Aerosol-generating product with downstream section

Abstract

FIELD: aerosol generating article.SUBSTANCE: aerosol generating article comprises a rod of aerosol generating substrate and a downstream section provided downstream of the rod of aerosol generating substrate and extending to a downstream end of the aerosol generating article. The downstream section contains a hollow tubular cooling element. The downstream section has a length of at least 45 millimeters, and the ratio of the length of the downstream section to the length of the aerosol generating substrate rod is at least 1.5. The maximum outer diameter of the aerosol generating product is less than 7 millimeters.EFFECT: efficient heating of the product is ensured by rapid penetration of heat supplied to the aerosol-generating product into the entire volume of the aerosol-forming substrate, which significantly reduces the duration of the preheating stage and provides the aerosol to the consumer quickly after heating begins.14 cl, 18 dwg

Description

[0001] The present invention relates to an aerosol-generating article comprising an aerosol-generating substrate and adapted to produce an inhalable aerosol upon heating.

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

[0003] A number of prior art documents disclose aerosol-generating devices for consuming aerosol-generating articles. Such devices include, for example, electrically heated aerosol-generating devices in which the aerosol is generated by transferring heat from one or more electrical heating elements of the device,

[0004] generating an aerosol, to an aerosol-generating substrate, a heated aerosol-generating article. For example, electrically heated aerosol-generating devices have been proposed that comprise an internal heating plate that is adapted to be inserted into an aerosol-generating substrate. It is also known to use an aerosol-generating article in combination with an external heating system. For example, document WO 2020 / 115151 describes the provision of one or more heating elements located along the periphery of an aerosol-generating article when the aerosol-generating article is received in a cavity of the aerosol-generating device. As an alternative, document WO 2015 / 176898 proposed inductively heated aerosol-generating articles comprising an aerosol-generating substrate and a susceptor located within the aerosol-generating substrate.

[0005] Aerosol-generating products that heat the tobacco-containing substrate rather than combust it pose a number of challenges that don't arise with conventional smoking products. First, tobacco-containing substrates are typically heated to significantly lower temperatures than those reached by the combustion front in a conventional cigarette. This can impact the release of nicotine from the tobacco-containing substrate and the delivery of nicotine to the consumer. At the same time, if the heating temperature is increased in an attempt to enhance nicotine delivery, the generated aerosol typically needs to be cooled to a greater extent and more quickly before reaching the consumer.However, technical solutions widely used to cool the mainstream smoke in conventional smoking products, such as providing a highly efficient filtration segment at the mouth end of a cigarette, can have undesirable effects on aerosol-generating products in which the tobacco-containing substrate is heated rather than burned, as they can reduce nicotine delivery. Accordingly, it would be desirable to develop new aerosol-generating products that can consistently deliver satisfactory aerosol to the consumer.

[0006] Furthermore, there is a general need for aerosol-generating products that are easy to use and have improved usability. For example, it would be desirable to provide an aerosol-generating product that can be easily inserted into the heating cavity of an aerosol-generating device and that can be securely held within the heating cavity so as to prevent slippage during use.

[0007] It would also be desirable to provide an aerosol generating article that is adapted such that an aerosol generating substrate can be more efficiently heated when the aerosol generating article is inserted into a heating cavity of an aerosol generating device, thereby minimizing waste of tobacco material.

[0008] This disclosure relates to an aerosol-generating article. The aerosol-generating article may comprise a rod of an aerosol-generating substrate. The aerosol-generating article may comprise a downstream section provided downstream of the rod of the aerosol-generating substrate and extending to a downstream end of the aerosol-generating article. The downstream section may comprise a hollow tubular cooling element. The downstream section may have a length of at least 45 millimeters. The maximum outer diameter of the aerosol-generating article may be less than 7 millimeters.

[0009] According to the present invention, there is provided an aerosol-generating article comprising: a rod of an aerosol-generating substrate; and a downstream section provided downstream of the rod of the aerosol-generating substrate and extending to a downstream end of the aerosol-generating article, wherein the downstream section comprises a hollow tubular cooling element, and wherein the downstream section has a length of at least 45 millimeters. According to the present invention, the maximum outer diameter of the aerosol-generating article is less than 7 millimeters.

[0010] The present invention relates to a "slim" aerosol-generating article having a relatively small maximum outer diameter compared to many conventional aerosol-generating articles. The slim aerosol-generating article comprises a relatively long downstream section having a length of at least 45 millimeters, which is significantly longer than the downstream sections of prior art aerosol-generating articles.

[0011] Using a reduced-diameter aerosol-generating substrate rod, such as a tobacco rod, may be advantageous for a number of reasons. Generally, it has been observed that the smaller the diameter of the aerosol-generating substrate rod, the lower the temperature required to raise the core temperature of the aerosol-generating substrate rod, allowing sufficient quantities of vaporizable compounds to be released from the aerosol-generating substrate to form the desired amount of aerosol. At the same time, without being limited by theory, it should be understood that a smaller diameter aerosol-generating substrate rod allows for more rapid penetration of heat supplied to the aerosol-generating article into the entire volume of the aerosol-generating substrate. This can significantly reduce the duration of the preheating stage and deliver the aerosol to the consumer relatively quickly after heating begins.

[0012] However, it was found that achieving the required aerosol cooling was more difficult with an aerosol-generating device with a reduced diameter. The heat output per unit volume of the aerosol-generating substrate was higher due to the reduced diameter of the aerosol-generating substrate core. Additionally, it was found that a reduced diameter of the hollow tubular cooling element reduced cooling efficiency due to the reduced surface area and volume.

[0013] In the aerosol-generating articles of the present invention, the provision of a relatively long downstream section increases the available distance and time during which the aerosol can be cooled downstream relative to the aerosol-generating substrate rod. Thus, the aerosol can be more efficiently cooled before delivery to the consumer. For example, in preferred embodiments, the increased length of the downstream section allows for the inclusion of a relatively long hollow tubular cooling element, thereby optimizing the cooling provided in the downstream section due to the increased length and volume of the internal cavity along which the aerosol travels during use.

[0014] Providing a relatively long downstream section also allows for the aerosol-generating substrate rod to be shortened without affecting the overall length of the aerosol-generating article. It may be desirable to have a reduced-length aerosol-generating substrate rod, for example, to maximize the portion of the aerosol-generating substrate rod that is heated when the aerosol-generating article is inserted into the heating cavity of the aerosol-generating device. This, in turn, optimizes the aerosol-generating efficiency of the aerosol-generating substrate rod, so that the amount of aerosol-generating substrate can be minimized to the extent possible without affecting aerosol generation. The amount of aerosol-generating substrate that is effectively wasted because it is not used for aerosol generation can also be minimized.However, it may also be important to maintain the overall length of the aerosol-generating device so that it can continue to be used in conjunction with existing aerosol-generating devices. It is also important that existing equipment and packaging can be used without modification.

[0015] It may be further desirable to provide an aerosol generating article having a relatively long overall length, since this can improve the fixation of the aerosol generating article within the heating cavity of the aerosol generating device and can provide an improvement in the mechanical integrity of the article.

[0016] Further, the relatively long overall length of the aerosol generating article as a result of the increased length of the downstream section means that the aerosol generating articles according to the present invention more closely resemble combustible cigarettes, which may be attractive to the consumer.

[0017] The aerosol-generating article according to the present invention comprises a rod of an aerosol-generating substrate. Furthermore, the aerosol-generating article according to the present invention comprises one or more elements provided downstream of the aerosol-generating substrate. If present, the one or more elements located downstream of the rod of the aerosol-generating substrate form a downstream section of the aerosol-generating article. The aerosol-generating article according to the present invention may comprise one or more elements provided upstream of the aerosol-generating substrate. If present, the one or more elements located upstream of the rod of the aerosol-generating substrate form an upstream section of the aerosol-generating article.

[0018] The aerosol generating substrate rod is preferably surrounded by a wrapper such as ficella.

[0019] The aerosol-generating substrate rod preferably has a length of at least 10 millimeters. Preferably, the aerosol-generating substrate rod has a length of at least 15 millimeters. More preferably, the aerosol-generating substrate rod has a length of at least 17 millimeters. Even more preferably, the aerosol-generating substrate rod has a length of at least 18 millimeters. Most preferably, the aerosol-generating substrate rod has a length of at least 20 millimeters.

[0020] The aerosol-generating substrate rod preferably has a length of less than 40 millimeters. Preferably, the aerosol-generating substrate rod has a length of less than 35 millimeters. More preferably, the aerosol-generating substrate rod has a length of less than 30 millimeters.

[0021] For example, the rod of the aerosol generating substrate preferably has a length of 10 millimeters to 0 millimeters, or 10 millimeters to 35 millimeters, or 10 millimeters to 30 millimeters, or 15 millimeters to 40 millimeters, or 15 millimeters to 35 millimeters, or 15 millimeters to 30 millimeters, or 20 millimeters to 40 millimeters, or 20 millimeters to 35 millimeters, or 20 millimeters to 30 millimeters.

[0022] The aerosol generating substrate rod preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol generating article.

[0023] The "outer diameter of the aerosol-generating substrate rod" may be calculated as the average value of multiple measurements of the diameter of the aerosol-generating substrate rod taken at different locations along the length of the aerosol-generating substrate rod.

[0024] Preferably, the aerosol-generating substrate rod has an outer diameter of at least approximately 5 millimeters. More preferably, the aerosol-generating substrate rod has an outer diameter of at least 5.25 millimeters. Even more preferably, the aerosol-generating substrate rod has an outer diameter of at least 5.5 millimeters.

[0025] The aerosol-generating substrate rod preferably has an outer diameter of less than 8 millimeters. More preferably, the aerosol-generating substrate rod has an outer diameter of less than 7.5 millimeters. Even more preferably, the aerosol-generating substrate rod has an outer diameter of less than 7 millimeters.

[0026] In general, it has been observed that the smaller the diameter of the aerosol-generating substrate rod, the lower the temperature required to raise the core temperature of the aerosol-generating substrate rod, so that sufficient quantities of vaporizable compounds are released from the aerosol-generating substrate to form the desired amount of aerosol. At the same time, without being limited by theory, it should be understood that a smaller diameter of the aerosol-generating substrate rod ensures that the heat supplied to the aerosol-generating article more quickly penetrates into the entire volume of the aerosol-generating substrate. However, when the diameter of the aerosol-generating substrate rod is too small, the volume-to-surface ratio of the aerosol-generating substrate becomes less favorable, since the amount of available aerosol-generating substrate decreases.

[0027] The diameter of the aerosol-generating substrate rod within the ranges described herein is particularly advantageous in terms of the balance between energy consumption and aerosol delivery. This advantage is particularly noticeable when an aerosol-generating article comprising an aerosol-generating substrate rod having a diameter as described herein is used in combination with an external heater located along the periphery of the aerosol-generating article. It has been observed that under such operating conditions, less thermal energy is required to achieve a sufficiently high temperature in the core of the aerosol-generating substrate rod and in the core of the article as a whole. Thus, when operating at low temperatures, the desired target temperature in the core of the aerosol-generating substrate can be achieved within a desirably reduced time frame and with lower energy consumption.

[0028] Using a smaller diameter aerosol-generating substrate rod can also advantageously reduce the overall weight of tobacco material required in the aerosol-generating product while maintaining the ability to produce the required aerosol levels. Consequently, tobacco waste can be reduced.

[0029] The ratio between the length of the aerosol-generating substrate rod and the total length of the aerosol-generating article is preferably at least 0.20. Preferably, the ratio between the length of the aerosol-generating substrate rod and the total length of the aerosol-generating article is at least 0.25. More preferably, the ratio between the length of the aerosol-generating substrate rod and the total length of the aerosol-generating article is at least 0.30.

[0030] The ratio between the length of the aerosol-generating substrate rod and the total length of the aerosol-generating article is preferably less than 0.50. Preferably, the ratio between the length of the aerosol-generating substrate rod and the total length of the aerosol-generating article is less than 0.45. More preferably, the ratio between the length of the aerosol-generating substrate rod and the total length of the aerosol-generating article is less than 0.40.

[0031] In some embodiments, the ratio between the length of the rod of the aerosol-generating substrate and the total length of the aerosol-generating article is from 0.20 to 0.50, preferably from 0.20 to 0.45, more preferably from 0.20 to 0.40. In other embodiments, the ratio between the length of the rod of the aerosol-generating substrate and the total length of the aerosol-generating article is from 0.25 to 0.50, preferably from 0.25 to 0.45, more preferably from 0.25 to 0.40. In further embodiments, the ratio between the length of the rod of the aerosol-generating substrate and the total length of the aerosol-generating article is from 0.30 to 0.50, preferably from 0.30 to 0.45, more preferably from 0.30 to 0.40.In still further embodiments, the ratio between the length of the aerosol-generating substrate rod and the total length of the aerosol-generating article is from 0.30 to 0.50, preferably from 0.30 to 0.45, more preferably from 0.30 to 0.40.

[0032] Preferably, the aerosol-generating substrate rod has a substantially constant cross-section along its length. Particularly preferably, the aerosol-generating substrate rod has a substantially circular cross-section.

[0033] The density of the aerosol-generating substrate is preferably at least 100 mg per cubic centimeter. More preferably, the density of the aerosol-generating substrate is at least 125 mg per cubic centimeter. Even more preferably, the density of the aerosol-generating substrate is at least 150 mg per cubic centimeter. Even more preferably, the density of the aerosol-generating substrate is at least 200 mg per cubic centimeter.

[0034] The density of the aerosol-generating substrate is preferably less than 1000 mg per cubic centimeter. More preferably, the density of the aerosol-generating substrate is less than 800 mg per cubic centimeter. More preferably, the density of the aerosol-generating substrate is less than 700 mg per cubic centimeter. More preferably, the density of the aerosol-generating substrate is less than 600 mg per cubic centimeter. More preferably, the density of the aerosol-generating substrate is less than 500 mg per cubic centimeter. More preferably, the density of the aerosol-generating substrate is less than 400 mg per cubic centimeter. More preferably, the density of the aerosol-generating substrate is less than 350 mg per cubic centimeter. More preferably, the density of the aerosol-generating substrate is less than 345 mg per cubic centimeter.More preferably, the density of the aerosol-generating substrate is less than 325 mg per cubic centimeter. Even more preferably, the density of the aerosol-generating substrate is less than 300 mg per cubic centimeter. Even more preferably, the density of the aerosol-generating substrate is less than 290 mg per cubic centimeter. Even more preferably, the density of the aerosol-generating substrate is less than 280 mg per cubic centimeter.

[0035] For example, the density of the aerosol-generating substrate is preferably from 100 mg per cubic centimeter to 1000 mg per cubic centimeter, preferably from 100 mg per cubic centimeter to 800 mg per cubic centimeter, more preferably from 100 mg per cubic centimeter to 700 mg per cubic centimeter, more preferably from 100 mg per cubic centimeter to 600 mg per cubic centimeter, more preferably from 100 mg per cubic centimeter to 500 mg per cubic centimeter, even more preferably from 100 mg per cubic centimeter to 400 mg per cubic centimeter.

[0036] For example, the density of the aerosol-generating substrate is preferably from 100 mg per cubic centimeter to 350 mg per cubic centimeter, preferably from 100 mg per cubic centimeter to 345 mg per cubic centimeter, more preferably from 125 mg per cubic centimeter to 325 mg per cubic centimeter, more preferably from 150 mg per cubic centimeter to 300 mg per cubic centimeter, more preferably from 150 mg per cubic centimeter to 290 mg per cubic centimeter, even more preferably from 200 mg per cubic centimeter to 280 mg per cubic centimeter.

[0037] The aerosol-generating substrate may contain tobacco material. The rod of the aerosol-generating substrate may contain tobacco material. The tobacco material may contain shredded tobacco material. The shredded tobacco material may be in the form of cut filler or shredded tobacco filler.

[0038] Preferably, the tobacco material has a bulk density of at least 100 mg per cubic centimeter. More preferably, the tobacco material has a bulk density of at least 125 mg per cubic centimeter. More preferably, the tobacco material has a bulk density of at least 150 mg per cubic centimeter. Even more preferably, the tobacco material has a bulk density of at least 200 mg per cubic centimeter. Preferably, the tobacco material has a bulk density of less than 345 mg per cubic centimeter. More preferably, the tobacco material has a bulk density of less than 325 mg per cubic centimeter. Even more preferably, the tobacco material has a bulk density of less than 300 mg per cubic centimeter.

[0039] Even more preferably, the tobacco material has a bulk density of less than 290 mg per cubic centimeter. Even more preferably, the tobacco material has a bulk density of less than 280 mg per cubic centimeter. For example, the tobacco material may have a bulk density of from 100 mg per cubic centimeter to 350 mg per cubic centimeter, preferably from 100 mg per cubic centimeter to 345 mg per cubic centimeter, more preferably from 125 mg per cubic centimeter to 325 mg per cubic centimeter, more preferably from 150 mg per cubic centimeter to 300 mg per cubic centimeter, more preferably from 150 mg per cubic centimeter to 290 mg per cubic centimeter, even more preferably from 200 mg per cubic centimeter to 280 mg per cubic centimeter.

[0040] The term "density" used in this document with respect to an aerosol-generating substrate refers to the bulk density of the aerosol-generating substrate. This can be calculated by measuring the total weight of the aerosol-generating substrate and dividing it by the volume of the aerosol-generating substrate rod (excluding any wrapper).

[0041] The bulk density of the tobacco material in the aerosol-generating substrate can be calculated by dividing the sum of the mass of the tobacco material in the rod of the aerosol-generating substrate by the volume of the aerosol-generating substrate (excluding any wrapper). The mass of the tobacco material in the aerosol-generating substrate can be determined by removing the tobacco material from the aerosol-generating substrate and weighing the tobacco material. The bulk density of the tobacco material in the aerosol-generating substrate can be determined after conditioning the aerosol-generating substrate in accordance with ISO 3402:1999.

[0042] The aerosol-generating substrate may contain shredded tobacco material. The rod of the aerosol-generating substrate may contain shredded tobacco material. The shredded tobacco material may be in the form of cut filler or shredded tobacco filler. The density of such aerosol-generating substrate or shredded tobacco material may be as described below.

[0043] In certain preferred embodiments, the aerosol-generating substrate rod comprises shredded tobacco material, such as tobacco cut filler, having a density of less than 350 mg per cubic centimeter, preferably less than 345 mg per cubic centimeter, preferably less than 325 mg per cubic centimeter, more preferably less than 300 mg per cubic centimeter, more preferably less than 290 mg per cubic centimeter, more preferably less than 280 mg per cubic centimeter. Preferably, the aerosol-generating substrate rod comprises shredded tobacco material having a bulk density of at least 100 mg per cubic centimeter. More preferably, the aerosol-generating substrate rod comprises shredded tobacco material having a bulk density of at least 125 mg per cubic centimeter.More preferably, the aerosol-generating substrate rod comprises shredded tobacco material having a bulk density of at least 150 mg per cubic centimeter. Even more preferably, the aerosol-generating substrate rod comprises shredded tobacco material having a bulk density of at least 200 mg per cubic centimeter.For example, the aerosol-generating substrate rod may comprise shredded tobacco material having a density of from 100 mg per cubic centimeter to 350 mg per cubic centimeter, preferably from 100 mg per cubic centimeter to 345 mg per cubic centimeter, preferably from 125 mg per cubic centimeter to 325 mg per cubic centimeter, more preferably from 150 mg per cubic centimeter to 300 mg per cubic centimeter, more preferably from 150 mg per cubic centimeter to 290 mg per cubic centimeter, even more preferably from 200 mg per cubic centimeter to 280 mg per cubic centimeter.

[0044] The RTD of the aerosol-generating substrate rod is preferably less than about 10 millimeters of water column. More preferably, the RTD of the aerosol-generating substrate rod is less than 9 millimeters of water column. Even more preferably, the RTD of the aerosol-generating substrate rod is less than 8 millimeters of water column.

[0045] RTD aerosol generating substrate rod,

[0046] is preferably at least 4 millimeters of water column. More preferably, the RTD of the aerosol-generating substrate rod is at least 5 millimeters of water column. Even more preferably, the RTD of the aerosol-generating substrate rod is at least 6 millimeters of water column.

[0047] In some embodiments, the RTD of the aerosol-generating substrate rod is from 4 millimeters of water to 10 millimeters of water, preferably from 5 millimeters of water to 10 millimeters of water, preferably from 6 millimeters of water to 25 millimeters of water. In other embodiments, the RTD of the aerosol-generating substrate rod is from 4 millimeters of water to 20 millimeters of water, preferably from 5 millimeters of water to 18 millimeters of water, preferably from 6 millimeters of water to 16 millimeters of water. In further embodiments, the RTD of the aerosol-generating substrate rod is from 4 millimeters of water. up to 15 millimeters of water column, preferably from 5 millimeters of water column to 14 millimeters of water column, more preferably from 6 millimeters of water column to 12 millimeters of water column.

[0048] The aerosol-generating substrate may be a solid aerosol-generating substrate. The aerosol-generating substrate preferably comprises an aerosol-forming agent. The aerosol-forming agent may be any suitable known compound or mixture of compounds that, when used, facilitate the formation of a dense and stable aerosol. The aerosol-forming agent may provide the aerosol with substantial resistance to thermal degradation at temperatures typically encountered during use of the aerosol-generating article. Suitable aerosol-forming agents are, for example: polyhydric alcohols, such as, for example, triethylene glycol, 1,3-butanediol, propylene glycol and glycerol; esters of polyhydric alcohols, such as, for example, glycerol mono-, di- or triacetate; aliphatic esters of mono-, di- or polycarboxylic acids, such as, for example, dimethyl dodecanedioate and dimethyl tetradecanedioate; and combinations thereof.

[0049] Preferably, the aerosol forming agent comprises one or more of glycerin and propylene glycol. The aerosol forming agent may consist of glycerin or propylene glycol, or a combination of glycerin and propylene glycol.

[0050] Preferably, the aerosol-generating substrate contains at least 5 percent by weight of the aerosol-forming substance based on the dry weight of the aerosol-generating substrate, more preferably at least 6 percent by weight of the aerosol-forming substance based on the dry weight of the aerosol-generating substrate, at least 8 percent by weight of the aerosol-forming substance based on the dry weight of the aerosol-generating substrate.

[0051] Preferably, the aerosol-generating substrate contains less than 90 percent by weight of the aerosol-forming substance based on the dry weight of the aerosol-generating substrate, more preferably less than 80 percent by weight of the aerosol-forming substance based on the dry weight of the aerosol-generating substrate, more preferably less than 70 percent by weight of the aerosol-forming substance based on the dry weight of the aerosol-generating substrate, more preferably less than 60 percent by weight of the aerosol-forming substance based on the dry weight of the aerosol-generating substrate, more preferably less than 50 percent by weight of the aerosol-forming substance based on the dry weight of the aerosol-generating substrate, more preferably less than 40 percent by weight of the aerosol-forming substance based on the dry weight of the aerosol-generating substrate.

[0052] More preferably, the aerosol-generating substrate contains less than 30 percent by weight of the aerosol-forming substance based on the dry weight of the aerosol-generating substrate, more preferably less than 25 percent by weight of the aerosol-forming substance based on the dry weight of the aerosol-generating substrate, more preferably less than 20 percent by weight of the aerosol-forming substance based on the dry weight of the aerosol-generating substrate.

[0053] For example, the aerosol-generating substrate may contain from 5 percent to 30 percent by weight of the aerosol-forming substance based on the dry weight of the aerosol-generating substrate, more preferably from 6 percent to 25 percent by weight of the aerosol-forming substance based on the dry weight of the aerosol-generating substrate, more preferably from 10 percent to 20 percent by weight of the aerosol-forming substance based on the dry weight of the aerosol-generating substrate.

[0054] For example, the aerosol-generating substrate may preferably comprise from 5 percent to 30 percent by weight of glycerin based on the dry weight of the aerosol-generating substrate, more preferably from 6 percent to 25 percent by weight of glycerin based on the dry weight of the aerosol-generating substrate, more preferably from 10 percent to 20 percent by weight of glycerin based on the dry weight of the aerosol-generating substrate. In certain preferred embodiments of the present invention, the aerosol-generating substrate comprises shredded tobacco material. For example, the shredded tobacco material may be in the form of cut filler, as described in more detail below. Alternatively, the shredded tobacco material may be in the form of a shredded sheet of homogenized tobacco material. Suitable homogenized tobacco materials for use in the present invention are described below.

[0055] In the context of this technical description, the term "cut filler" is used to describe a mixture of ground plant material, such as tobacco plant material, including, in particular, one or more of leaf blades, processed stems and veins, homogenized plant material.

[0056] Cut filler may also contain other trimmings, filler tobacco or casing.

[0057] Preferably, the chopped filler comprises at least 25 percent of plant leaf blades, more preferably at least 50 percent of plant leaf blades, even more preferably at least 75 percent of plant leaf blades, and most preferably at least 90 percent of plant leaf blades. Preferably, the plant material is one of tobacco, mint, tea, and cloves. Most preferably, the plant material is tobacco. However, as will be described in more detail below, the present invention is equally applicable to other plant material that has the ability to release substances upon application of heat, which can subsequently form an aerosol.

[0058] Preferably, the cut filler comprises tobacco plant material comprising leaf blades of one or more of light tobacco, dark tobacco, aromatic tobacco, and filler tobacco. For the purposes of the present invention, the term "tobacco" refers to any plant belonging to the genus Nicotiana.

[0059] Light tobacco varieties are tobacco varieties with typically large, light-colored leaves. Throughout the technical description, the term "light tobacco" is used for flue-cured tobacco varieties. Examples of light tobacco varieties include Chinese flue-cured, Brazilian flue-cured, American flue-cured tobacco such as Virginia tobacco, Indian flue-cured, Tanzanian flue-cured, and other African flue-cured tobaccos. Light tobacco is characterized by a high sugar-to-nitrogen ratio. From an organoleptic perspective, light tobacco is a type of tobacco that, after curing, is associated with a spicy and rich sensation.In the context of the present invention, light tobacco varieties are tobacco varieties with a reducing sugar content of from about 2.5 percent to about 20 percent based on the dry weight of the leaf and a total ammonia content of less than about 0.12 percent based on the dry weight of the leaf. Reducing sugars include, for example, glucose or fructose. Total ammonia content includes, for example, ammonia and ammonia salts.

[0060] Dark tobacco varieties are tobacco varieties with typically large, dark-colored leaves. Throughout the technical description, the term "dark tobacco" is used for air-cured varieties of tobacco. Dark tobacco varieties may also be fermented. Tobacco varieties used primarily for chewing, snuff, cigars, and pipe blends are also included in this category. These dark tobacco varieties are typically air-cured and possibly fermented. Organoleptically, dark tobacco is a type of tobacco that, after curing, produces a sensation similar to that of dark cigars. Dark tobacco is characterized by a low sugar-to-nitrogen ratio. Examples of dark tobaccos include Malawi Burley or other African Burley, dark cured Brazilian Galpao, and sun-cured or air-cured Indonesian Kasturi.According to the present invention, dark tobacco varieties are tobacco varieties with a reducing sugar content of less than about 5 percent based on the dry weight of the leaves and a total ammonia content of no more than about 0.5 percent based on the dry weight of the leaves.

[0061] Aromatic tobacco varieties are tobacco varieties that often have small, light-colored leaves. Throughout the technical description, the term "aromatic tobacco" is used to refer to other tobacco varieties characterized by a high content of aromatic substances, such as essential oils. From an organoleptic perspective, aromatic tobacco is a type of tobacco that, after curing, is associated with a spicy and aromatic sensation. Examples of aromatic tobacco varieties include Greek Oriental, Turkish Oriental, and semi-Oriental tobaccos, but also fire-cured tobaccos and American Burley tobaccos such as Perique, Shag, American Burley, or Maryland. Filler tobacco is not a specific type of tobacco, but includes types of tobacco that are primarily used to complement other types of tobacco used in a blend and that do not impart a specific, characteristic aromatic quality to the final product.Examples of filler tobacco include stems, midribs, or petioles from other types of tobacco. A specific example is flue-cured stems from the lower petioles of Brazilian flue-cured tobacco.

[0062] The cut filler suitable for use in the present invention may generally resemble the cut filler used in conventional smoking articles. The cut width of the cut filler is preferably from 0.3 millimeters to 2.0 millimeters, more preferably from 0.5 millimeters to 1.2 millimeters, and most preferably from 0.6 millimeters to 0.9 millimeters. The cut width can play a role in the heat distribution within the rod of the aerosol-generating substrate. The cut width can also play a role in the draw resistance of the article. Furthermore, the cut width can affect the overall density of the aerosol-generating substrate as a whole.

[0063] The length of the filaments of the cut filler is somewhat random, as the filament length will depend on the overall size of the object from which the filament is cut. However, by maintaining appropriate material conditions before cutting, for example by controlling the moisture content and overall fineness of the material, longer filaments can be cut. Preferably, the filaments have a length of approximately 10 millimeters to approximately 40 millimeters before combining to form the aerosol-generating substrate rod. Obviously, if the filaments are arranged in a longitudinal extension of the aerosol-generating substrate rod, where the longitudinal extension of a section is less than 40 millimeters, the final aerosol-generating substrate rod may contain filaments that are, on average, shorter than the original filament length.Preferably, the length of the cut filler threads is such that approximately 20 to 60 percent of the threads extend along the entire length of the aerosol-generating substrate rod. This prevents the threads from easily separating from the aerosol-generating substrate rod.

[0064] In preferred embodiments, the weight of the cut filler is from 80 milligrams to 400 milligrams, preferably from 150 milligrams to 250 milligrams, more preferably from 170 milligrams to 220 milligrams. This amount of cut filler generally provides sufficient material to form an aerosol. Additionally, in light of the aforementioned diameter and size limitations, this ensures a balanced density of the aerosol-generating substrate rod between energy absorption, draw resistance, and fluid passages in the aerosol-generating substrate rod, where the aerosol-generating substrate contains plant material.

[0065] Preferably, the cut filler is impregnated with an aerosol-forming agent. Impregnation of the cut filler can be accomplished by spraying or other suitable application methods. The aerosol-forming agent can be added to the mixture during the preparation of the cut filler. For example, the aerosol-forming agent can be added to the mixture in a direct-conditioning cylinder (DCCC).

[0066] Conventional equipment may be used to add the aerosol forming agent to the cut filler. The aerosol forming agent may be any suitable known compound or mixture of compounds that, when used, facilitate the formation of a dense and stable aerosol. The aerosol forming agent may provide the aerosol with substantial resistance to thermal degradation at temperatures typically encountered during use of the aerosol-generating article. Suitable aerosol forming agents include, for example: polyhydric alcohols, such as, for example, triethylene glycol, 1,3-butanediol, propylene glycol and glycerol; esters of polyhydric alcohols, such as, for example, glycerol mono-, di- or triacetate; aliphatic esters of mono-, di- or polycarboxylic acids, such as, for example, dimethyl dodecanedioate and dimethyl tetradecanedioate; and combinations thereof.

[0067] Preferably, the aerosol forming agent comprises one or more of glycerin and propylene glycol. The aerosol forming agent may consist of glycerin or propylene glycol, or a combination of glycerin and propylene glycol.

[0068] The amount of the aerosol forming agent is preferably at least 5% by weight based on the dry weight of the cut filler, preferably 5% to 30% by weight based on the dry weight of the cut filler, more preferably the amount of the aerosol forming agent is 6% to 20% by weight based on the dry weight of the cut filler, for example, the amount of the aerosol forming agent is 8% to 15% by weight based on the dry weight of the cut filler. When the aerosol forming agent is added to the cut filler in the amounts described above, the cut filler can become relatively sticky.This primarily helps to hold the cut filler in place within the product, as the cut filler particles tend to adhere to surrounding cut filler particles, as well as to surrounding surfaces (e.g., the inner surface of the wrapper surrounding the cut filler).

[0069] In some embodiments, the amount of aerosol-forming agent has a target value of approximately 13 percent by weight based on the dry weight of the cut filler. The most effective amount of aerosol-forming agent will also depend on the cut filler, regardless of whether the cut filler contains plant leaf blades or homogenized plant material. For example, among other factors, the type of cut filler will determine the extent to which the aerosol-forming agent can facilitate the release of substances from the cut filler.

[0070] For these reasons, an aerosol-generating substrate rod containing cut filler, as described above, is capable of efficiently generating sufficient aerosol quantities at relatively low temperatures. Temperatures of 150 to 200 degrees Celsius in the heating chamber may be sufficient for such cut filler alone to generate sufficient aerosol quantities, whereas aerosol-generating devices using sheets of molded tobacco leaf typically employ temperatures of approximately 250 degrees Celsius.

[0071] An additional benefit of operating at lower temperatures is that the need for aerosol cooling is reduced. Since low temperatures are typically used, a simpler cooling function may be sufficient. This, in turn, allows for a simpler and less complex design of the aerosol-generating device.

[0072] In other preferred embodiments, the aerosol generating substrate comprises homogenized plant material, preferably homogenized tobacco material.

[0073] As used herein, the term "homogenized plant material" encompasses any plant material formed by agglomerating plant particles. For example, sheets or webs of homogenized tobacco material for aerosol-generating substrates according to the present invention can be formed by agglomerating tobacco material particles obtained by grinding, milling, or crushing the plant material and, optionally, one or more of the lamellae of a tobacco leaf and the veins of a tobacco leaf. The homogenized plant material can be obtained by casting, extrusion, papermaking, or any other suitable methods known in the art.

[0074] The homogenized plant material may be provided in any suitable form.

[0075] In some embodiments, the homogenized plant material may be in the form of one or more sheets. As used herein, the term "sheet" in relation to the present invention describes a layered element having a width and length that are substantially greater than its thickness.

[0076] The homogenized plant material may be in the form of multiple balls or granules.

[0077] The homogenized plant material may be in the form of multiple strands, strips, or pieces. For the purposes of this document, the term "strand" describes an elongated element of material whose length significantly exceeds its width and thickness. The term "strand" should be understood to encompass strips, pieces, and any other homogenized plant material of similar shape. The strands of homogenized plant material may be formed from a sheet of homogenized plant material, for example, by cutting or dividing it into pieces, or by other methods, such as extrusion.

[0078] In some embodiments, the filaments may be formed in situ within the aerosol-generating substrate as a result of separating or splitting a sheet of homogenized plant material during the formation of the aerosol-generating substrate, for example, as a result of corrugating. The filaments of homogenized plant material within the aerosol-generating substrate may be separated from one another. Alternatively, each filament of homogenized plant material within the aerosol-generating substrate may be at least partially connected to an adjacent filament or filaments along the length of the filaments. For example, adjacent filaments may be connected via one or more fibers. This may occur, for example, if the filaments were formed as a result of separating a sheet of homogenized plant material during the production of the aerosol-generating substrate, as described above.

[0079] If the homogenized plant material is in the form of one or more sheets as described above, the sheets may be produced by a casting process. Alternatively, sheets of homogenized plant material may be produced by a papermaking process.

[0080] Each of the one or more sheets described herein can individually have a thickness of from about 100 micrometers to 600 micrometers, preferably from 150 micrometers to 300 micrometers, and most preferably from 200 micrometers to 250 micrometers. The individual thickness refers to the thickness of an individual sheet, while the cumulative thickness refers to the total thickness of all sheets that make up the aerosol-generating substrate. For example, if the aerosol-generating substrate is formed from two individual sheets, then the cumulative thickness is the sum of the thicknesses of the two individual sheets or the measured thickness of the two sheets when the two sheets are stacked on top of each other in the aerosol-generating substrate.

[0081] Each of the one or more sheets as described herein may individually have a grammage of from 100 grams per square meter to 600 grams per square meter.

[0082] Each of the one or more sheets as described herein may individually have a density of from 0.3 grams per cubic centimeter to 1.3 grams per cubic centimeter, and preferably from 0.7 grams per cubic centimeter to 1.0 grams per cubic centimeter.

[0083] In embodiments of the present invention in which the aerosol-generating substrate comprises one or more sheets of homogenized plant material, the sheets are preferably in the form of one or more assembled sheets. As used herein, the term "assembled" is used to describe a sheet of homogenized plant material that is rolled, bent, or otherwise compressed or narrowed in a direction substantially transverse to the cylindrical axis of the plug or rod.

[0084] One or more sheets of homogenized plant material may be assembled transversely relative to its longitudinal axis and surrounded by a wrapper to form a continuous rod or plug.

[0085] One or more sheets of homogenized plant material may be advantageously corrugated or similarly treated. As used herein, the term "corrugated" means a sheet having a plurality of substantially parallel folds or corrugations. The one or more sheets of homogenized plant material may be embossed, blind embossed,

[0086] Perforated or otherwise deformed to provide texture on one or both sides of the sheet.

[0087] Preferably, one or more sheets of homogenized plant material can be corrugated so that they have a plurality of folds or corrugations substantially parallel to the cylindrical axis of the plug. This treatment advantageously facilitates the collection of the corrugated sheet of homogenized plant material to form the plug.

[0088] One or more sheets of homogenized plant material may be preferably assembled. It will be understood that the corrugated sheets of homogenized plant material may alternatively or additionally have a plurality of substantially parallel folds or corrugations arranged at an acute or obtuse angle to the cylindrical axis of the plug. The sheet may be corrugated to such an extent that the integrity of the sheet is disrupted at the plurality of parallel folds or corrugations, causing material separation and resulting in pieces, threads, or strips of homogenized plant material.

[0089] One or more sheets of homogenized plant material can be cut into threads, as mentioned above. In such embodiments, the aerosol-generating substrate comprises a plurality of threads of homogenized plant material. The threads can be used to form a plug. Typically, the width of such threads is approximately 5 millimeters, or approximately 4 millimeters, or approximately 3 millimeters, or approximately 2 millimeters or less. The length of the threads can be greater than approximately 5 millimeters, from approximately 5 millimeters to approximately 15 millimeters, from approximately 8 millimeters to approximately 12 millimeters, or approximately 12 millimeters. Preferably, the threads have substantially the same length relative to each other.

[0090] The homogenized plant material may contain no more than 95% by weight of plant particles on a dry weight basis. Preferably, the homogenized plant material contains no more than 90% by weight of plant particles, more preferably no more than 80% by weight of plant particles, more preferably no more than 70% by weight of plant particles, more preferably no more than 60% by weight of plant particles, more preferably no more than 50% by weight of plant particles on a dry weight basis.

[0091] For example, the homogenized plant material may contain from 2.5 percent to 95 percent by weight of plant particles, or from 5 percent to 90 percent by weight of plant particles, or from 10 percent to 80 percent by weight of plant particles, or from 15 percent to 70 percent by weight of plant particles, or from 20 percent to 60 percent by weight of plant particles, or from 30 percent to 50 percent by weight of plant particles, based on dry weight.

[0092] In certain embodiments of the present invention, the homogenized plant material is a homogenized tobacco material containing tobacco particles. Sheets of homogenized tobacco material for use in such embodiments of the present invention may have a tobacco content of at least about 40 percent by weight on a dry weight basis, more preferably at least about 50 percent by weight on a dry weight basis, more preferably at least about 70 percent by weight on a dry weight basis, and most preferably at least about 90 percent by weight on a dry weight basis.

[0093] For the purposes of the present invention, the term "tobacco particles" describes particles of any plant belonging to the genus Nicotiana. The term "tobacco particles" encompasses ground or powdered tobacco leaf lamellas, ground or powdered tobacco leaf stems, tobacco dust, tobacco fines, and other particulate tobacco by-products generated during the processing, handling, and shipping of tobacco. In a preferred embodiment, the tobacco particles are substantially all derived from tobacco leaf lamellas. In contrast, separated nicotine and nicotine salts are compounds derived from tobacco, but are not considered tobacco particles for the purposes of the present invention and are not included in the percentage of particulate plant material.

[0094] The homogenized plant material may further comprise one or more aerosol forming agents. After vaporization, the aerosol forming agent may carry other vaporized compounds released from the aerosol-generating substrate upon heating, such as nicotine and flavorings, in the aerosol. Aerosol forming agents suitable for inclusion in the homogenized plant material are known in the art and include, but are not limited to: polyhydric alcohols such as triethylene glycol, propylene glycol, 1,3-butanediol, and glycerol; 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.

[0095] The homogenized plant material may contain an aerosol-forming substance in an amount ranging from 5% to 30% by weight on a dry weight basis, such as 10% to 25% by weight on a dry weight basis, or 15% to 20% by weight on a dry weight basis. The aerosol-forming substance can act as a humectant in the homogenized plant material.

[0096] In certain embodiments of the present invention, the aerosol-generating article further comprises a current-receiving element within the rod of the aerosol-generating substrate. For example, the elongated current-receiving element may be positioned substantially longitudinally within the rod of the aerosol-generating substrate and is in thermal contact with the aerosol-generating substrate.

[0097] In the context of this document, with respect to the present invention, the term "current collector" refers to a material that can convert electromagnetic energy into heat. When placed within a fluctuating electromagnetic field, eddy currents induced in the current collector cause the current collector to heat up. Because the current collector is placed in thermal contact with an aerosol-generating substrate, the aerosol-generating substrate is heated by the current collector.

[0098] When used to describe a current collecting member, the term "elongated" means that the current collecting member has a length dimension that is greater than its width dimension or its thickness dimension, for example, twice its width dimension or its thickness dimension.

[0099] The current-collecting element is located substantially longitudinally within the rod. This means that the lengthwise dimension of the elongated current-collecting element is approximately parallel to the longitudinal direction of the rod, for example, within plus or minus 10 degrees parallel to the longitudinal direction of the rod. In preferred embodiments, the elongated current-collecting element may be positioned in a radially central position within the rod and extend along the longitudinal axis of the rod.

[0100] Preferably, the current-collecting element extends the entire distance to the downstream end of the aerosol-generating substrate rod. In some embodiments, the current-collecting element may extend the entire distance to the upstream end of the aerosol-generating substrate rod. In particularly preferred embodiments, the current-collecting element has substantially the same length as the aerosol-generating substrate rod and extends from the upstream end of the rod to the downstream end of the rod.

[0101] The current collecting element is preferably in the form of a pin, rod, strip or plate.

[0102] The current collecting element preferably has a length of 10 millimeters to 40 millimeters, such as 15 millimeters to 35 millimeters or 17 millimeters to 30 millimeters.

[0103] The current collecting element preferably has a length of 5 millimeters to 15 millimeters, such as 6 millimeters to 12 millimeters or 8 millimeters to 10 millimeters.

[0104] The current collecting element preferably has a width of 1 millimeter to 5 millimeters.

[0105] The current collecting element may generally have a thickness of 0.01 millimeters to 2 millimeters, for example, 0.5 millimeters to 2 millimeters. In some embodiments, the current collecting element preferably has a thickness of 10 micrometers to 500 micrometers, more preferably 10 micrometers to 100 micrometers.

[0106] If the current collector has a constant cross-section, such as a circular cross-section, it has a preferred width or diameter of 1 millimeter to 5 millimeters.

[0107] If the current collector is in the form of a strip or plate, the strip or plate is preferably rectangular in shape with a width of preferably 2 millimeters to 8 millimeters, more preferably 3 millimeters to 5 millimeters. As an example, a strip-plate-shaped current collector may have a width of 4 millimeters.

[0108] If the current collector is in the form of a strip or plate, the strip or plate is preferably rectangular and has a thickness of 0.03 mm to 0.15 mm, more preferably 0.05 mm to 0.09 mm. As an example, a strip-plate current collector may have a thickness of 0.07 mm.

[0109] In a preferred embodiment, the elongated current collecting element is provided in the form of a strip or plate, preferably has a rectangular shape and has a thickness of 55 micrometers to 65 micrometers.

[0110] More preferably, the elongated current collecting element has a thickness of 57 micrometers to 63 micrometers. Even more preferably, the elongated current collecting element has a thickness of 58 micrometers to 62 micrometers. In a particularly preferred embodiment, the elongated current collecting element has a thickness of 60 micrometers.

[0111] Preferably, the elongated current-collecting element has a length equal to or shorter than the length of the aerosol-generating substrate. Preferably, the elongated current-collecting element has the same length as the aerosol-generating substrate.

[0112] The current collecting element may be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from an aerosol-generating substrate. Preferred current collecting elements comprise metal or carbon.

[0113] A preferred current collector may comprise or consist of a ferromagnetic material, such as a ferromagnetic alloy, ferritic iron, ferromagnetic steel, or stainless steel. A suitable current collector may be made of or comprise aluminum. Preferred current collectors may be formed from 400 series stainless steels, such as type 410, type 420, or type 430 stainless steel. Different materials will dissipate different amounts of energy when placed within electromagnetic fields of similar frequency and field strength.

[0114] Thus, all parameters of the current collector element, such as material type, length, width, and thickness, can be adjusted to ensure the required power dissipation within a known electromagnetic field. Preferred current collector elements can be heated to temperatures exceeding 250 degrees Celsius.

[0115] Suitable current-collecting elements may comprise a non-metallic core with a metallic layer disposed on the non-metallic core, for example, with metallic tracks formed on the surface of a ceramic core. The current-collecting element may have a protective outer layer, for example, a protective ceramic layer or a protective glass layer, enclosing the current-collecting element. The current-collecting element may comprise a protective coating formed of glass, ceramic, or an inert metal, formed over the core material of the current-collecting element.

[0116] The current-collecting element is located in thermal contact with the aerosol-generating substrate. Thus, when the current-collecting element is heated, the aerosol-generating substrate is heated, and an aerosol is formed. Preferably, the current-collecting element is located in direct physical contact with the aerosol-generating substrate, for example, within the aerosol-generating substrate.

[0117] As noted above, the aerosol-generating substrate rod may be surrounded by a wrapper. The wrapper surrounding the aerosol-generating substrate rod may be a paper wrapper or a non-paper wrapper. Paper wrappers suitable for use in certain embodiments of the present invention are known in the art and include, but are not limited to, cigarette papers and filter papers. Non-paper wrappers suitable for use in certain embodiments of the present invention are known in the art and include, but are not limited to, sheets of homogenized tobacco materials.

[0118] The paper wrapper may have a grammage of at least 15 g / m 2 (grams per square meter), preferably at least 20 g / m 2 The paper wrapper may have a grammage that is less than or equal to 35 g / m 2 , preferably less than or equal to 30 g / m 2The paper wrapper can have a grammage of 15 g / m 2 up to 35 g / m 2 , preferably from 20 g / m 2 up to 30 g / m 2 In a preferred embodiment, the paper wrapper may have a grammage of 25 g / m 2 The paper wrapper may have a thickness of at least 25 micrometers, preferably at least 30 micrometers, more preferably at least 35 micrometers. The paper wrapper may have a thickness that is less than or equal to 55 micrometers, preferably less than or equal to 50 micrometers, more preferably less than or equal to 45 micrometers. The paper wrapper may have a thickness of 25 micrometers to 55 micrometers, preferably from 30 micrometers to 50 micrometers, more preferably from 35 micrometers to 45 micrometers. In a preferred embodiment, the paper wrapper may have a thickness of 40 microns.

[0119] In certain preferred embodiments, the wrapper may be formed from a laminated material comprising multiple layers. Preferably, the wrapper is formed from a multilayer sheet comprising a layer of aluminum. The use of a multilayer sheet comprising aluminum advantageously prevents combustion of the aerosol-generating substrate if the aerosol-generating substrate is intended to be ignited rather than heated.

[0120] The paper layer of the multi-layer sheet may have a grammage of at least 35 g / m 2 , preferably at least 40 g / m 2 The paper layer of a multilayer sheet may have a grammage that is less than or equal to 55 g / m 2 , preferably less than or equal to 50 g / m 2 The paper layer of a multilayer sheet can have a grammage of 35 g / m 2 up to 55 g / m 2 , preferably from 40 g / m 2 up to 50 g / m 2In a preferred embodiment, the paper layer of the multilayer sheet may have a grammage of 45 g / m 2 .

[0121] The paper layer of the multilayer sheet may have a thickness of at least 50 micrometers, preferably at least 55 micrometers, more preferably at least 60 micrometers. The paper layer of the multilayer sheet may have a thickness of less than or equal to 80 micrometers, preferably less than or equal to 75 micrometers, more preferably less than or equal to 70 micrometers.

[0122] The paper layer of the multilayer sheet may have a thickness of 50 micrometers to 80 micrometers, preferably 55 micrometers to 75 micrometers, more preferably 60 micrometers to 70 micrometers. In a preferred embodiment, the paper layer of the multilayer sheet may have a thickness of 65 micrometers.

[0123] The metal layer of the multilayer sheet may have a grammage of at least 12 g / m2 , preferably at least 15 g / m 2 The metal layer of a multilayer sheet may have a grammage that is less than or equal to 25 g / m 2 , preferably less than or equal to 20 g / m 2 The metal layer of a multilayer sheet can have a grammage of 12 g / m 2 up to 25 g / m 2 , preferably from 15 g / m 2 up to 20 g / m 2 In a preferred embodiment, the metal layer of the multilayer sheet may have a grammage of 17 g / m 2 .

[0124] The metal layer of the multilayer sheet may have a thickness of at least 2 micrometers, preferably at least 3 micrometers, more preferably at least 5 micrometers. The metal layer of the multilayer sheet may have a thickness of less than or equal to 15 micrometers, preferably less than or equal to 12 micrometers, more preferably less than or equal to 10 micrometers.

[0125] The metal layer of the multilayer sheet may have a thickness of 2 micrometers to 15 micrometers, preferably 3 micrometers to 12 micrometers, more preferably 5 micrometers to 10 micrometers. In a preferred embodiment, the metal layer of the multilayer sheet may have a thickness of 6 micrometers.

[0126] The wrapper surrounding the aerosol-generating substrate core can be a paper wrapper containing PVOH (polyvinyl alcohol) or silicone (or polysiloxane). The addition of PVOH (polyvinyl alcohol) or silicone (or polysiloxane) can improve the wrapper's grease barrier properties.

[0127] PVOH or silicone (or polysiloxane) can be applied to the paper layer as a surface coating, for example, located on the outer surface of the paper layer of the wrapper surrounding the rod of the aerosol-generating substrate. PVOH or silicone (or polysiloxane) can be located on the outer surface of the paper layer of the wrapper and form a layer thereon. PVOH or silicone (or polysiloxane) can be located on the inner surface of the paper layer of the wrapper. PVOH or silicone (or polysiloxane) can be located on the inner surface of the paper layer of the aerosol-generating article and form a layer thereon. PVOH or silicone (or polysiloxane) can be located on the inner surface and the outer surface of the paper layer of the wrapper. PVOH or silicone (or polysiloxane) can be located on the inner surface and the outer surface of the paper layer of the wrapper and form a layer thereon.

[0128] The paper wrapper containing PVOH or silicone (or polysiloxane) may have a grammage of at least 20 g / m2, preferably at least 25 g / m2, more preferably at least 30 g / m2. The paper wrapper containing PVOH or silicone (or polysiloxane) may have a grammage that is less than or equal to 50 g / m2, preferably less than or equal to 45 g / m2, more preferably less than or equal to 40 g / m2. The paper wrapper containing PVOH or silicone (or polysiloxane) may have a grammage of from 20 g / m2 to 50 g / m2, preferably from 25 g / m2 to 45 g / m2. m, more preferably from 30 g / m2 to 40 g / m2. In particularly preferred embodiments, the paper wrapper containing PVOH or silicone (or polysiloxane) may have a grammage of 35 g / m2. 2 .

[0129] The paper wrapper containing PVOH or silicone (or polysiloxane) may have a thickness of at least 25 micrometers, preferably at least 30 micrometers, more preferably at least 35 micrometers. The paper wrapper containing PVOH or silicone (or polysiloxane) may have a thickness that is less than or equal to 50 micrometers, preferably less than or equal to 45 micrometers, more preferably less than or equal to 40 micrometers. The paper wrapper containing PVOH or silicone (or polysiloxane) may have a thickness of 25 micrometers to 50 micrometers, preferably 30 micrometers to 45 micrometers, more preferably 35 micrometers to 40 micrometers. In particularly preferred embodiments, the paper wrapper comprising PVOH or silicone (or polysiloxane) may have a thickness of 37 micrometers.

[0130] The wrapper surrounding the aerosol-generating substrate core may contain a flame retardant composition comprising one or more flame retardant compounds. The term "flame retardant compounds" is used herein to describe chemical compounds that, when added or otherwise incorporated into a supporting substrate, such as paper or plastic compounds, provide varying degrees of flame retardancy to the supporting substrate. In practice, flame retardant compounds may be activated by the presence of an ignition source and adapted to prevent or slow the further development of ignition through a variety of physical and chemical mechanisms.

[0131] The flame retardant composition may typically further comprise one or more non-flammability-retarding compounds, i.e., one or more compounds, such as a solvent, an auxiliary substance, or a filler, that do not actively contribute to providing flame protection to the supporting substrate, but are used to facilitate the application of the flame retardant compound or compounds to, or into, the wrapper, or both. Some of the non-flammability-retarding compounds of the flame retardant composition, such as solvents, are volatile and may evaporate from the wrapper upon drying after the flame retardant composition is applied to, or into, the base wrapping material, or both.Thus, although such non-flammability-retarding compounds are part of the flame retardant composition, they may no longer be present, or may only be found in trace amounts, in the wrapper of the aerosol-generating article.

[0132] A number of suitable flame retardant compounds are known to those skilled in the art. In particular, several flame retardant compounds and compositions suitable for treating cellulosic materials are known and have been disclosed, and they can find use in the manufacture of wrappers for aerosol-generating articles in accordance with the present invention.

[0133] For example, the flame retardant composition may comprise a polymer and a mixed salt based on at least one mono-, di- and / or tricarboxylic acid, at least one polyphosphoric, pyrophosphoric and / or phosphoric acid and a hydroxide or salt of an alkali or alkaline earth metal, wherein the at least one mono-, di- and / or tricarboxylic acid and hydroxide or salt form a carboxylate, and at least one polyphosphoric, pyrophosphoric and / or phosphoric acid and hydroxide or salt form a phosphate. Preferably, the flame retardant composition may further comprise an alkali or alkaline earth metal carbonate. Alternatively, the flame retardant composition may comprise cellulose modified with at least one C 10- fatty acid or fatty acid with a higher number of carbon atoms, tall oil fatty acid (TOFA), phosphorylated flaxseed oil, phosphorylated downstream corn oil. Preferably, at least one C is selected 10 - a fatty acid or a fatty acid with a higher number of carbon atoms from the group consisting of capric acid, myristic acid, palmitic acid, and combinations thereof.

[0134] In a wrapper containing a flame retardant composition suitable for use in an aerosol-generating article according to the present invention, the flame retardant composition may be provided in a treated portion of the wrapper. This means that the flame retardant composition is applied to a corresponding portion of the wrapper's base material, or into it, or both. Thus, in the treated portion, the wrapper has a total basis dry weight that is greater than the basis dry weight of the base material.The treated portion of the wrapper can extend over at least 10 percent of the area of ​​the outer surface of the aerosol-generating substrate rod surrounded by the wrapper, preferably over at least 20 percent of the area of ​​the outer surface of the aerosol-generating substrate rod surrounded by the wrapper, more preferably over at least 40 percent of the area of ​​the outer surface of the aerosol-generating substrate rod, even more preferably over at least 60 percent of the area of ​​the outer surface of the aerosol-generating substrate rod. Most preferably, the treated portion of the wrapper extends over at least 80 percent of the area of ​​the outer surface of the aerosol-generating substrate rod. In particularly preferred embodiments, the treated portion of the wrapper extends over at least 90 or even 95 percent of the area of ​​the outer surface of the aerosol-generating substrate rod.Most preferably, the treated portion of the wrapper extends over substantially the entire area of ​​the outer surface of the aerosol generating substrate rod.

[0135] The wrapper containing the flame retardant composition may have a grammage of at least 20 g / m 2 , preferably at least 25 g / m 2 , more preferably at least 30 g / m 2 The wrapper containing the flame retardant composition may have a grammage that is less than or equal to 45 g / m 2 , preferably less than or equal to 40 g / m 2 , more preferably less than or equal to 35 g / m 2 The wrapper containing the flame retardant composition may have a weight of 20 g / m 2 up to 45 g / m 2 , preferably from 25 g / m 2 up to 40 g / m 2 , more preferably from 30 g / m 2 up to 35 g / m 2In some preferred embodiments, the wrapper containing the flame retardant composition may have a grammage of 33 g / m 2 .

[0136] The wrapper containing the flame retardant composition may have a thickness of at least 25 micrometers, preferably at least 30 micrometers, even more preferably 35 micrometers. The wrapper containing the flame retardant composition may have a thickness of less than or equal to 50 micrometers, preferably less than or equal to 45 micrometers, even more preferably less than or equal to 40 micrometers. In some embodiments, the wrapper containing the flame retardant composition may have a thickness of 37 micrometers.

[0137] The aerosol-generating articles according to the present disclosure may further comprise an upstream section located upstream of the aerosol-generating substrate rod. The upstream section is preferably located immediately upstream of the aerosol-generating substrate rod. The upstream section preferably extends between the upstream end of the aerosol-generating article and the aerosol-generating substrate rod. The upstream section may comprise one or more upstream elements located upstream of the aerosol-generating substrate rod. Such one or more upstream elements are described in the present disclosure.

[0138] Aerosol-generating articles according to the present invention preferably comprise an upstream element positioned upstream of and adjacent to an aerosol-generating substrate. The upstream element advantageously prevents direct physical contact with the upstream end of the aerosol-generating substrate. For example, if the aerosol-generating substrate comprises a susceptor element, the upstream element can prevent direct physical contact with the upstream end of the susceptor element. This helps prevent displacement or deformation of the susceptor element during handling or transportation of the aerosol-generating article. This, in turn, helps maintain the shape and position of the susceptor element.Additionally, having an element located upstream helps prevent any loss of substrate, which can be advantageous, for example, if the substrate contains particulate plant material.

[0139] If the aerosol-generating substrate contains shredded tobacco, such as cut filler tobacco, an upstream section or element thereof can further help prevent the loss of loose tobacco particles from the upstream end of the product. This can be particularly important when the shredded tobacco has a relatively low density, for example.

[0140] The upstream section or its upstream element may also provide an additional degree of substrate protection,

[0141] aerosol generating substrate, during storage, since they cover at least to some extent the upstream end of the aerosol generating substrate, which may otherwise be exposed.

[0142] For aerosol-generating articles intended to be inserted into a cavity in an aerosol-generating device so that the aerosol-generating substrate can be heated from the outside within the cavity, an upstream section or its upstream element can advantageously facilitate the insertion of the upstream end of the article into the cavity. Inclusion of the upstream element can further protect the end of the aerosol-generating substrate rod during insertion of the article into the cavity, minimizing the risk of damage to the substrate.

[0143] The upstream section or its upstream element may also provide an improved appearance to the upstream end of the aerosol-generating article. Furthermore, if desired, the upstream section or its upstream element may be used to provide information about the aerosol-generating article, such as information about the brand, flavor, content, or information about the aerosol-generating device with which the article is intended.

[0144] The upstream element may be a porous element in the form of a plug. Preferably, the upstream element has a porosity of at least 50 percent in the longitudinal direction of the aerosol-generating article. More preferably, the upstream element has a porosity of from 50 percent to 90 percent in the longitudinal direction. The porosity of the upstream element in the longitudinal direction is determined by the ratio of the cross-sectional area of ​​the material forming the upstream element and the internal cross-sectional area of ​​the aerosol-generating article at the position of the upstream element.

[0145] The upstream element may be made of a porous material or may contain a plurality of holes. This can be achieved, for example, by laser perforation. Preferably, the plurality of holes are uniformly distributed across the cross-section of the upstream element.

[0146] The porosity or permeability of an upstream element may be advantageously designed to provide the aerosol generating article with a particular overall resistance to draw (RTD) without substantially affecting the filtration provided by other parts of the article.

[0147] The upstream element may be formed from an air-impermeable material. In such embodiments, the aerosol-generating article may be designed such that air flows into the aerosol-generating substrate rod through suitable ventilation means provided in the wrapper.

[0148] In certain preferred embodiments of the present invention, it may be desirable to minimize the RTD of an upstream element. For example, this may be the case for articles intended to be inserted into the cavity of an aerosol-generating device such that the aerosol-generating substrate is heated externally, as described herein. For such articles, it is desirable to provide the article with as low an RTD as possible so that the majority of the consumer's RTD experience is provided by the aerosol-generating device rather than the article.

[0149] The RTD of the upstream element is preferably less than 30 millimeters of water column. More preferably, the RTD of the upstream element is less than 20 millimeters of water column. Even more preferably, the RTD of the upstream element is less than or equal to 10 millimeters of water column. Even more preferably, the RTD of the upstream element is less than or equal to 5 millimeters of water column. Even more preferably, the RTD of the upstream element is less than or equal to 2 millimeters of water column. The RTD of the upstream element may be at least 0.1 millimeters of water column, or at least 0.25 millimeters of water column, or at least 0.5 millimeters of water column.

[0150] In some embodiments, the RTD of the upstream element is from 0.1 millimeters of water to 30 millimeters of water, preferably from 0.25 millimeters of water to 30 millimeters of water, preferably from 0.5 millimeters of water to 30 millimeters of water. In other embodiments, the RTD of the upstream element is from 0.1 millimeters of water to 20 millimeters of water, preferably from 0.25 millimeters of water to 20 millimeters of water, preferably from 0.5 millimeters of water to 20 millimeters of water. In further embodiments, the RTD of the upstream element is from 0.1 millimeters of water. up to 10 millimeters of water column, preferably from 0.25 millimeters of water column to 10 millimeters of water column, more preferably from 0.5 millimeters of water column to 10 millimeters of water column.In further embodiments, the RTD of the upstream element is from 0.1 millimeters of water to 5 millimeters of water, preferably from 0.25 millimeters of water to 5 millimeters of water, more preferably from 0.5 millimeters of water to 5 millimeters of water. In further embodiments, the RTD of the upstream element is from 0.1 millimeters of water to 2 millimeters of water, preferably from 0.25 millimeters of water to 2 millimeters of water, more preferably from 0.5 millimeters of water to 2 millimeters of water.

[0151] The upstream element preferably has an RTD of less than 2 millimeters of water per millimeter of length, more preferably less than 1.5 millimeters of water per millimeter of length, more preferably less than 1 millimeter of water per millimeter of length, more preferably less than 0.5 millimeters of water per millimeter of length, more preferably less than 0.3 millimeters of water per millimeter of length, more preferably less than 0.2 millimeters of water per millimeter of length.

[0152] Preferably, the combined RTD of the upstream section or its upstream element and the aerosol generating substrate rod is less than 15 millimeters of water, more preferably less than 12 millimeters of water, more preferably less than 10 millimeters of water.

[0153] In certain preferred embodiments, the upstream element is formed from a solid cylindrical plug-shaped element having a filled cross-section. Such a plug-shaped element may be referred to as a "smooth" element. The solid plug-shaped element may be porous, as described above, but is not tubular and therefore does not provide a channel for longitudinal flow. The solid plug-shaped element preferably has a substantially uniform cross-section.

[0154] In other preferred embodiments, the upstream element is formed from a hollow tubular segment defining a longitudinal cavity providing a channel for unimpeded flow. In such embodiments, the upstream element can provide protection for the aerosol-generating substrate, as described above, while having a minimal impact on the overall resistance to draw (RTD) and filtration properties of the product.

[0155] Preferably, the diameter of the longitudinal cavity of the hollow tubular segment forming the upstream element is at least 3 millimeters, more preferably at least 3.5 millimeters, more preferably at least 4 millimeters, and more preferably at least 4.5 millimeters. Preferably, the diameter of the longitudinal cavity is maximized to minimize the RTD of the upstream section or its upstream element.

[0156] Preferably, the wall thickness of the hollow tubular segment is less than 2 millimeters, more preferably less than 1.5 millimeters, and more preferably less than 1 millimeter.

[0157] The upstream element of the upstream section may be formed from any material suitable for use in an aerosol-generating article. The upstream element may be formed, for example, from the same material as one of the other components of the aerosol-generating article, such as a downstream filter segment or a hollow tubular cooling element. Suitable materials for forming the upstream element include filter materials, ceramics, polymeric material, cellulose acetate, cardboard, zeolite, or an aerosol-generating substrate. The upstream element may comprise a cellulose acetate plug. The upstream element may comprise a hollow cellulose acetate tube or a cardboard tube.

[0158] The upstream element is preferably formed from a heat-resistant material. For example, the upstream element is preferably formed from a material that can withstand temperatures no higher than 350 degrees Celsius. This ensures that the upstream element is not adversely affected by the heating means used to heat the aerosol-generating substrate.

[0159] Preferably, the upstream section or its upstream element has an outer diameter that is approximately equal to the outer diameter of the aerosol-generating article. Preferably, the outer diameter of the upstream section or its upstream element is from 5 millimeters to 8 millimeters, more preferably from 5.25 millimeters to 7.5 millimeters, more preferably from 5.5 millimeters to 7 millimeters.

[0160] Preferably, the upstream section or upstream element has a length of at least 2 millimeters, more preferably at least 3 millimeters, more preferably at least 4 millimeters.

[0161] Preferably, the upstream section or the upstream element has a length of 2 millimeters to 10 millimeters, more preferably 3 millimeters to 8 millimeters, more preferably 2 millimeters to 6 millimeters, more preferably 3 millimeters to 6 millimeters, more preferably 4 millimeters to 8 millimeters, more preferably 4 millimeters to 6 millimeters. In a particularly preferred embodiment, the upstream section or the upstream element has a length of 5 millimeters. The length of the upstream section or the upstream element can advantageously be varied to provide the desired overall length of the aerosol-generating article.For example, if it is desired to reduce the length of one of the other components of the aerosol generating article, the length of the upstream section or the upstream element may be increased to maintain the same overall length of the article.

[0162] Additionally, the length of the upstream section or its upstream element can be used to control the position of the aerosol-generating article within the cavity of the aerosol-generating device for articles intended for external heating. This can advantageously ensure that the position of the aerosol-generating substrate within the cavity can be optimized for heating, as well as the position of any ventilation.

[0163] The upstream section is preferably surrounded by a wrapper, such as a filament. The wrapper surrounding the upstream section is preferably a rigid filament, for example, a filament with a basis weight of at least 80 grams per square meter (g / m2), or at least 100 g / m2, or at least 110 g / m2. This provides structural rigidity to the upstream section.

[0164] The upstream section is preferably connected to the aerosol generating substrate rod and optionally at least a portion of the downstream section via an outer wrapper as described herein.

[0165] As mentioned above, the aerosol-generating article according to the present invention comprises a downstream section located downstream of the aerosol-generating substrate rod. The downstream section is preferably located immediately downstream of the aerosol-generating substrate rod. The downstream section of the aerosol-generating article preferably extends between the aerosol-generating substrate rod and the downstream end of the aerosol-generating article. The downstream section may comprise one or more elements, each of which will be described in more detail within the framework of the present disclosure.

[0166] The length of the downstream section may be at least 40 millimeters. The length of the downstream section may be at least 45 millimeters. The length of the downstream section may be more than 45 millimeters. The length of the downstream section may be at least 48 millimeters. The length of the downstream section may be at least 50 millimeters.

[0167] The length of the downstream section may be less than 75 millimeters. The length of the downstream section may be equal to or less than 70 millimeters. The length of the downstream section may be equal to or less than 65 millimeters.

[0168] For example, the length of the downstream section may be from 40 millimeters to 75 millimeters, or from 45 millimeters to 75 millimeters, or from 48 millimeters to 75 millimeters, or from 50 millimeters to 75 millimeters. In other embodiments, the length of the downstream section may be from 40 millimeters to 70 millimeters, or from 45 millimeters to 70 millimeters, or from 48 millimeters to 70 millimeters, or from 50 millimeters to 70 millimeters. In other embodiments, the length of the downstream section may be from 40 millimeters to 65 millimeters, or from 45 millimeters to 65 millimeters, or from 48 millimeters to 65 millimeters, or from 50 millimeters to 65 millimeters.

[0169] Providing a relatively long downstream section ensures that an appropriate length of the aerosol-generating article protrudes from the aerosol-generating device when the article is inserted into it. This appropriate protrusion length ensures ease of insertion and removal of the article from the device, and also ensures that the upstream portions of the article are properly inserted into the device, reducing the risk of damage, especially during insertion.

[0170] The ratio between the length of the downstream section and the total length of the aerosol generating article may be less than 0.85. Preferably, the ratio between the length of the downstream section and the total length of the aerosol generating article may be less than 0.80. More preferably, the ratio between the length of the downstream section and the total length of the aerosol generating article may be less than 0.75. Even more preferably, the ratio between the length of the downstream section and the total length of the aerosol generating article may be less than 0.70.

[0171] The ratio between the length of the downstream section and the total length of the aerosol-generating article may be at least 0.50. Preferably, the ratio between the length of the downstream section and the total length of the aerosol-generating article may be at least 0.55. More preferably, the ratio between the length of the downstream section and the total length of the aerosol-generating article may be at least 0.60. Even more preferably, the ratio between the length of the downstream section and the total length of the aerosol-generating article may be at least 0.65.

[0172] In some embodiments, the ratio between the length of the downstream section and the total length of the aerosol-generating article is from 0.50 to 0.85, preferably from 0.55 to 0.85, more preferably from 0.60 to 0.85, even more preferably from 0.65 to 0.85. In other embodiments, the ratio between the length of the downstream section and the total length of the aerosol-generating article is from 0.50 to 0.80, preferably from 0.55 to 0.80, more preferably from 0.60 to 0.80, even more preferably from 0.65 to 0.80. In further embodiments, the ratio between the length of the downstream section and the total length of the aerosol generating article is from 0.50 to 0.75, preferably from 0.55 to 0.75, more preferably from 0.60 to 0.75, even more preferably from 0.65 to 0.75.In further embodiments, the ratio between the length of the downstream section and the total length of the aerosol generating article is from 0.50 to 0.70, preferably from 0.55 to 0.70, more preferably from 0.60 to 0.70, even more preferably from 0.65 to 0.70.

[0173] The ratio between the length of the downstream section and the length of the upstream section may be less than 30. Preferably, the ratio between the length of the downstream section and the length of the upstream section may be less than 20. More preferably, the ratio between the length of the downstream section and the length of the upstream section may be less than 15. Even more preferably, the ratio between the length of the downstream section and the length of the upstream section may be less than 10.

[0174] The ratio between the length of the downstream section and the length of the upstream section may be at least 4. Preferably, the ratio between the length of the downstream section and the length of the upstream section may be at least 5. More preferably, the ratio between the length of the downstream section and the length of the upstream section may be at least 6. Even more preferably, the ratio between the length of the downstream section and the length of the upstream section may be at least 7.

[0175] In some embodiments, the ratio between the length of the downstream section and the length of the upstream section is from 4 to 30, preferably from 5 to 30, more preferably from 6 to 30, even more preferably from 7 to 18. In other embodiments, the ratio between the length of the downstream section and the length of the upstream section is from 4 to 20, preferably from 5 to 20, more preferably from 6 to 20, even more preferably from 7 to 20. In further embodiments, the ratio between the length of the downstream section and the length of the upstream section is from 4 to 15, preferably from 5 to 15, more preferably from 6 to 15, even more preferably from 7 to 15.In further embodiments, the ratio between the length of the downstream section and the length of the upstream section is from 4 to 10, preferably from 5 to 10, more preferably from 6 to 10, even more preferably from 7 to 10.

[0176] The ratio between the length of the downstream section and the rod length of the aerosol-generating substrate is preferably at least 1.0. More preferably, the ratio between the length of the downstream section and the rod length of the aerosol-generating substrate is at least 1.25. More preferably, the ratio between the length of the downstream section and the rod length of the aerosol-generating substrate is at least 1.5. More preferably, the ratio between the length of the downstream section and the rod length of the aerosol-generating substrate is at least 1.75.

[0177] The ratio between the length of the downstream section and the rod length of the aerosol-generating substrate is preferably less than 3.5. Preferably, the ratio between the length of the downstream section and the rod length of the aerosol-generating substrate is less than 3.25. More preferably, the ratio between the length of the downstream section and the rod length of the aerosol-generating substrate is less than 3.0. Even more preferably, the ratio between the length of the downstream section and the rod length of the aerosol-generating substrate is less than 2.75.

[0178] In some embodiments, the ratio between the length of the downstream section and the length of the rod of the aerosol-generating substrate is from 1.0 to 3.5, preferably from 1.25 to 3.5, more preferably from 1.50 to 3.5, even more preferably from 1.75 to 3.5. In other embodiments, the ratio between the length of the downstream section and the length of the rod of the aerosol-generating substrate is from 1.0 to 3.25, preferably from 1.25 to 3.25, more preferably from 1.50 to 3.25, even more preferably from 1.75 to 3.25. In further embodiments, the ratio between the length of the downstream section and the length of the aerosol generating substrate rod is from 1.0 to 3.0, preferably from 1.25 to 3.0, more preferably from 1.50 to 3.0, even more preferably from 1.75 to 3.0.In further embodiments, the ratio between the length of the downstream section and the length of the aerosol generating substrate rod is from 1.0 to 2.75, preferably from 1.25 to 2.75, more preferably from 1.50 to 2.75, even more preferably from 1.75 to 2.75.

[0179] The downstream section of the aerosol-generating article according to the present invention preferably comprises a hollow tubular cooling element provided downstream of the aerosol-generating substrate rod. The hollow tubular cooling element can advantageously provide an aerosol cooling element for the aerosol-generating article.

[0180] A hollow tubular cooling element may be provided immediately downstream of the aerosol-generating substrate rod. In other words, the hollow tubular cooling element may be adjacent to the downstream end of the aerosol-generating substrate rod. The hollow tubular cooling element may define an upstream end of a downstream section of the aerosol-generating article. The downstream end of the aerosol-generating article may coincide with the downstream end of the downstream section. In some embodiments, the downstream section of the aerosol-generating article comprises a single hollow tubular element. In other words, the downstream section of the aerosol-generating article may comprise only one hollow tubular element.In other embodiments, the downstream section comprises two or more hollow tubular elements, as described below.

[0181] In the context of the present disclosure, the term "hollow tubular element" means a generally elongated element defining a lumen or passage for air flow along its longitudinal axis. In particular, the term "tubular" will be used hereinafter to refer to a tubular element having a substantially cylindrical cross-section and defining at least one air flow channel establishing continuous fluid communication between an upstream end of the tubular element and a downstream end of the tubular element. However, it should be understood that alternative geometries (e.g., alternative cross-sectional shapes) of the tubular element may be possible. The hollow tubular cooling element may be a stand-alone, separate element of the aerosol-generating article that has a specific length and thickness.

[0182] The internal volume defined by the hollow tubular cooling element may be at least 100 cubic millimeters. In other words, the volume of the cavity or lumen defined by the hollow tubular cooling element may be at least 100 cubic millimeters. Preferably, the internal volume defined by the hollow tubular cooling element may be at least 300 cubic millimeters. The internal volume defined by the hollow tubular cooling element may be at least 700 cubic millimeters.

[0183] The internal volume defined by the hollow tubular cooling element may be less than or equal to 1200 cubic millimeters. Preferably, the internal volume defined by the hollow tubular cooling element may be less than or equal to 1000 cubic millimeters. The internal volume defined by the hollow tubular cooling element may be less than or equal to 900 cubic millimeters.

[0184] The internal volume defined by the hollow tubular cooling element may be from 100 to 1200 cubic millimeters. Preferably, the internal volume defined by the hollow tubular cooling element may be from 300 to 1000 cubic millimeters. The internal volume defined by the hollow tubular cooling element may be from 700 to 900 cubic millimeters.

[0185] In the context of the present invention, the hollow tubular cooling element provides a channel for unrestricted flow. This means that the hollow tubular cooling element provides an insignificant resistance to draw (RTD) level. The term "insignificant RTD level" is used to describe an RTD of less than 1 millimeter of water column per 10 millimeters of the length of the hollow tubular cooling element, preferably less than 0.4 millimeters of water column per 10 millimeters of the length of the hollow tubular cooling element, more preferably less than 0.1 millimeters of water column per 10 millimeters of the length of the hollow tubular cooling element.

[0186] The RTD of the hollow tubular cooling element is preferably less than or equal to 10 millimeters of water. More preferably, the RTD of the hollow tubular cooling element is less than or equal to 5 millimeters of water. Even more preferably, the RTD of the hollow tubular cooling element is less than or equal to 2.5 millimeters of water. Even more preferably, the RTD of the hollow tubular cooling element is less than or equal to 2 millimeters of water. Even more preferably, the RTD of the hollow tubular cooling element is less than or equal to 1 millimeter of water. The RTD of the hollow tubular cooling element may be at least 0 millimeters of water, or at least 0.25 millimeters of water, or at least 0.5 millimeters of water, or at least 1 millimeter of water.

[0187] In some embodiments, the RTD of the hollow tubular cooling element is from 0 millimeters of water to 10 millimeters of water, preferably from 0.25 millimeters of water to 10 millimeters of water, preferably from 0.5 millimeters of water to 10 millimeters of water. In other embodiments, the RTD of the hollow tubular cooling element is from 0 millimeters of water to 5 millimeters of water, preferably from 0.25 millimeters of water to 5 millimeters of water, preferably from 0.5 millimeters of water to 5 millimeters of water. In other embodiments, the RTD of the hollow tubular cooling element is from 1 millimeter of water to 5 millimeters of water. In further embodiments, the RTD of the hollow tubular cooling element is from 0 millimeters of water to 2.5 millimeters of water, preferably from 0.25 millimeters of water to 2.5 millimeters of water, more preferably from 0.5 millimeters of water to 2.5 millimeters of water.In further embodiments, the RTD of the hollow tubular cooling element is from 0 millimeters of water to 2 millimeters of water, preferably from 0.25 millimeters of water to 2 millimeters of water, more preferably from 0.5 millimeters of water to 2 millimeters of water. In a particularly preferred embodiment, the RTD of the hollow tubular cooling element is 0 millimeters of water.

[0188] In the aerosol-generating articles according to the present invention, the overall RTD of the article depends substantially on the RTD of the rod and optionally on the RTDs of downstream and / or upstream elements. This is because the hollow tubular cooling element is essentially empty and, thus, has essentially only a minor impact on the overall RTD of the aerosol-generating article.

[0189] Therefore, the flow channel must be free of any components that would impede the longitudinal flow of air. Preferably, the flow channel is substantially empty, and particularly preferably, the flow channel is empty.

[0190] As will be described in more detail in this disclosure, an aerosol-generating article may comprise a ventilation zone at a location along a downstream section. In some embodiments, the aerosol-generating article may comprise a ventilation zone at a location along a hollow tubular cooling element. This or any ventilation zone may extend through the peripheral wall of the hollow tubular cooling element. Thus, fluid communication is established between the flow channel defined internally by the hollow tubular cooling element and the external environment. The ventilation zone is further described in this disclosure.

[0191] The length of the hollow tubular cooling element is preferably at least 20 millimeters. More preferably, the length of the hollow tubular cooling element is at least 30 millimeters. The length of the hollow tubular cooling element can be at least 40 millimeters. More preferably, the length of the hollow tubular cooling element is at least 45 millimeters.

[0192] Length of hollow tubular cooling element

[0193] is preferably less than 60 millimeters. More preferably, the length of the hollow tubular cooling element is less than 55 millimeters. More preferably, the length of the hollow tubular cooling element is less than 50 millimeters.

[0194] For example, the length of the hollow tubular cooling element may be from 20 millimeters to 60 millimeters, or from 30 millimeters to 60 millimeters, or from 40 millimeters to 60 millimeters, or from 45 millimeters to 60 millimeters. In other embodiments, the length of the hollow tubular cooling element may be from 20 millimeters to 55 millimeters, or from 30 millimeters to 55 millimeters, or from 40 millimeters to 55 millimeters, or from 45 millimeters to 55 millimeters. In other embodiments, the length of the hollow tubular cooling element may be from 20 millimeters to 50 millimeters, or from 30 millimeters to 50 millimeters, or from 40 millimeters to 50 millimeters, or from 45 millimeters to 50 millimeters.

[0195] A relatively long hollow tubular cooling element provides and defines a relatively long internal cavity within the aerosol-generating article and downstream of the aerosol-generating substrate rod. As discussed in this disclosure, providing an empty cavity located downstream (preferably immediately downstream) of the aerosol-generating substrate enhances the nucleation of aerosol particles generated by the substrate. Providing a relatively long cavity maximizes these nucleation benefits, thereby improving aerosol formation and cooling.

[0196] The ratio between the length of the hollow tubular cooling element and the length of the aerosol-generating substrate rod is preferably at least 1.0. More preferably, the ratio between the length of the hollow tubular cooling element and the length of the aerosol-generating substrate rod is at least 1.25. More preferably, the ratio between the length of the hollow tubular cooling element and the length of the aerosol-generating substrate rod is at least 1.5. More preferably, the ratio between the length of the hollow tubular cooling element and the length of the aerosol-generating substrate rod is at least 1.75.

[0197] The ratio between the length of the hollow tubular cooling element and the length of the aerosol-generating substrate rod is preferably less than 3.5. Preferably, the ratio between the length of the hollow tubular cooling element and the length of the aerosol-generating substrate rod is less than 3.25. More preferably, the ratio between the length of the hollow tubular cooling element and the length of the aerosol-generating substrate rod is less than 3.0. Even more preferably, the ratio between the length of the hollow tubular cooling element and the length of the aerosol-generating substrate rod is less than 2.75.

[0198] In some embodiments, the ratio between the length of the hollow tubular cooling element and the length of the rod of the aerosol-generating substrate is from 1.0 to 3.5, preferably from 1.25 to 3.5, more preferably from 1.50 to 3.5, even more preferably from 1.75 to 3.5. In other embodiments, the ratio between the length of the hollow tubular cooling element and the length of the rod of the aerosol-generating substrate is from 1.0 to 3.25, preferably from 1.25 to 3.25, more preferably from 1.50 to 3.25, even more preferably from 1.75 to 3.25. In further embodiments, the ratio between the length of the hollow tubular cooling element and the length of the aerosol generating substrate rod is from 1.0 to 3.0, preferably from 1.25 to 3.0, more preferably from 1.50 to 3.0, even more preferably from 1.75 to 3.0.In further embodiments, the ratio between the length of the hollow tubular cooling element and the length of the aerosol generating substrate rod is from 1.0 to 2.75, preferably from 1.25 to 2.75, more preferably from 1.50 to 2.75, even more preferably from 1.75 to 2.75.

[0199] The ratio between the length of the hollow tubular cooling element and the length of the downstream section may be less than 1. Preferably, the ratio between the length of the hollow tubular cooling element and the length of the downstream section may be less than 0.90. More preferably, the ratio between the length of the hollow tubular cooling element and the length of the downstream section may be less than 0.85. Even more preferably, the ratio between the length of the hollow tubular cooling element and the length of the downstream section may be less than 0.80.

[0200] The ratio between the length of the hollow tubular cooling element and the length of the downstream section may be at least 0.35. Preferably, the ratio between the length of the hollow tubular cooling element and the length of the downstream section may be at least 0.45. More preferably, the ratio between the length of the hollow tubular cooling element and the length of the downstream section may be at least 0.50. Even more preferably, the ratio between the length of the hollow tubular cooling element and the length of the downstream section may be at least 0.60.

[0201] In some embodiments, the ratio between the length of the hollow tubular cooling element and the length of the downstream section is from 0.35 to 1, preferably from 0.45 to 1, more preferably from 0.50 to 1, even more preferably from 0.60 to 1. In other embodiments, the ratio between the length of the hollow tubular cooling element and the length of the downstream section is from 0.35 to 0.90, preferably from 0.45 to 0.90, more preferably from 0.50 to 0.90, even more preferably from 0.60 to 0.90. In further embodiments, the ratio between the length of the hollow tubular cooling element and the length of the downstream section is from 0.35 to 0.85, preferably from 0.45 to 0.85, more preferably from 0.50 to 0.85, even more preferably from 0.60 to 0.85.As an example, the ratio between the length of the hollow tubular cooling element and the length of the downstream section may preferably be 0.75.

[0202] The ratio between the length of the hollow tubular cooling element and the total length of the aerosol-generating article may be less than or equal to 0.80. Preferably, the ratio between the length of the hollow tubular cooling element and the total length of the aerosol-generating article may be less than or equal to 0.75. More preferably, the ratio between the length of the hollow tubular cooling element and the total length of the aerosol-generating article may be less than or equal to 0.70. Even more preferably, the ratio between the length of the hollow tubular cooling element and the total length of the aerosol-generating article may be less than or equal to 0.65.

[0203] The ratio between the length of the hollow tubular cooling element and the total length of the aerosol-generating article may be at least 0.40. Preferably, the ratio between the length of the hollow tubular cooling element and the total length of the aerosol-generating article may be at least 0.45. More preferably, the ratio between the length of the hollow tubular cooling element and the total length of the aerosol-generating article may be at least 0.50. Even more preferably, the ratio between the length of the hollow tubular cooling element and the total length of the aerosol-generating article may be at least 0.6.

[0204] In some embodiments, the ratio between the length of the hollow tubular cooling element and the total length of the aerosol-generating article is from 0.40 to 0.80, preferably from 0.45 to 0.80, more preferably from 0.50 to 0.80, even more preferably from 0.60 to 0.80. In other embodiments, the ratio between the length of the hollow tubular cooling element and the total length of the aerosol-generating article is from 0.40 to 0.75, preferably from 0.45 to 0.75, more preferably from 0.50 to 0.75, even more preferably from 0.60 to 0.75. In further embodiments, the ratio between the length of the hollow tubular cooling element and the overall length of the aerosol generating article is from 0.40 to 0.70, preferably from 0.45 to 0.70, more preferably from 0.50 to 0.70, even more preferably from 0.60 to 0.70.In further embodiments, the ratio between the length of the hollow tubular cooling element and the overall length of the aerosol generating article is from 0.40 to 0.65, preferably from 0.45 to 0.65, more preferably from 0.50 to 0.65, even more preferably from 0.60 to 0.65.

[0205] Providing a downstream section or hollow tubular cooling element with the ratios specified above maximizes the cooling and aerosol generation benefits of a relatively long hollow tubular cooling element while providing sufficient filtration for the aerosol-generating article, which is designed to be heated rather than burned. Furthermore, providing a longer hollow tubular cooling element can advantageously reduce the effective RTD of the downstream section of the aerosol-generating article, which will be primarily determined by the RTD of the downstream filter segment.

[0206] The thickness of the peripheral wall (in other words, the wall thickness) of the hollow tubular cooling element may be at least 100 micrometers. The wall thickness of the hollow tubular cooling element may be at least 150 micrometers. The wall thickness of the hollow tubular cooling element may be at least 200 micrometers, preferably at least 250 micrometers, and even more preferably at least 500 micrometers (or 0.5 millimeters).

[0207] The wall thickness of the hollow tubular cooling element may be less than or equal to 2 millimeters, preferably less than or equal to 1.5 millimeters, and even more preferably less than or equal to 1.25 millimeters. The wall thickness of the hollow tubular cooling element may be less than or equal to 1 millimeter. The wall thickness of the hollow tubular cooling element may be less than or equal to 500 millimeters.

[0208] The wall thickness of the hollow tubular cooling element may be from 100 micrometers to 2 millimeters, preferably from 150 micrometers to 1.5 millimeters, and even more preferably from 200 micrometers to 1.25 millimeters.

[0209] The wall thickness of the hollow tubular cooling element may preferably be 250 micrometers (0.25 micrometers).

[0210] At the same time, maintaining the thickness of the peripheral wall of the hollow tubular cooling element at a relatively small thickness ensures that the total internal volume of the hollow tubular cooling element, which becomes available for the aerosol to begin the nucleation process immediately after the aerosol components leave the rod of the aerosol generating substrate, and the cross-sectional surface area of ​​the hollow tubular cooling element are effectively maximized, while at the same time ensuring that the hollow tubular cooling element has the necessary structural strength to prevent the aerosol generating article from being compressed, and to provide some support for the rod of the aerosol generating substrate, and that the RTD of the hollow tubular cooling element is minimized.It is clear that large cross-sectional surface areas of the hollow tubular cooling element are associated with a decrease in the velocity of the aerosol flow along the aerosol-generating component, which is also expected to promote aerosol nucleation. Furthermore, it seems likely that by using a relatively thin hollow tubular cooling element, it is possible to substantially prevent the diffusion of ventilation air before it contacts and mixes with the aerosol flow, which, as is clear, will also further promote nucleation. In practice, by providing more controlled, localized cooling of the jet of evaporated compounds, the effect of cooling on the formation of new aerosol particles can be enhanced.

[0211] The hollow tubular cooling element preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol-generating substrate rod and the outer diameter of the aerosol-generating article.

[0212] The hollow tubular cooling element may have an outer diameter of 5 millimeters to 10 millimeters, such as 5.5 millimeters to 9 millimeters, or 6 millimeters to 8 millimeters. In a preferred embodiment, the hollow tubular cooling element has an outer diameter of less than 7 millimeters.

[0213] The hollow tubular cooling element may have an internal diameter. Preferably, the hollow tubular cooling element may have a constant internal diameter along the length of the hollow tubular cooling element. However, the internal diameter of the hollow tubular cooling element may vary along the length of the hollow tubular cooling element.

[0214] The hollow tubular cooling element may have an inner diameter of at least 2 millimeters. For example, the hollow tubular cooling element may have an inner diameter of at least 3 millimeters, at least 4 millimeters, or at least 5 millimeters.

[0215] Providing a hollow tubular cooling element having an inner diameter as described above can advantageously ensure sufficient rigidity and strength for the hollow tubular cooling element.

[0216] The hollow tubular cooling element may have an inner diameter of no more than 10 millimeters. For example, the hollow tubular cooling element may have an inner diameter of no more than 9 millimeters, no more than 8 millimeters, or no more than 7 millimeters.

[0217] Providing a hollow tubular cooling element having an inner diameter as described above can advantageously reduce the tightening resistance of the hollow tubular cooling element.

[0218] The hollow tubular cooling element may have an inner diameter of 2 millimeters to 10 millimeters, 3 millimeters to 9 millimeters, 4 millimeters to 8 millimeters, or 5 millimeters to 7 millimeters.

[0219] The ratio between the inner diameter of the hollow tubular cooling element and the outer diameter of the hollow tubular cooling element may be at least 0.8. For example, the ratio between the inner diameter of the hollow tubular cooling element and the outer diameter of the hollow tubular cooling element may be at least 0.85, at least 0.9, or at least 0.95.

[0220] The ratio between the inner diameter of the hollow tubular cooling element and the outer diameter of the hollow tubular cooling element may be no more than 0.99. For example, the ratio between the inner diameter of the hollow tubular cooling element and the outer diameter of the hollow tubular cooling element may be no more than 0.98.

[0221] The ratio between the inner diameter of the hollow tubular cooling element and the outer diameter of the hollow tubular cooling element can be 0.97.

[0222] Providing a relatively large inner diameter can advantageously reduce the tightening resistance of the hollow tubular cooling element and improve the cooling and nucleation of aerosol particles.

[0223] The lumen or cavity of the hollow tubular cooling element may have any cross-sectional shape. The lumen of the hollow tubular cooling element may have a circular cross-sectional shape.

[0224] The hollow tubular cooling element may comprise a paper-based material. The hollow tubular cooling element may comprise at least one layer of paper. The paper may be very rigid paper. The paper may be corrugated paper, such as corrugated heat-resistant paper or corrugated parchment paper.

[0225] The hollow tubular cooling element may preferably comprise cardboard. The hollow tubular cooling element may be a cardboard tube. The hollow tubular cooling element may be formed from cardboard. Cardboard is advantageously an economical material that provides a balance between deformability to ensure easy insertion of the article into the aerosol-generating device and sufficient rigidity to ensure proper engagement of the article within the device. Consequently, the cardboard tube can provide suitable resistance to deformation or compression during use.

[0226] The hollow tubular cooling element may be a paper tube. The hollow tubular cooling element may be a tube formed from spirally wound paper. The hollow tubular cooling element may be formed from multiple layers of paper. The paper may have a basis weight of at least 50 grams per square meter, at least 60 grams per square meter, at least 70 grams per square meter, or at least 90 grams per square meter.

[0227] The hollow tubular cooling element may comprise a polymeric material. For example, the hollow tubular cooling element may comprise a polymeric film. The polymeric film may comprise a cellulose film. The hollow tubular cooling element may comprise low-density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. The hollow tube may comprise cellulose acetate tow.

[0228] If the hollow tubular cooling element contains cellulose acetate tow, the cellulose acetate tow may have a denier value per fiber of 2 to 4 and a total denier value of 25 to 40.

[0229] In some embodiments, the aerosol-generating article according to the present invention may comprise a ventilation zone at a location along a downstream section. In more detail, in those embodiments in which the downstream section comprises a hollow tubular cooling element, the ventilation zone may be provided at a location along the hollow tubular cooling element. Alternatively, in those embodiments in which the downstream section comprises a downstream hollow tubular element, as described below, the ventilation zone may be provided at a location along the downstream hollow tubular element.

[0230] Thus, the ventilated cavity is located downstream of the aerosol-generating substrate rod. This offers several potential technical advantages.

[0231] First, the inventors of the present invention discovered that a single ventilated hollow tubular cooling element provides particularly effective aerosol cooling. Thus, satisfactory aerosol cooling can be achieved even with a relatively short downstream section. This is particularly desirable, as it enables the delivery of an aerosol-generating article where the aerosol-generating substrate (and, in particular, the tobacco-containing substrate) is heated rather than burned, thereby combining satisfactory aerosol delivery with effective aerosol cooling to temperatures desired by the consumer.

[0232] Secondly, the inventors unexpectedly discovered that such rapid cooling of volatile compounds released during heating of the aerosol-generating substrate promotes improved nucleation of aerosol particles. This effect is particularly noticeable when, as will be described in more detail below, the ventilation zone is positioned at a precisely defined location along the length of the hollow tubular cooling element relative to other components of the aerosol-generating article. Indeed, the inventors discovered that the beneficial effect of enhanced nucleation can significantly counteract the potentially less desirable dilution effects caused by the introduction of ventilation air.

[0233] The distance between the ventilation zone and the upstream end of the upstream element may be at least 25 millimeters. For the purposes of this document, the term "distance between the ventilation zone and another element or part of the aerosol-generating article" refers to the distance measured in the longitudinal direction, i.e., in the direction running along or parallel to the cylindrical axis of the aerosol-generating article.

[0234] Preferably, the distance between the ventilation zone and the upstream end of the upstream element is at least 26 millimeters. More preferably, the distance between the ventilation zone and the upstream end of the upstream element is at least 27 millimeters.

[0235] The distance between the ventilation zone and the upstream end of the upstream element may be less than or equal to 34 millimeters. Preferably, the distance between the ventilation zone and the upstream end of the upstream element is less than or equal to 33 millimeters. More preferably, the distance between the ventilation zone and the upstream end of the upstream element is less than or equal to 31 millimeters.

[0236] In some embodiments, the distance between the ventilation zone and the upstream end of the upstream element is from 25 millimeters to 34 millimeters, preferably from 26 millimeters to 34 millimeters, even more preferably from 27 millimeters to 34 millimeters.

[0237] In other embodiments, the distance between the ventilation zone and the upstream end of the upstream element is from 25 millimeters to 33 millimeters, preferably from 26 millimeters to 33 millimeters, more preferably from 27 millimeters to 33 millimeters.

[0238] In further embodiments, the distance between the ventilation zone and the upstream end of the upstream element is from 25 millimeters to 31 millimeters, preferably from 26 millimeters to 31 millimeters, more preferably from 27 millimeters to 31 millimeters.

[0239] In some particularly preferred embodiments, the distance between the ventilation zone and the upstream end of the upstream element is between 28 millimeters and 30 millimeters.

[0240] It has been found that aerosol generating articles comprising a ventilation zone at a location along a hollow tubular cooling element at a distance from an upstream end of the upstream element falling within the specified ranges described above have numerous advantages.

[0241] Firstly, such articles have been observed to provide particularly satisfactory aerosol delivery to the consumer, particularly if the aerosol-generating substrate contains tobacco.

[0242] Without being limited by theory, it should be understood that the intense cooling caused by ambient air drawn into the cavity of the hollow tubular cooling element in the ventilation zone accelerates the condensation of droplets of aerosol-forming substance (e.g., glycerin) released from the aerosol-generating substrate during heating. In turn, vaporized nicotine and organic acids, similarly released from the tobacco substrate, accumulate on the newly formed droplets of aerosol-forming substance and subsequently combine to form nicotine salts. Accordingly, the overall ratio of particulate aerosol to gas phase aerosol can be improved compared to existing aerosol-generating products.

[0243] The arrangement of the ventilation zone at a distance from the upstream end of the upstream element, as described above, advantageously reduces the time for the vaporized nicotine to flow before the vaporized nicotine particles reach the aerosol-forming substance droplets. At the same time, such arrangement of the ventilation zone relative to the upstream end of the upstream element ensures sufficient time and space for nicotine to accumulate and form nicotine salts to a significant extent before the aerosol stream reaches the user's mouth.

[0244] The ventilation zone may typically comprise a plurality of perforations in the peripheral wall of the hollow tubular cooling element. Preferably, the ventilation zone comprises at least one annular row of perforations. In some embodiments, the ventilation zone may comprise two annular rows of perforations. For example, the perforations may be formed on a production line during the manufacturing process of an aerosol-generating article. Preferably, each annular row of perforations comprises from 8 to 30 perforations.

[0245] The aerosol generating article according to the present invention may have a ventilation level of at least 2 percent.

[0246] The term "ventilation level" is used throughout this description to denote the volumetric ratio between the airflow admitted into the aerosol-generating article through the ventilation zone (ventilation airflow) and the sum of the aerosol-containing airflow and the ventilation airflow. The higher the ventilation level, the greater the dilution of the aerosol flow delivered to the consumer. The aerosol-generating article preferably has a ventilation level of at least 5 percent, more preferably at least 10 percent, even more preferably at least 12 percent, or at least 15 percent.

[0247] The aerosol-generating article according to the present invention may have a ventilation level of no more than 90 percent. Preferably, the aerosol-generating article according to the present invention has a ventilation level that is less than or equal to 80 percent, more preferably less than or equal to 70 percent, even more preferably less than or equal to 60 percent, and most preferably less than or equal to 50 percent.

[0248] Thus, the aerosol-generating article according to the present invention may have a ventilation level of from 2 percent to 90 percent, preferably from 5 percent to 90 percent, more preferably from 10 percent to 90 percent, even more preferably from 15 percent to 90 percent. The aerosol-generating article according to the present invention may have a ventilation level of from 2 percent to 80 percent, preferably from 5 percent to 80 percent, more preferably from 10 percent to 80 percent, even more preferably from 15 percent to 80 percent. The aerosol-generating article according to the present invention may have a ventilation level of from 2 percent to 70 percent, preferably from 5 percent to 70 percent, more preferably from 10 percent to 70 percent, even more preferably from 15 percent to 70 percent.The aerosol-generating article according to the present invention may have a ventilation level from 2 percent to 60 percent, preferably from 5 percent to 60 percent, more preferably from 10 percent to 60 percent, even more preferably from 15 percent to 60 percent. The aerosol-generating article according to the present invention may have a ventilation level from 2 percent to 50 percent, preferably from 5 percent to 50 percent, more preferably from 10 percent to 50 percent, even more preferably from 15 percent to 50 percent. The aerosol-generating article preferably has a ventilation level that is less than or equal to 30 percent, preferably less than or equal to 25 percent, more preferably less than or equal to 20 percent, even more preferably less than or equal to 18 percent.

[0249] In some embodiments, the aerosol-generating article has a ventilation level of 10 percent to 30 percent, preferably 12 percent to 30 percent, more preferably 15 percent to 30 percent. In other embodiments, the aerosol-generating article has a ventilation level of 10 percent to 25 percent, preferably 12 percent to 25 percent, more preferably 15 percent to 25 percent. In further embodiments, the aerosol-generating article has a ventilation level of 10 percent to 20 percent, preferably 12 percent to 20 percent, more preferably 15 percent to 20 percent. In particularly preferred embodiments, the aerosol-generating article has a ventilation level of 10 percent to 18 percent, preferably 12 percent to 18 percent, more preferably 15 percent to 18 percent.

[0250] Without being limited by theory, the present inventors have found that the temperature difference caused by introducing cooler outside air into the hollow tubular cooling element through the ventilation zone can have an advantageous effect on the nucleation and growth of aerosol particles.

[0251] The formation of an aerosol from a gaseous mixture containing various chemical compounds depends on the subtle interactions of nucleation, evaporation, condensation, and droplet coalescence, while simultaneously accounting for changes in concentration, temperature, and vapor velocity fields. The so-called classical nucleation theory is based on the assumption that the fraction of molecules in the gas phase is large enough to remain cohesive for a long time with sufficient probability (e.g., 0.5 in 1). These molecules represent a kind of critical threshold molecular clusters among transient molecular aggregates, meaning that, on average, smaller molecular clusters are more likely to disintegrate quickly into the gas phase, while larger clusters are, on average, more likely to grow.Such a critical cluster is identified as the key nucleation core from which droplet growth is expected due to the condensation of molecules from the vapor.

[0252] It is assumed that newly formed primary droplets begin with a certain initial diameter and can then grow by several orders of magnitude. This process is simplified and can be accelerated by rapid cooling of the surrounding vapor, which causes condensation. In this regard, it should be remembered that evaporation and condensation are two sides of the same mechanism: mass transfer between gas and liquid. While evaporation refers to the net mass transfer from liquid droplets to the gas phase, condensation is the net mass transfer from the gas phase to the droplet phase. Evaporation (or condensation) will cause a decrease in droplet volume (or growth) but will not change the number of droplets.

[0253] In this scenario, which may be further complicated by droplet coalescence, temperature and cooling rate may play a significant role in determining the system's response. In general, different cooling rates may result in significantly different temporal behavior regarding liquid phase (droplet) formation, as the nucleation process is typically nonlinear. Without being limited by theory, it is hypothesized that cooling may cause a rapid decrease in droplet number concentration, followed by a strong, short-term increase in droplet growth (nucleation burst). This nucleation burst may be more significant at lower temperatures. Furthermore, it may be that higher cooling rates may promote an earlier onset of nucleation. Conversely, a decrease in the cooling rate may have a beneficial effect on the final size attained by aerosol droplets.

[0254] Consequently, the rapid cooling caused by introducing outside air into the hollow tubular cooling element through the ventilation zone can be beneficially utilized to promote the nucleation and growth of aerosol droplets. However, at the same time, the immediate disadvantage of introducing outside air into the hollow tubular cooling element is the dilution of the aerosol flow delivered to the consumer.

[0255] The present inventors have unexpectedly discovered how the beneficial effect of improved nucleation, achieved by rapid cooling caused by the introduction of ventilation air into the article, can significantly counteract the less desirable effects of dilution. Thus, satisfactory aerosol delivery values ​​are consistently achieved by aerosol-generating articles according to the present invention.

[0256] The present inventors also unexpectedly found that the effect of dilution on the aerosol, which can be assessed by measurement, in particular the effect on the delivery of an aerosol forming substance (e.g., glycerol) contained in an aerosol generating substrate, is advantageously minimized when the ventilation level is within the ranges described above.

[0257] In particular, it was found that ventilation levels of 10 percent to 20 percent and even more preferably 12 to 18 percent lead to particularly satisfactory glycerol delivery values.

[0258] Since the ventilated hollow tubular cooling element does not substantially affect the overall RTD of the aerosol-generating article in aerosol-generating articles, according to the present invention, the overall RTD of the article can be advantageously precisely controlled by adjusting the length and density of the rod of the aerosol-generating substrate, or the length and, optionally, the length and density of any segment of the filter material that forms part of a downstream section, such as, for example, a downstream filter segment, or the length and density of a segment of the filter material provided upstream of the aerosol-generating substrate. Thus, aerosol-generating articles that have a given RTD can be manufactured on a consistent basis and with great accuracy, so that satisfactory RTD levels can be provided to the consumer even in the presence of ventilation.

[0259] The distance between the ventilation zone and the downstream end of the aerosol-generating substrate rod may be at least 4 millimeters, or at least 6 millimeters, or at least 8 millimeters. Preferably, the distance between the ventilation zone and the downstream end of the aerosol-generating substrate rod is at least 9 millimeters. More preferably, the distance between the ventilation zone and the downstream end of the aerosol-generating substrate rod is at least 10 millimeters.

[0260] The distance between the ventilation zone and the downstream end of the aerosol-generating substrate rod is preferably less than 17 millimeters. More preferably, the distance between the ventilation zone and the downstream end of the aerosol-generating substrate rod is less than 16 millimeters. Even more preferably, the distance between the ventilation zone and the downstream end of the aerosol-generating substrate rod is less than 16 millimeters. In particularly preferred embodiments, the distance between the ventilation zone and the downstream end of the aerosol-generating substrate rod is less than 15 millimeters.

[0261] In some embodiments, the distance between the ventilation zone and the downstream end of the aerosol-generating substrate rod is from 4 millimeters to 17 millimeters, preferably from 7 millimeters to 17 millimeters, even more preferably from 10 millimeters to 17 millimeters. In other embodiments, the distance between the ventilation zone and the downstream end of the aerosol-generating substrate rod is from 8 millimeters to 16 millimeters, preferably from 9 millimeters to 16 millimeters, more preferably from 10 millimeters to 16 millimeters. In further embodiments, the distance between the ventilation zone and the downstream end of the aerosol generating substrate rod is from 8 millimeters to 15 millimeters, preferably from 9 millimeters to 15 millimeters, more preferably from 10 millimeters to 15 millimeters.As an example, the distance between the ventilation zone and the downstream end of the aerosol generating substrate rod may be from 10 millimeters to 14 millimeters, preferably from 10 millimeters to 13 millimeters, even more preferably from 10 millimeters to 12 millimeters.

[0262] The advantage of arranging the ventilation zone within the ranges described above, away from the downstream end of the aerosol-generating substrate rod, is that it generally ensures that the ventilation zone is located just outside the heating device during use when the aerosol-generating article is inserted into the heating device, thereby reducing the risk of the user inadvertently blocking the ventilation zone with their lips or hands. Furthermore, it has been found that arranging the ventilation zone within the ranges described above, away from the downstream end of the aerosol-generating substrate rod, can advantageously improve nucleation, aerosol formation, and delivery.

[0263] The distance between the ventilation zone and the downstream end of the hollow tubular cooling element may be at least 3 millimeters. Preferably, the distance between the ventilation zone and the downstream end of the hollow tubular cooling element is at least 5 millimeters. More preferably, the distance between the ventilation zone and the downstream end of the hollow tubular cooling element is at least 7 millimeters.

[0264] The distance between the ventilation zone and the downstream end of the hollow tubular cooling element is preferably less than or equal to 14 millimeters. More preferably, the distance between the ventilation zone and the downstream end of the hollow tubular cooling element is less than or equal to 12 millimeters. Even more preferably, the distance between the ventilation zone and the downstream end of the hollow tubular cooling element is less than or equal to 10 millimeters.

[0265] In some embodiments, the distance between the ventilation zone and the downstream end of the hollow tubular cooling element is from 3 millimeters to 14 millimeters, preferably from 5 millimeters to 14 millimeters, even more preferably from 7 millimeters to 14 millimeters. In additional embodiments, the distance between the ventilation zone and the downstream end of the hollow tubular cooling element is from 3 millimeters to 12 millimeters, preferably from 5 millimeters to 12 millimeters, more preferably from 7 millimeters to 12 millimeters. In other embodiments, the distance between the ventilation zone and the downstream end of the hollow tubular cooling element is from 3 millimeters to 10 millimeters, preferably from 5 millimeters to 10 millimeters, more preferably from 7 millimeters to 10 millimeters.

[0266] The advantage of arranging the ventilation zone at a distance from the downstream end of the hollow tubular cooling element within the ranges described above is that it generally ensures that the ventilation zone is located just outside the heating device during use when the aerosol-generating article is inserted into the heating device, thereby reducing the risk of the user inadvertently blocking the ventilation zone with their lips or hands. It has also been found that arranging the ventilation zone at a distance from the downstream end of the hollow tubular cooling element within the ranges described above can advantageously result in the formation and delivery of a comparatively more uniform aerosol.

[0267] The distance between the ventilation zone and the downstream end of the aerosol-generating article may be at least 10 millimeters. Preferably, the distance between the ventilation zone and the downstream end of the aerosol-generating article is at least 12 millimeters. More preferably, the distance between the ventilation zone and the downstream end of the aerosol-generating article is at least 15 millimeters.

[0268] The distance between the ventilation zone and the downstream end of the aerosol-generating article is preferably less than or equal to 21 millimeters. More preferably, the distance between the ventilation zone and the downstream end of the aerosol-generating article is less than or equal to 19 millimeters. Even more preferably, the distance between the ventilation zone and the downstream end of the aerosol-generating article is less than or equal to 17 millimeters.

[0269] In some embodiments, the distance between the ventilation zone and the downstream end of the aerosol-generating article is from 10 millimeters to 21 millimeters, preferably from 12 millimeters to 21 millimeters, more preferably from 15 millimeters to 21 millimeters. In further embodiments, the distance between the ventilation zone and the downstream end of the aerosol-generating article is from 10 millimeters to 19 millimeters, preferably from 12 millimeters to 19 millimeters, more preferably from 15 millimeters to 19 millimeters. In other embodiments, the distance between the ventilation zone and the downstream end of the aerosol generating article is from 10 millimeters to 17 millimeters, preferably from 12 millimeters to 17 millimeters, more preferably from 15 millimeters to 17 millimeters.

[0270] The advantage of arranging the ventilation zone at a distance from the downstream end of the aerosol-generating article within the ranges described above is that it generally ensures that during use, when the aerosol-generating article is partially contained within the heating device, the portion of the aerosol-generating article extending beyond the heating device is of sufficient length for the user to comfortably hold the article between their lips, thereby reducing the risk of the user's lips or hands inadvertently blocking the ventilation zone. At the same time, the data indicate that if the length of the portion of the aerosol-generating article extending beyond the heating device were greater, the aerosol-generating article could easily be unintentionally and undesirably bent, which could impair the delivery of the aerosol or the overall intended use of the aerosol-generating article.

[0271] As discussed in this disclosure, a downstream section may comprise a downstream filter segment. The downstream filter segment may extend to a downstream end of the downstream section. The downstream filter segment may be located at a downstream end of the aerosol-generating article. The downstream end of the downstream filter segment may define a downstream end of the aerosol-generating article.

[0272] The downstream filter segment may be positioned downstream of the hollow tubular cooling element described above. The downstream filter segment may extend between the hollow tubular cooling element and the downstream end of the aerosol-generating article.

[0273] The downstream filter segment is preferably a solid plug, which can also be described as a "smooth" plug, and is non-tubular. Therefore, the filter segment preferably has a substantially uniform cross-section.

[0274] The downstream filter segment is preferably formed from a fibrous filter material. The fibrous filter material can be used to filter an aerosol generated from an aerosol-generating substrate. Suitable fibrous filter materials will be known to those skilled in the art. Particularly preferably, at least one downstream filter segment comprises a cellulose acetate filter segment formed from cellulose acetate tow.

[0275] In certain preferred embodiments, the downstream section comprises a single downstream filter segment. In alternative embodiments, the downstream section comprises two or more downstream filter segments axially aligned end-to-end with one another.

[0276] The downstream filter segment may optionally contain a flavoring agent, which may be provided in any suitable form. For example, the downstream filter segment may contain one or more capsules, beads, or granules of flavoring agent, or one or more threads or fibers filled with a flavoring agent.

[0277] The filter segment preferably located downstream has low particle filtration efficiency.

[0278] A downstream filter segment is preferably surrounded by a filter element. Preferably, the downstream filter segment is not ventilated, so that air does not enter the aerosol-generating article along the downstream filter segment.

[0279] The downstream filter segment is preferably connected to one or more adjacent upstream components of the aerosol generating article via a rim wrap.

[0280] The downstream filter segment preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article. The diameter of the downstream filter segment may be substantially the same as the outer diameter of the hollow tubular cooling element.

[0281] The outer diameter of the downstream filter segment may be between 5 millimeters and 10 millimeters. The diameter of the downstream filter segment may be between 5.5 millimeters and 9 millimeters. The diameter of the downstream filter segment may be between 6 millimeters and 8 millimeters. In preferred embodiments, the diameter of the downstream filter segment is less than 7 millimeters.

[0282] Unless otherwise specified, the resistance to draw (RTD) of an aerosol-generating component or article is measured in accordance with ISO 6565-2015. RTD refers to the pressure required to force air through the entire length of the component. The terms “pressure drop” or “resistance to draw” of a component or article may also refer to “resistance to draw”. Such terms generally refer to measurements in accordance with ISO 6565-2015, which are typically performed under test conditions at a volumetric flow rate of 17.5 milliliters per second at the outlet or downstream end of the component being measured, at a temperature of 22 degrees Celsius, a pressure of 101 kPa (approximately 760 Torr), and a relative humidity of 60%. Smoking conditions and smoking machine specifications are set out in ISO 3308 (ISO 3308:2000). Atmospheric conditions for preparation and testing are described in ISO 3402 (ISO 3402:1999).

[0283] The resistance to draw (RTD) of the downstream section may be at least 0 mmH2O. The RTD of the downstream section may be at least 3 mmH2O. The RTD of the downstream section may be at least 6 mmH2O.

[0284] The RTD of the downstream section may be no more than 12 mmH2O. The RTD of the downstream section may be no more than 11 mmH2O. The RTD of the downstream section may be no more than 10 mmH2O.

[0285] The drawstring resistance of the downstream section may be greater than or equal to 0 millimeters of water column and less than 12 millimeters of water column. Preferably, the drawstring resistance of the downstream section may be greater than or equal to 3 millimeters of water column and less than 12 millimeters of water column. The drawstring resistance of the downstream section may be greater than or equal to 0 millimeters of water column and less than 11 millimeters of water column. Even more preferably, the drawstring resistance of the downstream section may be greater than or equal to 3 millimeters of water column and less than 11 millimeters of water column. Even more preferably, the drawstring resistance of the downstream section may be greater than or equal to 6 millimeters of water column and less than 10 millimeters of water column. Preferably, the tightening resistance of the downstream section may be 8 mm H2O.

[0286] The resistance to draw (RTD) characteristics of a downstream section may be completely or largely related to the RTD characteristics of the downstream filter segment of the downstream section. In other words, the RTD of the downstream segment of the downstream section can completely determine the RTD of the downstream section.

[0287] The resistance to draw (RTD) of the downstream filter segment may be at least 0 millimeters of water column. The RTD of the downstream filter segment may be at least 3 millimeters of water column. The RTD of the downstream filter segment may be at least 6 millimeters of water column. The RTD of the downstream filter segment may be no more than 12 millimeters of water column. The RTD of the downstream filter segment may be no more than 11 millimeters of water column. The RTD of the downstream filter segment may be no more than 10 millimeters of water column.

[0288] The draw resistance of the downstream filter segment may be greater than or equal to 0 millimeters of water column and less than 12 millimeters of water column. Preferably, the draw resistance of the downstream filter segment may be greater than or equal to 3 millimeters of water column and less than 12 millimeters of water column. The draw resistance of the downstream filter segment may be greater than or equal to 0 millimeters of water column and less than 11 millimeters of water column. Even more preferably, the draw resistance of the downstream filter segment may be greater than or equal to 3 millimeters of water column and less than 11 millimeters of water column. Even more preferably, the draw resistance of the downstream filter segment may be greater than or equal to 6 millimeters of water column and less than 10 millimeters of water column.Preferably, the draw resistance of the downstream filter segment may be 8 mm H2O.

[0289] As mentioned above, the downstream filter segment can be formed from a fibrous filter material. The downstream filter segment can be formed from a porous material. The downstream filter segment can be formed from a biodegradable material. The downstream filter segment can be formed from a cellulosic material, such as cellulose acetate. For example, the downstream filter segment can be formed from a bundle of cellulose acetate fibers having a denier per fiber of 10 to 15. For example, the downstream filter segment is formed from a relatively low-density cellulose acetate tow, such as a cellulose acetate tow containing fibers with a denier per fiber of 12.

[0290] The downstream filter segment can be formed from a polylactic acid-based material. The downstream filter segment can be formed from a bioplastic material, preferably a starch-based bioplastic material. The downstream filter segment can be formed by injection molding or extrusion. Bioplastic-based materials are advantageous because they can provide downstream filter segment structures that are simple and inexpensive to manufacture with a defined and complex cross-sectional profile, which can contain multiple relatively large airflow channels passing through the downstream filter segment material, which provides suitable RTD characteristics.

[0291] The downstream filter segment may be formed from a sheet of suitable material that has been corrugated, pleated, gathered, woven, or folded into an element that forms a plurality of longitudinally extending channels. Such a sheet of suitable material may be formed from paper, cardboard, a polymer such as polylactic acid, or any other cellulose-based material, paper-based material, or bioplastic-based material. The cross-sectional profile of such a downstream filter segment may show randomly oriented channels.

[0292] The downstream filter segment may be formed in any other suitable manner. For example, the downstream filter segment may be formed from a bundle of longitudinally extending tubes. The longitudinally extending tubes may be formed from polylactic acid. The downstream filter segment may be formed by extrusion, casting, layering, injection, or milling of a suitable material. Thus, it is preferable that there be a small pressure drop (or RTD) from the upstream end of the downstream filter segment to the downstream end of the downstream filter segment.

[0293] The length of the downstream filter segment may be at least 5 millimeters. The length of the downstream filter segment may be at least 10 millimeters. The length of the downstream filter segment may be less than 25 millimeters. The length of the downstream filter segment may be less than 20 millimeters. For example, the length of the downstream filter segment may be from 5 millimeters to 25 millimeters, or from 10 millimeters to 25 millimeters, or from 5 millimeters to 20 millimeters, or from 10 millimeters to 20 millimeters.

[0294] The ratio between the length of the downstream filter segment and the length of the downstream section may be less than or equal to 0.55. Preferably, the ratio between the length of the downstream filter segment and the length of the downstream section may be less than or equal to 0.45. More preferably, the ratio between the length of the downstream filter segment and the length of the downstream section may be less than or equal to 0.35. Even more preferably, the ratio between the length of the downstream filter segment and the length of the downstream section may be less than or equal to 0.25.

[0295] The ratio between the length of the downstream filter segment and the length of the downstream section may be at least 0.05. Preferably, the ratio between the length of the downstream filter segment and the length of the downstream section may be at least 0.10. More preferably, the ratio between the length of the downstream filter segment and the length of the downstream section may be at least 0.15. Even more preferably, the ratio between the length of the downstream filter segment and the length of the downstream section may be at least 0.20.

[0296] In some embodiments, the ratio between the length of the downstream filter segment and the length of the downstream section is from 0.05 to 0.55, preferably from 0.10 to 0.55, more preferably from 0.15 to 0.55, even more preferably from 0.20 to 0.55. In other embodiments, the ratio between the length of the downstream filter segment and the length of the downstream section is from 0.05 to 0.45, preferably from 0.10 to 0.45, more preferably from 0.15 to 0.45, even more preferably from 0.20 to 0.45. In further embodiments, the ratio between the length of the downstream filter segment and the length of the downstream section is from 0.05 to 0.35, preferably from 0.10 to 0.35, more preferably from 0.15 to 0.35, even more preferably from 0.20 to 0.35.As an example, the ratio between the length of the downstream filter segment and the length of the downstream section may preferably be from 0.20 to 0.25, more preferably the ratio between the length of the downstream filter segment and the length of the downstream section may be 0.25.

[0297] The ratio between the length of the downstream filter segment and the total length of the aerosol generating article may be less than or equal to 0.40. Preferably, the ratio between the length of the downstream filter segment and the total length of the aerosol generating article may be less than or equal to 0.30. More preferably, the ratio between the length of the downstream filter segment and the total length of the aerosol generating article may be less than or equal to 0.25. Even more preferably, the ratio between the length of the downstream filter segment and the total length of the aerosol generating article may be less than or equal to 0.20.

[0298] The ratio between the length of the downstream filter segment and the total length of the aerosol-generating article may be at least 0.05. Preferably, the ratio between the length of the downstream filter segment and the total length of the aerosol-generating article may be at least 0.07. More preferably, the ratio between the length of the downstream filter segment and the total length of the aerosol-generating article may be at least 0.10. Even more preferably, the ratio between the length of the downstream filter segment and the total length of the aerosol-generating article may be at least 0.15.

[0299] In some embodiments, the ratio between the length of the downstream filter segment and the total length of the aerosol-generating article is from 0.05 to 0.40, preferably from 0.07 to 0.40, more preferably from 0.10 to 0.40, even more preferably from 0.15 to 0.40. In other embodiments, the ratio between the length of the downstream filter segment and the total length of the aerosol-generating article is from 0.05 to 0.30, preferably from 0.07 to 0.30, more preferably from 0.10 to 0.30, even more preferably from 0.15 to 0.30. In further embodiments, the ratio between the length of the downstream filter segment and the overall length of the aerosol generating article is from 0.05 to 0.25, preferably from 0.07 to 0.25, more preferably from 0.10 to 0.25, even more preferably from 0.15 to 0.25.As an example, the ratio between the length of the downstream filter segment and the total length of the aerosol generating article may be from 0.15 to 0.20, more preferably the ratio between the length of the downstream filter segment and the total length of the aerosol generating article may be 0.16.

[0300] In embodiments where the downstream section comprises a hollow tubular cooling element a and a downstream filter segment, the ratio of the length of the hollow tubular cooling element to the length of the downstream filter segment may be at least 1.25. In other words, the length of the hollow tubular cooling element may be equivalent to 125% of the length of the downstream filter segment. The ratio of the length of the hollow tubular cooling element to the length of the downstream filter segment may be at least 1.5. The ratio of the length of the hollow tubular cooling element to the length of the downstream filter segment may be at least 2.

[0301] The ratio of the length of the hollow tubular cooling element to the length of the downstream filter segment may be equal to or less than 8.5. The ratio of the length of the hollow tubular cooling element to the length of the downstream filter segment may be equal to or less than 6. The ratio of the length of the hollow tubular cooling element to the length of the downstream filter segment may be equal to or less than 4.

[0302] The length ratio of the hollow tubular cooling element to the length of the downstream filter segment may be from 1.25 to 8.5. The length ratio of the hollow tubular cooling element to the length of the downstream filter segment may be from 1.5 to 6. The length ratio of the hollow tubular cooling element to the length of the downstream filter segment may be from 2 to 4.

[0303] In certain preferred embodiments, the downstream section may comprise a ventilation zone at a location downstream of the downstream filter segment. In one example, the ventilation zone at a location downstream of the downstream filter segment may be provided instead of a ventilation zone provided at a location along the hollow tubular cooling element. In another example, the ventilation zone at a location downstream of the downstream filter segment may be provided in addition to the ventilation zone provided at a location on the hollow tubular cooling element.

[0304] A ventilation zone located downstream of the filter segment may comprise multiple perforations. Preferably, the ventilation zone located downstream of the filter segment comprises at least one annular row of perforations. In some embodiments, the ventilation zone located downstream of the filter segment may comprise two annular rows of perforations. For example, the perforations may be formed on a production line during the manufacturing process of an aerosol-generating article. Preferably, each annular row of perforations comprises from 8 to 30 perforations.

[0305] The downstream section may further comprise one or more additional hollow tubular elements.

[0306] In certain embodiments, the downstream section may comprise a hollow tubular support element located upstream of the hollow tubular cooling element described above.

[0307] Preferably, the hollow tubular support element is adjacent to the downstream end of the aerosol-generating substrate rod. Preferably, the hollow tubular support element is adjacent to the upstream end of the hollow tubular cooling element. Preferably, the hollow tubular support element and the hollow tubular cooling element are positioned adjacent to each other and together form a hollow tubular section within the downstream section.

[0308] The hollow tubular support element may be formed from any suitable material or combination of materials. For example, the support element may be formed from one or more materials selected from the group consisting of: cellulose acetate; cardboard; corrugated paper, such as corrugated heat-resistant paper or corrugated parchment paper; and polymeric materials, such as low-density polyethylene (LDPE). In a preferred embodiment, the support element is formed from cellulose acetate. Other suitable materials include polyhydroxyalkanoate (PHA) fibers. In a preferred embodiment, the hollow tubular support element comprises a hollow acetate tube.

[0309] The hollow tubular support member preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol-generating substrate rod and the outer diameter of the aerosol-generating article.

[0310] The hollow tubular support element may have an outer diameter of 5 millimeters to 10 millimeters, for example, 5.5 millimeters to 9 millimeters, or 6 millimeters to 8 millimeters. In a preferred embodiment, the hollow tubular support element has an outer diameter of less than 7 millimeters.

[0311] The hollow tubular support member may have a wall thickness of at least 1 millimeter, preferably at least 1.5 millimeters, more preferably at least 2 millimeters.

[0312] The hollow tubular support element may have a length of at least 5 millimeters. Preferably, the support element has a length of at least 6 millimeters, more preferably at least 7 millimeters.

[0313] The hollow tubular support member may have a length of less than 15 millimeters. Preferably, the hollow tubular support member has a length of less than 12 millimeters, more preferably less than 10 millimeters.

[0314] In some embodiments, the support element has a length of 5 millimeters to 15 millimeters, preferably 6 millimeters to 15 millimeters, more preferably 7 millimeters to 15 millimeters. In other embodiments, the support element has a length of 5 millimeters to 12 millimeters, preferably 6 millimeters to 12 millimeters, more preferably 7 millimeters to 12 millimeters. In further embodiments, the support element has a length of 5 millimeters to 10 millimeters, preferably 6 millimeters to 10 millimeters, more preferably 7 millimeters to 10 millimeters.

[0315] The length of the hollow tubular section is preferably at least 20 millimeters. More preferably, the length of the hollow tubular section is at least 30 millimeters. The length of the hollow tubular section can be at least 40 millimeters. More preferably, the length of the hollow tubular section is at least 45 millimeters.

[0316] The length of the hollow tubular section is preferably less than 60 millimeters. More preferably, the length of the hollow tubular section is less than 55 millimeters. More preferably, the length of the hollow tubular section is less than 50 millimeters.

[0317] For example, the length of the hollow tubular section may be from 20 millimeters to 60 millimeters, or from 30 millimeters to 60 millimeters, or from 40 millimeters to 60 millimeters, or from 45 millimeters to 60 millimeters. In other embodiments, the length of the hollow tubular section may be from 20 millimeters to 55 millimeters, or from 30 millimeters to 55 millimeters, or from 40 millimeters to 55 millimeters, or from 45 millimeters to 55 millimeters. In other embodiments, the length of the hollow tubular section may be from 20 millimeters to 50 millimeters, or from 30 millimeters to 50 millimeters, or from 40 millimeters to 50 millimeters, or from 45 millimeters to 50 millimeters.

[0318] Alternatively or in addition to the hollow tubular support element, the downstream section may further comprise a downstream hollow tubular element located downstream of the hollow tubular cooling element. The downstream hollow tubular element may be provided directly adjacent to the hollow tubular cooling element. Alternatively or preferably, the downstream hollow tubular element is separated from the hollow tubular cooling element by at least one other component. For example, the downstream section may comprise a downstream filter segment between the hollow tubular cooling element and the downstream hollow tubular element.Therefore, the downstream hollow tubular element is downstream of the downstream filter segment, and preferably the downstream hollow tubular element is adjacent to the downstream end of the downstream filter segment.

[0319] The downstream hollow tubular element preferably extends to the downstream end of the downstream section. Therefore, the downstream hollow tubular element preferably extends to the downstream end of the aerosol-generating article. In certain embodiments, the additional downstream hollow tubular element can be provided such that the downstream section comprises two adjacent downstream hollow tubular elements located downstream of the downstream filter segment.

[0320] The RTD of the downstream hollow tubular element is preferably less than or equal to 10 millimeters of water column. More preferably, the RTD of the downstream hollow tubular element is less than or equal to 5 millimeters of water column. Even more preferably, the RTD of the downstream hollow tubular element is less than or equal to 2.5 millimeters of water column. Even more preferably, the RTD of the downstream hollow tubular element is less than or equal to 2 millimeters of water column. Even more preferably, the RTD of the downstream hollow tubular element is less than or equal to 1 millimeter of water column.

[0321] The RTD of the downstream hollow tubular member may be at least 0 mm H2O, or at least 0.25 mm H2O, or at least 0.5 mm H2O, or at least 1 mm H2O.

[0322] In some embodiments, the RTD of the downstream hollow tubular member is from 0 millimeters H2O to 10 millimeters H2O, preferably from 0.25 millimeters H2O to 10 millimeters H2O, preferably from 0.5 millimeters H2O to 10 millimeters H2O. In other embodiments, the RTD of the downstream hollow tubular member is from 0 millimeters H2O to 5 millimeters H2O, preferably from 0.25 millimeters H2O to 5 millimeters H2O, preferably from 0.5 millimeters H2O to 5 millimeters H2O. In other embodiments, the RTD of the downstream hollow tubular member is from 1 millimeter H2O. up to 5 millimeters of water column. In further embodiments, the RTD of the downstream hollow tubular member is from 0 millimeters of water column to 2.5 millimeters of water column, preferably from 0.25 millimeters of water column.to 2.5 millimeters of water column, more preferably from 0.5 millimeters of water column to 2.5 millimeters of water column. In further embodiments, the RTD of the downstream hollow tubular member is from 0 millimeters of water column to 2 millimeters of water column, preferably from 0.25 millimeters of water column to 2 millimeters of water column, more preferably from 0.5 millimeters of water column to 2 millimeters of water column. In a particularly preferred embodiment, the RTD of the downstream hollow tubular member is 0 millimeters of water column.

[0323] Therefore, the flow channel of the downstream hollow tubular element must be free of any components that could restrict the longitudinal air flow. Preferably, the flow channel is substantially empty, and particularly preferably, the flow channel is empty.

[0324] The length of the downstream hollow tubular element is preferably at least 3 millimeters. More preferably, the length of the downstream hollow tubular element is at least 4 millimeters. The length of the downstream hollow tubular element can be at least 5 millimeters. More preferably, the length of the downstream hollow tubular element is at least 6 millimeters.

[0325] The length of the downstream hollow tubular element is preferably less than 20 millimeters. More preferably, the length of the downstream hollow tubular element is less than 15 millimeters. More preferably, the length of the downstream hollow tubular element is less than 12 millimeters. More preferably, the length of the downstream hollow tubular element is less than 10 millimeters.

[0326] For example, the length of the downstream hollow tubular element may be from 3 millimeters to 20 millimeters, or from 4 millimeters to 20 millimeters, or from 5 millimeters to 20 millimeters, or from 6 millimeters to 20 millimeters. In other embodiments, the length of the downstream hollow tubular element may be from 3 millimeters to 15 millimeters, or from 4 millimeters to 15 millimeters, or from 5 millimeters to 15 millimeters, or from 6 millimeters to 15 millimeters. In other embodiments, the length of the downstream hollow tubular member may be from 3 millimeters to 12 millimeters, or from 4 millimeters to 12 millimeters, or from 5 millimeters to 12 millimeters, or from 6 millimeters to 12 millimeters.In other embodiments, the length of the downstream hollow tubular member may be from 3 millimeters to 10 millimeters, or from 4 millimeters to 10 millimeters, or from 5 millimeters to 10 millimeters, or from 6 millimeters to 10 millimeters.

[0327] If a downstream hollow tubular element is included in a downstream section, the combined length of the hollow tubular cooling element and the downstream hollow tubular element (or elements) is preferably at least 20 millimeters. This corresponds to the sum of the length of the hollow tubular cooling element and the length of the downstream hollow tubular element (or elements), without taking into account the length of any components provided between them. More preferably, the combined length is at least 30 millimeters. The combined length can be at least 40 millimeters. More preferably, the combined length is at least 45 millimeters.

[0328] The combined length of the hollow tubular cooling element and the downstream hollow tubular element(s) is preferably less than 60 millimeters. More preferably, the combined length is less than 55 millimeters. More preferably, the combined length is less than 50 millimeters.

[0329] For example, the combined length of the hollow tubular cooling element and the downstream hollow tubular element(s) may be from 20 millimeters to 60 millimeters, or from 30 millimeters to 60 millimeters, or from 40 millimeters to 60 millimeters, or from 45 millimeters to 60 millimeters. In other embodiments, the combined length may be from 20 millimeters to 55 millimeters, or from 0 millimeters to 55 millimeters, or from 40 millimeters to 55 millimeters, or from 45 millimeters to 55 millimeters. In other embodiments, the combined length may be from 20 millimeters to 50 millimeters, or from 30 millimeters to 50 millimeters, or from 40 millimeters to 50 millimeters, or from 45 millimeters to 50 millimeters.

[0330] By ensuring the combined length within the ranges specified above, the total length of the hollow tubular elements in the downstream section is relatively large, which achieves the advantages specified above regarding the length of the hollow tubular cooling element.

[0331] The lumen or cavity of the downstream hollow tubular element may have any cross-sectional shape. The lumen of the downstream hollow tubular element may have a circular cross-sectional shape.

[0332] The downstream hollow tubular element may comprise a paper-based material. The downstream hollow tubular element may comprise at least one layer of paper. The paper may be very rigid paper. The paper may be corrugated paper, such as corrugated heat-resistant paper or corrugated parchment paper.

[0333] The downstream hollow tubular element may comprise cardboard. The downstream hollow tubular element may be a cardboard tube.

[0334] The downstream hollow tubular element may be a paper tube. The downstream hollow tubular element may be a tube formed from spirally wound paper. The downstream hollow tubular element may be formed from multiple layers of paper. The paper may have a basis weight of at least 50 grams per square meter, at least 60 grams per square meter, at least 70 grams per square meter, or at least 90 grams per square meter.

[0335] The downstream hollow tubular element may comprise a polymeric material. For example, the downstream hollow tubular element may comprise a polymeric film. The polymeric film may comprise a cellulose film. The downstream hollow tubular element may comprise low-density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. Preferably, the downstream hollow tubular element comprises cellulose acetate tow. For example, in preferred embodiments, the downstream hollow tubular element comprises a hollow acetate tube.

[0336] If the downstream hollow tubular member contains cellulose acetate tow, the cellulose acetate tow may have a denier per fiber of 2 to 4 and a total denier of 25 to 40.

[0337] If the downstream section also comprises an additional downstream hollow tubular element as described above, the additional downstream hollow tubular element may be formed from the same material as the downstream hollow tubular element or a different material.

[0338] In certain preferred embodiments, the downstream section may comprise a ventilation zone at a location on the downstream hollow tubular element. In one example, this ventilation zone at a location on the downstream hollow tubular element may be provided instead of a ventilation zone at a location on the hollow tubular cooling element. In another example, the ventilation zone at a location on the downstream hollow tubular element may be provided in addition to the ventilation zone provided at a location on the hollow tubular cooling element.

[0339] The ventilation zone at a location along the downstream hollow tubular element may comprise multiple perforations in the peripheral wall of the downstream hollow tubular element. Preferably, the ventilation zone at a location along the downstream hollow tubular element comprises at least one annular row of perforations. In some embodiments, the ventilation zone may comprise two annular rows of perforations. For example, the perforations may be formed on a production line during the manufacturing process of an aerosol-generating article. Preferably, each annular row of perforations comprises from 8 to 30 perforations.

[0340] The distance between the ventilation zone and the upstream end of the downstream hollow tubular element may be at least 1 millimeter. The distance between the ventilation zone and the upstream end of the downstream hollow tubular element may be at least 2 millimeters. Preferably, the distance between the ventilation zone and the upstream end of the downstream hollow tubular element is at least 3 millimeters.

[0341] The distance between the ventilation zone and the upstream end of the downstream hollow tubular element is preferably less than or equal to 10 millimeters. More preferably, the distance between the ventilation zone and the upstream end of the downstream hollow tubular element is less than or equal to 7 millimeters. Even more preferably, the distance between the ventilation zone and the upstream end of the downstream hollow tubular element is less than or equal to 5 millimeters.

[0342] In some embodiments, the distance between the ventilation zone and the upstream end of the downstream hollow tubular element is from 1 millimeter to 10 millimeters, preferably from 1 millimeter to 7 millimeters, more preferably from 1 millimeter to 5 millimeters. In additional embodiments, the distance between the ventilation zone and the upstream end of the downstream hollow tubular element is from 2 millimeters to 10 millimeters, preferably from 2 millimeters to 7 millimeters, more preferably from 2 millimeters to 5 millimeters.In other embodiments, the distance between the ventilation zone and the upstream end of the downstream hollow tubular element is from 3 millimeters to 10 millimeters, preferably from 3 millimeters to 7 millimeters, more preferably from 3 millimeters to 5 millimeters.

[0343] The advantage of arranging the ventilation zone at a distance from the upstream end of the downstream hollow tubular member within the ranges described above is that it generally ensures that during use, the ventilation zone is located just outside the heating device when the aerosol-generating article is inserted into the heating device, thereby reducing the risk of the ventilation zone being inadvertently blocked by the lips or hands of the user.

[0344] The downstream section may optionally further comprise an additional cooling element defining a plurality of longitudinally extending channels to make a high specific surface area available for heat exchange. In other words, one such additional cooling element is adapted to function essentially as a heat exchanger. The plurality of longitudinally extending channels may be formed by a sheet material that has been pleated, gathered, or folded to form channels. The plurality of longitudinally extending channels may be formed by a single sheet that has been pleated, gathered, or folded to form multiple channels. The sheet may also be corrugated before pleating, gathering, or folding. Alternatively, the plurality of longitudinally extending channels may be defined by several sheets that have been corrugated, pleated, gathered, or folded to form multiple channels.In some embodiments, the plurality of longitudinally extending channels may be defined by multiple sheets that have been corrugated, pleated, gathered, or folded together, i.e., two or more sheets that have been introduced into an overlapping arrangement and then corrugated, pleated, gathered, or folded as one.

[0345] As used herein, the term "corrugated" means a sheet having a plurality of substantially parallel folds or corrugations. Preferably, when the aerosol-generating article is assembled, the substantially parallel folds or corrugations extend in the longitudinal direction relative to the rod. As used herein, the terms "gathered," "pleated," or "folded" mean that the sheet of material is folded, bent, or otherwise compressed or narrowed substantially in the transverse direction relative to the axis of the rod cylinder. The sheet may be corrugated before being assembled, pleated, or folded. The sheet may be gathered, pleated, or folded without prior corrugation.

[0346] One such additional cooling element may have a total surface area from approximately 300 square millimeters per millimeter of length to approximately 1000 square millimeters per millimeter of length.

[0347] The additional cooling element preferably provides low resistance to air flow through the additional cooling element. Preferably, the additional cooling element does not substantially affect the draw resistance of the aerosol-generating article. To achieve this, it is preferable for the longitudinal porosity to be greater than 50 percent, and for the air flow path through the additional cooling element to be relatively unobstructed. The longitudinal porosity of the additional cooling element can be determined by the ratio of the cross-sectional area of ​​the material forming the additional cooling element to the internal cross-sectional area of ​​the aerosol-generating article in the portion containing the additional cooling element.

[0348] The additional cooling element preferably comprises a sheet material selected from the group consisting of metal foil, a sheet of polymeric material, and substantially non-porous paper or cardboard. In some embodiments, the aerosol cooling element may comprise a sheet material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), and aluminum foil. In a particularly preferred embodiment, the additional cooling element comprises a PLA sheet.

[0349] The aerosol generating product may have a total length of between 45 millimeters and 100 millimeters.

[0350] The overall length of the aerosol-generating article according to the present invention is preferably at least 50 millimeters. More preferably, the overall length of the aerosol-generating article according to the present invention is at least 60 millimeters. Even more preferably, the overall length of the aerosol-generating article according to the present invention is at least 70 millimeters.

[0351] The overall length of the aerosol-generating article according to the present invention is preferably less than or equal to 90 millimeters. More preferably, the overall length of the aerosol-generating article according to the present invention is preferably less than or equal to 85 millimeters. Even more preferably, the overall length of the aerosol-generating article according to the present invention is preferably less than or equal to 80 millimeters.

[0352] In some embodiments, the overall length of the aerosol-generating article is preferably from 50 millimeters to 90 millimeters, more preferably from 60 millimeters to 90 millimeters, even more preferably from 70 millimeters to 90 millimeters. In other embodiments, the overall length of the aerosol-generating article is preferably from 50 millimeters to 85 millimeters, more preferably from 60 millimeters to 85 millimeters, even more preferably from 70 millimeters to 85 millimeters. In further embodiments, the overall length of the aerosol-generating article is preferably from 50 millimeters to 80 millimeters, more preferably from 60 millimeters to 80 millimeters, even more preferably from 70 millimeters to 80 millimeters. In an illustrative embodiment, the overall length of the aerosol generating article is 75 millimeters.

[0353] The aerosol-generating article preferably has an outer diameter of at least 5 millimeters along the entire length of the article. If the diameter varies along the length of the aerosol-generating article, the outer diameter is preferably at least 5 millimeters at all points along the article's length.

[0354] Preferably, the aerosol-generating article has an outer diameter of at least 5.5 millimeters along the entire length of the article. More preferably, the aerosol-generating article has an outer diameter of at least 6 millimeters along the entire length of the article.

[0355] The aerosol-generating article preferably has a maximum outer diameter of less than 10 millimeters. This means that if the diameter of the aerosol-generating article varies along the article's length, the diameter is less than 10 millimeters at all points along the length. More preferably, the aerosol-generating article has a maximum outer diameter of less than 9 millimeters. Even more preferably, the aerosol-generating article has a maximum outer diameter of less than 8 millimeters. Even more preferably, the aerosol-generating article has a maximum outer diameter of less than 7 millimeters.

[0356] In some embodiments, the aerosol-generating article has an outer diameter of 5 millimeters to 10 millimeters, preferably 5.5 millimeters to 10 millimeters, more preferably 6 millimeters to 10 millimeters. In other embodiments, the aerosol-generating article has an outer diameter of 5 millimeters to 9 millimeters, preferably 5.5 millimeters to 9 millimeters, more preferably 6 millimeters to 9 millimeters. In further embodiments, the aerosol-generating article has an outer diameter of 5 millimeters to 8 millimeters, preferably 5.5 millimeters to 8 millimeters, more preferably 6 millimeters to 8 millimeters. In further embodiments, the aerosol generating article has an outer diameter of from 5 millimeters to 7 millimeters, preferably from 5.5 millimeters to 7 millimeters, more preferably from 6 millimeters to 7 millimeters.

[0357] The outer diameter of the aerosol-generating article may be substantially constant along the entire length of the article. Alternatively, different parts of the aerosol-generating article may have different outer diameters.

[0358] In particularly preferred embodiments, one or more components of the aerosol generating article are individually surrounded by their own wrapper.

[0359] In one embodiment, the aerosol-generating substrate rod and the downstream filter segment are wrapped separately. The upstream element, the aerosol-generating substrate rod, and the hollow tubular element are then combined with the outer wrapper. They are then combined with the downstream filter segment, which has its own wrapper, using tipping paper.

[0360] Preferably, at least one of the components of the aerosol generating article is wrapped in a hydrophobic wrapper.

[0361] The term "hydrophobic" refers to a surface that exhibits water-repellent properties. One common method for determining this property is by measuring the water contact angle. The water contact angle is the angle, typically measured using a liquid, where the liquid / vapor interface meets a solid surface. It quantitatively expresses the wettability of a solid surface by a liquid according to Young's equation. Hydrophobicity, or water contact angle, can be determined using TAPPI Test Method T558, and the result is reported as the contact angle at the interface, expressed in degrees, which can range from approximately zero to approximately 180 degrees.

[0362] In preferred embodiments, the hydrophobic wrapper is a wrapper comprising a paper layer having a water contact angle of about 30 degrees or more, and preferably about 35 degrees or more, or about 40 degrees or more, or about 45 degrees or more.

[0363] As an example, the paper layer may contain PVOH (polyvinyl alcohol) or silicon. PVOH may be applied to the paper layer as a surface coating, or the paper layer may be surface treated with PVOH or silicon.

[0364] In a particularly preferred embodiment, the aerosol generating article according to the present invention comprises, in a linear sequential arrangement, an upstream element, a rod of aerosol generating substrate located immediately downstream of the upstream element, a hollow tubular cooling element located immediately downstream of the rod of aerosol generating substrate, a downstream filter segment located immediately downstream of the hollow tubular cooling element, a downstream hollow tubular element located immediately downstream of the downstream filter segment, and one or more outer wrappers that combine the components.The upstream element defines the upstream section of the aerosol-generating product. The hollow tubular cooling element, the downstream filter segment, and the downstream hollow tubular element form the downstream section of the aerosol-generating product.

[0365] The aerosol-generating substrate rod may be adjacent to an upstream element. A hollow tubular cooling element may be adjacent to the aerosol-generating substrate rod. A downstream filter segment may be adjacent to the hollow tubular cooling element. The downstream hollow tubular element may be adjacent to the downstream filter segment. Preferably, the hollow tubular cooling element is adjacent to the aerosol-generating substrate rod, the downstream filter segment is adjacent to the hollow tubular cooling element, and the downstream hollow tubular element is adjacent to the downstream filter segment.

[0366] The present disclosure also relates to an aerosol-generating system comprising an aerosol-generating device having a distal end and a mouthpiece end. The aerosol-generating device may comprise a main portion. The main portion or body of the aerosol-generating device may define a cavity for removably receiving an aerosol-generating article at the mouthpiece end of the device. The aerosol-generating device may comprise a heating element or heater for heating an aerosol-generating substrate when the aerosol-generating article is received within the cavity of the device.

[0367] The cavity of the device may be referred to as the heating chamber of the aerosol-generating device. The cavity of the device may extend between the distal end and the mouthpiece, or near end. The distal end of the cavity of the device may be a closed end, and the mouthpiece, or near end of the cavity of the device may be an open end. An aerosol-generating article can be inserted into the cavity of the device, or heating chamber, through the open end of the cavity of the device. The cavity of the device may be cylindrical in shape to match the shape of the aerosol-generating article.

[0368] The term "contained within" may refer to the fact that a component or element is fully or partially contained within another component or element. For example, the term "an aerosol-generating article contained within a cavity of a device" refers to an aerosol-generating article that is fully or partially contained within the cavity of the device of the aerosol-generating article. When an aerosol-generating article is contained within a cavity of a device, the aerosol-generating article may abut against the distal end of the cavity of the device. When an aerosol-generating article is contained within a cavity of a device, the aerosol-generating article may be in substantial proximity to the distal end of the cavity of the device. The distal end of the cavity of the device may be defined by an end wall.

[0369] The device cavity length can range from 10 millimeters to 50 millimeters. The device cavity length can range from 20 millimeters to 40 millimeters. The device cavity length can range from 25 millimeters to 30 millimeters.

[0370] The length of the cavity of the device (or heating chamber) may be the same as or greater than the length of the rod of the aerosol-generating substrate. The length of the cavity of the device may be the same as or greater than the sum of the lengths of the upstream section or element and the rod of the aerosol-generating substrate. Preferably, the length of the cavity of the device is such that at least 75 percent of the length of the rod of the aerosol-generating substrate is inserted or contained within the cavity of the device when the aerosol-generating article is inserted into the aerosol-generating device. More preferably, the length of the cavity of the device is such that at least 80 percent of the length of the rod of the aerosol-generating substrate is inserted or contained within the cavity of the device when the aerosol-generating article is inserted into the aerosol-generating device.More preferably, the length of the device cavity is such that at least 90 percent of the length of the aerosol-generating substrate rod is inserted or contained within the cavity of the device when the aerosol-generating article is inserted into the aerosol-generating device. This maximizes the length of the aerosol-generating substrate rod along which the aerosol-generating substrate can heat up during use, thereby optimizing aerosol generation from the aerosol-generating substrate and reducing tobacco waste.

[0371] The length of the cavity of the device may be such that a downstream section or a portion thereof is configured to protrude from the cavity of the device when the aerosol-generating article is received within the cavity of the device. The length of the cavity of the device may be such that a portion of the downstream section (e.g., a hollow tubular cooling element or a downstream filter segment) is configured to protrude from the cavity of the device when the aerosol-generating article is received within the cavity of the device. The length of the cavity of the device may be such that a portion of the downstream section (e.g., a hollow tubular cooling element or a downstream filter segment) is configured to be received within the cavity of the device when the aerosol-generating article is received within the cavity of the device.

[0372] At least 25 percent of the length of the downstream section can be inserted or accommodated within the cavity of the device when the aerosol-generating article is inserted within the device. At least 30 percent of the length of the downstream section can be inserted or accommodated within the cavity of the device when the aerosol-generating article is inserted within the device.

[0373] At least 30 percent of the length of the hollow tubular element can be inserted or accommodated within the cavity of the device when the aerosol-generating article is inserted within the device. At least 40 percent of the length of the hollow tubular element can be inserted or accommodated within the cavity of the device when the aerosol-generating article is inserted within the device. At least 50 percent of the length of the hollow tubular element can be inserted or accommodated within the cavity of the device when the aerosol-generating article is inserted within the device. Various lengths of the hollow tubular element are described in more detail in this disclosure.

[0374] Optimizing the quantity or length of the article inserted into the aerosol-generating device can improve the article's resistance to accidental dislodgment during use. Specifically, when the aerosol-generating substrate is heated, the substrate can contract so that its outer diameter can decrease, thereby reducing the degree to which the inserted portion of the article inserted into the device can frictionally engage with the device cavity. The inserted portion of the article or the portion of the article configured to fit within the device cavity can have the same length as the device cavity.

[0375] The length of the device cavity can be from 15 millimeters to 80 millimeters. Preferably, the length of the device cavity is from 20 millimeters to 0 millimeters. More preferably, the length of the device cavity is from 25 millimeters to 60 millimeters. More preferably, the length of the device is from 25 millimeters to 50 millimeters.

[0376] The length of the device cavity may be between 25 millimeters and 29 millimeters. Preferably, the length of the device cavity is between 25 millimeters and 29 millimeters. More preferably, the length of the device cavity is between 26 millimeters and 29 millimeters. Even more preferably, the length of the device cavity is 27 millimeters or 28 millimeters.

[0377] The device cavity diameter may range from 4 millimeters to 10 millimeters. The device cavity diameter may range from 5 millimeters to 9 millimeters. The device cavity diameter may range from 6 millimeters to 8 millimeters. The device cavity diameter may range from 6 millimeters to 7 millimeters.

[0378] The diameter of the cavity of the device may be substantially the same as or larger than the diameter of the aerosol-generating article. The diameter of the cavity of the device may be the same as the diameter of the aerosol-generating article to form an interference fit with the aerosol-generating article.

[0379] The cavity of the device may be configured to form an interference fit with an aerosol-generating article received within the cavity of the device. The interference fit may refer to a tight fit. The aerosol-generating device may comprise a peripheral wall. Such a peripheral wall may define the cavity of the device or a heating chamber. The peripheral wall defining the cavity of the device may be configured to engage the aerosol-generating article received within the cavity of the device via an interference fit, such that there is substantially no gap or empty space between the peripheral wall defining the cavity of the device and the aerosol-generating article when it is received within the device.

[0380] Such an interference fit may create a hermetic fit or configuration between the cavity of the device and the aerosol-generating article contained therein.

[0381] With such a sealed configuration, there will be substantially no gap or empty space between the peripheral wall defining the cavity of the device and the aerosol generating article for air to flow therethrough.

[0382] An interference fit with the aerosol generating article may be created along the entire length of the cavity of the device or along a portion of the length of the cavity of the device.

[0383] An aerosol-generating device may comprise an airflow channel extending between an inlet opening of the channel and an outlet opening of the channel. The airflow channel may be configured to create fluid communication between the interior of the cavity of the device and the exterior of the aerosol-generating device. The airflow channel of the aerosol-generating device may be defined within the housing of the aerosol-generating device to provide fluid communication between the interior of the cavity of the device and the exterior of the aerosol-generating device. When the aerosol-generating article is housed within the cavity of the device, the airflow channel may be configured to provide airflow into the article to deliver the generated aerosol to the user, who takes a puff through the mouthpiece end of the article.

[0384] The airflow passage of the aerosol-generating device may be defined within the peripheral wall of the aerosol-generating device housing or by this peripheral wall. In other words, the airflow passage of the aerosol-generating device may be defined within the thickness of the peripheral wall, by the inner surface of the peripheral wall, or by a combination of both. The airflow passage may be partially defined by the inner surface of the peripheral wall or may be partially defined within the thickness of the peripheral wall. The inner surface of the peripheral wall defines the peripheral boundary of the cavity of the device.

[0385] The airflow channel of the aerosol-generating device may extend from an inlet located at the mouthpiece end or proximal end of the aerosol-generating device to an outlet located away from the mouthpiece end of the device. The airflow channel may extend along a direction parallel to the longitudinal axis of the aerosol-generating device.

[0386] The heater may be any suitable type. Preferably, in the present invention, the heater is an external heater.

[0387] Preferably, the heater can externally heat the aerosol-generating article when it is placed within the aerosol-generating device. Such an external heater can surround the aerosol-generating article when it is inserted into or placed within the aerosol-generating device.

[0388] In some embodiments, the heater is positioned to heat the outer surface of the aerosol-generating substrate. In some embodiments, the heater is configured to be inserted into the aerosol-generating substrate when the aerosol-generating substrate is contained within a cavity. The heater may be located within the cavity of the device or a heating chamber.

[0389] The heater may comprise at least one heating element. The at least one heating element may be a heating element of any suitable type. In some embodiments, the device comprises only one heating element. In some embodiments, the device comprises multiple heating elements. The heater may comprise at least one resistive heating element. Preferably, the heater comprises multiple resistive heating elements. Preferably, the resistive heating elements are electrically connected in a parallel arrangement. Advantageously, providing multiple resistive heating elements electrically connected in a parallel arrangement can facilitate the delivery of the desired electrical power to the heater while reducing or minimizing the voltage required to provide the desired electrical power.Advantageously, reducing or minimizing the voltage required to operate the heater can help reduce or minimize the physical size of the power supply.

[0390] Suitable materials for forming at least one resistive heating element include, but are not limited to: semiconductors such as doped ceramics, electrically conductive ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys, and composite materials made from a ceramic material and a metallic material. Such composite materials may comprise doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbides. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals.Examples of suitable metal alloys include stainless steel, alloys containing nickel, cobalt, chromium, aluminum, titanium, zirconium, hafnium, niobium, molybdenum, tantalum, tungsten, tin, gallium, manganese, and iron, and nickel-based, iron-based, cobalt-based superalloys, stainless steel, Timetal®, and iron-based, manganese-based, and aluminum-based alloys.

[0391] In some embodiments, at least one resistive heating element comprises one or more stamped portions made of an electrically resistive material, such as stainless steel. Alternatively, at least one resistive heating element may comprise a heating wire or filament, such as a Ni-Cr (nickel-chromium), platinum, tungsten, or alloy wire.

[0392] In some embodiments, at least one heating element comprises an electrically insulating substrate, wherein at least one resistive heating element is provided on the electrically insulating substrate.

[0393] The electrically insulating substrate may comprise any suitable material. For example, the electrically insulating substrate may comprise one or more of paper, glass, ceramic, anodized metal, coated metal, and polyimide. Ceramics may include mica, aluminum oxide (Al2O3), or zirconium dioxide (ZrO2). Preferably, the electrically insulating substrate has a thermal conductivity of less than or equal to approximately 40 watts per meter Kelvin, preferably less than or equal to approximately 20 watts per meter Kelvin, and ideally less than or equal to approximately 2 watts per meter Kelvin.

[0394] The heater may comprise a heating element comprising a rigid, electrically insulating substrate with one or more electrically conductive tracks or wires located on its surface. The size and shape of the electrically insulating substrate may allow it to be inserted directly into the aerosol-generating substrate. If the electrically insulating substrate is not sufficiently rigid, the heating element may comprise additional amplifying means. Current may flow through the one or more electrically conductive tracks to heat the heating element and the aerosol-generating substrate.

[0395] In some embodiments, the heater comprises an induction heating device. The induction heating device may comprise an induction coil and a power supply configured to supply a high-frequency oscillating current to the induction coil. In the context of this document, "high-frequency oscillating current" means an oscillating current with a frequency of from approximately 500 kHz to approximately 30 MHz. The heater may advantageously comprise a DC-to-AC converter for converting the DC current supplied by the DC power supply into an AC current. The induction coil may be designed to generate a high-frequency oscillating electromagnetic field upon receiving the high-frequency oscillating current from the power supply. The induction coil may be designed to generate a high-frequency oscillating electromagnetic field in the cavity of the device.In some embodiments, the induction coil may substantially surround the cavity of the device. The induction coil may extend at least partially along the length of the cavity of the device.

[0396] The heater may comprise an induction heating element. The induction heating element may be a current collector. As used herein, the term "current collector" refers to an element comprising a material capable of converting electromagnetic energy into heat. When the current collector is placed in an alternating electromagnetic field, the current collector heats up. Heating of the current collector may result from at least one of hysteresis losses and eddy currents induced in the current collector, depending on the electrical and magnetic properties of the current collector material.

[0397] The current-receiving element can be configured such that, when the aerosol-generating article is accommodated in the cavity of the aerosol-generating device, the oscillating electromagnetic field generated by the induction coil induces a current in the current-receiving element, which leads to heating of the current-receiving element. In these embodiments, the aerosol-generating device is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (field strength H) of from 1 to 5 kiloamperes per meter (kA / m), preferably from 2 to 3 kA / m, for example, approximately 2.5 kA / m. The electrical aerosol-generating device is preferably capable of generating a fluctuating electromagnetic field having a frequency of from 1 to 30 MHz, for example, from 1 to 10 MHz, for example, from 5 to 7 MHz.

[0398] In these embodiments, the current-receiving element is preferably positioned in contact with the aerosol-generating substrate. In some embodiments, the current-receiving element is positioned within the aerosol-generating device. In these embodiments, the current-receiving element may be positioned within a cavity. The aerosol-generating device may comprise only one current-receiving element. The aerosol-generating device may comprise multiple current-receiving elements. In some embodiments, the current-receiving element is preferably positioned to heat the outer surface of the aerosol-generating substrate.

[0399] The current collector may comprise any suitable material. The current collector may be formed from any material that can be inductively heated to a temperature sufficient to release volatile compounds from the aerosol-generating substrate. Suitable materials for the elongated current collector include graphite, molybdenum, silicon carbide, stainless steels, niobium, aluminum, nickel, nickel compounds, titanium, and composites of metallic materials. Some current collectors contain metal or carbon. Advantageously, the current collector may comprise or consist of a ferromagnetic material, such as ferritic iron, a ferromagnetic alloy such as ferromagnetic steel or stainless steel, ferromagnetic particles, and ferrite. A suitable current collector may be made of or comprise aluminum.The current collecting element preferably contains more than approximately 5 percent, preferably more than 20 percent, more preferably more than 50 percent, or more than 90 percent ferromagnetic or paramagnetic materials. Some elongated current collecting elements can be heated to temperatures in excess of 250 degrees Celsius.

[0400] The current-collecting element may comprise a non-metallic core with a metallic layer located on the non-metallic core. For example, the current-collecting element may comprise metallic tracks formed on the outer surface of a ceramic core or substrate.

[0401] In some embodiments, the aerosol-generating device may comprise at least one resistive heating element and at least one inductive heating element. In some embodiments, the aerosol-generating device may comprise a combination of resistive heating elements and inductive heating elements.

[0402] During use, the heater can be controlled to operate within a specified operating temperature range below the maximum operating temperature. The preferred operating temperature range is from approximately 150 degrees Celsius to approximately 300 degrees Celsius in the heating chamber (or cavity of the device). The heater's operating temperature range can be from approximately 150 degrees Celsius to approximately 250 degrees Celsius.

[0403] Preferably, the operating temperature range of the heater may be from about 150 degrees Celsius to about 200 degrees Celsius. More preferably, the operating temperature range of the heater may be from about 180 degrees Celsius to about 200 degrees Celsius. In particular, it was found that optimal and consistent aerosol delivery can be achieved by using an aerosol generating device containing an external heater that has an operating temperature range of about 180 degrees Celsius to about 200 degrees Celsius, wherein the aerosol generating articles have a relatively low RTD (for example, the RTD of the downstream section is less than 15 millimeters of water column), as mentioned in the present disclosure.

[0404] In embodiments where the aerosol-generating article comprises a ventilation zone at a location along a downstream section or a hollow tubular element, the ventilation zone may be arranged so as to be open when the aerosol-generating article is contained within the cavity of the device. Thus, the length of the cavity of the device or the heating chamber may be less than the distance from the upstream end of the aerosol-generating article to the ventilation zone located along the downstream section. In other words, when the aerosol-generating article is contained within the aerosol-generating device, the distance between the ventilation zone and the upstream end of the upstream element may be greater than the length of the heating chamber.

[0405] When the article is placed inside the cavity of the device, the ventilation zone may be located at a distance of at least 0.5 millimeters (in the downstream direction relative to the article) from the mouthpiece end (or the surface of the mouthpiece end) of the cavity of the device or the device itself. When the article is placed inside the cavity of the device, the ventilation zone may be located at a distance of at least 1 millimeter (in the downstream direction relative to the article) from the mouthpiece end (or the surface of the mouthpiece end) of the cavity of the device or the device itself. When the article is placed inside the cavity of the device, the ventilation zone may be located at a distance of at least 2 millimeters (in the downstream direction relative to the article) from the mouthpiece end (or the surface of the mouthpiece end) of the cavity of the device or the device itself.

[0406] It is preferable that the ratio between the distance between the ventilation zone and the upstream end of the upstream element and the length of the heating chamber is from 1.03 to 1.13.

[0407] This arrangement of the ventilation zone ensures that the ventilation zone is not blocked within the cavity of the device itself, while minimizing the risk of blocking by the user's lips or hands, since the ventilation zone is located as far upstream as possible relative to the end of the product located further downstream, without being blocked within the cavity of the device.

[0408] The aerosol-generating device may include a power supply. The power supply may be a DC power supply. In some embodiments, the power supply is a battery. The power supply may be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery, such as a lithium-cobalt, lithium-iron phosphate, or lithium-polymer battery. However, in some embodiments, the power supply may be another type of charge storage device, such as a capacitor. The power supply may require recharging and may have a capacity capable of storing sufficient energy for one or more user operations, such as one or more aerosol generation sessions.For example, the power supply may have sufficient capacity to continuously heat the aerosol-generating substrate for approximately six minutes, which corresponds to the typical time required to smoke a conventional cigarette, or for a period of time that is a multiple of six minutes. In another example, the power supply may have sufficient capacity to support a specified number of puffs or individual heater activations.

[0409] The following is a non-exhaustive list of non-limiting examples. Any one or more features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0410] EX1. An aerosol-generating article comprising: an aerosol-generating substrate rod.

[0411] EX2. An aerosol-generating article according to example EX1, wherein the rod of the aerosol-generating substrate has a length of at least 17 millimeters.

[0412] EX3. An aerosol-generating article according to any preceding example, wherein the aerosol-generating substrate rod comprises tobacco material.

[0413] EX4. An aerosol-generating article according to example EX3, wherein the tobacco material has a density of less than 350 milligrams per cubic centimeter.

[0414] EX5. An aerosol-generating article according to example EX4, wherein the tobacco material has a density of less than 300 milligrams per cubic centimeter.

[0415] EX6. An aerosol-generating article according to example EX3, EX4 or EX5, wherein the tobacco material has a density of at least 100 milligrams per cubic centimeter.

[0416] EX7. An aerosol-generating article according to Example EX3, wherein the tobacco material has a density of between 150 milligrams per cubic centimeter and 500 milligrams per cubic centimeter.

[0417] EX8. An aerosol-generating article according to example EX7, wherein the tobacco material has a density of from 200 milligrams per cubic centimeter to 400 milligrams per cubic centimeter.

[0418] EX9. An aerosol generating article according to any preceding example, comprising a downstream section provided downstream of the aerosol generating substrate rod.

[0419] EX10. An aerosol generating article according to example EX9, wherein the downstream section comprises a hollow tubular element adjacent to the downstream end of the aerosol generating substrate rod.

[0420] EX11. An aerosol generating article according to example EX10, wherein the hollow tubular element has a length of at least 40 millimeters.

[0421] EX12. An aerosol generating article according to example EX9, wherein the downstream section comprises a downstream filter segment.

[0422] EX13. An aerosol generating article according to example EX12, wherein the downstream section comprises a ventilation zone at a location downstream of the downstream filter segment.

[0423] EX14. An aerosol generating article according to example EX12 or EX13, wherein the downstream filter segment is a solid plug.

[0424] EX15. An aerosol generating article according to any one of the examples EX12-EX14, comprising a downstream hollow tubular element, wherein the downstream tubular element is positioned downstream of the downstream filter segment.

[0425] EX16. An aerosol generating article according to example EX15, wherein the downstream hollow tubular element is adjacent to the downstream end of the downstream filter segment.

[0426] EX17. An aerosol generating article according to example EX15 or EX16, wherein the ventilation zone is located at a location along a downstream hollow tubular element.

[0427] EX18. An aerosol generating article according to example EX17, wherein the ventilation zone is located at a location in the direction of the upstream end of the downstream end of the hollow tubular element.

[0428] EX19. An aerosol generating article according to any of the examples EX12-EX18, wherein the downstream section comprises a hollow tubular cooling element and wherein the downstream filter segment is adjacent to the downstream end of the hollow tubular cooling element.

[0429] EX20. An aerosol generating article according to any of the examples EX12-EX19, wherein the downstream filter segment has a length of at least 5 millimeters.

[0430] EX21. An aerosol generating article according to any of the examples EX12 to EX20, wherein the downstream filter segment has a length that is less than or equal to 20 millimeters.

[0431] EX22. An aerosol generating article according to any of EX12 or EX21, wherein the downstream filter segment has a length of between 5 millimeters and 20 millimeters.

[0432] EX23. An aerosol generating article according to example EX9, wherein the downstream section extends to the downstream end of the aerosol generating article.

[0433] EX24. An aerosol generating article according to example EX9 or EX23, wherein the downstream section comprises a hollow tubular cooling element.

[0434] EX25. An aerosol generating article according to example EX24, wherein the hollow tubular cooling element has a length of at least 20 millimeters.

[0435] EX26. An aerosol generating article according to example EX25, wherein the hollow tubular cooling element has a length of at least 25 millimeters.

[0436] EX27. An aerosol generating article according to any of examples EX24 to EX26, wherein the hollow tubular cooling element has a length that is less than or equal to 50 millimeters.

[0437] EX28. An aerosol generating article according to example EX27, wherein the hollow tubular cooling element has a length of from 20 millimeters to 50 millimeters.

[0438] EX29. An aerosol generating article according to any of EX9 or EX23-EX26, wherein the downstream section has a length of at least 45 millimeters.

[0439] EX30. An aerosol-generating article according to any preceding example, where the maximum outside diameter of the aerosol-generating article is less than 8 millimeters.

[0440] EX31. An aerosol-generating article according to example EX30, wherein the aerosol-generating article has a maximum outside diameter of between 5 millimeters and 8 millimeters.

[0441] EX32. An aerosol-generating article according to example EX30 or EX31, wherein the aerosol-generating article has a maximum outside diameter that is less than or equal to 7 millimeters.

[0442] EX33. An aerosol-generating article according to example EX32, wherein the aerosol-generating article has a maximum outside diameter of between 5.5 millimeters and 7 millimeters.

[0443] EX34. An aerosol generating article according to example EX9, wherein the ratio of the length of the downstream section to the length of the aerosol generating substrate rod is at least 1.5.

[0444] EX35. An aerosol generating article according to example EX9, wherein the ratio of the length of the downstream section to the total length of the aerosol generating article is at least 0.6.

[0445] EX36. An aerosol-generating article according to any preceding example, wherein the aerosol-generating article has an overall length of at least 50 millimetres.

[0446] EX37. An aerosol-generating article according to any preceding example, wherein the rod of the aerosol-generating substrate has a length that is less than or equal to 40 millimeters.

[0447] EX38. An aerosol-generating article according to example EX37, wherein the rod of the aerosol-generating substrate has a length that is less than or equal to 36 millimeters.

[0448] EX39. An aerosol-generating article according to any preceding example, wherein the rod of the aerosol-generating substrate has a length that is less than or equal to 30 millimeters.

[0449] EX40. An aerosol-generating article according to any preceding example, wherein the rod of the aerosol-generating substrate has a length that is less than or equal to 25 millimeters.

[0450] EX41. An aerosol-generating article according to any preceding example, wherein the rod of the aerosol-generating substrate has a length that is less than or equal to 20 millimeters.

[0451] EX42. An aerosol-generating article according to any preceding example, wherein the ratio of the length of the aerosol-generating substrate rod to the total length of the aerosol-generating article is less than or equal to 0.4.

[0452] EX43. An aerosol-generating article according to any preceding example, wherein the rod of the aerosol-generating substrate has a length of at least 17 millimetres.

[0453] EX44. An aerosol-generating article according to any preceding example, wherein the rod of the aerosol-generating substrate has a length of at least 20 millimeters.

[0454] EX45. An aerosol-generating article according to any preceding example, wherein the rod of the aerosol-generating substrate has a length of at least 25 millimeters.

[0455] EX46. An aerosol-generating article according to any preceding example, wherein the rod of the aerosol-generating substrate has a length of at least 29 millimeters.

[0456] EX47. An aerosol-generating article according to any preceding example, wherein the rod of the aerosol-generating substrate has a length of between 29 millimeters and 36 millimeters.

[0457] EX48. An aerosol generating article according to any preceding example, comprising an upstream element.

[0458] EX49. An aerosol generating article according to example EX48, wherein the upstream element is provided upstream of the aerosol generating substrate rod.

[0459] EX50. An aerosol generating article according to example EX48 or EX49, wherein the upstream element is provided adjacent to the upstream end of the aerosol generating substrate rod.

[0460] EX51. An aerosol generating article according to any of EX48-EX50, wherein the upstream element has a length of between 2 millimeters and 8 millimeters.

[0461] EX52. An aerosol generating article according to any of the examples EX48-EX51, wherein the upstream element has a length of between 2 millimeters and 6 millimeters.

[0462] EX53. An aerosol generating article according to any of the examples EX48-EX52, wherein the upstream element has a length of between 4 millimeters and 6 millimeters.

[0463] EX54. An aerosol generating article according to any of the examples EX48-EX53, wherein the upstream element comprises a hollow support segment having a central longitudinal cavity passing therethrough.

[0464] EX55. An aerosol-generating article according to example EX54, wherein the hollow tubular support member has a wall thickness of less than 1 millimeter.

[0465] EX56. An aerosol generating article according to one of the examples EX48-EX55, wherein the resistance to draw (RTD) of the upstream element is less than or equal to 10 millimeters of water column.

[0466] EX57. An aerosol-generating article according to any preceding example, wherein the aerosol-generating article has an overall length of at least 60 millimetres.

[0467] EX58. An aerosol-generating article according to example EX57, wherein the aerosol-generating article has an overall length of at least 65 millimetres.

[0468] EX59. An aerosol-generating article according to any preceding example, wherein the aerosol-generating article has an overall length that is less than or equal to 90 millimetres.

[0469] EX60. An aerosol-generating article according to any preceding example, wherein the aerosol-generating article has an overall length of between 65 millimeters and 90 millimeters.

[0470] EX61. An aerosol-generating article according to any preceding example, wherein the aerosol-generating substrate rod comprises one or more aerosol-forming substances.

[0471] EX62. An aerosol-generating article according to example EX61, wherein the aerosol-generating substrate rod has an aerosol-forming substance content that is less than or equal to 30 percent by weight on a dry weight basis.

[0472] EX63. An aerosol-generating article according to example EX62, wherein the aerosol-generating substrate rod has an aerosol-forming substance content that is less than or equal to 20 percent by weight on a dry weight basis.

[0473] EX64. An aerosol-generating article according to example EX63, wherein the aerosol-generating substrate rod has an aerosol-forming substance content that is less than or equal to 10 percent by weight on a dry weight basis.

[0474] EX65. An aerosol-generating article according to example EX62, wherein the aerosol-generating substrate rod has an aerosol-forming substance content of from 10 percent to 30 percent by weight, calculated on a dry weight basis.

[0475] EX66. An aerosol-generating article according to any of examples EX61-EX65, wherein the one or more aerosol-forming substances comprise one or more of glycerin and propylene glycol.

[0476] EX67. An aerosol generating article according to any preceding example, wherein the ratio of the length of the upstream element to the length of the hollow tubular element of the downstream section is from 0.01 to 0.15.

[0477] EX68. An aerosol-generating article according to any one of EX3 to EX67, wherein the tobacco material comprises shredded tobacco material.

[0478] EX69. An aerosol-generating article according to any preceding example, wherein the ratio of the length of the aerosol-generating substrate rod to the total length of the aerosol-generating article is at least 0.2, preferably 0.25.

[0479] EX70. Aerosol generating system comprising:

[0480] an aerosol-generating article according to any preceding example; and

[0481] an aerosol generating device comprising a heating chamber for containing an aerosol generating article and at least a heating element provided on the heating chamber or along its periphery.

[0482] Next, the present invention will be further described with reference to the drawings, in which:

[0483] Fig. 1 is a schematic side sectional view of an aerosol generating article according to the present disclosure;

[0484] Fig. 2 is a schematic side sectional view of an aerosol generating article in accordance with the present disclosure;

[0485] Fig. 3a and 3b are schematic side cross-sectional views of an aerosol generating article according to the present disclosure;

[0486] Fig. 4a and 4b are schematic side cross-sectional views of an aerosol generating article according to the present disclosure;

[0487] Fig. 5 is a schematic side sectional view of an aerosol generating article according to the present disclosure;

[0488] Fig. 6 is a schematic side sectional view of an aerosol generating article according to the present disclosure;

[0489] Fig. 7 is a schematic side sectional view of an aerosol generating article in accordance with the present disclosure;

[0490] Fig. 8 is a schematic side sectional view of an aerosol generating article in accordance with the present disclosure;

[0491] Fig. 9 is a schematic side sectional view of an aerosol generating article according to the present disclosure;

[0492] Fig. 10 is a schematic side sectional view of an aerosol generating article in accordance with the present disclosure;

[0493] Fig. 11 is a schematic side sectional view of an aerosol generating article according to the present disclosure;

[0494] Fig. 12 is a schematic side sectional view of an aerosol generating article according to the present disclosure;

[0495] Fig. 13 is a schematic side sectional view of an aerosol generating article according to the present disclosure;

[0496] Fig. 14 is a schematic side sectional view of an aerosol generating article according to the present disclosure;

[0497] Fig. 15 is a schematic side cross-sectional view of an aerosol generating article in accordance with the present disclosure; and

[0498] Fig. 16 is a schematic side sectional view of an aerosol generating system comprising an aerosol generating device and an aerosol generating article in accordance with the present disclosure.

[0499] The aerosol-generating articles shown in all figures of the present disclosure comprise a rod 12 of an aerosol-generating substrate and a downstream section 14 located downstream of the rod 12 of the aerosol-generating substrate. The aerosol-generating articles extend from an upstream or distal end 18 to a downstream or mouthpiece end 19. The downstream or mouthpiece end 19 is defined by the downstream end of the downstream section 14.

[0500] Each of the components of the aerosol-generating articles shown in the figures and described in this disclosure may be surrounded by corresponding wrappers or may be connected together by one or more wrappers that are not shown in the figures. The maximum outer diameter of each of the aerosol-generating articles shown in the figures is 6.5 mm, unless otherwise specifically stated.

[0501] The aerosol-generating substrate rod 12 is surrounded by a wrapper (not shown) and contains at least one of the types of aerosol-generating substrate described in the present disclosure, such as a plant-based filler, in particular, tobacco cut filler, homogenized tobacco, a gel composition, or homogenized plant material containing particles of a plant other than tobacco. The aerosol-generating article rod 12 shown in all figures has an average tobacco density of approximately 250 mg per cubic centimeter.

[0502] The downstream section 14 of the aerosol-generating article 10 shown in Fig. 1 comprises a hollow tubular cooling element 22, a downstream filter segment 24, and a downstream or mouthpiece-end hollow tubular element 26. The hollow tubular cooling element 22 is located immediately downstream of the rod 12 of the aerosol-generating substrate. In other words, the hollow tubular cooling element 22 is adjacent to the downstream end of the rod 12. The downstream filter segment 24 is adjacent to the downstream end of the hollow tubular cooling element 22, and the downstream hollow tubular element 26 is adjacent to the downstream end of the downstream filter segment 24.Consequently, the downstream filter segment 24 is positioned between the hollow tubular cooling element 22 and the downstream hollow tubular element 26. The downstream end 19 of the article 10 is defined by the downstream end of the downstream hollow tubular element 26.

[0503] The length of the rod 12 of the aerosol generating substrate is approximately 40mm.

[0504] The hollow tubular cooling element 22 is provided in the form of a hollow cylindrical tube made of cardboard or cellulose acetate. The hollow tubular cooling segment 22 defines an internal cavity that extends the entire distance from the upstream end of the hollow tubular cooling element 22 to the downstream end of the hollow tubular cooling element 22. The internal cavity is substantially empty, and therefore, a substantially unlimited air flow along the internal cavity is possible. The hollow tubular cooling element 22 may not substantially affect the overall RTD of the aerosol-generating article 10. The length of the hollow tubular cooling element 22 is approximately 25 mm. The wall thickness of the hollow tubular cooling element 22 is approximately 250 micrometers (μm).

[0505] The downstream filter segment 24 contains a cylindrical plug made of cellulose acetate tow. The length of the downstream filter segment 24 is approximately 10 mm.

[0506] The downstream hollow tubular element 26 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The downstream hollow tubular element 26 defines an internal cavity that extends the entire distance from the upstream end of the downstream hollow tubular element 26 to the downstream end of the downstream hollow tubular element 26. The internal cavity is substantially empty, and therefore, a substantially unlimited air flow along the internal cavity is possible. The downstream hollow tubular element 26 does not substantially affect the overall RTD of the aerosol-generating article 10. The length of the downstream hollow tubular element 26 is approximately 6 mm. The wall thickness of the downstream hollow tubular element 26 is approximately 1 mm.

[0507] The aerosol generating article 10 comprises a ventilation zone 36 provided in a location along the hollow tubular cooling element 22. The ventilation zone 36 comprises at least one annular row of perforations passing through the peripheral wall of the hollow tubular cooling element 22 and any wrapper (not shown) surrounding the hollow tubular cooling element 22. The ventilation zone 36 is provided at a distance of approximately 2 millimeters from the downstream end of the hollow tubular cooling element 22.

[0508] The aerosol generating article 101 shown in Fig. 2 is similar to the aerosol generating article 10 shown in Fig. 1, and differs only in the following aspects. The rod 12 of the aerosol generating substrate is shorter, and the hollow tubular cooling element 22 is longer. The length of the rod 12 of the aerosol generating substrate is approximately 25 mm. The length of the hollow tubular cooling element 22 is approximately 40 mm.

[0509] The aerosol generating article 102 shown in Fig. 3a is similar to the aerosol generating article 101 shown in Fig. 2, and differs only in the following aspects. The hollow tubular cooling element 22 is shorter, and the downstream hollow tubular element 27 is longer. The length of the hollow tubular cooling element 22 is approximately 25 mm. The length of the downstream hollow tubular element 27 is approximately 20 mm. In addition, a ventilation zone 36 is provided along the downstream hollow tubular element 27. The ventilation zone 36 is provided at a distance of approximately 2 millimeters from the upstream end of the downstream hollow tubular element 26.The ventilation zone 36 comprises at least one annular row of perforations passing through the peripheral wall of the downstream hollow tubular element 27 and any wrapper (not shown) surrounding the downstream hollow tubular element 27.

[0510] The aerosol generating article 103 shown in Fig. 3b is similar to the aerosol generating article 102 shown in Fig. 3a, and differs only in the following aspects. The downstream hollow tubular element 27 comprises two adjacent hollow tubular segments 271, 272. The first hollow tubular segment 271 is located between the downstream filter segment 24 and the second hollow tubular segment 272.

[0511] In Fig. 3b, the first hollow tubular segment 271 is provided in the form of a hollow cylindrical tube made of cardboard. The first hollow tubular segment 271 forms an internal cavity that extends the entire distance from the upstream end of the first hollow tubular segment 271 to the downstream end of the first hollow tubular segment 271. The internal cavity is substantially empty, and therefore, a substantially unlimited air flow along the internal cavity is possible. The first hollow tubular segment 271 may not substantially affect the overall RTD of the aerosol-generating article 103. The length of the first hollow tubular segment 271 is approximately 10 mm. The wall thickness of the first hollow tubular segment 271 is approximately 250 micrometers (μm).The ventilation zone 36 is provided at a distance of approximately 2 millimeters from the upstream end of the first hollow tubular segment 271 of the downstream hollow tubular element 27.

[0512] In Fig. 3b, the second hollow tubular segment 272 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The second hollow tubular segment 272 forms an internal cavity that extends the entire distance from the upstream end of the second hollow tubular segment 272 to the downstream end of the second hollow tubular segment 272. The internal cavity is substantially empty, and therefore, a substantially unlimited air flow along the internal cavity is possible. The second hollow tubular segment 272 does not substantially affect the overall RTD of the aerosol-generating article 103. The length of the second hollow tubular segment 272 is approximately 10 mm. The wall thickness of the second hollow tubular segment 272 is approximately 1 mm.

[0513] The aerosol generating articles 104, 105 shown in Fig. 4a and Fig. 4b are similar to the aerosol generating article 101 shown in Fig. 2 and differ only in that the aerosol generating articles 104, 105 additionally comprise an upstream section 16 located upstream of the aerosol generating substrate rod 12. The distal end 18 of the articles 104, 105 is defined by the upstream end of the upstream section 16. The upstream section 16 comprises an upstream element 341, 342 adjacent to the upstream end of the rod 12. The length of the upstream element 341, 342 is approximately 5 mm. In the article 104 shown in Fig. 4a, the upstream element 341 is provided in the form of a cylindrical plug made of cellulose acetate tow. In the article 105 shown in Fig.4b, the upstream element 342 is provided in the form of a hollow cylindrical tube made of cellulose acetate having a wall thickness of approximately 1 mm.

[0514] The downstream section 14 of the aerosol generating article 20 shown in Fig. 5 comprises a hollow tubular support member 28, a cooling member 32, and a downstream filter segment 24. The hollow tubular support member 28 is located immediately downstream of the aerosol generating substrate rod 12. In other words, the hollow tubular support element 28 is adjacent to the downstream end of the rod 12. The cooling element 32 is adjacent to the downstream end of the hollow tubular support element 28, and the downstream filter segment 24 is adjacent to the downstream end of the cooling element 32. Consequently, the cooling element 32 is located between the hollow tubular support element 28 and the downstream filter segment 24.The downstream end 19 of the article 20 is defined by the downstream end of the downstream filter segment 24.

[0515] The length of the rod 12 of the aerosol generating substrate is approximately 25mm.

[0516] The hollow tubular support member 28 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The hollow tubular support member 28 defines an internal cavity that extends the entire distance from the upstream end of the hollow tubular support member 28 to the downstream end of the hollow tubular support member 28. The internal cavity is substantially empty, and therefore, a substantially unrestricted air flow along the internal cavity is possible. The hollow tubular support member 28 may not substantially affect the overall RTD of the aerosol-generating article 20. The length of the hollow tubular support member 28 is approximately 8 mm. The wall thickness of the hollow tubular support member 28 is approximately 1.5 mm.

[0517] Cooling element 32 is formed from a thin polylactic acid (PLA) sheet material that has been corrugated, pleated, gathered, or bent to form channels. The length of cooling element 32 is approximately 18 mm.

[0518] The downstream filter segment 24 contains a cylindrical plug made of cellulose acetate tow. The length of the downstream filter segment 24 is approximately 7 mm.

[0519] The maximum outer diameter of the aerosol generating product 20 is approximately 7.3mm.

[0520] The aerosol generating article 201 shown in Fig. 6 is similar to the aerosol generating article 20 shown in Fig. 5, and differs only in that it additionally comprises a hollow tubular cooling element 22 and in that the rod 12 of the aerosol generating substrate is shorter. The length of the rod 12 of the aerosol generating substrate is approximately 12 mm. The hollow tubular cooling element 22 is located immediately downstream of the cooling element 32 and immediately upstream of the filter segment 24 located downstream. In other words, the hollow tubular cooling element 22 is adjacent to the cooling element 32 and the filter segment 24 located downstream.

[0521] The hollow tubular cooling element 22 is provided in the form of a hollow cylindrical tube made of cardboard. The hollow tubular cooling segment 22 defines an internal cavity that extends the entire distance from the upstream end of the hollow tubular cooling element 22 to the downstream end of the hollow tubular cooling element 22. The internal cavity is substantially empty, and therefore, a substantially unrestricted air flow along the internal cavity is possible. The hollow tubular cooling element 22 may not substantially affect the overall RTD of the aerosol-generating article 201. The length of the hollow tubular cooling element 22 is approximately 25 mm.

[0522] The wall thickness of the hollow tubular cooling element 22 is approximately 250 micrometers (μm).

[0523] The aerosol generating article 202 shown in Fig. 7 is similar to the aerosol generating article 201 shown in Fig. 6, and differs only in that it additionally comprises a downstream hollow tubular element 27. The downstream hollow tubular element 27 is adjacent to the downstream end of the downstream filter segment 24. Consequently, the downstream filter segment 24 is located between the hollow tubular cooling element 22 and the downstream hollow tubular element 27. The downstream end 19 of the article 202 is defined by the downstream end of the downstream hollow tubular element 27.

[0524] The downstream hollow tubular element 27 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The downstream hollow tubular element 27 defines an internal cavity that extends the entire distance from the upstream end of the downstream hollow tubular element 27 to the downstream end of the downstream hollow tubular element 27. The internal cavity is substantially empty, and therefore, a substantially unlimited air flow along the internal cavity is possible. The downstream hollow tubular element 27 may not substantially affect the overall RTD of the aerosol-generating article 202. The length of the downstream hollow tubular element 27 is approximately 5 mm. The wall thickness of the downstream hollow tubular element 27 is approximately 1 mm.

[0525] The aerosol generating article 30 shown in Fig. 8 comprises a rod 12 of an aerosol generating substrate and a downstream section 14 located downstream of the rod 12 of the aerosol generating substrate. In addition, the aerosol generating article 30 comprises an upstream section 16 located upstream of the rod 12 of the aerosol generating substrate. The distal end 18 of the article 30 is defined by the upstream end of the upstream section 16.

[0526] The downstream section 14 of the aerosol generating article 30 shown in Fig. 8 comprises a hollow tubular cooling element 22 and a downstream filter segment 24. The hollow tubular cooling element 22 is located immediately downstream of the aerosol generating substrate rod 12. In other words, the hollow tubular cooling element 22 is adjacent to the downstream end of the rod 12. The downstream filter segment 24 is adjacent to the downstream end of the hollow tubular cooling element 22. Consequently, the hollow tubular cooling element 22 is located between the rod 12 and the downstream filter segment 24. The downstream end 19 of the article 30 is defined by the downstream end of the downstream filter segment 24.

[0527] The length of the rod 12 of the aerosol generating substrate is approximately 25mm.

[0528] The hollow tubular cooling element 22 is provided in the form of a hollow cylindrical tube made of cardboard or cellulose acetate. The hollow tubular cooling segment 22 defines an internal cavity that extends the entire distance from the upstream end of the hollow tubular cooling element 22 to the downstream end of the hollow tubular cooling element 22. The internal cavity is substantially empty, and therefore, a substantially unlimited air flow along the internal cavity is possible. The hollow tubular cooling element 22 may not substantially affect the overall RTD of the aerosol-generating article 30. The length of the hollow tubular cooling element 22 is approximately 21 mm. The wall thickness of the hollow tubular cooling element 22 is approximately 250 micrometers (μm).

[0529] The downstream filter segment 24 contains a cylindrical plug made of cellulose acetate tow. The length of the downstream filter segment 24 is approximately 7 mm.

[0530] The upstream section 16 comprises an upstream element 341 adjacent to the upstream end of the rod 12. The upstream element 341 is provided in the form of a cylindrical plug made of cellulose acetate tow. The length of the upstream element 341 is approximately 5 mm.

[0531] The aerosol generating article 30 comprises a ventilation zone 36 provided in a location along the hollow tubular cooling element 22. The ventilation zone 36 comprises at least one annular row of perforations passing through the peripheral wall of the hollow tubular cooling element 22 and any wrapper (not shown) surrounding the hollow tubular cooling element 22. The ventilation zone 36 is provided at a distance of approximately 2 millimeters from the downstream end of the hollow tubular cooling element 22.

[0532] The aerosol generating article 301 shown in Fig. 9 is similar to the aerosol generating article 30 shown in Fig. 8, and differs only in that the rod 12 is shorter and the hollow tubular cooling element 22 is longer. In Fig. 9, the length of the rod 12 of the aerosol generating substrate is approximately 12 mm, and the length of the hollow tubular cooling element 22 is approximately 45 mm.

[0533] The aerosol generating article 302 shown in Fig. 10 is similar to the aerosol generating article 301 shown in Fig. 8, and differs only in that the rod 12 is shorter and the hollow tubular cooling element 22 is longer, and in that the article 302 additionally comprises a downstream hollow tubular element 27. In Fig. 10, the length of the rod 12 of the aerosol generating substrate is approximately 12 mm, and the length of the hollow tubular cooling element 22 is approximately 40 mm. Consequently, the downstream filter segment 24 is positioned between the hollow tubular cooling element 22 and the downstream hollow tubular element 27. The downstream end 19 of the article 302 is defined by the downstream end of the downstream hollow tubular element 27.

[0534] The downstream hollow tubular element 27 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The downstream hollow tubular element 27 defines an internal cavity that extends the entire distance from the upstream end of the downstream hollow tubular element 27 to the downstream end of the downstream hollow tubular element 27. The internal cavity is substantially empty, and therefore, a substantially unlimited air flow along the internal cavity is possible. The downstream hollow tubular element 27 may not substantially affect the overall RTD of the aerosol-generating article 302. The length of the downstream hollow tubular element 27 is approximately 5 mm. The wall thickness of the downstream hollow tubular element 27 is approximately 1 mm.

[0535] The aerosol generating article 304 shown in Fig. 11 is similar to the aerosol generating article 302 shown in Fig. 10, and differs only in that the ventilation zone 36 is alternatively provided along the downstream hollow tubular element 27. The ventilation zone 36 is provided at a distance of approximately 2 millimeters from the upstream end of the downstream hollow tubular element 27. The ventilation zone 36 comprises at least one annular row of perforations passing through the peripheral wall of the downstream hollow tubular element 27, and any wrapper (not shown) surrounding the downstream hollow tubular element 27.

[0536] The aerosol-generating article 40 shown in Fig. 12 comprises a rod 12 of an aerosol-generating substrate and a downstream section 14 located downstream of the rod 12 of the aerosol-generating substrate. In addition, the aerosol-generating article 40 comprises an upstream section 16 located upstream of the rod 12 of the aerosol-generating substrate. The distal end 18 of the article is defined by the upstream end of the upstream section 16.

[0537] The downstream section 14 of the aerosol generating article 40 shown in Fig. 3 comprises a hollow tubular support member 28, a hollow tubular cooling member 22, and a downstream filter segment 24. The hollow tubular support member 28 is located immediately downstream of the aerosol generating substrate rod 12. In other words, the hollow tubular support element 28 is adjacent to the downstream end of the rod 12. The hollow tubular cooling element 22 is adjacent to the downstream end of the hollow tubular support element 28, and the downstream filter segment 24 is adjacent to the downstream end of the hollow tubular cooling element 22. Consequently, the hollow tubular cooling element 22 is located between the hollow tubular support element 28 and the downstream filter segment 24.The downstream end 19 of the article 40 is defined by the downstream end of the downstream filter segment 24.

[0538] The length of the rod 12 of the aerosol generating substrate is approximately 20mm.

[0539] The hollow tubular support element 28 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The hollow tubular support element 28 defines an internal cavity that extends the entire distance from the upstream end of the hollow tubular support element 28 to the downstream end of the hollow tubular support element 28. The internal cavity is substantially empty, and therefore, a substantially unrestricted air flow along the internal cavity is possible. The hollow tubular support element 28 may not substantially affect the overall RTD of the aerosol-generating article 40. The length of the hollow tubular support element 28 is approximately 8 mm. The wall thickness of the hollow tubular support element 28 is approximately 1.5 mm.

[0540] The hollow tubular cooling element 22 is provided in the form of a hollow cylindrical tube made of cardboard or cellulose acetate. The hollow tubular cooling segment 22 defines an internal cavity that extends the entire distance from the upstream end of the hollow tubular cooling element 22 to the downstream end of the hollow tubular cooling element 22. The internal cavity is substantially empty, and therefore, a substantially unlimited air flow along the internal cavity is possible. The hollow tubular cooling element 22 may not substantially affect the overall RTD of the aerosol-generating article 40. The length of the hollow tubular cooling element 22 is approximately 8 mm. The wall thickness of the hollow tubular cooling element 22 is approximately 250 micrometers (μm).

[0541] The downstream filter segment 24 contains a cylindrical plug made of cellulose acetate tow. The length of the downstream filter segment 24 is approximately 12 mm.

[0542] The upstream section 16 comprises an upstream element 341 adjacent to the upstream end of the rod 12. The upstream element 341 is provided in the form of a cylindrical plug made of cellulose acetate tow. The length of the upstream element 341 is approximately 5 mm.

[0543] The aerosol generating article 40 comprises a ventilation zone 36 provided in a location along the hollow tubular cooling element 22. The ventilation zone 36 comprises at least one annular row of perforations passing through the peripheral wall of the hollow tubular cooling element 22 and any wrapper (not shown) surrounding the hollow tubular cooling element 22. The ventilation zone 36 is provided at a distance of approximately 2 millimeters from the downstream end of the hollow tubular cooling element 22.

[0544] The aerosol-generating article 40 comprises an elongated current-receiving element 44 located inside the rod 12 of the aerosol-generating substrate. The current-receiving element 44 is located substantially longitudinally inside the rod 12 to be approximately parallel to the longitudinal direction of the rod 12. The elongated current-receiving element 44 is located in thermal contact with the aerosol-generating substrate, and the aerosol-generating substrate is heated by the current-receiving element 44 when the current-receiving element 44 is inductively heated when placed inside a fluctuating electromagnetic field.

[0545] As shown in Fig. 12, the current collecting member 44 is arranged in a radial central position inside the rod and effectively extends along the longitudinal axis of the rod 12. The current collecting member 44 extends the entire distance from the end located upstream to the end located downstream of the rod 12. In fact, the current collecting member 44 has substantially the same length as the rod 12 of the aerosol-generating substrate.

[0546] The current-collecting element 44 is provided in any form described in the present disclosure and has a length substantially equal to the length of the rod 12. The section 16 located upstream of the flow advantageously prevents the current-collecting element 44 from shifting. In addition, this ensures that the consumer cannot accidentally touch the heated current-collecting element 44 after use.

[0547] The aerosol generating article 401 shown in Fig. 13 is similar to the aerosol generating article 40 shown in Fig. 12, and differs only in that the rod 12 is shorter and the hollow tubular cooling element 22 is longer. In Fig. 13, the length of the rod 12 of the aerosol generating substrate is approximately 12 mm, and the length of the hollow tubular cooling element 22 is approximately 25 mm.

[0548] The aerosol generating article 402 shown in Fig. 14 is similar to the aerosol generating article 40 shown in Fig. 12, and differs only in that the rod 12 is shorter and the hollow tubular cooling element 22 is longer, and in that the article 402 additionally contains a hollow tubular element 27 located downstream. In the article 402 shown in Fig. 14, the length of the rod 12 of the aerosol generating substrate is approximately 12 mm, and the length of the hollow tubular cooling element 22 is approximately 20 mm. Consequently, the downstream filter segment 24 is positioned between the hollow tubular cooling element 22 and the downstream hollow tubular element 27. The downstream end 19 of the article 402 is defined by the downstream end of the downstream hollow tubular element 27.

[0549] The downstream hollow tubular element 27 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The downstream hollow tubular element 27 defines an internal cavity that extends the entire distance from the upstream end of the downstream hollow tubular element 27 to the downstream end of the downstream hollow tubular element 27. The internal cavity is substantially empty, and therefore, a substantially unlimited air flow along the internal cavity is possible. The downstream hollow tubular element 27 may not substantially affect the overall RTD of the aerosol-generating article 402. The length of the downstream hollow tubular element 27 is approximately 5 mm. The wall thickness of the downstream hollow tubular element 27 is approximately 1 mm.

[0550] The aerosol generating article 403 shown in Fig. 15 is similar to the aerosol generating article 402 shown in Fig. 14, and differs only in that a ventilation zone 36 is provided along the downstream hollow tubular element 27. The ventilation zone 36 is provided at a distance of approximately 2 millimeters from the upstream end of the downstream hollow tubular element 27. The ventilation zone 36 comprises at least one annular row of perforations passing through a peripheral wall of the downstream hollow tubular element 27, and any wrapper (not shown) surrounding the downstream hollow tubular element 27.

[0551] Fig. 16 shows an aerosol generating system 1 comprising an illustrative aerosol generating device 50 and an aerosol generating article according to any of Figs. 1-15 shown and described above.

[0552] Fig. 16 shows a downstream portion of the mouthpiece end of the aerosol generating device 50, wherein a cavity of the device is defined and can accommodate an aerosol generating article. The aerosol generating device 50 comprises a housing (or main part) 4 extending between the mouthpiece end 2 and the distal end (not shown). The housing 4 comprises a peripheral wall 6. The peripheral wall 6 defines a cavity of the device for accommodating the aerosol generating article 10. The cavity of the device is defined by a closed distal end and an open mouthpiece end. The mouthpiece end of the cavity of the device is located on the mouthpiece end of the aerosol generating device 1. The aerosol generating article 10 is configured to be received through the mouthpiece end of the cavity of the device and is configured to be adjacent to the closed end of the cavity of the device.

[0553] The air flow channel 5 of the device is defined inside the peripheral wall 6. The air flow channel 5 extends between the inlet opening 7 located at the mouthpiece end of the aerosol generating device 1 and the closed end of the cavity of the device. Air can enter the aerosol generating substrate 12 through an opening (not shown) provided at the closed end of the cavity of the device, providing fluid communication between the air flow channel 5 and the aerosol generating substrate 12.

[0554] The aerosol-generating device 1 further comprises a heater (not shown) and a power source (not shown) for supplying power to the heater. A controller (not shown) is also provided for controlling such power supply to the heater. The heater is configured to controllably heat the aerosol-generating article during use, when the aerosol-generating article is placed inside the device 1. The heater is preferably configured to externally heat the aerosol-generating substrate of the aerosol-generating article for optimal aerosol generation. The ventilation zone of the aerosol-generating article is arranged to be open when the aerosol-generating article is placed inside the aerosol-generating device 1.

[0555] For the purposes of the present description and the appended claims, except where otherwise indicated, all numbers expressing quantities, amounts, percentages, etc., are to be understood as modified in all instances by the term "about." Also, all ranges include the disclosed maximum and minimum points and include any intermediate ranges therebetween, which may or may not be specifically listed herein. Therefore, in this context, the number A is understood as A + 10% of A. In this context, the number A can be considered to include numerical values ​​that are within the normal standard error for measuring the property that the number A modifies. The number A, in some cases, when used in the appended claims, may deviate by the percentages listed above, provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention.All ranges also include the disclosed high and low points and include any intermediate ranges therebetween that may or may not be specifically listed herein.

Claims

1. An aerosol-generating article comprising a rod of aerosol-generating substrate and a downstream section provided downstream of the rod of aerosol-generating substrate and extending toward a downstream end of the aerosol-generating article, wherein the downstream section comprises a hollow tubular cooling element, wherein the downstream section has a length of at least 45 millimetres, wherein the ratio of the length of the downstream section to the length of the rod of aerosol-generating substrate is at least 1.5, wherein the maximum outer diameter of the aerosol-generating article is less than 7 millimetres.

2. The aerosol generating article of claim 1, wherein the ratio of the length of the downstream section to the total length of the aerosol generating article is at least 0.

6.

3. An aerosol generating article according to claim 1 or 2, wherein the hollow tubular cooling element of the downstream section has a length of at least 40 millimetres.

4. An aerosol generating article according to any one of the preceding claims, wherein the hollow tubular cooling element is adjacent to a downstream end of the aerosol generating substrate rod.

5. An aerosol generating article according to any one of the preceding claims, wherein the hollow tubular cooling element of the downstream section has a wall thickness of less than 0.5 millimeters.

6. An aerosol-generating article according to any of the preceding claims, wherein the rod of the aerosol-generating substrate has a length of less than 30 millimetres.

7. An aerosol-generating article according to any one of the preceding claims, wherein the aerosol-generating article has an overall length of at least 60 millimetres.

8. An aerosol-generating article according to any of the preceding claims, wherein the ratio of the length of the aerosol-generating substrate rod to the total length of the aerosol-generating article is less than 0.

4.

9. An aerosol generating article according to any one of the preceding claims, further comprising a ventilation zone at a location along the hollow tubular cooling element of the downstream section.

10. An aerosol-generating article according to any one of the preceding claims, wherein the aerosol-generating substrate rod comprises shredded tobacco material.

11. The aerosol generating article of claim 10, wherein the shredded tobacco material has a density of less than 280 mg per cubic centimeter.

12. An aerosol-generating article according to any of the preceding claims, further comprising an upstream element provided upstream of the aerosol-generating substrate rod and adjacent to the upstream end of the aerosol-generating substrate rod.

13. An aerosol generating article according to any one of the preceding claims, wherein the downstream section further comprises a downstream filter segment provided downstream of the hollow tubular cooling element.

14. The aerosol generating article of claim 13, wherein the downstream section further comprises a downstream hollow tubular element downstream of the downstream filter segment, wherein the downstream hollow tubular element is located at the downstream end of the aerosol generating article.

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