An aerosol-generating substrate plug

Abstract

There is provided an aerosol-generating substrate plug (10) for a heated aerosol-generating article (1). The aerosol-generating substrate plug (10) comprises an aerosol-generating substrate (20). The aerosol-generating substrate (20) comprises one or more aerosol-formers. The aerosol-generating substrate (20) comprises an aerosol-former content greater than or equal to 5 percent by weight on a dry weight basis. The aerosol-generating substrate plug (10) comprises a wrapper (30). The wrapper (30) has a grammage of between 20 grams per square metre and 200 grams per square metre. The wrapper (20) circumscribes the aerosol-generating substrate (20). A thickness of the aerosol-generating substrate plug (10) is less than 50 percent of a length of the aerosol-generating substrate plug (10). The thickness of the aerosol-generating substrate plug (10) is less than 50 percent of a width of the aerosol-generating substrate plug (10). The thickness of the aerosol-generating substrate plug (10) is constant over at least 90 percent of the width of the aerosol-generating substrate plug (10). There also provided an aerosol-generating article (1) comprising the aerosol-generating substrate plug (10), and a method of manufacturing the aerosol-generating substrate plug (10).

Description

[0001] AN AEROSOL-GENERATING SUBSTRATE PLUG

[0002] The present disclosure relates to an aerosol-generating substrate plug for a heated aerosol-generating article. The present disclosure also relates to an aerosol-generating article comprising the aerosol-generating substrate plug, and a method of manufacturing the aerosolgenerating substrate plug.

[0003] Typically, conventional smoking articles, such as tobacco-containing cigarettes, are in the form of a cylindrical rod having a tobacco substrate positioned at an upstream end and a filter element positioned at a downstream end. During use, a consumer ignites the upstream end of the smoking article and draws on the downstream end of the smoking article to inhale the combustion products. The combustion line spans the entire transverse cross-section of the tobacco substrate and progresses towards the downstream end of the smoking article as the tobacco substrate is consumed, thereby allowing the entire tobacco substrate to reach a temperature sufficient to generate inhalable combustion products.

[0004] In recent years, heated aerosol-generating articles comprising an aerosol-generating substrate have been made available. In such heated aerosol-generating articles, the aerosolgenerating substrate is heated rather than combusted. Typically, an aerosol-generating device is arranged to heat a heating element that is positioned near, or in contact with, the aerosolgenerating substrate which causes the aerosol-generating substrate to heat up and release volatile compounds. These volatile compounds are then entrained in air that is drawn through the aerosolgenerating article. As the volatile compounds cool, they condense to form an aerosol that can be inhaled by a consumer

[0005] Atypical heated aerosol-generating article may appear similar and have similar dimensions to a conventional smoking article. For example, such an aerosol-generating article may be substantially cylindrical and comprise an aerosol-generating substrate in addition to other components such as mouthpiece filter element and a cooling element, which are arranged in the form of a cylindrical rod and wrapped in a cigarette paper.

[0006] However, in heated aerosol-generating articles, the absence of the previously mentioned combustion line means that a significant portion of the aerosol-generating substrate may not be sufficiently heated to form an aerosol during use. This is because, for example, some portions of the aerosol-generating substrate may be further away from the heating element than other portions of the aerosol-generating substrate. This is undesirable since the insufficiently heated portion of the aerosol-generating substrate contributes to the cost of manufacture and transport of the aerosol-generating article but does not contribute to the aerosol delivered to the consumer.

[0007] It is an objective of the present disclosure to provide an aerosol-generating substrate for a heated aerosol-generating article in which a greater portion of the aerosol-generating substrate can sufficiently heated to form an aerosol during use. It is also an objective of the present disclosure to provide an aerosol-generating substrate that can be manufactured relatively efficiently and cheaply.

[0008] The present disclosure provides an aerosol-generating substrate plug for a heated aerosolgenerating article. The aerosol-generating substrate plug may comprise an aerosol-generating substrate. The aerosol-generating substrate may comprise one or more aerosol-formers. The aerosol-generating substrate may comprise an aerosol-former content greater than or equal to 5 percent by weight on a dry weight basis. The aerosol-generating substrate plug may comprise a wrapper. The wrapper may have a grammage of between 20 grams per square metre and 200 grams per square metre. The wrapper may circumscribe the aerosol-generating substrate. A thickness of the aerosol-generating substrate plug may be less than 50 percent of a length of the aerosol-generating substrate plug. The thickness of the aerosol-generating substrate plug may be less than 50 percent of a width of the aerosol-generating substrate plug. The thickness of the aerosol-generating substrate plug may be constant over at least 90 percent of the width of the aerosol-generating substrate plug.

[0009] According to the present disclosure, there is provided an aerosol-generating substrate plug for a heated aerosol-generating article. The aerosol-generating substrate plug comprises an aerosol-generating substrate. The aerosol-generating substrate comprises one or more aerosolformers. The aerosol-generating substrate comprises an aerosol-former content greater than or equal to 5 percent by weight on a dry weight basis. The aerosol-generating substrate plug comprises a wrapper. The wrapper has a grammage of between 20 grams per square metre and 200 grams per square metre. The wrapper circumscribes the aerosol-generating substrate. A thickness of the aerosol-generating substrate plug is less than 50 percent of a length of the aerosolgenerating substrate plug. The thickness of the aerosol-generating substrate plug is less than 50 percent of a width of the aerosol-generating substrate plug. The thickness of the aerosolgenerating substrate plug is constant over at least 90 percent of the width of the aerosol-generating substrate plug.

[0010] An aerosol-generating substrate plug having a thickness less than 50 percent of a length and width of the aerosol-generating substrate plug, and a thickness that is constant over 90 percent of the width of the aerosol-generating substrate plug leads to an aerosol-generating substrate plug that is generally flat and thin. Advantageously, this may allow for a small temperature gradient across the thickness of the aerosol-generating substrate plug during heating, thereby allowing for heating of a greater proportion of the aerosol-generating substrate plug to a temperature at which an aerosol is released whilst minimising the risk of burning the hottest portion of the aerosolgenerating substrate plug closest to the heating element. Advantageously, this may also reduce a time required to heat the aerosol-generating substrate plug sufficiently to release an aerosol.

[0011] The dimensions of the aerosol-generating substrate plug mean that the transverse crosssection of the aerosol-generating substrate plug is advantageously non-circular. However, an aerosol-generating substrate within such an aerosol-generating substrate plug, such as tobacco cut filler, tends to expand in all directions which may cause the transverse cross-sectional shape of the aerosol-generating substrate plug to become distorted from its intended shape. For example, over time, the expansion of the aerosol-generating substrate, or even general handling of the aerosol-generating substrate plug, may cause the transverse cross-sectional shape to become circular. The provision of a wrapper having a grammage of between 20 grams per square metre and 200 grams per square metre means the wrapper may have the structural rigidity to maintain the advantageous transverse cross-sectional shape of aerosol-generating substrate plug. Moreover, a wrapper having a low grammage provides the flexibility that is advantageous in a continuous manufacturing process, however, a wrapper having a grammage that is too low may mean that the wrapper is not be able to maintain the transverse cross-sectional shape of the aerosol-generating substrate plug. On the other hand, a wrapper having a grammage that is too high may provide the required structural rigidity but may have reduced flexibility. Advantageously, a wrapper having a grammage of between 20 grams per square metre and 200 grams per square metre provides a balance between flexibility of the wrapper and the structural rigidity of the wrapper.

[0012] Moreover, the wrapper may seal an airflow path through the aerosol-generating substrate plug from one end of the aerosol-generating substrate plug to another end of the aerosolgenerating substrate plug. Advantageously, this may avoid loss of aerosol, particularly when used with an aerosol-generating device. Additionally, this may also ensure air flows through the entire aerosol-generating substrate.

[0013] The aerosol-generating substrate plug may comprise a substantially planar upper surface defined by a length extending in an x-direction and a width extending in a y-direction. The aerosolgenerating substrate plug may have a substantially planar lower surface defined by a length extending in an x-direction and a width extending in a y-direction. The substantially planar upper surface and the substantially planar lower surface may be spaced from each other by a thickness defined in a z-direction. The substantially planar upper surface and the substantially planar lower surface may be parallel to each other.

[0014] The aerosol-generating substrate plug may comprise a first side surface extending from the substantially planar upper surface to the substantially planar lower surface. The aerosolgenerating substrate plug may comprise a second side surface extending from the substantially planar upper surface to the substantially planar lower surface. The first side surface may be a substantially planar first side surface. The second side surface may be a substantially planar second side surface. The first side surface may be positioned opposite the second side surface. The first side surface may be parallel to the second side surface. The first side surface may be defined by a length extending in an x-direction and a thickness extending in a z-direction. The second side surface may be defined by a length extending in an x-direction and a thickness extending in a z-direction. The first side surface and the second side surface may be spaced from each other by a width in a y-direction. The first side surface may be substantially perpendicular to one or both the substantially planar upper surface and the substantially planar lower surface. The second side surface may be substantially perpendicular to one or both the substantially planar upper surface and the substantially planar lower surface.

[0015] The thickness of the aerosol-generating substrate plug may be less than 40 percent of a width of the aerosol-generating substrate plug. The thickness of the aerosol-generating substrate plug may be less than 35 percent of a width of the aerosol-generating substrate plug. The thickness of the aerosol-generating substrate plug may be less than 30 percent of a width of the aerosolgenerating substrate plug. The thickness of the aerosol-generating substrate plug may be less than 25 percent of a width of the aerosol-generating substrate plug. The thickness of the aerosolgenerating substrate plug may be less than 20 percent of a width of the aerosol-generating substrate plug.

[0016] The thickness of the aerosol-generating substrate plug may be constant over at least 95 percent of the width of the aerosol-generating substrate plug. The thickness of the aerosolgenerating substrate plug may be constant over at least 99 percent of the width of the aerosolgenerating substrate plug. As used herein, the term “constant”, when referring to the thickness of the aerosol-generating substrate plug, is used to mean that the thickness varies no more than ± 5 percent.

[0017] The aerosol-generating substrate plug may have a transverse cross-section that is substantially rectangular. The transverse cross-section of the aerosol-generating substrate plug may be substantially rectangular along at least 90 percent of the length of the aerosol-generating substrate plug. The transverse cross-section of the aerosol-generating substrate plug may be substantially rectangular along at least 95 percent of the length of the aerosol-generating substrate plug. The transverse cross-section of the aerosol-generating substrate plug may be substantially rectangular along substantially the entire length of the aerosol-generating substrate plug.

[0018] All interior angles of a, or any, transverse cross-section of the aerosol-generating substrate plug may be greater than or equal to 85 degrees. All interior angles of a, or any, transverse crosssection of the aerosol-generating substrate plug may be greater than or equal to 90 degrees. All interior angles of a, or any, transverse cross-section of the aerosol-generating substrate plug may be greater than or equal to 115 degrees.

[0019] All interior angles of a, or any, transverse cross-section of the aerosol-generating substrate plug may be less than or equal to 120 degrees. All interior angles of a, or any, transverse crosssection of the aerosol-generating substrate plug may be greater than or equal to 115 degrees. All interior angles of a, or any, transverse cross-section of the aerosol-generating substrate plug may be greater than or equal to 105 degrees. All interior angles of a, or any, transverse cross-section of the aerosol-generating substrate plug may be greater than or equal to 95 degrees.

[0020] All interior angles of a, or any, transverse cross-section of the aerosol-generating substrate plug may be between 85 and 120 degrees. All interior angles of a, or any, transverse cross-section of the aerosol-generating substrate plug may be between 85 and 115 degrees. All interior angles of a, or any, transverse cross-section of the aerosol-generating substrate plug may be between 85 and 105 degrees. All interior angles of a, or any, transverse cross-section of the aerosol-generating substrate plug may be between 85 and 95 degrees.

[0021] The thickness of the aerosol-generating substrate plug may be constant over at least 90 percent of the length of the aerosol-generating substrate plug. The thickness of the aerosolgenerating substrate plug may be constant over at least 95 percent of the length of the aerosolgenerating substrate plug. The thickness of the aerosol-generating substrate plug may be constant over at least 99 percent of the length of the aerosol-generating substrate plug. Preferably, the thickness of the aerosol-generating substrate plug may be constant over the entire length of the aerosol-generating substrate plug.

[0022] The aerosol-generating substrate plug may have a longitudinal cross-section that is substantially rectangular.

[0023] The aerosol-generating substrate plug may have a rectangular prism shape. The aerosolgenerating substrate plug may have a cubic shape. The aerosol-generating substrate plug may have a cuboid shape. The aerosol-generating substrate plug may have a rectangular cuboid shape.

[0024] The wrapper may have a grammage greater than or equal to 25 grams per square metre. The wrapper may have a grammage greater than or equal to 30 grams per square metre. The wrapper may have a grammage greater than or equal to 35 grams per square metre. The wrapper may have a grammage greater than or equal to 40 grams per square metre. The wrapper may have a grammage greater than or equal to 45 grams per square metre. The wrapper may have a grammage greater than or equal to 50 grams per square metre. The wrapper may have a grammage greater than or equal to 60 grams per square metre. The wrapper may have a grammage greater than or equal to 70 grams per square metre.

[0025] The wrapper may have a grammage less than or equal to 180 grams per square metre. The wrapper may have a grammage less than or equal to 160 grams per square metre. The wrapper may have a grammage less than or equal to 140 grams per square metre. The wrapper may have a grammage less than or equal to 120 grams per square metre. The wrapper may have a grammage less than or equal to 100 grams per square metre.

[0026] The wrapper may have a grammage of between 25 grams per square metre and 180 grams per square metre. The wrapper may have a grammage between 30 grams per square metre and 160 grams per square metre. The wrapper may have a grammage between 35 grams per square metre and 140 grams per square metre. The wrapper may have a grammage between 40 grams per square metre and 120 grams per square metre. The wrapper may have a grammage between 45 grams per square metre and 120 grams per square metre. The wrapper may have a grammage between 50 grams per square metre and 100 grams per square metre. The wrapper may have a mass of between 5 milligrams and 40 milligrams. The wrapper may have a mass of between 10 milligrams and 40 milligrams. Preferably, the wrapper may have a mass of between 10 milligrams and 30 milligrams.

[0027] The wrapper may have a thickness of between 10 micrometres and 300 micrometres. The wrapper may have a thickness of between 10 micrometres and 200 micrometres. The wrapper may have a thickness of between 10 micrometres and 150 micrometres. The wrapper may have a thickness of between 10 micrometres and 100 micrometres. The wrapper may have a thickness of between 10 micrometres and 75 micrometres. The wrapper may have a thickness of between 10 micrometres and 50 micrometres. The wrapper may have a thickness of between 10 micrometres and 40 micrometres. The wrapper may have a thickness of between 15 micrometres and 40 micrometres. The wrapper may have a thickness of between 20 micrometres and 40 micrometres. The wrapper may have a thickness of about 37 micrometres.

[0028] The wrapper may have a length substantially equal to the length of the aerosol-generating substrate. The wrapper may have a length substantially equal to the length of the aerosolgenerating substrate plug.

[0029] The wrapper may define or form an outer surface of the aerosol-generating substrate plug. The wrapper may define or form the substantially planar upper surface of the aerosol-generating substrate plug. The wrapper may define or form the substantially planar lower surface of the aerosol-generating substrate plug. The wrapper may define or form the first side surface of the aerosol-generating substrate plug. The wrapper may define or form the second side surface of the aerosol-generating substrate plug. Preferably, the wrapper defines or forms the substantially planar upper surface of the aerosol-generating substrate plug, the substantially planar lower surface of the aerosol-generating substrate plug, the first side surface of the aerosol-generating substrate plug and the second side surface of the aerosol-generating substrate plug.

[0030] The wrapper may define or form all longitudinal outer surfaces of the aerosol-generating substrate plug. That is, the wrapper may define or form all outer surfaces of the aerosol-generating substrate plug that extend in the x-direction and y-direction, or the x-direction and the z-direction. The wrapper may define or form at least 99 percent of the surface area of all longitudinal outer surfaces of the aerosol-generating substrate plug.

[0031] The wrapper may define or form at least 60 percent of the outer surface area of the aerosolgenerating substrate plug. The wrapper may define or form at least 70 percent of the outer surface area of the aerosol-generating substrate plug. The wrapper may define or form at least 95 percent of the outer surface area of the aerosol-generating substrate plug. The wrapper may define or form at least 98 percent of the outer surface area of the aerosol-generating substrate plug.

[0032] The wrapper may define or form less than 95 percent of the outer surface area of the aerosol-generating substrate plug. The wrapper may define or form less than 85 percent of the outer surface area of the aerosol-generating substrate plug. The wrapper may define or form less than 75 percent of the outer surface area of the aerosol-generating substrate plug. The wrapper may form an open-ended tube and the aerosol-generating substrate may be positioned within the open-ended tube. The aerosol-generating substrate may be exposed at one or both of the distal end and the proximal end of the aerosol-generating substrate plug. That is, the aerosol-generating substrate may be exposed at one or both of the extreme upstream end and the extreme downstream end of the aerosol-generating substrate plug. Alternatively, the wrapper may completely enclose the aerosol-generating substrate.

[0033] The wrapper may comprise an overlapping region in which a first portion of the wrapper overlaps a second portion of the wrapper. For example, opposing longitudinal edges of the wrapper may overlap to form the overlapping region.

[0034] The overlapping region may be positioned on the upper surface of the aerosol-generating substrate plug. The overlapping region may be positioned on the lower surface of the aerosolgenerating substrate plug.

[0035] The overlapping region may have a width greater than or equal to 2 millimetres. The overlapping region may have a width greater than or equal to 3 millimetres. The overlapping region may have a width greater than or equal to 4 millimetres. The overlapping region may have a width of greater than or equal to 5 millimetres.

[0036] The overlapping region may have a width less than or equal to 6 millimetres. The overlapping region may have a width of less than or equal to 5 millimetres. The overlapping region may have a width less than or equal to 4 millimetres. The overlapping region may have a width less than or equal to 3 millimetres.

[0037] The overlapping region may have a width of between 2 millimetres and 6 millimetres. The overlapping region may have a width of between 2 millimetres and 4 millimetres.

[0038] The overlapping region may have a width less than a width of the aerosol-generating substrate plug. The overlapping region may have a width less than 50 percent of a width of the aerosol-generating substrate plug. The overlapping region may have a width less than 25 percent of a width of the aerosol-generating substrate plug. The overlapping region may have a width less than 15 percent of a width of the aerosol-generating substrate plug.

[0039] The overlapping region may have a width greater than 5 percent of a width of the aerosolgenerating substrate plug. The overlapping region may have a width greater than 10 percent of a width of the aerosol-generating substrate plug. The overlapping region may have a width greater than 15 percent of a width of the aerosol-generating substrate plug. The overlapping region may have a width greater than 20 percent of a width of the aerosol-generating substrate plug.

[0040] The overlapping region may comprise a first surface of the wrapper bonded to a second surface of the wrapper. The overlapping region may comprise an inner surface of the wrapper bonded to an outer surface of the wrapper. For example, the overlapping region may comprise a lap seal. The overlapping region may comprise an inner surface of the wrapper bonded to an inner surface of the wrapper. For example, the overlapping region may comprise a fin seal. The surfaces of the wrapper in the overlapping region may be bonded with an adhesive. The surfaces of the wrapper in the overlapping region may be bonded with a strip or a line of adhesive. The strip or the line of adhesive may extend in a longitudinal direction. The strip or line of adhesive may have a length of between 90 percent and 100 percent of the length of the aerosolgenerating substrate plug. The strip or the line of adhesive may have a length substantially equal to the length of the aerosol-generating substrate plug. The strip or the line of adhesive may extend from the distal end of the aerosol-generating substrate plug to the proximal end of the aerosolgenerating substrate plug.

[0041] The adhesive may comprise a gum. The adhesive may comprise guar gum. The adhesive may comprise polyvinyl alcohol. The adhesive may comprise an aerosol-generating substrate. The adhesive may consist of an aerosol-generating substrate. For example, the adhesive may be a homogenised tobacco slurry. The adhesive may be, or may comprise, a flavourant and / or an aerosol-former.

[0042] The wrapper may be in physical contact with the aerosol-generating substrate. For example, an inner surface of the wrapper may be in physical contact with the entire circumference of the aerosol-generating substrate.

[0043] The wrapper, or a portion of the wrapper, may be air permeable.

[0044] The wrapper, or a portion of the wrapper, may have an air permeability between about 10 Coresta units and about 200 Coresta units. The wrapper, or a portion of the wrapper, may have an air permeability between about 20 Coresta units and about 150 Coresta units. The wrapper, or a portion of the wrapper, may have an air permeability between about 30 Coresta units and about 100 Coresta units. The wrapper, or a portion of the wrapper, may have an air permeability between about 40 Coresta units and about 80 Coresta units.

[0045] The wrapper, or a portion of the wrapper, may have an air permeability between about 5000 Coresta units and about 12000 Coresta units. The wrapper, or a portion of the wrapper, may have an air permeability between about 7500 Coresta units and about 12000 Coresta units.

[0046] The air permeability in Coresta units is the amount of air in cubic centimetres that passes through one square centimetre of the wrapper in one minute at a constant pressure difference of one kilopascal (that is, 1 Coresta unit corresponds to an air permeability of 1 cm3 / min. cm2 at a pressure differential of 1 kPa). The air permeability in Coresta units may be measured in accordance with ISO 2965:2009.

[0047] The wrapper may comprise one or more flavourants. Advantageously, the wrapper flavourant may be entrained in or released in the air flowing through the aerosol-generating substrate plug. The one or more flavourant may be any flavourant described herein in relation to the aerosol-generating substrate.

[0048] The wrapper may comprise one or more aerosol-formers. The one or more aerosol-formers may be any aerosol-former described herein in relation to the aerosol-generating substrate. The wrapper may comprise, or consist of, cellulosic material. The wrapper may comprise, or consist of, organic material or plant material, such as tobacco, mint, tea and cloves.

[0049] The wrapper may comprise, or consist of, hygroscopic material. The hygroscopic material may comprise one or more materials selected from a list consisting of polyvinyl alcohol, silicon, or a combination thereof. For example, the wrapper may comprise a surface treatment of hygroscopic material. Hygroscopic material may be dispersed within the wrapper.

[0050] The wrapper may be a sheet of material. The wrapper may comprise, or consist of, a sheet of cellulosic material such as paper. The wrapper may comprise, or consist of, a sheet of organic material or a sheet of plant material. The wrapper may comprise, or consist of, a sheet of homogenised tobacco material.

[0051] The wrapper may comprise one or more elements selected from a list consisting of ceramic fibres or particles, metallic strips or particles, or a combination thereof.

[0052] The wrapper may be a first wrapper and the aerosol-generating substrate plug may comprise a second wrapper. The second wrapper may circumscribe or encircle the aerosolgenerating substrate. The first wrapper may be in physical contact with the second wrapper. The aerosol-generating substrate plug may comprise a laminated wrapper comprising the first wrapper and the second rapper.

[0053] The second wrapper may have a length equal to the length of the first wrapper.

[0054] The second wrapper may be located between the first wrapper and the aerosol-generating substrate. The second wrapper may be in physical contact with the aerosol-generating substrate.

[0055] The first wrapper may be located between the second wrapper and the aerosol-generating substrate. The first wrapper may be in physical contact with the aerosol-generating substrate.

[0056] The second wrapper may have a higher thermal conductivity than the first wrapper. The second wrapper may comprise, or consist of, a thermally conductive material. The thermally conductive material may have a thermal conductivity of at least 10 W / mK. The thermally conductive material may be a metallic material. The thermally conductive material may comprise one or more materials selected from a list consisting of aluminium, stainless steel, or a combination thereof. The wrapper may comprise or consist of a sheet of thermally conductive material.

[0057] The second wrapper may comprise, or consist of, a metallic material such as aluminium. The second wrapper may comprise, or consist of, a sheet of metallic material such as a sheet of aluminium. The second wrapper may comprise, or consist of, a ceramic material. The second wrapper may comprise or consist of a sheet of ceramic material.

[0058] The first wrapper may comprise, or consist of, a sheet of cellulosic material and the second wrapper may comprise, or consist of, a sheet of thermally conductive material such as aluminium, and one or both of the first wrapper and the second wrapper may comprise a surface treatment of hygroscopic material.

[0059] The aerosol-generating substrate may extend substantially the entire length of the aerosolgenerating substrate plug. The aerosol-generating substrate may occupy at least 95 percent of the transverse cross- sectional area of the aerosol-generating substrate plug. The aerosol-generating substrate may occupy at least 95 percent of the transverse cross-sectional area of the aerosol-generating substrate plug. The aerosol-generating substrate may occupy at least 98 percent of the transverse cross-sectional area of the aerosol-generating substrate plug.

[0060] The aerosol-generating substrate may have a mass greater than or equal to 70 percent a mass of the aerosol-generating substrate plug. The aerosol-generating substrate may have a mass greater than or equal to 80 percent a mass of the aerosol-generating substrate plug. The aerosolgenerating substrate may have a mass greater than or equal to 90 percent a mass of the aerosolgenerating substrate plug. The aerosol-generating substrate may have a mass greater than or equal to 95 percent a mass of the aerosol-generating substrate plug.

[0061] The aerosol-generating substrate may have a mass greater than or equal to 50 milligrams.

[0062] The aerosol-generating substrate may have a mass greater than or equal to 80 milligrams. The aerosol-generating substrate may have a mass greater than or equal to 110 milligrams. The aerosol-generating substrate may have a mass greater than or equal to 150 milligrams. The aerosol-generating substrate may have a mass greater than or equal to 170 milligrams. The aerosol-generating substrate may have a mass greater than or equal to 180 milligrams. The aerosol-generating substrate may have a mass greater than or equal to 200 milligrams. The aerosol-generating substrate may have a mass greater than or equal to 230 milligrams. The aerosol-generating substrate may have a mass greater than or equal to 250 milligrams. The aerosol-generating substrate may have a mass greater than or equal to 300 milligrams. The aerosol-generating substrate may have a mass greater than or equal to 400 milligrams.

[0063] The aerosol-generating substrate may have a mass less than or equal to 500 milligrams.

[0064] The aerosol-generating substrate may have a mass less than or equal to 400 milligrams. The aerosol-generating substrate may have a mass less than or equal to 300 milligrams. The aerosol- generating substrate may have a mass less than or equal to 250 milligrams. The aerosol- generating substrate may have a mass less than or equal to 230 milligrams. The aerosol- generating substrate may have a mass less than or equal to 200 milligrams. The aerosolgenerating substrate may have a mass less than or equal to 180 milligrams. The aerosolgenerating substrate may have a mass less than or equal to 170 milligrams. The aerosolgenerating substrate may have a mass less than or equal to 150 milligrams. The aerosolgenerating substrate may have a mass less than or equal to 110 milligrams. The aerosol- generating substrate may have a mass less than or equal to 80 milligrams. The aerosol-generating substrate may have a mass less than or equal to 50 milligrams.

[0065] The aerosol-generating substrate may have a mass between 50 milligrams and 500 milligrams. The aerosol-generating substrate may have a mass between 80 milligrams and 500 milligrams. The aerosol-generating substrate may have a mass between 80 milligrams and 400 milligrams. The aerosol-generating substrate may have a mass between 80 milligrams and 300 milligrams. The aerosol-generating substrate may have a mass between 80 milligrams and 250 milligrams. The aerosol-generating substrate may have a mass between 80 milligrams and 200 milligrams. The aerosol-generating substrate may have a mass between 80 milligrams and 150 milligrams. Preferably, the aerosol-generating substrate may have a mass between 100 milligrams and 250 milligrams.

[0066] The aerosol-generating substrate may have a bulk density of greater than or equal to 0.05 milligrams per cubic millimetre. The aerosol-generating substrate may have a bulk density of greater than or equal to 0.1 milligrams per cubic millimetre. The aerosol-generating substrate may have a bulk density of greater than or equal to 0.15 milligrams per cubic millimetre. The aerosolgenerating substrate may have a bulk density of greater than or equal to 0.2 milligrams per cubic millimetre. The aerosol-generating substrate may have a bulk density of greater than or equal to 0.3 milligrams per cubic millimetre. The aerosol-generating substrate may have a bulk density of greater than or equal to 0.4 milligrams per cubic millimetre.

[0067] The aerosol-generating substrate may have a bulk density of less than or equal to 0.5 milligrams per cubic millimetre. The aerosol-generating substrate may have a bulk density of less than or equal to 0.4 milligrams per cubic millimetre. The aerosol-generating substrate may have a bulk density of less than or equal to 0.35 milligrams per cubic millimetre. The aerosol-generating substrate may have a bulk density of less than or equal to 0.3 milligrams per cubic millimetre.

[0068] The aerosol-generating substrate may have a bulk density of between 0.05 milligrams per cubic millimetre and 0.5 milligrams per cubic millimetre. The aerosol-generating substrate may have a bulk density of between 0.1 milligrams per cubic millimetre and 0.4 milligrams per cubic millimetre. The aerosol-generating substrate may have a bulk density of between 0.1 and 0.3 milligrams per cubic millimetre. The aerosol-generating substrate may have a bulk density of between 0.2 and 0.3 milligrams per cubic millimetre.

[0069] The aerosol-generating substrate may have a packing density greater than or equal to 0.3. The aerosol-generating substrate may have a packing density greater than or equal to 0.4. The aerosol-generating substrate may have a packing density greater than or equal to 0.5. The aerosolgenerating substrate may have a packing density greater than or equal to 0.6. The aerosolgenerating substrate may have a packing density greater than or equal to 0.7.

[0070] The aerosol-generating substrate may have a packing density less than or equal to 0.9. The aerosol-generating substrate may have a packing density less than or equal to 0.8. The aerosol-generating substrate may have a packing density less than or equal to 0.7. The aerosolgenerating substrate may have a packing density less than or equal to 0.6. The aerosol-generating substrate may have a packing density less than or equal to 0.5.

[0071] The aerosol-generating substrate may have a packing density of between 0.3 and 0.9. The aerosol-generating substrate may have a packing density of between 0.4 and 0.9. The aerosolgenerating substrate may have a packing density of between 0.5 and 0.9. The aerosol-generating substrate may have a packing density of between 0.5 and 0.8. The aerosol-generating substrate may have a packing density of between 0.5 and 0.7.

[0072] The aerosol-generating substrate may comprise, or consist of, a solid aerosol-generating substrate.

[0073] The aerosol-generating substrate may comprise a porous substrate. The porous substrate may comprise natural materials, synthetic, or semi-synthetic, or a combination thereof. The porous substrate may comprise sheet material, foam, or fibres, for example loose fibres; or a combination thereof. The porous substrate may comprise a woven, non-woven, or extruded material, or combinations thereof. Preferably the porous substrate comprises, cotton, paper, viscose, PLA, or cellulose acetate, of combinations thereof. The porous substrate may comprise a gathered sheet material, for example, made of cotton or cellulose acetate.

[0074] The porous substrate may hold or retain an aerosol-generating medium. The aerosolgenerating medium may comprise a liquid or gel impregnating the porous substrate. The aerosolgenerating medium may comprise a gel comprising an alkaloid compound; an aerosol former; and at least one gelling agent.

[0075] The aerosol-generating substrate may comprise, or consist of, a homogenised plant material, such as homogenised tobacco material. As used herein, the term “homogenised plant material” encompasses any plant material formed by the agglomeration of particles of plant. For example, sheets or webs of homogenised tobacco material for the aerosol-generating substrates of the present invention may be formed by agglomerating particles of tobacco material obtained by pulverising, grinding or comminuting one or more of tobacco leaf lamina and tobacco leaf stems. A homogenised plant material such as a homogenised tobacco material may be produced by casting, extrusion, paper making processes or other any other suitable processes known in the art.

[0076] The aerosol-generating substrate may comprise shredded aerosol-generating substrate. For example, the aerosol-generating substrate may comprise one or both: strips of aerosolgenerating substrate and strands of aerosol-generating substrate. The shredded aerosolgenerating substrate may be shredded tobacco material. The shredded aerosol-generating substrate may be shredded homogenised tobacco material. The shredded aerosol-generating substrate may be a shredded sheet of homogenised tobacco material such as a shredded cast leaf tobacco sheet.

[0077] The aerosol-generating substrate may comprise cut filler, such as tobacco cut filler. The cut filler may comprise one or more of bright tobacco, dark tobacco, aromatic tobacco and filler tobacco. Examples of bright tobaccos are Flue-Cured Brazil, Indian Flue-Cured, Chinese Flue- Cured, US Flue-Cured such as Virginia tobacco, and Flue-Cured from Tanzania. Examples of aromatic tobaccos are Oriental Turkey, Greek Oriental, semi-oriental tobacco but also Fire Cured, US Burley, such as Perique, and Rustica. Examples of dark tobacco are Dark Cured Brazil Galpao, Burley Malawi or other African Burley, Sun Cured or Air Cured Indonesian Kasturi. As used herein, the term “cut filler” is used to describe to a blend of shredded plant material, such as tobacco plant material, including, in particular, one or more of leaf lamina, processed stems and ribs, homogenised plant material.

[0078] The aerosol-generating substrate may comprise, or consist of, a sheet of aerosolgenerating material. The sheet of aerosol-generating material may be a sheet of tobacco material. The sheet of aerosol-generating material may be a sheet of homogenised tobacco material, such as a cast leaf tobacco sheet.

[0079] The sheet of aerosol-generating material may have a grammage of between 100 grams per square metre and 600 grams per square metre. The sheet of aerosol-generating material may have a grammage of between 100 grams per square metre and 300 grams per square metre.

[0080] The sheet of aerosol-generating material may have a density greater than or equal to 0.3 grams per cubic centimetre. The sheet of aerosol-generating material may have a density greater than or equal to 0.4 grams per cubic centimetre. The sheet of aerosol-generating material may have a density greater than or equal to 0.5 grams per cubic centimetre. The sheet of aerosolgenerating material may have a density greater than or equal to 0.6 grams per cubic centimetre. The sheet of aerosol-generating material may have a density greater than or equal to 0.7 grams per cubic centimetre. The sheet of aerosol-generating material may have a density less than or equal to 0.8 grams per cubic centimetre.

[0081] The sheet of aerosol-generating material may have a density less than or equal to 1 .0 grams per cubic centimetre. The sheet of aerosol-generating material may have a density less than or equal to 0.9 grams per cubic centimetre. The sheet of aerosol-generating material may have a density less than or equal to 0.8 grams per cubic centimetre. The sheet of aerosolgenerating material may have a density less than or equal to 0.7 grams per cubic centimetre. The sheet of aerosol-generating material may have a density less than or equal to 0.6 grams per cubic centimetre. The sheet of aerosol-generating material may have a density less than or equal to 0.5 grams per cubic centimetre. The sheet of aerosol-generating material may have a density less than or equal to 0.4 grams per cubic centimetre.

[0082] The sheet of aerosol-generating material may have a density between 0.3 grams per cubic centimetre and 1.3 grams per cubic centimetre. The sheet of aerosol-generating material may have a density between 0.3 grams per cubic centimetre and 1 .0 gram per cubic centimetre. The sheet of aerosol-generating material may have a density between 0.4 grams per cubic centimetre and 1.0 grams per cubic centimetre. The sheet of aerosol-generating material may have a density between 0.4 grams per cubic centimetre and 0.9 grams per cubic centimetre. The sheet of aerosolgenerating material may have a density between 0.5 grams per cubic centimetre and 0.9 grams per cubic centimetre.

[0083] The sheet of aerosol-generating material may be a gathered sheet of aerosol-generating material. That is, the sheet of aerosol-generating material may be convoluted, folded, or otherwise compressed or constricted substantially perpendicular to the transverse direction of the aerosolgenerating substrate plug. The sheet of aerosol-generating material may be a crimped sheet of aerosol-generating material. The sheet of aerosol-generating material may be a corrugated sheet of aerosolgenerating material. The crimped sheet of aerosol-generating material or the corrugated sheet of aerosol-generating material may comprise a plurality of parallel corrugations. The plurality of parallel corrugations may define, or form, a plurality of channels. The plurality of channels may be a plurality of longitudinally extending channels. That is, the plurality of channels may extend in a longitudinal direction of the aerosol-generating substrate plug.

[0084] The aerosol-generating 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 aerosolformers selected from: polyhydric alcohols, such as propylene glycol, polyethylene glycol, triethylene glycol, 1 , 3-butanediol and glycerine; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. It may be particularly preferable for the aerosolformer to be or comprise glycerine.

[0085] The aerosol-generating substrate may comprise an aerosol-former content greater than or equal to 10 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content greater than or equal to 15 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content greater than or equal to 20 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content greater than or equal to 25 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content greater than or equal to 30 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content greater than or equal to 40 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content greater than or equal to 50 percent by weight on a dry weight basis.

[0086] The aerosol-generating substrate may comprise an aerosol-former content less than or equal to 60 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content less than or equal to 50 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content less than or equal to 40 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content less than or equal to 30 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content less than or equal to 25 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content less than or equal to 20 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content less than or equal to 15 percent by weight on a dry weight basis.

[0087] The aerosol-generating substrate may comprise an aerosol-former content of between 5 percent and 30 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content of between 5 percent and 25 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content of between 5 percent and 20 percent by weight on a dry weight basis.

[0088] The aerosol-generating substrate may comprise an aerosol-former content of between 10 percent and 30 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content of between 10 percent and 25 percent by weight on a dry weight basis. The aerosol-generating substrate may comprise an aerosol-former content of between 10 percent and 20 percent by weight on a dry weight basis.

[0089] The aerosol-generating substrate may comprise nicotine. The aerosol-generating substrate may comprise natural nicotine, or synthetic nicotine, or a combination of natural nicotine and synthetic nicotine. The aerosol-generating substrate may comprise nicotine in the form of particles or powder.

[0090] The aerosol-generating substrate may comprise at least 0.5 percent by weight of nicotine, at least 1 percent by weight of nicotine, at least 1.5 percent by weight of nicotine, or at least 2 percent by weight of nicotine. That is, the aerosol-generating substrate may have a nicotine content of at least 0.5 percent by weight, at least 1 percent by weight, at least 1 .5 percent by weight, or at least 2 percent by weight.

[0091] The aerosol-generating substrate may be substantially tobacco-free or nicotine-free.

[0092] The aerosol-generating 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), cannabicitran (CBT). It may be preferable that the cannabinoid compound is CBD or THC. It may be particularly preferable that the cannabinoid compound is CBD.

[0093] The aerosol-generating substrate may comprise one or more flavourants. The one or more flavourants may comprise one or more of: one or more essential oils such as eugenol, peppermint oil and spearmint oil; one or both of menthol and eugenol; one or both of anethole and linalool; and a herbaceous material. Suitable herbaceous material includes herb leaf or other herbaceous material from herbaceous plants including, but not limited to, mints, such as peppermint and spearmint, lemon balm, basil, cinnamon, lemon basil, chive, coriander, lavender, sage, tea, thyme, and caraway. The one or more flavourants may comprise a tobacco material.

[0094] The aerosol-generating substrate may have a moisture content of about 5 to 25%, preferably of about 7 to 15%, at final product state. For example, the aerosol-generating substrate may be a homogenised tobacco material with a moisture of about 5 to 25%, preferably of about 7 to 15%, at final product state. The aerosol-generating substrate may comprise tobacco leaf; for example about 15 to 45%, preferably of about 20 to 35% of a blend of tobacco leaf, incorporating at least one of the following tobacco types: bright tobacco; dark tobacco; aromatic tobacco. Tobacco material such as tobacco leaf is preferably ground and graded to a particle size of about 100 to 380 mesh, preferably of about 170 to 320 mesh.

[0095] The aerosol-generating substrate may comprise cellulose fibres. For example, the aerosolgenerating substrate may comprise about 1 to 15% of cellulose fibres, preferably of about 3 to 7% of cellulose fibres. Preferably, cellulose fibres may have a length of about 10 to 250 pm, preferably of about 10 to 120 pm.

[0096] The aerosol-generating substrate may comprise organic fibres such as non-tobacco fibres, or tobacco fibres. For example, the aerosol-generating substrate may comprise about 5 to 20%, preferably about 7 to 15% of tobacco fibres. Tobacco fibres are preferably derived from stems and / or or stalks, graded to fibres of a length of about 10 to 350 pm, preferably of about 10 to 180 pm. The aerosol-generating substrate may comprise about 10 to 30 %, preferably of about 15 to 25%, of a non-tobacco organic fibre. For example, organic fibres may derive from cellulose, cotton, wood, tea botanical varieties as sub-products, and sub-processed waste, the tea industry. Organic fibres are preferably of a length of about 10 to 400 pm, preferably of about 10 to 200 pm.

[0097] The aerosol-generating substrate may comprise a binder. For example, the aerosolgenerating substrate may comprise about 1 to 10%, preferably of about 1 to 5%, of a binder such as any of common gums or pectins used in food and beverage (F&B) industries. Preferred binders may be natural pectins, such as fruit, for example citrus, or tobacco pectins; guar gums, land locust bean gums, such as hydroxyethyl and / or hydroxypropyl of those; starches, such as modified or derivatized starches; alginate; methyl, ethyl, ethylhydroxymethyl and carboxymethyl, celluloses; dextran; and xanthan gum. A preferable binder is guar or carboxymethyl cellulose.

[0098] The aerosol-generating substrate may comprise an organic botanical glycerite. For example, the aerosol-generating substrate may comprise about 15 to 55 %, preferably of about 20 to 35 %, of botanicals such as Clove, Echinacea sp., Fennel, Ginger, Hawthorn berry, Elderberry, Monarda, Mullein leaves, Nettle, Plantain, Turmeric, Yarrow, and compounds of those.

[0099] The aerosol-generating substrate may comprise organic botanical extracts. For example, the aerosol-generating substrate may comprise about 1 to 15 %, preferably of about 2 to 7 %, of any of the previously referred botanicals, as well as menthol (dl-Menthol, C10H20O, 2-lsopropyl- 5-methylcyclohexanol) such as obtained from Chaerophyllum macrospermum, Mesosphaerum sidifolium, or other related botanic varieties, as well as P-menthan-3-ol, as any secondary alcohol as diastereoisomers of 5-methyl-2-(propan-2-yl)cyclohexan-1-ol.

[0100] The aerosol-generating substrate may comprise botanical essential oils, for example about 0.5 to 5 %, preferably of about 1 to 3 %, of a botanical essential oil, for example a botanical essential oil such as of palm, coconut, and wooden-based essential oils. The aerosol-generating substrate may be in the form of a plurality of beads. The plurality of beads may have an average particle diameter of between 0.1 mm and 4 mm, for example between 0.5 mm and 4 mm.

[0101] The term “bead” refers to a discrete, solid particle formed of the aerosol-generating substrate. A bead may have a rounded, typically spherical, form. Otherterms may be used to define the substrate such as, for example, “granule”.

[0102] Providing the aerosol-generating substrate as a plurality of beads may provide certain advantages. Beads can be easily handled compared to other aerosol-forming substrates. Beads may also be cleaner to handle than powders and cut fillers, which may cause dust in factories, and may leak from aerosol-generating articles in transit or in use. By selecting beads with appropriate bead sizes and appropriate particle size distributions, air flow through the aerosol-generating substrate plug may be controlled more reproducibly than would be the case for, say, a cut filler substrate.

[0103] Where a particle is not perfectly spherical, but a diameter of the particle is referred to, the term “diameter” may refer to a largest dimension of the particle. Alternatively, the term “diameter” may refer to the diameter of a perfectly spherical particle having the same volume as the not perfectly spherical particle.

[0104] The term “average particle diameter”, as used herein, may refer to a number average particle diameter. Other methods of determining average particle diameter are known. Thus, the average particle diameter may be, for example, a volume average particle diameter.

[0105] The aerosol-generating substrate plug may have a volume greater than or equal to 150 cubic millimetres. The aerosol-generating substrate plug may have a volume greater than or equal to 200 cubic millimetres. The aerosol-generating substrate plug may have a volume greater than or equal to 250 cubic millimetres. The aerosol-generating substrate plug may have a volume greater than or equal to 350 cubic millimetres.

[0106] The aerosol-generating substrate plug may have less than or equal to 1000 cubic millimetres. The aerosol-generating substrate plug may have less than or equal to 900 cubic millimetres. The aerosol-generating substrate plug may have less than or equal to 800 cubic millimetres. The aerosol-generating substrate plug may have less than or equal to 700 cubic millimetres.

[0107] The aerosol-generating substrate plug may have a volume between 100 cubic millimetres and 1000 cubic millimetres. The aerosol-generating substrate plug may have a volume between 200 cubic millimetres and 1000 cubic millimetres. The aerosol-generating substrate plug may have a volume between 350 cubic millimetres and 650 cubic millimetres. The aerosol-generating substrate plug may have a volume between 450 cubic millimetres and 550 cubic millimetres.

[0108] The aerosol-generating substrate plug may have a thickness greater than or equal to 0.5 millimetres. The aerosol-generating substrate plug may have a thickness greater than or equal to 1 millimetre. The aerosol-generating substrate plug may have a thickness greater than or equal to 1.5 millimetres. The aerosol-generating substrate plug may have a thickness greater than or equal to 2 millimetres. The aerosol-generating substrate plug may have a thickness greater than or equal to 2.5 millimetres. The aerosol-generating substrate plug may have a thickness greater than or equal to 3 millimetres. The aerosol-generating substrate plug may have a thickness greater than or equal to 3.5 millimetres. The aerosol-generating substrate plug may have a thickness greater than or equal to 4 millimetres. The aerosol-generating substrate plug may have a thickness greater than or equal to 4.5 millimetres. The aerosol-generating substrate plug may have a thickness greater than or equal to 5 millimetres.

[0109] The aerosol-generating substrate plug may have a thickness less than or equal to 5.5 millimetres. The aerosol-generating substrate plug may have a thickness less than or equal to 5 millimetres. The aerosol-generating substrate plug may have a thickness less than or equal to 4.5 millimetres. The aerosol-generating substrate plug may have a thickness less than or equal to 4 millimetres. The aerosol-generating substrate plug may have a thickness less than or equal to 3.5 millimetres. The aerosol-generating substrate plug may have a thickness less than or equal to 2.5 millimetres. The aerosol-generating substrate plug may have a thickness less than or equal to 2 millimetres. The aerosol-generating substrate plug may have a thickness less than or equal to 1 .5 millimetres.

[0110] The aerosol-generating substrate plug may have a thickness between 0.5 millimetres and 6.5 millimetres. The aerosol-generating substrate plug may have a thickness between 1 millimetres and 6 millimetres. The aerosol-generating substrate plug may have a thickness between 2 millimetres and 6 millimetres. The aerosol-generating substrate plug may have a thickness between 2 millimetres and 5 millimetres. The aerosol-generating substrate plug may have a thickness between 2 millimetre and 4.5 millimetres. The aerosol-generating substrate plug may have a thickness between 2 millimetre and 4 millimetres. Preferably, the aerosol-generating substrate plug may have a thickness between 2.8 millimetres and 3.3 millimetres.

[0111] The aerosol-generating substrate plug may have a length greater than or equal to 6 millimetres. The aerosol-generating substrate plug may have a length equal to a greater than 10 millimetres. The aerosol-generating substrate plug may have a length equal to a greater than 14 millimetres. The aerosol-generating substrate plug may have a length greater than or equal to 18 millimetres. The aerosol-generating substrate plug may have a length greater than or equal to 22 millimetres. The aerosol-generating substrate plug may have a length greater than or equal to 26 millimetres. The aerosol-generating substrate plug may have a length greater than or equal to 30 millimetres.

[0112] The aerosol-generating substrate plug may have a length less than or equal to 32 millimetres. The aerosol-generating substrate plug may have a length less than or equal to 28 millimetres. The aerosol-generating substrate plug may have a length less than or equal to 24 millimetres. The aerosol-generating substrate Plug may have a length less than or equal to 20 millimetres. The aerosol-generating substrate Plug may have a length less than or equal to 16 millimetres. The aerosol-generating substrate plug may have a length less than or equal to 12 millimetres. The aerosol-generating substrate plug may have a length less than or equal to 8 millimetres.

[0113] The aerosol-generating substrate plug may have a length of between 6 millimetres and 34 millimetres. The aerosol-generating substrate plug may have a length of between 10 millimetres and 30 millimetres. The aerosol-generating substrate plug may have a length of between 14 millimetres and 26 millimetres. The aerosol-generating substrate plug may have a length of between 14 millimetres and 22 millimetres. The aerosol-generating substrate plug may have a length of between 14 millimetres and 18 millimetres.

[0114] The aerosol-generating substrate plug may have a length equal to a greater than 80 millimetres. The aerosol-generating substrate plug may have a length greater than or equal to 100 millimetres. The aerosol-generating substrate plug may have a length greater than or equal to 120 millimetres. The aerosol-generating substrate plug may have a length greater than or equal to 160 millimetres. The aerosol-generating substrate plug may have a length greater than or equal to 200 millimetres. The aerosol-generating substrate plug may have a length greater than or equal to 240 millimetres.

[0115] The aerosol-generating substrate plug may have a length less than or equal to 400 millimetres. The aerosol-generating substrate plug may have a length less than or equal to 360 millimetres. The aerosol-generating substrate plug may have a length less than or equal to 320 millimetres. The aerosol-generating substrate plug may have a length less than or equal to 280 millimetres. The aerosol-generating substrate plug may have a length less than or equal to 240 millimetres. The aerosol-generating substrate plug may have a length less than or equal to 200 millimetres.

[0116] The aerosol-generating substrate plug may have a length of between 80 millimetres and 400 millimetres. The aerosol-generating substrate plug may have a length of between 100 millimetres and 400 millimetres. The aerosol-generating substrate plug may have a length of between 120 millimetres and 400 millimetres. The aerosol-generating substrate plug may have a length of between 160 millimetres and 400 millimetres. The aerosol-generating substrate plug may have a length of between 200 millimetres and 400 millimetres.

[0117] The aerosol-generating substrate plug may have a width greater than or equal to 4 millimetres. The aerosol-generating substrate plug may have a width greater than or equal to 5 millimetres. The aerosol-generating substrate plug may have a width greater than or equal to 6 millimetres. The aerosol-generating substrate plug may have a width greater than or equal to 7 millimetres. The aerosol-generating substrate plug may have a width greater than or equal to 8 millimetres.

[0118] The aerosol-generating substrate plug may have a width less than or equal to 12 millimetres. The aerosol-generating substrate plug may have a width less than or equal to 11 millimetres. The aerosol-generating substrate plug may have a width less than or equal to 10 millimetres. The aerosol-generating substrate plug may have a width less than or equal to 9 millimetres. The aerosol-generating substrate plug may have a width less than or equal to 8 millimetres.

[0119] The aerosol-generating substrate plug may have a width between 4 millimetres and 12 millimetres. The aerosol-generating substrate plug may have a width between 6 millimetres and 10 millimetres.

[0120] The aerosol-generating substrate plug may have a length between 6 millimetres and 32 millimetres, a width between 4 millimetres and 12 millimetres, and a thickness between 0.5 millimetres and 5.5 millimetres.

[0121] Preferably, the aerosol-generating substrate plug may have a length between 10 millimetres and 30 millimetres, a width between 6 millimetres and 10 millimetres, and a thickness between 2 millimetres and 6 millimetres.

[0122] According to the present disclosure, there is provided an aerosol-generating article comprising the aerosol-generating substrate plug described herein, a first plug and an outer wrapper. The outer wrapper may circumscribe the first plug and the aerosol-generating substrate plug. The aerosol-generating article may be for use with an aerosol-generating device to generate an aerosol, for example the aerosol-generating article may be for use with an electrically operated aerosol-generating device.

[0123] The aerosol-generating article may comprise a substantially planar upper surface defined by a length extending in an x-direction and a width extending in a y-direction. The aerosolgenerating article may have a substantially planar lower surface defined by a length extending in an x-direction and a width extending in a y-direction. The substantially planar upper surface and the substantially planar lower surface may be spaced from each other by a thickness defined in a z-direction. The substantially planar upper surface and the substantially planar lower surface may be parallel to each other.

[0124] The aerosol-generating article may comprise a first side surface extending from the substantially planar upper surface to the substantially planar lower surface. The aerosol-generating article may comprise a second side surface extending from the substantially planar upper surface to the substantially planar lower surface. The first side surface may be a substantially planar first side surface. The second side surface may be a substantially planar second side surface. The first side surface may be positioned opposite the second side surface. The first side surface may be parallel to the second side surface. The first side surface may be defined by a length extending in an x-direction and a thickness extending in a z-direction. The second side surface may be defined by a length extending in an x-direction and a thickness extending in a z-direction. The first side surface and the second side surface may be spaced from each other by a width in a y-direction. The first side surface may be substantially perpendicular to one or both the substantially planar upper surface and the substantially planar lower surface. The second side surface may be substantially perpendicular to one or both the substantially planar upper surface and the substantially planar lower surface.

[0125] The first plug and the aerosol-generating substrate plug may be axially aligned in the longitudinal direction. The first plug may be positioned adjacent to the aerosol-generating substrate plug. That is, no element may be positioned between the first plug and the aerosol-generating substrate plug. The first plug may be positioned adjacent to, and spaced from, the aerosolgenerating substrate plug. For example, an empty cavity may be located between the first plug and the aerosol-generating substrate plug. The first plug may be spaced from the aerosolgenerating substrate plug by greater than or equal to 2 millimetres. The first plug may be spaced from the aerosol-generating substrate by less than or equal to 5 millimetres.

[0126] The first plug may be positioned upstream or downstream of the aerosol-generating substrate plug. The first plug may abut the upstream end or downstream end of the aerosolgenerating substrate plug. The first plug may be spaced from the upstream end or downstream end of the aerosol-generating substrate plug. The first plug may be positioned at an extreme upstream end or an extreme downstream end of the aerosol-generating article. The first plug may define or form an upstream end wall or a downstream end wall of the aerosol-generating article.

[0127] The first plug may be substantially air impermeable. The first plug may comprise a solid cross-section of material. In other words, the first plug does not define any cavity, gaps, voids or apertures, apart from those already defined by the material properties itself, such as pores. The first plug may be configured such that an air-flow path may be formed through the first plug during use, for example by an aerosol-generating device.

[0128] The first plug may be substantially air permeable. The first plug may comprise one or more apertures or through holes defined through the length of the first plug. The first plug may be a hollow element, for example a rectangular tube. The first plug may comprise a plug of a porous substrate.

[0129] The first plug may have a resistance to draw of between 0 mmh^O and 5 mmh^O. The first plug may have a resistance to draw of between 0 mmh^O and 4 mmh^O. The first plug may have a resistance to draw of between 0 mmh^O and 3 mmh^O. The first plug may have a resistance to draw of between 0 mmh^O and 2.5 mmh^O. The first plug may have a resistance to draw of between 0 mmh^O and 2 mmh^O. The first plug may have a resistance to draw of between 0 mmh^O and 1 mmh^O. The first plug may have a resistance to draw of between 0 mmh^O and 0.75 mmh^O.

[0130] The first plug may be substantially free of any aerosol-generating compounds. The first plug may comprise one or more flavourants described herein.

[0131] The first plug may comprise, or consist of, a fibrous material. The first plug may comprise, or consist of, a porous material. The first plug may comprise, or consist of, a fluid or air permeable material. The first plug may be comprise, or consist of, a biodegradable material. The first plug may comprise, or consist of, a cellulosic material such as cellulose acetate or paper. For example, the first plug may be formed from a bundle of cellulose acetate fibres having a denier per filament between about 10 and about 15. As another example, the first plug may be formed from relatively low density cellulose acetate tow, such as cellulose acetate tow comprising fibres of about 12 denier per filament, which may provide an RTD per unit length between about 0.8 and about 2.5 mmH20 per mm.

[0132] The first plug may comprise, or consist of, a polylactic acid based material. The first plug may comprise, or consist of, a bioplastic material, preferably a starch-based bioplastic material. The first plug may be made by injection moulding or by extrusion.

[0133] The first plug may comprise, or consist of, a cellulosic material or paper. The first plug may comprise at least 80 percent by weight of cellulosic material or paper. The first plug may comprise at least 90 percent by weight of cellulosic material or paper. The first plug may comprise at least 95 percent by weight of cellulosic material or paper.

[0134] The first plug may comprise, or consist of, a sheet of material that has been fluted, crimped, pleated, gathered, woven or folded into an element that defines a plurality of longitudinally extending channels. Preferably, the sheet of material has been fluted or crimped. The sheet of material may comprise, be, or consist of: paper, cardboard, or polymer, such as polylactic acid, or any other cellulose-based, paper-based material or bioplastic-based material. Preferably, the sheet of material is a cellulose-based material. The plurality of longitudinally extending channels may extend from an upstream end of the first plug to a downstream end of the first plug. The plurality of longitudinally extending channels may be uniformly or randomly distributed across the transverse cross-section of the first plug. The first plug may comprise a perimeter wall within which the sheet of material is positioned. The perimeter wall may form a tube, preferably a rectangular tube.

[0135] The first plug may be formed in any other suitable manner. For example, the first plug may be formed from a bundle of longitudinally extending tubes. The longitudinally extending tubes may be formed from polylactic acid. The first plug may be formed by extrusion, moulding, lamination, injection, or shredding of a suitable material.

[0136] The first plug may have the same transverse cross-section shape as the aerosolgenerating substrate plug. The first plug may have a substantially rectangular transverse crosssection.

[0137] The first plug may have a width at least 95 percent of a width of the aerosol-generating article. The first plug may have a width at least 98 percent of a width of the aerosol-generating article.

[0138] The first plug may have the same width as the aerosol-generating substrate plug. The first plug may have the same thickness as the aerosol-generating substrate plug.

[0139] The first plug may have a length of greater than or equal to 2 millimetres. The first plug may have a length of greater than or equal to 3 millimetres. The first plug has a length of greater than or equal to 4 millimetres. The first plug may have a length of less than or equal to 10 millimetres. The first plug may have a length of less than or equal to 7 millimetres. The first plug may have a length of less than or equal to about 5 millimetres.

[0140] The first plug may have a length of between 2 millimetres and 10 millimetres. The first plug may have a length of between 3 millimetres and 10 millimetres. The first plug may have a length of between 4 millimetres and 10 millimetres.

[0141] A ratio between a length of the first plug and a length of the aerosol-generating article may be greater than or equal to 0.05. A ratio between a length of the first plug and a length of the aerosol-generating article may be greater than or equal to 0.1 . A ratio between a length of the first plug and a length of the aerosol-generating article may be greater than or equal to 0.2. A ratio between a length of the first plug and a length of the aerosol-generating article may be greater than or equal to 0.3.

[0142] A ratio between a length of the first plug and a length of the aerosol-generating article may be less than or equal to 0.4. A ratio between a length of the first plug and a length of the aerosolgenerating article may be less than or equal to 0.3. A ratio between a length of the first plug and a length of the aerosol-generating article may be less than or equal to 0.2. A ratio between a length of the first plug and a length of the aerosol-generating article may be less than or equal to 0.1 . A ratio between a length of the first plug and a length of the aerosol-generating article may be less than or equal to 0.05.

[0143] A ratio between a length of the first plug and a length of the aerosol-generating article may be between 0.05 and 0.4. A ratio between a length of the first plug and a length of the aerosolgenerating article may be between 0.05 and 0.3. A ratio between a length of the first plug and a length of the aerosol-generating article may be between 0.05 and 0.2. A ratio between a length of the first plug and a length of the aerosol-generating article may be between 0.1 and 0.2.

[0144] A ratio between a length of the first plug and a length of the aerosol-generating substrate plug is may be greater than or equal to 0.15. A ratio between a length of the first plug and a length of the aerosol-generating substrate plug may be greater than or equal to 0.2. A ratio between a length of the first plug and a length of the aerosol-generating substrate plug may be greater than or equal to 0.3.

[0145] A ratio between a length of the first plug and a length of the aerosol-generating substrate plug may be less than or equal to 0.5. A ratio between a length of the first plug and a length of the aerosol-generating substrate plug may be less than or equal to about 0.45. A ratio between a length of the first plug and a length of the aerosol-generating substrate plug may be less than or equal to about 0.4.

[0146] A ratio between a length of the first plug and a length of the aerosol-generating substrate plug may be between 0.15 to 0.5. A ratio between a length of the first plug and a length of the aerosol-generating substrate plug may be between 0.2 and 0.5. A ratio between a length of the first plug and a length of the aerosol-generating substrate plug may be between 0.3 to 0.5. The aerosol-generating article may comprise a second plug. The outer wrapper may circumscribe the first plug, the second plug and the aerosol-generating substrate plug.

[0147] The first plug, the second plug and the aerosol-generating substrate plug may be axially aligned in the longitudinal direction. The second plug may be positioned adjacent to the aerosolgenerating substrate plug. That is, no element may be positioned between the second plug and the aerosol-generating substrate plug. The second plug may be positioned adjacent to, and spaced from, the aerosol-generating substrate plug. For example, an empty cavity may be located between the second plug and the aerosol-generating substrate plug. The second plug may be spaced from the aerosol-generating substrate plug by greater than or equal to 2 millimetres. The second plug may be spaced from the aerosol-generating substrate by less than or equal to 5 millimetres.

[0148] The second plug may be positioned upstream or downstream of the aerosol-generating substrate plug. The second plug may abut the upstream end or downstream end of the aerosolgenerating substrate plug. The second plug may be spaced from the upstream end ordownstream end of the aerosol-generating substrate plug. The second plug may be positioned at an extreme upstream end or an extreme downstream end of the aerosol-generating article. The second plug may define or form an upstream end wall or a downstream end wall of the aerosol-generating article.

[0149] The aerosol-generating substrate plug may be positioned between the first plug and the second plug. For example, the first plug may be positioned upstream of the aerosol-generating substrate plug and the second plug may be positioned downstream of the aerosol-generating substrate plug. As an alternative example, the first plug may be positioned downstream of the aerosol-generating substrate plug and the second plug may be positioned upstream of the aerosolgenerating substrate plug.

[0150] The second plug may be substantially air impermeable. The second plug may comprise a solid cross-section of material. In other words, the second plug does not define any cavity, gaps, voids or apertures, apart from those already defined by the material properties itself, such as pores. The second plug may be configured such that an air-flow path may be formed through the second plug during use, for example by an aerosol-generating device.

[0151] The second plug may be substantially air permeable. The second plug may comprise one or more apertures or through holes defined through the length of the second plug. The second plug may be a hollow element, for example a rectangular tube. The second plug may comprise a plug of a porous substrate.

[0152] The second plug may have a resistance to draw of between 0 mmh^O and 5 mmh^O. The second plug may have a resistance to draw of between 0 mmh^O and 4 mmh^O. The second plug may have a resistance to draw of between 0 mmh^O and 3 mmh^O. The second plug may have a resistance to draw of between 0 mmh^O and 2.5 mmh^O. The second plug may have a resistance to draw of between 0 mmh^O and 2 mmh^O. The second plug may have a resistance to draw of between 0 mmH20 and 1 mmH20. The second plug may have a resistance to draw of between 0 mmH20 and 0.75 mmH20.

[0153] The second plug may be substantially free of any aerosol-generating compounds. The second plug may comprise one or more flavourants described herein.

[0154] The second plug may comprise, or consist of, a fibrous material. The second plug may comprise, or consist of, a porous material. The second plug may comprise, or consist of, a fluid or air permeable material. The second plug may be comprise, or consist of, a biodegradable material. The second plug may comprise, or consist of, a cellulosic material such as cellulose acetate or paper. For example, the second plug may be formed from a bundle of cellulose acetate fibres having a denier per filament between about 10 and about 15. As another example, the second plug may be formed from relatively low density cellulose acetate tow, such as cellulose acetate tow comprising fibres of about 12 denier per filament, which may provide an RTD per unit length between about 0.8 and about 2.5 mmh^O per mm.

[0155] The second plug may comprise, or consist of, a polylactic acid based material. The second plug may comprise, or consist of, a bioplastic material, preferably a starch-based bioplastic material. The second plug may be made by injection moulding or by extrusion.

[0156] The second plug may comprise, or consist of, a cellulosic material or paper. The second plug may comprise at least 80 percent by weight of cellulosic material or paper. The second plug may comprise at least 90 percent by weight of cellulosic material or paper. The second plug may comprise at least 95 percent by weight of cellulosic material or paper.

[0157] The second plug may comprise, or consist of, a sheet of material that has been fluted, crimped, pleated, gathered, woven or folded into an element that defines a plurality of longitudinally extending channels. Preferably, the sheet of material has been fluted or crimped. The sheet of material may comprise, be, or consist of: paper, cardboard, or polymer, such as polylactic acid, or any other cellulose-based, paper-based material or bioplastic-based material. Preferably, the sheet of material is a cellulose-based material. The plurality of longitudinally extending channels may extend from an upstream end of the second plug to a downstream end of the second plug. The plurality of longitudinally extending channels may be uniformly or randomly distributed across the transverse cross-section of the second plug. The second plug may comprise a perimeter wall within which the sheet of material is positioned. The perimeter wall may form a tube, preferably a rectangular tube.

[0158] The second plug may be formed in any other suitable manner. For example, the second plug may be formed from a bundle of longitudinally extending tubes. The longitudinally extending tubes may be formed from polylactic acid. The second plug may be formed by extrusion, moulding, lamination, injection, or shredding of a suitable material.

[0159] The second plug may have the same transverse cross-section shape as the aerosolgenerating substrate plug. The second plug may have a substantially rectangular transverse crosssection. The second plug may have a width at least 95 percent of a width of the aerosol-generating article. The second plug may have a width at least 98 percent of a width of the aerosol-generating article.

[0160] The second plug may have the same width as the aerosol-generating substrate plug. The second plug may have the same thickness as the aerosol-generating substrate plug.

[0161] The second plug may have a length of greater than or equal to 2 millimetres. The second plug may have a length of greater than or equal to 3 millimetres. The second plug has a length of greater than or equal to 4 millimetres.

[0162] The second plug may have a length of less than or equal to 10 millimetres. The second plug may have a length of less than or equal to 7 millimetres. The second plug may have a length of less than or equal to about 5 millimetres.

[0163] The second plug may have a length of between 2 millimetres and 10 millimetres. The second plug may have a length of between 3 millimetres and 10 millimetres. The second plug may have a length of between 4 millimetres and 10 millimetres.

[0164] A ratio between a length of the second plug and a length of the aerosol-generating article may be greater than or equal to 0.05. A ratio between a length of the second plug and a length of the aerosol-generating article may be greater than or equal to 0.1 . A ratio between a length of the second plug and a length of the aerosol-generating article may be greater than or equal to 0.2. A ratio between a length of the second plug and a length of the aerosol-generating article may be greater than or equal to 0.3.

[0165] A ratio between a length of the second plug and a length of the aerosol-generating article may be less than or equal to 0.4. A ratio between a length of the second plug and a length of the aerosol-generating article may be less than or equal to 0.3. A ratio between a length of the second plug and a length of the aerosol-generating article may be less than or equal to 0.2. A ratio between a length of the second plug and a length of the aerosol-generating article may be less than or equal to 0.1. A ratio between a length of the second plug and a length of the aerosol-generating article may be less than or equal to 0.05.

[0166] A ratio between a length of the second plug and a length of the aerosol-generating article may be between 0.05 and 0.4. A ratio between a length of the second plug and a length of the aerosol-generating article may be between 0.05 and 0.3. A ratio between a length of the second plug and a length of the aerosol-generating article may be between 0.05 and 0.2. A ratio between a length of the second plug and a length of the aerosol-generating article may be between 0.1 and 0.2.

[0167] A ratio between a length of the second plug and a length of the aerosol-generating substrate plug is may be greater than or equal to 0.15. A ratio between a length of the second plug and a length of the aerosol-generating substrate plug may be greater than or equal to 0.2. A ratio between a length of the second plug and a length of the aerosol-generating substrate plug may be greater than or equal to 0.3. A ratio between a length of the second plug and a length of the aerosol-generating substrate plug may be less than or equal to 0.5. A ratio between a length of the second plug and a length of the aerosol-generating substrate plug may be less than or equal to about 0.45. A ratio between a length of the second plug and a length of the aerosol-generating substrate plug may be less than or equal to about 0.4.

[0168] A ratio between a length of the second plug and a length of the aerosol-generating substrate plug may be between 0.15 to 0.5. A ratio between a length of the second plug and a length of the aerosol-generating substrate plug may be between 0.2 and 0.5. A ratio between a length of the second plug and a length of the aerosol-generating substrate plug may be between 0.3 to 0.5.

[0169] The outer wrapper may be arranged to cover at least 20 percent, or at least 50 percent, or at least 80 percent, or at least 90 percent, or least 95 percent, or the entirety of a length of the aerosol-generating article.

[0170] The outer wrapper may fully circumscribe or encircle the aerosol-generating article along greater than or equal to 50 percent of a length of the aerosol-generating article. The outer wrapper may fully circumscribe or encircle the aerosol-generating article along greater than or equal to 75 percent of a length of the aerosol-generating article. The outer wrapper may fully circumscribe or encircle the aerosol-generating article along greater than or equal to 90 percent of a length of the aerosol-generating article. Preferably the outer wrapper may fully circumscribe or encircle the aerosol-generating article along 100 percent of a length of the aerosol-generating article.

[0171] The outer wrapper may define or form an outer surface of the aerosol-generating article. The outer wrapper may define or form the substantially planar upper surface of the aerosolgenerating article. The outer wrapper may define or form the substantially planar lower surface of the aerosol-generating article. The outer wrapper may define or form the first side surface of the aerosol-generating article. The outer wrapper may define or form the second side surface of the aerosol-generating article. Preferably, the outer wrapper defines or forms the substantially planar upper surface of the aerosol-generating article, the substantially planar lower surface of the aerosol-generating article, the first side surface of the aerosol-generating article and the second side surface of the aerosol-generating article.

[0172] The outer wrapper may define or form all longitudinal outer surfaces of the aerosolgenerating article. That is, the outer wrapper may define or form all outer surfaces of the aerosolgenerating article that extend in the x-direction and y-direction, or the x-direction and the z- direction. The outer wrapper may define or form at least 99 percent of the surface area of all longitudinal outer surfaces of the aerosol-generating article.

[0173] The outer wrapper may be confined to defining or forming the upper surface and the lower surface of the aerosol-generating article, such that side portions of the aerosol-generating article between the upper and lower surfaces are not defined or formed by the outer wrapper. The outer wrapper may be confined to extending around no more than 80% of a circumference of the aerosol-generating article, or extending around no more than 75% of the circumference of the aerosol-generating article, or extending around no more than 60% of the circumference of the aerosol-generating article, or extending around no more than 50% of the circumference of the aerosol-generating article.

[0174] The outer wrapper may have a length greater than a length of the wrapper of the aerosolgenerating substrate plug. The outer wrapper may circumscribe or encircle the entire length of the aerosol-generating substrate plug.

[0175] The outer wrapper may circumscribe or encircle only a downstream portion or an upstream portion of the first plug. For example, when the first plug is upstream of the aerosol-generating substrate plug, the outer wrapper may circumscribe or encircle only a downstream portion of the first plug and the upstream portion of the first plug may extend beyond the outer wrapper. As another example, when the first plug is downstream of the aerosol-generating substrate plug, the outer wrapper may circumscribe or encircle only an upstream portion of the first plug and the downstream portion of the first plug may extend beyond the outer wrapper.

[0176] The outer wrapper may circumscribe or encircle greater than or equal to 10 percent of a length of the first plug. The outer wrapper may circumscribe or encircle greater than or equal to 25 percent of a length of the first plug. The outer wrapper may circumscribe or encircle greater than or equal to 50 percent of a length of the first plug. The outer wrapper may circumscribe or encircle greater than or equal to 75 percent of a length of the first plug. The outer wrapper may circumscribe or encircle the entire length of the first plug.

[0177] The outer wrapper may circumscribe or encircle less than or equal to 75 percent of a length of the first plug. The outer wrapper may circumscribe or encircle less than or equal to 50 percent of a length of the first plug. The outer wrapper may circumscribe or encircle less than or equal to 25 percent of a length of the first plug.

[0178] The outer wrapper may circumscribe or encircle only a downstream portion or an upstream portion of the second plug. For example, when the second plug is upstream of the aerosolgenerating substrate plug, the outer wrapper may circumscribe or encircle only a downstream portion of the second plug and the upstream portion of the second plug may extend beyond the outer wrapper. As another example, when the second plug is downstream of the aerosolgenerating substrate plug, the outer wrapper may circumscribe or encircle only an upstream portion of the second plug and the downstream portion of the second plug may extend beyond the outer wrapper.

[0179] The outer wrapper may circumscribe or encircle greater than or equal to 10 percent of a length of the second plug. The outer wrapper may circumscribe or encircle greater than or equal to 25 percent of a length of the second plug. The outer wrapper may circumscribe or encircle greater than or equal to 50 percent of a length of the second plug. The outer wrapper may circumscribe or encircle greater than or equal to 75 percent of a length of the second plug. The outer wrapper may circumscribe or encircle the entire length of the second plug.

[0180] The outer wrapper may circumscribe or encircle less than or equal to 75 percent of a length of the second plug. The outer wrapper may circumscribe or encircle less than or equal to 50 percent of a length of the second plug. The outer wrapper may circumscribe or encircle less than or equal to 25 percent of a length of the second plug.

[0181] The outer wrapper may comprise, or consist of, cellulosic material. The outer wrapper may comprise, or consist of, organic material or plant material, such as tobacco, mint, tea and cloves.

[0182] The outer wrapper may comprise, or consist of, hygroscopic material. The hygroscopic material may comprise one or more materials selected from a list consisting of polyvinyl alcohol, silicon, or a combination thereof. For example, the outer wrapper may comprise a surface treatment of hygroscopic material. Hygroscopic material may be dispersed within the outer wrapper.

[0183] The outer wrapper may be a sheet of material. The outer wrapper may comprise, or consist of, a sheet of cellulosic material such as paper. The outer wrapper may comprise, or consist of, a sheet of organic material or a sheet of plant material. The outer wrapper may comprise, or consist of, a sheet of homogenised tobacco material.

[0184] The outer wrapper may comprise one or more elements selected from a list consisting of ceramic fibres or particles, metallic strips or particles, or a combination thereof.

[0185] The outer wrapper may have a thickness of between 10 and 200 micrometres. The outer wrapper may have a thickness of between 10 and 150 micrometres. The outer wrapper may have a thickness of between 10 and 100 micrometres. The outer wrapper may have a thickness of between 10 and 75 micrometres. The outer wrapper may have a thickness of between 10 and 50 micrometres. The outer wrapper may have a thickness of between 10 and 40 micrometres. The outer wrapper may have a thickness of between 15 and 40 micrometres. The outer wrapper may have a thickness of between 20 and 40 micrometres. Preferably, the outer wrapper may have a thickness of about 37 micrometres.

[0186] The outer wrapper may have a grammage of between 10 and 150 grams per square metre. The outer wrapper may have a grammage of between 10 and 75 grams per square metre. The outer wrapper may have a grammage of between 10 and 50 grams per square metre. The outer wrapper may have a grammage of between 20 and 40 grams per square metre. Preferably, the outer wrapper may have a grammage of about 30 grams per square metre.

[0187] The outer wrapper, or a portion of the outer wrapper, may be air permeable.

[0188] The outer wrapper, or a portion of the outer wrapper, may have an air permeability between about 10 Coresta units and about 200 Coresta units. The outer wrapper, or a portion of the outer wrapper, may have an air permeability between about 20 Coresta units and about 150 Coresta units. The outer wrapper, or a portion of the outer wrapper, may have an air permeability between about 30 Coresta units and about 100 Coresta units. The outer wrapper, or a portion of the outer wrapper, may have an air permeability between about 40 Coresta units and about 80 Coresta units.

[0189] The outer wrapper, or a portion of the outer wrapper, may have an air permeability between about 5000 Coresta units and about 12000 Coresta units. The outer wrapper, or a portion of the outer wrapper, may have an air permeability between about 7500 Coresta units and about 12000 Coresta units.

[0190] The aerosol-generating substrate plug may be positioned closer to the downstream end of the aerosol-generating article then the upstream end of the aerosol-generating article. Alternatively, the aerosol-generating substrate plug may be positioned closer to the upstream end of the aerosolgenerating article than the downstream end of the aerosol-generating article.

[0191] The thickness of the aerosol-generating article may be less than 50 percent of a length of the aerosol-generating article.

[0192] The thickness of the aerosol-generating article may be less than 50 percent of a width of the aerosol-generating article. The thickness of the aerosol-generating article may be less than 40 percent of a width of the aerosol-generating article. The thickness of the aerosol-generating article may be less than 35 percent of a width of the aerosol-generating article. The thickness of the aerosol-generating article may be less than 30 percent of a width of the aerosol-generating article. The thickness of the aerosol-generating article may be less than 25 percent of a width of the aerosol-generating article. The thickness of the aerosol-generating article may be less than 20 percent of a width of the aerosol-generating article.

[0193] The thickness of the aerosol-generating article may be constant over at least 90 percent of the width of the aerosol-generating article. The thickness of the aerosol-generating article may be constant over at least 95 percent of the width of the aerosol-generating article. The thickness of the aerosol-generating article may be constant over at least 99 percent of the width of the aerosol-generating article. As used herein, the term “constant” when referring to the thickness of the aerosol-generating article is used to mean that the thickness varies no more than ± 10 percent, preferably no more than ± 5 percent.

[0194] The aerosol-generating article may have a transverse cross-section that is substantially rectangular. The transverse cross-section of the aerosol-generating article may be substantially rectangular along at least 90 percent of the length of the aerosol-generating article. The transverse cross-section of the aerosol-generating article may be substantially rectangular along at least 95 percent of the length of the aerosol-generating article. The transverse cross-section of the aerosolgenerating article maybe substantially rectangular along substantially the entire length of the aerosol-generating article.

[0195] All interior angles of a, or any, transverse cross-section of the aerosol-generating article may be greater than or equal to 85 degrees. All interior angles of a, or any, transverse cross-section of the aerosol-generating article may be greater than or equal to 90 degrees. All interior angles of a, or any, transverse cross-section of the aerosol-generating article may be greater than or equal to 115 degrees.

[0196] All interior angles of a, or any, transverse cross-section of the aerosol-generating article may be less than or equal to 120 degrees. All interior angles of a, or any, transverse cross-section of the aerosol-generating article may be greater than or equal to 115 degrees. All interior angles of a, or any, transverse cross-section of the aerosol-generating article may be greater than or equal to 105 degrees. All interior angles of a, or any, transverse cross-section of the aerosol-generating article may be greater than or equal to 95 degrees.

[0197] All interior angles of a, or any, transverse cross-section of the aerosol-generating article may be between 85 and 120 degrees. All interior angles of a, or any, transverse cross-section of the aerosol-generating article may be between 85 and 115 degrees. All interior angles of a, or any, transverse cross-section of the aerosol-generating article may be between 85 and 105 degrees. All interior angles of a, or any, transverse cross-section of the aerosol-generating article may be between 85 and 95 degrees.

[0198] The thickness of the aerosol-generating article may be constant over at least 90 percent of the length of the aerosol-generating article. The thickness of the aerosol-generating article may be constant over at least 95 percent of the length of the aerosol-generating article. The thickness of the aerosol-generating article may be constant over at least 99 percent of the length of the aerosol-generating article. The thickness of the aerosol-generating article may be constant over the entire length of the aerosol-generating article.

[0199] The aerosol-generating article may have a longitudinal cross-section that is substantially rectangular.

[0200] The aerosol-generating article may have a rectangular prism shape. The aerosolgenerating article may have a cubic shape. The aerosol-generating article may have a cuboid shape. The aerosol-generating article may have a rectangular cuboid shape.

[0201] The aerosol-generating article may have an air-flow path defined through the aerosolgenerating article between a upstream end and the downstream end of the aerosol-generating article. The aerosol-generating article may have an air flow path extending through the aerosolgenerating article. The aerosol-generating article may have an air-flow path defined through the aerosol-generating article in an x / y plane from one side of the aerosol-generating article to the other side of the aerosol-generating article.

[0202] The aerosol-generating article may have a resistance to draw (RTD) of less than 20 millimetre H2O, for example less than 10 millimetre H2O, in the direction of the airflow path. Preferably, the aerosol-generating article has a RTD of less than 20 millimetre H2O, for example less than 10 millimetre H2O, in at least one direction in an x / y plane of the aerosol-generating article.

[0203] The aerosol-generating article may have a length (for example, an x-dimension) of between 10 millimetres and 100 millimetres, or between 10 millimetres and 50 millimetres, for example between 12 millimetres and 30 millimetres, for example between 14 millimetres and 26 millimetres, for example between 16 millimetres and 24 millimetres, for example between 18 millimetres and 22 millimetres, for example about 18 millimetres, or about 19 millimetres, or about 20 millimetres, or about 21 millimetres, or about 22 millimetres.

[0204] The aerosol-generating article may have a width (for example, a y-dimension) of between 5 millimetres and 20 millimetres, for example between 8 millimetres and 18 millimetres, for example between 10 millimetres and 16 millimetres, for example between 11 millimetres and 15 millimetres, for example between 12 millimetres and 14 millimetres, for example about 13 millimetres.

[0205] The aerosol-generating article may have a thickness (for example, a z-dimension) of between 1 millimetres and 10 millimetres, for example between 1.2 millimetres and 8 millimetres, for example between 1 .4 millimetres and 7 millimetres, for example between 1 .6 millimetres and 6 millimetres, for example between 1.7 millimetres and 5 millimetres, for example about 1.7 millimetres, or about 4.5 millimetres, or about 2 millimetres, or about 3 millimetres, or about 4 millimetres.

[0206] According to the present disclosure, there is provided a method of manufacturing an aerosol-generating substrate plug for a heated aerosol-generating article. The method comprising providing a continuous mass of aerosol-generating substrate. The aerosol-generating substrate comprising one or more aerosol-formers and having an aerosol-former content greater than or equal to 5 percent by weight on a dry weight basis. The method comprising dimensioning the continuous mass of aerosol-generating substrate to have a constant thickness over at least 90 percent of the width of the aerosol-generating substrate, and a thickness less than 50 percent a width of the aerosol-generating substrate. The method comprising circumscribing the continuous mass of aerosol-generating substrate with a wrapper to form a continuous aerosol-generating substrate plug. The wrapper having a grammage of between 20 grams per square metre and 200 grams per square metre. The method comprising severing the continuous aerosol-generating substrate plug into a plurality of discrete aerosol-generating substrate plugs. Each of the plurality of discrete aerosol-generating substrate plugs having a thickness and a length, the thickness being less than 50 percent of the length.

[0207] The continuous mass of aerosol-generating substrate may be any aerosol-generating substrate described herein. Preferably, the aerosol-generating substrate may comprise a shredded aerosol-generating substrate, such as tobacco cut filler. Preferably, the one or more aerosolformers comprises glycerine. Preferably, the aerosol-generating substrate comprises a binder such as guar or carboxymethyl cellulose.

[0208] The step of dimensioning the continuous mass of aerosol-generating substrate may comprise moving the continuous mass of aerosol-generating substrate through a constriction, preferably a converging constriction. The wrapper may comprise, or consist of, cellulosic material. The wrapper may be a continuous sheet of material, such as a continuous sheet of cellulosic material. The continuous sheet of material may be supplied from a bobbin.

[0209] As used herein, the term “aerosol-generating device” may refer to a device for use with an aerosol-generating article to enable the generation, or release, of an aerosol.

[0210] As used herein, the term “aerosol generating system” refers to a combination of an aerosolgenerating device and one or more aerosol-forming articles for use with the device. An aerosolgenerating system may include additional components, such as a charging unit for recharging an on-board electric power supply in an electrically operated or electric aerosol-generating device.

[0211] As used herein, the term “aerosol former” may refer to any suitable known compound or mixture of compounds that, in use, facilitates formation of an aerosol. The aerosol may be a dense and stable aerosol. The aerosol may be substantially resistant to thermal degradation at the operating temperature of the aerosol-forming substrate or aerosol-generating article.

[0212] As used herein with reference to the invention, the term “nicotine”, is used to describe nicotine, nicotine base or a nicotine salt.

[0213] As used herein with reference to the invention, the terms “proximal”, “distal”, “upstream” and “downstream” are used to describe the relative positions of components, or portions of components, of the aerosol-generating article.

[0214] As used herein, the term “longitudinal” refers to the direction corresponding to the main longitudinal axis of the aerosol-generating article, which extends between the upstream and downstream ends of the aerosol-generating article. During use, air may be drawn through the aerosol-generating article in the longitudinal direction.

[0215] As used herein, the term “sheet” denotes a laminar element having a width and length substantially greater than the thickness thereof. The width of a sheet may be greater than 10 mm, preferably greater than 20 mm or 30 mm. In certain embodiments, sheets of material for use in forming aerosol-forming substrates as described herein may have a thickness of between 10 pm and about 1000 pm, for example between 10 pm and about 300 pm.

[0216] As used herein, the term “homogenised tobacco material” encompasses any tobacco material formed by the agglomeration of particles of tobacco material. Sheets or webs of homogenised tobacco material are formed by agglomerating particulate tobacco obtained by grinding or otherwise powdering of one or both of tobacco leaf lamina and tobacco leaf stems. In addition, homogenised tobacco material may comprise a minor quantity of one or more of tobacco dust, tobacco fines, and other particulate tobacco by-products formed during the treating, handling and shipping of tobacco. The sheets of homogenised tobacco material may be produced by casting, extrusion, paper making processes or other any other suitable processes known in the art.

[0217] The term “cast leaf’ is used herein to refer to a product made by a casting process that is based on casting a slurry comprising plant particles (for example, clove particles or tobacco particles and clove particles in a mixture) and a binder (for example, guar gum) onto a supportive surface, such as a belt conveyor, drying the slurry and removing the dried sheet from the supportive surface. An example of the casting or cast leaf process is described in, for example, US-A- 5,724,998 for making cast leaf tobacco. In a cast leaf process, particulate plant materials are produced by pulverizing, grinding, or comminuting parts of the plant. The particles produced from one or more plants are mixed with a liquid component, typically water, to form a slurry. Other components in the slurry may include fibres, a binder and an aerosol former. The particulate plant materials may be agglomerated in the presence of the binder. The slurry is cast onto a supportive surface and dried into a sheet of homogenized plant material. Preferably, homogenized plant material used in articles according to the present invention may be produced by casting. Such homogenized plant material may comprise agglomerated particulate plant material.

[0218] As used herein, resistance to draw is expressed with the units of pressure “mm H2O” or “mm WG” or “mm of water gauge” and may be measured in accordance with ISO 6565:2002.

[0219] As used herein, the term “bulk density” refers to the total mass of the aerosol-generating substrate divided by the bulk volume of the aerosol-generating substrate.

[0220] As used herein, the term “packing density” refers to a ratio of the total volume of the components, such as solid and liquid components, of the aerosol-generating substrate to the bulk volume of the aerosol-generating substrate.

[0221] Below, there 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 another example, embodiment, or aspect described herein.

[0222] Example 1 . An aerosol-generating substrate plug for a heated aerosol-generating article, the aerosol-generating substrate plug comprising: an aerosol-generating substrate, the aerosol-generating substrate comprising one or more aerosol-formers and an aerosol-former content greater than or equal to 5 percent by weight on a dry weight basis; a wrapper having a grammage of between 20 grams per square metre and 200 grams per square metre, the wrapper circumscribing the aerosol-generating substrate; wherein a thickness of the aerosol-generating substrate plug is less than 50 percent of a length of the aerosol-generating substrate plug and the thickness of the aerosol-generating substrate plug is less than 50 percent of a width of the aerosol-generating substrate plug and wherein the thickness of the aerosol-generating substrate plug is constant over at least 90 percent of the width of the aerosol-generating substrate plug.

[0223] Example 2. An aerosol-generating substrate plug according to Example 1 , wherein the aerosolgenerating substrate plug comprises a substantially planar upper surface defined by a length extending in an x-direction and a width extending in a y-direction, and the aerosol-generating substrate plug comprises a substantially planar lower surface defined by a length extending in an x-direction and a width extending in a y-direction. Example 3. An aerosol-generating substrate plug according to Example 1 or 2, wherein the thickness of the aerosol-generating substrate plug is less than 40 percent of a width of the aerosolgenerating substrate plug, or the thickness of the aerosol-generating substrate plug is less than 30 percent of a width of the aerosol-generating substrate plug, or the thickness of the aerosolgenerating substrate plug is less than 20 percent of a width of the aerosol-generating substrate plug.

[0224] Example 4. An aerosol-generating substrate plug according to any preceding Example, wherein the thickness of the aerosol-generating substrate plug is constant over at least 95 percent of the width of the aerosol-generating substrate plug, or the thickness of the aerosol-generating substrate plug is constant over at least 99 percent of the width of the aerosol-generating substrate plug.

[0225] Example 5. An aerosol-generating substrate plug according to any preceding Example, wherein the aerosol-generating substrate plug has a transverse cross-section that is substantially rectangular.

[0226] Example 6. An aerosol-generating substrate plug according to any preceding Example, wherein all interior angles of a, or any, transverse cross-section of the aerosol-generating substrate plug are between 85 and 95 degrees.

[0227] Example 7. An aerosol-generating substrate plug according to any preceding Example, wherein the aerosol-generating substrate plug has a rectangular prism shape.

[0228] Example 8. An aerosol-generating substrate plug according to any preceding Example, wherein the wrapper has a grammage greater than or equal to 35 grams per square metre, or the wrapper has a grammage greater than or equal to 40 grams per square metre, or the wrapper has a grammage greater than or equal to 45 grams per square metre, or the wrapper has a grammage greater than or equal to 50 grams per square metre.

[0229] Example 9. An aerosol-generating substrate plug according to any preceding Example, wherein the wrapper has a grammage less than or equal to 120 grams per square metre, or the wrapper has a grammage less than or equal to 100 grams per square metre.

[0230] Example 10. An aerosol-generating substrate plug according to any preceding Example, wherein the wrapper has a length substantially equal to the length of the aerosol-generating substrate.

[0231] Example 11. An aerosol-generating substrate plug according to any preceding Example, wherein the wrapper has a length substantially equal to the length of the aerosol-generating substrate plug.

[0232] Example 12. An aerosol-generating substrate plug according to any preceding Example, wherein the wrapper defines or forms a substantially planar upper surface of the aerosolgenerating substrate plug, a substantially planar lower surface of the aerosol-generating substrate plug, a first side surface of the aerosol-generating substrate plug and a second side surface of the aerosol-generating substrate plug. Example 13. An aerosol-generating substrate plug according to any preceding Example, wherein the wrapper defines or forms at least 60 percent of the outer surface area of the aerosolgenerating substrate plug, or the wrapper defines or forms at least 70 percent of the outer surface area of the aerosol-generating substrate plug.

[0233] Example 14. An aerosol-generating substrate plug according to any preceding Example, wherein the wrapper forms an open-ended tube and the aerosol-generating substrate is positioned within the open-ended tube.

[0234] Example 15. An aerosol-generating substrate plug according to any preceding Example, wherein the aerosol-generating substrate is exposed at one or both of the distal end and the proximal end of the aerosol-generating substrate plug.

[0235] Example 16. An aerosol-generating substrate plug according to any preceding Example, wherein the wrapper comprises an overlapping region in which a first portion of the wrapper overlaps a second portion of the wrapper.

[0236] Example 17. An aerosol-generating substrate plug according to Example 16, wherein opposing longitudinal edges of the wrapper overlap to form the overlapping region.

[0237] Example 18. An aerosol-generating substrate plug according to Example 16 or 17, wherein the overlapping region is positioned on the upper surface of the aerosol-generating substrate plug or wherein the overlapping region is positioned on the lower surface of the aerosol-generating substrate plug.

[0238] Example 19. An aerosol-generating substrate plug according to any one of Example 16 to Example 18, wherein the overlapping region comprises a first surface of the wrapper bonded to a second surface of the wrapper.

[0239] Example 20. An aerosol-generating substrate plug according to any one of Example 16 to 19, wherein the overlapping region comprises an inner surface of the wrapper bonded to an outer surface of the wrapper.

[0240] Example 21 . An aerosol-generating substrate plug according to any one of Example 20, wherein the overlapping region comprises a lap seal.

[0241] Example 22. An aerosol-generating substrate plug according to any one of Example 16 to 19, wherein the overlapping region comprises an inner surface of the wrapper bonded to an inner surface of the wrapper.

[0242] Example 23. An aerosol-generating substrate plug according to Example 22, wherein the overlapping region comprises a fin seal.

[0243] Example 24. An aerosol-generating substrate plug according to Example 16 to 23, wherein the surfaces of the wrapper in the overlapping region are bonded with an adhesive.

[0244] Example 25. An aerosol-generating substrate plug according to Example 16 to 24, wherein the surfaces of the wrapper in the overlapping region are bonded with a strip or a line of adhesive.

[0245] Example 26. An aerosol-generating substrate plug according to Example 25, wherein the strip or the line of adhesive extends in a longitudinal direction. Example 27. An aerosol-generating substrate plug according to Example 25 or 26, wherein the strip or line of adhesive has a length of between 90 percent and 100 percent of the length of the aerosol-generating substrate plug.

[0246] Example 28. An aerosol-generating substrate plug according to any one of Example 25 to 27, wherein the strip or the line of adhesive has a length substantially equal to the length of the aerosolgenerating substrate plug.

[0247] Example 29. An aerosol-generating substrate plug according to any one of Example 25 to 28, wherein the strip or the line of adhesive extends from the distal end of the aerosol-generating substrate plug to the proximal end of the aerosol-generating substrate plug.

[0248] Example 30. An aerosol-generating substrate plug according to any preceding Example, wherein the wrapper is in physical contact with the aerosol-generating substrate.

[0249] Example 31. An aerosol-generating substrate plug according to any preceding Example, wherein an inner surface of the wrapper is in physical contact with the entire circumference of the aerosol-generating substrate.

[0250] Example 32. An aerosol-generating substrate plug according to any preceding Example, wherein the wrapper comprises one or more flavourants.

[0251] Example 33. An aerosol-generating substrate plug according to any preceding Example, wherein the wrapper comprises one or more aerosol-formers.

[0252] Example 34. An aerosol-generating substrate plug according to any preceding Example, wherein the wrapper comprises, or consist of, a sheet of cellulosic material such as paper.

[0253] Example 35. An aerosol-generating substrate plug according to any preceding Example, wherein the wrapper is a first wrapper and the aerosol-generating substrate plug comprises a second wrapper.

[0254] Example 36. An aerosol-generating substrate plug according to Example 35, wherein the first wrapper is in physical contact with the second wrapper.

[0255] Example 37. An aerosol-generating substrate plug according to Example 35 or 36, wherein the second wrapper comprises, or consists of, a metallic material such as aluminium.

[0256] Example 38. An aerosol-generating substrate plug according to any preceding Example, wherein the aerosol-generating substrate extends substantially the entire length of the aerosolgenerating substrate plug.

[0257] Example 39. An aerosol-generating substrate plug according to any preceding Example, wherein the aerosol-generating substrate has a mass greater than or equal to 90 percent a mass of the aerosol-generating substrate plug.

[0258] Example 40. An aerosol-generating substrate plug according to any preceding Example, wherein the aerosol-generating substrate has a mass between 100 milligrams and 250 milligrams. Example 41. An aerosol-generating substrate plug according to any preceding Example, wherein the aerosol-generating substrate has a bulk density of between 0.05 milligrams per cubic millimetre and 0.5 milligrams per cubic millimetre. Example 42. An aerosol-generating substrate plug according to any preceding Example, wherein the aerosol-generating substrate has a packing density of between 0.3 and 0.9.

[0259] Example 43. An aerosol-generating substrate plug according to any preceding Example, wherein the aerosol-generating substrate comprises a homogenised plant material, such as homogenised tobacco material.

[0260] Example 44. An aerosol-generating substrate plug according to any preceding Example, wherein the aerosol-generating substrate comprises shredded aerosol-generating substrate.

[0261] Example 45. An aerosol-generating substrate plug according to any preceding Example, wherein the aerosol-generating substrate comprises a sheet of aerosol-generating material.

[0262] Example 46. An aerosol-generating article comprising the aerosol-generating substrate plug according to any preceding Example, a first plug and an outer wrapper.

[0263] Example 47. An aerosol-generating article according to Example 46, wherein the outer wrapper circumscribes the first plug and the aerosol-generating substrate plug.

[0264] Example 48. An aerosol-generating article according to Example 46 or 47, wherein the aerosolgenerating article comprises a second plug.

[0265] Example 49. An aerosol-generating article according to Example 48, wherein the outer wrapper circumscribes the first plug, the second plug and the aerosol-generating substrate plug.

[0266] Example 50. An aerosol-generating article according to Example 48 or 49, wherein the first plug, the second plug and the aerosol-generating substrate plug are axially aligned in the longitudinal direction.

[0267] Example 51 . An aerosol-generating article according to any one of Example 48 to 50, wherein the aerosol-generating substrate plug is positioned between the first plug and the second plug.

[0268] Example 52. A method of manufacturing the aerosol-generating substrate plug according to any one of Example 1 to 45, the method comprising: providing a continuous mass of aerosol-generating substrate, the aerosol-generating substrate comprising one or more aerosol-formers and having an aerosol-former content greater than or equal to 5 percent by weight on a dry weight basis; dimensioning the continuous mass of aerosol-generating substrate to have a constant thickness over at least 90 percent of a width of the aerosol-generating substrate, and a thickness less than 50 percent of a width of the aerosol-generating substrate; circumscribing the continuous mass of aerosol-generating substrate with a wrapper to form a continuous aerosol-generating substrate plug, the wrapper having a grammage of between 20 grams per square metre and 200 grams per square metre; and severing the continuous aerosol-generating substrate plug into a plurality of discrete aerosol-generating substrate plugs, each of the plurality of discrete aerosol-generating substrate plugs having a thickness and a length, the thickness being less than 50 percent of the length. Example 53. Examples will now be further described with reference to the figures in which:

[0269] Figure 1 shows a perspective view of a first example of an aerosol-generating substrate plug according to the present disclosure;

[0270] Figure 2 shows a plan view of the aerosol-generating substrate plug of Figure 1 ;

[0271] Figure 3 shows a transverse cross-sectional view of a second example of an aerosolgenerating substrate plug according to the present disclosure;

[0272] Figure 4 shows a transverse cross-sectional view of a third example of an aerosolgenerating substrate plug according to the present disclosure;

[0273] Figure 5 shows an exploded view of a first example of an aerosol-generating article according to the present disclosure;

[0274] Figure 6 shows an exploded view of a second example of an aerosol-generating article according to the present disclosure;

[0275] Figure 7 shows a perspective view of the first example of an aerosol-generating article according to the present disclosure; and

[0276] Figure 8 shows a perspective view of a third example of an aerosol-generating article according to the present disclosure.

[0277] Figure 1 depicts an aerosol-generating substrate plug 10 for a heated aerosol-generating article 1. The aerosol-generating substrate plug 10 comprises an aerosol-generating substrate 20 and a wrapper 30.

[0278] The aerosol-generating substrate plug 10 comprises a substantially planar upper surface 11 defined by a length extending in an x-direction and a width extending in a y-direction. The aerosol-generating substrate plug 10 comprises a substantially planar lower surface 12 defined by a length extending in the x-direction and a width extending in the y-direction. The substantially planar upper surface 11 and the substantially planar lower surface 12 are spaced from each other by a thickness defined in a z-direction. The substantially planar upper surface 11 and the substantially planar lower surface 12 are parallel to each other.

[0279] The aerosol-generating substrate plug 10 comprises a substantially planar first side surface 13 extending from the substantially planar upper surface 11 to the substantially planar lower surface 12. The aerosol-generating substrate plug 10 comprises a substantially planar second side surface 14 extending from the substantially planar upper surface 11 to the substantially planar lower surface 12. The substantially planar first side surface 13 is positioned opposite, and is parallel to, the substantially planar second side surface 14.

[0280] The aerosol-generating substrate plug 10 has cuboid shape and the thickness of the aerosol-generating substrate plug 10 is constant over the entire width of the aerosol-generating substrate plug 10, thereby providing the aerosol-generating substrate plug 10 with a transverse cross-section (in the y / z plane) that is substantially rectangular. The aerosol-generating substrate plug 10 has a length of 26 millimetres, a width of 8 millimetres and a thickness of 3 millimetres. The wrapper 30 circumscribes the aerosol-generating substrate 20. The wrapper 30 forms the substantially planar upper surface 11 of the aerosol-generating substrate plug 10, the substantially planar lower surface 12 of the aerosol-generating substrate plug 10, the first side surface 13 of the aerosol-generating substrate plug 10, and the second side surface 14 of the aerosol-generating substrate plug 10.

[0281] The wrapper 30 is a sheet of cellulosic material having a grammage of about 40 grams per square metre and a thickness of about 40 micrometres. The wrapper 30 has a length substantially equal to a length of the aerosol-generating substrate 20. The wrapper 30 does not entirely enclose the aerosol-generating substrate 20 but, instead, the aerosol-generating substrate 20 is exposed at both the proximal end 15 and distal end 16 of the aerosol-generating substrate plug 10.

[0282] The aerosol-generating substrate 20 is in the form of tobacco cut filler and comprises an aerosol-former, namely glycerine, and has an aerosol-former content of about 5 percent by weight on a dry weight basis. The aerosol-generating substrate 20 extends from a proximal end 15 to the distal end 16 of the aerosol-generating substrate plug 10 and, thus, extends the entire length of the aerosol-generating substrate plug 10.

[0283] The aerosol-generating substrate 20 has a bulk density of about 0.24, a packing density of about 0.80, a density of about 0.3 grams per cubic centimetre, and a mass of about 144 milligrams.

[0284] Figure 2 depicts a plan of the aerosol-generating substrate plug 10 of Figure 1 , in particular the substantially planar upper surface 11 of the aerosol-generating substrate plug 10 is shown.

[0285] The wrapper 30 comprises an overlapping region 31 in which a first portion of the wrapper 30 overlaps a second portion of the wrapper 30. In more detail, opposing longitudinal edges 32 of the wrapper 30 overlap to form a lap seal. An inner surface of the wrapper 30 is bonded to an outer surface of the wrapper 30 by a line of adhesive 33, namely guar gum. The line of adhesive 33 extends in a longitudinal direction from the proximal end 15 of the aerosol-generating substrate plug 10 to the distal end 16 of the aerosol-generating substrate plug 10.

[0286] Figure 3 depicts a transverse cross-section 17 of a second example of an aerosolgenerating substrate plug 10. The aerosol-generating substrate plug 10 is similar to the aerosolgenerating substrate plug 10 of Figures 1 and 2. However, in this example, the aerosol-generating substrate 20 comprises a corrugated sheet of homogenised tobacco material comprising a plurality of parallel corrugations. The plurality of parallel corrugations form a plurality of longitudinally extending channels 21 that extend the entire length of the aerosol-generating substrate plug 10.

[0287] Figure 4 depicts a transverse cross-section 17 of a third example of an aerosol-generating substrate plug 10. In this example, the thickness of the aerosol-generating substrate plug 10 is not constant over the entire width of the aerosol-generating substrate plug 10. This is because the transverse cross-section 17 has rounded corners. However, the radius of the rounded corners is such that the thickness of the aerosol-generating substrate plug 10 is constant over at least 90 percent of the width of the aerosol-generating substrate plug 10. Furthermore, in this example, the aerosol-generating substrate 20 comprises a porous substrate that is impregnated with a liquid aerosol-generating medium.

[0288] Figure 5 depicts an exploded view of a first example of an aerosol-generating article 1 . The aerosol-generating article 1 comprises the aerosol-generating substrate plug 10 of Figure 1 , a first plug 40, a second plug 50 and an outer wrapper 60.

[0289] As seen in Figure 7, the outer wrapper 60 circumscribes the first plug 40, the second plug 50 and the aerosol-generating substrate plug 10. The aerosol-generating article 1 comprises a substantially planar upper surface 2 defined by a length extending in an x-direction and a width extending in a y-direction. The aerosol-generating article 1 comprises a substantially planar lower surface 3 defined by a length extending in the x-direction and a width extending in the y-direction. The substantially planar upper surface 2 and the substantially planar lower surface 3 are spaced from each other by a thickness defined in a z-direction. The substantially planar upper surface 2 and the substantially planar lower surface 3 are parallel to each other.

[0290] The aerosol-generating article 1 comprises a substantially planar first side surface 4 extending from the substantially planar upper surface 2 to the substantially planar lower surface 3. The aerosol-generating article 1 comprises a substantially planar second side surface 5 extending from the substantially planar upper surface 2 to the substantially planar lower surface 3. The substantially planar first side surface 4 is positioned opposite, and is parallel to, the substantially planar second side surface 5.

[0291] The aerosol-generating article 1 has cuboid shape and the thickness of the aerosolgenerating article 1 is constant over the entire width of the aerosol-generating article 1 , thereby providing the aerosol-generating article 1 with a transverse cross-section (in the y / z plane) that is substantially rectangular. The aerosol-generating article 1 has a length of 38 millimetres, a width of 8.2 millimetres and a thickness of 3.2 millimetres.

[0292] The first plug 40, the second plug 50 and the aerosol-generating substrate plug 10 are axially aligned in the longitudinal direction. The first plug 40 is positioned upstream of the aerosolgenerating substrate plug 10 and the second plug 50 is positioned downstream of the aerosolgenerating substrate plug 10, such that the aerosol-generating substrate plug 10 is positioned between the first plug 40 and the second plug 50. In more detail, the first plug 40 is positioned at an extreme upstream end of the aerosol-generating article 1 and defines an upstream end wall or distal end wall of the aerosol-generating article 1 , and the second plug 50 is positioned at an extreme downstream end of the aerosol-generating article 1 and defines a downstream end wall or a proximal end wall of the aerosol-generating article 1 .

[0293] The first plug 40 is positioned adjacent to the aerosol-generating substrate plug 10 but is spaced from the aerosol-generating substrate plug 10 by about 2 millimetres, thereby forming an empty cavity between the first plug 40 and the aerosol-generating substrate plug 10. Similarly, the second plug 50 is positioned adjacent to the aerosol-generating substrate plug 10 but is spaced from the aerosol-generating substrate plug 10 by about 2 millimetres, thereby forming another empty cavity between the second plug 50 and the aerosol-generating substrate plug 10. However, in other examples, one or both the first plug 40 and the second plug 50 may abut the aerosolgenerating substrate plug 10.

[0294] The first plug 40 is made entirely of cellulosic material and comprises an aperture 41 defined through the length of the first plug 40. The first plug 40 has a length of about 4 millimetres. The first plug 40 has a width equal to the width of the aerosol-generating substrate plug 10, and a thickness equal to the thickness of the aerosol-generating substrate plug 10.

[0295] The second plug 50 is made entirely of cellulosic material and comprises an aperture 51 defined through the length of the second plug 50. The second plug 50 has a length of about 4 millimetres. The second plug 50 has a width equal to the width of the aerosol-generating substrate plug 50, and a thickness equal to the thickness of the aerosol-generating substrate plug 10.

[0296] The first plug 40 and the second plug 50 are substantially free of any aerosol-generating compounds.

[0297] The outer wrapper 60 is a sheet of cellulosic material having a thickness of about 100 micrometres. The outer wrapper 60 has a length equal to the length of the aerosol-generating article 1 and circumscribes the entire length of the aerosol-generating article 1.

[0298] Figure 6 depicts an exploded view of a second example of an aerosol-generating article 1 . The aerosol-generating article 1 is similar to the aerosol-generating article 1 of Figure 5 except for the construction of the first plug 40 and the second plug 50. In this example, the first plug 40 and the second plug 50 comprise a gathered sheet of cellulosic material 42, 52 forming a plurality of longitudinally extending channels 43, 53. The plurality of longitudinally extending channels 43, 53 extend from an upstream end of the plugs to a downstream end of the plugs. The first plug 40 and the second plug 50 also comprise a perimeter wall within which each gathered sheet of cellulosic material 42, 52 is positioned.

[0299] Figure 7 depicts the aerosol-generating article 1 of Figure 5.

[0300] Figure 8 depicts a third example of an aerosol-generating article 1 . The aerosol-generating article 1 is similar to the aerosol-generating article 1 of Figure 5. However, in this example, the first plug 40 has a length of about 7 millimetres and forms a curved distal end surface of the aerosolgenerating article 1. The outer wrapper 60 also only circumscribes a downstream portion the first plug 40, in particular the outer wrapper 60 only circumscribes 4 millimetres of the length of the first plug 40. Similarly, the second plug 50 has a length of about 7 millimetres and forms a curved proximal end surface of the aerosol-generating article 1. The outer wrapper 60 also only circumscribes an upstream portion the second plug 50, in particular the outer wrapper 60 only circumscribes 4 millimetres of the length of the second plug 50.

[0301] In each of the examples of Figures 5 to 8, the first plug 40 and the second plug 50 have a similar construction. However, in other examples, each of the first plug 40 and the second plug 50 may have different constructions. For example, the first plug 40 may have the construction of Figure 5 whilst the second plug 50 may have the construction of Figure 6. As another example, the first plug 40 or the second plug 50 may be substantially air impermeable. Other combinations are possible.

[0302] For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ± 5% of A.

Claims

CLAIMS1 . An aerosol-generating substrate plug for a heated aerosol-generating article, the aerosolgenerating substrate plug comprising: an aerosol-generating substrate, the aerosol-generating substrate comprising one or more aerosol-formers and an aerosol-former content greater than or equal to 5 percent by weight on a dry weight basis; a wrapper having a grammage of between 20 grams per square metre and 200 grams per square metre, the wrapper circumscribing the aerosol-generating substrate; wherein a thickness of the aerosol-generating substrate plug is less than 50 percent of a length of the aerosol-generating substrate plug and the thickness of the aerosol-generating substrate plug is less than 50 percent of a width of the aerosol-generating substrate plug and wherein the thickness of the aerosol-generating substrate plug is constant over at least 90 percent of the width of the aerosol-generating substrate plug.

2. An aerosol-generating substrate plug according to claim 1 , wherein the aerosol-generating substrate plug has a transverse cross-section that is substantially rectangular.

3. An aerosol-generating substrate plug according to claim 1 or 2, wherein the wrapper has a grammage greater than or equal to 40 grams per square metre.

4. An aerosol-generating substrate plug according to any preceding claim, wherein the wrapper has a length substantially equal to a length of the aerosol-generating substrate.

5. An aerosol-generating substrate plug according to any preceding claim, wherein the wrapper defines or forms at least 70 percent of the outer surface area of the aerosol-generating substrate plug.

6. An aerosol-generating substrate plug according to any preceding claim, wherein the aerosol-generating substrate is exposed at one or both of a distal end and a proximal end of the aerosol-generating substrate plug.

7. An aerosol-generating substrate plug according to any preceding claim, wherein the aerosol-generating substrate plug comprises a substantially planar upper surface defined by a length extending in an x-direction and a width extending in a y-direction, and the aerosolgenerating substrate plug comprises a substantially planar lower surface defined by a length extending in an x-direction and a width extending in a y-direction.

8. An aerosol-generating substrate plug according to any preceding claim, wherein the wrapper comprises an overlapping region in which a first portion of the wrapper overlaps a second portion of the wrapper, the overlapping region comprising a first surface of the wrapper bonded to a second surface of the wrapper with a strip or a line of adhesive and wherein the strip or line of adhesive has a length of between 90 percent and 100 percent of the length of the aerosolgenerating substrate plug.

9. An aerosol-generating substrate plug according to any preceding claim, wherein the wrapper is a sheet of material, preferably a sheet of cellulosic material.

10. An aerosol-generating substrate plug according to any preceding claim, wherein the wrapper is a first wrapper and the aerosol-generating substrate plug comprises a second wrapper circumscribing the aerosol-generating substrate, the second wrapper having a higher thermal conductivity than the first wrapper.

11. An aerosol-generating substrate plug according to any preceding claim, wherein the aerosol-generating substrate has a bulk density of less than or equal to 0.5 milligrams per cubic millimetre.

12. An aerosol-generating substrate plug according to any preceding claim, wherein the aerosol-generating substrate has a packing density of between 0.5 and 0.9.

13. An aerosol-generating substrate plug according to any preceding claim, wherein the aerosol-generating substrate comprises a shredded aerosol-generating substrate, such as tobacco cut filler.

14. An aerosol-generating substrate plug according to any preceding claim, wherein the aerosol-generating substrate plug has a length greater than or equal to 100 millimetres.

15. A method of manufacturing the aerosol-generating substrate plug according to any preceding claim, the method comprising: providing a continuous mass of aerosol-generating substrate, the aerosol-generating substrate comprising one or more aerosol-formers and having an aerosol-former content greater than or equal to 5 percent by weight on a dry weight basis; dimensioning the continuous mass of aerosol-generating substrate to have a constant thickness over at least 90 percent of a width of the aerosol-generating substrate, and a thickness less than 50 percent of a width of the aerosol-generating substrate; circumscribing the continuous mass of aerosol-generating substrate with a wrapper to form a continuous aerosol-generating substrate plug, the wrapper having a grammage of between 20 grams per square metre and 200 grams per square metre; andsevering the continuous aerosol-generating substrate plug into a plurality of discrete aerosol-generating substrate plugs, each of the plurality of discrete aerosol-generating substrate plugs having a thickness and a length, the thickness being less than 50 percent of the length.

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