Aerosol-generating article having a cavity

Abstract

An aerosol-generating article is provided that includes an aerosol-forming material for generating an aerosol. The aerosol-generating article includes a first planar layer extending in a first plane and a second planar layer extending in a second plane, the second plane being parallel to and spaced apart from the first plane. The thickness of the article extends perpendicular to the first and second planes, and a cavity is defined between the first and second planar layers. The height of the cavity is defined by the distance between the lower surface of the first planar layer and the upper surface of the second planar layer. The thickness of the aerosol-generating article is less than 5 millimeters, and the height of the cavity is greater than 50 percent of the thickness of the aerosol-generating article.

Description

[Technical Field]

[0001] The present disclosure relates to aerosol-generating articles that include aerosol-forming materials. [Background technology]

[0002] A typical aerosol-generating article may look similar to a conventional cigarette. For example, such an aerosol-generating article may be a substantially cylindrical article comprising an aerosol-forming substrate and other components, such as a mouthpiece filter element, all wrapped in cigarette paper. The dimensions of a typical aerosol-generating article are often similar to those of a conventional cigarette. Summary of the Invention [Problem to be solved by the invention]

[0003] Studies have shown that in such typical aerosol-generating articles including a plug of aerosol-forming substrate, a large portion of the plug of aerosol-forming substrate may not be heated sufficiently to form an aerosol during use. This is undesirable because this portion of the plug of aerosol-forming substrate contributes to the costs of manufacturing and transporting the aerosol-generating article but does not contribute to the aerosol delivered to the end user. This can be true regardless of the method by which the aerosol-forming substrate is heated, for example, whether a resistance heater or an induction heater is used, and regardless of whether the plug of aerosol-forming substrate is heated from the inside or the outside.

[0004] It is an object of the present disclosure to provide an aerosol-generating article in which a substantial portion of the aerosol-forming substrate of the aerosol-generating article heats sufficiently during use to form an aerosol. [Brief explanation of the drawings]

[0005] [Figure 1] 1 is a side perspective view of an aerosol-generating article according to a first embodiment of the present disclosure. FIG. [Figure 2a] FIG. 2 is a side perspective view of an aerosol-generating article according to a second embodiment of the present disclosure. [Figure 2b] 2b is a schematic transverse cross-sectional view of the aerosol-generating article of FIG. 2a. [Figure 3a] FIG. 2 is a side perspective view of an aerosol-generating article according to a third embodiment of the present disclosure. [Figure 3b] FIG. 2 is an alternative side perspective view of an aerosol-generating article according to a third embodiment of the present disclosure. [Figure 4] FIG. 1 is a schematic end view of an aerosol-generating article according to a fourth embodiment of the present disclosure. [Figure 5] FIG. 5 is a schematic side view of the aerosol-generating article of FIG. 4. [Figure 6] FIG. 5 is a schematic plan view of the aerosol-generating article of FIG. 4. [Figure 7] 5 shows a schematic diagram of a corrugated element used in the aerosol-generating article of FIG. 4. [Figure 8] FIG. 10 shows a perspective view of an aerosol-generating article according to a fifth embodiment of the present disclosure. [Figure 9] 9 shows an exploded perspective view of the aerosol-generating article of FIG. 8. [Figure 10] 9 shows a further exploded perspective view of the aerosol-generating article of FIG. 8. [Figure 11] 9 shows a schematic cross-sectional view of the aerosol-generating article of FIG. 8. [Figure 12] 9 shows a schematic longitudinal cross-sectional view of the aerosol-generating article of FIG. 8. [Figure 13] FIG. 10 shows an exploded perspective view of an aerosol-generating article according to a sixth embodiment of the present disclosure. [Figure 14] 14 shows a schematic cross-sectional view of the aerosol-generating article of FIG. 13. [Figure 15] 14 shows a schematic transverse cross-sectional view of the aerosol-generating article of FIG. 13. DETAILED DESCRIPTION OF THE INVENTION

[0006] According to the present disclosure, an aerosol-generating article may be provided that includes an aerosol-forming material for generating an aerosol. The aerosol-generating article may include a first planar layer extending in a first plane and a second planar layer extending in a second plane, the second plane being parallel to and spaced apart from the first plane. The thickness of the aerosol-generating article may extend perpendicular to the first and second planes, and a cavity may be defined between the first and second planar layers. The height of the cavity may be defined by the distance between the lower surface of the first planar layer and the upper surface of the second planar layer. The thickness of the aerosol-generating article may be less than 5 millimeters. The height of the cavity may be greater than 50 percent of the thickness of the aerosol-generating article.

[0007] According to the present disclosure, an aerosol-generating article may be provided that includes an aerosol-forming substrate for generating an aerosol. The aerosol-generating article is a planar aerosol-generating article having a base defined by a length extending in the x-direction, a width extending in the y-direction, and a height extending in the z-direction. The aerosol-generating article may include a first planar layer extending in a first plane and a second planar layer extending in a second plane, the second plane being parallel to and spaced apart from the first plane. The thickness of the article may extend perpendicular to the first and second planes, and a cavity may be defined between the first and second planar layers. The height of the cavity may be defined by the distance between the lower surface of the first planar layer and the upper surface of the second planar layer. The thickness of the aerosol-generating article may be less than 5 millimeters. The height of the cavity may be greater than 50 percent of the thickness of the aerosol-generating article.

[0008] According to the present disclosure, an aerosol-generating article may be provided that includes an aerosol-forming substrate for generating an aerosol, the aerosol-generating article having a substantially planar upper surface defined by a length extending in the x-direction and a width extending in the y-direction, and a substantially planar lower surface defined by a length extending in the x-direction and a width extending in the y-direction. The substantially planar upper surface and the substantially planar lower surface may be vertically spaced apart from each other by a height defined in the z-direction. The aerosol-generating article may include a first planar layer extending in a first plane and a second planar layer extending in a second plane. The first planar layer may have a substantially planar upper surface and a first planar layer lower surface. The second planar layer may have a substantially planar lower surface and a second planar layer upper surface. The thickness of the aerosol-generating article may extend in a direction perpendicular to the first and second planes, and a cavity is defined between the first and second planar layers. The height of the cavity may be defined by the distance between the lower surface of the first planar layer and the upper surface of the second planar layer. The thickness of the aerosol-generating article may be less than 5 millimeters. The height of the cavity may be greater than 50 percent of the thickness of the aerosol-generating article.

[0009] The aerosol-generating articles of the present disclosure may be generally flat and thin, for example having a thickness of less than 5 millimeters. Advantageously, providing a generally flat and thin aerosol-generating article provides for rapid and efficient heating of the aerosol-forming material in the aerosol-generating article and improved uniformity in heating throughout its thickness.

[0010] Advantageously, the cavity height may be relatively high; for example, the cavity height may be greater than 50 percent of the thickness of the aerosol-generating article. Providing a generally high cavity height provides space for adequate airflow through the aerosol-generating article, even though the article is generally flat and thin. The cavity height allows air to flow more slowly through the cavity during use compared to cavities with smaller heights, which may provide improved contact between the airflow and the aerosol-forming material of the aerosol-forming article, enhanced mixing of the generated aerosol with the air in the cavity, and improved aerosolization.

[0011] The thickness of the aerosol-generating article may be defined by the distance between the upper surface of the aerosol-generating article and the lower surface of the aerosol-generating article. For example, the thickness of the aerosol-generating article may be defined between the upper surface of the first planar layer, e.g., the substantially planar upper surface of the first planar layer, and the lower surface of the second planar layer, e.g., the substantially planar lower surface of the second planar layer.

[0012] The first planar layer may comprise an upper surface of the aerosol-generating article and a lower surface of the aerosol-generating article, and the upper and lower surfaces may be vertically spaced apart from each other by a height defined in the z-direction. The upper surface of the first planar layer may be substantially planar and may be defined by a length extending in the x-direction and a width extending in the y-direction. The lower surface of the first planar layer may be substantially planar and may be defined by a length extending in the x-direction and a width extending in the y-direction. The upper surface of the first planar layer may be the outer upper surface of the aerosol-generating article.

[0013] The second planar layer may have an upper surface and a lower surface, and the upper and lower surfaces may be vertically spaced apart from each other by a height defined in the z direction. The upper surface of the second planar layer may be substantially planar and may be defined by a length extending in the x direction and a width extending in the y direction. The lower surface of the second planar layer may be substantially planar and may be defined by a length extending in the x direction and a width extending in the y direction. The lower surface of the second planar layer may be the outer lower surface of the aerosol-generating article.

[0014] Advantageously, the upper outer surface of the first planar layer and the lower outer surface of the second planar layer allow good contact with an external heater of the aerosol-generating device, particularly a planar external heater, thereby providing optimal heating of the aerosol-generating substrate.

[0015] Advantageously, the upper outer surface of the first planar layer and the lower outer surface of the second planar layer may provide a large surface area for heating by an external heater of the aerosol-generating device, thereby allowing the aerosol-generating substrate to be rapidly heated to a temperature sufficient to generate an aerosol.

[0016] Aerosol-generating articles according to the present disclosure may preferably be substantially flat or substantially planar. Such articles have a large base area relative to the volume of the article. Advantageously, a larger base area may provide a larger surface area for heating by the planar heater of the aerosol-generating device. Advantageously, a smaller height may result in a smaller temperature gradient or temperature difference across the height of the aerosol-generating article during heating. For example, if the base of the aerosol-generating article is in contact with (and heated by) the planar heater, a smaller distance or height between the base and the top surface may result in a smaller temperature difference between the base and the top surface opposite the base. Advantageously, this may allow a larger portion of the aerosol-forming substrate of the aerosol-generating article to be heated to a temperature at which an aerosol is emitted, while minimizing the risk of burning the hottest portion of the substrate closest to the heater. Alternatively, or additionally, this may reduce the time required to heat the aerosol-forming substrate sufficiently to emit an aerosol.

[0017] The aerosol-generating article may comprise an air flow inlet, an air flow outlet, and an air flow passage extending between the air flow inlet and the air flow outlet. The air flow passage may extend through the cavity between the air inlet and the air outlet.

[0018] The aerosol-generating article may be defined by an article length extending in the x-direction, an article width extending in the y-direction, and an article thickness extending in the z-direction, and an airflow passage may be defined through the aerosol-forming article between an airflow inlet and an airflow outlet, the airflow passage flowing through the cavity. For example, the airflow passage may extend through the cavity between an air inlet and an air outlet.

[0019] The airflow inlet may be defined by an inlet width and an inlet height, the inlet width being greater than 80 percent of the article width and the inlet height being greater than 25 percent of the article height, and optionally the airflow inlet being substantially rectangular.

[0020] The airflow outlet may be defined by an outlet width and an outlet height, the outlet width being greater than 80 percent of the article width and the outlet height being greater than 25 percent of the article height, and optionally the airflow outlet being substantially rectangular.

[0021] Advantageously, the dimensions of the air inlet may facilitate airflow into the aerosol-generating article, and the dimensions of the air outlet may facilitate airflow out of the aerosol-generating article.

[0022] The height of the cavity may be greater than 60 percent of the thickness of the article, for example greater than 70 percent of the thickness of the article, for example greater than 80 percent of the thickness of the article, preferably greater than 85 percent of the thickness of the article, or greater than 90 percent of the thickness of the article, for example greater than 95 percent of the thickness of the article.

[0023] An airflow inlet may be defined at a distal end of the article, the airflow inlet may be configured to allow air to flow into the cavity. An airflow outlet may be defined at a proximal end of the article, the airflow outlet may be configured to allow air to flow out of the cavity.

[0024] The aerosol-generating article may further define a mouthpiece in fluid communication with the cavity, for example an integral mouthpiece or a removable mouthpiece.

[0025] An aerosol-generating article according to any of the embodiments disclosed herein may have an airflow path extending through the aerosol-generating article. The aerosol-generating article may have an airflow path defined through the aerosol-generating article in the x / y plane, from one side of the aerosol-generating article to the other side of the aerosol-generating article. The airflow path may be defined through the aerosol-generating article between the distal end and the proximal end of the aerosol-generating article. The airflow path may be defined through the aerosol-generating article from the air inlet, through the cavity, to the air outlet. The airflow path may be defined through an airflow passage.

[0026] The resistance to draw (RTD) of the article along the airflow path between the air inlet and the air outlet may be less than 20 millimeters of H2O. Preferably, the aerosol-generating article has a resistance to draw (RTD) in the direction of the airflow path of less than 20 millimeters of H2O, for example less than 10 millimeters of H2O. Preferably, the aerosol-generating article has an RTD of less than 20 millimeters of H2O, for example less than 10 millimeters of H2O, in at least one direction in the x / y plane of the aerosol-generating article. Aerosol-generating articles with low resistance airflow paths may allow for better airflow management, enabling aerosol to be more efficiently extracted from the aerosol-generating article and directed to the user.

[0027] Unless otherwise specified, resistance to draw (RTD) is measured in accordance with ISO 6565-2015. RTD refers to the pressure required to force air through the entire length of a component, such as an aerosol-generating article. The terms "pressure drop" or "draw resistance" of a component or article can also refer to "resistance to draw." These terms generally refer to measurements made in accordance with ISO 6565-2015 and typically performed under test at a temperature of about 22 degrees Celsius, a pressure of about 101 kPa (about 760 Torr), and about 60 percent relative humidity, with a volumetric flow rate of about 17.5 milliliters per second at the output or downstream end of the component being measured.

[0028] An aerosol-generating article according to any of the embodiments disclosed herein may have substantially planar upper and lower surfaces. The vertical separation between the substantially planar upper and lower surfaces may define the height (e.g., z-dimension) of the aerosol-generating article. An airflow passage may be defined between the substantially planar upper and lower surfaces. The height of the aerosol-generating article may be less than 5 millimeters, for example, between 1.5 millimeters and 5 millimeters, for example, between 1.5 millimeters and 4 millimeters, for example, between 1.5 millimeters and 3 millimeters, for example, between 1.5 millimeters and 2 millimeters. One or both of the substantially planar upper and lower surfaces may comprise an aerosol-forming substrate. The aerosol-generating article may comprise an upper layer and a lower layer, at least one of which comprises or consists of an aerosol-forming substrate, the upper layer forming the substantially planar upper surface and the lower layer forming the substantially planar lower surface.

[0029] According to the present disclosure, an aerosol-generating article may be provided, comprising a first planar layer, a second planar layer, and an intermediate layer disposed between the first and second planar layers. The thickness of the aerosol-generating article may extend in a direction perpendicular to the first and second planar layers, and a cavity may be defined between the first and second planar layers. The height of the cavity may be defined by the distance between the lower surface of the first planar layer and the upper surface of the second planar layer. The thickness of the aerosol-generating article may be less than 5 millimeters. The height of the cavity may be greater than 50 percent of the thickness of the aerosol-generating article.

[0030] At least a portion of the intermediate layer may be disposed within the cavity. Alternatively, or additionally, at least a portion of the intermediate layer may be disposed outside the cavity, e.g., at least a portion of the intermediate layer may at least partially surround the cavity.

[0031] The intermediate layer may be a corrugated layer disposed between the first planar layer and the second planar layer, and at least one of the first planar layer, the second planar layer, and the corrugated layer may comprise or consist of an aerosol-forming substrate.

[0032] The intermediate layer may be attached to the first layer by an adhesive. Alternatively, or additionally, the intermediate layer may be attached to the second layer by an adhesive. The adhesive may comprise or consist of an aerosol-forming material.

[0033] The plurality of longitudinally extending passages may be defined by corrugations of a corrugated element located within the cavity, and a porous element may be located within at least one of the longitudinally extending passages.

[0034] The longitudinally extending passage may extend in the x / y plane between the distal and proximal ends of the aerosol-generating article.

[0035] The use of a corrugated structure in an aerosol-generating article may advantageously enable the production of an aerosol-generating article that has a very low RTD while being rigid enough for a user to handle. Furthermore, the use of a corrugated structure may enable the production of a low-density, low-RTD aerosol-generating article using high-speed manufacturing methods similar to those used to manufacture corrugated cardboard.

[0036] According to the present disclosure, an aerosol-generating article may be provided, the aerosol-generating article comprising: a first outer-planar surface; a second outer-planar surface; a cavity; a frame positioned between the first outer-planar surface and the second outer-planar surface, the frame at least partially defining the cavity; an aerosol-forming substrate positioned between the first outer-planar surface and the second outer-planar surface; an air inlet and an air outlet; and an airflow passage extending through the cavity between the air inlet and the air outlet. The aerosol-generating article may comprise a first planar layer extending in the first plane and a second planar layer extending in the second plane, the second plane being parallel to and spaced apart from the first plane. The thickness of the aerosol-generating article may extend in a direction perpendicular to the first and second planes, and the cavity is defined between the first and second planar layers. The height of the cavity may be defined by the distance between the lower surface of the first planar layer and the upper surface of the second planar layer. The thickness of the aerosol-generating article may be less than 5 millimeters. The height of the cavity may be greater than 50 percent of the thickness of the aerosol-generating article.

[0037] The first planar layer may comprise or form a first out-of-plane surface. The second planar layer may comprise or form a second out-of-plane surface. The first out-of-plane surface may face a lower surface of the first planar layer. The second out-of-plane surface may face a upper surface of the second planar layer.

[0038] The thickness of the aerosol-generating article may be defined between the first out-of-planar surface and the second out-of-planar surface.

[0039] The aerosol-generating article may comprise a planar frame positioned between a first planar layer and a second planar layer, and preferably the cavity is defined by the lower surface of the first planar layer, the upper surface of the second planar layer, and the inner wall of the planar frame.

[0040] Advantageously, the frame may allow the aerosol-generating article to be relatively thin yet maintain structural rigidity.

[0041] The frame may comprise a peripheral wall that at least partially surrounds or encloses the cavity. The frame may comprise a peripheral wall that completely surrounds or encloses the cavity.

[0042] Advantageously, the peripheral wall provides structural strength to maintain the shape of the aerosol-generating article while allowing a relatively large interior volume for aerosol-generating material for aerosol formation.

[0043] Optionally, at least one of the first planar layer, the second planar layer, and the frame may comprise or consist of an aerosol-forming substrate.

[0044] The cavity may be substantially empty.

[0045] The aerosol-forming substrate may be positioned within the cavity.

[0046] An intermediate layer, such as a corrugated layer, may be positioned within the cavity.

[0047] Any aerosol-generating article according to embodiments of the present disclosure may have a length (e.g., x-dimension) of 10 mm to 100 mm, or 15 mm to 55 mm, or 20 mm to 45 mm, such as 25 mm to 35 mm, for example about 25 mm, or 28 mm, or 30 mm, or 32 mm. Any aerosol-generating article according to embodiments of the present disclosure may have a length (e.g., x-dimension) of 10 mm to 50 mm, for example 12 mm to 30 mm, for example 14 mm to 26 mm, for example 16 mm to 24 mm, for example 18 mm to 22 mm, for example about 18 mm, or about 19 mm, or about 20 mm, or about 21 mm, or about 22 mm.

[0048] The aerosol-generating article may have a width (e.g., y dimension) of 5 mm to 20 mm, such as 6 mm to 15 mm, for example 7.5 mm to 13 mm, for example 8 mm to 18 mm, such as 9 mm to 12.5 mm, or such as 10 mm to 16 mm, for example 11 mm to 15 mm, for example 12 mm to 14 mm, such as about 9.5 mm, or 10 mm, or 11 mm, or 12 mm, or 13 mm.

[0049] The aerosol-generating article may have a thickness (e.g., z-dimension) of from 0.5 mm to 5 mm, such as from 1 mm to 4.75 mm, for example from 1.5 mm to 4.5 mm, for example from 2 mm to 4 mm, such as about 2.5 mm, or for example about 2.75 mm, or about 3 mm. The aerosol-generating article may have a thickness (e.g., z-dimension) of, for example, from 1.2 mm to 8 mm, such as from 1.4 mm to 7 mm, for example from 1.6 mm to 6 mm, for example from 1.7 mm to 5 mm, such as about 1.7 mm, or about 4.5 mm, or about 2 mm, or about 3 mm, or about 4 mm.

[0050] Advantageously, these thicknesses may provide a small temperature gradient or difference across the thickness of the aerosol-generating substrate during heating. Advantageously, this may allow a larger portion of the aerosol-generating substrate to be heated to a temperature at which an aerosol is emitted, while minimizing the risk of burning the hottest portion of the aerosol-generating substrate closest to the heater. Alternatively, or additionally, this may reduce the time required to heat the aerosol-generating substrate sufficiently to emit an aerosol.

[0051] The height of the cavity may be between 0.25 mm and 4.9 mm, such as between 0.375 mm and 4.5 mm, such as between 0.5 mm and 4 mm, such as between 0.625 mm and 3.5 mm, such as about 2 mm, or about 2.5 mm, or about 2.9 mm.

[0052] The cavity may have a width of 4.75 mm to 19.75 mm, such as 5.75 mm to 14.75 mm, such as 7.25 mm to 12.75 mm, such as 8.75 mm to 12.25 mm, such as about 9.25 mm, or 9.5 mm, or 10.5 mm, or 11.5 mm.

[0053] The thickness of the first planar layer and / or the second planar layer may be 150 microns to 1000 microns, for example 250 microns to 800 microns, for example 300 microns to 600 microns, for example 350 microns to 500 microns, for example about 200 microns, or about 250 microns, or about 300 microns, or about 350 microns, or about 400 microns.

[0054] Any aerosol-generating article according to the embodiments of the present disclosure, when viewed in a plan view, may have a shape that defines a polygon, a quadrilateral (e.g., a rectangle or square), an ellipse, or a circle, or a combination thereof. If the aerosol-generating article has substantially planar upper and lower surfaces, one or both of the upper and lower surfaces, when viewed in a plan view, may have a shape that defines a polygon, a quadrilateral (e.g., a rectangle or square), an ellipse, a circle, or a combination thereof. The periphery of the aerosol-generating article, when viewed in a plan view, may be formed with a plurality of straight sides, a plurality of curved sides, or a combination of straight and curved sides. If the aerosol-generating article has substantially planar upper and lower surfaces, the periphery of one or both of the upper and lower surfaces, when viewed in a plan view, may have a shape that defines a polygon, a quadrilateral (e.g., a rectangle or square), an ellipse, a circle, or a combination thereof.

[0055] The aerosol-generating article may consist entirely of the aerosol-forming substrate. Alternatively, the aerosol-forming substrate may be one of several component parts of the aerosol-generating article. The aerosol-forming substrate may comprise an aerosol-forming material.

[0056] The first planar layer may include an aerosol-forming material. Alternatively, or additionally, the second planar layer may include an aerosol-forming material. For example, the first planar layer may include a homogenized tobacco sheet. Alternatively, or additionally, the second planar layer may include a homogenized tobacco sheet.

[0057] Advantageously, the aerosol-forming material can be heated quickly and efficiently by an external heater.

[0058] The first planar layer preferably comprises an aerosol-forming layer containing an aerosol-forming material and at least one further layer (eg, an outer layer), or wrapper layer.

[0059] The second planar layer preferably comprises an aerosol-forming layer containing an aerosol-forming material and at least one further layer (eg, an outer layer), or wrapper layer.

[0060] Optionally, both the first planar layer and the second planar layer comprise an aerosol-forming layer containing an aerosol-forming material and at least one further layer (e.g., an outer layer), or wrapper layer. The aerosol-forming material may be located within the cavity.

[0061] The aerosol-forming substrate, in particular the aerosol-forming material, may comprise nicotine, which may be present in the form of tobacco material or in the form of a nicotine extract.

[0062] The aerosol-forming substrate, and in particular the aerosol-forming material, preferably comprises or consists of a homogenized tobacco material, such as a reconstituted tobacco material or a cast leaf tobacco material.

[0063] The aerosol-forming substrate may comprise or consist of a solid aerosol-forming material. The aerosol-forming substrate may comprise a liquid aerosol-forming substrate material, for example a liquid aerosol-forming material held within a porous matrix. The aerosol-forming substrate may comprise a gel aerosol-forming material.

[0064] The aerosol-forming substrate may comprise one or more aerosol formers. Suitable aerosol formers are well known in the art and include, but are not limited to, one or more aerosol formers selected from polyhydric alcohols (such as propylene glycol, polyethylene glycol, triethylene glycol, 1,3-butanediol, glycerin, etc.), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate), and aliphatic esters of monocarboxylic, dicarboxylic, or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.). It may be particularly preferred that the aerosol former is or comprises glycerin.

[0065] The aerosol-forming substrate may comprise at least 1, 2, 5, 10, or 15 percent by weight of aerosol formers. The aerosol-forming substrate may comprise more than 15 percent by weight of aerosol formers, for example more than 20 percent by weight, or more than 25 percent by weight, or more than 30 percent by weight, or more than 40 percent by weight, or more than 50 percent by weight of aerosol formers.

[0066] The aerosol-forming substrate may comprise 30% or less by weight of aerosol formers, 25% or less by weight of aerosol formers, or 20% or less by weight of aerosol formers, i.e., the aerosol-forming substrate may have an aerosol-former content of 30% or less by weight, 25% or less by weight, or 20% or less by weight.

[0067] The aerosol-forming substrate may comprise from 1 weight percent to 30 weight percent aerosol formers, from 1 weight percent to 25 weight percent aerosol formers, or from 1 weight percent to 20 weight percent aerosol formers.

[0068] The aerosol-forming substrate may comprise 5 to 30 percent by weight of aerosol formers, 5 to 25 percent by weight of aerosol formers, or 5 to 20 percent by weight of aerosol formers.

[0069] The aerosol-forming substrate may comprise 10 to 30 percent by weight of aerosol formers, 10 to 25 percent by weight of aerosol formers, or 10 to 20 percent by weight of aerosol formers.

[0070] The aerosol-forming substrate may comprise 15 to 30 percent by weight of aerosol formers, 15 to 25 percent by weight of aerosol formers, or 15 to 20 percent by weight of aerosol formers.

[0071] The aerosol-forming substrate may comprise at least 50 percent by weight of the aerosol former, at least 60 percent by weight of the aerosol former, or at least 70 percent by weight of the aerosol former.

[0072] The aerosol-forming substrate may comprise 85 weight percent or less of the aerosol former, 80 weight percent or less of the aerosol former, or 75 weight percent or less of the aerosol former.

[0073] The aerosol-forming substrate may comprise 50 to 85 percent by weight of aerosol formers, 50 to 80 percent by weight of aerosol formers, or 50 to 75 percent by weight of aerosol formers.

[0074] The aerosol-forming substrate may comprise 60 to 85 percent by weight of aerosol formers, 60 to 80 percent by weight of aerosol formers, or 60 to 75 percent by weight of aerosol formers.

[0075] The aerosol-forming substrate may comprise 70 to 85 percent by weight of aerosol formers, 70 to 80 percent by weight of aerosol formers, or 70 to 75 percent by weight of aerosol formers.

[0076] The aerosol-forming substrate may comprise nicotine. The aerosol-forming material may comprise natural nicotine, or synthetic nicotine, or a combination of natural and synthetic nicotine.

[0077] The aerosol-forming substrate may comprise at least 0.5 weight percent nicotine, at least 1 weight percent nicotine, at least 1.5 weight percent nicotine, or at least 2 weight percent nicotine, i.e. the aerosol-forming substrate may have a nicotine content of at least 0.5 weight percent, at least 1 weight percent, at least 1.5 weight percent, or at least 2 weight percent.

[0078] The aerosol-forming substrate may comprise one or more cannabinoid compounds, such as one or more of tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiol (CBD), cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), cannabigerol monomethyl ether (CBGM), cannabivarin (CBV), cannabidivarin (CBDV), tetrahydrocannabivarin (THCV), cannabichromene (CBC), cannabicyclol (CBL), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabielsoin (CBE), and cannabicitran (CBT). Preferably, the cannabinoid compound is CBD or THC. Particularly preferably, the cannabinoid compound is CBD.

[0079] The aerosol-forming substrate may contain one or more flavoring agents. The one or more flavoring agents may include one or more essential oils, such as eugenol, peppermint oil, or spearmint oil; one or both of menthol and eugenol; one or both of anethole and linalool; and one or more herbaceous materials. Suitable herbaceous materials include herb leaves or other herbaceous materials from herbaceous plants, including, but not limited to, mint (e.g., peppermint, spearmint), lemon balm, basil, cinnamon, lemon basil, chives, coriander, lavender, sage, tea, thyme, and caraway. The one or more flavoring agents may include tobacco materials.

[0080] The aerosol-forming substrate may have a moisture content of about 5 to 25 percent, preferably about 7 to 15 percent, in the final product state. For example, the aerosol-forming substrate may be a homogenized tobacco material having a moisture content of about 5 to 25 percent, preferably about 7 to 15 percent, in the final product state.

[0081] The aerosol-forming substrate may comprise tobacco, for example, a blend of about 15 to 45 percent, preferably about 20 to 35 percent, tobacco, incorporating at least one of bright tobacco, dark tobacco, and aromatic tobacco. The tobacco material, such as tobacco, is preferably ground and graded to a particle size of about 100 to 380 mesh, preferably about 170 to 320 mesh.

[0082] "Tobacco variety" means one of the different types of tobacco, based, for example, on the unique curing process that occurs before the tobacco is further processed into tobacco products.

[0083] Examples of bright tobaccos include Brazilian Fulcure, Indian Fulcure, Chinese Fulcure, American Fulcure, e.g., Virginia tobacco, and Tanzanian Fulcure.

[0084] Examples of aromatic tobaccos include Turkish Oriental, Greek Oriental, and Semi-Oriental tobaccos, but also fire-cured, US Burley, and varieties such as Perique and Rustica.

[0085] Examples of dark tobaccos include dark-cured Brazilian Galpao, Burley Malawi or other African Burley, Sun-cured or air-cured Indonesian Kastri.

[0086] The aerosol-forming substrate may contain cellulose fibers. For example, the aerosol-forming substrate may contain about 1 to 15 percent cellulose fibers, preferably about 3 to 7 percent cellulose fibers. The cellulose fibers may preferably have a length of about 10 to 250 μm, preferably about 10 to 120 μm.

[0087] The aerosol-forming substrate may contain organic fibers, such as non-tobacco fibers or tobacco fibers. For example, the aerosol-forming substrate may contain about 5 to 20 percent, preferably about 7 to 15 percent, tobacco fibers. The tobacco fibers are preferably derived from stems and / or petioles and graded into fibers with lengths of about 10 to 350 μm, preferably about 10 to 180 μm. The aerosol-forming substrate may contain about 10 to 30 percent, preferably about 15 to 25 percent, non-tobacco organic fibers. For example, organic fibers may be obtained from cellulose, cotton, wood, or tea plant varieties as by-products or secondary processing waste products of the tea industry. The organic fibers preferably have lengths of about 10 to 400 μm, preferably about 10 to 200 μm.

[0088] The aerosol-forming substrate may contain a binder. For example, the aerosol-forming substrate may contain about 1 to 10 percent, preferably about 1 to 5 percent, of a binder, such as one of the common gums or pectins used in the food and beverage (F&B) industry. Preferred binders may be natural pectin (e.g., fruit (e.g., citrus) pectin or tobacco pectin), guar gum, land locust bean gum (e.g., their hydroxyethyl and / or hydroxypropyl forms), starch (e.g., modified starch or derivatized starch), alginate, methylcellulose, ethylcellulose, ethylhydroxymethylcellulose, carboxymethylcellulose, dextran, or xanthan gum. A preferred binder is guar.

[0089] The aerosol-forming substrate may include organic vegetable glycerite. For example, the aerosol-forming substrate may include about 15 to 55 percent, preferably about 20 to 35 percent, of botanical ingredients such as clove, echinacea species, fennel, ginger, hawthorn berry, elderberry, monarda, mullein leaf, nettle, plantain, turmeric, yarrow, and mixtures thereof.

[0090] The aerosol-forming substrate may contain organic plant extracts. For example, the aerosol-forming substrate may contain about 1 to 15 percent, preferably 2 to 7 percent, of any of the aforementioned plants, as well as menthol (dl-menthol, CHO, 2-isopropyl-5-methylcyclohexanol) obtained from Chaerophyllum macrospermum, Mesosphaerum sidifolium, or other related plant varieties, and p-menthone-3-ol as an optional secondary alcohol, a diastereoisomer of 5-methyl-2-(propan-2-yl)cyclohexan-1-ol.

[0091] The aerosol-forming substrate may contain, for example, about 0.5 to 5 percent, preferably about 1 to 3 percent, of a plant essential oil (eg, palm oil, coconut oil, wood-based essential oils, etc.).

[0092] The aerosol-forming substrate preferably comprises an aerosol former, for example, about 5 to 35 percent, preferably about 10 to 25 percent, of the aerosol former. Suitable aerosol formers known in the art include glycerin, monohydric alcohols (such as menthol), polyhydric alcohols (such as triethylene glycol), esters of polyhydric alcohols (such as glycerol monoacetate, glycerol diacetate, or glycerol triacetate), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as the dimethyl esters thereof).

[0093] As used herein, the term "aerosol-generating article" may refer to an article that is capable of generating (or emitting) an aerosol.

[0094] The term "aerosol-forming substrate" as used herein may refer to a substrate capable of emitting an aerosol or volatile compound capable of forming an aerosol. Such a volatile compound may be emitted by heating the aerosol-forming substrate. The aerosol-forming substrate may comprise an aerosol-forming material. The aerosol-forming substrate may be adsorbed, coated, impregnated, or loaded onto a carrier or support. The aerosol-forming substrate may conveniently be part of an aerosol-generating article or a smoking article.

[0095] As used herein, the term "aerosol-generating device" may refer to a device used in conjunction with an aerosol-generating article to enable the generation (or emission) of an aerosol.

[0096] As used herein, the term "aerosol generation system" refers to the combination of an aerosol generation device and one or more aerosol-forming articles for use with the device. The aerosol generation system may include additional components, such as an electrically operated aerosol generator or a charging unit for recharging an on-board power supply in an electric aerosol generator.

[0097] As used herein, the term "aerosol former" may refer to any suitable known compound or mixture of compounds that facilitates the formation of an aerosol upon use. The aerosol may be a dense and stable aerosol. The aerosol may be substantially resistant to thermal decomposition at the operating temperature of the aerosol-forming substrate or aerosol-generating article.

[0098] As used herein in connection with the present invention, the term "nicotine" is used to describe nicotine, nicotine base, or nicotine salts.

[0099] As used herein in connection with the present invention, the terms "proximal," "distal," "upstream," and "downstream" are used to describe the relative locations of components or portions of components of an aerosol-generating article.

[0100] 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 may be drawn longitudinally through the aerosol-generating article.

[0101] As used herein, the term "sheet" refers to a laminar element having a width and length substantially greater than its thickness. The width of the sheet may be greater than about 10 millimeters, preferably greater than about 20 or 30 millimeters. In certain embodiments, the sheet of material used to form the aerosol-forming substrate described herein may have a thickness of from 10 microns to about 1000 microns, e.g., from 10 microns to about 300 microns.

[0102] As used herein, the term "homogenized tobacco material" encompasses any tobacco material formed by agglomeration of particles of tobacco material. A sheet or web of homogenized tobacco material is formed by agglomerating particulate tobacco obtained by grinding or otherwise pulverizing one or both of tobacco lamina and tobacco stems. In addition, homogenized tobacco material may contain one or more small amounts of tobacco dust, tobacco fines, and other particulate tobacco by-products formed during tobacco processing, handling, and shipping. A sheet of homogenized tobacco material may be produced by casting, extrusion, a papermaking process, or any other suitable process known in the art.

[0103] The term "cast leaf" is used herein to refer to a product made by a casting process based on casting a slurry containing plant particles (e.g., clove particles, or a mixture of tobacco and clove particles) and a binder (e.g., guar gum) onto a support surface (e.g., a belt conveyor), drying the slurry, and removing the dried sheet from the support surface. Examples of casting or cast leaf processes are described, for example, in U.S. Pat. No. 5,724,998 for making cast leaf tobacco. In the cast leaf process, particulate plant material is produced by pulverizing, grinding, or comminuting plant parts. Particles produced from one or more plant bodies are mixed with a liquid component (typically water) to form a slurry. Other components in the slurry may include fibers, binders, and aerosol formers. The particulate plant material may be agglomerated in the presence of a binder. The slurry is cast onto a support surface and allowed to dry into a sheet of homogenized plant material. Preferably, the homogenized plant material used in the article according to the present invention can be produced by casting. Such homogenized plant material may include agglomerated particulate plant material.

[0104] As used herein, withdrawal resistance is expressed in units of pressure "mmH2O" or "mm WG" or "millimeters of water column" and may be measured in accordance with ISO 6565:2002.

[0105] The present invention is defined in the claims. However, below is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of any other example, embodiment, or aspect described herein.

[0106] [Example] Example 1. An aerosol-generating article comprising an aerosol-forming material for generating an aerosol, the aerosol-forming article comprising a first planar layer extending in a first plane and a second planar layer extending in a second plane, the second plane being parallel to and spaced apart from the first plane, the thickness of the aerosol-forming article extending in a direction perpendicular to the first and second planes, a cavity being defined between the first and second planar layers, the height of the cavity being defined by the distance between the lower surface of the first planar layer and the upper surface of the second planar layer, the thickness of the aerosol-generating article being less than 5 mm, and the height of the cavity being greater than 50 percent of the thickness of the article.

[0107] Example 2. An aerosol-generating article as described in Example 1, wherein the thickness of the aerosol-generating article is defined by the distance between the upper surface of the aerosol-generating article and the lower surface of the aerosol-generating article, e.g., the distance between the upper surface of the first planar layer and the lower surface of the second planar layer.

[0108] Example 3. An aerosol-generating article as described in Example 1 or Example 2, wherein the thickness of the aerosol-generating article is defined by the distance between the upper surface of the first planar layer and the lower surface of the second planar layer.

[0109] Example 4. An aerosol-generating article according to any of Examples 1 to 3, wherein the aerosol-generating article is defined by an article length extending in the x-direction, an article width extending in the y-direction, and an article thickness extending in the z-direction, and wherein an airflow passage is defined through the aerosol-forming article between an airflow inlet and an airflow outlet, and wherein the airflow passage flows through the cavity.

[0110] Example 5. An aerosol-generating article as described in Example 4, wherein the airflow inlet is defined by an inlet width and an inlet height, the inlet width being greater than 80 percent of the article width and the inlet height being greater than 25 percent of the article height, and optionally the airflow inlet is substantially rectangular.

[0111] Example 6. An aerosol-generating article as described in any of Examples 1 to 5, wherein the height of the cavity is greater than 60 percent of the thickness of the aerosol-generating article, for example greater than 70 percent of the thickness of the aerosol-generating article, for example greater than 80 percent of the thickness of the aerosol-generating article, preferably greater than 85 percent of the thickness of the aerosol-generating article, or greater than 90 percent of the thickness of the aerosol-generating article, for example greater than 95 percent of the thickness of the aerosol-generating article.

[0112] Example 7. An aerosol-generating article as described in any of Examples 1 to 6, wherein the thickness of the aerosol-generating article is 0.5 mm to 5 mm, for example 1 mm to 4.75 mm, for example 1.5 mm to 4.5 mm, for example 2 mm to 4 mm, for example about 2.5 mm, or about 2.75 mm, or about 3 mm.

[0113] Example 8. An aerosol-generating article according to any one of Examples 1 to 7, wherein the height of the cavity is 0.25 mm to 4.9 mm, for example 0.375 mm to 4.5 mm, for example 0.5 mm to 4 mm, for example 0.625 mm to 3.5 mm, for example about 2 mm, or about 2.5 mm, or about 2.9 mm.

[0114] Example 9. An aerosol-generating article according to any of Examples 1-8, wherein the first planar layer and / or the second planar layer comprises an aerosol-forming material, e.g., the first planar layer and / or the second planar layer comprises a sheet of homogenized tobacco.

[0115] Example 10. An aerosol-generating article according to any of Examples 1-9, wherein the first planar layer and / or the second planar layer comprises an aerosol-forming layer comprising an aerosol-forming material and at least one further layer (e.g., an outer layer), or wrapper layer.

[0116] Example 11. An aerosol-generating article according to any one of Examples 1 to 10, wherein the thickness of the first layer and / or the second layer is 150 microns to 1000 microns, for example 250 microns to 800 microns, for example 300 microns to 600 microns, for example 350 microns to 500 microns, for example about 200 microns, or about 250 microns, or about 300 microns, or about 350 microns, or about 400 microns.

[0117] Example 12. An aerosol-generating article according to any one of Examples 1 to 11, wherein the aerosol-generating article has a width of 5 mm to 20 mm, for example 6 mm to 15 mm, for example 7.5 mm to 13 mm, for example 9 mm to 12.5 mm, for example about 9.5 mm, or 10 mm, or 11 mm, or 12 mm.

[0118] Example 13. An aerosol-generating article as described in Example 12, wherein the cavity has a width of 4.75 mm to 19.75 mm, for example 5.75 mm to 14.75 mm, for example 7.25 mm to 12.75 mm, for example 8.75 mm to 12.25 mm, for example about 9.25 mm, or 9.5 mm, or 10.5 mm, or 11.5 mm.

[0119] Example 14. An aerosol-generating article according to any one of Examples 1 to 13, wherein the article has a length of 10 mm to 100 mm, for example 15 mm to 55 mm, for example 20 mm to 45 mm, for example 25 mm to 35 mm, for example about 25 mm, or 28 mm, or 30 mm, or 32 mm.

[0120] Example 15. An aerosol-generating article according to any of Examples 1 to 14, wherein an airflow inlet is defined at the distal end of the aerosol-generating article, the airflow inlet being configured to allow air to flow into the cavity.

[0121] Example 16. An aerosol-generating article according to any one of Examples 1 to 15, wherein the aerosol-generating article further defines a mouthpiece in fluid communication with the cavity, for example an integral mouthpiece or a detachable mouthpiece.

[0122] Example 17. An aerosol-generating article as described in any of Examples 1 to 16, wherein an airflow path is defined through the aerosol-generating article from the air inlet, through the cavity, to the air outlet, and wherein the resistance to draw (RTD) of the aerosol-generating article along the airflow path between the air inlet and the air outlet is less than 20 millimeters HO.

[0123] Example 18. An aerosol-generating article according to any one of Examples 1 to 17, wherein the aerosol-forming material is located within a cavity.

[0124] Example 19. An aerosol-generating article according to any one of Examples 1 to 18, wherein an airflow path is defined through the aerosol-generating article between the distal end and the proximal end of the aerosol-generating article.

[0125] Example 20. An aerosol-generating article according to any one of Examples 1 to 19, further comprising an intermediate layer disposed between the first and second planar layers.

[0126] Example 21. An aerosol-generating article according to any one of Examples 1 to 20, wherein the plurality of longitudinally extending passages are defined by corrugations of a corrugated element located within the cavity.

[0127] Example 22. An aerosol-generating article according to Example 21, wherein the longitudinally extending passageway extends in the x / y plane between the distal and proximal ends of the aerosol-generating article.

[0128] Example 23. An aerosol-generating article according to any one of Examples 1 to 22, further comprising a planar frame positioned between the first planar layer and the second planar layer, preferably wherein the cavity is defined by the lower surface of the first layer, the upper surface of the second layer, and the inner wall of the planar frame.

[0129] The embodiments will now be further described with reference to the figures.

[0130] FIG. 1 illustrates a side perspective view of an aerosol-generating article 100 according to a first embodiment of the present disclosure. The aerosol-generating article 100 comprises a first planar layer 110 extending in a first plane and a second planar layer 120 extending in a second plane, the second plane being parallel to and spaced apart from the first plane. The thickness of the aerosol-generating article 100 extends in the z-dimension, perpendicular to the first and second planes. The aerosol-generating article 100 includes an aerosol-forming substrate. In one embodiment, the aerosol-generating article 100 may consist essentially of the aerosol-forming substrate. In another embodiment, the aerosol-forming substrate may be one of multiple component parts of the aerosol-generating article 100. The aerosol-forming substrate may be enclosed within the aerosol-generating article 100. The aerosol-forming substrate may at least partially define the exterior of the aerosol-generating article 100; for example, one or both of the first planar layer 110 and the second planar layer 120 may comprise or consist of an aerosol-forming substrate.

[0131] A suitable aerosol-forming substrate may be homogenized tobacco.

[0132] The aerosol-generating article 100 has a length extending in the x-dimension of 80 millimeters, a width extending in the y-dimension of 15 millimeters, and a height extending in the z-dimension (which may also be referred to as thickness) of 3.6 millimeters. The thickness of the aerosol-generating article is defined by the distance between the upper surface of the aerosol-generating article (which in this example is the upper surface of the first planar layer 110) and the lower surface of the aerosol-generating article (which in this example is the lower surface of the second planar layer 120).

[0133] The aerosol-generating article 100 comprises a cavity (not shown in FIG. 1 ). The cavity is defined between the first planar layer 110 and the second planar layer 120. The height of the cavity is defined by the distance between the lower surface of the first planar layer 110 and the upper surface of the second planar layer 120. The height of the cavity is greater than 50 percent of the thickness of the aerosol-generating article. The height of the cavity is greater than 1.8 millimeters, for example, about 2.5 millimeters. The width of the cavity is about 12 mm.

[0134] The aerosol-forming article includes an aerosol-forming material. In this embodiment, the first planar layer 110 and the second planar layer 120 each include a homogenized tobacco sheet and an outer layer. The outer layer of the first planar layer 110 forms the top surface of the first planar layer 110, and the outer layer of the second planar layer 120 forms the bottom surface of the second planar layer 120. Each outer layer includes a sheet of paper.

[0135] FIG. 2a illustrates a side perspective view of an aerosol-generating article 200 (which is a variation of the aerosol-generating article 100) according to a second embodiment of the present disclosure. Features common to the aerosol-generating article 100 are referred to with like reference numerals. An airflow path 230 is defined through the aerosol-generating article 200 between the upper planar layer 110 and the lower planar layer 120. The airflow path 230 extends between opposing first and second ends 201, 202 of the aerosol-generating article 200. The first end 201 may define the distal end of the aerosol-generating article 200, and the second end 202 may define the proximal end of the aerosol-generating article. The airflow path 230 may be directed toward a user's mouth to enable the user to inhale the aerosol generated as a result of heating the aerosol-forming substrate of the aerosol-generating article 200.

[0136] An airflow passage is defined through the aerosol-forming article 200 between the airflow inlet 240 and the airflow outlet (not shown in FIG. 2 ). The airflow passage extends through the cavity and is configured to allow air to flow from the air inlet 240, through the cavity, and out the air outlet 260 during use. The airflow inlet 240 is defined by an inlet width and an inlet height, where the inlet width is greater than 80 percent of the width of the aerosol-generating article 200 and the inlet height is greater than 25 percent of the height of the aerosol-generating article 200.

[0137] An airflow path is defined through the aerosol-generating article 200 from the air inlet 240, through the cavity, to the air outlet, and the resistance to withdrawal (RTD) of the aerosol-generating article 200 along the airflow path between the air inlet 240 and the air outlet 260 is less than 20 millimeters of H2O.

[0138] Figure 2b illustrates a schematic transverse cross-sectional view of the aerosol-generating article of Figure 2a. Figure 2b shows an internal cross-sectional view of the aerosol-generating article. In use, when a user puffs at air outlet 260, air is drawn through airflow inlet 240 and along the airflow passage into the aerosol-generating article. The air flows through cavity 270 to airflow outlet 260.

[0139] Aerosol-forming material 280 is positioned on both sides of cavity 270. In addition, aerosol-forming material may be positioned within cavity 270. In use, when the aerosol-generating article is heated by an external heater, the aerosol-forming material 280 in aerosol-generating article 200 is heated and the aerosol former is vaporized. The vapor is entrained in the airflow within the airflow passage as the user draws on air outlet 260. The vapor cools and condenses in the airflow, forming an aerosol, which may then be inhaled by the user.

[0140] Figure 3a illustrates a side perspective view of an aerosol-generating article 290 according to a third embodiment of the present disclosure, which is a variation of aerosol-generating articles 100, 200. Figure 3b illustrates an alternative side perspective view of aerosol-generating article 290. Features in common with aerosol-generating articles 100 and 200 are referred to with like reference numerals.

[0141] The aerosol-generating article 290 comprises a mouthpiece 250. The mouthpiece 250 is in fluid communication with the cavity. As shown in Figure 3b, the mouthpiece 250 comprises an air outlet 360. In this embodiment, the mouthpiece 250 is one piece. However, in other embodiments, the mouthpiece may be removable.

[0142] 4, 5, and 6 show end, side, and plan views, respectively, of an aerosol-generating article 300 according to a fourth embodiment of the present disclosure. The aerosol-generating article 300 comprises a first planar layer (upper layer 310) extending in a first plane and a second planar layer (lower layer 320) extending in a second plane parallel to and spaced apart from the first plane. The aerosol-generating article 300 further comprises an intermediate or separating layer 340 disposed between the upper layer 310 and the lower layer 320. The thickness of the article 300 extends in the z-direction, which is perpendicular to the first and second planes.

[0143] Planar upper layer 310 is formed from a sheet of paper having a thickness of 300 microns. Planar lower layer 320 is formed from a sheet of paper having a thickness of 300 microns. A cavity is defined between upper layer 310 and lower layer 320, and the height of the cavity is defined by the distance between the lower surface of upper layer 310 and the upper surface of lower layer 320.

[0144] An intermediate layer 340 is located within the cavity. The intermediate layer 340 is a corrugated element formed from a corrugated sheet of aerosol-forming material 345. A suitable aerosol-forming material may be homogenized tobacco. Thus, the intermediate layer 340 may be formed from a corrugated sheet of homogenized tobacco material 345.

[0145] 7 illustrates a corrugated sheet of aerosol-forming material 345. The corrugations have an amplitude 346 of 3 millimeters and a wavelength 347 of 3 millimeters. The sheet of aerosol-forming material 345 forming the middle layer 340 has a thickness of 150 microns.

[0146] Intersections 351 between top layer 310 and middle layer 340 and intersections 352 between bottom layer 320 and middle layer 340 include adhesive bonding the respective layers together.

[0147] The aerosol-generating article 300 has a length extending in the x-dimension of 80 millimeters, a width extending in the y-dimension of 15 millimeters, and a thickness extending in the z-dimension of 3.6 millimeters. The height of the cavity is greater than 50 percent of the thickness of the aerosol-generating article 300.

[0148] The corrugations of the intermediate layer 340 form a first set of longitudinally extending channels 361 bounded by the top layer 310 and the intermediate layer 340, and a second set of longitudinally extending channels 362 bounded by the bottom layer 320 and the intermediate layer 340. The first and second sets of longitudinally extending channels 361, 362 extend through the length of the intermediate layer 340 between a proximal end 371 of the aerosol-generating article 300 and a distal end 372 of the aerosol-generating article 300. The longitudinally extending channels 361, 362 extend in the x / y plane between the distal end 372 and the proximal end 371 of the aerosol-generating article 300.

[0149] The longitudinally extending channels 361, 362 define an airflow channel through the aerosol-forming article between the airflow inlet and the airflow outlet. The airflow channel extends through the cavity so that air flows through the cavity during use. The longitudinally extending channels 361, 362 define an airflow path through the aerosol-forming material 345. The airflow path therefore passes through both sides of the sheet of aerosol-forming material 345. The porosity of the aerosol-generating article along the airflow path is approximately 90 percent. This provides a very low resistance to draw (RTD) of less than 5 millimeters of water (mmH2O). In fact, the RTD is close to zero.

[0150] Aerosol-forming material 345 may be a sheet of any suitable aerosol-forming material.

[0151] During use of the aerosol-generating article 300, the aerosol-forming material 345 is heated, causing the aerosol-forming material 345 to release volatile compounds, which are then entrained in air drawn into the channels 361, 362 via the distal end 372. The volatile compounds then cool and condense to form an aerosol, which can be drawn out of the channels 361, 362 of the aerosol-generating article 300 via the proximal end 371.

[0152] 8 shows an aerosol-generating article 400 according to a fifth embodiment of the present disclosure. The aerosol-generating article 400 comprises a first planar outer layer 424 forming an upper planar outer surface 421, a second planar outer layer 425 forming a lower planar outer surface 422, and a frame 450 positioned between the first planar outer layer 424 and the second planar outer layer 425. The lower planar outer surface 422 is positioned parallel to the lower planar outer surface 421. The thickness of the aerosol-generating article is defined by the upper surface 421 of the first planar outer layer 424 and the lower surface 422 of the second planar outer layer 425.

[0153] Figures 9 and 10 show exploded views of the aerosol-generating article 400 of Figure 8. A frame 450 surrounds and at least partially defines a cavity 430. Figure 9 shows the cavity 430 in an empty state. Figure 10 shows the cavity 430 filled with an aerosol-forming substrate 440. Figures 11 and 12 show transverse and longitudinal cross-sectional views, respectively, of the aerosol-generating article 400 when the cavity 430 has been filled with an aerosol-forming substrate 440.

[0154] First planar outer layer 424 and second planar outer layer 425 are made from cigarette paper having a thickness of 35 micrometers and are in physical contact with and bonded to frame 450. First planar outer layer 424 overlies a first end of cavity 430 and forms a first cavity end wall 431. Second planar outer layer 425 overlies a second end of cavity 430 and forms a second cavity end wall 432, which is opposite first cavity end wall 431. That is, frame 450, first planar outer layer 424, and second planar outer layer 425 collectively define cavity 430.

[0155] The frame 450 has a hollow cubic shape and is made from cardboard. The frame 450 defines an opening that extends through the height (also referred to as thickness) of the frame 450, the opening at least partially forming the cavity 430 of the aerosol-generating article 400. The frame 450 includes a peripheral wall 451 that surrounds the cavity 430. The peripheral wall 451 includes a front wall 413 and a rear wall 414. More specifically, the peripheral wall 451 is defined by an inner cross-section 452 of the frame 450 and an outer cross-section 453 of the frame 450. The inner cross-section 452 of the peripheral wall 451 at least partially defines the perimeter of the cavity 430. The outer cross-section 453 of the peripheral wall 451 at least partially defines the perimeter of the aerosol-generating article 400. The peripheral wall 451 has a radial thickness measured between an inner cross-section 452 of the frame 450 and an outer cross-section 453 of the frame 450 of about 5 millimeters.

[0156] An air inlet 411 and an air outlet 412 are defined by and extend through a peripheral wall 451 of the frame 450. More specifically, the air inlet 411 extends through a front wall 413, and the air outlet 412 extends through a rear wall 414. An airflow passage extends through the cavity 430 between the air inlet 411 and the air outlet 412. The airflow inlet 411 is configured to allow air to flow into the cavity, and the airflow outlet 412 is configured to allow air to flow out of the cavity. As shown in FIGS. 10-12 , an aerosol-forming substrate 440 is positioned within the cavity 430. The aerosol-forming substrate 440 includes an aerosol-generating material in the form of tobacco cut filler and has an aerosol-former content of 5 weight percent on a dry weight basis. As shown, the aerosol-forming substrate 440 fills the entire volume of the cavity 430.

[0157] The aerosol-generating article 400 has a cubic shape and has a height (or thickness) of 4 millimeters extending in the z-dimension, measured between the first outer planar surface 421 and the second outer planar surface 422, a width of 10 millimeters extending in the y-dimension, and a length of 60 millimeters extending in the x-dimension. The frame 450 has a height (or thickness) of 3.93 millimeters extending in the z-dimension, a width of 10 millimeters extending in the y-dimension, and a length of 60 millimeters extending in the x-dimension. The cavity 430 has a height (or thickness) extending in the z-dimension that is greater than 50 percent of the thickness of the aerosol-generating article 400. In this example, the cavity has a thickness of 3.93 millimeters, a width of 9.93 millimeters extending in the y-dimension, and a length of 52 millimeters extending in the x-dimension.

[0158] The air inlet 411 is defined by an inlet width and an inlet height, with the inlet width being greater than 80 percent of the aerosol-generating article width and the inlet height being greater than 25 percent of the aerosol-generating article height. In this example, the airflow inlet is substantially rectangular, with an inlet width of 9 millimeters and an inlet height of 1.2 millimeters. FIG. 13 shows an aerosol-generating article 500 according to a sixth embodiment of the present disclosure. Features in common with the aerosol-generating article 400 are referred to with like reference numerals. The aerosol-generating article 500 differs from the aerosol-generating article 400 in that the aerosol-forming substrate is in the form of a sheet of aerosol-generating material 540, specifically a corrugated sheet of homogenized tobacco material. FIGS. 14 and 15 show cross-sectional and transverse cross-sectional views, respectively, of the aerosol-generating article 500 of FIG. 13.

[0159] The corrugated sheet of homogenized tobacco material 540 comprises a plurality of parallel corrugations having a plurality of substantially parallel peaks 543 and valleys 544. The plurality of parallel corrugations is defined by a corrugation profile that is sinusoidal, as seen in Figure 13. The plurality of parallel corrugations has a corrugation wavelength of approximately 4.6 millimeters. The corrugation amplitude is approximately the same as the height (or thickness) of the cavities 430, as indicated by the peaks 543 and valleys 544 coinciding with the first and second cavity end walls 431 and 432, respectively.

[0160] The parallel corrugations form a plurality of channels 545 between the sheet of aerosol-generating material 540 and the first cavity end wall 431, and a plurality of channels 546 between the sheet of aerosol-generating material 540 and the second cavity end wall 432. The channels 545, 546 extend longitudinally through the aerosol-generating article 500 and form at least a portion of an airflow passageway extending between the air inlet 411 and the air outlet 412.

[0161] During use of each aerosol-generating article 400, 500, the aerosol-forming substrate 440, 540 is heated, causing the aerosol-forming substrate 440, 540 to release volatile compounds, which are then entrained in air drawn into the cavity 430 through the air inlet 411. The volatile compounds then cool and condense to form an aerosol, which can be drawn from the aerosol-generating article 400, 500 through the air outlet 412.

[0162] By way of example applicable to any of the above-described embodiments, the composition of a suitable aerosol-forming substrate may be as follows: Percentages are given in weight percent of the final product. The aerosol-forming substrate may have a moisture content of about 5 to 25 percent, preferably about 7 to 15 percent, in the final product. The aerosol-forming substrate may further comprise:

[0163] Tobacco leaf, for example, comprising about 15-45 percent, preferably about 20-35 percent, of a tobacco leaf blend incorporating at least one of bright tobacco leaf, dark tobacco leaf, and aromatic tobacco leaf. The tobacco material is ground and graded to a particle size of about 100-380 mesh, preferably about 170-320 mesh. Cellulose fibers, for example, about 1 to 15 percent, preferably about 3 to 7 percent, of which the length is about 10 to 250 μm, preferably about 10 to 120 μm. Tobacco fiber, e.g., about 5 to 20 percent, preferably about 7 to 15 percent, tobacco fiber as a filler, of any tobacco species or a mixture of tobacco species, preferably derived from stems and / or petioles, and graded to fibers having lengths of about 10 to 350 μm, preferably about 10 to 180 μm. Binder. For example, about 1 to 10 percent, preferably about 1 to 5 percent, of a binder. Examples of binders include any gum or pectin commonly used in the food and beverage (F&B) industry. Preferred binders may be natural pectin (e.g., fruit (e.g., citrus) pectin or tobacco pectin), guar gum, land locust bean gum (e.g., their hydroxyethyl and / or hydroxypropyl forms), starch (e.g., modified starch or derivatized starch), alginate, methylcellulose, ethylcellulose, ethylhydroxymethylcellulose, carboxymethylcellulose, dextran, or xanthan gum. A preferred binder is guar. an aerosol former, for example, about 5 to 35 percent, preferably about 10 to 25 percent, of an aerosol former. Suitable aerosol formers known in the art include glycerin, monohydric alcohols (such as menthol), polyhydric alcohols (such as triethylene glycol), esters of polyhydric alcohols (such as glycerol monoacetate, glycerol diacetate, or glycerol triacetate), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as the dimethyl esters thereof).

[0164] "Tobacco variety" means one of the different types of tobacco, based, for example, on the unique curing process that occurs before the tobacco is further processed into tobacco products.

[0165] For illustrative purposes, further aerosol-forming substrate compositions that may also be suitable for use as the aerosol-forming substrate in any of the above-described embodiments are set out below. Percentages are given as weight percent of the finished product. The aerosol-forming substrate may comprise: An aerosol former (such as glycerin), for example about 10 to 40 percent, preferably about 20 to 30 percent. Organic fiber. For example, the organic fiber comprises about 10-30 percent, preferably about 15-25 percent, organic fiber of any suitable plant variety commonly available on the market and having a purity that meets applicable FDA food and beverage (F&B) grade requirements. For example, the organic fiber may be obtained from cellulose, cotton, wood, or tea plant varieties as by-products or by-processing waste from the F&B tea industry. The organic fiber preferably has a length of about 10-400 μm, preferably about 10-200 μm. Organic vegetable glycerides, such as from about 15 to 55 percent, preferably from about 20 to 35 percent, organic vegetable glycerides, such as those from clove, echinacea, fennel, ginger, hawthorn berry, elderberry, monarda, mullein leaf, nettle, plantain, turmeric, yarrow, and composites thereof. Organic plant extracts, such as about 1 to 15 percent, preferably 2 to 7 percent, organic plant extracts obtained from any of the aforementioned plants, as well as Chaerophyllum macrospermum, Mesosphaerum sidifolium, or other related plant varieties, including menthol (dl-menthol, CHO, 2-isopropyl-5-methylcyclohexanol), and p-menthone-3-ol as an optional secondary alcohol, as a diastereoisomer of 5-methyl-2-(propan-2-yl)cyclohexan-1-ol.

[0166] Alternatively, such an aerosol-forming substrate may also contain about 0.5 to 5 percent, preferably about 1 to 3 percent, of a plant-based essential oil (such as palm oil, coconut oil, wood-based essential oils, etc.).

[0167] For purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like are to be understood in all instances as modified by the term "about." Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein. Accordingly, in this context, the number "A" is to be understood as "A" ± 10 percent. Within this context, the number "A" may be considered to include numerical values ​​that are within the common standard error for measurement of the property that the number "A" modifies. The number "A," as used in the appended claims, may, in some cases, deviate by the percentages recited above, provided that the amount by which "A" deviates does not materially affect the basic and novel property(ies) of the claimed invention. Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein. The terms "in which" and "wherein" are used interchangeably throughout this specification.

Claims

1. 1. An aerosol-generating article comprising an aerosol-forming material for generating an aerosol, the aerosol-forming article comprising a first planar layer extending in a first plane and a second planar layer extending in a second plane, the second plane being parallel to and spaced apart from the first plane, the thickness of the aerosol-generating article extending in a direction perpendicular to the first and second planes, a cavity being defined between the first and second planar layers, the height of the cavity being defined by the distance between the lower surface of the first planar layer and the upper surface of the second planar layer, the thickness of the aerosol-generating article being less than 5 mm, and the height of the cavity being greater than 50 percent of the thickness of the article.

2. 2. The aerosol-generating article of claim 1, wherein the thickness of the aerosol-generating article is defined by the distance between the upper surface of the aerosol-generating article and the lower surface of the aerosol-generating article, e.g., the distance between the upper surface of the first planar layer and the lower surface of the second planar layer.

3. 3. The aerosol-generating article of claim 1, wherein the aerosol-generating article is defined by an article length extending in the x-direction, an article width extending in the y-direction, and an article thickness extending in the z-direction, and wherein an airflow passage is defined through the aerosol-forming article between an airflow inlet and an airflow outlet, the airflow passage extending through the cavity.

4. 4. The aerosol-generating article of claim 3, wherein the airflow inlet is defined by an inlet width and an inlet height, the inlet width being greater than 80 percent of the article width and the inlet height being greater than 25 percent of the article height, and optionally the airflow inlet being substantially rectangular.

5. An aerosol-generating article according to any one of claims 1 to 4, wherein the height of the cavity is greater than 60 percent of the thickness of the aerosol-generating article, for example greater than 70 percent of the thickness of the article, for example greater than 80 percent of the thickness of the aerosol-generating article, preferably greater than 85 percent of the thickness of the aerosol-generating article, or greater than 90 percent of the thickness of the aerosol-generating article, for example greater than 95 percent of the thickness of the aerosol-generating article.

6. 6. An aerosol-generating article according to any preceding claim, wherein the thickness of the article is from 0.5 millimetres to 5 millimetres, for example from 1 millimetre to 4.75 millimetres, for example from 1.5 millimetres to 4.5 millimetres, for example from 2 millimetres to 4 millimetres, for example about 2.5 millimetres, or about 2.75 millimetres, or about 3 millimetres.

7. 7. An aerosol-generating article according to any preceding claim, wherein the height of the cavity is between 0.25 mm and 4.9 mm, for example between 0.375 mm and 4.5 mm, for example between 0.5 mm and 4 mm, for example between 0.625 mm and 3.5 mm, for example about 2 mm, or about 2.5 mm, or about 2.9 mm.

8. 8. An aerosol-generating article as described in any one of claims 1 to 7, wherein either the first planar layer, the second planar layer, or both the first and second planar layers comprise the aerosol-forming material, for example, the first planar layer, either the second planar layer, or both the first and second planar layers comprise a homogenized tobacco sheet.

9. 9. The aerosol-generating article of claim 1, wherein either the first planar layer, the second planar layer, or both the first and second planar layers comprise an aerosol-forming layer comprising an aerosol-forming material and at least one further layer (e.g., an outer layer), or wrapper layer.

10. 10. An aerosol-generating article according to any preceding claim, wherein the cavity has a width of from 4.75 mm to 19.75 mm, for example from 5.75 mm to 14.75 mm, for example from 7.25 mm to 12.75 mm, for example from 8.75 mm to 12.25 mm, for example about 9.25 mm, or 9.5 mm, or 10.5 mm, or 11.5 mm.

11. 11. An aerosol-generating article according to any preceding claim, wherein the article has a length of from 10 mm to 100 mm, for example from 15 mm to 55 mm, for example from 20 mm to 45 mm, for example from 25 mm to 35 mm, for example about 25 mm, or 28 mm, or 30 mm, or 32 mm.

12. an airflow path is defined through the aerosol-generating article from the airflow inlet defined at the distal end of the aerosol-generating article, through the cavity, to the airflow outlet defined at the proximal end of the aerosol-generating article, and a resistance to draw (RTD) of the article along the airflow path between the airflow inlet and the airflow outlet is less than 20 millimeters H 2 The aerosol-generating article according to any one of claims 1 to 11, wherein the viscosity is less than 1000 MPa.

13. 13. The aerosol-generating article according to claim 1, wherein at least a portion of the aerosol-forming material is located within the cavity.

14. 14. An aerosol-generating article according to any preceding claim, wherein a plurality of longitudinally extending channels are defined by corrugations of a corrugated element located within the cavity.

15. 15. An aerosol-generating article as described in any one of claims 1 to 14, further comprising a planar frame positioned between the first planar layer and the second planar layer, preferably wherein the cavity is defined by the lower surface of the first planar layer, the upper surface of the second planar layer, and the inner wall of the planar frame.

Images