate. The rod of aerosol-generating substrate comprises about 20 to about 200 strands of non-tobacco material containing at least one aerosol former and adapted to emit at least one aerosol former, each strand having an equivalent diameter of at least about 0.1 millimeter. The strands are assembled so that the strands extend longitudinally.

[0022] By adjusting the size and number of strands of non-tobacco material within the rod, it is advantageously possible to control the density and porosity of the rod. In general, aerosol-generating substrates comprising multiple strands of non-tobacco material according to the present invention also advantageously exhibit a more uniform density than aerosol-generating substrates comprising pieces of tobacco material. In this way, the airflow permeability of the RTD and rod can be consistently fine-tuned.

[0023] Additionally, by varying the composition and internal porosity of the non-tobacco material from which the strands are formed, it is possible to vary the amount of aerosol former that can be loaded into the rod.

[0024] The weight of an aerosol-generating substrate containing strands of non-tobacco material is determined by the number, size, density, and spacing of the strands. Thus, the weight of an aerosol-generating substrate containing multiple strands of non-tobacco material can be adjusted by controlling the strand density, dimensions, aerosol former loading, and the arrangement of the strands within the rod. This reduces the weight discrepancy between aerosol-generating substrates of the same dimensions compared to aerosol-generating substrates containing pieces of tobacco material.

[0025] The regular arrangement of the strands within the rod optimizes heat transfer from the heater through the rod during use. At the same time, the size, geometry, and arrangement of the strands within the rod can be easily adapted to facilitate insertion of a heating element. For example, arranging the strands in a substantially linear, longitudinally extending manner within the rod greatly facilitates insertion of a longitudinally extending heater element, such as a heater blade.

[0026] Inserting and withdrawing the heater element of an aerosol-generating device into and from an aerosol-generating substrate comprising shreds of tobacco material can tend to detach the shreds of tobacco material from the aerosol-generating substrate. This can disadvantageously result in the need for more frequent cleaning of the heater element and other parts of the aerosol-generating device to remove detached shreds. In contrast, inserting and withdrawing the heater element of an aerosol-generating device into and from an aerosol-generating substrate comprising multiple strands of non-tobacco material advantageously significantly reduces the tendency for material to detach.

[0027] Rods according to the present invention can be made in a continuous process that can be carried out quickly and efficiently and that can be conveniently integrated into existing production lines for the manufacture of heated aerosol-generating articles.

[0028] The rod of the aerosol-generating substrate preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article.

[0029] The aerosol-generating substrate rod preferably has an outer diameter of at least 5 millimeters. The aerosol-generating substrate rod may have an outer diameter of from about 5 millimeters to approximately 12 millimeters, for example, from about 5 millimeters to about 10 millimeters, or from about 6 millimeters to about 8 millimeters. In one preferred embodiment, the aerosol-generating substrate rod has an outer diameter of 7.2 millimeters ±10 percent.

[0030] The aerosol-generating substrate rod may have a length of about 5 mm to about 100 mm. Preferably, the aerosol-generating substrate rod has a length of at least about 5 mm, and more preferably at least about 7 mm. Additionally or alternatively, the aerosol-generating substrate rod preferably has a length of less than about 25 mm, and more preferably less than about 20 mm. In one embodiment, the aerosol-generating substrate rod may have a length of about 10 mm. In one preferred embodiment, the aerosol-generating substrate rod has a length of about 12 mm.

[0031] Preferably, the rod of aerosol-generating substrate has a substantially uniform cross section along the length of the rod, and it is particularly preferred that the rod of aerosol-generating substrate has a substantially circular cross section.

[0032] The aerosol-generating article according to the present invention comprises an aerosol-generating substrate, which may be provided as a rod comprising strands of non-tobacco material surrounded by a wrapper. As used herein, the term "rod" is used to denote a generally cylindrical element of substantially circular, oval, or elliptical cross-section. In principle, other, more complex cross-sections of the strands are possible, such as star-, X-, or Y-shapes. However, in the context of the present invention, cross-sectional shapes that allow the strands to be reasonably tightly packed while at the same time having a favorable ratio between the surface area of the circle enclosed by the cross-section of the strand and the effective surface area of the cross-section of the strand are preferred. This is because, in the context of the present invention, shapes that allow a larger collective strand volume to be packed within the rod are generally preferred over shapes that correspond to a larger collective external surface area of the strands. In this regard, circular or quasi-circular shapes (e.g., oval or elliptical) are ideal. Triangular and rectangular cross-sections are also possible. However, in triangular and rectangular cross-sections, the strands may be packed too tightly, reducing the space available for airflow between the strands, etc.

[0033] The strands can be formed from a heat-resistant material coated with or immersed in the aerosol former. As used herein, the term "heat-resistant material" is used to describe a material that can withstand and remain substantially unaffected by heat when exposed to temperatures at least equal to or greater than typical operating temperatures of heated aerosol-generating articles. By way of example, the strands can be formed by an extrusion process.

[0034] As used herein, the term "aerosol former" describes any suitable, well-known compound or mixture of compounds that facilitates the formation of an aerosol during use and is substantially resistant to thermal decomposition at the operating temperature of the aerosol-generating article. Suitable aerosol formers are well-known in the art and include, but are not limited to, polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3-butanediol, and glycerin), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate and dimethyl tetradecanedioate). Preferred aerosol formers are polyhydric alcohols (e.g., propylene glycol, triethylene glycol, 1,3-butanediol, and most preferably glycerin) or mixtures thereof.

[0035] The aerosol former may be provided as a liquid or a gel. In some embodiments, the aerosol former may be provided in a composition further comprising nicotine or a flavoring agent or both.

[0036] By way of example, the heat resistant material may be a ceramic material. The heat resistant material may be glass, such as in the form of fiberglass.

[0037] In some embodiments, the non-tobacco material may comprise a flexible, string-like material that may be provided on a coil or roll, such as a flexible rod, which may comprise glass fibers, or may be an extruded, flexible, non-tobacco carrier that comprises a fibrous material.

[0038] The strands may be somewhat flexible, and the aerosol former may wick between the strands, or may be substantially viscous so as not to wick between the strands.

[0039] The non-tobacco material of the strand is preferably adapted to adsorb the aerosol former onto its surface or within its structure. In other words, the non-tobacco material of the strand is such that the aerosol former can be attached to the strand by adsorption and released by desorption. In some embodiments, the strand can be formed from a non-tobacco material such that the aerosol former (adsorbate) reversibly adheres to the surface of the strand (adsorbent) and forms a surface film thereon. This is based on the formation of bonds between the aerosol former molecules and the surface of the strand, such as weak van der Waals forces (physisorption), covalent bonds (chemisorption), or electrostatic attraction. In other embodiments, the strand can be formed from a non-tobacco material such that the aerosol former (adsorbate) reversibly penetrates the volume of the strand. This process can be chemical, i.e., involving a reaction between the aerosol former and the non-tobacco material of the strand, or the process can be purely physical (non-reactive), or the process can be a combination of chemical and physical processes.

[0040] This advantageously allows for improved control of the aerosol former loading, i.e., the amount of aerosol former provided in the rod of an aerosol-generating article according to the present invention. Without wishing to be bound by theory, it is understood that this may also advantageously facilitate control of the release profile. For example, it may be easier to control under which conditions (e.g., with respect to temperature) or at which stage during use aerosol release from the strand is favored or maximized.

[0041] This is an improvement over other non-tobacco materials commonly used in aerosol-generating articles, such as cellulose acetate tow: the aerosol formers do not adhere to the cellulose acetate fibers by sorption, but simply occupy the voids and gaps between adjacent fibers.

[0042] In some embodiments, compression or pinching of the strand of non-tobacco material loaded with the aerosol former may be necessary to release the aerosol former from the strand, or to enhance repeated or prolonged release of the aerosol former from the strand.

[0043] In some embodiments, all strands of non-tobacco material are evenly packed with aerosol former, resulting in a substantially uniform distribution of aerosol former across the cross-section of the rod of aerosol-generating substrate. Of course, gaps and voids between adjacent strands are common, and therefore the term "uniform distribution" is used herein to describe a concentration profile of aerosol former that is not entirely constant across the cross-section of the rod of aerosol-generating substrate.

[0044] In another embodiment, the plurality of strands includes a first group of strands having a first aerosol former loading and a second group of strands having a second aerosol former loading, the second aerosol former loading being greater than the first aerosol former loading. This advantageously allows for a non-uniform aerosol former distribution across the cross-section of the rod of the aerosol-generating substrate to be achieved. In other words, the aerosol former concentration profile across the cross-section of the rod of the aerosol-generating substrate can be tailored in a predetermined manner. For example, the strands disposed at the core of the rod can have a greater aerosol former loading than the strands disposed at the periphery of the rod.

[0045] The strands of non-tobacco material can be adapted to allow longitudinal air flow through the rod during use, and the number, size, and relative arrangement of the strands can be adjusted to ensure that the rod has the required porosity and that the RTD of the aerosol-generating article is within a range acceptable to consumers.

[0046] Preferably, each strand of non-tobacco material has an equivalent diameter of less than about 1 millimeter. Even more preferably, each strand of non-tobacco material has an equivalent diameter of less than about 0.5 millimeters.

[0047] In some embodiments, the plurality of strands comprises a first group of strands having a first equivalent diameter and a second group of strands having a second equivalent diameter, the second equivalent diameter being smaller than the first equivalent diameter, which may advantageously allow for finer control of the porosity of the rod, where different portions of the rod of the aerosol-generating substrate have different porosity values.

[0048] For example, a first group of strands may be disposed at a central location of the rod and a second group of strands may be disposed at a periphery of the rod, with the first group of strands preferably being substantially surrounded by strands of the second group of strands, thus providing a larger void space substantially axially within the rod while providing a smaller gap between adjacent strands at the periphery of the rod.

[0049] Preferably, each strand has a length substantially equal to the length of the rod of the aerosol-generating substrate. In one embodiment, each strand has a length of about 5 millimeters to about 80 millimeters. In one preferred embodiment, each tubular element has a length of about 7 millimeters to about 40 millimeters, and most preferably, each tubular element has a length of about 8 millimeters to about 28 millimeters.

[0050] The rod of the aerosol-generating substrate comprises fewer than about 200 strands of non-tobacco material. Preferably, the rod of the aerosol-generating substrate comprises fewer than about 150 strands of non-tobacco material. More preferably, the rod of the aerosol-generating substrate comprises fewer than about 100 strands of non-tobacco material.

[0051] The rod of the aerosol-generating substrate comprises at least about 20 strands of non-tobacco material. Preferably, the rod of the aerosol-generating substrate comprises at least about 30 strands of non-tobacco material. More preferably, the rod of the aerosol-generating substrate comprises at least about 40 strands of non-tobacco material. In particularly preferred embodiments, the rod of the aerosol-generating substrate comprises from about 20 to about 100 strands of non-tobacco material.

[0052] In some embodiments, the strands of non-tobacco material are aligned substantially parallel to one another within the aerosol-generating substrate. Preferably, the strands of non-tobacco material extend substantially along the longitudinal axis of the rod of the aerosol-generating substrate. This is advantageous in that it allows for precise determination and control of the porosity of the rod, i.e., the total volume of voids between the strands. This can affect the total amount of aerosol former that can be retained within the rod of the aerosol-generating substrate.

[0053] Furthermore, a portion of the overall volume of the voids will generally be occluded by the aerosol former, which can therefore affect the RTD of the aerosol-generating article. In embodiments in which the non-tobacco material of the strand is adapted to adsorb aerosol formers on its surface or within its structure, this is advantageously negated, as the aerosol is also, or substantially entirely, attached to the material of the strand.

[0054] In preferred embodiments, the strands are of substantially square cross-section, substantially rectangular cross-section, or substantially elliptical cross-section. Strands of substantially elliptical cross-section can be strands of substantially elliptical or circular cross-section.

[0055] In some embodiments, the strands of non-tobacco material within the rod are preferably disposed with a predetermined spacing between adjacent strands. By way of example, this may be achieved by providing particulate matter (such as carbon) disposed on the outer surface of the strands such that adjacent strands are at a fixed distance from each other, the distance being a substantial function of the average size (e.g., average equivalent diameter) of the particles.

[0056] As described above, the multiple strands of non-tobacco material forming the rod of the aerosol-generating substrate are surrounded by a wrapper. The wrapper can be formed of a porous or non-porous sheet material. The wrapper can be formed of any suitable material or combination of materials. Preferably, the wrapper is a paper wrapper. Optionally, the wrapper can be adhered to the outer ends of the multiple strands. For example, at least one of the inner surface of the wrapper and the outer ends of the multiple strands can be moistened during the manufacturing process so that the inner wrapper adheres to the ends of the strands during the wrapping process. Alternatively, adhesive can be applied to at least one of the inner surface of the wrapper and the outer ends of the multiple strands upstream of the wrapping process. Adhesion of the multiple strands and the wrapper can advantageously help maintain the position and spacing of the multiple strands within the rod.

[0057] A wrapper may optionally be at least partially folded over the strands at the upstream and downstream ends of the rod to hold the strands within the rod. Preferably, the wrapper is on the periphery of the strands at the upstream and downstream ends of the rod, leaving the remainder of the strands exposed. However, in some embodiments, the wrapper may be on the entire upstream and downstream ends of the rod. In such embodiments, air flow may be advantageously enabled by providing a wrapper with sufficient porosity to allow air flow through the ends of the rod.

[0058] Instead of folding the ends of the wrapper over the upstream and downstream strands of non-tobacco material, separate rim sections of paper or other material can be attached to the wrapper over at least the periphery of the upstream and downstream ends of the strands, as described above. In such embodiments where the wrapper is folded over the end of a rod or where separate rim sections are provided, an additional outer wrapper can be provided that covers the wrapper surrounding the multiple strands.

[0059] Aerosol-generating articles according to the present invention preferably comprise one or more elements in addition to the rod of aerosol-generating substrate, with the rod and one or more elements assembled within a substrate wrapper. For example, aerosol-generating articles according to the present invention may further comprise at least one of a mouthpiece, an aerosol-cooling element, and a support element such as a hollow acetate tube. For example, in one preferred embodiment, the aerosol-generating article comprises, in a linear, continuous arrangement, a rod of aerosol-generating substrate as described above, a support element located immediately downstream of the aerosol-forming substrate, an aerosol-cooling element located downstream of the support element, and an outer wrapper surrounding the rod, support element, and aerosol-cooling element.

[0060] In one embodiment of the present invention, a rod for use as an aerosol-generating substrate in an aerosol-generating article includes about 20 to about 200 strands of a non-tobacco material containing at least one aerosol former and adapted to emit at least one aerosol former, each strand having an equivalent diameter of at least about 0.1 millimeter, the strands assembled so that the strands extend longitudinally, and a wrapper surrounding the strands.

[0061] Such a rod may be produced by a method according to another aspect of the present invention, as defined above. In a first step of the method according to the present invention, a plurality of strands of non-tobacco material adapted to hold and release an aerosol former are provided, each strand having an equivalent diameter of at least about 0.1 millimeters. In a second step, about 20 to about 200 of the plurality of strands are assembled together so that the assembled strands extend longitudinally. By way of example, this may be accomplished by feeding the plurality of strands through a funnel element such that the plurality of strands are grouped into a substantially cylindrical cluster. The plurality of strands may be fed from different reels.

[0062] In a third step, the assembled strands are surrounded by a wrapper to form a continuous rod, and in a fourth step, the continuous rod is cut into a plurality of individual rods.

[0063] Preferably, the method includes the further step of applying at least one aerosol former to the strands prior to assembling the strands. More preferably, the method includes the further step of drying the strands after applying the at least one aerosol former to the strands prior to assembling the strands.

[0064] Alternatively, the method may include the further step of applying at least one aerosol former to the plurality of strands after the plurality of strands have been assembled. In a preferred embodiment, such a method may further include drying the plurality of strands after applying at least one aerosol former to the assembled strands.

[0065] As a further alternative, the method may include applying at least one aerosol former to the plurality of strands after the step of cutting the continuous rod into individual rods, the cutting means being provided at a cutting station to which the continuous rod is fed.

[0066] The steps of surrounding the multiple strands with a wrapper to form a continuous rod, and cutting the continuous rod to form individual rods, can be carried out using existing equipment and techniques, which are well known to those skilled in the art.

[0067] The invention will now be further described with reference to the figures. [Brief explanation of the drawings]

[0068] [Figure 1] 1 shows a schematic longitudinal cross-sectional view of an aerosol-generating article for use in an aerosol-generating device comprising a heater element. [Figure 2] 1 shows a schematic perspective view of an aerosol-generating substrate according to a first embodiment of the present invention, with the wrapper removed; [Figure 3] 3 shows a schematic perspective view of the aerosol-generating substrate of FIG. 2 with the wrapper in place. [Figure 4] 2 shows a longitudinal cross-sectional view of an aerosol generation system comprising an electrically operated aerosol generating device and the aerosol-generating article shown in FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0069] The aerosol-generating article 10 shown in Figure 1 comprises a rod of aerosol-generating substrate 12, a hollow cellulose acetate tube 14, a spacer element 16, and a mouthpiece filter 18. These four elements are arranged in continuous, coaxial alignment and surrounded by a substrate wrapper 20 to form the aerosol-generating article 10. The aerosol-generating article 10 has a mouth end 22 and a distal end 24 located at the opposite end of the article from the mouth end 22. The aerosol-generating article 10 shown in Figure 1 is particularly suitable for use in an electrically operated aerosol generating device that includes a heater for heating the rod of aerosol-generating substrate.

[0070] The rod of aerosol-generating substrate 12 has a length of about 12 millimeters and a diameter of about 7 millimeters. The rod 12 is cylindrical in shape and has a substantially circular cross section.

[0071] A rod embodiment of the aerosol-generating substrate 12 for use in the aerosol-generating article 10 of Figure 1 is shown in Figures 2 and 3. The rod 12 includes multiple strands 30 of non-tobacco material surrounded by a paper wrapper 32. In Figure 2, the multiple strands 30 of non-tobacco material are shown with the wrapper 32 removed.

[0072] As can be seen in Figure 2, each of the strands 30 extends longitudinally and has a length substantially corresponding to the length of the rod 12. The strands 30 are parallel to one another and stacked such that adjacent strands loosely contact one another. The strands 30 have a substantially circular cross-section and an equivalent diameter of about 1 millimeter. Longitudinal channels extending through the rod 12 are defined between the strands. Thus, the rod 12 is adapted to receive heater blades of an aerosol generating device, as described below, and to provide an airflow path for air that may be drawn through the rod 12 during use.

[0073] Figure 4 shows a portion of an electrically operated aerosol generating system 200 that utilizes a heater blade 210 to heat the rod of the aerosol-generating substrate 12 of the aerosol-generating article 10 shown in Figure 1. The heater blade 210 is mounted within an aerosol-generating article chamber within the housing of an electrically operated aerosol-generating device 212. The aerosol-generating device 212 defines a plurality of air holes 214, as shown by the arrows in Figure 4, for allowing air to flow through the aerosol-generating article 10. The aerosol-generating device 212 includes a power source and electronic components, which are not shown in Figure 4.

[0074] The aerosol-generating article 10 shown in Figure 1 is designed to be engaged with an aerosol-generating device 212 shown in Figure 4 for consumption. A user inserts the aerosol-generating article 10 into the aerosol-generating device 212 so that the heater blade 210 is inserted through the strand of non-tobacco material 30 and into the rod of the aerosol-generating substrate 12. The mouthpiece filter 18 projects outward from the oral end of the device 212. Once the aerosol-generating article 10 is engaged with the aerosol-generating device 212, the user draws on the oral end 22 of the aerosol-generating article 10, and the heater blade 210 heats the rod of the aerosol-generating substrate 12 to a temperature sufficient to generate an aerosol from the rod of the aerosol-generating substrate 12. The aerosol is drawn through the oral end filter 18 and into the user's mouth.

[0075] Of course, the aerosol-generating article 10 shown in FIG. 1 may also be suitable for use in other types of aerosol-generating devices.

Claims

1. 1. A heated aerosol-generating article for producing an inhalable aerosol, the heated aerosol-generating article comprising a rod of an aerosol-generating substrate, the rod of the aerosol-generating substrate comprising: about 20 to about 200 strands of non-tobacco material comprising at least one aerosol former and adapted to emit at least one aerosol former, each strand having an equivalent diameter of at least about 0.1 millimeter, said strands assembled such that they extend in said longitudinal direction; and a wrapper surrounding the strands.

2. 2. The heated aerosol-generating article of claim 1, wherein the non-tobacco material is adapted to adsorb the aerosol former onto its surface or within its structure.

3. 3. The heated aerosol-generating article of claim 1, wherein each strand of non-tobacco material has an equivalent diameter of less than about 1 millimeter.

4. 4. The heated aerosol-generating article according to claim 1, wherein each strand of non-tobacco material has a length substantially equal to the length of the rod of the aerosol-generating substrate.

5. 5. The heated aerosol-generating article according to claim 1, wherein the plurality of strands of non-tobacco material are aligned substantially parallel to one another within the aerosol-generating substrate.

6. 6. The heated aerosol-generating article according to any one of claims 1 to 5, wherein the strands have a substantially square cross-section, a substantially rectangular cross-section, or a substantially elliptical cross-section.

7. The heated aerosol-generating article according to any one of claims 1 to 6, wherein the strands comprise a heat-resistant material coated with or immersed in the aerosol former.

8. 1. A method of making a rod for use as an aerosol-generating substrate in an aerosol-generating article, said method comprising: providing a plurality of strands of non-tobacco material adapted to hold and release an aerosol former, each strand having an equivalent diameter of at least about 0.1 millimeter; assembling about 20 to about 200 strands such that the assembled strands extend in the longitudinal direction; surrounding the assembled strands with a wrapper to form a continuous rod; cutting the continuous rod into a plurality of individual rods.

9. 10. The method of claim 8, further comprising applying at least one aerosol former to the plurality of strands prior to assembling the plurality of strands.

10. 10. The method of claim 9, further comprising the step of drying the plurality of strands after the step of applying the at least one aerosol former to the strands and before the step of assembling the plurality of strands.

11. 10. The method of claim 8, further comprising applying at least one aerosol former to the plurality of strands after cutting the continuous rod.

12. 1. A rod for use as an aerosol-generating substrate in an aerosol-generating article, said rod comprising: about 20 to about 200 strands of non-tobacco material comprising at least one aerosol former and adapted to emit at least one aerosol former, each strand having an equivalent diameter of at least about 0.1 millimeter, said strands assembled such that they extend in said longitudinal direction; a wrapper surrounding said strands.

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